Shp2-Pdha Metabolic Axis Is Critical For Adipocyte Function By Mitigating Er Stress-Induced Adipocytes Dysfunction: Implication For Obesity-Driven Pancreatic Ductal Adenocarcinoma Progression.

Abstract Obesity remains a major risk factor for the development of pancreatic cancer. Animal studies demonstrated that obese mice develop larger and more metastatic pancreatic cancer compared to their lean counterpart. Within the tumor environment are adipocytes that secrete adipokines, which promote inflammation and directly stimulate pancreatic cancer cells. Understanding the mechanisms that alter adipocyte function and adipokine secretion is critical for circumventing adipocyte-mediated influence on pancreatic cancer progression. Targeting of the Src homology region 2 containing protein tyrosine phosphatase (SHP-2) in the cancer cells has recently shown promising potential, yet the effect of SHP2 inhibition on stromal components has not been addressed. Here we demonstrate that SHP2 and the mitochondrial protein pyruvate dehydrogenase (PDHA) are critical mediators of adipocyte function, through mitigation of ER stress in adipocytes. In order to understand the role of SHP2 and PDHA in adipocytes, we performed Oil Red O staining and western blot assays on cultured adipocytes. We found that the transition from pre-adipocytes to fully developed adipocytes is marked by significant accumulation of phospho-SHP2, PDHA and the ER stress marker Bip. Chemical inhibition of SHP2 or PDHA augmented ER stress and impaired lipid production in the adipocytes; these effects were reversed by the ER stress inhibitor, 4-Phenylbyturic acid (4-PBA). Moreover, pancreatic cancer cells exposed to conditioned media from differentiated adipocytes, in which either SHP2 or PDHA was inhibited, are less aggressive and invasive compared to PDAC cells grown in conditioned media from control adipocytes with no inhibitor treatment. Therefore, our studies indicate that SHP2 and PDHA, in adipocytes, are key mediators of obesity-driven pancreatic cancer progression. Future studies will focus on understanding the SHP2-PDHA axis in adipocytes and further to elucidate how cancer cell extrinsic effects of SHP2 inhibition could alter PDAC progression. Citation Format: Appolinaire A. Olou, Jarrid Jack, Sharon Manley, Joseph Ambrose, McKinnon Walsh, Austin Eades, Michael N. VanSaun. SHP2-PDHA metabolic axis is critical for adipocyte function by mitigating ER stress-induced adipocytes dysfunction: Implication for obesity-driven pancreatic ductal adenocarcinoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2824.