Window of opportunity trials with immune checkpoint inhibitors in triple-negative breast cancer.

Patients with triple-negative breast cancer (TNBC) have a relatively poor clinical outcome. The immune checkpoint inhibitor (ICI) pembrolizumab combined with chemotherapy is the current standard of care in TNBC patients with stage II and III. Monotherapy with ICIs has not been comprehensively assessed in the neoadjuvant setting in TNBC patients, given unfavorable results in metastatic trials. ICIs, however, have been tested in the window of opportunity (WOO) before surgery or standard chemotherapy-based neoadjuvant treatment. The WOO design is well suited to assess an ICI alone or in combination with other ICIs, targeted therapy, radiotherapy or cryotherapy, and measure their pharmacodynamic and clinical effect in this treatment-naive population. Some patients show a good response to ICIs in WOO studies. Biomarkers like tumor-infiltrating lymphocytes, programmed death ligand-1, and interferon-γ signature may predict activity and may identify patients likely to benefit from ICIs. Moreover, an increase in tumor-infiltrating lymphocytes, programmed death ligand-1 expression or T cell receptor expansion following administration of ICIs in the WOO setting could potentially inform of immunotherapy benefit, which would allow tailoring further treatment. This article reviews WOO trials that assessed immunotherapy in the early-stage TNBC population, and how these results could be translated to test de-escalation strategies of neoadjuvant chemotherapy and immunotherapy without compromising a patient's prognosis.

Recent update on IGF-1/IGF-1R signaling axis as a promising therapeutic target for triple-negative breast cancer.

Insulin-like growth factor 1/Insulin-like growth factor 1-receptor (IGF-1/IGF-1R) pathway is highly breast cancer subtype context-dependent. Triple-negative breast cancer (TNBC) is an aggressive, highly metastatic cancer showing early recurrence and poor prognosis. High expression of IGF-1 and its receptor IGF-1R, their interaction, autophosphorylation, and activation of intracellular signaling cascades have been significantly associated with TNBC pathophysiology. In the last five to seven years, marvelous work has been done to explore the role of IGF-1/IGF-1R axis in TNBC. In the present review, starting from the general introduction to IGF-1/IGF-1R pathway an up-to-date discussion was focused on its role in TNBC pathophysiology. Further we discussed the up/down stream molecular events of IGF-1/IGF-1R axis, clinical relevance of IGF-1 and IGF-1R levels in TNBC patients, anti-TNBC therapy and possible way-out for IGF-1/IGF-1R axis mediate therapy resistance in TNBC. Combination therapy strategy has been researched to overcome direct IGF-1/IGF-1R pathway inhibition mediated therapy resistance and produced promising results in the management of TNBC. The understanding of up/downstream of the IGF-1/IGF-1R axis provide immense focus on the pathway as a therapeutic target. It is expected within the next decade to determine its potentiality, or lack thereof, for TNBC treatment.

Standard chemotherapy impacts on in vitro cellular heterogeneity in spheroids enriched with cancer stem cells (CSCs) derived from triple-negative breast cancer cell line.

Triple-negative breast cancer is a heterogeneous disease with high recurrence and mortality, linked to cancer stem cells (CSCs). Our study characterized distinct cell subpopulations and signaling pathways to explore chemoresistance. We observed cellular heterogeneity among and within the cells regarding phenotyping and drug response. In untreated BT-549 cells, we noted plasticity properties in both CD44+/CD24+/CD146+ hybrid cells and CD44-/CD24+/CD146+ epithelial cells, enabling phenotypic conversion into CD44+/CD24-/CD146- epithelial-mesenchymal transition (EMT)-like like breast CSCs (BCSCs). Additionally, non-BCSCs may give rise to ALDH+ epithelial-like BCSCs. Enriched BCSCs demonstrated the potential to differentiation into CD44-/CD24-/CD146- cells and exhibited self-renewal capabilities. Similar phenotypic plasticity was not observed in untreated Hs 578T and HMT-3522 S1 cells. BT-549 cells were more resistant to paclitaxel/PTX than to doxorubicin/DOX, a phenomenon potentially linked to the presence of CD24+ cells prior to treatment. Under the CSCs-enriched spheroids model, BT-549 demonstrated extreme resistance to DOX, likely due to the enrichment of BCSCs CD44+/CD24-/CD146- and the tumor cells CD44-/CD24-/CD146-. Additionally, DOX treatment induced the enrichment of plastic and chemoresistant cells, further exacerbating resistance mechanisms. BT-549 exhibited high heterogeneity, leading to significant alterations in cell subpopulations under BCSCs enrichment, demonstrating increased phenotypic plasticity during EMT. This phenomenon appears to play a major role in DOX resistance, as indicated by the presence of the refractory cells CD44+/CD24-/CD146- BCSCs EMT-like, CD44-/CD24-/CD146- tumor cells, and elevated STAT3 expression. Gene expression data from BT-549 CSCs-enriched spheroids suggests that ferroptosis may be occurring via autophagic regulation triggered by RAB7A, highlighting this gene as a potential therapeutic target.

