Abstract：Objective: To explore the effects of RAD18 and REV1 gene knockdowns on cisplatin cytotoxicity in cisplatinresistant A549/DDP cell line. Methods: The expression of RAD18 and REV1 protein, and the FANCD2 and PCNA monoubiquitination level were detected by Western blotting. The siRNAs against RAD18 and REV1 genes(RAD18siRNA and REV1siRNA) were transfected into A549/DDP cells using Lipofectamine. The CCK8 assay was used to detect the changes of cell proliferation rate following treatment with cisplatin before and after transfection of RAD18siRNA and REV1siRNA in A549/DDP cells. Cisplatininduced cell apoptosis and cell cycle were detected by flow cytometry in A549/DDP cells pre and posttransfection of RAD18siRNA and REV1siRNA. Results: The expressions of RAD18 and REV1 proteins were significantly decreased after transfection of RAD18siRNA or REV1siRNA, indicating that the transfections were successful. Cisplatininduced monoubiquitinations of FANCD2 and PCNA were significantly decreased after transfection with RAD18siRNA, suggesting that the activation of the FA pathway and the TLS pathway was suppressed. Individual knockdown of RAD18 or REV1 by siRNAs transfection enhanced the cytotoxicity of cisplatin to A549/DDP cells, promoted cell apoptosis induced by cisplatin, and resulted in the arrest of S/G2 phase. Coknockdown of RAD18 and REV1 genes further enhanced the cytotoxicity of cisplatin to A549/DDP cells compared to RAD18 or REV1 knockdown alone. Conclusion: Knockdowns of RAD18 gene of the TLS pathway and the Fanconi anemia（FA） pathway upstream and REV1 gene of the TLS pathway could increase the sensitivity of cisplatinresistant A549/DDP cells to cisplatin by inhibiting the DNA damage repair capacity,and the sensitization can be further potentiated by coknockdown of RAD18 and REV1.
金君， 李坚， 袁荣霞. 共抑制RAD18和REV1基因显著增加顺铂对肺癌细胞的毒性[J]. 江苏大学学报:医学版, 2018, 28(02): 109-116.
JIN Jun, LI Jian, YUAN Rong-xia. Co-inhibition of RAD18 and REV1 gene markedly enhance the cytotoxicity of cisplatin to lung cancer A549 /DDP cell line. Journal of Jiangsu University(Medicine Edition), 2018, 28(02): 109-116.
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2018, Vol. 28 
