Treatment Of Triple-negative Breast Cancer Research Articles

Scutellaria barbata D.Don and Scleromitrion diffusum (Willd.) R.J.Wang inhibits the progression of triple negative breast cancer though the activation inhibition of NF-κB triggered by CAFs-derived IL6

Ethnopharmacological relevanceThe treatment options for triple-negative breast cancer (TNBC) are limited. Traditional Chinese Medicine (TCM) plays an important role in the treatment of TNBC. The herb pair Scutellaria barbata D.Don and Scleromitrion diffusum (Willd.) R.J.Wang (SH) is commonly used in clinical practice for its anti-tumor properties. It has been proven to have good therapeutic effects on tumor-related diseases, but the underlying molecular mechanisms are not yet fully explained. Aim of studyThrough bioinformatics, it was validated that IL6, primarily derived from cancer-associated fibroblasts (CAFs), is associated with poor prognosis. Additionally, cell and animal experiments confirmed that SH inhibits tumor proliferation, migration, and growth in an orthotopic tumor model by suppressing the IL6/NF-κB pathway. Materials and methodsGEO, TCGA and HPA databases were used to analyze the prognostic value of CAFs and IL6, then IL6 resource was detected. After the bioinformatics, the influence of CAFs and CAFs-derived IL6 on TNBC was verified by experiments both in vitro and in vivo. Cell clone formation assay, wound-Healing assay, and Transwell assay were used to detect the promotion of CAFs and CAFs-derived IL6 and the inhibition of SH in vitro. TNBC model in mice was used to prove the promotion of CAFs and CAFs-derived IL6 and the inhibition of SH in vivo. The biological pathway of NF-κB was explored by western blotting through detecting unique molecules. ResultsBioinformatics analysis revealed that higher proportion of CAFs and elevated level of IL6 were significantly associated with poor prognosis in TNBC. At the same time, IL6 was proved predominantly derived from CAFs. After the indication of bioinformatics, experiments in vitro demonstrated that both CAFs and IL6 could enhance the clone formation and migration ability of MDA-MD-231 cells (231), furthermore, the promotion of CAFs was related with the level of IL6. Based on these data, mechanism was detected that CAFs-derived IL6 enhancement was closely related to the activation of NF-κB signaling pathway, while the activation can be reduced by SH. In the end, the promotion of CAFs/CAFs-derived IL6/NF-κB and the efficacy of SH inhibition were both confirmed by experiments in vivo. ConclusionsBioinformatics data indicates that higher proportion of CAFs and higher level of CAFs-derived IL6 are significantly related to poorer survival of TNBC. CAFs and CAFs-derived IL6 were proved to promote the progression of TNBC both in vitro and in vivo, and the process of which was significantly related to the activation of NF-κB. SH inhibited the progress of TNBC, which was proved to be closely related to CAFs/CAFs-derived IL6/NF-κB.

Cannabinoids and triple-negative breast cancer treatment.

Triple-negative breast cancer (TNBC) accounts for about 10-20% of all breast cancer cases and is associated with an unfavorable prognosis. Until recently, treatment options for TNBC were limited to chemotherapy. A new successful systemic treatment is immunotherapy with immune checkpoint inhibitors, but new tumor-specific biomarkers are needed to improve patient outcomes. Cannabinoids show antitumor activity in most preclinical studies in TNBC models and do not appear to have adverse effects on chemotherapy. Clinical data are needed to evaluate efficacy and safety in humans. Importantly, the endocannabinoid system is linked to the immune system and immunosuppression. Therefore, cannabinoid receptors could be a potential biomarker for immune checkpoint inhibitor therapy or a novel mechanism to reverse resistance to immunotherapy. In this article, we provide an overview of the currently available information on how cannabinoids may influence standard therapy in TNBC.

A Bioinformatic Strategy for Investigating the Mechanism of Hispolon in the Treatment of Triple-Negative Breast Cancer Combined with In vitro Experiments.

