MSR1 Research Articles

Genomic and clinical characterization of a familial GIST kindred intolerant to imatinib

Familial gastrointestinal stromal tumors (GIST) are rare. We present a kindred with multiple family members affected with multifocal GIST who underwent whole genome sequencing of the germline and tumor. Affected individuals with GIST harbored a germline variant found within exon 13 of the KIT gene (c.1965T>G; p.Asn655Lys, p.N655K) and a variant in the MSR1 gene (c.877 C > T; p.Arg293*, pR293X). Multifocal GISTs in the proband and her mother were treated with preoperative imatinib, which resulted in severe intolerance. The clinical features of multifocal GIST, cutaneous mastocytosis, allergies, and gut motility disorders seen in the affected individuals may represent manifestations of the multifunctional roles of KIT in interstitial cells of Cajal or mast cells and/or may be suggestive of additional molecular pathways which can contribute to tumorigenesis.

MP40-03 CIRCULATING CHROMOSOME CONFORMATION SIGNATURES ENHANCE THE ACCURACY OF PSA FOR DETECTING PROSTATE CANCER - RESULTS FROM PERFORMANCE OF THE EPISWITCH TM PCA TEST IN THE PROSTAGRAM TRIAL

You have accessJournal of UrologyCME1 Apr 2023MP40-03 CIRCULATING CHROMOSOME CONFORMATION SIGNATURES ENHANCE THE ACCURACY OF PSA FOR DETECTING PROSTATE CANCER - RESULTS FROM PERFORMANCE OF THE EPISWITCHTM PCA TEST IN THE PROSTAGRAM TRIAL Jiten Jaipuria, Dmitri Pchejetski, David Eldred-Evans, Martin J Connor, Hashim U Ahmed, Alexandre Akoulitchev, Ewan Hunter, and Mathias Winkler Jiten JaipuriaJiten Jaipuria More articles by this author , Dmitri PchejetskiDmitri Pchejetski More articles by this author , David Eldred-EvansDavid Eldred-Evans More articles by this author , Martin J ConnorMartin J Connor More articles by this author , Hashim U AhmedHashim U Ahmed More articles by this author , Alexandre AkoulitchevAlexandre Akoulitchev More articles by this author , Ewan HunterEwan Hunter More articles by this author , and Mathias WinklerMathias Winkler More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003278.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PSA screening for prostate cancer (PCa) has a low overall accuracy despite high specificity. Novel blood biomarkers thus are prime candidates for improvement. 3-dimension chromatin conformations (CCCs) are known epigenetic regulators that manifest early in PCa tumorigenesis. EpiSwitch™ is a blood sample-based epigenetic assay developed by us which algorithmically analyses CCCs. We previously found diagnosed high-risk PCa associated with CCCSs in the loci of HSD3B2, VEGFC, APAF1, BMP6, ERG, MSR1, MUC1, ACAT1 and DAPK1 genes. Here, we evaluate the ability of EpiSwitch™ to detect PCa in a screening cohort of patients in the Prostagram trial. METHODS: We created a population cohort (n=147) of men, 50-69 years of age, comprising 109 volunteers participating in PCa screening in the Prostagram trial, and enriched it hospital tissue bank samples of 29 men with established localised PCa, and 9 cancer-negative controls. The cohort was then randomly split into training and testing groups in a 1:2 ratio. Samples were tested for PSA and the presence of CCCSs via the EpiSwitch™ assay. Batch adjustment by reference alignment procedure was used to control for batch effects. Feature engineering of the EpiSwitch™ markers with PSA was performed by recursive feature elimination using linear discriminant analysis, xgbtree, xgblinear, decision trees and random forest libraries in the R program. Shapley additive explanations values were used to quantify the contribution of each feature within the model. XGBoost algorithm model was used for final test optimisation and ultimately the EpiSwitch™PCa test was created. We compared combinations of - binary PSA threshold (>3 ng/ml), continuous PSA, and EpiSwitch™PCa-in terms of accuracy, positive (PPV) and negative predictive values (NPV) to determine PCa in the Prostagram cohort. RESULTS: ERG21 marker was discarded during the test optimisation to create the EpiSwitch™PCa assay. PSA>3ng/ml had a low PPV of 0.14 and a high NPV of 0.93 in the Prostagram cohort. Episwitch™PCa alone showed a PPV of 0.91 and NPV of 0.32. EpiSwitch™PCa combined with PSA>3ng/ml had a PPV of 0.81 and NPV of 0.78. However, EpiSwitch™PCa combined with continuous PSA yielded a remarkable PPV of 0.92, and NPV of 0.94, with an overall accuracy of 0.94. CONCLUSIONS: Combining the PSA test with specific CCCs in the blood has a potential for rapid PCa diagnosis with very high accuracy and low cost justifying further research in a prospective blinded cohort study. Source of Funding: Cost of the epigenetic assay was funded by Oxford biodynamics. Prostagram study was funded by the Wellcome trust. Data was analysed by Oxford biodynamics within the a priori statistical analysis plan of the Prostagram study. Analysis was performed with oversight of an independent academic statistician from the Prostagram study trial management group. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e545 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jiten Jaipuria More articles by this author Dmitri Pchejetski More articles by this author David Eldred-Evans More articles by this author Martin J Connor More articles by this author Hashim U Ahmed More articles by this author Alexandre Akoulitchev More articles by this author Ewan Hunter More articles by this author Mathias Winkler More articles by this author Expand All Advertisement PDF downloadLoading ...

