Long non‑coding RNA DLX6‑AS1 is associated with malignant progression and promotes proliferation and invasion in esophageal squamous cell carcinoma

Despite being one of the most prevalent and fatal types of cancer worldwide, the biological details of esophageal squamous cell carcinoma (ESCC) remain unknown. Recent studies have demonstrated the crucial roles of long non‑coding RNAs (lncRNAs) in diverse biological processes including cancer initiation, progression and metastasis. The aim of the present study was to assess the expression profile of distal‑less homeobox 6 antisense RNA 1 (DLX6‑AS1) in ESCC tissues and its contributions to ESCC cell proliferation, apoptosis and invasion. The expression of DLX6‑AS1 in a series of ESCC samples and paired adjacent noncancerous tissues was evaluated by reverse transcription‑quantitative polymerase chain reaction. Cell proliferation, apoptosis, wound healing and Transwell invasion assays were performed to evaluate the roles of DLX6‑AS1 in the ESCC cell lines EC109 and KYSE30 transfected with DLX6‑AS1 small interfering RNA (siRNA). Compared with the paired adjacent noncancerous tissues, DLX6‑AS1 expression was upregulated in the ESCC tissues and significantly associated with differentiation status, Tumor‑Node‑Metastasis stage, distant metastasis, and lymph node metastasis. Knockdown of DLX6‑AS1 significantly suppressed cell proliferation, invasion and migration abilities, and enhanced the apoptotic rate in the two ESCC cell lines. Furthermore, western blot assays revealed that silencing DLX6‑AS1 partly influenced the epithelial‑mesenchymal transition process in ESCC cells. These results imply that the oncogenic function of DLX6‑AS1 may be a novel candidate target for treating human ESCC.