Breast Cancer Immunotherapy: Facts and Hopes

A landscape of checkpoint blockade resistance in cancer: underlying mechanisms and current strategies to overcome resistance

The discovery of immune checkpoints and the development of immune checkpoint inhibitors (ICI) have achieved a durable response in advanced-stage cancer patients. However, there is still a high proportion of patients who do not benefit from ICI therapy due to a lack of response when first treated (primary resistance) or detection of disease progression months after objective response is observed (acquired resistance). Here, we review the current FDA-approved ICI for the treatment of certain solid malignancies, evaluate the contrasting responses to checkpoint blockade in different cancer types, explore the known mechanisms associated with checkpoint blockade resistance (CBR), and assess current strategies in the field that seek to overcome these mechanisms. In order to improve current therapies and develop new ones, the immunotherapy field still has an unmet need in identifying other molecules that act as immune checkpoints, and uncovering other mechanisms that promote CBR.

Efficacy and safety of a combination treatment of immune checkpoint inhibitors in metastatic breast cancer: a systematic review and meta-analysis

PURPOSE

Immune checkpoint inhibitors (ICIs) in combination with chemotherapy have showed its benefits in clinical studies, and here we conducted a further evaluation on the safety and efficacy of this treatment strategy.

METHODS

A systematic literature review was conducted in PubMed, Embase and Cochrane Library to identify clinical studies on ICIs and chemotherapy for metastatic breast cancer. The primary efficacy endpoints were progression-free survival (PFS) and overall survival (OS), and adverse events (AEs) were analyzed. Random or fixed effects models were used to estimate pooled Hazard ratio (HR), odds ratio (OR) and the data of 95% confidence interval (CI) depend on the Heterogeneity. Cochrane risk assessment tool was used to assess risk of bias. We also drew forest plots and funnel plots, respectively.

RESULTS

Seven studies with intend-to-treat (ITT) population for 3255 patients were analyzed. ICIs pooled therapy showed clinical benefits compared with chemotherapy alone, improving PFS (HR = 0.81, 95% CI: 0.74-0.90) of patients with metastatic triple negative breast cancer (mTNBC), especially in patients with PD-L1-positive tumors. However, it had no effect on OS (HR = 0.92, 95% CI 0.85-1.01). Besides, mTNBC patients received pooled therapy were less frequently to have AEs (OR = 1.30, 95% CI: 1.09-1.54). In patients with metastatic Human Epidermal Growth Factor Receptor 2 (HER2) negative breast cancer, pooled therapy showed no benefit for PFS (HR = 0.80, 95% CI: 0.50-1.28) and OS (HR = 0.87, 95% CI: 0.48-1.58).

CONCLUSION

Pooled therapy had improved PFS in mTNBC patients, especially in patients with PD-L1-positive tumors, and it was less likely to cause grade ≥ 3 AEs.

Role of TAP1 in the identification of immune-hot tumor microenvironment and its prognostic significance for immunotherapeutic efficacy in gastric carcinoma

Background

Gastric cancer (GC), a multifaceted gastrointestinal malignancy, is the fourth most prevalent contributor to cancer-related fatalities globally. As a member of the ATP-binding cassette (ABC) family, transporter associated with antigen processing 1 (TAP1) is crucial for conveying antigen peptides from the cytoplasm to the lumen of the endoplasmic reticulum and subsequently loading them onto the major histocompatibility complex (MHC) class I molecules. Recent studies have established the biological significance of TAP1 in upholding tumor survival and facilitating immune evasion by remodeling the tumor microenvironment (TME) and orchestrating immune infiltration. The study was conducted to elucidate the association of TAP1 expression with immunological characteristics, and sought to exploit the value of TAP1 as a biomarker reflecting the inflamed TME and immunotherapeutic response.

Methods

RNA-sequencing profiles and clinical annotations were obtained from The Cancer Genome Atlas-stomach adenocarcinoma (TCGA-STAD) cohort and Gene Expression Omnibus (GEO) portal. Preprocessing was conducting using the limma package. Weighted gene co-expression network analysis (WGCNA) was used to identify gene modules and TAP1 co-expressed genes (CEGs) based on correlation patterns. Consensus clustering and silhouette analysis determined the optimal number of TAP1-related groups. Gene expression profiles were integrated and classified using the pamr package. The Estimation of STromal and Immune cells in MAlignant Tumors using Expression data (ESTIMATE) algorithm and single-sample gene set enrichment analysis (ssGSEA) were used to evaluate immunological characteristics. Differential expression analysis was conducted using the limma package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Single-cell RNA sequencing (scRNA-seq) datasets were analyzed using the Seurat toolkit to characterize cell types.

Results

Within this investigation, no significant differences in TAP1 expression were observed among patients exhibiting various clinicopathological features, indicating that TAP1 expression was not specific to molecular subtypes. Subsequent analysis revealed a positive correlation between TAP1 and diverse immunological traits, encompassing immunomodulators, tumor-infiltrating immune cells, as well as immune checkpoints across multiple datasets. Besides, within a GC immunotherapy cohort, individuals displaying high TAP1 expression demonstrated an increased likelihood of achieving complete remission (CR) post-treatment, suggesting heightened sensitivity to immunotherapy. In the clinical cohort, TAP1 overexpression in GC patients was positively correlated with CD8.

Conclusions

TAP1 appears linked to an inflamed TME and serves as a prospective biomarker for discerning immunological attributes and gauging immunotherapeutic responses in GC, particularly in identifying immune-reactive tumors.

Celecoxib Augments Paclitaxel-Induced Immunogenic Cell Death in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a highly aggressive malignancy that lacks effective targeted therapies. Inducing immunogenic cell death (ICD) in tumor cells represents a promising strategy to enhance therapeutic efficacy by promoting antitumor immunity. Paclitaxel (PTX), a commonly used chemotherapy drug for TNBC, can induce ICD; however, the resulting immunogenicity is limited. Thus, there is an urgent need to explore strategies that improve the effectiveness of ICD in TNBC by incorporating immunoregulatory agents. This study investigated the potential of celecoxib (CXB) to enhance PTX-induced ICD by blocking the biosynthesis of PGE2 in the tumor cells. We observed that the combination of CXB and PTX promoted the maturation of dendritic cells and primed a T cell-dependent immune response, leading to enhanced tumor rejection in a vaccination assay. To further optimize drug delivery in vivo, we developed cRGD-modified liposomes for the targeted codelivery of CXB and PTX. This delivery system significantly improved drug accumulation and triggered robust antitumor immunity in an orthotopic mouse model of TNBC. Moreover, it served as an in situ vaccine to inhibit tumor recurrence and lung metastasis. Overall, our findings provide in-depth insights into the therapeutic mechanism underlying the combination of CXB and PTX, highlighting their potential as effective immune-based therapies for TNBC.

Is the percentage of hormone receptor positivity in HR+ HER2-metastatic breast cancer patients receiving CDK 4/6 inhibitor with endocrine therapy predictive and prognostic?

Purpose

There is no clear information in the literature about the relationship between the efficacy of CDK 4/6i combined with ET and HR positivity. However, we know that the longest overall survival was in the ER-strong positive/PR intermediate or strong positive groups. Therefore, we aimed to investigate CDK4/6i treatments that create positivity in HR.

Methods

Patients with the diagnosis of HR+/HER2- MBC who were treated with CDK 4/6i and HR >10% were retrospectively evaluated. To analyze the role of HR positivity, ER was moderately positive (10-49%) and ER was strongly positive (50-100%); PR was grouped as moderately positive (10-49%) and PR strongly positive (50-100%).

Results

Median follow-up of 150 patients included in the study was 15.2 months (95% CI, 2.1-40.9 months). The highest response in the whole group was obtained in the ER-strong positive/PR moderate or strong positive group, and the ER moderate positive/PR moderate or strong group. This was followed by the ER strong positive/PR negative group, and then the ER moderate positive/PR negative group. Although these advantages were not statistically significant, they were numerically higher (ORR: 83.8% vs. 83.3% vs. 77.4% vs. 62.5%, p=0.488, respectively). The highest survival in the whole group was achieved in the ER strong positive/PR moderate or strongly positive group, followed by the ER moderately positive/PR moderate or strongly positive group, the ER strongly positive/PR negative group followed by the ER moderate positive/PR negative group, respectively(p=0.410). However, these advantages were not statistically significant.

Conclusion

As a result, HR+/HER2- MBC patients receiving CDK 4/6i combined with ET suggest that the percentage of HR positivity may have a predictive and prognostic role.

Comprehensive characterization of B7 family members in breast cancer: B7-H5 switch reverses breast cancer from "immuno-cold" into "immuno-hot" status

The members of the classic B7 family regulate the immune microenvironment of several malignant tumors. However, the potential relationship between the B7 family and the breast cancer (BrCa) tumor immune microenvironment has remained elusive. In the present study, we provide a comprehensive explanation of the expression, clinical significance, mutation, and immune cell infiltration of B7 family molecules in BrCa. First, we recruited 10 patients with BrCa surgery from the Wuxi Maternal and Child Health Hospital and performed single-cell RNA sequencing (scRNA-seq) analysis to investigate the distribution of B7 family members in multiple immune cell subsets. We focused on B7-2, B7-H3, and B7-H5 molecules of the B7 family and constructed tumor microarrays by self-recruiting patients to perform multiple immunohistochemical (mIHC) analyses and study tumor expression of B7-2, B7-H3, B7-H5 and CD8+ immune cell infiltration. B7-H5 displayed a strong correlation with CD8+ immune cell infiltration. In summary, B7-H5 provides a new perspective for the identification of immunothermal subtypes of BrCa and could function as a switch to reverse BrCa from an "immunologically cold" state to an "immunologically hot" state.

