A single nucleotide polymorphism in the 3'-UTR of STAT3 regulates its expression and reduces risk of pancreatic cancer in a Chinese population

Association of JAK/STAT genetic variants with cutaneous melanoma

Background

The Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway regulates cutaneous melanoma (CM) development and progression. The JAK1, JAK2, and STAT3 proteins are encoded by polymorphic genes. This study aimed to verify whether single-nucleotide variants (SNVs) in JAK1 (c.1648+1272G>A, c.991-27C>T), JAK2 (c.-1132G>T, c.-139G>A), and STAT3 (c.*1671T>C, c.-1937C>G) altered the risk, clinicopathological aspects, and survival of CM patients as well as protein activity.

Methods

CM patients (N = 248) and controls (N = 274) were enrolled in this study. Genotyping was performed by real-time polymerase chain reaction (PCR), and JAK1, JAK2, and STAT3 expression was assessed by quantitative PCR (qPCR). STAT3 c.-1937C>G SNV was investigated by luciferase, qPCR, western blot, apoptosis, and cell cycle assays in SKMEL-28 cells with CC or GG genotype.

Results

Individuals with STAT3 c.*1671TT and c.-1937CC genotypes and TC haplotype of both SNVs were under about 2.0-fold increased risk of CM. Specific JAK1, JAK2, and STAT3 combined genotypes were associated with up to 4.0-fold increased risk of CM. Higher luciferase activity [4,013.34 vs. 2,463.32 arbitrary units (AU); p = 0.004], STAT3 expression by qPCR (649.20 vs. 0.03 AU; p = 0.003) and western blot (1.69 vs. 1.16 AU; p = 0.01), and percentage of cells in the S phase of the cell cycle (57.54 vs. 30.73%; p = 0.04) were more frequent in SKMEL-28 with STAT3 c.-1937CC than with GG genotype. CM cell line with CC genotype presented higher STAT3 protein levels than the one with GG genotype (1.93 versus 1.27 AU, p = 0.0027).

Conclusion

Our data present preliminary evidence that inherited abnormalities in the JAK/STAT pathway can be used to identify individuals at a high risk of CM, who deserve additional attention for tumor prevention and early detection.

Genetics and Functional Mechanisms of STAT3 Polymorphisms in Human Tuberculosis

Signal transducer and activator of transcription-3 (STAT3) plays an important role in biological balance. Our and others previous studies implied that STAT3 had a great effect on fast-acting innate immunity against tuberculosis (TB). We hypothesized that stat3 SNP down-regulation of STAT3 leads to a change in susceptibility to TB in humans. To test this hypothesis, we investigated STAT3 SNPs using SNP scan™ technique in a case-control study of TB patients (n = 470) and HC subjects (n = 356), and then conducted functional studies of them using cellular models. We found that SNPs in STAT3 3`-UTR of rs1053004 TT and rs1053005 AA genotypes or T-A haplotype were associated with susceptibility to TB or TB severity. While the TT/AA genotype correlated with the low constitutive expression of stat3 and IL-17A in PBMC, the variant stat3 of rs1053004-rs1053005 T-A haplotype indeed reduced stat3 expression in reporter assays. Interestingly, host PBMC expressing the rs1053005 AA genotype and low constitutive stat3 exhibited the reduced ability to mount fast-acting innate immunity against mycobacterial infection in cellular models. Finally, mechanistic experiments showed that the STAT3 down-regulation broadly depressed STAT3 downstream anti-mycobacterial activities involving VDR-related CAMP pathway as well as IL-32, iNOS and autophagy mechanisms, leading to an enhanced mycobacterial infection. The findings of this study suggest that low constitutive stat3 derived from the TT/AA genotype/T-A haplotype acts to down-regulate STAT3, depressing multiple anti-mycobacterial pathways/mechanisms downstream, which leads to an enhanced mycobacterial infection or TB in high-risk individuals.

