Flow cytometric analysis of the ERCC1, marker of DNA damage repair, in the tumor specimens embedded into paraffin blocks.

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.

Digoxin is a selective modifier increasing platinum drug anticancer activity.

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.

New Data on Molecular Targets of Tamoxifen Besides Estrogen Receptors, Their Clinical Significancy.

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.

[ERCC1 as a Marker of Ovarian Cancer Resistance to Platinum Drugs].

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.

Analysis of informativeness of immunohistochemical and flow cytometric methods for estrogen receptor α assessment.

Informative capacity analysis of immunohistochemistry (IHC) and flow cytometry (FCM) in the assessment of estrogen receptor α (ERα) expression in breast cancer tissue was performed. Similar frequencies of expression were shown by both methods: 27% of ERα-negative and 73% ERα-positive cases. However, IHC evaluation detected low levels in only 20% of ERα-positive cases, whereas low levels of ERα detected by FCM were 2 times more often (48%). Moreover, FCM revealed positive expression (23-60%) in 33% of IHC ERα-negative cases. Among IHC ER-positive cases, zero ERα expression was detected by FCM in 12.5%. The approaches to minimize errors in routine clinical determination of the estrogen receptor status were proposed.

[Discordance of estrogen receptor status between primary and metastatic breast cancer--possible reasons and prognostic value].

The aim of the review was systematization of the data on discordance in expression of estrogen receptors between primary and metastatic breast cancer, different metastases and repeated analyses of the same tissue. The possible reasons for the phenomenon are discussed. The authors emphasize the need to analyze estrogen receptors in breast cancer metastases, regardless of the receptor status of the primary tumor, for predicting the course of the metastatic disease and providing an adequate treatment of the metastatic tumor in strict accordance with its receptor status during drug therapy. The works cited in the search engine Pub Med to May 2013 were analyzed.

[Expression of estrogen receptors beta and beta1 in tissue of human non-small cell lung cancer].

Comparability of the level and intensity of estrogen receptors beta (ERbeta) expression in non-small cell lung cancer tissue of 32 patients was analyzed by flow cytometry using various antibodies--to the total fraction of ERbeta (clone 14C8) as well to the full-length ERbeta1 isoform (clone EMRO2). The differences in the ER expression indexes detected by anti-ERbeta or anti-ERbeta1 antibodies were revealed in some patients, but it had no influence on average indexes of the ERbeta expression in the patient groups investigated. It was confirmed by the findings on more frequent and more intensive expression of ERbeta in the non-small cell lung cancer tissue of female patients vs. the males irrespective of antibody type - anti-ER/ or anti-ERbeta1. Therefore, in comparative analysis of ERbeta 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 ERbeta, since there are individual differences between the ERbeta expression indexes revealing by various types of antibodies.

[Tamoxifen molecular targets different from estrogen receptors].

Experimental studies showing ever new biological effects of tamoxifen on tumor cells, both expressing and nonexpressing estrogen receptors, are providing a novel conception of the drug, likely well known at present. The review describes tamoxifen targets, whose blocking induces inhibition of tumor cell growth and angiogenesis, stimulation of the programmed cell death (apoptosis, autophagia and necrosis), inhibition of multiple drug resistance mechanism and inhibition of invasion and metastasizing. In all the events, the results of the tamoxifen interaction with the cells are prognostically favourable from the viewpoint of both the inhibition of the tumor growth and metastasizing and the susceptibility to the medicinal therapy, that is considered by some authors as an extremely important addition to the tamoxifen antiestrogenic effect. The strategy of long-term tamoxifen adjuvant therapy of breast cancer with positive status of the estrogen reseptors was developed by Craig V. Jordan as far back as in the seventies of the XXth century, however there are arguments allowing to consider it also useful for the treatment of other tumors. First of all it is the fact described lately in regard to expression of estrogen beta-reseptors in solid tumors of practically all known localization and histological types, that are also the targets of tamoxifen. Apart from estimation of estrogen receptors, it is believed by some authors that molecular and biological choice of patients is necessary with an account of expression of other cell targets of antiestrogen for complete realization of all the aspects of tamoxifen biological activity in long-term adjuvant therapy of malignant tumors of various localization.

[Glutoxime--an inhibitor of multiple drug resistance phenotype associated with Pgp expression].