Chromatin conformation changes in peripheral blood can detect prostate cancer and stratify disease risk groups

BackgroundCurrent diagnostic blood tests for prostate cancer (PCa) are unreliable for the early stage disease, resulting in numerous unnecessary prostate biopsies in men with benign disease and false reassurance of negative biopsies in men with PCa. Predicting the risk of PCa is pivotal for making an informed decision on treatment options as the 5-year survival rate in the low-risk group is more than 95% and most men would benefit from surveillance rather than active treatment. Three-dimensional genome architecture and chromosome structures undergo early changes during tumourigenesis both in tumour and in circulating cells and can serve as a disease biomarker.MethodsIn this prospective study we screened whole blood of newly diagnosed, treatment naïve PCa patients (n = 140) and cancer-free controls (n = 96) for the presence of 14,241 chromosomal loops in the loci of 425 genes.ResultsWe have detected specific chromosome conformation changes in the loci of ETS1, MAP3K14, SLC22A3 and CASP2 genes in peripheral blood from PCa patients yielding PCa detection with 80% sensitivity and 80% specificity. Further analysis between PCa risk groups yielded prognostic validation sets consisting of HSD3B2, VEGFC, APAF1, BMP6, ERG, MSR1, MUC1, ACAT1 and DAPK1 genes that achieved 80% sensitivity and 93% specificity stratifying high-risk category 3 vs low risk category 1 and 84% sensitivity and 89% specificity stratifying high risk category 3 vs intermediate risk category 2 disease.ConclusionsOur results demonstrate specific chromosome conformations in the blood of PCa patients that allow PCa diagnosis and risk stratification with high sensitivity and specificity.

Human serum albumin-based probes for molecular targeting of macrophage scavenger receptors.