Genetic polymorphisms in inflammatory genes and pancreatic cancer risk: a two-phase study on more than 14 000 individuals

There is overwhelming evidence that inflammation plays a key role in the pathogenesis of cancer and its progression. Inflammation is regulated through a complex network of genes and polymorphic variants in these genes have been found to be associated to risk of various human cancers, alone or in combination with environmental variables. Despite this, not much is known on the genetic variability of genes that regulate inflammation and risk of pancreatic ductal adenocarcinoma (PDAC). We performed a two-phase association study considering the genetic variability of 76 genes that are key players in inflammatory response. We analysed tagging single nucleotide polymorphisms (SNPs) and regulatory SNPs on 7207 PDAC cases and 7063 controls and observed several associations with PDAC risk. The most significant association was between the carriers of the A allele of the CCL4-rs1719217 polymorphism, which was reported to be also associated with the expression level of the CCL4 gene, and increased risk of developing PDAC (odds ratio = 1.12, 95% confidence interval = 1.06-1.18, P = 3.34 × 10-5). This association was significant also after correction for multiple testing, highlighting the importance of using potentially functional SNPs in order to discover more genetic variants associated with PDAC risk.

Role of Tmem163 in zinc-regulated insulin storage of MIN6 cells: Functional exploration of an Indian type 2 diabetes GWAS associated gene

Genome wide association study for type 2 diabetes discovered TMEM163 as a risk locus. Perturbations in TMEM163 expression was reported to be associated with impaired intracellular zinc homeostasis. Physiological concentration of zinc is instrumental to maintain insulin storage and functionality in pancreatic β cells. We found abundant TMEM163 expression in human pancreas, both at transcriptional and translational levels. Knockdown of endogenous Tmem163 in MIN6 cells resulted in increased intracellular zinc and total insulin content, coupled with compromised insulin secretion at high glucose stimuli. Furthermore, Tmem163 knockdown led to enhanced cellular glucose uptake. Upon next generation sequencing, one-third of the studied T2D patients were found to have a novel missense variant in TMEM163 gene. Study participants harboring this missense variant displayed a trend of higher glycemic indices. This is the first report on exploring the biological role of TMEM163 in relation to T2D pathophysiology.

Exome-wide analysis identifies three low-frequency missense variants associated with pancreatic cancer risk in Chinese populations

Germline coding variants have not been systematically investigated for pancreatic ductal adenocarcinoma (PDAC). Here we report an exome-wide investigation using the Illumina Human Exome Beadchip with 943 PDAC cases and 3908 controls in the Chinese population, followed by two independent replicate samples including 2142 cases and 4697 controls. We identify three low-frequency missense variants associated with the PDAC risk: rs34309238 in PKN1 (OR = 1.77, 95% CI: 1.48–2.12, P = 5.35 × 10⁻¹⁰), rs2242241 in DOK2 (OR = 1.85, 95% CI: 1.50–2.27, P = 4.34 × 10⁻⁹), and rs183117027 in APOB (OR = 2.34, 95% CI: 1.72–3.16, P = 4.21 × 10⁻⁸). Functional analyses show that the PKN1 rs34309238 variant significantly increases the level of phosphorylated PKN1 and thus enhances PDAC cells' proliferation by phosphorylating and activating the FAK/PI3K/AKT pathway. These findings highlight the significance of coding variants in the development of PDAC and provide more insights into the prevention of this disease.

Pancreatic ductal adenocarcinoma is a lethal human cancer with a poor 5-year overall survival rate. Here the authors perform an exome-wide analysis in a cohort of PDAC patients to identify three novel missense variants in PKN1, DOK2, and APOB genes, that are associated with PDAC risk.

