title: microRNA-155 regulates cell proliferation and invasion by targeting FOXO3a in glioma.
abstract: microRNAs (miRNAs) are short noncoding RNAs, which modulate the expression of numerous genes by targeting mRNAs. Numerous abnormal miRNA expression patterns are found in various human malignancies, and certain miRNAs act as oncogenes or tumor suppressors. microRNA-155 (miR‑155) may not only function as an oncogene but also as a tumor suppressor in various types of cancer cells, such as melanoma. Although miR-155 has been found to be upregulated in glioma, its role has not yet been eludicated in glioma tumorigenesis. Based on the prediction of the target genes of miR-155, we hypothesized that there is a significant association between miR-155 and FOXO3a, a negative regulator of Akt signaling. In the present study, we found that FOXO3a expression was significantly downregulated and miR-155 was upregulated in a panel of glioma cells and tissue specimens. Furthermore, we demonstrated that miR-155 induced cell proliferation by inhibiting apoptosis and promoted the migration and invasiveness of glioma cells, while miR-155 had no effect on the cell cycle as determined by gain-of-function and loss-of-function experiments. Moreover, we confirmed that miR-155 downregulated the expression of FOXO3a by directly targeting its 3'-UTR. These findings indicate that miR-155 may function as an oncogene by targeting FOXO3a in the development and progression of glioma.
authors: Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou 215006, P.R. China.
authors: Nan
authors: N
authors: Ling
authors: Junyi
authors: J
authors: Gu
authors: Zhe
authors: Z
authors: Lei
authors: Mengmeng
authors: M
authors: Li
authors: Jun
authors: J
authors: Zhao
authors: Hong-Tao
authors: HT
authors: Zhang
authors: Xiangdong
authors: X
authors: Li
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D017209:Apoptosis / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D005910:Glioma / Q000235:genetics* / Q000473:pathology; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D051058:Oncogene Protein v-akt / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D051058:Oncogene Protein v-akt