Tweaking EMT and MDR dynamics to constrain triple-negative breast cancer invasiveness by EGFR and Wnt/β-catenin signaling regulation

Beauvericin Reverses Epithelial-to-Mesenchymal Transition in Triple-Negative Breast Cancer Cells through Regulation of Notch Signaling and Autophagy

Metastasis stands as a prime contributor to triple-negative breast cancer (TNBC) associated mortality worldwide, presenting heightened severity and significant challenges due to limited treatment options. Addressing TNBC metastasis necessitates innovative approaches and novel therapeutics to specifically target its propensity for dissemination to distant organs. Targeted therapies capable of reversing epithelial-to-mesenchymal transition (EMT) play a crucial role in suppressing metastasis and enhancing the treatment response. Beauvericin, a promising fungal secondary metabolite, exhibits significant potential in diminishing the viability of EMT-induced TNBC cells by triggering intracellular oxidative stress, as evidenced by an enhanced reactive oxygen species level and reduced mitochondrial transmembrane potential. In monolayer cultures, it has exhibited an IC50 of 2.3 μM in both MDA-MB-468 and MDA-MB-231 cells, while in 3D spheroids, the IC50 values are 9.7 and 7.1 μM, respectively. Beauvericin has also reduced the migratory capability of MDA-MB-468 and MDA-MB-231 cells by 1.5- and 1.7-fold, respectively. Both qRT-PCR and Western blot analysis have shown significant upregulation in the expression of epithelial marker (E-cadherin) and downregulation in the expression of mesenchymal markers (N-cadherin, vimentin, Snail, Slug, and β-catenin), following treatment, indicating reversal of EMT. Furthermore, beauvericin has suppressed the Notch signaling pathway by substantially downregulating Notch-1, Notch-3, Hes-1, and cyclinD3 expression and induced autophagy as observed by elevated expression of autophagy markers LC3 and Beclin-1. In conclusion, beauvericin has successfully downregulated TNBC cell survival by inducing oxidative stress and suppressed their migratory potential by reversing EMT through the inhibition of Notch signaling and activation of autophagy.

Mechanism of Induction of P-gp Activity During MET Induced by DEX in Lung Cancer Cell Line

Lung cancer metastasis often leads to a poor prognosis for patients. Mesenchymal-epithelial transition (MET) is one key process associated with metastasis. MET has also been linked to multidrug drug resistance (MDR). MDR arises from the overactivity of drug efflux transporters such as P-glycoprotein (P-gp) which operate at the cell plasma membrane, under the regulatory control of the scaffold proteins ezrin (Ezr), radixin (Rdx), and moesin (Msn), collectively known as ERM proteins. The current study was intended to clarify the functional changing of P-gp and the underlying mechanisms in the context of dexamethasone (DEX)-induced MET in lung cancer cells. We found that the mRNA and membrane protein expression of Ezr and P-gp was increased in response to DEX treatment. Moreover, the DEX-treated group exhibited an increase in Rho123 efflux, and it was reversed by treatment with the P-gp inhibitor verapamil or Ezr siRNA. The decrease in cell viability with paclitaxel (PTX) treatment was mitigated by pretreatment with DEX. The increased expression and activation of P-gp during the progression of lung cancer MET was regulated by Ezr. The regulatory mechanism of P-gp expression and activity may differ depending on the cell status.

Single-cell transcriptomics reveals the intra-tumoral heterogeneity and SQSTM1/P62 and Wnt/β-catenin mediated epithelial to mesenchymal transition and stemness of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is characterized by the complex tumor microenvironment (TME) consisting of an abundance of mesenchymal stem cells (MSCs), which is known to facilitate epithelial-to-mesenchymal transition (EMT). The development of single-cell genomics is a powerful method for defining the intricate genetic landscapes of malignancies. In this study, we have employed single-cell RNA sequencing (scRNA-seq) to dissect the intra-tumoral heterogeneity and analyze the single-cell transcriptomic landscape to detect rare consequential cell subpopulations of significance. The scRNA-seq analysis of TNBC and Normal patient derived samples revealed that EMT markers and transcription factors were most upregulated in MSC population. Further, exploration of gene expression analysis among TNBC and Normal patient-derived MSCs ascertained the role of SQSTM1/P62 and Wnt/β-catenin in TNBC progression. Wnt/β-catenin and Wnt/PCP signaling pathways are prominent contributors of EMT, stemness, and cancer stem cell (CSC) properties of TNBC. SQSTM1/P62 cooperates with the components of the Wnt/PCP signaling pathway and is critically involved at the interface of autophagy and EMT. Moreover, siRNA targeting SQSTM1/P62 and inhibitor of Wnt/β-catenin (FH535) in conjunction was used to explore molecular modification of EMT and stemness markers. Although SQSTM1/P62 is not crucial for cell survival, cytotoxicity assay revealed synergistic interaction between the siRNA/inhibitor. Modulation of these important pathways helped in reduction of expression of genes and proteins contributing to CSC properties. Gene and protein expression analysis revealed the induction of EMT to MET. Moreover, co-treatment resulted in inactivation of non-canonical Wnt VANGL2-JNK signaling axis. The synergistic impact of inhibition of SQSTM1/P62 and Wnt/β-catenin signaling facilitates the development of a potential therapeutic regimen for TNBC.

