Tumor cell-produced matrix metalloproteinase 9 (MMP-9) drives malignant progression and metastasis of basal-like triple negative breast cancer

Increase in ADAR1p110 activates the canonical Wnt signaling pathway associated with aggressive phenotype in triple negative breast cancer cells

Triple-negative breast cancer (TNBC) represents a challenge in the search for new therapeutic targets. TNBCs are aggressive and generate resistance to chemotherapy. Tumors of TNBC patients with poor prognosis present a high level of adenosine deaminase acting on RNA1 (ADAR1). We explore the connection of ADAR1 with the canonical Wnt signaling pathway and the effect of modulation of its expression in TNBC. Expression data from cell line sequencing (DepMap) and TCGA samples were downloaded and analyzed. We lentivirally generated an MDA-MB-231 breast cancer cell line that overexpress (OE) ADAR1p110 or an ADAR knockdown. Abundance of different proteins related to Wnt/β-catenin pathway and activity of nuclear β-catenin were analyzed by Western blot and luciferase TOP/FOP reporter assay, respectively. Cell invasion was analyzed by matrigel assay. In mice, we study the behavior of tumors generated from ADAR1p110 (OE) cells and tumor vascularization immunostaining were analyzed. ADAR1 connects to the canonical Wnt pathway in TNBC. ADAR1p110 overexpression decreased GSK-3β, while increasing active β-catenin. It also increased the activity of nuclear β-catenin and increased its target levels. ADAR1 knockdown has the opposite effect. MDA-MB-231 ADAR1 (OE) cells showed increased capacity of invasion. Subsequently, we observed that tumors derived from ADAR1p110 (OE) cells showed increased invasion towards the epithelium, and increased levels of Survivin and CD-31 expressed in vascular endothelial cells. These results indicate that ADAR1 overexpression alters the expression of some key components of the canonical Wnt pathway, favoring invasion and neovascularization, possibly through activation of the β-catenin, which suggests an unknown role of ADAR1p110 in aggressiveness of TNBC tumors.

The Paracrine Effect of Hypoxic and Normoxic Cancer Secretion on the Proliferation of Brain Endothelial Cells (bEnd.3)

Background: This study aimed to investigate the disruption of cell cycle phases of bEnd.3 cells exposed to cancer paracrine secretion. Cancer cells have been reported to use the secretion of paracrine factors to compromise the endothelial barrier to prepare for their passage into the parenchyma. As cancer cells are known to act differently under conditions of hypoxia, we investigated how conditional media (CM) derived from breast and glioblastoma cells incubated under conditions of normoxia and hypoxia would affect proliferation of brain endothelial cells (bEnd.3). Methods: Brain endothelial cells (bEnd.3) were cultivated with normoxic and hypoxic CM generated from breast cancer MCF7 cells and glioblastoma U-87 cells. Cell proliferation was evaluated using the trypan blue exclusion assay and phases of the cell cycle were evaluated using flow cytometry. Results: bEnd.3 proliferations was suppressed more aggressively with hypoxic CM after 72 and 96 h; cell cycle analysis showed that paracrine treatment tended to prevent BECs from entering the G2 phase, thus suppressing cell division. Conclusions: MCF7 and U-87 cells induce suppressed proliferation of BECs deferentially under hypoxia by blocking cell cycle progression to the G2 phase.

Fusobacterium nucleatum and cancer

Accumulating evidence demonstrates that the oral pathobiont Fusobacterium nucleatum is involved in the progression of an increasing number of tumors types. Thus far, the mechanisms underlying tumor exacerbation by F. nucleatum include the enhancement of proliferation, establishment of a tumor‐promoting immune environment, induction of chemoresistance, and the activation of immune checkpoints. This review focuses on the mechanisms that mediate tumor‐specific colonization by fusobacteria. Elucidating the mechanisms mediating fusobacterial tumor tropism and promotion might provide new insights for the development of novel approaches for tumor detection and treatment.

RhoA-ROCK competes with YAP to regulate amoeboid breast cancer cell migration in response to lymphatic-like flow

Lymphatic drainage generates force that induces prostate cancer cell motility via activation of Yes-associated protein (YAP), but whether this response to fluid force is conserved across cancer types is unclear. Here, we show that shear stress corresponding to fluid flow in the initial lymphatics modifies taxis in breast cancer, whereas some cell lines use rapid amoeboid migration behavior in response to fluid flow, a separate subset decrease movement. Positive responders displayed transcriptional profiles characteristic of an amoeboid cell state, which is typical of cells advancing at the edges of neoplastic tumors. Regulation of the HIPPO tumor suppressor pathway and YAP activity also differed between breast subsets and prostate cancer. Although subcellular localization of YAP to the nucleus positively correlated with overall velocity of locomotion, YAP gain- and loss-of-function demonstrates that YAP inhibits breast cancer motility but is outcompeted by other pro-taxis mediators in the context of flow. Specifically, we show that RhoA dictates response to flow. GTPase activity of RhoA, but not Rac1 or Cdc42 Rho family GTPases, is elevated in cells that positively respond to flow and is unchanged in cells that decelerate under flow. Disruption of RhoA or the RhoA effector, Rho-associated kinase (ROCK), blocked shear stress-induced motility. Collectively, these findings identify biomechanical force as a regulator amoeboid cell migration and demonstrate stratification of breast cancer subsets by flow-sensing mechanotransduction pathways.

Prognostic and Immunological Roles of MMP-9 in Pan-Cancer

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) can degrade the extracellular matrix and participate in tumor progression. The relationship between MMP-9 and immune cells has been reported in various malignant tumors. However, there is a lack of comprehensive pan-cancer studies on the relationship between MMP-9 and cancer prognosis and immune infiltration.

METHOD

We used data from TCGA and GTEx databases to comprehensively analyze the differential expression of MMP-9 in normal and cancerous tissues. Survival analysis was performed to understand the prognostic role of MMP-9 in different tumors. We then analyzed the expression of MMP-9 across different tumors and at different clinical stages. Based on the results, we assessed the correlation between MMP-9 expression and immune-associated genes and immunocytes. Finally, we calculated the tumor mutation burden (TMB) of 33 cancer types and analyzed the correlation between MMP-9 and TMB, DNA microsatellite instability, and DNA repair genes.

RESULTS

MMP-9 significantly affected the prognosis and metastasis of various cancers. It was associated based on overall survival, disease-specific survival in five tumors, progression-free interval in seven tumors, and clinical stage in eight tumors, as well as with prognosis and metastasis in adrenocortical carcinoma and kidney renal clear cell carcinoma. It was also coexpressed with immune-related genes and DNA repair genes. The expression of MMP-9 was positively correlated with the markers of T cells, tumor-associated macrophages, Th1 cells, and T cell exhaustion. Furthermore, MMP-9 expression was highly correlated with macrophage M0 in 28 tumors. In addition, its expression was associated with TMB in eight cancer types and DNA microsatellite instability in six cancer types.

CONCLUSION

MMP-9 is related to immune infiltration in pan-cancer and can be used as a biomarker related to cancer prognosis and metastasis. Our findings provide prognostic molecular markers and new ideas for immunotherapy.

The Potential of Natural Products in the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks receptors for targeted therapy. Consequently, chemotherapy is currently the mainstay of systemic treatment options. However, the enrichment of cancer stem cells (CSC, a subpopulation with stem-cell characteristics and tumor-initiating propensity) promotes chemo-resistance and tumorigenesis, resulting in cancer recurrence and relapse. Furthermore, toxic side effects of chemotherapeutics reduce patient wellbeing. Natural products, specifically compounds derived from plants, have the potential to treat TNBC and target CSCs by inhibiting CSC signaling pathways. Literature evidence from six promising compounds were reviewed, including sulforaphane, curcumin, genistein, resveratrol, lycopene, and epigallocatechin-3-gallate. These compounds have been shown to promote cell cycle arrest and apoptosis in TNBC cells. They also could inhibit the epithelial-mesenchymal transition (EMT) that plays an important role in metastasis. In addition, those natural compounds have been found to inhibit pathways important for CSCs, such as NF-κB, PI3K/Akt/mTOR, Notch 1, Wnt/β-catenin, and YAP. Clinicals trials conducted on these compounds have shown varying degrees of effectiveness. Epidemiological case-control studies for the compounds commonly consumed in certain human populations have also been summarized. While in vivo and in vitro data are promising, further basic and clinical investigations are required. Likely, natural products in combination with other drugs may hold great potential to improve TNBC treatment efficacy and patient outcomes.

