Breast Cancer Microenvironment Research Articles

Investigating the immunological function of alpha-2-glycoprotein 1, zinc-binding in regulating tumor response in the breast cancer microenvironment

BackgroundAlpha-2-glycoprotein 1, zinc-binding (ZAG), a secreted protein encoded by the AZGP1 gene, is structurally similar to HLA class I. Despite its presumed immunological function, little is known about its role in tumor immunity. In this study, we thus aimed to determine the relationship between the expression of AZGP1/ZAG and the immunological profiles of breast cancer tissues at both the gene and protein level.MethodsUsing a publicly available gene expression dataset from a large-scale breast cancer cohort, we conducted gene set enrichment analysis (GSEA) to screen the biological processes associated with AZGP1. We analyzed the correlation between AZGP1 expression and immune cell composition in breast cancer tissues, estimated using CIBERSORTx. Previously, we evaluated the infiltration of 11 types of immune cells for 45 breast cancer tissues using flow cytometry (FCM). ZAG expression was evaluated by immunohistochemistry on these specimens and analyzed for its relationship with immune cell infiltration. The action of ZAG in M1/M2 polarization models using primary cultures of human peripheral blood mononuclear cells (PBMC)-derived macrophage (Mφ) was analyzed based on the expression of M1/M2 markers (CD86, CD80/CD163, MRC1) and HLA class I/II by FCM.ResultsAZGP1 expression was negatively correlated with multiple immunological processes and specific immune cell infiltration including Mφ M1 using GSEA and CIBERSORTx. ZAG expression was associated with decreased infiltration of monocytes/macrophages, non-classical monocytes, and myeloid-derived suppressor cells in tumor tissues assessed using FCM. In in vitro analyses, ZAG decreased the expression of CD80, CD163, MRC1, and HLA classes I/II in the M1 polarization model and the expression of CD163 and MRC1 in the M2 polarization model.ConclusionZAG is suggested to be a novel immunoregulatory factor affecting the Mφ phenotype in breast cancer tissues.

Distinct profiles of proliferating CD8+/TCF1+ T cells and CD163+/PD-L1+ macrophages predict risk of relapse differently among treatment-naïve breast cancer subtypes

Immunophenotypic analysis of breast cancer microenvironment is gaining attraction as a clinical tool improving breast cancer patient stratification. The aim of this study is to evaluate proliferating CD8 + including CD8 + TCF1 + Τ cells along with PD-L1 expressing tissue-associated macrophages among different breast cancer subtypes. A well-characterized cohort of 791 treatment-naïve breast cancer patients was included. The analysis demonstrated a distinct expression pattern among breast cancer subtypes characterized by increased CD8 + , CD163 + and CD163 + PD-L1 + cells along with high PD-L1 status and decreased fraction of CD8 + Ki67 + T cells in triple negative (TNBC) and HER2 + compared to luminal tumors. Kaplan–Meier and Cox univariate survival analysis revealed that breast cancer patients with high CD8 + , CD8 + Ki67 + , CD8 + TCF1 + cells, PD-L1 score and CD163 + PD-L1 + cells are likely to have a prolonged relapse free survival, while patients with high CD163 + cells have a worse prognosis. A differential impact of high CD8 + , CD8 + Ki67 + , CD8 + TCF1 + T cells, CD163 + PD-L1 + macrophages and PD-L1 status on prognosis was identified among the various breast cancer subtypes since only TNBC patients experience an improved prognosis compared to patients with luminal A tumors. Conversely, high infiltration by CD163 + cells is associated with worse prognosis only in patients with luminal A but not in TNBC tumors. Multivariate Cox regression analysis in TNBC patients revealed that increased CD8 + [hazard ratio (HR) = 0.542; 95% confidence interval (CI) 0.309–0.950; p = 0.032), CD8 + TCF1 + (HR = 0.280; 95% CI 0.101–0.779; p = 0.015), CD163 + PD-L1 + (HR: 0.312; 95% CI 0.112–0.870; p = 0.026) cells along with PD-L1 status employing two different scoring methods (HR: 0.362; 95% CI 0.162–0.812; p = 0.014 and HR: 0.395; 95% CI 0.176–0.884; p = 0.024) were independently linked with a lower relapse rate. Multivariate analysis in Luminal type A patients revealed that increased CD163 + was independently associated with a higher relapse rate (HR = 2.360; 95% CI 1.077–5.170; p = 0.032). This study demonstrates that the evaluation of the functional status of CD8 + T cells in combination with the analysis of immunosuppressive elements could provide clinically relevant information in different breast cancer subtypes.

