Project description:The mechanism by which rs6983267 at 8q24.21 increases cancer risk is unclear for the lack of protein?coding genes in the region although the variant is strongly associated with cancer pathogenesis. Here we identify long non-coding RNAs (lncRNAs) near the 8q24 region and show that expression of lncRNA CARLo-5 is significantly correlated with the risk allele of the cancer-associated variant rs6883267. We further report that the 8q24 enhancer region including the variant directly interacts with active regulatory region of the lncRNA CARLo-5 promtoer. Finally, we demonstrate that CARLo-5 has an oncogenic function by regulating cell proliferation and cell-cycle. Our data provide new insight of disease-related variants in a gene desert. Comparison and identification of cell cycle-related genes differentially expressed by CARLo-5 knockdown using Nanostring analysis in HCT116 cells.
Project description:The mechanism by which rs6983267 at 8q24.21 increases cancer risk is unclear for the lack of protein?coding genes in the region although the variant is strongly associated with cancer pathogenesis. Here we identify long non-coding RNAs (lncRNAs) near the 8q24 region and show that expression of lncRNA CARLo-5 is significantly correlated with the risk allele of the cancer-associated variant rs6883267. We further report that the 8q24 enhancer region including the variant directly interacts with active regulatory region of the lncRNA CARLo-5 promtoer. Finally, we demonstrate that CARLo-5 has an oncogenic function by regulating cell proliferation and cell-cycle. Our data provide new insight of disease-related variants in a gene desert.
Project description:Chromosome instability is a key event in cancer progression. The essential histone H3 variant CENP-A plays a fundamental role in defining centromere identity, structure, and function, but is innately overexpressed in several types of solid cancers. In the cancer background, excess CENP-A is deposited ectopically on chromosome arms, including at the 8q24/cMYC locus, by invading transcription-coupled H3.3 chaperone pathways. Intriguingly, in many cancers, transcription of lncRNAs is upregulated and correlates with poor prognosis, therapeutic resistance, and cancer recurrence in patients. Here, we report that the transcription of chromosome 8q24-derived oncogenic lncRNAs plays an unanticipated role in altering the chromatin landscape of the 8q24 locus. We report that transcription of oncogenic ncRNAs and associated R-loop formation at the 8q24 genomic locus results in the recruitment of H3.3 chaperone-CENP-A histone variant complexes to 8q24. Finally, we demonstrate that a transgene cassette which encodes a specific oncogenic lncRNA from the 8q24 region integrated into a naïve chromosome locus, recruits CENP-A to the new location specifically in a cis-acting manner. These data provide a plausible mechanistic link between locus-specific oncogenic lncRNAs, aberrant local chromatin structure, and the generation of new epigenetic memory in human cancer cells.
Project description:Chromosome instability is a key event in cancer progression. The essential histone H3 variant CENP-A plays a fundamental role in defining centromere identity, structure, and function, but is innately overexpressed in several types of solid cancers. In the cancer background, excess CENP-A is deposited ectopically on chromosome arms, including at the 8q24/cMYC locus, by invading transcription-coupled H3.3 chaperone pathways. Intriguingly, in many cancers, transcription of lncRNAs is upregulated and correlates with poor prognosis, therapeutic resistance, and cancer recurrence in patients. Here, we report that the transcription of chromosome 8q24-derived oncogenic lncRNAs plays an unanticipated role in altering the chromatin landscape of the 8q24 locus. We report that transcription of oncogenic ncRNAs and associated R-loop formation at the 8q24 genomic locus results in the recruitment of H3.3 chaperone-CENP-A histone variant complexes to 8q24. Finally, we demonstrate that a transgene cassette which encodes a specific oncogenic lncRNA from the 8q24 region integrated into a naïve chromosome locus, recruits CENP-A to the new location specifically in a cis-acting manner. These data provide a plausible mechanistic link between locus-specific oncogenic lncRNAs, aberrant local chromatin structure, and the generation of new epigenetic memory in human cancer cells.
Project description:Chromosome instability is a key event in cancer progression. The essential histone H3 variant CENP-A plays a fundamental role in defining centromere identity, structure, and function, but is innately overexpressed in several types of solid cancers. In the cancer background, excess CENP-A is deposited ectopically on chromosome arms, including at the 8q24/cMYC locus, by invading transcription-coupled H3.3 chaperone pathways. Intriguingly, in many cancers, transcription of lncRNAs is upregulated and correlates with poor prognosis, therapeutic resistance, and cancer recurrence in patients. Here, we report that the transcription of chromosome 8q24-derived oncogenic lncRNAs plays an unanticipated role in altering the chromatin landscape of the 8q24 locus. We report that transcription of oncogenic ncRNAs and associated R-loop formation at the 8q24 genomic locus results in the recruitment of H3.3 chaperone-CENP-A histone variant complexes to 8q24. Finally, we demonstrate that a transgene cassette which encodes a specific oncogenic lncRNA from the 8q24 region integrated into a naïve chromosome locus, recruits CENP-A to the new location specifically in a cis-acting manner. These data provide a plausible mechanistic link between locus-specific oncogenic lncRNAs, aberrant local chromatin structure, and the generation of new epigenetic memory in human cancer cells.
