Abstract
Long noncoding RNAs (lncRNAs) are important regulators of various cellular and biological processes. The present study aimed to investigate the functions of a novel lncRNA, ACTA2‑AS1:4, a transcript variant of smooth muscle α‑actin 2‑antisense 1 (ACTA2‑AS1), in regulating liver cancer progression. Expression of lncRNAs in liver cancer tissues and cell lines were analyzed by reverse transcription quantitative polymerase chain reaction (RT‑qPCR). Knockdown of ACTA2‑AS1:4 expression in LM3 liver cancer cells was achieved by transfection with small interfering RNAs (siRNAs) that specifically targeted ACTA2‑AS1:4. The proliferation and cell cycle progression of ACTA2‑AS1:4‑silenced LM3 cells were determined using MTS assay and flow cytometry, respectively. A Transwell system assay was used to evaluate the migration and invasion capacities of LM3 cells transfected with ACTA2‑AS1:4 siRNA. The expression levels of major genes associated with important cellular processes were finally determined by RT‑qPCR and western blot analysis. ACTA2‑AS1:4 expression in liver cancer tissues and multiple cell lines was markedly downregulated by specific siRNAs. This inhibition of ACTA2‑AS1:4 expression significantly promoted the proliferation, cell cycle progression, migration and invasion of LM3 cells. A decrease in ACTA2‑AS1:4 expression also suppressed E‑cadherin expression, increased N‑cadherin expression, decreased caspase 3 expression and increased cyclin D1 and matrix metalloproteinase expression in liver cancer cells. Downregulation of ACTA2‑AS1:4 affects a number of key mechanisms involved in liver cancer progression. These data may be important for the future of liver cancer diagnosis and subsequent treatments.