Landscape Analysis of Matrix Metalloproteinases Unveils Key Prognostic Markers for Patients With Breast Cancer

Estrogenic control of matrix metalloproteinases: a perspective on breast tumor invasion and metastasis

Metastasis is the major cause of mortality in breast cancer patients, and presents an invincible therapeutic challenge. It is a complex process of dissemination of tumor epithelial cells, which is associated with disruption of tissue homeostasis, and alterations in the tumor microenvironment through extracellular matrix (ECM) remodeling, stromal alteration, and epithelial-mesenchymal transition. Matrix metalloproteinases (MMPs) constitute a group of more than 25 zinc-dependent endopeptidases. By virtue of their ability to degrade a wide variety of ECM-associated proteins, they enable ECM remodelling during development, and disease. A large body of clinical data, and experimental evidences implicate MMPs in the invasion and metastasis of breast tumors. While MMPs are aberrantly expressed in breast tumors, few appear to have a dual role in disease progression; either promoting or inhibiting metastasis. Given the role of estrogen in breast cancer development, it is natural to ask whether this steroid hormone has any role in breast cancer metastasis. This review is a round-up of the prominent literature that presents estrogenic control of MMPs, which in turn implies its influence on the tumor microenvironment and metastasis.

Unveiling Matrix Metalloproteinase 13's Dynamic Role in Breast Cancer: A Link to Physical Changes and Prognostic Modulation

The biomechanical properties of the extracellular matrix (ECM) including its stiffness, viscoelasticity, collagen architecture, and temperature constitute critical biomechanical cues governing breast cancer progression. Matrix metalloproteinase 13 (MMP13) is an important marker of breast cancer and plays important roles in matrix remodelling and cell metastasis. Emerging evidence highlights MMP13 as a dynamic modulator of the ECM's physical characteristics through dual mechanoregulatory mechanisms. While MMP13-mediated collagen degradation facilitates microenvironmental softening, thus promoting tumour cell invasion, paradoxically, its crosstalk with cancer-associated fibroblasts (CAFs) and tumour-associated macrophages (TAMs) drives pathological stromal stiffening via aberrant matrix deposition and crosslinking. This biomechanical duality is amplified through feedforward loops with an epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) populations, mediated by signalling axes such as TGF-β/Runx2. Intriguingly, MMP13 exhibits context-dependent mechanomodulatory effects, demonstrating anti-fibrotic activity and inhibiting the metastasis of breast cancer. At the same time, angiogenesis and increased metabolism are important mechanisms through which MMP13 promotes a temperature increase in breast cancer. Targeting the spatiotemporal regulation of MMP13's mechanobiological functions may offer novel therapeutic strategies for disrupting the tumour-stroma vicious cycle.

The roles of HOXB9 and MMP12 in proliferation, migration, and invasion of human laryngeal cancer cells LCC and TU212

OBJECTIVE

HOXB9 and MMP12 are involved in the initiation and progression of various tumors. This study aimed to investigate the roles of HOXB9 and MMP12 in the proliferation, migration, and invasion of human laryngeal cancer cells (LCC and TU212).

METHOD

The experiment was divided into five groups: control, sh-HOXB9, sh-MMP12, sh-HOXB9 + MMP12-OE, and sh-MMP12 + HOXB9-OE. Cell proliferation was assessed using the CCK-8 assay, migration was evaluated using the scratch assay, and invasion was measured using the Transwell assay. The mRNA and protein expression levels of HOXB9, MMP12, MMP-9, fibronectin, β-catenin, N-cadherin, vimentin, and Snail were detected by qPCR and western blotting.

RESULTS

Compared with the control group, sh-HOXB9 and sh-MMP12 groups exhibited significantly reduced proliferation, migration, and invasion capacities, accompanied by decreased expression of HOXB9, MMP12, MMP-9, fibronectin, β-catenin, N-cadherin, and vimentin in both LCC and TU212 cells (p < 0.05). In the sh-HOXB9 + MMP12-OE group, no significant change in proliferation, migration, or invasion was observed in LCC compared with that in the sh-HOXB9 group (p > 0.05), but a notable increase was observed in TU212 cells (p < 0.05). Additionally, MMP12, MMP-9, fibronectin, β-catenin, N-cadherin, and vimentin expression levels significantly increased in both LCC and TU212 cells (p < 0.05). In the sh-MMP12 + HOXB9-OE group, there was a significant increase in the proliferation, migration, and invasion of both LCC and TU212 cells compared with the sh-MMP12 group (p < 0.05), along with elevated expression of HOXB9, MMP12, MMP-9, fibronectin, β-catenin, N-cadherin, and vimentin (p < 0.05).

