Evaluation of biomarkers, genetic mutations, and epigenetic modifications in early diagnosis of pancreatic cancer

BACKGROUND Pancreatic cancer(PC)is one of the deadliest malignancies with an alarming mortality rate.Despite significant advancement in diagnostics and therapeutics,early diagnosis remains elusive causing poor prognosis,marred by mutations and epigenetic modifications in key genes which contribute to disease progression.AIM To evaluate the various biological tumor markers collectively for early diagnosis which could act as prognostic biomarkers and helps in future therapeutics of PC in Kashmir valley.METHODS A total of 50 confirmed PC cases were included in the study to evaluate the levels of carbohydrate antigen 19-9(CA 19-9),tissue polypeptide specific antigen(TPS),carcinoembryonic antigen(CEA),vascular endothelial growth factor-A(VEGF-A),and epidermal growth factor receptor(EGFR).Mutational analysis was performed to evaluate the mutations in Kirsten rat sarcoma(KRAS),Breast cancer type 2(BRCA-2),and deleted in pancreatic cancer-4(DPC-4)genes.However,epigenetic modifications(methylation of CpG islands)were performed in the promoter regions of cyclin-dependent kinase inhibitor 2A(p16;CDKN2A),MutL homolog 1(hMLH1),and Ras association domain-containing protein 1(RASSF1A)genes.RESULTS We found significantly elevated levels of biological markers CA 19-9(P≤0.05),TPS(P≤0.05),CEA(P≤0.001),and VEGF(P≤0.001).Molecular genetic analysis revealed that KRAS gene mutation is predominant in codon 12(16 subjects,P≤0.05),and 13(12 subjects,P≤0.05).However,we did not find a mutation in DPC-4(1203G>T)and BRCA-2(617delT)genes.Furthermore,epigenetic modification revealed that CpG methylation in 21(P≤0.05)and 4 subjects in the promoter regions of the p16 and hMLH1 gene,respectively.CONCLUSION In conclusion,CA 19-9,TPS,CEA,and VEGF levels were significantly elevated and collectively have potential as diagnostic and prognostic markers in PC.Global data of mutation in the KRAS gene commonly in codon 12 and rare in codon 13 could augment the predisposition towards PC.Additionally,methylation of the p16 gene could also modulate transcription of genes thereby increasing the predisposition and susceptibility towards PC.

Two distinct subpopulations of marginal zone B cells exhibit differential antibody-producing capacities and radioresistance

Marginal zone(MZ)B cells,which are splenic innate-like B cells that rapidly secrete antibodies(Abs)against blood-borne pathogens,are composed of heterogeneous subpopulations.Here,we showed that MZ B cells can be divided into two distinct subpopulations according to their CD80 expression levels.CD80^(high)MZ B cells exhibited greater Ab-producing,proliferative,and IL-10-secreting capacities than did CD80^(low)MZ B cells.Notably,CD80^(high)MZ B cells survived 2-Gy whole-body irradiation,whereas CD80^(low)MZ B cells were depleted by irradiation and then repleted with one month after irradiation.Depletion of CD80^(low)MZ B cells led to accelerated development of type II collagen(CII)-induced arthritis upon immunization with bovine CII.CD80^(high)MZ B cells exhibited higher expression of genes involved in proliferation,plasma cell differentiation,and the antioxidant response.CD80^(high)MZ B cells expressed more autoreactive B cell receptors(BCRs)that recognized double-stranded DNA or CII,expressed more immunoglobulin heavy chain sequences with shorter complementarity-determining region 3 sequences,and included more clonotypes with no N-nucleotides or with B-1a BCR sequences than CD80^(low)MZ B cells.Adoptive transfer experiments showed that CD21^(+)CD23^(+)transitional 2 MZ precursors preferentially generated CD80^(low)MZ B cells and that a proportion of CD80^(low)MZ B cells were converted into CD80^(high)MZ B cells;in contrast,CD80^(high)MZ B cells stably remained CD80^(high)MZ B cells.In summary,MZ B cells can be divided into two subpopulations according to their CD80 expression levels,Ab-producing capacity,radioresistance,and autoreactivity,and these findings may suggest a hierarchical composition of MZ B cells with differential stability and BCR specificity.