Background: Inflammation and accumulation of macrophages are key features of unstable atherosclerotic plaques. The ability of macrophages to take up molecular probes can be exploited in new clinical imaging methods for the detection of unstable atherosclerotic lesions. We investigated whether modifications of human serum albumin (HSA) could be used to target macrophages efficiently in vitro.Materials and methods: Maleylated and aconitylated HSA were compared with unmodified HSA. Fluorescent or radiolabeled (89Zr) modified HSA was used in in vitro experiments to study cellular uptake by differentiated THP-1 cells and primary human macrophages. The time course of uptake was evaluated by flow cytometry, confocal microscopy, real-time microscopy and radioactivity measurements. The involvement of scavenger receptors (SR-A1, SR-B2, LOX-1) was assessed by knockdown experiments using RNA interference, by blocking experiments and by assays of competition by modified low-density lipoprotein.Results: Modified HSA was readily taken up by different macrophages. Uptake was mediated nonexclusively via the scavenger receptor SR-A1 (encoded by the MSR1 gene). Knockdown of CD36 and ORL1 had no influence on the uptake. Modified HSA was preferentially taken up by human macrophages compared with other vascular cell types such as endothelial cells and smooth muscle cells.Conclusions: Modified 89Zr-labeled HSA probes were recognized by different subsets of polarized macrophages, and maleylated HSA may be a promising radiotracer for radionuclide imaging of macrophage-rich inflammatory vascular diseases.

3582 Scavenger Receptor Expression is Differentially Affected by DNAzyme-Gold Nanoparticle Conjugates

OBJECTIVES/SPECIFIC AIMS: Scavenger receptor (SR) surface proteins are highly conserved motifs and are implicated in the uptake of nanotherapies. Gold nanoparticles functionalized with DNAzymes (DzNP) represent a promising novel nanotherapy for lung diseases such as asthma, particularly because they can be delivered directly to the lung. Our lab has been studying the therapeutic potential of a DzNP targeting GATA-3, a master transcription factor regulating Th2 inflammation. Although nanoparticle uptake through scavenger receptors has been described in macrophages in other models, the role of SRs in DzNP uptake in the lung is poorly understood. We hypothesize that scavenger receptors mediate DzNP uptake in alveolar macrophages. To begin examining this hypothesis, we examined whether DzNP exposure and uptake regulates gene expression of MARCO and MSR1, two class A scavenger receptors. METHODS/STUDY POPULATION: Using a silver stain, we measured dose dependent DzNP uptake in murine alveolar macrophages (MH-S). Using qRT-PCR, we measured gene expression of scavenger receptors MSR1 and MARCO in murine alveolar macrophages (MH-S) and after 24 hour exposure to 2251 DzNP, a DzNP targeting GATA-3, and dextran sulfate sodium (DSS), a known SR-A blocker. RESULTS/ANTICIPATED RESULTS: 2251 DzNP uptake in alveolar macrophages is dose dependent. MARCO gene expression levels significantly increase in murine alveolar macrophages when cultured with increasing concentrations of 2251 DzNP (10 pM-2 nM) or DSS 25-200 ug/ml) for 24 hours. However, MSR1 gene expression levels have minimal change when exposed to low concentrations of 2251 DzNP and DSS. At higher concentrations of 2251 DzNP and DSS, MSR1 expression levels are decreased. DISCUSSION/SIGNIFICANCE OF IMPACT: Alveolar macrophages exhibit a dose dependent increase in MARCO gene expression levels with increasing concentrations of 2251 DzNP and DSS, but MSR1 gene expression is not affected in a similar fashion. 2251 DzNP-induced increases in MARCO gene expression suggests that 2251 DzNP may facilitate its own uptake through MARCO. 2251 DzNP exposure negatively regulates MSR1 expression at higher doses and suggests that 2251 DzNP may inhibit its own uptake thought MSR1.

Abstract 1245: Identification of germline variants in cancer susceptibility genes in patients with hereditary breast and ovarian cancer syndrome by massive parallel sequencing in Argentinean population

