Glycolysis is a critical metabolic pathway in cancer cells, fulfilling their energy requirements, supporting biosynthesis, maintaining redox balance, and enabling survival in hostile environments. Alpha-enolase (ENO1) has been identified as a key promoter of tumor progression through its involvement in glycolysis. This study aims to elucidate the relationship between ENO1, glycolysis, and gemcitabine sensitivity in pancreatic cancer (PC). The expression levels of ENO1 in PC were analyzed using the GEPIA2 database, Kaplan-Meier survival plots, and immunohistochemistry (IHC). To assess the impact of ENO1 on gemcitabine sensitivity, we manipulated ENO1 expression in PC cell lines through overexpression and silencing techniques. Subsequent analyses included flow cytometry assays, glucose uptake and lactate production measurements, and cytotoxicity assays. The underlying mechanisms by which ENO1 modulates gemcitabine sensitivity were explored using Western blotting (WB). ENO1 was found to be significantly overexpressed in PC tissues, and elevated ENO1 levels were associated with poorer prognosis in PC patients. Overexpression of ENO1 reduced the sensitivity of PC cells to gemcitabine, enhancing cell proliferation, migration, and invasion by altering the cell cycle and inhibiting apoptosis. Conversely, silencing ENO1 decreased glycolysis in PC cells and heightened their sensitivity to gemcitabine. Furthermore, glycolysis inhibition-achieved through ENO1 knockdown, glucose deprivation, or treatment with 2-Deoxy-D-glucose (2-DG)-further enhanced the susceptibility of PC cells to gemcitabine. Mechanistically, ENO1 was found to regulate the expression of gemcitabine resistance-related genes, particularly ribonucleotide reductase catalytic subunit M1 (RRM1), via MYC through the glycolytic pathway, thereby contributing to gemcitabine resistance. This study demonstrates that ENO1 plays a crucial role in PC progression and is closely linked to gemcitabine resistance through its regulation of the glycolytic pathway.

Pancreatic cancer (PC) presents a significant challenge in treatment efficacy due to late-stage diagnosis and chemoresistance. The effects of the combination of a selective small-molecule AHR inhibitor and gemcitabine treatmenteffectiveness in PC cells has been a focus of research. This study utilized the PC cell lines BxPC-3 and Su.86.86 to investigate the impact of AHR activity modulation on gene and protein expression related to the gemcitabine response. Assays including viability measurement, combinational index calculation, qRT-PCR, Western blot analysis, immunocytofluorescence, and clonogenic assays, were employed. Additionally, patient tissue samples were analysed for AHR, ELAVL1, and DCK levels. The results show that AHR activity modulation influenced ELAVL1 localization, DCK expression, and gemcitabine response. Inhibition of AHR activity caused synergistic effects with gemcitabine, whereas activation had an antagonistic effect. Regarding colony formation, inhibition of AHR increased gemcitabine effectiveness by 30-41%, whereas activation decreased the response by 11-28%. Patient tissue analysis revealed correlations between AHR, ELAVL1, and DCK mRNA levels and showed increased levels of AHR protein (2.2-fold) and decreased DCK protein levels (36% decrease) in tumor tissue compared to next-to-cancer tissue. These findings demonstrate the potential of AHR modulation to improve gemcitabine treatment outcomes. This study highlights the significance of AHR modulation in influencing the gemcitabine response in PC cells. By inhibiting AHR activity, cells exhibited improved gemcitabine response, offering a promising avenue for enhancing treatment efficacy. These findings suggest that AHR could serve as a target for optimizing gemcitabine treatment and potentially reducing cancer aggressiveness.

Prostate cancer is one of the most common malignant tumors in men, which seriously threatens the survival and quality of life of patients. At present, there are serious limitations in the treatment of prostate cancer, such as drug tolerance, drug resistance and easy recurrence. Sonodynamic therapy and chemodynamic therapy are two emerging tumor treatment methods, which activate specific drugs or sonosensitizers through sound waves or chemicals to produce reactive oxygen species and kill tumor cells. Nanomaterials are a kind of nanoscale materials with many excellent physical properties such as high targeting, drug release regulation and therapeutic monitoring. Sonodynamic therapy and chemodynamic therapy combined with the application of nanomaterials can improve the therapeutic effect of prostate cancer, reduce side effects and enhance tumor immune response. This article reviews the application progress of nanomaterials in the treatment of prostate cancer, especially the mechanism, advantages and challenges of nanomaterials in sonodynamic therapy and chemodynamic therapy, which provides new ideas and prospects for research in this field.

The pharmaceutical and cosmetic industries are encountering a challenge in adopting new study models for product development. there has been a growing interest in organ-on-a-chip systems, and particularly for generating skin models. While numerous alternatives replicating high-fidelity skin models exist, there is a notable absence of melanoma study's methodology specifically on these microfluidic chips. This work introduces a novel skin-on-a-chip device featuring two microfluidic chambers, facilitating a 3D cell co-culture involving fibroblasts, keratinocytes, and melanoma cells. The design of this organ-on-a-chip has enabled the administration of the anticancer treatment Gemcitabine using an injection system within the chip. The results of this work have shown a significant impact on the co-culture distribution of cells, decreasing the population of cancerous cells after the administration of Gemcitabine. The work presented in this article demonstrates the effectiveness of the chip and the administration method for testing anti-melanoma therapies and position this technology as an enhanced fidelity model for studying melanoma while providing an alternative for real-time monitoring of drug testing.

Pancreatic cancer is known to be the most lethal cancer. Fewer new treatments are being developed for pancreatic cancer as compared to other cancers. The bioactive lipid S1P, which is mainly regulated by sphingosine kinase 1 (SK1) and sphingosine kinase 2 (SK2) enzymes, plays significant roles in pancreatic cancer initiation and exacerbation. S1P controls many signaling pathways to modulate the progression of pancreatic cancer through the G-coupled receptor S1PR1-5. Several papers reporting amelioration of pancreatic cancer via modulation of S1P levels or downstream signaling pathways have previously been published. In this paper, for the first time, we have reviewed the results of previous studies to understand how S1P and its receptors contribute to the development of pancreatic cancer, and whether S1P can be a therapeutic target. In addition, we have also reviewed papers dealing with the effects of SK1 and SK2, which are kinases that regulate the level of S1P, on the pathogenesis of pancreatic cancer. We have also listed available drugs that particularly focus on S1P, S1PRs, SK1, and SK2 for the treatment of pancreatic cancer. Through this review, we would like to suggest that the SK/S1P/S1PR signaling system can be an important target for treating pancreatic cancer, where a new treatment target is desperately warranted.

