THE COMPARISON OF THE EFFECTS OF PANOBINOSTAT AND PKF118-310 ON β-CATENIN-DEPENDENT TRANSCRIPTION IN HEAD AND NECK SQUAMOUS CELL CARCINOMA CELL LINES

Advanced head and neck squamous cell cancers (HNSCC) have unfavorable prognosis and new therapeutic options are necessary to improve treatment outcomes. The Wnt pathway plays an important role in the pathogenesis and progression of HNSCC. The aim of this study was to assess the effects of a histone deacetylase inhibitor - panobinostat on Wnt-dependent gene expression and cell migration. Cell viability in HNSCC cell lines (BICR6, CAL27, FaDu, H314, SCC-25) was evaluated by MTT assay. The expression of beta-catenin-target genes was assessed by qPCR and TCF/LEF-dependent reporter assay. Protein content was evaluated by Western blot. Cell migration was analyzed by the wound healing assay. Panobinostat showed differential modulation of gene expression. It reduced the level of Axin2 in CAL27 and SCC-25 cells but upregulated its expression in BICR6 and H314 cell lines. Moreover, it diminished the expression of MMP7 in BICR6, H314 and CAL27 cell lines. In contrast, the inhibitor of beta-catenin transcriptional activity - PKF118-310 down-regulated the expression of beta-catenin-target genes in HNSCC cell lines. Interestingly, panobinostat had opposite effects on cell migration in CAL27 and FaDu where it inhibited or stimulated migration, respectively. On the other hand, PKF118-310 reduced cell migration. The anti-cancer effects of panobinostat in HNSCC cells are rather not related to the inhibition of Wnt signaling. PKF118-310 attenuates Wnt signaling, but only in a limited number of HNSCC cell lines. Importantly, the inhibition of Wnt pathway reduces the capacity of cells for migration, suggesting that it may potentially reduce cell invasion therapeutically.