Colon cancer (CC) remains a significant global health burden, and the search for novel prognostic biomarkers and therapeutic targets is crucial. This study comprehensively analyzed the role of SIX2 (Sine Oculis Homeobox Homolog 2) in CC. Utilizing data from TCGA, GTEx, and CCLE databases, differential expression of SIX2 was observed in multiple cancers, with significant upregulation in many tumors compared to normal tissues. In CC, SIX2's differential expression was notable. Cox regression analysis revealed its prognostic significance, with overexpression associated with poor survival outcomes. SIX2 was strongly associated with gene alterations and correlated with key signaling pathways like WNT and TGF-β. In the tumor microenvironment, SIX2 was related to immune cell infiltration and immune-related molecules. Notably, in CC, it was associated with immunosuppressive cells and checkpoint molecules. Additionally, ABT737 was found to sensitize tumor immunotherapy in the context of SIX2. Animal experiments demonstrated that ABT737 effectively restricted the growth of CC in mice, and its combination with antiPD-1 immunotherapy was more effective. It could reduce the infiltration of CD163+ tumor-associated macrophages but without significantly increasing the infiltration of CD8+ T cells. Our findings suggest that SIX2 is a potential key player in CC, offering insights into future research and the development of targeted therapies.

The sine oculis homeobox homolog (SIX) family, a group of transcription factors characterized by a conserved DNA-binding homology domain, plays a critical role in orchestrating embryonic development and organogenesis across various organisms, including humans. Comprising six distinct members, from SIX1 to SIX6, each member contributes uniquely to the development and differentiation of diverse tissues and organs, underscoring the versatility of the SIX family. Dysregulation or mutations in SIX genes have been implicated in a spectrum of developmental disorders, as well as in tumor initiation and progression, highlighting their pivotal role in maintaining normal developmental trajectories and cellular functions. Efforts to target the transcriptional complex of the SIX gene family have emerged as a promising strategy to inhibit tumor development. While the development of inhibitors targeting this gene family is still in its early stages, the significant potential of such interventions holds promise for future therapeutic advances. Therefore, this review aimed to comprehensively explore the advancements in understanding the SIX family within gastrointestinal cancers, focusing on its critical role in normal organ development and its implications in gastrointestinal cancers, including gastric, pancreatic, colorectal cancer, and hepatocellular carcinomas. In conclusion, this review deepened the understanding of the functional roles of the SIX family and explored the potential of utilizing this gene family for the diagnosis, prognosis, and treatment of gastrointestinal cancers.

Ferroptosis, a form of cell death caused by iron-dependent peroxidation of lipids, plays an important role in cancer. Recent studies have shown that long noncoding RNAs (lncRNAs) are involved in the regulation of ferroptosis in tumor cells and are also closely related to tumor immunity. Immune cell infiltration in the tumor microenvironment affects the prognosis and clinical outcome of immunotherapy in melanoma patients, and immune cell classification may be able to accurately predict the prognosis of melanoma patients. However, the prognostic value of ferroptosis-related lncRNAs (FRLs) in melanoma has not been thoroughly explored, and it is difficult to define the immune characteristics of melanoma. We used The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression (GTEx) database, and the FerrDb database to identify FRLs. FRLs with prognostic value were evaluated in an experimental cohort utilizing univariate, LASSO (least absolute shrinkage and selection operator) and multivariate Cox regression, followed by in vitro assays evaluating the expression levels and the biological functions of three candidate FRLs. Kaplan-Meier (K-M) and receiver operating characteristic (ROC) curve analyses were used to assess the validity of the risk model, and the drug sensitivity of FRLs was examined by drug sensitivity analysis. The differentially expressed genes between the high- and low-risk groups in the risk model were enriched in the immune pathway, and we further found immune gene signatures (IRGs) that could predict the prognosis of melanoma patients through a series of methods including single-sample Gene Set Enrichment Analysis (ssGSEA). Finally, two GEO cohorts were used to validate the predictive accuracy and reliability of these two signature models. Our findings suggest that FRLs and IRGs have the potential to predict the prognosis of patients with cutaneous melanoma.

Several genes, important for development, are reduced or silenced in adulthood, and their abnormal expression has been related to the occurrence and development of malignant tumors. Human sine oculis homeobox homolog (SIX) proteins belong to the homeobox family and play important roles in the development of different organs. Importantly, SIXs are predicted to have chromatin-binding and DNA-binding transcription factor activity with reported roles in cancers. However, a comprehensive analysis of SIXs in colorectal cancers (CRCs) has not been performed.

To explore the expression pattern of six SIX proteins in CRCs and their relationship with the clinicopathological parameters of CRC patients as well as investigate the potential utilization of SIXs as novel prognostic indicators in CRCs.

