Metastatic triple negative breast cancer: Optimizing treatment options, new and emerging targeted therapies

Caspase-9 suppresses metastatic behavior of MDA-MB-231 cells in an adaptive organoid model

Caspase-9, a cysteine-aspartate protease traditionally associated with intrinsic apoptosis, has recently emerged as having non-apoptotic roles, including influencing cell migration-an aspect that has received limited attention in existing studies. In our investigation, we aimed to explore the impact of caspase-9 on the migration and invasion behaviors of MDA-MB-231, a triple-negative breast cancer (TNBC) cell line known for its metastatic properties. We established a stable cell line expressing an inducible caspase-9 (iC9) in MDA-MB-231 and assessed their metastatic behavior using both monolayer and the 3D organotypic model in co-culture with human Foreskin fibroblasts (HFF). Our findings revealed that caspase-9 had an inhibitory effect on migration and invasion in both models. In monolayer culture, caspase-9 effectively suppressed the migration and invasion of MDA-MB-231 cells, comparable to the anti-metastatic agent panitumumab (Pan). Notably, the combination of caspase-9 and Pan exhibited a significant additional effect in reducing metastatic behavior. Interestingly, caspase-9 demonstrated superior efficacy compared to Pan in the organotypic model. Molecular analysis showed down regulation of epithelial-mesenchymal transition and migratory markers, in caspase-9 activated cells. Additionally, flow cytometry analysis indicated a cell cycle arrest. Moreover, pre-treatment with activated caspase-9 sensitized cells to the chemotherapy of doxorubicin, thereby enhancing its effectiveness. In conclusion, the anti-metastatic potential of caspase-9 presents avenues for the development of novel therapeutic approaches for TNBC/metastatic breast cancer. Although more studies need to figure out the exact involving mechanisms behind this behavior.

A novel nanoformulation of parthenolide coated with polydopamine shows selective cytotoxicity and induces apoptosis in gastric cancer cells

An anticancer agent derived from a natural product, parthenolide (PN), was studied to formulate PN into poly(lactic-co-glycolic acid) (PLGA). Polydopamine (PDA) was employed to modify the surface of PN-PLGA. Following characterization, the PN-PLGA-PDA was evaluated for its in vitro release, cytotoxicity, and ability to induce apoptosis using flow cytometry and real-time quantitative PCR. According to the present study, PN-PLGA-PDA had a size of 195.5 nm which is acceptable for efficient enhanced permeation and retention (EPR) performance. The SEM results confirmed the size and spherical shape of the nanoparticles. The percentage of encapsulation efficiency was 96.9%. The zeta potential of PN-PLGA-PDA was - 31.8 mV which was suitable for its stability. FTIR spectra of the PN-PLGA-PDA indicated the chemical stability of the PN due to intermolecular hydrogen bonds between polymer and drug. The release of PN from PN-PLGA-PDA in PBS (pH 7.4) was only 20% during the first 48 h and less than 40% during 144 h. PN-PLGA-PDA exhibited anticancer properties in a dose-dependent manner that was more cytotoxic against cancer cells than normal cells. Moreover, real-time qPCR results indicated that the formulation activated apoptosis genes to exert its cytotoxic effect and activate the NF-kB pathway. Based on our findings, PN-PLGA-PDA could serve as a potential treatment for cancer.

Exploring the interplay between triple-negative breast cancer stem cells and tumor microenvironment for effective therapeutic strategies

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic malignancy with poor treatment outcomes. The interaction between the tumor microenvironment (TME) and breast cancer stem cells (BCSCs) plays an important role in the development of TNBC. Owing to their ability of self-renewal and multidirectional differentiation, BCSCs maintain tumor growth, drive metastatic colonization, and facilitate the development of drug resistance. TME is the main factor regulating the phenotype and metastasis of BCSCs. Immune cells, cancer-related fibroblasts (CAFs), cytokines, mesenchymal cells, endothelial cells, and extracellular matrix within the TME form a complex communication network, exert highly selective pressure on the tumor, and provide a conducive environment for the formation of BCSC niches. Tumor growth and metastasis can be controlled by targeting the TME to eliminate BCSC niches or targeting BCSCs to modify the TME. These approaches may improve the treatment outcomes and possess great application potential in clinical settings. In this review, we summarized the relationship between BCSCs and the progression and drug resistance of TNBC, especially focusing on the interaction between BCSCs and TME. In addition, we discussed therapeutic strategies that target the TME to inhibit or eliminate BCSCs, providing valuable insights into the clinical treatment of TNBC.

Advances in the study of tertiary lymphoid structures in the immunotherapy of breast cancer

Breast cancer, as one of the most common malignancies in women, exhibits complex and heterogeneous pathological characteristics across different subtypes. Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are two common and highly invasive subtypes within breast cancer. The stability of the breast microbiota is closely intertwined with the immune environment, and immunotherapy is a common approach for treating breast cancer.Tertiary lymphoid structures (TLSs), recently discovered immune cell aggregates surrounding breast cancer, resemble secondary lymphoid organs (SLOs) and are associated with the prognosis and survival of some breast cancer patients, offering new avenues for immunotherapy. Machine learning, as a form of artificial intelligence, has increasingly been used for detecting biomarkers and constructing tumor prognosis models. This article systematically reviews the latest research progress on TLSs in breast cancer and the application of machine learning in the detection of TLSs and the study of breast cancer prognosis. The insights provided contribute valuable perspectives for further exploring the biological differences among different subtypes of breast cancer and formulating personalized treatment strategies.

Antibody-Drug Conjugates in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) accounts for 15%-20% of all breast cancer. It is a heterogeneous breast cancer subtype with a poor prognosis. Given these negative features, there is a need for new treatment options beyond conventional chemotherapy in both the early stage and palliative setting. Impressive results have been reported with antibody-drug conjugates (ADCs) that link a cytotoxic payload to a monoclonal antibody, such as sacituzumab govitecan and trastuzumab deruxtecan, in the metastatic stage. The focus of this review is to discuss completed and ongoing trials involving ADCs in TNBC.

Cost-benefit evaluation of advanced therapy lines in metastatic triple-negative breast cancer in Germany

BACKGROUND

Triple-negative breast cancer (TNBC) is responsible for 10-20% cases of breast cancer and is resulting in rising healthcare costs. Thus, health-economic evaluations are needed to relate clinical outcomes and costs of treatment options and to provide recommendations of action from a health-economic perspective.

METHODS

We investigated the cost-benefit-ratio of approved treatment options in metastatic TNBC in Germany by applying the efficiency frontier approach. These included sacituzumab-govitecan (SG), eribulin, vinorelbine, and capecitabine. Clinical benefit was measured as (i) median overall survival (mOS) and (ii) health-related quality of life (HRQoL) in terms of time to symptom worsening (TSW). To assess medical benefits, literature was systematically reviewed in PubMed for (i) and (ii), respectively. Treatment costs were calculated considering annual direct outpatient treatment costs from a statutory healthcare payer perspective. It was intended that both, (i) and (ii), yield an efficiency frontier.

RESULTS

Annual direct outpatient treatment costs amounted to EUR 176,415.21 (SG), EUR 47,414.14 (eribulin), EUR 13,711.35 (vinorelbine), and EUR 3,718.84 (capecitabine). Systematic literature review of (i) and statistical analysis resulted in OS values of 14.3, 9.56, 9.44, and 7.46 months, respectively. Capecitabine, vinorelbine, and SG are part of the efficiency frontier including OS. The highest additional benefit per additional cost was determined for vinorelbine, followed by SG. Systematic review of (ii) revealed that no TSW data of TNBC patients receiving vinorelbine were available, preventing the presentation of an efficiency frontier including HRQoL.

CONCLUSIONS

Vinorelbine is most cost-effective, followed by SG. Health-economic evaluations support decision-makers to assess treatment options within one indication area. In Germany, the efficiency frontier can provide decision support for the pricing of innovative interventions. Results of our analysis may thus guide reimbursement determination.

Targeting EMSY-mediated methionine metabolism is a potential therapeutic strategy for triple-negative breast cancer

Cancer stem cells (CSCs) are the most intractable subpopulation of triple-negative breast cancer (TNBC) cells, which have been associated with a high risk of relapse and poor prognosis. However, eradication of CSCs continues to be difficult. Here, we integrate the multiomics data of a TNBC cohort (n = 360) to identify vital markers of CSCs. We discover that EMSY, inducing a BRCAness phenotype, is preferentially expressed in breast CSCs, promotes ALDH+ cells enrichment, and is positively correlated with poor relapse-free survival. Mechanistically, EMSY competitively binds to the Jmjc domain, which is critical for KDM5B enzyme activity, to reshape methionine metabolism, and to promote CSC self-renewal and tumorigenesis in an H3K4 methylation-dependent manner. Moreover, EMSY accumulation in TNBC cells sensitizes them to PARP inhibitors against bulk cells and methionine deprivation against CSCs. These findings indicate that clinically relevant eradication of CSCs could be achieved with a strategy that targets CSC-specific vulnerabilities in amino acid metabolism.

