J Cancer Prev.  2019 Dec;24(4):224-232. 10.15430/JCP.2019.24.4.224.

Effects of β-carotene on Expression of Selected MicroRNAs, Histone Acetylation, and DNA Methylation in Colon Cancer Stem Cells

• Kim D
• Kim Y
• Kim Y

• KMID: 2468812
• DOI: http://doi.org/10.15430/JCP.2019.24.4.224

Abstract

BACKGROUND
Beta-carotene (BC) is a carotenoid which exerts anti-cancer effects in several types of cancer, including colorectal cancer. Epigenetic modifications of genes, such as histone deacetylation and DNA hypermethylation, have also been detected in various types of cancer. To understand the molecular mechanism underlying cancer preventive and therapeutic effects of BC, microRNAs (miRNAs), histone acetylation, and global DNA methylation in colon cancer stem cells (CSCs) were investigated.
METHODS
HCT116 colon cancer cells positive for expression of CD44 and CD133 were sorted by flow cytometry and used in subsequent experiments. Cell proliferation was examined by the MTT assay and self-renewal capacity was analyzed by the sphere formation assay. The miRNA sequencing array was used to detect miRNAs regulated by BC. Histone acetylation levels were measured by the Western blot analysis. mRNA expression of DNA methyltransferases (DNMTs) was examined by qPCR and global DNA methylation levels were determined by enzyme-linked immunosorbent assay.
RESULTS
Treatment of CD44⁺CD133⁺ colon CSCs with BC caused a reduction in both cell proliferation and sphere formation. Analysis of the miRNA sequencing array showed that BC regulated expression of miRNAs associated with histone acetylation. Histone H3 and H4 acetylation levels were elevated by BC treatment. In addition, BC treatment down-regulated DNMT3A mRNA expression and global DNA methylation in colon CSCs.
CONCLUSIONS
These results suggest that BC regulates epigenetic modifications for its anti-cancer effects in colon CSCs.

Keyword

Beta carotene; microRNAs; DNA methylation; Epigenomics; Colorectal neoplasms

MeSH Terms

Acetylation*
beta Carotene
Blotting, Western
Cell Proliferation
Colon*
Colonic Neoplasms*
Colorectal Neoplasms
DNA Methylation*
DNA*
Enzyme-Linked Immunosorbent Assay
Epigenomics
Flow Cytometry
Histones*
Methyltransferases
MicroRNAs*
RNA, Messenger
Stem Cells*
Therapeutic Uses
DNA
Histones
Methyltransferases
MicroRNAs
RNA, Messenger
Therapeutic Uses
beta Carotene