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Purpose: Reliable biomarkers that predict prostate cancer outcomes are urgently needed to improve and personalize treatment approaches. With this goal in mind, we individually and collectively appraised common genetic polymorphisms related to estradiol metabolic pathways to find prostate cancer prognostic markers.Methods: The genetic profiles of 526 men with organ-confined prostate cancer were examined to find common genetic polymorphisms related to estradiol metabolic pathways and these findings were replicated in a cohort of 213 men with more advanced disease (follow-up time for both cohorts, >7.4 years). Specifically, we examined 71 single-nucleotide polymorphisms (SNP) in SULT2A1, SULT2B1, CYP1B1, COMT, CYP3A4, CYP3A5, CYP3A43, NQO1, and NQO2 and assessed the impact of the SNPs alone and in combination on prostate cancer progression and on circulating hormone levels.Results: According to a multivariate analysis, CYP1B1 (rs1800440), COMT (rs16982844), and SULT2B1 (rs12460535, rs2665582, rs10426628) were significantly associated with prostate cancer progression and hormone levels. Remarkably, by combining the SNP information with previously identified HSD17B2 markers, the patients could be stratified into four distinct prognostic subgroups. The most prominent association was observed for the eight-marker combination [CYP1B1 (rs1800440), SULT2B1 (rs12460535, rs2665582, and rs10426628), and HSD17B2 (rs4243229, rs1364287, rs2955162, and rs1119933)].Conclusion: This study identified specific germline variations in estradiol metabolism–related pathways, namely CYP1B1, SULT2B1, and HSD17B2, as novel prognostic markers that are cumulatively associated with increased risk of prostate cancer progression. This panel of markers warrants additional investigation and validation to help stratify patients according to their risk of progression. Clin Cancer Res; 20(11); 2971–83. ©2014 AACR.

PDF file - 126K, Supplementary Table 1. Genotype frequencies 1 of htSNPs in steroidogenic genes and their association with BCR in Caucasians (n=526). Supplementary Table 2. Association between htSNPs in the steroidogenic pathway and prostate cancer-specific mortality in Asians under ADT (n=601) Supplementary Table 3. Non-significant associations between htSNPs in candidate steroidogenic pathways and prostate cancer-specific mortality in Asians under ADT (n=601) Supplementary Table 4. Non-significant associations between htSNPs in candidate steroidogenic pathways and all cause mortality in Asians under ADT (n=601)

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. Clin Cancer Res; 20(3); 576–84. ©2013 AACR.

PDF file - 146KB, Supplementary Table 1. Genotype Frequencies of Polymorphisms in SULT2B1 and their Association with Biochemical Recurrence in 526 Cases with Localized Prostate Cancer. Supplementary Table 2. Genotype Frequencies of Polymorphisms in COMT and their Association with Biochemical Recurrence in 526 Cases with Localized Prostate Cancer. Supplementary Table 3. Genotype Frequencies of Polymorphisms in CYP1B1 and their Association with Biochemical Recurrence in 526 Cases with Localized Prostate Cancer. Supplementary Table 4. Genotype Frequencies of Polymorphisms in NQO1 and their Association with Biochemical Recurrence in 526 Cases with Localized Prostate Cancer. Supplementary Table 5. Genotype Frequencies of Polymorphisms in NQO2 and their Association with Biochemical Recurrence in 526 Cases with Localized Prostate Cancer. Supplementary Table 6. Association of SNPs with Prostate Cancer Progression for 213 Patients with Locally Advanced Prostate Cancer. Supplementary Table 7. Association of SNPs with the Overall Survival of 213 Patients with Locally Advanced Prostate Cancer.

PDF file 138K, Relationshio between sex-steroid hormone levels and molecular markers in SRD5A genes

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. Clin Cancer Res; 19(3); 699–709. ©2012 AACR.

