24 research outputs found

    Prof. Alpheus Mabose Segone

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    Alterations in the epigenetic machinery associated with prostate cancer health disparities

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    DATA AVAILABILITY STATEMENT : Data used in this study were published by Jaratlerdsiri et al., 2022, and made accessible via the European Genome-Phenome Archive (EGA; https://ega-archive.org, accessed on 1 June 2022) under study accession EGAS00001006425 and dataset accession EGAD00001009067 (Southern African Prostate Cancer Study, SAPCS) and EGAD00001009066 (Garvan/St. Vincent’s Prostate Cancer Study).SUPPLEMENTARY MATERIALS : FIGURE S1: Optimal cluster number identification; FIGURE S2: Consensus heatmap for variant data overlapping epigenetic machinery genes based on results from ten multi-omics integrative clustering algorithms with the assigned cluster numbers of (A) k = 3 and (B) k = 8; FIGURE S3: Silhouette plot quantifying Sample Similarity based on results from ten multi-omics integrative clustering algorithms with the assigned cluster numbers of (A) k = 3 and (B) k = 8; FIGURE S4: Mutational burden in African- and European-derived tumors; FIGURE S5: Damaging variant mutational burden in African- and European-derived tumors; TABLE S1: Patient Summary or African and European Study participants; TABLE S2: SuperPaths and their associated pathways included in this Study for their relationship to epigenetic processes; TABLE S3: List of genes assigned to Epigenetic Process Group 1 (chromatin organization and regulation); TABLE S4: List of genes assigned to Epigenetic Process Group 2 (histone modifications); TABLE S5: List of genes assigned to Epigenetic Process Group 3 (DNA methylation); TABLE S6: List of genes assigned to Epigenetic Process Group 4 (RNA regulation); TABLE S7: List of genes assigned to Epigenetic Process Group 5 (epigenetic regulation of gene expression); TABLE S8: MOVICS clustering results; TABLE S9: Statistical Summary for tumor mutational burden (per Mb) based on all coding variants in epigenetic machinery genes in African- and European-derived tumors; TABLE S10: Statistical Summary for tumor mutational burden (per Mb) based only on damaging variants (as per functional impact prediction) in epigenetic machinery genes in African- and European-derived tumors; TABLE S11: Independent test of epigenetic cancer Subtype (ECS) and Small Somatic mutation to compare mutation frequency; TABLE S12: Independent test of epigenetic cancer Subtype (ECS) and Structural variation to compare Structural variation frequency; TABLE S13: Clinical Summary based on hierarchical clustering results, with epigenetic cancer Subtype (ECS) as the grouping variable; TABLE S14: Top features, posterior probability, and rank order for joint analysis of Small Somatic mutation, Somatic Structural variant, and Somatic copy number alteration data identified by iClusterBayes; TABLE S15: Clinical Summary based on hierarchical clustering results for Somatic copy number alteration data only, with epigenetic copy number cancer Subtype (EcnCS) as the grouping variable.African ancestry is a significant risk factor for aggressive prostate cancer (PCa), with southern African ethnicity conferring a nearly 3-fold increased global risk for associated mortality. It is well understood that epigenetic alterations drive PCa initiation and progression, coupled with somatic alterations in genes encoding epigenetic enzymes. However, differences in the somatic alterations in these genes in African- versus European-derived prostate tumors and how they may contribute to PCa health disparities has yet to be investigated, which forms the objective of this study. With current PCa care almost exclusively based on and tailored for men of European ancestry, the identification of African-specific novel PCa epigenetic cancer drivers (n = 18), including therapeutic potential (6/18), offers clinical significance with the possibility of improving healthcare approaches and health outcomes for men of African ancestry.Prostate cancer is driven by acquired genetic alterations, including those impacting the epigenetic machinery. With African ancestry as a significant risk factor for aggressive disease, we hypothesize that dysregulation among the roughly 656 epigenetic genes may contribute to prostate cancer health disparities. Investigating prostate tumor genomic data from 109 men of southern African and 56 men of European Australian ancestry, we found that African-derived tumors present with a longer tail of epigenetic driver gene candidates (72 versus 10). Biased towards African-specific drivers (63 versus 9 shared), many are novel to prostate cancer (18/63), including several putative therapeutic targets (CHD7, DPF3, POLR1B, SETD1B, UBTF, and VPS72). Through clustering of all variant types and copy number alterations, we describe two epigenetic PCa taxonomies capable of differentiating patients by ancestry and predicted clinical outcomes. We identified the top genes in African- and European-derived tumors representing a multifunctional “generic machinery”, the alteration of which may be instrumental in epigenetic dysregulation and prostate tumorigenesis. In conclusion, numerous somatic alterations in the epigenetic machinery drive prostate carcinogenesis, but African-derived tumors appear to achieve this state with greater diversity among such alterations. The greater novelty observed in African-derived tumors illustrates the significant clinical benefit to be derived from a much needed African-tailored approach to prostate cancer healthcare aimed at reducing prostate cancer health disparities.The US Congressionally Directed Medical Research Programs (CDMRP) Prostate Cancer Research Program (PCRP) Idea Development Award, the Health Equity Research Outcomes Integrity Consortium (HEROIC) Award, the National Health and Medical Research Council (NHMRC) of Australia Project Grant and Ideas Grants, a Cancer Association of South Africa (CANSA) Development Gran, the National Research Foundation of South Africa andthe Petre Foundation, Australia.https://www.mdpi.com/journal/cancershj2023School of Health Systems and Public Health (SHSPH

    Post-Vasectomy Semen Analysis: Optimizing Laboratory Procedures and Test Interpretation through a Clinical Audit and Global Survey of Practices

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    Purpose: The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice. Materials and methods: We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic's Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries. Results: Results from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA's. A large percentage reported to recommend a second PVSA due to the possibility of legal actions. Conclusions: Our results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy

    Genome-wide interrogation of structural variation reveals novel African-specific prostate cancer oncogenic drivers

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    ADDITIONAL FILE 1: FIGURE S1. Concordant SV call generation from Manta and GRIDSS. FIGURE S2. Summary of SVs in each type, compared to other studies. FIGURE S3. CIRCOS plot of hyper-SV mutated tumours. FIGURE S4. The spread of SV breakpoints and samples in each 1 Mbp genomic bin. FIGURE S5. TMPRSS2-ERG fusion with interstitial region retention. TABLE S1. Clinical and pathological characteristics of 180 prostate cancer patients included in this study. TABLE S2. Biallelic assessment of CDK12 in hyper-duplicated samples. TABLE S3. Biallelic assessment of BRCA2 in hyper-deleted samples.ADDITIONAL FILE 2: TABLE S4. Summary of gene fusions identified from SVs. ADDITIONAL FILE 3: TABLE S5. SV calls resulting in gene fusions.DATA AND MATERIALS AVAILABILITY : The datasets analysed in this study were obtained and accessible through Jaratlerdsiri et al [6], with sequence data deposited in the European GenomePhenome Archive (EGA; https://ega-archive.org) under overarching accession EGAS00001006425 and including the Southern African Prostate Cancer Study (SAPCS) Dataset (EGAD00001009067) and Garvan/St Vincent’s Prostate Cancer Database (EGAD00001009066). The computational code used to analyse SV subtypes, SV hotspots and gene fusions is available on GitHub [68].BACKGROUND : African ancestry is a significant risk factor for advanced prostate cancer (PCa). Mortality rates in sub- Saharan Africa are 2.5-fold greater than global averages. However, the region has largely been excluded from the benefits of whole genome interrogation studies. Additionally, while structural variation (SV) is highly prevalent, PCa genomic studies are still biased towards small variant interrogation. METHODS : Using whole genome sequencing and best practice workflows, we performed a comprehensive analysis of SVs for 180 (predominantly Gleason score ≄ 8) prostate tumours derived from 115 African, 61 European and four ancestrally admixed patients. We investigated the landscape and relationship of somatic SVs in driving ethnic disparity (African versus European), with a focus on African men from southern Africa. RESULTS : Duplication events showed the greatest ethnic disparity, with a 1.6- (relative frequency) to 2.5-fold (count) increase in African-derived tumours. Furthermore, we found duplication events to be associated with CDK12 inactivation and MYC copy number gain, and deletion events associated with SPOP mutation. Overall, African-derived tumours were 2-fold more likely to present with a hyper-SV subtype. In addition to hyper-duplication and deletion subtypes, we describe a new hyper-translocation subtype. While we confirm a lower TMPRSS2-ERG fusion-positive rate in tumours from African cases (10% versus 33%), novel African-specific PCa ETS family member and TMPRSS2 fusion partners were identified, including LINC01525, FBXO7, GTF3C2, NTNG1 and YPEL5. Notably, we found 74 somatic SV hotspots impacting 18 new candidate driver genes, with CADM2, LSAMP, PTPRD, PDE4D and PACRG having therapeutic implications for African patients. CONCLUSIONS : In this first African-inclusive SV study for high-risk PCa, we demonstrate the power of SV interrogation for the identification of novel subtypes, oncogenic drivers and therapeutic targets. Identifying a novel spectrum of SVs in tumours derived from African patients provides a mechanism that may contribute, at least in part, to the observed ethnic disparity in advanced PCa presentation in men of African ancestry.The Medical Health and Medical Research Council (NHMRC) of Australia, University of Sydney Bridging Grant, the USA. Department of Defense (DoD) Prostate Cancer Research Program (PCRP) Idea Development.https://genomemedicine.biomedcentral.comam2023School of Health Systems and Public Health (SHSPH

