CPT1a Inhibitor Etomoxir Enhances The Anti-tumor Effect And Mechanism Of Sorafenib

Backgrounds and ObjectivesHepatocellular carcinoma(HCC),as an important cause of death of cancer patients,poses a great threat to the health of Chinese people.Normally,tumors are treated with surgery,chemotherapy and radiation.But these treatment methods all have different degree of disadvantage.The development of cancer is closely related to abnormal cell signal transduction and metabolism.Targeted therapy,that is,targeted inhibition of key molecules in the signaling pathway and metabolic pathway that distinguish tumor cells from normal cells through the use of small-molecule inhibitors,has become an important means of tumor treatment,and has produced remarkable results in clinical practice.Sorafenib,as a multi-kinase inhibitor,inhibits angiogenesis by targeting Raf,VEGFR and PDGF receptors,blocks cell proliferation,promotes tumor cell apoptosis,and plays an anti-tumor role.In the treatment of tumors,Sorafenib regulates MAPK,PI3K-AKT and other signaling pathways,and then has different inhibitory effects on liver cancer,lung cancer,ovarian cancer and other tumor cells.However,Sorafenib alone has limited efficacy in a variety of tumor cells,so it is an attractive option to combine Sorafenib with other drugs.Etomoxir is an inhibitor of carnitine palmitotransferase la(CPT1a),a key rate-limiting enzyme in the oxidative degradation of cellular fatty acids(FAO).Studies have shown that FAO plays a certain role in promoting the occurrence and development of cancer in a variety of cancers,and in vitro experiments have shown that CPT1 has been used as a target for cancer treatment in nasopharyngeal cancer,leukemia,breast cancer,gastric cancer,lung cancer and other tumor cells.Preliminary results showed that Sorafenib single drug had limited therapeutic effect on liver cancer.And resistance to Sorafenib alone can develop over time.This paper discusses the antitumor effect and mechanism of Sorafenib combined with Etomoxir.This study provides a new therapeutic strategy for tumor therapy.Methods and results1.Sorafenib's Single Drug on Tumor Cells(1)The MTT method was used to detect the cell survival rate of different tumor cells after using Sorafenib single-drug treatment.The results showed that Sorafenib had a certain effect on the growth and inhibition of tumor cells at the maximum concentration of blood drugs in the body,but its effect was limited.(2)Cloning experiments show that Sorafenib partially inhibits the growth of tumor cell concentration.(3)The results of the immune imprint show that Sorafenib activates the AKT signal path while suppressing the MAPK signal path.2.Etomoxir synergies to enhance Sorafenib's anti-tumor effect(1)The method of MTT proved that Sorafenib and Etomoxir had a synergistic inhibition effect on the growth of liver cancer cells,and had a certain effect on the growth of liver cancer cells at different concentrations.(2)The synergy inhibition of liver cancer cell growth between Sorafenib and Etomoxir is time-dependent and dose-dependent.(3)Sorafenib and Etomoxir combined for many types of tumor cells have synergyinhibition.(4)The cloning formation experiment proves that Sorafenib and Etomoxir can coordinate to inhibit the growth of the clone community.3.Etomoxir synergies to enhance Sorafenib causes apoptosis.(1)Immune imprinting experiments confirmed that Sorafenib and Etomoxir combined drug lures led to tumor apoptosis.(2)Using sh-RNA knock-down Bax significantly reduces apoptosis caused by the combination of two drugs,indicating that both may cause endogenous(mitochondrial pathway)apoptosis.4.Research on the mechanism of joint induced apoptosis of double drugs(1)Immune imprinting experiments showed that Etomoxir lowered the expression of the apoptotic protein survivin.(2)Through gene overexpression experiments to promote the expression of survivin,MTT and immunoprinting experiments show that the exogenous over-expression of survivin can significantly reduce tumor apoptosis caused by the combination of two drugs.It shows that survivin plays an important role in co-drugs to induce tumor apoptosis.(3)Immune imprinting test results show that although Etomoxir inhibited p-AKT(S473)expression,but the combination of the drug p-AKT(S473)compared with the control group did not have a significant change,it is assumed that the expression of survivin may also be regulated by other signaling pathways.Conclusions and implicationsSorafenib has a limited effect on tumor cells to inhibit growth.The combination of Etomoxir and Sorafenib works together to inhibit the growth of tumor cells and promote apoptosis.Through the study of the mechanism of the combination of two drugs,it is revealed that Etomoxir has coordinated to enhance the anti-tumor effect of the targeted drug Sorafenib by lowering the expression of survivin.The development of this study reveals the inherent anti-tumor mechanism of small molecule target inhibitors such as Sorafenib and Etomoxir,and provides a new target treatment strategy for tumors.