Introduction A case series of hypersensitivity reactions (HSRs) during intravenous administration of etoposide was observed following the introduction of in-line filters (ILFs) at a specialized university-affiliated center. This raised questions about the possible involvement of filters in these reactions. Despite there being very little published evidence to inform clinical decision making in this potentially clinically significant situation, the use of ILFs was discontinued at this center pending further investigation. The aims of this study were to evaluate the cumulative incidence of etoposide-related HSR with and without the use of ILF and to describe the reactions in adult and pediatric patients with cancer. Methods A retrospective cohort study was performed among all pediatric and adult patients treated with intravenous etoposide at a maximal concentration of 0.4 mg/mL at our center between 30 September 2015 and 16 August 2018. This covered periods of time during which ILFs were used, as well as 6 months before their implementation and after their withdrawal. Data were extracted from medical records and cumulative incidence was calculated for each of the time periods (pre-ILF, ILF, and post-ILF) as the proportion of patients who recorded an HSR (one or more). Confidence intervals were calculated for each proportion using Fisher's Exact 95%. Comparisons of proportions between time periods were performed using Exact Pearson Chi-squared tests. Data were stratified by a number of perfusion cycles (single cycle or multiple cycles) and by patient population (adult and pediatric). Results A total of 284 patients were included in the study. The overall cumulative incidence of etoposide HSR was 9.9%. The cumulative incidence of HSR tended to be higher during ILF use when compared with combined pre- and post-ILF periods (12.2% [95% CI: 7.9–17.8] vs. 5.2% [95% CI: 1.7–11.7], p = 0.09). In patients who received multiple cycles of etoposide, the cumulative incidence of HSRs was higher during ILF use when compared with combined pre- and post-ILF periods (15.0% [95% CI: 9.6–21.8] vs. 3.9% [95% CI: 0.8–11.0], p = 0.01). The majority of HSRs' maximal severity were grade 1 or 2 (85.7%) according to Common Terminology Criteria for Adverse Events ( CTCAE) version 4.0. Conclusions This study suggests a link between the use of ILFs and increased incidence of HSR during etoposide perfusion.

Cancer research has considerably progressed with the improvement of in vitro study models, helping to understand the key role of the tumor microenvironment in cancer development and progression. Over the last few years, complex 3D human cell culture systems have gained much popularity over in vivo models, as they accurately mimic the tumor microenvironment and allow high-throughput drug screening. Of particular interest, in vitrohuman 3D tissue constructs, produced by the self-assembly method of tissue engineering, have been successfully used to model the tumor microenvironment and now represent a very promising approach to further develop diverse cancer models. In this review, we describe the importance of the tumor microenvironment and present the existing in vitro cancer models generated through the self-assembly method of tissue engineering. Lastly, we highlight the relevance of this approach to mimic various and complex tumors, including basal cell carcinoma, cutaneous neurofibroma, skin melanoma, bladder cancer, and uveal melanoma.

Mammary epithelial cells (MECs) are known to have their metabolism reprogrammed following pregnancy to allow the increased energy requirements for lactation. The estrogen receptor α (ERα) is mainly associated with the regulation of biological pathways linked to mammary gland development but its influence on MECs metabolism is still unknown. Our hypothesis is that ERα reprograms cell metabolism in normal MECs, a phenomenon that would be reprogrammed during breast carcinogenesis. Few in vitro models are used to study MECs, and most of them do not express ERα. Primary MECs can be used to overcome this issue, but methods to purify these cells generally require flow cytometry and fluorescence-activated cell sorting (FACS), which require specialized instruments and expertise. Herein, we present in detail a FACS-free protocol for purification and primary culture of mouse MECs to study ERα metabolic functions using mass spectrometry (MS). Purified MECs from nulliparous mice remain differentiated for up to six days with >85% luminal epithelial cells in two-dimensional culture. When seeded in Matrigel, they form organoids that recapitulate the mammary gland morphology in vivo by developing lumens, contractile cells, and lobular structures. MECs express a functional ERα signaling pathway in both two- and three-dimensional cell culture, as shown at the mRNA and protein levels and by the phenotypic characterization. Extracellular metabolic flux analysis showed that estrogens induce a metabolic switch favouring aerobic glycolysis over mitochondrial respiration in MECs grown in two-dimensions, a phenomenon known as the Warburg effect. We also performed (MS)-based metabolomics in organoids. Estrogens altered the levels of metabolites from various pathways, including aerobic glycolysis, citric acid cycle, urea cycle, and amino acid metabolism, demonstrating that ERα reprograms cell metabolism in mammary organoids. To further understand this reprogramming, stable isotope tracer analysis in primary culture organoids are currently performed. In addition, pregnancy and breast-feeding are known to be protective against breast carcinogenesis. Consequently, we also performed MEC purification and organoid culture using mammary glands from multiparous mice. Intriguingly, organoid phenotypic characterization indicated a difference in organoid structures between MECs from nulliparous and multiparous mice. Furthermore, we observe significant differences in estrogenic response between both conditions, suggesting that pregnancy and/or lactation promotes the establishment of specific epigenetic marks that are preserved even ex vivo. Chromatin immunoprecipitation of specific histone marks and MS-based metabolic studies are ongoing to better understand the different responses of mammary organoids to estrogens between nulliparous and multiparous mice. Overall, we have optimized mouse MEC isolation and purification for two- and three-dimensional cultures and for MS-based metabolomics. We demonstrated that these organoids retain a functional ERα pathway over time and that ERα significantly reprograms multiple metabolic pathways. This model represents a valuable tool to study how estrogens modulate mammary gland biology, and particularly how these hormones reprogram metabolism during lactation and breast carcinogenesis. Citation Format: Aurélie Lacouture, Cynthia Jobin, Alisson Clemenceau, Cindy Weidmann, Line Berthiaume, Dominic Bastien, Isabelle Laverdière, Martin Pelletier, Caroline Diorio, Francine Durocher, Étienne Audet-Walsh. A FACS-free purification method to study estrogen signaling, organoid formation, and metabolic reprogramming in mammary epithelial cells [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-02-01.

