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SPSS output statistics for comparisons between survival curves from colony-formation assays.

D-2HG inhibits IDH-mediated NADPH production capacity, but not G6PD-mediated NADPH production capacity or IDH-mediated NADH production capacity.

IDH1WT/R132H cells are sensitized to metformin, compared with IDH1WT/WT cells.

The IDH1-mutant inhibitor AGI-5198 increases IDH-mediated NAPDH production capacity in IDH1-mutated cells.

Isocitrate dehydrogenase 1 (IDH1) is mutated in various types of human cancer to IDH1R132H, a structural alteration that leads to catalysis of α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate. In this study, we present evidence that small-molecule inhibitors of IDH1R132H that are being developed for cancer therapy may pose risks with coadministration of radiotherapy. Cancer cells heterozygous for the IDH1R132H mutation exhibited less IDH-mediated production of NADPH, such that after exposure to ionizing radiation (IR), there were higher levels of reactive oxygen species, DNA double-strand breaks, and cell death compared with IDH1 wild-type cells. These effects were reversed by the IDH1R132H inhibitor AGI-5198. Exposure of IDH1 wild-type cells to D-2-hydroxyglutarate was sufficient to reduce IDH-mediated NADPH production and increase IR sensitivity. Mechanistic investigations revealed that the radiosensitivity of heterozygous cells was independent of the well-described DNA hypermethylation phenotype in IDH1-mutated cancers. Thus, our results argue that altered oxidative stress responses are a plausible mechanism to understand the radiosensitivity of IDH1-mutated cancer cells. Further, they offer an explanation for the relatively longer survival of patients with IDH1-mutated tumors, and they imply that administration of IDH1R132H inhibitors in these patients may limit irradiation efficacy in this setting. Cancer Res; 75(22); 4790–802. ©2015 AACR.

IDH1R132H mutations reduce IDH-mediated NADPH production and radioresistance.

IDH1MT increase ROS levels and AGI-5198 attenuates this effect.

Human ovarian ageing encompasses the age-related decline in female fertility. Oxidative stress and mitochondrial dysfunction in oocytes are suggested as causal, but corroborating evidence is limited. Using immunofluorescence imaging on human ovarian tissue, we found oxidative damage by protein and lipid (per)oxidation at the primordial follicle stage. Additionally, using comprehensive metabolomics and lipidomics, a cohort of 150 human germinal vesicles and metaphase I oocytes and 15 corresponding cumulus cell samples displayed a shift in glutathione to oxiglutathione ratio and depletion of phospholipids. Age-related changes in polar metabolites suggested a decrease in mitochondrial function, as demonstrated by NAD+, purine and pyrimidine depletion, while glycolysis substrates and glutamine accumulated with age. Oocytes of advanced maternal age likely used alternative energy sources like glycolysis and the adenosine salvage pathway, and possibly increased ATP production in cumulus cells. These findings indicate that oocytes of advanced maternal age suffer from oxidative damage and mitochondrial dysfunction.Graphical abstract

Many clinics offer routine genetic testing of pregnancy loss tissue. This review presents a comprehensive literature search and meta-analysis on chromosomal abnormality rates of pregnancy loss tissue from women with a single or recurrent pregnancy loss. A total of 55 studies published since 2000 were included, analysed on the prevalence of test failure rates, abnormality detection rates and percentages of trisomy, monosomy X, structural abnormalities and other clinically (ir)relevant abnormalities detected by conventional karyotyping, array-comparative genomic hybridization (aCGH), single nucleotide polymorphism (SNP) array, fluorescence in-situ hybridization (FISH) and multiplex ligation-dependent probe amplification (MLPA). The detected prevalence of chromosomal abnormalities was 48% (95% confidence interval [CI] 39–57) using aCGH, 38% (95% CI 28–49) with FISH, 25% (95% CI 12–42) using MLPA, 60% (95% CI 58–63) using SNP array and 47% (95% CI 43–51) with conventional karyotyping. The percentage of detected abnormalities did not differ between women that suffered sporadic (46%; 95% CI 39–53) or recurrent (46%; 95% CI 39–52) pregnancy loss. In view of the high prevalence of chromosomal abnormalities in pregnancy loss tissue, and the low chance of recurrence of the same chromosomal aberration, it was concluded that detection of specific chromosomal abnormalities in pregnancy loss tissue has no clinical benefit. Therefore, routine testing of pregnancy loss tissue for chromosomal abnormalities is not recommended.