For several decades, induction therapy with nucleoside analogs, in particular cytarabine (Ara-C) and, to a lesser extent, fludarabine, has been the standard of care for patients diagnosed with acute myeloid leukemia (AML). However, the antitumor efficacy of nucleoside analogs is often limited by intrinsic and acquired drug resistance, thereby leading to poor therapeutic response and suboptimal clinical outcomes. In this study, we used genome-wide CRISPR-based pharmacogenomic screening to map the genetic factors that modulate the response to nucleoside analogs in AML and identified the E3 ubiquitin ligase, Herc1, as a key modulator of Ara-C response in mouse AML models driven by the KMT2A/MLLT3 fusion or by the constitutive coexpression of Hoxa9 and Meis1, both in vitro and in vivo. Loss of HERC1 enhanced nucleoside analog-induced cell death in both murine and human AML cell lines by compromising cell cycle progression. In-depth proteomic analysis and subsequent validation identified deoxycytidine kinase as a novel target of Herc1 in both mouse AML models. We observed that HERC1 is overexpressed in AML when compared with other cancer types and that higher HERC1 expression was associated with shorter overall survival in patients with AML in the The Cancer Gene Atlas program (TCGA) and BEAT-AML cohorts. Collectively, this study highlights the importance of HERC1 in the response of AML cells to nucleoside analogs, thereby establishing this E3 ubiquitin ligase as a novel predictive biomarker and potential therapeutic target for the treatment of AML.

Gemcitabine serves as a first-line chemotherapeutic treatment for pancreatic cancer (PC), but it is prone to rapid drug resistance. Increasing the sensitivity of PC to gemcitabine has long been a focus of research. Fasting interventions may augment the effects of chemotherapy and present new options. SIRT7 is known to link metabolism with various cellular processes through post-translational modifications. We found upregulation of SIRT7 in PC cells is associated with poor prognosis and gemcitabine resistance. Cross-analysis of RNA-seq and ATAC-seq data suggested that GLUT3 might be a downstream target gene of SIRT7. Subsequent investigations demonstrated that SIRT7 directly interacts with the enhancer region of GLUT3 to desuccinylate H3K122. Our group's another study revealed that GLUT3 can transport gemcitabine in breast cancer cells. Here, we found GLUT3 KD reduces the sensitivity of PC cells to gemcitabine, and SIRT7 KD-associated gemcitabine-sensitizing could be reversed by GLUT3 KD. While fasting mimicking induced upregulation of SIRT7 expression in PC cells, knocking down SIRT7 enhanced sensitivity to gemcitabine through upregulating GLUT3 expression. We further confirmed the effect of SIRT7 deficiency on the sensitivity of gemcitabine under fasting conditions using a mouse xenograft model. In summary, our study demonstrates that SIRT7 can regulate GLUT3 expression by binding to its enhancer and altering H3K122 succinylation levels, thus affecting gemcitabine sensitivity in PC cells. Additionally, combining SIRT7 knockdown with fasting may improve the efficacy of gemcitabine. This unveils a novel mechanism by which SIRT7 influences gemcitabine sensitivity in PC and offer innovative strategies for clinical combination therapy with gemcitabine.

Gemcitabine is the first-line treatment option for patients with locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). However, the frequent adoption of resistance to gemcitabine by cancer cells poses a significant challenge in treating this aggressive disease. In this study, we focused on analyzing the role of trefoil factor 1 (TFF1) in gemcitabine resistance in PDAC. Analysis of PDAC TCGA and cell line datasets indicated an enrichment of TFF1 in the gemcitabine-resistant classical subtype and suggested an inverse correlation between TFF1 expression and sensitivity to gemcitabine treatment. The genetic ablation of TFF1 in PDAC cells enhanced their sensitivity to gemcitabine treatment in both in vitro and in vivo tumor xenografts. The biochemical studies revealed that TFF1 contributes to gemcitabine resistance through enhanced stemness, increasing migration ability of cancer cells, and induction of anti-apoptotic genes. We further pursued studies to predict possible receptors exerting TFF1-mediated gemcitabine resistance. Protein-protein docking investigations with BioLuminate software revealed that TFF1 binds to the chemokine receptor CXCR4, which was supported by real-time binding analysis of TFF1 and CXCR4 using SPR studies. The exogenous addition of TFF1 increased the proliferation and migration of PDAC cells through the pAkt/pERK axis, which was abrogated by treatment with a CXCR4-specific antagonist AMD3100. Overall, the present study demonstrates the contribution of the TFF1-CXCR4 axis in imparting gemcitabine resistance properties to PDAC cells.

Pancreatic ductal adenocarcinoma (PDAC)/pancreatic cancer, is a highly aggressive malignancy with poor prognosis. Gemcitabine-based chemotherapy remains the cornerstone of PDAC treatment. Nonetheless, the development of resistance to gemcitabine among patients is a major factor contributing to unfavorable prognostic outcomes. The resistance exhibited by tumors is modulated by a constellation of factors such as genetic mutations, tumor microenvironment transforms, environmental contaminants exposure. Currently, comprehension of the relationship between environmental pollutants and tumor drug resistance remains inadequate. Our study found that PFOS/6:2 Cl-PFESA exposure increases resistance to gemcitabine in PDAC. Subsequent in vivo trials confirmed that exposure to PFOS/6:2 Cl-PFESA reduces gemcitabine's efficacy in suppressing PDAC, with the inhibition rate decreasing from 79.5 % to 56.7 %/38.7 %, respectively. Integrative multi-omics sequencing and molecular biology analyses have identified the upregulation of ribonucleotide reductase catalytic subunit M1 (RRM1) as a critical factor in gemcitabine resistance. Subsequent research has demonstrated that exposure to PFOS and 6:2 Cl-PFESA results in the upregulation of the RRM1 pathway, consequently enhancing chemotherapy resistance. Remarkably, the influence exerted by 6:2 Cl-PFESA exceeds that of PFOS. Despite 6:2 Cl-PFESA being regarded as a safer substitute for PFOS, its pronounced effect on chemotherapeutic resistance in PDAC necessitates a thorough evaluation of its potential risks related to gastrointestinal toxicity.

