This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hembree, J. R. Articles by Eckert, R. L. Search for Related Content PubMed PubMed Citation Articles by Hembree, J. R. Articles by Eckert, R. L.

Epidermal Growth Factor Suppresses Insulin-like Growth Factor Binding Protein 3 Levels in Human Papillomavirus Type 16-immortalized Cervical Epithelial Cells and Thereby Potentiates the Effects of Insulin-like Growth Factor 1¹

Departments of Physiology and Biophysics [J. R. H., C. A., R. L. E.], Dermatology [R. L. E.], Reproductive Biology [R. L. E.], and Biochemistry [J. R. H., R. L. E.], Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4970

Human ectocervical epithelial cells are a primary target for infection by oncogenic papillomaviruses, which are strongly implicated as causative agents in the genesis of cervical cancer. Growth factors have been implicated as agents that stimulate proliferation and enhance the possibility of malignant transformation. In the present study we utilize several human papillomavirus (HPV) type 16-immortalized ectocervical epithelial cell lines to investigate the effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on cell proliferation and the production of IGF binding proteins (IGFBPs). ECE16-1 cells, an HPV16-immortalized/nontumorigenic cell line, maintained in defined medium, produce and release high levels of IGFBP-3 (38/42 kDa) as well as smaller amounts of a 24-kDa IGFBP. Supplementation of defined medium with EGF causes a dose-dependent increase in cell growth and a concomitant decrease in the levels of IGFBP-3 released into the culture medium. EGF suppression of IGFBP-3 is maintained even when EGF-stimulated cell growth is suppressed 67% due to the simultaneous presence of 3 ng/ml of TGFß1, indicating that EGF suppression of IGFBP-3 levels is independent of EGF effects on cell growth. EGF suppression of IGFBP-3 production is correlated with a reduction in IGFBP-3 mRNA level. In the presence of EGF, the growth response of the cells to ng amounts of IGF-I is significantly enhanced. Moreover, the simultaneous presence of both EGF and IGF-I reduces the level of IGFBP-3 more efficiently than EGF alone. We also observe that the IGFBP-3 level is decreased and the 24-kDa IGFBP level is increased in HPV16-positive tumorigenic versus nontumorigenic cell lines. This is the first report of EGF acting as a positive regulator of IGF-I action via the IGFBPs. On the basis of these findings, we propose that EGF stimulates ECE16-1 cell growth via a dual-action mechanism by (a) stimulating growth directly via the EGF mitogenic pathway and (b) stimulating growth indirectly by reducing the levels of inhibitory IGFBPs and thereby potentiating the effects of IGF-I. In addition, the observation that more highly transformed cell types produce lower levels of IGFBP-3 and higher levels of 24-kDa IGFBP suggests that tumor cells in more advanced cervical cancers may have an altered response to IGF-I.

¹ This work was supported by a grant from the American Institute for Cancer Research (R. L. E.) and utilized the facilities of the Skin Diseases Research Center of Northeast Ohio (NIH AR49750).

² Supported as a postdoctoral trainee in the Metabolism Training Program (NIH DK07319).

³ To whom requests for reprints should be addressed, at Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106-4970.

Received 7/ 9/93. Accepted 4/15/94.

This article has been cited by other articles:

				F. R. Santer, B. Moser, G. A. Spoden, P. Jansen-Durr, and W. Zwerschke Human papillomavirus type 16 E7 oncoprotein inhibits apoptosis mediated by nuclear insulin-like growth factor-binding protein-3 by enhancing its ubiquitin/proteasome-dependent degradation Carcinogenesis, December 1, 2007; 28(12): 2511 - 2520. [Abstract] [Full Text] [PDF]

				V.H.W. Dissanayake, C. Tower, A. Broderick, L.J. Stocker, H.R. Seneviratne, R.W. Jayasekara, N. Kalsheker, F.B. Pipkin, and L. Morgan Polymorphism in the epidermal growth factor gene is associated with birthweight in Sinhalese and white Western Europeans Mol. Hum. Reprod., June 1, 2007; 13(6): 425 - 429. [Abstract] [Full Text] [PDF]

