Metastatic heterogeneity of breast cancer: Molecular mechanism and potential therapeutic targets

Nanoparticles for the Treatment of Bone Metastasis in Breast Cancer: Recent Advances and Challenges

Although the frequency of bone metastases from breast cancer has increased, effective treatment is lacking, prompting the development of nanomedicine, which involves the use of nanotechnology for disease diagnosis and treatment. Nanocarrier drug delivery systems offer several advantages over traditional drug delivery methods, such as higher reliability and biological activity, improved penetration and retention, and precise targeting and delivery. Various nanoparticles that can selectively target tumor cells without causing harm to healthy cells or organs have been synthesized. Recent advances in nanotechnology have enabled the diagnosis and prevention of metastatic diseases as well as the ability to deliver complex molecular "cargo" particles to metastatic regions. Nanoparticles can modulate systemic biodistribution and enable the targeted accumulation of therapeutic agents. Several delivery strategies are used to treat bone metastases, including untargeted delivery, bone-targeted delivery, and cancer cell-targeted delivery. Combining targeted agents with nanoparticles enhances the selective delivery of payloads to breast cancer bone metastatic lesions, providing multiple delivery advantages for treatment. In this review, we describe recent advances in nanoparticle development for treating breast cancer bone metastases.

Breast Tumor Metastasis and Its Microenvironment: It Takes Both Seed and Soil to Grow a Tumor and Target It for Treatment

Metastasis remains a major challenge in treating breast cancer. Breast tumors metastasize to organ-specific locations such as the brain, lungs, and bone, but why some organs are favored over others remains unclear. Breast tumors also show heterogeneity, plasticity, and distinct microenvironments. This contributes to treatment failure and relapse. The interaction of breast cancer cells with their metastatic microenvironment has led to the concept that primary breast cancer cells act as seeds, whereas the metastatic tissue microenvironment (TME) is the soil. Improving our understanding of this interaction could lead to better treatment strategies for metastatic breast cancer. Targeted treatments for different subtypes of breast cancers have improved overall patient survival, even with metastasis. However, these targeted treatments are based upon the biology of the primary tumor and often these patients' relapse, after therapy, with metastatic tumors. The advent of immunotherapy allowed the immune system to target metastatic tumors. Unfortunately, immunotherapy has not been as effective in metastatic breast cancer relative to other cancers with metastases, such as melanoma. This review will describe the heterogeneic nature of breast cancer cells and their microenvironments. The distinct properties of metastatic breast cancer cells and their microenvironments that allow interactions, especially in bone and brain metastasis, will also be described. Finally, we will review immunotherapy approaches to treat metastatic breast tumors and discuss future therapeutic approaches to improve treatments for metastatic breast cancer.

Toxoflavin analog D43 exerts antiproliferative effects on breast cancer by inducing ROS-mediated apoptosis and DNA damage

Triple-negative breast cancer (TNBC) is regarded as the deadliest subtype of breast cancer because of its high heterogeneity, aggressiveness, and limited treatment options. Toxoflavin has been reported to possess antitumor activity. In this study, a series of toxoflavin analogs were synthesized, among which D43 displayed a significant dose-dependent inhibitory effect on the proliferation of TNBC cells (MDA-MB-231 and HCC1806). Additionally, D43 inhibited DNA synthesis in TNBC cells, leading to cell cycle arrest at the G2/M phase. Furthermore, D43 consistently promoted intracellular ROS generation, induced DNA damage, and resulted in apoptosis in TNBC cells. These effects could be reversed by N-acetylcysteine. Moreover, D43 significantly inhibited the growth of breast cancer patient-derived organoids and xenografts with a favorable biosafety profile. In conclusion, D43 is a potent anticancer agent that elicits significant antiproliferation, oxidative stress, apoptosis, and DNA damage effects in TNBC cells, and D43 holds promise as a potential candidate for the treatment of TNBC.

The Age-Male-Albumin-Bilirubin-Platelets (aMAP) Risk Score Predicts Liver Metastasis Following Surgery for Breast Cancer in Chinese Population: A Retrospective Study

Objective

The current study is conducted to investigate the potential prognostic value of the age-male-albumin-bilirubin-platelets (aMAP) score in breast cancer patients with liver metastasis after surgery.

Methods

This is a retrospective study of 178 breast cancer patients who developed liver metastasis after surgery. These patients were treated and followed up from 2000 to 2018 at our hospital. The aMAP risk score was estimated in accordance with the following formula: . The optimal cutoff value of the aMAP was evaluated via X-tile. Kaplan-Meier, Log-rank and Cox proportional hazards regression models were applied to determine the clinical influence of the aMAP score on the survival outcomes. The nomogram models were established by multivariate analyses. The calibration curves and decision curve analysis were applied to evaluate the estimated performance of the nomogram models.

Results

A total of 178 breast cancer patients were divided into low aMAP score group (<47.6) and high aMAP score group (≥47.6) via X-tile plots. The aMAP score was a potential prognostic factor in multivariate analysis. The median disease free survival (p=0.0013) and overall survival (p=0.0003) in low aMAP score group were longer than in high aMAP score group. The nomograms were constructed to predict the DFS with a C-index of 0.722 (95% CI, 0.673-0.771), and the OS with a C-index of 0.708 (95% CI, 0.661-0.755). The aMAP-based nomograms had good predictive performance.

Conclusion

The aMAP score is a potential prognostic factor in breast cancer with liver metastasis after surgery. The aMAP score-based nomograms were conducive to discriminate patients at high risks of liver metastasis and develop adjuvant treatment and prevention strategies.

A new 4-gene-based prognostic model accurately predicts breast cancer prognosis and immunotherapy response by integrating WGCNA and bioinformatics analysis

Background

Breast cancer (BRCA) is a common malignancy in women, and its resistance to immunotherapy is a major challenge. Abnormal expression of genes is important in the occurrence and development of BRCA and may also affect the prognosis of patients. Although many BRCA prognosis model scores have been developed, they are only applicable to a limited number of disease subtypes. Our goal is to develop a new prognostic score that is more accurate and applicable to a wider range of BRCA patients.

Methods

BRCA patient data from The Cancer Genome Atlas database was used to identify breast cancer-related genes (BRGs). Differential expression analysis of BRGs was performed using the 'limma' package in R. Prognostic BRGs were identified using co-expression and univariate Cox analysis. A predictive model of four BRGs was established using Cox regression and the LASSO algorithm. Model performance was evaluated using K-M survival and receiver operating characteristic curve analysis. The predictive ability of the signature in immune microenvironment and immunotherapy was investigated. In vitro experiments validated POLQ function.

Results

Our study identified a four-BRG prognostic signature that outperformed conventional clinicopathological characteristics in predicting survival outcomes in BRCA patients. The signature effectively stratified BRCA patients into high- and low-risk groups and showed potential in predicting the response to immunotherapy. Notably, significant differences were observed in immune cell abundance between the two groups. In vitro experiments demonstrated that POLQ knockdown significantly reduced the viability, proliferation, and invasion capacity of MDA-MB-231 or HCC1806 cells.

Conclusion

Our 4-BRG signature has the potential as an independent biomarker for predicting prognosis and treatment response in BRCA patients, complementing existing clinicopathological characteristics.

Hypoxia-induced miR-181a-5p up-regulation reduces epirubicin sensitivity in breast cancer cells through inhibiting EPDR1/TRPC1 to activate PI3K/AKT signaling pathway

Breast carcinoma (BC) ranks as a predominant malignancy and constitutes the second principal cause of mortality among women globally. Epirubicin stands as the drug of choice for BC therapeutics. Nevertheless, the emergence of chemoresistance has significantly curtailed its therapeutic efficacy. The resistance mechanisms to Epirubicin remain not entirely elucidated, yet they are conjectured to stem from diminished tumor vascular perfusion and resultant hypoxia consequent to Epirubicin administration. In our investigation, we meticulously scrutinized the Gene Expression Omnibus database for EPDR1, a gene implicated in hypoxia and Epirubicin resistance in BC. Subsequently, we delineated the impact of EPDR1 on cellular proliferation, motility, invasive capabilities, and interstitial-related proteins in BC cells, employing methodologies such as the CCK-8 assay, Transwell assay, and western blot analysis. Our research further unveiled that hypoxia-induced miR-181a-5p orchestrates the regulation of BC cell duplication, migration, invasion, and interstitial-related protein expression via modulation of EPDR1. In addition, we identified TRPC1, a gene associated with EPDR1 expression in BC, and substantiated that EPDR1 influences BC cellular dynamics through TRPC1-mediated modulation of the PI3K/AKT signaling cascade. Our findings underscore the pivotal role of EPDR1 in the development of BC. EPDR1 was found to be expressed at subdued levels in BC tissues, Epirubicin-resistant BC cells, and hypoxic BC cells. The overexpression of EPDR1 curtailed BC cell proliferation, motility, invasiveness, and the expression of interstitial-related proteins. At a mechanistic level, the overexpression of hypoxia-induced miR-181a-5p was observed to inhibit the EPDR1/TRPC1 axis, thereby activating the PI3K/AKT signaling pathway and diminishing the sensitivity to Epirubicin in BC cells. In summation, our study demonstrates that the augmentation of hypoxia-induced miR-181a-5p diminishes Epirubicin sensitivity in BC cells by attenuating EPDR1/TRPC1 expression, thereby invigorating the PI3K/AKT signaling pathway. This exposition offers a theoretical foundation for the application of Epirubicin in BC therapy, marking a significant contribution to the existing body of oncological literature.

The Role of Breast Cancer Cells in Bone Metastasis: Suitable Seeds for Nourishing Soil

PURPOSE OF REVIEW

The purpose of this review was to describe the characteristics of breast cancer cells prone to developing bone metastasis and determine how they are regulated by the bone microenvironment.

