Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells

Background: Cell and tissue homeostasis results from the dynamic balance of cell – cell and cell – extracellular component crosstalk that regulates proliferation, differentiation, and apoptosis of cells as well as secretion and activation of soluble factors and/or deposition of extracellular matrix...

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Veröffentlicht in:Experimental Oncology
Datum:2014
Hauptverfasser: Bezdenezhnykh, N., Semesiuk, N., Lykhova, O., Zhylchuk, V., Kudryavets, Y.
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Veröffentlicht: Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України 2014
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Zitieren:Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells / N. Bezdenezhnykh, N. Semesiuk, O. Lykhova, V. Zhylchuk, Y. Kudryavets // Experimental Oncology. — 2014. — Т. 36, № 2. — С. 72-78. — Бібліогр.: 29 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-145344
record_format dspace
spelling Bezdenezhnykh, N.
Semesiuk, N.
Lykhova, O.
Zhylchuk, V.
Kudryavets, Y.
2019-01-20T18:07:05Z
2019-01-20T18:07:05Z
2014
Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells / N. Bezdenezhnykh, N. Semesiuk, O. Lykhova, V. Zhylchuk, Y. Kudryavets // Experimental Oncology. — 2014. — Т. 36, № 2. — С. 72-78. — Бібліогр.: 29 назв. — англ.
1812-9269
https://nasplib.isofts.kiev.ua/handle/123456789/145344
Background: Cell and tissue homeostasis results from the dynamic balance of cell – cell and cell – extracellular component crosstalk that regulates proliferation, differentiation, and apoptosis of cells as well as secretion and activation of soluble factors and/or deposition of extracellular matrix (ECM) components. Aim: The aim of the work was to study the crosstalk between tumor cells and stromal cell components using noncontact co-cultivation in vitro system. Materials and Methods: Human and rat breast cancer (BC) cell lines, normal human fibroblasts (NHF) and endothelial cells, and aspirates of bone marrow (BM) of BC patients with different clinical course of the disease (groups “Remission” (BM-R) and “Progression” (BM-P)) were used in noncontact co-cultivation system in vitro. The cell growth, expression of epithelial-mesenchymal transition (EMT) and tumor stem cell markers (E-cadherin, vimentin, CD44), Ki-67, p21 and Slug were investigated using immunocytochemical analysis. Results: Analysis of expression of E- and N-cadherin, vimentin and Slug in BC cells has shown that T-47D and MRS-T5 cells possess mesenchymal phenotype, while MCF-7 and MRS cells possess mostly epithelial phenotype with a part of cells with mesenchymal patterns. Upon noncontact co-cultivation of fibroblasts with Т-47D or MRS-Т5 cells, BC cells acquired higher proliferative activity compared to the control cells (р < 0.05) or MCF-7 and MRS cells co-cultivated with fibroblasts. Upon noncontact co-cultivation of Т-47D cells with normal fibroblasts and BM cells from BC patients from group “Progression” there were observed increased quantity of CD44+ Т-47D cells (by 26%), decreased quantity of Е-cadherin+ Т-47D cells, and appearance of vimentin-positive cells. In co-cultivation variant Т-47D + NHF + BM-R (“Remission“) the quantity of CD44+ Т-47D cells significantly decreased (р < 0.005) and E-cadherin expression remained unaltered compared to control cells. At the same time, in NHF cell population (co-cultivation variant Т-47D + NHF + BM-P) there was detected significant increase of quantity of р21+-cells (р < 0.005), cytoplasmic localization of p21, and nuclear localization of Slug. Expression of vimentin did not alter in any variant of co-cultivation. Conclusion: The new integration cell system for investigation of the mechanisms of interaction between tumor cells and the tumor microenvironment in vitro was developed. The significant changes in proliferative activity of TC dependently on its ­ЕМT-status were detected after their interaction with fibroblasts and endothelial cells in noncontact co-cultivation system. BM cells of BC patients had different modifying influence on TC dependent on clinical BC course. The activation of ЕМT program was revealed in TC upon noncontact co-cultivation with BM cells of BC patients with progression of the disease. Key Words: breast cancer, epithelial-mesenchymal transition, microenvironment, bone marrow, co-cultivation.
This study was supported with the grant NAS of Ukraine for Young Scientists “Development of new integration cell system for investigation of the mechanisms of interaction TC with microenvironment in vitro”, № 2.2.5.383 from 01.07.2013.
en
Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України
Experimental Oncology
Original contributions
Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
spellingShingle Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
Bezdenezhnykh, N.
