A Single-Nucleotide Polymorphism in 3'-Untranslated Region of Endothelin-1 Reduces Risk of Dementia After Ischemic Stroke

Association between KRAS gene polymorphisms and genetic susceptibility to breast cancer in a Chinese population

OBJECTIVE

The KRAS gene has a pathophysiological role in the development of many cancers. This study aims to investigate the relationship between KRAS polymorphisms and genetic susceptibility to breast cancer.

METHOD

The rs712, rs12587 and rs9266 gene loci in the KRAS gene of 421 subjects (141 breast cancer patients, 141 benign breast tumours and 139 healthy controls) were analysed by the polymerase chain reaction and SNaPshot sequencing. Transcriptomic information on KRAS and corresponding clinical information was downloaded from the TCGA and GTEx databases. Differences in KRAS expression between breast cancer tissues and control tissues were analysed.

RESULTS

We found no significant association between KRAS rs712 and rs12587 locus gene polymorphisms and an increased risk of developing benign breast tumours and breast cancer (p > 0.05). The KRAS rs9266 locus mutation heterozygous model CT and dominant model CT + TT were significantly associated with an increased risk of breast cancer (both p < 0.05). In addition, the TAT haplotype was expressed at an increased frequency, and the GAC haplotype was expressed at a reduced frequency in breast cancer compared with controls (both p < 0.05). We found that KRAS was over expressed in breast cancer tumour tissues compared with the control tissues (p < 0.0001).

CONCLUSION

The KRAS rs9266 gene polymorphism and the TAT haplotype may be associated with an increased risk of breast cancer in Chinese women. The GAC haplotype may be a protective factor against breast cancer.

Rs12976445 polymorphism is associated with the risk of post-SAH re-bleeding by modulating the expression of microRNA-125 and ET-1

This study aimed to study the association between rs12976445 polymorphism and the incidence of IA re-bleeding. Genotype and allele frequency analysis was performed to study the association between rs12976445 polymorphism and the risk of IA re-bleeding. Western blot, ELISA and real-time RT-PCR were conducted to measure the relative expression of miR-125a, ET1 mRNA and ET1 protein. Computational analysis and luciferase assays were utilized to investigate the association between the expression of miR-125a and ET1 mRNA. No significant differences were observed between IA patients with or without symptoms of re-bleeding. Subsequent analyses indicated that the T allele was significantly associated with the reduced risk of IA re-bleeding. In patients carrying the CC genotype, miR-125a level was up-regulated while ET1 mRNA/protein levels were reduced compared with those in patients carrying the CT or TT genotype. And ET1 mRNA was identified as a virtual target gene of miR-125a with a potential miR-125a binding site located on its 3’UTR. Accordingly, the ET mRNA/protein levels could be suppressed by the transfection of miR-125a precursors, but the transfection of ET1 siRNA exhibited no effect on the expression of miR-125a. Therefore, an increased level of miR-125a can lead to the increased risk of IA re-bleeding. Since miR-125a level is higher in CC-genotyped patients, it can be concluded that the presence of T allele in the rs12976445 polymorphism is associated with a lower risk of IA re-bleeding, and miR-125a may be used as a novel diagnostic and therapeutic target for IA rupture.

Positive Association between EDN1 rs5370 (Lys198Asn) Polymorphism and Large Artery Stroke in a Ukrainian Population

There are a lot of convincing evidences about the involvement of endothelin pathway proteins in the pathogenesis of atherosclerosis and its fatal complications. In this study, the analysis of a possible association between EDN1 rs5370 and EDNRA rs5335 gene polymorphisms and the risk of large artery stroke (LAS) in a Ukrainian population was conducted. 200 LAS patients and 200 unrelated controls were enrolled in a case-control study. The polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) was used for SNP genotyping. Our results revealed that EDN1 rs5370 polymorphism was associated with LAS development both before and after adjustment for atherosclerosis risk factors (sex, age, body mass index, arterial hypertension, type 2 diabetes mellitus, and smoking). The risk for a LAS incident in rs5370-T allele carriers was 1.6 times higher (CI = 1.066–2.403; P = 0.020) than in subjects with the GG genotype. No link between EDNRA rs5335 and LAS risk in a Ukrainian population was found. The present study indicated that EDN1 rs5370, but not EDNRA rs5335, can be the strong genetic predictor for LAS development in a Ukrainian population.

Aldehyde Dehydrogenase 2 (ALDH2) Glu504Lys Polymorphism Affects Collateral Circulation and Short-Term Prognosis of Acute Cerebral Infarction Patients

Background

Acute cerebral infarction is a major clinical subtype of ischemic stroke that has become a leading cause of death and disability worldwide. Aldehyde dehydrogenase 2 (ALDH2) is an important oxidative enzyme in alcohol metabolism. The polymorphism of ALDH2 Glu504Lys polymorphism modifies the activity of this enzyme. However, the potential association between the allelic variation of ALDH2 Glu504Lys with collateral circulation and short-term prognosis of acute cerebral infarction remains unclear.

Material/Methods

A total of 394 patients with acute cerebral infarction were recruited for ALDH2 genotyping using direct sequencing. Cerebrovascular stenosis and collateral circulation were evaluated by digital subtraction angiography (DSA). Short-term prognosis was assessed in accordance with the modified Ranking Scale (mRS).

Results

We identified 297 as EAS and 394 as IAS. There were more patients with occluded blood vessel in the opened group and far fewer in the unopened group. ALDH2 polymorphism was significantly different among the primary, secondary, and tertiary opened groups. ALDH2 gene Glu504Lys was significantly associated with short-term prognosis. The genotype GA+AA of ALDH2 gene Glu504Lys locus was an independent risk factor of poor 90-day prognosis.

Conclusions

ALDH2 Glu504Lys could be a risk factor for collateral circulation and a negative predictor for short-term prognosis in acute cerebral infarction in Han Chinese. ALDH2 Glu504Lys could be a new therapeutic target for patients with acute cerebral infarction.