Analysis of the expression of cell cycle regulating genes in gastrointestinal tumors

细胞周期调控基因的表达，正调节剂：采用免疫组化和Western blot法检测正常大肠粘膜、增生、腺瘤、腺瘤中癌和进展期大肠癌中G1期细胞周期蛋白（cyclin D、E）、细胞周期蛋白依赖性激酶（CDK 2、4）、负调节因子CDK抑制剂（CDK 4 I/pI 6）RB的表达。在正常粘膜中，每种蛋白质仅在腺体底部的少数细胞中检测到。在增生的粘膜中，cyclin D和E在腺体底部的上部大量细胞中表达。在腺瘤中，经常检测到这些蛋白的过表达，例如，cyclin D：55/66（83%），cyclin E：42/50（84%）。在腺瘤中的癌中，CDK 2、p16和RB以及细胞周期蛋白D、E的过度表达被注意到，cyclin D：8/8（100%），cyclin E：13/13（100%），CDK2：10/12（83%），p16：10/14（71%），RB：10/12（83%）。最后，在晚期癌中，所有蛋白质都过表达，例如，细胞周期蛋白D：2 ...更多信息 6/45（58%），cyclin E：41/45（91%），CDK2：34/45（76%），CDK4：39/45（87%），p16：59/60（98%），RB：34/45（76%）。Western印迹定量分析进一步证实了这些蛋白在结肠癌中的表达比正常粘膜高几倍。此外，与正常粘膜相比，RB的过度磷酸化（失活）形式的速率高1.46倍。在相邻切片上使用免疫组织化学进行的比较分析显示，过表达RB的癌细胞也过表达细胞周期蛋白E/CDK 2，过表达CDK 4的癌细胞也表达p16。综上所述，在基于腺瘤-癌序列的多步骤结肠癌发生过程中，cyclin D和E从增生或腺瘤阶段开始过表达，CDK 2和CDK 4 I/p16从腺瘤中的癌阶段开始过表达，CDK 4在进展期癌阶段过表达。因此，它表明，细胞周期调控因子，如G1周期蛋白，CDK和CDK抑制剂的表达在结肠癌的发生过程中有很深的参与。cyclin E/CDK 2的过度表达可能与RB蛋白的过度磷酸化有关。少

The expression of cell cycle regurating genes, eg., positive regulators : G1 cyclins (cyclin D,E), cyclin dependent kinases (CDK2,4), negative regulators : CDK inhibitor (CDK4I/pI6), RB,in normal mucosa, hyperplasia, adenoma, carcinoma in adenoma and advanced carcinoma of colorectum was analyzed by immunohistochemistry and Western blottings. In normal mucosa, each protein was detected only in a few cells of bottom parts of the gland. In hyperplastic mucosa, the expression of cyclin D and E was detected in large number of cells of upper parts from the bottom of the gland. In adenomas, the overexpression of these proteins are frequently detected, eg., cyclin D : 55/66 (83%), cyclin E : 42/50 (84%). In carcinoma in adenoma, the overexpression of CDK2, p16 and RB,as well as cyclin D,E,was noted, eg., cyclin D : 8/8 (100%), cyclin E : 13/13 (100%), CDK2 : 10/12 (83%), p16 : 10/14 (71%), RB : 10/12 (83%). Finally, in advanced carcinomas, all the proteins were overexpressed, eg., cyclin D : 2 … More 6/45 (58%), cyclin E : 41/45 (91%), CDK2 : 34/45 (76%), CDK4 : 39/45 (87%), p16 : 59/60 (98%), RB : 34/45 (76%). The quantitative analysis by Western blottings further confirmed a few times higher expression of these proteins in colon carcinomas compared to normal mucosa. Also, the rate of hyperphosphorylated (inactivated) form of RB was shown to be 1.46 times higher compared to normal mucosa. The comparative analysis using immunohistochemistry on the adjacent sections revealed that the cancer cells overexpressing RB also overexpressed cyclin E/CDK2 and those overexpressing CDK4 also expressed p16. In summary, during the multistep colon carcinogenesis based on adenoma-carcinoma sequence, cyclin D and E are overexpressed from the stage of hyperplasia or adenoma, CDK2 and CDK4I/p16 are overexpressed from the stage of carcinoma in adenoma, and CDK4 is overexpressed at the stage of advanced carcinoma. Thus, it was suggested that the expression of cell cycle regulators such as G1 cyclins, CDKs and CDK inhibitors are deeply involved in colon carcinogenesis. And, the overexpression of cyclin E/CDK2 was thought to be involved in hyperphosphorylation of RB protein. Less