Differential Effects of Normoxic versus Hypoxic Derived Breast Cancer Paracrine Factors on Brain Endothelial Cells

Simple Summary

The potential of breast cancer to spread to the brain increases the clinical complications of the disease; breast cancer is considered to have the second-highest capacity to spread to the brain after lung cancer. The brain is protected by highly specialized endothelial cells, forming a barrier against the entry of circulating molecules and cells. The ability of breast cancer cells to penetrate the protective endothelial barrier is still not completely understood. Here, we aimed to investigate the effect of breast cancer cells on the brain’s endothelial cells. We showed that breast cancer cells induce changes in endothelial cells by releasing factors that target the mitochondria, affecting the endothelial cells and their attachment to each other and, therefore, their function as a protective barrier of the brain. Understanding the mechanism that breast cancer cells utilize to affect endothelial cells under normoxic and hypoxic conditions contributes to the development of treatments to prevent the metastasis of cancer cells to the brain.

Abstract

Background: The blood-brain barrier (BBB) is a central nervous system protective barrier formed primarily of endothelial cells that regulate the entry of substances and cells from entering the brain. However, the BBB integrity is disrupted in disease, including cancer, allowing toxic substances, molecules, and circulating cells to enter the brain. This study aimed to determine the mitochondrial changes in brain endothelial cells co-cultured with cancer cells. Method: Brain endothelial cells (bEnd.3) were co-cultivated with various concentrations of breast cancer (MCF7) conditioned media (CM) generated under normoxic (21% O₂) and hypoxic conditions (5% O₂). The mitochondrial activities (including; dehydrogenases activity, mitochondrial membrane potential (ΔΨm), and ATP generation) were measured using Polarstar Omega B.M.G-Plate reader. Trans-endothelial electrical resistance (TEER) was evaluated using the EVOM system, followed by quantifying gene expression of the endothelial tight junction (ETJs) using qPCR. Results: bEnd.3 cells had reduced cell viability after 72 h and 96 h exposure to MCF7CM under hypoxic and normoxic conditions. The ΔΨm in bEnd.3 cells were hyperpolarized after exposure to the hypoxic MCF7CM (p < 0.0001). However, the normoxic MCF7CM did not significantly affect the state of ΔΨm in bEnd.3 cells. ATP levels in bEnd.3 co-cultured with hypoxic and normoxic MCF7CM was significantly reduced (p < 0.05). The changes in brain endothelial mitochondrial activity were associated with a decrease in TEER of bEnd.3 monolayer co-cultured with MCF7CM under hypoxia (p = 0.001) and normoxia (p < 0.05). The bEnd.3 cells exposed to MCF7CM significantly increased the gene expression level of ETJs (p < 0.05). Conclusions: MCF7CM modulate mitochondrial activity in brain endothelial cells, affecting the brain endothelial barrier function.

Biological and Mechanical Characterization of the Random Positioning Machine (RPM) for Microgravity Simulations

The rapid improvement of space technologies is leading to the continuous increase of space missions that will soon bring humans back to the Moon and, in the coming future, toward longer interplanetary missions such as the one to Mars. The idea of living in space is charming and fascinating; however, the space environment is a harsh place to host human life and exposes the crew to many physical challenges. The absence of gravity experienced in space affects many aspects of human biology and can be reproduced in vitro with the help of microgravity simulators. Simulated microgravity (s-μg) is applied in many fields of research, ranging from cell biology to physics, including cancer biology. In our study, we aimed to characterize, at the biological and mechanical level, a Random Positioning Machine in order to simulate microgravity in an in vitro model of Triple-Negative Breast Cancer (TNBC). We investigated the effects played by s-μg by analyzing the change of expression of some genes that drive proliferation, survival, cell death, cancer stemness, and metastasis in the human MDA-MB-231 cell line. Besides the mechanical verification of the RPM used in our studies, our biological findings highlighted the impact of s-μg and its putative involvement in cancer progression.

Celastrol inhibits the proliferation and induces apoptosis of colorectal cancer cells via downregulating NF-κB/COX-2 signaling pathways

BACKGROUND

Colorectal cancer (CRC) is the third-ranked malignant tumor in the world that contributes to the death of a major population of the world. Celastrol, a bioactive natural product isolated from the medicinal plant Tripterygium wilfordii Hook F, has been proved to be an effective anti-tumor inhibitor for multiple tumors.

OBJECTIVE

To reveal the therapeutic effect and underlying mechanisms of celastrol on CRC cells.

METHODS

CCK-8 and clonogenic assay were used to analyze the cell proliferation in CRC cells. Flow cytometry analysis was conducted to assess the cell cycle and cell apoptosis. Wound-healing and cell invasion assay were used to evaluate the migrating and invasion capability of CRC cells. The potential antitumor mechanism of celastrol was investigated by qPCR, western blot, and confocal immunofluorescence analyses.

RESULTS

Celastrol effectively inhibited CRC cell proliferation by activating caspase-dependent cell apoptosis and facilitating G1 cell cycle arrest in a dose-dependent manner, as well as cell migration and invasion by downregulating the MMP2 and MMP9. Mechanistic protein expression revealed that celastrol suppressed the expression of COX-2 by inhibiting the phosphorylation of NF-κB p65 and subsequently leading to cytoplasmic retention of p65 protein, thereby inhibiting its nuclear translocation and transcription activities.

CONCLUSION

These findings indicate that celastrol is an effective inhibitor for CRC, regulating the NF-κB/COX-2 pathway, leading to the inhibition of cell proliferation characterized by cell cycle arrest and caspase-dependent apoptosis, providing a potential alternative therapeutic agent for CRC patients.

Sauchinone inhibits the proliferation, migration and invasion of breast cancer cells by suppressing Akt-CREB-MMP13 signaling pathway

Sauchinone, a lignan isolated from Saururus chinenesis, is known to exhibit anti-inflammatory and anti-oxidant effects. Recently, sauchinone has been reported to inhibit the growth of various cancer cells, but its effects on breast cancer cells remain poorly understood. In the present study, we investigated the effects of sauchinone on the growth of breast cancer cells along with the underlying molecular mechanisms. Our results show that sauchinone treatment markedly inhibited the proliferation, migration, and invasion of breast cancer cells. Sauchinone reduced the phosphorylation of Akt, ERK, and CREB increased by transforming growth factor-β (TGF-β). In particular, sauchinone treatment suppressed the expression of matrix metalloproteinase (MMP)-13 (MMP13) by regulating the Akt-CREB signaling pathway. Sauchinone was less effective in inhibiting cell migration in Mmp13-knockdown cells than in control cells, suggesting that MMP13 may be a novel target for sauchinone. Our study suggests that sauchinone inhibits the growth of breast cancer cells by attenuating the Akt-CREB-MMP13 pathway. In addition, the targeted inhibition of MMP13 by sauchinone represents a promising approach for the treatment of breast cancer.

Triple-negative breast cancer cells rely on kinase-independent functions of CDK8 to evade NK-cell-mediated tumor surveillance

Triple-negative breast cancer (TNBC) is an aggressive malignant disease that is responsible for approximately 15% of breast cancers. The standard of care relies on surgery and chemotherapy but the prognosis is poor and there is an urgent need for new therapeutic strategies. Recent in silico studies have revealed an inverse correlation between recurrence-free survival and the level of cyclin-dependent kinase 8 (CDK8) in breast cancer patients. CDK8 is known to have a role in natural killer (NK) cell cytotoxicity, but its function in TNBC progression and immune cell recognition or escape has not been investigated. We have used a murine model of orthotopic breast cancer to study the tumor-intrinsic role of CDK8 in TNBC. Knockdown of CDK8 in TNBC cells impairs tumor regrowth upon surgical removal and prevents metastasis. In the absence of CDK8, the epithelial-to-mesenchymal transition (EMT) is impaired and immune-mediated tumor-cell clearance is facilitated. CDK8 drives EMT in TNBC cells in a kinase-independent manner. In vivo experiments have confirmed that CDK8 is a crucial regulator of NK-cell-mediated immune evasion in TNBC. The studies also show that CDK8 is involved in regulating the checkpoint inhibitor programmed death-ligand 1 (PD-L1). The CDK8-PD-L1 axis is found in mouse and human TNBC cells, underlining the importance of CDK8-driven immune cell evasion in these highly aggressive breast cancer cells. Our data link CDK8 to PD-L1 expression and provide a rationale for investigating the possibility of CDK8-directed therapy for TNBC.

