Ultrastructural changes in tumor cells treated with liposomal forms of anticancer drugs

Aim: To determine the main ultrastructural changes in MCF-7 sublines sensitive and resistant to cytotoxic action of anticancer drugs, resulting from the treatment with conventional and liposomal forms of cisplatin and doxorubicin. Methods: Electron microscopy, light microscopy, MTT-test. Results: It has been shown that the phenomenon of drug resistance is associated with complication of ultrastructural organization of cells and more high differentiation by the main cytomorphologic characteristics which promote their resistance to cytotoxic action of anticancer preparations. Cytoarchitectonics of all resistant cells possesses common patterns and doesn’t depend on the particular drugs toward which the resistance has been developed. It has been shown that the cells of the parental form MCF-7 line are more sensitive to cytotoxic action of doxorubicin than to cisplatin. Liposomal forms of anticancer drugs used at the same concentrations that the conventional ones, especially that of doxorubicin, caused more expressed alterations in ultrastructural organization of cells of all studied sublines with dominance of apoptotic processes. Conclusion: Evaluating an effect of equal concentrations of cisplatin and doxorubicin in conventional and liposomal forms, one may conclude on higher cytotoxic action of doxorubicin vs. cisplatin that is expressed in a wider spectrum of ultrastructural changes of cell architectonics in different sublines of MCF-7 cells and higher rate of apoptosis

In vitro modification of cisplatin cytotoxicity with magnetic fluid

Aim: To study cytotoxicity of cisplatin conjugated with magnetic fluid (nanocomposite) upon exposure to magnetic field on sensitive and resistant to cisplatin MCF-7 human breast cancer cells. Methods: Cytotoxic activity was evaluated by MTT-test, intracellular iron accumulation was analyzed cytochemically, genotoxicity was studied by micronucleus test and DNA comet assay, ultrastructure was studied by electron microscopy techniques. Results: Nanocomposite of cisplatin was more toxic to MCF-7/S and MCF-7/CP cells compared to cisplatin in conventional pharmaceutical form. In nanocomposite-treated cells we observed more expressed signs of dystrophy (especially following application of magnetic field) and drastic alterations of nuclei ultrastructure with significant accumulation of iron nanoparticle clusters. The potent toxic action of nanocomposite is confirmed by electron microscopy and by marked genotoxicity, especially against MCF-7/CP cells. Conclusion: The enhancement of cyto- and genotoxicity of cisplatin nanocomposite combined with magnetic field in comparison with effect of convetntional cisplatin alone was demonstrated

Lactoferrin expression in breast cancer in relation to biologic properties of tumors and clinical features of disease

Aim: To determine the patterns of lactoferrin (LF) expression in breast cancer (BC) in relation to biologic properties of the neoplasms and clinical features of the disease course. Materials and Methods: Clinical specimens of 266 BC patients (115 patients with BC of stages I–II — retrospective study, and 151 BC patients — prospective study) were analyzed. Morphological, immunohistochemical and statistical methods were used. Results: The number of LF-positive tumors in retrospective and prospective groups was similar (52.1 and 52.8%, respectively). Among common clinical criteria for prognosis of the disease outcome in BC patients (patient’s age; stage of the disease; histological type, differentiation grade, receptor status; presence of metastases), a strong correlation was found only between expression indexes of LF and estrogen receptors (ER). In ER-positive tumors expression of LF was significantly higher than in ER-negative tumors (35 vs 18%). 5-Year survival rate of BC patients was higher in LF-positive group (70 vs 52% in LF-negative group). The presence of regional metastasis tended to correlate with an increased number of LF-positive tumors. In the patients with invasive ductal carcinoma, expression level of LF moderately correlated with occurrence of luminal A subtype (r = 0.43), while in the patients with invasive lobular carcinoma this index strongly correlated with occurrence of luminal B subtype (r = 0.71). LF expression correlated positively with low and moderate differentiation grade of luminal B or basal tumors, and negatively with luminal B or basal tumors of high differentiation grade (r = −0.57 and −0.63, respectively). Conclusion: It has been shown that LF expression in breast tumors correlated with life expectancy of BC patients and important physiologic and clinical features of the disease, while the character of such relation strongly depended on molecular phenotype of tumor, i.e. luminal A, luminal B or basal

Peculiarities of antioxidant system and iron metabolism in organism during development of tumor resistance to cisplatin

