Valassiadou K E, Stefanaki K, Tzardi M, Datseris G, Georgoulias V, Melissas J, Tsiftsis D D, Delides G, Kanavaros P
Department of Surgical Oncology, University Hospital of Herakleion, Crete, Greece.
Anticancer Res. 1997 Jul-Aug;17(4A):2571-6.
The present study was undertaken to examine the distribution of p53, p21, mdm-2 and bcl-2 protein expression in human colorectal adenocarcinomas in order to obtain combined information about the immunophenotypes characterising these tumours. Formalin-fixed, paraffin-embedded tissue sections from 52 cases of colorectal adenocarcinomas were stained using immunohistochemical methods for the detection of p53, p21/waf1, mdm2 and bcl-2 proteins. P53, p21/waf1, mdm2 and bcl-2 proteins were expressed in 35/52, 45/52, 9/52 and 27/52 cases, respectively. All nine mdm2+ cases expressed p53 and p21 proteins as well. The three patterns observed in p53/p21 expression were: p53+/p21+, p53+/p21- and p53-/p21+ in 28, 7, and 17 cases, respectively. Consequently, p53+/mdm2-/p21+, p53+/mdm-/p21- and p53-/mdm2-/p21+ immunophenotypes were expressed in 19, 7, and 17 cases respectively. Four patterns of p53/bcl2 expression were identified: p53+/bcl2+, 20 cases; p53+/bcl2-, 15 cases; p53-/bcl2+, 7 cases; p53-/bcl2-, 10 cases. It was noteworthy that 9 of the 10 p53-/bcl2-tumours had negative lymph node status. The present results suggest that both p53 dependent and p53-independent induction of p21 expression may be involved in the molecular mechanisms controlling these tumours. High expression of the p53 protein in colorectal carcinomas could be due not only to p53 gene mutations but also to binding to mdm2 protein which leads to p53 protein stabilisation. In addition, tumours with p53-/bcl2- immunophenotype are frequently associated to negative lymph node status and seem to be less aggressive.
本研究旨在检测p53、p21、mdm-2和bcl-2蛋白在人类结肠腺癌中的表达分布，以获取有关这些肿瘤免疫表型的综合信息。采用免疫组织化学方法对52例结肠腺癌福尔马林固定、石蜡包埋的组织切片进行染色，以检测p53、p21/waf1、mdm2和bcl-2蛋白。p53、p21/waf1、mdm2和bcl-2蛋白分别在35/52、45/52、9/52和27/52例中表达。所有9例mdm2+病例也表达p53和p21蛋白。p53/p21表达中观察到的三种模式分别为：p53+/p21+、p53+/p21-和p53-/p21+，分别为28、7和17例。因此，p53+/mdm2-/p21+、p53+/mdm-/p21-和p53-/mdm2-/p21+免疫表型分别在19、7和17例中表达。鉴定出p53/bcl2表达的四种模式：p53+/bcl2+，20例；p53+/bcl2-，15例；p53-/bcl2+，7例；p53-/bcl2-，10例。值得注意的是，10例p53-/bcl2-肿瘤中有9例淋巴结状态为阴性。目前的结果表明，p21表达的p53依赖性和p53非依赖性诱导可能参与了控制这些肿瘤的分子机制。结肠腺癌中p53蛋白的高表达不仅可能归因于p53基因突变，还可能归因于与mdm2蛋白结合导致p53蛋白稳定。此外，具有p53-/bcl2-免疫表型的肿瘤常与淋巴结阴性状态相关，且似乎侵袭性较小。