Nano-Pulse Treatment Overcomes the Immunosuppressive Tumor Microenvironment to Elicit In Situ Vaccination Protection against Breast Cancer

We previously reported that nano-pulse treatment (NPT), a pulsed power technology, resulted in 4T1-luc mammary tumor elimination and a strong in situ vaccination, thereby completely protecting tumor-free animals against a second live tumor challenge. The mechanism whereby NPT mounts effective antitumor immune responses in the 4T1 breast cancer predominantly immunosuppressive tumor microenvironment (TME) remains unanswered. In this study, orthotopic 4T1 mouse breast tumors were treated with NPT (100 ns, 50 kV/cm, 1000 pulses, 3 Hz). Blood, spleen, draining lymph nodes, and tumors were harvested at 4-h, 8-h, 1-day, 3-day, 7-day, and 3-month post-treatment intervals for the analysis of frequencies, death, and functional markers of various immune cells in addition to the suppressor function of regulatory T cells (Tregs). NPT was verified to elicit strong in situ vaccination (ISV) against breast cancer and promote both acute and long-term T cell memory. NPT abolished immunosuppressive dominance systemically and in the TME by substantially reducing Tregs, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs). NPT induced apoptosis in Tregs and TAMs. It also functionally diminished the Treg suppression capacity, explained by the downregulation of activation markers, particularly 4-1BB and TGFβ, and a phenotypic shift from predominantly activated (CD44+CD62L-) to naïve (CD44-CD62L+) Tregs. Importantly, NPT selectively induced apoptosis in activated Tregs and spared effector CD4+ and CD8+ T cells. These changes were followed by a concomitant rise in CD8+CD103+ tissue-resident memory T cells and TAM M1 polarization. These findings indicate that NPT effectively switches the TME and secondary lymphatic systems from an immunosuppressive to an immunostimulatory state, allowing cytotoxic T cell function and immune memory formation to eliminate cancer cells and account for the NPT in situ vaccination.

NSUN2/YBX1 promotes the progression of breast cancer by enhancing HGH1 mRNA stability through m5C methylation

BACKGROUND

RNA m5C methylation has been extensively implicated in the occurrence and development of tumors. As the main methyltransferase, NSUN2 plays a crucial regulatory role across diverse tumor types. However, the precise impact of NSUN2-mediated m5C modification on breast cancer (BC) remains unclear. Our study aims to elucidate the molecular mechanism underlying how NSUN2 regulates the target gene HGH1 (also known as FAM203) through m5C modification, thereby promoting BC progression. Additionally, this study targets at preliminarily clarifying the biological roles of NSUN2 and HGH1 in BC.

METHODS

Tumor and adjacent tissues from 5 BC patients were collected, and the m5C modification target HGH1 in BC was screened through RNA sequencing (RNA-seq) and single-base resolution m5C methylation sequencing (RNA-BisSeq). Methylation RNA immunoprecipitation-qPCR (MeRIP-qPCR) and RNA-binding protein immunoprecipitation-qPCR (RIP-qPCR) confirmed that the methylation molecules NSUN2 and YBX1 specifically recognized and bound to HGH1 through m5C modification. In addition, proteomics, co-immunoprecipitation (co-IP), and Ribosome sequencing (Ribo-Seq) were used to explore the biological role of HGH1 in BC.

RESULTS

As the main m5C methylation molecule, NSUN2 is abnormally overexpressed in BC and increases the overall level of RNA m5C. Knocking down NSUN2 can inhibit BC progression in vitro or in vivo. Combined RNA-seq and RNA-BisSeq analysis identified HGH1 as a potential target of abnormal m5C modifications. We clarified the mechanism by which NSUN2 regulates HGH1 expression through m5C modification, a process that involves interactions with the YBX1 protein, which collectively impacts mRNA stability and protein synthesis. Furthermore, this study is the first to reveal the binding interaction between HGH1 and the translation elongation factor EEF2, providing a comprehensive understanding of its ability to regulate transcript translation efficiency and protein synthesis in BC cells.

CONCLUSIONS

This study preliminarily clarifies the regulatory role of the NSUN2-YBX1-m5C-HGH1 axis from post-transcriptional modification to protein translation, revealing the key role of abnormal RNA m5C modification in BC and suggesting that HGH1 may be a new epigenetic biomarker and potential therapeutic target for BC.

Toll-like receptors in breast cancer immunity and immunotherapy

Toll-like receptors (TLRs) are a key family of pattern recognition receptors (PRRs) in the innate immune system. The activation of TLRs will not only prevent pathogen infection but also respond to damage-induced danger signaling. Increasing evidence suggests that TLRs play a critical role in breast cancer development and treatment. However, the activation of TLRs is a double-edged sword that can induce either pro-tumor activity or anti-tumor effect. The underlying mechanisms of these opposite effects of TLR signaling in cancer are not fully understood. Targeting TLRs is a promising strategy for improving breast cancer treatment, either as monotherapies or by improving other current therapies. Here we provide an update on the role of TLRs in breast cancer immunity and immunotherapy.

Identifying therapeutic targets for breast cancer: insights from systematic Mendelian randomization analysis

Background

Breast cancer (BC) exhibits a high incidence rate, imposing a substantial burden on healthcare systems. Novel drug targets are urgently needed for BC. Mendelian randomization (MR) has gained widespread application for identifying fresh therapeutic targets. Our endeavor was to pinpoint circulatory proteins causally linked to BC risk and proffer potential treatment targets for BC.

Methods

Through amalgamating protein quantitative trait loci from 2,004 circulating proteins and comprehensive genome-wide association study data from the Breast Cancer Association Consortium, we conducted MR analyses. Employing Steiger filtering, bidirectional MR, Bayesian colocalization, phenotype scanning, and replication analyses, we further solidified MR study outcomes. Additionally, protein-protein interaction (PPI) network was harnessed to unveil latent associations between proteins and prevailing breast cancer medications. The phenome-wide MR (Phe-MR) was employed to assess potential side effects and indications for the druggable proteins of BC. Finally, we further affirmed the drugability of potential drug targets through mRNA expression analysis and molecular docking.

Results

Through comprehensive analysis, we identified five potential drug targets, comprising four (TLR1, A4GALT, SNUPN, and CTSF) for BC and one (TLR1) for BC_estrogen receptor positive. None of these five potential drug targets displayed reverse causation. Bayesian colocalization suggested that these five latent drug targets shared variability with breast cancer. All drug targets were replicated within the deCODE cohort. TLR1 exhibited PPI with current breast cancer therapeutic targets. Furthermore, Phe-MR unveiled certain adverse effects solely for TLR1 and SNUPN.

Conclusion

Our study uncovers five prospective drug targets for BC and its subtypes, warranting further clinical exploration.

Proteomic, single-cell and bulk transcriptomic analysis of plasma and tumor tissues unveil core proteins in response to anti-PD-L1 immunotherapy in triple negative breast cancer

BACKGROUND

Anti-PD-1/PD-L1 treatment has achieved durable responses in TNBC patients, whereas a fraction of them showed non-sensitivity to the treatment and the mechanism is still unclear.

METHODS

Pre- and post-treatment plasma samples from triple negative breast cancer (TNBC) patients treated with immunotherapy were measured by tandem mass tag (TMT) mass spectrometry. Public proteome data of lung cancer and melanoma treated with immunotherapy were employed to validate the findings. Blood and tissue single-cell RNA sequencing (scRNA-seq) data of TNBC patients treated with or without immunotherapy were analyzed to identify the derivations of plasma proteins. RNA-seq data from IMvigor210 and other cancer types were used to validate plasma proteins in predicting response to immunotherapy.

RESULTS

A random forest model constructed by FAP, LRG1, LBP and COMP could well predict the response to immunotherapy. The activation of complement cascade was observed in responders, whereas FAP and COMP showed a higher abundance in non-responders and negative correlated with the activation of complements. scRNA-seq and bulk RNA-seq analysis suggested that FAP, COMP and complements were derived from fibroblasts of tumor tissues.

CONCLUSIONS

We constructe an effective plasma proteomic model in predicting response to immunotherapy, and find that FAP+ and COMP+ fibroblasts are potential targets for reversing immunotherapy resistance.

Mismatch repair protein deficiency in triple-negative breast carcinomas

BACKGROUND

Breast cancer, particularly triple-negative breast cancer (TNBC), poses a significant global health burden. Chemotherapy was the mainstay treatment for TNBC patients until immunotherapy was introduced. Studies indicate a noteworthy prevalence (0.2% to 18.6%) of mismatch repair protein (MMRP) deficiency in TNBC, with recent research highlighting the potential of immunotherapy for MMRP-deficient metastatic breast cancer. This study aims to identify MMRP deficiency in TNBC patients using immunohistochemistry.

METHODS

A retrospective cohort study design was used and included TNBC patients treated between 2015 and 2021 at King Hussein Cancer Center. Immunohistochemistry was conducted to assess MMRP expression.

RESULTS

Among 152 patients, 14 (9.2%) exhibited deficient MMR (dMMR). Loss of PMS2 expression was observed in 13 patients, 5 of whom showed loss of MLH1 expression. Loss of MSH6 and MSH2 expression was observed in one patient. The median follow-up duration was 44 (3-102) months. Despite the higher survival rate (80.8%, 5 years) of dMMR patients than of proficient MMR patients (62.3%), overall survival did not significantly differ between the two groups.