Study on the mechanism of MDSC-platelets and their role in the breast cancer microenvironment.

Myeloid-derived suppressor cells (MDSCs) are key immunosuppressive cells in the tumor microenvironment (TME) that play critical roles in promoting tumor growth and metastasis. Tumor-associated platelets (TAPs) help cancer cells evade the immune system and promote metastasis. In this paper, we describe the interaction between MDSCs and TAPs, including their generation, secretion, activation, and recruitment, as well as the effects of MDSCs and platelets on the generation and changes in the immune, metabolic, and angiogenic breast cancer (BC) microenvironments. In addition, we summarize preclinical and clinical studies, traditional Chinese medicine (TCM) therapeutic approaches, and new technologies related to targeting and preventing MDSCs from interacting with TAPs to modulate the BC TME, discuss the potential mechanisms, and provide perspectives for future development. The therapeutic strategies discussed in this review may have implications in promoting the normalization of the BC TME, reducing primary tumor growth and distant lung metastasis, and improving the efficiency of anti-tumor therapy, thereby improving the overall survival (OS) and progression-free survival (PFS) of patients. However, despite the significant advances in understanding these mechanisms and therapeutic strategies, the complexity and heterogeneity of MDSCs and side effects of antiplatelet agents remain challenging. This requires further investigation in future prospective cohort studies.

Vasculogenic mimicry regulates immune infiltration and mutational status of the tumor microenvironment in breast cancer to influence tumor prognosis.

Vasculogenic mimicry (VM) refers to the direct formation of microcirculatory ducts by invasive malignant tumors via cellular phenotypic transformation. However, there is a lack of VM-based biomarkers for breast cancer. We obtained transcriptomic expression data, single cell sequencing data, and clinical data of patients from The Cancer Genome Atlas Program (TCGA) database and GEO database, performed single cell analysis to obtain specific type annotations of breast cancer cells and analyzed their spatial expression analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) analyses as well as Gene Set Enrichment Analysis (GSEA) analyses were performed to clarify the biological pathways and tumor functional enrichment relationships of the major expressed genes of VM in the breast cancer bulk data specimens. VM biomarkers were constructed. Meanwhile, the relationship between VM scores and tumor immune infiltration in breast cancer was analyzed using MCPcounter and ssGSEA methods. In addition, we assessed the specific relationship between NDRG1, a key VM gene in breast cancer, and tumor colonization, adhesion and invasion by biological experiments in breast cancer cell lines. The main cell types of breast cancer (BRCA) samples were annotated by single cell transcriptome analysis. Most of the VM-high group was present in epithelial cells, whereas the VM-low group was present in immune and stromal cells. Multiple tumor pathways such as TGFβ p53 and MAPK were closely associated with VM-mediated breast cancer infiltration and invasion. A prognostic model of breast cancer based on VM key genes was constituted. Prognostic stratification of breast cancer was successfully achieved for the TCGA-BRCA and GSE58812 datasets. Through immune infiltration analysis, we found that differential expression of VM markers was associated with multiple immune cell regulation. In MDA-MB-231 and MDA-MB-453 cell lines, we found that the NDRG1 gene significantly promoted colony formation of breast cancer cells. Our constructed VM-related gene-based model of breast cancer biology holds promise for prognostic prediction and patient stratification of breast cancer. This may provide a potentially clinically valuable aid in promoting a deeper understanding of the biological regulation of VM in breast cancer and exploring the specific mechanisms of tumor angiogenesis and breast cancer development.

Adipose-derived stem cell exosomes promote tumor characterization and immunosuppressive microenvironment in breast cancer

