TITLE:
Roles of Matrix Metalloproteinases in Invasion and Metastasis of Clear Cell Renal Cell Carcinoma: A Narrative Review
AUTHORS:
Bowen Liu, Yixiang Liao
KEYWORDS:
Matrix Metalloproteinases, Renal Cell Carcinoma, Neoplasm Invasiveness, Neoplasm Metastasis, Tissue Inhibitor of Metalloproteinases, Tumor Microenvironment
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.14 No.9,
September
7,
2026
ABSTRACT: Clear cell renal cell carcinoma (ccRCC) accounts for most kidney cancers, and metastatic dissemination rather than the primary tumor causes most kidney-cancer deaths. Degradation and reorganization of the extracellular matrix (ECM) are prerequisites for local invasion, intravasation, and colonization of distant organs, and matrix metalloproteinases (MMPs) are the principal effectors of these processes. This narrative review synthesizes peer-reviewed evidence published between 2021 and 2026 on the expression, regulation, mechanistic functions, and translational relevance of MMPs and their endogenous inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), in ccRCC invasion and metastasis. Tissue and bioinformatic studies report overexpression of gelatinases (MMP-2, MMP-9) and membrane-type MMP-14, together with several other family members, in ccRCC; however, the direct ccRCC evidence is largely transcriptomic and immunohistochemical, whereas part of the supporting tissue-level data derive from mixed-histology renal carcinoma cohorts rather than pure clear cell populations. Higher MMP expression or enzymatic content generally associates with advanced stage, aggressive histology, and shorter survival. Mechanistic work converges on a small set of regulatory axes, including ERK/MAPK signaling through the transcription factors ETS1 and activator protein 1 (AP-1), metabolic reprogramming through G6PD, and epithelial-mesenchymal transition (EMT) programs driven by SPOCK1, CD44, and FXR, each of which funnels into MMP induction. Dysregulation of TIMPs, including TIMP-1 overexpression with pro-survival functions and TIMP-3 loss, further tilts the proteolytic balance toward invasion, while non-coding RNAs and macrophage-derived exosomes modulate the MMP/TIMP axis within the tumor microenvironment. Translationally, MMPs show promise as components of prognostic models, radiomic predictors, and liquid-biopsy readouts, but therapeutic targeting remains unrealized in ccRCC; the failure of broad-spectrum MMP inhibitors has shifted interest toward engineered, highly selective protein inhibitors and rational combinations with anti-angiogenic and immune-checkpoint therapy. Realizing the clinical value of the MMP axis in ccRCC will require activity-based biomarkers, ccRCC-specific interventional studies, and trial designs that account for the context-dependent functions of individual family members.