Silence of FANCD2 gene of FA/BRCA pathway reverse the resistance to cisplatin in lung cancer A549/DDP cell line
JIANG He-guo1, DAI Chunhua1, LI Jian1, CHEN Yongchang2, LAN Ting2, WU Min2
（1.Department of Pulmonary Medicine, Affiliated Hospital of Jiangsu University, Zhenjiang Jiangsu 212001; 2. Institute of Basal Medicine Science, Jiangsu University, Zhenjiang Jiangsu 212013, China)
Abstract：Objective: To investigate the effect of FANCD2 gene silence on the resistance to cisplatin (DDP) in lung adenocarcinoma A549/DDP cell line. Methods: FANCD2 genes of A549/DDP cells were silenced by transfection of the designed and synthesized siRNA targeted FANCD2(FANCD2-siRNA) through Lipofectamine. CCK-8 technique was used to measure the cell proliferation rate of A549 and A549/DDP cells treated with DDP before and after siRNA transfection. Western blotting was carried out to detect the expression of monoubiquitination (L) and non-monoubiquitination (S) FANCD2 protein and L/S ratio before and after siRNA transfection. Immunofluorescence assay was performed to determine the formation of FANCD2 nuclear foci. Results: The cell proliferation rate and the levels of FANCD2 monoubiquitination (L/S ratio) were markedly higher in A549/DDP cells than in A549 cells treated with DDP (P<0.05). After transfection of FANCD2-siRNA, the levels of FANCD2 monoubiquitination, nuclear foci formation of FANCD2, and the cell proliferation rate were significantly decreased in A549 and A549/DDP cells following DDP treatment (P<0.05). Conclusion: Silence of FANCD2 gene inhibited the function of FA/BRCA pathway by decreasing the monoubiquitination level and nuclear focus formation of FANCD2, resulting in the decrease of cell proliferation, and partial reversion of chemoresistance to cisplatin in lung cancer cell of DDP-resistance.