Adipose-derived stem cells (ASC) or autologous fat transplantation could be used to ameliorate breast cancer postoperative deformities. This study aims to explore the action of ASC and ASC-exosomes (ASC-exos) in breast cancer characterization and tumor microenvironment immunity, which provided a new method into the application of ASC-exos. ASC were extracted from human adipose tissue for the isolation and verification of ASC-exos. ASC-exos were co-cultured with CD4+T cells, CD14+ monocytes and MCF-7 cells, respectively. The tumor formation of nude mice was also constructed. Cell characterization was determined by CCK8, scratch assay, and Transwell. Hematoxylin–eosin (HE), immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to observe the histopathology and protein expression. CD4+T cell and CD14+ monocytes differentiation was detected by flow cytometry. Western blot, qRT-PCR and RNAseq were used to detect the action of ASC-exos on gene and protein expression. CD4+T cells could take up ASC-exos. ASC-exos inhibited Th1 and Th17 differentiation and promoted Treg differentiation of CD4+T cells. ASC-exos inhibited M1 differentiation and promoted M2 differentiation of CD14+ monocytes. ASC-exos promoted the migration, proliferation, and invasion, while inhibited apoptosis of MCF-7 cells. ASC-exos promoted the tumor formation of breast cancer. The effect of ASC-exos on tumor microenvironment immunity was in accordance with the above in vitro results. TOX, CD4 and LYZ1 genes were upregulated, while Mettl7b and Serpinb2 genes were downregulated in ASC-exos group. Human T-cell leukemia virus 1 infection pathway was significantly enriched in ASC-exos. Thus, ASC-exos promoted breast cancer characterization and tumor microenvironment immunosuppression by regulating macrophage and T cell differentiation.

Immunopathological Mechanisms Observed in the Intratumoral Microenvironment and Their Relationship with Worse Prognosis in Triple-Negative Breast Cancer

Background: In the 21st century, the main cause of death in both sexes worldwide is cardiovascular disease, followed by neoplasms. In women, the main cause of morbidity and mortality is breast cancer. Therefore, understanding the immunological mechanisms associated breast cancer and its correlation with poor prognosis is very important. Methods: In this study, a search was done on PubMed and Google Scholar, using the following medical subject headings (MeSH) in the search engine: “triple negative breast cancer”, “breast cancer microenvironment”, “immune cells”, “prognosis”, “regulatory t reg”, “T cells” and “tumor-associated neutrophils”. Thus, a total of 81 articles were found and reviewed, published between 2002 and 2023. Results and conclusions: It is essential to understand the immunological mechanisms associated with the tumor microenvironment, to create new targeted treatment schemes for each variant of breast cancer, for example triple negative in order to reduce the mortality rate and increase disease-free survival.

Upregulation of vesicle-associated membrane protein 7 in breast cancer tissues.

Vesicle-associated membrane protein 7 (VAMP7) plays oncogenic roles in cancers. However, its clinical significance in breast cancer (BC) tissues remains unknown. To elucidate the clinical implications of VAMP7, as well as its involvement in the tumor microenvironment and molecular pathways of breast cancer. BC (n=100) and non-cancerous breast tissues (n= 100) were collected for an immunohistochemical experiment (1:200). The protein expression level of VAMP7 was determined by using a semi-quantitative scoring method. High-throughput RNA-sequencing data of BC tissues were analyzed to confirm the mRNA expression trend of VAMP7. Additionally, the largest BC prognosis cohort data were collected to mine the potential impact VAMP7 has on BC progression. The association between VAMP7 and the microenvironment of BC was evaluated by using a CIBERSORT algorithm. Moreover, we explored the co-expressed molecular mechanisms of VAMP7 in BC by calculating Pearson correlation coefficients and overexpressed genes. Finally, the biological mechanism underlying the relationship between VAMP7 and the key pathways was also explored using gene set enrichment analysis (GSEA). Potential therapeutic strategies were predicted targeting VAMP7. VAMP7 protein was significantly over-expressed in BC tissue than that in controls (p< 0.001). Compared with 459 normal breast tissues and 113 non-cancerous breast tissues, the expression level of VAMP7 mRNA was significantly increased in 1111 BC tissues. CD4+T cells, macrophages, and naïve B cells had a higher infiltration rate in BC tissues with high VAMP7 expression, while regulatory T cells and CD8+T cells had a lower infiltration rate. Over-expressed VAMP7 was associated with macrophages activation and transition from M1 to M2 polarization. Upregulated VAMP7 could predicted poorer OS, DMFS, PPS, and RFS outcomes. Upregulated VAMP7 co-expressed genes were significantly enriched in the cell cycle checkpoints. GSEA confirmed that over-expressed VAMP7 are markedly associated with functional enrichment in cell cycle related categories, including mitotic spindle, G2M checkpoint, and E2F targets. KU-55933 was predicted as a putative therapeutic drug for BC targeting VAMP7. VAMP7 was upregulated in BC tissue and correlated with poor prognosis of BC patients. VAMP7 may promote BC progression by targeting the cell cycle pathway.

