The advent of molecular classification has ushered breast cancer treatment into the era of precision medicine. Nevertheless, clinical management continues to face significant challenges posed by drug resistance and tumor heterogeneity. Recent advances have identified novel programmed cell death (PCD) mechanisms-including ferroptosis, cuproptosis, disulfidptosis, and pyroptosis-as critical regulators of breast cancer progression, therapeutic responsiveness, and immune microenvironment remodeling. This review systematically elucidates the mechanistic foundations of these PCD pathways and investigates their molecular regulatory networks within breast cancer pathogenesis. Furthermore, we evaluate current targeted intervention strategies and assess their clinical translation potential, ultimately providing a theoretical framework for pioneering therapeutic approaches.

Macrophage is the important sentinel cell type of innate immune system, and bridge with the adaptive immune response via antigen presentation. Tissue-resident macrophages are universal in almost all organs and play essential roles in maintaining specific organ homeostasis, inflammation responses, and disease genesis, including tumorigenesis. Macrophage is generally divided into two extreme statuses, M1 and M2, with sophisticated continuous subtypes due to different stimuli and microenvironments. Tumor-associated macrophage (TAM) is regarded as the key factor related to the prognosis, staging, classification, and treatment strategy of various cancers. However, emerging evidence indicated potential opposite functions of TAM in different tumor models. Recent studies found that different originated resident macrophages show notably different profiles in the same tissue niche. More evidence pointed out that the strategies to repolarize the subtypes of TAM or resident macrophages are valuable in carcinoma treatments. In the breast cancer model, studies pointed that macrophages located differently in histology show obvious different cell markers and functions. In this review, we will illustrate the profiles of resident macrophages in breast cancer with various aspects, including origination, polarization, tumoricidal activity, tumorigenesis, and the factors that could regulate the functions of macrophages.

Triple-negative breast cancer (TNBC) is currently the type of breast cancer with the worst prognosis; it lacks specific treatments, such as ER/PR antagonistic endocrine and anti-HER2 targeted therapies. Although immunotherapy with immune checkpoints has shown some efficacy in many solid tumors, clinical data in TNBC suggest significant limitations. The essence of ferroptosis is the impaired metabolism of intracellular lipid oxides, which in turn causes the activation and abnormalities of the immune system, including ROS, and not only plays an important role in liver injury and organ aging but also a large amount of data points to the close correlation between the ferroptosis process and tumor development. In this study, through the analysis of large-throughput biological data of breast tumors, combined with the characteristics of the biological process of ferroptosis, the specific gene IDH2 was found to be significantly highly expressed in TNBC and functionally correlated with ferroptosis. Through clinical specimens validated at the gene and protein levels, in vitro tumor cell line validation, and in vivo mouse models, we found that the high expression of IDH2 in TNBC has a role in inhibiting the ferroptosis process in TNBC, thus promoting the proliferation of TNBC cells and other malignant features.

Inhibitor of differentiation 4 (ID4) is a highly conserved DNA‐binding inhibitory protein of mammals, and its main role is to bind basic helix–loop–helix (b‐HLH) so that it loses its DNA‐binding activity, which in turn regulates the transcription of key genes, regulating cell differentiation and proliferation as the physiological function. Breast tissue is a highly heterogeneous tissue organ with a strong capacity for remodeling and differentiation, and studies of breast carcinogenesis suggest that the mechanisms regulating the differentiation of breast tissue interact critically with tumorigenesis. The expression level of ID4 and its regulatory mechanism play a crucial role in the study of breast cancer, but its oncogenic or oncostatic role has not yet been unanimously identified, and its regulatory mechanism in breast cancer still needs to be further elucidated. This review summarizes and analyzes the relevant studies of ID4 and the research progress in breast cancer, integrating the development of breast tissue and tumorigenesis with the regulatory role of ID4, to provide some insights into develop new treatment strategies and diagnostic biomarkers.

Macrophages are the major type of immune cell in the testis of both humans and rodents. Testicular macrophages (TMs) play critical roles in maintaining the testicular microenvironment, such as Leydig cell-dependent hormone production, spermatogenesis , and immune balance. A substantial number of studies have used rodent models to investigate the functions of TMs with various methods and harvest macrophages from the testis. Studies have demonstrated that enzyme digestion, an essential part of these methods, can improve the number and purity of TMs while unavoidably altering the immunoprofile of macrophages, which is detrimental for further study in terms of immune investigation. Here, we modified the existing method of microglia isolation and set up a novel method without the enzyme digestion step to isolate TMs. According to the characteristics of testicular tissue looseness and the physical and biological characteristics of macrophages, by combining mechanical separation, gradient centrifugation, and immuno-magnetic bead selection, we can effectively avoid the enzymatic digestion of testis tissue and maintain the immune characteristics of macrophages. Additionally, we verified the purity of TM with flow cytometry (FC) at approximately 91–95%, and the production of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) was lower than that isolated with enzyme digestion. In contrast to the traditional method, this novel protocol can assist those who have no convenient access to fluorescence-activated cell sorting (FACS) to isolate a sufficient number of TMs and, most importantly, avoid altering the immunoprofile of TMs without enzyme digestion.