Hispolon, a phenolic compound isolated from the medicinal yellow fungal mulberry, exhibits a strong anti-triple-negative breast cancer (TNBC) effect. However, the antitumor mechanisms of Hispolon have not been fully explored. In this study, we systematically investigated the mechanism of Hispolon against TNBC based on bioinformatics and in vitro experiments. The Hispolon-related targets were first collected from the SwissTarget database. Differential Expression Genes (DEG) were screened between TNBC and normal breast tissue using the Gene Expression Comprehensive (GEO) dataset. The overlapping targets between Hispolon and DEG were analyzed by plotting Venn maps. Protein-protein interaction (PPI) network was constructed to analyze the interactions among these targets. The focus was on mining the core targets of anti-TNBC effects of Hispolon via the Cytohubba and MCODE plugin of Cytoscape 3.7.2 software. We performed survival analysis on these core targets to screen the best-matched targets, including EGFR, KIT, and PLAU. This correlated strongly with our validation of Hispolon by molecular docking. In addition, Gene Ontology (GO) anal-ysis and KEGG pathway analysis were performed using R software (ClusterProfiler package). Finally, in vitro experiments were performed to assess the accuracy of predicted target genes. The ADME results suggested that Hispolon has great potential to develop into a drug. Twenty overlapping targets were screened by matching the 107 targets of Hispolon to the 2,013 targets of TNBC DEG. Seven core targets of Hispolon against TNBC were initially identified, including EGFR, IGFBP3, MMP9, MMP2, MMP1, PLAU, and KIT. GO enrich-ment analysis demonstrated that the biological process of Hispolon acting on TNBC mainly involves lymphocyte activation in immune response and phosphatidylinositol-mediated signal-ing. Additionally, the relaxin signaling pathway, estrogen signaling pathway, proteoglycans in cancer, and others might be the key pathways of Hispolon against TNBC. Furthermore, Hispo-lon inhibited the proliferation of MDA-MB-231 cells in a concentration-dependent manner and regulated the RNA and protein expression of the core targets EGFR, PLAU, and KIT for the treatment of TNBC. In this study, the polygenic pharmacological mechanism of action of Hispolon against TNBC was explored through network pharmacology and in vitro experiments, provid-ing a new insight into the mechanism of TCM monomer against TNBC.

Photo-Activated Oxidative Stress Amplifier: A Strategy for Targeting Glutathione Metabolism and Enhancing ROS-Mediated Therapy in Triple-Negative Breast Cancer Treatment.

Amplifying oxidative stress within tumor cells can effectively inhibit the growth and metastasis of triple-negative breast cancer (TNBC). Therefore, the development of innovative nanomedicines that can effectively disrupt the redox balance represents a promising yet challenging therapeutic strategy for TNBC. In this study, an oxidative stress amplifier, denoted as PBCH, comprising PdAg mesoporous nanozyme and a CaP mineralized layer, loaded with GSH inhibitor L-buthionine sulfoximine (BSO), and further surface-modified with hyaluronic acid that can target CD44, is introduced. In the acidic tumor microenvironment, Ca2+ is initially released, thereby leading to mitochondrial dysfunction and eventually triggering apoptosis. Additionally, BSO suppresses the synthesis of intracellular reduced GSH and further amplifies the level of oxidative stress in cancer cells. Furthermore, PdAg nanozyme can be activated by near-infrared light to induce photothermal and photodynamic effects, causing a burst of ROS and simultaneously promoting cell apoptosis via provoking immunogenic cell death. The high-performance therapeutic effects of PBCH, based on the synergistic effect of aforementioned multiple oxidative damage and photothermal ablation, are validated in TNBC cells and animal models, declaring its potential as a safe and effective anti-tumor agent. The proposed approach offers new perspectives for precise and efficient treatment of TNBC.

Recent Advances in Immunotherapy for Breast Cancer: A Review.