Clinical and immunological relevance of SLAMF6 expression in the tumor microenvironment of breast cancer and melanoma

Compelling evidence shows that the frequency of T cells in the tumor microenvironment correlates with prognosis as well as response to immunotherapy. However, considerable heterogeneity exists within tumor-infiltrating T cells, and significance of their genomic and transcriptomic landscape on clinical outcomes remains to be elucidated. Signaling lymphocyte activation molecule 6 (SLAMF6) is expressed on intra-tumoral progenitor-exhausted T cells, which exhibit the capacity to proliferate, self-renew and produce terminally-exhausted T cells in pre-clinical models and patients. Here, we investigated the impact of SLAMF6 expression on prognosis in two immunologically different tumor types using publicly available databases. Our findings demonstrate that high SLAMF6 expression is associated with better prognosis, expression of TCF7 (encoding T-cell factor 1), and increased gene signatures associated with conventional type 1 dendritic cells and effector function of T cells in melanoma and breast cancer. Single-cell profiling of breast cancer tumor microenvironment reveals SLAMF6 expression overlaps CD8 T cells with a T-effector signature, which includes subsets expressing TCF7, memory and effector-related genes, analogous to progenitor-exhausted T cells. These findings illustrate the significance of SLAMF6 in the tumor as a marker for better effector responses, and provide insights into the predictive and prognostic determinants for cancer patients.

Tumor microenvironment and immune system preservation in early-stage breast cancer: routes for early recurrence after mastectomy and treatment for lobular and ductal forms of disease

BackgroundIntra-ductal cancer (IDC) is the most common type of breast cancer, with intra-lobular cancer (ILC) coming in second. Surgery is the primary treatment for early stage breast cancer. There are now irrefutable data demonstrating that the immune context of breast tumors can influence growth and metastasis. Adjuvant chemotherapy may be administered in patients who are at a high risk of recurrence. Our goal was to identify the processes underlying both types of early local recurrences.MethodsThis was a case-control observational study. Within 2 years of receiving adjuvant taxan and anthracycline-based chemotherapy, as well as modified radical mastectomy (MRM), early stage IDC and ILC recurred. Vimentin, α-smooth muscle actin (SMA), platelet-derived growth factor (PDGF), matrix metalloproteinase (MMP1), and clustered differentiation (CD95) were investigated.ResultsOf the samples in the ductal type group, 25 showed local recurrence, and 25 did not. Six individuals in the lobular-type group did not experience recurrence, whereas seven did. Vimentin (p = 0.000 and 0.021), PDGF (p = 0.000 and 0.002), and CD95 (p = 0.000 and 0.045) expressions were significantly different in ductal and lobular carcinoma types, respectively. Measurement of ductal type was the sole significant difference found in MMP1 (p = 0.000) and α-SMA (p = 0.000). α-SMA and CD95 were two variables that helped the recurrence mechanism in the ductal type according to the pathway analysis. In contrast, the CD95 route is a recurrent mechanism for the lobular form.ConclusionsWhile the immune system plays a larger role in ILC, the tumor microenvironment and immune system both influence the recurrence of IDC. According to this study, improving the immune system may be a viable cancer treatment option.

Nanoparticle-integrated dissolving microneedles for the co-delivery of R848/aPD-1 to synergistically reverse the immunosuppressive microenvironment of triple-negative breast cancer

Nowadays, effective immunotherapy against triple-negative breast cancer (TNBC) remains challenging due to the immunosuppressive tumor microenvironment. Immune checkpoint inhibitor is mostly employed to restore the activity of tumor-specific immune cells, which however brings little therapeutic outcome owing to the limited number of tumor-infiltrating CD8+ T cells and the inefficient delivery of immune drugs to the tumor tissue. Aiming to solve these problems, we herein constructed a tailor-made dissolving microneedle co-encapsulating the TLR7/8 agonist R848 and the immune checkpoint inhibitor aPD-1, termed αNP-RNP@DMN, and fabricated it as a transdermal drug delivery system. This well-designed microneedle patch, endowed with efficient tumor drug delivery ability, was able to mature tumor-infiltrating dendritic cells (TIDCs) and further promote the infiltration of CD8+ T cells into the tumor tissue with the aid of R848. Moreover, the introduction of aPD-1 blocked the programmed cell death protein 1/programmed cell death ligand 1(PD-1/PD-L1) immune checkpoints, synergistically reversing the immunosuppressive microenvironment of TNBC. In vivo therapeutic results demonstrated that αNP-RNP@DMN not only significantly prolonged the survival time of 4T1 tumor-bearing mice, but also inhibited tumor recurrence and lung metastasis after surgery, implying the great potential of this effective drug delivery system for enhanced immunotherapy of superficial tumors. Statement of significanceThe limited number of tumor-infiltrating CD8+ T cells and the inefficient delivery of immune drugs to the tumor tissue hinder the effective immunotherapy of triple-negative breast cancer (TNBC). Herein, a dissolving microneedle co-encapsulating TLR7/8 agonist R848 and immune checkpoint inhibitor aPD-1 was developed and fabricated as a transdermal drug delivery system. This tailor-made microneedle patch not only promoted drug accumulation in tumor sites in a safe and painless manner, but also lifted the immune-suppressive state of tumor-infiltrating dendritic cells (TIDCs). The activated TIDCs further enhanced T-cell infiltration into the tumor tissue, thus successfully boosting the therapeutic efficacy of aPD-1. This study demonstrated that this well-designed microneedle patch could be served as an effective drug delivery system for enhanced immunotherapy of TNBC.

