This Ph.D. project sought to determine the expression, regulation, and function of the KIT-SCF receptor-ligand system in human epithelia] ovarian cancer.
The expression of c- KIT and SCF in normal ovaries, in cultured ovarian surface epithelium (OSE), and in epithelia] ovarian tumors was analyzed. Normal OSE expressed SCF, but not c- KIT ; however, epithelia] invaginations and inclusion cysts often expressed KIT protein. Of 15 benign ovarian tumors and tumors of low malignant potential, 87% expressed c- KIT , and 92% of these co-expressed SCF, suggesting the possibility of autocrine growth regulation. Of 35 malignant ovarian cancers, 71% expressed c- KIT (92% co-expressed SCF), with a trend for decreased c- KIT expression in advanced stage disease. Of 34 patients with malignant tumors for whom follow-up information was available (median follow-up time of 24 months), 9 had tumors that did not express c- KIT , 8 (89%) of whom have died and the remaining 1 has recurrent disease. Of the 25 patients with tumors expressing c- KIT , 56% are still alive, eight of whom have no evidence of disease. Importantly, statistical analysis indicated that patients whose tumors did not express c- KIT had a significantly shorter (p < 0.05) disease-free survival time than patients who had KIT-expressing tumors.
Studies were carried out to identify intraovarian growth regulatory factors which may regulate c- KIT and SCF expression in ovarian cancer cells, and to determine whether activated KIT can affect the proliferation and survival of these cells. HEY cells, which co-expressed KIT and SCF, were treated with transforming growth factor (TGF)-α, TGF-β, and dibutyryl cyclic AMP (dbcAMP) and their cellular proliferation and expression of c- KIT and SCF were examined.
A series of transfection studies were carried out to determine if enforced c- kit expression inhuman ovarian carcinoma cells could regulate cellular proliferation. Transient transfection of c- kit into HEY cells resulted in decreased proliferation. Similarly, stable transfection of c- kit into A2780-cp cells, which do not express endogenous c- KIT , also resulted in a decreased proliferative rate. In contrast to the ovarian cancer cells, increased proliferation was documented for NIH 3T3 fibroblast cells transiently transfected with c- kit .
Together, these results suggest that the positive prognostic value of c- KIT expression in ovarian tumors is related to its negative growth regulatory function in ovarian cancer cells. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/6348 |
| Date | January 2001 |
| Creators | Tonary, Angela Marie. |
| Contributors | Vanderhyden, Barbara C., |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 180 p. |
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