Novel mutation and polymorphism of PRSS1 gene in the Chinese patients with hereditary pancreatitis and chronic pancreatitis:

Classification of PRSS1 variants responsible for chronic pancreatitis: An expert perspective from the Franco-Chinese GREPAN study group

BACKGROUND

PRSS1 was the first reported chronic pancreatitis (CP) gene. The existence of both gain-of-function (GoF) and gain-of-proteotoxicity (GoP) pathological PRSS1 variants, together with the fact that PRSS1 variants have been identified in CP subtypes spanning the range from monogenic to multifactorial, has made the classification of PRSS1 variants very challenging.

METHODS

All currently reported PRSS1 variants (derived primarily from two databases) were manually reviewed with respect to their clinical genetics, functional analysis and population allele frequency. They were classified by variant type and pathological mechanism within the framework of our recently proposed ACMG/AMP guidelines-based seven-category system.

RESULTS

The total number of distinct germline PRSS1 variants included for analysis was 100, comprising 3 copy number variants (CNVs), 12 5' and 3' variants, 19 intronic variants, 5 nonsense variants, 1 frameshift deletion variant, 6 synonymous variants, 1 in-frame duplication, 3 gene conversions and 50 missense variants. Based upon a combination of clinical genetic and functional analysis, population data and in silico analysis, we classified 26 variants (all 3 CNVs, the in-frame duplication, all 3 gene conversions and 19 missense) as "pathogenic", 3 variants (missense) as "likely pathogenic", 5 variants (four missense and one promoter) as "predisposing", 13 variants (all missense) as "unknown significance", 2 variants (missense) as "likely benign", and all remaining 51 variants as "benign".

CONCLUSIONS

We describe an expert classification of the 100 PRSS1 variants reported to date. The results have immediate implications for reclassifying many ClinVar-registered PRSS1 variants as well as providing optimal guidelines/standards for reporting PRSS1 variants.

PRSS1 mutation: a possible pathomechanism of pancreatic carcinogenesis and pancreatic cancer

Background

Previous studies revealed somatic mutations of the cationic trypsinogen gene (PRSS1) in patients with chronic pancreatitis and pancreatic cancer. However, whether PRSS1 mutations trigger pancreatic cancer and/or promote malignant proliferation and metastasis in pancreatic cancer remains largely unclear, as well as the potential underlying mechanisms.

Methods

In the present study, whole-exome sequencing was applied for screening, and the R116C mutation was validated by Sanger sequencing. Phosphorylation antibody array, RNA-Seq, and RT-qPCR were adopted to screen and validate that R116C mutation promoted pancreatic cancer progression via the JAK1-STAT5 pathway.

Results

It showed that migration and invasion were significantly increased in R116C-bearing PANC-1 cells compared with wild type counterparts. In a transgenic mouse model of iZEG-PRSS1_R116C, primary pancreatic intraepithelial neoplasia (PanINs) was observed in the pancreatic duct.

Conclusions

These findings suggested a novel pathway mediating pancreatic cancer development, with PRSS1 mutation and overexpression playing an “inside job” role in pancreatic carcinogenesis and tumor development.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s10020-019-0111-4.

Do pancreatic cancer and chronic pancreatitis share the same genetic risk factors? A PANcreatic Disease ReseArch (PANDoRA) consortium investigation

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a five-year survival of less than 6%. Chronic pancreatitis (CP), an inflammatory process in of the pancreas, is a strong risk factor for PDAC. Several genetic polymorphisms have been discovered as susceptibility loci for both CP and PDAC. Since CP and PDAC share a consistent number of epidemiologic risk factors, the aim of this study was to investigate whether specific CP risk loci also contribute to PDAC susceptibility. We selected five common SNPs (rs11988997, rs379742, rs10273639, rs2995271 and rs12688220) that were identified as susceptibility markers for CP and analyzed them in 2,914 PDAC cases, 356 CP cases and 5,596 controls retrospectively collected in the context of the international PANDoRA consortium. We found a weak association between the minor allele of the PRSS1-PRSS2-rs10273639 and an increased risk of developing PDAC (ORhomozygous  = 1.19, 95% CI 1.02-1.38, p = 0.023). Additionally all the SNPs confirmed statistically significant associations with risk of developing CP, the strongest being PRSS1-PRSS2-rs10273639 (ORheterozygous  = 0.51, 95% CI 0.39-0.67, p = 1.10 × 10-6 ) and MORC4-rs 12837024 (ORhomozygous  = 2.07 (1.55-2.77, ptrend  = 0.7 × 10-11 ). Taken together, the results from our study do not support variants rs11988997, rs379742, rs10273639, rs2995271 and rs12688220 as strong predictors of PDAC risk, but further support the role of these SNPs in CP susceptibility. Our study suggests that CP and PDAC probably do not share genetic susceptibility, at least in terms of high frequency variants.

