Published online Apr 15, 2024. doi: 10.4251/wjgo.v16.i4.1547
Peer-review started: December 8, 2023
First decision: December 22, 2023
Revised: January 8, 2024
Accepted: February 7, 2024
Article in press: February 7, 2024
Published online: April 15, 2024
Processing time: 124 Days and 19.9 Hours
Hepatocellular carcinoma (HCC) is a malignant tumor with high incidence and poor prognosis. Studies have confirmed that long noncoding RNAs (lncRNAs) are directly or indirectly involved in the occurrence and development of tumors and the regulation of various biological functions, including HCC, in which the expression of lncRNA HAND2-AS1 is downregulated in HCC tissues, but the specific mechanism of its involvement in HCC progression still needs to be further explored. In addition, ultrasound targeted microbubble destruction mediated gene transfection is a promising new method in recent years. Therefore, studying the role of ultrasound microbubbles (UTMBs) mediated HAND2-AS1 in HCC progression can provide a new reference for the treatment of HCC.
lncRNA HAND2-AS1 expression was downregulated in HCC tissues and cells, which may be involved in tumor progression. We tried to transfect lncRNA HAND2-AS1 into HCC cell line HepG2 by ultrasound targeted microbubble destruction mediated gene transfection technology to detect the effect of HAND2-AS1 on the proliferation, invasion, epithelial mesenchymal transition and apoptosis of HepG2 cells, and further explore the specific regulatory mechanism. In addition, we established a subcutaneous tumor xenograft mouse model to observe the effect of lncRNA HAND2-AS1 on the tumor forming ability of mice. We aimed to clarify the role of lncRNA HAND2-AS1 in HCC progression through in vivo and in vitro studies, in order to provide new ideas for the treatment of HCC.
We transfected lncRNA HAND2-AS1 into HepG2 cells through ultrasound targeted microbubble destruction mediated gene transfection technology, and detected the effect of lncRNA HAND2-AS1 on the biological behavior of HepG2 cells through a series of experiments in vitro, and found the downstream target genes of lncRNA HAND2-AS1 through online bioinformatics data retrieval, and further clarified the specific mechanism of lncRNA HAND2-AS1 participating in HCC cell growth. In addition, we successfully established a subcutaneous tumor xenograft mouse model and verified the inhibitory effect of lncRNA HAND2-AS1 on tumor formation in vivo in mice. Our results clarify the feasibility of ultrasound targeted microbubble destruction mediated gene transfection technology, and provide a new idea for finding gene therapy for HCC.
We detected the expression levels of lncRNA HAND2-AS1 and miR-873-5p in tumor cells and tumor tissues by real-time quantitative polymerase chain reaction. The proliferation, apoptosis and invasion of HepG2 cells were detected by cell counting kit-8 assay, flow cytometry and Transwell cell invasion assay, respectively. Western botting was used to detect the protein expression levels of tissue inhibitor of matrix metalloproteinase-2 (TIMP2), matrix metalloproteinase (MMP)-2, MMP9 and epithelial mesenchymal transition related proteins in tumor cells and tumor tissues. In addition, immunohistochemistry was used to detect the expression of TIMP2, MMP2, MMP9 and Ki67 in tumor tissues. Luciferase reporter gene analysis was used to verify the targeting relationship of lncRNA HAND2-AS1 and miR-873-5p, as well as miR-873-5p and TIMP2. The SPSS program (version 21.0; SPSS, Chicago, IL) was used for all statistical analyses.
UTMBs loaded with lncRNA HAND2-AS1 inhibited the proliferation, invasion, and epithelial mesenchymal transition of HepG2 cells, and promoted apoptosis. We found that miR-873-5p was a target gene of lncRNA HAND2-AS1, and overexpression of miR-873-5p abolished the inhibitory effect of lncRNA HAND2-AS1 on tumor cell growth. In addition, miR-873-5p targeted the 3'UTR of TIMP2, and TIMP2 again reversed the promoting effect of miR-873-5p on tumor cell growth, and the mechanism study showed that this was mediated by blocking the MMP2/MMP9 signaling pathway. In the subcutaneous tumor xenograft mouse model, we observed that UTMBs carrying lncRNA HAND2-AS1 inhibited tumor formation in mice. Our results provide a new idea for gene therapy of HCC. Considering that this study only uses HepG2 cells, we will verify the results of this study in a variety of HCC cell lines later.
We delivered lncRNA HAND2-AS1 into HeGp2 cells by UTMBs, and found that UTMBs carrying lncRNA HAND2-AS1 suppressed the cell invasion, proliferation and epithelial-mesenchymal transition, and the mechanistic findings indicated that lncRNA HAND2-AS1 suppressed the MMP2/MMP9 signaling pathway and then suppressed tumor progression by upregulating TIMP2 via targeting miR-873-5p. Furthermore, in vivo results demonstrated that tumor formation was inhibited in xenograft mice injected with lncRNA HAND2-AS1-bearing UTMBs.
We identified the regulatory role of lncRNA HAND2-AS1/miR-873-5p/TIMP2 axis in HCC progression, which is a classic ceRNA pattern. Subsequently, we will take lncRNA HAND2-AS1 as a starting point to explore whether it is involved in tumor immune evasion microenvironment, or its relationship with tyrosine kinase inhibitors and immune checkpoint inhibitors, which were mentioned in the discussion section of the manuscript.