CONCLUSION

Approximately 9% of TNBC patients exhibit dMMR. dMMR could be used to predict outcomes and identify patients with TNBC who may benefit from immunotherapy.

Comprehensive studies on the biological activities of human metastatic (MDA-MB-231) and non-metastatic (MCF-7) breast cancer cell lines, directly or combinedly treated using non-thermal plasma-based approaches

Progressive incidence and a pessimistic survival rate of breast cancer in women worldwide remains one of the most concerning topics. Progressing research indicates a potentially high effectiveness of use cold atmospheric plasma (CAP) systems. The undoubted advantage seems its simplicity in combination with other anti-cancer modalities. Following observed trend of studies, one inventory CAP system was applied to directly treat human breast cancer cell lines and culturing in two different Plasma Activated Media (PAM) for combined utilization. Proposed CAP treatments on MCF-10 A, MCF-7, and MDA-MB-231 cell lines were studied in terms of impact on cell viability by MTT assay. Disturbances in cell motility following direct and combined CAP application were assessed by scratch test. Finally, the induction of apoptosis and necrosis was verified with annexin V and propidium iodide staining. Reactive species generated during CAP treatment were determined based on optical emission spectrometry analysis along with colorimetric methods to qualitatively assess the NO2-, NO3-, H2O2, and total ROS with free radicals concentration. The most effective approach for CAP utilization was combined treatment, leading to significant disruption in cell viability, motility and mostly apoptosis induction in breast cancer cell lines. Determined CAP dose allows for mild outcome, showing insignificant harm for the non-cancerous MCF-10 A cell line, while the highly aggressive MDA-MB-231 cell line shows the highest sensitivity on proposed CAP treatment. Direct CAP treatment seems to drive the cells into the sensitive state in which the effectiveness of PAM is boosted. Observed anti-cancer response of CAP treatment was mostly triggered by RNS (mostly NO2- ions) and ROS along with free radicals (such as H2O2, OH•, O2-•, 1O2, HO2•). The combined application of one CAP source represent a promising alternative in the development of new and effective modalities for breast cancer treatment.

High expression of CCNB2 is an independent predictive poor prognostic biomarker and correlates with immune infiltrates in breast carcinoma

Background

Cyclin B2 (CCNB2) is associated with cell cycle progression, acting as a cell cycle checkpoint in progression of G2/M transition. In many cancer patients, it has been observed that overexpression of CCNB2 enhances tumor invasiveness and leads to adverse prognosis. However, the association of CCNB2 with the tumor microenvironment remains unclear. Therefore, it is necessary to clarify the associations of CCNB2 with the immune status and prognosis of breast carcinoma (BRCA).

Methods

Gene expression and clinical data for BRCA were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases, followed by association analyses of CCNB2 expression with prognosis, immune cell infiltration, and immune checkpoints. This study further performed drug sensitivity analysis and constructed a prognostic nomogram for CCNB2.

Results

3619 differentially expressed genes were identified in BRCA, including CCNB2 that emerged as a key gene in the network. High CCNB2 expression correlated with poor prognosis. Functional analysis demonstrated enrichment of CCNB2 co-expressed genes with the cell cycle, cancer progression, cell energy, and immune pathways. Microsatellite instability and tumor mutation burden analyses indicated CCNB2 as a candidate immunotherapy target. Tumor-infiltrating myeloid-derived suppressor cells, regulatory T cells, and T helper 2 cells were associated with CCNB2-related tumor progression and metastasis. CCNB2 expression positively correlated with immune checkpoints, indicating that high CCNB2 expression might facilitate tumor immune escape. Tumors with high CCNB2 expression showed sensitivity to phosphoinositide 3-kinase-protein kinase B-mammalian target of rapamycin and cyclin-dependent kinase (CDK) 4/6 inhibitors, and the nomogram had good prognostic predictive ability for patients with BRCA.

Conclusions

CCNB2 may play a crucial role in tumorigenesis and serve as an independent prognostic biomarker associated with tumor microenvironment, tumor immune infiltration and immunotherapy in BRCA.

Immunotherapeutic Strategies Targeting Breast Cancer Stem Cells

Breast cancer is the most commonly diagnosed cancer in women and is a leading cause of cancer death in women worldwide. Despite the implementation of multiple treatment options, including immunotherapy, breast cancer treatment remains a challenge. In this review, we aim to summarize present challenges in breast cancer immunotherapy and recent advancements in overcoming treatment resistance. We elaborate on the inhibition of signaling cascades, such as the Notch, Hedgehog, Hippo, and WNT signaling pathways, which regulate the self-renewal and differentiation of breast cancer stem cells and, consequently, disease progression and survival. Cancer stem cells represent a rare population of cancer cells, likely originating from non-malignant stem or progenitor cells, with the ability to evade immune surveillance and develop resistance to immunotherapeutic treatments. We also discuss the interactions between breast cancer stem cells and the immune system, including potential agents targeting breast cancer stem cell-associated signaling pathways, and provide an overview of the emerging approaches to breast cancer stem cell-targeted immunotherapy. Finally, we consider the development of breast cancer vaccines and adoptive cellular therapies, which train the immune system to recognize tumor-associated antigens, for eliciting T cell-mediated responses to target breast cancer stem cells.

Recent Developments in Combination Immunotherapy with Other Therapies and Nanoparticle-Based Therapy for Triple-Negative Breast Cancer (TNBC)

Triple-negative breast cancer (TNBC), lacking specific receptors found in other breast cancer subtypes, poses significant treatment challenges due to limited therapeutic options. Therefore, it is necessary to develop novel treatment approaches for TNBC. In the last few decades, many attempts have been reported for alternative tools for TNBC treatment: immunotherapy, radiotherapy, targeted therapy, combination therapy, and nanotechnology-based therapy. Among them, combination therapy and nanotechnology-based therapy show the most promise for TNBC treatment. This review outlines recent advancements in these areas, highlighting the efficacy of combination therapy (immunotherapy paired with chemotherapy, targeted therapy, or radiotherapy) in both preclinical and clinical stages and nanotechnology-based therapies utilizing various nanoparticles loaded with anticancer agents, nucleic acids, immunotherapeutics, or CRISPRs in preclinical stages for TNBC treatment.

Pectinose induces cell cycle arrest in luminal A and triple-negative breast cancer cells by promoting autophagy through activation of the p38 MAPK signaling pathway

Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. However, Pectinose whether has capability to restrict the proliferation of tumor cells remain unclear. Here, we report that Pectinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was dramatically inhibited by Pectinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of Cyclin A, Cyclin B, p21and p27. Mechanistically, we further identified that Pectinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of Pectinose suppressing on breast cancer cell lines proliferation and cell cycle process. Additionally, Pectinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Taken together, our findings were the first to reveal that Pectinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells,especially in luminal A and triple-negative breast cancer.

Mesenchymal-like immune-altered is the fourth robust triple-negative breast cancer molecular subtype

BACKGROUND

Robust molecular subtyping of triple-negative breast cancer (TNBC) is a prerequisite for the success of precision medicine. Today, there is a clear consensus on three TNBC molecular subtypes: luminal androgen receptor (LAR), basal-like immune-activated (BLIA), and basal-like immune-suppressed (BLIS). However, the debate about the robustness of other subtypes is still open.

METHODS

An unprecedented number (n = 1942) of TNBC patient data was collected. Microarray- and RNAseq-based cohorts were independently investigated. Unsupervised analyses were conducted using k-means consensus clustering. Clusters of patients were then functionally annotated using different approaches. Prediction of response to chemotherapy and targeted therapies, immune checkpoint blockade, and radiotherapy were also screened for each TNBC subtype.

RESULTS

Four TNBC subtypes were identified in the cohort: LAR (19.36%); mesenchymal stem-like (MSL/MES) (17.35%); BLIA (31.06%); and BLIS (32.23%). Regarding the MSL/MES subtype, we suggest renaming it to mesenchymal-like immune-altered (MLIA) to emphasize its specific histological background and nature of immune response. Treatment response prediction results show, among other things, that despite immune activation, immune checkpoint blockade is probably less or completely ineffective in MLIA, possibly caused by mesenchymal background and/or an enrichment in dysfunctional cytotoxic T lymphocytes. TNBC subtyping results were included in the bc-GenExMiner v5.0 webtool ( http://bcgenex.ico.unicancer.fr ).

CONCLUSION

The mesenchymal TNBC subtype is characterized by an exhausted and altered immune response, and resistance to immune checkpoint inhibitors. Consensus for molecular classification of TNBC subtyping and prediction of cancer treatment responses helps usher in the era of precision medicine for TNBC patients.

Identification of SMC2 and SMC4 as prognostic markers in breast cancer through bioinformatics analysis

BACKGROUND

Breast cancer (BRCA) is one of the most common malignant tumors. The structural maintenance of chromosome (SMC) gene family has been shown to play an important role in human cancers. However, the role of SMC families in BRCA is unclear. This study aimed to explore the role and potential clinical value of whole SMCs in BRCA.

METHODS

TIMER and UALCAN database were used to analysis the expression level. Genetic variations were analyzed by cBioPortal. Promoter methylation and protein level were analyzed by UCLCAN. GO and KEGG were analyzed by Metascape database. Prognostic value of SMCs was analyzed by Kaplan-Meier and multivariate cox regression analyses. Immune infiltration analysis was conducted by CIBERSORT. Immunotherapy outcome prediction was conducted by Cancer Immunome Atlas. Targeted drug therapy outcome prediction was taken by GDSC and R language. The cell viability was tested by CCK8 and migration was tested by wound healing assay. Xenograft model was used to investigate the in vivo role of SMC2.