Breast cancer is one of the most common malignant tumors in women in the world, and its incidence is increasing year by year, which seriously threatens the physical and mental health of women. Triple negative breast cancer (TNBC) is a special molecular type of breast cancer in which estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 are negative. Compared with other molecular types of breast cancer, triple-negative breast cancer (TNBC) has high aggressiveness and metastasis, high recurrence rate, lack of effective therapeutic targets, and usually poor clinical treatment effect. Chemotherapy was the main therapeutic means used in the past. With the advent of the immune era, immunotherapy has made a lot of progress in the treatment of triple-negative breast cancer (TNBC), bringing new therapeutic hope for the treatment of triple-negative breast cancer. This review combines the results of cutting-edge medical research, mainly summarizes the research progress of immunotherapy, and summarizes the main treatment methods of triple-negative breast cancer (TNBC) immunotherapy, including immune checkpoint inhibitors, tumor vaccines, adoptive immunotherapy and the application of traditional Chinese and western medicine. It provides a new idea for the treatment of triple negative breast cancer (TNBC).

FOXO4 suppresses cisplatin resistance of triple-negative breast cancer by inhibiting autophagy

BackgroundResistance to chemotherapy containing cisplatin (DDP) is a main challenge in the treatment of triple-negative breast cancer (TNBC). Forkhead box O4 (FOXO4) is frequently downregulated in DDP-resistant cells. However, it is unclear whether FOXO4 down-regulation is related to DDP resistance. Here, we investigated the relationship between FOXO4 and DDP resistance in TNBC. MethodsWe established the DDP-resistant cell lines MDA-MB-231/DDP and BT-549/DDP through in vitro selection. CCK-8 and colony formation assays analyzed cell growth. The resistance index was calculated. Cell autophagy was evaluated. Western blotting and qRT-PCR measured protein and gene expression. The binding between FOXO4 and TGF-β1 was determined by the dual-luciferase reporter assay. ResultsFOXO4 expression was significantly lower in MDA-MB-231/DDP and BT-549/DDP cells. FOXO4 overexpression increased the sensitivity of TNBC cells to DDP. The PI3K class Ⅲ and Beclin-1 levels and LC3-II/LC3-I ratio elevated significantly in DDP-resistant cells. Moreover, the autophagic flux was enhanced in DDP-resistant cells. 3-MA enhanced the sensitivity of TNBC cells to DDP by inhibiting autophagy. Overexpression of FOXO4, treatment with 3-MA, and their combination significantly reduced the drug resistance index. FOXO4 directly targeted TGF-β1. Additionally, TGF-β1 knockdown inhibited autophagy and restored the sensitivity of DDP-resistant cells to DDP. Mechanistically, FOXO4 affected TNBC resistance to DDP by regulating autophagy and TGF-β1. ConclusionFOXO4 overexpression, in combination with autophagy inhibitors, can significantly improve the sensitivity of TNBC-resistant cells to DDP. These findings reveal the role and mechanism of FOXO4 in DDP sensitivity and may provide evidence for the development of TNBC therapies.

Opportunities and Challenges in the Development of Antibody-Drug Conjugate for Triple-Negative Breast Cancer: The Diverse Choices and Changing Needs.

Triple-negative breast cancer (TNBC) is a highly heterogeneous breast cancer subtype, which is also characterized by the aggressive phenotype, high recurrence rate, and poor prognosis. Antibody-drug conjugate (ADC) is a monoclonal antibody with a cytotoxic payload connected by a linker. ADC is gaining more and more attention as a targeted anti-cancer agent. Clinical studies of emerging ADC drugs such as sacituzumab govitecan and trastuzumab deruxtecan in patients with metastatic breast cancer (including TNBC) are progressing rapidly. In view of its excellent clinical efficacy and good tolerability, Sacituzumab govitecan gained accelerated approval by the FDA for the treatment of advanced metastatic TNBC in 2020. This review discusses the treatment status and challenges in TNBC, with an emphasis on the current status of ADC development and clinical trials in TNBC and metastatic breast cancer. We also summarize the clinical experience and future exploration directions of ADC development for TNBC patients.

Enhanced expression of galectin-9 in triple negative breast cancer cells following radiotherapy: Implications for targeted therapy.

