Outcomes In Triple-negative Breast Cancer Research Articles

Prognostic impact of tumor‑associated stroma in triple-negative breast cancer.

To establish the histological categorization of tumor‑associated stroma (TAS) that reflects the biological behavior of triple-negative breast cancer (TNBC). One-hundred-and-twenty surgically resected cases of TNBC were examined. We histologically categorized the TAS in the invasive frontal region into two groups: mature stroma (MS) and immature stroma (IS). The designation of IS was applied for tumors in which the largest myxoid stroma filled a high-power magnification field. When there were no myxoid stroma that meet the criteria for IS, TAS was categorized as MS. The tumors with type MS were observed in 103 (85.8%) of patients, whereas 17 (14.2%) of patients had tumors with IS. In total, 72 out of 120 patients with TNBC exhibited high tumor-infiltrating lymphocytes (TILs) representing 60% of the cohort. The incidences of high TILs were 66% (68 out of 103) in the MS group but only 23.5% (4 of 17) in the IS group (p = 0.001). Progression-free survival (PFS) and overall survival (OS) curves were different between IS and MS groups (p < 0.001 each), and Cox multivariate regression analysis revealed that IS was an independent indicator for lower PFS and OS rates (p < 0.001; p = 0.008). Our findings suggest that TAS characteristics, particularly the distinction between IS and MS, play a significant role in the prognosis of TNBC. The presence of IS, associated with poor prognosis and low TILs, contrasts with the favorable outcomes observed in cases with MS. Understanding these TAS dynamics could aid in identifying patients with varying prognostic outcomes in TNBC, necessitating further research into the mechanisms behind these observations.

Combining ultrasound technology with targeted fucoidan/arginine-gelatin nanoparticles loaded with doxorubicin to enhance therapeutic efficacy and modulate bioeffects in drug-resistant triple-negative breast cancer.

Triple-negative breast cancer (TNBC) presents formidable challenges due to its aggressive nature and high recurrence rates, compounded by the involvement of epithelial-mesenchymal transition (EMT) in its progression and metastasis. Standard chemotherapy, which typically employs doxorubicin (DOX), remains a primary treatment approach. However, multidrug resistance (MDR) mechanisms, which include ATP-binding cassette transporters and EMT, contribute to treatment failures. Ultrasound has emerged as a promising modality among the various strategies explored to address MDR in TNBC. It serves as a diagnostic tool and holds therapeutic potential by inducing various biological effects depending on the exposure level. Targeted nanoparticles offer a means to enhance drug delivery efficiency. Our study aims to advance ultrasound technology combined with biocompatible nanoparticles using simplified preparation methods to improve treatment outcomes for drug-resistant TNBC. In particular, employing DOX-loaded fucoidan/arginine-gelatin nanoparticles facilitated the targeted delivery of chemotherapy drugs to tumors by effectively interacting with P-selectin, resulting in tumor growth inhibition. Furthermore, these nanoparticles mitigated MDR and EMT, particularly when combined with ultrasound treatment. This integrated approach of nanoparticle delivery with ultrasonography opens up a promising and innovative avenue for clinical cancer research.

Clinico-pathological Profile of Triple-negative Breast Cancer (TNBC) And Comparative Analysis Of Oncological Outcomes Of TNBC Vs. Non-TNBC: A Tertiary Care Centre Experience From Eastern India

Clinico-pathological Profile of Triple-negative Breast Cancer (TNBC) And Comparative Analysis Of Oncological Outcomes Of TNBC Vs. Non-TNBC: A Tertiary Care Centre Experience From Eastern India

