ObjectiveTo investigate the expression level of angiopoietin-like protein 2 (ANGPTL2) in pancreatic cancer patients with or without diabetes and the clinical value of ANGPTL2 as a prognostic marker in patients with pancreatic cancer. MethodsSerum samples were collected from 125 pancreatic cancer patients who were treated in The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University Cancer Hospital, and Wuming Hospital of Guangxi Medical University from January 2015 to January 2018, among whom 64 had pancreatic cancer alone and 61 had pancreatic cancer and diabetes, and 66 individuals who underwent physical examination were enrolled as control group. ELISA was used to measure the serum level of ANGPTL2, and the association of the expression level of ANGPTL2 with clinical indices, survival, and prognosis was analyzed. A one-way analysis of variance was used for comparison of normally distributed continuous data between three groups, and the Bonferroni test was used for comparison between two groups. The independent-samples Kruskal-Wallis H test was used for comparison of continuous data with skewed distribution between three groups and the one-way ANOVA analysis was used for comparison between two groups. The chi-square test was used for comparison of categorical data between groups. Spearman correlation analysis was also performed to investigate correlation. The Kaplan-Meier method was used to plot survival curves, and the log-rank test was used for comparison of survival rate. The Cox risk model was used to perform univariate and multivariate analyses to determine independent risk factors for the prognosis of pancreatic cancer. ResultsThe pancreatic cancer+diabetes group had a significantly higher serum concentration of ANGPTL2 than the pancreatic cancer group and the control group ［7.79 (7.12-8.17) ng/ml vs 5.74 (508-6.40) ng/ml and 3.72 (3.25-4.16) ng/ml, χ2=126.367, P＜0.001］. Serum ANGPTL2 concentration was positively correlated with carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) (r=0.560 and 0.731, both P＜0.001). The univariate analysis showed that tumor size, distant organ metastasis, degree of tumor differentiation， CEA, ANGPTL2, and HbA1c were closely associated with the long-term survival of pancreatic cancer patients, and the multivariate analysis showed that tumor size (HR=2.657,P=0.005), distant organ metastasis (HR=5.000,P=0.014), degree of tumor differentiation (HR=2.466,P=0.004), CEA(HR=1.110,P＜0.001) and ANGPTL2(HR=1.901,P=0.001) were independent risk factors for the prognosis of pancreatic cancer patients. For all pancreatic cancer patients, the high ANGPTL2 expression group had a significantly lower 2-year survival rate than the low ANGPTL2 expression group (8.51% vs 25.81%, χ2=5.651, P=0.017). For the pancreatic cancer patients with diabetes, the high ANGPTL2 expression group had a significantly lower 2-year survival rate than the low ANGPTL2 expression group (2.20% vs 32.70%, χ2=24.895, P＜0.001).ConclusionANGPTL2 can be used as an effective clinical index to evaluate the prognosis of pancreatic cancer patients, especially those with diabetes.

Mosaic variants resulting from postzygotic mutations are prevalent in the human genome and play important roles in human diseases. However, except for cancer-related variants, there is no collection of postzygotic mosaic variants in noncancer disease-related and healthy individuals. Here, we present MosaicBase, a comprehensive database that includes 6698 mosaic variants related to 266 noncancer diseases and 27,991 mosaic variants identified in 422 healthy individuals. Genomic and phenotypic information of each variant was manually extracted and curated from 383 publications. MosaicBase supports the query of variants with Online Mendelian Inheritance in Man (OMIM) entries, genomic coordinates, gene symbols, or Entrez IDs. We also provide an integrated genome browser for users to easily access mosaic variants and their related annotations for any genomic region. By analyzing the variants collected in MosaicBase, we find that mosaic variants that directlycontribute to disease phenotype show features distinct from those of variants in individuals with mild or no phenotypes, in terms of their genomic distribution, mutation signatures, and fraction of mutant cells. MosaicBase will not only assist clinicians in genetic counseling and diagnosis but also provide a useful resource to understand the genomic baseline of postzygotic mutations in the general human population. MosaicBase is publicly available at http://mosaicbase.com/ or http://49.4.21.8:8000.