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High-grade serous ovarian carcinoma (HGSOC) originates mainly from the fallopian tube (FT) epithelium and always carries early TP53 mutations. We previously reported that tumors initiate in the FT fimbria epithelium because of apoptotic failure and the expansion of cells with DNA double-strand breaks (DSB) caused by bathing of the FT epithelial cells in reactive oxygen species (ROSs) and hemoglobin-rich follicular fluid (FF) after ovulation. Because ovulation is frequent and HGSOC is rare, we hypothesized that luteal-phase progesterone (P4) could eliminate p53-defective FT cells. Here we show that P4, via P4 receptors (PRs), induces necroptosis in Trp53−/− mouse oviduct epithelium and in immortalized human p53-defective fimbrial epithelium through the TNF-α/RIPK1/RIPK3/MLKL pathway. Necroptosis occurs specifically at diestrus, recovers at the proestrus phase of the estrus cycle, and can be augmented with P4 supplementation. These results reveal the mechanism of the well-known ability of progesterone to prevent ovarian cancer.

Purpose: Resistance to the antiemetic ondansetron is still a major problem resulting in discomfort and poor compliance with chemotherapy in acute myeloid leukemia (AML) patients. Based on our hypothesis that this clinical resistance to ondansetron is associated with ABCB1 genetic polymorphisms, we investigated whether ABCB1 gene variations affect the efficacy of ondansetron in chemotherapy-induced nausea and vomiting. Methods: AML patients (n -- 215) treated for 3 days with high-dose cytarabine were enrolled in this study. Thirty minutes before the beginning of chemotherapy, 8 mg ondansetron was administered intravenously, followed by 24 mg by continuous infusion and 8 mg intravenously, once per day, until 2 days after chemotherapy. Chemotherapy-induced nausea and vomiting occurrence in the acute and delayed phases was calculated. ABCB1 and CYP2D6 polymorphisms were analyzed by allele-specific matrix-assisted laser desorption. Basic clinical characteristics of the AML patients were collected from medical records. Findings: No differences in genotype distribution frequencies of ABCB1 polymorphisms and haplotypes were observed in patients with different CYP2D6- predicted phenotypes. During the acute phase, patients with the CG haplotype (C3435T and G2677T) were associated with a high risk of grade 3/4 nausea and vomiting (P -- 0.003 and P -- 0.026, respectively). After adjustment for age, sex, smoking status, alcohol drinking status, body surface area, body mass index, and Eastern Cooperative Oncology Group--Performance Status, multivariate survival analysis implicated the CG haplotype as a predictive marker of the risk of grade 3/4 chemotherapy-induced nausea and vomiting in AML patients (P -- 0.003 and P -- 0.039, respectively). In addition, a significant association between the 3435CC genotype and grade 3/4 vomiting in AML patients was observed (P -- 0.016). However, no association between these ABCB1 gene polymorphisms and ondansetron efficacy was found in the delayed phase. Implications: These findings suggest that ABCB1 gene polymorphisms are associated with antiemetic efficacy of ondansetron in the acute phase after highdose cytarabine chemotherapy in AML patients. [ABSTRACT FROM AUTHOR]

Background: Glycyrrhizin is a major ingredient of licorice which is widely used in the treatment of various diseases such as chronic hepatitis. Licorice or glycyrrhizin has been shown to alter the activity of CYP3A in rodents. The influence of glycyrrhizin on CYP3A has not been elucidated in humans., Objective: To investigate the effects of repeated glycyrrhizin ingestion on the oral pharmacokinetics of midazolam, a probe drug for CYP3A activity in humans., Methods: Sixteen healthy adult male subjects were enrolled in a two-phase randomized crossover design. In each phase the volunteers received placebo or glycyrrhizin for 14 days. On the 15th day, midazolam was administered and blood samples were obtained to determine midazolam plasma concentrations. Bioequivalence was assessed by determining geometric mean ratios (GMRs) and 90% confidence intervals (90% CI)., Results: The geometric mean (geometric coefficient of variation) for the AUC(0-infinity) of midazolam in the placebo group was 196.4 ng x h/ml (30.3%) and after glycyrrhizin treatment, 151.3 ng x h/ml (34.7%). The GMRs and 90% CI for AUC(0-infinity) and Cmax of midazolam in the presence/ absence of glycyrrhizin were 0.77 (0.70, 0.89) and 0.83 (0.74, 1.01), respectively. The 90% CI for AUC(0-infinity) and Cmax for the GMR of glycyrrhizin over placebo were both out of the no-effect boundaries of 0.80-1.25., Conclusions: Administration of glycyrrhizin resulted in a modest induction of CYP3A that was clinically relevant according to the bioequivalence analysis.