The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression

Just as the androgen receptor (AR), the estrogen receptor α (ERα) is expressed in the prostate and is thought to influence prostate cancer (PCa) biology. Yet, the incomplete understanding of ERα functions in PCa hinders our ability to fully comprehend its clinical relevance and restricts the repurposing of estrogen-targeted therapies for the treatment of this disease. Using two human PCa tissue microarray cohorts, we first demonstrated that nuclear ERα expression was heterogeneous among patients, being only detected in half of tumors. Positive nuclear ERα levels were correlated with disease recurrence, progression to metastatic PCa, and patient survival. Using in vitro and in vivo models of the normal prostate and PCa, bulk and single-cell RNA-Seq analyses revealed that estrogens partially mimic the androgen transcriptional response and induce specific biological pathways linked to proliferation and metabolism. Bioenergetic flux assays and metabolomics confirmed the regulation of cancer metabolism by estrogens, supporting proliferation. Using cancer cell lines and patient-derived organoids, selective estrogen receptor modulators, a pure anti-estrogen, and genetic approaches impaired cancer cell proliferation and growth in an ERα-dependent manner. Overall, our study revealed that, when expressed, ERα functionally reprograms PCa metabolism, is associated with disease progression, and could be targeted for therapeutic purposes.

A Non-Canonical Role for the Glycosyltransferase Enzyme UGT2B17 as a Novel Constituent of the B Cell Receptor Signalosome

In chronic lymphocytic leukemia (CLL), an elevated glycosyltransferase UGT2B17 expression (UGT2B17^HI) identifies a subgroup of patients with shorter survival and poor drug response. We uncovered a mechanism, possibly independent of its enzymatic function, characterized by an enhanced expression and signaling of the proximal effectors of the pro-survival B cell receptor (BCR) pathway and elevated Bruton tyrosine kinase (BTK) phosphorylation in B-CLL cells from UGT2B17^HI patients. A prominent feature of B-CLL cells is the strong correlation of UGT2B17 expression with the adverse marker ZAP70 encoding a tyrosine kinase that promotes B-CLL cell survival. Their combined high expression levels in the treatment of naïve patients further defined a prognostic group with the highest risk of poor survival. In leukemic cells, UGT2B17 knockout and repression of ZAP70 reduced proliferation, suggesting that the function of UGT2B17 might involve ZAP70. Mechanistically, UGT2B17 interacted with several kinases of the BCR pathway, including ZAP70, SYK, and BTK, revealing a potential therapeutic vulnerability. The dual SYK and JAK/STAT6 inhibitor cerdulatinib most effectively compromised the proliferative advantage conferred by UGT2B17 compared to the selective BTK inhibitor ibrutinib. Findings point to an oncogenic role for UGT2B17 as a novel constituent of BCR signalosome also connected with microenvironmental signaling.

Uridine Diphosphate Glucuronosyl Transferase 2B28 (UGT2B28) Promotes Tumor Progression and Is Elevated in African American Prostate Cancer Patients

Prostate cancer (PCa) is the second most diagnosed cancer in the United States and is associated with metabolic reprogramming and significant disparities in clinical outcomes among African American (AA) men. While the cause is likely multi-factorial, the precise reasons for this are unknown. Here, we identified a higher expression of the metabolic enzyme UGT2B28 in localized PCa and metastatic disease compared to benign adjacent tissue, in AA PCa compared to benign adjacent tissue, and in AA PCa compared to European American (EA) PCa. UGT2B28 was found to be regulated by both full-length androgen receptor (AR) and its splice variant, AR-v7. Genetic knockdown of UGT2B28 across multiple PCa cell lines (LNCaP, LAPC-4, and VCaP), both in androgen-replete and androgen-depleted states resulted in impaired 3D organoid formation and a significant delay in tumor take and growth rate of xenograft tumors, all of which were rescued by re-expression of UGT2B28. Taken together, our findings demonstrate a key role for the UGT2B28 gene in promoting prostate tumor growth.