Photothermal nanocomposite reactivate "immune-hot" for triple-negative breast cancer treatment via glutamine metabolism reprograming.

Herein, a photothermal nanocomposite PAI@CB839 nanoparticles (NPs) was constructed to perform a heat-immune therapy for triple-negative breast cancer (TNBC). Firstly, a photothermal agent animated IR780 was modified on a mPEG-NH2 using 4,4'-dicarboxylazobenzene as a linker. The synthesized PAI exhibited superior photothermal efficiency of the IR780 even after assembling in water. As a functional carrier, PAI was used to load and deliver the glutaminase inhibitor CB839 to tumor tissue. In the hypoxic environment of tumor cells, the azo bond would break, triggering the release of cargo. Upon irradiation, the outstanding photothermal properties of IR780 resulted in tumor cell damage. This process could promote immunogenic cell death and program tumor to "immune-hot" condition. Concurrently, CB839 strengthened the antitumor immune response by remodulating the immunosuppressive TME through disturbing Glu abnormal metabolism, which further inhibited TNBC growth and metastasis. In conclusion, PAI@CB839 NPs exhibited great antitumor efficiency, which pave a new way for TNBC therapeutic regimen development.

Non-coding RNAs as modulators of radioresponse in triple-negative breast cancer: a systematic review.

Triple-negative breast cancer (TNBC), characterized by high invasiveness, is associated with poor prognosis and elevated mortality rates. Despite the development of effective therapeutic targets for TNBC, systemic chemotherapy and radiotherapy (RdT) remain prevalent treatment modalities. One notable challenge of RdT is the acquisition of radioresistance, which poses a significant obstacle in achieving optimal treatment response. Compelling evidence implicates non-coding RNAs (ncRNAs), gene expression regulators, in the development of radioresistance. This systematic review focuses on describing the role, association, and/or involvement of ncRNAs in modulating radioresponse in TNBC. In adhrence to the PRISMA guidelines, an extensive and comprehensive search was conducted across four databases using carefully selected entry terms. Following the evaluation of the studies based on predefined inclusion and exclusion criteria, a refined selection of 37 original research articles published up to October 2023 was obtained. In total, 33 different ncRNAs, including lncRNAs, miRNAs, and circRNAs, were identified to be associated with radiation response impacting diverse molecular mechanisms, primarily the regulation of cell death and DNA damage repair. The findings highlighted in this review demonstrate the critical roles and the intricate network of ncRNAs that significantly modulates TNBC's responsiveness to radiation. The understanding of these underlying mechanisms offers potential for the early identification of non-responders and patients prone to radioresistance during RdT, ultimately improving TNBC survival outcomes.

Salidroside sensitizes Triple-negative breast cancer to ferroptosis by SCD1-mediated lipogenesis and NCOA4-mediated ferritinophagy.