Semesiuk, N.
Lykhova, O.
Zhylchuk, V.
Kudryavets, Y.
Original contributions
title_short Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
title_full Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
title_fullStr Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
title_full_unstemmed Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
title_sort impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells
author Bezdenezhnykh, N.
Semesiuk, N.
Lykhova, O.
Zhylchuk, V.
Kudryavets, Y.
author_facet Bezdenezhnykh, N.
Semesiuk, N.
Lykhova, O.
Zhylchuk, V.
Kudryavets, Y.
topic Original contributions
topic_facet Original contributions
publishDate 2014
language English
container_title Experimental Oncology
publisher Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України
format Article
description Background: Cell and tissue homeostasis results from the dynamic balance of cell – cell and cell – extracellular component crosstalk that regulates proliferation, differentiation, and apoptosis of cells as well as secretion and activation of soluble factors and/or deposition of extracellular matrix (ECM) components. Aim: The aim of the work was to study the crosstalk between tumor cells and stromal cell components using noncontact co-cultivation in vitro system. Materials and Methods: Human and rat breast cancer (BC) cell lines, normal human fibroblasts (NHF) and endothelial cells, and aspirates of bone marrow (BM) of BC patients with different clinical course of the disease (groups “Remission” (BM-R) and “Progression” (BM-P)) were used in noncontact co-cultivation system in vitro. The cell growth, expression of epithelial-mesenchymal transition (EMT) and tumor stem cell markers (E-cadherin, vimentin, CD44), Ki-67, p21 and Slug were investigated using immunocytochemical analysis. Results: Analysis of expression of E- and N-cadherin, vimentin and Slug in BC cells has shown that T-47D and MRS-T5 cells possess mesenchymal phenotype, while MCF-7 and MRS cells possess mostly epithelial phenotype with a part of cells with mesenchymal patterns. Upon noncontact co-cultivation of fibroblasts with Т-47D or MRS-Т5 cells, BC cells acquired higher proliferative activity compared to the control cells (р < 0.05) or MCF-7 and MRS cells co-cultivated with fibroblasts. Upon noncontact co-cultivation of Т-47D cells with normal fibroblasts and BM cells from BC patients from group “Progression” there were observed increased quantity of CD44+ Т-47D cells (by 26%), decreased quantity of Е-cadherin+ Т-47D cells, and appearance of vimentin-positive cells. In co-cultivation variant Т-47D + NHF + BM-R (“Remission“) the quantity of CD44+ Т-47D cells significantly decreased (р < 0.005) and E-cadherin expression remained unaltered compared to control cells. At the same time, in NHF cell population (co-cultivation variant Т-47D + NHF + BM-P) there was detected significant increase of quantity of р21+-cells (р < 0.005), cytoplasmic localization of p21, and nuclear localization of Slug. Expression of vimentin did not alter in any variant of co-cultivation. Conclusion: The new integration cell system for investigation of the mechanisms of interaction between tumor cells and the tumor microenvironment in vitro was developed. The significant changes in proliferative activity of TC dependently on its ­ЕМT-status were detected after their interaction with fibroblasts and endothelial cells in noncontact co-cultivation system. BM cells of BC patients had different modifying influence on TC dependent on clinical BC course. The activation of ЕМT program was revealed in TC upon noncontact co-cultivation with BM cells of BC patients with progression of the disease. Key Words: breast cancer, epithelial-mesenchymal transition, microenvironment, bone marrow, co-cultivation.
issn 1812-9269
url https://nasplib.isofts.kiev.ua/handle/123456789/145344
citation_txt Impact of stromal cell components of tumor microenvironment on epithelial-mesenchymal transition in breast cancer cells / N. Bezdenezhnykh, N. Semesiuk, O. Lykhova, V. Zhylchuk, Y. Kudryavets // Experimental Oncology. — 2014. — Т. 36, № 2. — С. 72-78. — Бібліогр.: 29 назв. — англ.
