Background: Long non-coding RNA is considered to be essential to modulate the development and progression of human malignant cancers. And long non-coding RNA can act as crucial modulators by sponging the corresponding microRNA in tumorigenesis. We aimed to elucidate the function of ACTA2-AS1 and its molecular mechanism in colon adenocarcinoma.
Materials and methods: The expression of ACTA2-AS1, miR-4428 and BCL2L11 in colon adenocarcinoma tissues were detected via qRT-PCR. SW480 and HT29 cells were transfected with shRNA ACTA2-AS1, OE ACTA2-AS1, miRNA mimics of miR-4428, miR-4428 inhibitor, si-BCL2L11 and over-expression of si-BCL2L11. Cell proliferation, colony formation and apoptosis were respectively assessed using CCK-8 assay, colony assay and flow cytometry. Luciferase reporter assay was performed to verify the targets of ACTA2-AS1 and miR-4428. Tumor subcutaneous xenograft mode was constructed to explore tumor growth in vivo.
Results: ACTA2-AS1 was obviously downregulated in human colon adenocarcinoma tissues and colon adenocarcinoma cell lines. Silence or over-expression of ACTA2-AS1 promoted or inhibited cell proliferation and colony formation abilities, and regulated apoptosis. The silence of ACTA2-AS1 resulted in the decrease of Bax and increase of Bal2, while restored in OE ACTA2-AS1 group when compared with the control transfected cells. In addition, luciferase reporter assay revealed that ACTA2-AS1 interacted with miR-4428 and suppressed its expression. miR-4428 could bind to 3' untranslated region of BCL2L11 and modulated the expression of BCL2L11 negatively. Knockdown of ACTA2-AS1 and over-expression of BCL2L11 reversed the biological function that ACTA2-AS1 mediated by knockdown ACTA2-AS1 alone.
Conclusion: Our data demonstrated that ACTA2-AS1 could suppress colon adenocarcinoma progression via sponging miR-4428 to regulate BCL2L11 expression.
Keywords: ACTA2-AS1; BCL2L11; Colon adenocarcinoma; miR-4428.