Interferon-γ inducible protein 30 promotes the epithelial-mesenchymal transition-like phenotype and chemoresistance by activating EGFR/AKT/GSK3β/β-catenin pathway in glioma

AIMS

Previous studies have indicated that IFI30 plays a protective role in human cancers. However, its potential roles in regulating glioma development are not fully understood.

METHODS

Public datasets, immunohistochemistry, and western blotting (WB) were used to evaluate the expression of IFI30 in glioma. The potential functions and mechanisms of IFI30 were examined by public dataset analysis; quantitative real-time PCR; WB; limiting dilution analysis; xenograft tumor assays; CCK-8, colony formation, wound healing, and transwell assays; and immunofluorescence microscopy and flow cytometry.

RESULTS

IFI30 was significantly upregulated in glioma tissues and cell lines compared with corresponding controls, and the expression level of IFI30 was positively associated with tumor grade. Functionally, both in vivo and in vitro evidence showed that IFI30 regulated the migration and invasion of glioma cells. Mechanistically, we found that IFI30 dramatically promoted the epithelial-mesenchymal transition (EMT)-like process by activating the EGFR/AKT/GSK3β/β-catenin pathway. In addition, IFI30 regulated the chemoresistance of glioma cells to temozolomide directly via the expression of the transcription factor Slug, a key regulator of the EMT-like process.

CONCLUSION

The present study suggests that IFI30 is a regulator of the EMT-like phenotype and acts not only as a prognostic marker but also as a potential therapeutic target for temozolomide-resistant glioma.

Activation of Wnt Pathway Suppresses Growth of MUG-Chor1 Chordoma Cell Line

Chordoma as a malignant bone tumor, occurs along the axial skeleton and does not have an effective therapy. Brachyury, which is a crucial player for the formation of early embryonic notochord, is abundantly found in both sporadic and familial chordoma. During embryonic development, Brachyury expression was reported to be regulated by the Wnt pathway. The objective of the study is to investigate the role of Wnt signaling in a human chordoma cell line in terms of proliferation, survival, and invasiveness. We tried to elucidate the signaling events that regulate Chordoma cancer. In this regard, Wnt pathway was activated or inhibited using various strategies including small molecules, siRNA-based knockdown and overexpression applications. The results indicated the negative regulatory effect of Wnt signaling activity on proliferation and migration capacity of the chordoma cells. It was revealed that when GSK3β was inhibited, the Wnt pathway was activated and negatively regulated T/Bra expression. Activity of the Wnt pathway caused cell cycle arrest, reduced migration potential of the cells, and led to cell death. Therefore, the present study suggests that the Wnt pathway plays a key role in suppressing the proliferation and invasive characteristics of human chordoma cells and has a great potential as a therapeutic target in further clinical studies.

γ-Secretase Inhibitor Potentiates the Activity of Suberoylanilide Hydroxamic Acid by Inhibiting Its Ability to Induce Epithelial to Mesenchymal Transition and Stemness via Notch Pathway Activation in Triple-Negative Breast Cancer Cells

Histone deacetylase inhibitors, such as suberoylanilide hydroxamic acid (SAHA), possess great therapeutic value for triple-negative breast cancer patients. However, their inherent ability to induce epithelial to mesenchymal transition in various malignancies has been of greater concern. Herein, we hypothesize that SAHA facilitates epithelial to mesenchymal transition (EMT) via activation of the Notch pathway. From the literature survey, it is evident that histone deacetylase mediates the formation of the co-repressor complex upon interacting with the DNA binding domain, thereby inhibiting the transcription of the Notch downstream genes. Hence, we hypothesize that the use of SAHA facilitates the transcriptional activation of the Notch target genes, by disrupting the co-repressor complex and recruiting the coactivator complex, thereby facilitating EMT. In this study, we have observed that SAHA upregulates the expression profile of the Notch downstream proteins (such as Notch intracellular domain, Hes-1, c-Myc, etc.) and the Notch ligands (such as Jagged-1 and Jagged-2), thereby aberrantly activating the signaling pathway. Therefore, we have focused on combination therapy using a γ-secretase inhibitor LY411575 that would enhance the efficacy of SAHA by blocking the canonical Notch pathway mediated via its intracellular domain. It was observed that co-treatment significantly mediates apoptosis, generates cellular reactive oxygen species, depolarizes mitochondria, and diminishes the stemness properties. Besides, it also mediates autophagy-independent cell death and diminishes the expression of inflammatory cytokines, along with the downregulation in the expression of the Notch downstream genes and mesenchymal markers. Altogether, our study provides a mechanistic basis for combating EMT potentiated by SAHA, which could be utilized as a rational strategy for the treatment of solid tumors, especially triple-negative breast cancer.

