Downregulation of non‑muscle myosin IIA expression inhibits migration and invasion of gastric cancer cells via the c‑Jun N‑terminal kinase signaling pathway

: Non‑muscle myosin IIA (NMIIA) has been found to be overexpressed in gastric cancer tissues. However, the roles of NMIIA in the migration and invasion of gastric cancer cells have not yet been elucidated. The aim of the present study was to assess the effects of NMIIA knockdown on the migratory and invasive capacities of gastric cancer cells and to investigate the potential underlying mechanisms in vitro. First, the expression of NMIIA was assessed in gastric cancer tissues and non‑cancerous tissues using western blot analysis. The expression levels of NMIIA protein in 51 out of 63 gastric cancer tissue specimens were higher compared to those in their matched non‑tumoric gastric tissue specimens, and differences between the two groups were statistically significant (P<0.001). After downregulation of NMIIA using RNA interference, the migratory and invasive abilities of the SGC‑7901 and MGC‑803 gastric cancer cell lines were observed using a wound‑healing assay and a Transwell assay, respectively. Knockdown of NMIIA significantly decreased the amount of wound closure as well as the number of cells which transgressed through the Matrigel (P<0.01). Finally, the levels of c‑Jun N‑terminal kinase (JNK), phosphorylated (p)‑JNK, c‑Jun and p‑c‑Jun were detected using western blot analysis in order to explore the association between NMIIA and the JNK signaling pathway. Knockdown of NMIIA decreased the levels of p‑JNK and p‑c‑Jun in the two gastric cancer cell lines (P<0.05). In conclusion, the present study indicated that knockdown of NMIIA inhibited the migration and invasion of gastric cancer cells, which may be, at least in part, mediated via the JNK signaling pathway.