				M. Takaoka, C. E. Smith, M. K. Mashiba, T. Okawa, C. D. Andl, W. S. El-Deiry, and H. Nakagawa EGF-mediated regulation of IGFBP-3 determines esophageal epithelial cellular response to IGF-I Am J Physiol Gastrointest Liver Physiol, February 1, 2006; 290(2): G404 - G416. [Abstract] [Full Text] [PDF]

				M. Takaoka, H. Harada, C. D. Andl, K. Oyama, Y. Naomoto, K. L. Dempsey, A. J. Klein-Szanto, W. S. El-Deiry, A. Grimberg, and H. Nakagawa Epidermal Growth Factor Receptor Regulates Aberrant Expression of Insulin-Like Growth Factor-Binding Protein 3 Cancer Res., November 1, 2004; 64(21): 7711 - 7723. [Abstract] [Full Text] [PDF]

				A. C. Baege, G. L. Disbrow, and R. Schlegel IGFBP-3, a Marker of Cellular Senescence, Is Overexpressed in Human Papillomavirus-Immortalized Cervical Cells and Enhances IGF-1-Induced Mitogenesis J. Virol., June 1, 2004; 78(11): 5720 - 5727. [Abstract] [Full Text] [PDF]

				X. Wu, G. Tortolero-Luna, H. Zhao, D. Phatak, M. R. Spitz, and M. Follen Serum Levels of Insulin-like Growth Factor I and Risk of Squamous Intraepithelial Lesions of the Cervix Clin. Cancer Res., August 1, 2003; 9(9): 3356 - 3361. [Abstract] [Full Text] [PDF]

				A. J. Berger, A. Baege, T. Guillemette, J. Deeds, R. Meyer, G. Disbrow, R. Schlegel, and R. Schlegel Insulin-Like Growth Factor-Binding Protein 3 Expression Increases during Immortalization of Cervical Keratinocytes by Human Papillomavirus Type 16 E6 and E7 Proteins Am. J. Pathol., August 1, 2002; 161(2): 603 - 610. [Abstract] [Full Text] [PDF]

				H. Yu and T. Rohan Role of the Insulin-Like Growth Factor Family in Cancer Development and Progression J Natl Cancer Inst, September 20, 2000; 92(18): 1472 - 1489. [Abstract] [Full Text] [PDF]

				B. Mannhardt, S. A. Weinzimer, M. Wagner, M. Fiedler, P. Cohen, P. Jansen-Dürr, and W. Zwerschke Human Papillomavirus Type 16 E7 Oncoprotein Binds and Inactivates Growth-Inhibitory Insulin-Like Growth Factor Binding Protein 3 Mol. Cell. Biol., September 1, 2000; 20(17): 6483 - 6495. [Abstract] [Full Text]

				H. M. Khandwala, I. E. McCutcheon, A. Flyvbjerg, and K. E. Friend The Effects of Insulin-Like Growth Factors on Tumorigenesis and Neoplastic Growth Endocr. Rev., June 1, 2000; 21(3): 215 - 244. [Abstract] [Full Text]

				C. Agarwal, A. Lambert, R. A.S. Chandraratna, E. A. Rorke, and R. L. Eckert Vitamin D Regulates Human Ectocervical Epithelial Cell Proliferation and Insulin-Like Growth Factor-Binding Protein-3 Level Biol Reprod, March 1, 1999; 60(3): 567 - 572. [Abstract] [Full Text]

				C. Agarwal, R. A. S. Chandraratna, A. T. Johnson, E. A. Rorke, and R. L. Eckert AGN193109 Is a Highly Effective Antagonist of Retinoid Action in Human Ectocervical Epithelial Cells J. Biol. Chem., May 24, 1996; 271(21): 12209 - 12212. [Abstract] [Full Text] [PDF]

				H. Huynh, X. Yang, and M. Pollak Estradiol and Antiestrogens Regulate a Growth Inhibitory Insulin-like Growth Factor Binding Protein 3 Autocrine Loop in Human Breast Cancer Cells J. Biol. Chem., January 12, 1996; 271(2): 1016 - 1021. [Abstract] [Full Text] [PDF]

				S.-Y. Chan and R. W.-C. Wong Expression of Epidermal Growth Factor in Transgenic Mice Causes Growth Retardation J. Biol. Chem., December 1, 2000; 275(49): 38693 - 38698. [Abstract] [Full Text] [PDF]