Plant-derived extracellular vesicles release combined with systemic DOX exhibits synergistic effects in 3D bioprinted triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer, lacking targeted therapeutic options. Hydrogels, particularly gelatin methacrylate (GelMA), have emerged as promising materials for localized drug delivery due to their biocompatibility and tunable properties. This study investigates a dual-delivery system for enhancing the treatment efficacy of triple-negative breast cancer (TNBC) using a combination of extracellular vesicles (EVs) derived from Citrus limon L. and the chemotherapeutic drug doxorubicin (DOX). We fabricated 3D bioprinted GelMA scaffolds to achieve localized and controlled release of EVs and evaluated their synergistic effects with systemic DOX delivery on both primary and metastatic 3D TNBC models.The GelMA scaffolds, especially those with 95 % methacrylation, exhibited higher stiffness, which enhanced their sustained release. Following 48-h incubation, the combination of EVs and DOX significantly increased cytotoxicity in the primary 3D TNBC model, reducing cell viability to approximately 30 % compared to controls. This was notably more effective than treatments with DOX or EVs alone. During the extended 7-day incubation period, the combination treatment continued to show superior efficacy, with persistently high levels of ROS generation and further reduction in cell viability. In a metastatic 3D TNBC model, a significant sensitivity to the combined treatment was observed, which notably inhibited aggregate formation and migration. Importantly, EVs-embedded scaffolds promoted the proliferation of human fibroblasts, highlighting their non-toxic nature, while concurrently inhibiting TNBC cell growth. This approach provides a promising strategy to improve the treatment outcomes of TNBC by exploiting the synergistic effects of local EVs release and systemic chemotherapy.

SLFN12 Expression Significantly Effects the Response to Chemotherapy Drugs in Triple-Negative Breast Cancer.

Schlafen12 (SLFN12) is an intermediate human Schlafen protein shown to correlate with survivability in triple-negative breast cancer (TNBC). SLFN12 causes differential expressions of significant cancer genes, but how they change in response to chemotherapy remains unknown. Our aim is to identify the effect of chemotherapy on genes that improve TNBC outcomes and other SLFN family members following SLFN12 knockout or overexpression. We overexpressed SLFN12 using a lentiviral vector and knocked out SLFN12 (AdvShSLFN12) using a hairpin adenovirus in MDA-MB-231 TNBC cells. Cells were treated with camptothecin, paclitaxel, zoledronic acid, or carboplatin to evaluate the SLFN12 signature cancer genes associated with improved TNBC outcomes using qPCR. Additionally, cells were treated alone and in combination with AdvShSLFN12, IFN-α2 (known SLFN12 stimulator), carboplatin, and paclitaxel. After treatment, the viable cell numbers were analyzed utilizing a colorimetric crystal violet assay for cell viability. The SLFN family and SLFN12 cancer signature gene mRNA expressions were analyzed by RT-qPCR. Treating SLFN12-overexpressing TNBC cells with chemotherapy agents resulted in the differential expressions of eight cancer-related genes. Notably, GJB3 was downregulated following treatment with each chemotherapeutic drug. Inducing SLFN12 with IFN-α2 resulted in decreased cell viability and increased SLFN12 mRNA levels following treatment with paclitaxel or carboplatin. These results suggest that SLFN12 overexpression significantly affects the expressions of genes driving phenotypic changes in response to chemotherapy and influences additional SLFN family members following IFN-α2 treatment. This may contribute to improving the survival of patients with SLFN12 overexpression. Additionally, patient SLFN12 levels can be used as a factor when pursuing personalized chemotherapy treatments.

Systemic chemokine-modulatory regimen combined with neoadjuvant chemotherapy in patients with triple-negative breast cancer

BackgroundHigher cytotoxic T lymphocyte (CTL) numbers in the tumor microenvironment (TME) predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) and positive long-term outcomes in triple-negative breast cancer (TNBC). pCR...

Spatial Architecture of Single-Cell and Vasculature in Tumor Microenvironment Predicts Clinical Outcomes in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited treatment options, which warrants the identification of novel therapeutic targets. Deciphering nuances in the tumor microenvironment (TME) may unveil insightful links between antitumor immunity and clinical outcomes; however, such connections remain underexplored. Here, we employed a data set derived from imaging mass cytometry of 71 TNBC patient specimens at single-cell resolution and performed in-depth quantifications with a suite of multiscale computational algorithms. The TNBC TME reflected a heterogeneous ecosystem with high spatial and compositional heterogeneity. Spatial analysis identified 10 recurrent cellular neighborhoods—a collection of local TME characteristics with unique cell components. The prevalence of cellular neighborhoods enriched with B cells, fibroblasts, and tumor cells, in conjunction with vascular density and perivasculature immune profiles, could significantly enrich long-term survivors. Furthermore, relative spatial colocalization of SMAhi fibroblasts and tumor cells compared with B cells correlated significantly with favorable clinical outcomes. Using a deep learning model trained on engineered spatial data, we can predict with high accuracy (mean AUC of 5-fold cross-validation = 0.71) how a separate cohort of patients in the NeoTRIP clinical trial will respond to treatment based on baseline TME features. These data reinforce that the TME architecture is structured in cellular compositions, spatial organizations, vasculature biology, and molecular profiles and suggest novel imaging-based biomarkers for the treatment development in the context of TNBC.

Obesity and lack of breastfeeding: a perfect storm to augment risk of breast cancer?

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer with higher rates of recurrence and distant metastasis, as well as decreased 5-year survival rates. Racial disparities are evident in the incidence and mortality rates of triple negative breast cancer particularly increased in young African American women. Concurrently, young African American women have multiple risk factors for TNBC including higher rates of premenopausal abdominal obesity (higher waist-hip ratio) and lower rates of breastfeeding with higher parity, implicating these factors as potentially contributors to poor outcomes. By understanding the mechanisms of how premenopausal obesity and lack of breastfeeding may be associated with increased risk of triple negative breast cancer, we can determine the best strategies for intervention and awareness to improve outcomes in TNBC.

Immune modulation and epigenetic therapies for enhanced outcome of treatment in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by the absence of human epidermal growth factor receptor 2, estrogen receptor, and progesterone receptor expression. While traditional TNBC treatment primarily relies on systemic chemotherapy, epigenetic modification has an important role in immune evasion and tumor progression. Recent classifications of TNBC into &amp;ldquo;hot&amp;rdquo; and &amp;ldquo;cold&amp;rdquo; tumors, based on immune activity and mutation burden, have revealed that poor response to immune checkpoint inhibitors (ICIs) in these tumors is due to low tumor-infiltrating lymphocytes and the presence of immunosuppressive cells. Emerging treatments such as ICIs and poly(ADP-ribose) polymerase inhibitors offer promising alternatives. The tumor microenvironment (TME) shapes immune responses in TNBC, and a limited subset of patients has shown encouraging responses to ICIs in treating TNBC at both early and advanced stages. However, combination therapies face challenges, including medication interactions and side effects. Epigenetic modulators, such as histone deacetylase and DNA methyltransferase inhibitors, also show promise in reversing epigenetic changes by enhancing anti-tumor immunity in TNBC. The frequent expression of indoleamine 2,3-dioxygenase 1 (IDO1) in TNBC, which catalyzes the conversion of tryptophan to kynurenine, contributes to immune suppression in TNBC patients. High IDO1 levels impair the tumoricidal activity of natural killer cells and correlate with poor responses to anti-PD-L1 therapy, which can be improved using IDO1 inhibitors. Targeting myeloid-derived suppressor cells, regulatory T-cells, and tumor-associated macrophage, along with utilizing epigenetic mechanisms, show promise in modulating the immunosuppressive TME in TNBC. Combining these approaches with standard therapies, along with biomarker-guided patient selection, can enhance treatment efficacy. Clinical trials and preclinical models are essential for optimizing these strategies. This study emphasizes the importance of understanding the mechanisms of modulation, tumor-immune interactions, and the potential of epigenetic therapies in improving treatment outcomes in TNBC.

TNBC-DX genomic test in early-stage triple-negative breast cancer treated with neoadjuvant taxane-based therapy