Therapy for acute myeloid leukemia (AML) involves intense cytotoxic treatment and yet approximately 70% of AML are refractory to initial therapy or eventually relapse. This is at least partially driven by the chemo-resistant nature of the leukemic stem cells (LSCs) that sustain the disease, and therefore novel anti-LSC therapies could decrease relapses and improve survival. We performed in silico analysis of highly prognostic human AML LSC gene expression signatures using existing datasets of drug–gene interactions to identify compounds predicted to target LSC gene programs. Filtering against compounds that would inhibit a hematopoietic stem cell (HSC) gene signature resulted in a list of 151 anti-LSC candidates. Using a novel in vitro LSC assay, we screened 84 candidate compounds at multiple doses and confirmed 14 drugs that effectively eliminate human AML LSCs. Three drug families presenting with multiple hits, namely antihistamines (astemizole and terfenadine), cardiac glycosides (strophanthidin, digoxin and ouabain) and glucocorticoids (budesonide, halcinonide and mometasone), were validated for their activity against human primary AML samples. Our study demonstrates the efficacy of combining computational analysis of stem cell gene expression signatures with in vitro screening to identify novel compounds that target the therapy-resistant LSC at the root of relapse in AML.

Irinotecan is a cytotoxic agent used widely for the treatment of solid tumors, particularly for metastatic colorectal cancers. Treatment with this drug frequently results in severe neutropenia and diarrhea that can markedly impact the course of treatment and patients' quality of life. Pharmacogenomic tailoring of irinotecan-based chemotherapy has been the subject of several investigations, but with limited data on ATP-binding cassette (ABC) and solute carrier (SLC) transporter genes.In this study, we aimed to discover toxicity-associated markers in seven transporter genes participating in irinotecan pharmacokinetics involving the ABC transporter genes ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, and ABCG2 and the solute carrier organic anion transporter gene SLCO1B1 and using a haplotype-tagging single-nucleotide polymorphisms (n=210 htSNPs) strategy. The profiles of 167 metastatic colorectal cancer Canadian patients treated with FOLFIRI-based regimens were examined and the findings were replicated in an independent cohort of 250 Italian patients.In combined cohorts, a two-marker ABCC5 rs3749438 and rs10937158 haplotype (T-C) predicted lower risk of severe diarrhea [odds ratio (OR) of 0.43; P=0.001]. The co-occurrence of ABCG1 rs225440T and ABCC5 rs2292997A predicted the risk of severe neutropenia (OR=5.93; P=0.0002), which was further improved when incorporating the well-known risk marker UGT1A1*28 rs8175347 (OR=7.68; P0.0001). In contrast, carriers of one protective marker (UGT1 rs11563250G) but none of these risk alleles experienced significantly less severe neutropenia (8.2 vs. 34.0%; P0.0001).This combination of predictive genetic markers could potentially lead to better risk assessment and may thus improve personalized treatment.

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 theUGT1locus, encoding half of all human UGTs and primarily involved in estrogen metabolism, remains unexplored. We investigated whether variants ofUGT1are 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 theUGT1locus 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 fourUGT1intronic variants with hazard ratios (HRs) of 1.59–1.88 (PUGT1A10,UGT1A9, andUGT1A6. Conversely, decreased BCR was associated with three htSNPs in introns ofUGT1A10andUGT1A9(HR=0.56–058;P≤0.01). An unfavorableUGT1haplotype 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 ofUGT1are potential predictors of recurrence of PCa after prostatectomy.

