MicroRNA-29a inhibits glioblastoma stem cells and tumor growth by regulating the PDGF pathway
Background and purpose
microRNAs are small noncoding RNAs that play important roles in cancer regulation. In this study, we investigated the expression, functional effects and mechanisms of action of microRNA-29a (miR-29a) in glioblastoma (GBM).
miR-29a expression levels in GBM cells, stem cells (GSCs) and human tumors as well as normal astrocytes and normal brain were measured by quantitative PCR. miR-29a targets were uncovered by target prediction algorithms, and verified by immunoblotting and 3′ UTR reporter assays. The effects of miR-29a on cell proliferation, death, migration and invasion were assessed with cell counting, Annexin V-PE/7AAD flow cytometry, scratch assay and transwell assay, respectively. Orthotopic xenografts were used to determine the effects of miR-29a on tumor growth.
Mir-29a was downregulated in human GBM specimens, GSCs and GBM cell lines. Exogenous expression of miR-29a inhibited GSC and GBM cell growth and induced apoptosis. miR-29a also inhibited GBM cell migration and invasion. PDGFC and PDGFA were uncovered and validated as direct targets of miR-29a in GBM. miR-29a downregulated PDGFC and PDGFA expressions at the transcriptional and translational levels. PDGFC and PDGFA expressions in GBM tumors, GSCs, and GBM established cell lines were higher than in normal brain and human astrocytes. Mir-29a expression inhibited orthotopic GBM xenograft growth.
miR-29a is a tumor suppressor miRNA in GBM, where it inhibits cancer stem cells and tumor growth by regulating the PDGF pathway.
KeywordsmicroRNA (miRNA) Glioblastoma (GBM) Glioblastoma stem cells (GSC) Platelet-derived growth factor (PDGF)
This study was supported by NIH grant UO1 CA CA220841 (Roger Abounader).
- 8.Cortez MA, Nicoloso MS, Shimizu M, Rossi S, Gopisetty G, Molina JR, Carlotti C, Tirapelli D, Neder L, Brassesco MS, Scrideli CA, Tone LG, Georgescu MM, Zhang W, Puduvalli V, Calin GA (2010) miR-29b and miR-125a regulate podoplanin and suppress invasion in glioblastoma. Genes Chromosom Cancer 49(11):981–990CrossRefGoogle Scholar
- 12.CBTRUS (1998) Central brain tumor registry of the United States. CBTRUS, ChicagoGoogle Scholar
- 18.Heidaran MA, Pierce JH, Yu JC, Lombardi D, Artrip JE, Fleming TP, Thomason A, Aaronson SA (1991) Role of alpha beta receptor heterodimer formation in beta platelet-derived growth factor (PDGF) receptor activation by PDGF-AB. J Biol Chem 266(30):20232–20237Google Scholar
- 21.Nister M, Libermann TA, Betsholtz C, Pettersson M, Claesson-Welsh L, Heldin CH, Schlessinger J, Westermark B (1988) Expression of messenger RNAs for platelet-derived growth factor and transforming growth factor-alpha and their receptors in human malignant glioma cell lines. Cancer Res 48(14):3910–3918Google Scholar
- 22.Hermanson M, Funa K, Hartman M, Claesson-Welsh L, Heldin CH, Westermark B, Nister M (1992) Platelet-derived growth factor and its receptors in human glioma tissue: expression of messenger RNA and protein suggests the presence of autocrine and paracrine loops. Cancer Res 52(11):3213–3219Google Scholar
- 24.Martinho O, Longatto-Filho A, Lambros MB, Martins A, Pinheiro C, Silva A, Pardal F, Amorim J, Mackay A, Milanezi F, Tamber N, Fenwick K, Ashworth A, Reis-Filho JS, Lopes JM, Reis RM (2009) Expression, mutation and copy number analysis of platelet-derived growth factor receptor A (PDGFRA) and its ligand PDGFA in gliomas. Br J Cancer 101(6):973–982CrossRefGoogle Scholar
- 25.Lokker NA, Sullivan CM, Hollenbach SJ, Israel MA, Giese NA (2002) Platelet-derived growth factor (PDGF) autocrine signaling regulates survival and mitogenic pathways in glioblastoma cells: evidence that the novel PDGF-C and PDGF-D ligands may play a role in the development of brain tumors. Cancer Res 62(13):3729–3735Google Scholar
- 38.Liu Y, Duan N, Duan S (2018) MiR-29a inhibits glioma tumorigenesis through a negative feedback loop of TRAF4/Akt signaling. Biomed Res Int 2018:2461363Google Scholar
- 39.Ru P, Guo D (2017) microRNA-29 mediates a novel negative feedback loop to regulate SCAP/SREBP-1 and lipid metabolism. RNA Dis 4(1):e1525Google Scholar
- 42.Aldaz B, Sagardoy A, Nogueira L, Guruceaga E, Grande L, Huse JT, Aznar MA, Diez-Valle R, Tejada-Solis S, Alonso MM, Fernandez-Luna JL, Martinez-Climent JA, Malumbres R (2013) Involvement of miRNAs in the differentiation of human glioblastoma multiforme stem-like cells. PLoS ONE 8(10):e77098CrossRefGoogle Scholar
- 45.Floyd DH, Zhang Y, Dey BK, Kefas B, Breit H, Marks K, Dutta A, Herold-Mende C, Synowitz M, Glass R, Abounader R, Purow BW (2014) Novel anti-apoptotic microRNAs 582–5p and 363 promote human glioblastoma stem cell survival via direct inhibition of caspase 3, caspase 9, and Bim. PLoS ONE 9(5):e96239CrossRefGoogle Scholar