DNA repair gene polymorphisms, tumor control, and treatment toxicity in prostate cancer patients treated with permanent implant prostate brachytherapy

BACKGROUND

Radiotherapy and brachytherapy are common treatments for localized prostate cancer (PCa). However, very few studies evaluated the association of variations in DNA damage response genes and treatment outcomes and toxicity in brachytherapy-treated patients.

PURPOSE

To evaluate the association of inherited germline variations in DNA repair-associated genes with tumor control and treatment toxicity in patients treated with low-dose-rate prostate brachytherapy (LDRB).

MATERIAL AND METHODS

The cohort consists of 475 I-125 LDRB patients with a median follow-up of 51 months after seed implantation. Patients were genotyped for 215 haplotype tagging single nucleotide variations (htSNPs) in 29 candidate genes of DNA damage response and repair pathways. Their association with biochemical recurrence (BCR) was assessed using Cox regression models and Kaplan-Meier survival curves. Linear regressions and analysis of covariance (ANCOVA) between early and late International Prostate Symptom Score (IPSS) with htSNPs were used to evaluate the association with urinary toxicity.

RESULTS

After adjustment for the established risk factors, six htSNPs in five genes were found to be significantly associated with an altered risk of BCR, with adjusted hazard ratios (HR_adj. ) ranging between 3.6 and 11.1 (P < .05). Compared to carriers of the ERCC3 rs4150499C allele, patients homozygous for the T allele (n = 22) had a significant higher risk of BCR with a HR of 11.13 (IC₉₅  = 3.9-32.0; P < .0001; q < 0.001). The Kaplan-Meier survival curve revealed a mean BCR-free survival time reduced from 213 ± 7 to 99 ± 12 months (log-rank P < .0001) for homozygous T carriers compare to noncarriers. For late IPSS (>6 months after treatment), htSNP rs6544990 from MSH2 showed a statistically significant b-coefficient of 1.85 ± 0.52 (P < .001; q < 0.1). Homozygous carriers of the MSH2 rs6544990C allele (n = 62) had a mean late IPSS 3.6 points higher than patients homozygous for the A allele (n = 132). This difference was significant when tested by ANCOVA using pretreatment IPSS as a covariate (P < .01).

CONCLUSIONS

This study suggests an association of the intronic variants of the DNA nucleotide excision repair ERCC3 and DNA mismatch repair MSH2 genes with elevated risk of BCR and late urinary toxicity respectively after LDRB. Further validation is required before translational clinical advances.

Combination of germline variations associated with survival of folinic acid, fluorouracil and irinotecan-treated metastatic colorectal cancer patients

Aim: Germline variants could modify survival of metastatic colorectal cancer patients (mCRC). Patients & methods: The association of 285 haplotype-tagging SNPs in 11 candidate genes and overall survival (OS) was tested in two cohorts totalizing 417 FOLFIRI-treated mCRC. Gene expression was investigated in vitro and in public datasets. Results: In the combined cohort, CES1 rs9921399T>C was associated with prolonged OS (hazard ratio [HR] = 0.40) whereas ABCC1 rs17501011G>A (HR = 2.08) and UGT1 rs1113193G>A (HR = 2.12) were associated with shorter OS (p ≤ 0.005). A combined effect of these polymorphisms was observed with HR of 1.98-2.97 (p < 0.05). The ABCC1 rs17501011A variant reduced reporter-gene activity (p < 0.05) whereas ABCC1 tumor expression was associated with shorter survival (p ≤ 0.013). Conclusion: We identified a combination of genetic determinants that could predict mCRC survival.