RECENT FINDINGS

The bone is a site of frequent breast cancer metastasis. Bone metastasis accounts for 70% of advanced breast cancer cases and remains incurable. It can lead to skeletal-related events, such as bone fracture and pain, and seriously affect the quality of life of patients. Breast cancer cells escape from the primary lesion and spread to the bone marrow in the early stages. They can then enter the dormant state and restore tumourigenicity after several years to develop overt metastasis. In the last few years, an increasing number of studies have reported on the factors promoting bone metastasis of breast cancer cells, both at the primary and metastatic sites. Identifying factors associated with bone metastasis aids in the early recognition of bone metastasis tendency. How to target these factors and minimize the side effects on the bone remains to be further explored.

Value of CT-based radiomics in evaluating the response of bone metastases to systemic drug therapy in breast cancer patients

BACKGROUND

This study aimed to investigate the value of nonenhanced computed tomography (CT)-based radiomics in determining disease progression in breast cancer patients with bone marrow metastases and to develop a model for assessing treatment efficacy.

METHODS

A total of 134 breast cancer patients with bone metastases were enrolled from three hospitals. Nonenhanced CT was performed after two cycles of drug treatment. The images were categorized into an invalid and a valid group according to disease progression status. The largest osteolytic lesions' maximum cross-sections in the CT images were selected as regions of interest (ROIs) for feature extraction. Variance threshold, SelectKBest, and least absolute shrinkage and selection operator (LASSO) were used to reduce feature dimensionality. K-nearest neighbor algorithm (KNN), support vector machine (SVM), extreme gradient boosting (XGBoost), random forest (RF), logistic regression (LR), and decision tree (DT) algorithms were trained to establish radiomics models. Receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic performance of the models.

RESULTS

The KNN classifier demonstrated the best performance compared to the random grouping method. In the validation group, the area under the ROC curve (AUC) was 0.810. In the cross-validation method, the RF classifier showed the best performance with an AUC of 0.84.

CONCLUSION

Nonenhanced CT-based radiomics provides a promising method for evaluating the efficacy of systemic drug therapy in breast cancer patients with osteolytic bone metastases.

Circular RNA and its potential diagnostic and therapeutic values in breast cancer

Breast cancer (BC) is one of the most common malignant tumors in women and still poses a significant threat to women worldwide. Recurrence of BC in situ, metastasis to distant organs, and resistance to chemotherapy are all attached to high mortality in patients with BC. Non-coding RNA (ncRNA) of the type known as "circRNA" links together from one end to another to create a covalently closed, single-stranded circular molecule. With characteristics including plurality, evolutionary conservation, stability, and particularity, they are extensively prevalent in various species and a range of human cells. CircRNAs are new and significant contributors to several kinds of disorders, including cardiovascular disease, multiple organ inflammatory responses and malignancies. Recent studies have shown that circRNAs play crucial roles in the occurrence of breast cancer by interacting with miRNAs to regulate gene expression at the transcriptional or post-transcriptional levels. CircRNAs offer the potential to be therapeutic targets for breast cancer treatment as well as prospective biomarkers for early diagnosis and prognosis of BC. Here, we are about to present an overview of the functions of circRNAs in the proliferation, invasion, migration, and resistance to medicines of breast cancer cells and serve as a promising resource for future investigations on the pathogenesis and therapeutic strategies.

Immunogenic cell death-related classification reveals prognosis and effectiveness of immunotherapy in breast cancer

Lack of specific biomarkers and effective drug targets constrains therapeutic research in breast cancer (BC). In this regard, therapeutic modulation of damage-associated molecular patterns (DAMPs)-induced immunogenic cell death (ICD) may help improve the effect of immunotherapy in individuals with BC. The aim of this investigation was to develop biomarkers for ICD and to construct ICD-related risk estimation models to predict prognosis and immunotherapy outcomes of BC. RNA-seq transcriptome information and medical data from individuals with BC (n = 943) were obtained from TCGA. Expression data from a separate BC cohort (GEO: GSE20685) were used for validation. We identified subtypes of high and low ICD gene expression by consensus clustering and assessed the connection between ICD subtypes and tumor microenvironment (TME). In addition, different algorithms were used to construct ICD-based prognostic models of BC. BC samples were categorized into subtypes of high and low ICD expression depending on the expression of genes correlated with ICD. The subtype of ICD high-expression subtypes are correlated with poor prognosis in breast cancer, while ICD low-expression subtypes may predict better clinical outcomes. We also created and verified a predictive signature model depending on four ICD-related genes (ATG5, CD8A, CD8B, and HSP90AA1), which correlates with TME status and predicts clinical outcomes of BC patients. We highlight the connection of ICD subtypes with the dynamic evolution of TME in BC and present a novel ICD-based prognostic model of BC. In clinical practice, distinction of ICD subtype and assessment of ICD-related biomarkers should help guide treatment planning and improve the effectiveness of tumor immunotherapy.

Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance

The production and release of tumor-derived small extracellular vesicles (TDSEVs) from cancerous cells play a pivotal role in the propagation of cancer, through genetic and biological communication with healthy cells. TDSEVs are known to orchestrate the invasion-metastasis cascade via diverse pathways. Regulation of early metastasis processes, pre-metastatic niche formation, immune system regulation, angiogenesis initiation, extracellular matrix (ECM) remodeling, immune modulation, and epithelial-mesenchymal transition (EMT) are among the pathways regulated by TDSEVs. MicroRNAs (miRs) carried within TDSEVs play a pivotal role as a double-edged sword and can either promote metastasis or inhibit cancer progression. TDSEVs can serve as excellent markers for early detection of tumors, and tumor metastases. From a therapeutic point of view, the risk of cancer metastasis may be reduced by limiting the production of TDSEVs from tumor cells. On the other hand, TDSEVs represent a promising approach for in vivo delivery of therapeutic cargo to tumor cells. The present review article discusses the recent developments and the current views of TDSEVs in the field of cancer research and clinical applications.

Cell-cell communication characteristics in breast cancer metastasis

Breast cancer, a highly fatal disease due to its tendency to metastasize, is the most prevalent form of malignant tumors among women worldwide. Numerous studies indicate that breast cancer exhibits a unique predilection for metastasis to specific organs including the bone, liver, lung, and brain. However, different types of, The understanding of the heterogeneity of metastatic breast cancer has notably improved with the recent advances in high-throughput sequencing techniques. Focusing on the modification in the microenvironment of the metastatic organs and the crosstalk between tumor cells and in situ cells, noteworthy research points include the identification of two distinct modes of tumor growth in bone metastases, the influence of type II pneumocyte on lung metastases, the paradoxical role of Kupffer cells in liver metastases, and the breakthrough of the blood-brain barrier (BBB) breach in brain metastases. Overall, this review provides a comprehensive overview of the characteristics of breast cancer metastases, shedding light on the pivotal roles of immune and resident cells in the development of distinct metastatic foci.

Comprehending the cuproptosis and cancer-immunity cycle network: delving into the immune landscape and its predictive role in breast cancer immunotherapy responses and clinical endpoints

Background

The role of cuproptosis, a phenomenon associated with tumor metabolism and immunological identification, remains underexplored, particularly in relation to the cancer-immunity cycle (CIC) network. This study aims to rigorously examine the impact of the cuproptosis-CIC nexus on immune reactions and prognostic outcomes in patients with breast cancer (BC), striving to establish a comprehensive prognostic model.

Methods

In the study, we segregated data obtained from TCGA, GEO, and ICGC using CICs retrieved from the TIP database. We constructed a genetic prognostic framework using the LASSO-Cox model, followed by its validation through Cox proportional hazards regression. This framework's validity was further confirmed with data from ICGC and GEO. Explorations of the tumor microenvironment were carried out through the application of ESTIMATE and CIBERSORT algorithms, as well as machine learning techniques, to identify potential treatment strategies. Single-cell sequencing methods were utilized to delineate the spatial distribution of key genes within the various cell types in the tumor milieu. To explore the critical role of the identified CICs, experiments were conducted focusing on cell survival and migration abilities.

Results

In our research, we identified a set of 4 crucial cuproptosis-CICs that have a profound impact on patient longevity and their response to immunotherapy. By leveraging these identified CICs, we constructed a predictive model that efficiently estimates patient prognoses. Detailed analyses at the single-cell level showed that the significance of CICs. Experimental approaches, including CCK-8, Transwell, and wound healing assays, revealed that the protein HSPA9 restricts the growth and movement of breast cancer cells. Furthermore, our studies using immunofluorescence techniques demonstrated that suppressing HSPA9 leads to a notable increase in ceramide levels.

Conclusion

This research outlines a network of cuproptosis-CICs and constructs a predictive nomogram. Our model holds great promise for healthcare professionals to personalize treatment approaches for individuals with breast cancer. The work provides insights into the complex relationship between the cuproptosis-CIC network and the cancer immune microenvironment, setting the stage for novel approaches to cancer immunotherapy. By focusing on the essential gene HSPA9 within the cancer-immunity cycle, this strategy has the potential to significantly improve the efficacy of treatments against breast cancer.

Recent advances in the potential role of RNA N4-acetylcytidine in cancer progression

N4-acetylcytidine (ac4C) is a highly conserved chemical modification widely found in eukaryotic and prokaryotic RNA, such as tRNA, rRNA, and mRNA. This modification is significantly associated with various human diseases, especially cancer, and its formation depends on the catalytic activity of N-acetyltransferase 10 (NAT10), the only known protein that produces ac4C. This review discusses the detection techniques and regulatory mechanisms of ac4C and summarizes ac4C correlation with tumor occurrence, development, prognosis, and drug therapy. It also comments on a new biomarker for early tumor diagnosis and prognosis prediction and a new target for tumor therapy. Video Abstract.

Exploring Biomarkers in Breast Cancer: Hallmarks of Diagnosis, Treatment, and Follow-Up in Clinical Practice

Breast cancer is a prevalent malignancy in the present day, particularly affecting women as one of the most common forms of cancer. A significant portion of patients initially present with localized disease, for which curative treatments are pursued. Conversely, another substantial segment is diagnosed with metastatic disease, which has a worse prognosis. Recent years have witnessed a profound transformation in the prognosis for this latter group, primarily due to the discovery of various biomarkers and the emergence of targeted therapies. These biomarkers, encompassing serological, histological, and genetic indicators, have demonstrated their value across multiple aspects of breast cancer management. They play crucial roles in initial diagnosis, aiding in the detection of relapses during follow-up, guiding the application of targeted treatments, and offering valuable insights for prognostic stratification, especially for highly aggressive tumor types. Molecular markers have now become the keystone of metastatic breast cancer diagnosis, given the diverse array of chemotherapy options and treatment modalities available. These markers signify a transformative shift in the arsenal of therapeutic options against breast cancer. Their diagnostic precision enables the categorization of tumors with elevated risks of recurrence, increased aggressiveness, and heightened mortality. Furthermore, the existence of therapies tailored to target specific molecular anomalies triggers a cascade of changes in tumor behavior. Therefore, the primary objective of this article is to offer a comprehensive review of the clinical, diagnostic, prognostic, and therapeutic utility of the principal biomarkers currently in use, as well as of their clinical impact on metastatic breast cancer. In doing so, our goal is to contribute to a more profound comprehension of this complex disease and, ultimately, to enhance patient outcomes through more precise and effective treatment strategies.

PFKP deubiquitination and stabilization by USP5 activate aerobic glycolysis to promote triple-negative breast cancer progression

BACKGROUND

Triple-negative breast cancer (TNBC) remains the most challenging subtype of breast cancer and lacks definite treatment targets. Aerobic glycolysis is a hallmark of metabolic reprogramming that contributes to cancer progression. PFKP is a rate-limiting enzyme involved in aerobic glycolysis, which is overexpressed in various types of cancers. However, the underlying mechanisms and roles of the posttranslational modification of PFKP in TNBC remain unknown.

METHODS

To explore whether PFKP protein has a potential role in the progression of TNBC, protein levels of PFKP in TNBC and normal breast tissues were examined by CPTAC database analysis, immunohistochemistry staining (IHC), and western blotting assay. Further CCK-8 assay, colony formation assay, EDU incorporation assay, and tumor xenograft experiments were used to detect the effect of PFKP on TNBC progression. To clarify the role of the USP5-PFKP pathway in TNBC progression, ubiquitin assay, co-immunoprecipitation (Co-IP), mass spectrometry-based protein identification, western blotting assay, immunofluorescence microscopy, in vitro binding assay, and glycolysis assay were conducted.

RESULTS

Herein, we showed that PFKP protein was highly expressed in TNBC, which was associated with TNBC progression and poor prognosis of patients. In addition, we demonstrated that PFKP depletion significantly inhibited the TNBC progression in vitro and in vivo. Importantly, we identified that PFKP was a bona fide target of deubiquitinase USP5, and the USP5-mediated deubiquitination and stabilization of PFKP were essential for cancer cell aerobic glycolysis and TNBC progression. Moreover, we found a strong positive correlation between the expression of USP5 and PFKP in TNBC samples. Notably, the high expression of USP5 and PFKP was significantly correlated with poor clinical outcomes.

CONCLUSIONS

Our study established the USP5-PFKP axis as an important regulatory mechanism of TNBC progression and provided a rationale for future therapeutic interventions in the treatment of TNBC.

Prognosis stratification and response to treatment in breast cancer based on one-carbon metabolism-related signature

Introduction

Breast cancer (BC) is the most common malignant tumor in the female population. Despite staging and treatment consensus guidelines, significant heterogeneity exists in BC patients' prognosis and treatment efficacy. Alterations in one-carbon (1C) metabolism are critical for tumor growth, but the value of the role of 1C metabolism in BC has not been fully investigated.

Methods

To investigate the prognostic value of 1C metabolism-related genes in BC, 72 1C metabolism-related genes from GSE20685 dataset were used to construct a risk-score model via univariate Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression algorithm, which was validated on three external datasets. Based on the risk score, all BC patients were categorized into high-risk and low-risk groups. The predictive ability of the model in the four datasets was verified by plotting Kaplan-Meier curve and receiver operating characteristic (ROC) curve. The candidate genes were then analyzed in relation to gene mutations, gene enrichment pathways, immune infiltration, immunotherapy, and drug sensitivity.

Results

We identified a 7-gene 1C metabolism-related signature for prognosis and structured a prognostic model. ROC analysis demonstrated that the model accurately predicted the 2-, 3-, and 5-year overall survival rate of BC patients in the four cohorts. Kaplan-Meier analysis revealed that survival time of high-risk patients was markedly shorter than that of low-risk patients (p < 0.05). Meanwhile, high-risk patients had a higher tumor mutational burden (TMB), enrichment of tumor-associated pathways such as the IL-17 signaling pathway, lower levels of T follicular helper (Tfh) and B cells naive infiltration, and poorer response to immunotherapy. Furthermore, a strong correlation was found between MAT2B and CHKB and immune checkpoints.

Discussion

These findings offer new insights into the effect of 1C metabolism in the onset, progression, and therapy of BC and can be used to assess BC patients' prognosis, study immune infiltration, and develop potentially more effective clinical treatment options.

Development and Validation of a Nomogram for Predicting Survival Based on Ferritin and Transferrin Ratio in Breast Cancer Patients

BACKGROUND

Our objective is to develop a predictive model utilizing the ferritin and transferrin ratio (FTR) and clinical factors to forecast overall survival (OS) in breast cancer (BC) patients.

METHODS

We conducted a retrospective analysis of clinical data from 2858 BC patients diagnosed between 2013 and 2021. Subsequently, the cohort of 2858 BC patients underwent random assignment into distinct subsets: a training cohort comprising 2002 patients and a validation cohort comprising 856 patients, maintaining a proportional ratio of 7:3. Employing multivariable Cox regression analysis within the training cohort, we derived a prognostic nomogram. The predictive performance was assessed using calibration curves, C-index, and decision curve analysis.

RESULTS

The final prognostic model included the TNM stage, subtype, hemoglobin levels, and the ferritin-transferrin ratio. The nomogram achieved a C-index of .794 (95% CI: .777-.810). The nomogram demonstrated superior predictive accuracy for OS at 3, 5, and 7 years for BC, with area under the time-dependent curves of .812, .782, and .773, respectively. These values notably outperformed those of the conventional TNM stage. Decision curve analysis reaffirmed the greater net benefit of our nomogram compared to the TNM stage. These findings were subsequently validated in the independent validation cohort.

CONCLUSION

The FTR-based prognostic model may predict a patient's OS better than the TNM stage in a clinical setting. The nomogram can provide an early, affordable, and reliable tool for survival prediction, as well as aid clinicians in treatment option-making and prognosis evaluation. However, further multi-center prospective trials are required to confirm the reliability of the existing nomogram.

Polymeric Micelle-Based Nanogels as Emerging Drug Delivery Systems in Breast Cancer Treatment: Promises and Challenges

Breast cancer is a pervasive global health issue that disproportionately impacts the female population. Over the past few years, there has been considerable interest in nanotechnology due to its potential utility in creating drug-delivery systems designed to combat this illness. The primary aim of these devices is to enhance the delivery of targeted medications, optimise the specific cells that receive the drugs, tackle treatment resistance in malignant cells, and introduce novel strategies for preventing and controlling diseases. This research aims to examine the methodologies utilised by various carrier nanoparticles in the context of therapeutic interventions for breast cancer. The main objective is to investigate the potential application of novel delivery technologies to attain timely and efficient diagnosis and treatment. Current cancer research predominantly examines diverse drug delivery methodologies for chemotherapeutic agents. These methodologies encompass the development of hydrogels, micelles, exosomes, and similar compounds. This research aims to analyse the attributes, intricacies, notable advancements, and practical applications of the system in clinical settings. Despite the demonstrated efficacy of these methodologies, an apparent discrepancy can be observed between the progress made in developing innovative therapeutic approaches and their widespread implementation in clinical settings. It is critical to establish a robust correlation between these two variables to enhance the effectiveness of medication delivery systems based on nanotechnology in the context of breast cancer treatment.

HNRNPA2B1 induces cell proliferation and acts as biomarker in breast cancer

BACKGROUND

Numerous studies have shown that m6A plays an important regulatory role in the development of tumors. HNRNPA2B1, one of the m6A RNA methylation reading proteins, has been proven to be elevated in human cancers.

OBJECTIVE

In this study, we aimed to identify the role of HNRNPA2B1 in breast cancer.

METHODS

HNRNPA2B1 expression was investigated via RT-qPCR and TCGA database in breast cancer. Then, the function of HNRNPA2B1 on cancer cell was measured by CCK8 assays, colony formation and scratch assays. In addition, HNRNPA2B1 expression in BRCA was explored via the Wilcoxon signed-rank test, KruskalWallis test and logistic regression. The association with HNRNPA2B1 expression and survival were considered by KaplanMeier and Cox regression analyses. The biological function of HNRNPA2B1 was analyzed via gene set enrichment analysis (GSEA) and the cluster Profiler R software package.

RESULTS

We found that HNRNPA2B1 was highly expressed and induced cell proliferation and migration in breast cancer. Moreover, we observed HNRNPA2B1 induced tumor growth in vivo. In addition, we also found HNRNPA2B1 expression was associated with characteristics and prognosis in breast cancer patients.

CONCLUSION

Our findings suggested that HNRNPA2B1 promoted tumor growth and could function as a new potential molecular marker in breast cancer.

Liposomal Nano-Based Drug Delivery Systems for Breast Cancer Therapy: Recent Advances and Progresses

Breast cancer is a highly prevalent disease on a global scale, with a 30% incidence rate among women and a 14% mortality rate. Developing countries bear a disproportionate share of the disease burden, while countries with greater technological advancements exhibit a higher incidence. A mere 7% of women under the age of 40 are diagnosed with breast cancer, and the prevalence of this ailment is significantly diminished among those aged 35 and younger. Chemotherapy, radiation therapy, and surgical intervention comprise the treatment protocol. However, the ongoing quest for a definitive cure for breast cancer continues. The propensity for cancer stem cells to metastasize and resistance to treatment constitute their Achilles' heel. The advancement of drug delivery techniques that target cancer cells specifically holds significant promise in terms of facilitating timely detection and effective intervention. Novel approaches to pharmaceutical delivery, including nanostructures and liposomes, may bring about substantial changes in the way breast cancer is managed. These systems offer a multitude of advantages, such as heightened bioavailability, enhanced solubility, targeted tumor destruction, and diminished adverse effects. The application of nano-drug delivery systems to administer anti-breast cancer medications is a significant subject of research. This article delves into the domain of breast cancer, conventional treatment methods, the incorporation of nanotechnology into managerial tactics, and strategic approaches aimed at tackling the disease at its core.

Characteristics, healthcare utilization, and outcomes of patients with HER2-low breast cancer

PURPOSE

Treatment for HER2-low [defined as ImmunoHistoChemistry (IHC) 1 + or 2 + and negative/normal in Situ Hybridization (ISH)] breast cancer patients is rapidly evolving, yet we lack critical information about the HER2-low population.

METHODS

We conducted a retrospective cohort study of women aged 18 years or older diagnosed with breast cancer between 2010 and 2016 in North Carolina. Analyses were conducted for the overall cohort and a stage IV sub-cohort. We examined demographic and clinical characteristics, and characterized prevalence of HER2-low disease and healthcare utilization. We estimated adjusted rate ratios for the association between HER2 classifications and utilization outcomes, and hazard ratios for 3-year all cause mortality (stage IV only).

RESULTS

The overall and stage IV cohorts included 12,965 and 635 patients, respectively. HER2-low patients represented more than half of both cohorts (59% overall, 53% stage IV). HER2-low patients were more likely than IHC 0 patients to have hormone receptor (HR)-positive disease. In the stage IV cohort, HER2-low patients were more likely to be Black (26% vs. 16% IHC 0, p = 0.0159). In both cohorts, rates of hospitalizations were slightly higher among HER2-low patients. There were no survival differences between HER2-low and IHC 0 among stage IV patients.

CONCLUSION

New treatment options for HER2-low breast cancer may have potential for significant impact at the population level particularly for patients with stage IV disease. In light of racial differences between HER2-low and IHC 0 patients observed in our cohort, research- and practice-based efforts to ensure equitable adoption of new treatment guidelines for patients with HER2-low metastatic breast cancer will be essential.

Retrospective Analysis of Parameters Affecting Metastatic Breast Cancer

Objectives

While metastatic breast cancer (MBC), which is the most common cause of death in women, has been seen as an incurable surgical problem in the past decade, as the heterogeneous nature of breast cancer becomes clear with increasing molecular studies and advances in oncological protocols, life expectancy is increasing. In this study, we aimed to examine the clinicopathological features of the patients we followed up with MBC.

Methods

Patients who were operated on with the diagnosis of breast cancer in our hospital between 2018 and 2023 and who were later found to have metastases were retrospectively analyzed from the database. The age of the patients, the histological and molecular type, stage and grade of the tumor, the time from diagnosis to metastasis, the location of metastasis, the duration of treatment and follow-up were investigated. Patients who were operated on in other centers and/or were out of follow-up were excluded from the study. For the statistical analysis of the findings, number cruncher statistical system (NCSS) 2020 statistical software (NCSS LLC, Kaysville, Utah, USA) was used at a significance level of 0.05.

Results

Metastasis was detected in 77.1% (n=37) of a total of 48 female patients, and recurrence was found in 22.9% (n=11). The mean age of the patients was 57 years. There was no statistically significant difference between the patients in terms of demographics. When evaluated according to the TNM stage, 24.3% (n=9) of the patients were in the early stage and 75.7% (n=28) were in the locally advanced stage; the number of locally advanced patients was found to be higher than the early stage. In histology examination, 27.1% (n=13) of the patients were luminal A, 31.3% (n=15) luminal B, 16.7% (n=8) HER2 positive, and 25% (n=12) triple negative. Ki67 was higher than 14% in 64.6% (n=31) patients. Breast conserving surgery was performed in 41.6% (n=20) of the patients, and mastectomy was performed in 58.3% (n=28) patients. Metastasis in 34.2% (n=13) of the cases within 1-2 years, in 42.1% (n=16) within 2-5 years, and in 23.7% (n=9) after 5 years took place. Sites of metastasis were bone (37.7%, n=28), liver (28.9%, n=11), brain (10.5%, n=4), and lung (7.9%, n=3). More than one metastasis site was observed in 21.05% (n=8) of patients with metastases. There was no statistically significant difference between luminal A, luminal B, HER 2 groups and triple-negative breast cancer in terms of metastasis time and location (p>0.05). Adjuvant hormone therapy was more common in the luminal A group, whereas neoadjuvant therapy was more common in the HER2+ group. A total of 20 deaths were observed in 48 patients (41.7%). The median disease-free survival was 64 months.

Conclusion

Despite all the developments in metastatic breast cancer, the 5-year survival rate is 27%. Targeted personalized therapies may be promising when the mechanism of metastasis and specific pathways in breast cancer emerge.

Enhanced Tumor Targeting and Penetration of Proteolysis-Targeting Chimeras through iRGD Peptide Conjugation: A Strategy for Precise Protein Degradation in Breast Cancer

Proteolysis-targeting chimeras (PROTACs) have recently emerged as a promising technology for drug development. However, poor water solubility, limited tissue selectivity, and inadequate tumor penetration pose significant challenges for PROTAC-based therapies in cancer treatment. Herein, we developed an iRGD-PROTAC conjugation strategy utilizing tumor-penetrating cyclic peptide iRGD (CRGDK/RGPD/EC) to deliver PROTACs deep into breast cancer tissues. As a conceptual validation study, iRGD peptides were conjugated with a bromodomain-containing protein 4 (BRD4) PROTAC through a GSH-responsive linker. The resulting iRGD-PROTAC conjugate iPR showed enhanced water solubility, tumor-targeting capability, and penetration within tumor tissues, resulting in increased antibreast cancer efficacy in animal models and patient-derived organoids. This study demonstrates the advantages of combining iRGD and PROTACs in improving drug delivery and highlights the importance of tissue selectivity and penetration ability in PROTAC-based therapeutics.

Hypoxia-Responsive Golgi-Targeted Prodrug Assembled with Anthracycline for Improved Antitumor and Antimetastasis Efficacy

Tumor metastasis is an intricate multistep process regulated via various proteins and enzymes modified and secreted by swollen Golgi apparatus in tumor cells. Thus, Golgi complex is considered as an important target for the remedy of metastasis. Currently, Golgi targeting technologies are mostly employed in Golgi-specific fluorescent probes for diagnosis, but their applications in therapy are rarely reported. Herein, we proposed a prodrug (INR) that can target and destroy the Golgi apparatus, which consisted of indomethacin (IMC) as the Golgi targeting moiety and retinoic acid (RA), a Golgi disrupting agent. The linker between IMC and RA was designed as a hypoxia-responsive nitroaromatic structure, which ensured the release of the prototype drugs in the hypoxic tumor microenvironment. Furthermore, INR could be assembled with pirarubicin (THP), an anthracycline, to form a carrier-free nanoparticle (NP) by emulsion-solvent evaporation method. A small amount of mPEG2000-DSPE was added to shield the positive charges and improve the stability of the nanoparticle to obtain PEG-modified nanoparticle (PNP). It was proved that INR released the prototype drugs in tumor cells and hypoxia promoted the release. The Golgi destructive effect of RA in INR was amplified owing to the Golgi targeting ability of IMC, and IMC also inhibited the protumor COX-2/PGE2 signaling. Finally, PNP exhibited excellent curative efficacy on 4T1 primary tumor and its pulmonary and hepatic metastasis. The small molecular therapeutic prodrug targeting Golgi apparatus could be adapted to multifarious drug delivery systems and disease models, which expanded the application of Golgi targeting tactics in disease treatment.

Notch3 restricts metastasis of breast cancers through regulation of the JAK/STAT5A signaling pathway

PURPOSE

To explore the potential role of signal transducer and activator of transcription 5A (STAT5A) in the metastasis of breast cancer, and its mechanism of regulation underlying.

METHODS AND RESULTS

TCGA datasets were used to evaluate the expression of STAT5A in normal and different cancerous tissues through TIMER2.0, indicating that STAT5A level was decreased in breast cancer tissues compared with normal ones. Gene Set Enrichment Analysis predicted that STAT5A was associated with the activation of immune cells and cell cycle process. We further demonstrated that the infiltration of immune cells was positively associated with STAT5A level. Influorescence staining revealed the expression and distribution of F-actin was regulated by STAT5A, while colony formation assay, wound healing and transwell assays predicted the inhibitory role of STAT5A in the colony formation, migratory and invasive abilities in breast cancer cells. In addition, overexpression of the Notch3 intracellular domain (N3ICD), the active form of Notch3, resulted in the increased expression of STAT5A. Conversely, silencing of Notch3 expression by siNotch3 decreased STAT5A expression, supporting that STAT5A expression is positively associated with Notch3 in human breast cancer cell lines and breast cancer tissues. Mechanistically, chromatin immunoprecipitation showed that Notch3 was directly bound to the STAT5A promoter and induced the expression of STAT5A. Moreover, overexpressing STAT5A partially reversed the enhanced mobility of breast cancer cells following Notch3 silencing. Low expression of Notch3 and STAT5A predicted poorer prognosis of patients with breast cancer.

CONCLUSION

The present study demonstrates that Notch3 inhibits metastasis in breast cancer through inducing transcriptionally STAT5A, which was associated with tumor-infiltrating immune cells, providing a novel strategy to treat breast cancer.

Transferrin receptor in primary and metastatic breast cancer: Evaluation of expression and experimental modulation to improve molecular targeting

BACKGROUND

Conjugation of transferrin (Tf) to imaging or nanotherapeutic agents is a promising strategy to target breast cancer. Since the efficacy of these biomaterials often depends on the overexpression of the targeted receptor, we set out to survey expression of transferrin receptor (TfR) in primary and metastatic breast cancer samples, including metastases and relapse, and investigate its modulation in experimental models.

METHODS

Gene expression was investigated by datamining in twelve publicly-available datasets. Dedicated Tissue microarrays (TMAs) were generated to evaluate matched primary and bone metastases as well as and pre and post chemotherapy tumors from the same patient. TMA were stained with the FDA-approved MRQ-48 antibody against TfR and graded by staining intensity (H-score). Patient-derived xenografts (PDX) and isogenic metastatic mouse models were used to study in vivo TfR expression and uptake of transferrin.

RESULTS

TFRC gene and protein expression were high in breast cancer of all subtypes and stages, and in 60-85% of bone metastases. TfR was detectable after neoadjuvant chemotherapy, albeit with some variability. Fluorophore-conjugated transferrin iron chelator deferoxamine (DFO) enhanced TfR uptake in human breast cancer cells in vitro and proved transferrin localization at metastatic sites and correlation of tumor burden relative to untreated tumor mice.

CONCLUSIONS

TfR is expressed in breast cancer, primary, metastatic, and after neoadjuvant chemotherapy. Variability in expression of TfR suggests that evaluation of the expression of TfR in individual patients could identify the best candidates for targeting. Further, systemic iron chelation with DFO may upregulate receptor expression and improve uptake of therapeutics or tracers that use transferrin as a homing ligand.

RGCC-mediated PLK1 activity drives breast cancer lung metastasis by phosphorylating AMPKα2 to activate oxidative phosphorylation and fatty acid oxidation

BACKGROUND

More than 90% of the mortality of triple-negative breast cancer (TNBC) patients is attributed to cancer metastasis with organotropism. The lung is a frequent site of TNBC metastasis. However, the precise molecular mechanism for lung-specific metastasis of TNBC is not well understood.

METHODS

RNA sequencing was performed to identify patterns of gene expression associated with lung metastatic behavior using 4T1-LM3, MBA-MB-231-LM3, and their parental cells (4T1-P, MBA-MB-231-P). Expressions of RGCC, called regulator of cell cycle or response gene to complement 32 protein, were detected in TNBC cells and tissues by qRT-PCR, western blotting, and immunohistochemistry. Kinase activity assay was performed to evaluate PLK1 kinase activity. The amount of phosphorylated AMP-activated protein kinase α2 (AMPKα2) was detected by immunoblotting. RGCC-mediated metabolism was determined by UHPLC system. Oxidative phosphorylation was evaluated by JC-1 staining and oxygen consumption rate (OCR) assay. Fatty acid oxidation assay was conducted to measure the status of RGCC-mediated fatty acid oxidation. NADPH and ROS levels were detected by well-established assays. The chemical sensitivity of cells was evaluated by CCK8 assay.

RESULTS

RGCC is aberrantly upregulated in pulmonary metastatic cells. High level of RGCC is significantly related with lung metastasis in comparison with other organ metastases. RGCC can effectively promote kinase activity of PLK1, and the activated PLK1 phosphorylates AMPKα2 to facilitate TNBC lung metastasis. Mechanistically, the RGCC/PLK1/AMPKα2 signal axis increases oxidative phosphorylation of mitochondria to generate more energy, and promotes fatty acid oxidation to produce abundant NADPH. These metabolic changes contribute to sustaining redox homeostasis and preventing excessive accumulation of potentially detrimental ROS in metastatic tumor cells, thereby supporting TNBC cell survival and colonization during metastases. Importantly, targeting RGCC in combination with paclitaxel/carboplatin effectively suppresses pulmonary TNBC lung metastasis in a mouse model.

CONCLUSIONS

RGCC overexpression is significantly associated with lung-specific metastasis of TNBC. RGCC activates AMPKα2 and downstream signaling through RGCC-driven PLK1 activity to facilitate TNBC lung metastasis. The study provides implications for RGCC-driven OXPHOS and fatty acid oxidation as important therapeutic targets for TNBC treatment.

TRPML1 as a potential therapeutic target for triple-negative breast cancer: a review

Triple-negative breast cancer (TNBC) is the most refractory subtype of breast cancer, and effective treatments are urgently needed owing to its poor prognosis. Surgery, radiotherapy, and chemotherapy, alone or in combination, are the leading choices for TNBC therapy. Although promising approaches and procedures have emerged, several challenges, such as off-target effects, drug resistance, and severe side effects, remain to be addressed. Recently, transient receptor potential channel mucolipin 1 (TRPML1) has attracted the attention of researchers because its expression has been implicated in numerous diseases, including cancer. TRPML1 regulates biological events and signaling pathways, including autophagic flux, exocytosis, ionic homeostasis, and lysosomal biogenesis, all contributing to tumorigenesis and cancer progression. TRPML1 also functions as a building block for cancer cell growth, mitogenic signaling, priming tissues for metastasis, and activation of transcriptional programs, processes involved in several malignant tumors. This review provides an overview of breast cancer epidemiology and diagnostic techniques and then discusses the existing therapeutics. Additionally, we elaborate on the development of, and associated challenges to, TNBC diagnostics and treatment and the feasibility of TRPML1 as a therapeutic target for TNBC.

Multidimensional analysis to elucidate the possible mechanism of bone metastasis in breast cancer

BACKGROUND

Breast cancer (BC) patients tend to suffer from distant metastasis, especially bone metastasis.

METHODS

All the analysis based on open-accessed data was performed in R software, dependent on multiple algorithms and packages. The RNA levels of specific genes were detected using quantitative Real-time PCR as a method of detecting the RNA levels. To assess the ability of BC cells to proliferate, we utilized the CCK8 test, colony formation, and the 5-Ethynyl-20-deoxyuridine assay. BC cells were evaluated for invasion and migration by using Transwell assays and wound healing assays.

RESULTS

In our study, we identified the molecules involved in BC bone metastasis based on the data from multiple BC cohorts. Then, we comprehensively investigated the effect pattern and underlying biological role of these molecules. We found that in the identified molecules, the EMP1, ACKR3, ITGA10, MMP13, COL11A1, and THY1 were significantly correlated with patient prognosis and mainly expressed in CAFs. Therefore, we explored the CAFs in the BC microenvironment. Results showed that CAFs could activate multiple carcinogenic pathways and most of these pathways play an important role in cancer metastasis. Meanwhile, we noticed the interaction between CAFs and malignant, endothelial, and M2 macrophage cells. Moreover, we found that CAFs could induce the remodeling of the BC microenvironment and promote the malignant behavior of BC cells. Then, we identified MMP13 for further analysis. It was found that MMP13 can enhance the malignant phenotype of BC cells. Meanwhile, biological enrichment and immune infiltration analysis were conducted to present the effect pattern of MMP13 in BC.

CONCLUSIONS

Our result can improve the understanding of researchers on the underlying mechanisms of BC bone metastasis.

Effects of RNA methylation on Tumor angiogenesis and cancer progression

Tumor angiogenesis plays vital roles in the growth and metastasis of cancer. RNA methylation is one of the most common modifications and is widely observed in eukaryotes and prokaryotes. Accumulating studies have revealed that RNA methylation affects the occurrence and development of various tumors. In recent years, RNA methylation has been shown to play an important role in regulating tumor angiogenesis. In this review, we mainly elucidate the mechanisms and functions of RNA methylation on angiogenesis and progression in several cancers. We then shed light on the role of RNA methylation-associated factors and pathways in tumor angiogenesis. Finally, we describe the role of RNA methylation as potential biomarker and novel therapeutic target.

Impact of disulfidptosis-associated clusters on breast cancer survival rates and guiding personalized treatment

Background

Breast cancer (BC) poses a serious threat to human health. Disulfidptosis is a recently discovered form of cell death associated with cancer prognosis and progression. However, the relationship between BC and disulfidptosis remains unclear.

Methods

We integrated single-cell sequencing and transcriptome sequencing in BC to assess the abundance and mutation status of disulfidptosis-associated genes (DAGs). Subsequently, we clustered the samples based on DAGs and constructed a prognostic model associated with disulfidptosis. Additionally, we performed pathway enrichment, immune response, and drug sensitivity analyses on the model. Finally, we validated the prognostic genes through Immunohistochemistry (IHC).

Results

The single-cell analysis identified 21 cell clusters and 8 cell types. By evaluating the abundance of DAGs in different cell types, we found specific expression of the disulfidoptosis core gene SLC7A11 in mesenchymal stem cells (MSCs). Through unsupervised clustering of DAGs, we identified two clusters. Utilizing differentially expressed genes from these clusters, we selected 7 genes (AFF4, SLC7A11, IGKC, IL6ST, LIMD2, MAT2B, and SCAND1) through Cox and Lasso regression to construct a prognostic model. External validation demonstrated good prognostic prediction of our model. BC patients were stratified into two groups based on riskscore, with the high-risk group corresponding to a worse prognosis. Immune response analysis revealed higher TMB and lower TIDE scores in the high-risk group, while the low-risk group exhibited higher CTLA4/PD-1 expression. This suggests that both groups may respond to immunotherapy, necessitating further research to elucidate potential mechanisms. Drug sensitivity analysis indicated that dasatinib, docetaxel, lapatinib, methotrexate, paclitaxel, and sunitinib may have better efficacy in the low-risk group. Finally, Immunohistochemistry (IHC) validated the expression of prognostic genes, demonstrating higher levels in tumor tissue compared to normal tissue.

Conclusion

Our study has developed an effective disulfidptosis-related prognostic prediction tool for BC and provides personalized guidance for the clinical management and immunotherapy selection of BC patients.

SND1, a novel co-activator of HIF1α, promotes tumor initiation in PyMT-induced breast tumor

The multifunctional protein staphylococcal nuclease domain-containing protein 1 (SND1) is conserved and has been implicated in several aspects of tumor development, such as proliferation, epithelial-mesenchymal transition, and immune evasion. Despite this, the precise role of SND1 in the initiation and metastasis of mammary gland tumors remains largely unexplored. In this study, we utilized a mouse model of breast tumors induced by polyomavirus middle T antigen (PyMT) to demonstrate that the knockout of SND1 significantly delayed the onset of primary mammary tumor formation induced by PyMT. Histological staining and cytometric analysis were conducted to confirm the reduction of tumor-initiating cells and lung metastasis following depletion of SND1. Additionally, our findings demonstrate that enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), a crucial epigenetic modifier implicated in PyMT-induced breast tumors, serves as an essential mediator of SND1-promoted primary mammary tumor formation. Mechanistic investigations revealed that SND1 functions as a transcriptional co-activator of hypoxia-inducible factor 1 subunit alpha (HIF1α), thereby regulating the downstream target gene EZH2 and promoting tumorigenesis. Overall, this study provides novel insights into the role of SND1 as a co-activator of HIF1α in the acceleration of PyMT-induced spontaneous breast tumor formation through the promotion of EZH2 transcription. The findings provide novel insights into the relationship between SND1 and the formation of tumor-initiating cells.

The role of ATP binding cassette (ABC) transporters in breast cancer: Evaluating prognosis, predicting immunity, and guiding treatment

Breast cancer is currently the most prevalent form of cancer worldwide. Nevertheless, there remains limited clarity regarding our understanding of the tumor microenvironment and metabolic characteristics associated with it. ATP-binding cassette (ABC) transporters are the predominant transmembrane transporters found in organisms. Therefore, it is essential to investigate the role of ABC transporters in breast cancer. Transcriptome data from breast cancer patients were downloaded from the TCGA database. ABC transporter-related genes were obtained from the Genecards database. By LASSO regression, ABC-associated prognostic signature was constructed in breast cancer. Subsequently, immune microenvironment analysis was performed. Finally, cell experiments were performed to verify the function of ABCB7 in the breast cancer cell lines MDA-MB-231 and MCF-7. Using the ABC transporter-associated signature, we calculated a risk score for each breast cancer patient. Patients with breast cancer were subsequently categorized into high-risk and low-risk groups, utilizing the median risk score as the threshold. Notably, patients in the high-risk group exhibited significantly worse prognosis (P<0.05). Additionally, differences were observed in terms of immune cell infiltration levels, immune correlations, and gene expression of immune checkpoints between the two groups. Functional experiments conducted on breast cancer cell lines MDA-MB-231 and MCF-7 demonstrated that ABCB7 knockdown significantly diminished cell activity, proliferation, invasion, and migration. These findings emphasize the significance of understanding ABC transporter-mediated metabolic and transport characteristics in breast cancer, offering promising directions for further research and potential therapeutic interventions.

Contralateral axillary lymph node metastasis in breast cancer: An oligometastatic-like disease

BACKGROUND

Contralateral axillary lymph node metastasis (CAM) is rare. It remains controversial whether CAM should be regarded as a regional or distant metastatic disease. Our study aims to investigate the accurate clinical orientation and management of CAM.

METHODS

Two hundred and ninety-nine female patients diagnosed with breast cancer from 2000 to 2014 and confirmed to develop CAM, oligometastasis (OM) or locoregional recurrence (LRR) at Fudan University Shanghai Cancer Center (FUSCC) were included in this study. Baseline information and survival outcomes were analyzed and compared among the three groups.

RESULTS

Patients with CAM exhibited similar overall survival (OS) and progression-free survival (PFS) to those with OM, but worse than those with LRR (HR: 0.47 [95 % CI: 0.27-0.85], p = 0.0097; HR:0.39 [95 % CI: 0.24-0.63], p < 0.0001, respectively). Considering the patients presented with CAM or OM as a whole, we found that local treatment combined with systemic treatment did not provide a superior survival benefit over systemic treatment alone.

CONCLUSION

CAM was similar to an oligometastatic-like disease, and patients with these diseases may benefit from systemic treatment. Adding local treatment failed to significantly improve OS.

Ginsenoside Rh1, a novel casein kinase II subunit alpha (CK2α) inhibitor, retards metastasis via disrupting HHEX/CCL20 signaling cascade involved in tumor cell extravasation across endothelial barrier

Tumor cell extravasation across endothelial barrier has been recognized as a pivotal event in orchestrating metastasis formation. This event is initiated by the interactions of extravasating tumor cells with endothelial cells (ECs). Therefore, targeting the crosstalk between tumor cells and ECs might be a promising therapeutic strategy to prevent metastasis. In this study, we demonstrated that Rh1, one of the main ingredients of ginseng, hindered the invasion of breast cancer (BC) cells as well as diminished the permeability of ECs both in vitro and in vivo, which was responsible for the attenuated tumor cell extravasation across endothelium. Noteworthily, we showed that ECs were capable of inducing the epithelial-mesenchymal transition (EMT) and invadopodia of BC cells that are essential for tumor cell migration and invasion through limiting the nuclear translocation of hematopoietically expressed homeobox (HHEX). The decreased nuclear HHEX paved the way for initiating the CCL20/CCR6 signaling axis, which in turn contributed to damaged endothelial junctions, uncovering a new crosstalk mode between tumor cells and ECs. Intriguingly, Rh1 inhibited the kinase activity of casein kinase II subunit alpha (CK2α) and further promoted the nuclear translocation of HHEX in the BC cells, which resulted in the disrupted crosstalk between chemokine (C-C motif) ligand 20 (CCL20) in the BC cells and chemokine (C-C motif) receptor 6 (CCR6) in the ECs. The prohibited CCL20-CCR6 axis by Rh1 enhanced vascular integrity and diminished tumor cell motility. Taken together, our data suggest that Rh1 serves as an effective natural CK2α inhibitor that can be further optimized to be a therapeutic agent for reducing tumor cell extravasation.

Construction and Validation of a Novel Nomogram for Predicting the Risk of Metastasis in a Luminal B Type Invasive Ductal Carcinoma Population

Background

Postoperative distant metastasis is the main cause of death in breast cancer patients. We aimed to construct a nomogram to predict the risk of metastasis of luminal B type invasive ductal carcinoma.

Methods

We applied the data of 364 luminal B type breast cancer patients between 2008 and 2013. Patients were categorized into modeling group and validation group randomly (1:1). The breast cancer metastasis nomogram was developed from the logistic regression model using clinicopathological variables. The area under the receiver-operating characteristic curve (AUC) was calculated in modeling group and validation group to evaluate the predictive accuracy of the nomogram.

Results

The multivariate logistic regression analysis showed that tumor size, No. of the positive level 1 axillary lymph nodes, human epidermal growth factor receptor 2 (HER2) status and Ki67 index were the independent predictors of the breast cancer metastasis. The AUC values of the modeling group and the validation group were 0.855 and 0.818, respectively. The nomogram had a well-fitted calibration curve. The positive and negative predictive values were 49.3% and 92.7% in the modeling group, and 47.9% and 91.0% in the validation group. Patients who had a score of 60 or more were thought to have a high risk of breast cancer metastasis.

Conclusions

The nomogram has a great predictive accuracy of predicting the risk of breast cancer metastasis. If patients had a score of 60 or more, necessary measures, like more standard treatment methods and higher treatment adherence of patients, are needed to take to lower the risk of metastasis and improve the prognosis.

Suspension state affects the stemness of breast cancer cells by regulating the glycogen synthase kinase-3β

Circulating tumor cells (CTCs) are considered an important factor involved in tumor metastasis and can overcome mechanical interactions to gain the ability to distant metastasis. The previous study had shown that the suspension state could regulate the stemness of breast cancer cells (BCCs). However, the specific molecular mechanisms involved have not yet been explored clearly. In this study, MCF-7 and MDA-MBA-231 BCCs were cultured in suspension and adherent. The effect of suspension state on BCCs was further elucidated by observing suspension cell clusters, sorting CD44+/CD24- cell subpopulation and detecting self-renewal ability. Furthermore, it was found that glycogen synthase kinase-3β (GSK-3β) was significantly down-regulated in MCF-7 suspension cells along with the activation of the Wnt/β-catenin signaling, but the converse was true for MDA-MB-231 cells. Subsequently, GSK-3β was differentially expressed in MCF-7 suspension cells. The activation of the Wnt/β-catenin signaling, epithelial-mesenchymal transition (EMT) and stemness were all inhibited when GSK-3 was overexpressed in suspension MCF-7 cells. While GSK-3β was down-regulated, it further promoted the Wnt/β-catenin signaling, mesenchymal characteristic and stemness of MCF-7 cells. This study demonstrated that suspension state could activate the Wnt/β-catenin signaling by inhibiting GSK-3β to promote the stemness of epithelial BCCs, providing a therapeutic strategy for targeted CTCs.

