Differential Effects of Serine Proteases on the Migration of Normal and Tumor Cells: Implications for Tumor Microenvironment

Abstract

The supporting role of proteases in tumor progression and invasion is well known; however, the use of proteases as therapeutic agents has also been demonstrated. In this article, the authors report on the differential effects of exogenous serine proteases on the motility of tumor and normal cells. The treatment of normal and tumor cells with a single dose of pancreatic serine proteases, trypsin (TR) and chymotrypsin (CH), leads to a concentration-dependent response by cells, first accelerating and then slowing mobility. Tumor cells are 10 to 20 times more sensitive to exogenous TR/CH, suggesting that a single dose of proteases may cause discordant movements of normal and tumor cells within the tumor environment. The inhibitory effects of TR on cell motility are contradicted by thrombin (TH), particularly in the regulation of normal cells' migration. The purpose of this investigation was to ascertain the role of protease-activated receptors (PARs) in terms of normal and tumor cell motility. Duplicate treatments with proteases resulted in diminished mobility of both normal and tumor cells. Repeated application of TR and TH in 1-hour treatment intervals initially desensitizes cell surface PARs. However, cell surface PARs reappear regardless of subsequent protease treatments in both normal and tumor cells. The resensitization process is retarded in tumor cells when compared with normal cells. This is evidenced by lower expression of PARs as well as by their relocalization at the tumor cell surfaces. Under these conditions, normal cells remain responsive to exogenous proteases in terms of cell motility. Exogenous proteases do not modulate motility of repeatedly stimulated tumor cells, and consequently, the migration of tumor cells appears disconnected from the PAR signaling pathways. The use of activating peptides in lieu of the cognate proteases for a given PAR system indicated that proteases may act through additional targets not regulated by PAR signaling. We hypothesize that the divergent migration patterns of normal and tumor cells due to exposure to proteases is in part mediated by PARs. Thus, treatment with exogenous proteases may cause rearrangement of the tumor and stromal cells within the tumor microenvironment. Such topographical effects may lead to the inhibition of tumor progression and metastasis development.

Expression of proteinase-activated receptor 1-4 (PAR 1-4) in human cancer

“…The result of the literature review is summarized in Tables 1, 2, 3, and 4, (Arora et al 2008;Beaulieu and Church 2007;Bromberg et al 2001;Caruso et al 2006;Cooper et al 2003;Elzer et al 2008;Fujimoto et al 2006;Ghio et al 2006;Granovsky-Grisaru et al 2006;Hazarika et al 2004;Hjortoe et al 2004;Ikeda et al 2003Ikeda et al , 2006Jahan et al 2007;Jin et al 2003;Kang et al 2003;Kaufmann et al 1998Kaufmann et al , 1999Kaufmann et al , 2000Kim et al 2002;Massi et al 2005;Matej et al 2007;Miyata et al 2000;Mize et al 2008;Ohta et al 2003;Okamoto et al 2001;Radjabi et al 2008;Rudroff et al 2002;Sánchez-Hernández et al 2008;Seo et al 2007;Shibata et al 2004;Yoshii et al 2005;Zhang et al 2004). …”

Lymphotoxin‐β receptor‐NIK signaling induces alternative RELB/NF‐κB2 activation to promote metastatic gene expression and cell migration in head and neck cancer

“…The finding that LTβ activation of the alternative pathway promotes expression of MET and migration, could help explain why and how HNSCC preferentially spread to local lymph nodes, where LTβ is abundantly expressed by lymphoid cells. 26,39,40 In HNSCC tumor samples from the TCGA datasets, we observed tissue site-specific alterations of the signaling molecules involved in the alternative NF-κB pathway. LTβR genomic amplification at the chromosome 12p13.3 locus and/or its overexpression occurs in ∼13% HNSCC cases, particularly those arising from larynx and oral cavity, which are mostly HPV (−).…”

“…Our results revealed a novel mechanism whereby LTβ/LTβR signaling mediated activation of the alternative NF‐κB pathway promotes migration and other mediators implicated in pathogenesis of HNSCC. The finding that LTβ activation of the alternative pathway promotes expression of MET and migration, could help explain why and how HNSCC preferentially spread to local lymph nodes, where LTβ is abundantly expressed by lymphoid cells …”

Trypsin Potentiates Human Fibrocyte Differentiation

“…Although trypsin is generally thought of as a digestive enzyme, trypsin is also active in multiple cellular processes, including development and tumor invasion [33]–[42]. Trypsin is involved in gastric inflammation through cleavage of the proteinase-activated receptors (PAR1–4) [43]–[45], and PAR1 and PAR2 digestion has also been implicated in cancer signaling [46], [47].…”