Pim-1 expression in prostatic intraepithelial neoplasia and human prostate cancer.
BACKGROUND
PIM-1, an oncogene product of serine/threonine kinase, has been found to play an important role in induction/suppression of apoptosis, cell cycle progression, and transcriptional regulation by phosphorylating the target proteins involved in these processes. Recently, the expression of PIM-1 has been shown to correlate significantly with measures of prostate cancer clinical outcome.


METHODS
Immunohistochemical analysis was used to characterize the patterns of PIM-1 expression in high grade prostatic intraepithelial neoplasia (HGPIN) and cancer in 121 radical prostatectomy specimens.


RESULTS
Moderate to strong cytoplasmic staining was observed in 68% of cancers, 12% presented nuclear positivity as well. Moderate to strong expression was seen in 76% of tumors with Gleason score (GS) 7 or higher compared to 58% in tumors with GS 6 or lower (P = 0.04). The staining intensity was moderate or strong in 97% of HGPIN lesions. PIM-1 was overexpressed in HGPIN compared to cancer in 65% of cases. Expression in benign glands was negative or only weakly positive.


CONCLUSIONS
Our data suggest that PIM-1 overexpression in HGPIN may be an early event in the development of prostate malignancy. Additionally, PIM-1 expression provides supplementary information for distinguishing HGPIN from benign epithelium.
Valdman
Alexander
A
Department of Surgical Science, Section of Urology, Urology Research Laboratory, Karolinska Hospital, Stockholm, Sweden.
Fang
Xiaolei
X
Pang
See-Tong
ST
Ekman
Peter
P
Egevad
Lars
L
D000368:Aged; D002471:Cell Transformation, Neoplastic; D003937:Diagnosis, Differential; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011468:Prostatectomy; D019048:Prostatic Intraepithelial Neoplasia / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D051573:Proto-Oncogene Proteins c-pim-1
D011518:Proto-Oncogene Proteins; C496634:PIM1 protein, human; D017346:Protein Serine-Threonine Kinases; D051573:Proto-Oncogene Proteins c-pim-1