Post-marketing safety surveillance of sacituzumab govitecan: an observational, pharmacovigilance study leveraging FAERS database

Background and objective: Sacituzumab govitecan (SG), the first antibody-drug conjugate targeting human trophoblast cell-surface antigen 2 (Trop-2), has been approved by the Food and Drug Administration (FDA) for the treatment of advanced or metastatic breast cancer and urothelial cancer. However, there is currently a dearth of information regarding the safety profiles of SG in a large sample cohort. The objective of the present study is to investigate SG-related adverse events (AEs) in real-world settings leveraging the FDA Adverse Event Reporting System (FAERS) database to guide the safety management of clinical medication. Methods: The FAERS database was retrospectively queried to extract reports associated with SG from April 2020 to March 2023. To identify and evaluate potential AEs in patients receiving SG, various disproportionality analyses such as reporting odds ratio (ROR), the proportional reporting ratio (PRR), the Bayesian confidence propagation neural network (BCPNN), and the multi-item gamma Poisson shrinker (MGPS) were employed. Results: Overall, 2069 reports of SG as the "primary suspect" were identified. Noteworthy, SG was significantly associated with an increased risk of blood lymphatic system disorders (ROR, 7.18; 95% CI, 6.58-7.84) and hepatobiliary disorders (ROR, 2.68; 95% CI, 2.17-3.30) at the System Organ Class (SOC) level. Meanwhile, 61 significant disproportionality preferred terms (PTs) simultaneously complied with all four algorithms were adopted. Therein, anemia, thrombocytopenia, neutropenia, leukopenia, diarrhea, asthenia, alopecia, and electrolyte imbalance were consistent with the common AEs described in the clinical trials and specification of SG. Furthermore, unexpected significant AEs include colitis (ROR, 12.09; 95% CI, 9.1-16.08), heart rate increased (ROR, 5.11; 95% CI, 3.84-6.79), sepsis (ROR, 4.77; 95% CI, 3.59-6.34), cholestasis (ROR, 6.28; 95% CI, 3.48-11.36), blood bilirubin increased (ROR, 4.65; 95% CI, 2.42-8.94) and meningitis (ROR, 7.23; 95% CI, 2.71-19.29) were also be detected. The median time to onset of SG-related AEs was 14 [interquartile range (IQR), 7-52] days, with the majority occurring within the initial month of SG treatment. Conclusion: Our study validates the commonly known AEs and also found some potentially emerging safety issues related to SG in real-world clinical practice, which could provide valuable vigilance evidence for clinicians and pharmacists to manage the safety issues of SG.

Antiproliferative Modulation and Pro-Apoptotic Effect of BR2 Tumor-Penetrating Peptide Formulation 2-Aminoethyl Dihydrogen Phosphate in Triple-Negative Breast Cancer

Breast cancer is the most common cancer in women, the so-called "Triple-Negative Breast Cancer" (TNBC) subtype remaining the most challenging to treat, with low tumor-free survival and poor clinical evolution. Therefore, there is a clear medical need for innovative and more efficient treatment options for TNBC. The aim of the present study was to evaluate the potential therapeutic interest of the association of the tumor-penetrating BR2 peptide with monophosphoester 2-aminoethyl dihydrogen phosphate (2-AEH2P), a monophosphoester involved in cell membrane turnover, in TNBC. For that purpose, viability, migration, proliferative capacity, and gene expression analysis of proteins involved in the control of proliferation and apoptosis were evaluated upon treatment of an array of TNBC cells with the BR2 peptide and 2-AEH2P, either separately or combined. Our data showed that, while possessing limited single-agent activity, the 2-AEH2P+BR2 association promoted significant cytotoxicity in TNBC cells but not in normal cells, with reduced proliferative potential and inhibition of cell migration. Mechanically, the 2-AEH2P+BR2 combination promoted an increase in cells expressing p53 caspase 3 and caspase 8, a reduction in cells expressing tumor progression and metastasis markers such as VEGF and PCNA, as well as a reduction in mitochondrial electrical potential. Our results indicate that the combination of the BR2 peptide with 2-AEH2P+BR2 may represent a promising therapeutic strategy in TNBC with potential use in clinical settings.

Xianlinglianxiafang Inhibited the growth and metastasis of triple-negative breast cancer via activating PPARγ/AMPK signaling pathway

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high invasion and metastasis rates. Xian-Ling-Lian-Xia formula (XLLX) is a traditional Chinese medicine prescription widely used in China for treating TNBC. Clinical studies have shown that XLLX significantly reduces the recurrence and metastasis rate of TNBC and improves disease-free survival. However, the potential molecular mechanisms of XLLX on TNBC are not clear yet. Here, we investigated the effects of XLLX on TNBC using a mouse model and tumor cell lines. The results showed that XLLX significantly inhibited the proliferation, migration, and invasion abilities of TNBC cell lines MDA-MB-231 and 4T1 in vitro, induced apoptosis, and regulated the expression of proliferation, apoptosis, and EMT marker proteins in tumor cells. In in vivo experiments, XLLX treatment significantly reduced the progression of TNBC tumors and lung metastasis. Transcriptomics reveals that XLLX treatment significantly enriched differentially expressed genes in the peroxisome proliferator-activated receptor gamma (PPARγ) and AMP-dependent protein kinase (AMPK) signaling pathways. The western blot results confirmed that XLLX significantly upregulated the protein expression of PPARγ and p-AMPK in TNBC cells, tumors, and lung tissues. It is noteworthy that GW9662 (a PPARγ inhibitor) and Compound C (an AMPK inhibitor) partially reversed the anti-proliferation and anti-metastasis effects of XLLX in TNBC cells. Therefore, XLLX may effectively inhibit the growth and metastasis of TNBC by activating the PPARγ/AMPK signaling pathway.

Exploiting Long Non-Coding RNAs and Circular RNAs as Pharmacological Targets in Triple-Negative Breast Cancer Treatment

Breast cancer is one of the most frequent causes of cancer death among women worldwide. In particular, triple-negative breast cancer (TNBC) represents the most aggressive breast cancer subtype because it is characterized by the absence of molecular targets, thus making it an orphan type of malignancy. The discovery of new molecular druggable targets is mandatory to improve treatment success. In that context, non-coding RNAs represent an opportunity for modulation of cancer. They are RNA molecules with apparently no protein coding potential, which have been already demonstrated to play pivotal roles within cells, being involved in different processes, such as proliferation, cell cycle regulation, apoptosis, migration, and diseases, including cancer. Accordingly, they could be used as targets for future TNBC personalized therapy. Moreover, the peculiar characteristics of non-coding RNAs make them reliable biomarkers to monitor cancer treatment, thus, to monitor recurrence or chemoresistance, which are the most challenging aspects in TNBC. In the present review, we focused on the oncogenic or oncosuppressor role of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) mostly involved in TNBC, highlighting their mode of action and depicting their potential role as a biomarker and/or as targets of new non-coding RNA-based therapeutics.

Novel Method to Obtain Contact Angles of Tumor Biopsies

Characterizing the strength of a solid-liquid interface can be done by depositing a single drop of liquid on a planar solid surface and measuring the angle of the formed semicircle, called the contact angle. The contact angle of pure water is indicative of a surface's hydrophobicity and is a useful metric in biomedical applications such as tissue scaffolding and drug/tissue interactions. However, the roughness and inhomogeneity of most biological surfaces make obtaining accurate contact angles of such materials challenging. Here, we developed an instrument and methodology to obtain contact angles of tissue sections. Breast cancer tumor and nearby healthy tissue sections were used as the model biological surface. The custom instrument was built on existing equipment by improving drop dispensing accuracy in the nanoliter range, an XYZ stage, additional side view cameras, and microscope-based sample visualization. The method takes into account the inherent surface inhomogeneity and topology of tissue and the required method of illumination for contact angle acquisition. As such, the system uses an inverted microscope with a high sensitivity camera, an XYZ stage for accurate droplet placement on tissue, and multiple cameras to obtain contact angles around the entire perimeter of the drop. We tested the system with breast cancer biopsies and adjacent normal tissue from 75 patients and report here a trend of tumor exhibiting higher water contact angles, and thus higher hydrophobicity, compared to their respective normal adjacent tissue. The system described here can be used to characterize any type of biological tissue, which can be sectioned, with any liquid including water or solutions with dissolved or suspended therapeutic molecules and particles.

Cost-effectiveness of trastuzumab deruxtecan in previously treated human epidermal growth factor receptor 2-low metastatic breast cancer

Background

Results from DESTINY-Breast04 trial revealed that trastuzumab deruxtecan (T-DXd) improved both progression-free survival and overall survival for patients with human epidermal growth factor receptor 2 (HER2)-low metastatic breast cancer (mBC). However, the economic impact of this practice remains unclear. The purpose of this study was to evaluate the cost-effectiveness of T-DXd on HER2-low mBC from the viewpoint of U.S. payers.

Methods

Using the clinical data from the DESTINY-Breast04 trial, a three-state Markov model was created to assess the economic and health effects of T-DXd versus chemotherapy. The incremental cost-effectiveness ratio (ICER) and willingness-to-pay threshold were determined and compared. One-way and probabilistic sensitivity analysis were used to measure parameter uncertainty.

