RESUMO
OBJECTIVES: Altered immune homeostasis and involvement of T cells has been reported in chronic pancreatitis (CP). We evaluated the role of Bach2 (BTB and CNC homology basic leucine zipper transcription factor 2), a key regulator of immune homeostasis in the chronicity of CP. METHODS: Expression of Bach2 and T-cell transcription factors, enumeration of BACH2+/CD4+ T-lymphocytes were performed by qRT-PCR and flow cytometry respectively. Bach2silenced human CD4+ T-lymphocytes were exposed to CP tissue extract to assess T-cell lineage commitment. Aryl hydrocarbon receptor (Ahr) and Deubiquitinase enzyme A (DUBA/OTUD5gene) were evaluated as markers of persistent Th17 cell differentiation. Bach2 gene (exons) was sequenced to identify risk variants and functionally validated. RESULTS: Decrease in Bach2 (p < 0.0001) and increase (p < 0.001) in TBX21, RORC, Ahr, PRDM1, IL23R mRNA were noted in pancreatic tissues, while BACH2+/CD4+ T-lymphocytes were decreased (p < 0.01) in circulation and tissues. Exposure of Bach2 silenced CD4+ T-lymphocytes to CP tissue extract showed increased Ahr, decreased OTUD5, and enhanced Th17 cell differentiation. Sequencing of Bach2 gene revealed association of novel variant (rs9111 in 5'-UTR) with advanced disease and luciferase assay confirmed its role in Bach2 repression. CONCLUSION: Bach2 repression mediates Th17 cell induced inflammation and rs9111-TT in individuals with primary genetic susceptibility to CP is associated with clinical features of advanced disease.
RESUMO
In this study, circulating microRNAs (miRNAs) are being investigated as non-invasive biomarkers for early diagnosis and prognosis of human cancers. Since the prognosis for pancreatobiliary subtype of periampullary carcinoma is poor, we assessed the prognostic relevance of miRNAs in combination with CA19-9 as noninvasive biomarker in periampullary carcinoma. Circulating miRNAs in plasma and serum CA19-9 were evaluated in periampullary carcinoma patients (n = 109) undergoing Whipple's pancreaticoduodenectomy and in healthy volunteers (n = 92). Tumour tissues were subjected to staging and subtyping prior to determining differentially expressed miRNAs in them by quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analysis involved correlation, receiver operating characteristic, logistic regression, survival analyses and Cox-proportional regression. Of the three differentially expressed circulating miRNA, miRNA192 was significantly increased both in circulation and in tumour tissue and correlated with tumour stage and aggressiveness (r = 0.96, P < 0.0001). Area under the curve of circulating miRNA192 + CA19-9 combination was 0.877 (95% confidence interval, 0.72 to 0.96) for stage III and 0.92 (95% confidence interval, 0.77 to 0.88) for tumour aggressiveness. The combination was associated with poor survival (median: 22 months, P = 0.0008) in stage III patients. Cox-proportional regression analysis revealed prognostic importance of combination of circulating miR192 and CA19-9 (HR = 1.005, P = 0.0001) in periampullary carcinoma. In conclusion, combination of circulating miRNA192 with serum CA19-9 is a better prognostic biomarker than CA19-9 alone.