RESULTS

Expression levels of SMC1A, SMC2, SMC4, SMC5 and SMC6 mRNA were increased in BRCA tissues, and negatively correlated with promoter methylation. Overexpression of SMC2 and SMC4 was negatively correlated with survival. Function of SMCs family regulatory genes was mainly related to ATPase activity. Expression of most SMCs was negatively correlated with immunotherapy and drug therapy outcomes. Interfere SMC2 and SMC4 decreased IC50 values of 5-fluorouracil and oxaliplatin and inhibited the migration of MCF7 cells. Tumor growth and weights were significantly decreased in si-SMC2 groups.

CONCLUSIONS

Combined bioinformatics and clinical specimen analysis verified SMC2 and SMC4 as independent prognostic factors in BRCA, suggesting their significance for the diagnosis and treatment of BRCA.

Virtual patient analysis identifies strategies to improve the performance of predictive biomarkers for PD-1 blockade

Patients with metastatic triple-negative breast cancer (TNBC) show variable responses to PD-1 inhibition. Efficient patient selection by predictive biomarkers would be desirable, but is hindered by the limited performance of existing biomarkers. Here, we leveraged in-silico patient cohorts generated using a quantitative systems pharmacology model of metastatic TNBC, informed by transcriptomic and clinical data, to explore potential ways to improve patient selection. We tested 90 biomarker candidates, including various cellular and molecular species, by a cutoff-based biomarker testing algorithm combined with machine learning-based feature selection. Combinations of pre-treatment biomarkers improved the specificity compared to single biomarkers at the cost of reduced sensitivity. On the other hand, early on-treatment biomarkers, such as the relative change in tumor diameter from baseline measured at two weeks after treatment initiation, achieved remarkably higher sensitivity and specificity. Further, blood-based biomarkers had a comparable ability to tumor- or lymph node-based biomarkers in identifying a subset of responders, potentially suggesting a less invasive way for patient selection.

Role of ICAM-1 in triple-negative breast cancer

Intercellular adhesion molecule-1 (ICAM-1) is related to the occurrence and development of a variety of tumors. However, the role of ICAM-1 in the regulation of growth, metastasis, and clinical prognosis of the specific molecular subtypes of breast cancer, triple-negative breast cancer (TNBC), remains to be elucidated. This study explored the role of ICAM-1 in breast cancer and its triple-negative subtypes by systematic bioinformatics methods. The results showed that the expression of ICAM-1 in breast cancer tissues was significantly higher than that in normal tissues, especially in TNBC subtypes. In breast cancer, ICAM-1 mainly activates pathways related to apoptosis and epithelial-mesenchymal transition, while its overexpression in TNBC is associated with inflammatory response, apoptosis, and other processes. TNBC patients displaying higher ICAM-1 expression demonstrate enhanced responses to immunotherapy. High ICAM-1 expression is sensitive to drugs targeting tumor cell proliferation, apoptosis, and angiogenesis. In conclusion, breast cancer is characterized by significantly high expression of ICAM-1, with TNBC subtypes expressing ICAM-1 at much higher levels than other subtypes. The diagnosis, prognosis, development, distant metastases, and immunotherapy of TNBC are correlated with high expression of ICAM-1. This research provides available data for the further study of the diagnosis and treatment of TNBC.

Enhancing antitumor immunity with stimulus-responsive mesoporous silicon in combination with chemotherapy and photothermal therapy

Due to the immunosuppressive tumor microenvironment (TME) and potential systemic toxicity, chemotherapy often fails to elicit satisfactory anti-tumor responses, so how to activate anti-tumor immunity to improve the therapeutic efficacy remains a challenging problem. Photothermal therapy (PTT) serves as a promising approach to activate anti-tumor immunity by inducing the release of tumor neoantigens in situ. In this study, we designed tetrasulfide bonded mesoporous silicon nanoparticles (MSNs) loaded with the traditional drug doxorubicin (DOX) inside and modified their outer layer with polydopamine (DOX/MSN-4S@PDA) for comprehensive anti-tumor studies in vivo and in vitro. The MSN core contains GSH-sensitive tetrasulfide bonds that enhance DOX release while generating hydrogen sulfide (H2S) to improve the therapeutic efficacy of DOX. The polydopamine (PDA) coating confers acid sensitivity and mild photothermal properties upon exposure to near-infrared (NIR) light, while the addition of hyaluronic acid (HA) to the outermost layer enables targeted delivery to CD44-expressing tumor cells, thereby enhancing drug accumulation at the tumor site and reducing toxic side effects. Our studies demonstrate that DOX/MSN@PDA-HA can reverse the immunosuppressive tumor microenvironment in vivo, inducing potent immunogenic cell death (ICD) of tumor cells and improving anti-tumor efficacy. In addition, DOX/MSN@PDA-HA significantly suppresses tumor metastasis to the lung and liver. In summary, DOX/MSN@PDA-HA exhibits controlled drug release, excellent biocompatibility, and remarkable tumor inhibition capabilities through synergistic chemical/photothermal combined therapy.

D-arabinose induces cell cycle arrest by promoting autophagy via p38 MAPK signaling pathway in breast cancer

Breast cancer patients often have a poor prognosis largely due to lack of effective targeted therapy. It is now well established that monosaccharide enhances growth retardation and chemotherapy sensitivity in tumor cells. We investigated whether D-arabinose has capability to restrict the proliferation of tumor cells and its mechanism. Here, we report that D-arabinose induced cytotoxicity is modulated by autophagy and p38 MAPK signaling pathway in breast cancer cell lines. The proliferation of cells was evaluated by CCK-8 and Colony formation assay. The distribution of cells in cell cycle phases was analyzed by flow cytometry. Cell cycle, autophagy and MAPK signaling related proteins were detected by western blotting. Mouse xenograft model was used to evaluate the efficacy of D-arabinose in vivo. The proliferation of cells was dramatically inhibited by D-arabinose exposure in a dose-dependent manner, which was relevant to cell cycle arrest, as demonstrated by G2/M cell cycle restriction and ectopic expression of cell cycle related proteins. Mechanistically, we further identified that D-arabinose is positively associated with autophagy and the activation of the p38 MAPK signaling in breast cancer. In contrast, 3-Ma or SB203580, the inhibitor of autophagy or p38 MAPK, reversed the efficacy of D-arabinose. Additionally, D-arabinose in vivo treatment could significantly inhibit xenograft growth of breast cancer cells. Our findings were the first to reveal that D-arabinose triggered cell cycle arrest by inducing autophagy through the activation of p38 MAPK signaling pathway in breast cancer cells.

Cordycepin enhances anti-tumor immunity in breast cancer by enhanceing ALB expression

Objective

The treatment of breast cancer still faces great challenges, and it is necessary to continuously explore effective drugs and targets to promote immune precision medicine. This study aims to investigate the immune-related regulatory mechanism of cordycepin in breast cancer.

Methods

Network pharmacology was employed to discovery the action of cordyceps on breast cancer targets, molecular docking was employed to analyze the interaction pattern between core components and targets, and biological information analysis was used to explore the target-related immune mechanism and verified in vitro experiments.

Results

The results of this study indicate that cordycepin can effectively inhibit breast cancer. The roles of cordycepin's active component and its target gene ALB were elucidated through the combined use of network pharmacology and molecular docking. Bioinformatics analysis revealed convincing associations between ALB and many immune pathway marker genes. ALB was inhibited in tumor expression, and cordycepin was found to enhance the expression of ALB in vitro to play an anti-tumor role.

Conclusion

Cordycepin regulates immune suppression of tumor, which is expected to open a new chapter of breast cancer immunotherapy.

Identification of the new molecular subtypes related to inflammation in breast cancer

Breast cancer is a prevalent ailment among women, and the inflammatory response plays a crucial role in the management and prediction of breast cancer (BRCA). However, the new subtypes based on inflammation in BRCA research are still undefined. The databases including The Cancer Genome Atlas and gene expression omnibus were utilized to gather clinical data and somatic mutation information for approximately 1069 BRCA patients. Through Consensus Clustering, novel subtypes linked to inflammation were identified. A comparative analysis was conducted on the prognosis, and immune cell infiltration, and somatic mutation of the new subtypes. Additionally, an investigation into drug therapy and immunotherapy was conducted to distinguish high-risk individuals from low-risk ones. The findings of this investigation proposed the categorization of BRCA into innovative subtypes predicated on the inflammatory response and 6 key genes were a meaningful approach. Specifically, the low-, medium-, and high-inflammation subtypes exhibited varying degrees of association with clinicopathological features, tumor microenvironment, and prognosis. Notably, the high-inflammation subtype was characterized by a strong correlation with immunosuppressive microenvironments and a higher frequency of somatic mutations, which was an indication of poorer health. This study revealed that a brand-new classification could throw new light on the effective prognosis. The integration of multiple key genes was a new characterization that could promote more immunotherapy strategies and contribute to predicting the efficacy of the chemotherapeutic drugs.

