Objective: To examine the role of TESTIN as a candidate tumor suppressor gene in head and neck carcinogenesis.
Design: Mutation and messenger RNA (mRNA) expression analyses.
Setting: Academic research.
Patients: Paired normal and tumor samples were obtained from 38 patients with primary head and neck squamous cell carcinoma.
Main outcome measures: Analysis and comparison of TESTIN gene mRNA expression and its relationship to clinicopathologic variables.
Results: Mutation analysis showed a nucleotide and amino acid change in 6 of the 38 tumor samples (16.0%). Semiquantitative mRNA expression analysis of TESTIN revealed a decreased expression in approximately 50% of the tumors compared with their matched normal controls. Interestingly, comparison of clinicopathologic variables to mRNA expression status of TESTIN revealed a significant difference in terms of cancer history (P = .03). Moreover, a higher smoking ratio and a family cancer history were also associated with downregulation of TESTIN, although the difference was not statistically significant (P = .43 and P = .16, respectively). Kaplan-Meier survival analysis demonstrated a worse survival rate among the patients with low TESTIN expression compared with the patients with normal-high TESTIN expression.
Conclusions: Our findings suggest that inactivation of TESTIN is involved in head and neck carcinogenesis through its downregulation. Further studies in various human cancer tissues using a large sample size and in vitro functional studies as well as clinical comparison research studies would give us a better evaluation of TESTIN's role and its possible future application in molecular diagnosis and treatment of different cancer types, including head and neck squamous cell carcinoma.