Optimizations are expected in the development of immunotherapy for the treatment of Triple-negative breast cancer (TNBC). We studied the expression of galectin-9 (Gal-9) after irradiation and assessed the differential impacts of its targeting with or without radiotherapy. Tumor resections from TNBC patients who received neoadjuvant radiotherapy revealed higher levels of Gal-9 in comparison to their baseline level, only in non-responder patients. Gal-9 expression was also found to be increased in TNBC tumor biopsies and cell lines after irradiation. We investigated the therapeutic advantage of targeting Gal-9 after radiotherapy in mice. Irradiated 4T1 cells or control non-irradiated 4T1 cells were injected into BALB/c mice. Anti-Gal-9 antibody treatment decreased tumor progression only in mice injected with irradiated 4T1 cells. This proof-of-concept study demonstrates that Gal-9 could be considered as a dynamic biomarker after radiotherapy for TNBC and suggests that Gal-9 induced-overexpression could represent an opportunity to develop new therapeutic strategies for TNBC patients.

Aptamer-functionalized triptolide with release controllability as a promising targeted therapy against triple-negative breast cancer

Targeted delivery and precise release of toxins is a prospective strategy for the treatment of triple-negative breast cancer (TNBC), yet the flexibility to incorporate both properties simultaneously remains tremendously challenging in the X-drug conjugate fields. As critical components in conjugates, linkers could flourish in achieving optimal functionalities. Here, we pioneered a pH-hypersensitive tumor-targeting aptamer AS1411-triptolide conjugate (AS-TP) to achieve smart release of the toxin and targeted therapy against TNBC. The multifunctional acetal ester linker in the AS-TP site-specifically blocked triptolide toxicity, quantitatively sustained aptamer targeting, and ensured the circulating stability. Furthermore, the aptamer modification endowed triptolide with favorable water solubility and bioavailability and facilitated endocytosis of conjugated triptolide by TNBC cells in a nucleolin-dependent manner. The integrated superiorities of AS-TP promoted the preferential intra-tumor triptolide accumulation in xenografted TNBC mice and triggered the in-situ triptolide release in the weakly acidic tumor microenvironment, manifesting striking anti-TNBC efficacy and virtually eliminated toxic effects beyond clinical drugs. This study illustrated the therapeutic potential of AS-TP against TNBC and proposed a promising concept for the development of nucleic acid-based targeted anticancer drugs.

Self-Oxygenated Hydrogel Enhances Immune Cell Response and Infiltration Via Triggering Dual DNA Damage to Activate cGAS-STING and Inhibiting CAFs.

Immune checkpoint inhibitors (ICIs) offer promise in breaking through the treatment and survival dilemma of triple-negative breast cancer (TNBC), yet only immunomodulatory subtype and ≈5% TNBC patients respond as monotherapy due to lack of effector immune cells (internal problem) and physical barrier (external limitation) formed by cancer-associated fibroblasts (CAFs). A hydrogel drug-delivery platform, ALG@TBP-2/Pt(0)/nintedanib (ALG@TPN), is designed to induce strong immune functions and the dual elimination of the internal and external tumor microenvironment (TME). Activated by white light, through type I and II photodynamic therapy (PDT), TBP-2 generates large amounts of reactive oxygen species (ROS) intracellularly, oxidizing mitochondrial DNA (mtDNA). The unique catalase activity of Pt(0) converts endogenous H2O2 to O2, reducing the anoxia-limiting PDT and enhancing ROS generation efficacy. Abundant ROS can oxidize Pt(0) to cytotoxic Pt(II), damaging the nuclear DNA (nDNA). Dual damage to mtDNA and nDNA might bi-directionally activate the cGAS/STING pathway and enhance the immune cell response. Besides, nintedanib demonstrates a significant inhibitory effect on CAFs, weakening the immune barrier and deepening immune cell infiltration. Overall, the study provides a self-oxygenating hydrogel with the "PDT/chemotherapy/anti-CAFs" effect, triggering the cGAS/STING pathway to reshape the TME. Both internal and external interventions increase anti-TNBC immune responses.

