SummaryProstate cancer resistance to castration occurs because tumors acquire the metabolic capability of converting precursor steroids to 5α-dihydrotestosterone (DHT), promoting signaling by the androgen receptor (AR) and the development of castration-resistant prostate cancer (CRPC)1–3. Essential for resistance, DHT synthesis from adrenal precursor steroids or possibly from de novo synthesis from cholesterol commonly require enzymatic reactions by 3β-hydroxysteroid dehydrogenase (3βHSD), steroid-5α-reductase (SRD5A) and 17β-hydroxysteroid dehydrogenase (17βHSD) isoenzymes4,5. Abiraterone, a steroidal 17α-hydroxylase/17,20-lyase (CYP17A1) inhibitor, blocks this synthetic process and prolongs survival6,7. We hypothesized that abiraterone is converted by an enzyme to the more active Δ4-abiraterone (D4A) that blocks multiple steroidogenic enzymes and antagonizes the androgen receptor (AR), providing an additional explanation for abiraterone’s clinical activity. Here we show that abiraterone is converted to D4A in mice and patients with prostate cancer. D4A inhibits CYP17A1, 3βHSD and SRD5A, which are required for DHT synthesis. Furthermore, competitive AR antagonism by D4A is comparable to the potent antagonist, enzalutamide. D4A also has more potent antitumor activity against xenograft tumors than abiraterone. Our findings suggest an additional explanation – conversion to a more active agent – for abiraterone’s survival extension. We propose that direct treatment with D4A would be more clinically effective than abiraterone treatment.

Biofilms of Candida albicans include both yeast cells and hyphae. Prior studies indicated that a zap1⌬/⌬ mutant, defective in zinc regulator Zap1, has increased accumulation of yeast cells in biofilms. This altered yeast-hypha balance may arise from internal regulatory alterations or from an effect on the production of diffusible quorum-sensing (QS) molecules. Here, we develop biosensor reporter strains that express yeastspecific YWP1-RFP or hypha-specific HWP1-RFP, along with a constitutive TDH3-GFP normalization standard. Seeding these biosensor strains into biofilms allows a biological activity assay of the surrounding biofilm milieu. A zap1⌬/⌬ biofilm induces the yeast-specific YWP1-RFP reporter in a wild-type biosensor strain, as determined by both quantitative reverse transcription-PCR (qRT-PCR) gene expression measurements and confocal microscopy. Remediation of the zap1⌬/⌬ zinc uptake defect through zinc transporter gene ZRT2 overexpression reverses induction of the yeast-specific YWP1-RFP reporter. Gas chromatography-mass spectrometry (GC-MS) measurements of known organic QS molecules show that the zap1⌬/⌬ mutant accumulates significantly less farnesol than wild-type or complemented strains and that ZRT2 overexpression does not affect farnesol accumulation. Farnesol is a well-characterized inhibitor of hypha formation; hence, a reduction in farnesol levels in zap1⌬/⌬ biofilms is unexpected. Our findings argue that a Zap1-and zinc-dependent signal affects the yeast-hypha balance and that it is operative in the low-farnesol environment of the zap1⌬/⌬ biofilm. In addition, our results indicate that Zap1 is a positive regulator of farnesol accumulation.

Our study provides insights into the benefits and limitations of the use of a higher mass resolution and mass accuracy instrument for untargeted GC/MS-based metabolomics with multi-dimensional chromatography in future studies addressing clinical conditions or exposome studies.

