OBJECTIVE To investigate the role of e IF3a in the regulation of DNA repair pathways in cancer chemotherapeutic response.METHODS Immunohistochemistry was used to determine the expression of e IF3a in lung and breast cancer tissues followed by association analysis of e IF3a expression with patient′s response to chemotherapy.Ectopic overexpression and RNA interference knockdown of e IF3a were carried out in NIH3T3and H1299 cell lines,respectively,to determine the effect of altered e IF3a expression on cellular response to chemotherapeutic drugs by using MTT assay.The DNA repair capacity of these cells was evaluated by using host-cell reactivation,NHEJ and HR assay.Real-time reverse transcriptase PCR and Western Blot analyses were carried out to determine the effect of e IF3a on the DNA repair genes by using cells with altered e IF3a expression.RESULTS e IF3a expression associates with response of lung and breast cancer patients to platinum and anthracycline.e IF3a knockdown or overexpression,respectively,increased and decreased the cellular resistance to cisplatin and anthracycline anticancer drugs,DNA repair activity,and expression of NER and NHEJ DNA repair proteins.CONCLUSION e IF3a plays an important role in regulating the expression of NER and NHEJ DNA repair proteins which,in turn,contributes to cellular response to DNA-damaging anticancer drugs and patients′response to platinum and anthracycline chemotherapy.
Background:Platinum-based chemotherapy is the first-line treatment of non-small cell lung cancer(NSCLC);it is therefore important to discover biomarkers that can be used to predict the efficacy and toxicity of this treatment.Four important transporter genes are expressed in the kidney,including organic cation transporter 2(OCT2),multidrug and toxin extrusion 1(MATEl),ATP-binding cassette subfamily B member 1 {ABCB1),and ATP-binding cassette subfamily C member 2(ABCC2),and genetic polymorphisms in these genes may alter the efficacy and adverse effects of platinum drugs.This study aimed to evaluate the association of genetic polymorphisms of these transporters with platinumbased chemotherapy response and toxicity in NSCLC patients.Methods:A total of 403 Chinese NSCLC patients were recruited for this study.All patients were newly diagnosed with NSCLC and received at least two cycles of platinum-based chemotherapy.The tumor response and toxicity were evaluated after two cycles of treatment,and the patients' genomic DNA was extracted.Seven single-nucleotide polymorphisms in four transporter genes were selected to investigate their associations with platinum-based chemotherapy toxicity and response.Results:OCT2 rs316019 was associated with hepatotoxicity(P = 0.026) and hematological toxicity(P = 0.039),and MATEl rs2289669 was associated with hematological toxicity induced by platinum(P = 0.016).In addition,ABCC2rs717620 was significantly associated with the platinum-based chemotherapy response(P = 0.031).ABCB1 polymorphisms were associated with neither response nor toxicity.Conclusion:OCT2 rs316019,MATEl rs2289669,and ABCC2 rs717620 might be potential clinical markers for predicting chemotherapy toxicity and response induced by platinum-based treatment in NSCLC patients.Trial registration Chinese Clinical Trial Registry
Chen-Yue QianYi ZhengYing WangJuan ChenJun-Yan LiuHong-Hao ZhouJi-Ye YinZhao-Qian Liu
