Antitumor and antimetastatic activities of vaccine prepared from cisplatin-resistant lewis lung carcinoma

To study antitumor and antimetastatic activities of antitumor vaccine (ATV) prepared from cisplatin (CP) sensitive and resistant strains of Lewis lung carcinoma (LLC). Methods: The inhibition of tumor growth, and the mean survival time of the tumor-bearing animals, the number and the volume of metastases were measured as the indices of ATV efficacy. The activity of cytotoxic T-lymphocytes and natural killer cells, peritoneal macrophages (Mph), the level of tumor necrosis factor and the total proteolytic activity of blood plasma (PA) were assessed. Results: ATV from CP resistant LLC prepared using cytolectin (CL) of В. subtilis В-7025 significantly inhibited growth of CP resistant tumors (by 52%) and increased mean survival time (MST) of animals (by 44.6%). The index of metastasis inhibition for ATV prepared from CP sensitive or resistant LLC was 154.5% and 227.0%, respectively. In all vaccine-treated animals, Mph activity was shown to be significantly increased. In spite of high antitumor and antimetastatic effects of ATV prepared from CP resistant LLC, PA in plasma of animals inoculated with CP resistant LLC was increased significantly upon vaccine administration

Hepcidin as a possible marker in determination of malignancy degree and sensitivity of breast cancer cells to cytostatic drugs

Aim: To investigate the role of hepcidin (Hepc) in the formation of cells malignant phenotype in vitro and its expression in the dyna mics of growth of Walker-256 carcinosarcoma with different sensitivity to doxorubicin (Dox). Materials and Methods: The cell lines used in the analysis included T47D, MCF-7, MDA-MB-231, MDA-MB-468, MCF/CP, and MCF/Dox. Hepc expression was studied by immunocytochemical method. “Free” iron content was determined by EPR spectroscopy. Determination of Hepc expression in homogenates of tumor tissue and in blood serum of rats with Dox-sensitive and -resistant Walker-256 carcinosarcoma was performed. Results: It was found that Hepc levels in breast cancer (BC) cells with high degree of malignancy (MDA-MB-231, MDAMB-468) and drug-resistant phenotype (MCF/CP, MCF/Dox) were by 1.5–2 times higher (p < 0.05) in comparison with sensitive and less malignant BC cells. The development of drug-resistant phenotype in Walker-256 carcinosarcoma cells was accompanied by increasing of Hepc and “free” iron content (by 2.4 and 1.2 times, respectively). Conclusion: The data of in vitro and in vivo research evidenced on involvement of Hepc in formation of BC cells malignant phenotype and their resistance to Dox

Influence of exogenous lactoferrin on the oxidant/ antioxidant balance and molecular profile of hormone receptor-positive and -negative human breast cancer cells in vitro

Aim: To investigate the mechanisms of cytotoxic activity and pro-/antioxidant effect of lactoferrin on hormone receptor-positive and receptor-negative breast cancer cells in vitro. Materials and Methods: The study was performed on receptor-positive (MCF-7, T47D) and receptor-negative (MDA-MB-231, MDA-MB-468) human breast cancer cell lines. Immunocytochemical staining, flow cytometry, low-temperature electron paramagnetic resonance, and the Comet assay were used. Results: Upon treatment with lactoferrin, the increased levels of reactive oxygen species (ROS) (p < 0.05), NO generation rate by inducible NO-synthase (p < 0.05) and the level of “free” iron (p < 0.05) were observed. Moreover, the effects of lactoferrin were more pronounced in receptor-negative MDA-MB-231 and MDA-MB-468 cells. These changes resulted in increased expression of proapoptotic Bax protein (p < 0.05), reduced expression of the antiapoptotic Bcl-2 protein (p < 0.05) and level of not-oxidized mitochondrial cardiolipin (1.4–1.7-fold, p < 0.05). This, in turn, caused an increase in the percentage of apoptotic cells (by 14–24%, p < 0.05). Cytotoxic effects of lactoferrin were accompanied by an increase in the percentage of DNA in the comet tail and blocking cell cycle at G₂/M phase, especially in receptor-negative cell lines. Conclusion: The study showed that exogenous lactoferrin causes a violation of an antioxidant balance by increasing the level of ROS, “free” iron and NO generation rate, resalting in the blocking of cell cycle at G₂/M-phase and apoptosis of malignant cells

HEPCIDIN AS A POSSIBLE MARKER IN DETERMINATION OF MALIGNANCY DEGREE AND SENSITIVITY OF BREAST CANCER CELLS TO CYTOSTATIC DRUGS

Aim: To investigate the role of hepcidin (Hepc) in the formation of cells malignant phenotype in vitro and its expression in the dyna mics of growth of Walker-256 carcinosarcoma with different sensitivity to doxorubicin (Dox). Materials and Methods: The cell lines used in the analysis included T47D, MCF-7, MDA-MB-231, MDA-MB-468, MCF/CP, and MCF/Dox. Hepc expression was studied by immunocytochemical method. “Free” iron content was determined by EPR spectroscopy. Determination of Hepc expression in homogenates of tumor tissue and in blood serum of rats with Dox-sensitive and -resistant Walker-256 carcinosarcoma was performed. Results: It was found that Hepc levels in breast cancer (BC) cells with high degree of malignancy (MDA-MB-231, MDAMB-468) and drug-resistant phenotype (MCF/CP, MCF/Dox) were by 1.5–2 times higher (p < 0.05) in comparison with sensitive and less malignant BC cells. The development of drug-resistant phenotype in Walker-256 carcinosarcoma cells was accompanied by increasing of Hepc and “free” iron content (by 2.4 and 1.2 times, respectively). Conclusion: The data of in vitro and in vivo research evidenced on involvement of Hepc in formation of BC cells malignant phenotype and their resistance to Dox

Surface enhanced infrared absorption of nucleic acids on gold substrate

Data on surface enhanced infrared absorption (SEIRA) of nucleic acids deposited on the metal surface have been obtained in the experiment in FTIR reflectance mode. As metal surface, we used Au of 200-500 Е thickness on glass substrate. Roughness of Au was about 50 Е. In our experimental conditions, the enhancement factor of SEIRA was 3 to 5. We obtained different enhancement factors for different vibrations of nucleic acids. Application of this method to tumour nucleic acid gave a possibility to reveal some structural peculiarities of their sugar-phosphate backbone and those after application of anti-cancer drugs

INFLUENCE OF EXOGENOUS LACTOFERRIN ON THE OXIDANT/ ANTIOXIDANT BALANCE AND MOLECULAR PROFILE OF HORMONE RECEPTOR-POSITIvE AND -NEGATIvE HUMAN BREAST CANCER CELLS IN VITRO

Aim: To investigate the mechanisms of cytotoxic activity and pro-/antioxidant effect of lactoferrin on hormone receptor-positive and receptor-negative breast cancer cells in vitro. Materials and Methods: The study was performed on receptor-positive (MCF-7, T47D) and receptor-negative (MDA-MB-231, MDA-MB-468) human breast cancer cell lines. Immunocytochemical staining, flow cytometry, low-temperature electron paramagnetic resonance, and the Comet assay were used. Results: Upon treatment with lactoferrin, the increased levels of reactive oxygen species (ROS) (p < 0.05), NO generation rate by inducible NO-synthase (p < 0.05) and the level of “free” iron (p < 0.05) were observed. Moreover, the effects of lactoferrin were more pronounced in receptor-negative MDA-MB-231 and MDA-MB-468 cells. These changes resulted in increased expression of proapoptotic Bax protein (p < 0.05), reduced expression of the antiapoptotic Bcl-2 protein (p < 0.05) and level of not-oxidized mitochondrial cardiolipin (1.4–1.7-fold, p < 0.05). This, in turn, caused an increase in the percentage of apoptotic cells (by 14–24%, p < 0.05). Cytotoxic effects of lactoferrin were accompanied by an increase in the percentage of DNA in the comet tail and blocking cell cycle at G₂/M phase, especially in receptor-negative cell lines. Conclusion: The study showed that exogenous lactoferrin causes a violation of an antioxidant balance by increasing the level of ROS, “free” iron and NO generation rate, resalting in the blocking of cell cycle at G₂/M-phase and apoptosis of malignant cells