Protease‐activated receptor 2 promotes actomyosin dependent transforming microvesicles generation from human breast cancer

Abstract

Apart from blood coagulation, coagulation proteases are involved inextricably in cancer progression/propagation via intra/inter-cellular signaling, mediated predominantly by protease-activated receptors (PARs). Microvesicles (MVs), a plasma membrane shredded component, has recently been identified as an important contributor to human breast cancer metastasis. However, the role of PAR2 in promoting MVs generation from breast cancer cells remains largely unexplored. The objective of this study is to investigate whether coagulation protease-mediated human breast cancer propagation commences via MVs and also to decipher the underlying signaling mechanism. Here, we elicited that coagulation factor-FVIIa and Trypsin activates PAR2, which governs MVs shedding from MDAMB231 cells by altering actomyosin dynamics. Treatment of cells with PAR2 activators facilitate MVs generation by activating three independent (MAPK, P38, and Rho) signaling cascades. MAPK, signals through activating MLCK followed by MLC phosphorylation to alter myosin organization whereas, P38 reorganizes actin dynamics by the sequential activation of MK2 and HSP27. RhoA-dependent ROCK-II activation again contributes to remodeling myosin II activity. Further, both our in vitro and in vivo analyses showed that these MVs potentiate invasive and migratory property to the recipient cells. Breast cancer patients blood show an elevation of TF-bearing, pro-metastatic MVs than normal. These findings give an insight into the detailed signaling mechanism involved in the production of MVs with transforming ability from PAR2-activated human breast cancer cells. Understanding these mechanistic details will certainly help to identify crucial targets for therapeutic interventions in MVs-associated human breast cancer metastasis.

Triple-negative breast cancer-derived microvesicles transfer microRNA221 to the recipient cells and thereby promote epithelial-to-mesenchymal transition

“…The exposure of human TNBC cells, MDAMB231 to hypoxia, results in the liberation of MV in a Rab22A-dependent manner, which is capable of promoting focal adhesion formation, invasion, and metastasis to the neighboring recipient cells (27). In the recent past, we have shown that activation of PAR2 by coagulation factors induces prometastatic MV generation from human TNBC cells (10,11).…”

“…Recently, we showed that human TNBC tissues express PAR2 significantly higher than normal breast tissues (11). Moreover, the MV count was also relatively higher in the blood of such cancer patients (11). It has been reported that miR221 is over-expressed in human BC and is associated with increased malignancy (43).…”

“…Recently, we showed that human TNBC tissues express PAR2 significantly higher than normal breast tissues (11). Moreover, the MV count was also relatively higher in the blood of such cancer patients (11).…”

“…EVs are transported via body fluids including urine, blood, synovial fluid, saliva and even are found in interstitial spaces between cells (8,9). Previous studies have revealed that MV from human TNBC cells are capable of inducing migration and invasion to otherwise nonmetastatic BC cells (10,11).…”

“…PAR2-driven AKT/ NF-B activation also promotes human TNBC cell migration and invasion via matrix metalloprotease-2 (MMP-2) induction (19). Previously, we have explored that PAR2 induction not only promotes human TNBC progression but also induces the release of MV with metastatic potential from human TNBC cells (10,11).…”