[Detection of the p53 protein accumulation and p53 gene mutation in squamous cell carcinoma of the lung]

Abstract

Objective: To investigate the effects of p53 protein accumulation and p53 gene mutation in the pathogenesis of squamous cell carcinoma of lung.

Methods: Immunohistochemistry and PCR-SSCP techniques were used to detect p53 protein accumulation and p53 gene mutation.

Results: p53 protein accumulations was found in 52.5% (63/120) of the samples. p53 gene mutation was detected in 56.7% (68/120) of the same specimens by PCR-SSCP. In 24 cases (35.3%, 24/68), the mutations was locating on exon 5, 11 cases (16.2%, 11/68) on exon 6, 18 cases (26.5%, 18/68) on exon 7 and 15 cases (22.1%, 15/68) on exon 8 respectively. The rate of p53 gene mutation/overexpression was 60%. p53 gene mutation/overexpression rate of moderately (63.6%, 28/44) or poorly (63.5%, 40/63) differentiated pulmonary squamous cell carcinoma was significantly higher than that of the well differentiated carcinoma (30.8%, 4/13). In comparing with non-lymph node metastasis group (43.1%, 28/65), p53 gene mutation/overexpression rate in metastasis group (80%, 44/55) was significantly higher. p53 gene mutation/overexpression rate of pulmonary squamous cell carcinoma in advanced stage (76.3%, 45/59) was significantly higher than that in the early stage (44.3%, 27/61). p53 gene mutation/overexpression rate in heavy smoking group (72.4%, 55/76) was significantly higher than that in non-smoking group (38.6%, 17/44). No statistically significant correlation was found between p53 gene mutation/overexpression and sex, age, tumor location or invasion of the surrounding tissue.

Conclusions: p53 gene mutation/overexpression may play an important role in the pathogenesis of squamous cell carcinoma of lung and can be considered as a predicting marker of prognosis.