Abstract 2670: Metabolomic and molecular insights into pancreatic cancer-induced cachexia.
Authors: Marie-France Penet, Paul T. Winnard, Flonné Wildes, Yelena Mironchik, Tariq Shah, Anirban Maitra, Zaver M. Bhujwalla
Journal: Cancer Research (2013)

Abstract Pancreatic cancer is an aggressive and lethal neoplasm that induces cachexia and is typically detected at an advanced stage. Better understanding of the disease, early detection, and new therapeutic targets are urgently needed. Here we have investigated the metabolism of multiple pancreatic tumors, and their effect on mouse body weight. To understand the interactions between the tumor and normal tissue, we are developing a cell-based optical biosensor using genetically engineered myoblasts to detect the early onset of cachexia-inducing signals in muscle tissue. We have also characterized the expression of choline kinase (Chk), which is known to be overexpressed in aggressive cancer, and cyclooxygenase 2 (COX-2), a critically important inflammation mediator that significantly influences cancer angiogenesis, invasion, and metastasis. Human pancreatic adenocarcinoma cell lines Pa02C and Pa04C (Jones et al, Science 2008), as well as Panc1, and BxPC3 (obtained from ATCC), were inoculated subcutaneously in male SCID mice. Mouse bodyweight was followed for approximately 6 weeks. Tumors (500 mm3) were excised and freeze-clamped for immunoblot and high-resolution 1H MRS analyses. A loss of body weight was observed after inoculation of Pa04C and Panc1 cells but not BxPc3 and Pa02C cells. Panc1 tumors exhibited high expression levels of COX-2 and the highest levels of Chk. However, Pa04C tumors showed low levels of those two proteins. 1H MRS analysis revealed that Panc1 tumors contained the highest level of total choline, mainly due to a high level of phosphocholine, correlating with the high level of Chk. Panc1 tumors were also characterized by a high level of lactate. Pa04C tumors presented with the second highest levels of total choline and lactate. To determine the effect of pancreatic cancer cells on muscle, we transiently co-transfected primary human myoblasts with constitutive EF-1α driven eGFP expression and with either a control vector, triple-tandem repeat of a NFκB cis-element lacking a minimal promoter (mp) sequence, or with the same tandem repeat fused to a minimal promoter sequence (3xNFκB-mp) driving tdTomato expression. The transfected myoblasts were differentiated into myotubes and then treated for 24 h with conditioned medium from pancreatic tumor cells. We observed that the 3xNFκB-mp promoter was inducible in the presence of conditioned medium obtained from both Panc1 and Pa04C cells. No red fluorescence was induced in undifferentiated myoblasts or in confluent myoblasts. The acquisition of in vivo 1H MRSI is ongoing, and should further improve the characterization of those pancreatic cell lines, and the correlation between the metabolites measured in vivo and weight loss. Our data identify increased total choline and lactate as potential imaging biomarkers to detect pancreatic cancer, and Chk and COX-2 as potential therapeutic targets of this devastating disease. This work was supported by NIH P50CA103175. Citation Format: Marie-France Penet, Paul T. Winnard, Flonné Wildes, Yelena Mironchik, Tariq Shah, Anirban Maitra, Zaver M. Bhujwalla. Metabolomic and molecular insights into pancreatic cancer-induced cachexia. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2670. doi:10.1158/1538-7445.AM2013-2670