Comparability of the level and intensity of estrogen receptors ß (ERß expression in non-small cell lung cancer tissue of 32 patients was analyzed by flow cytometry using various antibodies - to the total fraction of ERß (clone 14C8) as well to the full-length ERß1 isoform (clone EMRO2). The differences in the ER expression indexes detected by anti-ERß or anti-ERß1 antibodies were revealed in some patients, but it had no influence on average indexes of the ERß expression in the patient groups investigated. It was confirmed by the findings on more frequent and more intensive expression of ERß in the non-small cell lung cancer tissue of female patients vs. the males irrespective of antibody type - anti-ERß or anti-ERß1. Therefore, in comparative analysis of ERß expression in the groups of the patients with different clinicomorphologic characteristics of the disease it is possible to use both the antibodies. For individual disease prognosis in the routine clinical practice it is recommended to use the antibodies to the total fraction of ERß, since there are individual differences between the ERß expression indexes revealing by various types of antibodies.

A review of the literature data on expression of estrogen receptor alpha and beta (ERa and ERβ) in tumors different from breast cancer. The results regarding the ERa and ERβ expression frequency in non-small cell and small cell lung cancer, colorectal cancer, esophageal, ovarian, prostate and brain tumors are presented. High frequency of estrogen receptor expression (in up to 50 and more per cent of cases) in various types of tumors, differences between ERa and ERβ in expression frequency, prognostic significance and prediction of the neoplastic process aggressiveness as well as in biological implications of interaction with antiestrogens (antagonistic and/or agonistic effect) are shown. The data on comparative evaluation of ERa and ERβ expression in lung, ovarian, prostate tumor cells and corresponding nonneoplastic tissues are reported. Authors consider necessary to include the ERa and ERβ detection into the routine clinical practice not only in breast cancer but in other tumors as well. Prospects of the clinical application of antiestrogens, in particular tamoxifen, in adjuvant therapy of different tumors with positive ER status are discussed.

The review is concerned with the crucial marker of nucleotide excision repair ERCC1 and its contribution to platinum resistance of ovarian cancer. All the variants of the laboratory and clinical ERCC1 assessment in the ovarian cancer tissue (single nucleotide polymorphisms of the ERCC1 gene, levels of mRNA or protein) are considered. Data on the prognostic and predictive value of ERCC1 as a marker of the response to platinum-based therapy in ovarian cancer are systematized. The authors discuss the possible causes of heterogeneity of the results and emphasize the necessity of a unified and integrated approach to evaluation of ERCC1 in the tumor. The publications cited in the Search Engine Pub Med up to January 2015 were analyzed.

The differences in expression of ERCC1 were estimated between tumor specimens embedded into paraffin blocks and surgical biopsy specimens of non-small cell lung cancer as well as breast and ovarian cancers. Concordance or differences not higher than 20% were observed in 73% of the cases. The number of the cases with more significant differences in ERCC1 expression was less than 17%. The results show that ERCC1 detection in surgical biopsy specimens by flow cytometry is the more preferable method due to reduced preanalytical phase of the analysis.

Background. A search for pathogenetically grounded approaches to the treatment of non-small cell lung cancer is undoubtedly one of the top priorities, because of the results of its treatment cannot be regarded as satisfactory. Discovery of a new type of receptors, estrogen receptors ß, that expressed in non-small cell lung cancer, created the preconditions for the development of a new treatment strategy for non-small cell lung cancer, namely antiestrogen therapy. Objective was to answer to the clinically significant question of how many patients with non-small cell lung cancer and lung metastases are potential candidates for antiestrogen treatment. Materials and methods. A comparative quantitative estimation of the level and frequency of the estrogen receptors ß expression in non-small cell lung cancer tissues and also in lung metastases (74 in total) was carried out by flow cytometry. Results. The estrogen receptors ß expression was detected in the majority of the investigated tumors and lung metastases, in 92 and 86 % of patients, respectively. The average level of estrogen receptors ß expression in non-small cell lung cancer tissue was higher then in metastases (42 % and 34.6 % respectively). The differences was statistically significant (p = 0.03). Primary tumors with a high and low+moderate estrogen receptors ß expression levels were detected in 35 % and 65 % of cases respectively and metastases with such expression levels - in 14 % and 86 % of cases respectively. Conclusion. 1. The estrogen receptors ß expression in the tumor predicts a more favorable course of the disease. One of the reasons for this may be a greater metastatic potential of tumor cells with low estrogen receptors ß expression. 2. The group of potential candidates for carrying out the adjuvant antiestrogen therapy comprises about 70 % of patients with primary lung tumors and with metastatic lesions of lung.