An EMT-Related Gene Signature to Predict the Prognosis of Triple-Negative Breast Cancer

INTRODUCTION

Epithelial-mesenchymal transition (EMT) is an important biological process in tumor invasion and metastasis, and thus a potential indicator of the progression and drug resistance of breast cancer. This study comprehensively analyzed EMT-related genes in triple-negative breast cancer (TNBC) to develop an EMT-related prognostic gene signature.

METHODS

With the application of The Cancer Genome Atlas (TCGA) database, Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), and the Genotype-Tissue Expression (GTEx) database, we identified EMT-related signature genes (EMGs) by Cox univariate regression and LASSO regression analysis. Risk scores were calculated and used to divide patients with TNBC into high-risk group and low-risk groups by the median value. Kaplan-Meier (K-M) and receiver operating characteristic (ROC) curve analyses were applied for model validation. Independent prognostic predictors were used to develop nomograms. Then, we assessed the risk model in terms of the immune microenvironment, genetic alteration and DNA methylation effects on prognosis, the probability of response to immunotherapy and chemotherapy, and small molecule drugs predicted by The Connectivity Map (Cmap) database.

RESULTS

Thirteen EMT-related genes with independent prognostic value were identified and used to stratify the patients with TNBC into high- and low-risk groups. The survival analysis revealed that patients in the high-risk group had significantly poorer overall survival than patients in the low-risk group. Populations of immune cells, including CD4 memory resting T cells, CD4 memory activated T cells, and activated dendritic cells, significantly differed between the high- and low-risk groups. Moreover, some therapeutic drugs to which the high-risk group might show sensitivity were identified.

CONCLUSIONS

Our research identified the significant impact of EMGs on prognosis in TNBC, providing new strategies for personalizing TNBC treatment and improving clinical outcomes.

Exploration of epithelial-mesenchymal transition-related lncRNA signature and drug sensitivity in breast cancer

Background

Breast cancer (BRCA) has become the most diagnosed cancer worldwide for female and seriously endanger female health. The epithelial-mesenchymal transition (EMT) process is associated with metastasis and drug resistance in BRCA patients. However, the prognostic value of EMT-related lncRNA in BRCA still needs to be revealed. The aim of this study is to construct an EMT-related lncRNA (ERL) signature with accuracy predictive ability for the prognosis of BRCA patients.

Methods

RNA-seq expression data and Clinical characteristics obtained from the TCGA (The Cancer Genome Atlas) were used in the study. First, we identified the EMT-related lncRNA by the Pearson correlation analysis. An EMT-related lncRNAs prognostic risk signature was constructed using univariate Cox regression and Lasso-penalized Cox regression analyses. The model's performance was validated using Kaplan-Meier (KM) survival analysis, ROC curve and C-index. Finally, a nomogram was constructed for clinical practice in evaluating the patients with BRCA and validated by calibration curve and decision curve analysis (DCA). We also evaluated the drug sensitivity of signature lncRNA and the tumor immune cell infiltration in breast cancer.

Results

We constructed a 10-lncRNA risk score signature based on the lncRNAs associated with the EMT process. We could assign BRCA patients to the high- and low-risk group according to the median risk score. The prognostic risk signature showed excellent accuracy and demonstrated sufficient independence from other clinical characteristics. The immune cell infiltration analysis showed that the prognostic risk signature was related to the infiltration of the immune cell subtype. Drug sensitivity analysis proved ERLs signature could effectively predict the sensitivity of patients to common chemotherapy drugs in BRCA and provide guidance for chemotherapy drugs for high-risk and low-risk patients.

Conclusion

Our ERL signature and nomogram have excellent prognostic value and could become reliable tools for clinical guidance.