Recent evidence indicates that microRNAs might participate in prostate cancer initiation, progression and treatment response. Germline variations in microRNAs might alter target gene expression and modify the efficacy of prostate cancer therapy. To determine whether genetic variants in microRNAs and microRNA target sites are associated with the risk of biochemical recurrence (BCR) after radical prostatectomy (RP). We retrospectively studied two independent cohorts composed of 320 Asian and 526 Caucasian men with pathologically organ-confined prostate cancer who had a median follow-up of 54.7 and 88.8 months after RP, respectively. Patients were systematically genotyped for 64 single-nucleotide polymorphisms (SNPs) in microRNAs and microRNA target sites, and their prognostic significance on BCR was assessed by Kaplan-Meier analysis and Cox regression model. After adjusting for known clinicopathologic risk factors, two SNPs (MIR605 rs2043556 and CDON rs3737336) remained associated with BCR. The numbers of risk alleles showed a cumulative effect on BCR [perallele hazard ratio (HR) 1.60, 95% confidence interval (CI) 1.16-2.21, p for trend = 0.005] in Asian cohort, and the risk was replicated in Caucasian cohort (HR 1.55, 95% CI 1.15-2.08, p for trend = 0.004) and in combined analysis (HR 1.57, 95% CI 1.26-1.96, p for trend

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. Clin Cancer Res; 20(3); 576–84. ©2013 AACR.

Acute myeloid leukemia (AML) is an aggressive form of blood cancer defined by the uncontrolled proliferation of immature myeloblast cells in the blood and bone marrow, leading to hematopoietic failure. The 5-year survival rate is 28% in patients aged 20 years and older and 64% in patients aged 19 years and younger (SEER 2019). A large portion of these patients succumb to the disease partially due to the chemo-resistant nature of leukemic stem cells (LSCs). Hence, novel therapies targeting unique LSC biology that spare hematopoietic stem cells (HSCs) are needed to eliminate and avoid reoccurrence of this disease. We had previously identified FDA-approved anti-inflammatory glucocorticoids mometasone, halcinonide, and budesonide as compounds that induce terminal differentiation of the LSC (CD34+CD38-) and progenitor cell (CD34+CD38+) populations to leukemic blast cells (CD15+CD34-) in refractory human AML (Laverdière & Boileau et al., Blood Can. J. 2018). Following the paradigm of successful differentiation treatment in AML (acute promyelocytic leukemia with all-trans retinoic acid), the effects and mechanism of action of the glucocorticoids on LSCs need to be further investigated for other AML subtypes. Furthermore, dexamethasone, a glucocorticoid currently used to successfully treat acute lymphoblastic leukemia (ALL), is being studied in a Phase II clinical trial for induction and post-remission chemotherapy in older patients with de novo or therapy-related AML (clinicalTrials.gov, NCT03609060). To identify the subtypes of AML that are sensitive to steroid-induced LSC differentiation, we began by screening a panel of cell lines (F36P, MOLM-13, Kasumi-6, Kasumi-1 and K562) and observed that only Kasumi-1, a pediatric leukemia carrying the t(8;21) mutation leading to the fused RUNX1-RUNX1T1 gene, was responsive to glucocorticoid treatment, although without differentiation. This is consistent with the finding of Simon et al. who observed a loss of bulk AML cells in RUNX1 AML samples following dexamethasone treatment (Simon et al., Clin Cancer Res. 2017). However, we observed expansion of bulk cells following differentiation of LSCs in primary AML, indicating different mechanisms of steroid response in different samples: differentiation of LSCs or overall loss of AML cells. We will further investigate these compounds in a panel of 10 genetically defined primary AML samples to classify which oncogenetic drivers or subtypes of AML are linked to sensitivity to the three glucocorticoids, including which drive cell death vs LSC differentiation. We will perform ex vivo and in vivo studies of the glucocorticoids to assess the extent of engraftment in treated versus DMSO treated samples. This additional data will be presented at the annual meeting. In addition, to explore the mechanism of action of these steroids in AML, we investigated the roles of the cytokines interleukin-3 (IL-3), interleukin-6 (IL-6), stem cell factor (SCF), granulocyte colony stimulating factor (GCSF), thrombopoietin (TPO) and FMS-like tyrosine kinase 3 ligand (FLT3L), used to culture AML, on the differentiation effects induced by the glucocorticoids. We observed that only FLT3L was required for the complete differentiation of LSCs. In summary, we have observed that the three glucocorticoid steroids (mometasone, halcinonide, and budesonide), as well as dexamethasone to a lesser extent, can induce two different responses in a sample-dependent manner: terminal differentiation of LSCs or overall cell loss. We have also observed that the differentiation response requires FLT3L for maturation of the AML cells. Our current studies involve in vivo and genomic assays to determine the effect on functional LSCs and the genetic markers of sensitivity and we will present these results. Disclosures Minden: Trillium Therapetuics: Other: licensing agreement.