Background. Beta-III tubulin (TUBB3) is a tumor-specific isoform of the microtubule protein beta-tubulin. TUBB3 is considered to be a marker of adverse prognosis and tumor resistance to therapy with taxanes and Vinka alkaloids. Association between TUBB3 expression and histological type of the tumor has not been studied properly yet. Objective. The expression level of TUBB3 in non-small cell lung cancer biopsy specimens has been measured on 2 groups of patients with adenocarcinoma and squamous cell carcinoma. Materials and methods. The samples with adenocarcinoma (n = 43) and squamous cell carcinoma (n = 39) were converted to suspension, filtered, fixed with 4 % formaldehyde, stained with monoclonal antibodies for TUBB3 and DyLight 650-conjugated secondary antibodies to mouse IgG and analyzed by flow-cytometry. The method was developed in N.N. Blokhin Russian Cancer Research Center. Results. The average level of TUBB3 expression in the adenocarcinoma group is higher than in the squamous cell carcinoma group (33.1 ± 12.4 % of cells expressing the marker in adenocarcinoma vs. 26.0 ± 13.6 % in squamous cell carcinoma; differences were statistically significant). The average level of TUBB3 expression in adenocarcinoma is 29.7 ± 8.1 % in female and is 34.9 ± 13.9 % in male (differences statistically insignificant). Since the group of patients with adenocarcinoma was presented by both men and women, while the group of patients with squamous cell carcinoma was only men, from the analysis was excluded all female patients. Differences between the groups remained statistically significant. Conclusion. TUBB3 expression in tumor tissue does not depend on the gender, at least among patients with adenocarcinoma of the lung, and at the same time, the level of TUBB3 in adenocarcinoma tissue is higher in comparison with squamous cell carcinoma tissue.

Using the model of breast cancer Ehrlich ascites tumor in mice, we showed that a sigle intraperitoneal injection of cardiac glycoside digoxin 1 h before the intraperitoneal injection of cisplatin increased the anticancer effect of the cytostatic drug more than twice when recalculated for the dose. It is assumed that the modifying effect of digoxin is determined by the direct inhibition of glycolysis in tumor cells. Taking into account the design of the study, we consider promising the clinical evaluation of the effectiveness of digoxin as a modifier of cisplatin efficiency in intracavitary therapy of ascites cancers with pleural and abdominal dissenmination.

Currently, there is a marked tendency towards improvement of early detection of breast cancer that allows patients at extremely low risk for developing recurrent disease to be identified. Therefore, it is necessary to search for biological markers of unfavorable prognosis for patients with hormone-dependent breast cancer. In order to introduce these markers into routine clinical practice, they should be validated in welldesigned clinical studies, provide additional predictive information and be easily reproducible. The standard immunohistochemical parameters (estrogen and progesterone receptors and Ki67 cell proliferation index) can be served as these markers. However, the dynamic changes in these parameters during hormone therapyrather than their initial expression levels in the tumor are of great significance for the individualized hormone therapy.

