Chronic Exposure of Cisplatin Induces GRP78 Expression in Ovarian Cancer

Abstract

Glucose regulated protein 78 (GRP78) is a type of molecular chaperone. Previous research indicates that it may possibly be induced by exposure of cisplatin in ovarian cancer and related to survival rate. Methods: The expression of GRP78 in HOSE cells and ovarian cancer cells are tested by Western Blotting. Kaplan Meier Analysis is utilized to show the relationship between GRP78 expression and survival rate of patients who receives cisplatin treatment. Both acute cisplatin treatment and chronic exposure to cisplatin are carried out on ovarian cancer cell lines, followed by the subsequent Western Blotting. Results: GRP78 is expressed in both HOSE cells and Ovarian Cancer Cells, but the HOSE cell line shows evidently less expression of GRP78 than the tested ovarian cancer cell lines. Kaplan Meier Analysis shows that higher GRP78 expression level correlates to lower 5-year progression free survival rate. Chronic exposure to cisplatin induces GRP78 expression. Conclusions: GRP78 is expressed in both HOSE cells and ovarian cancer cells. The hypothesis is that efficient metabolism of cancer cells, which relates to accumulation of unfolded polypeptides in the ER, may be responsible for the over-expression of GRP78 of some ovarian cancer cell lines. Kaplan Meier Analysis suggests an important role of GRP78 in cancer progression and the potential of GRP78 as an ovarian cancer diagnosis marker. Chronic exposure to cisplatin induces GRP78 may increase the chemoresistance that GRP78 generates. Why acute cisplatin treatment cannot induce GRP78 needs further researches.