Treatment Of Triple-negative Breast Cancer Research Articles

Biogenic Synthesis and Characterization of Ethyl Ferulate Gold Nanoparticle and its Efficacy against Triple-Negative Breast Cancer Cells

Background: Triple-Negative Breast Cancer (TNBC) presents a significant challenge due to its aggressive nature and lack of responsive hormone receptors, predominantly affecting younger premenopausal women. Ethyl ferulate (EF), a notable phytochemical, has demonstrated promising anti-cancer properties. This study aimed to enhance the efficacy of EF by synthesizing and characterizing ethyl ferulate gold nanoparticles (EF-AuNps) to passively target TNBC cells via the enhanced permeability and retention (EPR) effect. Methods: We synthesized EF-AuNps using a direct reduction method and characterized the NPs by employing various techniques, including UV-visible spectroscopy, DLS, XRD, EDX, TEM, and FT-IR. The anti-proliferative activity against MDA-MB-231 cells was assessed using MTT and colony formation assays, alongside evaluating cell viability with PI-FACS and live/dead assays. Furthermore, a Western blot was performed to determine the mechanism of action of EFAuNps in TNBC cells. Result: We successfully synthesized triangular EF-AuNps (<100nm) and observed a substantial inhibition of cell proliferation (IC50 18μg/ml). Compared to EF alone, EF-AuNps significantly enhanced cell death in TNBC cells, as confirmed by flow cytometry and viability assays. Besides, Western blot analysis verified that the expression of apoptotic-related signal proteins, such as survivin, caspase 3, and caspase 9, were modulated by EF-AuNps. Conclusion: EF-AuNps showed higher anti-cancer efficacy than EF in the MDA-MB-231 cell line. These findings suggest the therapeutic potential of EF-AuNps for TNBC treatment, advocating for further preclinical and clinical investigations into this promising anti-cancer formulation.

LINC01572 promotes triple-negative breast cancer progression through EIF4A3-mediated β-catenin mRNA nuclear exportation.

Long noncoding RNAs have been reported to be involved in the development of breast cancer. LINC01572 was previously reported to promote the development of various tumors. However, the potential biological function of LINC01572 in breast cancer remains largely unknown. R language was used to perform bioinformatic analysis of The Cancer Genome Atlas data. The expression level of RNAs was examined by RT-qPCR. The effect of knocking down or overexpression LINC01572 in triple-negative breast cancer (TNBC) cell lines was evaluated by detecting cell proliferation, migrant action. RNA immunoprecipitation assay and RNA pull-down assay were performed to explore the regulatory relationship between LINC01572, EIF4A3, and β-catenin. Bioinformatics analysis identifies LINC01572 as an oncogene of breast cancer. LINC01572 is over-expressed in TNBC tissues and cell lines, correlated with poor clinical prognosis in BC patients. Cell function studies confirmed that LINC01572 facilitated the proliferation and migration of TNBC cells in both vivo and vitro. Mechanistically, β-catenin mRNA and EIF4A3 combine spatially to form a complex, LINC01572 helps transport this complex from the nucleus to the cytoplasm, thereby facilitating the translation of β-catenin. Our findings confirm that LINC01572 acts as a tumor promoter and may act as a biomarker in TNBC. In addition, novel molecular regulatory relationships involving LINC01572/EIF4A3/β-catenin are critical to the development of TNBC, which led to a new understanding of the mechanisms of TNBC progression and shows a new target for precision treatment for TNBC.

The anti-PD-L1/CTLA-4 bispecific antibody KN046 in combination with nab-paclitaxel in first-line treatment of metastatic triple-negative breast cancer: a multicenter phase II trial

