title: MicroRNA 335 is required for differentiation of malignant glioma cells induced by activation of cAMP/protein kinase A pathway.
abstract: Glioma is the most common malignant cancer affecting the central nerve system, with dismal prognosis. Differentiation-inducing therapy is a novel strategy that has been preliminarily proved effective against malignant glioma. We have reported previously that activation of cAMP/protein kinase A (PKA) pathway is capable of inducing glioma cell differentiation, characterized by astrocyte-like shape and dramatic induction of astrocyte biomarker glial fibrillary acidic protein (GFAP). However, little progress has been made on molecular mechanisms related. Here we demonstrate that microRNA 335 (miR-335) is responsible for the glioma cell differentiation stimulated by activation of cAMP/PKA pathway. In the cAMP elevator cholera toxin-induced differentiation model of rat C6 glioma cells, miR-335 was significantly up-regulated, which was mimicked by other typical cAMP/PKA pathway activators (e.g., forskolin, dibutyryl-cAMP) and abolished by PKA-specific inhibitor (9R,10S,12S)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i] [1,6]benzodiazocine-10-carboxylic acid, hexyl ester (KT5720). In an assay measuring gain and loss of miR-335 function, exogenetic miR-335 resulted in induction of GFAP, whereas miR-335 specific inhibitor antagomir-335 violently blocked cholera toxin-induced GFAP up-regulation. It is noteworthy that in human U87-MG glioma cells and human primary culture glioma cells, miR-335 also mediated cholera toxin-induced differentiation. Taken together, our findings suggest that miR-335 is potently required for differentiation of malignant glioma cells induced by cAMP/PKA pathway activation, and a single microRNA may act as an important fate determinant to control the differentiation status of malignant gliomas, which has provided a new insight into differentiation-inducing therapy against malignant gliomas.
authors.affiliation: Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Minfeng
authors.initials: M
authors.lastname: Shu
authors.forename: Yuehan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhu
authors.forename: Haipeng
authors.initials: H
authors.lastname: Zhang
authors.forename: Sihan
authors.initials: S
authors.lastname: Wu
authors.forename: Jingkao
authors.initials: J
authors.lastname: Chen
authors.forename: Guangmei
authors.initials: G
authors.lastname: Yan
mesh_terms: D000818:Animals; D001483:Base Sequence; D001932:Brain Neoplasms / Q000473:pathology*; D002454:Cell Differentiation / Q000502:physiology*; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D017931:DNA Primers; D004789:Enzyme Activation; D005786:Gene Expression Regulation / Q000187:drug effects; D005910:Glioma / Q000473:pathology*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; C556347:MIRN335 microRNA, human; D035683:MicroRNAs; D002772:Cholera Toxin; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases