Published online Nov 15, 2021. doi: 10.4251/wjgo.v13.i11.1766
Peer-review started: February 22, 2021
First decision: May 8, 2021
Revised: May 19, 2021
Accepted: September 22, 2021
Article in press: September 22, 2021
Published online: November 15, 2021
Processing time: 262 Days and 20.7 Hours
The role of transforming growth factor beta (TGF-β) signaling, including both the cytokine and their receptors, in the etiology of colorectal cancer (CRC) has been of particular interest lately.
To investigate the association between promoter polymorphism in TGF-β receptor 2 TGF-ΒR2G[-875]A with a CRC risk in a cohort of Bulgarian patients using a case-control gene association study approach, as well as the protein levels of TGF-β1 in the peripheral blood.
A cohort of 184 CRC patients and 307 sex and age-matched healthy subjects were recruited in the study. A genotyping of the TGF-ΒR2G[-875]A (rs3087465) polymorphism was performed by primer-introduced restriction analyses-polymerase chain reaction approaches.
The frequency of TGF-ΒR2G[-875]A genotype was decreased in male patients with CRC than in healthy men (31.3% vs 44.8%; P = 0.058). Among males, the TGF-ΒR2G[-509]G genotype was related to a significantly increased risk of CRC development (OR = 1.820, 95%CI: 0.985-3.362, P = 0.055) than the GA + AA genotype. Also, TGF-ΒR2[-875]*A-allele itself was rarer in men with CRC than healthy men (19.1% vs 26.9%, P = 0.086) and was associated with a protective effect (OR = 0.644; 95%CI: 0.389-1.066; P = 0.086). Regarding the genotypes, we found that TGF-β1 serum levels were higher in GG genotype in healthy persons above 50 years than the CRC patients [36.3 ng/mL interquartile range (IQR) 19.9-56.5 vs 22.4 ng/mL IQR 14.8-29.7, P = 0.014]. We found significant differences between higher levels of TGF-β1 serum levels in healthy controls above 50 years (GG genotype) and CRC patients (GG genotype) at the early stage (36.3 ng/mL IQR 19.9-56.5 vs 22.8 ng/mL IQR 14.6-28.6, P = 0.037) and advanced CRC (36.3 ng/mL IQR 19.9-56.5 vs 21.6 ng/mL IQR 15.9-33.9, P = 0.039).
In summary, our results demonstrated that TGF-ΒR2 AG and AA genotypes were associated with a reduced risk of CRC, as well as circulating levels of TGF-β could prevent CRC development in a gender-specific manner. Notably, male carriers of TGF-ΒR2 -875A allele genotypes had a lower risk of CRC development and progression, suggesting that TGF-ΒR2 -875A/G polymorphism significantly affects the protective biological factors that also impact the risk of colon and rectal carcinogenesis.
Core Tip: Disruptions in transforming growth factor beta (TGF-β)-associated cancer mechanisms are essential in early-stage tumor development, whereas activation of TGF-β-signaling can encourage invasion and metastasis of cancer. Our findings from this case-control study suggested that the highest risk for developing colorectal neoplasia was found for the GG genotype. The increased risk for colorectal cancer (CRC) development was associated with male CRC patients homozygous for the GG genotype. In contrast, male carriers of TGF-ΒR2 -875A allele genotypes of TGF-ΒR2 had a lower risk of CRC development and progression. No other studies for this polymorphism and CRC association from the literature are available to the best of our knowledge.