Remodeling the ECM: Implications for Metastasis and Tumor Dormancy

While most primary tumors can be effectively treated, therapeutics fail to efficiently eliminate metastases. Metastases arise from cancer cells that leave the primary tumor and seed distant sites. Recent studies have shown that cancer cells disseminate early during tumor progression and can remain dormant for years before they resume growth. In these metastatic organs, cancer cells reside in microenvironments where they interact with other cells, but also with the extracellular matrix (ECM). The ECM was long considered to be an inert, non-cellular component of tissues, providing their architecture. However, in recent years, a growing body of evidence has shown that the ECM is a key driver of cancer progression, and it can exert effects on tumor cells, regulating their metastatic fate. ECM remodeling and degradation is required for the early steps of the metastatic cascade: invasion, tumor intravasation, and extravasation. Similarly, ECM molecules have been shown to be important for metastatic outgrowth. However, the role of ECM molecules on tumor dormancy and their contribution to the dormancy-supportive niches is not well understood. In this perspective article, we will summarize the current knowledge of ECM and its role in tumor metastasis and dormancy. We will discuss how a better understanding of the individual components of the ECM niche and their roles mediating the dormant state of disseminated tumor cells (DTCs) will advance the development of new therapies to target dormant cells and prevent metastasis outgrowth.

Role of matrix metalloproteinase MMP-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP-1) in the clinical progression of pediatric acute lymphoblastic leukemia

BACKGROUND

Matrix metalloproteinases (MMPs) play a crucial role in cancer progression and metastasis, however their role in pediatric Acute lymphoblastic leukemia (ALL) is still unrevealed.

METHODS

The diagnostic, prognostic and predictive value of tissue inhibitor of metalloproteinase (TIMP-1), MMP-2, MMP-9 and CD34+CD38- cancer stem cells (CSCs) were assessed in bone marrow (BM) samples of 76 ALL children using Flow Cytometry analysis.

RESULTS

There was a significant increase in TIMP-1 [1.52 (0.41-10) versus 0.91(0.6-1.12); respectively, p < 0.001], and CSCs CD34⁺CD38^- [1 (0.03-18.6) versus 0.3 (0.01-1.1), p < 0.001] expression in ALL patients compared to controls. While there were no significant differences regarding MMP-2 and MMP-9 expression between the two groups. The sensitivity, specificity, area under curve (AUC) of MMP-2 were (80.3%, 53.3% and 0.568, p = 0.404), and of MMP-9 were (53.9%, 40% and 0.660, p = 0.053). While that of TIMP-1 were (78.9%, 100% and 0.892, p < 0.001), and that of CD34⁺CD38^- CSCs were (78.9%, 73.3% and 0.855, p < 0.001). Increased TIMP-1 expression associated with the high-risk disease (p < 0.001). CD34⁺CD38^- CSCs and MMP-2 overexpression associated with MRD at day-15, increased BM blast cell count at diagnosis and at day-15 (p < 0.05). TIMP-1 overexpression is associated with shorter DFS and OS rates (p = 0.009 and p = 0.048). Multivariate logistic regression analysis showed that both TIMP-1 [OR: 4.224, p = 0.046], and CD34⁺CD38^- CSCs [OR: 6.873, p = 0.005] could be potential independent diagnostic factors for pediatric ALL.

CONCLUSION

TIMP-1 and CD34⁺CD38^- CSCs could be possible useful diagnostic markers for pediatric ALL. Also, TIMP-1 is a promising prognostic marker for poor outcome of the patients.

Production of a Soluble Recombinant Antibody Fragment against MMP9 Using Escherichia coli

Matrix metalloproteinase 9 (MMP9) is involved in several aspects of the pathology of cancer, including invasion, metastasis, and angiogenesis. In this study, we expressed a recombinant scFv-type anti-MMP9 antibody in soluble form using Escherichia coli, purified it, and confirmed its antigen-binding ability. The convenient, rapid, inexpressive system used in this study for producing recombinant antibody fragments needs only five days, and thus can be used for the efficient production of scFv against MMP9, which can be used in a range of applications and industrial fields, including diagnosis and treatment of inflammatory and cancer-related diseases.

3D Cancer Models: Depicting Cellular Crosstalk within the Tumour Microenvironment

The tumour microenvironment plays a critical role in tumour progression and drug resistance processes. Non-malignant cell players, such as fibroblasts, endothelial cells, immune cells and others, interact with each other and with the tumour cells, shaping the disease. Though the role of each cell type and cell communication mechanisms have been progressively studied, the complexity of this cellular network and its role in disease mechanism and therapeutic response are still being unveiled. Animal models have been mainly used, as they can represent systemic interactions and conditions, though they face recognized limitations in translational potential due to interspecies differences. In vitro 3D cancer models can surpass these limitations, by incorporating human cells, including patient-derived ones, and allowing a range of experimental designs with precise control of each tumour microenvironment element. We summarize the role of each tumour microenvironment component and review studies proposing 3D co-culture strategies of tumour cells and non-malignant cell components. Moreover, we discuss the potential of these modelling approaches to uncover potential therapeutic targets in the tumour microenvironment and assess therapeutic efficacy, current bottlenecks and perspectives.

Serum matrix metalloproteinase-13 as a diagnostic biomarker for cutaneous squamous cell carcinoma

Background

A significant proportion of newly diagnosed patients with cutaneous squamous cell carcinoma (cSCC) have metastasis and eventually die of the disease, necessitating the exploration of novel biomarkers for early detection of cSCC aggressiveness, risk assessment and monitoring. Matrix metalloproteinase-13 (MMP-13) has been implicated in cSCC pathogenesis. Serum MMP-13 levels have been shown to predict survival in patients with esophageal SCC, but their diagnostic value for cSCC has not been explored.

Methods

We conducted a case-control study to examine serum MMP-13 as a biomarker for cSCC. Patients with cSCC undergoing surgical resection and health controls undergoing plastic surgery were recruited. ELISA for measurement of serum MMP-13 and immunohistochemistry for detection of tissue MMP-13 were performed, and the results were compared between the case and the control group, and among different patient groups. ROC curve analysis was performed to determine the diagnostic value of serum MMP-13 levels.

Results

The ratio of male to female, and the age between the case (n = 77) and the control group (n = 50) were not significantly different. Patients had significantly higher serum MMP-13 levels than healthy controls. Subjects with stage 3 cSCC had markedly higher serum MMP-13 levels than those with stage 1 and stage 2 cSCC. Patients with invasive cSCC had remarkably higher serum MMP-13 than those with cSCC in situ. Post-surgery serum MMP-13 measurement was done in 12 patients, and a significant MMP-13 decrease was observed after removal of cSCC. Tumor tissues had a remarkably higher level of MMP-13 than control tissues. Serum MMP-13 predicted the presence of invasive cSCC with an AUC of 0.87 (95% CI [0.78 to 0.95]) for sensitivity and specificity of 81.7 and 82.4%, respectively for a cut-off value of 290 pg/mL. Serum MMP-13 predicted lymph node involvement with an AUC of 0.94 (95% CI [0.88 to 0.99]) for sensitivity and specificity of 93.8 and 88.5%, respectively for a cut-off value of 430 pg/mL.

Conclusion

Serum MMP-13 might serve as a valuable biomarker for early detection of cSCC invasiveness and monitoring of cSCC progression.

Integrative Bioinformatics Study of Tangeretin Potential Targets for Preventing Metastatic Breast Cancer

Agents that target metastasis are important to improve treatment efficacy in patients with breast cancer. Tangeretin, a citrus flavonoid, exhibits antimetastatic effects on breast cancer cells, but its molecular mechanism remains unclear. Tangeretin targets were retrieved from PubChem, whereas metastatic breast cancer regulatory genes were downloaded from PubMed. In total, 58 genes were identified as potential therapeutic target genes of tangeretin (PTs). GO and KEGG pathway enrichment analyses of PTs were performed using WebGestalt (WEB-based Gene SeT AnaLysis Toolkit). The PPI network was analyzed using STRING-DB v11.0 and visualized by Cytoscape software. Hub genes were selected on the basis of the highest degree score as calculated by the CytoHubba plugin. Genetic alterations of the PTs were analyzed using cBioPortal. The prognostic values of the PTs were evaluated with the Kaplan-Meier plot. The expression of PTs across breast cancer samples was confirmed using GEPIA. The reliability of the PTs in metastatic breast cancer cells was validated using ONCOMINE. Molecular docking was performed to foresee the binding sites of tangeretin with PIK3Cα, MMP9, PTGS2, COX-2, and IKK. GO analysis showed that PTs participate in the biological process of stimulus response, are the cellular components of the nucleus and the membrane, and play molecular roles in enzyme regulation. KEGG pathway enrichment analysis revealed that PTs regulate the PI3K/Akt pathway. Genetic alterations for each target gene were MTOR (3%), NOTCH1 (4%), TP53 (42%), MMP9 (4%), NFKB1 (3%), PIK3CA (32%), PTGS2 (15%), and RELA (5%). The Kaplan-Meier plot showed that patients with low mRNA expression levels of MTOR, TP53, MMP9, NFKB1, PTGS2, and RELA and high expression of PIK3CA had a significantly better prognosis than their counterparts. Further validation of gene expression by using GEPIA revealed that the mRNA expression of MMP9 was significantly higher in breast cancer tissues than in normal tissues, whereas the mRNA expression of PTGS2 showed the opposite. Analysis with ONCOMINE demonstrated that the mRNA expression levels of MMP9 and NFKB1 were significantly higher in metastatic breast cancer cells than in normal tissues. The results of molecular docking analyses revealed the advantage of tangeretin as an inhibitor of PIK3CA, MMP9, PTGS2, and IKK. Tangeretin inhibits metastasis in breast cancer cells by targeting TP53, PTGS2, MMP9, and PIK3CA and regulating the PI3K/Akt signaling pathway. Further investigation is needed to validate the results of this study.