Cost-effectiveness of Pembrolizumab in Combination with Chemotherapy as Neoadjuvant Treatment and Continued as a Single Agent Adjuvant Treatment for High-Risk Early-Stage Triple-Negative Breast Cancer in Hong Kong.

The phaseIII randomized KEYNOTE-522 trial demonstrated that pembrolizumab in combination with chemotherapy as neoadjuvant treatment followed by adjuvant pembrolizumab (pembrolizumab + chemotherapy) provided significant improvements in event-free survival (EFS) and overall survival (OS) for patients with high-risk early-stage triple-negative breast cancer (eTNBC). The objective was to assess the cost-effectiveness of pembrolizumab + chemotherapy compared to neoadjuvant chemotherapy alone (chemotherapy) in patients with high-risk eTNBC from a Hong Kong third-party payer perspective. A multistate transition model with four health states (event-free), locoregional recurrence, distant metastases, and death) was developed to assess the lifetime medical costs and health outcomes (3% annual discount), along with incremental cost-effectiveness ratios (ICERs) using efficacy and safety data from the KEYNOTE-522 trial. The health state utilities were derived from KEYNOTE-522 Euro-QoL-five-dimension five-level questionnaire (EQ-5D-5L) data. Costs were expressed in 2022 Hong Kong dollars (HKD).Scenario and sensitivity analyses were performed to assess the robustness of results. Over a 32-year time horizon, base case results showed that pembrolizumab + chemotherapy was associated with a 3.42year longer EFS and expected gains of 3.05 lifeyears (LYs) and 2.45 quality-adjusted lifeyears (QALYs) compared to chemotherapy. The resultant ICERs were HKD135,200 per QALY gained and HKD108,463 per LY gained, which were lower than the World Health Organization (WHO) cost-effectiveness threshold of three times gross domestic product (GDP) per capita for Hong Kong of HKD1,171,308 per QALY. The one-way sensitivity analyses (OWSA) and probabilistic sensitivity analysis (PSA) showed the results were robust across various inputs and alternative scenarios. On the basis of the analysis conducted for a 56-year-old cohort with high-risk eTNBC and assumptions in the model, pembrolizumab + chemotherapy represents a cost-effective proposition (as the ICER is approximately 35% of the GDP per capita in Hong Kong) for patients with high-risk eTNBC in Hong Kong.

Ivermectin Synergizes with Modulated Electro-hyperthermia and Improves Its Anticancer Effects in a Triple-Negative Breast Cancer Mouse Model.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, with limited treatment options. Modulated electro-hyperthermia (mEHT) is a novel adjuvant cancer therapy that induces selective cancer damage. However, mEHT upregulates heat shock protein beta 1 (HSPB1), a cancer-promoting stress chaperone molecule. Thus, we investigated whether ivermectin (IVM), an anthelmintic drug, may synergize with mEHT and enhance its anticancer effects by inhibiting HSPB1 phosphorylation. Isogenic 4T1 TNBC cells were inoculated into BALB/c mice and treated with mEHT, IVM, or a combination of both. IVM synergistically improved the tumor growth inhibition achieved by mEHT. Moreover, IVM downregulated mEHT-induced HSPB1 phosphorylation. Thus, the strongest cancer tissue damage was observed in the mEHT + IVM-treated tumors, coupled with the strongest apoptosis induction and proliferation inhibition. In addition, there was no significant body weight loss in mice treated with mEHT and IVM, indicating that this combination was well-tolerated. In conclusion, mEHT combined with IVM is a new, effective, and safe option for the treatment of TNBC.

Eurochevalierines A-I, Sesquiterpene Alkaloid Hybrids with Anti-Triple Negative Breast Cancer Activity from Penicillium sp. HZ-5.