A novel cross-communication of HIF-1α and HIF-2α with Wnt signaling in TNBC and influence of hypoxic microenvironment in the formation of an organ-on-chip model of breast cancer

The microenvironment role is very important in cancer development. The epithelial-mesenchymal transition of the cancer cells depends upon specific signaling and microenvironmental conditions, such as hypoxic conditions. The crosstalk between hypoxia and Wnt signaling through some molecular mechanism in TNBC is related. Cross-communication between hypoxia and Wnt signaling in cancer cells is known, but the detailed mechanism in TNBC is unknown. This review includes the role of the hypoxia microenvironment in TNBC and the novel crosstalk of the Wnt signaling and hypoxia. When targeted, the new pathway and crosstalk link may be a solution for metastatic TNBC and chemoresistance. The microenvironment influences cancer's metastasis, which changes from person to person. Therefore, organ-on-a-chip is a very novel model to test the drugs clinically before going for human trials, focusing on personalized medications can be done. The effect of the hypoxia microenvironment on breast cancer stem cells is still unknown. Apart from all the published papers, this paper mainly focuses only on the hypoxic microenvironment and its association with the growth of TNBC. The medicines or small proteins, drugs, mimics, and inhibitors targeting wnt and hypoxia genes are consolidated in this review paper.

Biological functions and molecular interactions of Wnt/β-catenin in breast cancer: Revisiting signaling networks

Changes in lifestyle such as physical activity and eating habits have been one of the main reasons for development of various diseases in modern world, especially cancer. However, role of genetic factors in initiation of cancer cannot be ignored and Wnt/β-catenin signaling is such factor that can affect tumor progression. Breast tumor is the most malignant tumor in females and it causes high mortality and morbidity around the world. The survival and prognosis of patients are not still desirable, although there have been advances in introducing new kinds of therapies and diagnosis. The present review provides an update of Wnt/β-catenin function in breast cancer malignancy. The upregulation of Wnt is commonly observed during progression of breast tumor and confirms that tumor cells are dependent on this pathway Wnt/β-catenin induction prevents apoptosis that is of importance for mediating drug resistance. Furthermore, Wnt/β-catenin signaling induces DNA damage repair in ameliorating radio-resistance. Wnt/β-catenin enhances proliferation and metastasis of breast tumor. Wnt/β-catenin induces EMT and elevates MMP expression. Furthermore, Wnt/β-catenin participates in tumor microenvironment remodeling and due to its tumor-promoting factor, drugs for its suppression have been developed. Different kinds of upstream mediators Wnt/β-catenin signaling in breast cancer have been recognized that their targeting is a therapeutic approach. Finally, Wnt/β-catenin can be considered as a biomarker in clinical trials.

pH-/Redox-Responsive Nanodroplet Combined with Ultrasound-Targeted Microbubble Destruction for the Targeted Treatment of Drug-Resistant Triple Negative Breast Cancer

Multiple drug resistance (MDR) exists in divergent cancers including triple negative breast cancer (TNBC) and partly results in the resistance to many first-line anti-cancer agents, bringing a big challenge to TNBC management. To develop novel TNBC therapeutics, in our study, a hyaluronic acid (HA)-carboxymethyl chitosan (CMC) conjugate linked via a disulfide-bond (HA-SS-CMC, HSC) was synthesized to fabricate nanodroplets (NDs). The NDs encapsulating doxorubicin (DOX) and perfluorohexane (DOX-HSC-NDs) were prepared via a homogenization/emulsification strategy and exhibited not only high biocompatibility but also noticeable tumor cell targeting ability and dual pH/redox responsiveness. Besides, DOX-HSC-NDs can be used as a contrast-enhanced ultrasound imaging agent for specific tumor imaging. DOX-HSC-NDs in combination with ultrasound targeted microbubble destruction could improve intracellular drug aggregation and retention of MDR cells and work against multiple mechanisms of drug resistance through synergistic strategies, including up-regulating the reactive oxygen species (ROS) level, promoting apoptosis, and scavenging glutathione, while reducing the expression levels of P-glycoprotein and inhibiting the epithelial-mesenchymal transition. This combination strategy showed protective effects against TNBC in both MDA-MB-231/ADR cells and tumor-bearing mice. Our study for the first time developed and reported the ultrasound-augmented HSC-NDs as the DOX nanocarrier and provided scientific evidence to support the future application of DOX-HSC-NDs as a potential TNBC therapy.

