Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.

Previous studies have shown that let-7 can repress the post-transcriptional translation of LIN28, and LIN28 in turn could block the maturation of let-7, forming a double-negative feedback loop. In this study, we investigated the effect of germline genetic variants on regulation of the homeostasis of...

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Main Authors: Ao-Xiang Chen, Ke-Da Yu, Lei Fan, Ji-Yu Li, Chen Yang, A-Ji Huang, Zhi-Ming Shao
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-09-01
Series:PLoS Genetics
Online Access:http://europepmc.org/articles/PMC3164678?pdf=render
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author Ao-Xiang Chen
Ke-Da Yu
Lei Fan
Ji-Yu Li
Chen Yang
A-Ji Huang
Zhi-Ming Shao
author_facet Ao-Xiang Chen
Ke-Da Yu
Lei Fan
Ji-Yu Li
Chen Yang
A-Ji Huang
Zhi-Ming Shao
author_sort Ao-Xiang Chen
collection DOAJ
description Previous studies have shown that let-7 can repress the post-transcriptional translation of LIN28, and LIN28 in turn could block the maturation of let-7, forming a double-negative feedback loop. In this study, we investigated the effect of germline genetic variants on regulation of the homeostasis of the let-7/LIN28 loop and breast cancer risk. We initially demonstrated that the T/C variants of rs3811463, a single nucleotide polymorphism (SNP) located near the let-7 binding site in LIN28, could lead to differential regulation of LIN28 by let-7. Specifically, the C allele of rs3811463 weakened let-7-induced repression of LIN28 mRNA, resulting in increased production of LIN28 protein, which could in turn down-regulate the level of mature let-7. This effect was then validated at the tissue level in that the normal breast tissue of individuals with the rs3811463-TC genotype expressed significantly lower levels of let-7 and higher levels of LIN28 protein than those individuals with the rs3811463-TT genotype. Because previous in vitro and ex vivo experiments have consistently suggested that LIN28 could promote cellular transformation, we then systematically evaluated the relationship between rs3811463 as well as other common LIN28 SNPs and the risk of breast cancer in a stepwise manner. The first hospital-based association study (n = 2,300) demonstrated that two SNPs were significantly associated with breast cancer risk, one of which was rs3811463, while the other was rs6697410. The C allele of the rs3811463 SNP corresponded to an increased risk of breast cancer with an odds ratio (OR) of 1.25 (P = 0.0091), which was successfully replicated in a second independent study (n = 1,156) with community-based controls. The combined P-value of the two studies was 8.0 × 10⁻⁵. Taken together, our study demonstrates that host genetic variants could disturb the regulation of the let-7/LIN28 double-negative feedback loop and alter breast cancer risk.
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spelling doaj.art-8d86bd48cda74f299f364a09513819942022-12-22T03:46:12ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042011-09-0179e100225910.1371/journal.pgen.1002259Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.Ao-Xiang ChenKe-Da YuLei FanJi-Yu LiChen YangA-Ji HuangZhi-Ming ShaoPrevious studies have shown that let-7 can repress the post-transcriptional translation of LIN28, and LIN28 in turn could block the maturation of let-7, forming a double-negative feedback loop. In this study, we investigated the effect of germline genetic variants on regulation of the homeostasis of the let-7/LIN28 loop and breast cancer risk. We initially demonstrated that the T/C variants of rs3811463, a single nucleotide polymorphism (SNP) located near the let-7 binding site in LIN28, could lead to differential regulation of LIN28 by let-7. Specifically, the C allele of rs3811463 weakened let-7-induced repression of LIN28 mRNA, resulting in increased production of LIN28 protein, which could in turn down-regulate the level of mature let-7. This effect was then validated at the tissue level in that the normal breast tissue of individuals with the rs3811463-TC genotype expressed significantly lower levels of let-7 and higher levels of LIN28 protein than those individuals with the rs3811463-TT genotype. Because previous in vitro and ex vivo experiments have consistently suggested that LIN28 could promote cellular transformation, we then systematically evaluated the relationship between rs3811463 as well as other common LIN28 SNPs and the risk of breast cancer in a stepwise manner. The first hospital-based association study (n = 2,300) demonstrated that two SNPs were significantly associated with breast cancer risk, one of which was rs3811463, while the other was rs6697410. The C allele of the rs3811463 SNP corresponded to an increased risk of breast cancer with an odds ratio (OR) of 1.25 (P = 0.0091), which was successfully replicated in a second independent study (n = 1,156) with community-based controls. The combined P-value of the two studies was 8.0 × 10⁻⁵. Taken together, our study demonstrates that host genetic variants could disturb the regulation of the let-7/LIN28 double-negative feedback loop and alter breast cancer risk.http://europepmc.org/articles/PMC3164678?pdf=render
spellingShingle Ao-Xiang Chen
Ke-Da Yu
Lei Fan
Ji-Yu Li
Chen Yang
A-Ji Huang
Zhi-Ming Shao
Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
PLoS Genetics
title Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
title_full Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
title_fullStr Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
title_full_unstemmed Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
title_short Germline genetic variants disturbing the Let-7/LIN28 double-negative feedback loop alter breast cancer susceptibility.
title_sort germline genetic variants disturbing the let 7 lin28 double negative feedback loop alter breast cancer susceptibility
url http://europepmc.org/articles/PMC3164678?pdf=render
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