Abstract A072: Serum sex steroids as prognostic biomarkers in patients receiving androgen-deprivation therapy for recurrent prostate cancer post-radiotherapy: A post hoc analysis of the PR.7 trial

Background and Objective: Nadir testosterone values following initiation of androgen deprivation therapy have been shown in several studies to be prognostic for outcome, including time to castration-resistant prostate cancer (TTCRPC) and cancer specific survival (CSS). The biologic reasons for this remain unclear. Using cryopreserved serum from the PR.7 trial of intermittent vs. continuous androgen deprivation therapy(ADT), we determined to assess the role of related sex steroids as prognostic biomarkers in men on androgen deprivation therapy for recurrent cancer post-radiotherapy.

Patients and Methods: Canadian patients in the PR.7 trial randomized to the continuous arm were included. Patients were excluded who did not receive ADT(n=3), had &lt;2 years of follow-up (n=2), received exogenous estrogens or glucocorticoids(n=5), or samples were unavailable(n=36). LC-MS/MS was performed using a validated method to simultaneously analyze ten steroids: dehydroepiandrosterone (DHEA), testosterone (T), dihydrotestosterone (DHT), androst-5-ene-β,17β-diol (5-diol), androstenedione (4-dione), androsterone (AD), estrone (E1), estradiol (E2), progesterone, and androstane-3β,17β-diol (3βdiol). Descriptive statistics and correlation analyses were performed, with longitudinal changes categorized as stable, increasing, decreasing, or mixed. The prognostic value of individual steroid tertiles as well as E1:E2, E2:T, and DHT:T ratios were assessed by Kaplan-Meier analysis and Cox proportional hazards adjusted for baseline clinical variables. Outcomes assessed were TTCRPC, CSS, and overall survival (OS).

Results: A total of 219 patients were included in the analysis who had a cryopreserved serum available within 2 years of randomization, with 104 patients having 2 subsequent annual samples available for measurement. Values for DHT, T, 4-dione, AD, DHEA, and 5-diol tended to be correlated among samples. Lower DHEA and AD values were significant associated with older age as was lower DHEA and DHT values with poorer performance status. Higher tertiles of E1 and E2 were associated with sooner TTCRP (log-rank, p=0.03, p=0.02, respectively). Similar trends were seen for 4-dione in predicting TTCRPC (log-rank, p=0.07). Upon adjustment, the highest tertile of E2:T had increased hazard ratios (HR) for CSS (HR=2.36, 95% CI I: 0.90-6.21; p=0.08) and TTCRPC (HR=1.70, 95% CI: 0.90-3.23; p=0.10) relative to the lowest tertile. In an analysis of the subset of patients with longitudinal values, increasing levels of AD over time were associated with poorer CSS and OS (log-rank: p=0.04 and p &lt;0.01, respectively). On adjusted analysis, increasing AD levels had a HR for CSS of 3.43 (95% CI: 0.63-18.67; p=0.15) and a HR for OS of 4.75 (95% CI: 1.49-15.17; p &lt;0.01). Limitations include the number of events for some groups.

Conclusions: Increased levels of E1, E2, and AD during ADT correlated with adverse TTCRPC and CSS. Serum sex steroids, including both androgens and estrogens, may act as prognostic biomarkers in men receiving ADT for recurrent prostate cancer. Further investigation is warranted to support clinical use.

Citation Format: Paul Toren, Azik Hoffman, Keyue Ding, France-Hélène Joncas, Frédéric Pouliot, Yves Fradet, Éric Lévesque, Chantal Guillemette, Laurence Klotz. Serum sex steroids as prognostic biomarkers in patients receiving androgen-deprivation therapy for recurrent prostate cancer post-radiotherapy: A post hoc analysis of the PR.7 trial [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A072.