Tamoxifen induces ferroptosis in MCF-7 organoid

BACKGROUND

Breast cancer is the most common female malignant tumor type globally. The occurrence and development of breast cancer involve ferroptosis, which is closely related to its treatment. The development of breast cancer organoids facilitates the analysis of breast cancer molecular background and tumor biological behavior, including clinical pathological characteristics, drug response, or drug resistance relationship, and promotes the advancement of precision treatment for breast cancer. The three-dimensional (3D) cell culture of breast cancer MCF-7 organoid is more similar to the in vivo environment and thus obtains more realistic results than 2D cell culture. Our study examined the new mechanism of tamoxifen in treating breast cancer through breast cancer MCF-7 organoids.

METHODS

We used 3D cells to culture breast cancer MCF-7 organoid, as well as tamoxifen-treated MCF-7 and tamoxifen-resistant MCF-7 (MCF-7 TAMR) cells. We used transcriptome sequencing. We detected GPX4 and SLC7A11 protein levels using Western blotting and the content of ATP, glutathione, and ferrous ions using the Cell Counting Lite 3D Kit. We assessed cell viability using the Cell Counting Kit-8 (CCK-8) assay.

RESULTS

Tamoxifen significantly inhibited the growth of MCF-7 organoids and significantly induced ferroptosis in MCF-7 organoids. The ferroptosis inhibitor reversed the significant tamoxifen-induced MCF-7 organoid inhibition activity. Moreover, the ferroptosis activator enhanced the tamoxifen-induced MCF-7 TAMR cell activity inhibition.

CONCLUSION

Our study revealed that ferroptosis plays an important role in tamoxifen-induced MCF-7 organoid cell death and provides a new research idea for precise treatment of breast cancer through an organoid model.

microRNA-944 inhibits breast cancer cell proliferation and promotes cell apoptosis by reducing SPP1 through inactivating the PI3K/Akt pathway

Breast cancer is a common malignancy in women with poor prognosis. This study aimed to investigate the molecular mechanism of microRNA-944 (miR-944) mediated secreted phosphoprotein-1 (SPP1) in breast cancer progression and its regulatory effect on the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. Differential gene analysis was performed to identify key genes associated with breast cancer development by screening breast cancer-related microarray data. The expression of miR-944 and SPP1 and their relationship were determined in clinical samples and cells. sh-SPP1, oe-SPP1, LY294002 or miR-944 mimic were transfected into MCF-7 cells to investigate the role of miR-944 mediated SPP1 in breast cancer development and its regulatory effect on the PI3K/Akt pathway. Finally, the tumorigenicity of breast cancer cells was observed in nude mice. Through bioinformatics analysis, we identified SPP1 as a key gene in breast cancer, and miR-944 as an upstream miRNA of SPP1. In breast cancer tissues and cells, the expression of miR-944 was decreased while that of SPP1 was increased. miR-944 negatively regulated the expression of SPP1. In breast cancer cells, SPP1 activated the PI3K/Akt pathway to promote cell proliferation and inhibit apoptosis. In vitro cell experiments showed that the downregulation of miR-944 promoted the high expression of SPP1, which then activated the PI3K/Akt signaling pathway, promoting breast cancer cell proliferation. In vivo experiments further confirmed the anti-cancer role of miR-944 mediated SPP1 in breast cancer. Our study highlights the role of miR-944 mediated SPP1 in inhibiting breast cancer progression by blocking the PI3K/Akt pathway.

Sufentanil inhibits the metastasis and immune response of breast cancer via mediating the NF-κB pathway

OBJECTIVE

Breast cancer (BC) causes cancer-related death in women. Sufentanil is used for cancer pain and postoperative analgesia. This study aimed to explore the role of sufentanil in BC.

METHODS

BC cells were treated with sufentanil, and cell viability was evaluated using the cell counting kit-8 (CCK-8) assay. Biological behaviors were analyzed using EDU assay, flow cytometry, transwell assay, western blotting, and ELISA. The levels of NF-κB pathway-related factors were examined using western blotting. A xenograft tumor model was established to assess the effects of sufentanil on tumor growth in vivo.

RESULTS

Sufentanil at the concentration of 20, 40, 80, and 160 nM suppressed cell viability (IC50 = 39.84 in MDA-MB-231 cells, and IC50 = 47.46 in BT549 cells). Sufentanil inhibited the proliferation, invasion, epithelial-mesenchymal transition (EMT), and inflammation, but induced apoptosis of BC cells. Mechanically, sufentanil suppressed the activation of the NF-κB pathway. Rescue experiments showed that RANKL (NF-κB receptor agonist) abrogated the effects induced by sufentanil. Moreover, sufentanil inhibited tumor growth, inflammatory response, but promoted apoptosis via the NF-κB pathway in vivo.

CONCLUSIONS

Sufentanil decelerated the progression of BC by regulating the NF-κB pathway, suggesting sufentanil may be used in BC therapy.

Analysis of clinicopathological features and prognostic factors of breast cancer brain metastasis

BACKGROUND

Breast cancer (BC) has become the most common malignancy in women. The incidence and detection rates of BC brain metastasis (BCBM) have increased with the progress of imaging, multidisciplinary treatment techniques and the extension of survival time of BC patients. BM seriously affects the quality of life and sur-vival prognosis of BC patients. Therefore, clinical research on the clinicopathological features and prognostic factors of BCBM is valuable. By analyzing the clinicopathological parameters of BCBM patients, and assessing the risk factors and prognostic indicators, we can perform hierarchical diagnosis and treatment on the high-risk population of BCBM, and achieve clinical benefits of early diagnosis and treatment.

AIM

To explore the clinicopathological features and prognostic factors of BCBM, and provide references for diagnosis, treatment and management of BCBM.

METHODS

The clinicopathological data of 68 BCBM patients admitted to the Air Force Medical Center, Chinese People's Liberation Army (formerly Air Force General Hospital) from 2000 to 2022 were collected. Another 136 BC patients without BM were matched at a ratio of 1:2 based on the age and site of onset for retrospective analysis. Categorical data were subjected to χ2 test or Fisher's exact probability test, and the variables with P < 0.05 in the univariate Cox proportional hazards model were incorporated into the multivariate model to identify high-risk factors and independent prognostic factors of BCBM, with a hazard ratio (HR) > 1 suggesting poor prognostic factors. The survival time of patients was estimated by the Kaplan-Meier method, and overall survival was compared between groups by log-rank test.

RESULTS

Multivariate Cox regression analysis showed that patients with stage III/IV tumor at initial diagnosis [HR: 5.58, 95% confidence interval (CI): 1.99-15.68], lung metastasis (HR: 24.18, 95%CI: 6.40-91.43), human epidermal growth factor receptor 2 (HER2)-overexpressing BC and triple-negative BC were more prone to BM. As can be seen from the prognostic data, 52 of the 68 BCBM patients had died by the end of follow-up, and the median time from diagnosis of BC to the occurrence of BM and from the occurrence of BM to death or last follow-up was 33.5 and 14 mo, respectively. It was confirmed by multivariate Cox regression analysis that patients with neurological symptoms (HR: 1.923, 95%CI: 1.005-3.680), with bone metastasis (HR: 2.011, 95%CI: 1.056-3.831), and BM of HER2-overexpressing and triple-negative BC had shorter survival time.

CONCLUSION

HER2-overexpressing, triple-negative BC, late tumor stage and lung metastasis are risk factors of BM. The presence of neurological symptoms, bone metastasis, and molecular type are influencing prognosis factors of BCBM.

Integrated single-cell and bulk RNA sequencing analysis identifies a neoadjuvant chemotherapy-related gene signature for predicting survival and therapy in breast cancer

Neoadjuvant chemotherapy (NAC) is a well-established treatment modality for locally advanced breast cancer (BC). However, it can also result in severe toxicities while controlling tumors. Therefore, reliable predictive biomarkers are urgently needed to objectively and accurately predict NAC response. In this study, we integrated single-cell and bulk RNA-seq data to identify nine genes associated with the prognostic response to NAC: NDRG1, CXCL14, HOXB2, NAT1, EVL, FBP1, MAGED2, AR and CIRBP. Furthermore, we constructed a prognostic risk model specifically linked to NAC. The clinical independence and generalizability of this model were effectively demonstrated. Additionally, we explore the underlying cancer hallmarks and microenvironment features of this NAC response-related risk score, and further assess the potential impact of risk score on drug response. In summary, our study constructed and validated a nine-gene signature associated with NAC prognosis, which was accomplished through the integration of single-cell and bulk RNA data. The results of our study are of crucial significance in the prediction of the efficacy of NAC in BC, and may have implications for the clinical management of this disease.

Genetic Testing Enhances the Precision Diagnosis and Treatment of Breast Cancer

The contemporary comprehension of breast cancer has progressed to the molecular level. As a heterogeneous malignancy, conventional pathological diagnosis and histological classification could no longer meet the needs of precisely managing breast cancer. Genetic testing based on gene expression profiles and gene mutations has emerged and substantially contributed to the precise diagnosis and treatment of breast cancer. Multigene assays (MGAs) are explored for early-stage breast cancer patients, aiding the selection of adjuvant therapy and predicting prognosis. For metastatic breast cancer patients, testing specific genes indicates potentially effective antitumor agents. In this review, genetic testing in early-stage and metastatic breast cancer is summarized, as well as the advantages and challenges of genetic testing in breast cancer.

