Rucaparip (Rubraca®) induces necrosis via upregulating the expression of RIP1 and RIP3 in ovarian cancer cells.

Abstract

In the current study we investigated the inhibitory effect of rucaparib (Rubraca®) on human ovarian cancer SKOV3 and A2780 cells and its possible mechanism. Cancer cells and human normal ovarian epithelial IOSE80 cells were treated with Rubraca® at different concentrations. Cell viability was measured by MTT assay. Necrotizing apoptosis was detected by Annexin V-FITC/PI double staining combined with flow cytometry. Reactive oxygen species were measured by 2',7'-dichlorofluorescent yellow diacetate (DCFH-DA) fluorescent probe. The expression of receptor-interacting protein kinase 1 (RIP1) and RIP3 protein was determined by Western Blot. Our data showed that Rubraca® inhibited the proliferation of ovarian cancer SKOV3 and A2780 cells in a dose-and time-dependent manner. After Rubraca® treatment, the apoptotic rate of SKOV3 and A2780 cells (Annexin V+/PI-cells) did not change significantly, but the proportion of necrotic cells (PI+cells or Annexin V+/PI+cells) increased significantly, which was different from the control group. Furthermore, Rubraca® could significantly induce SKOV3 and A2780 cells to produce excessive reactive oxygen species and significantly upregulate the expression of RIP1 and RIP3. When pretreated with reactive oxygen species inhibitor N-acetyl-L-cysteine (NAC) or RIP1 inhibitor (Nec-1), the necrosis apoptotic rate of SKOV3 and A2780 cells decreased significantly. In summary, Rubraca® could significantly inhibit the proliferation of ovarian cancer SKOV3 and A2780 cells, which may be partially achieved via upregulating the expression of RIP1 and RIP3 proteins, and activating the process of necrotic apoptosis.