Abstract: Objective To investigate effects of siRNAs targeted protein kinase C α (PKCα) on the proliferation and apoptosis in A549 cell line .Methods Six PKCα siRNAs were designed and chemical synthesized. Candicated PKCα siRNA was transfected into A549 cells, the PKCα mRNA level was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and advanced MTT assays were employed. Then, the effects of more effective PKCα siRNAs on A549 were further investigated by using clone formation assay , hoechst 33258 staining, propidium iodide (PI) staining , Annexin V-FITC and PI dual staining and western blot. Results Six candicated PKCα siRNAs were designed and named No.1, No.2, No.3, No.4, No.5, No.6 PKCα siRNA, respectively. Compared with controls, PKCα mRNA levels were all significantly downregulated and the cell proliferation were inhibited in A549 cells treated with candicated PKCα siRNAs except No.5 (P<0.05).The No.3, No.6 and No.1 PKCα siRNAs, which can more effectively inhibit A549 cell growth and PKCα expression, were identified among 6 candidate PKCα siRNAs. Compared with controls, the clone formation was significantly inhibited (P<0.05), percentages of hypodiploid cells and early apoptosis rates were significantly increased (P<0.01), and the expression of PKCα protein was significantly decreased in A549 cells treated with No.3, No.6 or No.1 PKCα siRNA (P<0.01). In addition, the typical morphologic changes of apoptosis were found in PKCα siRNA-treated A549 cells. Conclusion Three PKCα siRNAs in six candicated PKCα siRNAs can effectively downregulate PKCα protein expression, induce apoptosis and inhibit proliferation in A549 cells.

Key words: Protein kinase Cα (PKCα), RNA interference (RNAi), short interference RNA (siRNA), human lung carcinoma, A549