[Deletion of p15 and p16 genes and overexpression of STK15 gene in human laryngeal squamous cell carcinoma].

Objective: To investigate the association of p15 and p16 genes deletion, and STK15 gene overexpression with laryngeal squamous cell carcinoma (LSCC).

Methods: The cancer tissue and surrounding normal tissue were taken during operation from 50 cases of LSCC who had undergone neither chemotherapy nor radiotherapy preoperatively. DNA was extracted and PCR was used to test the homozygous deletion of p15 exon 2 (p15E2) and p16 exon 2 (p16E2). RNA was extracted, cDNA was synthesized by reverse transcription, and the expression of STK15 gene was tested by PCR with beta-actin as inner control. At the same time the expression of STK15 in human LSCC Hep-2 cell line was tested. The ratio of ADV (average density value) of STK15 gene to the ADV of beta-actin gene was calculated.

Results: The rate of p15E2 deletion was 12% (6/50) and that of p16E2 was 14% (7/50). The p15E2 and p16E2 codeletion rate was 6% (3/50). In 34 of the 50 cases (68%) the expression of STK15 gene in tumor tissue was higher than that of the paired surrounding normal tissue with a significant difference. The ratio of ADV of STK15 gene to ADV of beta-actin gene was 1.03 +/- 0.30 in the cancer tissue, and 0.89 +/- 0.22 in the paired normal tissue with a significant difference (t = 4.333, P < 0.01). The expression of STK15 gene was higher than that of beta-actin in Hep-2 cell line.

Conclusion: The homozygous deletion of p15E2 and p16E2 and overexpression of STK15 gene may play a role in the oncogenesis and malignant progression of laryngeal squamous cell carcinoma.