Agradecimentos: Mrs. Maija-Leena Lehtonen and Mrs. Eeva-Maija Kiljander are acknowledged for their excellent technical help in the experiments. We thank the Biocenter Oulu Virus Core laboratory for providing the facilities for the lentiviral silencing. DDS Ahmed MA Al-Samadi and DDS Fabricio Passador-Santos are acknowledged for their valuable comments on the manuscript. This study was supported by the Finnish Cancer Society (TS, IL, KJ), The Sigrid Juselius Foundation (TS), Oulu University Hospital MRC and VTR funding (TS), The Finska Läkaresällskapet foundation (IL, KJ), The Maritza and Reino Salonen Foundation (IL, KJ), and the Turku University Hospital VTR funding (RG). JK was supported by the Finnish Cultural Foundation, the Thelma Mäkikyrö Foundation and Science without borders (CAPES, Brazil). AFPL was supported by FAPESP (2009/54067-3 and 2010/19278-0) and CNPq grants (470268/2013-1). RDC was supported by Science without borders (CAPES, Brazil), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES, Brasília, Brazil (AUXPE-PVES-570/2013) and Fundação de Amparo a Pesquisa do Estado de São Paulo-FAPESP, São Paulo, Brazil (2013/01607-6). The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article. Ver menos

Abstract: Complex molecular pathways regulate cancer invasion. This study overviewed proteins and microRNAs (miRNAs) involved in oral tongue squamous cell carcinoma (OTSCC) invasion. The human highly aggressive OTSCC cell line HSC-3 was examined in a 3D organotypic human leiomyoma model. Non-invasive and invasive cells were laser-captured and protein expression was analyzed using mass spectrometry-based proteomics and miRNA expression by microarray. In functional studies the 3D invasion assay was replicated after silencing candidate miRNAs, miR-498 and miR-940, in invasive OTSCC cell lines (HSC-3 and SCC-15). Cell migration, proliferation and viability were also studied in the silenced cells. In HSC-3 cells, 67 proteins and 53 miRNAs showed significant fold-changes between non-invasive vs. invasive cells. Pathway enrichment analyses allocated "Focal adhesion" and "ECM-receptor interaction" as most important for invasion. Significantly, in HSC-3 cells, miR-498 silencing decreased the invasion area and miR-940 silencing reduced invasion area and depth. Viability, proliferation and migration weren't significantly affected. In SCC-15 cells, down-regulation of miR-498 significantly reduced invasion and migration. This study shows HSC-3 specific miRNA and protein expression in invasion, and suggests that miR-498 and miR-940 affect invasion in vitro, the process being more influenced by mir-940 silencing in aggressive HSC-3 cells than in the less invasive SCC-15 Ver menos