Superparamagnetic iron oxide nanoparticles (SPIONs) emerge as a promising tool for early cancer diagnostics and targeted therapy. However, both toxicity and biological activity of SPIONs should be evaluated in detail. The aim of this study was to synthesize superparamagnetic cobalt ferrite nanoparticles (Co-SPIONs), and to investigate their uptake, toxicity and effects on cancer stem-like properties in human pancreatic cancer cell line MiaPaCa2 and human ovarian cancer cell line A2780. Co-SPIONs were produced by Massart's co-precipitation method. The cells were treated with Co-SPIONs at three different concentrations (0.095, 0.48, and 0.95μg/mL) for 24 and 48h. Cell viability and proliferation were analyzed after treatment. The stem-like properties of cells were assessed by investigating the cell clonogenicity and expression of cancer stem cell-associated markers, including CD24/ESA in A2780 cell line and CD44/ALDH1 in MiaPaCa2 cell line. Magnetically activated cell sorting was used for the separation of magnetically labeled and unlabeled cells. Both cancer cell lines accumulated Co-SPIONs, however differences in response to nanoparticles were observed between MiaPaCa2 and A2780 cell. In particular, A2780 cells were more sensitive to exposition to Co-SPIONs than MiaPaCa2 cells, indicating that a safe concentration of nanoparticles must be estimated individually for a particular cell type. Higher doses of Co-SPIONs decreased both the clonogenicity and ESA marker expression in A2780 cells. Co-SPIONs are not cytotoxic to cancer cells, at least when used at a concentration of up to 0.95μg/mL. Co-SPIONs have a dose-dependent effect on the clonogenic potential and ESA marker expression in A2780 cells. Magnetic detection of low concentrations of Co-SPIONS in cancer cells is a promising tool for further applications of these nanoparticles in cancer diagnosis and treatment; however, extensive research in this field is needed.

Preclinical studies demonstrate that exercise reduces tumor incidence and growth. Rapid release of extracellular vesicles (EVs) during exercise suggests their potential role as mediators of exercise-induced systemic effects and physiological adaptation. This study investigated the impact of exercise-induced plasma EVs on tumor growth and immune tumor microenvironment in murine models of triple-negative breast cancer (TNBC): EO771 (a C57BL/6-derived TNBC cell line) and 4T1 (a BALB/c-derived TNBC cell line). Size exclusion chromatography was used to isolate exercise-induced EVs from plasma of healthy female mice (BALB/c and C56BL/6, n = 30 per strain) that underwent ten 30-min moderate-intensity treadmill running sessions over 2 weeks. Nanoparticle tracking analysis, Western blot, and electron microscopy confirmed the presence of EVs in the samples. Tumor-bearing mice (n = 72 per strain) were administered with exercise-induced EVs before or/and after tumor implantation. Local and systemic immune responses were assessed using flow cytometry, enzyme-linked immunosorbent assay (ELISA), and quantitative polymerase chain reaction (qPCR). Administration of exercise-induced EVs, particularly before tumor implantation, significantly suppressed tumor growth and reduced tumor burden in both TNBC models. In EO771, endpoint tumor volumes were 278-330 mm³ in treated groups compared to 799 mm³ in untreated (p < 0.0001), while in 4T1, treated groups showed volumes of 287-564 mm³ vs. 696 mm³ in untreated (p = 0.0002). Notable differences in tumor-infiltrating lymphoid and myeloid cell subpopulations indicated immunomodulatory effects of exercise-induced EVs, particularly in the 4T1 model, where their continuous administration significantly increased intratumoral cluster of differentiation 8 (CD8) T lymphocyte proportion (5.77% vs. 0.90% in untreated, p < 0.0001). Similarly, in the EO771 model, exercise-induced EVs administered before tumor implantation led to a marked rise in intratumoral CD8 T lymphocytes (2.24% vs. 1.08% in untreated, p = 0.0181). Our findings indicate that exercise-induced EV treatment elicits a pro-inflammatory antitumor immune response, suggesting a shift of immunologically cold TNBC tumors towards a more inflamed phenotype associated with better outcomes. Our study supports the further investigation of EVs as modulators of antitumor immunity and their potential utility in enhancing the efficacy of immunotherapy.

The management of advanced ovarian cancer is challenging due to the high frequency of recurrence, often associated with the development of resistance to platinum-based chemotherapy. Molecular analyses revealed the complexity of ovarian cancer with particular emphasis on the immune system, which may contribute to disease progression and response to treatment. Cytokines and chemokines mediate the cross-talk between cancer and immune cells, and therefore, present as potential biomarkers, reflecting the tumor microenvironment. A panel of circulating C-C motif chemokine ligand (CCL) and C-X-C motif chemokine ligand (CXCL) chemokines were examined in the serum of 40 high-grade patients with ovarian cancer prior to primary surgery. The level of immune infiltration in tumors was also analyzed. The preoperative levels of chemokines differ between patients. Elevated levels of circulating CXCL4 + CCL20 + CXCL1 combination can discriminate patients with shorter recurrence-free survival and overall survival. The presence of tumor-infiltrating T lymphocytes was detected in half of the patients. The mRNA expression analysis suggests the presence of antitumoral and immunosuppressive elements in the tumor microenvironment. The combination of circulating CXCL9 + CXCL10 can distinguish immune-infiltrated tumors that will lead to shorter recurrence-free survival. The results suggest that preoperative profiling of circulating chemokines in patients with ovarian cancer may provide valuable information regarding tumor recurrence and immune infiltration. The findings demonstrate that combinations have better prognostic utility than single chemokines, and may serve as patient stratification tools.