The expression level of SIXs in normal tissues of different organs and related cancerous tissues was analyzed in the Human Protein Atlas. Kaplan-Meier Plotter and GEPIA2 were used to analyze the prognostic values of SIXs. To analyze the potential signaling pathways with SIX family involvement, LinkedOmics was used to perform Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of SIX4-related genes. Subsequently, immunohistochemical experiments were performed on CRC tissues and adjacent normal tissues, and we examined the SIX4 expression level in 87 pairs of patients with tissue microarray. The relationship between SIX4 and clinicopathological parameters in CRC patients was tested using the χ 2 test and Fisher's exact probability to verify the results of the database analysis.

The RNA levels of SIX1-4 and SIX6 were relatively low in normal human tissues, while SIX5 was highly expressed at both the RNA and protein levels. However, the protein level of SIX4 was found to be elevated in various malignancies. In CRC tissues, SIX1, SIX2 and SIX4 were elevated in cancer tissues compared with adjacent normal tissue. Among all SIXs, a high level of SIX4 was found to be associated with poor overall and disease-free survival in patients with CRC. For different clinicopathological parameters, increased SIX4 expression was positively correlated with advanced CRC. The top 50 SIX4-related genes were involved with oxidative phosphorylation and the respiratory chain signaling pathways.

The current results provided a comprehensive analysis of the expression and prognostic values of SIX family members in CRC. Among different SIXs, SIX4 plays an oncogenic role in CRC to promote the development of malignancy. In CRC, SIX4 mRNA and protein expression is higher than that in normal tissues and associated with shorter CRC patient survival, suggesting that SIX4 may be a potential therapeutic target for treatment of CRC patients.

Jianpi Huayu decoction (JHD) is a traditional Chinese medicinal preparation used to treat a variety of malignant tumors including HCC, although the underlying mechanism remains unknown. Exosomes in the tumor microenvironment mediate intercellular signaling among cancer cells, but precise contributions to hepatocellular carcinoma (HCC) progression are still elusive.

In this work, the main objective was to examine the mechanisms underlying anti-tumor effects of JHD and the potential contributions of exosomal signaling.

LC-MS/MS was used for quality control of JDH preparation, while nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and western blotting were used for verification of exosomes. In vitro assays included CCK8, wound healing assay, transwell invasion assay, qRT-PCR and western blotting were performed to investigate the effects of JHD on HCC cells and the molecular mechanism. Furthermore, the effects of JHD on subcutaneous tumor model of nude mice were also determined.

JHD inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of cultured HCC cells. Further, exosomes isolated from EMT-induced HCC cells promoted the migration, invasion and EMT of other cultured HCC cells, while exosomes isolated from EMT-induced HCC cells after JHD treatment had little effect. In addition, JHD reduced the expression of exosomal miR-23a-3p in cultured HCC cells. miR-23a-3p was significantly up-regulated in tumor compared with that in adjacent non-cancerous tissues of patients with HCC. HCC patients with high miR-23a-3p expression had poor overall survival after hepatectomy. Meanwhile, miR-23a-3p enhanced HCC cell proliferation, EMT, and expression of Smad signaling proteins. More importantly, overexpression of miR-23a-3p can reverse the inhibition of EMT and Smad signaling pathway caused by JHD treatment. In vivo assays, treatment with JHD also reduced the growth of HCC-derived tumors in nude mice, reduced the expression of miR-23a-3p in serum exosomes and the level of EMT in tumor cells.

the antitumor effects of JHD on HCC are mediated at least in part by inhibition of EMT due to downregulation of exosome-mediated intercellular miR-23a-3p transfer and subsequent blockade of Smad signaling. Disrupting this exosomal miR-23a-3p/Smad signaling pathway may be an effective treatment.

Multidrug resistance (MDR) is the biggest challenge in cancer therapy. In this study, we explored the molecular mechanism of MDR in human liver cancer and explored the related diagnostic and prognostic values of the targeted genes in patients with hepatocellular carcinoma. We constructed a multidrug-resistant liver cancer cell line, HepG2/Dox, using the parental subline HepG2. The (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to test the viability of the liver cancer cells. Western blotting was performed to test the expression of ABCB1, β-catenin, and β-actin. Luciferase assays were performed to confirm the relationship between miR-381 and its target genes. The diagnostic and prognostic values of target genes were analyzed using publicly available data from The Cancer Genome Atlas. The Mann-Whitney U test and logistic regression were performed to evaluate the association between ABCB1 or CTNNB1 expression and clinical features in patients with liver hepatocellular carcinoma (LIHC). Finally, Kaplan-Meier and Cox regression analyses were performed to test the effect of ABCB1 or CTNNB1 expression on the overall survival of patients with LIHC. ABCB1 expression was upregulated in HepG2/Dox cells. ABCB1 was found to be a direct target of hsa-miR-381 and was negatively regulated by has-miR-381. Moreover, hsa-miR-381 directly targeted the CTNNB1 3' UTR and decreased the luciferase activity of CTNNB1. Transfection with miR-183 partially reversed chemotherapeutic drug resistance by downregulating the expression of ABCB1 and CTNNB1 in HepG2/Dox cells. Spearman's analysis results showed that CTNNB1 and ABCB1 were positively correlated in patients with liver cancer, and increased CTNNB1 and ABCB1 expression occurred in patients with liver cancer. High expression of ABCB1 and CTNNB1 indicated poor prognosis in patients with liver cancer; however, neither ABCB1 nor CTNNB1 expression was an independent diagnostic factor in patients with LIHC. Overexpression of hsa-miR-381 partially reversed the MDR of HepG2 cells by directly targeting and negatively regulating the expression of CTTNB1 and ABCB1. Moreover, high expression of ABCB1 or CTNNB1 indicated poor prognosis in patients with liver cancer.