Inhibition of WNT signaling by conjugated microRNA nano-carriers: A new therapeutic approach for treating triple-negative breast cancer a perspective review

Triple-Negative Breast Cancer is the most aggressive form and accounts the 15%-25% of all breast cancer. Receptors are absent in triple-negative breast cancer, which makes them unresponsive to the current hormonal therapies. The patients with TNBC are left with the option of cytotoxic chemotherapy. The Wnt pathways are connected to cancer, and when activated, they result in mammary hyperplasia and tumors. The tumor suppressor microRNAs can block tumor cell proliferation, invasion, and migration, lead to cancer cell death, and are also known to down-regulate the WNT signaling. Nanoparticles with microRNA have been seen to be more effective when compared with their single release. In this review, we have tried to understand how Wnt signaling plays a crucial role in TNBC, EMT, metastasis, anti-drug resistance, and regulation of Wnt by microRNA. The role of nano-carriers in delivering micro-RNA. The clinical biomarkers, including the present state-of-the-art, involve novel pathways of Wnt.

Multi-targeting TACE/ADAM17 and gamma-secretase of notch signalling pathway in TNBC via drug repurposing approach using Lomitapide

The aberrant expression of the Notch signalling pathway genes aids in potentiating the belligerent characteristics of numerous malignancies. Besides imparting abnormal proliferation and metastasis, the Notch also aids in the metabolic reprogramming of tumor cells. Since the activation of the Notch pathway is mediated via TACE/ADAM protease and the γ-secretase complex, hence it is crucial in determining a multi-targeted therapeutic approach to target these major proteases to downregulate the aberrant Notch signalling pathway. In this study, Lomitapide was chosen based on its binding score (-305.108 kJ/mol and - 173.174 kJ/mol) against the crucial proteases, TACE and γ-secretase, respectively. Further, the remarkable antitumor properties of Lomitapide were established on the TNBC cell lines (MDA-MB-231 and MDA-MB-468), along with the EMT-induced MDA-MB-468 cells. Apart from inducing ∼2 to 2.5-fold increase in the cellular ROS levels, Lomitapide treatment induced significant apoptosis, arrested cell cycle progression and reduced sphere and colony forming abilities of the TNBC cells. Differentiated epithelial phenotype with diminished CD44-stem cell marker was also observed upon treatment. Furthermore, reduction of migration potential, decrease in the gene expression profile of the EMT markers, along with downregulation of the Notch signalling genes were evident in the treated TNBC cells. Altogether, the present study attributes the repurposing of Lomitapide as an effective therapeutic agent against the major proteases of the Notch pathway to combat TNBC progression and dissemination.

PLAGL2 increases adriamycin resistance and EMT in breast cancer cells by activating the Wnt pathway

BACKGROUND

Adriamycin (ADR) is an effective treatment for breast cancer; nevertheless, it is often linked with acquired resistance in breast cancer cells, reducing ADR's therapeutic efficacy and increasing the risk of recurrence and poor prognosis. It has been revealed that the zinc-finger transcription factor pleomorphic adenoma gene like-2 (PLAGL2) is required for epithelial to mesenchymal transition (EMT) in cancer cells. Recent data indicates that PLAGL2 is also involved in regulating chemotherapeutic drug resistance, albeit the exact mechanism by which this happens remains unknown.

OBJECTIVE

This study examines the effect of PLAGL2 on adriamycin resistance and EMT in breast cancer cells.

METHODS

The small interfering RNA (siRNA) targeting PLAGL2 was transfected to breast cancer cells to alter PLAGL2 expression. Cell counting kit-8 (CCK-8) and colony formation assay detected cell growth and proliferation rate. Moreover, wound-healing and transwell assays were conducted to evaluate migration and invasion. Western blot (WB) checked the apoptosis and EMT-associated proteins.

RESULTS

PLAGL2 expression is associated with breast cancer cells' acquired resistance to ADR in this investigation. Additionally, deletion of PLAGL2 was associated with enhanced sensitivity to ADR, reduced proliferation, migration, and invasion capabilities, increased E-cadherin levels, and reduced Wnt6, β-catenin, and DVL1 levels in ADR-resistant breast cancer cells (MCF-7/ADR and MDA-MB-231/ADR cells). PLAGL2 could bind to the promoter region of Wnt6 and promote its expression. Additionally, the results of this research established that Wnt signaling is implicated in breast cancer cells' resistance to ADR since BML-284, a Wnt signaling activator partly restored the sensitivity of MCF-7/ADR and MDA-MB-231/ADR cells to ADR.

CONCLUSION

PLAGL2 promotes adriamycin resistance and cell aggressiveness in breast cancer cells via activating the Wnt signaling pathway.

ADAM12 promotes gemcitabine resistance by activating EGFR signaling pathway and induces EMT in bladder cancer

BACKGROUND

Gemcitabine (GEM)-based chemotherapy regimens is widely used in bladder cancer (BC) patients. However, GEM resistance may occur and result in treatment failure and disease progression. A disintegrin and metalloprotease 12 (ADAM12) plays a critical role in many cancers. However, the role of ADAM12 in GEM resistance of BC remains unclear.

