Regulation of Tumor Metabolism and Extracellular Acidosis by the TIMP-10-CD63 Axis in Breast Carcinoma

Tissue Inhibitor of Metalloproteinases-1 Overexpression Mediates Chemoresistance in Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is among the most aggressive breast cancer subtypes. Despite being initially responsive to chemotherapy, patients develop drug-resistant and metastatic tumors. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a secreted protein with a tumor suppressor function due to its anti-proteolytic activity. Nevertheless, evidence indicates that TIMP-1 binds to the CD63 receptor and activates noncanonical oncogenic signaling in several cancers, but its role in mediating TNBC chemoresistance is still largely unexplored. Here, we show that mesenchymal-like TNBC cells express TIMP-1, whose levels are further increased in cells generated to be resistant to cisplatin (Cis-Pt-R) and doxorubicin (Dox-R). Moreover, public dataset analyses indicate that high TIMP-1 levels are associated with a worse prognosis in TNBC subjected to chemotherapy. Knock-down of TIMP-1 in both Cis-Pt-R and Dox-R cells reverses their resistance by inhibiting AKT activation. Consistently, TNBC cells exposed to recombinant TIMP-1 or TIMP-1-enriched media from chemoresistant cells, acquire resistance to both cisplatin and doxorubicin. Importantly, released TIMP-1 reassociates with plasma membrane by binding to CD63 and, in the absence of CD63 expression, TIMP-1-mediated chemoresistance is blocked. Thus, our results identify TIMP-1 as a new biomarker of TNBC chemoresistance and lay the groundwork for evaluating whether blockade of TIMP-1 signal is a viable treatment strategy.

Small extracellular vesicles in metabolic remodeling of tumor cells: Cargos and translational application

Warburg effect is characterized by excessive consumption of glucose by the tumor cells under both aerobic and hypoxic conditions. This metabolic reprogramming allows the tumor cells to adapt to the unique microenvironment and proliferate rapidly, and also promotes tumor metastasis and therapy resistance. Metabolic reprogramming of tumor cells is driven by the aberrant expression and activity of metabolic enzymes, which results in the accumulation of oncometabolites, and the hyperactivation of intracellular growth signals. Recent studies suggest that tumor-associated metabolic remodeling also depends on intercellular communication within the tumor microenvironment (TME). Small extracellular vesicles (sEVs), also known as exosomes, are smaller than 200 nm in diameter and are formed by the fusion of multivesicular bodies with the plasma membrane. The sEVs are instrumental in transporting cargoes such as proteins, nucleic acids or metabolites between the tumor, stromal and immune cells of the TME, and are thus involved in reprogramming the glucose metabolism of recipient cells. In this review, we have summarized the biogenesis and functions of sEVs and metabolic cargos, and the mechanisms through they drive the Warburg effect. Furthermore, the potential applications of targeting sEV-mediated metabolic pathways in tumor liquid biopsy, imaging diagnosis and drug development have also been discussed.

Comparing TIMP-1 and Hsp70 in Blood and Saliva as Potential Prognostic Markers in HNSCC

(1) Background: Currently, there is no clinically used liquid biomarker in head and neck squamous cell carcinoma (HNSCC) patients. One reason could be the limited shedding of tumor material in early disease stages. Molecular diagnostics assessing both blood and especially saliva could potentially improve the accuracy of biomarkers. In this prospective study, two markers, tissue inhibitor of metalloprotease-1 (TIMP-1) and heat shock protein 70 (Hsp70), were analyzed in HNSCC patients. The purpose of the study was to evaluate differences between saliva and serum as sample material. Further, their prognostic and predictive value and usefulness for early detection was assessed. (2) Methods: A total of 73 HNSCC patients were prospectively monitored by collecting blood and saliva before, during, and after therapy, as well as in the follow-up period between 2018 and 2021. In total, 212 serum and 194 saliva samples were collected. A control group consisting of 40 subjects (15 patients with local infections in the head and neck area and 25 without infections) were examined as well. The collected samples were evaluated for the two proteins by using an enzyme-linked immunosorbent assay (ELISA). (3) RESULTS: The TIMP-1 concentration correlated significantly in blood and saliva, whereas the Hsp70 concentration did not. Saliva TIMP-1 was significantly higher in tumor patients compared to the control group (p = 0.013). High pretreatment TIMP-1 saliva levels were associated with significantly poorer disease-free survival (DFS) (p = 0.02). A high saliva TIMP-1/Hsp70 ratio was significantly associated with poorer DFS (HR: 1.4; 95% CI: 1.04-1.88; p = 0.026) and a high TIMP-1 serum concentration was significantly associated with poorer PFS (HR: 1.9; 95% CI: 1.2, 2.8; p = 0.003) and poorer overall survival (OS) (HR: 2.9; 95% CI: 1.4, 5.9; p = 0.003) in the Cox proportional hazards model. The saliva TIMP-1 to Hsp70 ratio was significantly higher at the time of recurrence (p = 0.015). Conclusion: TIMP-1 in serum is a promising prognostic marker for HNSCC. Saliva TIMP-1 and the saliva TIMP-1 to Hsp70 ratio provides additional information on the disease-free survival.

A CAF-Fueled TIMP-1/CD63/ITGB1/STAT3 Feedback Loop Promotes Migration and Growth of Breast Cancer Cells

Simple Summary

Carcinoma-associated fibroblasts (CAFs) are a major cellular component of the tumor microenvironment and influence cancer cell behavior in numerous ways. A large part of their actions is based on their high secretory activity, leading to the exposure of cancer cells to all kinds of bioactive factors, such as interleukin-6 (IL-6). Here, we present data showing that CAF-derived TIMP-1 activates STAT3 in breast cancer cells in cooperation with CD63 and integrin β1. In turn, STAT3 increases TIMP-1 secretion by breast cancer cells, leading to a TIMP-1/CD63/integrin β1/STAT3 positive feedback loop, which can be further fueled by IL-6. Functionally, this feedback loop is important for the CAF-induced increase in migratory activity and for CAF-induced resistance to the anti-estrogen fulvestrant.

Abstract

TIMP-1 is one of the many factors that CAFs have been shown to secret. TIMP-1 can act in a tumor-supportive or tumor-suppressive manner. The purpose of this study was to elucidate the role of CAF-secreted TIMP-1 for the effects of CAFs on breast cancer cell behavior. Breast cancer cells were exposed to conditioned medium collected from TIMP-1-secreting CAFs (CAF-CM), and the specific effects of TIMP-1 on protein expression, migration and growth were examined using TIMP-1-specifc siRNA (siTIMP1), recombinant TIMP-1 protein (rhTIMP-1) and TIMP-1 level-rising phorbol ester. We observed that TIMP-1 increased the expression of its binding partner CD63 and induced STAT3 and ERK1/2 activation by cooperating with CD63 and integrin β1. Since TIMP-1 expression was found to be dependent on STAT3, TIMP-1 activated its own expression, resulting in a TIMP-1/CD63/integrin β1/STAT3 feedback loop. IL-6, a classical STAT3 activator, further fueled this loop. Knock-down of each component of the feedback loop prevented the CAF-induced increase in migratory activity and inhibited cellular growth in adherent cultures in the presence and absence of the anti-estrogen fulvestrant. These data show that TIMP-1/CD63/integrin β1/STAT3 plays a role in the effects of CAFs on breast cancer cell behavior.