[Regulation of EGF-receptor expression by TGFalpha in human prostate androgen-unresponsive cancer cells].
OBJECTIVE
To elucidate the regulation of epidermal growth factor receptor (EGFR) expression by transforming growth factor (TGFalpha) and epidermal growth factor (EGF) in human prostate androgen-unresponsive cancer cells.


METHODS
EGFR mRNA expression and its protein level were measured by means of RT-PCR and Western blot respectively in human prostate cancer androgen-unresponsive cell lines, ARCaP and PC3, all treated with exogenous TGFalpha.


RESULTS
In the TGFalpha group, the levels of EGFR mRNA were 5.01 0.45 and 9.05 0.63 in PC3 and ARCaP respectively, significantly higher than in the control group (P < 0.05). The level of EGFR protein in PC3 treated with TGFalpha was 2.28 0.53, higher than in the control group (P < 0.05); however, the level of EGFR protein in ARCaP treated with TGFalpha was only 1.24 0.22, not different from the control (P > 0.05).


CONCLUSIONS
TGFalpha/EGF-EGFR pathway serves as a key growth regulator in prostate cancer. TGFalpha, but not EGF, preferentially maintains an autocrine loop in human androgen-unresponsive prostate cancer.
Chen
Weiguo
W
Department of Urology, the First Affiliated Hospital of Suzhou University, Suzhou, Jiangsu 215006, China. wg.chen@sohu.com
Yan
Chunyin
C
Pu
Jinxian
J
Hou
Jianquan
J
Wen
Duangai
D
Guo
Zhenhua
Z
D015153:Blotting, Western; D045744:Cell Line, Tumor; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*
D012333:RNA, Messenger; D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors