Minimally invasive therapies, such as microwave ablation (MWA), are widely used for the treatment of solid tumors. Previous studies suggest that MWA is feasible for the treatment of small breast cancer, and thermal ablation may induce adaptive antitumor immunity. However, the induced immune responses are mostly weak, and the immunomodulation effects of MWA in breast cancer are unclear. Immunostimulant OK-432 can induce tumor-specific T-cell responses and may augment the immunity induced by MWA. We treated 4T1 breast cancer bearing BALB/c mice with MWA, OK-432, MWA plus OK-432, or left without treatment. Survival time was evaluated with the Kaplan–Meyer method comparing survival curves by log-rank test. On day 25 after ablation, surviving mice received tumor rechallenge, and the rechallenged tumor volumes were calculated every 5 days. Immunohistochemistry and flow cytometry were used to evaluate the T-cell immune responses in ablated tissues and spleens. The tumor-specific immunity was assessed by enzyme-linked immunospot assays. Besides, the cytokine patterns were identified from enzyme-linked immunosorbent assay. Microwave ablation plus OK-432 resulted in longer survival than single treatment and protect most surviving mice from tumor rechallenge. Both local and systemic T-cell responses were induced by MWA and were further enhanced by subsequent administration of OK-432. Moreover, the combination of MWA and OK-432 induced stronger tumor-specific immune responses than MWA alone. In addition, OK-432 and MWA synergistically promoted the production of Th1-type but not Th2-type cytokines, and polarized T-cell responses to Th1-dominant state. The T-cell immune responses were activated by MWA in breast cancer. Furthermore, the combination of MWA and OK-432 induced Th1-type response and elicited specific antitumor immunity.

Triple-negative breast cancer (TNBC), characterized by high aggression and invasiveness, has a worse prognosis than other subtypes of breast cancer. Establishing a novel animal model is helpful to understand the mechanisms involved in the progress of TNBC metastasis. In a self-established mouse model consisting normal human breast tissues and normal human bone tissues, TNBC cell line SUM-1315 could spontaneously form species-specific bone metastasis. The expression level of miR-1976 in SUM-1315-bo (derived from metastatic bone tumor) was found lower than that in SUM-1315-br (derived from orthotopic breast tumor). MiR-1976 was found to be downregulated in TNBC tissues, and lower expression of miR-1976 was correlated with worse overall survival in a patient cohort obtained from TCGA database. MiR-1976 knockdown promoted epithelial–mesenchymal transition (EMT) and cancer stem cell (CSC) properties in vitro and in vivo. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma (PIK3CG) was verified as a target gene by sequencing, biotinylated miRNA pull-down, and luciferase reporter assay. Moreover, overexpression and suppression analysis implicated PIK3CG as a mediator of the biological effects of miR-1976. Our study demonstrated that miR-1976 knockdown could promote EMT and CSCs by PIK3CG. These findings may reveal mechanisms of TNBC metastasis, and represent a potential treatment target for patients with TNBC.

Chemoresistance is a major obstacle in the neoadjuvant chemotherapy (NCT) of locally advanced breast cancer (LABC). Identification of miRNAs as prognostic biomarkers may help overcome chemoresistance of breast cancer (BC). This study aimed to evaluate the expression level of miR-1275 in plasma samples and its biological functions in the chemoresistance of BC. The expression levels of miR-1275 in plasma samples and cells were measured by RT-qPCR. CRISPR/Cas9-mediated gene editing was used to construct miR-1275 knock-out cells in MCF-7. We found that miR-1275 was significantly downregulated in plasma from patients resistant to chemotherapy and in chemoresistant BC cell lines, while patients with low levels of miR-1275 showed poor overall survival. miR-1275 knock-out promoted chemoresistance in BC cells by increasing the properties of cancer stem cells (CSCs). Mechanistically, we identified that MDK was determined to be direct downstream protein of miR-1275 which initiated PI3K/Akt signaling in breast cancer cells. We demonstrated that the high expression level of miR-1275 in plasma predicted better response to NCT. The reduction of miR-1275 promoted BC cells chemoresistance by increasing CSCs properties via targeting MDK/AKT axis. The potential of miR-1275 as a new prognostic biomarker and therapeutic target of BC patients was identified.

We aimed to determine the ablation characteristics of discontinuous moving shot technique (DMST) in microwave ablation (MWA), radiofrequency ablation (RFA) and laser ablation (LA), and analyze the differences compared with fixed electrode technique (FET) in an ex vivo porcine liver model. FET was defined as the ablation needle remaining fixed during ablation. In DMST, ablation needle moved backward for a fixed distance twice along the long axis during ablation. Four moving distances (0.5 cm, 0.75 cm, 1 cm and 2 cm) were used in DMST. Long-axis diameter (LAD) and short-axis diameter (SAD) of ablation zones were measured. The ratio of LAD/SAD was calculated. The shape and size of ablation zones were different between DMST and FET. Compared with FET, DMST could achieve greater LAD when the moving distance became long enough. In MWA with DMST, SAD decreased with the extension of moving distance and finally became smaller than the SAD in FET. While in LA and RFA, the change of moving distance did not affect SAD significantly. In MWA, RFA and LA, the characteristics of ablation zone of DMST were different from that of FET. This unique ablation technique may be suitable for conformal thermal ablation.

Background: Aneuploid circulating endothelial cells (CECs) are an indicator in breast cancer (BC). Significant changes of aneuploid CECs occurred during neoadjuvant chemotherapy (NCT). This study aimed to explore the predictive and prognostic values of aneuploid CECs in locally advanced breast cancer (LABC) patients with different NCT responses. Methods: Breast cancer patients received an EC4-T4 NCT regimen. A novel subtraction enrichment and immunostaining fluorescence in situ hybridization (SE-iFISH) strategy was applied for the detection of CECs (CD45–/CD31+/DAPI+). Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of aneuploid CEC counts in distinguishing NCT-resistant patients from sensitive ones. All patients were observed for progression-free survival (PFS) and overall survival (OS). Results: The CEC counts at any time point did not show the ability to predict the efficacy of NCT. The difference in the CECs between post-chemotherapy levels and baseline could be sufficient to distinguish chemotherapy-resistant cases from other cases in Hormone+Her-2-/+ (HR+) BC patients. Patients with reduction of CECs after all courses of NCT were associated with higher probability of PFS. Conclusion: Variations in aneuploid CECs during NCT may predict chemotherapy response in patients with HR+ breast cancer. The decrease in the number of aneuploid CECs after all courses of NCT indicates better treatment outcomes in patients with LABC.