lncRNA-MIAT regulates cell biological behaviors in gastric cancer through a mechanism involving the miR-29a-3p/HDAC4 axis

: Gastric cancer (GC) is one of the most common malignant diseases worldwide. Although significant progress has been made in the early detection and treatment of GC over the past decades, the prognosis is still not satisfactory and the underlying mechanisms of carcinogenesis remain unknown. Long non-coding RNA MIAT has been established as a key player in the regulation of various biological and pathological processes including chronic lymphocytic leukemias, acute myocardial infarction and neuroendocrine prostate cancer. However, the function of MIAT in GC remains largely unknown. The expressions of lncRNA MIAT, miR-29a-3p and HDAC4 mRNA were analysed using quantitative real-time PCR (qRT-PCR). RNA interference approach was used to investigate the cellular functions of MIAT and miR-29a-3p. Cell Counting Kit-8 (CCK-8) assay and flow cytometry assay were performed to detect cell proliferation and apoptosis. Cell migration and invasion abilities were evaluated by Transwell assays. In the present study, we first confirmed the high expression level of MIAT in GC tissues and cell lines. In addition, knockdown of MIAT suppressed the proliferation, migration and invasion of GC cells in vitro. Furthermore, our results demonstrated that MIAT competitively binds to miR-29a-3p and consequently upregulates the expression of HDAC4, which is a downstream target of miR-29a-3p. In conclusion, the present study highlighted the involvement of the MIAT/miR-29a-3p/HDAC4 axis in the development of GC, which provided potential diagnostic and therapeutic targets for GC.