Down regulation of bcl-2 by p53 in nasopharyngeal carcinoma and lack of detection of its specific t(14;18) chromosomal translocation in fixed tissues

Histopathology. 1996 Apr;28(4):317-23. doi: 10.1046/j.1365-2559.1996.d01-431.x.

Abstract

High levels of bcl-2 protein have been found in a wide variety of human cancers. Since p53 gene inactivation occurs in over half of human cancers, it is possible that loss of p53-mediated repression of bcl-2 gene expression accounts, at least in part, for the frequent abnormalities in bcl-2 protein production seen in tumours. By using immunohistochemical methods, we have analysed thirty-three nasopharyngeal carcinomas for p53 and bcl-2 expression. We found an inverse correlation between the expression of these two proteins (P < 0.001). Moreover, we utilized universal oligonucleotide primers of a region 5' to the bcl-2 MBR and at the 3' end of JH segments to initiate a DNA polymerase chain reaction that amplified these bcl-2-JH junctures. Of the twelve nasopharyngeal carcinomas expressing bcl-2, none showed a t(14;18) chromosome translocation. These findings may indicate potential mechanisms by which bcl-2 regulates apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Carcinoma / genetics*
  • Chromosomes, Human, Pair 14 / drug effects*
  • Chromosomes, Human, Pair 18 / drug effects*
  • Down-Regulation / drug effects
  • Down-Regulation / genetics*
  • Humans
  • Molecular Sequence Data
  • Nasopharyngeal Neoplasms / genetics*
  • Proto-Oncogene Proteins c-bcl-2 / drug effects*
  • Tissue Fixation
  • Translocation, Genetic / drug effects*
  • Tumor Suppressor Protein p53 / biosynthesis
  • Tumor Suppressor Protein p53 / immunology
  • Tumor Suppressor Protein p53 / pharmacology*

Substances

  • Proto-Oncogene Proteins c-bcl-2
  • Tumor Suppressor Protein p53