3-Methyladenine-enhanced susceptibility to sorafenib in hepatocellular carcinoma cells by inhibiting autophagy

Abstract

As an effective targeted therapy for advanced hepatocellular carcinoma (HCC), sorafenib resistance has been frequently reported in recent years, with the activation of autophagy by cancer cells under drug stress being one of the crucial reasons. Sorafenib treatment could enhance autophagy in HCC cells and autophagy is also considered as an important mechanisms of drug resistance. Therefore, the inhibition of autophagy is a potential way to improve the sensitivity and eliminate drug resistance to restore their efficacy. To determine whether autophagy is involved in sorafenib resistance and investigate its role in the regulation of HepG2 cells’ (an HCC cell line) chemosensitivity to sorafenib, we simultaneously treated HepG2 with sorafenib and 3-Methyladenine (3-MA) (a common autophagy inhibitor). First, by performing cell counting kit 8 cell viability assay, Hoechst 33342 apoptosis staining, and Annexin V-fluorescein isothiocyanate/propidium iodide apoptosis kit detection, we found that both sorafenib and 3-MA effectively inhibitted the proliferative activity of HepG2 cells and induced their apoptosis to a certain extent. This effect was significantly enhanced after these two drugs were combined, which was also confirmed by the increased expression of apoptosis-related proteins. Subsequently, by using AAV-GFP-LC3 transfection methods and transmission electron microscopy, we found that both the number and activity of autophagosomes in HepG2 cells in sorafenib and 3-MA group were significantly reduced, suggesting that autophagy activity was inhibited, and this result was consistent with the expression results of autophagy-related proteins. Therefore, we conclude that 3-MA may attenuate the acquired drug resistance of sorafenib by counteracting its induction of autophagy activity, thus enhancing its sensitivity to advanced HCC therapy.

Anti-HER2 monoclonal antibodies intensify the susceptibility of human gastric cancer cells to etoposide by promoting apoptosis, but not autophagy

“…Hydroxychloroquine, verteporfin, and clarithromycin are still under clinical investigations [NCT04524702, NCT03774472, NCT03067051, NCT03033225, NCT04302324, NCT04063189, NCT02542657, NCT03031483, NCT00461084]. 3-Methyladenine, Lys05, 7-methyl-5-phenylpyrazolo[4,3- e ]tetrazolo[4,5- b ][ 1 , 2 , 4 ]triazine sulfonamide derivatives, miconazole and α –Hederin deserve for attention in a group of autophagy inhibitors undergoing preclinical trials [ 49 – 53 ]. In our study, we checked the concentrations of important proteins engaged in autophagy and we proved that Beclin-1 concentration was dependent on the chemotherapeutic agent dose.…”

Autophagy is involved in neurofibromatosis type I gene‑modulated osteogenic differentiation in human bone mesenchymal stem cells

“…S2767-1; Selleck Chemicals) for 24 h at 37˚C for the detection of autophagy and associated pathways. The concentrations used in the present study were based on those used in previous studies ( 21 , 22 ). In addition, osteogenic differentiation experiments were conducted on day 14 following transfection.…”

Autophagy Modulators in Cancer Therapy

“…3-Methyladenine therapy of human ovarian serous papillary cystadenocarcinoma or hepatocellular carcinoma [155,156] SAR405 colorectal and melanoma tumors treatment [159] Lys05 ovarian carcinoma or CML therapy [160][161][162] therapy of human ovarian serous papillary cystadenocarcinoma or hepatocellular carcinoma [155,156]…”

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