This multicenter, phase II study (NCT03872791) aims to evaluate the efficacy and safety of the anti-PD-L1/CTLA-4 bispecific antibody KN046 combined with nab-paclitaxel in the first-line treatment of patients with metastatic triple-negative breast cancer (TNBC). The primary endpoints included objective response rate (ORR) and duration of response (DoR), and secondary endpoints included progression-free survival (PFS), overall survival (OS) rate, safety, and the correlation of PD-L1 status with clinical efficacy. This trial met pre-specified endpoints. 27 female patients were enrolled sequentially to receive KN046 in two dose levels (3 mg/kg or 5 mg/kg). Among the 25 evaluable patients, the ORR achieved 44.0% (95% CI, 24.4% − 65.1%), and the median DoR was not mature. The median PFS reached 7.33 months (95%CI, 3.68 − 11.07 months), and the median OS was 30.92 months (95%CI, 14.75 - NE months). In PD-L1 positive patients, PFS was 8.61 months (versus 4.73 months) and the 2-year OS rate was 62.5% (versus 57.1%) compared to PD-L1 negative patients. Patients tolerated well the combination therapy. In general, KN046 combined with nab-paclitaxel showed favorable efficacy and survival benefits with tolerable toxicity in the first-line treatment of metastatic TNBC, especially PD-L1 positive, which is worth further investigation.

Treatment patterns, healthcare resource utilization and outcomes for early stage triple-negative breast cancer in Japan.

Aim: There is limited information regarding the treatment and outcomes of early stage triple-negative breast cancer (esTNBC) in real-world settings in Japan. Materials & methods: Retrospective analyses of the Medical Data Vision database assessed treatment patterns, healthcare resource utilization (HCRU), patient characteristics, outcomes and prognostic factors among four groups (neoadjuvant therapy+surgery+adjuvant therapy; neoadjuvant therapy+surgery; surgery+adjuvant therapy; surgery only) of esTNBC patients. Results: Treatment patterns, HCRU and demographics varied among the four groups. HCRU was greater and prognosis tended to be worse in the neoadjuvant+surgery+adjuvant therapy group. Conclusion: Our results provide insights into the treatment practices, HCRU and prognosis of esTNBC in Japan. The treatment practices were heterogeneous, reflecting the decision-making process in Japan during the study period.

Abstract IA05: Leveraging preclinical models of triple negative breast cancer for translational research

Abstract We have developed multiple novel preclinical syngeneic triple negative breast cancer(TNBC) genetically engineered mouse (GEM) models, which have been characterized genomically and with respect to their immune microenvironments. By integrating the immunological characterization of murine syngeneic mammary tumor models with analyses of human breast cancer datasets, we have demonstrated a relationship between EMT and myeloid cells, specifically tumor-associated macrophages (TAMs). We also have leveraged our syngeneic GEM models to define the response to immune checkpoint blockade therapy (ICBT) with emphasis on the myeloid cell environment. We have used our GEM models to test single agent drugs along with standard-of-care therapies for appropriate durations. Finally, we have tested these treatment regimens on established metastases with sufficient tumor burdens. Specifically, we will present results illustrating how CSF-1R targeting therapy combined with metronomic chemotherapy enhances a B and T cell response for the treatment of metastatic TNBC. In additional we well discuss how targeting the RNA helicase eIF4A that unwinds the secondary structures in the 5’UTR of mRNAs to facilitate translation initiation triggers an interferon response to suppress TNBC. Citation Format: Jeffrey M Rosen, Diego Pedroza, Na Zhao, Xiang H-F Zhang, Charles M Perou. Leveraging preclinical models of triple negative breast cancer for translational research [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr IA05.

Abstract B039: Butyrate and propionate-reduced oncogenic phenotypes in triple-negative breast cancer

