Abstract: Objective To investigate the effect of protein kinase C (PKC)ζ inhibitor T5450996 on the proliferation and invasion of skin squamous carcinoma cell line A-431. Methods PKCζ inhibitor T5450996 was screened through Z′-LYTE™ kit. Cell proliferation assay and cell cycle analysis were used to observe the effects of T5450996 on the proliferation of skin squamous carcinoma A-431 cells. Scratch assay and invasion assay were used to explore the effects of T5450996 on the migration and invasion of skin squamous carcinoma A-431 cells. Results The PKCζ inhibitor T5450996 can inhibit the activity of PKCζ kinase, and the IC50 value of T5450996 was about 35 μmol/L. Compared to the control group, 35 μmol/L and 70 μmol/L concentrations of T5450996 significantly suppressed the proliferation of A-431 cells and blocked the cell cycle of A-431 cells. The results of scratch assay and invasion assay indicated that the migration and invasion capacities of A-431 cells were markedly impaired after the treatments with 35 μmol/L and 70 μmol/L concentrations of T5450996 (P＜ 0.05). However, 20 μmol/L concentration of T5450996 showed no significant effect (P＞0.05). Conclusion PKCζ inhibitor T5450996 significantly inhibits the proliferation and invasion capacities of skin squamous carcinoma cell line A- 431, and which may be a small molecular inhibitor with potential applications in the future.

Key words: protein kinase C, protein kinase inhibitors, skin neoplasms, cell proliferation, neoplasm invasiveness, neoplasm metastasis, A-431