Abstract B015: Targeting hexosamine biosynthesis pathway for the treatment of desmoid tumors
Authors: Przybyl Joanna , Tolwani Angela , Varma Sushama , van de Rijn Matt 
Published: September 2022

Cancer cells rewire metabolic pathways and energy production to support the enhanced proliferation, invasion and resistance to treatment. The three main glucose metabolism pathways that support growth of cancer cells are: a) the glycolysis pathway for energy production; b) the pentose phosphate pathway for biomass production; and c) the hexosamine biosynthesis pathway (HBP) for protein glycosylation. It is known that the activation of HBP leads to altered glycosylation of oncogenes, transcription factors and kinases in many types of cancer. These aberrations may lead to increased proliferation and survival of tumor cells, and may be associated with resistance to therapy. A better understanding of the role of HBP in malignancies has the potential for clinical implications. Several studies demonstrated that pharmacological inhibition of GFPT2 (glutamine-fructose-6-phosphate transaminase 2, the first and rate-limiting enzyme in HBP) and the enzymes that act downstream of HBP may exhibit anti-tumorigenic effect both in vitro and in vivo, and may modulate sensitivity to chemo-, radio- and immunotherapy. Most of these studies focused on carcinomas and the role of HPB in sarcoma has not been studied. We recently reported a remarkable enrichment of genes involved in HBP in a subset of leiomyosarcoma (LMS) and demonstrated that expression of GFPT2 in LMS is associated with poor clinical outcome. We identified the c-Myc oncoprotein as a potential target of HPB that may be stabilized by aberrant glycosylation in LMS. Here we show the results of a large-scale screening of 260 primary specimens of 33 types of soft tissue lesions. In addition to expression in a subset of LMS, we observed near universal expression of GFPT2 in 34 of 35 desmoid type fibromatosis (DTF), independent of the mutation type of the CTNNB1 gene. Gene Set Enrichment Analysis of a previously published 3SEQ transcriptomic dataset composed of DTF and 9 other types of fibrotic lesions identified significant enrichment of other genes implicated in HBP and multiple glycosylation-associated pathways in DTF compared to the other types of fibrotic lesions. Our analysis identified ATF6 (activating transcription factor 6) as a possible target regulated by aberrant glycosylation as a consequence of HBP activation in DTF. ATF6 is a glycoprotein that has been demonstrated to underlie the resistance to chemotherapy in osteosarcoma, to have a pro-oncogenic role in primary liver cancers and has been proposed as a therapeutic target in cystic fibrosis. Others have shown that targeting HBP can provide therapeutic benefit in a number of preclinical models of carcinoma. Our studies offer new insights into the mechanisms of DTF tumorigenesis and, when confirmed by in vitro studies, will provide a rationale to explore the potential of therapeutic targeting of HBP in DTF.

Citation Format: Joanna Przybyl, Angela Tolwani, Sushama Varma, Matt van de Rijn. Targeting hexosamine biosynthesis pathway for the treatment of desmoid tumors [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr B015.