STUDY QUESTION Are genes known to be involved in somatic cell ageing, particularly related to longevity pathways, associated with the accelerated ageing process of the ovary? SUMMARY ANSWER Growth, metabolism, and cell-cycle progression-related pathways that are involved in somatic cell ageing are also associated with ovarian ageing. WHAT IS KNOWN ALREADY Ovarian ageing is characterized by a gradual decline in ovarian follicle quantity, a decline in oocyte quality, and lower chances of pregnancy. Genetic pathways modulating the rate of somatic cell ageing have been researched intensively. Ovarian ageing does not follow the same timeline as somatic cell ageing, as signs of ovarian ageing occur at a younger female age, while the somatic cells are still relatively young. It is not known whether the generally recognized somatic cell longevity genes also play a role during ovarian ageing. Looking at somatic cell longevity genes can lead to new hypotheses and possible treatment options for subfertility caused by ovarian ageing. STUDY DESIGN, SIZE, DURATION In this observational study, we analysed a dataset of individual gene expression profiles of 38 germinal vesicle (GV) oocytes from 38 women aged between 25 and 43 years. We correlated female age (calendar age in years) and biological age (factors known to be associated with ovarian ageing such as dosage of FSH needed for ovarian hyperstimulation, and antral follicle count (AFC)) with gene expression signatures of longevity pathways. PARTICIPANTS/MATERIALS, SETTING, METHODS Transcripts of 38 GV oocytes were used for individual gene expression analysis. R version 3.5.1 was used to process and analyse data. The GeneAge database (build 19) was used to obtain mouse ageing-related genes. Human to mouse orthologues were obtained using the R package biomaRt. Correlations and significance between gene expression data and age were tested for using Pearson's product moment correlation coefficient using ranked expression data. Distributions were compared with an ANOVA, and the Tukey Honest Significant Difference method was used to control for the Type I error rate across multiple comparisons. MAIN RESULTS AND THE ROLE OF CHANCE Of the 136 genes in the GeneAge database, the expression of 15 anti-longevity genes identified in oocytes showed a positive correlation with female calendar age and FSH dosage administered during ICSI treatment, and a negative correlation with AFC. Expression of 32 pro-longevity genes was negatively correlated with calendar age and FSH dosage, and positively correlated with AFC. In general, anti- and pro-longevity genes changed in opposing directions with advancing maternal age in oocytes. Notably, the anti-longevity genes include many ‘growth’-related genes involved in the mechanistic target of rapamycin (mTOR) Complex 1 pathway, such as EIF5A2, EIF3H, EIF4E, and mTOR. The pro-longevity genes include many cell-cycle progression-related genes involved in DNA damage repair (e.g. XRCC6, ERCC2, and MSH2) or cell-cycle checkpoint regulation genes (e.g. ATM, BRCA1, TP53, TP63, TP73, and BUB1B). LIMITATIONS, REASONS FOR CAUTION Using mature oocytes instead of GV-stage oocytes discarded from ICSI treatments may provide different results. No correction for multiple testing was carried out on individual genes because a small set of longevity-related genes was selected a priori for the analysis. The global trend was corrected for multiple testing and remained significant. This work was an observational study and, as no additional experimental work was performed, the associations described do not directly demonstrate the involvement of such genes in oocyte ageing. WIDER IMPLICATIONS OF THE FINDINGS Growth, metabolism, and cell-cycle progression-related pathways that are known to be involved in somatic cell ageing were associated with ovarian ageing. If experimental data are obtained to support these associations, we suggest that interventions known to modulate these processes could benefit women suffering from ovarian ageing. STUDY FUNDING/COMPETING INTEREST(S) G.E.J. is supported by a VENI grant from ZonMw (https://www.zonmw.nl). Work in the Houtkooper group is financially supported by an ERC Starting grant (No. 638290), a VIDI grant from ZonMw (No. 91715305), and the Velux Stiftung (No. 1063). M.G. declares several research and educational grants from Guerbet, Merck and Ferring (all location VUmc), outside the scope of the submitted work. The other authors report no competing interest TRIAL REGISTRATION NUMBER N/A.

