Revised timeline and distribution of the earliest diverged human maternal lineages in southern Africa

The oldest extant human maternal lineages include mitochondrial haplogroups L0d and L0k found in the southern African click-speaking forager peoples broadly classified as Khoesan. Profiling these early mitochondrial lineages allows for better understanding of modern human evolution. In this study, we profile 77 new early-diverged complete mitochondrial genomes and sub-classify another 105 L0d/L0k individuals from southern Africa. We use this data to refine basal phylogenetic divergence, coalescence times and Khoesan prehistory. Our results confirm L0d as the earliest diverged lineage (∼172 kya, 95%CI: 149-199 kya), followed by L0k (∼159 kya, 95%CI: 136-183 kya) and a new lineage we name L0g (∼94 kya, 95%CI: 72-116 kya). We identify two new L0d1 subclades we name L0d1d and L0d1c4/L0d1e, and estimate L0d2 and L0d1 divergence at ∼93 kya (95%CI:76-112 kya). We concur the earliest emerging L0d1’2 sublineage L0d1b (∼49 kya, 95%CI:37-58 kya) is widely distributed across southern Africa. Concomitantly, we find the most recent sublineage L0d2a (∼17 kya, 95%CI:10-27 kya) to be equally common. While we agree that lineages L0d1c and L0k1a are restricted to contemporary inland Khoesan populations, our observed predominance of L0d2a and L0d1a in non-Khoesan populations suggests a once independent coastal Khoesan prehistory. The distribution of early-diverged human maternal lineages within contemporary southern Africans suggests a rich history of human existence prior to any archaeological evidence of migration into the region. For the first time, we provide a genetic-based evidence for significant modern human evolution in southern Africa at the time of the Last Glacial Maximum at between ∼21-17 kya, coinciding with the emergence of major lineages L0d1a, L0d2b, L0d2d and L0d2a

Next generation mapping reveals novel large genomic rearrangements in prostate cancer

Complex genomic rearrangements are common molecular events driving prostate carcinogenesis. Clinical significance, however, has yet to be fully elucidated. Detecting the full range and subtypes of large structural variants (SVs), greater than one kilobase in length, is challenging using clinically feasible next generation sequencing (NGS) technologies. Next generation mapping (NGM) is a new technology that allows for the interrogation of megabase length DNA molecules outside the detection range of single-base resolution NGS. In this study, we sought to determine the feasibility of using the Irys (Bionano Genomics Inc.) nanochannel NGM technology to generate whole genome maps of a primary prostate tumor and matched blood from a Gleason score 7 (4 + 3), ETS-fusion negative prostate cancer patient. With an effective mapped coverage of 35X and sequence coverage of 60X, and an estimated 43% tumor purity, we identified 85 large somatic structural rearrangements and 6,172 smaller somatic variants, respectively. The vast majority of the large SVs (89%), of which 73% are insertions, were not detectable ab initio using high-coverage short-read NGS. However, guided manual inspection of single NGS reads and de novo assembled scaffolds of NGM-derived candidate regions allowed for confirmation of 94% of these large SVs, with over a third impacting genes with oncogenic potential. From this single-patient study, the first cancer study to integrate NGS and NGM data, we hypothesise that there exists a novel spectrum of large genomic rearrangements in prostate cancer, that these large genomic rearrangements are likely early events in tumorigenesis, and they have potential to enhance taxonomy.This work was supported by Movember Australia and the Prostate Cancer Foundation Australia (PCFA) as part of the Movember Revolutionary Team Award (MRTA) to the Garvan Institute of Medical Research program on prostate cancer bone metastasis (ProMis to P.I.C. and V.M.H.) dedicated to establishing NGM for clinically relevant prostate cancer, and the Australian Prostate Cancer Research Centre NSW (APCRC-NSW). Participant recruitment and sampling was supported by the Cancer Association of South Africa (CANSA to M.S.R.B and V.M.H.). W.J. is supported by APCRC-NSW, E.K.F.C. and D.C.P. are partly supported by ProMis, P.I.C. is supported by Mrs Janice Gibson and the Ernest Heine Family Foundation, Australia, and V.M.H. is supported by the University of Sydney Foundation and Petre Foundation, Australia.www.impactjournals.com/oncotargetam2018School of Health Systems and Public Health (SHSPH

Effects of human TRIM5α polymorphisms on antiretroviral function and susceptibility to human immunodeficiency virus infection