Abstract 3889: RPL28 promoter polymorphism rs4806668 is associated with reduced survival in FOLFIRI-treated metastatic colorectal cancer patients

Fluorouracil (5-FU), folinic acid, and irinotecan (FOLFIRI) is a standard treatment of metastatic colorectal cancer (mCRC). Our study aimed to investigate genetic variability in candidate genes in relation to patients' outcomes using two independent cohorts of 417 FOLFIRI-treated mCRC cases recruited in Canada and Italy. We used a haplotype-tagging polymorphism (htSNP) approach to maximize the coverage of genetic variability of the selected genes and genotyping was performed using time-of-flight mass spectrometry iPLEX Sequenom Technology. Associations between polymorphisms and clinical outcomes were tested using Cox proportional hazards model adjusted for covariates. Of the genes tested, RPL28 encodes a ribosomal protein and its silencing was shown to enhance sensitivity to 5-FU and irinotecan in vitro.1 RPL28 rs4806668G&gt;T was associated with a shorter progression-free survival (PFS) in the Canadian (hazard ratio (HR) 3.23, P = 0.013), Italian (HR 3.28, P = 0.021) and combined (HR 3.36, P &lt; 0.001) cohorts. This marker was also associated with a reduced overall survival (OS) in the Canadian (HR 3.09, P = 0.032), Italian (HR 3.05, P = 0.030) and combined (HR 3.07, P = 0.002) cohorts. These carriers of the rs4806668 TT genotype associated with reduced survival represent less than 5% of the population of European ancestry and its frequency varies greatly among ethnic groups. This htSNP, located in the promoter region of RPL28, is in strong linkage disequilibrium with six other polymorphisms and may affect RPL28 gene expression. In support, the rs4806668T allele was associated with increased RPL28 expression in colon tissues of healthy individuals of the GTEx cohort, compared to rs4806668G carriers. Functional investigations are required to elucidate the underlying molecular mechanism. These results suggest a role for the ribosomal RPL28 protein in cancer cell response to FOLFIRI treatment.

This work is supported by the Canadian Institutes of Health Research.

1Allen et al. Mol Cancer Ther. 2012 Jan;11(1):119-31

Citation Format: Adrien Labriet, Éric Lévesque, Elena De Mattia, Erika Cecchin, Derek Jonker, Félix Couture, David Simonyan, Angela Buonadonna, Mario D'Andrea, Lyne Villeneuve, Giuseppe Toffoli, Chantal Guillemette. RPL28 promoter polymorphism rs4806668 is associated with reduced survival in FOLFIRI-treated metastatic colorectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3889.

Abstract 5237: Sex-dependent association of circulating sex steroids, pituitary hormones and treatment-free survival in patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most frequent adult leukemia in the western world, and is not considered a hormone-regulated cancer but sex is a known risk factor with a significant male/female ratio (2:1) in its incidence with male patients more frequently developing progressive disease. We hypothesized that variable hormonal exposure may have a sexually dimorphic effect on CLL progression. However, a detailed evaluation of sex steroids and pituitary hormones in CLL patients is still lacking. In 156 CLL patients, we quantitatively profiled 15 circulating sex steroids (androgens, estrogens and progesterone) by sensitive and specific mass spectrometry and two pituitary hormones (luteinizing hormone (LH) and follicular secreting hormone (FSH)) by immunoassay. Data were analyzed separately by sex and in relation to treatment-free survival (TFS). Univariate and multivariate analyses of TFS were performed using Cox's proportional hazard model with hormone levels as continuous variables. Median age of CLL patients was 59.8 and 62.9 years for men and postmenopausal women, respectively. Common CLL prognostic markers had very similar frequencies between male and female cases. Median TFS was shorter for male patients than for women (80.7 vs. 135.0 months, P=0.033). Circulating profiles of hormones in CLL patients were significantly different from those of healthy donors whereas male cases had higher steroid levels than female patients. In male CLL cases, sex steroid levels were not significantly associated with TFS; however, higher LH levels were associated with shorter TFS in multivariate analyses with an adjusted hazard ratio (HRadj) of 2.11 (P = 0.004). In female CLL cases, high levels of potent androgens testosterone, dihydrotestosterone (DHT) and the sum of methoxy estrogens were significantly associated with improved TFS with HRadj values of 0.24 (P =0.007), 0.54 (P=0.023) and 0.31 (P =0.034), respectively. This study is the first to establish a link between outcome of CLL patients and circulating sex steroid and pituitary hormones, revealing a sex-specific hormonal imbalance associated with disease progression. This work was supported by a Canadian Institutes of Health Research grant to CG. EPA holds scholarships from Université Laval foundation - Leadership and sustainable development award and CHU de Québec foundation - Fernand Labrie excellence award.