CONCLUSION

HOXB9 and MMP12 may modulate the Wnt/β-catenin signaling pathway and regulate the proliferation, migration, invasion, and EMT of LCC and TU212 cells.

Coralyne Targets the Catalytic Domain of MMP9: An In Silico and In Vitro Investigation

Coralyne (COR) is a protoberberine-like isoquinoline alkaloid, and it is known for double-stranded (ds) DNA intercalation and topoisomerase inhibition. It can also sensitize cancer cells through various mechanisms. COR reduces the proliferation and migration of breast cancer cells by inhibiting the expression and activity of matrix metalloproteinase 9 (MMP9). However, the mechanism involved in the inhibitory activity of COR on MMP9 is not known. In the present study, in silico docking studies showed that COR binds to the active site of MMP9 catalytic domain (MMP9-CD) with considerable affinity. The binding affinity of COR to the MMP9-CD, estimated by three different web servers: CB Dock, Seam Dock, and PyRx, was found to be either -7.4 or -7.5 kcal/mol. Another web server that is routinely used for docking studies, Docking Server, has predicted a binding affinity of -5.9 kcal/mol. All four docking servers predicted the same binding site for COR within the MMP9-CD. Corroborating our docking results, molecular dynamic simulation studies have also shown that COR interacts with the same key active site amino acid residues of the MMP9-CD that are essential for its proteolytic function. Molecular mechanics with generalized born and surface area (MMGBSA) calculations using Schrodinger's prime module have shown that the binding free energy with which COR binds to MMP9 is -50 kcal/mol. It inhibited activity of recombinant human MMP9 activity and induced significant cytotoxicity and reduced the proliferation of MDA-MB 468 cells. Overall, our in silico and in vitro experiments show that COR potentially inhibits the activity of MMP9 by directly binding to the active site of its catalytic domain and possibly inhibits proliferation of MDA-MB 468 cells.

Transcriptomics Studies Reveal Functions of Transglutaminase 2 in Breast Cancer Cells Using Membrane Permeable and Impermeable Inhibitors

Transglutaminase 2 (TG2) performs many functions both under physiological and pathological conditions. In cancer, its expression is associated with aggressiveness, propensity to epithelial-mesenchymal transition, and metastasis. Since TG2 performs key functions both outside and inside the cell, using inhibitors with different membrane permeability we analyzed the changes in the transcriptome induced in two triple-negative cell lines (MDA-MB-436 and MDA-MB-231) with aggressive features. By characterizing pathways and gene networks, we were able to define the effects of TG2 inhibitors (AA9, membrane-permeable, and NCEG2, impermeable) in relation to the roles of the enzyme in the intra- and extracellular space within the context of breast cancer. The deregulated genes revealed p53 and integrin signaling to be the common pathways with some genes showing opposite changes in expression. In MDA-MB-436, AA9 induced apoptosis, modulated cadherin, Wnt, gastrin and cholecystokinin receptors (CCKR) mediated signaling, with RHOB and GNG2 playing significant roles, and affected the Warburg effect by decreasing glycolytic enzymes. In MDA-MB-231 cells, AA9 strongly impacted HIF-mediated hypoxia, including AKT and mTOR pathway. These effects suggest an anti-tumor activity by blocking intracellular TG2 functions. Conversely, the use of NCEG2 stimulated the expression of ATP synthase and proteins involved in DNA replication, indicating a potential promotion of cell proliferation through inhibition of extracellular TG2. To effectively utilize these molecules as an anti-tumor strategy, an appropriate delivery system should be evaluated to target specific functions and avoid adverse effects. Additionally, considering combinations with other pathway modulators is crucial.

Dose-dependent bidirectional pharmacological effects of vinorelbine-based metronomic combination chemotherapy on tumor growth and metastasis and mechanisms in melanoma mouse model

BACKGROUND

There is evidence that the empirical setting of doses and schedules of antineoplastic agents in metronomic chemotherapy (MC) might lead to undesirable outcomes, such as promoting tumor growth or metastasis at certain low doses. However, details about the dose effect of antineoplastic agents in MC have not been fully known yet.