Exosomes play an important role in intercellular communication and metastatic progression of hepatocellular carcinoma (HCC). However, cellular communication between heterogeneous HCC cells with different metastatic potentials and the resultant cancer progression are not fully understood in HCC. Here, HCC cells with high-metastatic capacity (97hm and Huhm) were constructed by continually exerting selective pressure on primary HCC cells (MHCC-97H and Huh7). Through performing exosomal miRNA sequencing in HCC cells with different metastatic potentials (MHCC-97H and 97hm), many significantly different miRNA candidates were found. Among these miRNAs, miR-92a-3p was the most abundant miRNA in the exosomes of highly metastatic HCC cells. Exosomal miR92a-3p was also found enriched in the plasma of HCC patient-derived xenograft mice (PDX) model with high-metastatic potential. Exosomal miR-92a-3p promotes epithelial-mesenchymal transition (EMT) in recipient cancer cells via targeting PTEN and regulating its downstream Akt/Snail signaling. Furthermore, through mRNA sequencing in HCC cells with different metastatic potentials and predicting potential transcription factors of miR92a-3p, upregulated transcript factors E2F1 and c-Myc were found in high-metastatic HCC cells promote the expression of cellular and exosomal miR-92a-3p in HCC by directly binding the promoter of its host gene, miR17HG. Clinical data showed that a high plasma exosomal miR92a-3p level was correlated with shortened overall survival and disease-free survival, indicating poor prognosis in HCC patients. In conclusion, hepatoma-derived exosomal miR92a-3p plays a critical role in the EMT progression and promoting metastasis by inhibiting PTEN and activating Akt/Snail signaling. Exosomal miR92a-3p is a potential predictive biomarker for HCC metastasis, and this may provoke the development of novel therapeutic and preventing strategies against metastasis of HCC.

Transforming growth factor beta (TGF-β) is a multifunctional cytokine with important functions in cell proliferation and differentiation. TGF-β is highly expressed in several types of cancers and promotes tumor invasion and metastasis. However, the role of TGF-β in osteosarcoma progression is poorly understood. In the present study, we found that TGF-β is highly expressed in osteosarcoma cells and tissues, and is associated with high Ennecking stage (P = 0.033), metastasis, and recurrence. TGF-β-knockdown osteosarcoma cell lines were established using siRNA (si-TGF-β). Cells transfected with si-TGF-β exhibited significantly reduced proliferation, migration/invasion, and colony formation abilities, and increased levels of cell apoptosis. In addition, si-TGF-β treatment reduced spheroid size, the ratio of CD133-positive cells, and expression of SOX-2, Nanog, and Oct-3/4 in osteosarcoma cells. Mechanistically, PI3K/mTOR phosphorylation is inhibited by TGF-β knockdown. Pretreatment with 25 µM LY294002, a PI3K-specific inhibitor, further enhanced the si-TGF-β-induced suppression of osteosarcoma progression. Taken together, these results reveal a novel role for TGF-β in osteosarcoma progression and modulation of stemness-related traits and indicate that TGF-β may be of value as a therapeutic target for the treatment of osteosarcoma.

Multiple studies have confirmed the pro-oncogenic effects of PAX3 in an array of cancers, but its role in prostate cancer (PCa) remains largely undefined. The aim of this study is to investigate the role of PAX3 in PCa. PAX3 expression was compared between PCa tumor tissue and nontumor tissues and PCa cell lines and normal prostate epithelial cells (PNT2) by western blot analysis and immunohistochemistry staining. MTT and immunofluorescence assays were used to detect PCa cell proliferation. Flow cytometry was used to evaluate cell apoptosis in PCa. Transwell assays were used for the determination of cell migration and PCa cell invasion. PAX3 expression was higher in PCa tissues and human PCa cell lines. Moreover, PAX3 silencing inhibited the proliferation, metastasis, and epithelial-mesenchymal transition (EMT) of PCa cells, and increased the rates of apoptosis. PAX3 silencing inhibited transforming growth factor-β (TGF-β)/Smad signaling in PCa cells. The effects of si-PAX3 on the proliferation, apoptosis, metastasis, and EMT of PCa cells were alleviated by TGF-β1 treatment. PAX3 silencing inhibits PCa progression through the inhibition of TGF-β/Smad signaling. This reveals PAX3 as a novel biomarker and therapeutic target for future PCa treatments.