miR-29a activates Hes1 by targeting Nfia in esophageal carcinoma cell line TE-1

Abstract

MicroRNA (miR)‑29a has been associated with carcinogenesis in humans; however, its functional significance in esophageal squamous cell carcinoma (ESCC) is yet to be determined. In the present study, the expression of miR‑29a was markedly downregulated in ESCC tissue and the ESCC TE‑1 cell line, compared with normal esophageal tissue and cells. Furthermore, the present study identified that the forced expression of miR‑29a in TE‑1 cells significantly reduced cell proliferation and migration. miR‑29a overexpression did not affect the expression of Notch1, however, it did increase the gene expression levels of hairy and enhancer of split 1 (Hes1), which is the key effector of the Notch signaling pathway. Direct targeting by miR‑29a resulted in the downregulation of nuclear factor 1 A (Nfia), which represses the transcriptional activity of the Hes1 promoter. Furthermore, knockdown of Nfia increased Hes1 expression and inhibited cell growth in TE‑1 cells. These results indicate that a low level of miR‑29a expression is involved in ESCC tumorigenesis, and exogenous expression of miR‑29a may repress cancer cell growth by downregulating Nfia and activating the Notch signaling pathway.