Inhibition of Mcl-1 expression by citrate enhances the effect of Bcl-xL inhibitors on human ovarian carcinoma cells.

The inhibition of two major anti-apoptotic proteins, Bcl-xL and Mcl-1, appears essential to destroy chemoresistant cancer cells. We have studied their concomitant inhibition, using ABT 737 or siRNA targeting XL1 and citrate, a molecule which reduces the expression level of Mcl-1.Two cisplatin-chemoresistant ovarian cell lines (SKOV3 and IGROV1-R10) were exposed to ABT 737 or siRNA targeting XL1 and citrate at various individual concentrations, or combined. Cell proliferation, cell cycle repartition and nuclear staining with DAPI were recorded. Western blot analyses were performed to detect various proteins implied in apoptotic cell death pathways.Mcl-1 expression was barely reduced when cells were exposed to citrate alone, whereas a mild reduction was observed after ABT 737 treatment. Concomitant inhibition of Bcl-xL and Mcl-1 using ABT 737 or siXL1 associated with citrate was far more effective in inhibiting cell proliferation and inducing cell death than treatment alone.Given that few, if any, specific inhibitors of Mcl-1 are currently available, anti-glycolytic agents such as citrate could be tested in association with synthetic inhibitors of Bcl-xL.

siPGK1 sensitizes chemoresistant human ovarian cancer cell lines to cisplatin.

Enhanced glycolysis provides essential intermediates for cancer cell proliferation. Its inhibition could be a promising approach for destroying tumors, especially those developing in hypoxic conditions, which are presumably the most chemoresistant. In hypoxic cells, glycolysis provides the main part of ATP. Phosphoglycerate kinase-1 (PGK1) catalyzes a crucial reaction of glycolysis that reconstitutes the two molecules of ATP previously consumed. PGK1 inhibition could arrest growth or kill hypoxic and/or chemoresistant cells. We tested siPGK1 transfection in two human ovarian cancer cells lines of increasing chemoresistance, and showed that: Expression of PGK1 was significantly reduced and associated with blockade of cell growth in the G(1) phase; siPGK1 associated with cisplatin was more effective than cisplatin-alone at inhibiting proliferation of chemoresistant cells; siPGK1 -alone and -associated with cisplatin strongly increased expression of the BH3-only pro-apoptotic protein BCL-2 Interacting Mediator of cell death (BIM). PGK1 might be a key target for sensitizing chemoresistant cells to cisplatin.

Parenthood in survivors of Hodgkin lymphoma: an EORTC-GELA general population case-control study.

PURPOSE: We investigated the impact of Hodgkin lymphoma (HL) on parenthood, including factors influencing parenthood probability, by comparing long-term HL survivors with matched general population controls. PATIENTS AND METHODS: A Life Situation Questionnaire was sent to 3,604 survivors treated from 1964 to 2004 in successive clinical trials. Responders were matched with controls (1:3 or 4) for sex, country, education, and year of birth (10-year groups). Controls were given an artificial date of start of treatment equal to that of their matched case. The main end point was presence of biologic children after treatment, which was evaluated by using conditional logistic regression analysis. Logistic regression analysis was used to analyze factors influencing spontaneous post-treatment parenthood. RESULTS: In all, 1,654 French and Dutch survivors were matched with 6,414 controls. Median follow-up was 14 years (range, 5 to 44 years). After treatment, the odds ratio (OR) for having children was 0.77 (95% CI, 0.68 to 0.87; P < .001) for survivors compared with controls. Of 898 survivors who were childless before treatment, 46.7% achieved post-treatment parenthood compared with 49.3% of 3,196 childless controls (OR, 0.87; P = .08). Among 756 survivors with children before treatment, 12.4% became parents after HL treatment compared with 22.2% of 3,218 controls with children before treatment (OR, 0.49; P < .001). Treatment with alkylating agents, second-line therapy, and age older than 35 years at treatment appeared to reduce the chances of spontaneous post-treatment parenthood. CONCLUSION: Survivors of HL had slightly but significantly fewer children after treatment than matched general population controls. The difference concerned only survivors who had children before treatment and appears to have more personal than biologic reasons. The chance of successful post-treatment parenthood was 76%.

Premature ovarian failure and fertility in long-term survivors of Hodgkin's lymphoma: a European Organisation for Research and Treatment of Cancer Lymphoma Group and Groupe d'Etude des Lymphomes de l'Adulte Cohort Study.

PURPOSE: In this large cohort of Hodgkin's lymphoma survivors with long follow-up, we estimated the impact of treatment regimens on premature ovarian failure (POF) occurrence and motherhood, including safety of nonalkylating chemotherapy and dose-response relationships for alkylating chemotherapy and age at treatment. PATIENTS AND METHODS: The Life Situation Questionnaire was sent to 1,700 women treated in European Organisation for Research and Treatment of Cancer and Groupe d'Étude des Lymphomes de l'Adulte trials between 1964 and 2004. Women treated between ages 15 and 40 years and currently not using hormonal contraceptives (n = 460) were selected to assess occurrence of POF. Cumulative POF risk was estimated using the life-table method. Predictive factors were assessed by Cox regression analysis. RESULTS: Median follow-up was 16 years (range, 5 to 45 years). Cumulative risk of POF after alkylating chemotherapy was 60% (95% CI, 41% to 79%) and only 3% (95% CI, 1% to 7%) after nonalkylating chemotherapy (doxorubicin, bleomycin, vinblastine, and dacarbazine; epirubicin, bleomycin, vinblastine, and prednisone). Dose relationship between alkylating chemotherapy and POF occurrence was linear. POF risk increased by 23% per year of age at treatment. In women treated without alkylating chemotherapy at age younger than 32 years and age 32 years or older, cumulative POF risks were 3% (95% CI, 1% to 16%) and 9% (95% CI, 4% to 18%), respectively. If menstruation returned after treatment, cumulative POF risk was independent of age at treatment. Among women who ultimately developed POF, 22% had one or more children after treatment, compared with 41% of women without POF. CONCLUSION: Nonalkylating chemotherapy carries little to no excess risk of POF. Dose-response relationships for alkylating chemotherapy and age at treatment are both linear. Timely family planning is important for women at risk of POF.