Glycerophosphodiesters are the products of phospholipase-mediated deacylation of phospholipids. In Saccharomyces cerevisiae, a single gene, GIT1, encodes a permease responsible for importing glycerophosphodiesters, such as glycerophosphoinositol and glycerophosphocholine, into the cell. In contrast, the Candida albicans genome contains four open reading frames (ORFs) with a high degree of similarity to S. cerevisiae GIT1 (ScGIT1) Here, we report that C. albicans utilizes glycerophosphoinositol (GroPIns) and glycerophosphocholine (GroPCho) as sources of phosphate at both mildly acidic and physiological pHs. Insertional mutagenesis of C. albicans GIT1 (CaGIT1) (orf19.34), the ORF most similar to ScGit1, abolished the ability of cells to use GroPIns as a phosphate source at acidic pH and to transport

Background: Glycerophosphocholine (GroPCho) is a phospholipid metabolite found throughout the human body. Results: Loss of Git3 and Git4 in C. albicans abolishes GroPCho transport, and Git3-deficient cells exhibit reduced virulence. Conclusion: The major GroPCho transporter, Git3, is required for full virulence. Significance: This report is the first to identify a eukaryotic GroPCho-specific transporter and the first to implicate GroPCho utilization in pathogenicity.

The glycerol phosphate pathway produces more than 90% of the liver triacylglycerol (TAG). LysoPA, an intermediate in this pathway, is produced by glycerol-3-phosphate acyltransferase. Glycerophosphodiester phosphodiesterase domain containing 3 (GDPD3), whose gene was recently cloned, contains lysophospholipase D activity, which produces LysoPA from lysophospholipids. Whether human GDPD3 plays a role in hepatic TAG homeostasis is unknown. We hypothesized that human GDPD3 increases LysoPA production and availability in the glycerol phosphate pathway, promoting TAG biosynthesis. To test our hypothesis, we infected C57BL/6J mice with adeno-associated virus encoding a hepatocyte-specific albumin promoter that drives GFP (control) or FLAG-tagged human GDPD3 overexpression and fed the mice chow or a Western diet to induce hepatosteatosis. Hepatic human GDPD3 overexpression induced LysoPA production and increased FA uptake and incorporation into TAG in mouse hepatocytes and livers, ultimately exacerbating Western diet-induced liver steatosis. Our results also showed that individuals with hepatic steatosis have increased GDPD3 mRNA levels compared with individuals without steatosis. Collectively, these findings indicate that upregulation of GDPD3 expression may play a key role in hepatic TAG accumulation and may represent a molecular target for managing hepatic steatosis.

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Rodent and nonhuman primate studies indicate that developmental programming by reduced perinatal nutrition negatively impacts life course cardio-metabolic health. We have developed a baboon model in which we feed control mothers (CON) ad libitum while nutrient restricted mothers are fed 70% of ad libitum global feed in pregnancy and lactation. Offspring of nutrient restricted mothers are intrauterine growth restricted (IUGR) at term. By 3.5 years IUGR baboons showed signs of insulin resistance, indicating a pre-diabetic phenotype, in contrast to healthy CON offspring. We hypothesized that a novel breath analysis approach would provide markers of the altered cardio-metabolic state in a non-invasive manner. Here we assess whether exhaled breath volatile organic compounds (VOCs) collected from this unique cohort of juvenile baboons with documented cardio-metabolic dysfunction resulting from in utero programming can be detected from their breath signatures. Breath was collected from male and female CON and IUGR baboons at 4.8 ± 0.2 years (human equivalent ∼13 years). Breath VOCs were quantified using a two-dimensional gas chromatography mass spectrometer. Two-way ANOVA, on 76 biologically relevant VOCs identified 27 VOCs (p < 0.05) with altered abundances between groups (sex, birthweight, and sex x birthweight). The 27 VOCs included 2-pentanone, 2-octanone, 2,2,7,7-tetramethyloctane and 3-methyl-1-heptene, which have not previously been associated with cardio-metabolic disease. Unsupervised principal component analysis of these VOCs could discriminate the four clusters defining males, females, CON and IUGR. This study, which is the first to assess quantifiable breath signatures associated with cardio-metabolic programing for any model of IUGR, demonstrates the translational value of this unique model to identify metabolites of programmed cardio-metabolic dysfunction in breath signatures. Future studies are required to validate the translatability of these findings to humans.