STUDY QUESTION: What is the difference between the gene expression profiles of single human germinal vesicle (GV) oocytes from women of different ages?SUMMARY ANSWER: There were no statistically significant differences in gene expression profiles of human GV oocytes from women of different ages (range: 25-43).WHAT IS KNOWN ALREADY: It is well established that reproductive capacity declines as women age, which is attributed to oocyte quality since this decline is counterbalanced in older women receiving young donor oocytes. Altered gene expression of human oocytes at different stages of development in relation to female age is one of the suggested mechanisms that could explain the decrease in oocyte quality.STUDY DESIGN, SIZE, DURATION: Between 2012 and 2014, 40 human GV oocytes of 40 women were obtained during follicular aspiration as part of routine ICSI treatment. Gene expression profiles of 38 GV oocytes were determined in four different age groups: 25-30, 31-35, 36-38 and 39-43 years of age.PARTICIPANTS/MATERIALS, SETTING, METHODS: GV oocytes were donated for research and frozen between 3.5 and 7.5 h after follicular aspiration. Subsequently, GV oocytes were thawed and prepared for gene expression profile analysis using Agilent microarrays containing ~42 000 Human Gene Expression probe-sets. Gene expression profiles were visualized by hierarchical clustering and the top 500 most differing genes were determined by multidimensional scaling (MDS). Transcripts were analysed in a class comparison between the four age groups and for indicators of biological age: antral follicle count (AFC) and the total dosage of FSH needed for ovarian stimulation. Individual transcripts were analysed using linear regression. A false discovery rate MAIN RESULTS AND THE ROLE OF CHANCE: Visualization of gene expression profiles of GV oocytes with hierarchal clustering and MDS demonstrated no clear grouping of samples based on female age, AFC or FSH dosage. The gene expression profile of GV oocytes classified in four age groups revealed no significantly differentially expressed genes between the four different age groups. There were also no significantly differentially expressed genes in the linear regression analysis for individual transcripts against age.LARGE SCALE DATA: Not applicable.LIMITATIONS, REASONS FOR CAUTION: Immature (GV) oocytes obtained from ovarian stimulation cycles were used. Findings may therefore differ for oocytes at other developmental stages and for in-vivo matured oocytes under physiological conditions. Due to our relatively large, but still limited study sample (40 GV oocytes), we cannot exclude that there might be smaller age-related gene-expression differences, i.e. due to a lack of power.WIDER IMPLICATIONS OF THE FINDINGS: We did not find an effect of female age on gene expression profiles of individual human GV oocytes. Other studies have suggested that gene-expression profiles are affected in mature oocytes, which might imply that female age affects oocyte maturation. Alternatively, other mechanisms in human oocytes might cause the age-related fertility decline.STUDY FUNDING/COMPETING INTEREST(S): This study received no external funding and there are no competing interests.

Isocitrate dehydrogenase 1 (IDH1) is mutated in various types of human cancer to IDH1R132H, a structural alteration that leads to catalysis of α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate. In this study, we present evidence that small-molecule inhibitors of IDH1R132H that are being developed for cancer therapy may pose risks with coadministration of radiotherapy. Cancer cells heterozygous for the IDH1R132H mutation exhibited less IDH-mediated production of NADPH, such that after exposure to ionizing radiation (IR), there were higher levels of reactive oxygen species, DNA double-strand breaks, and cell death compared with IDH1 wild-type cells. These effects were reversed by the IDH1R132H inhibitor AGI-5198. Exposure of IDH1 wild-type cells to D-2-hydroxyglutarate was sufficient to reduce IDH-mediated NADPH production and increase IR sensitivity. Mechanistic investigations revealed that the radiosensitivity of heterozygous cells was independent of the well-described DNA hypermethylation phenotype in IDH1-mutated cancers. Thus, our results argue that altered oxidative stress responses are a plausible mechanism to understand the radiosensitivity of IDH1-mutated cancer cells. Further, they offer an explanation for the relatively longer survival of patients with IDH1-mutated tumors, and they imply that administration of IDH1R132H inhibitors in these patients may limit irradiation efficacy in this setting. Cancer Res; 75(22); 4790–802. ©2015 AACR.