INTRODUCTION: Triple-negative breast cancer (TNBC) is the primary cause of breast cancer-induced death in women. Literature has confirmed the benefits of Salidroside (Sal) in treating TNBC. However, the study about potential therapeutic targets and mechanisms of Sal-anchored TNBC remains limited. OBJECTIVE: This study was designed to explore the main targets and potential mechanisms of Sal against TNBC. METHODS: Network pharmacology, bioinformatics, and machine learning algorithm strategies were integrated to examine the role, potential targets, and mechanisms of the Sal act in TNBC. MDA-MB-231 cells and tumor-bearing nude mice were chosen for in vitro and in vivo experimentation. Cell viability and cytotoxicity were determined using CCK-8, LDH test, and Calcein-AM/PI staining. Antioxidant defense, lipid peroxidation, and iron metabolism were explored using glutathione, glutathione peroxidase, malondialdehyde (MDA), C11-BODIPY 581/591 probe, and FerroOrange dye. Glutathione peroxidase 4 (GPX4) or stearoyl-CoA desaturase 1 (SCD1) overexpression or nuclear receptor co-activator 4 (NCOA4) deficiency was performed to demonstrate the mechanism of Sal on TNBC. RESULTS: The prediction results confirmed that 22 ferroptosis-related genes were identified in Sal and TNBC, revealing that the potential mechanism of the Sal act on TNBC was linked with ferroptosis. Besides, these genes were mainly involved in the mTOR, PI3K/AKT, and autophagy signaling pathway by functional enrichment analysis. The in vitro validation results confirmed that Sal inhibited TNBC cell proliferation by modulating ferroptosis via elevation of intracellular Fe2+ and lipid peroxidation. Mechanistically, Sal sensitized TNBC cells to ferroptosis by inhibiting the PI3K/AKT/mTOR axis, thereby suppressing SCD1-mediated lipogenesis of monounsaturated fatty acids to induce lipid peroxidation, additionally facilitating NCOA4-mediated ferritinophagy to increase intracellular Fe2+ content. The GPX4 or SCD1 overexpression or NCOA4 deficiency results further supported our mechanistic studies. In vivo experimentation confirmed that Sal is vital for slowing down tumor growth by inducing ferroptosis. CONCLUSIONS: Overall, this study elucidates TNBC pathogenesis closely linked to ferroptosis and identifies potential biomarkers in TNBC. Meanwhile, the study elucidates that Sal sensitizes TNBC to ferroptosis by SCD1-mediated lipogenesis and NCOA4-mediated ferritinophagy, regulated by PI3K/AKT/mTOR signaling pathways. Our findings provide a theoretical basis for applying Sal to treat TNBC.

NAT10/ac4C/JunB facilitates TNBC malignant progression and immunosuppression by driving glycolysis addiction.

BACKGROUND: N4-Acetylcytidine (ac4C), a highly conserved post-transcriptional mechanism, plays a pivotal role in RNA modification and tumor progression. However, the molecular mechanism by which ac4C modification mediates tumor immunosuppression remains elusive in triple-negative breast cancer (TNBC). METHODS: NAT10 expression was analyzed in TNBC samples in the level of mRNA and protein, and compared with the corresponding normal tissues. ac4C modification levels also measured in the TNBC samples. The effects of NAT10 on immune microenvironment and tumor metabolism were investigated. NAT10-mediated ac4C and its downstream regulatory mechanisms were determined in vitro and in vivo. The combination therapy of targeting NAT10 in TNBC was further explored. RESULTS: The results revealed that the loss of NAT10 inhibited TNBC development and promoted T cell activation. Mechanistically, NAT10 upregulated JunB expression by increasing ac4C modification levels on its mRNA. Moreover, JunB further up-regulated LDHA expression and facilitated glycolysis. By deeply digging, remodelin, a NAT10 inhibitor, elevated the surface expression of CTLA-4 on T cells. The combination of remodelin and CTLA-4 mAb can further activate T cells and inhibite tumor progression. CONCLUSION: Taken together, our study demonstrated that the NAT10-ac4C-JunB-LDHA pathway increases glycolysis levels and creates an immunosuppressive tumor microenvironment (TME). Consequently, targeting this pathway may assist in the identification of novel therapeutic strategies to improve the efficacy of cancer immunotherapy.

Repurposing propofol for breast cancer therapy through promoting apoptosis and arresting cell cycle.