METHODS

We analyzed the relationship between ADAM12 expression and tumor characteristics using the data downloaded from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. Then, we established GEM resistant BC cell lines and used quantitative real-time PCR, western blot, cell counting kit-8, immunohistochemistry, and xenograft mouse model to investigate the role of ADAM12 in GEM resistance.

RESULTS

In general, ADAM12 was found to be upregulated in GEM resistant BC cells. ADAM12 knockdown increased the chemosensitivity of BC cells. We further proved that ADAM12 could promote GEM resistance by activating the epidermal growth factor receptor (EGFR) signaling pathway in BC. Furthermore, the epithelial-mesenchymal transition (EMT) phenotype was observed in GEM resistant BC cells. ADAM12 induced EMT process and promotes tumor progression in BC.

CONCLUSION

Our findings suggested that ADAM12 was a key gene for GEM resistance and positively correlated with malignancy of BC. It might serve as a novel and valuable therapeutic target for BC.

Dimeric-(-)-epigallocatechin-3-gallate inhibits the proliferation of lung cancer cells by inhibiting the EGFR signaling pathway

Non-small cell lung cancer (NSCLC) is one of the most general malignant tumors. The overexpression of epidermal growth factor receptor (EGFR) is a common marker in NSCLC, and it plays an important role in the proliferation, invasion, and metastasis of cancer cells. At present, drugs developed with EGFR as a target suffer from drug resistance, so it is necessary to study new compounds for the treatment of NSCLC. The active substance in green tea is EGCG, which has anti-cancer effects. In this study, we synthesized dimeric-(-)-epigallocatechin-3-gallate (prodelphinidin B-4-3,3‴-di-O-gallate, PBOG), and explored the effect of PBOG on lung cancer cells. PBOG can inhibit the proliferation and migration of NCI-H1975 cells, promote cell apoptosis, and inhibit cell cycle progression. In addition, PBOG can bind to the EGFR ectodomain protein and change the secondary structure of the protein. At the same time, PBOG decreases the expression of EGFR and downstream protein phosphorylation. Animal experiments confirmed that PBOG can inhibit tumor growth by inhibiting EGFR phosphorylation. Collectively, our study results show that PBOG may induce a decrease in intracellular phosphorylated EGFR expression by binding to the EGFR ectodomain protein, thereby inducing apoptosis and inhibiting cell cycle progression, thus providing a new strategy to treat lung cancer.

Targeting regulated cell death (RCD) with small-molecule compounds in triple-negative breast cancer: a revisited perspective from molecular mechanisms to targeted therapies

Triple-negative breast cancer (TNBC) is a subtype of human breast cancer with one of the worst prognoses, with no targeted therapeutic strategies currently available. Regulated cell death (RCD), also known as programmed cell death (PCD), has been widely reported to have numerous links to the progression and therapy of many types of human cancer. Of note, RCD can be divided into numerous different subroutines, including autophagy-dependent cell death, apoptosis, mitotic catastrophe, necroptosis, ferroptosis, pyroptosis and anoikis. More recently, targeting the subroutines of RCD with small-molecule compounds has been emerging as a promising therapeutic strategy, which has rapidly progressed in the treatment of TNBC. Therefore, in this review, we focus on summarizing the molecular mechanisms of the above-mentioned seven major RCD subroutines related to TNBC and the latest progress of small-molecule compounds targeting different RCD subroutines. Moreover, we further discuss the combined strategies of one drug (e.g., narciclasine) or more drugs (e.g., torin-1 combined with chloroquine) to achieve the therapeutic potential on TNBC by regulating RCD subroutines. More importantly, we demonstrate several small-molecule compounds (e.g., ONC201 and NCT03733119) by targeting the subroutines of RCD in TNBC clinical trials. Taken together, these findings will provide a clue on illuminating more actionable low-hanging-fruit druggable targets and candidate small-molecule drugs for potential RCD-related TNBC therapies.

Multi-targeted drug repurposing approach for breast cancer via integrated functional network analysis

The present study focuses on the interconnected functional network of altered metabolism and EMT (epithelial to mesenchymal transition) signaling in breast cancer. We have interlinked the metabolic and EMT signaling circuits and selected Insulin receptor (IR), Integrin beta 1 (ITGB1), and CD36 as target proteins based on network analysis. Extensive computational approaches discerned the potential drug molecules from the library of 1293 FDA-approved drugs to block all three target proteins. Using molecular docking, molecular dynamics simulation, and MMPBSA binding free energy studies, Capmatinib, Ponatinib, Naldemedine, and Pimozide were identified as potential repurposed drugs to block the function of all three target proteins. Among in silico selected candidate drugs, Pimozide, a known anti-psychotic drug, was further validated using in-vitro studies for its anti-cell proliferative potential on breast cancer cell lines (namely, MCF7, MDAMB231 and MDAMB468). The inhibitory concentration (IC50) values of MCF7, MDAMB231 and MDAMB468 was found to be 16.26 µM, 20.82 µM and 13.10 µM, respectively. The effect of Pimozide on EMT-induced MDAMB231 and MDAMB468 cells was evident from their IC50 values of 7.85 µM and 6.83 µM, respectively. The potent anti-cancer property of Pimozide has opened up avenues for drug repurposing towards 'multi-targeted therapy' in EMT dynamics.

