MicroRNA-433 inhibits liver cancer cell migration by repressing the protein expression and function of cAMP response element-binding protein.

Abstract

We show for the first time that potent microRNA-433 (miR-433) inhibition of expression of the cAMP response element-binding protein CREB1 represses hepatocellular carcinoma (HCC) cell migration. We identified a miR-433 seed match region in human and mouse CREB1 3'-UTRs. Overexpression of miR-433 markedly decreased human CREB1 3'-UTR reporter activity, and the inhibitory effect of miR-433 was alleviated upon mutation of its binding site. Ectopic expression of miR-433 reduced CREB1 protein levels in a variety of human and mouse cancer cells, including HeLa, Hepa1, Huh7, and HepG2. Human CREB1 protein levels in highly invasive MHCC97H cells were diminished by expression of miR-433 but were induced by miR-433 antagomir (anti-miR-433). The expression of mouse CREB1 protein negatively correlated with miR-433 levels in nuclear receptor Shp(-/-) liver tissues and liver tumors compared with wild-type mice. miR-433 exhibited a significant repression of MHCC97H cell migration, which was reversed by anti-miR-433. Overexpressing miR-433 inhibited focus formation dramatically, demonstrating that miR-433 may exert a tumor suppressor function. Knockdown of CREB1 by siRNAs impeded MHCC97H cell migration and invasion and antagonized the effect of anti-miR-433. Interestingly, CREB1 siRNA decreased MHCC97H cell proliferation, which was not influenced by anti-miR-433. Overexpressing CREB1 decreased the inhibitory activity of miR-433. The CpG islands surrounding miR-433 were hypermethylated, and the DNA methylation agent 5'-aza-2'-deoxycytidine, but not the histone deacetylase inhibitor trichostatin A, drastically stimulated the expression of miR-433 and miR-127 in HCC cells. The latter is clustered with miR-433. The results reveal a critical role of miR-433 in mediating HCC cell migration via CREB1.

• Authors: Zhihong Yang, Hiroyuki Tsuchiya, Yuxia Zhang, M Elizabeth Hartnett, Li Wang
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 288 Issue 40 Pg. 28893-9 (Oct 04 2013) ISSN: 1083-351X [Electronic] United States
• PMID: 23979134 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• CREB1 protein, human
• Creb1 protein, mouse
• Cyclic AMP Response Element-Binding Protein
• MIRN433 microRNA, human
• MicroRNAs
• Mirn433 microRNA, mouse
• RNA, Small Interfering

Topics

• Acetylation
• Animals
• Base Sequence
• Carcinoma, Hepatocellular (genetics, pathology)
• Cell Line, Tumor
• Cell Movement (genetics)
• Cell Proliferation
• Cyclic AMP Response Element-Binding Protein (genetics, metabolism)
• DNA Methylation (genetics)
• Gene Expression Regulation, Neoplastic
• Humans
• Liver Neoplasms (genetics, pathology)
• Mice
• MicroRNAs (metabolism)
• Molecular Sequence Data
• RNA, Small Interfering (metabolism)