Extracellular vesicles released by hypoxia-induced tumor-associated fibroblasts impart chemoresistance to breast cancer cells via long noncoding RNA H19 delivery.

Recently, extracellular vesicles (EVs) have been emphasized in regulating the hypoxic tumor microenvironment of breast cancer (BC), where tumor-associated fibroblasts (TAFs) play a significant role. In this study, we describe possible molecular mechanisms behind the pro-tumoral effects of EVs, secreted by hypoxia (HP)-induced TAFs, on BC cell growth, metastasis, and chemoresistance. These mechanisms are based on long noncoding RNA H19 (H19) identified by microarray analysis. We employed an in silico approach to identify differentially expressed lncRNAs that were associated with BC. Subsequently, we explored possible downstream regulatory mechanisms. We isolated EVs from TAFs that were exposed to HP, and these EVs were denoted as HP-TAF-EVs henceforth. MTT, transwell, flow cytometry, and TUNEL assays were performed to assess the malignant phenotypes of BC cells. A paclitaxel (TAX)-resistant BC cell line was constructed, and xenograft tumor and lung metastasis models were established in nude mice for invivo verification. Our observation revealed that lncRNA H19 was significantly overexpressed, whereas miR-497 was notably downregulated in BC. HP induced activation of TAFs and stimulated the secretion of EVs. Coculture of HP-TAF-EVs and BC cells led to an increase in TAX resistance of the latter. HP-TAF-EVs upregulated methylation of miR-497 by delivering lncRNA H19, which recruited DNMT1, thus lowering the expression of miR-497. In addition, lncRNA H19-containing HP-TAF-EVs hindered miR-497 expression, enhancing tumorigenesis and TAX resistance of BC cells invivo. Our study presents evidence for the contribution of lncRNA H19-containing HP-TAF-EVs in the reduction of miR-497 expression through the recruitment of DNMT1, which in turn promotes the growth, metastasis, and chemoresistance of BC cells.

Site-specific controlled-release nanoparticles for immune reprogramming via dual metabolic inhibition against triple-negative breast cancer

Metabolic heterogeneity and the tumor immunosuppressive microenvironment (TIME) of triple-negative breast cancer (TNBC) hinder therapeutic effectiveness. Although emerging metabolic therapy and immunotherapy show promise, they are limited by off-target effects and immune escape. Here, a redox-activatable, sequentially-releasing nanoparticle (AMANC@M) for tumor-targeted delivery of anticancer agents and CRISPR/Cas9 has been developed. AMANC@M can reverse the TIME through dual metabolic inhibition, thereby enhancing TNBC therapy. AMANC@M demonstrates excellent biosafety and targets tumors precisely through biomimetic hybrid membrane-mediated homologous homing and the enhanced permeability and retention (EPR) effect. Once internalized into tumor cells, the CRISPR/Cas9 system (“energy nanolock”) is released through glutathione (GSH) cleavage and effectively knocks down the expression of lactate dehydrogenase A (LDHA) to suppress glycolysis. After peeling off of the gene editing shell, a newly synthesized targeted drug, CPI-Z2 (“nutrihijacker” and “energy nanolock”), is released in a controlled manner to block the mitochondrial tricarboxylic acid (TCA) cycle. Nitric oxide (NO) produced from loaded L-arginine enhances the efficiency of CPI-Z2 and reduces drug resistance. Combined with NO therapy, both blockades of nutrients and energy production transform the hypoxia and acidic TIME into an immunocompetent tumor microenvironment (TME) for tumor elimination. Furthermore, AMANC@M offers capabilities for photothermal (PT) therapy and provides clear imaging through PT, photoacoustic (PA), or computed tomography (CT) signals in tumor tissue. Thus, this study provides a new and promising sequentially stimuli-responsive targeting strategy for nanoparticle development, making it a potential treatment candidate for TNBC and other tumors.

