An evaluation study of reported pancreatic adenocarcinoma risk-associated SNPs from genome-wide association studies in Chinese population

Genetic polymorphism of the Dab2 gene and its association with Type 2 Diabetes Mellitus in the Chinese Uyghur population

Objective

The human Disabled-2 (Dab2) protein is an endocytic adaptor protein, which plays an essential role in endocytosis of transmembrane cargo, including low-density lipoprotein cholesterol (LDL-C). As a candidate gene for dyslipidemia, Dab2 is also involved in the development of type 2 diabetes mellitus(T2DM). The aim of this study was to investigate the effects of genetic variants of the Dab2 gene on the related risk of T2DM in the Uygur and Han populations of Xinjiang, China.

Methods

A total of 2,157 age- and sex-matched individuals (528 T2DM patients and 1,629 controls) were included in this case-control study. Four high frequency SNPs (rs1050903, rs2255280, rs2855512 and rs11959928) of the Dab2 gene were genotyped using an improved multiplex ligation detection reaction (iMLDR) genotyping assay, and the forecast value of the SNP for T2DM was assessed by statistical analysis of clinical data profiles and gene frequencies.

Results

We found that in the Uygur population studied, for both rs2255280 and rs2855512, there were significant differences in the distribution of genotypes (AA/CA/CC), and the recessive model (CC vs. CA + AA) between T2DM patients and the controls (P < 0.05). After adjusting for confounders, the recessive model (CC vs. CA + AA) of both rs2255280 and rs2855512 remained significantly associated with T2DM in this population (rs2255280: OR = 5.303, 95% CI [1.236 to -22.755], P = 0.025; rs2855512: OR = 4.892, 95% CI [1.136 to -21.013], P = 0.033). The genotypes (AA/CA/CC) and recessive models (CC vs. CA + AA) of rs2855512 and rs2255280 were also associated with the plasma glucose and HbA1c levels (all P < 0.05) in this population. There were no significant differences in genotypes, all genetic models, or allele frequencies between the T2DM and control group in the Han population group (all P > 0.05).

Conclusions

The present study suggests that the variation of the Dab2 gene loci rs2255280 and rs2855512 is related to the incidence of T2DM in the Uygur population, but not in the Han population. In this study, these variations in Dab2 were an independent predictor for T2DM in the Uygur population of Xinjiang, China.

Disparities in pancreatic cancer care and research in Native Americans: Righting a history of wrongs

Disparities in pancreatic cancer incidence and outcomes exist in Native American populations. These disparities are multifactorial, difficult to quantify, and are influenced by historical, socioeconomic, and health care structural factors. The objective of this article was to assess these factors and offer a call to action to overcome them. The authors reviewed published data on pancreatic cancer in Native American populations with a focus on disparities in incidence, outcomes, and research efforts. The historical context of the interactions between Native Americans and the United States health care system was also analyzed to form actionable items to build trust and collaboration. The incidence of pancreatic cancer in Native Americans is higher than that in the general US population and has the worst survival of any major racial or ethnic group. These outcomes are influenced by a patient population with often poor access to high-quality cancer care, historical trauma potentially leading to reduced care utilization, and a lack of research focused on etiologies and comorbid conditions that contribute to these disparities. A collaborative effort between nontribal and tribal leaders and cancer centers is key to addressing disparities in pancreatic cancer outcomes and research. More population-level studies are needed to better understand the incidence, etiologies, and comorbid conditions of pancreatic cancer in Native Americans. Finally, a concerted, focused effort should be undertaken between nontribal and tribal entities to increase the access of Native Americans to high-quality care for pancreatic cancer and other lethal malignancies.

Susceptibility loci for pancreatic cancer in the Brazilian population

BACKGROUND

Pancreatic adenocarcinoma (PA) is a very aggressive cancer and has one of the poorest prognoses. Usually, the diagnosis is late and resistant to conventional treatment. Environmental and genetic factors contribute to the etiology, such as tobacco and alcohol consumption, chronic pancreatitis, diabetes and obesity. Somatic mutation in pancreatic cancer cells are known and SNP profile by GWAS could access novel genetic risk factors for this disease in different population context. Here we describe a SNP panel for Brazilian pancreatic cancer, together with clinical and epidemiological data.