Abstract Breast cancer is the most frequent cancer and ovarian cancer the seventh most frequent cancer among females worldwide, representing approximately 25% and 4% of all cancers. In Argentina, breast cancer and Ovarian cancer cause 6163 and 1332 deaths per year, respectively. Both breast and ovarian cancers are heterogeneous diseases composed of different tumor types with distinctive features and behaviors. The main risk factors for breast and ovarian cancer include age, family history, and genetics.The genetic components of both of the diseases have been well established, contributing to up to 10% of all breast cancer cases and 15% of all ovarian cancer cases.The two major susceptibility genes for both diseases are BRCA1 and BRCA2, and several other susceptibility genes have been identified. However, in the majority of high-risk breast and/or ovarian cancer (HBOC) families, the genetic predisposition factors remain unidentified, making the genetic counseling of these families challenging. The aim of the current study is to utilize an NGS approach to identify genetic factors that predispose individuals to hereditary breast and/or ovarian cancer (HBOC) in the high-risk Argentinian BRCA1/2 mutation-negative HBOC patients.16 patients were analyzed, the DNA was extracted from a blood samples and was subjected to a targeted massively parallel sequencing platform comprising 141 cancer predisposition genes. We detected in these patient 6 pathogenic variants in SBDS, FANCA, MC1R, WRN, MSR1 and SDHD genes. The effect of these variants are of type: non-synonymous (67%) and stop codon gains (33%). We also found 6 variants of uncertain significance (VUS) in APC, RAD50, SDHB, FANCD2, MLH1 and CDH1 genes.In conclusion, the identification of new variants could help to discover new genes associated to HBOC in the population of Argentina.These findings provide an excellent premise for further studies and could be utilized in the design of more efficient clinical management strategies for HBOC. Citation Format: Alejandra Franco, Fernando Orti, Sandra Perdomo, Cecilia Riggi, Cecilia Frecha, Javier Oliver. Identification of germline variants in cancer susceptibility genes in patients with hereditary breast and ovarian cancer syndrome by massive parallel sequencing in Argentinean population [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 1245.

Association between RNASEL, MSR1, and ELAC2 single nucleotide polymorphisms and gene expression in prostate cancer risk

BackgroundThere is contradictory evidence of the effects that environmental factors—dietary habits (ingestion rates of red meat, soy products, fish, etc.) and work environment (exposure to metals, pesticides, several toxic products, etc.)—and KLK3, AR, RNASEL, MSR1, and ELAC2 expression patterns have on prostate cancer (PCa). In our study, we investigated the potential association between KLK3, AR, RNASEL, MSR1, and ELAC2 polymorphisms, expression patterns, exposure to environmental factors, and PCa in a Spanish cohort. Blood and fresh tissue samples were collected from 322 subjects with prostate-specific antigen (PSA)>4ng/ml to determine their genotypes (RNASEL, MSR1, and ELAC2) and assess messenger ribonucleic acid expression levels (by quantitative amplification testing). Main findingsAmong clinical parameters, a 63.6% of patients with CC variants in rs11545302 (ELAC2) had PSA>20ng/ml (P = 0.008), and rs486907 (RNASEL), with 52.8% of patients with CT variants with Gleason score>7. Regarding TNM stage, patients with GG variants, rs4792311 (ELAC2) generally had stage 1 tumors. Genetic expression analysis revealed RNASEL (P = 0.007) was underexpressed in PCa tissue, whereas KLK3 (P = 0.041) was overexpressed. As to environmental factors, the intake of dried fruits (P = 0.036) and practice of sports (P = 0.024) revealed an effect in PCa. Moreover, environmental factors were observed to affect gene expression patterns. Thus, RNASEL (P = 0.018) and ELAC2 (P = 0.023) were found to be underexpressed in patients who ate processed foods frequently; MSR1 (P = 0.024) and AR (P = 0.004) were underexpressed in patients who did not practice sports; and KLK3 (P = 0.039; P = 0.046) underexpressed in patients exposed to dust and toxic products. ConclusionsThis is the first study to analyze the correlation between RNASEL, MSR1, and ELAC2 genotypes and messenger ribonucleic acid expression in PCa. RNASEL and KLK3 show different expression patterns in normal vs. tumor tissue, which supports their reported relevance in human cancer. The results obtained confirm that RNASEL plays a crucial role in PCa. Environmental factors such as exercise, exposure to toxic agents, and intake of processed foods are associated with PCa.