Investigation of the Relationship Between Tumor Microenvironment and Prognostic Parameters in Invasive Breast Carcinomas of No Special Type: A Retrospective Analysis.

The tumor microenvironment is a heterogeneous and constantly changing territory that plays an active role in tumor formation and progression. It constantly interacts with tumor cells, plays an active role in tumor development, and even appears as a parameter of prognostic importance, and the importance of the tumor microenvironment in breast cancer has been emphasized by recent studies. In this study, we aimed to retrospectively evaluate the relationship between the tumor microenvironment and prognostic parameters in invasive breast carcinomas of no special type. A total of 271 cases diagnosed as invasive breast carcinoma of no special type from resection materials in our center between 2007 and 2015 were included in the study. Hematoxylin-eosin stained slides with a thickness of 4-5 micrometers were evaluated in terms of tumor infiltrating lymphocytes, peritumoral and intratumoral desmoplastic reaction, intratumoral and peritumoral tumor budding, stromal features, and tumor growth pattern. When parameters related to the tumor microenvironment were compared with other prognostic parameters, there was a significant relationship between TILs and tumor grade, size, stage, immunohistochemical subgroup and Ki-67 proliferation index. A significant relationship was detected between intratumoral stromal reaction and tumor grade, size, molecular subgroup and the Ki-67 proliferation index (p < 0.05). When stroma and other prognostic parameters were compared, tumors with desmoplastic stroma had higher grades and higher Ki-67 proliferation indexes, and they were observed more frequently in the triple negative molecular subgroup. We believe that including parameters related to tumor microenvironment in breast cancer reports, which hold a prognostic and predictive importance, will contribute to patient management. Considering the fact that these can be easily evaluated from routinely used hematoxylin-eosin stained slides, this does not cause additional costs or excessive time loss.

Reprogramming of Lipid Metabolism Mediates Crosstalk, Remodeling, and Intervention of Microenvironment Components in Breast Cancer.

Due to the unique characteristics of breast cancer initiation sites and significant alterations in tumor metabolism, breast cancer cells rely on lipid metabolic reprogramming to effectively regulate metabolic programs during the disease progression cascade. This adaptation enables them to meet the energy demands required for proliferation, invasion, metastasis, and responses to signaling molecules in the breast cancer microenvironment. In this review, we comprehensively examined the distinctive features of lipid metabolic reprogramming in breast cancer and elucidated the underlying mechanisms driving aberrant behavior of tumor cells. Additionally, we emphasize the potential role and adaptive changes in lipid metabolism within the breast cancer microenvironment, while summarizing recent preclinical studies. Overall, precise control over lipid metabolism rewiring and understanding of plasticity within the breast cancer microenvironment hold promising implications for developing targeted treatment strategies against this disease. Therefore, interventions targeting the lipid metabolism in breast cancer may facilitate innovative advancements in clinical applications.

Identification of a PANoptosis-related Gene Signature for Predicting the Prognosis, Tumor Microenvironment and Therapy Response in Breast Cancer.

Breast cancer (BC) is the most prevalent malignancy among women worldwide. Mounting evidence suggests that PANoptosis participates in cancer development and therapy. However, the role of PANoptosis in BC remains unclear. In this study, we identified ten PANoptosis-related genes using Cox regression analysis, random forest (RF) algorithm and least absolute shrinkage and selection operator (LASSO) algorithm. A PANoptosis-related score (PRS) was calculated based on the coefficient of LASSO. Notably, we divided the patients into high- and low-risk groups according to the PRS and revealed a negative correlation between PRS and overall survival. Next, a nomogram model was constructed and validated to improve the clinical application of PRS. Functional enrichment analyses and the Bayesian network demonstrated that differentially expressed genes between high- and low-risk groups were mainly enriched in immune-related pathways. Besides, we found significant differences in tumor mutation burden and tumor immune microenvironment between patients in these two groups using bulk-RNA and single-cell RNA sequencing data. Furthermore, charged multivesicular body protein 2B (CHMP2B) was identified as the hub gene by combining LASSO, weighted gene co-expression network analysis, RF and eXtreme Gradient Boosting. Importantly, using immunohistochemistry analysis based on our tissue microarray, we found that CHMP2B was highly expressed in tumor tissue, and CD4 and CD8 were more likely to be positive in the CHMP2B-negative group. Survival analyses revealed that CHMP2B adversely impacted the survival of BC patients. In conclusion, we not only constructed a highly accurate predictive model based on PRS, but also revealed the importance of PANoptosis-related gene signature in the modulation of the tumor microenvironment and drug sensitivity in BC.

