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Purpose To investigate the mechanism underlying the modulation of M1 macrophage polarization by exosomes released from hyperthermia-treated triple-negative breast cancer (TNBC) cells. Materials and methods In this study, the effects of hyperthermia on TNBC cells were examined using cell counting kit-8, apoptosis, and cell cycle assays. Transmission electron microscopy was used to identify the structure of exosomes, while bicinchoninic acid and nanoparticle tracking analysis were used to detect particle size and amounts of exosomes released after hyperthermia. The polarization of macrophages incubated with exosomes derived by hyperthermia-pretreated TNBC cells were assessed by RT-qPCR and flow cytometry analysis. Next, RNA sequencing was performed to determine the targeting molecules changed in hyperthermia-treated TNBC cells in vitro. Finally, the mechanism underlying the modulation of macrophage polarization by exosomes derived from hyperthermia-treated TNBC cells was examined by using RT-qPCR, immunofluorescence and flow cytometry analysis. Results Hyperthermia markedly reduced cell viability in TNBC cells and promoted the secretion of TNBC cell-derived exosomes. The hub genes of hyperthermia-treated TNBC cells were significantly correlated with macrophage infiltration. Additionally, hyperthermia-treated TNBC cell-derived exosomes promoted M1 macrophage polarization. Furthermore, the expression levels of heat shock proteins, including HSPA1A, HSPA1B, HSPA6, and HSPB8, were significantly upregulated upon hyperthermia treatment, with HSPB8 exhibiting the highest upregulation. Moreover, hyperthermia can induce M1 macrophage polarization by promoting exosome-mediated HSPB8 transfer. Conclusion This study demonstrated a novel mechanism that hyperthermia can induce M1 polarization of macrophages via exosome-mediated HSPB8 transfer. These results will help with future development of an optimized hyperthermia treatment regime for clinical application, especially for combination treatment with immunotherapy.

Recurrence, metastasis, and drug resistance are still big challenges in breast cancer therapy. Internal and external stresses have been proven to substantially facilitate breast cancer progression through molecular and systemic mechanisms. For example, endoplasmic reticulum stress (ERS) results in activation of the unfolded protein response (UPR), which are considered an important cellular stress response. More and more reports indicate its key role in protein homeostasis and other diverse functions involved in the process of breast cancer progression. Therefore, therapies targeting the activation of ERS and its downstream signaling pathways are potentially helpful and novel tools to counteract and fight breast cancer. However, recent advances in our understanding of ERS are focused on characterizing and modulating ERS between healthy and disease states, and so little attention has been paid to studying the role and clinical application of targeting ERS in a certain cancer. In this review, we summarize the function and main mechanisms of ERS in different molecular types of breast cancer, and focus on the development of agents targeting ERS to provide new treatment strategies for breast cancer.

Transforming growth factor-β (TGF-β) signaling pathway is a key regulator of various cancer biologies, including cancer cell migration, invasion, angiogenesis, proliferation, as well as apoptosis, and it is one of indispensable signaling pathways during cancer metastasis. TGF-β signaling pathway can regulate and be regulated by a series of molecular and signaling pathways where microRNAs (miRNAs) seem to play important roles. miRNAs are small non-coding RNAs that can regulate expressions of their target genes. Emerging evidence suggest that miRNAs participate in various biological and pathologic processes such as cancer cells apoptosis, proliferation, invasion, migration, and metastasis by influencing multiple signaling pathways. In this article, we focus on the interaction between miRNAs and TGF-β in breast cancer (BC) metastasis through modulating invasion-metastasis-related factors, including epithelial-to-mesenchymal transition (EMT), cancer stem cells (CSCs), matrix metalloproteinase (MMP), tissue inhibitors of MMPs (TIMPs), cell adhesion molecules (CAMs), and tumor microenvironment (TME). Through a clear understanding of the complicated links between TGF-β pathway and miRNAs, it may provide a novel and safer therapeutic target to prevent BC metastasis.

Objective The purpose of this study was to evaluate the impact of the negative lymph node (LN) count on the survival of the breast cancer patients in early stage after the axillary dissection.

Since the rate of persistence to adjuvant endocrine therapy such as 5-year aromatase inhibitors (AI) would decrease over time in patients with hormone-sensitive breast cancer, it is necessary to investigate if a patient support program could modify patients’ beliefs and improve their persistence to AI treatment. This was a prospective, multicenter, controlled, observational study to evaluate the efficacy of a patient support program in improving postmenopausal patients’ persistence to adjuvant AI medication for early stage breast cancer (NCT00769080). The primary objective was to compare the rates of 1-year persistence to upfront adjuvant AI for patients in the two observational arms (standard treatment group and standard treatment plus patient support program group). In this study, 262 patients were enrolled in the standard treatment group and 241 patients in the standard treatment plus patient support program group. The mean 1-year persistence rates were 95.9 and 95.8 % for the standard treatment group and the standard treatment plus patient support program group, respectively (P = 0.95). The mean times to treatment discontinuation were 231.2 days in the standard treatment group and 227.8 days in the standard treatment plus patient support program group, with no statistically significant difference between the two groups (P = 0.96). There was also no statistically significant difference in the reason for treatment discontinuation (P = 0.32). There was a significant relationship between the patient centered care questionnaire and poor persistence (odds ratio = 3.9; 95 % CI, 1.1–13.7; P = 0.035), suggesting that the persistence rate of patients with whom the doctor always or usually spends time is greater than that of patients with whom the doctor sometimes or never spends time. Patients’ persistence to adjuvant AI medication for postmenopausal, early stage breast cancer is relatively high in the first year and is not significantly increased by adding a patient support program to standard treatment.