METHODS

78 pancreatic adenocarcinoma and 256 non-pancreatic cancer subjects had 25 SNPs genotyped by real-time PCR. Unconditional logistic regression methods were used to assess the main effects on PA risk, using allelic, co-dominant and dominant inheritance models.

RESULTS

9 SNPs were nominally associated with pancreatic adenocarcinoma risk, with 5 of the minor alleles conferring protective effect while 4 related as risk factor. In epidemiological and clinical data, tobacco smoking, diabetes and pancreatitis history were significantly related to pancreatic adenocarcinoma risk. Polygenic risk scores computed using the SNPs in the study showed strong associations with PA risk.

CONCLUSION

We could assess for the first time some SNPs related with PA in Brazilian populations, a result that could be used for genetic screening in risk population such as familial pancreatic cancer, smokers, alcohol users and diabetes patients.

Replication and Genetic Risk Score Analysis for Pancreatic Cancer in a Diverse Multiethnic Population

BACKGROUND

Genome-wide association studies (GWAS) have identified several SNPs associated with pancreatic cancer. No studies yet have attempted to replicate these SNPs in US minority populations. We aimed to replicate the associations of 31 GWAS-identified SNPs with pancreatic cancer and build and test a polygenic risk score (PRS) for pancreatic cancer in an ethnically diverse population.

METHODS

We evaluated 31 risk variants in the Multiethnic Cohort and the Southern Community Cohort Study. We included 691 pancreatic ductal adenocarcinoma (PDAC) cases and 13,778 controls from African-American, Japanese-American, Latino, Native Hawaiian, and white participants. We tested the association between each SNP and PDAC, established a PRS using the 31 SNPs, and tested the association between the score and PDAC risk.

RESULTS

Eleven of the 31 SNPs were replicated in the multiethnic sample. The PRS was associated with PDAC risk [OR top vs. middle quintile = 2.25 (95% confidence interval, 1.73-2.92)]. Notably, the PRS was associated with PDAC risk in all ethnic groups except Native Hawaiian (OR per risk allele ranged from 1.33 in Native Hawaiians to 1.91 in African Americans; P heterogeneity = 0.12).

CONCLUSIONS

This is the first study to replicate 11 of the 31 GWAS-identified risk variants for pancreatic cancer in multiethnic populations, including African Americans, Japanese Americans, and Latinos. Our results also suggest a potential utility of PRS with GWAS-identified risk variants for the identification of individuals at increased risk for PDAC across multiple ethnic groups.

IMPACT

PRS can potentially be used to stratify pancreatic cancer risk across multiple ethnic groups.

Single-nucleotide polymorphisms based genetic risk score in the prediction of pancreatic cancer risk

BACKGROUND

Disease-related single nucleotide polymorphisms (SNPs) based genetic risk score (GRS) has been proven to provide independent inherited risk other than family history in multiple cancer types.

AIM

To evaluate the potential of GRS in the prediction of pancreatic cancer risk.

METHODS

In this case-control study (254 cases and 1200 controls), we aimed to evaluate the association between GRS and pancreatic ductal adenocarcinoma (PDAC) risk in the Chinese population. The GRS was calculated based on the genotype information of 18 PDAC-related SNPs for each study subject (personal genotyping information of the SNPs) and was weighted by external odd ratios (ORs).

RESULTS

GRS was significantly different in cases and controls (1.96 ± 3.84 in PDACs vs 1.09 ± 0.94 in controls, P < 0.0001). Logistic regression revealed GRS to be associated with PDAC risk [OR = 1.23, 95% confidence interval (CI): 1.13-1.34, P < 0.0001]. GRS remained significantly associated with PDAC (OR = 1.36, 95%CI: 1.06-1.74, P = 0.015) after adjusting for age and sex. Further analysis revealed an association of increased risk for PDAC with higher GRS. Compared with low GRS (< 1.0), subjects with high GRS (2.0) were 99% more likely to have PDAC (OR: 1.99, 95%CI: 1.30-3.04, P = 0.002). Participants with intermediate GRS (1.0-1.9) were 39% more likely to have PDAC (OR: 1.39, 95%CI: 1.03-1.84, P = 0.031). A positive trend was observed (P trend = 0.0006).

CONCLUSION

GRS based on PDAC-associated SNPs could provide independent information on PDAC risk and may be used to predict a high risk PDAC population.