PRSS1 (R122H) mutation in an Indian family with low penetrance is associated with pancreatitis phenotype

Mutations in PRSS1 gene namely R122H and N29I cause hereditary pancreatitis. They are autosomal dominant with a high penetrance (80%) reported in North American, North-east Asian, and North European ethnicities. However, the mutations are reportedly absent in Indian, African, and South American ethnicities. We report here for the first time a family from India that is positive for R122H mutation in the PRSS1 gene. The proband is symptomatic with chronic pancreatitis, however, the father although heterozygous for R122H is asymptomatic.

Targeted Gene Next-Generation Sequencing in Chinese Children with Chronic Pancreatitis and Acute Recurrent Pancreatitis

OBJECTIVE

To identify causal mutations in certain genes in children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP).

STUDY DESIGN

After patients were enrolled (CP, 55; ARP, 14) and their clinical characteristics were investigated, we performed next-generation sequencing to detect nucleotide variations among the following 10 genes: cationic trypsinogen protease serine 1 (PRSS1), serine protease inhibitor, Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), chymotrypsin C (CTRC), calcium-sensing receptor (CASR), cathepsin B (CTSB), keratin 8 (KRT8), CLAUDIN 2 (CLDN2), carboxypeptidase A1 (CPA1), and ATPase type 8B member 1 (ATP8B1). Mutations were searched against online databases to obtain information on the cause of the diseases. Certain novel mutations were analyzed using the SIFT2 and Polyphen-2 to predict the effect on protein function.

RESULTS

There were 45 patients with CP and 10 patients with ARP who harbored 1 or more mutations in these genes; 45 patients had at least 1 mutation related to pancreatitis. Mutations were observed in the PRSS1, SPINK1, and CFTR genes in 17 patients, the CASR gene in 5 patients, and the CTSB, CTRC, and KRT8 genes in 1 patient. Mutations were not found in the CLDN, CPA1, or ATP8B1 genes. We found that mutations in SPINK1 may increase the risk of pancreatic duct stones (OR, 11.07; P = .003). The patients with CFTR mutations had a higher level of serum amylase (316.0 U/L vs 92.5 U/L; P = .026).

CONCLUSION

Mutations, especially those in PRSS1, SPINK1, and CFTR, accounted for the major etiologies in Chinese children with CP or ARP. Children presenting mutations in the SPINK1 gene may have a higher risk of developing pancreatic duct stones.

The Differential Role of Human Cationic Trypsinogen (PRSS1) p.R122H Mutation in Hereditary and Nonhereditary Chronic Pancreatitis: A Systematic Review and Meta-Analysis

Background

Environmental factors and genetic mutations have been increasingly recognized as risk factors for chronic pancreatitis (CP). The PRSS1 p.R122H mutation was the first discovered to affect hereditary CP, with 80% penetrance. We performed here a systematic review and meta-analysis to evaluate the associations of PRSS1 p.R122H mutation with CP of diverse etiology.

Methods

The PubMed, EMBASE, and MEDLINE database were reviewed. The pooled odds ratio (OR) with 95% confidence intervals was used to evaluate the association of p.R122H mutation with CP. Initial analysis was conducted with all etiologies of CP, followed by a subgroup analysis for hereditary and nonhereditary CP, including alcoholic or idiopathic CP.

Results

A total of eight case-control studies (1733 cases and 2415 controls) were identified and included. Overall, PRSS1 p.R122H mutation was significantly associated with an increased risk of CP (OR = 4.78[1.13-20.20]). Further analysis showed p.R122H mutation strongly associated with the increased risk of hereditary CP (OR = 65.52[9.09-472.48]) but not with nonhereditary CP, both alcoholic and idiopathic CP.

Conclusions

Our study showing the differential role of p.R122H mutation in various etiologies of CP indicates that this complex disorder is likely influenced by multiple genetic factors as well as environmental factors.

Etiology, pathology, management and prognosis of chronic pancreatitis in Chinese population: A retrospective study

