Grandgenett, Paul M

Cancer cachexia is a multifactorial syndrome involving muscle and fat wasting, inflammation, and metabolic dysfunction. Across cancer subtypes, pancreatic cancer has one of the highest cachexia incidence rates at ∼80%. Given the advanced age of most pancreatic cancer patients, we sought to query cancer-associated muscle wasting using an age-matched murine model. We found that histamine and histamine decarboxylase (HDC) activity were specifically elevated in the muscles of aged tumor-bearing mice. We further found that (1) wasting stimuli induced histamine production and enhanced HDC activity; (2) exogenous histamine was sufficient to induce atrophy-associated gene expression; (3) inhibition of HDC activity by α-fluoromethylhistidine (FMH) protected against atrophy; (4) treatment of tumor-bearing mice with FMH rescued muscle wasting; and (5) a calcineurin inhibitor was able to rescue histamine-associated increases in calcium/atrogene signaling. In summary, we present a novel metabolic pathway that has significant implications for the treatment of cachectic cancer patients.

Abstract Adenosquamous cancer of the pancreas (ASCP) is a subtype of pancreatic cancer that has a worse prognosis and greater metastatic potential than the more common pancreatic ductal adenocarcinoma (PDAC) subtype. To distinguish the genomic landscape of ASCP and identify actionable targets for this lethal cancer, we applied DNA content flow cytometry to a series of 15 tumor samples including five patient-derived xenografts (PDX). We interrogated purified sorted tumor fractions from these samples with whole-genome copy-number variant (CNV), whole-exome sequencing, and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) analyses. These identified a variety of somatic genomic lesions targeting chromatin regulators in ASCP genomes that were superimposed on well-characterized genomic lesions including mutations in TP53 (87%) and KRAS (73%), amplification of MYC (47%), and homozygous deletion of CDKN2A (40%) that are common in PDACs. Furthermore, a comparison of ATAC-seq profiles of three ASCP and three PDAC genomes using flow-sorted PDX models identified genes with accessible chromatin unique to the ASCP genomes, including the lysine methyltransferase SMYD2 and the pancreatic cancer stem cell regulator RORC in all three ASCPs, and a FGFR1-ERLIN2 fusion associated with focal CNVs in both genes in a single ASCP. Finally, we demonstrate significant activity of a pan FGFR inhibitor against organoids derived from the FGFR1-ERLIN2 fusion–positive ASCP PDX model. Our results suggest that the genomic and epigenomic landscape of ASCP provide new strategies for targeting this aggressive subtype of pancreatic cancer. Significance: These data provide a unique description of the ASCP genomic and epigenomic landscape and identify candidate therapeutic targets for this dismal cancer.