Expression of bcl-2, bcl-x, bax and bak in renal parenchyma, oncocytomas and renal cell carcinomas.
Proteins of the bcl-2 family are important regulators of programmed cell death. Alterations in the expression of these proteins may contribute to the progression of cancer. Expression of bcl-2, bcl-x, bax and bak was investigated by immunohistochemistry and Western-blotting of regular and alterated renal parenchyma as well as in 57 renal cell carcinomas. Bcl-2, bcl-x and in part bax were found to be overexpressed in inflammed renal parenchyma, whereas atrophic tubuli predominantly stained for bcl-2 and to a lesser degree for bcl-x and bax. Only little bak expression was detected in alterated tubuli. Moderate to strong expression for bcl-2, bcl-x, bax and bak was found in 24, 38, 2 and 13 of 57 carcinomas, respectively. Bcl-2, bcl-x, bax and bak expression were correlated to tumor type. Chromophilic carcinomas stained stronger for bcl-2, bcl-x and bax, whereas chromophobic carcinomas stained stronger for bcl-x, bax and bak compared to clear cell carcinomas. Expression of bak correlated with that of bcl-x and with an unfavorable histology as indicated by nuclear grading in these tumors. Our findings suggest that expression of bcl-2 and bcl-x may be important for cell survival only in a subset of renal cell carcinomas, and that the anti-apoptotic effect of these proteins appears to be frequently bypassed possibly by other factors impeding programmed cell death.
Pammer
J
J
Institut für Klinische Pathologie, Allgemeines Krankenhaus Wien, Osterreich.
Exner
M
M
Regele
H
H
Haitel
A
A
Weninger
W
W
Horvat
R
R
Susani
M
M
D018249:Adenoma, Oxyphilic / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000378:metabolism* / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
C494772:BAK1 protein, human; C494826:BAX protein, human; C494811:BCL2L1 protein, human; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein