Differential Expression of Histamine H3 Receptor In Healthy, Preneoplastic, and Tumoral Pancreatic Tissue: A Pilot Study.

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide, with a mortality rate almost equal to its incidence, highlighting the urgent need for novel biomarkers and therapeutic targets. This pilot study aims to investigate the potential value of histamine H3 receptor (H3R) as a prognostic biomarker for this lethal disease. We analyzed the H3R expression in PDAC using the RNA sequencing data set from The Cancer Genome Atlas (Pan-Cancer Atlas). In addition, H3R protein levels were evaluated by immunohistochemistry in 27 PDAC samples and compared with adjacent preneoplastic pancreatic tissue of the same patient, and with 10 non-related healthy pancreatic tissues. This preliminary study shows that the H3R is barely expressed in healthy tissue. Interestingly, H3R was detected in 96% of PDAC samples, and its expression in tumoral tissue was significantly higher when compared with its expression in preneoplastic tissue, and it was associated with a better prognosis in terms of overall survival. Present findings suggest that H3R may serve as a potential prognostic biomarker in PDAC. Future research aimed at elucidating the role of H3R in PDAC biology and its prognostic value in larger patient cohorts is warranted.