Nine new sesquiterpene alkaloids, eurochevalierines A-I (1-9), were separated from the rice cultures of the endophytic fungus Penicillium sp. HZ-5 originated from the fresh leaf of Hypericum wilsonii N. Robson. The structures' illumination was conducted by single-crystal X-ray diffraction, extensive spectroscopic analysis, alkaline hydrolysis reaction, and Snatzke's method. Importantly, the antitumor activities screen of these isolates indicated that 1 could suppress triple negative breast cancer (TNBC) cell proliferation and induce apoptosis, with an IC50 value of 5.4 μM, which is comparable to the positive control docetaxel (DXT). Flow cytometry experiments mentioned that compound 1 significantly reduced mitochondrial membrane potential (MMP) of TNBC cells. In addition, 1 could activate caspase-3 and elevated the levels of reactive oxygen species (ROS) and expressions of suppressive cytokines and chemokines. Further Western blot analysis showed that 1 could selectively induce mitochondria-dependent apoptosis in TNBC cells via the BAX/BCL-2 pathway. Remarkably, these finding provide a new natural product skeleton for the treatment of TNBC.

Copper-Based Composites Nanoparticles Improve Triple-Negative Breast Cancer Treatment with Induction of Apoptosis-Cuproptosis and Immune Activation.

The synergistic effect of apoptosis and cuproptosis, along with the activation of the immune system, presents a promising approach to enhance the efficacy against triple-negative breast cancer (TNBC). Here, two prodrugs are synthesized: a reactive oxygen species (ROS)-responsive prodrug PEG-TK-DOX and a glutathione (GSH)-responsive prodrug PEG-DTPA-SS-CPT. These prodrugs are self-assembled and chelated Cu2+ to prepare nanoparticle PCD@Cu that simultaneously loaded doxorubicin (DOX), camptothecin (CPT), and Cu2+. The elevated levels of ROS and GSH in TNBC cells disrupted the PCD@Cu structure, leading to the release of Cu+, DOX, and CPT and the depletion of GSH. DOX and CPT triggered apoptosis with immunogenic cell death (ICD) in TNBC cells. Simultaneously, PCD@Cu downregulated the expression of copper transporting ATPase 2 (ATP7B), causing a significant accumulation of copper ions in TNBC cells. This further induced the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT) and downregulation of iron-sulfur (Fe-S) cluster proteins, ultimately leading to cuproptosis and ICD in TNBC. In vitro and in vivo experiments confirmed that PCD@Cu induced apoptosis and cuproptosis in TNBC and activated the immune system, demonstrating strong anti-tumor capabilities. Moreover, PCD@Cu exhibited an excellent biosafety profile. Overall, this study provides a promising strategy for effective TNBC therapy.

Combinatorial Delivery of Docetaxel- and Erlotinib-Loaded Functionalized Nanostructured Lipid Carriers for the Treatment of Triple-Negative Breast Cancer Using Quality-by-Design Approach.

This study explored the combined administration of docetaxel (DOC) and erlotinib (ERL) using nanostructured lipid carriers (NLCs), with folic acid (FA) conjugation to enhance their synergistic anticancer efficacy against triple-negative breast cancer. NLCs were developed through hot melt homogenization-ultrasound dispersion, and optimized by a quality-by-design (QbD) approach using Plackett-Burman design and Box-Behnken design. Plots were generated based on maximum desirability. Spherical, nanosized dispersions (<200 nm) with zeta potential ranging from -16.4 to -14.15 mV were observed. These nanoformulations demonstrated ~95% entrapment efficiency with around 5% drug loading. Stability tests revealed that the NLCs remained stable for 6 months under storage conditions at 4 °C. In vitro release studies indicated sustained release over 24 h, following Higuchi and Korsmeyer-Peppas models for NLCs and FA NLCs, respectively. Additionally, an in vitro pH-stat lipolysis model exhibited a nearly fivefold increase in bioaccessibility compared to drug-loaded suspensions. The DOC-ERL-loaded formulations exhibited dose- and time-dependent cytotoxicity, revealing synergism at a 1:3 molar ratio in MDA-MB-231 and 4T1 cells, with combination indices of 0.35 and 0.37, respectively. Co-treatment with DOC-ERL-loaded FA NLCs demonstrated synergistic anticancer effects in various in vitro assays.