Citation Format: Eric P. Allain, Karin Venzl, Patrick Caron, Véronique Turcotte, David Simonyan, Michaela Gruber, Trang Le, Éric Lévesque, Chantal Guillemette, Katrina Vanura. Sex-dependent association of circulating sex steroids, pituitary hormones and treatment-free survival in patients with chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5237.

Engineered, highly reactive substrates of microbial transglutaminase enable protein labeling within various secondary structure elements

Microbial transglutaminase (MTG) is a practical tool to enzymatically form isopeptide bonds between peptide or protein substrates. This natural approach to crosslinking the side-chains of reactive glutamine and lysine residues is solidly rooted in food and textile processing. More recently, MTG's tolerance for various primary amines in lieu of lysine have revealed its potential for site-specific protein labeling with aminated compounds, including fluorophores. Importantly, MTG can label glutamines at accessible positions in the body of a target protein, setting it apart from most labeling enzymes that react exclusively at protein termini. To expand its applicability as a labeling tool, we engineered the B1 domain of Protein G (GB1) to probe the selectivity and enhance the reactivity of MTG toward its glutamine substrate. We built a GB1 library where each variant contained a single glutamine at positions covering all secondary structure elements. The most reactive and selective variants displayed a >100-fold increase in incorporation of a recently developed aminated benzo[a]imidazo[2,1,5-cd]indolizine-type fluorophore, relative to native GB1. None of the variants were destabilized. Our results demonstrate that MTG can react readily with glutamines in α-helical, β-sheet, and unstructured loop elements and does not favor one type of secondary structure. Introducing point mutations within MTG's active site further increased reactivity toward the most reactive substrate variant, I6Q-GB1, enhancing MTG's capacity to fluorescently label an engineered, highly reactive glutamine substrate. This work demonstrates that MTG-reactive glutamines can be readily introduced into a protein domain for fluorescent labeling.

Improved Progression-Free Survival in Irinotecan-Treated Metastatic Colorectal Cancer Patients Carrying the HNF1A Coding Variant p.I27L

Hepatocyte nuclear factor 1-alpha (HNF1A) is a liver-enriched transcription factor that plays a key role in many aspects of hepatic functions including detoxification processes. We examined whether HNF1A polymorphisms are associated with clinical outcomes in two independent cohorts combining 417 European ancestry patients with metastatic colorectal cancer (mCRC) treated with irinotecan-based chemotherapy. The intronic rs2244608A>G marker was predictive of an improved progression-free survival with a trend in the Canadian cohort and reaching significance in the Italian cohort, with hazard ratios (HR) of 0.74 and 0.72, P = 0.076 and 0.038, respectively. A strong association between rs2244608A>G and improved PFS was found in the combined analysis of both cohorts (HR = 0.72; P = 0.002). Consistent with an altered HNF1A function, mCRC carriers of the rs2244608G minor allele displayed enhanced drug exposure by 45% (P = 0.032) compared to non-carriers. In Caucasians, rs2244608A>G is in strong linkage with the coding variant rs1169288c.79A>C (HNF1A p.I27L). In healthy donors, we observed an altered hepatic (ABCC1, P = 0.009, ABCC2, P = 0.048 and CYP3A5, P = 0.001; n = 89) and intestinal (TOP1, P = 0.004; n = 75) gene expression associated with the rs1169288C allele. In addition, the rs1169288C polymorphism could significantly increase the ABCC1 promoter activity by 27% (P = 0.008) and 15% (P = 0.041) in the human kidney HEK293 and the human liver HepG2 cell lines, respectively. Our findings suggest that the HNF1A rs2244608, or the tightly linked functional coding variant p.I27L, might be a potential prognostic marker with irinotecan-based regimens.