OBJECTIVES

Vinorelbine combined with cisplatin or fluorouracil (VNR/CDDP or VNR/FU) was selected to investigate its effects on tumor growth or metastasis as well as mechanisms.

METHODS

Experimental techniques, including immunohistochemistry, western blot, immunofluorescence, and flow cytometry, were used to explore the mechanisms, along with cell proliferation, apoptosis, migration, and invasion.

RESULTS

The results showed that VNR/CDDP or VNR/FU promoted tumor growth and metastasis at low doses and inhibited them at high ones. Except that expressions of apoptotic proteins were elevated at both low and high doses, low-dose treatments enhanced angiogenesis and promoted the mobilization and recruitment of myeloid-derived suppressor cells (MDSCs), while high-dose treatments reversed these effects. Additionally, low concentrations of VNR/CDDP or VNR/FU stimulated tumor cell functions such as anti-apoptosis, migration, and invasion, but high concentrations only suppressed cell proliferation and increased apoptosis.

CONCLUSION

This study elucidated a bidirectional action mode regulated by multiple mechanisms at different doses in MC and also highlighted the risks of low-dose metronomic administration of antineoplastic agents in the clinic. More preclinical and clinical studies focusing on the dose-effect of metronomic regimens are urgently needed because an effective therapeutic regimen should be an optimal setting of drugs, doses, schedules, or combinations.

MMP12 is a Potential Predictive and Prognostic Biomarker of Various Cancers Including Lung Adenocarcinoma

OBJECTIVE

This study sought to explore the clinical value of matrix metalloproteinases 12 (MMP12) in multiple cancers, including lung adenocarcinoma (LUAD).

METHODS

Using >10,000 samples, this retrospective study demonstrated the first pan-cancer analysis of MMP12. The expression of MMP12 between cancer groups and their control groups was analyzed using Wilcoxon rank-sum tests. The clinical significance of MMP12 expression in multiple cancers was assessed using receiver operating characteristic curves, Kaplan-Meier curves, and univariate Cox analysis. A further LUAD-related analysis based on 4565 multi-center and in-house samples was performed to verify the findings regarding MMP12 in pan-cancer analysis partly.

RESULTS

MMP12 mRNA is highly expressed in 13 cancers compared to their controls, and the MMP12 protein level is elevated in some of these cancers (e.g., colon adenocarcinoma) (P < .05). MMP12 expression makes it feasible to distinguish 21 cancer tissues from normal tissues (AUC = 0.86). A high MMP12 expression is a prognosis risk factor in eight cancers, such as adrenocortical carcinoma (hazard ratio >1, P < .05). The elevated MMP12 expression is also a prognosis protective factor in breast-invasive carcinoma and colon adenocarcinoma (hazard ratio <1, P < .05). Some pan-cancer findings regarding MMP12 are verified in LUAD-MMP12 expression is upregulated in LUAD at both the mRNA and protein levels (P < .05), has the potential to distinguish LUAD with considerable accuracy (AUC = .91), and plays a risk prognosis factor for patients with the disease (P < .05).

CONCLUSIONS

MMP12 is highly expressed in most cancers and may serve as a novel biomarker for the prediction and prognosis of numerous cancers.

MIRS: An AI scoring system for predicting the prognosis and therapy of breast cancer

Tumor-infiltrating immune cells (TIICs) and metastasis are crucial characteristics for tumorigenesis. However, the potential role of their combination in breast cancer (BRCA) remains elusive. Herein, on the basis of quantifying TIICs and tumor metastasis together, we established a precise prognostic scoring system named metastatic and immunogenomic risk score (MIRS) using a neural network model. MIRS showed better performance when compared with other published signatures. MIRS stratifies patients into a high risk subtype (MIRShigh) and a low risk subtype (MIRSlow). The MIRShigh patients exhibit significantly lower survival rate compared with MIRSlow patients (P < 0.0001 ), higher response to chemotherapy, but lower response to immunotherapy. Conversely, higher infiltration level of TIICs and significantly prolonged survival (P = 0.029 ) are observed in MIRSlow patients, indicating sensitive response in immunotherapy. This work presents a promising indicator to guide treatment options of the BRCA population and provides a predicted webtool that is almost universally applicable to BRCA patients.