    African-specific molecular taxonomy of prostate cancer

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    Data availability DNA-sequencing data have been deposited at the European Genome- Phenome Archive (EGA) under overarching accession EGAS00001006425 and including the Southern African Prostate Cancer Study (SAPCS) Dataset (EGAD00001009067 and Garvan/St Vincent’s Prostate Cancer Database EGAD00001009066). Academic researchers meeting the data-access policy criteria may apply for data access through the respective data access committees. CPGEA data are available through http://www.cpgea.com. PCAWG data are available at ICGC Data Portal (https://dcc.icgc.org/releases/PCAWG).Prostate cancer is characterized by considerable geo-ethnic disparity. African ancestry is a significant risk factor, with mortality rates across sub-Saharan Africa of 2.7-fold higher than global averages. The contributing genetic and non-genetic factors, and associated mutational processes, are unknown. Here, through whole-genome sequencing of treatment-naive prostate cancer samples from 183 ancestrally (African versus European) and globally distinct patients, we generate a large cancer genomics resource for sub-Saharan Africa, identifying around 2 million somatic variants. Significant African-ancestry-specific findings include an elevated tumour mutational burden, increased percentage of genome alteration, a greater number of predicted damaging mutations and a higher total of mutational signatures, and the driver genes NCOA2, STK19, DDX11L1, PCAT1 and SETBP1. Examining all somatic mutational types, we describe a molecular taxonomy for prostate cancer differentiated by ancestry and defined as global mutational subtypes (GMS). By further including Chinese Asian data, we confirm that GMS-B (copy-number gain) and GMS-D (mutationally noisy) are specific to African populations, GMS-A (mutationally quiet) is universal (all ethnicities) and the African–European-restricted subtype GMS-C (copy-number losses) predicts poor clinical outcomes. In addition to the clinical benefit of including individuals of African ancestry, our GMS subtypes reveal different evolutionary trajectories and mutational processes suggesting that both common genetic and environmental factors contribute to the disparity between ethnicities. Analogous to gene–environment interaction—defined here as a different effect of an environmental surrounding in people with different ancestries or vice versa—we anticipate that GMS subtypes act as a proxy for intrinsic and extrinsic mutational processes in cancers, promoting global inclusion in landmark studies.The National Health and Medical Research Council (NHMRC) of Australia, NHMRC Ideas Grants, University of Sydney Bridging Grant, the US Department of Defense (DoD) Prostate Cancer Research Program (PCRP) Idea Development Award TARGET Africa.http://www.nature.com/natuream2023School of Health Systems and Public Health (SHSPH

    Post-vasectomy semen analysis: Optimizing laboratory procedures and test interpretation through a clinical audit and global survey of practices

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    Purpose: The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice. Materials and Methods: We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic’s Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries. Results: Results from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA’s. A large percentage reported to recommend a second PVSA due to the possibility of legal actions. Conclusions: Our results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy.American Center for Reproductive Medicin

    Does varicocele repair improve conventional semen parameters? A meta-analytic study of before-after data