Abstract Objectives Triple negative breast cancer (TNBC) is the most aggressive form of breast cancer affecting 5% of all patients with no known treatment. Hispanic women show a higher risk of developing this type of cancer at an early age. Heterogeneity of TNBC between patients makes it challenging to devolop a effective treatment. The compostion of microbiome amongst the patients has a high variablity that could affect the production of the microbial products. The changes in microbial products have not been previously evaluated and could possibly contribute to chronic inflammation in the patients. Short-chain fatty acids (SCFA), i.e. butyrate, acetate, and propionate which are metabolical products of the microbiome that can potentially inhibit cell growth, proliferation and migration of cancer cells, may represent an alternative treatment for TNBC. Here, we measured the impact of SCFAs treament on viability and migration of MDA-231 cell lines. Methods MDA-231 cell line is an aggressive triple-negative breast cancer (TNBC) cell line common for evaluating new therapeutic strategies. MDA-231 cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum and we evaluated oncogenic phenotypes (cell viability and migration) after SCFA treatment. Cells were treated with butyrate, acetate, and propionate in cell culture media at seven concentrations starting at 125mM (1:2 dilution factor) for 24, 48 and 72 hours (h). We determined the cell viability using Alamar blue and determined the half-maximal inhibitory concentration (IC50) after SCFA treatment at all time points. Furthermore, we performed a wound-healing assay for 24h to evaluate the impact of SCFA on cell migration. MDA-231 cells were cultured to a 100% confluency and a scratch was performed in the cell monolayer to create an artificial gap, simulating the wound. Immediately after performing the wound, the cells were treated with SCFA at concentrations of 1mM and 5mM. Results Higher concentrations of butyrate and propionate reduced cell viability for MDA-231 was reduced. Particularly, butyrate showed an IC50 at 24h, 48h and 72h of 4.7mM, 4.34 mM and 3.6mM, respectively. However, propionate showed an IC50 only at 48h and 72h of 21.09 mM and 19.5 mM, respectively. There was no impact in cell viability after acetate treatment. In relation to migration, MDA-231 cell lines treated with butyrate and propionate at 5mM show a slower migration rate at 24h when compared to the untreated cells. Conclusions Our results suggest that butyrate and propionate can reduce oncogenic phenotypes in MDA-231. Future work will measure the impact of SCFA on cell proliferation, motility, and epithelial-mesenchymal transition. SCFAs may represent a promising target for novel treatment strategies for TNCB. Citation Format: Liah M Román-Calderón, Ariana S García-López, Jeannette L Salgado-Montilla, Gabriel Borges-Vélez, Esther A Peterson-Peguero, Josué Pérez-Santiago. Butyrate and propionate-reduced oncogenic phenotypes in triple-negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B039.

ANXA2 (annexin A2) is crucial to ATG7-mediated autophagy, leading to tumor aggressiveness in triple-negative breast cancer cells

ABSTRACT Triple-negative breast cancer (TNBC) is associated with a poor prognosis and metastatic growth. TNBC cells frequently undergo macroautophagy/autophagy, contributing to tumor progression and chemotherapeutic resistance. ANXA2 (annexin A2), a potential therapeutic target for TNBC, has been reported to stimulate autophagy. In this study, we investigated the role of ANXA2 in autophagic processes in TNBC cells. TNBC patients exhibited high levels of ANXA2, which correlated with poor outcomes. ANXA2 increased LC3B-II levels following bafilomycin A1 treatment and enhanced autophagic flux in TNBC cells. Notably, ANXA2 upregulated the phosphorylation of HSF1 (heat shock transcription factor 1), resulting in the transcriptional activation of ATG7 (autophagy related 7). The mechanistic target of rapamycin kinase complex 2 (MTORC2) played an important role in ANXA2-mediated ATG7 transcription by HSF1. MTORC2 did not affect the mRNA level of ANXA2, but it was involved in the protein stability of ANXA2. HSPA (heat shock protein family A (Hsp70)) was a potential interacting protein with ANXA2, which may protect ANXA2 from lysosomal proteolysis. ANXA2 knockdown significantly increased sensitivity to doxorubicin, the first-line chemotherapeutic regimen for TNBC treatment, suggesting that the inhibition of autophagy by ANXA2 knockdown may overcome doxorubicin resistance. In a TNBC xenograft mouse model, we demonstrated that ANXA2 knockdown combined with doxorubicin administration significantly inhibited tumor growth compared to doxorubicin treatment alone, offering a promising avenue to enhance the effectiveness of chemotherapy. In summary, our study elucidated the molecular mechanism by which ANXA2 modulates autophagy, suggesting a potential therapeutic approach for TNBC treatment. Abbreviation: ATG: autophagy related; ChIP: chromatin-immunoprecipitation; HBSS: Hanks’ balanced salt solution; HSF1: heat shock transcription factor 1; MTOR: mechanistic target of rapamycin kinase; TNBC: triple-negative breast cancer; TFEB: transcription factor EB; TFE3: transcription factor binding to IGHM enhancer 3

