Desmoid tumors (DT) are locally invasive soft tissue growths with no directed therapies and high rates of recurrence. Two mutated genes (CTNNB1and APC2) have been linked to patients who develop desmoids, both which translated to proteins in the Wnt canonical pathway. It is our hypothesis that the desmoid tumor microenvironment has altered metabolism, similar to that of pancreatic ductal adenocarcinoma (PDAC). Pancreatic tumors are like desmoid tumors, in that they consist of an abundance of desmoidic stromal tissue, are driven by mutations of K-ras, another Wnt protein, and accumulate β-catenin. In a recent study of the PDAC metabolism, it was found that the activated fibroblasts cells in PDAC release alanine to fuel the TCA cycle, rather than glucose and glutamine-derivatives, which therefore facilitates tumor survival and growth. It is possible that the alanine secretions observed in PDAC represent metabolic reprogramming of tumors driven by the canonical Wnt pathway. We will use stable isotopic resolved metabolomics (SIRM) to better define the desmoid tumor and adjacent normal fibroblast metabolism through the TCA cycle, glycolysis, and the synthesis of non-essential amino acids. By using 13C-labeled tracers in cell media and tail injections, we will be able to use 1 and 2D NMR spectroscopy to follow the metabolism differences of primary cell lines and animal tissue. Matched primary cell lines will be used to determine the metabolic flux of the TCA cycle, glycolysis, and the synthesis of nonessential amino acids. We will also evaluate the cell lines by β-catenin mutation status, as the S45F has been noted to be more aggressive and recur more frequently than T41A. Following the cellbased SIRM, we will evaluate the metabolism of two animal models. The first model is representative of Familial adenomatous polyposis (FAP), Apc1638N, and has been studied extensively by our laboratory. The second animal model is currently being developed and will contain the two CTNNB1 mutations, T41A and S45F. We will determine if the metabolic flux follows the same patterns in the animal models as in the cells. We will compare the two Wnt pathway protein mutations, as this would be first time the metabolism of these two will be evaluated. This study of primary cells and animal models using SIRM will provide valuable insight into the metabolism of desmoid tumors and the surrounding normal tissue to better understand the microenvironment and potentially why these tumors recur so frequently.
LAY VERSION OF ABSTRACT- “Stable isotope resolved metabolomics to interrogate the interactions between stroma and desmoid tumors.”