Identification of biomarkers to optimize treatment strategies for early-stage triple-negative breast cancer (TNBC) is crucial. This study presents the development and validation of TNBC-DX, a novel test aimed at predicting both short- and long-term outcomes in early-stage TNBC. The objective of this study was to evaluate the association between TNBC-DX and efficacy outcomes [pathologic complete response (pCR), distant disease-free survival (DDFS) or event-free survival (EFS), and overall survival (OS)] in the validation cohorts. Information from 1259 patients with early-stage TNBC (SCAN-B, CALGB-40603, and BrighTNess) was used to establish the TNBC-DX scores. Independent validation of TNBC-DX was carried out in three studies: (i) WSG-ADAPT-TN; (ii) MMJ-CAR-2014-01; and (iii) NeoPACT, including 527 patients with stage I-III TNBC undergoing neoadjuvant chemotherapy. In WSG-ADAPT-TN, patients were randomized to receive nab-paclitaxel plus gemcitabine or carboplatin. In MMJ-CAR-2014-01, patients received carboplatin plus docetaxel. In NeoPACT, patients received carboplatin plus docetaxel and pembrolizumab. TNBC-DX test was created incorporating the 10-gene Core Immune Gene module, the 4-gene tumor cell proliferation signature, tumor size, and nodal staging. In the two independent validation cohorts without pembrolizumab, the TNBC-DX pCR score was significantly associated with pCR after adjustment for clinicopathological variables and treatment regimen [odds ratio per 10-unit increment 1.34, 95% confidence interval (CI) 1.20-1.52, P < 0.001]. pCR rates for the TNBC-DX pCR-high, pCR-medium, and pCR-low categories were 56.3%, 53.6%, and 22.5% respectively (odds ratio for pCR-high versus pCR-low 3.48, 95% CI 1.72-7.15, P < 0.001). Inaddition, the TNBC-DX risk score was significantly associated with DDFS [hazard ratio (HR) high-risk versus low-risk 0.24, 95% CI 0.15-0.41, P < 0.001] and OS (HR 0.19, 95% CI 0.11-0.35, P < 0.001). In the validation cohort with pembrolizumab, the TNBC-DX scores were significantly associated with pCR, EFS, and OS. TNBC-DX predicts pCR to neoadjuvant taxane-carboplatin in stage I-III TNBC and helps to forecast the patient's long-term survival in the absence of neoadjuvant anthracycline-cyclophosphamide, and independent of pembrolizumab use.

179P Multimodal deep learning integrating MRI and molecular profiles for predicting outcomes in triple-negative breast cancer

179P Multimodal deep learning integrating MRI and molecular profiles for predicting outcomes in triple-negative breast cancer

A Prognostic Risk Signature of Two Autophagy-Related Genes for Predicting Triple-Negative Breast Cancer Outcomes.

Triple-negative breast cancer (TNBC) is recognized as the most aggressive molecular subtype of breast cancer. Recent studies have highlighted the complex role of autophagy in the pathogenesis of TNBC. In this study, we evaluated 18,330 genes, including 1111 autophagy-related genes, (ARGs), across 579 TNBC samples from online databases. Differentially expressed ARGs in TNBC were identified using high-throughput RNA-seq data from the Cancer Genome Atlas (TCGA). Prognostic factors were examined through Cox regression and multivariate Cox analyses, with predictive efficacy assessed using receiver operating characteristic (ROC) curves. A nomogram integrating the risk signature with clinicopathological factors, such as TNM stage, was developed. Immunohistochemical analysis of clinical samples was also conducted. EIF4EBP1 and NPAS3 were significantly correlated with prognostic outcomes in patients with TNBC. Multivariate Cox regression analysis demonstrated that the expression levels of these two genes were accurate predictors of disease progression in TNBC samples from TCGA and the GSE31519 dataset. The efficacy of this predictive model was validated using ROC curve analysis and calibration plots, confirming its ability to accurately estimate the 1-, 2-, and 3-year survival rates for individuals with TNBC. Additionally, EIF4EBP1 and NPAS3 expression influenced drug sensitivity in TNBC cell lines, with notably lower NPAS3 expression in TNBC tissues, particularly in Stage III cases. This study is the first to report NPAS3 expression in patients with TNBC. The autophagy-related genes EIF4EBP1 and NPAS3 may serve as independent prognostic factors for individuals with TNBC.

The Conflicting Prognostic Role of the Stroma–Tumor Ratio in Breast Cancer Molecular Subtypes

The tumor microenvironment plays a key role in tumor progression. The proportion of the stroma-to-tumor cells (stroma-tumor ratio [STR]) has a variable prognostic significance in breast cancer (BC) molecular classes. In this study, we evaluated the mechanisms of stroma formation and composition in different molecular subtypes, which could explain the different prognostic values. This study interrogated 2 large well-characterized BC cohorts. Firstly, an in-house BC cohort (n = 822) encompassing all BC molecular subtypes from the Nottingham series was used. In each subtype, stromal assessment was carried out, and tumors were assigned to 2 groups: high and low STR, and further correlation with tumor characteristics and patient outcomes was investigated. The contribution of tumor-infiltrating lymphocytes (TILs) to the stroma has also been studied. Secondly, the public domain data set (The Cancer Genome Atlas data [TCGA], n = 978) was used as a validation cohort and for differential gene expression (DGE) analysis. DGE was performed to identify a set of genes associated with high STR in the 3 main molecular subtypes. High STR was associated with favorable patient outcomes in the whole cohort and in the luminal subtype, whereas high STR showed an association with poor outcomes in triple-negative BC (TNBC). No association with outcome was found in the HER2 enriched BC. DGE analysis identified various pathways in luminal and TNBC subtypes, with immune upregulation and hypoxia pathways enriched in TNBC, and pathways related to fibrosis and stromal remodeling enriched in the luminal group instead. Low STR accompanied by high TILs was shown to carry the most favorable prognosis in TNBC. In line with the DGE results, TILs played a major prognostic role in the stroma of TNBC but not in the luminal or HER2-enriched subtypes. The underlying molecular mechanisms and composition of the stroma in BC are variable in the molecular subtypes and explain the difference in its prognostic significance.

