Long non-coding RNA XIST promotes the development of esophageal cancer by sponging miR-494 to regulate CDK6 expression

Abstract

Objective: Esophageal cancer is one of the deadliest cancers worldwide occurring at upper gastrointestinal tract. This study aimed to explore the possible role of long non-coding RNA X Inactive Specific Transcript (XIST) in the development of esophageal cancer.

Material and methods: The lncRNA XIST expressions both in esophageal cancer tissues and in cells were investigated. The TE-1 and SKGT-4 cells were transfected with LV-sh-XIST and LV-scramble for the further detection of the effects of XIST expression on cell biological processes, including proliferation, apoptosis and the expression of apoptosis-related proteins, migration, invasion and the expression of epithelial-mesenchymal transition markers. Additionally, the regulatory relationships between lncRNA XIST and miR-494, between miR-494 and CDK6, between miR-494/CDK6 and JAK2/STAT3 pathway were investigated.

Results: LncRNA XIST was overespressed in esophageal cancer tissues and cells. Suppression of XIST significantly inhibited the proliferation, migration and invasion, but induced apoptosis of two kinds of cells, TE-1 and SKGT-4. Moreover, miR-494 was down-regulated in esophageal cancer tissues and cells. XIST could sponge miR-494 and inhibition of miR-494 reversed the effects of XIST suppression on the malignant behaviors of TE-1 cells. Also, CDK6 was a target of miR-494 and CDK6 knockdown reversed the effects of miR-494 inhibition on the malignant behaviors of TE-1 cells. Besides, the expression of p-JAK2 and p-STAT3 was increased after miR-494 inhibition, which was reversed after inhibition of miR-494 and CDK6 at the same time.

Conclusions: The data presented in this study revealed that XIST abnormal expression may play an oncogenic role in the development of esophageal cancer via miR-494/CDK6 axis through JAK2/STAT3 signal pathway. This study may provide theoretical basis for the molecular mechanism investigation of esophageal cancer.

Keywords: Cyclin dependent kinase 6 (CDK6); Esophageal cancer; JAK2/STAT3 pathway; Long non-coding RNA; X inactive specific transcript; miR-494.