Results

In the overall HER2-low population, T-DXd provided additional 0.47 quality-adjusted life-years (QALYs) at an increased cost of $149,222 compared with chemotherapy, yielding an ICER of $317,494/QALY. The ICER was $353,903/QALY in the hormone receptor (HR)-positive subgroup, which decreased to $259,825/QALY in the HR-negative subgroup. The sensitivity analysis found that T-DXd would not be cost-effective in the base-case. The expected cost of T-DXd will be less than $4,281/cycle ($11.33/mg) or $1,903/cycle ($5.03/mg) to achieve a 50 or 90% cost-benefit probability, respectively.

Conclusions

T-DXd provides significant health benefit for patients with HER2-low mBC compared with chemotherapy but is unlikely to be cost-effective in the United States.

A Phase IIb, single arm, multicenter trial of sacituzumab govitecan in Chinese patients with metastatic triple-negative breast cancer who received at least two prior treatments

Refractory or relapsing metastatic triple-negative breast cancer (mTNBC) has a poor prognosis. Sacituzumab govitecan (SG) is a novel antibody-drug conjugate, targeting human trophoblast cell-surface antigen 2 (Trop-2). This is the first report of SG's efficacy and safety in Chinese patients with mTNBC. EVER-132-001 (NCT04454437) was a multicenter, single-arm, Phase IIb study in Chinese patients with mTNBC who failed ≥2 prior chemotherapy regimens. Eligible patients received 10 mg/kg SG on Days 1 and 8 of each 21-day treatment cycle, until disease progression/unacceptable toxicity. The primary endpoint was objective response rate (ORR) assessed by the Independent Review Committee. Secondary endpoints included: duration of response (DOR), clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS) and safety. Eighty female Chinese patients (median age 47.6 years; range 24-69.9 years) received ≥1 SG dose with a median of 8 treatment cycles by the cutoff date (August 6, 2021). Median number of prior systemic cancer treatments was 4.0 (range 2.0-8.0). ORR and CBR were reported 38.8% (95% confidence interval [CI]: 28.06-50.30) and 43.8% (95% CI, 32.68-55.30) of patients, respectively. The median PFS was 5.55 months (95% CI, 4.14-N/A). SG-related Grade ≥3 treatment-emergent adverse events (TEAEs) were reported in 71.3%, the most common were neutrophil count decreased (62.5%), white blood cell count decreased (48.8%) and anemia (21.3%); 6.3% discontinued SG because of TEAEs. SG demonstrated substantial clinical activity in heavily pretreated Chinese patients with mTNBC. The observed safety profile was generally manageable.

Subtyping-based platform guides precision medicine for heavily pretreated metastatic triple-negative breast cancer: The FUTURE phase II umbrella clinical trial

Triple-negative breast cancer (TNBC) is a heterogeneous disease and lacks effective treatment. Our previous study classified TNBCs into four subtypes with putative therapeutic targets. Here, we report the final results of FUTURE, a phase II umbrella trial designed to explore whether the subtyping-based strategy may improve the outcomes in metastatic TNBC patients. A total of 141 patients with a median of three previous lines of therapies in the metastatic setting were enrolled in seven parallel arms. Confirmed objective responses were achieved in 42 patients (29.8%; 95% confidence interval [CI], 22.4-38.1). The median values of progression-free survival and overall survival were 3.4 (95% CI: 2.7-4.2) and 10.7 (95% CI: 9.1-12.3) months, respectively. Given Bayesian predictive probability, efficacy boundaries were achieved in four arms. Furthermore, integrated genomic and clinicopathological profiling illustrated associations of clinical and genomic parameters with treatment efficacy, and the efficacy of novel antibody-drug conjugates was explored in preclinical TNBC models of subtypes for which treatment was futile. In general, the FUTURE strategy recruits patients efficiently and provides promising efficacy with manageable toxicities, outlining a direction for further clinical exploration.

Association Between Biomarkers and Clinical Outcomes of Pembrolizumab Monotherapy in Patients With Metastatic Triple-Negative Breast Cancer: KEYNOTE-086 Exploratory Analysis

PURPOSE

In the two-cohort phase II KEYNOTE-086 study (ClinicalTrials.gov identifier: NCT02447003), first-line and second-line or later pembrolizumab monotherapy demonstrated antitumor activity in metastatic triple-negative breast cancer (mTNBC; N = 254). This exploratory analysis evaluates the association between prespecified molecular biomarkers and clinical outcomes.

METHODS

Cohort A enrolled patients with disease progression after one or more systemic therapies for metastatic disease irrespective of PD-L1 status; Cohort B enrolled patients with previously untreated PD-L1-positive (combined positive score [CPS] ≥ 1) metastatic disease. The association between the following biomarkers as continuous variables and clinical outcomes (objective response rate [ORR], progression-free survival [PFS], and overall survival [OS]) was evaluated: PD-L1 CPS (immunohistochemistry), cluster of differentiation 8 (CD8; immunohistochemistry), stromal tumor-infiltrating lymphocyte (sTIL; hematoxylin and eosin staining), tumor mutational burden (TMB; whole-exome sequencing [WES]), homologous recombination deficiency-loss of heterozygosity, mutational signature 3 (WES), mutational signature 2 (apolipoprotein B mRNA editing catalytic polypeptide-like; WES), T-cell-inflamed gene expression profile (Tcell_infGEP; RNA sequencing), and 10 non-Tcell_infGEP signatures (RNA sequencing); Wald test P values were calculated, and significance was prespecified at α = 0.05.

RESULTS

In the combined cohorts (A and B), PD-L1 (P = .040), CD8 (P < .001), sTILs (P = .012), TMB (P = .007), and Tcell_infGEP (P = .011) were significantly associated with ORR; CD8 (P < .001), TMB (P = .034), Signature 3 (P = .009), and Tcell_infGEP (P = .002) with PFS; and CD8 (P < .001), sTILs (P = .004), TMB (P = .025), and Tcell_infGEP (P = .001) with OS. None of the non-Tcell_infGEP signatures were associated with outcomes of pembrolizumab after adjusting for the Tcell_infGEP.

CONCLUSION

In this exploratory biomarker analysis from KEYNOTE-086, baseline tumor PD-L1, CD8, sTILs, TMB, and Tcell_infGEP were associated with improved clinical outcomes of pembrolizumab and may help identify patients with mTNBC who are most likely to respond to pembrolizumab monotherapy.

Efficacy and Safety of Atezolizumab Monotherapy or Combined Therapy with Chemotherapy in Patients with Metastatic Triple-negative Breast Cancer: A Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Several successful attempts have been recorded with PD-L1 blockade via atezolizumab monotherapy or combination therapy with chemotherapy in patients with metastatic triple-negative breast cancer (mTNBC). Due to the lack of a large-scale study, we present a meta-analysis aimed at evaluating the safety and efficacy of this promising strategy in patients with mTNBC.

METHODS

A comprehensive literature search was conducted using electronic databases to identify eligible RCTs. Twelve studies, including 2479 mTBNC patients treated with atezolizumab monotherapy or in combination with chemotherapy, were included up to January 2022. The PRISMA checklist protocol and the I2 statistic were applied for quality assessment and heterogeneity tests of the selected trials, respectively. Fixed and random-effects models were estimated based on the heterogeneity tests, and statistical analysis was performed using CMA.

RESULTS

Our pooled findings demonstrated that the median overall survival (OS) and progression-free survival (PFS) were 16.526 and 5.814 months in mTNBC patients, respectively. Furthermore, when comparing efficacy indicators between PD-L1-positive and PD-L1-negative groups, mTNBC patients with PD-L1 had better OS, PFS, and ORR than PD-L1-negative patients. Also, the immune-related adverse event incident for alopecia was higher (51.9%) than other complications across atezolizumab therapy.

CONCLUSION

Moreover, the pooled analysis indicated that the overall rate of lung metastasis following atezolizumab therapy was 42.8%, which was higher than the rates of metastasis in bone (26.9%), brain (5.4%), and lymph node (6.5%). Atezolizumab showed a manageable safety profile and had promising and durable anti-tumor efficacy in TMBC patients. Higher PD-L1 expression may be closely correlated with better clinical efficacy.

Heterologous prime-boost cellular vaccination induces potent antitumor immunity against triple negative breast cancer

Introduction

Triple negative breast cancer (TNBC) is the most aggressive and hard-to-treat subtype of breast cancer, affecting 10-20% of all women diagnosed with breast cancer. Surgery, chemotherapy and hormone/Her2 targeted therapies are the cornerstones of treatment for breast cancer, but women with TNBC do not benefit from these treatments. Although the prognosis is dismal, immunotherapies hold significant promise in TNBC, even in wide spread disease because TNBC is infiltrated with more immune cells. This preclinical study is proposing to optimize an oncolytic virus-infected cell vaccine (ICV) based on a prime-boost vaccination strategy to address this unmet clinical need.

Methods

We used various classes of immunomodulators to improve the immunogenicity of whole tumor cells in the prime vaccine, followed by their infection with oncolytic Vesicular Stomatitis Virus (VSVd51) to deliver the boost vaccine. For in vivo studies, we compared the efficacy of a homologous prime-boost vaccination regimen to a heterologous strategy by treating 4T1 tumor bearing BALB/c mice and further by conducting re-challenge studies to evaluate immune memory responses in surviving mice. Due to the aggressive nature of 4T1 tumor spread (akin to stage IV TNBC in human patients), we also compared early surgical resection of primary tumors versus later surgical resection combined with vaccination.