Repurposing proteasome inhibitors for improved treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is associated with poor prognosis and limited treatment options due to the lack of important receptors (estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor 2 [HER2]) used for targeted therapy. However, high-throughput in vitro drug screening of cell lines is a powerful tool for identifying effective drugs for a disease. Here, we determine the intrinsic chemosensitivity of TNBC cell lines to proteasome inhibitors (PIs), thereby identifying potentially potent 2-drug combinations for TNBC. Eight TNBC cell lines (BT-549, CAL-148, HCC1806, HCC38, HCC70, MDA-MB-436, MDA-MB-453, and MDA-MB-468) and two controls (MCF-10A and MCF-7) were first exposed to 18 drugs (11 PIs and 7 clinically relevant chemotherapeutic agents) as monotherapy, followed by prediction of potent 2-drug combinations using the IDACombo pipeline. The synergistic effects of the 2-drug combinations were evaluated with SynergyFinder in four TNBC cell lines (CAL-148, HCC1806, HCC38, and MDA-MB-468) and three controls (BT-474, MCF-7, and T47D) in vitro, followed by further evaluation of tumor regression in zebrafish tumor models established using HCC1806 and MCF-7 cells. Monotherapy identified nine effective drugs (bortezomib, carfilzomib, cisplatin, delanzomib, docetaxel, epoxomicin, MLN-2238, MLN-9708, and nedaplatin) across all cell lines. PIs (e.g., bortezomib, delanzomib, and epoxomicin) were highly potent drugs in TNBC cells, of which bortezomib and delanzomib inhibited the chymotrypsin-like activity of the 20 S proteasome by 100% at 10 µM. Moreover, several potent 2-drug combinations (e.g., bortezomib+nedaplatin and epoxomicin+epirubicin) that killed virtually 100% of cells were also identified. Although HCC1806- and MCF-7-derived xenografts treated with bortezomib+nedaplatin and carboplatin+paclitaxel were smaller, HCC1806 cells frequently metastasized to the trunk region. Taken together, we show that PIs used in combination with platinum agents or topoisomerase inhibitors exhibit increased efficiency with almost 100% inhibition in TNBC cell lines, indicating that PIs are therefore promising compounds to use as combination therapy for TNBC.

Advances in Monoclonal Antibody Therapies for Triple-Negative Breast Cancer: Immunotherapeutic and Targeted Strategies.

Triple-negative breast cancer (TNBC) presents considerable obstacles because of its highly aggressive characteristics and limited availability of specific therapeutic interventions. The utilization of monoclonal antibody (mAb)-based immunotherapy is a viable approach to tackle these difficulties. This review aims to examine the present state of mAb-based immunotherapy in TNBC, focusing on the underlying mechanisms of action, clinical applications, and existing challenges. The effectiveness of mAbs in reducing tumor development, regulating immune responses, and changing the tumor microenvironment has been demonstrated in many clinical investigations. The challenges encompass several aspects such as the discovery of biomarkers, understanding resistance mechanisms, managing toxicity, considering costs, and ensuring accessibility. The future is poised to bring forth significant advancements in the field of biomedicine, particularly in the areas of new mAbs, personalized medicine, and precision immunotherapy. In conclusion, mAb-based immunotherapy has promise in revolutionizing the treatment of TNBC, hence providing a possible avenue for enhanced patient outcomes and quality of life.

Androgen and Estrogen β Receptor Expression Enhances Efficacy of Antihormonal Treatments in Triple-Negative Breast Cancer Cell Lines.