DDIT3 is associated with breast cancer prognosis and immune microenvironment: an integrative bioinformatic and immunohistochemical analysis.

DNA damage-inducible transcript 3 (DDIT3) is a transcription factor central to apoptosis, differentiation, and stress response. DDIT3 has been extensively studied in cancer biology. However, its precise implications in breast cancer progression and its interaction with the immune microenvironment are unclear. In this study, we utilized a novel multi-omics integration strategy, combining bulk RNA sequencing, single-cell sequencing, spatial transcriptomics and immunohistochemistry, to explore the role of DDIT3 in breast cancer and establish the correlation between DDIT3 and poor prognosis in breast cancer patients. We identified a robust prognostic signature, including six genes (unc-93 homolog B1, TLR signaling regulator, anti-Mullerian hormone, DCTP pyrophosphatase 1, mitochondrial ribosomal protein L36, nuclear factor erythroid 2, and Rho GTPase activating protein 39), associated with DDIT3. This signature stratified the high-risk patient groups, characterized by increased infiltration of the regulatory T cells and M2-like macrophages and fibroblast growth factor (FGF)/FGF receptor signaling activation. Notably, the high-risk patient group demonstrated enhanced sensitivity to immunotherapy, presenting novel therapeutic opportunities. Integrating multi-omics data helped determine the spatial expression pattern of DDIT3 in the tumor microenvironment and its correlation with immune cell infiltration. This multi-dimensional analysis provided a comprehensive understanding of the intricate interplay between DDIT3 and the immune microenvironment in breast cancer. Overall, our study not only facilitates understanding the role of DDIT3 in breast cancer but also offers innovative insights for developing prognostic models and therapeutic strategies. Identifying the DDIT3-related prognostic signature and its association with the immune microenvironment provided a promising avenue for personalized breast cancer treatment.

A bioinformatic analysis found low expression and clinical significance of ATF4 in breast cancer

BackgroundActivating Transcription Factor 4 (ATF4) expression exhibits differential patterns across different types of tumors. Besides, the pathogenesis of breast cancer is complex, and the exact relationship between ATF4 and ATF4 remains uncertain. MethodsThe analysis of ATF4 expression was conducted by utilizing The Cancer Genome Atlas (TCGA) pan-cancer data, while the gene expression profile of breast cancer was checked by the comprehensive database-Gene Expression Omnibus database. In order to gain a more comprehensive understanding of the specific cell types that exhibit ATF4 expression within the microenvironment of breast cancer, we conducted a single-cell analysis of ATF4 using two distinct datasets of human breast cancer (GSE114717 and GSE11088, respectively). The spatial distribution of ATF4 within a tissue was demonstrated based on datasets obtained from the Human Protein Atlas (HPA) and SpatialDB. The clinical prognostic significance of ATF4 was assessed by analyzing clinical survival data obtained from TCGA, GSE4830, and GSE25055 datasets. We used the R package clusterProfiler to carry out an enrichment analysis of ATF4. We assessed how ATF4 impacts the growth and movement of breast cancer cell lines. We manipulated ATF4 levels using plasmid transfection techniques. ResultsThe expression of ATF4 was found to be suboptimal and demonstrated a significant correlation with enhanced disease-specific survival (p = 0.012) and overall survival (p = 0.032) in breast cancer as well as other malignancies. We conducted an analysis to investigate the interaction between the infiltration level of immune cells and the expression of ATF4, using samples obtained from TCGA with known immune cell infiltration scores. Furthermore, a notable positive correlation exists between the elevated expression of ATF4 and immune-related genomes, specifically those associated with chemokine as well as immunity. Subsequent examination revealed a notable augmentation in the cytodifferentiation of T cells into regulatory T (Treg) cells within tissues exhibiting elevated levels of ATF4 expression. ATF4 exhibits notable upregulation in the MDA-MB-231 cell, thereby exerting a substantial impact on cell proliferation and migration upon its knockdown. Conversely, the overexpression of ATF4 in the MCF7 Luminal A breast cancer cell line can also modulate cellular function. ConclusionsOur study suggests that ATF4 helps T cells differentiate into Treg cells in breast cancer. ATF4 can represent a clinically useful biomarker to predict the overall survival rate, especially in patients with different subtypes of breast cancer. Provide certain guidance value for the development of targeted drugs or inhibitors targeting ATF4.

