We identified a rare causal variant in MTTP, c.1691T>C p.I564T (rs745447480) encoding microsomal triglyceride transfer protein (MTP) causing progressive non-alcoholic fatty liver disease with cirrhosis and hepatocellular carcinoma unrelated to metabolic syndrome, without manifestations of abetalipoproteinemia, in a four generation family with South Asian ancestry. Variant-expressing hepatocyte-like-cells (HLCs) derived from human induced pluripotent stem cells generated from homozygous donor skin fibroblasts had lower lipoprotein ApoB secretion, compared to wild type cells. Cytoplasmic triglyceride accumulation in HLCs triggered endoplasmic reticulum stress, secretion of pro-inflammatory mediators, production of reactive oxygen species, delineating the progression of disease associated with homozygosity for MTTP p.I564T
For the cohort of 59 samples, we performed TruSeq DNA PCR-Free whole-genome sequencing library preparation according to manufacturer’s instructions (llumina, ILMN, San Diego, CA) on the automated NGS Star liquid handling platform (Hamilton, Bonaduz, Switzerland) followed by 2x150 bp paired-end sequencing on the HiSeqX or NovaSeq6000 (ILMN). An average coverage of >100x was achieved. For whole transcriptome analysis, the TruSeq Total Stranded RNA kit was used, starting with 250 ng of total RNA, to generate RNA libraries following the manufacturer’s recommendations (ILMN). 2x100bp paired-end reads were sequenced on the NovaSeq 6000 with a median of 50 mio. reads per sample (ILMN).
Multiple signatures of somatic mutations have been identified in human cancer genomes. To investigate whether mutational signatures continue to be generated, and if so their temporal patterns of activity, subsets of cell lines were cultured in vitro for extended periods and subjected to single cell cloning and whole genome or exome sequencing or directly to single cell whole genome sequencing. As expected, signatures of past exogenous exposures, such as tobacco smoke and ultraviolet light, were not generated in vitro. In contrast, signatures of normal and defective DNA repair and replication continued to be generated at essentially constant mutation rates. Signatures of APOBEC cytidine deaminase DNA-editing activity exhibited a distinctive pattern with substantial fluctuations in mutation rate over time and episodic bursts of mutations. The initiating factors for these bursts are unclear although retrotransposon mobilisation may play a role. This cell line set now constitutes a comprehensive resource of live experimental models of mutational processes of both known and unknown aetiologies potentially retaining the patterns of activity and regulatory influences operative in human cells in vivo.
Each tumor sample was cut into three pieces, yielding two end-pieces for cryovials and a middle portion placed in 10% buffered formalin. End pieces were homogenized manually and with a paddle blender (Stomacher). All paraffin-embedded blocks, including formalin-fixed tumor samples and molecular-fixed fallopian tubes, were sectioned and stained with hematoxylin and eosin prior to expert histopathological review to confirm the presence of high grade serous carcinoma. Homogenized end pieces were then flash frozen, and RNA was extracted using the miRNeasy Mini kit. Nanodrop was used to assess quality (260/280) and quantity. Total RNA samples were also QC checked using the Caliper HT RNA HiSens assay. Samples ranging from 60-255ng RNA were re-arrayed into a 96-well plate. 5'-RACE PCR was carried out as described in "The interface of malignant and immunologic clonal dynamics in high-grade serous ovarian cancer" (Zhang et al.). Briefly, this involved first round and nested PCR with TRB (TCR beta chain) and IGH (immunoglobulin heavy chain) gene-specific primers. The indexed libraries were sequenced on the Illumina HiSeq platform with paired-end 250bp reads using v2 chemistry reagents.
Obesity poses risks to maternal health and increases the likelihood of short- and long-term adverse pregnancy outcomes in the offspring. The placenta, a key organ at the maternal-fetal interface, responds to maternal obesity and regulates fetal growth. To investigate the molecular features of physiological adaptation, we perform single-nuclei RNA-seq on human placentas and compared the transcriptomic profiles of women with obesity delivering appropriate- or large-for-gestational age (i.e., AGA and LGA) babies with those from normal-weight healthy controls with AGA babies. The snRNA-seq libraries were generated with Chromium Single Cell 3’ kit v3.1 (10X Genomics) and sequenced on Illumina NovaSeq 6000 at Novogene.
We recruited 1,521 women from the Old Order Amish (OOA) population of Lancaster County, Pennsylvania, with the primary goal of identifying genetic factors that influence mammographic density. All women were between the ages of 40 and 88 years, with a mean of 54 years. Additional study design details, including eligibility criteria, are described elsewhere (Douglas et al., 2008). The present-day OOA of Lancaster County are the descendants of approximately 550 individuals from central Western Europe who immigrated to the U.S. in the early eighteenth century. All living individuals derive from a single, 14-generation pedigree (Lee et al., 2010). Although the OOA are a genetically closed founder population, allele frequencies and LD profiles are remarkably similar between the OOA and U.S. participants in the International HapMap project (HapMap CEU) for common SNPs (MAF>/=5%) (Van Hout et al., 2010). We recently completed genome-wide linkage and association analyses of mammographic density, including dense and non-dense areas of the breast and the ratio of dense to total area of the breast. Summary-level data from our GWAS are available here and through the Marker of DEnsity (MODE) Consortium.