AbstractTRIM5α acts on several retroviruses, including human immunodeficiency virus (HIV-1), to restrict cross-species transmission. Using natural history cohorts and tissue culture systems, we examined the effect of polymorphism in human TRIM5α on HIV-1 infection. In African Americans, the frequencies of two non-coding SNP variant alleles in exon 1 and intron 1 of TRIM5 were elevated in HIV-1-infected persons compared with uninfected subjects. By contrast, the frequency of the variant allele encoding TRIM5α 136Q was relatively elevated in uninfected individuals, suggesting a possible protective effect. TRIM5α 136Q protein exhibited slightly better anti-HIV-1 activity in tissue culture than the TRIM5α R136 protein. The 43Y variant of TRIM5α was less efficient than the H43 variant at restricting HIV-1 and murine leukemia virus infections in cultured cells. The ancestral TRIM5 haplotype specifying no observed variant alleles appeared to be protective against infection, and the corresponding wild-type protein partially restricted HIV-1 replication in vitro. A single logistic regression model with a permutation test indicated the global corrected P value of <0.05 for both SNPs and haplotypes. Thus, polymorphism in human TRIM5 may influence susceptibility to HIV-1 infection, a possibility that merits additional evaluation in independent cohorts

Spectrum of mitochondrial genomic variation and associated clinical presentation of prostate cancer in South African men

BACKGROUND : Prostate cancer incidence and mortality rates are significantly increased in African–American men, but limited studies have been performed within Sub–Saharan African populations. As mitochondria control energy metabolism and apoptosis we speculate that somatic mutations within mitochondrial genomes are candidate drivers of aggressive prostate carcinogenesis. METHODS : We used matched blood and prostate tissue samples from 87 South African men (77 with African ancestry) to perform deep sequencing of complete mitochondrial genomes. Clinical presentation was biased toward aggressive disease (Gleason score >7, 64%), and compared with men without prostate cancer either with or without benign prostatic hyperplasia. RESULTS : We identified 144 somatic mtDNA single nucleotide variants (SNVs), of which 80 were observed in 39 men presenting with aggressive disease. Both the number and frequency of somatic mtDNA SNVs were associated with higher pathological stage. CONCLUSIONS : Besides doubling the total number of somatic PCa-associated mitochondrial genome mutations identified to date, we associate mutational load with aggressive prostate cancer status in men of African ancestry.NIH R21- CA170081, Australian Prostate Cancer Research Centre NSW, the J. Craig Venter Institute, the Garvan Institute, the Petre Foundation, Australia, the Cancer Association of South Africa (CANSA).http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-0045hb201

Effective Project Management of a Pan-African Cancer Research Network : Men of African Descent and Carcinoma of the Prostate (MADCaP)

CITATION: Odiaka, E. 2018. Effective Project Management of a Pan-African Cancer Research Network : Men of African Descent and Carcinoma of the Prostate (MADCaP). Journal of Global Oncology, 4:1-12, doi:10.1200/JGO.18.00062.The original publication is available at https://ascopubs.orgPurpose Health research in low- and middle-income countries can generate novel scientific knowledge and improve clinical care, fostering population health improvements to prevent premature death. Project management is a critical part of the success of this research, applying knowledge, skills, tools, and techniques to accomplish required goals. Here, we describe the development and implementation of tools to support a multifaceted study of prostate cancer in Africa, focusing on building strategic and operational capacity. Methods Applying a learning organizational framework, we developed and implemented a project management toolkit (PMT) that includes a management process flowchart, a cyclical centerspecific schedule of activities, periodic reporting and communication, and center-specific monitoring and evaluation metrics. Results The PMT was successfully deployed during year one of the project with effective component implementation occurring through periodic cycles of dissemination and feedback to local center project managers. A specific evaluation was conducted 1 year after study initiation to obtain enrollment data, evaluate individual quality control management plans, and undertake risk log assessments and follow-up. Pilot data obtained identified areas in which centers required mentoring, strengthening, and capacity development. Strategies were implemented to improve project goals and operational capacity through local problem solving, conducting quality control checks and following compliancy with study aims. Moving forward, centers will perform quarterly evaluations and initiate strengthening measures as required. Conclusion The PMT has fostered the development of both strategic and operational capacity across project centers. Investment in project management resources is essential to ensuring high-quality, impactful health research in low- and middle-income countries.https://ascopubs.org/doi/abs/10.1200/JGO.18.00062Publisher's versio

