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.
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.
Harn
H J
HJ
Department of Pathology, National Defense Medical Center, Taipei, Taiwan.
Ho
L I
LI
Liu
C A
CA
Liu
G C
GC
Lin
F G
FG
Lin
J J
JJ
Chang
J Y
JY
Lee
W H
WH
D001483:Base Sequence; D002277:Carcinoma / Q000235:genetics*; D002883:Chromosomes, Human, Pair 14 / Q000187:drug effects*; D002887:Chromosomes, Human, Pair 18 / Q000187:drug effects*; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009303:Nasopharyngeal Neoplasms / Q000235:genetics*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects*; D016707:Tissue Fixation; D014178:Translocation, Genetic / Q000187:drug effects*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000276:immunology / Q000494:pharmacology*
D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53