Breast cancer is the most prevalent cancer among women worldwide, characterized by a high mortality rate and propensity for metastasis. Although surgery is the standard treatment for breast cancer, there is still no effective method to inhibit tumor metastasis and improve the prognosis of patients with breast cancer after surgery. Propofol, one of the most widely used intravenous anesthetics in surgery, has exhibited a positive association with improved survival outcomes in patients with breast cancer post­surgery. However, the underlying molecular mechanism remains to be elucidated. The present study revealed that triple negative breast cancer cells, MDA­MB­231 and 4T1, exposed to propofol exhibited a significant decrease in cell viability. Notably, propofol exhibited minimal cytotoxic effects on HUVECs under the same conditions. Furthermore, propofol significantly inhibited the migration and invasion ability of MDA­MB­231 and 4T1 cells. Propofol promoted apoptosis in 4T1 cells through upregulation of Bax and cleaved caspase 3, while downregulating B­cell lymphoma­extra large. Concomitantly, propofol induced cell cycle arrest of 4T1 cells by downregulating cyclin E2 and phosphorylated cell division cycle 6. Furthermore, propofol exhibited excellent anticancer efficacy in a 4T1 breast cancer allograft mouse model. The present study sheds light on the potential of propofol as an old medicine with a novel use for breast cancer treatment.

Primary breast lymphoma mimicking triple-negative breast cancer: a case report with clinical and pathological implications.

BACKGROUND: Primary breast lymphoma (PBL) is a rare type of extranodal lymphoma, the diagnostic process for which presents significant challenges owing to an overlap in clinical and pathological features with those observed in triple-negative breast cancer (TNBC). However, the current literature reveals a paucity of information regarding the ramifications of potential diagnostic errors, particularly in the context of emergent therapeutic strategies for TNBC. Thus, we present a unique report of a case of PBL. CASE PRESENTATION: A 76-year-old female with no past medical or family history presented to the hospital with the chief complaint of a mass in the right breast. Two masses were palpated in the right breast: one 56 mm mass (No. 1) located at 10 o'clock, and a 21 mm large, elastic, hard mass (No. 2) at 4 o'clock. Needle biopsy was performed only on the larger 56 mm mass (No. 1). The results showed invasive carcinoma that was negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. The preoperative diagnosis was right breast cancer (T3N0M0 Stage IIB) of the TNBC subtype. The patient refused the preoperative chemotherapy recommended by the treatment team; therefore, right breast mastectomy and sentinel lymph-node biopsy were performed instead. The histopathological diagnosis of the first mass was diffuse large B-cell lymphoma (DLBCL); that of the second mass (No. 2) was an invasive breast carcinoma of no special type. Postoperative treatment consisted of endocrine therapy (letrozole) for breast cancer, while the DLBCL was treated with chemotherapy and three courses of intrathecal chemotherapy. At the time of this report, the patient is still living, and neither tumor had recurred in the 2 years following surgery. CONCLUSIONS: On rare occasions, PBL can preoperatively mimic TNBC. While this case did not lead to serious consequences, because surgery was eventually selected as the first therapy, clinicians should be aware that the diagnosis of PBL is challenging using only a core-needle biopsy and can often be misdiagnosed as TNBC.

Uncovering novel pathogenic variants and pathway mutations in triple-negative breast cancer among the endogamous mizo tribe.

PURPOSE: The incidence of triple-negative breast cancer (TNBC) in India is higher compared to Western populations. The objective of this study is to identify novel and less reported variants in TNBC in Mizoram, a state with a high cancer incidence in India. METHODS: We analysed whole exome sequencing data from triple-negative breast cancer (TNBC) patients in the Mizo population to identify key and novel variants. Moreover, we analysed reported breast cancer-related genes and pathway alterations. RESULTS: Somatic mutation analysis revealed that TP53 was the most frequently mutated gene and TP53, CACNA1E, IGSF3, RYR1, and FAM155A as significantly mutated driver genes. Based on the ACMG guidelines, we identified a rare pathogenic germline variant of BRCA1 (p.C1697R) in 13% and a likely pathogenic frameshift insertion in RBMX (p.P106Ffs) in 73% of the patients. We also found that the ATM, STK11, and CDKN2A genes were significantly mutated in germline TNBC samples compared to healthy samples. Moreover, we identified novel somatic variants in CHEK2 (p.K182M) and NF1 (p.C245X), and novel germline variants RB1 (p.D111G), CDH1 (p.A10Gfs), CDKN2A (p.V96G), CDKN2A (p.S12Afs*22), MAP3K1 (CAAdelins0), MSH6 (p.L1226_L1230del), and PMS2 (TTCdelins0). Pathway analysis revealed that most somatic mutations were highly associated with PI3K-Akt signalling pathway and MAPK signalling pathways in TNBC. CONCLUSIONS: These findings identified novel variants and key genes contributing to disease development and progression. Further analysis of less studied genes, including RBMX, MRC1, ATM, CTNNB1, and CDKN2A, in TNBC may reveal new potential genes for targeted therapeutic strategies and contribute to clinical advancements in the treatment of TNBC.