Results

In vitro results demonstrated that immunogenic cell death (ICD) markers and pro-inflammatory cytokines were released at the highest levels following treatment of mouse 4T1 TNBC cells with oxaliplatin chemotherapy and influenza vaccine. These ICD inducers also contributed towards higher dendritic cell recruitment and activation. With the top ICD inducers at hand, we observed that treatment of TNBC-bearing mice with the influenza virus-modified prime vaccine followed by VSVd51 infected boost vaccine resulted in the best survival. Furthermore, higher frequencies of both effector and central memory T cells along with a complete absence of recurrent tumors were observed in re-challenged mice. Importantly, early surgical resection combined with prime-boost vaccination led to improved overall survival in mice.

Conclusion

Taken together, this novel cancer vaccination strategy following early surgical resection could be a promising therapeutic avenue for TNBC patients.

The Prognostic and Therapeutic Implications of the Chemoresistance Gene BIRC5 in Triple-Negative Breast Cancer

Chemoresistance affects TNBC patient treatment responses. Therefore, identifying the chemoresistant gene provides a new approach to understanding chemoresistance in TNBC. BIRC5 was examined in the current study as a tool for predicting the prognosis of TNBC patients and assisting in developing alternative therapies using online database tools. According to the examined studies, BIRC5 was highly expressed in 45 to 90% of TNBC patients. BIRC5 is not only abundantly expressed but also contributes to resistance to chemotherapy, anti-HER2 therapy, and radiotherapy. Patients with increased expression of BIRC5 had a median survival of 31.2 months compared to 85.8 months in low-expression counterparts (HR, 1.73; CI, 1.4−2.13; p = 2.5 × 10−7). The overall survival, disease-free survival, relapse-free survival, distant metastasis-free survival, and the complete pathological response of TNBC patients with high expression of BIRC5 who received any chemotherapy (Taxane, Ixabepilone, FAC, CMF, FEC, Anthracycline) and anti-HER2 therapy (Trastuzumab, Lapatinib) did not differ significantly from those patients receiving any other treatment. Data obtained indicate that the BIRC5 promoter region was substantially methylated, and hypermethylation was associated with higher BIRC5 mRNA expression (p < 0.05). The findings of this study outline the role of BIRC5 in chemotherapy-induced resistance of TNBC, further indicating that BIRC5 may serve as a promising prognostic biomarker that contributes to chemoresistance and could be a possible therapeutic target. Meanwhile, several in vitro studies show that flavonoids were highly effective in inhibiting BIRC5 in genetically diverse TNBC cells. Therefore, flavonoids would be a promising strategy for preventing and treating TNBC patients with the BIRC5 molecule.

TROP2 (trophoblast cell-surface antigen 2): a drug target for breast cancer

INTRODUCTION

Breast cancer (BC) is the most common diagnosed cancer and the second leading cause of cancer-associated death in women, with the triple negative (TNBC) subtype being characterized by the poorest prognosis. New therapeutic targets are urgently needed to overcome the high metastatic potential, aggressiveness and poor survival of these tumors. Trop2 transmembrane glycoprotein, acting as an intracellular calcium signal transducer, recently emerged as a new potential target in epithelial cancers, in particular in breast cancer.

AREAS COVERED

We summarize the key features of Trop2 structure and function, describing the therapeutic strategies targeting this protein in cancer. Particular attention is paid to antibody-drug conjugates (ADCs), actually representing the most successful strategy.

EXPERT OPINION

ADCs targeting Trop2 recently received an accelerated FDA approval for the therapy of metastatic TNBC. The prospects for these novel ADCs in BC subtypes other than TNBC are discussed, taking into account the main pitfalls relative to Trop2 structure and function.

Emergence of Nanotechnology as a Powerful Cavalry against Triple-Negative Breast Cancer (TNBC)

Triple-negative breast cancer (TNBC) is considered one of the un-manageable types of breast cancer, involving devoid of estrogen, progesterone, and human epidermal growth factor receptor 2 (HER 2) receptors. Due to their ability of recurrence and metastasis, the management of TNBC remains a mainstay challenge, despite the advancements in cancer therapies. Conventional chemotherapy remains the only treatment regimen against TNBC and suffers several limitations such as low bioavailability, systemic toxicity, less targetability, and multi-drug resistance. Although various targeted therapies have been introduced to manage the hardship of TNBC, they still experience certain limitations associated with the survival benefits. The current research thus aimed at developing and improving the strategies for effective therapy against TNBC. Such strategies involved the emergence of nanoparticles. Nanoparticles are designated as nanocavalries, loaded with various agents (drugs, genes, etc.) to battle the progression and metastasis of TNBC along with overcoming the limitations experienced by conventional chemotherapy and targeted therapy. This article documents the treatment regimens of TNBC along with their efficacy towards different subtypes of TNBC, and the various nanotechnologies employed to increase the therapeutic outcome of FDA-approved drug regimens.

Tocilizumab overcomes chemotherapy resistance in mesenchymal stem-like breast cancer by negating autocrine IL-1A induction of IL-6

Triple-negative breast cancer (TNBC) patients with mesenchymal stem-like (MSL) subtype have responded poorly to chemotherapy whereas patients with basal-like 1 (BL1) subtype achieved the best clinical response. In order to gain insight into pathways that may contribute to the divergent sensitivity to chemotherapy, we compared the inflammatory profile of the two TNBC subtypes treated with docetaxel. Cellular signaling analysis determined that docetaxel activated MAPK pathway in MSL TNBCs but not BL1 TNBCs. The subsequent MAPK pathway activation in MSL TNBCs led to an IL-1A mediated cascade of autocrine inflammatory mediators including IL-6. Utilizing the humanized IL-6R antibody, tocilizumab, our in vitro and in vivo data show that MSL TNBCs treated with tocilizumab together with chemotherapy results in delayed tumor progression compared to MSL TNBCs treated with docetaxel alone. Our study highlights a molecular subset of TNBC that may be responsive to tocilizumab therapy for potential translational impact.

Comprehensive metabolomics expands precision medicine for triple-negative breast cancer

Metabolic reprogramming is a hallmark of cancer. However, systematic characterizations of metabolites in triple-negative breast cancer (TNBC) are still lacking. Our study profiled the polar metabolome and lipidome in 330 TNBC samples and 149 paired normal breast tissues to construct a large metabolomic atlas of TNBC. Combining with previously established transcriptomic and genomic data of the same cohort, we conducted a comprehensive analysis linking TNBC metabolome to genomics. Our study classified TNBCs into three distinct metabolomic subgroups: C1, characterized by the enrichment of ceramides and fatty acids; C2, featured with the upregulation of metabolites related to oxidation reaction and glycosyl transfer; and C3, having the lowest level of metabolic dysregulation. Based on this newly developed metabolomic dataset, we refined previous TNBC transcriptomic subtypes and identified some crucial subtype-specific metabolites as potential therapeutic targets. The transcriptomic luminal androgen receptor (LAR) subtype overlapped with metabolomic C1 subtype. Experiments on patient-derived organoid and xenograft models indicate that targeting sphingosine-1-phosphate (S1P), an intermediate of the ceramide pathway, is a promising therapy for LAR tumors. Moreover, the transcriptomic basal-like immune-suppressed (BLIS) subtype contained two prognostic metabolomic subgroups (C2 and C3), which could be distinguished through machine-learning methods. We show that N-acetyl-aspartyl-glutamate is a crucial tumor-promoting metabolite and potential therapeutic target for high-risk BLIS tumors. Together, our study reveals the clinical significance of TNBC metabolomics, which can not only optimize the transcriptomic subtyping system, but also suggest novel therapeutic targets. This metabolomic dataset can serve as a useful public resource to promote precision treatment of TNBC.

An Inter-Supplementary Biohybrid System Based on Natural Killer Cells for the Combinational Immunotherapy and Virotherapy of Cancer

Oncolytic adenoviruses (Ads) have gained great attention in cancer therapy because they cause direct cytolytic infection and indirectly induce antitumor immunity. However, their efficacy is compromised by host antiviral immune response, poor tumor delivery, and the immunosuppressive tumor microenvironment (TME). Here, a natural killer (NK) cell-mediated Ad delivery system (Ad@NK) is generated by harnessing the merits of the two components for combinational immunotherapy and virotherapy of cancer. In this biohybrid system, NK cells with a tumor-homing tropism act as bioreactors and shelters for the loading, protection, replication, amplification, and release of Ads, thereby leading to a highly efficient systemic tumor-targeted delivery. As feedback, Ad infection offers NK cells an enhanced antitumor immunity by activating type I interferon signaling in a STAT4-granzyme B-dependent manner. Moreover, it is found that the Ad@NK system can relieve immunosuppression in the TME by promoting the maturation of dendritic cells and the polarization of macrophages to M1 phenotype. Both in vitro and in vivo data indicate the excellent antitumor and antimetastatic functions of Ad@NKs by destroying tumor cells, inducing immunogenic cell death, and immunomodulating TME. This work provides a clinical basis for improved oncolytic virotherapy in combination with NK cell therapy based on the inter-supplementary biohybrid system.

Valproic Acid Prodrug Affects Selective Markers, Augments Doxorubicin Anticancer Activity and Attenuates Its Toxicity in a Murine Model of Aggressive Breast Cancer

We studied the unique inhibitor of the histone deacetylases (HDAC) valproate-valpromide of acyclovir (AN446) that upon metabolic degradation release the HDAC inhibitor (HDACI) valproic acid (VPA). Among the HDAC inhibitors that we have tested, only AN446, and to a lesser extent VPA, synergized with doxorubicin (Dox) anti-cancer activity. Romidepsin (Rom) was additive and the other HDACIs tested were antagonistic. These findings led us to test and compare the anticancer activities of AN446, VPA, and Rom with and without Dox in the 4T1 triple-negative breast cancer murine model. A dose of 4 mg/kg once a week of Dox had no significant effect on tumor growth. Rom was toxic, and when added to Dox the toxicity intensified. AN446, AN446 + Dox, and VPA + Dox suppressed tumor growth. AN446 and AN446 + Dox were the best inhibitory treatments for tumor fibrosis, which promotes tumor growth and metastasis. Dox increased fibrosis in the heart and kidneys, disrupting their function. AN446 most effectively suppressed Dox-induced fibrosis in these organs and protected their function. AN446 and AN446 + Dox treatments were the most effective inhibitors of metastasis to the lungs, as measured by the gap area. Genes that control and regulate tumor growth, DNA damage and repair, reactive oxygen production, and generation of inflammation were examined as potential therapeutic targets. AN446 affected their expression in a tissue-dependent manner, resulting in augmenting the anticancer effect of Dox while reducing its toxicity. The specific therapeutic targets that emerged from this study are discussed.

Cancer nanotechnology: current status and perspectives

Modern medicine has been waging a war on cancer for nearly a century with no tangible end in sight. Cancer treatments have significantly progressed, but the need to increase specificity and decrease systemic toxicities remains. Early diagnosis holds a key to improving prognostic outlook and patient quality of life, and diagnostic tools are on the cusp of a technological revolution. Nanotechnology has steadily expanded into the reaches of cancer chemotherapy, radiotherapy, diagnostics, and imaging, demonstrating the capacity to augment each and advance patient care. Nanomaterials provide an abundance of versatility, functionality, and applications to engineer specifically targeted cancer medicine, accurate early-detection devices, robust imaging modalities, and enhanced radiotherapy adjuvants. This review provides insights into the current clinical and pre-clinical nanotechnological applications for cancer drug therapy, diagnostics, imaging, and radiation therapy.

Economic Evaluation of Sacituzumab Govitecan for the Treatment of Metastatic Triple-Negative Breast Cancer in China and the US

BACKGROUND

The effectiveness of Sacituzumab Govitecan (SG) for metastatic triple-negative breast cancer (mTNBC) has been demonstrated. We aimed to evaluate its cost-effectiveness on mTNBC from the Chinese and United States (US) perspective.

METHODS

A partitioned survival model was developed to compare the cost and effectiveness of SG versus single-agent chemotherapy based on clinical data from the ASCENT phase 3 randomized trial. Cost and utility data were obtained from the literature. The incremental cost-effectiveness ratio (ICER) was measured, and one-way and probabilistic sensitivity analyses (PSA) were performed to observe model stability. A Markov model was constructed to validate the results.

RESULTS

In China, SG yielded an additional 0.35 quality-adjusted life-year (QALY) at an additional cost of Chinese Renminbi ¥2257842. The ICER was ¥6375856 ($924037)/QALY. In the US, SG yielded the same additional QALY at an extra cost of $175393 and the ICER was $494479/QALY. Similar results were obtained from the Markov model. One-way sensitivity analyses showed that SG price had the greatest impact on the ICER. PSA showed the probability of SG to be cost-effective when compared with chemotherapy was zero at the current willing-to-pay threshold of ¥217341/QALY and $150000/QALY in China and the US, respectively. The probability of cost-effectiveness of SG would approximate 50% if its price was reduced to ¥10.44/mg in China and $3.65/mg in the US.

CONCLUSION

SG is unlikely to be a cost-effective treatment of mTNBC at the current price both in China and the US.

Tackling metastatic triple-negative breast cancer with sacituzumab govitecan

Introduction Metastatic triple-negative breast cancer (TNBC) is an aggressive cancer with poor survival that is difficult to treat due to a lack of targeted options. Conventional therapies targeting hormone receptors (HR) and human epidermal growth factor 2 (HER2) are ineffective and often chemotherapy is standard-of-care. Sacituzumab govitecan is an antibody drug conjugate (ADC) comprised of an active metabolite of irinotecan, SN-38, bound to a humanized monoclonal antibody targeting trophoblastic cell-surface antigen 2 (Trop-2). Trop-2 is highly expressed on the surface of TNBC cells, making it an attractive target. Areas covered We explore the mechanism, pharmacology, efficacy, safety, and tolerability of sacituzumab govitecan. A literature search was conducted via PubMed using keywords such as 'sacituzumab govitecan,' and 'metastatic TNBC.' Expert opinion Sacituzumab govitecan has promising survival benefits in patients with previously treated mTNBC based on data from the ASCENT trial. Common adverse effects were neutropenia, diarrhea, and nausea, however these effects were manageable with supportive care. Sacituzumab govitecan has shown promise in cancers outside of TNBC, such as urothelial and lung and is being evaluated in HR-positive breast cancers. It is likely we will see this therapy used in combination with other novel targeted agents as current clinical trials mature.

Impact of the Pd2Spm (Spermine) Complex on the Metabolism of Triple-Negative Breast Cancer Tumors of a Xenograft Mouse Model

The interest in palladium(II) compounds as potential new anticancer drugs has increased in recent years, due to their high toxicity and acquired resistance to platinum(II)-derived agents, namely cisplatin. In fact, palladium complexes with biogenic polyamines (e.g., spermine, Pd₂Spm) have been known to display favorable antineoplastic properties against distinct human breast cancer cell lines. This study describes the in vivo response of triple-negative breast cancer (TNBC) tumors to the Pd₂Spm complex or to cisplatin (reference drug), compared to tumors in vehicle-treated mice. Both polar and lipophilic extracts of tumors, excised from a MDA-MB-231 cell-derived xenograft mouse model, were characterized through nuclear magnetic resonance (NMR) metabolomics. Interestingly, the results show that polar and lipophilic metabolomes clearly exhibit distinct responses for each drug, with polar metabolites showing a stronger impact of the Pd(II)-complex compared to cisplatin, whereas neither drug was observed to significantly affect tumor lipophilic metabolism. Compared to cisplatin, exposure to Pd₂Spm triggered a higher number of, and more marked, variations in some amino acids, nucleotides and derivatives, membrane precursors (choline and phosphoethanolamine), dimethylamine, fumarate and guanidine acetate, a signature that may be relatable to the cytotoxicity and/or mechanism of action of the palladium complex. Putative explanatory biochemical hypotheses are advanced on the role of the new Pd₂Spm complex in TNBC metabolism.

Precision Medicine and Triple-Negative Breast Cancer: Current Landscape and Future Directions

Simple Summary

The implementation of precision medicine will revolutionize cancer treatment paradigms. Notably, this goal is not far from reality: genetically similar cancers can be treated similarly. The heterogeneous nature of triple-negative breast cancer (TNBC) made it a suitable candidate to practice precision medicine. Using TNBC molecular subtyping and genomic profiling, a precision medicine-based clinical trial is ongoing. This review summarizes the current landscape and future directions of precision medicine and TNBC.

Abstract

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous subtype of breast cancer associated with a high recurrence and metastasis rate that affects African-American women disproportionately. The recent approval of targeted therapies for small subgroups of TNBC patients by the US ‘Food and Drug Administration’ is a promising development. The advancement of next-generation sequencing, particularly somatic exome panels, has raised hopes for more individualized treatment plans. However, the use of precision medicine for TNBC is a work in progress. This review will discuss the potential benefits and challenges of precision medicine for TNBC. A recent clinical trial designed to target TNBC patients based on their subtype-specific classification shows promise. Yet, tumor heterogeneity and sub-clonal evolution in primary and metastatic TNBC remain a challenge for oncologists to design adaptive precision medicine-based treatment plans.

One therapeutic approach for triple-negative breast cancer: Checkpoint kinase 1 inhibitor AZD7762 combination with neoadjuvant carboplatin

Carboplatin treatment is associated with potential benefits in practice in the neoadjuvant chemotherapy for Triple-negative breast cancer (TNBC) patients. In order to enhance its anti-tumor effects, new concepts for successful combination therapy are needed. Here, we interestingly found that the combination treatment of carboplatin with the Chk1 inhibitor AZD7762 synergistically inhibits TNBC cell growth in multiple TNBC cell lines in vitro. Mechanistically, we proved that prolonged carboplatin-treated induce cell mitotic arrest, and cells would fail to initiate the G2-M transition following the inhibition of the Chk1 pathway, leading to accumulation of DNA lesions. With this drug-in-combination treatment, the incidence of mitotic catastrophes including spindle multipolarity and cytokinesis failure is remarkably enhanced, which subsequently drives tumor cells multinucleation, polyploidization and apoptosis. Thus, our findings not only propose Chk1 as a therapeutic target for combination therapy with DNA-damaging agents such as carboplatin in TNBC, but also highlight that the induction of mitotic catastrophe could be considered as an alternative strategy for TNBC therapy.

