Inhibition of long non-coding RNA MALAT1 elevates microRNA-429 to suppress the progression of hypopharyngeal squamous cell carcinoma by reducing ZEB1.

OBJECTIVE

Hypopharyngeal squamous cell carcinoma (HSCC) is a common type of malignant tumor. Long non-coding RNAs (lncRNAs) are known to participate in HSCC development, while the role of lncRNA MALAT1 in HSCC remains largely unknown. We aimed to explore function of the lncRNA MALAT1/miR-429/ZEB1 axis in HSCC progression.

METHODS

Levels of MALAT1, miR-429 and ZEB1 in HSCC tissues samples were assessed. The FaDu cells were respectively treated with relative sequence or plasmid of MALAT1, miR-429, or ZEB1. Then, CCK-8 assay, colony formation assay, flow cytometry and Transwell assay were used to determine the cell proliferation, apoptosis, cell cycle, migration and invasion of the cells. The PI3K/Akt/mTOR signaling pathway-related proteins, proliferation-related proteins, cell cycle-related proteins, apoptosis-related proteins, and migration-related proteins were detected using Western blot analysis. The cell growth in vivo was observed. The targeting relationships between MALAT1 and miR-429, and between miR-429 and ZEB1 were confirmed.

RESULTS

MALAT1 and ZEB1 expression in HSCC was upregulated while miR-429 expression was downregulated. Reduced MALAT1 and ZEB1, and upregulated miR-429 inactivated the PI3K/Akt/mTOR signaling pathway, suppressed in vitro viability, colony formation ability, migration and invasion, as well as cell growth in vivo, and promoted the apoptosis of FaDu cells. Downregulated miR-429 reversed the role of MALAT1 inhibition in FaDu cell growth. LncRNA MALAT1 served as a sponge of miR-429, thus regulating ZEB1 expression.

CONCLUSION

Inhibition of MALAT1 was able to elevate miR-429 to suppress the progression of HSCC via reducing ZEB1. Our research provided a potential therapeutic target for HSCC.