Mediterranean Diet Food Components as Possible Adjuvant Therapies to Counteract Breast and Prostate Cancer Progression to Bone Metastasis

Bone metastasis is a serious and often lethal complication of particularly frequent carcinomas, such as breast and prostate cancers, which not only reduces survival but also worsens the patients’ quality of life. Therefore, it is important to find new and/or additional therapeutic possibilities that can counteract the colonization of bone tissue. High adherence to the Mediterranean diet (MD) is effective in the prevention of cancer and improves cancer patients’ health, thus, here, we considered its impact on bone metastasis. We highlighted some molecular events relevant for the development of a metastatic phenotype in cancer cells and the alterations of physiological bone remodeling, which occur during skeleton colonization. We then considered those natural compounds present in MD foods with a recognized role to inhibit or reverse the metastatic process both in in vivo and in vitro systems, and we reported the identified mechanisms of action. The knowledge of this bioactivity by the dietary components of the MD, together with its wide access to all people, could help not only to maintain healthy status but also to improve the quality of life of patients with bone metastases.

Transcriptome Profile Analysis of Triple-Negative Breast Cancer Cells in Response to a Novel Cytostatic Tetrahydroisoquinoline Compared to Paclitaxel

The absence of chemotherapeutic target hormone receptors in breast cancer is descriptive of the commonly known triple-negative breast cancer (TNBC) subtype. TNBC remains one of the most aggressive invasive breast cancers, with the highest mortality rates in African American women. Therefore, new drug therapies are continually being explored. Microtubule-targeting agents such as paclitaxel (Taxol) interfere with microtubules dynamics, induce mitotic arrest, and remain a first-in-class adjunct drug to treat TNBC. Recently, we synthesized a series of small molecules of substituted tetrahydroisoquinolines (THIQs). The lead compound of this series, with the most potent cytostatic effect, was identified as 4-Ethyl-N-(7-hydroxy-3,4-dihydroisoquinolin-2(1H)-yl) benzamide (GM-4-53). In our previous work, GM-4-53 was similar to paclitaxel in its capacity to completely abrogate cell cycle in MDA-MB-231 TNBC cells, with the former not impairing tubulin depolymerization. Given that GM-4-53 is a cytostatic agent, and little is known about its mechanism of action, here, we elucidate differences and similarities to paclitaxel by evaluating whole-transcriptome microarray data in MDA-MB-231 cells. The data obtained show that both drugs were cytostatic at non-toxic concentrations and caused deformed morphological cytoskeletal enlargement in 2D cultures. In 3D cultures, the data show greater core penetration, observed by GM-4-53, than paclitaxel. In concentrations where the drugs entirely blocked the cell cycle, the transcriptome profile of the 48,226 genes analyzed (selection criteria: (p-value, FDR p-value < 0.05, fold change −2< and >2)), paclitaxel evoked 153 differentially expressed genes (DEGs), GM-4-53 evoked 243 DEGs, and, of these changes, 52/153 paclitaxel DEGs were also observed by GM-4-53, constituting a 34% overlap. The 52 DEGS analysis by String database indicates that these changes involve transcripts that influence microtubule spindle formation, chromosome segregation, mitosis/cell cycle, and transforming growth factor-β (TGF-β) signaling. Of interest, both drugs effectively downregulated “inhibitor of DNA binding, dominant negative helix-loop-helix” (ID) transcripts; ID1, ID3 and ID4, and amphiregulin (AREG) and epiregulin (EREG) transcripts, which play a formidable role in cell division. Given the efficient solubility of GM-4-53, its low molecular weight (MW; 296), and capacity to penetrate a small solid tumor mass and effectively block the cell cycle, this drug may have future therapeutic value in treating TNBC or other cancers. Future studies will be required to evaluate this drug in preclinical models.

