Abstract:Objective: To examine whether silencing of FANCF gene by siRNA interference technique could sensitize lung adenocarcinoma CALU-1 cell line to cisplatin(DDP). Methods: Three siRNAs targeted to FANCF (FANCF-siRNAs) were designed and synthesized. After separately transfected into CALU-1 cells, the RT-PCR was used to determine the expression of FANCF mRNA, the siRNA with the highest transfection efficiency was selected. Western Blotting was carried out to detect the expression of FANCF protein, and the levels of FANCD2 protein monoubiquitination, which was defined by the radio of monoubiquitinationFANCD2 (L) and nonmonoubiquitinationFANCD2 (S), in CALU-1 cells treated with cisplatin before and after FANCF-siRNA transfection. Immunofluorescence assay was performed to determine the formation of FANCD2 nuclear foci. CCK-8 technique was used to measure the cell proliferation rate of CALU-1 cells treated with DDP pre- and post-transfection of FANCFsiRNA. Results: After transfection of FANCF-siRNA, we found that silencing of FANCF gene decreased the levels of FANCD2 monoubiquitination (L/S ratio), and nuclear foci formation of FANCD2 in CALU-1 cells. Meanwhile, silencing of FANCF gene significantly decreased the cell proliferation rate in CALU-1 cells treated with DDP ( both P< 0.05). Conclusion: Silencing of FANCF gene by FANCF-siRNA transfection could potentiate the sensitivity to cisplatin in CALU-1 cells, suggesting that FANCF gene may be a potential target in therapeutic strategies for the treatment of lung cancer. [Key words]FANCF; FA/BRCA pathway; siRNA; cisplatin; sensitivity