Currently, there is a marked tendency towards improvement of early detection of breast cancer that allows patients at extremely low risk for developing recurrent disease to be identified. Therefore, it is necessary to search for biological markers of unfavorable prognosis for patients with hormone-dependent breast cancer. In order to introduce these markers into routine clinical practice, they should be validated in welldesigned clinical studies, provide additional predictive information and be easily reproducible. The standard immunohistochemical parameters (estrogen and progesterone receptors and Ki67 cell proliferation index) can be served as these markers. However, the dynamic changes in these parameters during hormone therapyrather than their initial expression levels in the tumor are of great significance for the individualized hormone therapy.

Tamoxifen is the first target agent with a high-end position in breast cancer therapy till now. In recent years experimental researches revealed new biological effects of tamoxifen on tumor cells. The present study continues the theme of the review published in 2012, where a plenty of tamoxifen effects besides interaction with estrogen receptors was discussed. Thus, there is described a wide range of the drug targets which are the key points of signal cascades activating the cell proliferation and determining the course of the growth of the cancer and its sensitivity to chemotherapy. Also clinical trials of tamoxifen based on existing of targets besides the estrogen receptors are reviewed. Furthermore, the data on the antiviral, antibacterial, antifungal and antiparasitic activities of tamoxifen are indicated.

Objective of the research was determination level of RRM1 expression in ovarian cancer tissue. Materials and methods. To avoid disadvantages of those evaluations, the present study of the RRM1 expression level in ovarian cancer tissue determination was held using strictly quantitative immunofluorescence flow cytometry-associated method developed by the authors. Results. RRM1 expression was detected in 100 % of samples of ovarian serous adenocarcinoma, with significant differences in the indicator level in variable patients. The high level of RRM1 (≥ 40 % of cells expressing the marker) was detected in 65 % of the tumor samples studied, low (< 40 %) - in 35 % of cases. Data on the lower expression of RRM1 in one-third of the test samples from primary serous ovarian cancer corresponds with clinical observations of gemcitabine monotherapy efficiency in 25-30 % of patients. Conclusion. The authors believe that a strictly quantitative determination of the marker level in tumor tissue can help to overcome the ambiguity of RRM1 clinical significance estimation in gemcitabine treatment effectiveness prediction.

Peritoneal dissemination and growth of tumor cells in the ascitic fluid in stages III and IV of recurrent ovarian cancer is difficult to treat; resistance to many anticancer drugs used in the treatment of solid ovarian cancer is observed at this stage. The author’s hypothesis that the differences in the molecular phenotype of tumor cells for various types of the disease could be an explanation for this. A comparative evaluation of the expression and coexpression of a number of molecular markers (immunofluorescence assay with flow cytometry) was performed using solid and ascitic ovarian cancer cells. In contrast to solid ovarian cancer, ascitic ovarian cancer cells present leukocyte common antigen CD45 and mesenchymal marker vimentin in addition to epithelial marker cytokeratin. In addition to the inhibition of anoikis (specific mechanism of epithelial cell death in a liquid medium in the absence of contact with the substrate), ascitic ovarian cancer cells are characterized by (1) emperipolesis (intracellular migration of leukocytes without damage to the tumor cell), and (2) phenotype of epithelial-mesenchymal transition. Thus, the data on clinically significant molecular differences between solid and recurrent ascitic ovarian cancer was first obtained, opening up opportunities for anticancer therapy, which previously was not used in the treatment of ovarian cancer.