Determining the frequency of pathogenic germline variants from exome sequencing in patients with castrate-resistant prostate cancer

ObjectivesTo determine the frequency of pathogenic inherited mutations in 157 select genes from patients with metastatic castrate-resistant prostate cancer (mCRPC).DesignObservational.SettingMultisite US-based cohort.ParticipantsSeventy-one adult male patients with histological confirmation of prostate...

Role of TGFβ signaling in the pathogenesis of Alzheimer's disease.

Aging is the main risk factor for Alzheimer’s disease (AD); being associated with conspicuous changes on microglia activation. Aged microglia exhibit an increased expression of cytokines, exacerbated reactivity to various stimuli, oxidative stress, and reduced phagocytosis of β-amyloid (Aβ). Whereas normal inflammation is protective, it becomes dysregulated in the presence of a persistent stimulus, or in the context of an inflammatory environment, as observed in aging. Thus, neuroinflammation can be a self-perpetuating deleterious response, becoming a source of additional injury to host cells in neurodegenerative diseases. In aged individuals, although transforming growth factor β (TGFβ) is upregulated, its canonical Smad3 signaling is greatly reduced and neuroinflammation persists. This age-related Smad3 impairment reduces protective activation while facilitating cytotoxic activation of microglia through several cellular mechanisms, potentiating microglia-mediated neurodegeneration. Here, we critically discuss the role of TGFβ-Smad signaling on the cytotoxic activation of microglia and its relevance in the pathogenesis of AD. Other protective functions, such as phagocytosis, although observed in aged animals, are not further induced by inflammatory stimuli and TGFβ1. Analysis in silico revealed that increased expression of receptor scavenger receptor (SR)-A, involved in Aβ uptake and cell activation, by microglia exposed to TGFβ, through a Smad3-dependent mechanism could be mediated by transcriptional co-factors Smad2/3 over the MSR1 gene. We discuss that changes of TGFβ-mediated regulation could at least partially mediate age-associated microglia changes, and, together with other changes on inflammatory response, could result in the reduction of protective activation and the potentiation of cytotoxicity of microglia, resulting in the promotion of neurodegenerative diseases.

Prognostic role of genetic biomarkers in clinical progression of prostate cancer.

The aim of this study was to analyze the use of 12 single-nucleotide polymorphisms in genes ELAC2, RNASEL and MSR1 as biomarkers for prostate cancer (PCa) detection and progression, as well as perform a genetic classification of high-risk patients. A cohort of 451 men (235 patients and 216 controls) was studied. We calculated means of regression analysis using clinical values (stage, prostate-specific antigen, Gleason score and progression) in patients and controls at the basal stage and after a follow-up of 72 months. Significantly different allele frequencies between patients and controls were observed for rs1904577 and rs918 (MSR1 gene) and for rs17552022 and rs5030739 (ELAC2). We found evidence of increased risk for PCa in rs486907 and rs2127565 in variants AA and CC, respectively. In addition, rs627928 (TT–GT), rs486907 (AG) and rs3747531 (CG–CC) were associated with low tumor aggressiveness. Some had a weak linkage, such as rs1904577 and rs2127565, rs4792311 and rs17552022, and rs1904577 and rs918. Our study provides the proof-of-principle that some of the genetic variants (such as rs486907, rs627928 and rs2127565) in genes RNASEL, MSR1 and ELAC2 can be used as predictors of aggressiveness and progression of PCa. In the future, clinical use of these biomarkers, in combination with current ones, could potentially reduce the rate of unnecessary biopsies and specific treatments.

Genetic differences of prostate cancer between Eastern and Western population

Morbidity and mortality of prostate cancer vary widely between Eastern and Western population,which is mainly due to genetic factors.In order to further explore the different mechanisms of occurrence and development of prostate cancer,the prostate cancer susceptibility genes,such as RNASEL,ELAC2,PTEN,MSR1 and TMPRSS2-ERG are selected,and the genotype and allele distribution differences among Hispanic whites,African American,European,Chinese and Japanese are compared. Key words: Prostate neoplasms; Genetic predisposition to disease; Gene fusion

Abstract LB-331: Polymorphisms in inflammation pathway genes and endometrial cancer