Phosphorylation of OGFOD1 by Cell Cycle-Dependent Kinase 7/9 Enhances the Transcriptional Activity of RNA Polymerase II in Breast Cancer Cells

Simple Summary

Among the causes of accelerating cancer properties, dysregulated transcription is considerably prominent in many cancers. However, it is difficult to target transcriptional machineries due to their fundamental importance. Compared to breast cancer cell lines, we found that OGFOD1 aggravates cancers by enhancing RNA polymerase II transcriptional activity and it is improved by cell cycle-dependent kinases. Overall, we uncovered the novel mechanism for how OGFOD1 maliciously functions in breast cancers, suggesting it as a rational cancer treatment target protein.

Abstract

2-oxoglutarate and iron-dependent oxygenase domain-containing protein 1 (OGFOD1) expression is upregulated in a variety of cancers and has been related to poor prognosis. However, despite this significance to cancer progression, the precise oncogenic mechanism of OGFOD1 is not understood. We demonstrated that OGFOD1 plays a role in enhancing the transcriptional activity of RNA polymerase II in breast cancer cells. OGFOD1 directly binds to the C-terminal domain of RNA polymerase II to alter phosphorylation status. The elimination of OGFOD1 resulted in decreased tumor development. Additionally, cell cycle-dependent kinase 7 and cell cycle-dependent kinase 9, critical enzymes for activating RNA polymerase II, phosphorylated serine 256 of OGFOD1, whereas a non-phosphorylated mutant OGFOD1 failed to enhance transcriptional activation and tumor growth. Consequently, OGFOD1 helps promote tumor growth by enhancing RNA polymerase II, whereas simultaneous phosphorylation of OGFOD1 by CDK enzymes is essential in stimulating RNA polymerase II-mediated transcription both in vitro and in vivo, and expression of target genes.

Msi1 promotes breast cancer metastasis by regulating invadopodia-mediated extracellular matrix degradation via the Timp3-Mmp9 pathway

Metastasis is the main cause of death in breast cancer patients. The initial step of metastasis is invadopodia-mediated extracellular matrix (ECM) degradation, which enables local breast tumor cells to invade surrounding tissues. However, the molecular mechanism underlying invadopodia-mediated metastasis remains largely unknown. Here we found that the RNA-binding protein Musashi1 (Msi1) exhibited elevated expression in invasive breast tumors and promoted lung metastasis of mammary cancer cells. Suppression of Msi1 reduced invadopodia formation in mammary cancer cells. Furthermore, Msi1 deficiency decreased the expression and activity of Mmp9, an important enzyme in ECM degradation. Mechanistically, Msi1 directly suppressed Timp3, an endogenous inhibitor of Mmp9. In clinical breast cancer specimens, TIMP3 and MSI1 levels were significantly inversely correlated both in normal breast tissue and breast cancer tissues and associated with overall survival in breast cancer patients. Taken together, our findings demonstrate that the MSI1-TIMP3-MMP9 cascade is critical for invadopodia-mediated onset of metastasis in breast cancer, providing novel insights into a promising therapeutic strategy for breast cancer metastasis.

Triptolide inhibits matrix metalloproteinase-9 expression and invasion of breast cancer cells through the inhibition of NF-κB and AP-1 signaling pathways

Triptolide is a diterpenoid epoxide that is endogenously produced by the thunder god vine, Tripterygium wilfordii Hook F. Triptolide has demonstrated a variety of biological activities, including anticancer activities, in previous studies. Invasion and metastasis are the leading causes of mortality for patients with breast cancer, and the increased expression of matrix metalloproteinase-9 (MMP-9) has been shown to be associated with breast cancer invasion. Therefore, the aim of the present study was to investigate the effect of triptolide on 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced cell invasion and MMP-9 expression in breast cancer cells. The expression of signal molecules was examined by western blotting, zymography and quantitative polymerase chain reaction; an electrophoretic mobility gel shift assay was also used, and cell invasiveness was measured by an in vitro Matrigel invasion assay. The MCF-7 human breast cancer cell line was treated with triptolide at the highest concentrations at which no marked cytotoxicity was evident. The results demonstrated that triptolide decreased the expression of MMP-9 through inhibition of the TPA-induced phosphorylation of extracellular signal-regulated kinase (ERK) and the downregulation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activity. In addition, a Transwell assay revealed that triptolide reduced the ability of MCF-7 cells to invade Matrigel. These data demonstrate that the anti-invasive effect of triptolide is associated with the inhibition of ERK signaling and NF-κB and AP-1 activation, and suggest that triptolide may be a promising drug for breast cancer.

Combined Radiochemotherapy: Metalloproteinases Revisited

Besides cytotoxic DNA damage irradiation of tumor cells triggers multiple intra- and intercellular signaling processes, that are part of a multilayered, treatment-induced stress response at the unicellular and tumor pathophysiological level. These processes are intertwined with intrinsic and acquired resistance mechanisms to the toxic effects of ionizing radiation and thereby co-determine the tumor response to radiotherapy. Proteolysis of structural elements and bioactive signaling moieties represents a major class of posttranslational modifications regulating intra- and intercellular communication. Plasma membrane-located and secreted metalloproteinases comprise a family of metal-, usually zinc-, dependent endopeptidases and sheddases with a broad variety of substrates including components of the extracellular matrix, cyto- and chemokines, growth and pro-angiogenic factors. Thereby, metalloproteinases play an important role in matrix remodeling and auto- and paracrine intercellular communication regulating tumor growth, angiogenesis, immune cell infiltration, tumor cell dissemination, and subsequently the response to cancer treatment. While metalloproteinases have long been identified as promising target structures for anti-cancer agents, previous pharmaceutical approaches mostly failed due to unwanted side effects related to the structural similarities among the multiple family members. Nevertheless, targeting of metalloproteinases still represents an interesting rationale alone and in combination with other treatment modalities. Here, we will give an overview on the role of metalloproteinases in the irradiated tumor microenvironment and discuss the therapeutic potential of using more specific metalloproteinase inhibitors in combination with radiotherapy.

Xmrks the Spot: Fish Models for Investigating Epidermal Growth Factor Receptor Signaling in Cancer Research

Studies conducted in several fish species, e.g., Xiphophorus hellerii (green swordtail) and Xiphophorus maculatus (southern platyfish) crosses, Oryzias latipes (medaka), and Danio rerio (zebrafish), have identified an oncogenic role for the receptor tyrosine kinase, Xmrk, a gene product closely related to the human epidermal growth factor receptor (EGFR), which is associated with a wide variety of pathological conditions, including cancer. Comparative analyses of Xmrk and EGFR signal transduction in melanoma have shown that both utilize STAT5 signaling to regulate apoptosis and cell proliferation, PI3K to modulate apoptosis, FAK to control migration, and the Ras/Raf/MEK/MAPK pathway to regulate cell survival, proliferation, and differentiation. Further, Xmrk and EGFR may also modulate similar chemokine, extracellular matrix, oxidative stress, and microRNA signaling pathways in melanoma. In hepatocellular carcinoma (HCC), Xmrk and EGFR signaling utilize STAT5 to regulate cell proliferation, and Xmrk may signal through PI3K and FasR to modulate apoptosis. At the same time, both activate the Ras/Raf/MEK/MAPK pathway to regulate cell proliferation and E-cadherin signaling. Xmrk models of melanoma have shown that inhibitors of PI3K and MEK have an anti-cancer effect, and in HCC, that the steroidal drug, adrenosterone, can prevent metastasis and recover E-cadherin expression, suggesting that fish Xmrk models can exploit similarities with EGFR signal transduction to identify and study new chemotherapeutic drugs.

