Two recent genome-wide association studies (GWAS) identified three common variants in SMAD7 (rs4464148, rs4939827 and rs12953717) that confer modest susceptibility to colorectal cancer.
SNP rs7229639 in the SMAD7 gene was found to be associated with CRC risk with an odds ratio (95% confidence interval) associated with the minor allele (A) of 1.22 (1.15-1.29) in the combined analysis of all 11 studies (p = 2.93 × 10(-11) ).
As partial validation of our approach, a known CRC risk variant in SMAD7 (in both the TGF-β and WNT pathways: rs11874392) was associated with CRC risk in our data.
We found that two of the loci most strongly linked with colorectal cancer (CRC) risk, 8q24 (upstream of MYC) and 18q21 (in the intron of SMAD7), as well as 20q13 (in the intron of LAMA5), are tightly associated with the prognosis of rectal cancer patients.
The two stage association studies showed that missense variant rs3764482 (c. 83C>T; p. rs3764482" genes_norm="4092">S28F) in the gene SMAD7 was consistently and significantly associated with CRC risk.
Among the European CRC-susceptibility SNPs, rs4939827 in SMAD7 was associated with a significant decreased risk of Korean CRC (age-/gender-adjusted odds ratio [95% confidence interval]: additive model, 0.67 [95% CI, 0.47-0.95]; dominant model, 0.59 [95% CI, 0.39-0.91]). rs4779584 and rs10795668 were associated with CRC risk in females and males, respectively.
SMAD7rs11874392 presented consistently significant associations with a risk of CRC at both stages, with odds ratio = 1.41 (95% confidence interval = 1.21-1.63) using additive modes in combined analyses.
Eight miRSNPs (rs1804191, rs397768, rs41116 in APC; rs1137918, s227091, rs4585 in ATM; rs712, rs1137282, rs61764370 in KRAS; rs8674 in PARP1 and rs16950113 in SMAD7) were tested for their association with CRC risk in a case-control study (1111 cases and 1469 healthy controls).
The aim of this study was to investigate the influence of a SMAD7 gene polymorphism (rs2337107) on risk of CRC and clinicopathological features in an Iranian population.
Common colorectal cancer risk variants in SMAD7 are associated with survival among prediagnostic nonsteroidal anti-inflammatory drug users: a population-based study of postmenopausal women.
Recently we have demonstrated variation in SMAD7, defined by the single nucleotide polymorphism rs12953717, to be strongly associated with risk of colorectal cancer.
When assessed by a priori defined functional pathways, tumor growth factor β (TGFβ) signaling was associated with CRC risk (<i>P</i> ≤ 0.001), with most statistically significant genes being <i>SMAD7 (P<sub>BH</sub></i> = 0.008) and <i>SMAD3 (P<sub>BH</sub></i> = 0.008), and 18 SNPs in the vitamin D receptor (VDR) binding sites (<i>P</i> = 0.036).
For SMAD7 gene, rs4939827 and rs4464148 are risk factors for CRC among Caucasian whereas rs12953717 could elevate the susceptibility to CRC in both Caucasian and Asian.
We used meta-analysis of an efficient empirical-Bayes estimator to detect potential multiplicative interactions between each of the SNPs [rs16892766 at 8q23.3 (EIF3H/UTP23), rs6983267 at 8q24 (MYC), rs10795668 at 10p14 (FLJ3802842), rs3802842 at 11q23 (LOC120376), rs4444235 at 14q22.2 (BMP4), rs4779584 at 15q13 (GREM1), rs9929218 at 16q22.1 (CDH1), rs4939827 at 18q21 (SMAD7), rs10411210 at 19q13.1 (RHPN2), and rs961253 at 20p12.3 (BMP2)] and select major CRC risk factors (sex, body mass index, height, smoking status, aspirin/nonsteroidal anti-inflammatory drug use, alcohol use, and dietary intake of calcium, folate, red meat, processed meat, vegetables, fruit, and fiber).
These findings suggest that individuals with this SMAD7 variant that develop CRC are more probably to have tumors with greater invasiveness and methylation of RUNX3, which potentially contributes to their poorer observed survival.
Moreover, we found cumulative effects of three genetic factors (rs7758229, rs6983267, and rs4939827 in SMAD7) and one environmental factor (alcohol drinking) which appear to increase CRC risk approximately twofold.