Transferrin Coated d-penicillamine-Au-Cu Nanocluster PLGA Nanocomposite Reverses Hypoxia-Induced EMT and MDR of Triple-Negative Breast Cancers

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, lacks effective targeted therapies due to negative expression of the targetable bioreceptors. Additionally, hypoxic condition in solid tumors contributes to the epithelial to mesenchymal transition (EMT), which aggravates cancer progression, multidrug resistance (MDR), migration, and stemness of the TNBC. A therapeutic module has been established in this regard by coating PLGA nanoparticle with d-penicillamine templated Au-Cu bimetallic nanoclusters. Further, the resultant nanomaterials were coated with recombinant transferrin protein to specifically target transferrin receptor overexpressing TNBC. The synthesized nanocomposites showed strong orange emission band at 630 nm with fluorescence quantum yield of 2%, rendering it suitable for theranostic applications. Experimental results demonstrated efficient cellular internalization and significant innate anti-cell proliferative potential of the nanocomposites. The fabricated nanocomposites were also able to induce cell death in spheroids, which was confirmed by live/dead dual staining results. Furthermore, when EMT-induced TNBC cells were treated with nanocomposites, they generated reactive oxygen species (ROS), depolarized the mitochondrial membrane potential, and induced apoptosis. Gene expression by real-time PCR indicated that treatment of EMT-induced TNBC cells with nanocomposites facilitated mesenchymal to epithelial transition (MET). In MDA-MB-468 cells, treatment with nanocomposites resulted in a 1.35-fold rise in E-cadherin an epithelial marker and a 1.36-fold decrease in vimentin a mesenchymal marker. Similarly, 2.87-fold and 1.76-fold decrease in stemness markers ALDH1A3 and EpCAM were observed in MDA-MB-231. Furthermore, 4.63-fold decrease in expression of ABCC1, a prominent contributor of MDR, was observed in MDA-MB-231. Protein expression studies revealed that nanocomposites reduced p-STAT-3 by 1.61-fold in MDA-MB-231 and by 7.8-fold in MDA-MB-468. Importantly, nanocomposites downregulated the expression of β-catenin by 3-fold in MDA-MB-231 and by 3.11-fold in MDA-MB-468. Downregulation of EMT with concomitant alteration of STAT-3 and β-catenin signaling pathways led to reduced migration ability of the TNBC cells.

PEG-poly(amino acid)s/EpCAM aptamer multifunctional nanoparticles arrest the growth and metastasis of colorectal cancer

Tanshinone II-A (TSIIA) is a derivative of a phenanthrene-quinone extracted from a TCM herb, Salvia miltiorrhiza, and has been widely adopted in the treatment of colorectal cancer (CRC). It is known that TSIIA can lead to the apoptosis and differentiation of certain cell lines and it suppresses the proliferation and metastasis of tumors. However, its poor water solubility and low bioavailability when taken orally have prevented this drug being utilized effectively in the body. A nanoparticle (NP) drug carrier system is a technology that can effectively improve drug utilization and targeting ability. In this study, a new NP drug carrier system is reported: EpCAM targeting TSIIA-encapsulated poly(amino acid)s NPs (EpCAM-TSIIA-NPs). The results show that this new targeted NP drug carrier system has higher cytotoxicity, better water solubility and better targeting ability, and can effectively suppress the proliferation and metastasis of tumors. In addition, the invasion and metastasis mechanism of colorectal cancer (CRC) under β-catenin nuclear meditation suppressed by EpCAM-TSIIA-NPs is also discussed. It is found that the immune-targeted type EpCAM-TSIIA-NPs could effectively enhance the expression of APC and axin when compared to normal NPs. It could improve the stability of β-catenin destruction complex and suppress the occurrence and progression of tumors by stopping the nuclear activities of β-catenin.

Resveratrol and Its Analogs: Potent Agents to Reverse Epithelial-to-Mesenchymal Transition in Tumors

Epithelial-to-mesenchymal transition (EMT), a complicated program through which polarized epithelial cells acquire motile mesothelial traits, is regulated by tumor microenvironment. EMT is involved in tumor progression, invasion and metastasis via reconstructing the cytoskeleton and degrading the tumor basement membrane. Accumulating evidence shows that resveratrol, as a non-flavonoid polyphenol, can reverse EMT and inhibit invasion and migration of human tumors via diverse mechanisms and signaling pathways. In the present review, we will summarize the detailed mechanisms and pathways by which resveratrol and its analogs (e.g. Triacetyl resveratrol, 3,5,4'-Trimethoxystilbene) might regulate the EMT process in cancer cells to better understand their potential as novel anti-tumor agents. Resveratrol can also reverse chemoresistance via EMT inhibition and improvement of the antiproliferative effects of conventional treatments. Therefore, resveratrol and its analogs have the potential to become novel adjunctive agents to inhibit cancer metastasis, which might be partly related to their blocking of the EMT process.