Expression of p57kip2 and Rb proteins and their relationships with the genesis and prognosis of human colorectal adenocarcinoma

doi:10.3321/j.issn:1673-8225.2003.11.013

Abstract：Aim The abnormality of mammalian cell cycle regulation is an important cause of cell over- proliferation and oncogenesis, there was not report about relationships between p57kip2 protein as negative factor of cell cycle regulation and colorectal adenocarcinoma in China.This article aims to investigate the effects of inhibitoring factor of cell cycle regulation p57kip2 and retinoblastinoma proteins (Rb protein) in the genesis and progression of colorectal adenocarcinoma.Methods The expression of p57kip2 and Rb proteins in tumor tissues of 37 patients with colorectal adenocarcinoma and in normal mucosal tissues of 26 subjects were detected with SP immunohistochemical technique.Results p57kip2 protein positive- expression rate in tumor tissues of colorectal adenocarcinoma was 40.5% , which was lower than that in normal mucosal tissues of colon and rectum (χ 2=5.039,P< 0.05), p57kip2 protein positive- expression correlated significantly with tumor cell differentiation and lymph node metastasis (χ 2=8.914,χ 2=4.416, P< 0.05); Rb gene protein positive- expression rate in tumor tissues was 51.4%, which was also lower than that in normal mucosal tissues of colon and rectum (χ 2=4.234, P< 0.05); Rb protein positive- expression correlated significantly with lymph node metastasis(χ 2=14.596, P< 0.05), but did not correlated with tumor cell differentiation( P >0.05).Rb protein positive- expression rate in the tumor tissues of p57kip2 protein positive- expression group was 66.7% ;and Rb protein positive- expression rate in the tumor tissues of p57kip2 protein negative- expression group was 40.9% .There was significant positive correlation between the two groups( r=0.369, P< 0.05) .Conclusion The decreased expression of p57kip2 and/or Rb proteins may play an important role in the genesis of colorectal adenocarcinoma and may be helpful to the determination of malignant degree and lymph node metastasis of the tumors.There was an additional mechanism between p57kip2 and Rb proteins in cell cycle regulation of colorectal adenocarcinoma.