Abstract 5160: A GPCR candidate in pancreatic ductal adenocarcinoma: A potential repurposing opportunity

Abstract

Abstract The 5-year survival of patients with pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer (90%), is very low (~9% all stages). PDAC thus requires new, effective and safe therapies. By comparing transcriptomic data for PDAC (in The Cancer Genome Atlas) with that of normal pancreas (in the GTEx database), we discovered that many G protein-coupled receptors (GPCRs) are increased in expression in PDAC. One such GPCR is the histamine receptor H1 (HRH1). GPCRs regulate metabolism, growth/death and functional activities of normal and cancer cells, including features of the malignant phenotype. GPCRs are the largest family of targets of approved drugs but have been largely ignored in cancer therapy. We found that HRH1 is prominently (~32-fold) overexpressed in PDAC tumors compared to normal pancreatic tissue and that high HRH1 expression is an unfavorable prognostic marker for PDAC patients. HRH1 mRNA is also highly expressed in multiple human PDAC cell lines. Studies with such cell lines revealed that histamine, acting via HRH1, increases intracellular Ca2+, cell proliferation and migration, effects blocked by multiple FDA-approved HRH1 antihistamines. PDAC tumors and cancer cells isolated from KPC mice also have high HRH1 expression compared to normal mouse pancreas. Similar to human PDAC cells, the KPC cells showed histamine/HRH1-promoted increase in intracellular Ca2+. Altogether, our findings identify HRH1 as a prominently overexpressed, functional GPCR in human and mouse PDAC tumors and cells. HRH1 may thus be a novel therapeutic target; its blockade by FDA-approved antihistamines represents a novel potential repurposing approach for the treatment of PDAC. Citation Format: Cristina Salmerón, Krishna Sriram, Alyssa Baird, Paul A. Insel. A GPCR candidate in pancreatic ductal adenocarcinoma: A potential repurposing opportunity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5160.