Abstract: Objective To investigate the frequency of P16INK4a, CDK4 and CCND1 gene mutations in Chinese melanoma patients and find out the possible clinical significance. Methods The samples in this study were from 134 melanoma patients(37 acral melanomas,87 mucosal melanomas,10 non-acral skin melanomas), hospitalized in Beijing Cancer Hospital from January 2010 to December 2014.The mutation status of P16INK4a,CDK4 and CCND1 was detected by PCR amplification and Sanger sequence.Statistical analyses were used to investigate the correlation between gene mutation and prognosis. Results Among the 134 samples, the mutation frequency of P16INK4a, CDK4, CCND1 was 8.2%（11/134）, 0.75 %(1/134) ,0 %(0/134) respectively.81.8% (9/11) of the P16INK4a gene mutation may affect protein function.The median survival time of melanoma patients with P16INK4a mutations was significantly shorter than the patients without P16INK4a mutations (c2= 8.872,P＜0.01).P16INK4a gene mutation is an independent prognostic factor for melanoma (P <0.05). Conclusions P16INK4a may be a breaking point of targeted therapy for melanoma.

Key words: Melanoma, P16INK4a, CDK4, CCND1, Gene mutation