Combinations of immunosuppressive drugs are routinely used post-transplantation to prevent rejection and/or other complications and optimize outcomes. The prodrug ester mycophenolate mofetil (MMF) is frequently used in solid-organ and stem cell transplantation settings. A growing body of evidence supports therapeutic monitoring of this immunosuppressant to optimize its efficacy and reduce toxicity. Thus, pharmacodynamic monitoring of MMF is a strategy that could potentially improve patient outcomes. Pharmacodynamic measurements require evaluation of inosine-5'-monophosphate dehydrogenase (IMPDH) activity, the target enzyme of the active moiety mycophenolic acid. Various nonradioactive methods using chromatographic separations have been used to quantify xanthosine monophosphate, the catalytic product of the enzyme, to indirectly evaluate IMPDH activity. However, no methods have used mass spectrometry based detection, which provides more specificity and sensitivity. Here, we describe a liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) method for the quantification of xanthosine monophosphate and adenosine monophosphate (for normalization) in lysates of peripheral blood mononuclear cells (PBMCs) from hematopoietic stem cell transplant (HSCT) recipients. Linearity, precision, and accuracy were validated over a large range of concentrations for each compound. The method could measure analytes with high sensitivity, accuracy (93-116%), and reproducibility (CV7.5%). Its clinical application was validated in PBMC lysates obtained from healthy individuals (n = 43) and HSCT recipients (n = 19). This reliable and validated LC-MS/MS method could be a useful tool for pharmacodynamic monitoring of patients treated with MMF.

Tacrolimus (Tacro) is a potent immunosuppressant and a central agent in the prevention of posttransplantation rejection. Tacro is characterized by a narrow therapeutic index and wide interindividual pharmacokinetic fluctuation. The contribution of human UDP-glucuronosyltransferase (UGT) in its metabolism has not been extensively studied. In vitro metabolism studies support that the liver produced Tacro-glucuronide (Tacro-G) while its formation was minimal or undetectable in the presence of intestine and kidney microsomes. Among 16 human UGTs tested, UGT1A4 was the sole enzyme involved in Tacro-G formation. This conclusion is supported by the finding of inhibition with a specific substrate of UGT1A4 lamotrigine with K(i) values similar for both human liver and UGT1A4 microsomes and the correlation with trifluoperazine-glucuronide formation by liver microsomes (r(s) = 0.551; p = 0.02). Formation of Tacro-G by liver samples varied among individuals (6.4-fold variation; n = 16), and common nonsynonymous variants may contribute to this variability. In the human embryonic kidney 293 cellular model, no significant differences in enzyme kinetics could be revealed for UGT1A4*2 (P(24)T) and *3 (L(48)V), whereas the allozyme *4 (R(11)W) displayed a 2-fold higher velocity (p < 0.01) compared with the UGT1A4*1 enzyme preparation. In human liver samples, carriers of the UGT1A4 variants did not display statistically different efficiency in Tacro-G formation compared with homozygote for the reference genotype UGT1A4*1/*1. We conclude that UGT1A4 is the major isoform involved in Tacro glucuronidation, whereas additional studies are required to assess the contribution of UGT1A4 genetic factors in tacrolimus glucuronidation variability.

The risk of severe irinotecan-induced neutropenia has been shown to be related to the UGT1 variant UGT1A1*28, which increases exposure to the potent metabolite SN-38. Our goal was to identify a novel UGT1 marker(s) using 28 haplotype-tagged single nucleotide polymorphisms genotyped by mass spectrometry. By characterizing the UGT1 sequence from a cohort of 167 Canadian metastatic colorectal cancer (mCRC) patients and a validation cohort of 250 Italian mCRC patients, we found rs11563250G, located in the intergenic region downstream of UGT1, to be significantly associated with reduced risk of severe neutropenia (odds ratio (OR)=0.21; P=0.043 and OR=0.27; P=0.036, respectively, and OR=0.31 when combined; P=0.001), which remained significant upon correction for multiple testing in the combined cohort (P=0.041). For the two-marker haplotype rs11563250G and UGT1A1*1 (rs8175347 TA6), the OR was of 0.17 (P=0.0004). Genetic testing of this marker may identify patients who might benefit from increased irinotecan dosing.

