title: Concerted functions of HDAC1 and microRNA-574-5p repress alternatively spliced ceramide synthase 1 expression in human cancer cells.
abstract: Histone deacetylases (HDACs) and microRNAs (miRs) have pro-survival roles, but the mechanism behind this is unclear. Repression of ceramide synthase 1 (CerS1), altering C(18) -ceramide generation, was linked to drug resistance and metastasis. Here we report that the CerS1 promoter was repressed by HDAC1-dependent inhibition of Sp1 recruitment to two specific GC-boxes spanning the -177 and -139 region. Moreover, an alternatively spliced variant CerS1 mRNA (CerS1-2) was detected mainly in cancer cells or primary tumour tissues compared to controls, which was targeted by miR-574-5p for degradation. A specific 3'UTR-targeting site, localized within the retained intron between exons 6 and 7, was identified, and its mutation, or miR-574-5p knockdown prevented the degradation of CerS1-2 mRNA. Interference with HDAC1 and miR-574-5p reconstituted CerS1-2 expression and C(18) -ceramide generation in multiple human cancer cell lines, which subsequently inhibited proliferation and anchorage-independent growth. Accordingly, knockdown of CerS1 partially protected cancer cells from MS-275/miR-574-5p siRNA-mediated growth inhibition. Thus, these data suggest that the HDAC1/miR-574-5p axis might provide a novel therapeutic target to reconstitute tumour suppressor CerS1/ceramide signalling.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical University of South Carolina, SC, USA.
authors.forename: Marisa
authors.initials: M
authors.lastname: Meyers-Needham
authors.forename: Suriyan
authors.initials: S
authors.lastname: Ponnusamy
authors.forename: Salih
authors.initials: S
authors.lastname: Gencer
authors.forename: Wenhui
authors.initials: W
authors.lastname: Jiang
authors.forename: Raquela J
authors.initials: RJ
authors.lastname: Thomas
authors.forename: Can E
authors.initials: CE
authors.lastname: Senkal
authors.forename: Besim
authors.initials: B
authors.lastname: Ogretmen
mesh_terms: D020413:3' Untranslated Regions; D017398:Alternative Splicing; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D056284:Histone Deacetylase 1 / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics; D051049:Sphingosine N-Acyltransferase / Q000235:genetics* / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; C558811:MIRN574 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins; C493790:CERS1 protein, human; C438311:CERS2 protein, human; D051049:Sphingosine N-Acyltransferase; C110550:HDAC1 protein, human; D056284:Histone Deacetylase 1