BRCA promoter methylation in triple-negative breast cancer is preserved in xenograft models and represents a potential therapeutic marker for PARP inhibitors.

PURPOSE: Most triple-negative breast cancers (TNBC) are sporadic in nature and often associated with dysfunction of the BRCA1 or BRCA2 genes. Since somatic BRCA mutations are rare in breast cancer (BC), this dysfunction frequently is the result of BRCA promoter methylation. Despite the phenotypic similarities of these tumors to those with germline or somatic BRCA mutation, the evidence of response to PARP inhibitors is unclear. METHODS: We analyzed the prevalence of BRCA promoter methylation in 29 BC metastases through the well-established Illumina Infinium EPIC Human Methylation Bead Chip. In cases with BRCA methylation, the xenograft of the same tumor was tested. Additionally, we compared BC xenografts with an identified BRCA methylation to their matched primary tumors and subsequently investigated the efficacy of PARP inhibitors on tumor organoids from a BRCA2 promoter-methylated BC. RESULTS: BRCA2 promotor hypermethylation was identified in one pleural metastasis of a young patient as well as in the xenograft tissue. We also identified five more xenograft models with BRCA2 promotor hypermethylation. Analysis of one matched primary tumor confirmed the same BRCA2 methylation. PARP inhibitor treatment of tumor organoids derived from the BRCA2 methylated xenograft tumor tissue of the young patient showed a significant decline in cell viability, similar to organoids with somatic BRCA1 mutation, while having no effect on organoids with BRCA1 wildtype. CONCLUSION: BRCA promotor hypermethylation seems to be a rare event in metastatic BC but is preserved in subsequent xenograft models and might represent an attractive therapeutic marker for PARP inhibitors.

Efficacy and safety of Anlotinib based neoadjuvant chemotherapy for locally advanced triple negative breast cancer (TNBC).

BACKGROUND: Anlotinib, an oral multitarget tyrosine kinase inhibitor, has shown the ability to inhibit tumor angiogenesis. This study aimed to assess the effectiveness and safety of anlotinib plus docetaxel, epirubicin, and cyclophosphamide (TEC) as a neoadjuvant chemotherapy regimen for locally advanced TNBC. METHODS: Locally advanced TNBC patients who had received no prior systemic treatment were eligible for this study. The enrolled patients were scheduled to undergo six cycles of anlotinib (12 mg, d1-14, q3w) plus docetaxel (75 mg/m2, d1, q3w), epirubicin (75 mg/m2, d1, q3w) and cyclophosphamide (600 mg/m2, d1, q3w) prior to surgery, unless there was disease progression or severe toxicity. The primary objective of this study was the safety of this therapeutic regimen, and the secondary objective was the tumor response. The safety of this regimen was assessed using Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 and the efficacy of this treatment was measured using the Response Evaluation Criteria in Solid Tumors version 1.1. RESULTS: A total of 18 patients were included in this study. Participants completed an average of 5.56 neoadjuvant treatment cycles. The objective response rate (ORR) was 83.33%, and the disease control rate was 100%, respectively. The pCR was 55.6%. No patients discontinued therapy because of Adverse effects (AEs). Grade 3 or 4 AEs were observed in 5 cases (27.8%), with neutropenia and palmar-plantar erythrodysesthesia syndrome being the most common. CONCLUSIONS: Anlotinib combined with TEC as neoadjuvant therapy demonstrated manageable toxicity and promising antitumor activity for locally advanced TNBC. Further investigation of this combination regimen is warranted.

Synergistic effect of bazedoxifene and abemaciclib co­treatment in triple­negative breast cancer cells in vitro.