The antimammary tumor effects of ethanolic extract of propolis from Adamawa region (Cameroon) are by apoptosis via reactive oxygen species-mediated mitochondrial pathway

Identification of novel natural treatment to combat cancer is a current need. This study was aimed at assessing the anticancer effects of ethanol-extracted Cameroonian propolis (EEP). The antitumor effect of EPP was evaluated in vitro by measuring; cell viability, cell cycle, cell death mechanism, cell migration/invasion, reactive oxygen species (ROS), mitochondrial potential (ΔΨm), caspase activity, and apoptosis-regulating proteins (Bcl-2 and Bcl-XL) in cell lines. In vivo, the effect of EEP against 7,12 dimethylbenz(a)anthracene (DMBA)-induced breast tumorigenesis in rats was assessed. EEP was found to induce cytotoxicity against ER negative MDA-MB-231 breast cancer cells by activating apoptosis through ROS-mediated mitochondrial pathway. The extract equally triggered caspase-3 and caspase-9, increment of ROS level, disruption of ΔΨm and down-regulation of Bcl-XL and Bcl-2 proteins. Besides, EPP prevented migration and invasion activities by inhibiting MMP-2 activity. At all doses it prevented breast tumor incidence (20% in EEP 150 mg/kg vs 70% in DMBA) as well as tumor burden. Tumor sections from EEP-treated rats showed middle proliferation of mammary ducts with weak inflammatory responses. In summary, Cameroonian propolis exhibited antimammary tumor effects via the intrinsic pathway of apoptosis.

Crocin and Metformin suppress metastatic breast cancer progression via VEGF and MMP9 downregulations: in vitro and in vivo studies

Metastatic breast cancer remains a serious health concern and numerous investigations recommended medicinal plants as a complementary therapy. Crocin is one of the known anticancer bio-component. Recently, the inhibitory effect of metformin has been studied on the various aspects of cancer. However, no study reported their combination effects on metastatic breast cancer. In the present study, we have assessed their anti-metastatic effects on in vitro and in vivo breast cancer models. Using MTT assay, scratch, and adhesion tests, we have evaluated the cytotoxic, anti-invasive and anti-adhesion effects of crocin and metformin on 4T1 cell line, respectively. Their protective effects and MMP9 as well as VEGF protein expression levels (Western blotting) investigated in the 4T1 murine breast cancer model. Our results showed that both crocin and metformin reduced cell viability, delayed scratch healing and inhibited the cell adhesion, in vitro. While crocin alone restored the mice's weight reduction, crocin, metformin, and their combination significantly reduced the tumor volume size and enhanced animal survival rate in murine breast cancer model, responses that were associated with VEGF and MMP9 down-regulation. These findings suggest that a combination of crocin and metformin could serve as a novel therapeutic approach to enhance the effectiveness of metastatic breast cancer therapy.

Study of long non-coding RNA highly upregulated in liver cancer (HULC) in breast cancer: A clinical & in vitro investigation

Background & objectives:

Breast cancer remains the most common malignancy among women worldwide. Long non-coding RNAs (lncRNAs) have been shown to play critical roles in tumour initiation and progression. This study was aimed to evaluate the potential role of lncRNA highly upregulated in liver cancer (HULC) in breast cancer.

Methods:

The expression of HULC was evaluated in breast cancer patients and cell lines using real-time quantitative reverse transcription polymerase chain reaction. Small interfering RNA-based knockdown was also employed to study the potential role of HULC in breast cancer cell lines including ZR-75-1, MCF7 and MDA-MB-231.

Results:

HULC was significantly upregulated in tumour tissues compared to non-tumoural margins (P<0.001). The receiver operating characteristic (ROC) curve analysis demonstrated the biomarker potential of HULC (ROC^AUC=0.78, P<0.001). The HULC knockdown induced apoptosis and suppressed cellular migration in breast cancer cell lines.

Interpretation & conclusions:

Our results indicated that HULC was upregulated in breast cancer and might play a role in tumourigenesis. The HULC may have a potential to be exploited as a new biomarker and therapeutic target in breast cancer.

A Novel Role for Brain and Acute Leukemia Cytoplasmic (BAALC) in Human Breast Cancer Metastasis

Brain and Acute Leukemia, Cytoplasmic (BAALC) is a protein that controls leukemia cell proliferation, differentiation, and survival and is overexpressed in several cancer types. The gene is located in the chromosomal region 8q22.3, an area commonly amplified in breast cancer and associated with poor prognosis. However, the expression and potential role of BAALC in breast cancer has not widely been examined. This study investigates BAALC expression in human breast cancers with the aim of determining if it plays a role in the pathogenesis of the disease. BAALC protein expression was examined by immunohistochemistry in breast cancer, and matched lymph node and normal breast tissue samples. The effect of gene expression on overall survival (OS), disease-free and distant metastasis free survival (DMFS) was assessed in silico using the Kaplan-Meier Plotter (n=3,935), the TCGA invasive breast carcinoma (n=960) and GOBO (n=821) data sets. Functional effects of BAALC expression on breast cancer proliferation, migration and invasion were determined in vitro. We demonstrate herein that BAALC expression is progressively increased in primary and breast cancer metastases when compared to normal breast tissue. Increased BAALC mRNA is associated with a reduction in DMFS and disease-free survival, but not OS, in breast cancer patients, even when corrected for tumor grade. We show that overexpression of BAALC in MCF-7 breast cancer cells increases the proliferation, anchorage-independent growth, invasion, and migration capacity of these cells. Conversely, siRNA knockdown of BAALC expression in Hs578T breast cancer cells decreases proliferation, invasion and migration. We identify that this BAALC associated migration and invasion is mediated by focal adhesion kinase (FAK)-dependent signaling and is accompanied by an increase in matrix metalloproteinase (MMP)-9 but not MMP-2 activity in vitro. Our data demonstrate a novel function for BAALC in the control of breast cancer metastasis, offering a potential target for the generation of anti-cancer drugs to prevent breast cancer metastasis.

The multiple roles of actin-binding proteins at invadopodia

Invadopodia are actin-rich membrane protrusions that facilitate cancer cell dissemination by focusing on proteolytic activity and clearing paths for migration through physical barriers, such as basement membranes, dense extracellular matrices, and endothelial cell junctions. Invadopodium formation and activity require spatially and temporally regulated changes in actin filament organization and dynamics. About three decades of research have led to a remarkable understanding of how these changes are orchestrated by sequential recruitment and coordinated activity of different sets of actin-binding proteins. In this chapter, we provide an update on the roles of the actin cytoskeleton during the main stages of invadopodium development with a particular focus on actin polymerization machineries and production of pushing forces driving extracellular matrix remodeling.

Alpha 1-antichymotrypsin contributes to stem cell characteristics and enhances tumorigenicity of glioblastoma

BACKGROUND

Glioblastomas (GBMs) are the main primary brain tumors in adults with almost 100% recurrence rate. Patients with lateral ventricle proximal GBMs (LV-GBMs) exhibit worse survival compared to distal locations for unknown reasons. One hypothesis is the proximity of these tumors to the cerebrospinal fluid (CSF) and its chemical cues that can regulate cellular phenotype. We therefore investigated the role of CSF on GBM gene expression and the role of a CSF-induced gene, SERPINA3, in GBM malignancy in vitro and in vivo.

METHODS

We utilized human CSF and GBM brain tumor-initiating cells (BTICs). We determined the impact of SERPINA3 expression in glioma patients using The Cancer Genome Atlas (TCGA) database. SERPINA3 expression changes were evaluated at mRNA and protein levels. The effects of knockdown (KD) and overexpression (OE) of SERPINA3 on cell migration, viability and cell proliferation were evaluated. Stem cell characteristics on KD cells were evaluated by differentiation and colony formation experiments. Tumor growth was studied by intracranial and flank injections.

RESULTS

GBM-CSF increased BTIC migration accompanied by upregulation of the SERPINA3 gene. In patient samples and TCGA data, we observed SERPINA3 to correlate directly with brain tumor grade and indirectly with GBM patient survival. SERPINA3 KD induced a decrease in cell proliferation, migration, invasion, and stem cell characteristics, while SERPINA3 OE increased cell migration. In vivo, SERPINA3 KD BTICs showed increased survival in a murine model.

CONCLUSIONS

SERPINA3 plays a key role in GBM malignancy and its inhibition results in a better outcome using GBM preclinical models.

