Abstract C103: Differential acquisition of extracellular lipid correlates with pancreatic cancer subtype and metastatic tropism

Abstract

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease, and the third leading cause of cancer-related death with a 5-year overall survival rate of less than 5%. Recent studies have identified two major subtypes of pancreatic cancer, basal and classical, that are predictive of patient prognosis, with basal tumors corresponding with more aggressive disease. While transcriptional signatures define basal and classical tumors and cell lines, little is known regarding the metabolic vulnerabilities linked to the basal versus classical state. Using unbiased computational interrogation to uncover metabolic genes correlating with known markers of classical PDAC, we identified high expression of Proprotein convertase subtilisin/kexin type-9 (PCSK9) – a negative regulator of receptor mediated uptake of cholesterol containing low-density lipoprotein (LDL) – as correlating with several established markers of classical PDAC. In contrast, PCSK9 expression is suppressed in Basal PDAC. Accordingly, basal PDAC uptake high levels of LDL, are sensitive to LDL depletion and show higher dependence on cholesterol uptake, relative to classical PDAC. As lipoproteins are produced in the liver, we hypothesized that basal PDAC cells may more efficiently seed and grow within the liver. Consistent with this hypothesis, low PCSK9 expression is correlated with liver metastasis in mouse models of PDAC and patient PDAC specimens. Ongoing studies will interrogate the role of PCSK9 and cholesterol uptake and utilization in metastatic tropism, and uncover unique features and vulnerabilities of the most aggressive variant of PDAC. Citation Format: Gilles Rademaker, Grace A. Hernandez, Longhui Qiu, Kwun W. Wen, Aakriti Jain, Grace A. Kim, Roberto Zoncu, Rushik M. Perera. Differential acquisition of extracellular lipid correlates with pancreatic cancer subtype and metastatic tropism [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C103.