Harsh environments in poorly perfused tumor regions may select for traits driving cancer aggressiveness. Here, we investigated whether tumor acidosis interacts with driver mutations to exacerbate cancer hallmarks. We adapted mouse organoids from normal pancreatic duct (mN10) and early pancreatic cancer (mP4, KRAS-G12D mutation, ± p53 knockout) from extracellular pH 7.4 to 6.7, representing acidic niches. Viability was increased by acid adaptation, a pattern most apparent in wild-type (WT) p53 organoids, and exacerbated upon return to pH 7.4. This led to increased survival of acid-adapted organoids treated with gemcitabine and/or erlotinib, and, in WT p53 organoids, acid-induced attenuation of drug effects. New genetic variants became dominant during adaptation, yet they were unlikely to be its main drivers. Transcriptional changes induced by acid and drug adaptation differed overall, but acid adaptation increased the expression of gemcitabine resistance genes. Thus, adaptation to acidosis increases cancer cell viability after chemotherapy.

Gemcitabine-based chemotherapy is a cornerstone of standard care for gallbladder cancer (GBC) treatment. Still, drug resistance remains a significant challenge, influenced by factors such as tumor-associated microbiota impacting drug concentrations within tumors. Enterococcus faecium, a member of tumor-associated microbiota, was notably enriched in the GBC patient cluster. In this study, we investigated the biochemical characteristics, catalytic activity, and kinetics of the cytidine deaminase of E. faecium (EfCDA). EfCDA showed the ability to convert gemcitabine to its metabolite 2',2'-difluorodeoxyuridine. Both EfCDA and E. faecium can induce gemcitabine resistance in GBC cells. Moreover, we determined the crystal structure of EfCDA, in its apo form and in complex with 2', 2'-difluorodeoxyuridine at high resolution. Mutation of key residues abolished the catalytic activity of EfCDA and reduced the gemcitabine resistance in GBC cells. Our findings provide structural insights into the molecular basis for recognizing gemcitabine metabolite by a bacteria CDA protein and may provide potential strategies to combat cancer drug resistance and improve the efficacy of gemcitabine-based chemotherapy in GBC treatment.

Pancreatic ductal adenocarcinoma (PDAC) is a solid-tumor malignancy. To enhance the treatment landscape of PDAC, a 3D model optimized for rigorous drug screening is essential. Within the PDAC tumor microenvironment, a dense stroma comprising a large extracellular matrix and cancer-associated fibroblasts (CAFs) is well-known for its vital role in modulating tumor growth, cellular heterogeneity, bidirectional paracrine signaling, and chemoresistance. In this study, we employed a fibroblast-populated collagen lattice (FPCL) modeling approach that has the ability to replicate fibroblast contractility in the collagenous matrix to build dense stroma. This FPCL model allows CAF differentiation by facilitating multifaceted cell-cell interactions between cancer cells and CAFs, with the differentiation further influenced by mechanical forces and hypoxia carried within the 3D structure. Our FPCL models displayed hallmark features, including ductal gland structures and differentiated CAFs with spindle shapes. Through morphological explorations alongside in-depth transcriptomic and metabolomic profiling, we identified substantial molecular shifts from the nascent to mature model stages and potential metabolic biomarkers, such as proline. The initial pharmacological assays highlighted the effectiveness of our FPCL model in screening for improved therapeutic strategies. In conclusion, our PDAC modeling platform mirrors complex tumor microenvironmental dynamics and offers an unparalleled perspective for therapeutic exploration.

Pancreatic cancer is lethal due to poor prognosis with 5-year survival rate lesser than 5 %. Gemcitabine is currently used to treat pancreatic cancer and development of chemoresistance is a major obstacle to overcome pancreatic cancer. Nicotine is a known inducer of drug resistance in pancreatic tumor micro-environment. Present study evaluates chemoresistance triggered by nicotine while treating with gemcitabine and chemosensitization using Embelin. Embelin is a naturally occurring benzoquinone from Embelia ribes possessing therapeutic potency. To develop nicotine-induced chemo-resistance, pancreatic cancer cells PANC-1 and MIA PaCa-2 were continuously treated with nicotine followed by exposure to gemcitabine. Gemcitabine sensitivity assay and immunoblotting was performed to assess the chemo-resistance. Antiproliferative assays such as migration assay, clonogenic assay, Mitochondrial Membrane Potential (MMP) assay, dual staining assay, comet assay, Reactive Oxygen Species (ROS) assay, cell cycle analysis and immunoblotting assays were performed to witness the protein expression involved in chemoresistance and chemosensitization. Epithelial to mesenchymal transition was observed in nicotine induced chemoresistant cells. Gemcitabine sensitivity assay revealed that relative resistance was increased to 6.26 (p < 0.0001) and 6.45 (p < 0.0001) folds in resistant PANC-1 and MIA PaCa-2 compared to parental cells. Protein expression studies confirmed resistance markers like hENT1 and dCK were downregulated with subsequent increase in RRM1 expression in resistant cells. Embelin considerably decreased the cell viability with an IC50 value of 4.03 ± 0.08 μM in resistant PANC-1 and 2.11 ± 0.04 μM in resistant MIA PaCa-2. Cell cycle analysis showed Embelin treatment caused cell cycle arrest at S phase in resistant PANC-1 cells; in resistant MIA PaCa-2 cells there was an escalation in the Sub G1. Embelin upregulated Bax, γH2AX, p53, ERK1/2 and hENT1 expression with concomitant down regulation of Bcl-2 and RRM1. Bioactive molecule embelin, its combination with gemcitabine could provide new vistas to overcome chemo resistance in pancreatic cancer.

Pancreatic cancer (PC) remains a lethal disease, and gemcitabine resistance is prevalent. However, the biomarkers suggestive of gemcitabine resistance remain unclear.

