Me. Harper et al., AN IMMUNOCYTOCHEMICAL ANALYSIS OF TGF-ALPHA-EXPRESSION IN BENIGN AND MALIGNANT PROSTATIC TUMORS, The Prostate, 23(1), 1993, pp. 9-23
Transforming growth factor alpha (TGFalpha) expression was analyzed im
munocytochemically on formalin-fixed wax-embedded sections obtained fr
om 24 benign prostatic hyperplasia (BPH) specimens and 76 prostatic ca
rcinoma tissues, 3 human prostatic tumor xenografts, normal kidney, an
d salivary gland. Low amounts of TGFalpha immunopositivity were encoun
tered in the epithelium of BPH glandular tissues, whereas in the prost
atic adenocarcinoma samples, a greater heterogeneity and intensity of
TGFalpha immunostaining was observed. The most intense staining was ex
hibited by the least differentiated tumors, although a few of these we
re weakly stained. Statistical analysis of the relationship of histopa
thological grade of tumor with TGFalpha expression in the carcinomas s
howed a significant correlation of these parameters, 0.01 > P > 0.001.
The expression of the proliferation markers Ki-67 and PCNA was also a
nalyzed in the carcinoma specimens, and the relationship of these to T
GFalpha expression indicated that there was no significant correlation
in this series of tumors between increased growth activity and TGFalp
ha expression (p approximately 0.25 with both markers). The prostatic
carcinoma xenografts TEN12 and TEN15 contained low levels of immunorea
ctive TGFalpha, which was uniformly distributed, whilst heterogeneous
immunostaining was observed in the uroepithelial xenograft TEN16. In t
he normal human kidney, TGFalpha was concentrated in the epithelium of
the distal convoluted tubules (DCT) and the collecting tubules (CT),
and lower amounts were identified in the proximal convoluted tubules (
PCT). As in the prostatic carcinomas, the immunostaining was eliminate
d by prior absorption of the antibody with pure TGFalpha and not with
human or mouse EGF. No crossreactivity of the TGFalpha antibody with s
alivary EGF was demonstrated. This study concludes that, in prostate c
arcinoma, the least differentiated tumors more often expressed greater
amounts of immunoreactive TGFalpha; however, no relationship between
TGFalpha expression and cellular proliferation markers was found. (C)
1993 Wiley-Liss, Inc.