Elevated expression of inhibitor of apoptosis proteins in prostate cancer.
OBJECTIVE
Inhibitor of apoptosis (IAP) family proteins are suppressors of apoptosis that have been implicated in apoptosis resistance in some cancers. Their expression and relevance to the prognosis of prostate cancer were investigated.


METHODS
The expression of four members of the IAP family (cellular inhibitor of apoptosis protein 1, cellular inhibitor of apoptosis protein 2, X chromosome-linked IAP, and survivin) was examined by immunohistochemistry and immunoblotting in human prostate cancers and in prostate tissues from transgenic mice expressing SV40 large T antigen under control of a probasin promoter.


RESULTS
Tumor-associated elevations in the levels of all four IAP family members were common in prostate cancers of both humans and mice, suggesting concomitant up-regulation of multiple IAP family proteins. Compared with normal prostatic epithelium, increased IAP expression was often evident even in prostatic intraepithelial neoplasia lesions (carcinoma in situ), suggesting that deregulation of IAP expression occurs early in the pathogenesis of prostate cancer. IAP expression did not correlate with Gleason grade or prostate-specific antigen levels.


CONCLUSIONS
The findings demonstrate that tumor- associated elevations in the expression of several IAP family proteins occur as a frequent and early event in the etiology of prostate cancer.
Krajewska
Maryla
M
The Burnham Institute, La Jolla, California 92037, USA.
Krajewski
Stan
S
Banares
Steven
S
Huang
Xianshu
X
Turner
Bruce
B
Bubendorf
Lukas
L
Kallioniemi
Olli-P
OP
Shabaik
Ahmed
A
Vitiello
Antonella
A
Peehl
Donna
D
Gao
Guo-Jian
GJ
Reed
John C
JC
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism; D017209:Apoptosis; D045744:Cell Line, Tumor; D015331:Cohort Studies; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D051034:Inhibitor of Apoptosis Proteins; D019169:Jurkat Cells; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D051616:Neuronal Apoptosis-Inhibitory Protein; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D011401:Promoter Regions, Genetic; D011467:Prostate / Q000378:metabolism; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism*; D014176:Protein Biosynthesis; D011506:Proteins; D000077022:Survivin; D013997:Time Factors; D015854:Up-Regulation; D051636:X-Linked Inhibitor of Apoptosis Protein
D000952:Antigens, Polyomavirus Transforming; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; C496800:NAIP protein, human; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D051616:Neuronal Apoptosis-Inhibitory Protein; D011506:Proteins; D000077022:Survivin; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D017430:Prostate-Specific Antigen