Expression of p21waf1, p53 and proliferating cell nuclear antigen in lung cancer / 中国组织工程研究

ABSTRACT

BACKGROUND: The different level of proteins regulating cell cycle and theircorrelation is the main criteria to differentiate the benign and malignant cellular proliferation.OBJECTIVE: To investigate the expression status of p21waf1 and p53 in lung cancer as well as proliferating cell nuclear antigen (PCNA)DESIGN:A case-control study.SETTING: Department of Respiratory Medicine, Renmin Hospital ,Wuhan UniversityPAITICIPANTSThis case-control study involved 135 patients who underwent lobectomy or fiberoptic bronchoscopy for primary lung cancer or benign chronic pulmonary diseases at Renmin Hospital of Wuhan University from October 1996 through May 1999. They were divided into two groups lung cancer group (76 patients, including 56 men and 20 women,aged 18-74 years of age) and chronic pulmonary diseases group (59 cases,including 42 men and 17 women, aged 16-70 years of age).METHODS: Phosphate buffer solution replaced the first antibody as the negative control. Immunohistochemistry was performed using a modified streptavidin-biotinylated peroxidase technique according to the manufacturer's recommendations (Maxim Corporation). For p21waf1 staining, we used hydrated autoclaving as a pretreatment. Antigen retrieval was performed in a standard microwave unit for p53 staining. PCNA staining did not need The ratio of the positive cells indicated by yellowish brown nucleus due to staining was counted for 5 successive high-fold microscopic fields when it was≥ 10%, it was taken as positive; when it was ＜10%, it was regarded as high-fold microscopic fields for the percentage of the positive cells indicated by yellowish brown nucleus due to staining in each field, and the average value of the five fields was taken as labeling index (LI) for proliferated nuclear antigens.MAIN OUTCOME MEASURES: The expression leyels of p21waf1, p53and PCNA in lung cancer.cancer were 75% (57/76) and 47%(36/76) respectively. The labeling index of PCNA in lung cancer group was significantly higher than that of the chronic pulmonary diseases group (0.44±0.32 vs 0.09±0.14, respectively).significantly higher than that of small cell lung cancer (0.51 ±0.33 vs in lung cancer tissues. In chronic pulmonary diseases group, the expression of p21waf1 and p53 showed a close relationship with PCNA.CONCLUSION: It was found that p21waf1 and p53 were obviously upregulated in lung cancer and the degree of cellular proliferation in lung cancer was rather high. The capacity of DNA damage repair in squamous lung cancer may be stronger than that in small cell lung cancer.