Purpose: The F3II cell line is a highly invasive variant of mammary carcinoma. Although it is frequently used as a model to evaluate the efficacy of immunotherapy, its impact on the immune system remains poorly understood. The main objectives of this study were to evaluate the effects of F3II tumors on the development of chronic inflammation and to characterize tumor-associated immunosuppression. Methods: Following the experimental implantation of F3II tumors in BALB/c mice, alterations in the liver and spleen anatomy and the numbers of circulating leukocytes, myeloid-derived suppressor cells (MDSCs), and regulatory T cells were measured using hematological techniques, histopathological analysis, and flow cytometry. The capacity of the F3II tumor-bearing mice to reject MB16F10 allogeneic tumor transplantation was also evaluated. In addition, the restoration of immune parameters in tumor-bearing mice was evaluated after standard breast cancer chemotherapy and surgical tumor excision. Results: F3II tumor implantation increased the levels of chronic inflammatory markers, such as the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios, and caused myeloid alterations, including extramedullary granulopoiesis and megakaryopoiesis, along with the recruitment of MDSCs to the spleen. Chemotherapy or surgical F3II tumor removal completely rescued the tumor-associated extramedullary granulopoiesis and megakaryopoiesis. Notably, the presence of F3II tumors reduced the capacity of BALB/c mice to reject MB16F10 allogeneic tumor transplantation. Conclusion These results support the occurrence of F3II tumor-mediated immune cell dysfunction, which mimics the immune alterations characterized by chronic systemic inflammation and immunosuppression observed in breast cancer in clinical settings.Thus, the F3II tumor model is relevant for evaluating novel breast cancer immunotherapies and combinations in preclinical studies. This model could also be useful for identifying appropriate therapeutic targets and developing proof-of-concept experiments in the future.

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases,yet its association with progressive periodontitis remains unexplored.To investigate the involvement and significance of ferroptosis in periodontitis progression,we assessed sixteen periodontitis-diagnosed patients.Disease progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid(GCF)collection was performed for further analyses.Clinical metrics,proteomic data,in silico methods,and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with ferroptosis.Subsequent western blot analyses validated key findings.Finally,a single-cell RNA sequencing(scRNA-seq)dataset(GSE164241)for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis progression.Periodontitis progression was identified as occurring at a faster rate than traditionally thought.GCF samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic profiles.In addition,specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins,including SNCA,CA1,HBB,SLC4A1,and ANK1 was strongly associated with the clinical progression status of periodontitis.Moreover,we found specific proteins-drivers or suppressors-associated with ferroptosis(SNCA,FTH1,HSPB1,CD44,and GCLC),revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of periodontitis.Additionally,the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to ferroptosis.Our analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients,which offer new insights into the molecular mechanisms of progressive periodontal disease.These findings may lead to novel diagnostic and therapeutic strategies.