Triple-negative breast cancer (TNBC) is an aggressive disease with the capability of metastasizing quickly. However, treatment options for patients with TNBC still remain limited. CDK4/6 inhibitors have been approved by the U.S. Food and Drug Administration and are administered for the treatment of hormone receptor-positive breast cancer subtypes, but not yet for TNBC. Although pre-clinical research is being conducted on their efficacy in treating TNBC, acquired resistance to CDK4/6 inhibitors is now a growing clinical problem. One of the identified resistance mechanisms is through the IL-6/STAT3 signaling pathway. In the present study, the CDK4/6 inhibitor, abemaciclib, was tested in combination with the IL-6 inhibitor, bazedoxifene, on human (SUM159 and MDA-MB-231) and murine (4T1) TNBC cell lines. Both abemaciclib and bazedoxifene monotherapies inhibited cell cycle progression and cell viability, migration and invasion, and induced apoptosis; however, the combination treatment exerted a greater effect than either monotherapy. These findings support the concept of CDK4/6 and IL-6 dual inhibition as a novel targeted therapy against TNBC.

Epithelial-Mesenchymal Transition Indexes in Triple-Negative Breast Cancer Progression and Metastases.

Background Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer characterized by the lack of expression of estrogen and progesterone receptors and the absence of HER2 protein overexpression or gene amplification. How TNBC becomes so aggressive at the molecular level is not yet fully understood. The epithelial-mesenchymal transition (EMT) has been increasingly recognized as playing a pivotal role in cancer progression and metastasis. This study aimed to elucidate the connection between TNBC progression with EMT-related markers, including vimentin, beta-catenin, and E-cadherin. Methodology Rigorous immunohistochemical analysis was employed to assess the expression of vimentin, beta-catenin, and E-cadherin in primary tumors, tumor buds, and lymph node metastases (LNMs) from 137 cases with an invasive ductal carcinoma triple-negative phenotype diagnosed between 2018 and 2024. The EMT index, which was especially important in our work, is the sum of vimentin and beta-catenin expression divided by that of E-cadherin. Estimated Pearson correlation, multiple linear regression, and Kruskal-Wallis tests were used to determine the relationships of the EMT index with tumor buds and tumor-infiltrating lymphocytes (TILs). Results Vimentin highly correlated within separate regions of interest with Pearson correlation ranging from 0.90 to 0.92 (p < 0.001). Strong negative correlations between E-cadherin and vimentin (r = -0.81 to - 0.89, p < 0.001) showed its role in preserving the epithelial phenotype. The presence of tumor buds, aggregates, or clusters of cancer cells shed from the primary tumor mass invading the connective tissue showed very strong associations with the EMT index (r = 0.91, p < 0.001). Its presence is suggestive of aggressive disease and may identify a high-risk subpopulation that may benefit from more active surveillance or adjuvant treatment. Similarly, TILs correlated inversely with the EMT index (r = -0.90, p < 0.001). The most significant predictor of the EMT index, i.e., vimentin, had a model R-squared value of 1.000 in the regression analysis. Conclusions This study brings to light the importance of EMT-related markers in TNBC progression, with special emphasis on tumor buds as possible prognostic indicators for aggressive disease. The negative correlation of TILs with the EMT index indicates that an effective immune response could antagonize EMT-mediated tumor progression. These results suggest that EMT-based treatments in TNBC should be designed from a multimarker perspective by including interactions among several markers to optimize predictions and therapeutics. The results hold the potential to set future research directions and actionable outcomes that could influence clinical utility in the battle against TNBC.

Serum and Fecal Metabolite Profiles Linking With Gut Microbiome in Triple-Negative Breast Cancer Patients.