Abstract Experimental and epidemiological evidence have suggested that chronic inflammation may play a critical role in endometrial carcinogenesis. To investigate this hypothesis, we carried out a two-stage study to evaluate single nucleotide polymorphisms (SNPs) in inflammatory pathway genes in association with endometrial cancer risk. In stage 1, 64 candidate pathway genes were identified and 4,542 directly genotyped or imputed SNPs were analyzed among 830 endometrial cancer cases and 2,322 controls using data from the Shanghai Endometrial Cancer Genetics Study. Linkage disequilibrium of stage 1 SNPs significantly associated with endometrial cancer (P<0.05) indicated that the majority of associations could be linked to one of 24 distinct loci. We then selected one SNP from each of the 24 loci for follow-up genotyping. Of these, 21 SNPs were successfully designed and genotyped in the stage 2 sample, which consisted of eight additional studies including 4,890 endometrial cancer cases and 5,403 controls. Four of the 21 SNPs in or near the FABP1, CXCL3, MSR1, and MMP9 genes were significantly associated with endometrial cancer in the combined data sets. The allelic odds ratios were 0.90 (0.82-0.97) for FABP1, 1.17 (1.05-1.31) for CXCL3, 0.86 (0.78-0.96) for MSR1, and 0.90 (0.85-0.95) for MMP9. The SNPs in CXCL3 and MMP9 were significantly associated with endometrial cancer in both the discovery and replication samples. Of these findings, the association for the MMP9 promoter polymorphism rs3918249 (P=0.00047) remained significant after adjustment for the total number of comparisons. These findings suggest that genetic polymorphisms in the MMP9 gene and possibly in or near the FABP1, CXCL3, and MSR1 genes may contribute to genetic susceptibility to endometrial cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-331. doi:1538-7445.AM2012-LB-331

A tumor suppressor function of the Msr1 gene in leukemia stem cells of chronic myeloid leukemia

AbstractWe have shown that Alox5 is a critical regulator of leukemia stem cells (LSCs) in a BCR-ABL–induced chronic myeloid leukemia (CML) mouse model, and we hypothesize that the Alox5 pathway represents a major molecular network that regulates LSC function. Therefore, we sought to dissect this pathway by comparing the gene expression profiles of wild type and Alox5−/− LSCs. DNA microarray analysis revealed a small group of candidate genes that exhibited changes in the levels of transcription in the absence of Alox5 expression. In particular, we noted that the expression of the Msr1 gene was upregulated in Alox5−/− LSCs, suggesting that Msr1 suppresses the proliferation of LSCs. Using CML mouse model, we show that Msr1 is downregulated by BCR-ABL and this down-regulation is partially restored by Alox5 deletion, and that Msr1 deletion causes acceleration of CML development. Moreover, Msr1 deletion markedly increases LSC function through its effects on cell cycle progression and apoptosis. We also show that Msr1 affects CML development by regulating the PI3K-AKT pathway and β-Catenin. Together, these results demonstrate that Msr1 suppresses LSCs and CML development. The enhancement of the tumor suppressor function of Msr1 may be of significance in the development of novel therapeutic strategies for CML.

The Tumor Suppressor Role of the Msr1 Gene in Cancer Stem Cells of Chronic Myeloid Leukemia.