Bioinformatic tools identified ribonucleotide reductase catalytic subunit M1 (RRM1) in gemcitabine-related datasets. A cox regression model revealed the predictive value of RRM1 with clinical features. An external clinical cohort confirmed the prognostic value of RRM1. RRM1 expression was validated in gemcitabine-resistant cells in vitro and in orthotopic PC model. CCK8, flow cytometry, transwell migration, and invasion assays were used to explore the effect of RRM1 on gemcitabine-resistant cells. The CIBERSORT algorithm investigated the impact of RRM1 on immune infiltration.

The constructed nomogram based on RRM1 effectively predicted prognosis and was further validated. Moreover, patients with higher RRM1 had shorter overall survival. RRM1 expression was significantly higher in PC tissue and gemcitabine-resistant cells in vitro and in vivo. RRM1 knockdown reversed gemcitabine resistance, inhibited migration and invasion. The infiltration levels of CD4 + T cells, CD8 + T cells, neutrophils, and plasma cells correlated markedly with RRM1 expression, and communication between tumor and immune cells probably depends on NF-κB/mTOR signaling.

RRM1 may be a potential marker for prognosis and a target marker for gemcitabine resistance in PC.

The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4-/-/NFATc1High).

Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4-/-/NFATc1High cancers. In vitro and in vivo oncogenic transcription factor complex formation was studied by immunoprecipitation, proximity ligation assays, and validated cross model and species. The impact of SMAD4 status on therapeutically targeting canonical KRAS signaling was mechanistically deciphered and corroborated by genome-wide gene expression analysis and genetic perturbation experiments, respectively. Validation of a novel tailored therapeutic option was conducted in patient-derived organoids and cells and transgenic as well as orthotopic PDAC models.

Our findings determined the tumor biology of an aggressive and chemotherapy-resistant SMAD4-/-/NFATc1High subgroup. Mechanistically, we identify SMAD4 deficiency as a molecular prerequisite for the formation of an oncogenic NFATc1/SMAD3/cJUN transcription factor complex, which drives the expression of RRM1/2. RRM1/2 replenishes nucleoside pools that directly compete with metabolized gemcitabine for DNA strand incorporation. Disassembly of the NFATc1/SMAD3/cJUN complex by mitogen-activated protein kinase signaling inhibition normalizes RRM1/2 expression and synergizes with gemcitabine treatment in vivo to reduce the proliferative index.

Our results suggest that PDAC characterized by SMAD4 deficiency and oncogenic NFATc1/SMAD3/cJUN complex formation exposes sensitivity to a mitogen-activated protein kinase signaling inhibition and gemcitabine combination therapy.

The treatment of pancreatic cancer remains a significant clinical challenge due to the limited number of patients eligible for curative (R0) surgery, failures in the clinical development of targeted and immune therapies, and the pervasive acquisition of chemotherapeutic resistance. Refractory pancreatic cancer is typified by high invasiveness and resistance to therapy, with both attributes related to tumor cell stemness. These malignant characteristics mutually enhance each other, leading to rapid cancer progression. Over the past two decades, numerous studies have produced evidence of the pivotal role of glycogen synthase kinase (GSK)3β in the progression of over 25 different cancer types, including pancreatic cancer. In this review, we synthesize the current knowledge on the pathological roles of aberrant GSK3β in supporting tumor cell proliferation and invasion, as well as its contribution to gemcitabine resistance in pancreatic cancer. Importantly, we discuss the central role of GSK3β as a molecular hub that mechanistically connects chemoresistance, tumor cell invasion, and stemness in pancreatic cancer. We also discuss the involvement of GSK3β in the formation of desmoplastic tumor stroma and in promoting anti-cancer immune evasion, both of which constitute major obstacles to successful cancer treatment. Overall, GSK3β has characteristics of a promising therapeutic target to overcome chemoresistance in pancreatic cancer.

Background: Gemcitabine is a first-line chemotherapy for pancreatic adenocarcinoma (PAAD), but many PAAD patients do not respond to gemcitabine-containing treatments. Being able to predict such nonresponders would hence permit the undelayed administration of more promising treatments while sparing gemcitabine life-threatening side effects for those patients. Unfortunately, the few predictors of PAAD patient response to this drug are weak, none of them exploiting yet the power of machine learning (ML). Methods: Here, we applied ML to predict the response of PAAD patients to gemcitabine from the molecular profiles of their tumors. More concretely, we collected diverse molecular profiles of PAAD patient tumors along with the corresponding clinical data (gemcitabine responses and clinical features) from the Genomic Data Commons resource. From systematically combining 8 tumor profiles with 16 classification algorithms, each of the resulting 128 ML models was evaluated by multiple 10-fold cross-validations. Results: Only 7 of these 128 models were predictive, which underlines the importance of carrying out such a large-scale analysis to avoid missing the most predictive models. These were here random forest using 4 selected mRNAs [0.44 Matthews correlation coefficient (MCC), 0.785 receiver operating characteristic-area under the curve (ROC-AUC)] and XGBoost combining 12 DNA methylation probes (0.32 MCC, 0.697 ROC-AUC). By contrast, the hENT1 marker obtained much worse random-level performance (practically 0 MCC, 0.5 ROC-AUC). Despite not being trained to predict prognosis (overall and progression-free survival), these ML models were also able to anticipate this patient outcome. Conclusions: We release these promising ML models so that they can be evaluated prospectively on other gemcitabine-treated PAAD patients.

Gemcitabine is an effective chemotherapeutic agent for biliary tract cancers (BTCs), including gallbladder cancer (GBC) and cholangiocarcinoma (CCA). However, few other effective agents are currently available, particularly for GEM-refractory BTCs. We previously identified microRNA-451a (miR-451a) as a potential therapeutic target in GBC. To elucidate the antineoplastic effects of miR-451a and its underlying mechanisms, we transfected miR-451a into GBC, gemcitabine-resistant GBC (GR-GBC), and gemcitabine-resistant CCA (GR-CCA) cell lines. Furthermore, mimicking in vivo conditions, tumorigenic GBC organoids and three-dimensional (3D) cell culture systems were employed to investigate the anti-proliferative effects of miR-451a on BTCs, and its effect on stem cell properties. We found that miR-451a significantly inhibited cell proliferation, induced apoptosis, and reduced chemoresistant phenotypes, such as epithelial-mesenchymal transition, in both GBC and GR-GBC. The principal mechanism is probably the negative regulation of the phosphatidylinositol 3-kinase/AKT pathway, partially accomplished by directly downregulating macrophage migration inhibitory factor. The Gene Expression Omnibus database revealed that miR-451a was the most significantly downregulated microRNA in CCA tissues. The introduction of miR-451a resulted in similar antineoplastic effects in GR-CCA. Furthermore, miR-451a reduced cell viability in 3D spheroid models and tumorigenic GBC organoids. These findings suggest that the supplementation of miR-451a is a potential treatment strategy for GEM-refractory BTCs.

