Background & objective: Abnormality of cell cycle regulation is an important cause of cell over-proliferation and oncogenesis. But the relationship between cell cycle regulators and gastric carcinoma is uncertain. This study was to investigate the expression and significance of cell cycle regulators, including P16(INK4), Cyclin D1, P21(WAF1), and P53, in gastric carcinoma.
Methods: The expressions of P16(INK4), Cyclin D1, P21(WAF1), and P53 in 53 specimens of gastric carcinoma were observed by SP immunohistochemistry. Multivariate Cox regression was used to analyze factors affecting prognosis.
Results: Positive rate of P53 in gastric carcinoma was higher than that in adjacent tissues (60.4% vs. 0, P < 0.01); those in well, and poorly differentiated adenocarcinoma were significantly higher than that in mucoid carcinoma (65.4%, and 68.2% vs. 0, P < 0.01). Over-expression rate of Cyclin D1 in gastric carcinoma was higher than that in adjacent tissues (69.8% vs. 5.7%, P < 0.01). Positive rate of P16(INK4) in gastric carcinoma was lower than that in adjacent tissues (60.3% vs. 88.6%, P < 0.05). Positive rate of P21(WAF1) in gastric carcinoma was lower than that in adjacent tissues (26.4% vs. 56.6%, P < 0.01). Positive rate of P16(INK4) was significantly related with the depth of tumor invasion (P < 0.05), and lymph node metastasis (P < 0.01). Multivariate Cox regression analysis indicated that lymph node metastasis and the expression of P16(INK4) were independent prognostic factors of gastric carcinoma.
Conclusions: Down-regulation of P16(INK4) and P21(WAF1), and over-expression of Cyclin D1 and P53 are significantly related to genesis and progression of gastric carcinoma. Down-regulation of P16(INK4) may be correlated to infiltration, metastasis, and prognosis of gastric carcinoma.