MMP12 serves as an immune cell-related marker of disease status and prognosis in lung squamous cell carcinoma

Background

Worldwide, lung squamous cell carcinoma (LUSC) has wreaked havoc on humanity. Matrix metallopeptidase 12 (MMP12) plays an essential role in a variety of cancers. This study aimed to reveal the expression, clinical significance, and potential molecular mechanisms of MMP12 in LUSC.

Methods

There were 2,738 messenger RNA (mRNA) samples from several multicenter databases used to detect MMP12 expression in LUSC, and 125 tissue samples were validated by immunohistochemistry (IHC) experiments. Receiver operator characteristic (ROC) curves, Kaplan-Meier curves, and univariate and multivariate Cox regression analyses were used to assess the clinical value of MMP12 in LUSC. The potential molecular mechanisms of MMP12 were explored by gene enrichment analysis and immune correlation analysis. Furthermore, single-cell sequencing was used to determine the distribution of MMP12 in multiple tumor microenvironment cells.

Results

MMP12 was significantly overexpressed at the mRNA level (p < 0.05, SMD = 3.13, 95% CI [2.51-3.75]), which was verified at the protein level (p < 0.001) by internal IHC experiments. MMP12 expression could be used to differentiate LUSC samples from normal samples, and overexpression of MMP12 itself implied a worse clinical prognosis and higher levels of immune cell infiltration in LUSC patients. MMP12 was involved in cancer development and progression through two immune-related signaling pathways. The high expression of MMP12 in LUSC might act as an antigen-presenting cell-associated tumor neoantigen and activate the body's immune response.

Conclusions

MMP12 expression is upregulated in LUSC and high expression of MMP12 serves as a risk factor for LUSC patients. MMP12 may be involved in cancer development by participating in immune-related signaling pathways and elevating the level of immune cell infiltration.

Deciphering Stromal Changes between Metastatic and Non-metastatic Canine Mammary Carcinomas

Cancer-associated stroma (CAS) is widely recognized to influence development and progression of epithelial tumours including breast cancer. Canine mammary tumours (CMTs) such as simple canine mammary carcinomas represent valuable models for human breast cancer also with respect to stromal reprogramming. However, it remains unclear whether and how CAS changes in metastatic tumours compared to non-metastatic ones. To characterize stromal changes between metastatic and non-metastatic CMTs and identify potential drivers of tumour progression, we analysed CAS and matched normal stroma from 16 non-metastatic and 15 metastatic CMTs by RNA-sequencing of microdissected FFPE tissue. We identified 1438 differentially regulated genes between CAS and normal stroma, supporting previous results demonstrating stromal reprogramming in CMTs to be comparable with CAS in human breast cancer and validating deregulation of pathways and genes associated with CAS. Using primary human fibroblasts activated by treatment with TGFβ, we demonstrate some of the strongest expression changes to be conserved in fibroblasts across species. Furthermore, we identify 132 differentially expressed genes between CAS from metastatic and non-metastatic tumours, with strong changes in pathways including chemotaxis, regulation of apoptosis, immune response and TGFβ signalling and validate deregulation of several targets using RT-qPCR. Finally, we identify specific upregulation of COL6A5, F5, GALNT3, CIT and MMP11 in metastatic CAS, suggesting high stromal expression of these targets to be linked to malignancy and metastasis of CMTs. In summary, our data present a resource supporting further research into stromal changes of the mammary gland in relation to metastasis with implications for both canine and human mammary cancer.

Emerging Intrinsic Therapeutic Targets for Metastatic Breast Cancer

Breast cancer is now the most common cancer worldwide, and it is also the main cause of cancer-related death in women. Survival rates for female breast cancer have significantly improved due to early diagnosis and better treatment. Nevertheless, for patients with advanced or metastatic breast cancer, the survival rate is still low, reflecting a need for the development of new therapies. Mechanistic insights into metastatic breast cancer have provided excellent opportunities for developing novel therapeutic strategies. Although high-throughput approaches have identified several therapeutic targets in metastatic disease, some subtypes such as triple-negative breast cancer do not yet have an apparent tumor-specific receptor or pathway to target. Therefore, exploring new druggable targets in metastatic disease is a high clinical priority. In this review, we summarize the emerging intrinsic therapeutic targets for metastatic breast cancer, including cyclin D-dependent kinases CDK4 and CDK6, the PI3K/AKT/mTOR pathway, the insulin/IGF1R pathway, the EGFR/HER family, the JAK/STAT pathway, poly(ADP-ribose) polymerases (PARP), TROP-2, Src kinases, histone modification enzymes, activated growth factor receptors, androgen receptors, breast cancer stem cells, matrix metalloproteinases, and immune checkpoint proteins. We also review the latest development in breast cancer immunotherapy. Drugs that target these molecules/pathways are either already FDA-approved or currently being tested in clinical trials.