Background: Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by poor prognosis due to the absence of effective targeted therapies. Emerging evidence indicates that the gut microbiota and its metabolites play a key role in the occurrence and development of TNBC. This study aimed to explore the metabolic changes and potential mechanisms associated with TNBC. Objectives: This study aimed to explore the potential relationship between targeted metabolites and the gut microbiota in TNBC. Design: We recruited 8 participants, including 4 with TNBC and 4 with benign fibroadenomas as controls. Methods: The gut microbiota was analyzed using metagenomics on fecal samples. Liquid chromatography-mass spectrometry (LC-MS) was employed to identify differential metabolites in serum and fecal samples. The correlation between the gut microbiota and metabolites was analyzed using Spearman's correlation analysis. Results: Analysis of altered serum metabolites in the TNBC group revealed changes, particularly in carboxylic acids and derivatives, benzene, and substituted derivatives. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis revealed significant enrichment in 18 pathways. Regarding fecal metabolites, differences between the 2 groups also included carboxylic acids and derivatives, benzene, and substituted derivatives, with 28 metabolic pathways enriched based on KEGG pathway analysis. Metagenomics analysis showed differences in the relative abundance of Anaerococcus, Fischerella, and Schizosaccharomyces at the genus level, which have been previously associated with breast cancer. Furthermore, 4 serum metabolites-L-glutamine, citrate, creatinine, and creatine-along with 9 fecal metabolites, were associated with the aforementioned microbiota. Conclusion: Our findings highlight distinct metabolite profiles in the serum and feces of patients with TNBC. The identification of gut microbiota and their associated metabolites provides new insights into the pathophysiological mechanisms underlying TNBC.

Leveraging single-cell transcriptomic data to uncover immune suppressive cancer cell subsets in triple-negative canine breast cancers.

Introduction: Single-cell RNA sequencing (scRNA-seq) has become an essential tool for uncovering the complexities of various physiological and immunopathological conditions in veterinary medicine. However, there is currently limited information on immune-suppressive cancer subsets in canine breast cancers. In this study, we aimed to identify and characterize immune-suppressive subsets of triple-negative canine breast cancer (TNBC) by utilizing integrated scRNA-seq data from published datasets. Methods: Published scRNA-seq datasets, including data from six groups of 30 dogs, were subjected to integrated bioinformatic analysis. Results: Immune modulatory TNBC subsets were identified through functional enrichment analysis using immune-suppressive gene sets, including those associated with anti-inflammatory and M2-like macrophages. Key immune-suppressive signaling, such as viral infection, angiogenesis, and leukocyte chemotaxis, was found to play a role in enabling TNBC to evade immune surveillance. In addition, interactome analysis revealed significant interactions between distinct subsets of cancer cells and effector T cells, suggesting potential T-cell suppression. Discussion: The present study demonstrates a versatile and scalable approach to integrating and analyzing scRNA-seq data, which successfully identified immune-modulatory subsets of canine TNBC. It also revealed potential mechanisms through which TNBC promotes immune evasion in dogs. These findings are crucial for advancing the understanding of the immune pathogenesis of canine TNBC and may aid in the development of new immune-based therapeutic strategies.

Genomic and transcriptomic profiling of pre- and postneoadjuvant chemotherapy triple negative breast cancer tumors.

Our understanding of neoadjuvant treatment with microtubule inhibitors (MTIs) for triple negative breast cancer (TNBC) remains limited. To advance our understanding of the role of breast cancer driver genes' mutational status with pathological complete response (pCR; ypT0/isypN0) prediction and to identify distinct gene sets for MTIs like eribulin and paclitaxel, we carried out targeted genomic (n = 50) and whole transcriptomic profiling (n = 64) of TNBC tumor samples from the Japan Breast Cancer Research Group 22 (JBCRG-22) clinical trial. Lower PIK3CA, PTEN, and HRAS mutations were found in homologous recombination deficiency (HRD)-high (HRD score ≥ 42) tumors with higher pCR rates. When HRD-high tumors were stratified by tumor BRCA mutation status, the pCR rates in BRCA2-mutated tumors were higher (83% vs. 36%). Transcriptomic profiling of TP53-positive tumors identified downregulation of FGFR2 (false discovery rate p value = 2.07e-7), which was also the only common gene between HRD-high and -low tumors with pCR/quasi-pCR treated with paclitaxel and eribulin combined with carboplatin, respectively. Differential enrichment analysis of the HRD-high group posttreatment tumors revealed significant correlation (p = 0.006) of the glycan degradation pathway. FGFR2 expression and the differentially enriched pathways play a role in the response and resistance to MTIs containing carboplatin treatment in TNBC patients.

Developing combination therapies with biologics in triple-negative breast cancer.

