ABSTRACT
OBJECTIVE: Intraductal Papillary Mucinous Neoplasms (IPMNs) are cystic lesions and bona fide precursors for pancreatic ductal adenocarcinoma (PDAC). Recently, we showed that acinar to ductal metaplasia, an injury repair program, is characterized by a transcriptomic program similar to gastric spasmolytic polypeptide expressing metaplasia (SPEM), suggesting common mechanisms of reprogramming between the stomach and pancreas. The aims of this study were to assay IPMN for pyloric markers and to identify molecular drivers of this program. DESIGN: We analyzed RNA-seq studies of IPMN for pyloric markers, which were validated by immunostaining in patient samples. Cell lines expressing Kras G12D +/- GNAS R201C were manipulated to identify distinct and overlapping transcriptomic programs driven by each oncogene. A PyScenic-based regulon analysis was performed to identify molecular drivers in the pancreas. Expression of candidate drivers was evaluated by RNA-seq and immunostaining. RESULTS: Pyloric markers were identified in human IPMN. GNAS R201C drove expression of these markers in cell lines and siRNA targeting of GNAS R201C or Kras G12D demonstrates that GNAS R201C amplifies a mucinous, pyloric phenotype. Regulon analysis identified a role for transcription factors SPDEF, CREB3L1, and CREB3L4, which are expressed in patient samples. siRNA-targeting of Spdef inhibited mucin production. CONCLUSION: De novo expression of a SPEM phenotype has been identified in pancreatitis and a pyloric phenotype in Kras G12D -driven PanIN and Kras G12D ;GNAS R201C -driven IPMN, suggesting common mechanisms of reprogramming between these lesions and the stomach. A transition from a SPEM to pyloric phenotype may reflect disease progression and/or oncogenic mutation. IPMN-specific GNAS R201C amplifies a mucinous phenotype, in part, through SPDEF.
ABSTRACT
OBJECTIVE: Schistosomiasis remains a chronic disease of global importance, especially in many rural areas of the world where co-infection with Plasmodium falciparum is common. It is critical to decipher the role of single or co-infected disease scenarios on immune system regulation in such individuals and how such co-infections can either ameliorate or complicate immune response and the consequent disease outcome. First, 10 ml of urine samples, collected between 10:00 am and 2:00 pm, was filtered for diagnosis of schistosomiasis, while egg count, indicative of disease severity, was determined by microscopy. Furthermore, genomic DNA samples extracted from dried blood spots collected on filter paper from one hundred and forty-four Schistosoma haematobium-infected school-children was tested for P. falciparum parasite positivity by an allele-specific nested-PCR analysis of merozoite surface protein (msp)-1 and -2 genes and a real-time PCR assay. In addition, among P. falciparum parasite-positive individuals, we carried out a Taqman SNP genotyping assay to extrapolate the effect of host CD14 (-159 C/T; rs2569190) genetic variants on schistosome egg count. RESULTS: Of the 144 individuals recruited, P. falciparum parasite positivity with msp-1 gene were 34%, 43% and 55% for MAD20, RO33 and K1 alleles respectively. Of the co-infected individuals, CD14 genetic variants ranged from 18.8% vs 21.5%, 33.3% vs 44.4%, 9.7% vs 11.8% for single versus schistosome co-infection for the wild type (CC), heterozygous (CT) and mutant (TT) variants respectively. Though the mean egg count for co-infected individuals with CD14 wild type (33.7 eggs per 10 ml of urine) and heterozygote variants (37.5 eggs per 10 ml of urine) were lower than that of schistosome infection alone (52.48 and 48.08 eggs/10 ml of urine respectively), it lacked statistical significance (p-value 0.12 and 0.29), possibly reflecting the benefit of the CD14 activation in schistosome plus malaria co-infection and not schistosome infection alone. In addition, the lower mean egg count in co-infected individuals reveal the benefit of downstream Th1 immune response mitigated by CD14 innate activation that is absent in schistosome infection alone.
