[DNA aptamers selection for breast cancer]. / Selektsiia dnk-aptamerov dlia diagnostiki raka molochnoi zhelezy.

A method of selection of DNA aptamers to breast tumor tissue based on the use of postoperative material has been developed. Breast cancer tissues were used as the positive target; the negative targets included benign tumor tissue, adjacent healthy tissues, breast tissues from mastopathy patients, and also tissues of other types of malignant tumors. During selection a pool of DNA aptamers demonstrating selective binding to breast cancer cells and tissues and insignificant binding to breast benign tissues has been obtained. These DNA aptamers can be used for identification of protein markers, breast cancer diagnostics, and targeted delivery of anticancer drugs.

Antitumor effect of arabinogalactan and platinum complex.

The article presents the results of investigation of antitumor properties of platinum-arabinogalactan complex. We showed the ability of the complex to inhibit the growth of Ehrlich ascites tumor cells. It is found that the distribution of the platinum-arabinogalactan complex is not specific only for tumor cells in mice. The complex was found in all tissues and organs examined (ascites cells, embryonic cells, kidney, and liver). The mechanism of action of the arabinogalactan-platinum complex may be similar to cisplatin as the complex is able to accumulate in tumor cells.

The antitumor effect of magnetic nanodisks and DNA aptamer conjugates.

Here we describe a method of forming large arrays (up to 10(9) pieces) of free magnetic Ni-nanodisks 50 nm thick coated on both sides with layers of 5 nm thick Au. The antitumor effect of the magnetic nickel gold-coated nanodisks and DNA aptamer conjugates was evaluated in vivo and in vitro. Under the influence of rotating magnetic field, the studied nanodisks can cause the death of Ehrlich ascites carcinoma cells.

Development of a biosensor for electrochemical detection of tumor-associated proteins in blood plasma of cancer patients by aptamers.

A molecular biosensor based on DNA aptamers (aptasensor) for the diagnosis of lung cancer in blood plasma samples was designed. To create the aptasensor, the aptamer 17_80, obtained in the study of postoperative material, was used. The affinity and binding selectivity of the aptamer 17_80 to the lung tumor tissue was confirmed on histological sections of postmortem samples of lung tissue. Using affinity enrichment and mass spectrometry, a possible target molecule of the aptamer 17_80, vimentin, was found.

New composites of betulin esters with arabinogalactan as highly potent anti-cancer agents.

Betulin and its esters are the natural compounds with high in vitro cytotoxicity toward many cancer cells. However, the poor water solubility of these compounds has limited their applications. We prepared new composites of betulin esters using two methods, namely ball-milling of the mixtures of betulin esters with arabinogalactan and preparation of thin films of these mixtures by evaporating the aqueous solutions. These composites revealed higher water solubility as compared with the initial substances without losing the structural integrity and functionality. As a result, the new composites have shown much higher inhibitory effects against different cancer cell lines such as Ehrlich ascites carcinoma cells and lung carcinoma cells (A549) in comparison with the initial substances. The cell viability studies based on Annexin V and Propidium iodide probes have confirmed the high proapoptotic effect of betulin ester derivatives against cancer cells.

Effects of cisplatin on lymphocyte structure and functions in mice with ehrlich ascitic carcinoma.

The effects of cisplatin on [Ca2+]in, pHin, NAD(P)H level, and lymphocyte membrane microviscosity were studied in mice with Ehrlich ascitic carcinoma. The level of free [Ca2+]in in lymphocytes from mice with Ehrlich ascitic carcinoma was 4-fold reduced compared to that in intact animals on day 13 of tumor development, while [H+]in level was elevated. Cisplatin caused no changes in the level of free Ca2+, but reduced cytosol acidification. Lymphocyte membrane fluidity in mice with tumors was increased in the lipid bilayer and in the protein-lipid contact zone and did not depend on cisplatin treatment. The level of NAD(P)H was low in mice with tumors, but increased sharply after cisplatin treatment. It seems that functional activity of lymphocytes decreased at the stage of well-developed tumor, which promoted inhibition of the lymphocyte defense properties. Cisplatin did not modify the structure and functions of lymphocytes and presumably even improved their energy status.

Lipid peroxidation in erythrocyte membranes of women with benign and malignant neoplasms of the endometrium.

The content of primary and secondary products of membrane peroxidation, total cholesterol concentration, and relative microviscosity of erythrocyte membranes were measured in women with endometrial cancer and uterine leiomyoma. The content of conjugated dienes in erythrocytes was highest in female patients with malignant tumors of the endometrium. The relative microviscosity of erythrocyte membranes in patients with uterine leiomyoma and endometrial cancer was elevated in the zone of lipid--lipid and protein--lipid contacts.

Formation of systemic structural trace in rat kidneys after cold adaptation.

We studied the adaptive response of rats to cold exposure. It was found that the development of the adaptive response and formation of systemic structural trace in the kidneys occurred within 1 month after the start of adaptation. Activation of proliferative processes in the kidneys was accompanied by an increase in intracellular calcium concentration.

Influence of ATP on Ehrlich ascites carcinoma cell free cytoplasmic calcium concentration in the course of tumor growth.

The changes in free cytoplasmic calcium concentration ([Ca2+](in)) and the effects of extracellular ATP on [Ca2+](in) have been studied in Ehrlich ascites carcinoma cells in the dynamics of their growth. The basal level of [Ca2+](in) and the effects of ATP on the ascites cells were determined by the stage of tumor growth and depended on the content of reactive oxygen species (ROS). The sharp increase in basal and ATP-induced elevation of [Ca2+](in) levels were observed at the 12th day of ascites cell growth. Inhibition of ROS formation by N-acetyl-L-cysteine decreased [Ca2+](in) and suppressed the cell reaction to ATP. We suggest that the increased sensitivity of the ascites cells to ATP observed on the 12th day may be also attributed to a decrease in ecto-ATPase activity.