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fulltext 72 Experimental Oncology 36, 72–78, 2014 (June) IMPACT OF STROMAL CELL COMPONENTS OF TUMOR MICROENVIRONMENT ON EPITHELIAL-MESENCHYMAL TRANSITION IN BREAST CANCER CELLS N. Bezdenezhnykh1,*, N. Semesiuk1, O. Lykhova1, V. Zhylchuk2,3, Y. Kudryavets1 1R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Kyiv 03022, Ukraine 2Rivne Region Oncology Hospital, Rivne 33001, Ukraine 3Danylo Halytsky Lviv National Medical University, Lviv 79010, Ukraine Background: Cell and tissue homeostasis results from the dynamic balance of cell – cell and cell – extracellular component crosstalk that regulates proliferation, differentiation, and apoptosis of cells as well as secretion and activation of soluble factors and/or deposi- tion of extracellular matrix (ECM) components. Aim: The aim of the work was to study the crosstalk between tumor cells and stromal cell components using noncontact co-cultivation in vitro system. Materials and Methods: Human and rat breast cancer (BC) cell lines, normal human fibroblasts (NHF) and endothelial cells, and aspirates of bone marrow (BM) of BC patients with different clinical course of the disease (groups “Remission” (BM-R) and “Progression” (BM-P)) were used in noncontact co-cultivation system in vitro. The cell growth, expression of epithelial-mesenchymal transition (EMT) and tumor stem cell markers (E-cadherin, vimentin, CD44), Ki-67, p21 and Slug were investigated using immunocytochemical analysis. Results: Analysis of expression of E- and N-cadherin, vimentin and Slug in BC cells has shown that T-47D and MRS-T5 cells possess mesenchymal phenotype, while MCF-7 and MRS cells possess mostly epithelial phenotype with a part of cells with mesenchymal patterns. Upon noncontact co-cultivation of fibroblasts with Т-47D or MRS-Т5 cells, BC cells acquired higher proliferative activity compared to the control cells (р < 0.05) or MCF-7 and MRS cells co-cultivated with fibroblasts. Upon noncontact co-cultivation of Т-47D cells with normal fibroblasts and BM cells from BC patients from group “Progression” there were observed increased quantity of CD44+ Т-47D cells (by 26%), decreased quantity of Е-cadherin+ Т-47D cells, and appearance of vimentin-positive cells. In co-cultivation variant Т-47D + NHF + BM-R (“Remis- sion“) the quantity of CD44+ Т-47D cells significantly decreased (р < 0.005) and E-cadherin expression remained unaltered compared to control cells. At the same time, in NHF cell population (co-cultivation variant Т-47D + NHF + BM-P) there was detected sig- nificant increase of quantity of р21+-cells (р < 0.005), cytoplasmic localization of p21, and nuclear localization of Slug. Expression of vimentin did not alter in any variant of co-cultivation. Conclusion: The new integration cell system for investigation of the mechanisms of interaction between tumor cells and the tumor microenvironment in vitro was developed. The significant changes in proliferative activity of TC dependently on its ЕМT-status were detected after their interaction with fibroblasts and endothelial cells in noncontact co-cultivation system. BM cells of BC patients had different modifying influence on TC dependent on clinical BC course. The activa- tion of ЕМT program was revealed in TC upon noncontact co-cultivation with BM cells of BC patients with progression of the disease. Key Words: breast cancer, epithelial-mesenchymal transition, microenvironment, bone marrow, co-cultivation. In most cases the cancer-related mortality is caused by haematogenous spread of cancer cells into distant organs and their subsequent growth to overt metastases. After surgical removal of the primary tumor, minimal re- sidual disease (MRD) is defined as the presence of tumor cells (TC) that are not detectable by the current routine diagnostic procedures used for tumor staging in cancer patients, but become apparent after a period of time [1]. The crosstalk between tumor and cells of its microenviron- ment crucially determines the fate of tumor progression. The stroma is a very heterogeneous milieu including vari- ous cell types and adhesion molecules, both contributing to the functional activity and structural support of the tumor microenvironment (TME) [2]. S. Paget laid the foundations of the TME research area by formulating the seed and soil theory. The tumor is directed into one or several pos- sible molecular evolution pathways by signals originating in native and/or modified microenvironmental factors. Many of these pathways may lead to metastasis. The TME has some characteristics: 1) the molecular composi- tion of the TME is established by TC and by resident/ infil trating non-tumor cells; 2) intercellular