miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in gastric cancer through regulation of the PI3K/AKT/mTOR pathway
- 457 Downloads
Gastric cancer (GC) is a deadly malignancy worldwide. In the past, it has been shown that cellular signaling pathway alterations play a crucial role in the development of GC. In particular, deregulation of the PI3K/AKT/mTOR pathway seems to affect multiple GC functions including growth, proliferation, metabolism, motility and angiogenesis. Targeting alterations in this pathway by microRNAs (miRNAs) represents a potential therapeutic strategy, especially in inhibitor-resistant tumors. The objective of this study was to evaluate the expression of 3 pre-selected miRNAs, miR-101-2, miR-125b-2 and miR-451a, in a series of primary GC tissues and matched non-GC tissues and in several GC-derived cell lines, and to subsequently evaluate the functional role of these miRNAs.
Twenty-five primary GC samples, 25 matched non-GC samples and 3 GC-derived cell lines, i.e., AGS, MKN28 and MKN45, were included in this study. miRNA and target gene expression levels were assessed by quantitative RT-PCR and western blotting, respectively. Subsequently, cell viability, clone formation, cell death, migration and invasion assays were performed on AGS cells.
miR-101-2, miR-125b-2 and miR-451a were found to be down-regulated in the primary GC tissues and the GC-derived cell lines tested. MiRNA mimic transfections significantly reduced cell viability and colony formation, increased cell death and reduced cell migration and invasion in AGS cells. We also found that exogenous expression of miR-101-2, miR-125b-2 and miR-451a decreased the expression of their putative targets MTOR, PIK3CB and TSC1, respectively.
Our expression analyses and in vitro functional assays suggest that miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in primary GCs as well as in GC-derived AGS cells.
KeywordsGastric cancer microRNAs miR-101-2 miR-125b-2 miR-451a PI3K/AKT/mTOR pathway
This study was supported by the Chilean National Fund for Scientific and Technological Development (FONDECYT NO. 1090171), the Chilean National Commission for Scientific and Technological Research (CONICYT) through a PhD scholarship and financial support for a doctoral thesis (NO. 24121456) and a Postdoctoral Scholarship from the Universidad de La Frontera.
The FV-1000 microscope experiments/data analyses were performed in part through use of the VUMC Cell Imagining Shared Resource (supported by NIH grants CA68485, DK20593, DK58404, DK59637, and EY08126).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interests.
- 2.A. Yousuf, M.Y. Bhat, A.A. Pandith, D. Afroze, N.P. Khan, K. Alam, P. Shah, M.A. Shah, S. Mudassar, A. Jemal, F. Bray, M.M. Center, J. Ferlay, E. Ward, D. Forman, M.G.M.T. Gene, Silencing by promoter hypermethylation in gastric cancer in a high incidence area. Cell. Oncol. 37, 245–52 (2014)CrossRefGoogle Scholar
- 5.M. Labots, T.E. Buffart, J.C. Haan, N.C.T. van Grieken, M. Tijssen, C.J.H. van de Velde, H.I. Grabsch, B. Ylstra, B. Carvalho, R.J.A. Fijneman, H.M.W. Verheul, G.A. Meijer, High-level copy number gains of established and potential drug target genes in gastric cancer as a lead for treatment development and selection. Cell. Oncol. 37, 41–52 (2014)CrossRefGoogle Scholar
- 9.The Cancer Genome Atlas Research Network, Comprehensive Molecular Characterization of Gastric Adenocarcinoma. Nature. 513, 202–9 (2014)Google Scholar
- 30.E. Bandres, N. Bitarte, F. Arias, J. Agorreta, P. Fortes, X. Agirre, R. Zarate, J.A. Diaz-Gonzalez, N. Ramirez, J.J. Sola, P. Jimenez, J. Rodriguez, J. Garcia-Foncillas, microRNA-451 regulates macrophage migration inhibitory factor production and proliferation of gastrointestinal cancer cells. Clin. Cancer Res. 15, 2281–90 (2009)CrossRefPubMedGoogle Scholar
- 32.J. Godlewski, M.O. Nowicki, A. Bronisz, G. Nuovo, J. Palatini, M. De Lay, J. Van Brocklyn, M.C. Ostrowski, E.A. Chiocca, S.E. Lawler, MicroRNA-451 regulates LKB1/AMPK signaling and allows adaptation to metabolic stress in glioma cells. Mol. Cell 37, 620–32 (2010)PubMedCentralCrossRefPubMedGoogle Scholar
- 44.S.A. Lang, A. Gaumann, G.E. Koehl, U. Seidel, F. Bataille, D. Klein, L.M. Ellis, U. Bolder, F. Hofstaedter, H.-J. Schlitt, E.K. Geissler, O. Stoeltzing, Mammalian target of rapamycin is activated in human gastric cancer and serves as a target for therapy in an experimental model. Int. J. Cancer 120, 1803–10 (2007)CrossRefPubMedGoogle Scholar
- 46.W. Li, L. Xie, X. He, J. Li, K. Tu, L. Wei, J. Wu, Y. Guo, X. Ma, P. Zhang, Z. Pan, X. Hu, Y. Zhao, H. Xie, G. Jiang, T. Chen, J. Wang, S. Zheng, J. Cheng, D. Wan, S. Yang, Y. Li, J. Gu, Diagnostic and prognostic implications of microRNAs in human hepatocellular carcinoma. Int. J. Cancer 123, 1616–22 (2008)CrossRefPubMedGoogle Scholar
- 52.B. Brenner, M.B. Hoshen, O. Purim, M. Ben David, K. Ashkenazi, G. Marshak, Y. Kundel, R. Brenner, S. Morgenstern, M. Halpern, N. Rosenfeld, A. Chajut, Y. Niv, M. Kushnir, MicroRNAs as a potential prognostic factor in gastric cancer. World J. Gastroenterol. 17, 3976–85 (2011)PubMedCentralCrossRefPubMedGoogle Scholar