Gemcitabine is considered a standard treatment for pancreatic cancer, but developing drug resistance greatly limits the effectiveness of chemotherapy and increases the rate of recurrence. Lysyl oxide-like 2 (LOXL2) is highly expressed in pancreatic cancer and is involved in carcinogenesis and EMT regulation. However, studies on the role of LOXL2 in drug resistance are limited. Here, we investigated the mechanism of LOXL2 induction and the effect of LOXL2 on EMT and CSC in gemcitabine-resistant pancreatic cancer. Glucose metabolism was activated in gemcitabine-resistant pancreatic cancer cells, and NF-κB signaling was regulated accordingly. Activated NF-κB directly induces transcription by binding to the promoters of LOXL2 and ZEB1. The EMT process was significantly inhibited by the coregulation of ZEB1 and LOXL2. In addition, LOXL2 inhibition reduced the expression of cancer stemness markers and stemness by regulating MAPK signaling activity. LOXL2 inhibits tumor growth of gemcitabine-resistant pancreatic cancer cells and increases the sensitivity to gemcitabine in mouse models. KEY MESSAGES: We identified a specific mechanism for inducing LOXL2 overexpression in gemcitabine-resistant pancreatic cancer. Taken together, our results suggest LOXL2 has an important regulatory role in maintaining gemcitabine resistance and may be an effective therapeutic target to treat pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has a devastating prognosis without effective treatment options. Thus, there is an urgent need for more effective and safe therapies. Here, inorganic-organic hybrid nanoparticles (GMP-IOH-NPs) are presented as a novel drug-delivery system for the selective delivery of extraordinarily high concentrations of gemcitabine monophosphate (GMP), not only to the primary tumor but also to metastatic sites. GMP-IOH-NPs have a composition of [ZrO]2+ [GMP]2 - with GMP as drug anion (76% of total IOH-NP mass). Multiscale fluorescence imaging confirms an efficient uptake in tumor cells, independent of the activity of the human-equilibrative-nucleoside transporter (hENT1), being responsible for gemcitabine (GEM) transport into cells and a key factor for GEM resistance. Delivering already phosphorylated GMP via GMP-IOH-NPs into tumor cells also allows the cellular resistance induced by the downregulation of deoxycytidine kinase to be overcome. GMP-IOH-NPs show high accumulation in tumor lesions and only minor liver trapping when given intraperitoneally. GMP-IOH-NPs result in a higher antitumor efficacy compared to free GEM, which is further enhanced applying cetuximab-functionalized GMP-CTX-IOH-NPs. By maximizing the therapeutic benefits with high drug load, tumor-specific delivery, minimizing undesired side effects, overcoming mechanisms of chemoresistance, and preventing systemic GEM inactivation, GMP-IOH-NPs are anticipated to have a high chance to significantly improve current PDAC-patient outcome.

Pancreatic cancer is characterized by a poor prognosis, with its five-year survival rate lower than that of any other cancer type. Gemcitabine, a standard treatment for pancreatic cancer, often has poor outcomes for patients as a result of chemoresistance. Therefore, novel therapeutic targets must be identified to overcome gemcitabine resistance. Here, we found that SLC38A5, a glutamine transporter, is more highly overexpressed in gemcitabine-resistant patients than in gemcitabine-sensitive patients. Furthermore, the deletion of SLC38A5 decreased the proliferation and migration of gemcitabine-resistant PDAC cells. We also found that the inhibition of SLC38A5 triggered the ferroptosis signaling pathway via RNA sequencing. Also, silencing SLC38A5 induced mitochondrial dysfunction and reduced glutamine uptake and glutathione (GSH) levels, and downregulated the expressions of GSH-related genes NRF2 and GPX4. The blockade of glutamine uptake negatively modulated the mTOR-SREBP1-SCD1 signaling pathway. Therefore, suppression of SLC38A5 triggers ferroptosis via two pathways that regulate lipid ROS levels. Similarly, we observed that knockdown of SLC38A5 restored gemcitabine sensitivity by hindering tumor growth and metastasis in the orthotopic mouse model. Altogether, our results demonstrate that SLC38A5 could be a novel target to overcome gemcitabine resistance in PDAC therapy.

RRM2 is the catalytic subunit of ribonucleotide reductase (RNR), which catalyzes de novo synthesis of deoxyribonucleotide triphosphates (dNTPs) and plays critical roles in cancer cell proliferation. RRM2 protein level is controlled by ubiquitination mediated protein degradation system; however, its deubiquitinase has not been identified yet. Here we showed that ubiquitin-specific peptidase 12 (USP12) directly interacts with and deubiquitinates RRM2 in non-small cell lung cancer (NSCLC) cells. Knockdown of USP12 causes DNA replication stress and retards tumor growth in vivo and in vitro. Meanwhile, USP12 protein levels were positively correlated to RRM2 protein levels in human NSCLC tissues. In addition, high expression of USP12 was associated with poor prognosis in NSCLC patients. Therefore, our study reveals that USP12 is a RRM2 regulator and targeting USP12 could be considered as a potential therapeutical strategy for NSCLC treatment.

