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Home    Ανοσοϊστοχημική μελέτη των P53 επαγόμενων πρωτεϊνών P21WAF1/CIP1 και MDM2, καθώς και της BCL-2 πρωτεΐνης σε αδενοκαρκινώματα του παχέος εντέρου. Συσχετισμός με την ιστολογική διαφοροποίηση, το στάδιο κατά Dukes' και το δείκτη πολλαπλασιασμού Ki-67  

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Identifier 000035349
Title Ανοσοϊστοχημική μελέτη των P53 επαγόμενων πρωτεϊνών P21WAF1/CIP1 και MDM2, καθώς και της BCL-2 πρωτεΐνης σε αδενοκαρκινώματα του παχέος εντέρου. Συσχετισμός με την ιστολογική διαφοροποίηση, το στάδιο κατά Dukes' και το δείκτη πολλαπλασιασμού Ki-67
Alternative Title Immunohistochemical expression of p53 induced proteins mdm2, p21/waf1 and anti-apoptotic protein bcl-2 in human colorectal adenocarcinomas. Correlation with tumour grade, Dukes' stage and proliferating factor Ki-67/MIB1 expression
Creator Valassiadou, Kalliopi
Abstract P53 gene has a central role in mammalian cell cycle control conserving genomic stability. P53 exerts its action mainly by transcriptional activation of target genes and apoptotic signals. The present study was undertaken to examine the distribution of p53 downstream effector proteins p21waf1 and mdm2 and bcl-2 anti-apoptotic protein in human colorectal adenocarcinomas, in relation to p53 protein expression, proliferation nuclear antigen Ki-67/MIB1, Dukes' stage and histological grade in order to obtain combined information about the involvement of these proteins in the genetic pathway of colorectal tumorigenesis and to estimate possible clinical use in evaluating the biological behaviour of these tumours.immunophenotypes characterising these tumours. Formalin-fixed, paraffin-embedded tissue sections from 98 colorectal adenocarcinomas and 11 adenomas were stained using immunohistochemical methods for the detection of these proteins. P53, p21waf1/cip1, mdm2 and bcl-2 proteins were expressed in 63/98, 72/98, 50/98 and 52/98 cases of adenocarcinomas and in 4/11, 10/11, 8/11 and 10/11 adenomas, respectively. There was an extremely high correlation in parallel expression of p53 and mdm2 proteins in adenocarcinomas (p<0,001) and also proportionate relation between level of mdm2 expression and Dukes' stage (p<0.05), indicating involvement of mdm2 during progressive extension of the tumour. P21waf1 level of expression was inversely related to p53 protein expression (p<0,05) in adenocarcinomas, indicating that both p53-dependent and p53-independent induction of p21waf1 expression may be involved in the molecular mechanisms controlling these tumours. Moreover, p21waf1 level of expression was inversely related to Dukes' stage (p<0.05), indicating that tumour extension leads to progressive loss of cell-cycle arrest mechanisms in colorectal adenocarcinomas. There was no correlation between bcl-2 expression and p53 expression, Ki-67/MIB1 expression, histological grade or Dukes' stage of adenocarcinomas. The above finding indicates that even p53 is regarded as a downregulator of bcl-2 protein, there are also other factors regulating its expression as supported by the literature. Ki-67/MIB1 expression was not correlated with p53 or p21waf1 expression in adenocarcinomas, but only with tumour grade. Ki-67/MIB1 levels were higher in low grade tumours (p<0,005). Concequently, Ki-67/MIB1 could be a used as an indirect marker for predicting the biological aggressiveness of these tumours.
Language Greek
Issue date 1999-07-01
Date available 1999-10-01
Collection   School/Department--School of Medicine--Department of Medicine--Doctoral theses
  Type of Work--Doctoral theses
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