A Novel Cytotoxic Mechanism for Triple-Negative Breast Cancer Cells Induced by the Type II Heat-Labile Enterotoxin LT-IIc through Ganglioside Ligation.

Triple-negative breast cancer (TNBC), which constitutes 10-20 percent of all breast cancers, is aggressive, has high metastatic potential, and carries a poor prognosis due to limited treatment options. LT-IIc, a member of the type II subfamily of ADP-ribosylating-heat-labile enterotoxins that bind to a distinctive set of cell-surface ganglioside receptors-is cytotoxic toward TNBC cell lines, but has no cytotoxic activity for non-transformed breast epithelial cells. Here, primary TNBC cells, isolated from resected human tumors, showed an enhanced cytotoxic response specifically toward LT-IIc, in contrast to other enterotoxins that were tested. MDA-MB-231 cells, a model for TNBC, were used to evaluate potential mechanisms of cytotoxicity by LT-IIc, which induced elevated intracellular cAMP and stimulated the cAMP response element-binding protein (CREB) signaling pathway. To dissect the role of ADP-ribosylation, cAMP induction, and ganglioside ligation in the cytotoxic response, MDA-MB-231 cells were exposed to wild-type LT-IIc, the recombinant B-pentamer of LT-IIc that lacks the ADP-ribosylating A polypeptide, or mutants of LT-IIc with an enzymatically inactivated A1-domain. These experiments revealed that the ADP-ribosyltransferase activity of LT-IIc was nonessential for inducing the lethality of MDA-MB-231 cells. In contrast, a mutant LT-IIc with an altered ganglioside binding activity failed to trigger a cytotoxic response in MDA-MB-231 cells. Furthermore, the pharmacological inhibition of ganglioside expression protected MDA-MB-231 cells from the cytotoxic effects of LT-IIc. These data establish that ganglioside ligation, but not the induction of cAMP production nor ADP-ribosyltransferase activity, is essential to initiating the LT-IIc-dependent cell death of MDA-MB-231 cells. These experiments unveiled previously unknown properties of LT-IIc and gangliosides in signal transduction, offering the potential for the targeted treatment of TNBC, an option that is desperately needed.

Ultrasound Controllable Release of Proteolysis Targeting Chimeras for Triple-Negative Breast Cancer Treatment.

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer, which is highly aggressive and incurable. Here, we proposed an ultrasound activatable bromodomain-containing protein 4 (BRD4) proteolysis targeting chimera (PROTAC) release strategy for the first time for precisely controlled protein degradation in preclinical TNBC model. Through combination of PROTAC and ultrasound-targeted microbubble destruction (UTMD) technology, the present strategy also aims to concurrently solve the major limitations of poor loading capacity of microbubbles and undesirable targeting and membrane permeability of PROTAC. PROTAC (ARV-825)-encapsulated microbubbles, ARV-MBs, were developed for the efficacious treatment of TNBC invitro and invivo. The microbubbles we synthesized showed ultrasound-responsive drug release ability, which could effectively promote the penetration of PROTAC into tumor site and tumor cell. Under ultrasound, ARV-MBs could play an effective antitumor effect by potentiating the ubiquitination and degradation of BRD4 in tumor. The current study may provide a new idea for promoting clinical translation of drug-loaded microbubbles and PROTAC, and offer a new efficacious therapeutic modality for TNBC.

Coptisine exerts anti-tumour effects in triple-negative breast cancer by targeting mitochondrial complex I.

