OBJECTIVETo explore the relationship between p53 gene mutations and STK15 abnormal expression in the development of human laryngeal squamous-cell carcinoma (LSCC).

METHODSLSCC tissues and matched normal tissues were taken during operation from 55 patients without previous chemotherapy or radiotherapy. Following polymerase chain reaction amplification direct sequencing single strand conformational polymorphism (PCR-SSCP) combined with silver staining were used to detect mutations of p53 gene in exons 7 and 8 (p53E7 and p53E8) using genomic DNA from 110 specimens including 55 LSCC tissues and 55 matched normal tissues. STK15 expression were evaluated by RT-PCR with beta-actin as internal control.

RESULTSThe mutation rate of p53E7 was 30.9% (compared to normal tissues, chi(2) = 8.66, P < 0.01). There was no mutation in p53E8. In 38 of the 55 cases (69.1%), the STK15 mRNA expression level was higher than that of the paired normal tissue. The STK15 to beta-actin ratio of average density value was 1.22 +/- 0.49 in the cancer tissue, and 0.99 +/- 0.54 in the normal tissues (t = 4.539, P < 0.01). In 14 of the 17 cases (82.4%) with p53E7 mutations, the STK15 expression was higher than that of normal tissue. In the 38 cases with STK15 over-expression, p53E7 mutation was found in 14 cases (36.8%). The rate of concurrence of p53E gene mutations and STK15 over-expression (25.5%) was higher than that of only p53E gene mutations (chi(2) = 26.025, P < 0.01).

CONCLUSIONThere is significant association between p53 gene mutation and STK15 over-expression in laryngeal squamous-cell carcinoma.