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    Purpose The purpose of this meta-analysis is to study the impact of varicocele repair in the largest cohort of infertile males with clinical varicocele by including all available studies, with no language restrictions, comparing intra-person conventional semen parameters before and after the repair of varicoceles. Materials and Methods The meta-analysis was performed according to PRISMA-P and MOOSE guidelines. A systematic search was performed in Scopus, PubMed, Cochrane, and Embase databases. Eligible studies were selected according to the PICOS model (Population: infertile male patients with clinical varicocele; Intervention: varicocele repair; Comparison: intra-person before-after varicocele repair; Outcome: conventional semen parameters; Study type: randomized controlled trials [RCTs], observational and case-control studies). Results Out of 1,632 screened abstracts, 351 articles (23 RCTs, 292 observational, and 36 case-control studies) were included in the quantitative analysis. The before-and-after analysis showed significant improvements in all semen parameters after varicocele repair (except sperm vitality); semen volume: standardized mean difference (SMD) 0.203, 95% CI: 0.129–0.278; p<0.001; I2=83.62%, Egger’s p=0.3329; sperm concentration: SMD 1.590, 95% CI: 1.474–1.706; p<0.001; I2=97.86%, Egger’s p<0.0001; total sperm count: SMD 1.824, 95% CI: 1.526–2.121; p<0.001; I2=97.88%, Egger’s p=0.0063; total motile sperm count: SMD 1.643, 95% CI: 1.318–1.968; p<0.001; I2=98.65%, Egger’s p=0.0003; progressive sperm motility: SMD 1.845, 95% CI: 1.537%–2.153%; p<0.001; I2=98.97%, Egger’s p<0.0001; total sperm motility: SMD 1.613, 95% CI 1.467%–1.759%; p<0.001; l2=97.98%, Egger’s p<0.001; sperm morphology: SMD 1.066, 95% CI 0.992%–1.211%; p<0.001; I2=97.87%, Egger’s p=0.1864. Conclusions The current meta-analysis is the largest to date using paired analysis on varicocele patients. In the current meta-analysis, almost all conventional semen parameters improved significantly following varicocele repair in infertile patients with clinical varicocele. Keywords Controlled before-after studies; Infertility, male; Meta-analysis; Varicocel

    Prof Alpheus Mabose Segone

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    South African guidelines for receptor radioligand therapy (RLT) with Lu-177-PSMA in prostate cancer

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    BACKGROUND : Prostate cancer is an important cause of morbidity and mortality in South Africa, as it is in the rest of the world. In African men, however, prostate cancer tends to follow a more aggressive course when compared to their European counterparts. This is attributed to a plethora of diverse factors of which an underlying genetic component has been shown to be an important aspect. Such differences highlight the need for individualised therapy and for local guidelines. The aim of this guideline is to aid nuclear physicians and other clinicians who manage patients with prostate cancer in the correct identification and treatment of patients who are likely to benefit from receptor radioligand therapy. RECOMMENDATIONS : There are a multitude of treatment modalities available for the treatment of prostate cancer and these therapies may be required at various time points during the course of the disease in any individual patient. A multidisciplinary approach is crucial in deciding which therapy, or combination of therapies, would be most advantageous at particular time points. The multidisciplinary team should include a urologist, oncologist and nuclear medicine physician as a minimum, and should ideally also involve a palliative/pain specialist, a dietician and a psychologist. CONCLUSION : Treatment with 177Lu-PSMA has emerged as a promising systemic modality, which involves the delivery of targeted radiation therapy in the form of ÎČ-particles to sites of tumour tissue. Therapy is provided on an outpatient basis, is well tolerated with relatively few side effects and has a positive effect on overall survival and quality of life. At present, it is used mostly in the setting of advanced, castrate-resistant cancer. Patients are selected (amongst other criteria) based on the prior PSMA-based SPECT/PET/CT imaging (99mTc-,68Ga- or 18F-PSMA), which should demonstrate sufficient receptor expression in order to consider PSMA-based targeted radionuclide therapy. Such imaging of an intended target prior to its therapeutic targeting is known as a theranostic approach.http://sajs.redbricklibrary.com/index.php/sajsam2020Nuclear Medicin
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