Abstract 188We have previously shown that the arachidonate 5-lipoxygenase gene (Alox5) functions as a critical regulator of leukemia stem cells (LSCs) in BCR-ABL-induced chronic myeloid leukemia (CML) in mice (Chen Y, Hu Y, Zhang H, Peng C, Li S. Loss of the Alox5 gene impairs leukemia stem cells and prevents chronic myeloid leukemia. Nature Genetics 41:783-792, 2009). We believe that the Alox5 pathway represents a major molecular network in LSCs. Therefore, we decided to further dissect this pathway by comparing gene expression profiles between wild type and Alox5−/− LSCs from CML mice using the DNA microarray analysis. We identified a small group of candidate genes that were changed in expression in the absence of Alox5. Among these genes, we have identified the Msr1 gene and chosen to test the function of this gene in regulating LSC function, because this gene was up-regulated, indicating that it might play a tumor suppressor role in LSCs. In our CML mouse model, we observed that recipients of BCR-ABL transduced Msr1−/− bone marrow cells developed CML much rapidly than recipients of BCR-ABL transduced wide type bone marrow cells. To test whether this accelerated CML is related to abnormal function of LSCs, we carried out a serial transplantation assay by transferring bone marrow cells from primary recipients of BCR-ABL-transduced wild type or Msr1−/− donor bone marrow cells into secondary and next-generation of recipient mice to biologically assess the effect of Msr1 on LSCs. BCR-ABL-expressing wild type leukemia cells from bone marrow of CML mice were only able to transfer CML once, whereas BCR-ABL-expressing Msr1−/− leukemia cells were able to transfer lethal CML for five genrations. This observation indicates that BCR-ABL-expressing Msr1−/− LSCs have markedly increased stem cell function. To further compare the stem cell function, we performed the leukemia stem cell competition assay by 1:1 mixing wild type (CD45.1) and Msr1−/− (CD45.2) bone marrow cells from CML mice. At day 25 or 30 after transplantation, more than 60% and 95% of GFP+Gr-1+ cells in peripheral blood of the mice were CD45.2+Msr1−/− myeloid leukemia cells, and all these mice developed CML and died of CML derived from Msr1−/− LSCs. To confirm the tumor suppressor role of Msr1 in CML development, we co-expressed BCR-ABL and Msr1 in MSR1−/− bone marrow cells by retroviral transduction, followed by transplantation of these cells into recipient mice. The ectopically-expressed Msr1 in MSR1−/− bone marrow cells rescued the accelerated CML phenotype, and some recipient mice did not even develop the CML. Together, these results demonstrate that Msr1 plays a tumor suppressor role in LSCs. The Msr1 pathway is a novel molecular network in LSCs, and it will be important to fully study this pathway for developing curative therapeutic strategies for CML. Disclosures:No relevant conflicts of interest to declare.

Scavenger receptor A is expressed by macrophages in response to Porphyromonas gingivalis, and participates in TNF‐α expression

Porphyromonas gingivalis is a periodontopathic bacterium closely associated with generalized aggressive periodontal disease. Pattern recognition receptors (PRRs) participate in host response to this organism. It is likely that PRRs not previously recognized as part of the host response to P. gingivalis also participate in host response to this organism. Employing qRT-PCR, we observed increased msr1 gene expression at 2, 6, and 24 h of culture with P. gingivalis strain 381. Flow cytometry revealed increased surface expression of SR-A protein by the 24 h time point. Macrophages cultured with an attachment impaired P. gingivalis fimA- mutant (DPG3) expressed intermediate levels of SR-A expression. Heat-killed P. gingivalis stimulated SR-A expression similar to live bacteria, and purified P. gingivalis capsular polysaccharide stimulated macrophage SR-A expression, indicating that live whole organisms are not necessary for SR-A protein expression in macrophage response. As SR-A is known to play a role in lipid uptake by macrophages, we tested the ability of low-density lipoprotein (LDL) to influence the SR-A response of macrophages to P. gingivalis, and observed no effect of LDL on P. gingivalis-elicited SR-A expression. Lastly, we observed that SR-A knockout (SR-A(-/-)) mouse macrophages produced significantly more tumor necrosis factor (TNF)-alpha than wild type mouse macrophages cultured with P. gingivalis. These data identify that SR-A is expressed by macrophages in response to P. gingivalis, and support that this molecule plays a role in TNF-alpha production by macrophages to this organism.