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.

Purpose: Reliable biomarkers that predict prostate cancer outcomes are urgently needed to improve and personalize treatment approaches. With this goal in mind, we individually and collectively appraised common genetic polymorphisms related to estradiol metabolic pathways to find prostate cancer prognostic markers. Methods: The genetic profiles of 526 men with organ-confined prostate cancer were examined to find common genetic polymorphisms related to estradiol metabolic pathways and these findings were replicated in a cohort of 213 men with more advanced disease (follow-up time for both cohorts, >7.4 years). Specifically, we examined 71 single-nucleotide polymorphisms (SNP) in SULT2A1, SULT2B1, CYP1B1, COMT, CYP3A4, CYP3A5, CYP3A43, NQO1, and NQO2 and assessed the impact of the SNPs alone and in combination on prostate cancer progression and on circulating hormone levels. Results: According to a multivariate analysis, CYP1B1 (rs1800440), COMT (rs16982844), and SULT2B1 (rs12460535, rs2665582, rs10426628) were significantly associated with prostate cancer progression and hormone levels. Remarkably, by combining the SNP information with previously identified HSD17B2 markers, the patients could be stratified into four distinct prognostic subgroups. The most prominent association was observed for the eight-marker combination [CYP1B1 (rs1800440), SULT2B1 (rs12460535, rs2665582, and rs10426628), and HSD17B2 (rs4243229, rs1364287, rs2955162, and rs1119933)]. Conclusion: This study identified specific germline variations in estradiol metabolism–related pathways, namely CYP1B1, SULT2B1, and HSD17B2, as novel prognostic markers that are cumulatively associated with increased risk of prostate cancer progression. This panel of markers warrants additional investigation and validation to help stratify patients according to their risk of progression. Clin Cancer Res; 20(11); 2971–83. ©2014 AACR.

Recent evidence indicates that microRNAs might participate in prostate cancer initiation, progression and treatment response. Germline variations in microRNAs might alter target gene expression and modify the efficacy of prostate cancer therapy. To determine whether genetic variants in microRNAs and microRNA target sites are associated with the risk of biochemical recurrence (BCR) after radical prostatectomy (RP). We retrospectively studied two independent cohorts composed of 320 Asian and 526 Caucasian men with pathologically organ-confined prostate cancer who had a median follow-up of 54.7 and 88.8 months after RP, respectively. Patients were systematically genotyped for 64 single-nucleotide polymorphisms (SNPs) in microRNAs and microRNA target sites, and their prognostic significance on BCR was assessed by Kaplan-Meier analysis and Cox regression model. After adjusting for known clinicopathologic risk factors, two SNPs (MIR605 rs2043556 and CDON rs3737336) remained associated with BCR. The numbers of risk alleles showed a cumulative effect on BCR [perallele hazard ratio (HR) 1.60, 95% confidence interval (CI) 1.16-2.21, p for trend = 0.005] in Asian cohort, and the risk was replicated in Caucasian cohort (HR 1.55, 95% CI 1.15-2.08, p for trend = 0.004) and in combined analysis (HR 1.57, 95% CI 1.26-1.96, p for trend0.001). Results warrant replication in larger cohorts. This is the first study demonstrating that SNPs in microRNAs and microRNA target sites can be predictive biomarkers for BCR after RP.

The involvement of the complement pathway in cancer is supported by a growing body of evidence, and yet its role in acute myeloid leukemia (AML) has not been extensively studied. We examined the expression of 87 genes in the complement, coagulation, and fibrinolysis-proteolytic pathways in 374 cytogenetically normal AML samples and observed that these samples can be divided into subgroups on the basis of complement gene expression. Three complement regulatory genes were linked to poor outcome as individual factors in a multivariate analysis (CFH, CFD, and SERPING1) in multiple cohorts. The combined expression of these genes was significantly associated with poorer overall survival in two cohorts of patients60 years of age, independent of other factors (p ≤ 0.0004). For patients with an intermediate molecular risk, this three-gene risk marker enabled stratification of patients into prognostic subgroups with survival ranging from 17.4% to 44.1%. Thus, the expression of complement pathway genes is linked to outcome in AML, and a three-gene risk marker may improve the risk assessment of patients.