INTRODUCTION: Novel compounds have entered the triple-negative breast cancer (TNBC) treatment algorithm, namely immune checkpoints inhibitors (ICIs), PARP inhibitors and antibody-drug conjugates (ADCs). The optimization of treatment efficacy can be enhanced with the use of combination treatments, and the incorporation of novel compounds. In this review, we discuss the combination treatments under development for the treatment of TNBC. AREAS COVERED: The development of new drugs occurring in recent years has boosted the research for novel combinations to target TNBC heterogeneity and improve outcomes. ICIs, ADCs, tyrosine kinase inhibitors (TKIs), and PARP inhibitors have emerged as leading players in this new landscape, while other compounds like novel intracellular pathways inhibitors or cancer vaccines are drawing more and more interest. The future of TNBC is outlined in combination approaches, and based on new cancer targets, including many chemotherapy-free treatments. EXPERT OPINION: A large number of TNBC therapies have either proved clinically ineffective or weighted by unacceptable safety profiles. Others, however, have provided promising results and are currently in late-stage clinical trials, while a few have actually changed clinical practice in recent years. As novel, more and more selective drugs come up, combination strategies focusing the concept of synergy are fully warranted for the future.

89Zr-Labeled DFO@Durvalumab-HSA nanoparticles: In vitro potential for triple-negative breast cancer.

This study presents the development and evaluation of a DFO@mAb-NP (DFO@Durvalumab-HSA-DTX nanoparticle) nanoplatform for imaging in triple-negative breast cancer (TNBC). The nanoplatform demonstrated significant changes postconjugation with DFO, evidenced by increased particle size from 178.1 ± 5 nm to 311 ± 26 nm and zeta potential alteration from -31.9 ± 3 mV to -40.5 ± 0.8 mV. Fourier-transform infrared spectroscopy and ultraviolet spectral analyses confirmed successful DFO conjugation, with notable shifts in peak wavelengths. High labeling efficiency was achieved with 89Zr, as indicated by thin layer radio chromatography and high-performance liquid radio chromatography results, with labeling efficiencies of 98 ± 2% for 89Zr-DFO@mAb and 96 ± 3% for 89Zr-DFO@mAb-NP. The nanoplatforms maintained stability over 24 h, showing less than 5% degradation. Lipophilicity assays revealed logP values of 0.5 ± 0.03 for 89Zr-DFO@mAb-NP and 0.98 ± 0.2 for 89Zr-DFO@mAb, indicating a higher lipophilic tendency in the radiolabeled Durvalumab. Cell uptake experiments showed an initial high uptake in MDA-MB-468 cells (45.1 ± 3.2%), which decreased over time, highlighting receptor-specific interactions. These comprehensive findings suggest the promising potential of the DFO@mAb-NP nanoplatform for targeted imaging in TNBC, with implications for improved diagnostic accuracy and treatment strategies.

Discovery of dual-targeted molecules based on Olaparib and Rigosertib for triple-negative breast cancer with wild-type BRCA.

PARP inhibitors (PARPis) demonstrate significant potential efficacy in the clinical treatment of BRCA-mutated triple-negative breast cancer (TNBC). However, a majority of patients with TNBC do not possess BRCA mutations, and therefore cannot benefit from PARPis. Previous studies on multi-targeted molecules derived from PARPis or disruptors of RAF-RAF pathway have offered an alternative approach to develop novel anti-TNBC agents. Hence, to broaden the application of PARP inhibitors for TNBC patients with wild-type BRCA, a series of dual-targeted molecules were constructed via integrating the key pharmacophores of Olaparib (Ola) and Rigosertib into a single entity. Subsequent studies exhibited that the resulting compounds 13a-14c obtained potential anti-proliferative activity against BRCA-defected or wild-type TNBC cells. Among them, an optimal compound 13b showed good inhibitory activity toward PARP-1, displayed approximately 34-fold higher inhibitory activity than that of Ola in MDA-MB-231 cells, and exerted multi-functional mechanisms to induce apoptosis. Moreover, 13b displayed superior antitumor efficacy (TGI, 61.3 %) than the single administration of Ola (TGI, 38.5 %), 11b (TGI, 51.8 %) or even their combined administration (TGI, 56.7 %), but did not show significant systematic toxicity. These findings suggest that 13b may serve as a potential candidate for BRCA wild-type TNBC.