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Tissue inhibitor of metalloproteinases-1 (TIMP-1) regulates the proteolytic activity of matrix metalloproteinases (MMPs), playing an important role in the homeostasis of the extracellular matrix. Beyond its well-known role in tissue maintenance, TIMP-1 has been associated with multiple MMP-independent cytokine-like functions. The protein structure of TIMP-1, with two distinct domains, one interacting with MMPs and another able to bind multiple partners, provides a rationale for this multifunctionality. The identification of CD63 as a cell surface receptor for TIMP-1, able to mediate intracellular signaling through the Erk/MAPK axis, provided a molecular basis for the role of TIMP-1 in cellular signaling. However, several lines of evidence suggest that TIMP-1 may be able to associate with many interaction partners, thus attaining multiple functions. To enable the identification of previously unknown interaction partners that may underpin the core cellular functions of TIMP-1, known as well as unknown, we performed a yeast two-hybrid screening using a mammary gland complementary DNA (cDNA) library. We report here the identification of multiple interactors, including MHC class II-associated invariant chain γ (CD74). We verified that CD74 interacts with TIMP-1 in breast cancer cells and that this interaction contributes to cellular internalization of TIMP-1 and mediates intracellular signaling through the Akt signaling axis in breast cancer cells. These data provide new insights into the complex nature of the functions of TIMP-1 and their potential mechanistic basis., (© 2023 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Colorectal cancer (CRC) is the third most prevalent cancer worldwide causing an estimated 700 000 deaths annually. Different types of treatment are available for patients with advanced metastatic colorectal cancer, including targeted biological agents, such as cetuximab, a monoclonal antibody that targets EGFR. We have previously reported a study indicating multiple levels of interaction between metallopeptidase inhibitor 1 (TIMP-1) and the epidermal growth factor (EGF) signaling axis, which could explain how TIMP-1 levels can affect the antitumor effects of EGFR inhibitors. We also reported an association between TIMP-1-mediated cell invasive behavior and KRAS status. To gain insight into the molecular mechanisms underlying the effects of TIMP-1 in CRC, we examined by transcriptomics, proteomics, and kinase activity profiling a matched pair of isogenic human CRC isogenic DLD-1 CRC cell clones, bearing either an hemizygous KRAS wild-type allele or KRAS G13D mutant allele, exposed, or not, to TIMP-1. Omics analysis of the two cell lines identified the receptor tyrosine kinase c-Kit, a proto-oncogene that can modulate cell proliferation and invasion in CRC, as a target for TIMP-1. We found that exposure of DLD-1 CRC cells to exogenously added TIMP-1 promoted phosphorylation of c-Kit, indicative of a stimulatory effect of TIMP-1 on the c-Kit signaling axis. In addition, TIMP-1 inhibited c-Kit shedding in CRC cells grown in the presence of exogenous TIMP-1. Given the regulatory roles that c-Kit plays in cell proliferation and migration, and the realization that c-Kit is an important oncogene in CRC, it is likely that some of the biological effects of TIMP-1 overexpression in CRC may be exerted through its effect on c-Kit signaling., (© 2019 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Current standard treatments for metastatic colorectal cancer (CRC) are based on combination regimens with one of the two chemotherapeutic drugs, irinotecan or oxaliplatin. However, drug resistance frequently limits the clinical efficacy of these therapies. In order to gain new insights into mechanisms associated with chemoresistance, and departing from three distinct CRC cell models, we generated a panel of human colorectal cancer cell lines with acquired resistance to either oxaliplatin or irinotecan. We characterized the resistant cell line variants with regards to their drug resistance profile and transcriptome, and matched our results with datasets generated from relevant clinical material to derive putative resistance biomarkers. We found that the chemoresistant cell line variants had distinctive irinotecan- or oxaliplatin-specific resistance profiles, with non-reciprocal cross-resistance. Furthermore, we could identify several new, as well as some previously described, drug resistance-associated genes for each resistant cell line variant. Each chemoresistant cell line variant acquired a unique set of changes that may represent distinct functional subtypes of chemotherapy resistance. In addition, and given the potential implications for selection of subsequent treatment, we also performed an exploratory analysis, in relevant patient cohorts, of the predictive value of each of the specific genes identified in our cellular models., (Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Introduction: Topoisomerase 1 (TOP1) and 2A (TOP2A) are potential predictive biomarkers for irinotecan and anthracycline treatment, respectively, in colorectal cancer (CRC), and we have recently reported a high frequency of gene gain of the TOP1 and TOP2A genes in CRC. Furthermore, Mismatch Repair (MMR) subtypes of CRC have been associated with benefit from adjuvant chemotherapy of primary CRC. Given the involvement of the topoisomerase enzymes in DNA replication and repair, we raised the hypothesis that an association may exist between TOP gene copy numbers and MMR proficiency/deficiency in CRC., Material and Methods: Test cohort: FISH analysis with an in-house TOP1/CEN20 probe mix and a commercially available TOP2A/CEN17 (Dako, Glostrup, Denmark) probe mix was performed on archival formalin fixed paraffin embedded (FFPE) tissue samples from 18 patients with proficient MMR (pMMR) CRC and 18 patients with deficient MMR (dMMR) CRC. TOP1 and TOP2A gene copy numbers and their ratios per nucleus were correlated with MMR status using the Mann-Whitney test. Validation cohort: FFPE samples from 154 patients with primary stage III CRC (originally included in the RANX05 study) were classified according to MMR status by immunohistochemical analysis using validated antibodies for MLH1, MLH2, MSH6 and PMS2, and information on TOP1, CEN20, TOP2A and CEN17 status was previously published for this cohort., Results: The observed TOP1 gene copy numbers in the 36 CRC test cohort were significantly greater (p < 0.01) in the pMMR subgroup (mean: 3.84, SD: 2.03) than in the dMMR subgroup (mean: 1.50, SD: 0.12). Similarly, the TOP2A copy numbers were significantly greater (p < 0.01) in the pMMR subgroup (mean: 1.99, SD: 0.52) than in the dMMR subgroup (mean: 1.52, SD: 0.10). These findings were confirmed in the validation cohort, where in the pMMR subgroup 51% had ≥2 extra TOP1 copies per cell, while all tumors classified as dMMR had diploid TOP1 status and mean TOP2A copy numbers were 2.30 (SD: 1.36) and 1.80 (SD: 0.31) (p = 0.01) in the pMMR subgroup vs. dMMR subgroup, respectively., Discussion and Conclusion: Our results show that TOP1 and TOP2A gene copy numbers are increased in the pMMR subgroup. We propose that this preference may reflect a selective pressure to gain and/or maintain the gained extra copies of topoisomerase genes whose products are required to cope with high replication stress present in the pMMR tumors, thereby providing a survival advantage selectively in pMMR tumors. Future studies should test this concept and explore potential differences between pMMR and dMMR tumors in response to Top1 and Top2 inhibitors., (Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

The backbone of current cytotoxic treatment of metastatic colorectal cancer (mCRC) consists of a fluoropyrimidine together with either oxaliplatin (XELOX/FOLFOX) or irinotecan (XELIRI/FOLFIRI). With an overall objective response rate of approximately 50% for either treatment combination, a major unsolved problem is that no predictors of response to these treatments are available. To address this issue, we profiled 742 microRNAs in laser-capture microdissected cancer cells from responding and non-responding patients receiving XELOX/FOLFOX as first-line treatment for mCRC, and identified, among others, high expression of miR-625-3p, miR-181b and miR-27b to be associated with poor clinical response. In a validation cohort of 94 mCRC patients treated first-line with XELOX, high expression of miR-625-3p was confirmed to be associated with poor response (OR = 6.25, 95%CI [1.8; 21.0]). Independent analyses showed that miR-625-3p was not dysregulated between normal and cancer samples, nor was its expression associated with recurrence of stage II or III disease, indicating that miR-625-3p solely is a response marker. Finally, we also found that these miRNAs were up-regulated in oxaliplatin resistant HCT116/oxPt (miR-625-3p, miR-181b and miR-27b) and LoVo/oxPt (miR-181b) colon cancer cell lines as compared with their isogenic parental cells. Altogether, our results suggest an association between miR-625-3p and response to first-line oxaliplatin based chemotherapy of mCRC., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)