Central Centrifugal Cicatricial Alopecia in the Adolescent Population: An Overview of Available Literature

Central centrifugal cicatricial alopecia (CCCA) is a lymphocytic scarring alopecia that predominantly affects women of African descent. Recent studies have demonstrated prevalence in children and adolescents, as well as Asian populations. A thorough search of Pubmed, Cochrane Database of Systematic Reviews, OVID Medline and Google Scholar was conducted using keywords such as "central centrifugal cicatricial alopecia", "scarring hair loss", "scarring alopecia", "hot comb alopecia", "pediatric" and "adolescent". The results yielded few articles in the literature that directly addressed CCCA in the adolescent population, with three articles providing details of the presentation in the form of case series and retrospective reviews. The presentation in the adolescent population was found to be varied, ranging from asymptomatic to symptomatic and involving diffuse to patchy hair loss in only the vertex and/or frontal and parietal scalp. Genetic and environmental etiologies were found to be statistically significant, and markers of metabolic dysregulation predisposing patients to diabetes mellitus and breast cancer were also uncovered. The differential diagnosis of patients who present with hair loss in the adolescent population should therefore be broad, and a low threshold for biopsies should be adopted to confirm CCCA in suspected patients. This will have future implications for reduced morbidity and public health.

Plasma Levels of Metalloproteinase 3 (MMP-3) and Metalloproteinase 7 (MMP-7) as New Candidates for Tumor Biomarkers in Diagnostic of Breast Cancer Patients

Matrix metalloproteinases (MMPs) are a group of enzymes that mediate both physiological and pathological processes such as carcinogenesis. The role of matrix metalloproteinase-3 (MMP-3) and (MMP-7) in the pathogenesis of breast cancer (BC) has been demonstrated, suggesting that they may be considered as potential markers of this condition. The aim of this study was to assess plasma concentrations and diagnostic utility of MMP-3 and MMP-7 in 100 patients with early-stage breast cancer with Luminal A subtype or Luminal B HER-negative subtype, before and after surgical treatment, and in the following control groups: patients with a benign tumor (fibroadenoma) and healthy subjects. The concentrations of MMP-3 and MMP-7 were referenced to the levels of the widely recognized marker for BC diagnosis CA 15-3. MMP-3 and MMP-7 was measured by ELISA method and CA 15-3 by CMIA. Plasma levels of MMP-7 were significantly higher in Luminal A and Luminal B HER2-negative subtype breast cancer patients as compared to the healthy group. MMP-7 demonstrated comparable but mostly higher to CA 15-3 or MMP-3 values of diagnostic sensitivity, specificity, positive and negative predictive values and AUC (0.6888 for Luminal A subtype; 0.7612 for Luminal B HER2-negative; 0.7250 for BC total group, respectively) in the groups tested. The combined use of the tested parameters resulted in a further increase in diagnostic criteria and AUC. These results suggest the usefulness of combining MMP-7 with CA 15-3 in the diagnostics of breast cancer, especially in Luminal B HER2-negative subtypes patients, as a new candidate for tumor markers.

