Comparative analysis of mRNA and protein expression for epidermal growth factor receptor and ligands relative to the proliferative index in human prostate tissue.
The expression of epidermal growth factor receptor (EGF-R), transforming growth factor alpha (TGFalpha), and epidermal growth factor (EGF) was evaluated in a series of prostate cancer (CaP; n = 55) and benign prostate hyperplasia (BPH; n = 44) specimens using immunocytochemistry (ICC) and Northern blotting. In situ hybridization (ISH), performed on a subgroup of these specimens, proved to be a more informative technique for the assessment of messenger RNA (mRNA) in this heterogeneous tissue. A comparative analysis was made in relation to the proliferative index, assessed using the MIB-1 antibody. Elevated levels of EGF-R and TGFalpha, mRNA, and protein were observed in carcinoma cells compared with benign, secretory epithelium using in situ hybridization and immunocytochemistry. In carcinoma specimens evidence of an autocrine growth loop is provided by a correlation between EGF-R and TGFalpha, mRNA (P < .0001), and protein expression (P < .01). A trend toward increased expression of EGF-R and TGFalpha protein with dedifferentiation and a similar trend in the growth fraction suggest a role in tumor progression. Although there was a correlation between EGF-R and the proliferative index (P < .01), no relationship was found between this latter parameter and TGFalpha immunoreactivity (P > .05), indicating that this growth factor may be linked with other aspects of malignant activity rather than directly stimulating proliferation.
Glynne-Jones
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Tenovus Cancer Research Centre, University of Wales College of Medicine, Heath Park, Wales, UK.
Goddard
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Harper
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ME
D002455:Cell Division; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008024:Ligands; D008297:Male; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000378:metabolism
D008024:Ligands; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors