An Integrative Bioinformatics Approach to Investigating TIMP3 and Immune Cell Infiltration: Prognostic and Clinicopathological Implications

Tissue inhibitor of metalloproteinase 3 (TIMP3) serves as a prominent endogenous inhibitor of matrix metalloproteinases (MMPs), playing a crucial role in inhibiting metastasis, and angiogenesis. However, its exact contributions to colorectal cancer (CRC) remain largely unidentified. We aimed to ascertain the prognostic significance of TIMP3 in CRC patients through a bioinformatic approach. GEPIA, UALCAN, Kaplan–Meier plotter, LinkedOmics, cBioPortal, GeneMANIA, TIMER, TISIDB, the ScTIME database, TISMO, TIDE, CAMOIP, and TISCH2 were employed to comprehensively analyze the differential expression, prognostic value, genetic alterations, signaling pathways, immune cell infiltration, tumor microenvironment (TME) and associated genes of TIMP3 in CRC patients. Compared to adjacent normal tissues, we observed a significant downregulation of TIMP3 expression in CRC samples. Gene interaction networks elucidated that TIMP3 and its associated genes play a pivotal role in cancer progression, particularly in processes critical to colorectal cancer, such as extracellular matrix organization and angiogenesis. Analysis of the TME further indicates that TIMP3 expression was intricately associated with diverse immune cell types infiltration levels, chemokines, and immunomodulators. Most importantly, those with elevated TIMP3 expression had improved immunological scores. Moreover, TIMP3 exhibited strong correlations with major infiltration-related immune cells, including B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, dendritic cells, and fibroblasts. Furthermore, improved immunotherapeutic responses against PD-1/PD-L1 were linked to elevated TIMP3 levels. In TIMP3-high groups, there was a considerable increase in IL10, PDCD1, CD80, CXCL9, and CXCR3. This highlights the extensive influence of TIMP3 downregulation on the immune milieu within CRC. Our findings emphasize the multifaceted involvement of TIMP3 in CRC, not only influencing the molecular pathways associated with cancer progression, but also intricately shaping the immune microenvironment. As a result, TIMP3 appears promising as a potential CRC therapeutic target.