Matrix metalloproteinases as therapeutic targets in breast cancer

Matrix metalloproteinases (MMPs) are the most prominent proteinases involved in tumorigenesis. They were initially recognized to promote tumor progression by remodeling the extracellular matrix through their proteolytic activity. However, accumulating evidence has revealed that some MMPs have protective roles in cancer progression, and the same MMP can exert opposing roles depending on the cell type in which it is expressed or the stage of cancer. Moreover, studies have shown that MMPs are involved in cancer progression through their roles in other biological processes such as cell signaling and immune regulation, independent of their catalytic activity. Despite the prognostic significance of tumoral or stromal expression of MMPs in breast cancer, their roles and molecular mechanisms in breast cancer progression remain unclear. As the failures of early clinical trials with broad-spectrum MMP inhibitors were mainly due to a lack of drug specificity, substantial efforts have been made to develop highly selective MMP inhibitors. Some recently developed MMP inhibitory monoclonal antibodies demonstrated promising anti-tumor effects in preclinical models of breast cancer. Importantly, anti-tumor effects of these antibodies were associated with the modulation of tumor immune microenvironment, suggesting that the use of MMP inhibitors in combination with immunotherapy can improve the efficacy of immunotherapy in HER2-positive or triple-negative breast cancer. In this review, the current understanding of the roles of tumoral or stromal MMPs in breast cancer is summarized, and recent advances in the development of highly selective MMP inhibitors are discussed.

Loss of MMP-27 Predicts Mandibular Bone Invasion in Oral Squamous Cell Carcinoma

Simple Summary

The growth of oral squamous cell carcinoma into the mandible poses significant challenges to head and neck surgery. The resulting need for extensive procedures has a decisive influence on subsequent esthetics and function and therefore also on the patient’s quality of life. The molecular mechanism behind this remains obscure to date. Hence, we investigated the influence of MMP-27, Osteoprotegerin and RANKL, three proteins with importance in bone remodeling. The results showed that tumors exhibited less bone-invasive behavior in the presence of MMP-27. This may be an incentive for further studies to elucidate the molecular mechanisms of mandibular bone invasion in OSCC.

Abstract

Invasion of the mandibular bone is frequent in oral squamous cell carcinoma (OSCC), which often results in extensive ablative and reconstructive procedures for the patient. The purpose of this single-center, retrospective study was to identify and evaluate potential biomarkers and risk factors for bone invasion in OSCC. Initially, in silico gene expression analysis was performed for different HNSCC tumor T-stages to find factors associated with invasive (T4a) tumor growth. Afterwards, the protein expression of bone-metabolizing MMP-27, TNFRSF11B (Osteoprotegerin, OPG), and TNFSF11 (RANKL) was investigated via Tissue Microarrays (TMAs) for their impact on mandibular bone invasion. TMAs were assembled from the bone–tumor interface of primary OSCCs of the floor of the mouth and gingiva from 119 patients. Sixty-four carcinomas with patho-histological jaw invasion (pT4a) were compared to 55 carcinomas growing along the mandible without invasion (pT2, pT3). Tissue samples were additionally evaluated for patterns of invasion using the WPOI grading system. Statistical analysis of in silico data revealed decreased MMP-27 mRNA expression to be strongly associated with the pT4a-stage in OSCC, indicating invasive tumor growth with infiltration of adjacent anatomical structures. Our own clinico-pathological data on OSCCs presented a significant decrease of MMP-27 in tumors invading the nearby mandible (pT4a), compared to pT2 and pT3 tumors without bone invasion. Loss of MMP27 evolved as the strongest predictor of mandibular bone invasion in binary logistic regression analysis. To our knowledge, this is the first study investigating the role of MMP-27 expression in OSCC and demonstrating the importance of the loss of MMP-27 in mandibular bone invasion.

CDKN2A-mediated molecular subtypes characterize the hallmarks of tumor microenvironment and guide precision medicine in triple-negative breast cancer

Currently, breast cancer (BRCA) has become the most common cancer in the world, whose pathological mechanism is complex. Among its subtypes, triple-negative breast cancer (TNBC) has the worst prognosis. With the increasing number of diagnosed TNBC patients, the urgent need of novel biomarkers is also rising. Cyclin-dependent kinase inhibitor 2A (CDKN2A) has recently emerged as a key regulator associated with ferroptosis and cuproptosis (FAC) and has exhibited a significant effect on BRCA, but its detailed mechanism remains elusive. Herein, we conducted the first converge comprehensive landscape analysis of FAC-related gene CDKN2A in BRCA and disclosed its prognostic value in BRCA. Then, an unsupervised cluster analysis based on CDKN2A-correlated genes unveiled three subtypes, namely cold-immune subtype, IFN-γ activated subtype and FTL-dominant subtype. Subsequent analyses depicting hallmarks of tumor microenvironment (TME) among three subtypes suggested strong association between TNBC and CDKN2A. Given the fact that the most clinically heterogeneous TNBC always displayed the most severe outcomes and lacked relevant drug targets, we further explored the potential of immunotherapy for TNBC by interfering CDKN2A and constructed the CDKN2A-derived prognostic model for TNBC patients by Lasso-Cox. The 21-gene–based prognostic model showed high accuracy and was verified in external independent validation cohort. Moreover, we proposed three drugs for TNBC patients based on our model via targeting epidermal growth factor receptor. In summary, our study indicated the potential of CDKN2A as a pioneering prognostic predictor for TNBC and provided a rationale of immunotherapy for TNBC, and offered fresh perspectives and orientations for cancer treatment via inducing ferroptosis and cuproptosis to develop novel anti-cancer treatment strategies.