Aim : To study in vivo the peculiarities of changes of iron metabolism and antioxidant system in dynamics of growth of Guerin carcinoma with different sensitivity to cisplatin. Materials and Methods: In order to evaluate the content of metallothionein-1 (MT-1) in tumor homogenates and blood serum of rats with cisplatin-sensitive and cisplatin-resistant Guerin carcinoma the immunoenzyme method was used. The evaluation of ceruloplasmin activity, content of “free iron” complexes, superoxide and NO-generating acti­vity of NADPH-oxidase and iNOS activity in neutrophils, blood serum and tumor homogenates was measured by EPR-spectro­scopy. Results: Maximal accumulation of MT-1 in blood serum and tumor, more pronounced in resistant strain, at the border of latent and exponential phase of growth has been shown that is the evidence of protective role of this protein in the respect to the generation of free radical compounds. It has been determined that in animals with cisplatin-resistant strain of Guerin carcinoma, increase of “free iron” complexes is more apparent both on the level of tumor and organism on the background on increase of CP/TR ratio that is the consequence of organism antioxidant protection system disorder. Conclutions: Mentioned changes in metabolism of iron with its accumulation in tumor and further reprogramming of mitochondria metabolism and activity of NADPH-oxidase for non-transformed cells are favorable conditions for the formation of oxidative phenotype of tumor. Key Words: Guerin carcinoma, metallothionein-1, antioxidant system, transferrin, ceruloplasmin, “free iron” complexes, activity of NADPH-oxidase and iNOS neutrophils

The use of nanoferromagnetics to increase the cytotoxic effect of antitumor drugs

Aim: To investigate the influence of ferromagnetic nanoparticles on antitumor effect of doxorubicin and mitochondria oxidative phosphorylation. Methods: The study was carried out on the mice-hybrids (C57Bl/6xDBA/2) with intraperitoneally (i/p) transplantated Ehrlich ascitic carcinoma. Single i/p injection of doxorubicin (Dox), stabilized ferromagnetic nanoparticles (Fe3O4; 20–40 nm; FM) or their combination were performed 7 days after tumor transplantation. The cytotoxic effect of agents, morphology and cell cycle of tumor cells were studied 24, 48 and 72 h after Dox administration. Results: The investigations showed that ferromagnetic nanoparticles increased the cytotoxic effect of doxorubicin on Ehrlich ascіtic carcinoma mainly 48 h after agents’ administration. The largest number of apoptotic cells was observed in group of animals in which doxorubicin was administered before ferromagnetic nanoparticles. Moreover, the ferromagnetic nanoparticles at concentration 1.45 μg Fe/ml and, particularly, 7.25 μg Fe/ml decreased mitochondria oxygen consumption in phosphorylation state that may negatively influence their living capability. Conclusions: Obtained data point out the perspective of use of certain sized FM nanoparticles to increase the cytotoixc effect of antitumor drugs

Modifying effects of lactoferrin in vitro on molecular phenotype of human breast cancer cells

Aim: To assess the role of endogenous lactoferrin (LF) in the formation of the molecular phenotype of human breast cancer (BC) cell lines with varying degrees of malignancy, including cisplatin/doxorubicin resistant cell lines, and identify possible impact of exogenous LF. Materials and Methods: 5 breast cell lines of different origin — MCF-10 A, MCF-7, including doxorubicin/cisplatin resistant ones, T47D, MDA-MB-231, and MDA-MB-468. Immunocytochemistry: expression of LF, Ki-67, adhesion molecules E- and N-cadherin, CD44, CD24 rating the invasive potential of cells. Results: Expression of LF in human BC cell lines varies. It is associated with the heterogeneity of molecular profiles of cell lines in terms of adhesion. A link has been established between the level of LF expression in the resistant cell line MCF-7/CP and MCF-7/Dox, features of their molecular profile and invasive properties. Exogenous LF was shown to be capable of modifying the molecular profile and invasive properties of all the studied cell lines including resistant ones (MCF-7/CP and MCF-7/Dox). Conclusions: The sensitivity of cytostatic-resistant cell lines (MCF-7/CP and MCF-7/Dox) tends to increase under the influence of exogenous LF. It is likely that this effect is due to LF-mediated inhibition of the expression of proteins associated with drug resistance. Key Words: lactoferrin, cell lines of human breast cancer, molecular phenotype, proliferative activity, invasive potential, adhesion molecules

Modifying effects of 5-azacytidine on metal-containing proteins profile in guerin carcinoma with different sensitivity to cytostatics

Aim: To assess the influence of the treatment with 5-azacytidine (5-aza) on the profile of metal-containing proteins and factors of their regulation in Guerin carcinoma cells in vivo. Materials and Methods: The study was conducted on Wistar rats transplanted with wild-type Guerin carcinoma (Guerin/WT) and its strains resistant to cisplatin (Guerin/CP) or doxorubicin (Guerin/Dox). Animals were distributed in 6 groups treated with 5-aza and control animals without treatment. 5-Aza was injected by i.v. route (1 injection in 4 days at a dose of 2 mg/kg starting from the 4th day after tumor transplantation, 4 injections in total). Ferritin levels in blood serum and tumor tissue were measured by ELISA, transferrin and free iron complexes — by low-temperature EPR, miRNA-200b, -133a and -320a levels and promoter methylation — by real-time quantitative reverse transcription polymerase chain reaction. Results: The study has shown that 5-aza treatment caused demethylation of promoter regions of fth1 and tfr1 genes in all studied Guerin carcinoma strains. 5-Aza treatment resulted in a significant decrease of ferritin levels in tumor tissue (by 32.1% in Guerin/WT strain, by 29.8% in Guerin/Dox and by 69.1% in Guerin/CP). These events were accompanied by 3.5-fold and 2-fold increase of free iron complexes levels in tumor tissue of doxorubicin and cisplatin resistant strains, respectively. Also, 5-aza treatment resulted in significantly elevated levels of miR-200b, -133a, 320a expression in tumor tissue. After 5-aza treatment, ferritin levels in blood serum of animals with Guerin/Dox were increased by 23.9%, while in Guerin/Wt and Guerin/CP they were decreased by 17 and 16%, respectively. Conclusion: Alterations of epigenetic regulation upon in vivo treatment with 5-aza change the levels of metal-containing proteins due to DNA demethylation and altered miRNA expression profiles in Guerin carcinoma cells

LACTOFERRIN EXPRESSION IN BREAST CANCER IN RELATION TO BIOLOGIC PROPERTIES OF TUMORS AND CLINICAL FEATURES OF DISEASE

Aim: To determine the patterns of lactoferrin (LF) expression in breast cancer (BC) in relation to biologic properties of the neoplasms and clinical features of the disease course. Materials and Methods: Clinical specimens of 266 BC patients (115 patients with BC of stages I–II — retrospective study, and 151 BC patients — prospective study) were analyzed. Morphological, immunohistochemical and statistical methods were used. Results: The number of LF-positive tumors in retrospective and prospective groups was similar (52.1 and 52.8%, respectively). Among common clinical criteria for prognosis of the disease outcome in BC patients (patient’s age; stage of the disease; histological type, differentiation grade, receptor status; presence of metastases), a strong correlation was found only between expression indexes of LF and estrogen receptors (ER). In ER-positive tumors expression of LF was significantly higher than in ER-negative tumors (35 vs 18%). 5-Year survival rate of BC patients was higher in LF-positive group (70 vs 52% in LF-negative group). The presence of regional metastasis tended to correlate with an increased number of LF-positive tumors. In the patients with invasive ductal carcinoma, expression level of LF moderately correlated with occurrence of luminal A subtype (r = 0.43), while in the patients with invasive lobular carcinoma this index strongly correlated with occurrence of luminal B subtype (r = 0.71). LF expression correlated positively with low and moderate differentiation grade of luminal B or basal tumors, and negatively with luminal B or basal tumors of high differentiation grade (r = −0.57 and −0.63, respectively). Conclusion: It has been shown that LF expression in breast tumors correlated with life expectancy of BC patients and important physiologic and clinical features of the disease, while the character of such relation strongly depended on molecular phenotype of tumor, i.e. luminal A, luminal B or basal

Alteration in lipid composition of plasma membranes of sensitive and resistant Guerin carcinoma cells due to the action of free and liposomal form of cisplatin

Aim - to study in vivo changes of lipid composition of plasma membranes of sensitive and resistant to cisplatin Guerin carcinoma cells under influence of free and liposomal cisplatin forms. The isolation of plasma membranes from parental (sensitive) and resistant to cisplatin Guerin carcinoma cells was by differential ultracentrifugation in sucrose density gradient. Lipids were detected by method of thin-layer chromatography. It was determined, that more effective action of cisplatin liposomal form on resistant cells is associated with essential abnormalities of conformation of plasma membrane due to change of lipid components and architectonics of rafts. It results in the increase of membrane fluidity. Conclusion: reconstructions in lipid composition of plasma membranes of cisplatin-resistant Guerin carcinoma cells provide more intensive delivery of drug into the cells, increase of its concentration and more effective interaction with cellular structural elements. Key Words: tumor, plasma membranes, lipids, drug resistance, cisplatin liposomal form

Alteration in lipid composition of plasma membranes of sensitive and resistant Guerin carcinoma cells due to the action of free and liposomal form of cisplatin

Aim: To study in vivo changes of lipid composition of plasma membranes of sensitive and resistant to cisplatin Guerin carcinoma cells under influence of free and liposomal cisplatin forms. Materials and Methods: The isolation of plasma membranes from parental (sensitive) and resistant to cisplatin Guerin carcinoma cells was by differential ultracentrifugation in sucrose density gradient. Lipids were detected by method of thin-layer chromatography. Results: It was determined that more effective action of cisplatin liposomal form on resistant cells is associated with essential abnormalities of conformation of plasma membrane due to change of lipid components and architectonics of rafts. It results in the increase of membrane fluidity. Conclusion: Reconstructions in lipid composition of plasma membranes of cisplatin-resistant Guerin carcinoma cells provide more intensive delivery of drug into the cells, increase of its concentration and more effective interaction with cellular structural elements