Depletion of histone deacetylase 1 inhibits metastatic abilities of gastric cancer cells by regulating the miR-34a/CD44 pathway.

Overexpression of histone deacetylases (HDACs) is associated with higher metastatic rates and a poor prognosis in gastric cancer. However, the underlying mechanisms involved remain unclear. The present study aimed to investigate the molecular pathways that are involved in HDAC1-mediated metastatic activities in gastric cancer cells. First we used a microRNA (miRNA or miR) microarray to screen potential miRNAs whose expression can be altered by HDAC1 depletion. Of these miRNAs, miR-34a is important as it is often inactivated in cancer cells and acts as a tumor suppressor for various types of cancer. The reverse transcription-quantitative polymerase chain reaction (RT‑qPCR) results confirmed that miR-34a was upregulated by HDAC1 knockdown. Cells depleted of HDAC1 had lower abilities to migrate, invade and adhere, which were restored by a miR-34a antagomiR. Depletion of HDAC1 also resulted in impaired microfilaments and microtubules, while co-transfection of the miR-34a antagomiR attenuated these changes in the cellular cytoskeleton. The HDAC1/miR-34a axis regulated the expression and activation of CD44 and its downstream factors including Bcl-2, Ras homolog family member A (RhoA), LIM domain kinase 1 (LIMK-1) and matrix metalloproteinase (MMP)-2. The latter three proteins were responsible for the organization of tubulin and actin cytoskeleton and the formation of cellular pseudopodia. In conclusion, results of the present study indicated that HDAC1 depletion inhibits the metastatic abilities of gastric cancer cells by regulating the miRNA-34a/CD44 pathway, which may be a potential target for the treatment of gastric cancer.