Relation between cell-to-cell adhesion and angiogenesis and clinico-morphological prognostic factors in patients with gastric cancer

To study the relation between the expression of the molecules of cell-to-cell adhesion (Е-cadherin, a- and b-catenins) and vascular endothelial growth factor (VEGF) and traditional clinico-morphological characteristics of tumors to evaluate their prognostic value in the patients with gastric cancer. Methods: To analyze the expression of Е-cadherin, a- and b-catenins, and VEGF the paraffin embedded tumor samples were studied by immunohistochemical analysis with the use of respective monoclonal antibodies. Results: The presence of E-cadherin in tumors correlated with the absence of metastases in regional lymph nodes and was observed, as a rule, in the patients at the early stages of the disease. The presence of b-catenin expression has been detected in gastric tumors of the patients without distant metastases, while the level of VEGF expression correlated with the degree of gastric wall injury. It has been demonstrated that the expression of E-cadherin and a-catenin is associated with favourable disease course and is a characteristic pattern for early stages of gastric cancer of intestinal type. However, VEGF expression is typical for the late stages of gastric cancer of diffuse type and is associated with poor prognosis. Conclusion: At the base of combined clinical, histological and immunohistochemical analysis of gastric tumors it has been shown that E-cadherin, a-catenin and VEGF could be used as informative markers of the disease course.Цель: изучение связи экспрессии молекул межклеточной адгезии (Е-кадгерина, α- и β-катенина) и фактора роста эндотелия сосудов (VEGF) с традиционными клинико-морфологическими характеристиками опухолей для определения их прогностического значения у больных раком желудка. Методы: для определения данных белков в парафиновых срезах тканей пациентов использовали иммуногистохимический метод с использованием моноклональных антител, специфических к Е-кадгерину, α- и β-катенину, а также VEGF. Результаты: присутствие в карциномах Е-кадгерина коррелировало с отсутствием метастазов в регионарных лимфатичнеских узлах и наблюдалось, как правило, у больных на ранних стадиях болезни. Наличие экспрессии β-катенина отмечалось в карциномах желудка тех больных, которые не имели отдаленных метастазов, а уровень экспрессии VEGF четко коррелировал со степенью поражения стенки желудка. Показано, что экспрессия Е-кадгерина и α-катенина ассоциируется с благоприятным прогнозом и является характерным признаком ранних стадий рака желудка кишечного типа. В то же время экспрессия VEGF характерна для поздних стадий рака желудка диффузного типа и указывает на неблагоприятный прогноз. Выводы: в результате комплексного клинического, гистологического и иммуногистохимического анализа рака желудка установлено, что определение Е-кадгерина, α-катенина и VEGF может быть использовано в качестве информативных маркеров течения заболевания

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

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

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