Host-derived Interleukin 1α induces an immunosuppressive tumor microenvironment via regulating monocyte-to-macrophage differentiation

Tumor-associated macrophages exhibit high heterogeneity and contribute to the establishment of an immunosuppressive tumor microenvironment (TME). Although numerous studies have demonstrated that extracellular factors promote macrophage proliferation and polarization, the regulatory mechanisms governing the differentiation process to generate phenotypically, and functionally diverse macrophage subpopulations remain largely unexplored. In this study, we examined the influence of interleukin 1α (IL-1α) on the development of an immunosuppressive TME using orthotopic transplantation murine models of breast cancer. Deletion of host Il1α led to the rejection of inoculated congenic tumors. Single-cell sequencing analysis revealed that CX3CR1+ macrophage cells were the primary sources of IL-1α in the TME. The absence of IL-1α reprogrammed the monocyte-to-macrophage differentiation process within the TME, characterized by a notable decrease in the subset of CX3CR+ ductal-like macrophages and an increase in iNOS-expressing inflammatory cells. Comparative analysis of gene signatures in both human and mouse macrophage subsets suggested that IL-1α deficiency shifted the macrophage polarization from M2 to M1 phenotypes, leading to enhanced cytotoxic T lymphocyte activity in the TME. Importantly, elevated levels of IL-1α in human cancers were associated with worse prognosis following immunotherapy. These findings underscore the pivotal role of IL-1α in shaping an immune-suppressive TME through the regulation of macrophage differentiation and activity, highlighting IL-1α as a potential target for breast cancer treatment.

Effects of Chemotherapy on the Immune System: Implications for Cancer Treatment and Patient Outcomes

Chemotherapy is a cornerstone of cancer treatment, but it can also induce immune suppression, which can have significant implications for patient outcomes. This review paper aims to give a general overview of how chemotherapy affects the immune system and how it affects cancer treatment. Chemotherapy can directly affect immune cells, leading to cytotoxic effects, cell differentiation and function alterations, and cell communication and signaling pathways disruptions. Such immune suppression can weaken the anti-tumor immune response and increase the risk of immune-related toxicities. Understanding the mechanisms of chemotherapy-induced immune suppression is crucial for optimizing treatment strategies. Strategies to mitigate immune suppression include immunomodulatory agents as adjuvants to chemotherapy, combination therapies to enhance immune function, and supportive care measures of the immune system. Additionally, identifying potential biomarkers to predict immune suppression and guide treatment decisions holds promise for personalized cancer medicine. Future directions in this field involve further elucidating underlying mechanisms, exploring novel combination therapies, and developing targeted interventions to minimize immune suppression. By understanding and addressing chemotherapy-induced immune suppression, we can optimize cancer treatment strategies, enhance the anti-tumor immune response, and improve patient outcomes.

CTLA4 expression profiles and their association with clinical outcomes of breast cancer: a systemic review

Purpose

The cytotoxic T-lymphocyte-associated protein 4 (CTLA4) is involved in the progression of various cancers, but its biological roles in breast cancer (BRCA) remain unclear. Therefore, we performed a systematic multiomic analysis to expound on the prognostic value and underlying mechanism of CTLA4 in BRCA.

Methods

We assessed the effect of CTLA4 expression on BRCA using a variety of bioinformatics platforms, including Oncomine, GEPIA, UALCAN, PrognoScan database, Kaplan-Meier plotter, and R2: Kaplan-Meier scanner.

Results

CTLA4 was highly expressed in BRCA tumor tissue compared to normal tissue (P < 0.01). The CTLA4 messenger RNA levels in BRCA based on BRCA subtypes of Luminal, human epidermal growth factor receptor 2, and triple-negative BRCA were considerably higher than in normal tissues (P < 0.001). However, the overexpression of CTLA4 was associated with a better prognosis in BRCA (P < 0.001) and was correlated with clinicopathological characteristics including age, T stage, estrogen receptors, progesterone receptors, and prediction analysis of microarray 50 (P < 0.01). The infiltration of multiple immune cells was associated with increased CTLA4 expression in BRCA (P < 0.001). CTLA4 was highly enriched in antigen binding, immunoglobulin complexes, lymphocyte-mediated immunity, and cytokine-cytokine receptor interaction.

Conclusion

This study provides suggestive evidence of the prognostic role of CTLA4 in BRCA, which may be a therapeutic target for BRCA. Furthermore, CTLA4 may influence BRCA prognosis through antigen binding, immunoglobulin complexes, lymphocyte-mediated immunity, and cytokine-cytokine receptor interaction. These findings help us understand how CTLA4 plays a role in BRCA and set the stage for more research.

Identification of N7-methylguanosine-related miRNAs as potential biomarkers for prognosis and drug response in breast cancer

Objectives

The impact of N7-methylguanosine (m7G) on tumor progression and the regulatory role of microRNAs (miRNAs) in immune function significantly influence breast cancer (BC) prognosis. Investigating the interplay between m7G modification and miRNAs provides novel insights for assessing prognostics and drug responses in BC.

Materials and methods

RNA sequences (miRNA and mRNA profiles) and clinical data for BC were acquired from the Cancer Genome Atlas (TCGA) database. A miRNA signature associated with 15 m7G in this cohort was identified using Cox regression and LASSO. The risk score model was evaluated using Kaplan-Meier and time-dependent ROC analysis, categorizing patients into high-risk and low-risk groups. Functional enrichment analyses were conducted to explore potential pathways. The immune system, including scores, cell infiltration, function, and drug sensitivity, was examined and compared between high-risk and low-risk groups. A nomogram that combines risk scores and clinical factors was developed and validated. Single-sample gene set enrichment analysis (ssGSEA) was employed to explore m7G-related miRNA signatures and immune cell relationships in the tumor microenvironment. Additionally, drug susceptibility was compared between risk groups.

Results

Fifteen m7G-related miRNAs were independently correlated with overall survival (OS) in BC patients. Time-dependent ROC analysis yielded area under the curve (AUC) values of 0.742, 0.726, and 0.712 for predicting 3-, 5-, and 10-year survival rates, respectively. The Kaplan-Meier analysis revealed a significant disparity in OS between the high-risk and low-risk groups (p = 1.3e-6). Multiple regression identified the risk score as a significant independent prognostic factor. An excellent calibration nomogram with a C-index of 0.785 (95 % CI: 0.728-0.843) was constructed. In immune analysis, low-risk patients exhibited heightened immune function and increased responsiveness to immunotherapy and chemotherapy compared to high-risk patients.

Conclusion

This study systematically analyzed m7G-related miRNAs and revealed their regulatory mechanisms concerning the tumor microenvironment (TME), pathology, and the prognosis of BC patient. Based on these miRNAs, a prognostic model and nomogram were developed for BC patients, facilitating prognostic assessments. These findings can also assist in predicting treatment responses and guiding medication selection.

Cutting-edge approaches for targeted drug delivery in breast cancer: beyond conventional therapies

Breast cancer is a global health challenge with staggering statistics underscoring its pervasive impact. The burden of this disease is measured in terms of its prevalence and the challenges it poses to healthcare systems, necessitating a closer look at its epidemiology and impact. Current breast cancer treatments, including surgery, chemotherapy, radiation therapy, and targeted therapies, have made significant strides in improving patient outcomes. However, they are not without limitations, often leading to adverse effects and the development of drug resistance. This comprehensive review delves into the complex landscape of breast cancer, including its incidence, current treatment modalities, and the inherent limitations of existing therapeutic approaches. It also sheds light on the promising role of nanotechnology, encompassing both inorganic and organic nanoparticles equipped with the ability to selectively deliver therapeutic agents to tumor sites, in the battle against breast cancer. The review also addresses the emerging therapies, their associated challenges, and the future prospects of targeted drug delivery in breast cancer management.

Impact of Neoadjuvant Chemotherapy (NAC) on Biomarker Expression in Breast Cancer

Background and Objectives: This study aimed to explore biomarker change after NAC (neoadjuvant chemotherapy) and to investigate biomarker expression as a prognostic factor in patients with residual disease (RD) after NAC. Materials and Methods: We retrospectively evaluated 104 patients with invasive breast cancer, who underwent NAC and surgery at Pusan National University Hospital from 2015 to July 2022. The expression of the biomarker was assessed, and the overall survival (OS) and disease-free survival (DFS) were investigated. Results: After NAC, 24 patients (23.1%) out of 104 total patients had a pathological complete response (pCR). We found that changes in at least one biomarker were observed in 41 patients (51.2%), among 80 patients with RD. In patients with RD after NAC (n = 80), a subtype change was identified in 20 patients (25.0%). Any kind of change in the HER2 status was present 19 (23.7%) patients. The hormone receptor (HR)+/HER2+ subtype was significantly associated with better disease-free survival (DFS) (HR, 0.13; 95% CI, 0.02-0.99; p = 0.049). No change in p53 was associated with better DFS, and negative-to-positive change in p53 expression after NAC was correlated with worse DFS (p < 0.001). Negative-to-positive change in p53 was an independent, worse DFS factor in the multivariate analysis (HR,18.44; 95% CI, 1.86-182.97; p = 0.013). Conclusions: Biomarker change and subtype change after NAC were not infrequent, which can affect the further treatment strategy after surgery. The expression change of p53 might have a prognostic role. Overall, we suggest that the re-evaluation of biomarkers after NAC can provide a prognostic role and is needed for the best decision to be made on further treatment.