The triple-negative breast cancer (TNBC) subtype is characterized by the lack of expression of ERα (estrogen receptor α), PR (progesterone receptor) and no overexpression of HER-2. However, TNBC can express the androgen receptor (AR) or estrogen receptor β (ERβ). Also, TNBC secretes steroid hormones and is influenced by hormonal fluctuations, so the steroid inhibition could exert a beneficial effect in TNBC treatment. The aim of this study was to evaluate the effect of dutasteride, anastrozole and ASP9521 in in vitro processes using human TNBC cell lines. For this, immunofluorescence, sensitivity, proliferation and wound healing assays were performed, and hormone concentrations were studied. Results revealed that all TNBC cell lines expressed AR and ERβ; the ones that expressed them most intensely were more sensitive to antihormonal treatments. All treatments reduced cell viability, highlighting MDA-MB-453 and SUM-159. Indeed, a decrease in androgen levels was observed in these cell lines, which could relate to a reduction in cell viability. In addition, MCF-7 and SUM-159 increased cell migration under treatments, increasing estrogen levels, which could favor cell migration. Thus, antihormonal treatments could be beneficial for TNBC therapies. This study clarifies the importance of steroid hormones in AR and ERβ-positive cell lines of TNBC.

Inhibition of ATM promotes PD-L1 expression by activating JNK/c-Jun/TNF-α signaling axis in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a heterogeneous subtype of breast cancer. Anti-PD-1/PD-L1 treatment for advanced TNBC is still limited to PD-L1-positive patients. Ataxia telangiectasia mutated (ATM) is a switch molecule for homologous recombination and repair. In this study, we found a significant negative correlation between ATM and PD-L1 in 4 TNBC clinical specimens by single-cell RNA sequencing (scRNA-seq), which was confirmed by immunochemical staining in 86 TNBC specimens. We then established ATM knockdown TNBC stable cell lines to perform in vitro studies and animal experiments, proving the negative regulation of PD-L1 by ATM via suppression of tumor necrosis factor-alpha (TNF-α), which was confirmed by cytokine array analysis of TNBC cell line and analysis of clinical specimens. We further found that ATM inhibits TNF-α via inactivating JNK/c-Jun by scRNA-seq, Western blot and luciferase reporter assays. Finally, we identified a negative correlation between changes in phospho-ATMS1981 and PD-L1 levels in TNBC post- and pre-neoadjuvant therapy. This study reveals a novel mechanism by which ATM negatively regulates PD-L1 by downregulating JNK/c-Jun/TNF-α in TNBC, shedding light on the wide application of immune checkpoint blockade therapy for treating multi-line-resistant TNBC.

Exploring the multifaceted impact of lanthanides on physiological pathways in human breast cancer cells

Lanthanum (La) and cerium (Ce), rare earth elements with physical properties similar to calcium (Ca), are generally considered non-toxic when used appropriately. However, their ions possess anti-tumor capabilities. This investigation explores the potential applications and mechanisms of LaCl3 or CeCl3 treatment in triple-negative breast cancer (TNBC) cell lines. TNBC, characterized by the absence of estrogen receptor (ERα), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression, is prone to early metastasis and resistant to hormone therapy. Our results demonstrate that La/Ce treatment reduces cell growth, and when combined with cisplatin, it synergistically inhibits cell growth and the PI3K/AKT pathway. La and Ce induce oxidative stress by disrupting mitochondrial function, leading to protein oxidation. Additionally, they interfere with protein homeostasis and induce nucleolar stress. Furthermore, disturbance in F-actin web formation impairs cell migration. This study delves into the mechanism by which calcium-like elements La and Ce inhibit breast cancer cell growth, shedding light on their interference in mitochondrial function, protein homeostasis, and cytoskeleton assembly.

Binary prodrug nanoassemblies combining chemotherapy and ferroptosis activation for efficient triple-negative breast cancer therapy

Chemotherapy has been recommended as the standard protocol for triple-negative breast cancer (TNBC) at the advanced stage. However, the current treatment is unsatisfactory due to inefficient drug accumulation and rapid chemo-resistance. Thus, rational design of advanced drug delivery systems that can induce multiple cell death pathways is a promising strategy to combat TNBC. Ferroptosis is a powerful non-apoptotic cell death modality, showing potential in tumor inhibition. Herein, we propose a binary prodrug nanoassemblies that combines chemotherapy with ferroptosis for TNBC treatment. In this system, paclitaxel is linked with paracetamol (ferroptosis activator) by a disulfide linkage to construct self-assembly prodrug. Meanwhile, 2-distearoyl-sn-glycerol-3-phosphoethanolamine-N-methyl(polyethylene glycol)-2000-tyrosine (DSPE-PEG2k-tyrosine) is applied for large neutral amino acid transporter 1 (LAT1) targeting, which is highly expressed in TNBC. The prodrug nanoassemblies exhibit good stability and a glutathione (GSH)-responsive release profile. Furthermore, the LAT1-targeted nanoassemblies show stronger cytotoxicity, higher cellular uptake, and more obvious ferroptosis activation than non-decorated ones. In a TNBC mice model, the prodrug nanoassemblies demonstrate strong anti-tumor efficacy. The application of ferroptosis-assisting chemotherapy may provide a promising strategy for TNBC therapy.