Interaction of Glutoxime with P-glucoprotein (Pgp), a multiple drug resistance marker, as well as the Glutoxime impact on doxorubicin intracellular accumulation were investigated. It was shown that the Glutoxime effect on the Pgp expressing tumor cells resulted in a decrease of the cell specific fluorescence intensity, conditioned by binding of the monoclonal antibodies to the transport protein. That was evident of Glutoxime competition with the monoclonal antibodies for binding to Pgp and indicative of the modificator interaction with the transport protein. The effect was proved with the use of two cultures of human tumor cells of different histogenesis, i.e., the cells of Jurkat T-cellular leukemia and nonsmall cell lung cancer A549. Inhibition of the Pgp functional activity by Glutoxime was also demonstrateds. The authors suggested that it could be caused by direct competition of the modificator with the antitumor agent for binding to the precipitation sites on Pgp. Glutoxime could be considered as an inhibitor of multiple drug resistance associated with the Pgp function.

Estrogen receptors, antiestrogens, and non-small cell lung cancer.

This review considers data on expression of different types of estrogen receptors (ERα and ERß) in in vitro cultured cells of non-small cell lung cancer and also in human and animal lung tumors. Estrogens are shown to play an important role in genesis and development of non-small cell lung cancer because the estrogen-stimulated cell proliferation as well as antiestrogen-caused inhibition of proliferation occurred only in the cells expressing different types of estrogen receptors. In general, the situation is similar to that observed in breast cancer, but in the cells of non-small cell lung cancer not ERα are expressed in more than half of cases but ERß. Just estrogen receptors ß play the crucial role in inducing cell proliferation in response to estrogens, and ERß is a prognostic marker of a favorable course of non-small cell lung cancer. Data on the interactions between ER and EGFR signaling pathways, as well as on the additive antitumor effect of antiestrogens (tamoxifen and fulvestrant) combined with tyrosine kinase inhibitors (gefitinib, erlotinib, and vandetanib) are considered. The review also includes data on the influence of estrogens on genesis and development of lung cancer in humans and animals and the frequency of ERα and ERß expression in non-small cell lung cancer in tissues from patients of the two sexes. Problems of quantitative determination of α and ß estrogen receptors in the tumor cells are also discussed.

[Parameters of specific antibody interaction with P-gp in T-cell leukemia Jurkat cells].

UNLABELLED: Special features of Pgp expression evaluation by flow cytometry were investigated. Indexes of interaction of FITC-conjugated Becton Dickinson Pharmingen monoclonal antibodies to external Pgp epitope (clone 17F9) were analyzed depending on the cell concentration (400000 to 3000000 cells/ml) and the specific antibody concentration (5, 10 and 20 microl of the market product solution per 300 microl of the cell suspension). RESULTS: 1. Optimal condition of incubation with the antibodies was revealed--after the cell fixation in 4% formaldehyde. 2. Character of the increase of the cell fluorescence average intensity in the suspension totally according to the concentration of the Pgp-specific antibodies did not depend on the number of the cells. 3. Both the absolute value of the average intensity of the cell specific fluorescence as well as cell number out of the isotypic control fluorescence region depended on the ratio of the cell number to monoclonal antibody concentration. CONCLUSION: 1. It was shown that Pgp was practically expressed in all Jurkat cells. 2. By the Pgp expression level, the Jurkat cell culture was sufficiently homogeneous and stable in various passages. 3. Jurkat cells could be used as test culture in estimation of the market antibody activity. 4. For immunofluorescent assay of the Pgp expression in human tumor biopsy specimens, it is necessary to use not less than three concentrations of the specific antibodies, not less than three concentrations of the cells in the suspension as well as concurrent assay of the cell culture characterized previously. In particular, for investigated Pgp monoclonal antibodies, it is possible to use Jurkat cell culture. It allows revealing not only the fact of the Pgp expression but the level of the expression as well, i.e. to estimate severity of multidrug resistance phenotype.

[Estrogen receptor expression in tumors different from breast cancer].

A review of the literature data on expression of estrogen receptor alpha and beta (ERalpha and ERbeta) in tumors different from breast cancer. The results regarding the ERalpha and ERbeta 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 ERalpha and ERbeta 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 ERalpha and ERbeta expression in lung, ovarian, prostate tumor cells and corresponding nonneoplastic tissues are reported. Authors consider necessary to include the ERalpha and ERbeta 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.