Expression And Clinical Significance Of P27mRNA And Protein, CyclinD1 Protein, P53 Protein In Colorectal Carcinoma

Purpose To investigate the expression and clinical significance of p27mRNA and protein, cyclinDl protein, p53 protein in colorectal carcinoma. Method In situ hybridization (ISH) for p27mRNA was performed in 58 cases of colorectal carcinomas and corresponding normal mucosas. Immunohistochemical staining (S-P method) for p27 protein, cyclinDl protein and p53 protein were performed in 58 cases of colorectal carcinomas and corresponding normal mucosas . Results 1. The positive rates of p27mRNA expression both in colorectal carcinoma and normal colorectal mucosa were 100%. The positive rate of p27 protein in colorectal carcinoma was 55.17%, while in normal colorectal mucosa it was 96.55% (P<0.01). The expression of p27 protein was inversely correlated with degree of differentiation of carcinoma (P<0.01), but not with gender, age, Dukes' stage, depth of tumor invasion, lymph node metastasis and tumor location (P>0.05) . There was no significant association between p27mRNA and p27 protein. 2. The positive rate of cyclinDl protein in colorectal carcinoma was 55.17%, while no cyclinDl protein expression was found in normal colorectal mucosa (P<0.01). In the group in which age 60, the positive rate of cyclinDl protein was higher than that in the group in which age<60 (P<0.05) . The expression of cyclinDl protein was inversely correlated with degree of differentiation of carcinoma (P<0.01), well and moderately differentiated carcinomas had higher cyclinD1 protein expression than poorly differentiated carcinomas, but not with gender, Dukes' stage, depth of tumor invasion, lymph node metastasis and tumor location(P>0.05) . 3. The positive rate of p53 protein in colorectal carcinoma was 53.45%, while no p53 protein expression was found in normal colorectal mucosa (P <0.01). No significant correlations were found between the expression of p53 protein and any clinicopathological parameters such as gender, age, degree of differentiation, Dukes' stage, depth of tumor invasion, lymph node metastasis and tumor location (P>0.05 ). 4. A positive correlation was found between the expressions of p27 protein and cyclinDl protein (r=0.582, P<0.01). No significant correlation was found between the expressions of p27 protein and p53 protein (r=0.201, P>0.05) . No significant correlation was found between the expressions of cyclinDl protein and p53 protein(r=0.132, P>0.05). Conclusions 1. p27 protein expression is regulated mainly at the post-transcriptional level. 2. Inactivation of p27 protein, overexpression of cyclinDl protein and p53 protein might promote cell cycle progression and carcinogenesis of colorectal carcinoma. p27 protein and cyclinDl protein play important role in carcinogenesis of colorectal carcinoma together ; p53 protein plays an important role in carcinogenesis of colorectal carcinoma independently. 3. Protein examination of p27 protein and cyclinDl protein might be important marker in evaluating the malignant degree and prognosis of colorectal carcinoma. Protein examination of cyclinDl protein and p53 protein assists early diagnosis of colorectal carcinoma..