The purpose of this study was to investigate the etiology, pathological characteristics, management and prognosis of chronic pancreatitis in the Chinese population. The clinical data of 142 patients with chronic pancreatitis were retrospectively studied. All patients were of Chinese nationality and hospitalized from January 2008 to December 2011. Their ages ranged from 14 to 76 years, with a mean of 43 years. Of 142 patients, there were 72 cases of obstructive chronic pancreatitis (50.70%), 19 cases of alcoholic chronic pancreatitis (13.38%), 14 cases of autoimmune pancreatitis (9.86%) and 37 cases of undetermined etiology (26.06%). Pathologically, the average inflammatory mass diameter was 3.8 ± 3.3 cm, biliary obstruction occurred in 36 cases, gall stones in 70 cases, calcification in 88 cases, ductal dilatation in 61 cases, side branch dilatation in 32 cases, ductal irregularity in 10 cases, lymphocytic inflammation in 23 cases, obliterative phlebitis in 14 cases, extra pancreatic lesion in 19 cases and fibrosis in 142 cases. Location of pancreatic lesion in the region of head (n=97), neck (n=16), body (n=12), tail (n=15) and whole pancreas (n=2) influenced the choice of surgical procedures. Ninety-four patients (66.20%) received surgical treatment and 33.80% received other treatments. After operation, 80.85% of 94 patients experienced decreased pain, and 8.51% of 94 showed recovery of endocrine function but with a complication rate of 12.77%. All the operations were performed successfully. According to the pain scale of European Organization for Research and Treatment of Cancer (QLQ-C30) a decrease from 76 ± 22 to 14 ± 18 was observed. Etiology, pathological characteristics, management and prognosis of chronic pancreatitis in the Chinese population vary from others.

AFP computational secreted network construction and analysis between human hepatocellular carcinoma (HCC) and no-tumor hepatitis/cirrhotic liver tissues

Alpha-fetoprotein (AFP) computational secreted network construction and analysis of human hepatocellular carcinoma (HCC) is very useful to identify novel markers and potential targets for prognosis and therapy. By integration of gene regulatory network infer and the database for annotation, visualization, and integrated discovery, we identified and constructed significant molecule AFP secreted network from 25 no-tumor hepatitis/cirrhotic liver tissues and 25 HCC patients in the same GEO Dataset GSE10140-10141. Our result verified AFP secreted module in the upstream of no-tumor hepatitis/cirrhotic liver tissues (AMELY, LCN2, and REG3A activation; DKK1, SFRP4, and SPINK1 inhibition) and its downstream (PRSS1, REG3A, and TSHB activation; AMELY and DKK1 inhibition), and also in the upstream of HCC (LCN2, REG3A, and SFRP4 activation; AMELY and DKK1 inhibition) and its downstream (AMELY activation; DKK1, LCN2, PRSS1, SEMA3B, and SPINK1 inhibition). Importantly, we data-mined that AFP secreted cluster of HCC is involved in disease mutation (only in HCC terms) without cell surface receptor linked signal transduction, neuroactive ligand-receptor interaction, cell-cell signaling, and pancreas (only in no-tumor hepatitis/cirrhotic liver tissues terms), the condition which is vital to invasion of HCC. Our result demonstrated that common terms in both no-tumor hepatitis/cirrhotic liver tissues and HCC include secreted extracellular region, extracellular region part, extracellular space, signal peptide, signal, disulfide bond, glycosylation site N-linked (GlcNAc...), and glycoprotein, and these terms are less relative to invasion; therefore, we deduced the weaker AFP secreted network in HCC consistent with our number computation. We predicted AFP high expression localization within cells of HCC and without secretion to extracellular matrix. It would be necessary of AFP secreted function to decrease invasion of HCC.

Prevalence of pancreatic diabetes in patients carrying mutations or polymorphisms of the PRSS1 gene in the Han population

OBJECTIVE

This study updated the estimated prevalence of type 3c diabetes damage to the pancreas through different genotypes of PRSS1 and their clinical characteristics in the Han population.

SUBJECTS AND METHODS

Cross-sectional analysis was performed of the most recent (2003-2007) patients with pancreatitis from six hospitals of the Han population in South China (n = 253).

RESULTS

There were 32 patients with pancreatitis carrying a PRSS1 gene abnormality within intron region among 253 cases of pancreatitis, including 27 patients carrying novel single nucleotide polymorphisms, namely, IVS 3 +75 A --> G conversion, and five patients with the mutation IVS3 + 10 T --> G. Among these patients, there were only three cases of patients with diabetes (9.37%). This was lower than the prevalence of abnormalities in the exons of the PRSS1 gene (51.92%): 12 patients with c.361 G --> A, eight patients with c.415 T --> A, and five patients with c.365G --> A. Among them were 12 persons with diabetes, including five requiring insulin to regulate blood sugar. What is more, among the 27 patients carrying PRSS1 gene polymorphism (c.486 C --> T, within the exon 4), there were 15 persons with diabetes symptoms. More than 40% of these patients required insulin to regulate blood sugar.

CONCLUSIONS

An abnormality within the intron region of the PRSS1 gene represents one of the causes of pancreatitis in Chinese patients, but it is not related to pancreatic diabetes. However, the exon abnormality obviously raises the morbidity rate of type 3c diabetes, which relies on insulin.