General C-H Arylation Strategy for the Synthesis of Tunable Visible Light-Emitting Benzo[a]imidazo[2,1,5-c,d]indolizine Fluorophores

Herein we report the discovery of the benzo[a]imidazo[2,1,5-c,d]indolizine motif displaying tunable emission covering most of the visible spectrum. The polycyclic core is obtained from readily available amides via a chemoselective process involving Tf₂O-mediated amide cyclodehydration, followed by intramolecular C-H arylation. Additionally, these fluorescent heterocycles are easily functionalized using electrophilic reagents, enabling divergent access to varied substitution. The effects of said substitution on the compounds' photophysical properties were rationalized by density functional theory calculations. For some compounds, emission wavelengths are directly correlated to the substituent's Hammett constants. Easily introduced nonconjugated reactive functional groups allow the labeling of biomolecules without modification of emissive properties. This work provides a straightforward platform for the synthesis of new moderately bright fluorescent dyes remarkable for their chemical stability, predictability, and unusually high excitation-emission differential.

Epigenetic regulation of steroid inactivating UDP-glucuronosyltransferases by microRNAs in prostate cancer

Androgens play a central role in prostate cancer progression. Systemic and local androgen bioavailability is controlled by UDP-glucuronosyltransferases conjugating enzymes (UGT), namely UGT2B15, UGT2B17 and UGT2B28. Reporter vector assays in HEK293 cells initially validated in silico-predicted regulatory potential of candidate miRNAs to target UGT transcripts, including miR-376c, miR-409 and miR-494 for UGT2B17, miR-331-5p and miR-376c for UGT2B15 while none were efficient for UGT2B28. miR-376c was shown as the most effective to downregulate UGT2B15 and UGT2B17 through interactions with a site conserved in both UGTs. Ectopic miR-376c expression in prostate cancer cells significantly reduced UGT2B15 and UGT2B17 expression (>32%; P<0.005) with a consequent decrease in dihydrotestosterone glucuronidation (-37%; P<0.001). Consistent with reduced androgen inactivation, ectopic expression of miR-376c changed expression of androgen responsive genes and enhanced cell proliferation with no effect on androgen receptor levels. Sustaining a role of miR-376c in the regulation of androgen-inactivating UGTs, its expression was significantly downregulated in prostatic tumors and further reduced in metastases (P<0.0001), whereas the opposite was observed for UGT2B15/17 (P=0.031). In high-grade tumors (Gleason ≥8), UGT2B15/17 and miR-376c were inversely correlated (r=-0.557; P=0.048) with also a significant relationship in metastases (r=-0.747; P=0.003). In line with a modification in androgen bioavailability, PSA mRNA levels were also negatively correlated to those of UGT2B15/17 (r=-0.573; P=0.01) but positively linked to levels of miR-376c (r=0.577; P=0.039). This study reveals that the androgen-inactivating UGT2B15 and UGT2B17 genes are direct targets of miR-376c and thus may influence steroid metabolism during prostate cancer progression.

The UGT1 locus is a determinant of prostate cancer recurrence after prostatectomy

