Transglutaminase-2 facilitates extracellular vesicle-mediated establishment of the metastatic niche

Abstract

The ability of breast cancer cells to interconvert between epithelial and mesenchymal states contributes to their metastatic potential. As opposed to cell autonomous effects, the impact of epithelial-mesenchymal plasticity (EMP) on primary and metastatic tumor microenvironments remains poorly characterized.Herein we utilize global gene expression analyses to characterize a metastatic model of EMP as compared to their non-metastatic counterparts. Using this approach we demonstrate that upregulation of the extracellular matrix crosslinking enzyme tissue transglutaminase-2 (TGM2) is part of novel gene signature that only emerges in metastatic cells that have undergone induction and reversion of epithelialmesenchymal transition (EMT). Consistent with our model system patient survival is diminished when primary tumors demonstrate enhanced levels of TGM2 in conjunction with its substrate, fibronectin.Targeted depletion of TGM2 inhibits metastasis, while overexpression of TGM2 is sufficient to enhance this process. In addition to being present within cells, we demonstrate a robust increase in the amount of TGM2 and crosslinked fibronectin present within extracellular vesicle (EV) fractions derived from metastatic breast cancer cells. Confocal microscopy of these EVs suggests that FN becomes fibrillated on their surface via a TGM2 and Tesin1-dependent process. Upon in vivo administration, the ability of tumor-derived EVs to induce metastatic niche formation and enhance subsequent pulmonary tumor growth requires the presence and activity of TGM2. Finally, we develop a novel 3D model of the metastatic niche to demonstrate that education of pulmonary fibroblasts via pretreatment with tumorderived EVs promotes subsequent growth of breast cancer cells in a TGM2-dependent fashion. Overall, our studies illustrate a novel mechanism through which EMP contributes to metastatic niche development and distant metastasis via tumor-derived EVs containing abberent levels of TGM2 and fibular FN.

The pleiotropic role of transcription factor STAT3 in oncogenesis and its targeting through natural products for cancer prevention and therapy

“…Cancer metastasis is a complicated process where cancer cells trumpet from their origin to distant organs with the help of the circulatory system leading to the development of tumors in other parts of the body or distant organs. Invasion is another important feature of the cancerous cells where malignant cells directly penetrate or invade the nearby tissues 96–98 . Tumor metastasis and invasion of the malignant cells are considered as important hallmarks of carcinogenesis.…”

Transglutaminase‐2, RNA‐binding proteins and mitochondrial proteins selectively traffic to MDCK cell‐derived microvesicles following H‐Ras‐induced epithelial–mesenchymal transition

“…To focus on the 222 selectively enriched proteins in 21D1‐sMVs in the context of signaling pathways implicated in EMT we performed global STRING based protein‐protein interaction network analysis. This interrogation revealed prominent protein‐protein interactions of the MAPK cascade (HRAS/ARAF/MAPK3), transglutaminase 2 (TGM2) ternary complex (TGM2, FN1, ITGB1), integrin signaling (ITGA5, ITGA6, FN1), and non‐canonical Wnt signaling (WNT5A, GNG5, GNG10, HRAS) [2,30–32] (Figure 2C). Because of the unexpected finding of specific sorting of TGM2 and key components of the TGM2/FN1 complex in 21D1‐sMVs we decided to interrogate the 1574 protein identifications common to both MDCK‐/21D1‐sMVs (Figure 2A) for other known TGM2 interaction partners.…”

High‐risk endometrial cancer proteomic profiling reveals that FBXW7 mutation alters L1CAM and TGM2 protein levels

“…In light of these diverse functions, it is not unexpected that TGM2 has been implicated in the etiology of at least 20 other cancer types (reviewed by Eckert 39 ), and preclinical experiments in ovarian cancer cells have shown that small molecule TGM2 inhibitors inhibited adhesion to the peritoneum in vivo and sensitized cells to paclitaxel in vitro 40 . In ovarian cancer cells, TGM2 is upregulated by TGF‐β, modulates spheroid formation, induces epithelial‐to‐mesenchymal transition and metastasis, increases survival (reviewed by Eckert 39 ), and is required for metastatic niche formation by extracellular vesicles 41 . TGM2 is a potential plasma biomarker 42 and prognostic factor 43 for EC and is induced by progesterone and calcitonin in Ishikawa EC cells, 44 but little else is known regarding its function in EC.…”