Abstract 2676: Gender-associated improvement in gemcitabine’s therapeutic outcome by Palmatine

Abstract

Abstract Despite a plethora of therapeutic strategies, improved survival is only modest for patients diagnosed with pancreatic ductal adenocarcinoma (PDAC). Additionally, between 2000 and 2018, pancreatic cancer incidence significantly increased with the greatest increase among women ages 15-35 years. We identified a protoberberine alkaloid, Palmatine (PMT), that was effective in slowing tumor growth and improving therapeutic outcome of gemcitabine (GEM) in pancreatic tumor bearing mice. Interestingly, the improved therapeutic outcome with the combination was observed in a sex-associated manner in mice. Intriguingly, PMT reduced proliferation of cells isolated from surgically resected tumor samples in 71% of female and 33% of male pancreatic cancer patients. We also observed that the correlation between PMT effects on cancer-related biological functions was associated with downregulation of STAT3 signaling. RNA-seq data from STAT3-KD pancreatic cancer cells revealed enrichment of genes associated with fatty acid metabolism. Of these, mRNA expression of ELOVL2 (Elongation of Very Long Chain Fatty Acids-Like 2) was most significantly increased suggesting a negative regulatory role for STAT3 in ELOVL2 expression. In silico analysis of the pancreatic cancer UalcanPan database shows that ELOVL2 is significantly reduced in human pancreatic tumors relative to normal pancreas and that high expression of ELOVL2 is associated with increased survival. The fatty acid elongase, ELOVL2, is involved in the production of docahexaenoic acid (DHA). Our experimental data show that PMT increased ELOVL2 expression. Taken together, these findings suggest the potential utility of PMT in therapeutic sensitization of GEM through deregulation of STAT3-mediated ELOVL2 signaling. These observations further suggest a sex-associated role for PMT in improving outcomes that may in part involve ELOVL2 function. Supported in part through VA Merit Award BX003876 and Owens Foundation pilot (APK). Citation Format: Meagan Marie Ybarra, Xiaoyu Yang, Amanda Munoz, Michelle Villarreal, Joel Michalek, Li-Ju Wang, Yidong Chen, Ikeno Yuji, Glenn Halff, Susan Weintraub, Rita Gosh, Addanki P. Kumar. Gender-associated improvement in gemcitabine’s therapeutic outcome by Palmatine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2676.