Inhibition of the Axl pathway impairs breast and prostate cancer metastasis to the bones and bone remodeling

Approximately 90% of cancer-related deaths result from cancer metastasis. In prostate and breast cancers, bone is the most common site of cancer cell dissemination. Key steps in the metastatic cascade are promoted through upregulation of critical cell signaling pathways in neoplastic cells. The present study assessed the role of the receptor tyrosine kinase Axl in prostate and breast cancer cell metastasis to bones using (i) Axl knockdown neoplastic cells and osteoclast progenitor cells in vitro, (ii) intracardiac injection of Axl knockdown tumor cells in vivo, and (iii) selective Axl inhibitor BGB324. Axl inhibition in neoplastic cells significantly decreased their metastatic potential, and suppression of Axl signaling in osteoclast precursor cells also reduced the formation of mature osteoclasts. In vivo, Axl knockdown in prostate and breast cancer cells significantly suppressed the formation and progression of bone metastases. Hence, therapeutic targeting of Axl may impair tumor metastasis to the bones through neoplastic and host cell signaling axes.

CD44 modulates metabolic pathways and altered ROS-mediated Akt signal promoting cholangiocarcinoma progression

CD44 is a transmembrane glycoprotein, the phosphorylation of which can directly trigger intracellular signaling, particularly Akt protein, for supporting cell growth, motility and invasion. This study examined the role of CD44 on the progression of Cholangiocarcinoma (CCA) using metabolic profiling to investigate the molecular mechanisms involved in the Akt signaling pathway. Our results show that the silencing of CD44 decreases Akt and mTOR phosphorylation resulting in p21 and Bax accumulation and Bcl-2 suppression that reduces cell proliferation. Moreover, an inhibition of cell migration and invasion regulated by CD44. Similarly, the silencing of CD44 showed an alteration in the epithelial-mesenchymal transition (EMT), e.g. an upregulation of E-cadherin and a downregulation of vimentin, and the reduction of the matrix metalloproteinase (MMP)-9 signal. Interestingly, a depletion of CD44 leads to metabolic pathway changes resulting in redox status modification and Trolox (anti-oxidant) led to the recovery of the cancer cell functions. Based on our findings, the regulation of CCA progression and metastasis via the redox status-related Akt signaling pathway depends on the alteration of metabolic profiling synchronized by CD44.

Fuzheng Yiliu Formula Regulates Tumor Invasion and Metastasis through Inhibition of WAVE3 Expression

Objective

To explore the mechanism of action of Fuzheng Yiliu formula (FZYLF) in regulation of the invasion and metastasis of MDA-MB-231/Adr human breast cancer cells through WAVE3.

Methods

The MDA-MB-231/Adr cells with high invasive ability were screened by Transwell, and the plasmid with high WAVE3 expression was made for transfection. Plasmid transfection efficiency and protein expression level were verified by polymerase chain reaction (PCR) and western blotting (WB). The effect of FZYLF on cell proliferation and invasion was investigated before and after WAVE3 silencing by flow cytometry. A nude mouse model of tumor metastasis was established to study the antitumor activity of FZYLF.

Results

The expression levels of mRNA and proteins of intracellular WAVE3 increased significantly after plasmid transfection, mRNA from 1.37± 0.41 to 9.88 ± 1.31 and protein from 1 ± 0.08 to 5.09 ± 0.03 (P < 0.01). Intervention with FZYLF could significantly affect the activity of MDA-MB-231/Adr cells and inhibit invasion and metastasis, IC₅₀ from 71.04 to 46.41 mg/mL and from 162 ± 14.82 to 81.4 ± 12.05 (P < 0.05 or P < 0.01), and significantly reduce the expression levels of WAVE3 (from 1 ± 0.02 to 0.63 ± 0.04), MMP-9 (from 1 ± 0.05 to 0.63 ± 0.03), NF-κB (p65) (from 1 ± 0.02 to 0.62 ± 0.02), and p-IκBα (from 1 ± 0.03 to 0.68 ± 0.02) (P < 0.05 or P < 0.01). The T/C (%) of FZYLF (13 g crude drug/kg) was 62.06% for MDA-MB-231/Adr tumor xenografted in nude mice, with a tumor inhibition rate of 39.64%.

Conclusion

FZYLF can inhibit the invasion and proliferation of the MDA-MB-231/Adr human breast cancer cells, and the mechanism of action may be related to the regulation of WAVE3 expression.

Advanced Approaches to Breast Cancer Classification and Diagnosis

The International Agency for Research on Cancer (IARC) has recently reported a 66% increase in the global number of cancer deaths since 1960. In the US alone, about one in eight women is expected to develop invasive breast cancer(s) (breast cancer) at some point in their lifetime. Traditionally, a BC diagnosis includes mammography, ultrasound, and some high-end molecular bioimaging. Unfortunately, these techniques detect BC at a later stage. So early and advanced molecular diagnostic tools are still in demand. In the past decade, various histological and immuno-molecular studies have demonstrated that BC is highly heterogeneous in nature. Its growth pattern, cytological features, and expression of key biomarkers in BC cells including hormonal receptor markers can be utilized to develop advanced diagnostic and therapeutic tools. A cancer cell's progression to malignancy exhibits various vital biomarkers, many of which are still underrepresented in BC diagnosis and treatment. Advances in genetics have also enabled the development of multigene assays to detect genetic heterogeneity in BC. However, thus far, the FDA has approved only four such biomarkers-cancer antigens (CA); CA 15-3, CA 27-29, Human epidermal growth factor receptor 2 (HER2), and circulating tumor cells (CTC) in assessing BC in body fluids. An adequately structured portable-biosensor with its non-invasive and inexpensive point-of-care analysis can quickly detect such biomarkers without significantly compromising its specificity and selectivity. Such advanced techniques are likely to discriminate between BC and a healthy patient by accurately measuring the cell shape, structure, depth, intracellular and extracellular environment, and lipid membrane compositions. Presently, BC treatments include surgery and systemic chemo- and targeted radiation therapy. A biopsied sample is then subjected to various multigene assays to predict the heterogeneity and recurrence score, thus guiding a specific treatment by providing complete information on the BC subtype involved. Thus far, we have seven prognostic multigene signature tests for BC providing a risk profile that can avoid unnecessary treatments in low-risk patients. Many comparative studies on multigene analysis projected the importance of integrating clinicopathological information with genomic-imprint analysis. Current cohort studies such as MINDACT, TAILORx, Trans-aTTOM, and many more, are likely to provide positive impact on long-term patient outcome. This review offers consolidated information on currently available BC diagnosis and treatment options. It further describes advanced biomarkers for the development of state-of-the-art early screening and diagnostic technologies.

Role of the V1G1 subunit of V-ATPase in breast cancer cell migration

V-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.

IgG-Engineered Protective Antigen for Cytosolic Delivery of Proteins into Cancer Cells

Therapeutic immunotoxins composed of antibodies and bacterial toxins provide potent activity against malignant cells, but joining them with a defined covalent bond while maintaining the desired function is challenging. Here, we develop novel immunotoxins by dovetailing full-length immunoglobulin G (IgG) antibodies and nontoxic anthrax proteins, in which the C terminus of the IgG heavy chain is connected to the side chain of anthrax toxin protective antigen. This strategy enabled efficient conjugation of protective antigen variants to trastuzumab (Tmab) and cetuximab (Cmab) antibodies. The conjugates effectively perform intracellular delivery of edema factor and N terminus of lethal factor (LF_N) fused with diphtheria toxin and Ras/Rap1-specific endopeptidase. Each conjugate shows high specificity for cells expressing human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), respectively, and potent activity across six Tmab- and Cmab-resistant cell lines. The conjugates also exhibit increased pharmacokinetics and pronounced in vivo safety, which shows promise for further therapeutic development.

Microenvironmental Th9 and Th17 lymphocytes induce metastatic spreading in lung cancer

Immune microenvironment plays a critical role in lung cancer control versus progression and metastasis. In this investigation, we explored the effect of tumor-infiltrating lymphocyte subpopulations on lung cancer biology by studying in vitro cocultures, in vivo mouse models, and human lung cancer tissue. Lymphocyte conditioned media (CM) induced epithelial-mesenchymal transition (EMT) and migration in both primary human lung cancer cells and cell lines. Correspondingly, major accumulation of Th9 and Th17 cells was detected in human lung cancer tissue and correlated with poor survival. Coculturing lung cancer cells with Th9/Th17 cells or exposing them to the respective CM induced EMT in cancer cells and modulated the expression profile of genes implicated in EMT and metastasis. These features were reproduced by the signatory cytokines IL-9 and IL-17, with gene regulatory profiles evoked by these cytokines partly overlapping and partly complementary. Coinjection of Th9/Th17 cells with tumor cells in WT, Rag1-/-, Il9r-/-, and Il17ra-/- mice altered tumor growth and metastasis. Accordingly, inhibition of IL-9 or IL-17 cytokines by neutralizing antibodies decreased EMT and slowed lung cancer progression and metastasis. In conclusion, Th9 and Th17 lymphocytes induce lung cancer cell EMT, thereby promoting migration and metastatic spreading and offering potentially novel therapeutic strategies.

Cellular and Molecular Players in the Interplay between Adipose Tissue and Breast Cancer

The incidence and severity of obesity are rising in most of the world. In addition to metabolic disorders, obesity is associated with an increase in the incidence and severity of a variety of types of cancer, including breast cancer (BC). The bidirectional interaction between BC and adipose cells has been deeply investigated, although the molecular and cellular players involved in these mechanisms are far from being fully elucidated. Here, we review the current knowledge on these interactions and describe how preclinical research might be used to clarify the effects of obesity over BC progression and morbidity, with particular attention paid to promising therapeutic interventions.

Response to trastuzumab and investigation of expression profiles of matrix metalloproteinase-related proteins in primary breast cancer stem cells

Breast cancer (BC) is the leading cause of cancer deaths in women. One of the reasons for the failure of BC treatment is reportedly the ineffectiveness of chemotherapeutic drugs against breast cancer stem-like cells (BCSCs). HER2 receptors have an important role in the self-renewal of BCSCs. Matrix metalloproteinase (MMP) and cytokine levels were found to be higher in BCSCs, which demonstrates their potential metastatic capacity. Therefore, the aim of this study was to evaluate the response of BCSCs to trastuzumab and to investigate the MMP levels in primary breast cancer cells and HER2⁺ BCSCs. Tumour tissue samples were obtained during surgical intervention from ten breast cancer patients, and primary culture cells were established from these tissues. Four major molecular subgroups were sorted from the primary culture: HER2⁺ BCSCs (CD44⁺CD24^-HER2⁺), HER2^- BCSCs (CD44⁺CD24^-HER2^-), HER2^- primary culture cells (CD44⁺CD24⁺HER2^-) and triple positive primary culture cells (CD44⁺CD24⁺HER2⁺). These cells were cultured and treated with trastuzumab, paclitaxel, carboplatin, and the combination of those three drugs for 96 h. Cellular responses to these drugs were determined by XTT cytotoxicity test. MMPs and cytokine array analysis showed that MMPs and TIMP-1, TIMP-2 proteins were expressed more in HER2⁺ BCSCs than in primary culture. HER2^- BCSCs were more resistant to drugs than HER2⁺ BCSCs. Our findings suggest that the presence of HER2^- BCSCs may be responsible for primary trastuzumab resistance in HER2⁺ BC cell population. Further studies investigating the function of MMPs are needed for drug targeting of BCSCs.

3D Co-cultured Endothelial Cells and Monocytes Promoted Cancer Stem Cells' Stemness and Malignancy

Cancer stem cells (CSCs) are self-renewing and constitute the primary cause of cancer relapse post-cancer therapy. The CSC niche is composed of various nonmalignant stromal cells that support CSCs' survival during cancer chemoradiotherapy. Understanding the cross-talk between CSCs and stromal cells could pave the way for developing therapeutic strategies to eradicate CSCs. Traditionally, CSC research has been relying on animal models, which can give rise to complications and poor translation in clinical practice. An efficient model to co-culture CSCs and stromal cells is urgently needed. Hence, we leveraged our expertise in enriching CSCs from in vitro cell lines with a 3D alginate-based platform, as reported previously. We established a 3D co-culture system that allowed us to study the interactions between stromal cells and CSCs over an extended period. We showed that the self-renewal capacity and stemness of CSCs were significantly enhanced when co-cultured with 3D cultured human umbilical vein endothelial cells (HUVECs) or a human monocyte cell line (THP1). Strikingly, the expression of MDR1 in 3D co-cultured CSCs was upregulated, leading to enhanced chemotoxic drug tolerance. We suggest that our in vitro co-culture model can impact CSC research and clinical practice when the goal is to develop therapeutics that target and eradicate CSCs by targeting stromal cells.

S-Adenosylmethionine Inhibits Cell Growth and Migration of Triple Negative Breast Cancer Cells through Upregulating MiRNA-34c and MiRNA-449a

Triple-negative breast cancer (TNBC) is one of the most common malignancies worldwide and shows maximum invasiveness and a high risk of metastasis. Recently, many natural compounds have been highlighted as a valuable source of new and less toxic drugs to enhance breast cancer therapy. Among them, S-adenosyl-L-methionine (AdoMet) has emerged as a promising anti-cancer agent. MicroRNA (miRNA or miR)-based gene therapy provides an interesting antitumor approach to integrated cancer therapy. In this study, we evaluated AdoMet-induced modulation of miRNA-34c and miRNA-449a expression in MDA-MB-231 and MDA-MB-468 TNBC cells. We demonstrated that AdoMet upregulates miR-34c and miR-449a expression in both cell lines. We found that the combination of AdoMet with miR-34c or miR-449a mimic strongly potentiated the pro-apoptotic effect of the sulfonium compound by a caspase-dependent mechanism. For the first time, by video time-lapse microscopy, we showed that AdoMet inhibited the in vitro migration of MDA-MB-231 and MDA-MB-468 cells and that the combination with miR-34c or miR-449a mimic strengthened the effect of the sulfonium compound through the modulation of β-catenin and Small Mother Against Decapentaplegic (SMAD) signaling pathways. Our results furnished the first evidence that AdoMet exerts its antitumor effects in TNBC cells through upregulating the expression of miR-34c and miR-449a.

MicroRNA‑34a‑5p serves as a tumor suppressor by regulating the cell motility of bladder cancer cells through matrix metalloproteinase‑2 silencing

Bladder cancer (BC), a common urologic cancer, is the fifth most frequently diagnosed tumor worldwide. hsa-miR-34a displays antitumor activity in several types of cancer. However, the functional mechanisms underlying hsa-miR-34a in BC remains largely unknown. We observed that hsa-mir-34a levels were significantly and negatively associated with clinical disease stage as well as regional lymph node metastasis in human BC. In a series of in vitro investigations, overexpression of hsa-miR-34a inhibited cell migration and invasion in BC cell lines 5637 and UMUC3 as detected by Transwell assays. We further found that hsa-miR-34a inhibited cell migration and invasion by silencing matrix metalloproteinase-2 (MMP-2) expression and thus interrupting MMP-2-mediated cell motility. Our analysis of BC datasets from The Cancer Genome Atlas database revealed a negative correlation between hsa-miR-34a and MMP-2. Moreover, higher MMP-2 protein expression was observed in the BC tissues when compared with that noted in the normal tissue. MMP-2 levels were also significantly associated with clinical disease stage and poor survival rate in human BC. These findings indicate that MMP-2 plays a critical role in regulating BC progression. Therefore, hsa-miR-34a is a promising treatment to target MMP-2 for the prevention and inhibition of cell migration and invasion in BC.

Oncogenic allelic interaction in Xiphophorus highlights hybrid incompatibility

The Bateson–Dobzhansky–Muller (BDM) model describes negative epistatic interactions that occur between genes with a different evolutionary history to account for hybrid incompatibility and is a central theory explaining genetic mechanisms underlying speciation. Since the early 1900 s when the BDM model was forwarded examples of BDM incompatibility have been described in only a few nonvertebrate cases. This study reports the only vertebrate system, with clearly defined interacting loci, that supports the BDM model. In addition, this study also poses that tumorigenesis serves as a novel mechanism that accounts for postzygotic isolation.

Mixing genomes of different species by hybridization can disrupt species-specific genetic interactions that were adapted and fixed within each species population. Such disruption can predispose the hybrids to abnormalities and disease that decrease the overall fitness of the hybrids and is therefore named as hybrid incompatibility. Interspecies hybridization between southern platyfish and green swordtails leads to lethal melanocyte tumorigenesis. This occurs in hybrids with tumor incidence following progeny ratio that is consistent with two-locus interaction, suggesting melanoma development is a result of negative epistasis. Such observations make Xiphophorus one of the only two vertebrate hybrid incompatibility examples in which interacting genes have been identified. One of the two interacting loci has been characterized as a mutant epidermal growth factor receptor. However, the other locus has not been identified despite over five decades of active research. Here we report the localization of the melanoma regulatory locus to a single gene, rab3d, which shows all expected features of the long-sought oncogene interacting locus. Our findings provide insights into the role of egfr regulation in regard to cancer etiology. Finally, they provide a molecular explainable example of hybrid incompatibility.

