Project description:<p>This study contains all authorized whole genome sequence data of the HeLa cell line from datasets currently in dbGaP. These data have been approved for health, medical, and/or biomedical research purposes. Access to these data can be granted for one year. Accessible data will include the studies listed on this page and any additional authorized datasets that become available during this one-year period.</p> <p><a href="http://acd.od.nih.gov/hlgda.htm">The HeLa Genome Data Access Working Group of the Advisory Committee to the Director (ACD)</a> will review requests from the research community for access to these datasets and assess whether the requests align with the terms of use defined in the HeLa Genome Data Use Agreement. The Working Group's findings will be reported to the ACD, and the ACD will make recommendations to the NIH Director about whether a request should be approved or disapproved. The NIH Director will decide whether access to the data will be granted.</p>
Project description:Reanalysis of three large human tissue proteomics datasets using a bespoke GENCODE database and multiOTHER algorithm high confidence pipeline.
Project description:The HeLa cell line was established in 1951 from cervical cancer cells taken from a patient, Henrietta Lacks. This was the first successful attempt to immortalize human-derived cells in vitro. The robust growth and unrestricted distribution of HeLa cells resulted in its broad adoption--both intentionally and through widespread cross-contamination--and for the past 60 years it has served a role analogous to that of a model organism. The cumulative impact of the HeLa cell line on research is demonstrated by its occurrence in more than 74,000 PubMed abstracts (approximately 0.3%). The genomic architecture of HeLa remains largely unexplored beyond its karyotype, partly because like many cancers, its extensive aneuploidy renders such analyses challenging. We carried out haplotype-resolved whole-genome sequencing of the HeLa CCL-2 strain, examined point- and indel-mutation variations, mapped copy-number variations and loss of heterozygosity regions, and phased variants across full chromosome arms. We also investigated variation and copy-number profiles for HeLa S3 and eight additional strains. We find that HeLa is relatively stable in terms of point variation, with few new mutations accumulating after early passaging. Haplotype resolution facilitated reconstruction of an amplified, highly rearranged region of chromosome 8q24.21 at which integration of the human papilloma virus type 18 (HPV-18) genome occurred and that is likely to be the event that initiated tumorigenesis. We combined these maps with RNA-seq and ENCODE Project data sets to phase the HeLa epigenome. This revealed strong, haplotype-specific activation of the proto-oncogene MYC by the integrated HPV-18 genome approximately 500 kilobases upstream, and enabled global analyses of the relationship between gene dosage and expression. These data provide an extensively phased, high-quality reference genome for past and future experiments relying on HeLa, and demonstrate the value of haplotype resolution for characterizing cancer genomes and epigenomes.
Project description:CRISPR screening is a powerful tool to identify host factors for pathogenic agents including viruses and bacterial toxins. Here, we present a protocol to conduct a genome-scale CRISPR screen on HeLa cells for host factors involved in the toxin action of Clostridioides difficile TcdB4. We describe in detail how to prepare the library, set up the screen, obtain the gene sequences, and analyze the results. This protocol can also be modified for other genome-scale libraries, cell lines, and cytotoxins. For complete details on the use and execution of this protocol, please refer to Luo et al. (2022).
Project description:The HeLa cell line is one of the most popular cell lines in biomedical research, despite its well-known chromosomal instability. We compared the genomic and transcriptomic profiles of 4 different HeLa batches and showed that the gain and loss of genomic material varies widely between batches, drastically affecting basal gene expression. Moreover, different pathways were activated in response to a hypoxic stimulus. Our study emphasizes the large genomic and transcriptomic variability among different batches, to the point that the same experiment performed with different batches can lead to distinct conclusions and irreproducible results. The HeLa cell line is thought to be a unique cell line but it is clear that substantial differences between the primary tumour and the human genome exist and that an indeterminate number of HeLa cell lines may exist, each with a unique genomic profile.