Mesenchymal Stromal Cells (MSCs): An Ally of B-Cell Acute Lymphoblastic Leukemia (B-ALL) Cells in Disease Maintenance and Progression within the Bone Marrow Hematopoietic Niche

Simple Summary

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer. Even though the cure rate actually exceeds 85%, the prognosis of relapsed/refractory patients is dismal. Recent literature data indicate that the bone marrow (BM) microenvironment could play a crucial role in the onset, maintenance and progression of the disease. In particular, mesenchymal stromal cells (MSCs), which are key components of the BM niche, actively crosstalk with leukemic cells providing crucial signals for their survival and resistance to therapy. We hereby review the main mechanisms exploited by MSCs to nurture and protect B-ALL cells that could become appealing targets for innovative microenvironment remodeling therapies to be coupled with classical leukemia-directed strategies.

Abstract

Mesenchymal stromal cells (MSCs) are structural components of the bone marrow (BM) niche, where they functionally interact with hematopoietic stem cells and more differentiated progenitors, contributing to hematopoiesis regulation. A growing body of evidence is nowadays pointing to a further crucial contribution of MSCs to malignant hematopoiesis. In the context of B-cell acute lymphoblastic leukemia (B-ALL), MSCs can play a pivotal role in the definition of a leukemia-supportive microenvironment, impacting on disease pathogenesis at different steps including onset, maintenance and progression. B-ALL cells hijack the BM microenvironment, including MSCs residing in the BM niche, which in turn shelter leukemic cells and protect them from chemotherapeutic agents through different mechanisms. Evidence is now arising that altered MSCs can become precious allies to leukemic cells by providing nutrients, cytokines, pro-survivals signals and exchanging organelles, as hereafter reviewed. The study of the mechanisms exploited by MSCs to nurture and protect B-ALL blasts can be instrumental in finding new druggable candidates to target the leukemic BM microenvironment. Some of these microenvironment-targeting strategies are already in preclinical or clinical experimentation, and if coupled with leukemia-directed therapies, could represent a valuable option to improve the prognosis of relapsed/refractory patients, whose management represents an unmet medical need.

ESR2 Drives Mesenchymal-to-Epithelial Transition in Triple-Negative Breast Cancer and Tumorigenesis In Vivo

Estrogen receptors (ERs) have pivotal roles in the development and progression of triple-negative breast cancer (TNBC). Interactions among cancer cells and tumor microenvironment are orchestrated by the extracellular matrix that is rapidly emerging as prominent contributor of fundamental processes of breast cancer progression. Early studies have correlated ERβ expression in tumor sites with a more aggressive clinical outcome, however ERβ exact role in the progression of TNBC remains to be elucidated. Herein, we introduce the functional role of ERβ suppression following isolation of monoclonal cell populations of MDA-MB-231 breast cancer cells transfected with shRNA against human ESR2 that permanently resulted in 90% reduction of ERβ mRNA and protein levels. Further, we demonstrate that clone selection results in strongly reduced levels of the aggressive functional properties of MDA-MB-231 cells, by transforming their morphological characteristics, eliminating the mesenchymal-like traits of triple-negative breast cancer cells. Monoclonal populations of shERβ MDA-MB-231 cells undergo universal matrix reorganization and pass on a mesenchymal-to-epithelial transition state. These striking changes are encompassed by the total prevention of tumorigenesis in vivo following ERβ maximum suppression and isolation of monoclonal cell populations in TNBC cells. We propose that these novel findings highlight the promising role of ERβ targeting in future pharmaceutical approaches for managing the metastatic dynamics of TNBC breast cancer.