Lysine lactylation (Kla) might be a novel therapeutic target for breast cancer

BACKGROUND

Histone lysine lactylation (Kla) is a newly identified histone modification, which plays a crucial role in cancer progression. Hence, we determined the prognostic value of Kla in breast cancer (BC).

METHODS

We obtained RNA expression profiles of BC from The Cancer Genome Atlas (TCGA), following screening out Kla-specific genes. Furthermore, we determined the prognostic value of Kla by constructing a cox model based on Kla-specific genes. Subsequently, we identified expression of lactate accumulation-related genes and prognostic Kla-specific genes through Human Protein Atlas (HPA), and further performed a correlation analysis based on their expression. Meanwhile, we explored the effects of Kla on BC tumor microenvironment (TME), drug therapy and immunotherapy. Moreover, we predicted the pathways influenced by Kla via gene set enrichment analysis (GSEA).

RESULTS

A total of 1073 BC samples and 112 normal controls were obtained from TCGA, and 23 tumor samples were removed owing to inadequate clinical information. We identified 257 differentially expressed Kla-specific genes (DEKlaGs) in BC. A cox model involved with CCR7, IGFBP6, NDUFAF6, OVOL1 and SDC1 was established, and risk score could be visualized as an independent biomarker for BC. Meanwhile, Kla was remarkably associated with BC immune microenvironment, drug therapy and immunotherapy. Kla was identified to be related to activation of various BC-related KEGG pathways.

CONCLUSION

In conclusion, Kla contributes to drug resistance and undesirable immune responses, and plays a crucial role in BC prognosis, suggesting that Kla was expected to be a new therapeutic target for BC.

The Effect of Berberine Follow by Blue Light Irradiation and Valproic Acid on the Growth Inhibition of MDA-MB-231 Breast Cancer Cells

Breast cancer is the second most common cancer after lung cancer in the world. Due to the anti-cancer properties of Berberine (Ber), in this study, the effect of combination therapy of Ber in the presence of blue LED irradiation and Valproic acid (Val) on the MDA-MB-231 breast cancer cell line was investigated. For this reason, after culturing the cells using different concentrations of Ber and Val, breast cancer cells were treated in both mono-treatment and combination therapy. In combination therapy, two modes were considered: (1) treatment with Val and then treatment with Ber in the dark or in presence of blue light irradiation (PDT)at a wavelength of 465 nm and energy of 30 J/cm2 for 15 min, and (2) treatment with Ber in the dark or PDT and then treated with Val. In all cases, cell viability, morphological changes, and colonization were assessed. Evaluation of apoptosis was performed by fluorescence microscope and flow cytometry. According to the results, combination therapy has a higher mortality rate compared to mono-treatment, and in combination therapy, treatment of cells first with Ber (10 µg/mL)-PDT and then treatment with Val (250 µg/mL) caused a significant reduction (P < 0/05) in the survival rate of cancer cells. According to the findings, it can be said that the use of Ber-PDT in combination with Val, in addition to reducing the dose of the drug, has shown a synergistic effect which can suggest the potential of this strategy as a new treatment.

Characterization of tumor microenvironment infiltration and therapeutic responses of cell cycle-related genes' signature in breast cancer

BACKGROUND

It is unknown how the cell cycle plays a role in breast cancer (BC). This study aimed to establish a clinically applicable predictive model to predict the therapeutic responses and overall survival in BC patients.

MATERIALS AND METHODS

Cell cycle-related genes (CCGs) were identified within the Cancer Genome Atlas cohort (n is equal to 1001) and the Gene Expression Omnibus cohort (n is equal to 3265). An analysis of univariate and multivariate Cox was then conducted to develop a nomogram based on CCGs. After validating the nomogram, risk cohort stratification was established and the predictive value was examined. Finally, immune cell infiltration and therapeutic responses were analysed.

RESULTS

Based on 15 CCGs, 4 prognostic predictors were identified and entered into the nomogram. According to the curves of calibration, the estimated and observed value of the nomogram is in optimal agreement. Subsequently, stratification into two risk cohorts showed that the predictive value, immune cell infiltration and overall survival were better among patients with low risk. Immune checkpoint expression in patients with BC at higher risk was downregulated. Furthermore, the results of the study revealed that doxorubicin, paclitaxel, docetaxel, cisplatin and vinorelbine all had higher IC50 values in patients with high-risk BC.

CONCLUSION

The nomogram based on CCG could assess tumour immune micro-environment regulation and therapeutic responses of immunotherapy in BC. Moreover, it may provide novel information on the control of immune micro-environment infiltration in BC and aid in the development of targeted immunotherapy.

A facile, flexible, and multifunctional thermo-chemotherapy system for customized treatment of drug-resistant breast cancer

Anticancer drug resistance invariably emerges and poses a significant barrier to curative therapy for various breast cancers. This results in a lack of satisfactory therapeutic medicine for cancer treatment. Herein, a universal vector system for drug-resistance breast cancer was designed to meet the needs of reversed multidrug resistance, thermo-chemotherapy, and long-term drug release behavior. The vector system comprises polycaprolactone (PCL) nanofiber mesh and magnetic nanoparticles (MNPs). PCL has excellent biocompatibility and electrospinning performance. In this study, MNPs were tailored to be thermogenic in response to an alternating magnetic field (AMF). PCL nanofiber can deliver various chemotherapy drugs, and suitable MNPs encapsulated in the nanofiber can generate hyperthermia and synergistic effect with those chemotherapy drugs. Therefore, a more personalized treatment system can be developed for different breast malignancies. In addition, the PCL nanofiber mesh (NFM) enables sustained release of the drugs for up two months, avoiding the burden on patients caused by repeated administration. Through model drugs doxorubicin (DOX) and chemosensitizers curcumin (CUR), we systematically verified the therapeutic effect of DOX-resistance breast cancer and inhibition of tumor generation in vivo. These findings represent a multifaceted platform of importance for validating strategic reversed MDR in pursuit of promoted thermo-chemotherapeutic outcomes. More importantly, the low cost and excellent safety and efficacy of this nanofiber mesh demonstrate that this can be customized multi-function vector system may be a promising candidate for refractory cancer therapy in clinical.

Comprehensive evaluation of cell death-related genes as novel diagnostic biomarkers for breast cancer

Background

Breast cancer (BRCA) ranks first among cancers in terms of incidence and mortality rates in women, primarily owing to metastasis, chemo-resistance, and heterogeneity. To predict long-term prognosis and design novel therapies for BRCA, more sensitive markers need to be explored.

Methods

Data from 1089 BRCA patients were downloaded from TCGA database. Pearson's correlation analysis and univariate and multivariate Cox regression analyses were performed to assess the role of cell death-related genes (CDGs) in predicting BRCA prognosis. Kaplan-Meier survival curves were generated to compare the overall survival in the two subgroups. A nomogram was constructed using risk scores based on the five CDGs and other clinicopathological features. CCK-8, EdU incorporation, and colony formation assays were performed to verify the inhibitory effect of NFKBIA on BRCA cell proliferation. Transwell assay, flow cytometry, and immunohistochemistry analyses were performed to ascertain the biological function of NFKBIA.

Results

Five differentially expressed CDGs were detected among 156 CDGs. The risk score for each patient was then calculated based on the expression levels of the five CDGs. Distinct differences in immune infiltration, expression of immune-oncological targets, mutation status, and half-maximal inhibitory concentration values of some targeted drugs were observed between the high- and low-risk groups. Finally, in vitro cell experiments verified that NFKBIA overexpression suppresses the proliferation and migration of BRCA cells.

Conclusions

Our study revealed that some CDGs, especially NFKBIA, could serve as sensitive markers for predicting the prognosis of patients with BRCA and designing more personalized clinical therapies.

PAR2 deficiency tunes inflammatory microenvironment to magnify STING signalling for mitigating cancer metastasis via anionic CRISPR/Cas9 nanoparticles

Metastasis is one of the most significant causes for deterioration of breast cancer, contributing to the clinical failure of anti-tumour drugs. Excessive inflammatory responses intensively promote the occurrence and development of tumour, while protease-activated receptor 2 (PAR2) as a cell membrane receptor actively participates in both tumour cell functions and inflammatory responses. However, rare investigations linked PAR2-mediated inflammatory environment to tumour progression. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology is an emerging and powerful gene editing technique and can be applied for probing the new role of PAR2 in breast cancer metastasis, but it still needs the development of an efficient and safe delivery system. This work constructed anionic bovine serum albumin (BSA) nanoparticles to encapsulate CRISPR/Cas9 plasmid encoding PAR2 sgRNA and Cas9 (tBSA/Cas9-PAR2) for triggering PAR2 deficiency. tBSA/Cas9-PAR2 remarkably promoted CRISPR/Cas9 to enter and transfect both inflammatory and cancer cells, initiating precise PAR2 gene editing in vitro and in vivo. PAR2 deficiency by tBSA/Cas9-PAR2 effectively suppressed NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome signalling in inflammatory microenvironment to magnify stimulator of interferon genes (STING) signalling, reactive oxygen species (ROS) accumulation and epithelial-mesenchymal transition (EMT) reversal, consequently preventing breast cancer metastasis. Therefore, this study not only demonstrated the involvement and underlying mechanism of PAR2 in tumour progression via modulating inflammatory microenvironment, but also suggested PAR2 deficiency by tBSA/Cas9-PAR2 as an attractive therapeutic strategy candidate for breast cancer metastasis.