K48-linked deubiquitination of VGLL4 by USP15 enhances the efficacy of tumor immunotherapy in triple-negative breast cancer

Immunotherapy based on PD-1/PD-L1 antagonists has been demonstrated to be efficacious in inducing tumor remission in patients with triple-negative breast cancer (TNBC). However, tumor immune evasion caused by the PD-1/PD-L1 pathway inhibits the immunotherapeutic effect of PD-1/PD-L1 inhibitors against TNBC. Therefore, identifying potential targets for blocking the PD-1/PD-L1 pathway is a compelling strategy for TNBC treatment. Here, we discovered that VGLL4 could inhibit PD-L1 transcription by suppressing STAT3 activation, thereby enhancing the efficacy of anti-PD-1 antibody immunotherapy in TNBC. Low expression of USP15, a deubiquitinating enzyme of VGLL4, was associated with reduced CD8+ T cell infiltration and poor prognosis in TNBC patients. USP15 was found to inhibit PD-L1 transcription, leading to increased CD8+ T cell infiltration and thus enhancing the efficacy of TNBC immunotherapy. Furthermore, SART3 regulated VGLL4 stability and PD-L1 transcription by influencing the nuclear translocation of USP15. In conclusion, our study provides new insights into the biological regulation of PD-L1, identifies a previously unrecognized regulator of this critical immune checkpoint, and highlights potential therapeutic targets for overcoming immune evasion in TNBC.

Integrative analysis based on the cell cycle-related genes identifies TPX2 as a novel prognostic biomarker associated with tumor immunity in breast cancer

BACKGROUND

This study aims to identify the essential cell cycle-related genes associated with prognosis in breast cancer (BRCA), and to verify the relationship between the central gene and immune infiltration, so as to provide detailed and comprehensive information for the treatment of BRCA.

MATERIALS AND METHODS

Gene expression profiles (GSE10780, GSE21422, GSE61304) and the Cancer Genome Atlas (TCGA) BRCA data were used to identify differentially expressed genes (DEGs) and further functional enrichment analysis. STRING and Cytoscape were employed for the protein-protein interaction (PPI) network construction. TPX2 was viewed as the crucial prognostic gene by the Survival and Cox analysis. Furthermore, the connection between TPX2 expression and immune infiltrating cells and immune checkpoints in BRCA was also performed by the TIMER online database and R software.

RESULTS

A total of 18 cell cycle-related DEGs were identified in this study. Subsequently, an intersection analysis based on TCGA-BRCA prognostic genes and the above DEGs identified three genes (TPX2, UBE2C, CCNE2) as crucial prognostic candidate biomarkers. Moreover, we also demonstrated that TPX2 is closely associated with immune infiltration in BRCA and a positive relation between TPX2 and PD-L1 expression was firstly detected.

CONCLUSIONS

These results revealed that TPX2 is a potential prognostic biomarker and closely correlated with immune infiltration in BRCA, which could provide powerful and efficient strategies for breast cancer immunotherapy.

Preoperative single-dose camrelizumab and/or microwave ablation in women with early-stage breast cancer: A window-of-opportunity trial

BACKGROUND

Immune checkpoint blockade has shown low response rates for advanced breast cancer, and combination strategies are needed. Microwave ablation (MWA) may be a trigger of antitumor immunity. This window-of-opportunity trial (ClinicalTrials.gov: NCT04805736) was conducted to determine the safety and feasibility of preoperative camrelizumab (an anti-PD-1 antibody) combined with MWA in the treatment of early-stage breast cancer.

METHODS

Sixty participants were randomized to preoperatively receive single-dose camrelizumab alone (n = 20), MWA alone (n = 20), or camrelizumab+MWA (n = 20). A random number table was used to allocate interventions. The primary outcome was the safety and feasibility of MWA combined with camrelizumab.

FINDINGS

Camrelizumab and MWA were well tolerated alone and in combination without delays in prescheduled surgery. No treatment-related grade III/IV adverse events were observed. Different from in the single-dose camrelizumab or MWA group, participants showed stable counts of blood cells after combination therapy. After combination therapy, peripheral CD8+ T cells showed enhanced cytotoxic and effect-memory functions. Clonal expansional CD8+ T cells showed higher cytotoxic activity and effector memory- and tumor-specific signatures than emergent clones after combination therapy. Enhanced interactions between clonal expansional CD8+ T cells and monocytes were observed, suggesting that monocytes contributed to the enhanced functions of clonal expansional CD8+ T cells. Major histocompatibility complex (MHC) class I-related pathways and interferon signaling pathways were activated in monocytes by combination therapy.

CONCLUSIONS

Camrelizumab combined with MWA was feasible for early-stage breast cancer. Peripheral CD8+ T cells were activated after combination therapy, dependent on monocytes with activated MHC class I pathways.

FUNDING

This study was supported by the Natural Science Foundation of Jiangsu Province (BK20230017).

Comparative efficacy and safety of targeted therapy and immunotherapy for HER2-positive breast cancer: a systematic review and network meta-analyses

Background

In recent years, novel therapies targeting specific molecular pathways and immunotherapies have exhibited promising outcomes for treating human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Our work aimed to assess the effectiveness and safety of these emerging treatment regimens for this disease.

Material and methods

We systematically searched databases including PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials their inception to August 2023 to identify relevant randomized controlled trials (RCTs). The quality of eligible RCTs was evaluated with the Cochrane risk-of-bias tool, version 2 (RoB2). Investigated outcomes encompassed progression-free survival (PFS), overall survival (OS), disease-free survival (DFS), pathologic complete remission (pCR), and adverse events (AEs). They were expressed as hazard ratio (HR) with 95% conference intervals (CI) or risk ratio (RR) with 95% CI.

Results

Our analysis identified a total of 28 RCTs suitable for inclusion in the NMA. Regarding the PFS, all these treatment regimens exhibited comparable effectiveness. In terms of OS, Capecitabine+Trastuzumab, Lapatinib+Trastuzumab and Pyrotinib+Capecitabine exhibited better effect compared to other treatments. Regarding pCR and AEs, all these treatment regimens exhibited comparable effectiveness, especially Lapatinib+Trastuzumab and Pyrotinib+Capecitabine.

Conclusion

Our study highlights the prominent role of targeted therapies and immunotherapies in treating HER2-positive breast cancer. The efficacy of trastuzumab-containing regimens was superior to other treatment options, while maintaining a comparable safety profile. Based on these findings, trastuzumab-containing regimens emerge as a preferable and recommended choice in clinical practice for managing HER2-positive breast cancer.

Systematic Review Registration

PROSPERO, identifier CRD42023414348.

A novel immune-related long noncoding RNA (lncRNA) pair model to predict the prognosis of triple-negative breast cancer

Background

Breast cancer (BC) is the most prevalent cancer type and is the principal cause of cancer-related death in women. Anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) immunotherapy has shown promising effects in metastatic triple-negative breast cancer (TNBC), but the potential factors affecting its efficacy have not been elucidated. Immune-related long noncoding RNAs (irlncRNAs) have been reported to be involved in immune escape to influence the carcinogenic process through the PD-1/PD-L1 signaling pathway. Therefore, exploring the potential regulatory mechanism of irlncRNAs in PD-1/PD-L1 immunotherapy in TNBC is of great importance.

Methods

We retrieved transcriptome profiling data from The Cancer Genome Atlas (TCGA) and identified differentially expressed irlncRNA (DEirlncRNA) pairs. Least absolute shrinkage and selection operator (LASSO) regression analysis was performed to construct a risk assessment model.

Results

Receiver operating characteristic (ROC) curve analysis indicated that the risk model may serve as a potential prediction tool in TNBC patients. Clinical stage and risk score were proved to be independent prognostic predictors by univariate and multivariate Cox regression analyses. Subsequently, we investigated the correlation between the risk model and tumor-infiltrating immune cells and immune checkpoints. Finally, we identified USP30-AS1 through the StarBase and Multi Experiment Matrix (MEM) databases, predicted the potential target genes of USP30-AS1, and then discovered that these target genes were closely associated with immune responses.

Conclusions

Our study constructed a risk assessment model by irlncRNA pairs regardless of expression levels, which contributed to predicting the efficacy of immunotherapy in TNBC. Furthermore, the lncRNA USP30-AS1 in the model was positively correlated with the expression of PD-L1 and provided a potential therapeutic target for TNBC.

miR-29a-KLF4 signaling inhibits breast tumor initiation by regulating cancer stem cells

Cancer stem cells (CSCs) are known for their potent ability to drive tumor initiation and recurrence, yet the molecular mechanisms regulating CSCs are still unclear. Our study found a positive correlation between increased levels of miR-29a and better survival rates in early-stage breast cancer patients, but a negative correlation in late-stage patients, suggesting a dual function of miR-29a in regulating breast cancer. Furthermore, miR-29a showed significant downregulation in the ALDH+ breast cancer stem cell population compared to non-stem cancer cells. Overexpression of miR-29a in human breast cancer cells reduced the proportion of CSCs, suppressed their ability to form mammospheres, and inhibited the expression of stemness genes SOX2, KLF4, and hTERT in vitro. Conversely, knockdown of miR-29a in breast cancer cells showed opposite effects. Tumor xenograft experiments revealed that miR-29a overexpression significantly inhibited tumorigenesis initiated by MDA-MB-231 cell transplantation in nude mice. We further demonstrated that Krüppel-like factor 4 (KLF4), a key gene that regulates cell stemness, was a direct target of miR-29a in breast cancer cells. miR-29a suppressed the expression of KLF4 at both mRNA and protein levels. Reintroduction of KLF4 into breast cancer cells rescued the miR-29a-induced CSC suppression phenotype. In summary, our study is the first to demonstrate that miR-29a-KLF4 signaling inhibits breast tumor initiation by regulating CSCs, which provides novel therapeutic targets for preventing breast tumor initiation.