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. Clin Cancer Res; 19(3); 699–709. ©2012 AACR.

A liquid chromatography-tandem mass spectrometry method was developed for the quantification of circulating levels of multiple immunosuppressant drugs including cyclosporine (CsA), tacrolimus, methotrexate (Mtx), prednisone, prednisolone, methylprednisone, total and free mycophenolic acid (MPA), as well as MPA phenolic (MPAG) and acyl (AcMPAG) glucuronide metabolites. Linearity, precision and accuracy were validated within the typical therapeutic range of concentrations for each compound. The assay was linear over 0.125-25ng/mL for tacrolimus, 1-500ng/mL for prednisone/methylprednisone, 2-400ng/mL for Mtx, 2-1000ng/mL for prednisolone and from 7.5 to 1500ng/mL for CsA with the lowest limit of quantification (LLOQ) being 0.125, 1.00, 2.00, 2.00 and 7.5ng/mL, respectively. The calibration curve concentrations for MPA and MPAG ranged from 50 to 50,000ng/mL (LLOQ: 50ng/mL) and 10 to 10,000ng/mL (LLOQ: 10ng/mL) for AcMPAG. Mean recoveries in blood and plasma were 84%±5.7%. The method could measure individual drugs with high sensitivity, accuracy (bias≤14%), and reproducibility (CV≤12.8%). Its clinical application was validated by measuring levels of these drugs in samples obtained from hematopoietic stem cell transplant recipients treated with combined immunosuppressive drug therapy. Our results indicate that this approach is suitable for simultaneous determination of in vivo levels of immunosuppressive drugs commonly used in combined therapies.

BACKGROUND AND AIMS: UGT2B4 is a member of the UDP-glucuronosyltransferase (UGT) superfamily, a major detoxifying system in humans. UGT2B4 is involved in bile acids metabolism and highly expressed in liver and extrahepatic tissues. The aim of this study was to uncover new molecular mechanisms underlying interindividual variability in the UGT2B4 pathway. METHODS: We carried out a comprehensive scan for additional exons at this locus and discovered multiple alternative splicing events. We then assessed the expression profile of alternatively spliced transcripts in human tissues and the activity of the corresponding overexpressed proteins toward bile acids. RESULTS: We discovered three previously unidentified UGT2B4 exons, increasing the total known gene length to 46 kb. Molecular analyses revealed at least eight distinct mRNAs produced by (i) alternative promoter usage, (ii) complete and partial exon skipping, and (iii) use of alternative 3' splice sites. These splice variants were predominantly expressed in liver, gastrointestinal tract, and other extrahepatic tissues. Quantitative analyses of splicing events further sustain their prevalence in the liver. UGT2B4 proteins produced from these mRNA variants had undetectable transferase activity in human cells. However, when stably co-expressed with the active UGT2B4 isoform 1, three newly identified UGT2B4 isoforms (i2, i3, and i5) were found to negatively regulate glucuronidation. CONCLUSION: In addition to heritable genetic mutations and control of gene expression, the newly discovered diversity of UGT2B4 mRNAs may introduce variability in this glucuronidation pathway.

