Snf5 (Ini1/Baf47/Smarcb1), a core member of the Swi/Snf chromatin remodeling complex, is a potent tumor suppressor whose mechanism of action is largely unknown. Biallelic loss of Snf5 leads to the onset of aggressive cancers in both humans and mice. We have developed an innovative and widely applicable analytical technique for cross-species validation of cancer models and show that the gene expression profiles of our Snf5 murine models closely resemble those of human Snf5-deficient rhabdoid tumors. We exploit this system to produce what we believe to be the first report documenting the effects on gene expression of inactivating a Swi/Snf subunit in normal mammalian cells and to identify the transcriptional pathways regulated by Snf5. We demonstrate that the tumor suppressor activity of Snf5 depends on its regulation of cell cycle progression; Snf5 inactivation leads to aberrant up-regulation of E2F targets and increased levels of p53 that are accompanied by apoptosis, polyploidy, and growth arrest. Further, conditional mouse models demonstrate that inactivation of p16Ink4a or Rb (retinoblastoma) does not accelerate tumor formation in Snf5 conditional mice, whereas mutation of p53 leads to a dramatic acceleration of tumor formation.
Enhancer-derived RNAs (eRNAs) play critical roles in diverse biological processes by facilitating their target gene expression. However, the abundance and function of eRNAs in early embryos are not clear. Here, we present a comprehensive eRNA atlas by systematically integrating publicly available datasets of mouse early embryos. We characterize the transcriptional and regulatory network of eRNAs and show that different embryo developmental stages have distinct eRNA expression and regulatory profiles. Paternal eRNAs are activated asymmetrically during zygotic genome activation (ZGA). Moreover, we identify an eRNA, MZGAe1, which plays an important function in regulating mouse ZGA and early embryo development. MZGAe1 knockdown leads to a developmental block from 2-cell embryo to blastocyst. We create an online data portal, M2ED2, to query and visualize eRNA expression and regulation. Our study thus provides a systematic landscape of eRNA and reveals the important role of eRNAs in regulating mouse early embryo development.
Background: Hepatocellular carcinoma (HCC) is an extremely malignant cancer with poor survival. H2AFY gene encodes for a variant of H2A histone, and it has been found to be dysregulated in various tumors. However, the clinical value, biological functions and correlations with immune infiltration of H2AFY in HCC remain unclear.Methods: We analyzed the expression and clinical significance of H2AFY in HCC using multiple databases, including Oncomine, HCCDB, TCGA, ICGC, and so on. The genetic alterations of H2AFY were analyzed by cBioPortal and COSMIC databases. Co-expression networks of H2AFY and its regulators were investigated by LinkedOmics. The correlations between H2AFY and tumor immune infiltration were explored using TIMER, TISIDB databases, and CIBERSORT method. Finally, H2AFY was knocked down with shRNA lentiviruses in HCC cell lines for functional assays in vitro.Results: H2AFY expression was upregulated in the HCC tissues and cells. Kaplan–Meier and Cox regression analyses revealed that high H2AFY expression was an independent prognostic factor for poor survival in HCC patients. Functional network analysis indicated that H2AFY and its co-expressed genes regulates cell cycle, mitosis, spliceosome and chromatin assembly through pathways involving many cancer-related kinases and E2F family. Furthermore, we observed significant correlations between H2AFY expression and immune infiltration in HCC. H2AFY knockdown suppressed the cell proliferation and migration, promoted cycle arrest, and apoptosis of HCC cells in vitro.Conclusion: Our study revealed that H2AFY is a potential biomarker for unfavorable prognosis and correlates with immune infiltration in HCC.