Exploring the dynamic interplay between exosomes and the immune tumor microenvironment: implications for breast cancer progression and therapeutic strategies

Breast cancer continues to pose a substantial worldwide health concern, demanding a thorough comprehension of the complex interaction between cancerous cells and the immune system. Recent studies have shown the significant function of exosomes in facilitating intercellular communication and their participation in the advancement of cancer. Tumor-derived exosomes have been identified as significant regulators in the context of breast cancer, playing a crucial role in modulating immune cell activity and contributing to the advancement of the illness. This study aims to investigate the many effects of tumor-derived exosomes on immune cells in the setting of breast cancer. Specifically, we will examine their role in influencing immune cell polarization, facilitating immunological evasion, and modifying the tumor microenvironment. Furthermore, we explore the nascent domain of exosomes produced from immune cells and their prospective involvement in the prevention of breast cancer. This paper focuses on new research that emphasizes the immunomodulatory characteristics of exosomes produced from immune cells. It also explores the possibility of these exosomes as therapeutic agents or biomarkers for the early identification and prevention of breast cancer. The exploration of the reciprocal connections between exosomes formed from tumors and immune cells, together with the rising significance of exosomes derived from immune cells, presents a potential avenue for the advancement of novel approaches in the field of breast cancer therapy and prevention.

Dual inhibitors of DNMT and HDAC induce viral mimicry to induce antitumour immunity in breast cancer

The existing conventional treatments for breast cancer, including immune checkpoint blockade, exhibit limited effects in some cancers, particularly triple-negative breast cancer. Epigenetic alterations, specifically DNMT and HDAC alterations, are implicated in breast cancer pathogenesis. We demonstrated that DNMTs and HDACs are overexpressed and positively correlated in breast cancer. The combination of DNMT and HDAC inhibitors has shown synergistic antitumour effects, and our previously designed dual DNMT and HDAC inhibitor (termed DNMT/HDACi) 15a potently inhibits breast cancer cell proliferation, migration, and invasion and induces apoptosis in vitro and in vivo. Mechanistically, 15a induces a viral mimicry response by promoting the expression of endogenous retroviral elements in breast cancer cells, thus increasing the intracellular level of double-stranded RNA to activate the RIG-I-MAVS pathway. This in turn promotes the production of interferons and chemokines and augments the expression of interferon-stimulated genes and PD-L1. The combination of 15a and an anti-PD-L1 antibody had an additive effect in vivo. These findings indicate that this DNMT/HDACi has immunomodulatory functions and enhances the effectiveness of immune checkpoint blockade therapy. A novel dual DNMT and HDAC inhibitor induces viral mimicry, which induces the accumulation of dsRNA to activate tumoral IFN signalling and cytokine production to enhance the immune response in breast cancer.

Light-Enhanced Hypoxia-Responsive Gene Editing for Hypoxia-Resistant Photodynamic and Immunotherapy

Hypoxia is a key hallmark of solid tumors and can cause resistance to various treatments such as photodynamics and immunotherapy. Microenvironment-responsive gene editing provides a powerful tool to overcome hypoxia resistance and remodel hypoxic microenvironments for enhanced tumor therapy. Here, a light-enhanced hypoxia-responsive multifunctional nanocarrier is developed to perform spatiotemporal specific dual gene editing for enhanced photodynamic and immunotherapy in breast cancer. As a gated molecule of nanocarrier, the degradation of azobenzene moieties under hypoxic conditions triggers controllable release of Cas9 ribonucleoprotein in hypoxic site of the tumor. Hyaluronic acid is conjugated with chloramine e6 to coat mesoporous silica nanoparticles for targeted delivery in tumors and generation of high levels of reactive oxygen species, which can result in increased hypoxia levels for effective cleavage of azobenzene bonds to improve gene editing efficiency and reduce toxic side effects with light irradiation. Moreover, dual targeting HIF-1α and PD-L1 in the anoxic microenvironments can overcome hypoxia resistance and remodel immune microenvironments, which reduces tumor plasticity and resistance to photodynamic and immunotherapy. In summary, a light-enhanced hypoxia responsive nanocomposite is developed for controllable gene editing which holds great promise for synergistic hypoxia-resistant photodynamic and immunotherapy.

Targeting the Warburg effect: A revisited perspective from molecular mechanisms to traditional and innovative therapeutic strategies in cancer

Cancer reprogramming is an important facilitator of cancer development and survival, with tumor cells exhibiting a preference for aerobic glycolysis beyond oxidative phosphorylation, even under sufficient oxygen supply condition. This metabolic alteration, known as the Warburg effect, serves as a significant indicator of malignant tumor transformation. The Warburg effect primarily impacts cancer occurrence by influencing the aerobic glycolysis pathway in cancer cells. Key enzymes involved in this process include glucose transporters (GLUTs), HKs, PFKs, LDHs, and PKM2. Moreover, the expression of transcriptional regulatory factors and proteins, such as FOXM1, p53, NF-κB, HIF1α, and c-Myc, can also influence cancer progression. Furthermore, lncRNAs, miRNAs, and circular RNAs play a vital role in directly regulating the Warburg effect. Additionally, gene mutations, tumor microenvironment remodeling, and immune system interactions are closely associated with the Warburg effect. Notably, the development of drugs targeting the Warburg effect has exhibited promising potential in tumor treatment. This comprehensive review presents novel directions and approaches for the early diagnosis and treatment of cancer patients by conducting in-depth research and summarizing the bright prospects of targeting the Warburg effect in cancer.

Why does HER2-positive breast cancer metastasize to the brain and what can we do about it?

Breast cancer is the most frequent malignancy in women. However, in the middle and late stages, some people develop distant metastases, which considerably lower the quality of life and life expectancy. The brain is one of the sites where metastasis frequently happens. According to epidemiological research, brain metastases occur at a late stage in 30-50% of patients with HER2-positive breast cancer, resulting in a poor prognosis. Additionally, few treatments are available for HER2-positive brain metastatic breast cancer, and the mortality rate is remarkable owing to the complexity of the brain's anatomical structure and physiological function. In this review, we described the stages of the brain metastasis of breast cancer, the relationship between the microenvironment and metastatic cancer cells, and the unique molecular and cellular mechanisms. It involves cancer cells migrating, invading, and adhering to the brain; penetrating the blood-brain barrier; interacting with brain cells; and activating signal pathways once inside the brain. Finally, we reviewed current clinically used treatment approaches for brain metastasis in HER2-positive breast cancer; summarized the traditional treatment, targeted treatment, immunotherapy, and other treatment modalities; compared the benefits and drawbacks of each approach; discussed treatment challenges; and emphasized the importance of identifying potential targets to improve patient survival rates and comprehend brain metastasis in breast cancer.

Successful immunotherapy with PD-1 Iinhibitor for advanced pancreatic cancer: report of two cases and review of literature

Pancreatic cancer is a highly malignant tumor, and most patients are diagnosed at an advanced stage. Unfortunately, due to the immunosuppressive tumor microenvironment of pancreatic cancer, the benefits of immunotherapy for patients with advanced pancreatic cancer are still unclear. Here, we present two cases of advanced pancreatic cancer being controlled by immunotherapy, with pathological diagnoses of ductal adenocarcinoma and acinar cell carcinoma, respectively. Next-generation sequencing (NGS) of both patients is high tumor mutation burden (tumor mutation burden-High) and microsatellite stable. The patient with pancreatic ductal adenocarcinoma was diagnosed as a locally advanced disease (stage III). She received irreversible electroporation, used the programmed death receptor-1 (PD-1) inhibitor (pembrolizumab) combined with chemotherapy (S-1), and then used only the PD-1 inhibitor as a maintenance treatment. As a result, the patient's lesion was significantly reduced, with a partial response time of up to 31 months. The patient with acinar cell carcinoma was diagnosed as a metastatic disease (stage IV), next-generation sequencing revealed mutations in SMAD4 and KMT2D, and two chemotherapy regimens were used unsuccessfully. Then, the combination of chemotherapy with PD-1 (tislelizumab) and vascular endothelial growth factor/vascular endothelial growth factor receptor (anlotinib) inhibitors were used, and the lesions of the patient were significantly reduced, and the progression-free survival after immunotherapy was 19 months. In advanced pancreatic cancer, a prognosis of this magnitude is rare. Our cases reveal the potential of immunotherapy as a cornerstone treatment in the management of advanced pancreatic cancer.

Anti-Cancer Potency of Copper-Doped Carbon Quantum Dots Against Breast Cancer Progression

Introduction

The anti-cancer potency of copper-doped carbon quantum dots (Cu-CDs) against breast cancer progression needs more detailed investigations.

Methods

With urea and ethylene glycol applied as carbon sources and copper sulfate used as a reactive dopant, Cu-CDs were synthesized in the current study by a one-step hydrothermal synthesis method, followed by the characterization and biocompatibility evaluations of Cu-CDs. Subsequently, the anti-cancer potency of Cu-CDs against breast cancer progression was confirmed by these biochemical, molecular, and transcriptomic assessments, including viability, proliferation, migration, invasion, adhesion, clonogenicity, cell cycle distribution, apoptosis, redox homeostasis, and transcriptomic assays of MDA-MB-231 cells.

Results

The biocompatibility of Cu-CDs was confirmed based on the non-significant changes in the pathological and physiological parameters in the Cu-CDs treated mice, as well as the noncytotoxic effect of Cu-CDs on normal cells. Moreover, the Cu-CDs treatments not only decreased the viability, proliferation, migration, invasion, adhesion, and clonogenicity of MDA-MB-231 cells but also induced the redox imbalance, cell cycle arrest, and apoptosis of MDA-MB-231 cells via ameliorating the mitochondrial dysfunctions and regulating the MAPK signaling pathway.