Project description:An inherited variant on chromosome 8q24, rs6983267, is significantly associated with cancer pathogenesis. We present evidence that this region is a transcriptional enhancer, that the risk region physically interacts with the MYC proto-oncogene, and that the alleles of rs6983267 differentially bind transcription factor 7-like 2 (TCF7L2). These data provide strong support for a biological mechanism underlying this non-protein coding risk variant. Total RNA and genomic DNA were isolated from colon tissue in 5 individuals. cDNA and DNA were analyzed on separate tracks, with the genomic DNA used to identify sprurious cross-hybridization
Project description:An inherited variant on chromosome 8q24, rs6983267, is significantly associated with cancer pathogenesis. We present evidence that this region is a transcriptional enhancer, that the risk region physically interacts with the MYC proto-oncogene, and that the alleles of rs6983267 differentially bind transcription factor 7-like 2 (TCF7L2). These data provide strong support for a biological mechanism underlying this non-protein coding risk variant.
Project description:To determine if there is a physical interaction between the FOXF1 promoter and putative enhancer sequences ~250kb upstream of the promoter chromosome conformation capture-on-chip (4C) analysis was performed. An unanticipated and tremendous amount of the non-coding sequences of the human genome are transcribed. Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides and their functions remain enigmatic. We demonstrate that deletions of lncRNA genes cause a lethal lung developmental disorder, Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACD/MPV), with parent of origin effects. We identify non-coding overlapping deletions 250 kb upstream to FOXF1 in nine patients with ACD/MPV that arose de novo specifically on the maternally inherited chromosome and delete a fetal lung-specific EST, part of an lncRNA. These deletions define distant cis-regulatory region that harbors a differentially methylated CpG island, binds GLI2 depending on the methylation status of this CpG island, and physically interacts with and up-regulates the FOXF1 promoter, consistent with the absence of the fetal lung-transcribed lncRNA perturbing FOXF1 regulation. LncRNA-mediated chromatin interactions may be responsible for position effect phenomenon and potentially cause many disorders of human development. 4C analysis using 16q24.1 specific 3x720K arrays demonstrated physical interaction between the FOXF1 promoter and distant putative regulatory sequences, about 250 kb upstream in human pulomonary microvascular endothelial cells; 2 biological replicates performed; this chromatin looping was not detected in lymphoblasts that do not express FOXF1 and hence serve as a negative control.
Project description:lncRNAs play important roles in various physiological and pathological processes. However, the detailed molecular mechanisms by which lncRNAs act are still incomplete. Here, we functionally characterized the nuclear-enriched lncRNA SNHG1 which is highly expressed in several types of cancer relative to surrounding normal tissues. SNHG1 was regulated by oncogenic factor c-Myc and could promote tumor growth. We found that SNHG1 was involved in the Akt signaling pathway through promoting the neighboring transcription of protein-coding gene SLC3A2 in cis, by binding to the Mediator complex to facilitate enhancer-promoter interaction. Transcriptome analysis further revealed that several stress response genes, as well as signaling pathways, were regulated by SNHG1. Importantly, SNHG1 coordinated the expression of ATF3 through preventing FUBP1 from binding to its upstream regulatory region. Collectively, our findings demonstrate that lncRNA SNHG1 can function both in cis and in trans with distinct mechanisms to promote tumorigenesis and progression. Even, Odd probes targeting SNHG1 sequence, and control probes targeting LacZ. Probes was coupled with biotin, the captured DNA was prepared for library then sequencing.
Project description:To determine if there is a physical interaction between the FOXF1 promoter and putative enhancer sequences ~250kb upstream of the promoter chromosome conformation capture-on-chip (4C) analysis was performed. An unanticipated and tremendous amount of the non-coding sequences of the human genome are transcribed. Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides and their functions remain enigmatic. We demonstrate that deletions of lncRNA genes cause a lethal lung developmental disorder, Alveolar Capillary Dysplasia with Misalignment of Pulmonary Veins (ACD/MPV), with parent of origin effects. We identify non-coding overlapping deletions 250 kb upstream to FOXF1 in nine patients with ACD/MPV that arose de novo specifically on the maternally inherited chromosome and delete a fetal lung-specific EST, part of an lncRNA. These deletions define distant cis-regulatory region that harbors a differentially methylated CpG island, binds GLI2 depending on the methylation status of this CpG island, and physically interacts with and up-regulates the FOXF1 promoter, consistent with the absence of the fetal lung-transcribed lncRNA perturbing FOXF1 regulation. LncRNA-mediated chromatin interactions may be responsible for position effect phenomenon and potentially cause many disorders of human development.