Abstract |
Colorectal cancer (CRC) risk is modulated by diet and there is convincing evidence of reduced risk with higher non-digestible carbohydrates (NDCs) consumption. Resistant starch (RS), a NDC, positively modulates the expression of oncogenic microRNAs, suggesting that this could be a mechanism through which NDCs protect against CRC. The present study aimed to investigate the effects of supplementation with two NDCs, RS, and polydextrose (PD), on microRNA expression in the macroscopically-normal human rectal epithelium using samples from the DISC Study, a randomized, double-blind, placebo-controlled dietary intervention. We screened 1008 miRNAs in pooled post-intervention rectal mucosal samples from participants allocated to the double placebo group and those supplemented with both RS and PD. A total of 111 miRNAs were up- or down-regulated by at least twofold in the RS + PD group compared with the control group. From these, eight were selected for quantification in individual participant samples by qPCR, and fold-change direction was consistent with the array for seven miRNAs. The inconsistency for miR-133b and the lower fold-change values observed for the seven miRNAs is probably because qPCR of individual participant samples is a more robust and sensitive method of quantification than the array. miR-32 expression was increased by approximately threefold (P = 0.033) in the rectal mucosa of participants supplemented with RS + PD compared with placebo. miR-32 is involved in the regulation of processes such as cell proliferation that are dysregulated in CRC. Furthermore, miR-32 may affect non-canonical NF-κB signaling via regulation of TRAF3 expression and consequently NIK stabilization.
|
Authors | Fiona C Malcomson, Naomi D Willis, Iain McCallum, Long Xie, Bart Lagerwaard, Seamus Kelly, D Michael Bradburn, Nigel J Belshaw, Ian T Johnson, John C Mathers |
Journal | Molecular carcinogenesis
(Mol Carcinog)
Vol. 56
Issue 9
Pg. 2104-2111
(09 2017)
ISSN: 1098-2744 [Electronic] United States |
PMID | 28418082
(Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
|
Copyright | © 2017 The Authors. Molecular Carcinogenesis Published by wiley periodicals, Inc. |
Chemical References |
- Glucans
- MIRN32 microRNA, human
- MicroRNAs
- Starch
- polydextrose
|
Topics |
- Adult
- Aged
- Colon
(drug effects, metabolism)
- Dietary Supplements
- Digestion
- Double-Blind Method
- Female
- Glucans
(pharmacology)
- Humans
- Intestinal Mucosa
(drug effects)
- Male
- MicroRNAs
(biosynthesis)
- Middle Aged
- Polymerase Chain Reaction
(methods)
- Rectum
(drug effects, metabolism)
- Starch
(pharmacology)
|