CTLA-4 Expression and Its Clinical Significance in Breast Cancer

Breast cancer is the leading cause of women's death among all cancers. The main reason associated with this is the development of metastasis and therapy-resistant breast carcinoma (BC), which pose the main challenge of oncology nowadays. Evidence suggest that these tumors seem to have inhibitory mechanisms that may favor their progression and surveillance. Cancer cells can evade antitumor T cell responses by expressing some immune inhibitory molecules such as the cytotoxic T-lymphocyte antigen-4 (CTLA-4), whose clinical meaning has emerged in the last few years and is poorly understood in the BC context. This systematic literature review aims at identifying studies on CTLA-4 expression in BC, and address what is known about its clinical meaning. A literature search was performed in PubMed and LILACS databases, using the MESH terms "breast cancer"; "CTLA-4 Antigen/antagonists and inhibitors"; and "Lymphocytes, Tumor-Infiltrating/immunology", published in the last 10 years. In total, 12 studies were included in this review. Systematic review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Despite the small number of eligible studies, the literature reports some associations between CTLA-4 expression in the tumor microenvironment and worse BC outcomes, regardless of its molecular subtype. CTLA-4 expression in BC is a putative marker of clinical significance and a rationale therapeutic target in the emerging field of immunotherapy.

Chitosan oligosaccharide decorated liposomes combined with TH302 for photodynamic therapy in triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is an aggressive tumor with extremely high mortality that results from its lack of effective therapeutic targets. As an adhesion molecule related to tumorigenesis and tumor metastasis, cluster of differentiation-44 (also known as CD44) is overexpressed in TNBC. Moreover, CD44 can be effectively targeted by a specific hyaluronic acid analog, namely, chitosan oligosaccharide (CO). In this study, a CO-coated liposome was designed, with Photochlor (HPPH) as the 660 nm light mediated photosensitizer and evofosfamide (also known as TH302) as the hypoxia-activated prodrug. The obtained liposomes can help diagnose TNBC by fluorescence imaging and produce antitumor therapy by synergetic photodynamic therapy (PDT) and chemotherapy.

RESULTS

Compared with the nontargeted liposomes, the targeted liposomes exhibited good biocompatibility and targeting capability in vitro; in vivo, the targeted liposomes exhibited much better fluorescence imaging capability. Additionally, liposomes loaded with HPPH and TH302 showed significantly better antitumor effects than the other monotherapy groups both in vitro and in vivo.

CONCLUSION

The impressive synergistic antitumor effects, together with the superior fluorescence imaging capability, good biocompatibility and minor side effects confers the liposomes with potential for future translational research in the diagnosis and CD44-overexpressing cancer therapy, especially TNBC.

The silencing of FNDC1 inhibits the tumorigenesis of breast cancer cells via modulation of the PI3K/Akt signaling pathway

Fibronectin type III domain-containing protein 1 (FNDC1) is a protein that contains a major component of the structural domain of fibronectin. Although many studies have indicated that FNDC1 serves vital roles in the development of various diseases, the role of FNDC1 in the progression of breast cancer (BC) remains elusive. The aim of the present study was to investigate the biological functions of FNDC1 in BC cells and the associated mechanisms. The expression levels of FNDC1 in BC tissues and normal breast tissues were analyzed using The Cancer Genome Atlas database (TCGA). Kaplan-Meier curves were mined from TCGA to examine the clinical prognostic significance of FNDC1 mRNA in patients with BC. The expression of FNDC1 was knocked down by transfection with shRNA in BC cells. Cell viability, colony formation ability, migration and invasion were assayed following the silencing of FNDC1 in BC cells. The expression of proteins was measured using a western blotting assay. The bioinformatic data indicated that the FNDC1 mRNA expression levels were significantly upregulated in BC tissues compared with normal breast tissues, and the high mRNA expression levels of FNDC1 were associated with a lower overall survival in patients with BC. The downregulation of FNDC1 inhibited the proliferation, colony formation, migration and invasion of BC cells. Investigation of the mechanisms revealed that the silencing of FNDC1 decreased the protein expression levels of MMPs and epithelial-to-mesenchymal markers. Furthermore, the silencing of FNDC1 led to the inactivation of the PI3K/Akt signaling pathway. FNDC1 was highly upregulated and acted as an oncogene in BC. Therefore, targeting FNDC1 may be a potential strategy for the treatment of BC.

MCPIP1-mediated NFIC alternative splicing inhibits proliferation of triple-negative breast cancer via cyclin D1-Rb-E2F1 axis

Triple-negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis and the highest metastatic and recurrence potential, which represents 15–20% of all breast cancers in Chinese females, and the 5-year overall survival rate is about 80% in Chinese women. Recently, emerging evidence suggested that aberrant alternative splicing (AS) plays a crucial role in tumorigenesis and progression. AS is generally controlled by AS-associated RNA binding proteins (RBPs). Monocyte chemotactic protein induced protein 1 (MCPIP1), a zinc finger RBP, functions as a tumor suppressor in many cancers. Here, we showed that MCPIP1 was downregulated in 80 TNBC tissues and five TNBC cell lines compared to adjacent paracancerous tissues and one human immortalized breast epithelial cell line, while its high expression levels were associated with increased overall survival in TNBC patients. We demonstrated that MCPIP1 overexpression dramatically suppressed cell cycle progression and proliferation of TNBC cells in vitro and repressed tumor growth in vivo. Mechanistically, MCPIP1 was first demonstrated to act as a splicing factor to regulate AS in TNBC cells. Furthermore, we demonstrated that MCPIP1 modulated NFIC AS to promote CTF5 synthesis, which acted as a negative regulator in TNBC cells. Subsequently, we showed that CTF5 participated in MCPIP1-mediated antiproliferative effect by transcriptionally repressing cyclin D1 expression, as well as downregulating its downstream signaling targets p-Rb and E2F1. Conclusively, our findings provided novel insights into the anti-oncogenic mechanism of MCPIP1, suggesting that MCPIP1 could serve as an alternative treatment target in TNBC.

Bio-Inspired and Smart Nanoparticles for Triple Negative Breast Cancer Microenvironment

Triple negative breast cancer (TNBC) with poor prognosis and aggressive nature accounts for 10-20% of all invasive breast cancer (BC) cases and is detected in as much as 15% of individuals diagnosed with BC. Currently, due to the absence of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) receptor, there is no hormone-based therapy for TNBC. In addition, there are still no FDA-approved targeted therapies for patients with TNBC. TNBC treatment is challenging owing to poor prognosis, tumor heterogeneity, chemotherapeutic side effects, the chance of metastasis, and multiple drug-resistance. Therefore, various bio-inspired tumor-homing nano systems responding to intra- and extra- cellular stimuli are an urgent need to treat TNBC patients who do not respond to current chemotherapy. In this review, intensive efforts have been made for exploring cell-membrane coated nanoparticles and immune cell-targeted nanoparticles (immunotherapy) to modulate the tumor microenvironment and deliver accurate amounts of therapeutic agents to TNBC without stimulating the immune system.

CD44 Targeted Nanomaterials for Treatment of Triple-Negative Breast Cancer

Identified as the second leading cause of cancer-related deaths among American women after lung cancer, breast cancer of all types has been the focus of numerous research studies. Even though triple-negative breast cancer (TNBC) represents 15-20% of the number of breast cancer cases worldwide, its existing therapeutic options are fairly limited. Due to the pivotal role of the presence/absence of specific receptors to luminal A, luminal B, HER-2+, and TNBC in the molecular classification of breast cancer, the lack of these receptors has accounted for the aforementioned limitation. Thereupon, in an attempt to participate in the ongoing research endeavors to overcome such a limitation, the conducted study adopts a combination strategy as a therapeutic paradigm for TNBC, which has proven notable results with respect to both: improving patient outcomes and survivability rates. The study hinges upon an investigation of a promising NPs platform for CD44 mediated theranostic that can be combined with JAK/STAT inhibitors for the treatment of TNBC. The ability of momelotinib (MMB), which is a JAK/STAT inhibitor, to sensitize the TNBC to apoptosis inducer (CFM-4.16) has been evaluated in MDA-MB-231 and MDA-MB-468. MMB + CFM-4.16 combination with a combination index (CI) ≤0.5, has been selected for in vitro and in vivo studies. MMB has been combined with CD44 directed polymeric nanoparticles (PNPs) loaded with CFM-4.16, namely CD44-T-PNPs, which selectively delivered the payload to CD44 overexpressing TNBC with a significant decrease in cell viability associated with a high dose reduction index (DRI). The mechanism underlying their synergism is based on the simultaneous downregulation of P-STAT3 and the up-regulation of CARP-1, which has induced ROS-dependent apoptosis leading to caspase 3/7 elevation, cell shrinkage, DNA damage, and suppressed migration. CD44-T-PNPs showed a remarkable cellular internalization, demonstrated by uptake of a Rhodamine B dye in vitro and S0456 (NIR dye) in vivo. S0456 was conjugated to PNPs to form CD44-T-PNPs/S0456 that simultaneously delivered CFM-4.16 and S0456 parenterally with selective tumor targeting, prolonged circulation, minimized off-target distribution.

