Project description:Dynamic chemical modifications of RNA represent novel and fundamental mechanisms that regulate stemness and tissue homeostasis. Rejuvenation and wound repair of mammalian skin are sustained by epidermal progenitor cells, which are localized within the basal layer of the skin epidermis. N6-methyladenosine (m6A) is one of the most abundant modifications found in eukaryotic mRNA and lncRNA (long non-coding RNA). In this report, we survey changes of m6A RNA methylomes upon epidermal differentiation, and identify Pvt1, a lncRNA whose m6A modification is critically involved in sustaining stemness of epidermal progenitor cells. With genome-editing and a mouse genetics approach, we show that ablation of m6A methyltransferase or Pvt1 impairs the self-renewal and wound healing capability of skin. Mechanistically, methylation of Pvt1 transcripts enhances its interaction with MYC and stabilizes the MYC protein in epidermal progenitor cells. Our study presents a global view of epitranscriptomic dynamics that occur during epidermal differentiation and identifies the m6A modification of Pvt1 as a key signaling event involved in skin tissue homeostasis and wound repair.
Project description:lncRNA PVT1 is an emerging lncRNA of significance in cancer due to alterations in both the RNA and genomic locus in multiple cancers and its established relationship to the oncogene MYC. Several recent studies have documented potential important roles for the lncRNA in ovarian cancer. Herein RNA sequencing was performed to determine the impact of PVT1 on global gene expression by performing RNA sequencing in SK-OV3 cells after silencing PVT1 (siPVT1) of cells grown upon transient knockdown of the lncRNA PVT1. SK-OV3 cells were cultured to 50% confluence in 6 well plates. Pooled siRNA’s to human PVT1 or non targeting control siRNA’s from Dharmacon were used to transfect SK-OV3 cells for 48 hrs in full serum media carefully maintaining cell confluence to not exceed approximately 80%. This was followed by RNA extraction and verification of knockdown using primers to PVT1 followed by sequencing. We find that 450 protein coding genes were differentially expressed between control (siControl) and siPVT1 cells with 50 additional found to be non-protein coding. The top 50 differentially expressed genes include 12 that were downregulated by siPVT1 and 32 that were upregulated. Several pathways associated with metabolic and stress processes, ribosome biogenesis and ncRNA processing were altered based on GO pathway analysis. Additional pathways included pathways associated with cell motility and differentiation.
Project description:LncRNA profiling of hepatocellular carcinoma vs. matched noncancerous liver tissue, aimed to analyze the lncRNA expression profile of hepatocellular carcinoma (HCC) and identify prognosis-related lncRNAs.
Project description:Background Cutaneous squamous cell carcinoma (cSCC) is one of the most common and fastest increasing forms of cancer worldwide with metastatic potential. Long non-coding RNAs (lncRNAs) are a group of RNA-molecules with essential regulatory functions for both physiological and pathological processes. Objectives To investigate the function and mode of action of lncRNA plasmacytoma variant translocation 1 (PVT1) in cSCC. Methods The expression level of PVT1 was quantified in healthy skin, benign skin diseases and cSCCs by qRT-PCR and single molecule in situ hybridization. The function of PVT1 in cSCC was investigated both in vivo (tumour xenograft) and in vitro (competitive cell growth assay, EdU-incorporation assay, colony formation assay and tumour spheroid formation assay) by CRISPR-Cas9-mediated PVT1 or PVT1 exon 2 knockout and by locked nucleic acid (LNA) GapmeR-mediated PVT1-knockdown. RNAseq-analysis was conducted to identify genes and processes regulated by PVT1. Results We identified PVT1 as a lncRNA upregulated in cutaneous squamous cell carcinoma in situ (cSCCIS) and cSCC and associated with oncogenic phenotype of cSCC. The increased expression of PVT1 in cSCC was regulated by MYC. Both CRISPR-Cas9-deletion of the entire PVT1 locus and LNA GapmeR-mediated knockdown of PVT1-transcript impaired malignant behaviour of cSCC cells which suggested that PVT1 is an oncogenic transcript in cSCC. Furthermore, knockout of PVT1 exon 2 inhibited cSCC tumour growth both in vivo and in vitro demonstrating that exon 2 is a critical element for the oncogenic role of PVT1. Mechanistically, we show that PVT1 is localized in the cell nucleus and acts as a suppressor of cellular senescence by inhibiting CDKN1A expression and preventing cell cycle arrest. Conclusions Our study reveals a previously unrecognized role for exon 2 of PVT1 in its oncogenic role and that PVT1 suppresses cellular senescence. PVT1 may be a biomarker and therapeutic target in cSCC.
Project description:To explore critical roles of lncRNA and mRNA playing in the pathogenesis of hepatocellular carcinoma, the Agilent microarray was used to simultaneously profile lncRNA and mRNA expression in 7 pairs of HCC and matched adjacent tumor-free tissues.
Project description:Sulfatide significantly promoted hepatocellular carcinoma cells survival, proliferation and angiogenesis. To understand the molecular mechanisms of sulfatide, the transcriptional profiles of lncRNAs in human hepatocellular carcinoma cells SMMC-7721 was investigated with ArrayStar lncRNA microarray with sulfatide treatment. Galactose-cerebroside treatment served as the control.
Project description:In order to understand the role of lncRNA Pvt1 in skeletal muscle physiopathology we silenced this transcript in-vitro, using C2C12 cell cultures, and in-vivo, in leg muscles of CD1 wild-type and denervated mice.
Project description:Despite increasing understanding of the prognostic importance of vascular stiffening linked to perivascular fibrosis in hypertension, the molecular and cellular regulation of this process is poorly understood. We aimed to study the functional role of microRNA-214 (miR-214) in the induction of perivascular fibrosis and endothelial dysfunction driving vascular stiffening. Out of 381 miRs screened in the perivascular tissues (PVAT) in response to angiotensin II (Ang II)-mediated hypertension, miR-214 showed the highest induction (8-fold, p<0.01). MiR-214 induction was pronounced in perivascular and circulating T cells, but not in PVAT adipocytes. Global deletion of miR-214-/- prevented Ang II-induced periaortic fibrosis Col1a1, Col3a1, Col5a1 and Tgfb1 expression, hydroxyproline accumulation and vascular stiffening, without difference in blood pressure. Mechanistic studies revealed that miR-214-/- mice were protected against endothelial dysfunction, oxidative stress and increased Nox2, all of which were induced by Ang II in WT mice. Ang II-induced recruitment of T cells into PVAT was abolished in miR-214-/- mice. Adoptive transfer of miR-214-/- T cells into RAG1-/- mice resulted in reduced perivascular fibrosis compared to the effect of WT T cells. Ang II induced hypertension caused significant change in the expression of 1380 T cell genes in WT, but only 51 in miR-214-/-. T cell activation, proliferation and chemotaxis pathways were differentially affected. miR-214-/- prevented Ang II-induction of pro-fibrotic T cell cytokines (IL-17, TNF, IL-9 and IFN) and chemokine receptors (CCR1, CCR2, CCR4, CCR5, CCR6 and CXCR3). This manifested in reduced in vitro and in vivo T cell chemotaxis resulting in attenuation of profibrotic perivascular inflammation. Translationally, we show that miR-214 is increased in plasma of hypertensive patients and is directly correlated to pulse wave velocity as a measure of vascular stiffness.