Preliminary Report on the Association Between STAT3 Polymorphisms and Susceptibility to Acute Kidney Injury After Cardiopulmonary Bypass

Cardiopulmonary bypass-associated acute kidney injury (CPB-AKI) is a well-recognized complication which is clearly linked to increased morbidity and mortality. Due to important role of inflammation in CPB-AKI pathogenesis, we explored the association between polymorphisms in STAT3, an inflammation-associated transcription factor, and the risk of CPB-AKI. In this study, STAT3 rs1053004 and rs744166 polymorphisms were analyzed in 129 patients undergoing coronary artery bypass grafting in Jorjani heart center, Bandar Abbas, Iran. The genotypes were determined using sequence-specific primers (PCR-SSP). Sixty-three patients met the criteria for AKI after cardiac surgery (AKI group). The remaining 66 patients did not develop AKI (non-AKI group). Rs1053004 GG genotype was significantly associated with a decreased risk (OR 0.4, 95% CI 0.17-0.9, P = 0.03) of CPB-AKI. Subgroup analyses revealed that GG genotype has also a protective effect in older patients (Age ≥ 60) (OR 0.19, 95% CI 0.04-0.8, P = 0.01). However, rs744166 did not show any difference between AKI and non-AKI groups. The result of our study for the first time provides evidence that rs1053004 polymorphism is significantly associated with a decreased risk of CPB-AKI in Iranian population, especially in older subjects.

Association of polymorphism rs1053005 in STAT3 with chronic hepatitis B virus infection in Han Chinese population

Background

Signal transducer and activator of transcription 3 (STAT3) is involved in hepatitis B virus (HBV) infection and HBV-related hepatocellular carcinoma (HCC). The association between polymorphism rs1053005 and haplotypes formed by rs1053004 and rs1053005 in the 3′UTR of STAT3 and chronic HBV infection has yet to be investigated.

Methods

This study included 567 patients with chronic HBV infection (239 chronic hepatitis, 141 liver cirrhosis and 187 HCC), 98 HBV infection resolvers, and 169 healthy controls. STAT3 rs1053004 and rs1053005 polymorphisms were genotyped by TaqMan SNP Genotyping Assays.

Results

The rs1053004 genotype CC [P value by Bonferroni correction (P_c) = 0.002] and allele C (P_c = 0.019) were more frequent in patients with chronic HBV infection than in healthy controls. The rs1053005 genotype GG was also more frequent in patients with chronic HBV infection than in healthy controls (P_c = 0.046). The rs1053004-rs1053005 haplotype T-G was less frequent in patients with chronic HBV infection than in healthy controls (P_c < 0.001). Haplotype C-A was more frequent in patients with liver cirrhosis than in patients with HCC (P_c = 0.042). The rs1053004 genotype TC, rs1053005 genotype AG and rs1053004-rs1053005 haplotype T-A were associated with higher HBV DNA levels.

Conclusions

STAT3 rs1053004 and rs1053005 polymorphisms and haplotypes formed by rs1053004 and rs1053005 are associated with chronic HBV infection and the haplotypes appear to be also associated with the development of liver disease. Studies in large sample sizes of patients and control populations are required to verify and extend these findings.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0569-x) contains supplementary material, which is available to authorized users.

BRCA1 missense polymorphisms are associated with poor prognosis of pancreatic cancer patients in a Chinese population

Pancreatic cancer is a highly lethal disease with limited prognostic marker. BRAC1 and BRCA2 are two classic tumor suppressor genes which play an important role in DNA repair. Somatic mutations and germline genetic variants on BRCA1/2 have been found associated with the tumorigenesis of pancreatic cancer. However, the correlations between BRCA1/2 polymorphism and pancreatic cancer prognosis remained unknown. In this study, we genotyped three tag missense variants on BRCA1/2 in 603 sporadic pancreatic cancer patients in a Chinese population. We found rs1799966 on BRCA1 was associated with poor prognosis of pancreatic cancer patients with hazard ratio being 1.23 (95% CI: 1.09–1.40, P = 0.0010). Further stratification analyses showed that significant correlation was particularly in locally advanced stage patients with hazard ratio being 1.36 (95% CI: 1.13–1.64, P = 0.0014), but not in patients in local stage (P = 0.1139) or metastatic stage (P = 0.5185). Two missense variants (rs766173 and rs144848) on BRAC2 showed no significant correlation with pancreatic cancer patients’ overall survival. In conclusion, we identified a germline missense variant on BRAC1 significantly associated with poor prognosis of pancreatic cancer patients with locally advanced stage. These results may contribute to the precision medicine of this disease.