Albumin is an attractive candidate carrier for the development of novel therapeutic drugs. Gemcitabine has been FDA approved for the treatment of solid tumors; however, new drugs that optimize gemcitabine delivery are not available for clinical use. The aim of this study was to test the efficacy of a novel albumin-encapsulated gemcitabine prodrug, JNTX-101, and investigate whether Cav-1 expression predicts the therapeutic efficacy of JNTX-101. We first determined the treatment efficacy of JNTX-101 in a panel of pancreatic/lung cancer cell lines and found that increases in Cav-1 expression resulted in higher uptake of albumin, while Cav-1 depletion attenuated the sensitivity of cells to JNTX-101. In addition, decreased Cav-1 expression markedly reduced JNTX-101-induced apoptotic cell death in a panel of cells, particularly in low-serum conditions. Furthermore, we tested the therapeutic efficacy of JNTX-101 in xenograft models and the role of Cav-1 in JNTX-101 sensitivity using a Tet-on-inducible tumor model in vivo. Our data suggest that JNTX-101 effectively inhibits cell viability and tumor growth, and that Cav-1 expression dictates optimal sensitivity to JNTX-101. These data indicate that Cav-1 correlates with JNTX-101 sensitivity, especially under nutrient-deprived conditions, and supports a role for Cav-1 as a predictive biomarker for albumin-encapsulated therapeutics such as JNTX-101.

Metabolic reprogramming is known as an emerging mechanism of chemotherapy resistance, but the metabolic signatures of pancreatic ductal adenocarcinomas (PDACs) remain unclear. Here, we characterize the metabolomic profile of PDAC organoids and classify them into glucomet-PDAC (high glucose metabolism levels) and lipomet-PDAC (high lipid metabolism levels). Glucomet-PDACs are more resistant to chemotherapy than lipomet-PDACs, and patients with glucomet-PDAC have a worse prognosis. Integrated analyses reveal that the GLUT1/aldolase B (ALDOB)/glucose-6-phosphate dehydrogenase (G6PD) axis induces chemotherapy resistance by remodeling glucose metabolism in glucomet-PDAC. Increased glycolytic flux, G6PD activity, and pyrimidine biosynthesis are identified in glucomet-PDAC with high GLUT1 and low ALDOB expression, and these phenotypes could be reversed by inhibiting GLUT1 expression or by increasing ALDOB expression. Pharmacological inhibition of GLUT1 or G6PD enhances the chemotherapy response of glucomet-PDAC. Our findings uncover potential metabolic heterogeneity related to differences in chemotherapy sensitivity in PDAC and develop a promising pharmacological strategy for patients with chemotherapy-resistant glucomet-PDAC through the combination of chemotherapy and GLUT1/ALDOB/G6PD axis inhibitors.

The therapeutic options for treating pancreatic ductal adenocarcinoma (PDAC) are limited, and resistance to gemcitabine, a cornerstone of PDAC chemotherapy regimens, remains a major challenge. N6-methyladenosine (m6A) is a prevalent modification in mRNA that has been linked to diverse biological processes in human diseases. Herein, by characterizing the global m6A profile in a panel of gemcitabine-sensitive and gemcitabine-insensitive PDAC cells, we identified a key role for elevated m6A modification of the master G0-G1 regulator FZR1 in regulating gemcitabine sensitivity. Targeting FZR1 m6A modification augmented the response to gemcitabine treatment in gemcitabine-resistant PDAC cells both in vitro and in vivo. Mechanistically, GEMIN5 was identified as a novel m6A mediator that specifically bound to m6A-modified FZR1 and recruited the eIF3 translation initiation complex to accelerate FZR1 translation. FZR1 upregulation maintained the G0-G1 quiescent state and suppressed gemcitabine sensitivity in PDAC cells. Clinical analysis further demonstrated that both high levels of FZR1 m6A modification and FZR1 protein corresponded to poor response to gemcitabine. These findings reveal the critical function of m6A modification in regulating gemcitabine sensitivity in PDAC and identify the FZR1-GEMIN5 axis as a potential target to enhance gemcitabine response.

Increased FZR1 translation induced by m6A modification engenders a gemcitabine-resistant phenotype by inducing a quiescent state and confers a targetable vulnerability to improve treatment response in PDAC.

Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the most difficult to treat cancers. Gemcitabine is still the standard of care treatment for PDAC but with modest survival benefit and well reported resistance. Here we explored potential of inhibiting p21 activated kinase 4 (PAK4), a downstream protein of KRAS oncogenic pathway, in combination with Gemcitabine in PDAC cells. PAK4 inhibition by KPT-9274 led to significant potentiation of Gemcitabine activity in PDAC cells, with an increase in apoptosis, DNA damage and cell cycle arrest. At molecular level, PAK4 inhibition dose dependently inhibited Gemcitabine-induced β-catenin, c-JUN and Ribonucleotide Reductase subunit 2 (RRM2) levels. PAK4 inhibition further inhibited levels of phosphorylated ERK (p-ERK); Gemcitabine-induced phosphorylated AKT (p-AKT), phosphorylated and total c-Myc. These results suggest possible role of β-catenin, p-ERK and p-AKT, key effector proteins of Wnt/β-catenin, MAPK and PI3K pathways respectively, in sensitisation of Gemcitabine activity with PAK4 inhibition. Our data unravel probable molecular mechanisms behind combination of PAK4 inhibition with Gemcitabine to counter PDAC, which may be unequivocally proved further with knock down of PAK4. Our findings provide a strong rationale to exploit the combination therapy of Gemcitabine and PAK4 inhibitor for PDAC at pre-clinical and clinical levels.

Although the mechanisms as well as pathways associated with cancer stem cell (CSC) maintenance, expansion, and tumorigenicity have been extensively studied and the role of tumor cell (TC)-derived exosomes in this process is well understood, there is a paucity of research focusing specifically on the functional mechanisms of CSC-derived exosomes (CSC-Exo)/-exosomal-ncRNAs and their impact on malignancy. This shortcoming needs to be addressed, given that these vesicular and molecular components of CSCs could have a great impact on the cancer initiation, progression, and recurrence through their interaction with other key tumor microenvironment (TME) components, such as MSCs/MSC-Exo and CAFs/CAF-Exo. In particular, understanding CSCs/CSC-Exo and its crosstalk with MSCs/MSC-Exo or CAFs/CAF-Exo that are associated with the proliferation, migration, differentiation, angiogenesis, and metastasis through an enhanced process of self-renewal, chemotherapy as well as radiotherapy resistance may aid cancer treatment. This review contributes to this endeavor by summarizing the characteristic features and functional mechanisms of CSC-Exo/MSC-Exo/CAF-Exo and their mutual impact on cancer progression and therapy resistance.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers based on five-year survival rates. Genes contributing to chemoresistance represent novel therapeutic targets that can improve treatment response. Increased expression of ANGPTL4 in tumors correlates with poor outcomes in pancreatic cancer.

