Abstract: Prion diseases are associated with the accumulation of a misfolded, protease resistant form of the prion protein, PrPres . In humans there are a variety of different prion related diseases that are sporadic, inherited, or acquired by infection. Gerstmann-Straussler-Sheinker syndrome (GSS) is an inherited prion disease in which PrPres accumulates as amorphous aggregates as well as in amyloid plaques. GSS has been associated with a variety of point mutations in the prion protein: 102, 105, 117, 131, 145, 187, 198, 202, 212, 217, and 232. The F198S mutation was discovered in a large Indiana kindred. Previous studies in vitro have…shown that the 198 mutation results in structural instability of the prion protein. In the current study, we demonstrate in a cell model that the F198S mutant protein can be folded properly in a cellular context, but is unable to refold to a native state after denaturation. Further, the F198S mutation significantly affects glycosylation of the mutant protein.
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Abstract: Pancreatic ductal adenocarcinoma (PDAC) is an important cause of cancer death with no clear prognostic biomarker. Expression of prion (PrP) has been reported to be a marker of poor prognosis in a series of Caucasian PDAC cases. We determined the prognostic value of PrP in a racially and geographically diverse population-based series of PDAC cases. PrP expression was examined in 142 PDAC cases from three cancer registries. Cases included 71 Caucasian, 54 Asian/Pacific Islanders and 17 Blacks diagnosed from 1983–2000, and followed through 2008. Hazard ratios (HR) and 95% confidence intervals (CIs) for the association of PrP expression with survival…were computed after adjustment for case attributes. The risk of death was about four times higher (HR=3.8; 95% PDAC cases with PrP+ tumors (median survival 5 months) compared to the 34 cases with PrP- tumors (median survival 20 months). Of 51 cases with resected, localized PDAC median survival was 74 months for 17 cases with PrP- tumors versus 14 months for 34 cases with PrP+ tumors (HR=6.7; 95% CI: 2.6, 17.4). All 6 surviving cases had PrP- negative tumors (median survival, > 10 years). PrP may have potential as a prognostic biomarker in PDAC patient management.
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