In vitro and in vivo activity of a novel oxamide-hydrazone hybrid derivative against triple-negative breast cancer.

Triple-negative breast cancer is a subtype of breast cancer with poor clinical outcome, and currently, no effective targeted therapies are available. Since cancer develops owing to deregulation of apoptosis, employing therapeutic strategies with the ability to target the molecules involved in apoptosis induction would provide a valid approach to hinder tumor progression. Hydrazide-hydrazones and oxamide molecules are the subject of intense studies due to their anticancer effects via apoptosis induction. In the present study, we attempted to elucidate the mechanism of action of a synthesized compound (compound A) in inducing cell death. Annexin/PI and Western blotting analyses, DAPI staining, mitochondrial membrane potential probe, and flow cytometry were applied for the in vitro evaluations. 4T1 syngeneic mouse model and immunohistochemistry were used for the in vivo assessments. Compound A caused cell death by inducing apoptosis in MDA-MB-231 cells in a mitochondrial-dependent manner at high concentrations after 72 h of incubation. Compound A also impeded tumor growth in a 4T1 syngeneic mouse model as evidenced by hematoxylin and eosin staining of the tumors. Furthermore, it significantly diminished the expression of pro-caspase-3, Ki67, and CD31 markers in the tumor sections. Conclusively, this study for the first time reports the anti-cancer efficacy of compound A in both in vitro and in vivo models and its potential in the treatment of triple-negative breast cancer.

LINC00571 drives tricarboxylic acid cycle metabolism in triple-negative breast cancer through HNRNPK/ILF2/IDH2 axis

BackgroundTriple-negative breast cancer is a complex breast malignancy subtype characterized by poor prognosis. The pursuit of effective therapeutic approaches for this subtype is considerably challenging. Notably, recent research has illuminated the key role of the tricarboxylic acid cycle in cancer metabolism and the complex landscape of tumor development. Concurrently, an emerging body of evidence underscores the noteworthy role that long non-coding RNAs play in the trajectory of breast cancer development. Despite this growing recognition, the exploration of whether long non-coding RNAs can influence breast cancer progression by modulating the tricarboxylic acid cycle has been limited. Moreover, the underlying mechanisms orchestrating these interactions have not been identified.MethodsThe expression levels of LINC00571 and IDH2 were determined through the analysis of the public TCGA dataset, transcriptome sequencing, qRT‒PCR, and Western blotting. The distribution of LINC00571 was assessed using RNA fluorescence in situ hybridization. Alterations in biological effects were evaluated using CCK-8, colony formation, EdU, cell cycle, and apoptosis assays and a tumor xenograft model. To elucidate the interaction between LINC00571, HNRNPK, and ILF2, RNA pull-down, mass spectrometry, coimmunoprecipitation, and RNA immunoprecipitation assays were performed. The impacts of LINC00571 and IDH2 on tricarboxylic acid cycle metabolites were investigated through measurements of the oxygen consumption rate and metabolite levels.ResultsThis study revealed the complex interactions between a novel long non-coding RNA (LINC00571) and tricarboxylic acid cycle metabolism. We validated the tumor-promoting role of LINC00571. Mechanistically, LINC00571 facilitated the interaction between HNRNPK and ILF2, leading to reduced ubiquitination and degradation of ILF2, thereby stabilizing its expression. Furthermore, ILF2 acted as a transcription factor to enhance the expression of its downstream target gene IDH2.ConclusionsOur study revealed that the LINC00571/HNRNPK/ILF2/IDH2 axis promoted the progression of triple-negative breast cancer by regulating tricarboxylic acid cycle metabolites. This discovery provides a novel theoretical foundation and new potential targets for the clinical treatment of triple-negative breast cancer.

