Suppression of long non-coding RNA MALAT1 inhibits survival and metastasis of esophagus cancer cells by sponging miR-1-3p/CORO1C/TPM3 axis.

Abstract

Esophageal cancer (EC) is a malignancy causing lots of mortality worldwide. Long non-coding RNAs (lncRNAs) are involved in the progression of multiple cancer types. The present study aimed to explore the function and associated mechanisms of lncRNA metastasis-associated lung adenocarcinoma transcript1 (MALAT1) in EC development by focusing on its interaction with miR-1-3p. The levels of MALAT1 and miR-1-3p were investigated in clinical EC specimens. Then, the expression of MALAT1 was knocked down in EC cell lines, and the effects of MALAT1 inhibition on the viability, migration, and invasion, and miR-1-3p/Coronin-1C (CORO1C)/Tropomyosin3 (TPM3) axis in EC cells were detected. The interaction between MALAT1 and miR-1-3p in the progression of EC was further determined by suppressing the expression of miR-1-3p in MALAT1 inhibition cells. The results were further verified with EC xenograft mice model. MALAT1 level was downregulated, while miR-1-3p level was upregulated in EC specimens. The inhibition of MALAT1 suppressed the viability, migration, and invasion in EC cell lines. The changes in phenotypes of EC cells were associated with the upregulation of miR-1-3p level and inhibition of CORO1C/TPM3 activity. Furthermore, the results of dual-luciferase assay showed the direct binding of MALAT1 to the seed sequence of miR-1-3p. The suppressed level of miR-1-3p not only induced the activity of CORO1C/TPM3 signaling, but also upregulated MALAT1 expression, indicating the reciprocal regulation between the two factors. The inhibition of MALAT1 also inhibited tumor growth and epithelial-mesenchymal transition (EMT) in mice model, which was reversed by miR-1-3p inhibition. Collectively, MALAT1 was important to the survival and metastasis of EC cells by sponging miR-1-3p.