Villedieu M, Louis MH, Dutoit S, Brotin E, Lincet H, Duigou F, Staedel C, Gauduchon P, Poulain L. Absence of Bcl-xL down-regulation in response to cisplatin is associated with chemoresistance in ovarian carcinoma cells☆.
Gynecol Oncol 2007;
105:31-44. [PMID:
17275076 DOI:
10.1016/j.ygyno.2006.12.011]
[Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 11/28/2006] [Accepted: 12/05/2006] [Indexed: 11/15/2022]
Abstract
OBJECTIVE
Recurrence and subsequent acquired chemoresistance to platinum-based treatments constitute major hurdles to ovarian carcinoma therapy. Our objective was to examine the involvement of Bcl-xL anti-apoptotic protein in resistance to cisplatin.
METHODS
We described the effect of cisplatin on cell cycle and apoptosis induction in sensitive (IGROV1 and OAW42) and resistant (IGROV1-R10 and SKOV3) ovarian carcinoma cell lines. We correlated it with Bcl-xL mRNA and protein expression after exposure to cisplatin. We then used bcl-xS gene transfer to impede Bcl-xL activity.
RESULTS
Our study showed that Bcl-xL basal expression was high in both sensitive and resistant cell lines, as well as in all the studied ovarian tumor samples. Thus, Bcl-xL basal expression could not allow to predict sensitivity. Wondering whether variation of Bcl-xL level in response to cisplatin could be a better determinant of sensitivity, we investigated the expression of this protein in the cell lines after treatment. Cisplatin-induced down-regulation of Bcl-xL was strictly associated with apoptosis and absence of recurrence in vitro. Conversely, the maintenance of Bcl-xL expression in response to cisplatin appeared as a sine qua non condition to escape to treatment. To try to sensitize SKOV3 cells by impeding anti-apoptotic activity of Bcl-xL, we transfected bcl-xS gene in these cells. Bcl-xS exogenous expression was only slightly cytotoxic on its own, but highly sensitized SKOV3 resistant cells to cisplatin-induced apoptosis, and delayed recurrence.
CONCLUSION
This work thus provides one more argument to put Bcl-xL forward as a pertinent target of inhibition to overcome chemoresistance of epithelial ovarian carcinoma.
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