Current therapies for acute myeloid leukemia (AML) are able to achieve complete remission in 80-85% of patients; however large portions of these cases relapse. The 5-year survival rate is estimated at 30%. Thus, the development of more efficient approaches to treat AML is absolutely needed. Similarly to normal hematopoiesis, leukemias are organized as cellular hierarchies supported by leukemic stem cells (LSCs). LSCs are relatively resistant to chemotherapy and may act as a cancer cell reservoir that leads to relapse. The discovery of therapeutics that can eradicate these cells is essential to achieve complete patient recovery. We hypothesize that by using an in silico strategy and stem cell gene expression data we can identify bioactive compounds that target LSCs with minimal impact on normal hematopoietic stem cell (HSC) function. We had previously generated human LSC and HSC expression signatures from 16 primary AML and 4 independent pooled cord blood samples that were prognostic for patient survival (Eppert et al Nat Med 2011). By interrogating existing gene expression profiles of drug response with our LSC and HSC signatures, as well as additional novel signatures, we identified 92 molecules predicted to inhibit human LSC properties without harming HSCs. Nearly 60% of the positive hits were anti-infectives, psychotropics, hormones and steroids, anticancer or cardiovascular therapies. In support of the efficacy of this bioinformatic approach, we identified known chemotherapeutic agents such as azacitidine, daunorubicin and doxorubicin, although these were predicted to harm HSCs. We assessed the anti-LSC activity of one sub-group known to target a class of G-protein-coupled receptors (GPCR) to further validate the list of candidate compounds. Using a primary human AML sample (8227) with known LSC phenotype (CD34+), we tested 2 candidate anti-GPCR compounds (hits A and B) and observed that they were highly effective in targeting both bulk cells and LSCs. The IC50 for bulk cells was 3.4 µM and 4.2 µM for compounds A and B, respectively (A - 6 day treatment, B - 2 day treatment). The IC50 of the CD34+ cell fraction, which included stem and progenitor cells, was 5.9 µM and 4.1 µM, respectively. Thus, these compounds are effective at targeting both bulk and LSC-enriched AML cell populations. The efficacy of these predicted compounds against the primitive cells within the CD34+ population was assessed using colony formation assays on human AML. 8227 cells treated with compound B resulted in significantly fewer colonies compared to the DMSO control (3.8 ± 3.0 vs 13.3 ± 2.8; at 4.5 µM). To test whether our candidate compounds target leukemic cells and not normal blood cells, we examined 3 additional primary human AML samples and a cord blood sample. There was only a minor effect on normal cells, including stem and progenitor cells, but significant cell death in all leukemia samples (70% and more at ≥ 3 µM). Next, we will determine the effectiveness of our compounds in vivo using established xenografts of primary human AML samples and cord blood samples. In conclusion, using our in silico approach we successfully identified novel anti-LSC compounds that have efficacy in vitro with minimal toxicity on primary HSCs. Furthermore, as each predicted compound is associated with specific molecular pathways, our approach has improved our understanding of LSC biology by acting as a screen for LSC-related pathways. In the near future, we will continue investigating the 92 candidate compounds to identify, develop, and transition a novel anti-LSC compound into clinical use. Disclosures No relevant conflicts of interest to declare.

Therapy-resistant leukemic stem cells (LSCs) sustain acute myeloid leukemia (AML) and must be eliminated to cure a patient. However, there are no specific anti-LSC therapies, partially due to poor understanding of the unique molecular biology of these cells. Human LSCs share many properties with normal hematopoietic stem cells (HSCs), with similar gene expression profiles and molecular regulators. GPR56 is an adhesion class G-protein coupled receptor (GPCR) that has recently been implicated in the developmental origins of murine HSCs as well as regulating the function of adult murine HSCs, although this is controversial. Previous studies have observed that GPR56 is involved in cell adhesion, migration and differentiation in AML cell lines. Whether GPR56 is part of the molecular regulation of LSCs remains unknown. This study aims to establish whether GPR56 regulates the function of human LSCs and HSCs. To explore the role of GPR56 in human stem cells, we first investigated the cell-specific expression of GPR56 by qRT-PCR. GPR56 is highly expressed in primary human LSCs, normal blood HSCs, and normal progenitors but not in more mature populations in normal or leukemic blood. Next, to determine if GPR56 is clinically relevant in human disease, we examined GPR56 gene expression in three cohorts of cytogenetically normal AML samples (intermediate risk) and observed a positive correlation with poor outcome across all cohorts (GPR56 P We next examined the effect of full length GPR56 overexpression in normal HSC using xenograft assays to determine the functional role of GPR56 in human blood stem cells. Lineage negative cord blood cells transduced with GPR56 overexpression lentiviral vectors were injected into immune-deficient mice and the engraftment of human CD45+ cells was measured by flow cytometry after 12 weeks. In this in vivo analysis, over-expression of GPR56 increased the total engraftment of human cells in immune-deficient recipients compared to cells transduced with a control gene (hRluc, p This data suggests that GPR56 may regulate human blood stem cells, including LSCs, and that GPR56 expression may contribute to poor outcome in high prognostic risk subgroups of human acute myeloid leukemia through effects on leukemic stem cells. We are further exploring a functional role for GPR56 in the regulation of LSCs and HSCs using in vitro and in vivo assays in primary tissue. This will provide insight into the molecular regulation HSCs and LSCs and potentially explain the correlation between high levels of GPR56 and poor outcome in AML patients. Disclosures No relevant conflicts of interest to declare.