Increased ACSL6 Expression Predicts a Favorable Prognosis in Triple-negative Breast Cancer.

Long-chain acyl-coenzyme A synthases (ACSLs) are responsible for the catalysis of fatty acids into their corresponding fatty acyl-CoAs. The dysregulation of ACSLs has been increasingly recognized in cancer patients. However, the function of ACSL6 in triple-negative breast cancer (TNBC) is still completely unknown. In this study, immunohistochemistry was applied to detect ACSL6 protein expression using a TNBC tissue microarray. Additionally, the mRNA levels of ACSL6 in human normal tissues and pancancer tissues were analyzed using Genotype Tissue Expression (GTEx) datasets and The Cancer Genome Atlas (TCGA) database. The correlations between the levels of ACSL6 expression and clinical characteristics were analyzed. The survival analysis of ACSL6 in TNBC was carried out using the Kaplan‒Meier Plotter online tool. Associations of ACSL6 with immune infiltration analyses were conducted using the ESTIMATE, CIBERSORT, and TISIDB databases. The relationship between ACSL6 and sensitivity to drugs was analyzed from Genomics of Drug Sensitivity in Cancer (GDSC). The results indicated a significant increase in ACSL6 expression in TNBC tissues compared to adjacent normal tissues. However, high ACSL6 expression was significantly associated with favorable survival outcomes in TNBC patients. Enrichment analysis revealed that coexpressed genes of ACSL6 were significantly enriched in various immunity processes. ACSL6 was positively correlated with the infiltration of memory CD4 T cells, while a negative correlation was found between ACSL6 and M2 macrophages and resting dendritic cells. Further analysis revealed that high levels of ACSL6 correlated with increased survival outcomes in cancer patients who received immunotherapy. Altogether, the current findings highlight the potential value of ACSL6 as a diagnostic and prognostic marker in the treatment of TNBC.

Exploring the resistance mechanism of triple-negative breast cancer to paclitaxel through the scRNA-seq analysis.

The triple negative breast cancer (TNBC) is the most malignant subtype of breast cancer with high aggressiveness. Although paclitaxel-based chemotherapy scenario present the mainstay in TNBC treatment, paclitaxel resistance is still a striking obstacle for cancer cure. So it is imperative to probe new therapeutic targets through illustrating the mechanisms underlying paclitaxel chemoresistance. The Single cell RNA sequencing (scRNA-seq) data of TNBC cells treated with paclitaxel at different points were downloaded from the Gene Expression Omnibus (GEO) database. The Seurat R package was used to filter and integrate the scRNA-seq expression matrix. Cells were further clustered by the FindClusters function, and the gene marker of each subset was defined by FindAllMarkers function. Then, the hallmark score of each cell was calculated by AUCell R package, the biological function of the highly expressed interest genes was analyzed by the DAVID database. Subsequently, we performed pseudotime analysis to explore the change patterns of drug resistance genes and SCENIC analysis to identify the key transcription factors (TFs). Finally, the inhibitors of which were also analyzed by the CTD database. We finally obtained 6 cell subsets from 2798 cells, which were marked as AKR1C3+, WNT7A+, FAM72B+, RERG+, IDO1+ and HEY1+HCC1143 cell subsets, among which the AKR1C3+, IDO1+ and HEY1+ cell subsets proportions increased with increasing treatment time, and then were regarded as paclitaxel resistance subsets. Hallmark score and pseudotime analysis showed that these paclitaxel resistance subsets were associated with the inflammatory response, virus and interferon response activation. In addition, the gene regulatory networks (GRNs) indicated that 3 key TFs (STAT1, CEBPB and IRF7) played vital role in promoting resistance development, and five common inhibitors targeted these TFs as potential combination therapies of paclitaxel were identified. In this study, we identified 3 paclitaxel resistance relevant IFs and their inhibitors, which offers essential molecular basis for paclitaxel resistance and beneficial guidance for the combination of paclitaxel in clinical TNBC therapy.

