Project description:Sex exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRASG12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of the epithelial cell tight junction and MHC class I complex components. Deletion of Kdm5d in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive Kdm5d expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC.
Project description:Sex exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRASG12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of the epithelial cell tight junction and MHC class I complex components. Deletion of Kdm5d in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive Kdm5d expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC.
Project description:Sex exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRASG12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase KDM5D as a transcriptionally up-regulated gene driven by KRAS*-mediated activation of the STAT4 transcription factor. KDM5D-dependent chromatin mark and transcriptome changes showed repression of regulators of the epithelial cell tight junction and MHC class I complex components. Deletion of Kdm5d in iKAP cancer cells increased tight junction integrity, decreased cell invasiveness, and enhanced cancer cell killing by CD8+ T cells. Conversely, iAP mice engineered with a Kdm5d transgene to provide constitutive Kdm5d expression specifically in iAP cancer cells exhibited an increased propensity for more invasive tumors in vivo. Thus, KRAS*-STAT4-mediated upregulation of Y chromosome KDM5D contributes significantly to the sex differences in KRAS* CRC via its disruption of cancer cell adhesion properties and tumor immunity, providing an actionable therapeutic strategy for metastasis risk reduction for men afflicted with KRAS* CRC.
Project description:Regulation of gene expression by chromatin modification through methylation of histone lysine residues is a dynamic, reversible process that when deregulated is associated with cancer development. In multiple myeloma, combined inhibition of the histone demethylases JARID1B, UTX and JmjD3 by the small molecule GSK-J4 prevents cellular glutamine utilization leading to amino acids deprivation, activates the integrated stress response via GCN2-dependent ATF4 activation, and induces apoptosis. This response is associated with a profound upregulation of metallothionein genes. Combined with clinical data demonstrating that overexpression of JARID1B is associated with shorter survival in multiple myeloma patients, this study highlights histone demethylases as epigenetic drug targets and places this demethylase inhibitor chemotype as having unique potential relative to established anti-myeloma treatment options. In total there are 7 different samples analyzed and one input control. Treatments are carried out with the demethylase inhibitor (or DMSO as negative control) at 6h and 48h, or with LNA targeting demethylases (or scrambled LNA) at 7 days. A negative control at 0h is included.
Project description:Multiple sclerosis (MS) is a T-cell mediated autoimmune disease that has a sexually dimorphic pattern in disease susceptibility. Consistent with many autoimmune diseases, females are more susceptible than males to MS. Sexual dimorphisms may be due to differences in sex hormones, sex chromosome genes, or both. Regarding sex chromosome genes, a small percentage of X chromosome genes escape the dosage compensation mechanism of X inactivation and have higher expression in females (XX) compared to males (XY). According to the high throughput analysis, the top sexually dimorphic gene with higher expression in CD4+ T cells from females (vs. males) and from XX mice (vs. XY) was Kdm6a, a histone demethylase and transcription factor on the X chromosome. Deletion of Kdm6a specifically in CD4+ T cells ameliorated clinical disease and reduced neuropathology in the classic CD4+ T cell mediated autoimmune disease, experimental autoimmune encephalomyelitis (EAE). Global transcriptome analysis in CD4+ T cells from EAE mice with a specific deletion of Kdm6a showed upregulation of Th2 and Th1 activation pathways and downregulation of neuroinflammation signaling pathways. Together, this demonstrates that the X escapee Kdm6a regulates multiple immune response genes, providing a mechanism for sex differences in autoimmune disease susceptibility.
Project description:Multiple sclerosis (MS) is a T-cell mediated autoimmune disease that has a sexually dimorphic pattern in disease susceptibility. Consistent with many autoimmune diseases, females are more susceptible than males to MS. Sexual dimorphisms may be due to differences in sex hormones, sex chromosome genes, or both. Regarding sex chromosome genes, a small percentage of X chromosome genes escape the dosage compensation mechanism of X inactivation and have higher expression in females (XX) compared to males (XY). According to the high throughput analysis, the top sexually dimorphic gene with higher expression in CD4+ T cells from females (vs. males) and from XX mice (vs. XY) was Kdm6a, a histone demethylase and transcription factor on the X chromosome. Deletion of Kdm6a specifically in CD4+ T cells ameliorated clinical disease and reduced neuropathology in the classic CD4+ T cell mediated autoimmune disease, experimental autoimmune encephalomyelitis (EAE). Global transcriptome analysis in CD4+ T cells from EAE mice with a specific deletion of Kdm6a showed upregulation of Th2 and Th1 activation pathways and downregulation of neuroinflammation signaling pathways. Together, this demonstrates that the X escapee Kdm6a regulates multiple immune response genes, providing a mechanism for sex differences in autoimmune disease susceptibility.
Project description:Cancer is characterized by gene expression aberrations. Studies have largely focused on coding sequences and promoters, despite the fact that distal regulatory elements play a central role in controlling transcription patterns. Here we utilize the histone mark H3K4me1 to analyze gain and loss of enhancer activity genome wide in primary colon cancer lines relative to normal colon crypts. We identified thousands of variant enhancer loci (VELs) that comprise a signature that is robustly predictive of the in vivo colon cancer transcriptome. Furthermore, VELs are enriched in haplotype blocks containing colon cancer genetic risk variants, implicating these genomic regions in colon cancer pathogenesis. We propose that reproducible changes in the epigenome at enhancer elements drive a unique transcriptional program to promote colon carcinogenesis. Examination of 3 histone modifications and global expression data in primary colon cancer cell lines and normal colon crypt controls
Project description:High-fat diet and obesity are high risk factors for colorectal cancer. The underlying mechanism is still unclear. Environmental factors alter the epigenome to affect gene expression thus the phenotype. In response to external stimuli, the cis-regulatory regions, especially enhancer loci, are key elements for regulating selective gene expression. We thus explored the effects of high-fat diet and the accompanying obesity on gene expression and the enhancer landscape in colon epithelium. High-fat diet exposed binding sites of transcription factors downstream of signaling pathways important in the initiation and progression of colon cancer. Meantime, colon specific enhancers were lost rendering the cells potential for dedifferentiation. The alteration at enhancer regions drives a specific transcription program promoting colon cancer progression. The comprehensive interrogation of enhancer changes by high-fat diet in colon epithelium provides a number of insights into the underlying biology of high-fat diet and obesity in increasing colon cancer risk, and provides potential therapeutic targets to treat obese colon cancer patients. ChIP sequencing of active enhancer mark h3k27ac in colon epithelium from wild type mice and NAG-1 transgenic mice treated with either low-fat diet or high-fat diet. The gene expression component of the study is included in GSE46843.