interactions between TC and components of their microenvironment are crucial in determining cancer progression; 3) tumor — microenvironment interactions are bidirectional; 4) certain tumor — microenvironment interactions may initiate tumor progression ; 5) microenvironmental factors play opposing roles in tumor progression by either promoting or alterna- tively antagonizing this process [3]. The TME was recognized as the product of a de- veloping crosstalk between different cells types: endo- thelial cells, carcinoma-associated fibroblasts (CAFs), adipocytes, mesenchymal cells, mesenchymal stem cells (MSCs; bone marrow derived — (BM-MSCs), or carcino- ma-associated (CA-MSCs)), and cells from the immune and inflammatory systems (tumor-associated macro- phages (TAM), regulatory T cells, etc.). The stromal cells interact not only with TC but also with each other. TC in- duce changes in fibroblasts, which contact with them [4], transforming them into myofibroblasts, which activate program of epithelial-mesenchymal transition (EMT) in TC resulting in the domination of mesenchymal features Submitted: May 8, 2014. *Correspondence: E-mail: beznalia@mail.ru Abbreviations used: BC — breast cancer; BM — bone marrow; ECM — extracellular matrix; EMT — epithelial-mesenchymal transi- tion; MC — mononuclear cells; MET — mesenchymal-epithelial transition; MRD — minimal residual disease; TAM — tumor-associ- ated macrophage; TC — tumor cells; TME — tumor microenviron- ment; TNF — tumor necrosis factor. Exp Oncol 2014 36, 2, 72–78 Experimental Oncology 36, 72–78, 2014 (June) 73 and development of highly metastatic phenotype [5]. All these processes take place with involvement of soluble (humoral) factors of microenvironment (cytokines, growth factors, etc.), which, in turn, activate other links of interac- tion, involved in “malignant transition”, in particular, tran- scriptional factors. In the result of this, epithelial cells lost the capacity to form dense intercellular contacts, their adhesive properties decrease while capacity for inva- sion and migration develop. However, when such cells achieve their “destination point”, the inverse process takes place — mesenchymal-epithelial transition (MET), during which they again acquire epithelial phenotype with increased adhesion that gives opportunity to them to fas- ten onto the substrate and to give growth to se condary metastatic focus [6]. Thus, a major TAM-derived inflam- matory cytokine shown to be highly expressed in breast carcinomas is tumor necrosis factor alpha (TNF-α) which is a multifactorial cytokine. TNF-α activity varies under different physiological conditions and in a cell-type- dependent manner contributes to a sense of ambiguity regarding its antitumor effects. Indeed, the permanent expression of TNF-α in breast tumors actually supports tumor growth and plays a role in the metastatic behavior of breast carcinomas [7]. Furthermore, in BM of breast cancer (BC) patients with advanced cancer significantly higher TNF-α concentration was detected [8]. Therefore, the further study of intercellular interaction and cell trans- differentiation may reveal new targets in antimetastatic therapy. It is well known that certain organs and tissues are typical as dominant sites of metastasis for many types of tumor. For example, bone marrow (BM) and bones often become such distant sites in BC. Today is well known the important role of stromal cells, in particular fibroblasts, as elements of TME, in control of their phe- notype and biological behavior [9]. However, the role of BM cells as components of TME is poorly understood. Therefore, th e determination of influence of BM cells, especially in comparative aspect with fibroblast elements, on the phenotypic conversion and proliferative activity of cells of BC at their co-cultivation, is of special interest. In routine practice for in vitro research of compounds of different nature (antitumor drugs, cytotoxic factors) isolated cell cultures (primary cell cultures and stable cell lines) are used. Experimental systems in vitro with use of human cell lines represent important instrument for estimation of the level and mechanisms of toxicity of antitumor drugs with the aim of precise definition of their possible antitumor action in vivo. The main disadvantage of such in vitro system is an absence of numerous components of interaction, which exist in vivo. The principally new approach for determination of intercellular interaction in vitro has been developed by A.P. Li and co-authors [10] who created a system of integrated discrete cultures of normal cells of diffe- rent histogenesis and BC cells for the study of simulta- neous combined toxic action of drugs on the TC-targets