Project description:Sphingolipids are essential components in eukaryotes and have various cellular functions. Recent developments in genome-editing technologies have facilitated gene disruption in various organisms and cell lines. We here show the disruption of various sphingolipid metabolic genes in human cervical carcinoma HeLa cells by using transcription activator-like effector nucleases (TALENs). A TALEN pair targeting the human CERT gene (alternative name COL4A3BP) encoding a ceramide transport protein induced a loss-of-function phenotype in more than 60% of HeLa cells even though the cell line has a pseudo-triploid karyotype. We have isolated several loss-of-function mutant clones for CERT, UGCG (encoding glucosylceramide synthase), and B4GalT5 (encoding the major lactosylceramide synthase), and also a CERT/UGCG double-deficient clone. Characterization of these clones supported previous proposals that CERT primarily contributes to the synthesis of SM but not GlcCer, and that B4GalT5 is the major LacCer synthase. These newly established sphingolipid-deficient HeLa cell mutants together with our previously established stable transfectants provide a 'sphingolipid-modified HeLa cell panel,' which will be useful to elucidate the functions of various sphingolipid species against essentially the same genomic background.
Project description:Closing gaps in draft genome assemblies can be costly and time-consuming, and published genomes are therefore often left 'unfinished.' Here we show that genome-wide chromosome conformation capture (3C) data can be used to overcome these limitations, and present a computational approach rooted in polymer physics that determines the most likely genome structure using chromosomal contact data. This algorithm--named GRAAL--generates high-quality assemblies of genomes in which repeated and duplicated regions are accurately represented and offers a direct probabilistic interpretation of the computed structures. We first validated GRAAL on the reference genome of Saccharomyces cerevisiae, as well as other yeast isolates, where GRAAL recovered both known and unknown complex chromosomal structural variations. We then applied GRAAL to the finishing of the assembly of Trichoderma reesei and obtained a number of contigs congruent with the know karyotype of this species. Finally, we showed that GRAAL can accurately reconstruct human chromosomes from either fragments generated in silico or contigs obtained from de novo assembly. In all these applications, GRAAL compared favourably to recently published programmes implementing related approaches.
Project description:Exiqon miRNA array contains LNA-modified oligos which minimizes the Tm-range within which probe hybridizes with the transcript in query, thus minimizing the mis-match. Taking advantage of this, we used the miRCURY LNA array to investigate genome wide signatures for miRNA expression in response to heat shock stress. We also did mRNA expression profiling using the same RNA to look for possible miRNA-mRNA interaction in response to heat shock stress. For the differentially expressed miRNAs, target predictions were done using both miRanda and TargetScan. The consensus set was used for subsequent experimental validation.
Project description:Human LATS1 and LATS2 (LATS1/2) are tumor suppressors that have been shown to be mutated or downregulated in several human cancers including leukemia, lung, prostate and breast cancers. However, the precise mechanisms and the proteins modulated by LATS1/2 that are responsible for these events remain largely unknown. To elucidate potential signaling pathways, the current study investigated the expression profile in HeLa cells with reduced expression of LATS1/2. Using RNA-mediated intereference, both LATS1 and LATS2 were substantially knocked-down, and accordingly, this lead to an increase in multiple phenotypes associated with tumor progression, including enhanced cell proliferation, resistance to drug-induced cell death, and increase cell migration. Using whole human genome oligo (60-mer) arrays (Agilent), gene modulated by loss of LATS1/2 were identified and functionally grouped into categories including cell proliferation, cell death, cell adhesion and motility, as well as cell communication. Selected genes, including known tumor suppressor genes and oncogenes such as CDKN1A, WISP2, SLIT2, TP53INP1, BIRC4BP, SPRY2, SPRY4, SPRED1, FAT4,and CYR61 were confirmed by qRT-PCR to be significantly differentially expressed. Importantly, the collection of genes identified suggests that LATS1/2 functions through diverse mechanisms and multiple signaling pathways including the Hippo signaling pathway, as well as the p53, Ras-ERK, or WNT networks, in inhibit tumor progression.