Conclusion

Our findings confirmed the biosafety and excellent anti-cancer potency of Cu-CDs against breast cancer progression by tapping into mechanisms that disrupt malignant behaviors and oxidative homeostasis of breast cancer cells.

The metabolism-related lncRNA signature predicts the prognosis of breast cancer patients

Long non-coding RNAs (lncRNAs) involved in metabolism are recognized as significant factors in breast cancer (BC) progression. We constructed a novel prognostic signature for BC using metabolism-related lncRNAs and investigated their underlying mechanisms. The training and validation cohorts were established from BC patients acquired from two public sources: The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). The prognostic signature of metabolism-related lncRNAs was constructed using the least absolute shrinkage and selection operator (LASSO) cox regression analysis. We developed and validated a new prognostic risk model for BC using the signature of metabolism-related lncRNAs (SIRLNT, SIAH2-AS1, MIR205HG, USP30-AS1, MIR200CHG, TFAP2A-AS1, AP005131.2, AL031316.1, C6orf99). The risk score obtained from this signature was proven to be an independent prognostic factor for BC patients, resulting in a poor overall survival (OS) for individuals in the high-risk group. The area under the curve (AUC) for OS at three and five years were 0.67 and 0.65 in the TCGA cohort, and 0.697 and 0.68 in the GEO validation cohort, respectively. The prognostic signature demonstrated a robust association with the immunological state of BC patients. Conventional chemotherapeutics, such as docetaxel and paclitaxel, showed greater efficacy in BC patients classified as high-risk. A nomogram with a c-index of 0.764 was developed to forecast the survival time of BC patients, considering their risk score and age. The silencing of C6orf99 markedly decreased the proliferation, migration, and invasion capacities in MCF-7 cells. Our study identified a signature of metabolism-related lncRNAs that predicts outcomes in BC patients and could assist in tailoring personalized prevention and treatment plans.

Cancer cell-derived exosomal miR-20a-5p inhibits CD8+ T-cell function and confers anti-programmed cell death 1 therapy resistance in triple-negative breast cancer

Circulating miRNAs (cirmiRNAs) can be packaged into the exosomes, participating in intercellular communication, which affects the malignant progression and therapy resistance of triple-negative breast cancer (TNBC). Currently, immune checkpoint inhibitors that regulate T-cell function, especially antibodies against programmed cell death 1 (PD-1) or its ligand PD-L1, are emerging as new promising therapy for TNBC patients. However, only very limited patients showed complete or partial response to anti-PD-1 treatment. Dysfunction of CD8+ T cells is one of the key reasons for the immune escape of TNBC. The regulation of exosome-derived cirmiRNAs on CD8+ T cells in TNBC deserves more investigation. Here, the cirmiR-20a-5p level was significantly upregulated in the plasma of TNBC patients and culture supernatant of TNBC cells. High abundance of cirmiR-20a-5p was correlated with a worse prognosis of TNBC. cirmiR-20a-5p was secreted in the form of exosomes by TNBC cells. Exosomal cirmiR-20a-5p was internalized into CD8+ T cells and resulted into the dysfunction of CD8+ T. A mechanism study uncovered that cirmiR-20a-5p targeted the nuclear protein ataxia-telangiectasia (NPAT) and decreased NPAT expression in CD8+ T cells. An in vivo xenograft mouse model showed that cirmiR-20a-5p conferred TNBC to anti-PD-1 treatment resistance. Collectively, these findings indicated that cirmiR-20a-5p released by TNBC cells via exosome promotes cancer cell growth and leads to the immunosuppression by inducing CD8+ T cell dysfunction. This study suggests that targeting cirmiR-20a-5p might be a novel strategy for overcoming the resistance of TNBC to anti-PD-1 immunotherapy.

Pan-cancer analysis of 60S Ribosomal Protein L7-Like 1 (RPL7L1) and validation in liver hepatocellular carcinoma

BACKGROUND AND AIMS

There is an association between cancer and increased ribosome biogenesis. At present, the RPL7L1 (60S Ribosomal Protein L7-Like 1) were less reported by literature search. Study reports that RPL7L1 is associated with mouse embryonic and skeletal muscle. The study of RPL7L1 on tumors has not been reported.

METHODS

Our team downloaded the pan-cancer dataset that is uniformly normalized from the UCSC database (N=19131). Our study examined the relationship between RPL7L1 expression level and clinical prognosis with methylation, anti-tumour immunity, functional states, MSI, TMB, DNSss, LOH and chemotherapeutic responses in 43 cancer types and subtypes.

RESULTS AND CONCLUSIONS

RPL7L1 was overexpressed in nine tumor types. Gene mutation, tumor microenvironment and methylation modification of RPL7L1 plays a key role in patient prognosis. And the high expression of RPL7L1 was associated with TMB, MSI, LOH especially LIHC and HNSC. We experimentally verified that genes can promote the proliferation and migration of tumor cells. Our study suggested that RPL7L1 biomarker can be used for treating cancer, detecting it, and predicting its prognosis.

Macrophages-Based Biohybrid Microrobots for Breast Cancer Photothermal Immunotherapy by Inducing Pyroptosis

Pyroptosis-based immunotherapy can escape drug resistance as well as inhibit metastasis. It is urgently required to develop a delivery platform to induce targeted tumor-specific pyroptosis for cancer immunotherapy. Herein, macrophages-based biohybrid microrobots (IDN@MC) are constructed with IR-macrophage and decitabine-loaded Metal-organic frameworks (DZNPs). The integration of fluorescence photosensitizers and pH-sensitive DZNPs endow the microrobots properties such as photothermal conversion, fluorescent navigation, targeted drug delivery, and controlled drug release. In light of the inherent tumor targeting, tumor accumulation of IDN@MC is facilitated. Due to the sustained release of decitabine from packaged DZNPs, the host macrophages are differentiated into M1 phenotypes to exert the tumor phagocytosis at the tumor site, directly transporting the therapeutic agents into cancer cells. With laser control, the rapid and durable caspase 3-cleaved gasdermin E (GSDME)-related tumor pyroptosis is achieved with combined photothermal-chemotherapy, releasing inflammatory factors such as lactate dehydrogenase and interleukin-18. Subsequently, the robust and adaptive immune response is primed with dendritic cell maturation to initiate T-cell clone expansion and modulation of the immune suppressive microenvironment, thus enhancing the tumor immunotherapy to inhibit tumor proliferation and metastasis. This macrophages-based biohybrid microrobot is an efficient strategy for breast cancer treatment to trigger photo-induced pyroptosis and augment the immune response.

Development of a machine learning-based radiomics signature for estimating breast cancer TME phenotypes and predicting anti-PD-1/PD-L1 immunotherapy response

BACKGROUNDS

Since breast cancer patients respond diversely to immunotherapy, there is an urgent need to explore novel biomarkers to precisely predict clinical responses and enhance therapeutic efficacy. The purpose of our present research was to construct and independently validate a biomarker of tumor microenvironment (TME) phenotypes via a machine learning-based radiomics way. The interrelationship between the biomarker, TME phenotypes and recipients' clinical response was also revealed.

METHODS

In this retrospective multi-cohort investigation, five separate cohorts of breast cancer patients were recruited to measure breast cancer TME phenotypes via a radiomics signature, which was constructed and validated by integrating RNA-seq data with DCE-MRI images for predicting immunotherapy response. Initially, we constructed TME phenotypes using RNA-seq of 1089 breast cancer patients in the TCGA database. Then, parallel DCE-MRI images and RNA-seq of 94 breast cancer patients obtained from TCIA were applied to develop a radiomics-based TME phenotypes signature using random forest in machine learning. The repeatability of the radiomics signature was then validated in an internal validation set. Two additional independent external validation sets were analyzed to reassess this signature. The Immune phenotype cohort (n = 158) was divided based on CD8 cell infiltration into immune-inflamed and immune-desert phenotypes; these data were utilized to examine the relationship between the immune phenotypes and this signature. Finally, we utilized an Immunotherapy-treated cohort with 77 cases who received anti-PD-1/PD-L1 treatment to evaluate the predictive efficiency of this signature in terms of clinical outcomes.

RESULTS

The TME phenotypes of breast cancer were separated into two heterogeneous clusters: Cluster A, an "immune-inflamed" cluster, containing substantial innate and adaptive immune cell infiltration, and Cluster B, an "immune-desert" cluster, with modest TME cell infiltration. We constructed a radiomics signature for the TME phenotypes ([AUC] = 0.855; 95% CI 0.777-0.932; p < 0.05) and verified it in an internal validation set (0.844; 0.606-1; p < 0.05). In the known immune phenotypes cohort, the signature can identify either immune-inflamed or immune-desert tumor (0.814; 0.717-0.911; p < 0.05). In the Immunotherapy-treated cohort, patients with objective response had higher baseline radiomics scores than those with stable or progressing disease (p < 0.05); moreover, the radiomics signature achieved an AUC of 0.784 (0.643-0.926; p < 0.05) for predicting immunotherapy response.

CONCLUSIONS

Our imaging biomarker, a practicable radiomics signature, is beneficial for predicting the TME phenotypes and clinical response in anti-PD-1/PD-L1-treated breast cancer patients. It is particularly effective in identifying the "immune-desert" phenotype and may aid in its transformation into an "immune-inflamed" phenotype.