Study of RNA38 reverses apatinib resistance in hepatocellular carcinoma via regulating NTNG1

Abstract

Presenter: Xing Gao | Guangxi Medical University Background: Apatinib is a small-molecule anti-angiogenesis drug, shows favorable efficacy in advanced liver cancer. However, drug resistance hinders the further survival and benefit of patients. RBM38 is a RNA-binding protein, binds to RNA for the post-transcriptional regulation. Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to analyze the expression levels of RBM38 and NTNG1in hepatocellular carcinoma cells. The role of RBM38 and NTNG1 in hepatocellular carcinoma (HCC) cells drug resistance were further detected by Cell counting kit-8 (CCK-8) assays. Cell cycle and cell proliferation were analyzed by flow cytometry. Cell migration and invasion were detected using a transwell assay. The expression of the related drug-resistant proteins were assessed by western blot. The xenograft model was established to examine the potential role of RBM38 reverses apatinib resistance in HCC. Results: Our study found that the RBM38 is closely related to the sensitivity of HCC to apatinib. After apatinib stimulation, the level of RBM38 was increased in liver cancer cells. While the expression of RBM38 was inhibited in apatinib-resistant liver cancer cells. The results of in vitro and in vivo experiments demonstrated that overexpression of the RBM38 gene reverses the apatinib resistance of liver cancer cells, the expression of ABCG2 and other related drug-resistant proteins also decreased. Overexpression of RBM38 inhibits proliferation, invasion, migration and induces apoptosis of liver cancer cells, and suppresses xenograft tumor formation. In the present study, high-throughput gene chip screening revealed that NTNG1 is the most significant differentially expressed genes following RBM38 gene overexpression. After apatinib stimulation, the level of NTNG1 was decreased in liver cancer cells. While the expression of NTNG1 was increased in apatinib-resistant liver cancer cells. After NTNG1 was further overexpressed in the apatinib-resistant liver cancer cell model overexpressed by RBM38, in vitro and in vivo experiments confirmed that the sensitivity of liver cancer cells to apatinib was reduced, and the expression of ABCG2 and other related drug-resistant proteins also increased. Overexpression of NTNG1 promotes inhibits proliferation, invasion, migration, and inhibits apoptosis of liver cancer cells, and enhances xenograft tumor formation. Conclusion: This study preliminarily clarified the biological effect and molecular mechanism of RBM38 reverses apatinib resistance in hepatocellular carcinoma via regulating NTNG1, providing a new theoretical basis and experimental basis for the drug resistance mechanism of advanced liver cancer targeted therapy.