CRISPR interference to evaluate modifiers of C9ORF72-mediated toxicity in FTD

Treatments for neurodegenerative disease, including Frontotemporal dementia (FTD) and Amyotrophic lateral sclerosis (ALS), remain rather limited, underscoring the need for greater mechanistic insight and disease-relevant models. Our ability to develop novel disease models of genetic risk factors, disease modifiers, and other FTD/ALS-relevant targets is impeded by the significant amount of time and capital required to develop conventional knockout and transgenic mice. To overcome these limitations, we have generated a novel CRISPRi interference (CRISPRi) knockin mouse. CRISPRi uses a catalytically dead form of Cas9, fused to a transcriptional repressor to knockdown protein expression, following the introduction of single guide RNA against the gene of interest. To validate the utility of this model we have selected the TAR DNA binding protein (TDP-43) splicing target, stathmin-2 (STMN2). STMN2 RNA is downregulated in FTD/ALS due to loss of TDP-43 activity and STMN2 loss is suggested to play a role in ALS pathogenesis. The involvement of STMN2 loss of function in FTD has yet to be determined. We find that STMN2 protein levels in familial FTD cases are significantly reduced compared to controls, supporting that STMN2 depletion may be involved in the pathogenesis of FTD. Here, we provide proof-of-concept that we can simultaneously knock down Stmn2 and express the expanded repeat in the Chromosome 9 open reading frame 72 (C9ORF72) gene, successfully replicating features of C9-associated pathology. Of interest, depletion of Stmn2 had no effect on expression or deposition of dipeptide repeat proteins (DPRs), but significantly decreased the number of phosphorylated Tdp-43 (pTdp-43) inclusions. We submit that our novel CRISPRi mouse provides a versatile and rapid method to silence gene expression in vivo and propose this model will be useful to understand gene function in isolation or in the context of other neurodegenerative disease models

Genetic aspects of HIV-1 risk in an African setting

Thesis (PhD (Pathology. Medical Virology))--Stellenbosch University, 2006.Host susceptibility to human immunodeficiency virus-1 (HIV-1) infection and disease progression to acquired immunodeficiency syndrome (AIDS) varies widely amongst individuals. This observation led to the identification of host genetic factors playing a vital role in HIV-1 pathogenesis. Previous studies mainly focusing on Caucasian-based populations have indicated possible associations between genetic variants and host susceptibility to HIV-1/AIDS. The limited studies performed on African-based populations have emphasised the need for extensive investigation of both previously reported and particularly novel genetic variants within the older and genetically diverse Sub-Saharan African populations. In this study, the case-control samples were represented by African individuals of Xhosa descent, all residing in the Western Cape Province of South Africa. This included 257 HIV-1 seropositive patients and 110 population-matched HIV-1 seronegative controls. Mutational screening was performed in a subset of individuals for the entire coding regions of the CC chemokine receptor 5 (CCR5) and CC chemokine receptor 2 (CCR2) genes, and the 3’ untranslated region of the CXC chemokine ligand (CXCL12) gene, as previously reported (Petersen, 2002). Further analysis of these genes in a larger study sample involved the genotyping of previously identified mutations and single nucleotide polymorphisms (SNPs), which forms part of the present study. In addition, mutational screening was performed for the entire coding region of the CXC chemokine receptor 4 (CXCR4) gene, partial coding region of the mannose binding lectin (MBL) gene, and the promoter regions of interleukin 4 (IL4), interleukin 10 (IL10) and the solute carrier 11A1 (SLC11A1) genes. This was followed by genotyping of SNPs occurring in CCR5, CCR2, CXCL12, MBL, IL4, IL10, CX3C chemokine receptor 1 (CX3CR1), CC chemokine ligand 5 (CCL5) and tumour necrosis factor alpha (TNFα) genes. Significant associations were observed with HIV-1 susceptibility in the Xhosa population of South Africa. These included the CCR5-2733A>G, CX3CR1V249I, IL10-819C>T and IL10-592C>A SNPs being associated with a reduced risk for HIV-1 infection, while the CCR5-2135C>T and SDF1-3’G>A (CXCL12-3’G>A) SNPs were associated with increased susceptibility to HIV-1 infection. Furthermore, certain haplotypes for IL4 and IL10 showed association with reduced risk for HIV-1 infection. This included the identification of a novel IL4 haplotype restricted to the HIV-1 seronegative control group. This study emphasises the importance of considering genetic diversity across all populations, as certain HIV-1/AIDS associations appear to be restricted to specific ethnic groups. These findings have also provided an understanding for further elucidating the functional roles of genetic variants in determining HIV-1/AIDS susceptibility. Ultimately, such genetic association studies will contribute to establishing HIV-1/AIDS risk profiles for African-based populations from pandemic-stricken Sub-Saharan Africa

The role of chemokine and chemokine receptor genes in genetic susceptibility to HIV infection in South Africa

Thesis (MSc)--Stellenbosch University, 2002.ENGLISH ABSTRACT: Please see fulltext for abstractAFRIKAANSE OPSOMMING: Sien asb volteks vir opsommin

Inflammatory Genetic Markers of Prostate Cancer Risk

cancer