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.

Background:In novel treatment approaches, therapeutics should be designed to target cancer stem cells (CSCs). Quantum dots (QDs) are a promising new tool in fighting against cancer. However, little is known about accumulation and cytotoxicity of QDs in CSCs. Methods: Accumulation and cytotoxicity of CdTe-MPA (mercaptopropionic acid) QDs in CSCs were assessed using flow cytometry and fluorescence-activated cell sorting techniques as well as a colorimetric cell viability assay. Results: We investigated the expression of two cell surface-associated glycoproteins, CD44 and CD133, in four different cancer cell lines (glioblastoma, melanoma, pancreatic, and prostate adenocarcinoma). Only the melanoma cells were positive to both markers of CD44 and CD133, whereas the other cells were only CD44-positive. The QDs accumulated to a similar extent in all subpopulations of the melanoma cells. The phenotypical response after QD treatment was compared with the response after ionizing radiation treatment. The percentage of the CD44 high- CD133high subpopulation decreased from 72% to 55%-58% for both treatments. The stem-like subpopulation CD44 high CD133 low/-increased from 26%-28% in the untreated melanoma cells to 36%-40% for both treatments. Conclusion:Treatment of melanoma cells with QDs results in an increase of stem-like cell subpopulations. The changes in phenotype distribution of the melanoma cells after the treatment with QDs are comparable with the changes after ionizing radiation.

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Introduction. CD8 h CD57 + T-cell subpopulation and its functionally different subsets play an important role in antitumour immunity. The relation of competitive subsets may influence the overall effect of CD8 h CD57 + T-cell mediated antitumour immunity and determine an individual response to antitumour immunotherapy. The aim of this study was to evaluate the proportion of cytotoxic, immunomodulating and immunosuppressive subsets of the CD8 h CD57 + T-cell subpopulation in the peripheral blood of cancer patients and agematched healthy controls.Materials and methods. We studied the expression of biomarkers representing the cytotoxic (perforin), immunosuppressive (FOXP3, NKG2A) and immunomodulating (IFNγ) properties of CD8 + CD57 + T cells in the peripheral blood of 49 cancer patients: 30 with clear cell renal cell carcinoma (age median 58, range 43-81), 19 with high risk cutaneous melanoma (age median 68, range 45-86) and 26 controls (age median 55, range 41-81) by multicolour flow cytometry.Results. The percentage of immunosuppressive CD8 h CD57 + FOXP3 + T-cell subset in CD8 h CD57 + T-cell population varied. It was absent in 65% of controls, while only 23% and 26% of such patients were observed in renal cell carcinoma (RCC) and melanoma groups, respectively. Even 40% of RCC and 37% of melanoma patients had a high percentage of CD8 h CD57 + FOXP3 + T-cell subset, while in the control group we found no such subjects.The cytotoxic CD8 h CD57 + Perforin + T-cell subset was significantly increased in RCC patients, but showed no relevant rise in melanoma patients, whereas the immunomodulating CD8 h CD57 + IFNγ + subset was significantly increased in melanoma patients but showed no relevant rise in RCC patients when compared to controls.Conclusions. The amount of various functionally different subsets in CD8 h CD57 + T-cell subpopulation varies greatly among cancer patients. These differences may influence the overall CD8 h CD57 + T-cell mediated antitumour immune response and determine an individual response to antitumour immunotherapy.