and on the normal cells of organism (liver, kidneys, lungs, vascular endothelium, etc.). The same scheme with some modification has been developed by us for testing the toxicity of chemical compounds, in par- ticular, heavy metal salts, in vitro, so-called multi-organ system of toxicity (MOST) [11]. For investigation of cel- lular interaction in progression of disease, we have developed in this work new cellular system with use of primary and stable cell lines of different genesis: hu- man and rat BC TC, normal human fibroblasts (NHF) and normal rat fibroblasts (NRF), normal porcine endothelial cells (PAE), cells from BM aspirates from BC patients with different disease stage. The aim of the work was to study in vitro the crosstalk between TC and stromal cell components using noncon- tact co-cultivation in vitro system. MATERIALS AND METHODS Clinical materials. In co-cultivation in vitro system, mononuclear cells (MC) isolated from BM of BC pa- tients with II and III stages of the disease (n = 6), were used. BC patients were cured in Rivne Regional On- cological Hospital (Rivne, Ukraine). The patients were informed about the survey and provided written consent for participation in the research. The study was carried out with approval of the local Ethics Committee (R.E. Ka- vetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine). After conducted treatment (radical surgical inter- vention and adjuvant chemotherapy) BC patients have been distributed into 2 groups: “Progression” (n = 3) and “Remission” (n = 3), at the basis of their clinical state, presence of TC in BM and high level of tumor-associated cytokines in plasma of BM and peripheral blood [12, 13]. The BM aspirates (3–4 ml) were taken from sternum with an incision in the skin to avoid contamination with epithelial cells. BM samples were obtained from BC pa- tients prior to therapy. MC were isolated by Ficoll-Hypaque density gradient LSM 1077 (PAA, Austria) centrifugation at 1,500 rpm for 20 min. MC were washed three times with RPMI-1640 and were cryopreserved (3–5•106 cells per vial). Cell lines. In our co-cultivation study the following cell lines were used: NHF, NRF of Wistar rats, normal porcine endothelial cells (PAE), human BC cell lines — T-47D and MCF-7 and their sublines modified by long- term action of interferon (IFN) (MCF-7 + IFN and T-47D + IFN), rat mammary carcinoma — MRS [14, 15], which are characterized by domination in population of low tumorigenic cells with epithelial phenotype as well as highly tumorigenic subline MRS-T5, which is cha- racterized by the presence of cells of only me senchymal phenotype. All cell lines have been obtained from Bank of Cell Lines from Human and Animal Tissues of R.E. Ka- vetsky Institute of Experimental Pathology, Oncology and Radiobiology of National Academy of Sciences of Ukraine (Kyiv, Ukraine). The modeling system of noncontact cell co-cul- tivation. The cells of different type which were cultured separately, serve as control (Fig. 1, a). For co-cultivation experiment, the wells were combined with each other via specially made channels in the wall of wells in such a way 74 Experimental Oncology 36, 72–78, 2014 (June) that interaction of cells through their nutrient medium could occur (Fig. 1, b). NHF TC BM cells NHF TC BM cells Stromal cells TC Stromal cells TC a b Fig. 1. Scheme of noncontact co-cultivation in vitro: a — control wells — isolated; b — wells with noncontact co-cultivation Cells were cultivated in plastic glassware (“ТРР”, Italy) in DMEM medium (“PAA”, Austria), which contained 2 mM of L-glutamine and NaHCO3 with 10% of FBS (“PAA”, Austria) in humidified atmosphere at 37 °С and 5% CO2. Quantity of cells after their co-cultivation has been determined by staining with crystal violet (“Sigma”, USA) with further registration of optical density of well content using multiwell spectrometer (Labsystems Multiskan PLUS, Finland) [16]. Immunocytochemical analysis. The slides of cyto- spins were fixed in methanol + acetone (1:1) solution for 2 h at −20 °С, and then incubated with 1% BSA solution for 20 min. For immunocytochemical analysis, the following monoclonal antibodies have been applied: anti-E-cad- herin (Thermo Scientific, UK), anti-CD325 ( N-Cadherin) (BioLegend, USA), anti-vimentin (Diagnostic BioSys- tems, USA), anti-CD44 (Diagnostic BioSystems, USA), Slug (GeneTex, USA), р21/waf1 (NeoMarkers, USA), Ki-67 (Thermo Scientific, UK). Primary antibodies were used according to the instructions of manufacturers. For visualization, Poly Vue system (Thermo Scientific, UK) was used. The slides were also stained with Mayer’s hema- toxylin (“Sigma”, USA) and examined using microscope AxioVert (“Сarl Zeiss”, Germany) with ×320 magnification. Data were analyzed by calculation of positive (+) cells using classical H-score method: S = 1В•A + 2В•B + 3В•C, where S — H-score index, which value lies within the limits from 0 (no expression) to 300 (intensive ex- pression in 100% of cells); А — percentage of poorly stained cells; В — percentage of moderately stained cells; C — percen tage of strongly stained cells. Statistics. Statistical processing of obtained re- sults has been carried out using mathematical program STATISTIСA 6.0. Significance of differences between mean values has been conducted with use of Stu- dent’s t-criterion. RESULTS AND DISCUSSION First of all, the expression of ЕМT markers (E- and N-cadherin, vimentin and Slug) was analyzed in TC which were cultured separately as a control and later were used in noncontact co-cultivation system. It was found that the mesenchymal antigen expression profile was the most typical for cells of T-47D and MRS-T5 lines. MCF-7 and MRS cell lines are characterized by the prevalence of cells with epithelial phenotype with the presence of cells with mesenchymal features (Table). Then, TC and stromal elements (fibroblasts, endo- thelial cells) were co-cultivated in vitro using the system described above. In the case of co-cultivation of TC and fibroblasts, the proliferation of fibroblasts was close to that of control cells but the quantity of TC varied de- pendently on domination of epithelial or mesenchymal phenotype of these cells. In particular, the quantity of TC with domination of mesenchymal features (Т-47D, MRS-Т5 cells) in noncontact co-cultivation with fibroblasts was more prominently increased compared to control cells (р < 0.05), than quantity of TC with prevalence of epithelial phenotype (MCF-7, MRS) (Fig. 2). In the case of co-culti- vation of fibroblasts (RNF) with rat TC with me senchymal or epithelial features (variant of co-cultivation MRS + RNF + MRS-T5) significant inhibition of MRS-T5 cells with me senchymal phenotype in presence of epithelial MRS cells was detected (see Fig. 2). So, the cells with more differentiated epithelial phenotype may significantly repress growth potential of cells with mesenchymal phe- notype [17]. 0 20 40 60 80 100 120 140 160 180 200 NHF1 T-47D NHF2 MCF-7 Variant of co-cultivation Vi ab le c el ls , % 0 20 40 60 80 100 120 140 160 NR F M RS NR F T5 M RS T5 M RS NR F T5 Variant of co-cultivation Vi ab le c el ls , % a b Fig. 2. Quantity of viable NHF and human TC (a) and NRF and rat TC (b) upon their combined noncontact co-cultivation. OY axis rep- resents the percent of viable cells compared to respective control cells cultured in separate wells (taken as 100% of viable cells) It is well known that tumor and stromal cells in microen- vironment can interact and crosstalk between them might be bidirectional. Tumor angiogenesis is a prerequisite for tumor progression and metastasis. It is a complex process Table. EMT marker expression in human BC cell lines Antigens E-cadherin N-cadherin Slug TC T-47D MCF-7 MRS T5 T-47D MCF-7 MRS T5 T-47D MCF-7 MRS T5E M E M E M Scores (H-score system) 98±11 126±7 270±21 22±9 39±4 81±11 53±3 72±8 221±28 174±16 136 ±21 54±10 156±26 224±32 269±11 Experimental Oncology 36, 72–78, 2014 (June) 75 that requires cooperative reciprocal interaction of tumor and endothelial cells and involves soluble and cellular components. This requires a coordinated expression of proangiogenic factors and suppression of antiangio- genic factors, which leads to endothelial cell proliferation, migration and vessel formation. M. Buess et al. [18] sug- gest that the interaction of endothelial cells with TC that express the CD44+/CD24− signature (indicating a low pro- liferative potential) might explain association of the CD44+/ CD24− signature with highly proliferative tumors that have an unfavorable prognosis. The differences in proliferative activities of human BC cells (control cells and IFN-modified cells) in co- cultivation with cellular TME components (fibroblasts and endothelial cells) were identified. For this study, we used the following design of noncontact cultivation cell system: • set 1: 1) MCF-7/MCF-7 (IFN modified) + NHF; 2) MCF-7/MCF-7 (IFN modified) + PAE; • set 2: 1) T-47D/T-47D (IFN modified) + NHF; 2) T-47D/T-47D (IFN modified) + PAE. So, we obtained the following results: using MCF-7 cell line and MCF-7 + IFN subline, we observed an inhibition the BC proliferation independently on vari- ant of stromal cells (NHF or PAE). This inhibition was more significant in the case with MCF-7 + IFN cells (20–25%) compared with control cells (Fig. 3). 