The BIRC Family Genes Expression in Patients with Triple Negative Breast Cancer

The BIRC (baculoviral IAP repeat-containing; BIRC) family genes encode for Inhibitor of Apoptosis (IAP) proteins. The dysregulation of the expression levels of the genes in question in cancer tissue as compared to normal tissue suggests that the apoptosis process in cancer cells was disturbed, which may be associated with the development and chemoresistance of triple negative breast cancer (TNBC). In our study, we determined the expression level of eight genes from the BIRC family using the Real-Time PCR method in patients with TNBC and compared the obtained results with clinical data. Additionally, using bioinformatics tools (Ualcan and The Breast Cancer Gene-Expression Miner v4.5 (bc-GenExMiner v4.5)), we compared our data with the data in the Cancer Genome Atlas (TCGA) database. We observed diverse expression pattern among the studied genes in breast cancer tissue. Comparing the expression level of the studied genes with the clinical data, we found that in patients diagnosed with breast cancer under the age of 50, the expression levels of all studied genes were higher compared to patients diagnosed after the age of 50. We observed that in patients with invasion of neoplastic cells into lymphatic vessels and fat tissue, the expression levels of BIRC family genes were lower compared to patients in whom these features were not noted. Statistically significant differences in gene expression were also noted in patients classified into three groups depending on the basis of the Scarff-Bloom and Richardson (SBR) Grading System.

Design, synthesis, and biological evaluation of quinazolin-4(3H)-one derivatives co-targeting poly(ADP-ribose) polymerase-1 and bromodomain containing protein 4 for breast cancer therapy

This study was aimed to design the first dual-target small-molecule inhibitor co-targeting poly (ADP-ribose) polymerase-1 (PARP1) and bromodomain containing protein 4 (BRD4), which had important cross relation in the global network of breast cancer, reflecting the synthetic lethal effect. A series of new BRD4 and PARP1 dual-target inhibitors were discovered and synthesized by fragment-based combinatorial screening and activity assays that together led to the chemical optimization. Among these compounds, 19d was selected and exhibited micromole enzymatic potencies against BRD4 and PARP1, respectively. Compound 19d was further shown to efficiently modulate the expression of BRD4 and PARP1. Subsequently, compound 19d was found to induce breast cancer cell apoptosis and stimulate cell cycle arrest at G1 phase. Following pharmacokinetic studies, compound 19d showed its antitumor activity in breast cancer susceptibility gene 1/2 (BRCA1/2) wild-type MDA-MB-468 and MCF-7 xenograft models without apparent toxicity and loss of body weight. These results together demonstrated that a highly potent dual-targeted inhibitor was successfully synthesized and indicated that co-targeting of BRD4 and PARP1 based on the concept of synthetic lethality would be a promising therapeutic strategy for breast cancer.

A Mechanistic Investigation on the Anticancer Properties of SYA013, a Homopiperazine Analogue of Haloperidol with Activity against Triple Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is one of the most malignant cancers associated with early metastasis, poor clinical prognosis, and high recurrence rate. TNBC is a distinct subtype of breast cancer that lacks estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 receptors (HER2). Development of effective TNBC therapies has been limited partially due to the lack of specific molecular targets and chemotherapy involving different cytotoxic drugs suffers from significant side effects and drug-resistance development. Therefore, there is an unmet need for the development of novel and efficient therapeutic drugs with reduced side effects to treat TNBC. We have previously reported that certain analogues of haloperidol (a typical antipsychotic drug used for treating mental/mood disorders such as schizophrenia and bipolar disorder) suppress the viability of a variety of solid tumor cell lines, and we have identified 4-(4-(4-chlorophenyl)-1,4-diazepan-1-yl)-1-(4-fluoro-phenyl)butan-1-one (SYA013) with such antiproliferative properties. Interestingly, unlike haloperidol, SYA013 shows moderate selectivity toward σ2 receptors. In this study, we explored the potential of SYA013 in modulating the important biological events associated with cell survival and progression as well as the mechanistic aspects of apoptosis in a representative TNBC cell line (MDA-MB-231). Our results indicate that SYA013 inhibits the proliferation of MDA-MB-231 cells in a concentration-dependent manner and suppresses cell migration and invasion. Apoptotic studies were also conducted in MDA-MB-468 cells (cells derived from a 51-year old Black female with metastatic adenocarcinoma of the breast.). In addition, we have demonstrated that SYA013 induces MDA-MB-231 cell death through the intrinsic apoptotic pathway and may suppress tumor progression and metastasis. Taken together, our study presents a mechanistic pathway of the anticancer properties of SYA013 against TNBC cell lines and suggests a potential for exploring SYA013 as a lead agent for development against TNBC.

Atezolizumab (in Combination with Nab-Paclitaxel): A Review in Advanced Triple-Negative Breast Cancer

Atezolizumab (Tecentriq^®), an immune checkpoint inhibitor against programmed death ligand 1 (PD-L1), is the first immunotherapy agent to be approved (for use in combination with nab-paclitaxel) in the USA, the EU (as first-line) and Japan for the treatment of advanced triple-negative breast cancer (TNBC). Approval was based on the results of the phase III IMpassion130 trial in patients with unresectable locally advanced or metastatic TNBC, in which atezolizumab plus nab-paclitaxel significantly prolonged progression-free survival (PFS) when compared to placebo plus nab-paclitaxel in the intent-to-treat (ITT) population and the PD-L1+ subgroup. Statistically significant overall survival (OS) benefits were not seen in two interim analyses and final OS data are awaited. The tolerability and safety profile of atezolizumab plus nab-paclitaxel was consistent with those of each individual drug. The most common treatment-related adverse events included neutropenia, peripheral neuropathy and reduced neutrophil count. Adverse events of special interest occurred with higher frequency in patients who received atezolizumab plus nab-paclitaxel than placebo plus nab-paclitaxel, and were mostly immune-related (e.g. immune-related rash, hypothyroidism and hepatitis). Health-related quality of life was not significantly impacted by the addition of atezolizumab to nab-paclitaxel therapy. Thus, atezolizumab plus nab-paclitaxel is a useful immunochemotherapy option for patients with unresectable locally advanced or metastatic TNBC, including those whose tumours have PD-L1 expression ≥ 1%.

Effects of Annona muricata Extract on Triple-Negative Breast Cancer Cells Mediated Through EGFR Signaling

Purpose

To evaluate the antiproliferative activity and the mechanisms of action of Annona muricata ethyl acetate (AMEA) extract and one of its active fractions on BT-20 TNBC cells.

Methods

The triple-negative human breast cancer BT-20 cells were used. After the preparation and extraction of Annona muricata ethyl acetate (AMEA), the ethyl acetate extract was exposed to a preparative thin layer chromatography (TLC) plate. From this preparative TLC plate, eight individual bands were collected. Each band was scraped and removed from the plate and soaked in ethyl acetate. After filtration, all eight fractions were then tested on the BT-20 TNBC cells using the MTS cell viability assay. The expressions of EGFR, p-EGFR, AKT, p-AKT, MAPK, p-MAPK, cyclin D1, and NF-κB p65 were measured using Western blot analysis.

Results

The AMEA showed a significant decrease in NF-κB p65 protein expression and BT-20 cell viability, as determined via the MTS assay. Furthermore, the AMEA was subjected to preparative thin layer chromatography (TLC), and eight fractions were obtained. From the eight fractions, only fraction 4 (F4) showed a significant reduction in cell viability in the MTS assay. Immunoblotting analysis revealed that AMEA and F4 formed an antiproliferative effect. These effects were complemented by a downregulation of cyclin D1 assembly, causing cell-cycle arrest at the G1/S phase. Furthermore, NF-κB was measured because of its involvement in the progression of cancers.

Conclusion

The antiproliferative influence is produced through EGFR-mediated signaling pathways, which include AKT, MAPK, NF-κB, and cyclin D1 inhibition. Further studies will be required to demonstrate the possible applications of this natural product in breast cancer therapy.

WDHD1 is essential for the survival of PTEN-inactive triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer that lacks the oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, making it difficult to target therapeutically. Targeting synthetic lethality is an alternative approach for cancer treatment. TNBC shows frequent loss of phosphatase and tensin homologue (PTEN) expression, which is associated with poor prognosis and treatment response. To identify PTEN synthetic lethal interactions, TCGA analysis coupled with a whole-genome siRNA screen in isogenic PTEN-negative and -positive cells were performed. Among the candidate genes essential for the survival of PTEN-inactive TNBC cells, WDHD1 (WD repeat and high-mobility group box DNA-binding protein 1) expression was increased in the low vs. high PTEN TNBC samples. It was also the top hit in the siRNA screen and its knockdown significantly inhibited cell viability in PTEN-negative cells, which was further validated in 2D and 3D cultures. Mechanistically, WDHD1 is important to mediate a high demand of protein translation in PTEN-inactive TNBC. Finally, the importance of WDHD1 in TNBC was confirmed in patient samples obtained from the TCGA and tissue microarrays with clinic-pathological information. Taken together, as an essential gene for the survival of PTEN-inactive TNBC cells, WDHD1 could be a potential biomarker or a therapeutic target for TNBC.