Triple Negative Breast Cancer: How Neurokinin-1 Receptor Antagonists Could Be Used as a New Therapeutic Approach

Breast cancer (BC) is the most frequently diagnosed cancer and the leading cause of cancer death among females. BC cells not showing HER-2/Neu amplification and not expressing estrogen/ progesterone receptors are named triple-negative BC (TNBC) cells. TNBC represents 10-15% of all BC and is associated with an aggressive clinical course. TNBC patient prognosis, survival and response to current therapies are poor and for this reason, it is crucial to search for new therapeutic targets in TNBC to develop new therapeutic strategies. One of these targets is the neurokinin-1 receptor (NK-1R). It is well known that the substance P (SP)/NK-1R system is involved in cancer progression. TNBC cells overexpress the NK-1R and, after binding to this receptor, SP promotes the proliferation/ migration of TNBC cells. Non-peptide NK-1R antagonists (e.g., aprepitant) are known to exert, via the NK-1R, an antitumor action; TNBC cells die by apoptosis. In this review, we update the data on a promising therapeutic innovation: the use of NK-1R antagonists for the treatment of TNBC patients.

Mesenchymal stem cells promote metastasis through activation of an ABL-MMP9 signaling axis in lung cancer cells

Mesenchymal stem cells (MSCs) are recruited and activated by solid tumors and play a role in tumor progression and metastasis. Here we show that MSCs promote metastasis in a panel of non-small cell lung cancer (NSCLC) cells. MSCs elicit transcriptional alterations in lung cancer cells leading to increased expression of factors implicated in the epithelial-to-mesenchymal transition (EMT) and secreted proteins including matrix metalloproteinase-9 (MMP9). MSCs enhance secretion of enzymatically active MMP9 in a panel of lung adenocarcinoma cells. High expression of MMP9 is linked to low survival rates in lung adenocarcinoma patients. Notably, we found that ABL tyrosine kinases are activated in MSC-primed lung cancer cells and functional ABL kinases are required for MSC-induced MMP9 expression, secretion and proteolytic activity. Importantly, ABL kinases are required for MSC-induced NSCLC metastasis. These data reveal an actionable target for inhibiting MSC-induced metastatic activity of lung adenocarcinoma cells through disruption of an ABL kinase-MMP9 signaling axis activated in MSC-primed lung cancer cells.

Duality of B Cell-CXCL13 Axis in Tumor Immunology

Tumor immunity is a rapidly evolving area of research consisting of many possible permutations of immune cell tumor interactions that are dependent upon cell type, tumor type, and stage in tumor progression. At the same time, the majority of cancer immunotherapies have been focused on modulating the T cell-mediated antitumor immune response and have largely ignored the potential utility that B cells possess with respect to tumor immunity. Therefore, this motivated an exploration into the role that B cells and their accompanying chemokine, CXCL13, play in tumor immunity across multiple tumor types. Both B cells and CXCL13 possess dualistic impacts on tumor progression and tumor immunity which is furthered detail in this review. Specifically, various B cells subtypes are able to suppress or enhance several important immunological functions. Paradoxically, CXCL13 has been shown to drive several pro-growth and invasive signaling pathways across multiple tumor types, while also, correlating with improved survival and immune cell tumor localization in other tumor types. Potential tools for better elucidating the mechanisms by which B cells and CXCL13 impact the antitumor immune response are also discussed. In addition, multiples strategies are proposed for modulating the B cell-CXCL13 axis for cancer immunotherapies.

SSi6 promotes cell death by apoptosis through cell cycle arrest and inhibits migration and invasion of MDA-MB-231 human breast cancer cells

Triple-negative breast cancer subtype is the most aggressive type of breast cancer due to the lack of specific therapeutic targets, having limited treatment options, low survival prognosis and high recurrence rates. In this work, we describe the effects of a semisynthetic derivative of [6]-gingerol (6G) called SSi6, produced by the addition of a 2,4-dinitrophenylhydrazine reagent on several aspects of triple-negative breast cancer biology. Human breast cancer cell lines MDA-MB-231 and MCF-10A were used in the experiments. MTT assays were used to detect cell viability. Cell cycle and apoptosis assay were analyzed using flow cytometer Accuri C6 and analysis of proteins as retinoblastoma Rb and kinases Cdk4/6 were analyzed by western blotting. SSi6 induced cytotoxic effects on triple-negative breast cancer cells, with higher selectivity when compared to the non-tumor MCF-10A cells. In addition, SSi6 inhibited migration and invasion of triple-negative breast cancer cells and was able to arrest cell cycle at the G1-phase, mainly by decreasing Cdk4/6-Rb axis levels. Therefore, SSi6 provoked the induction of apoptosis in triple-negative breast cancer cells. SSi6 was more efficient in producing these effects, compared to the original 6G natural product. This study may contribute to a better understanding of the effects of natural and semisynthetic products on the in-vitro metastatic processes in the MDA-MB-231 triple-negative breast cancer cell line. Additional, it can be useful to understand the effects of chemical modifications on already effective natural compounds aiming at the improvement of their bioactive properties, such as in the increase of the cytotoxic selectivity against tumor cells, compared to non-tumor ones.

Bioguided Fractionation of Local Plants against Matrix Metalloproteinase9 and Its Cytotoxicity against Breast Cancer Cell Models: In Silico and In Vitro Study

Matrix metalloproteinase9 (MMP9) is known to be highly expressed during metastatic cancer where most known potential inhibitors failed in the clinical trials. This study aims to select local plants in our state, as anti-breast cancer agent with hemopexin-like domain of MMP9 (PEX9) as the selective protein target. In silico screening for PEX9 inhibitors was performed from our in house-natural compound database to identify the plants. The selected plants were extracted using methanol and then a step-by-step in vitro screening against MMP9 was performed from its crude extract, partitions until fractions using FRET-based assay. The partitions were obtained by performing liquid–liquid extraction on the methanol extract using n-hexane, ethylacetate, n-butanol, and water representing nonpolar to polar solvents. The fractions were made from the selected partition, which demonstrated the best inhibition percentage toward MMP9, using column chromatography. Of the 200 compounds screened, 20 compounds that scored the binding affinity −11.2 to −8.1 kcal/mol toward PEX9 were selected as top hits. The binding of these hits were thoroughly investigated and linked to the plants which they were reported to be isolated from. Six of the eight crude extracts demonstrated inhibition toward MMP9 with the IC₅₀ 24 to 823 µg/mL. The partitions (1 mg/mL) of Ageratum conyzoides aerial parts and Ixora coccinea leaves showed inhibition 94% and 96%, whereas their fractions showed IC₅₀ 43 and 116 µg/mL, respectively toward MMP9. Using MTT assay, the crude extract of Ageratum exhibited IC₅₀ 22 and 229 µg/mL against 4T1 and T47D cell proliferations, respectively with a high safety index concluding its potential anti-breast cancer from herbal.

Breast Cancer Cell-Neutrophil Interactions Enhance Neutrophil Survival and Pro-Tumorigenic Activities

Breast cancer remains the most prevalent cancer in women with limited treatment options for patients suffering from therapy-resistance and metastatic disease. Neutrophils play an important role in breast cancer progression and metastasis. We examined the pro-tumorigenic nature of the breast cancer cell-neutrophil interactions and delineated the differences in neutrophil properties between the chemotherapy-resistant and the parent tumor microenvironment. Our data demonstrated that high neutrophil infiltration is associated with disease aggressiveness and therapy resistance. In the human breast cancer dataset, expression of neutrophil-related signature gene expression was higher in tumors from therapy-resistant patients than therapy-sensitive patients. We observed that breast cancer-derived factors significantly enhanced neutrophil survival, polarization, and pro-inflammatory cytokine expression. Breast cancer cell-derived supernatant treated neutrophils significantly expressed high levels of interleukin-1β (IL-1β), CC-chemokine ligand-2-4 (CCL2, CCL3, CCL4), inducible nitric oxide synthase (iNOS), and matrix metallopeptidase-9 (MMP9), and formed extracellular traps (NETs). Moreover, neutrophils showed increased secretion of MMP9 when cultured with the supernatant of chemotherapy-resistant Cl66-Doxorubicin (Cl66-Dox) and Cl66-Paclitaxel (Cl66-Pac) cells in comparison with the supernatant of Cl66-parent cells. Together, these data suggest an important role of breast cancer cell-neutrophil interactions in regulating pro-tumor characteristics in neutrophils and its modulation by therapy resistance.