Prognostic Value of IGFBP6 in Breast Cancer: Focus on Glucometabolism.

IGFBP6, a member of the IGF binding protein (IGFBP) family, is a specific inhibitor of insulin-like growth factor II (IGF-II) and can inhibit the growth of malignant tumors overexpressing IGF-II. Type 2 diabetes (T2D) is a basic disorder of glucose metabolism that can be regulated by IGF-related pathways. We performed bioinformatics analysis of the TCGA database to explore the possible mechanism of IGFBP6 in breast cancer (BC) metabolism and prognosis and collected clinical samples from BC patients with and without T2D to compare and verify the prognostic effect of IGFBP6. In our study, the levels of IGFBP1-6 were positively correlated with overall survival (OS) in patients with breast cancer. IGFBP6 was upregulated in estrogen receptor (ER)-positive BC, and ER-positive and progesterone receptor (PR) positive patients had a higher expression level of IGFBP6 than ER-negative and PR-negative patients. IGFBP6 could be used as an independent prognostic factor in BC. The expression of IGFBP6 was decreased in BC tissue, and BC tissue from patients with T2D had lower IGFBP6 expression levels than BC tissue from patients without T2D. IGFBP6 is mainly involved in the PI3K-Akt and TGF-β signaling pathways and tumor microenvironment regulation. In terms of metabolism, the expression of IGFBP6 was negatively correlated with that of most glucose metabolism-related genes. IGFBP6 expression was mainly correlated with mutations in TP53, PIK3CA, CDH1, and MAP3K1. In addition, the upregulation of IGFBP6 in BC increased the drug sensitivity to docetaxel, paclitaxel and gemcitabine. Overall, these results indicated that high expression of IGFBP6 is associated with a good prognosis in BC patients, especially in those without T2D. It is not only involved in the maintenance of the tumor microenvironment in BC but also inhibits the energy metabolism of cancer cells through glucose metabolism-related pathways. These findings may provide a new perspective on IGFBP6 as a potential prognostic marker for BC.

Factors affecting heterogeneity in breast cancer microenvironment: A narrative mini review.

Breast cancer (BC) heterogeneity is a key trait of BC tumors with crucial implications on tumorigenesis, diagnosis, and therapeutic modalities. It is influenced by tumor intrinsic features and by the tumor microenvironment (TME) composition of different intra-tumoral regions, which in turn affect cancer progression within patients. In this mini review, we will highlight the mechanisms that generate cancer heterogeneity in BC and how they affect the responses to cancer therapies.

Identification of Breast Cancer Subtypes Based on Endoplasmic Reticulum Stress-Related Genes and Analysis of Prognosis and Immune Microenvironment in Breast Cancer Patients.

Introduction: Endoplasmic reticulum stress (ERS) was a response to the accumulation of unfolded proteins and plays a crucial role in the development of tumors, including processes such as tumor cell invasion, metastasis, and immune evasion. However, the specific regulatory mechanisms of ERS in breast cancer (BC) remain unclear. Methods: In this study, we analyzed RNA sequencing data from The Cancer Genome Atlas (TCGA) for breast cancer and identified 8 core genes associated with ERS: ELOVL2, IFNG, MAP2K6, MZB1, PCSK6, PCSK9, IGF2BP1, and POP1. We evaluated their individual expression, independent diagnostic, and prognostic values in breast cancer patients. A multifactorial Cox analysis established a risk prognostic model, validated with an external dataset. Additionally, we conducted a comprehensive assessment of immune infiltration and drug sensitivity for these genes. Results: The results indicate that these eight core genes play a crucial role in regulating the immune microenvironment of breast cancer (BRCA) patients. Meanwhile, an independent diagnostic model based on the expression of these eight genes shows limited independent diagnostic value, and its independent prognostic value is unsatisfactory, with the time ROC AUC values generally below 0.5. According to the results of logistic regression neural networks and risk prognosis models, when these eight genes interact synergistically, they can serve as excellent biomarkers for the diagnosis and prognosis of breast cancer patients. Furthermore, the research findings have been confirmed through qPCR experiments and validation. Conclusion: In conclusion, we explored the mechanisms of ERS in BRCA patients and identified 8 outstanding biomolecular diagnostic markers and prognostic indicators. The research results were double-validated using the GEO database and qPCR.