N2 Variations in RNASEL, MSR1 and E-cadherin genes and prostate cancer in Poland

N2 Variations in RNASEL, MSR1 and E-cadherin genes and prostate cancer in Poland

Selected aspects of inherited susceptibility to prostate cancer and tumours of different site of origin

Epidemiologic research conducted over the last two decades has led us to believe that inherited factors play an important role in the aetiology of prostate cancer, but the genes which underlie the inherited susceptibility are elusive. The most compelling associations to date are with genes involved in DNA damage repair, including BRCA2. In Poland we have initiated a programme to identify DNA variants which confer an increased risk of prostate cancer and other cancers. Here we review our recent results. We found that germline mutations in BRCA1, CHEK2 and NBS1 confer an increased prostate cancer risk in Polish men. We provide evidence that CHEK2 is a multi-organ cancer susceptibility gene. We show that inherited variation in RNASEL and MSR1 genes do not contribute to prostate cancer development in Poland.

Meta-analysis of association of rare mutations and common sequence variants in theMSR1 gene and prostate cancer risk

MSR1 has been reported to be associated with increased risk of prostate cancer (PCa). We performed a meta-analysis of all eight published studies to evaluate the pooled effect of three rare mutations (R293X, S41T, and D174Y) and five common sequence variants (PRO3, INDEL1, IVS5-59, P275A, and INDEL7), stratified by race and sporadic/hereditary cancer. Several variants were significantly or marginally significantly associated with sporadic, not hereditary PCa risk, including R293X in white men (random effect OR = 1.34, P = 0.09) and D174Y in black men (random effect OR = 2.41, P = 0.04). The associations were not significant when the initial study was excluded. However, the frequency of the D174Y mutation was consistently higher among cases in all three studies that examined black men. Overall, this meta-analysis suggests the MSR1 gene does not independently confer a major risk to PCa but may confer a moderate risk to PCa, especially in black men.

Systematic replication study of reported genetic associations in prostate cancer: Strong support for genetic variation in the androgen pathway

Association studies have become a common and popular method to identify genetic variants predisposing to complex diseases. Despite considerable efforts and initial promising findings, the field of prostate cancer genetics is characterized by inconclusive reports and no prostate cancer gene has yet been established. We performed a literature review and identified 79 different polymorphisms reported to influence prostate cancer risk. Of these, 46 were selected and tested for association in a large Swedish population-based case-control prostate cancer population. We observed significant (P < 0.05) confirmation for six polymorphisms located in five different genes. Three of them coded for key enzymes in the androgen biosynthesis and response pathway; the CAG repeat in the androgen receptor (AR) gene (P = 0.03), one SNP in the CYP17 gene (P = 0.04), two SNPs in the SRD5A2 gene (P = 0.02 and 0.02, respectively), a deletion of the GSTT1 gene (P = 0.006), and one SNP in the MSR1 gene, IVS5-59C > A, (P = 0.009). Notwithstanding the difficulties to replicate findings in genetic association studies, our results strongly support the importance of androgen pathway genes in prostate cancer etiology.

Prevalent mutations in prostate cancer

Quantitative and structural genetic alterations cause the development and progression of prostate cancer. A number of genes have been implicated in prostate cancer by genetic alterations and functional consequences of the genetic alterations. These include the ELAC2 (HPC2), MSR1, and RNASEL (HPC1) genes that have germline mutations in familial prostate cancer; AR, ATBF1, EPHB2 (ERK), KLF6, mitochondria DNA, p53, PTEN, and RAS that have somatic mutations in sporadic prostate cancer; AR, BRCA1, BRCA2, CHEK2 (RAD53), CYP17, CYP1B1, CYP3A4, GSTM1, GSTP1, GSTT1, PON1, SRD5A2, and VDR that have germline genetic variants associated with either hereditary and/or sporadic prostate cancer; and ANXA7 (ANX7), KLF5, NKX3-1 (NKX3.1), CDKN1B (p27), and MYC that have genomic copy number changes affecting gene function. More genes relevant to prostate cancer remain to be identified in each of these gene groups. For the genes that have been identified, most need additional genetic, functional, and/or biochemical examination. Identification and characterization of these genes will be a key step for improving the detection and treatment of prostate cancer.