0 20 40 60 80 100 120 140 160 MCF-7 PAE MCF-7 NHF Variant of co-cultivation Vi ab le c el ls , % 0 20 40 60 80 100 120 140 MCF-7 + IFN PAE MCF-7 + ІFN NHF Variant of co-cultivation Vi ab le c el ls , % a b Fig. 3. Proliferative activities of MCF-7 (a) and IFN-modified MCF-7 (b) cells in noncontact co-cultivation system with NHF and PAE cells. OY axis represents the percent of viable cells compared to respective control cells cultured in separate wells (taken as 100% of viable cells) Interestingly, proliferative activity of NHF and PAE was changed, too: quantities of stromal elements were higher (about 10% in case co-cultivation with PAE and 3–20% in case co-cultivation with NHF). To explain this fact we will investigate the phenotype of these cells. It is known that tumor can induce phenotypic changes associated with transcriptional reprogramming of en- dothelial cells, which can be detected by expression profiling: production of growth factors by TC that in- duce endothelial cells to express specific ligands and their cognate receptors coordinately [19]. In another set of our study, the proliferative activi- ties of BC and stromal cells were different indicating a significant interplay of cells. In particular, cultivation of T-47D cells with NHF or PAE as well as cultivation of IFN-modified T-47D cells with NHF or PAE resulted in increased proliferation of both cell types (Fig. 4). 0 50 100 150 200 250 T-47D PAE T-47D NHF Variant of co-cultivation Vi ab le c el ls , % 0 50 100 150 200 250 T-47D + IFN PAE T-47D + ІFN NHF Variant of co-cultivation Vi ab le c el ls , % a b Fig. 4. Proliferative activities of T-47D (a) and IFN-modified T-47D (b) cells in noncontact co-cultivation system with NHF and PAE cells. OY axis represents the percent of viable cells compared to respective control cells cultured in separate wells (taken as 100% of viable cells) BM is considered to be depot for TC and is di- rect participant of MRD [20–22]. So, the influence of BM components to TC as an additional factor was studied. Cells from aspirates of BM of BC patients were used in new integrated system in vitro. The significant changes of phenotypic features of both tumor and normal cells in noncontact co-cultivation system with addition of BM cells were detected (Fig. 5): variant of co-cultivation Т-47D + NHF + BM (“Progression”) and Т-47D + NHF + BM (“Remission”). To investigate changes at the cellular and molecular level we decided to analyze the expression of some protein markers associated with EMT. The investigation of expression of cell cycle regulator p21 has shown that the quantity of p21-positive T-47D cells as well as intracellular localization of p21 remained unchanged in different variants of co-cultivation (see Fig. 5, a). The subcellular localization of p21 is very 76 Experimental Oncology 36, 72–78, 2014 (June) important because this protein performs opposite functions in nucleus and cytoplasm. In particular, if p21 localizes in nucleus, it acts as regulator of cell cycle through inactivation of transcriptional factors Е2F1, c-Myc, STAT3 [23], as well as inhibitor of replica- tion due to oppression of subunit of DNA-polymerase of δ-protein PCNА. When p21 localizes in cytoplasm, it performs formation of stress-fibrin and focal contacts that assists the migration of cells. Moreover, p21 in cy- toplasm demonstrates antiapoptotic functions through decrease of proapoptotic kinases activity (ASK-1, JNK, p38) and inhibition of proxapase-2. 0 50 100 150 200 250 300 350 cytoplasmic nucleus Localization of p21 Ex pr es si on o f р 21 , s co re s Т-47D isolated Т-47D + NHF + BM (“Progression”) Т-47D + NHF + BM (“Remission”) 0 50 100 150 200 250 300 350 CD44 Ki-67 Vimentin E-cadherin Protein markers Ex pr es si on o f p ro te in s, s co re s * a b ** *** Fig. 5. Expression of р21 (a), and CD44, Ki-67, vimentin, Е-cadherin (b) in T-47D cells in noncontact co-cultivation sys- tem in vitro with NHF and BM cells. *p ≤ 0.005; **p ≤ 0.05; ***p; evaluation by Н-Score, scores Next, we investigated CD44 expression. CD44 is ad- hesion molecule, which plays important role in inter- action “tumor — microenvironment” and is involved in processes of migration and invasion of TC. More- over, CD44 is used as marker of progression and metastasis at different types of cancer, in particular, BC. TCs with phenotype CD44+CD24− are considered as cancer stem cells (CSC). In our study, the quantity of CD44-positive (CD44+) Т-47D cells were increased by 26% at their co-cultivation with BM cells (variant Т-47D + NHF + BM (“Progression”)) compared with control of cells in isolated wells. Interestingly, the quan- tity of CD44+-cells was significantly decreased in vari- ant of co-cultivation Т-47D + NHF + BM (“Remission”) compared to isolated control (р < 0.005) and com- pared to these in co-cultivation variant