Objective: To evaluate the relationship between alteration of p16 gene, its protein expression and the pathogenesis and development of rhabdomyosarcoma (RMS).
Methods: 44 cases of RMS were examined for alteration of p16 gene with PCR-SSCP and 47 cases of RMS were examined for p16 protein expression with immunohistochemical method.
Results: The homozygous deletion of p16 gene was observed in 2 cases and mutations in 6 cases. Of these 8 cases with altered p16 gene, 6 had extensive invasion, recurrence or metastasis. The total negative rate of p16 protein expression in RMS was 38.3% (18/47 cases). Of these 8 cases with alterations of p16 gene, negative expression for p16 protein was observed in 7 cases and positive in only 1 cases. In contrast, no structural abnormalities of the p16 gene were detected in another 11 cases with negative expression of p16 protein. Higher rates of p16 gene abnormality and loss of p16 protein were observed in ARMS than in ERMS. Higher rate of extensive invasion, recurrence or metastasis was also found in the group negative for p16 protein.
Conclusion: The abnormalities of p16 gene and loss of p16 protein expression may be related to the pathogenesis and development of some RMS.