Evaluation of anticancer role of a novel ruthenium(II)-based compound compared with NAMI-A and cisplatin in impairing mitochondrial functionality and promoting oxidative stress in triple negative breast cancer models

Platinum-based compounds are the most widely used anticancer drugs but, their elevated toxicity and chemoresistance has stimulated the study of others, such as ruthenium-based compounds. NAMI-A and UNICAM-1 were tested in vitro, comparing the mechanisms of toxicity, in terms of mitochondrial functionality and cellular oxidative stress. UNICAM-1, showed a clear mitochondrial target and a cytotoxic dose-dependent response thanks to its ability to promote an imbalance of cellular redox status. It impaired directly mitochondrial respiratory chain, promoting mitochondrial superoxide anion production, leading to mitochondrial membrane depolarization. All these aspects, could make UNICAM-1 a valid alternative for chemotherapy treatment of breast cancer.

Tumor-Associated Macrophages in Human Breast, Colorectal, Lung, Ovarian and Prostate Cancers

Tumor-associated macrophages (TAMs) are major innate immune cells that constitute up to 50% of the cell mass of human tumors. TAMs are highly heterogeneous cells that originate from resident tissue-specific macrophages and from newly recruited monocytes. TAMs’ variability strongly depends on cancer type, stage, and intratumor heterogeneity. Majority of TAMs are programmed by tumor microenvironment to support primary tumor growth and metastatic spread. However, TAMs can also restrict tumor growth and metastasis. In this review, we summarized the knowledge about the role of TAMs in tumor growth, metastasis and in the response to cancer therapy in patients with five aggressive types of cancer: breast, colorectal, lung, ovarian, and prostate cancers that are frequently metastasize into distant organs resulting in high mortality of the patients. Two major TAM parameters are applied for the evaluation of TAM correlation with the cancer progression: total amount of TAMs and specific phenotype of TAMs identified by functional biomarkers. We summarized the data generated in the wide range of international patient cohorts on the correlation of TAMs with clinical and pathological parameters of tumor progression including lymphatic and hematogenous metastasis, recurrence, survival, therapy efficiency. We described currently available biomarkers for TAMs that can be measured in patients’ samples (tumor tissue and blood). CD68 is the major biomarker for the quantification of total TAM amounts, while transmembrane receptors (stabilin-1, CD163, CD206, CD204, MARCO) and secreted chitinase-like proteins (YKL-39, YKL-40) are used as biomarkers for the functional TAM polarization. We also considered that specific role of TAMs in tumor progression can depend on the localization in the intratumoral compartments. We have made the conclusion for the role of TAMs in primary tumor growth, metastasis, and therapy sensitivity for breast, colorectal, lung, ovarian, and prostate cancers. In contrast to other cancer types, majority of clinical studies indicate that TAMs in colorectal cancer have protective role for the patient and interfere with primary tumor growth and metastasis. The accumulated data are essential for using TAMs as biomarkers and therapeutic targets to develop cancer-specific immunotherapy and to design efficient combinations of traditional therapy and new immunomodulatory approaches.

Anti-metastatic action of an N 4-aryl substituted thiosemicarbazone on advanced triple negative breast cancer

Purpose

Advanced triple negative breast cancer (ATNBC) is defined by a lack of expression of hormones receptors as well as HER2/neu and its high probability of visceral metastasis. This pathology is associated with a poor prognosis. Previously, we found that T2, an N⁴-arylsubstituted thiosemicarbazone (N⁴-TSC), had cytotoxic effect on human breast cancer cells lines. Hence, in this study, we investigated the anti-metastasic action of T2 on ATNBC.

Methods

In order to deepen T2 action mode on ATNBC, we first confirmed T2 cytotoxicity on a panel of TNBC cells and then continued studying T2 effects in vitro an in vivo on the syngeneic 4T1 mouse model.

Results

We found that T2 had a cytotoxic effect comparable to chemotherapeutics used in present treatment schemes for ATNBC. T2 treatment not only induced apoptosis, but it also down-modulated 4T1 invasive and metastatic-associated capacities, such as clonogenicity, migration and metallo-proteases activity. Moreover, this agent reduced the number of 4T1 cancer stem cells. Finally, T2 treatment induced a more differentiated cell phenotype and the overexpression of the metastasis suppressor gene NDRG-1. In vivo assays showed that T2 reduced tumor burden, down modulated local tumor invasion and significantly reduced the number of lung metastases in the 4T1 advanced TNBC murine model, while the compound did not exhibit intolerable toxicity.

Conclusion

This study provided evidence that T2 not only exerted an anti-tumor activity but it also showed anti-invasive and anti-metastatic actions on ATNBC in vivo and in vitro, suggesting that T2 could be considered as a promising therapy that deserves further analysis.

Self-Assembled Dual-Targeted Epirubicin-Hybrid Polydopamine Nanoparticles for Combined Chemo-Photothermal Therapy of Triple-Negative Breast Cancer

PURPOSE

Folic acid and cyclic arginylglycylaspartic acid peptides were introduced to the surface of negatively charged lipid-coated hybrid polydopamine-cysteine cores for the delivery of epirubicin (EPI) (E/PCF-NPs). The combined chemo-photothermal therapy using E/PCF-NPs for triple-negative breast cancer was evaluated.

MATERIALS AND METHODS

The temperature elevation and thermal toxicity of nanoparticles were studied. The morphology and properties of E/PCF-NPs were characterized by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. Physicochemical properties, including particle size, zeta potential, drug loading, entrapment efficiency (EE%), stability and in vitro release, were determined. The cell viability, reactive oxygen species (ROS) levels, ratios of oxidized nicotinamide adenine dinucleotide to its reduced form (NAD+/NADH), apoptosis assays, and cellular uptake of E/PCF-NPs were determined on 4T1 cells. Pharmacokinetic studies and tissue distributions were performed and detected by an ultra-high performance liquid chromatography/mass spectrometry system. The antitumor effects of E/PCF-NPs under near-infrared (NIR) laser irradiation were also evaluated.

RESULTS

The sphere-like morphology of E/PCF-NPs showed a high EE%, uniform size of 106.7 nm, remarkable stability, and highly improved cytotoxicity under NIR laser, when compared to that of photothermal treatment alone. In vitro release of EPI from E/PCF-NPs was pH sensitive, and a greater response was achieved under NIR laser irradiation. Compared to chemotherapy or photothermal treatment alone, the combined treatment in vitro significantly inhibited the survival rate of 4T1 cells to 17.7%, induced ROS generation, and reduced NAD+/NADH significantly. Treatment with E/PCF-NPs under irradiation induced 4T1 cell apoptosis in approximately 93.6% cells. In vitro cellular uptake of E/PCF-NPs was time-dependent. The long-circulating and higher tumor accumulation of E/PCF-NPs resulted in complete ablation of breast tumor tissue through the enhanced photothermal effect by NIR laser irradiation-mediated cell apoptosis.

CONCLUSION

E/PCF-NPs show enhanced anti-cancer effects due to synergistic effects of chemotherapy with photothermal therapy and may be potential therapeutic agents for cancer treatment.

[EGFR tyrosine kinase inhibitor HS-10296 induces autophagy and apoptosis in triplenegative breast cancer MDA-MB-231 cells]

OBJECTIVE

To investigate the inhibitory effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFRTKI) HS-10296 on the proliferation of triple-negative breast cancer (TNBC) MDA-MB-231 cells and explore the possible molecular mechanism.

METHODS

MDA-MB-231 cells were treated with HS-10296 for 24, 48, or 72 h, and CCK-8 assay was used to assess the changes in the cell viability. The inhibitory effect of HS-10296 on cell proliferation was determined by clonogenic assay. JC-1 and flow cytometry were employed for analyzing the cell apoptosis, and the ultrastructure of the cells was observed under electron microscope. After pretreatment with autophagy inhibitor chloroquine (CQ), MDA-MB-231 cells were divided into control group, CQ treatment group, HS-10296 (4 and 6 μmol/L) treatment groups and combined treatment groups, and the sensitivity of the treated cells to HS-10296 was determined using CCK-8 assay. The effects of HS-10296 on EGFR pathway and apoptosis- and autophagy-related proteins in MDA-MB-231 cells were investigated using Western blotting.

RESULTS

HS-10296 significantly inhibited the proliferation of MDA-MB-231 cells with IC₅₀ values at 24, 48 and 72 h of 8.393, 2.777 and 2.016 μmol/L, respectively. JC-1 and flow cytometry showed that HS-10296 induced obvious apoptosis of MDA-MB-231 cells, which showed an apoptosis rate of (21.63 ± 2.97)% following treatment with 8 μmol/L HS-10296. Autophagy vesicles were observed in the cells treated with HS-10296 under electron microscope. In MDA-MB-231 cells pretreated with CQ, inhibition of autophagy significantly enhanced HS-10296-induced cell death. Western blotting showed that the apoptosis-related protein caspase-3 was activated after HS-10296 treatment to cut its substrate PARP. The expression of autophagy-related protein light chain 3B (LC3B) was significantly enhanced after HS-10296 treatment (P &lt; 0.01), which also resulted in inhibited phosphorylation of EGFR and AKT proteins in the cells.

CONCLUSIONS

HS-10296 can inhibit the proliferation and induce autophagy and apoptosis of MDA-MB-231 cells by inhibiting the EGFR/PI3K/AKT signaling pathway.