Triple-Negative Breast Cancer: Molecular Particularities Still a Challenge.

Worldwide, breast cancer (BC) is one of the most common cancers in women and is responsible for the highest number of cancer-related deaths among women, with a special clinical behavior and therapy response. Triple-negative breast cancer (TNBC) is seen as a highly invasive BC, characterized by a short survival, higher mortality, recurrence, and metastasis when it is compared to the other BC subtypes. The molecular subtyping of TNBC based on mRNA expression levels does not accurately reflect protein expression levels, which impacts targeted therapy effectiveness and prognostic predictions. Most TNBC cases exhibit a high frequency of homologous recombination (HR) DNA repair deficiency (HRD) signatures and are associated with a complex genomic profile. Biomarker research in TNBC includes investigating genetic mutations, gene expression patterns, immune system-related markers, and other factors that can provide valuable information for diagnosis, treatment selection, and patient outcomes. Additionally, these biomarkers are often crucial in the development of personalized and precision medicine approaches, where treatments are customized to each patient's unique characteristics. This ongoing research is essential for improving the management and outcomes of TNBC, which is a challenging and heterogeneous form of breast cancer. The findings of this research have practical implications for refining treatment strategies, particularly in selecting appropriate systemic therapies and integrating traditional treatment modalities like surgery and radiotherapy into comprehensive care plans for TNBC patients.

Metal-Phenolic Vehicles Potentiate Cycle-Cascade Activation of Pyroptosis and cGAS-STING Pathway for Tumor Immunotherapy.

The treatment of triple-negative breast cancer (TNBC) faces challenges due to its limited immune response and weak tumor immunogenicity. A collaborative strategy involves combining the activation of pyroptosis and the stimulator of interferon genes (STING) pathway to enhance tumor immunogenicity and fortify the antitumor immune response, which may improve therapeutic outcomes in TNBC. In this study, we report the fabrication of a zinc-phenolic nanocapsule (RMP@Cap), which is loaded with mitoxantrone (MTO) and anti-PD-L1 antibodies (aPD-L1) and coated with erythrocyte membrane, for TNBC immunotherapy. The delivery of RMP@Cap can induce tumor cell pyroptosis and, therefore, trigger the release of mitochondrial DNA, which further combines with zinc agonists to intensify STING activation, resulting in a cascade amplification of the therapeutic effect on tumors. Additionally, the incorporation of aPD-L1 into the zinc-phenolic nanocapsule relieves the inhibitory effect of tumor cells on recruited cytotoxic T cells, thereby improving the tumor-killing capacity. Furthermore, the incorporation of a camouflaged erythrocyte membrane coating enables nanocapsules to achieve prolonged in vivo circulation, resulting in improved tumor accumulation for effective antitumor therapy. This study demonstrates a synergistic therapeutic modality involving pyroptosis, coupled with the simultaneous activation and cyclic amplification of the STING pathway in immunotherapy.

High-motility pro-tumorigenic monocytes drive macrophage enrichment in the tumor microenvironment.

