OVEREXPRESSION OF THE INSULIN-LIKE GROWTH-FACTOR-I RECEPTOR AND AUTOCRINE STIMULATION IN HUMAN CERVICAL-CANCER CELLS

Citation
Ma. Steller et al., OVEREXPRESSION OF THE INSULIN-LIKE GROWTH-FACTOR-I RECEPTOR AND AUTOCRINE STIMULATION IN HUMAN CERVICAL-CANCER CELLS, Cancer research, 56(8), 1996, pp. 1761-1765
Citations number
30
Categorie Soggetti
Oncology
Journal title
ISSN journal
00085472
Volume
56
Issue
8
Year of publication
1996
Pages
1761 - 1765
Database
ISI
SICI code
0008-5472(1996)56:8<1761:OOTIGR>2.0.ZU;2-Z
Abstract
We characterized mechanisms of growth control involving insulin-like g rowth factor-1 (IGF-I), IGF-2, and IGF-I receptor (IGF-IR) by investig ating their expression in human cervical cancer cell lines, primary ce rvical tumor cell cultures, and normal ectocervical epithelial cells m aintained in short-term culture, By reverse transcription followed by PCR, IGF-1 mRNA was not detected in any of the cell lines, whereas IGF -2-mRNA transcripts were detected in all of them, Using the RNase prot ection assay, low levels of IGF-2 mRNA were also detected in all of th e cervical cancer cell lines, primary cervical tumor cell cultures, an d normal ectocervical cultures tested, but no IGF-1 transcripts were d etected, Scatchard analysis revealed 3- and 5-fold increases in IGF-1R expression by the primary cervical cancer cell cultures and cervical cancer cell lines, respectively, compared with the normal ectocervical cells, In proliferation assays, epidermal growth factor (EGF) consist ently enhanced cervical cancer cell growth, but an antisense oligonucl eotide to IGF-2 uniformly inhibited the EGF-induced mitogenic effect, These studies suggest that autocrine production of IGF-2 and overexpre ssion of the IGF-1R are important components controlling the prolifera tion of cervical carcinoma cells, and that autocrine IGF-2 production in cervical cancer cells may participate in the mitogenic signaling of EGF.