We used statistical analysis of publicly available gene expression data (TCGA-PAAD) to test whether expression of ANGPTL4 and its downstream targets, ITGB4 and APOL1, were correlated with patient survival. We measured the impact of ANGPTL4 overexpression in a common pancreatic cancer cell line, MIA PaCa-2 cells, using CRISPRa for overexpression and DsiRNA for knockdown. We characterized global gene expression changes associated with high levels of ANGPTL4 and response to gemcitabine treatment using RNA-sequencing. Gemcitabine dose response curves were calculated on modified cell lines by measuring cell viability with CellTiter-Glo (Promega). Impacts on cell migration were measured using a time course scratch assay.

We show that ANGPTL4 overexpression leads to in vitro resistance to gemcitabine and reduced survival times in patients. Overexpression of ANGPTL4 induces transcriptional signatures of tumor invasion and metastasis, proliferation and differentiation, and inhibition of apoptosis. Analyses revealed an overlapping signature of genes associated with both ANGPTL4 activation and gemcitabine response. Increased expression of the genes in this signature in patient PDAC tissues was significantly associated with shorter patient survival. We identified 42 genes that were both co-regulated with ANGPTL4 and were responsive to gemcitabine treatment. ITGB4 and APOL1 were among these genes. Knockdown of either of these genes in cell lines overexpressing ANGPTL4 reversed the observed gemcitabine resistance and inhibited cellular migration associated with epithelial to mesenchymal transition (EMT) and ANGPTL4 overexpression.

These data suggest that ANGPTL4 promotes EMT and regulates the genes APOL1 and ITGB4. Importantly, we show that inhibition of both targets reverses chemoresistance and decreases migratory potential. Our findings have revealed a novel pathway regulating tumor response to treatment and suggest relevant therapeutic targets in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, primarily due to its late diagnosis, high propensity to metastasis, and the development of resistance to chemo-/radiotherapy. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) are intimately involved in the treatment resistance of pancreatic cancer cells via interacting with critical signaling pathways and may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC.

We carried out a systematic review on lncRNAs-based research in the context of pancreatic cancer and presented an overview of the updated information regarding the molecular mechanisms underlying lncRNAs-modulated pancreatic cancer progression and drug resistance, together with their potential value in diagnosis, prognosis, and treatment of PDAC. Literature mining was performed in PubMed with the following keywords: long non-coding RNA, pancreatic ductal adenocarcinoma, pancreatic cancer up to January 2022. Publications relevant to the roles of lncRNAs in diagnosis, prognosis, drug resistance, and therapy of PDAC were collected and systematically reviewed.

LncRNAs, such as HOTAIR, HOTTIP, and PVT1, play essential roles in regulating pancreatic cancer cell proliferation, invasion, migration, and drug resistance, thus may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. They participate in tumorigenesis mainly by targeting miRNAs, interacting with signaling molecules, and involving in the epithelial-mesenchymal transition process.

The functional lncRNAs play essential roles in pancreatic cancer cell proliferation, invasion, migration, and drug resistance and have potential values in diagnosis, prognostic prediction, and treatment of PDAC.

The invasiveness of pancreatic cancer and its resistance to anticancer drugs define its malignant potential, and are considered to affect the peritumoral microenvironment. Cancer cells with resistance to gemcitabine exposed to external signals induced by anticancer drugs may enhance their malignant transformation. Ribonucleotide reductase large subunit M1 (RRM1), an enzyme in the DNA synthesis pathway, is upregulated during gemcitabine resistance, and its expression is associated with worse prognosis for pancreatic cancer. However, the biological function of RRM1 is unclear. In the present study, it was demonstrated that histone acetylation is involved in the regulatory mechanism related to the acquisition of gemcitabine resistance and subsequent RRM1 upregulation. The current in vitro study indicated that RRM1 expression is critical for the migratory and invasive potential of pancreatic cancer cells. Furthermore, a comprehensive RNA sequencing analysis showed that activated RRM1 induced marked changes in the expression levels of extracellular matrix‑related genes, including N‑cadherin, tenascin‑C and COL11A. RRM1 activation also promoted extracellular matrix remodeling and mesenchymal features, which enhanced the migratory invasiveness and malignant potential of pancreatic cancer cells. The present results demonstrated that RRM1 has a critical role in the biological gene program that regulates the extracellular matrix, which promotes the aggressive malignant phenotype of pancreatic cancer.

The acquisition of resistance to traditional chemotherapy and the chemoresistant metastatic relapse of minimal residual disease both play a key role in the treatment failure and poor prognosis of cancer. Understanding how cancer cells overcome chemotherapy-induced cell death is critical to improve patient survival rate. Here, we briefly describe the technical approach directed at obtaining chemoresistant cell lines and we will focus on the main defense mechanisms against common chemotherapy triggers by tumor cells. Such as, the alteration of drug influx/efflux, the enhancement of drug metabolic neutralization, the improvement of DNA-repair mechanisms, the inhibition of apoptosis-related cell death, and the role of p53 and reactive oxygen species (ROS) levels in chemoresistance. Furthermore, we will focus on cancer stem cells (CSCs), the cell population that subsists after chemotherapy, increasing drug resistance by different processes such as epithelial-mesenchymal transition (EMT), an enhanced DNA repair machinery, and the capacity to avoid apoptosis mediated by BCL2 family proteins, such as BCL-XL, and the flexibility of their metabolism. Finally, we will review the latest approaches aimed at decreasing CSCs. Nevertheless, the development of long-term therapies to manage and control CSCs populations within the tumors is still necessary.

We aimed to verify the role of hENT1 as a prognostic predictor for patients with resectable pancreatic ductal adenocarcinoma (PDAC) who underwent radical resection followed by intra-arterial infusion of gemcitabine-based regimen.

