Intracellular localization of matrix metalloproteinases and their inhibitors in cultured tumor cell lines: Flow cytometric analysis

Abstract

Abstract. Coordinate cell-surface expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) on cancer cells, tumor-infiltrating lymphocytes (TIL) and cancer-associated myofibroblasts has been shown to play an important role in tumor invasion and metastasis in organ tissues. However, precise localization of tumor cell lines in vitro has remained obscure. The aim of this study was to investigate the spatial localization of these proteolytic enzymes in 21 tumor cell lines consisting of 8 gastric, 4 pancreatic, 2 gallbladder, 1 extrahepatic bile duct cancer and 6 T-or B-cell tumors. The cell-surface and/or intracellular localization of MMP-2, -7, and -9, membrane type-1 (MT1)-MMP and TIMP-2 and -4 was quantitatively determined by flow cytometry in living (non-permeabilized) and permeabilized tumor cell lines. As a result, all of the tumor cell lines showed a high level of intracellular expression, but a low or undetectable level of cell-surface expression of MMPs and TIMPs. The findings revealed that intracellular MMPs and TIMPs in tumor cell lines were preserved as latent pro-enzymes.

Matrix-metalloproteinases as targets for controlled delivery in cancer: An analysis of upregulation and expression

“…When in the intracellular environment, most MMPs remain preserved in a latent proenzyme state[43], yet activated forms and even novel isoforms have been identified intracellularly[28,44,45]. …”

Stimuli‐responsive nanotherapeutics for precision drug delivery and cancer therapy

“…Matrix metalloproteinases (MMPs) are calcium‐dependent endopeptidases that utilize three amino acids as ligands for zinc ion coordination to achieve their catalytic activity (Isaacson, Martin, Subrahmanyam, & Ghandehari, ). MMPs have been proven to be associated with cancer‐cell invasion and metastasis (Koyama, ; Thorsen et al, ), and they are overexpressed in TME in comparison to normal tissue for most kinds of cancer (Soslau et al, ). Therefore, a novel multifunctional theranostic nanoparticle (CLIO‐ICT) is synthesized by conjugation of FDA‐approved superparamagnetic crosslinked iron oxide (CLIO) nanoparticles ferumoxytol to an MMP‐activatable peptide conjugate of azademethylcolchicine (ICT2588).…”

Higher risk of matrix metalloproteinase (MMP‐2, 7, 9) and tissue inhibitor of metalloproteinase (TIMP‐2) genetic variants to gallbladder cancer

“…TIMP‐2 that acts as a major endogenous inhibitor of MMP‐2 and other active MMPs, has important effects on various malignancies . MMPs are shown to have high level of intracellular expression in gallbladder tumour and gallbladder tumour cell lines .…”