The prognostic significance of common deletions in uridine diphospho-glucuronosyltransferase 2B (UGT2B) genes encoding sex steroid metabolic enzymes has been recently recognized in localized prostate cancer (PCa) after radical prostatectomy (RP). However, the role of germline variations at the UGT1 locus, encoding half of all human UGTs and primarily involved in estrogen metabolism, remains unexplored. We investigated whether variants of UGT1 are potential prognostic markers. We studied 526 Caucasian men who underwent RP for clinically localized PCa. Genotypes of patients for 34 haplotype-tagged single-nucleotide polymorphisms (htSNPs) and 11 additional SNPs across the UGT1 locus previously reported to mark common variants including functional polymorphisms were determined. The risk of biochemical recurrence (BCR) was estimated using adjusted Cox proportional hazards regression and Kaplan-Meier analysis. We further investigated whether variants are associated with plasma hormone levels by mass spectrometry. In multivariable models, seven htSNPs were found to be significantly associated with BCR. A greater risk was revealed for four UGT1 intronic variants with hazard ratios (HRs) of 1.59-1.88 (P<0.002) for htSNPs in UGT1A10, UGT1A9, and UGT1A6. Conversely, decreased BCR was associated with three htSNPs in introns of UGT1A10 and UGT1A9 (HR=0.56-058; P≤0.01). An unfavorable UGT1 haplotype comprising all risk alleles, with a frequency of 14%, had a HR of 1.68 (95% CI=1.13-2.50; P=0.011). Significant alteration in circulating androsterone levels was associated with this haplotype, consistent with changes in hormonal exposure. This study provides the first evidence, to our knowledge, that germline polymorphisms of UGT1 are potential predictors of recurrence of PCa after prostatectomy.

Cyclosporine and methotrexate-related pharmacogenomic predictors of acute graft-versus-host disease

Effective immunosuppression is mandatory to prevent graft-versus-host disease and to achieve a successful clinical outcome of hematopoietic stem cell transplantation. Here we tested whether germline single nucleotide polymorphisms in 20 candidate genes related to methotrexate and cyclosporine metabolism and activity influence the incidence of graft-versus-host disease in patients who undergo stem cell transplantation for hematologic disorders. Recipient genetic status of the adenosine triphosphate-binding cassette sub-family C1 and adenosine triphosphate-binding cassette sub-family C2 transporters, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/ inosine monophosphate cyclohydrolase within the methotrexate pathway, and nuclear factor of activated T cells (cytoplasmic 1) loci exhibit a remarkable influence on severe acute graft-versus-host disease prevalence. Indeed, an increased risk of acute graft-versus-host disease was observed in association with single nucleotide polymorphisms located in 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (hazard ratio=3.04; P=0.002), nuclear factor of activated T cells (cytoplasmic 1) (hazard ratio=2.69; P=0.004), adenosine triphosphate-binding cassette sub-family C2 (hazard ratio=3.53; P=0.0018) and adenosine triphosphate-binding cassette sub-family C1 (hazard ratio=3.67; P=0.0005). While donor single nucleotide polymorphisms of dihydrofolate reductase and solute carrier family 19 (member 1) genes are associated with a reduced risk of acute graft-versus-host disease (hazard ratio=0.32-0.41; P=0.0009-0.008), those of nuclear factor of activated T cells (cytoplasmic 2) are found to increase such risk (hazard ratio=3.85; P=0.0004). None of the tested single nucleotide polymorphisms was associated with the occurrence of chronic graft-versus-host disease. In conclusion, by targeting drug-related biologically relevant genes, this work emphasizes the potential role of germline biomarkers in predicting acute graft-versus-host disease. Further investigations are warranted to improve our understanding of these relationships to personalize immunosuppressive therapy and optimize outcomes.

Improved zinc-catalyzed Simmons-Smith reaction: access to various 1,2,3-trisubstituted cyclopropanes

The Simmons-Smith reaction of zinc carbenoids with alkenes is a powerful method to access cyclopropanes containing various substitution patterns. This work exploits the high reactivity of aryldiazomethanes toward zinc halides to generate aryl-substituted carbenoids catalytically. These carbenoids are able to cyclopropanate various alkenes diastereoselectively, including unfunctionalized substrates such as styrenes. The zinc catalyst can be modified to tolerate the use of free allylic alcohols.

Importance of 5α-reductase gene polymorphisms on circulating and intraprostatic androgens in prostate cancer

PURPOSE

Polymorphisms in the genes SRD5A1 and SRD5A2 encoding androgen biosynthetic 5α-reductase enzymes have been associated with an altered risk of biochemical recurrence after radical prostatectomy in localized prostate cancer.