We collected surgical samples from 102 patients with resectable PDAC who received radical resection followed by intra-arterial infusion of gemcitabine-based regimen. The hENT1 expression with the help of immunohistochemistry was conducted using formalin-fixed and paraffin embedded tissues. The Kaplan-Meier analyses and Cox regression were used to evaluate the mortality hazard associated with the discrepancy between strong and weak of hENT1 expression. Patients' clinical and pathological characteristics were compared between the two groups, then the role of hENT1 as a prognostic predictor was further explored.

A total of 102 patients were included to assess the hENT1 expression. 50 patients were classified into high hENT1 expression group, the other 52 patients were attributed into low hENT1 expression group. High hENT1 expression was related to a significantly improved overall survival (OS) (p = 0.014) and disease-free survival (DFS) (p = 0.004). Both univariate (p = 0.001) and multivariate analyses (p < 0.001) indicated that high hENT1 expression was related to a decreased mortality.

High expression of hENT1 is positive prognostic factor for adjuvant intra-arterial gemcitabine-based chemotherapy in resectable PDAC.

Background Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers based on five-year survival rates. Genes contributing to chemoresistance represent novel therapeutic targets that can improve treatment response. Increased expression of ANGPTL4 in tumors correlates with poor outcomes in pancreatic cancer. Methods We used statistical analysis of publicly available gene expression data (TCGA-PAAD) to test whether expression of ANGPTL4 and its downstream targets, ITGB 4 and APOL1 , were correlated with patient survival. We measured the impact of ANGPTL4 overexpression in a common pancreatic cancer cell line, MIA PaCa-2 cells, using CRISPRa for overexpression and DsiRNA for knockdown. We characterized global gene expression changes associated with high levels of ANGPTL4 and response to gemcitabine treatment using RNA-sequencing. Gemcitabine dose response curves were calculated on modified cell lines by measuring cell viability with CellTiter-Glo (Promega). Impacts on cell migration were measured using a time course scratch assay. Results We show that ANGPTL4 overexpression leads to in vitro resistance to gemcitabine and reduced survival times in patients. Overexpression of ANGPTL4 induces transcriptional signatures of tumor invasion and metastasis, proliferation and differentiation, and inhibition of apoptosis. Analyses revealed an overlapping signature of genes associated with both ANGPTL4 activation and gemcitabine response. Increased expression of the genes in this signature in patient PDAC tissues was significantly associated with shorter patient survival. We identified 42 genes that were both co-regulated with ANGPTL4 and were responsive to gemcitabine treatment. ITGB4 and APOL1 were among these genes. Knockdown of either of these genes in cell lines overexpressing ANGPTL4 reversed the observed gemcitabine resistance and inhibited cellular migration associated with epithelial to mesenchymal transition (EMT) and ANGPTL4 overexpression. Conclusions These data suggest that ANGPTL4 promotes EMT and regulates the genes APOL1 and ITGB4 . Importantly, we show that inhibition of both targets reverses chemoresistance and decreases migratory potential. Our findings have revealed a novel pathway regulating tumor response to treatment and suggest relevant therapeutic targets in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, is characterized by a high mortality rate and poor prognosis. Current treatments for PDAC, are ineffective due to a prominent immunosuppressive PDAC tumor microenvironment (TME). Although B lymphocytes are highly infiltrated into PDAC, the importance of B lymphocytes in tumorigenesis is largely neglected. B cells play a dual role in the PDAC tumor microenvironment, acting as either anti-tumorigenic or pro-tumorigenic depending on where they are localized. Tumor-infiltrating B cells, which reside in ectopic lymph nodes, namely tertiary lymphoid structures (TLS), produce anti-tumor antibodies and present tumor antigens to T cells to contribute to cancer immunosurveillance. Alternatively, regulatory B cells (Bregs), dispersed inside the TME, contribute to the dampening of anti-tumor immune responses by secreting anti-inflammatory cytokines (IL-10 and IL-35), which promote tumor growth and metastasis. Determining the role of Bregs in the PDAC microenvironment is thus becoming increasingly attractive for developing novel immunotherapeutic approaches. In this minireview, we shed light on the emerging role of B cells in PDAC development and progression, with an emphasis on regulatory B cells (Bregs). Furthermore, we discussed the potential link of Bregs to immunotherapies in PDAC. These current findings will help us in understanding the full potential of B cells in immunotherapy.

As a malignant digestive system tumor, pancreatic cancer has unique metabolic characteristics. In recent years, the study of pancreatic cancer metabolism is in full swing, which provides a new direction for the treatment of pancreatic cancer patients. However, there is no systematic report of pancreatic cancer metabolism. In this paper, bibliometrics and visualization methods were used to analyze the number of publications, countries/regions, authors, institutions, journals, co-cited references, and keywords of pancreatic cancer metabolism articles, to summarize the research trends and predict research hotspots.

We searched, screened and downloaded articles on pancreatic cancer metabolism through the Web of Science Core Collection (WoSCC). Using CiteSpace, VOSviewer and Bibliometrix Package to analyze publications, countries/regions, authors, institutions, journals, co-cited references, and keywords of pancreatic cancer metabolism to identify research trends and predict research hotspots.

According to the inclusion and exclusion criteria, a total of 5,255 articles were retrieved during the period 1943-2022. The number of publications on pancreatic cancer metabolism is increasing year by year. The United States (n=1602, 30.49%), China (n=1074, 20.44%), and Italy (n=313, 5.96%) are the three countries with the largest number of publications and citations, and there is close cooperation between countries. LI J (n=55) is the most prolific author. FUDAN UNIV (n=348) is the most published institution. CANCERS (n=118), PLOS ONE (n=93), and CANCER RESEARCH (n=80) are the most popular journals in this field. "Nutriment-deficient environment", "cancer chemoprevention" and "targeting cancer stem cell" are the main areas of focus. "immunotherapy", "ferroptosis" and "targeted therapy" are hot keywords in recent years. Taking pancreatic cancer metabolism as an entry point to study the role of traditional Chinese medicine (TCM) mainly focuses on curcumin and resveratrol, lack of broader and deeper research on TCM.

The number of publications on pancreatic cancer metabolism has generally increased, and scholars have generally paid more attention to this field. "immunotherapy", "ferroptosis" and "targeted therapy" are the current research hotspots. The in-depth study of pancreatic cancer metabolism will provide new ideas for the treatment of pancreatic cancer.