Abstract 1541: Secreted serglycin in tumor microenvironment promotes tumor malignancies in a CD44-dependent manner

Abstract

Abstract Tumor microenvironment (TME) plays an important role in cancer progression; however, the communication between TME and cancer cells remains largely unclear. CD44, a type I cell surface receptor functioning in cell-cell and cell-extracellular matrix interactions, has been implicated in tumor formation and progression. Using gain-of-function and loss-of-function approaches, we report in this study that serglycin (SRGN), a glycoprotein secreted from cancer-associated fibroblasts (CAFs) as well as aggressive cancer cells, works to promote the malignant behaviors of non-small cell lung cancer cells through its interaction with CD44. We showed that SRGN promotes cell transformation and tumor formation and metastasis using in vitro and in vivo tumorigenic assays. Furthermore, we showed that SRGN induced lung cancer cell stemness in a CD44-dependent manner. SRGN enhanced cancer cells sphere formation via Nanog induction, accompanied with increased drug resistance and resistance to anoikis. We also demonstrated that SRGN promotes cell migratory activity through promoting epithelial-mesenchymal transition (EMT) and enhancing adhesions turnover by upregulating vimentin expression and SRC activity via CD44/NF-KB/Claudin-1 axis. In support, Claudin-1 expression was tightly associated with SRGN expression in primary lung cancer tissues (p < 0.0001). In summary, we demonstrate that the crosstalk between tumor cells and TME promotes malignant phenotypes through the interaction of tumor-borne CD44 and CAF- or tumor-derived SRGN, suggesting that targeting CD44 or its ligands may represent an attractive strategy for development of cancer therapy. Citation Format: Jing-You Guo, Shiaw-Wei Tyan, Han-Shui Hsu, Fen-Yau Li, Jeou-Yuan Chen. Secreted serglycin in tumor microenvironment promotes tumor malignancies in a CD44-dependent manner. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1541. doi:10.1158/1538-7445.AM2015-1541