Nanoemulsion potentiates the anti-cancer activity of Myricetin by effective inhibition of PI3K/AKT/mTOR pathway in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is a heterogeneous tumor with a poor prognosis and high metastatic potential, resulting in poor clinical outcomes, necessitating investigation to devise effective therapeutic strategies. Multiple studies have substantiated the anti-cancer properties of the naturally occurring flavonoid "Myricetin" in various malignancies. However, the therapeutic application of Myricetin is impeded by its poor water solubility and low oral bioavailability. To overcome this limitation, we aimed to develop nanoemulsion of Myricetin (Myr-NE) and evaluate its advantage over Myricetin alone in TNBC cells. The nanoemulsion was formulated using Capryol 90 (oil), Tween 20 (surfactant), and Transcutol HP (co-surfactant). The optimized nano-formulation underwent an evaluation to determine its size, zeta potential, morphology, stability, drug encapsulation efficiency, and in vitro release properties. The anti-cancer activity of Myr-NE was further studied to examine its distinct impact on intracellular drug uptake, cell-viability, anti-tumor signaling, oxidative stress, clonogenicity, and cell death, compared with Myricetin alone in MDA-MB-231 (TNBC) cells. The in vitro drug release and intracellular drug uptake of Myricetin was significantly increased in Myr-NE formulation as compared to Myricetin alone. Moreover, Myr-NE exhibited significant inhibition of cell proliferation, clonogenicity, and increased apoptosis with ~ 2.5-fold lower IC50 as compared to Myricetin. Mechanistic investigation revealed that nanoemulsion augmented the anti-cancer efficacy of Myricetin, most likely by inhibiting the PI3K/AKT/mTOR pathway, eventually leading to enhanced cell death in TNBC cells. The study provides substantial experimental evidence to support the notion that the Myr-NE formulation has the potential to be an effective therapeutic drug for TNBC treatment.

Local dose-dense chemotherapy for triple-negative breast cancer via minimally invasive implantation of 3D printed devices

Dose-dense chemotherapy is the preferred first-line therapy for triple-negative breast cancer (TNBC), a highly aggressive disease with a poor prognosis. This treatment uses the same drug doses as conventional chemotherapy but with shorter dosing intervals, allowing for promising clinical outcomes with intensive treatment. However, the frequent systemic administration used for this treatment results in systemic toxicity and low patient compliance, limiting therapeutic efficacy and clinical benefit. Here, we report local dose-dense chemotherapy to treat TNBC by implanting 3D printed devices with time-programmed pulsatile release profiles. The implantable device can control the time between drug releases based on its internal microstructure design, which can be used to control dose density. The device is made of biodegradable materials for clinical convenience and designed for minimally invasive implantation via a trocar. Dose density variation of local chemotherapy using programmable release enhances anti-cancer effects in vitro and in vivo. Under the same dose density conditions, device-based chemotherapy shows a higher anti-cancer effect and less toxic response than intratumoral injection. We demonstrate local chemotherapy utilizing the implantable device that simulates the drug dose, number of releases, and treatment duration of the dose-dense AC (doxorubicin and cyclophosphamide) regimen preferred for TNBC treatment. Dose density modulation inhibits tumor growth, metastasis, and the expression of drug resistance-related proteins, including p-glycoprotein and breast cancer resistance protein. To the best of our knowledge, local dose-dense chemotherapy has not been reported, and our strategy can be expected to be utilized as a novel alternative to conventional therapies and improve anti-cancer efficiency.

Current and future trends in neoadjuvant immunotherapy for the treatment of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) comprises 15-20% of all breast cancers (BC). Lacking targeted therapy options, TNBC becomes the focal point of clinical investigations aiming not only to identify drugs with enhanced response potential but also to uncover new immunological and/or metabolic pathways conducive to more effective treatments. Currently, neoadjuvant treatment for TNBC relies on standard chemotherapy in conjunction with immunotherapy, given the improved response observed with this drug combination. This review delves into the latest therapeutic updates in TNBC treatment and explores potential advancements shaping the future landscape of this disease in the neoadjuvant setting.