EXPERIMENTAL DESIGN

To gain potential insights into SRD5A biologic effects, we examined the relationship between SRD5A prognostic markers and endogenous sex-steroid levels measured by mass spectrometry in plasma samples and corresponding prostatic tissues of patients with prostate cancer.

RESULTS

We report that five of the seven SRD5A markers differentially affect sex-steroid profiles of dihydrotestosterone and its metabolites in both the circulation and prostatic tissues of patients with prostate cancer. Remarkably, a 32% increase in intraprostatic testosterone levels was observed in the presence of the high-risk SRD5A rs2208532 polymorphism. Moreover, SRD5A2 markers were associated predominantly with circulating levels of inactive glucuronides. Indeed, the rs12470143 SRD5A2 protective allele was associated with high circulating androstane-3α, 17β-diol-17-glucuronide (3α-diol-17G) levels as opposed to lower levels of both 3α-diol-17G and androsterone-glucuronide observed with the rs2208532 SRD5A2 risk allele. Moreover, SRD5A2 rs676033 and rs523349 (V89L) risk variants, in strong linkage disequilibrium, were associated with higher circulating levels of 3α-diol-3G. The SRD5A2 rs676033 variant further correlated with enhanced intraprostatic exposure to 5α-reduced steroids (dihydrotestosterone and its metabolite 3β-diol). Similarly, the SRD5A1 rs166050C risk variant was associated with greater prostatic exposure to androsterone, whereas no association was noted with circulating steroids.

CONCLUSIONS

Our data support the association of 5α-reductase germline polymorphisms with the hormonal milieu in patients with prostate cancer. Further studies are needed to evaluate if these variants influence 5α-reductase inhibitor efficacy.

Molecular markers in key steroidogenic pathways, circulating steroid levels, and prostate cancer progression

PURPOSE

Prostate cancer is a heterogeneous genetic disease, and molecular methods for predicting prognosis in patients with aggressive form of the disease are urgently needed to better personalize treatment approaches. The objective was to identify host genetic variations in candidate steroidogenic genes affecting hormone levels and prostate cancer progression.

EXPERIMENTAL DESIGN

The study examined two independent cohorts composed of 526 Caucasian men with organ-confined prostate cancer and 601 Taiwanese men on androgen-deprivation therapy. Caucasians were genotyped for 109 haplotype-tagging single-nucleotide polymorphisms (SNP) in CYP17A1, ESR1, CYP19A1, and HSD3B1, and their prognostic significance on disease progression was assessed using Kaplan-Meier survival curves and Cox regression models. Positive findings, including previously identified SRD5A1, SRD5A2, HSD17B2, HSD17B3, and HSD17B12 polymorphisms, were then explored in Taiwanese men (n = 32 SNPs). The influence of positive markers on the circulating hormonal levels was then appraised in Caucasians using specific and sensitive mass spectrometry-based methods.

RESULTS

After adjusting for known risk factors, variants of CYP17A1 (rs6162), HSD17B2 (rs4243229 and rs7201637), and ESR1 (rs1062577) were associated with progressive disease in both cohorts. Indeed, the presence of these variations was significantly associated with progression in Caucasians (HR, 2.29-4.10; P = 0.0014-2 × 10(-7)) and survival in Taiwanese patients [HR = 3.74; 95% confidence interval (CI): 1.71-8.19, P = 0.009]. Remarkably, the CYP17A1 rs6162 polymorphism was linked to plasma dehydroepiandrosterone-sulfate (DHEA-S) levels (P = 0.03), HSD17B2 rs7201637 with levels of dihydrotestosterone (P = 0.03), and ESR1 rs1062577 with levels of estrone-S and androsterone-glucuronide (P ≤ 0.05).

CONCLUSION

This study identifies, in different ethnic groups and at different disease stages, CYP17A1, HSD17B2, and ESR1 as attractive prognostic molecular markers of prostate cancer progression.