Enrichment of tumor-associated macrophages (TAMΦs) in the tumor microenvironment correlates with worse clinical outcomes in triple-negative breast cancer (TNBC) patients, prompting the development of therapies to inhibit TAMΦ infiltration. However, the lackluster efficacy of CCL2-based chemotaxis blockade in clinical trials suggests that a new understanding of monocyte/macrophage infiltration may be necessary. Here we demonstrate that random migration, and not only chemotaxis, drives macrophage tumor infiltration. We identified tumor- associated monocytes (TAMos) that display a dramatically enhanced migration capability, induced rapidly by the tumor microenvironment, that drives effective tumor infiltration, in contrast to low-motility differentiated macrophages. TAMo, not TAMΦ, promotes cancer cell proliferation through activation of the MAPK pathway. IL-6 secreted both by cancer cells and TAMo themselves enhances TAMo migration by increasing dendritic protrusion dynamics and myosin- based contractility via the JAK2/STAT3 signaling pathway. Independent from CCL2 mediated chemotaxis, IL-6 driven enhanced migration and pro-proliferative effect of TAMo were validated in a syngeneic TNBC mouse model. Depletion of IL-6 in cancer cells significantly attenuated monocyte infiltration and reversed TAMo-induced cancer cell proliferation. This work reveals the critical role random migration plays in monocyte driven TAMΦ enrichment in a tumor and pinpoints IL-6 as a potential therapeutic target in combination with CCL2 to ameliorate current strategies against TAMΦ infiltration.

Role of AURKB Inhibition in Reducing Proliferation and Enhancing Effects of Radiotherapy in Triple-Negative Breast Cancer.

Breast cancer is a leading cause of cancer-related deaths in females. Triple-negative breast cancer (TNBC) subtype is the most aggressive form of breast cancer that lacks biomarkers and effective targeted therapies. Its high degree of heterogeneity as well as innate and acquired resistance to treatment creates further barriers in achieving positive clinical outcomes in TNBC. Thus, development of novel treatment approaches in TNBC is of high clinical significance. Multimodality approaches with targeted agents and radiotherapy (RT) are promising for increasing efficacy of treatment and circumventing resistance. Here we examined anticancer effects of the Aurora Kinase B (AURKB) inhibitor AZD1152 as a single agent and in combination with RT using various TNBC cell lines, MDA-MB-468, MDA-MB-231 and SUM-159. We observed that AZD1152 alone effectively inhibited colony formation in TNBC cell lines. The combination of AZD1152 at IC50 concentrations together with ionizing radiation further reduced colony formation as compared to the single agent treatment. Our data support the notion that inhibition of the AURKB pathway is a promising strategy for treatment and radiosensitization of TNBC and warrants further translational studies.

Intermittent Fasting Attenuates Obesity-Induced Triple-Negative Breast Cancer Progression by Disrupting Cell Cycle, Epithelial-Mesenchymal Transition, Immune Contexture, and Proinflammatory Signature.

Obesity is associated with one-fifth of cancer deaths, and breast cancer is one of the obesity-related cancers. Triple-negative breast cancer (TNBC) lacks estrogen and progesterone receptors and human epidermal growth factor receptor 2, leading to the absence of these therapeutic targets, followed by poor overall survival. We investigated if obesity could hasten TNBC progression and intermittent fasting (IF) could attenuate the progression of obesity-related TNBC. Our meta-analysis of the TNBC outcomes literature showed that obesity led to poorer overall survival in TNBC patients. Fasting-mimicking media reduced cell proliferation disrupted the cell cycle, and decreased cell migration and invasion. IF decreased body weight in obese mice but no change in normal mice. Obese mice exhibited elevated plasma glucose and cholesterol levels, increased tumor volume and weight, and enhanced macrophage accumulation in tumors. The obesity-exacerbated TNBC progression was attenuated after IF, which decreased cyclin B1 and vimentin levels and reduced the proinflammatory signature in the obesity-associated tumor microenvironment. IF attenuated obesity-induced TNBC progression through reduced obesity and tumor burdens in cell and animal experiments, supporting the potential of a cost-effective adjuvant IF therapy for TNBC through lifestyle change. Further evidence is needed of these IF benefits in TNBC, including from human clinical trials.

Novel HLA-Ilo/HLA-IIhi phenotype and immune evasion in triple-negative breast cancer.

1095 Background: Immune checkpoint inhibitors (ICIs) are a therapeutic option for patients with triple-negative breast cancer (TNBC), however resistance and non-response remain an unmet clinical need. Human leukocyte antigens (HLAs) play an important role in induction and regulation of host immune responses. Downregulation of HLA class I expression is one mechanism by which cancer cells evade the immune control. HLA typing and understanding the role of HLAs can provide valuable insight into optimizing immunotherapy efficacy in TNBC. In this study, we evaluate the association of HLA I/II phenotypes with biomarkers of tumor immune interaction and overall survival (OS) in a real-world breast cancer cohort. Methods: A targeted RNA-seq assay was performed on 142 breast cancer samples. HLA I and HLA II expressions were estimated as average expression of HLA-A, HLA-B, HLA-C and HLA-DP, HLA-DQ, HLA-DR genes, respectively, by a percentile rank values [0-100]. Cohen D index was used to estimate ratio of HLA-I and II in each specimen. We particularly focused on the HLA-Ilow(lo)/HLA-IIhigh(hi) ratio given a proposed mechanism of immune escape by tumor cells (low expression of HLA-I) in response to a highly immune infiltrated state where there is increased expression of HLA-II by the immune cells. We studied the co-expression of HLA-Ilo/HLA-IIhi with other checkpoint targets using Spearman correlation(rs). The impact of HLA phenotypes on OS were analyzed using Kaplan-Meier analysis and Chi-squared assessed associations. Results: The cohort consisted of 106 non-TNBC (ER+/HER2- or HER2+) and 36 TNBC tumors. Most samples originated from metastatic visceral sites (96, 68%) followed by primary breast (33, 23%), and lymph nodes (13, 9%). Among TNBC, HLA-Ilo/HLA-IIhi phenotype displayed a significantly higher co-expression of immune checkpoint targets such as PD-1, PD-L1, TIM3 and LAG-3 than HLA-Ihi/HLA-IIlo phenotype (p&lt;0.001). However, this difference was not observed between HLA-Ilo/HLA-IIhi and HLA-Ihi/HLA-IIlo phenotypes in non-TNBC tumors. In TNBC, there was no significant difference in OS between HLA-Ilo/HLA-IIhi when compared to HLA-Ihi/HLA-IIlo (43 vs. 37 months, p=0.21). Similarly, in non-TNBC, there were no significant differences in OS between HLA-Ilo/HLA-IIhi when compared to HLA-Ihi/HLA-IIlo (107 vs. 66 months, p=0.5). Conclusions: Concurrent loss of HLA I with increased HLA II expression was associated with co-expression of immune checkpoint molecules indicative of immune escape mechanism but not survival outcomes in TNBC. This same effect was not seen in non-TNBC with a more immunologically silent environment. Characterization of HLA phenotypes by immune profiling provides insight into the complex interplay of tumor immune microenvironment and offers an opportunity for developing novel approaches to overcome the immune evasion with cancer vaccines and adoptive cell therapies in TNBC.

Tripartite Motif-Containing 2, a Glutamine Metabolism-Associated Protein, Predicts Poor Patient Outcome in Triple-Negative Breast Cancer Treated with Chemotherapy.

Breast cancer (BC) remains heterogeneous in terms of prognosis and response to treatment. Metabolic reprogramming is a critical part of oncogenesis and a potential therapeutic target. Glutaminase (GLS), which generates glutamate from glutamine, plays a role in triple-negative breast cancer (TNBC). However, targeting GLS directly may be difficult, as it is essential for normal cell function. This study aimed to determine potential targets in BC associated with glutamine metabolism and evaluate their prognostic value in BC. The iNET model was used to identify genes in BC that are associated with GLS using RNA-sequencing data. The prognostic significance of tripartite motif-containing 2 (TRIM2) mRNA was assessed in BC transcriptomic data (n = 16,575), and TRIM2 protein expression was evaluated using immunohistochemistry (n = 749) in patients with early-stage invasive breast cancer with long-term follow-up. The associations between TRIM2 expression and clinicopathological features and patient outcomes were evaluated. Pathway analysis identified TRIM2 expression as an important gene co-expressed with high GLS expression in BC. High TRIM2 mRNA and TRIM2 protein expression were associated with TNBC (p < 0.01). TRIM2 was a predictor of poor distant metastasis-free survival (DMFS) in TNBC (p < 0.01), and this was independent of established prognostic factors (p < 0.05), particularly in those who received chemotherapy (p < 0.05). In addition, TRIM2 was a predictor of shorter DMFS in TNBC treated with chemotherapy (p < 0.01). This study provides evidence of an association between TRIM2 and poor patient outcomes in TNBC, especially those treated with chemotherapy. The molecular mechanisms and functional behaviour of TRIM2 and the functional link with GLS in BC warrant further exploration using in vitro models.