Triple-negative breast cancer (TNBC) has a poor prognosis due to limited therapeutic options. Recent studies have shown that TNBC is highly dependent on mitochondrial oxidative phosphorylation. The aim of this study was to investigate the potential of coptisine, a novel compound that inhibits the complex I of the mitochondrial electron transport chain (ETC), as a treatment for TNBC. In this study, mitochondrial metabolism in TNBC was analysed by bioinformatics. In vitro and in vivo experiments (in mice) were conducted to evaluate the potential of coptisine as an ETC complex I-targeting therapeutic agent and to investigate the molecular mechanisms underlying coptisine-induced mitochondrial dysfunction. The therapeutic effect of coptisine was assessed in TNBC cells and xenograft mouse model. We demonstrated that mitochondrial ETC I was responsible for this metabolic vulnerability in TNBC. Furthermore, a naturally occurring compound, coptisine, exhibited specific inhibitory activity against this complex I. Treatment with coptisine significantly inhibited mitochondrial functions, reprogrammed cellular metabolism, induced apoptosis and ultimately inhibited the proliferation of TNBC cells. Additionally, coptisine administration induced prominent growth inhibition that was dependent on the presence of a functional complex I in xenograft mouse models. Altogether, these findings suggest the promising potential of coptisine as a potent ETC complex I inhibitor to target the metabolic vulnerability of TNBC.

Aptamer functionalized hypoxia-potentiating agent and hypoxia-inducible factor inhibitor combined with hypoxia-activated prodrug for enhanced tumor therapy

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer. Hypoxia-activated prodrugs (HAPs) have shown promise as potential therapeutic agents for TNBC. While increasing hypoxia levels may promote the HAP activation, it raises concerns regarding HIF1α-dependent drug resistance. It is desirable to develop a targeted approach that enhances tumor hypoxia for HAP activation without promoting HIF1α-dependent drug resistance in TNBC treatment. Herein, we proposed a multi-responsive carrier-free self-assembled nanomedicine named AQ4N@CA4T1ASO. This nanomedicine first targeted tumors by the TNBC-targeting aptamers (T1), and then disassembled in the reductive and acidic conditions within tumors. The released Combretastatin 4 (CA4) could exacerbate hypoxia, thereby promoting the conversion of inactive Banoxantrone (AQ4N) to its active form, AQ4. Simultaneously, the released antisense oligonucleotide (ASO) could attenuate hypoxia-induced HIF1α mRNA expression, thereby sensitizing the tumor to chemotherapy. Overall, this smart nanomedicine represents a profound targeted therapy strategy, combining “hypoxia-potentiating, hypoxia-activated, chemo-sensitization” approaches for TNBC treatment. In vivo study demonstrated significant suppression of tumor growth, highlighting the promising potential of this nanomedicine for future clinical translation.

Antiplatelet drug ticagrelor suppresses triple negative breast cancer metastasis by targeting PI3K

Metastatic recurrence is still a major challenge in breast cancer treatment. Patients with triple negative breast cancer (TNBC) develop early recurrence and relapse more frequently. Due to the lack of specific therapeutic targets, new targeted therapies for TNBC are urgently needed. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway is one of the active pathways involved in chemoresistance and survival of TNBC, being considered as a potential target for TNBC treatment. Our present study identified ticagrelor, an anti-platelet drug, as a pan-PI3K inhibitor with potent inhibitory activity against four isoforms of class I PI3K. At doses normally used in clinic, ticagrelor showed weak cytotoxicity against a panel of breast cancer cells, but significantly inhibited the migration, invasion and the actin cytoskeleton organization of human TNBC MDA-MB-231 and SUM-159PT cells. Mechanistically, ticagrelor effectively inhibited PI3K downstream mTOR complex 1 (mTORC1) and mTORC2 signaling by targeting PI3K and decreased the protein expression of epithelial-mesenchymal transition (EMT) markers. In vivo, ticagrelor significantly suppressed tumor cells lung metastasis in 4T1 tumor bearing BALB/c mice model and experimental lung metastasis model which was established by tail vein injection of GFP-labeled MDA-MB-231 cells. The above data demonstrated that ticagrelor can inhibit the migration and invasion of TNBC both in vitro and in vivo by targeting PI3K, suggesting that ticagrelor, a pan-PI3K inhibitor, might represent a promising therapeutic agent for the treatment of metastatic TNBC.