Choroid plexus carcinomas (CPCs) have dismal prognoses with limited clinical options. A lack of characterized cell lines has hindered the development of new treatment strategies. Here, we perform whole genome sequencing analyses of two cell lines established from CPCs. Whole genome sequencing (WGS),was performed in CCHE-45 and NGT131 cell lines. Both cell lines harbored pathogenic TP53 point mutations; CCHE-45 additionally displayed TP53 loss. Furthermore, alterations of the NOTCH and WNT pathways were also detected in both cell lines. Two protein-coding gene fusions, BZW2-URGCP, and CTTNBP2-ERBB4, mutations of two oncodrivers, GBP-4 and KRTAP-12-2, and several copy number alterations were observed in CCHE-45, but not NGT131. The discovered difference's importance and implications highlight the possible diversity of choroid plexus carcinoma and call for additional research to fully understand disease pathogenesis. Whole genome sequencing revealed that the two choroid plexus carcinoma cell lines shared TP53 mutations and other common pathway alterations and activation of NOTCH and WNT pathways. Noticeable differences were also observed. These cell lines can serve as valuable models to propose new treatments in these rare but deadly brain tumors.
To elucidate the timing and mechanism of the clonal expansion of somatic mutations in cancer-associated genes in the normal endometrium, we conducted target sequencing of 112 genes for 1,298 endometrial glands and matched blood samples from 36 women. By collecting endometrial glands from different parts of the endometrium, we showed that multiple glands with the same somatic mutations occupied substantial areas of the endometrium. The 112 genes are as follows: ABCC1, ACRC, ANK3, ARHGAP35, ARID1A, ARID5B, ATCAY, ATM, ATR, BARD1, BCOR, BRCA1, BRCA2, BRD4, BRIP1, CAMTA1, CDC23, CDYL, CFAP54, CHD4, CHEK1, CHEK2, CTCF, CTNNB1, CUX1, DGKA, DISP2, DYNC2H1, EMSY, FAAP24, FAM135B, FAM175A, FAM65C, FANCA, FANCB, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCL, FANCM, FAT1, FAT3, FBN2, FBXW7, FGFR2, FRG1, GPR50, HEATR1, HIST1H4B, HNRNPCL1, HOOK3, KIAA1109, KIF26A, KMT2B, KMT2C, KRAS, LAMA2, LRP1B, MLH1, MON2, MRE11A, MSH2, MSH6, MTOR, NBN, PALB2, PHEX, PIK3CA, PIK3R1, PLXNB2, PLXND1, PMS2, POLE, POLR3B, PPP2R1A, PTEN, PTPN13, RAD50, RAD51, RAD51B, RAD51C, RAD51D, RAD52, RAD54B, RAD54L, RICTOR, SACS, SIGLEC9, SLC19A1, SLX4, SPEG, STT3A, TAF1, TAF2, TAS2R31, TFAP2C, TNC, TONSL, TP53, TTC6, UBA7, VNN1, WT1, XIRP2, ZBED6, ZC3H13, ZFHX3, ZFHX4, ZMYM4.
Age-related loss of function in the human haematopoietic system is well documented, manifesting as reduced regenerative capacity, age-related cytopenias and immune dysfunction. However, the cellular and population level changes that underpin both this functional decline and the increased risk of clonal haematopoiesis and blood cancer in the elderly remain elusive. Here we performed whole genome sequencing on >3350 single haematopoietic stem cell / multipotent progenitors (HSC/MPP) derived colonies across 10 haematologically normal subjects aged 0 to 81. We found that HSC/MPPs accumulated 17 single nucleotide variants per year post birth and had a reduction in telomere length of 50bp per year throughout young adult life. We reconstructed phylogenies of the sampled HSC/MPPs to interrogate changes in clonal dynamics through life. Haematopoiesis in adults aged less than 65 was predominantly polyclonal, with few known driver mutations. In contrast, individuals aged over 75 displayed a profound change in clonal structure, with frequent clonal expansions, many unexplained by known driver mutations. The ratio of non-synonymous to synonymous mutations revealed widespread positive selection, estimating around 1000 driver mutations in the dataset (10-fold more than the number of known drivers). We identified novel genes ZNF318 and HIST2H3D as being under positive selection, despite not being enriched in myeloid malignancies. Our data show that HSC clonal dynamics is more complex than previously thought. One implication is that by old age, the majority of HSCs carry at least one of a number of largely undescribed driver mutations, which may underlie aspects of their functional decline.
This study seeks to find low frequency or rare genetic variants in genes carried by subjects from families with unexplained familial risk of head and neck cancer. Whole exome sequencing was used to identify genetic variation in head and neck cancer cases.