Background. Beta-III tubulin (TUBB3) is a tumor-specific isoform of the microtubule protein beta-tubulin. TUBB3 is considered to be a marker of adverse prognosis and tumor resistance to therapy with taxanes and Vinka alkaloids. Association between TUBB3 expression and histological type of the tumor has not been studied properly yet. Objective. The expression level of TUBB3 in non-small cell lung cancer biopsy specimens has been measured on 2 groups of patients with adenocarcinoma and squamous cell carcinoma. Materials and methods. The samples with adenocarcinoma (n = 43) and squamous cell carcinoma (n = 39) were converted to suspension, filtered, fixed with 4 % formaldehyde, stained with monoclonal antibodies for TUBB3 and DyLight 650-conjugated secondary antibodies to mouse IgG and analyzed by flow-cytometry. The method was developed in N.N. Blokhin Russian Cancer Research Center. Results. The average level of TUBB3 expression in the adenocarcinoma group is higher than in the squamous cell carcinoma group (33.1 ± 12.4 % of cells expressing the marker in adenocarcinoma vs. 26.0 ± 13.6 % in squamous cell carcinoma; differences were statistically significant). The average level of TUBB3 expression in adenocarcinoma is 29.7 ± 8.1 % in female and is 34.9 ± 13.9 % in male (differences statistically insignificant). Since the group of patients with adenocarcinoma was presented by both men and women, while the group of patients with squamous cell carcinoma was only men, from the analysis was excluded all female patients. Differences between the groups remained statistically significant. Conclusion. TUBB3 expression in tumor tissue does not depend on the gender, at least among patients with adenocarcinoma of the lung, and at the same time, the level of TUBB3 in adenocarcinoma tissue is higher in comparison with squamous cell carcinoma tissue.

Introduction. The disruption of BRCA1 function leads to the development of several cancers including breast cancer, ovarian cancer, non-small cell lung cancer, gastric cancer, pancreatic cancer. Recently it was demonstrated that BRCA1 protein as well as another DNA repair protein, ERCC1, could be prognostic markers of the course of the disease and predictive markers of platinum-based chemotherapy efficiency. Nevertheless, the obtained data are controversial. Aim. In current study the comparison of BRCA1 expression in breast cancer with favorable and unfavorable prognosis based on estrogen receptor status (ER+ and ER - ) was carried out to evaluate its potential prognostic significance for subsets of breast cancer with different platinum chemotherapy sensitivity. Materials and methods. The estimation of BRCA1 expression was made in 50 samples of breast cancer tissue (40 ER+ and 10 ER - ) using the quantitative immunofluorescent method coupled with flow cytometry. Tumor cell suspensions were incubated with primary anti-BRCA1 antibodies (Abs) (SD118, Calbiochem) and secondary fluorescent Abs (DyLight650, ab98729). Cell fluorescence was measured at the Flow Cytometer FACSCanto II (Becton Dickinson, USA) using the program FACSDiva 6.0. The level of BRCA1 expression was analyzed using the program FlowJo 10.0 with statistical approach of Kolmogorov-Smirnov. The level of BRCA1 expression was determined as the ratio of specifically fluorescent cells to the total number of cells. Results. 1. The expression of BRCA1 was revealed in all breast cancer samples with mean expression level 36.8 ± 7.6 % and median 37 %. 2. Using the method of Student t-test statistically significant difference in mean value of BRCA1 expression level (p = 0.02) was revealed between ER+ and ER - breast cancer groups (38.0 ± 7.5 % and 32.0 ± 6.3 %, respectively) 3. Comparison of BRCA1 expression level in ER+ and ER - breast cancer groups using Mann - Whitney test also demonstrated statistically significant difference (p = 0.016). 4. These differences in mean value of BRCA1 expression level were especially prominent (p = 0.007) upon the comparison of ER+ and ER- breast cancer groups with BRCA1 expression levels below median (32.4 ± 5.0 % and 26.8 ± 2.9 %, respectively). 5. Comparison of BRCA1 expression levels in ER- breast tumors and the median for all studied breast cancer samples (37 %) demonstrated the correlation of decreased level of BRCA1 expression and negative ER status of the tumor. BRCA1 expression levels below the median were shown for 80 % of breast cancer patients with negative ER status in tumor, and over the median - in 2 0 % of cases, respectively. Conclusion. The results of current studies demonstrated that BRCA1 protein is expressed at different levels in the tumor tissue of all breast cancer patients. Lower level of BRCA1 expression in ER-negative as compared to ER-positive tumors, and established unfavorable prognostic value of ER-negative breast cancer status point to poor prognostic value of lower level of BRCA1 expression.