ctDNA whole exome sequencing in pancreatic ductal adenocarcinoma unveils organ-dependent metastatic mechanisms and identifies actionable alterations in fast progressing patients.

Understanding progression mechanisms and developing new targeted therapies is imperative in pancreatic ductal adenocarcinoma (PDAC). In this study, 80 metastatic PDAC patients were prospectively recruited and divided into discovery (n=37) and validation (n=43) cohorts. Tumor and plasma samples taken at diagnosis were pair analyzed using whole exome sequencing (WES) in patients belonging to the discovery cohort alone. The variant allele frequency (VAF) of KRAS mutations was measured by ddPCR in plasma at baseline and response assessment in all patients. Plasma WES identified at least one pathogenic variant across the cohort, uncovering oncogenic mechanisms, DNA repair, microsatellite instability, and alterations in the TGFb pathway. Interestingly, actionable mutations were mostly found in plasma rather than tissue. Patients with shorter survival showed enrichment in cellular organization regulatory pathways. Through WES we could identify a specific molecular profile of patients with liver metastasis, which exhibited exclusive mutations in genes related to the adaptive immune response pathway, highlighting the importance of the immune system in liver metastasis development. Moreover, KRAS mutations in plasma (both at diagnosis and persistent at follow-up) correlated with shorter progression free survival (PFS). Patients presenting a reduction of over 84.75 % in KRAS VAF at response assessment had similar PFS to KRAS-negative patients. Overall, plasma WES reveals molecular profiles indicative of rapid progression, potentially actionable targets, and associations between adaptive immune response pathway alterations and liver tropism.

Genetic variants in the NF-κB signaling pathway (NFKB1, NFKBIA, NFKBIZ) and risk of critical outcome among COVID-19 patients.

The NF-κB signaling pathway is a key regulator of inflammation in the response to SARS-CoV-2 infection. This pathway has been implicated in the hyperinflammatory state that characterizes the severe forms of COVID-19. The genetic variation of the NF-κB components might thus explain the predisposition to critical outcomes of this viral disease. We aimed to study the role of the common NFKB1 rs28362491, NFKBIA rs696 and NFKBIZ rs3217713 variants in the risk of developing severe COVID-19 with ICU admission. A total of 470 Spanish patients requiring respiratory support in the ICU were studied (99 deceased and 371 survivors). Compared to healthy population controls (N = 300), the NFKBIA rs696 GG genotype was increased in the patients (p = 0.045; OR = 1.37). The NFKBIZ rs3217713 insertion homozygosis was associated with a significant risk of death (p = 0.02; OR = 1.76) and was also related to increased D-dimer values (p = 0.0078, OR = 1.96). This gene has been implicated in sepsis in mice and rats. Moreover, we found a trend toward lower expression of the NFKBIZ transcript in total blood from II patients. In conclusion, variants in the NF-κB genes might be associated with the risk of developing severe COVID-19, with a significant effect of the NFKBIZ gene on mortality. Our results were based on a limited number of patients and require validation in larger cohorts from other populations.