CPSF3 inhibition blocks pancreatic cancer cell proliferation through disruption of core histone mRNA processing.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with limited effective treatment options, potentiating the importance of uncovering novel drug targets. Here, we target cleavage and polyadenylation specificity factor 3 (CPSF3), the 3' endonuclease that catalyzes mRNA cleavage during polyadenylation and histone mRNA processing. We find that CPSF3 is highly expressed in PDAC and is associated with poor prognosis. CPSF3 knockdown blocks PDAC cell proliferation and colony formation in vitro and tumor growth in vivo. Chemical inhibition of CPSF3 by the small molecule JTE-607 also attenuates PDAC cell proliferation and colony formation, while it has no effect on cell proliferation of nontransformed immortalized control pancreatic cells. Mechanistically, JTE-607 induces transcriptional readthrough in replication-dependent histones, reduces core histone expression, destabilizes chromatin structure, and arrests cells in the S-phase of the cell cycle. Therefore, CPSF3 represents a potential therapeutic target for the treatment of PDAC.

Lorazepam Stimulates IL6 Production and Is Associated with Poor Survival Outcomes in Pancreatic Cancer.

PURPOSE: This research investigates the association between benzodiazepines (BZD) and cancer patient survival outcomes, the pancreatic cancer tumor microenvironment, and cancer-associated fibroblast (CAF) signaling. EXPERIMENTAL DESIGN: Multivariate Cox regression modeling was used to retrospectively measure associations between Roswell Park cancer patient survival outcomes and BZD prescription records. IHC, H&E, Masson's trichrome, RNAscope, and RNA sequencing were used to evaluate the impact of lorazepam (LOR) on the murine PDAC tumor microenvironment. ELISA and qPCR were used to determine the impact of BZDs on IL6 expression or secretion by human-immortalized pancreatic CAFs. PRESTO-Tango assays, reanalysis of PDAC single-cell sequencing/TCGA data sets, and GPR68 CRISPRi knockdown CAFs were used to determine the impact of BZDs on GPR68 signaling. RESULTS: LOR is associated with worse progression-free survival (PFS), whereas alprazolam (ALP) is associated with improved PFS, in pancreatic cancer patients receiving chemotherapy. LOR promotes desmoplasia (fibrosis and extracellular matrix protein deposition), inflammatory signaling, and ischemic necrosis. GPR68 is preferentially expressed on human PDAC CAFs, and n-unsubstituted BZDs, such as LOR, significantly increase IL6 expression and secretion in CAFs in a pH and GPR68-dependent manner. Conversely, ALP and other GPR68 n-substituted BZDs decrease IL6 in human CAFs in a pH and GPR68-independent manner. Across many cancer types, LOR is associated with worse survival outcomes relative to ALP and patients not receiving BZDs. CONCLUSIONS: We demonstrate that LOR stimulates fibrosis and inflammatory signaling, promotes desmoplasia and ischemic necrosis, and is associated with decreased pancreatic cancer patient survival.

Unintended Effects of GPCR-Targeted Drugs on the Cancer Phenotype.

G protein-coupled receptors (GPCRs) are the most common class of therapeutic targets, accounting for ~35% of all FDA-approved drugs. Cancer patients receive numerous medications not only to combat cancer but also to alleviate pain, nausea, and anxiety, many of which target GPCRs. Emerging evidence has implicated GPCRs as drivers of cancer progression, therapeutic resistance, and metastasis. Therefore, the effects of commonly prescribed GPCR-targeted drugs must be reevaluated in the context of cancer. Epidemiological and experimental evidence indicate that widely used GPCR-targeted drugs may promote or inhibit cancer progression. It is crucial that we more fully understand the indirect effects of GPCR-targeted drugs on the cancer phenotype. This review summarizes recent advances in characterizing these interactions and highlights future research opportunities.