with BM cells of patients from “Progression” group (р < 0.005) (see Fig. 5, b). The next step was to study of E-cadherin expres- sion in T-47D cells in different variants of co-cultivation: the quantity of E-cadherin+ T-47D cells in co-cultivation variant Т-47D + NHF + BM (“Progression”) was de- creased by 1.8 times compared to isolated control and was not changed compared to these in co-cultivation variant Т-47D + NHF + BM (“Remission”) (see Fig. 5, b). E-cadherin is a marker of epithelial phenotype. Loss of the E-cadherin molecule is thought to enable metas- tasis by disrupting intercellular contacts — an early step in metastatic dissemination and prominently associated with tumor invasiveness and poor prognosis [24]. Vimentin is a protein of cytoskeleton normally ex- pressed in cells of mesenchymal origin [25]. It is used widely as a marker of the EMT and can induces changes in cell shape, motility, and adhesion during of this pro- cess [26]. Its expression was investigated in T-47D cells which were included in different variants of co-cultivation. Thus, this protein was not detected in control T-47D cells (isolated) as well as in T-47D cells of variant co-cultivation Т-47D + NHF + BM (“Remission”), but the expression of vimentin was observed in T-47D cells in co-cultivation with NHF and BM cells (“Progression”) (see Fig. 5, b). Such changes of phenotypic profile of T-47D cells are the results of their co-cultivation with components of microenvironment (NHF and BM cells of BC patients with different BC course). These indicate the sig- nificant influence of BM cells and humoral factors, which they produce, on the BC cells which depended on the state of tumor process in BC patients (progres- sion or remission of the disease). The phenotypic profile of TC in co-cultivation variant with BM cells of BC pa- tients of “Remission” group did not differ from control cells. But the activation of ЕМT program were observed in TC in co-cultivation variant with BM cells of BC pa- tients of “Progression” group, which was associated with obtaining of more aggressive features by cells and possible increase of their metastatic potential. The phenotypic profile of NHF after their co-cul- tivation with T-47D and BM cells of BC patients with different courses of tumor process was changed too. The expression of vimentin, p21 and Slug was inves- tigated. So, changes of expression of vimentin were not detected in NHF in any variants of co-cultivation. Changes of expression of transcription factor of me- senchymal cells Slug were detected. In co-cultivation NHF with TC and BM cells of BC patients Slug was relo- calized to the nucleus of NHF (p < 0.002). Interestingly, the presence of p21 protein only in cytoplasm of NHF was observed (Fig. 6). The quantity of p21+ NHF cells was significantly increased upon co-cultivation with BM cells of BC patients (“Progression” group) com- pared with control (р < 0.005). These results in some way explain the well- known data about differentiation of fibroblasts into myofibroblasts in co-cultivation with TC [27]. Stro- mal elements, which include also fibroblasts, may be inductors of transcription factors in TC that support the domination of mesenchymal features in cells. Such modulations of intracellular processes occur through the secretion by cells of series of factors (cytokines, factors of growth, etc.). One of such fac- Experimental Oncology 36, 72–78, 2014 (June) 77 tors may be epi thelial-stromal interaction 1 (EPST1). EPST1 has been identified as interferon response gene exactly in co-cultivation of BC cells with stromal fibroblasts [28, 29]. Its expression was increased in postsurgical tumor material of BC patients in con- trast to control mammary gland tissues. The highest intensity of expression of EPST1 was determined exactly in regions of tumor, which closely contacted with stroma [29]. 0 50 100 150 200 250 300 350 p2 cytoplasmic SLUG cytoplasmic SLUG nucleus Vimentin Protein markers Ex pr es si on o f p ro te in s, s co re s NHF isolated NHF + Т-47D + BM (“Progression”) NHF + Т-47D + BM (“Remission”) * *** **** **** ** Fig. 6. Expression of р21 (a), Slug and vimentin in NHF cells upon noncontact co-cultivation with TC and BM cells from BC patients. *p < 0.005; **p < 0.005; ***p < 0.02; ****p < 0.002; evaluation by Н-Score, scores In conclusion, the new integration cell system for investigation of the mechanisms of interaction between TC and TME in vitro was developed. The significant changes in proliferative activity of TC dependently on its ЕМT-status were detected after their interaction with fibroblasts and endothelial cells in noncontact co-cultivation system. 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