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.