Abstract
Retinoids have been demonstrated to inhibit epithelial cell growth and differentiation. We examined the anti-proliferative effects of retinoic acid (RA) in an HPV positive and negative cervical carcinoma cell line. Our findings indicate that HPV-negative C33A cervical carcinoma cells are more sensitive to the growth inhibitory activity of retinoic acid (RA) than are HPV-positive CaSki cervical carcinoma cells. However, conditioned medium from RA-treated C33A cells displayed strong growth inhibitory activity in both C33A and CaSki cells. Since RA has been shown to modulate the expression of insulin-like growth factor binding proteins (IGFBPs) in many cells, we examined RA regulated expression of IGFBPs in medium isolated from RA treated C33A cells. IGFBP-5 was detectable in medium from C33A cells exposed to RA, and addition of purified exogenous IGFBP-5 resulted in growth inhibition of C33A cells. These results indicate that RA exerts it's anti-neoplastic effect in HPV negative cervical carcinoma cells via the overproduction of IGFBP-5.
Original language | English (US) |
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Pages (from-to) | 706-709 |
Number of pages | 4 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 239 |
Issue number | 3 |
DOIs | |
State | Published - Oct 29 1997 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by Grants AG07218 and AG13637 from the NIH. The authors are grateful to Ted Busby for puri®ed IGFBP-5, and to Dr. Kenichi Higo for useful comments on the manuscript.