Establishment and characterization of the cell-line of a human edometrial adenoacanthoma

Kisspeptin Regulates Cell Invasion and Migration in Endometrial Cancer

Kisspeptin (a product of the KISS1 gene and its receptor) plays an important role in obstetrics, gynecology, and cancer cell metastasis and behavior. In hypothalamic-pituitary-gonadal axis and placentation, Kisspeptin/Kisspeptin receptor affects hormone release and represses trophoblast invasion into maternal deciduae. Endometrial cancer is one of the common gynecological cancers and is usually accompanied by metastasis, the risk factor that causes death. Recently, research has demonstrated that Kisspeptin/Kisspeptin receptor expression in aggressive-stage endometrial cancer tissues. However, the detailed mechanism of Kisspeptin/Kisspeptin receptor in regulating the motility of endometrial cancers is not well understood. In this study, we use endometrial cancer cell lines RL95-2, Ishikawa, HEC-1-A, and HEC-1-B as models to explore the molecular mechanism of Kisspeptin on cell motility. First, we discovered that Kisspeptin/Kisspeptin receptor was expressed in endometrial cancer cells, and Kisspeptin significantly regulated the migration and invasion of endometrial cancer cells. Furthermore, we explored the epithelial-mesenchymal transition marker expression and the underlying signals were regulated on Kisspeptin treatment. In conclusion, we suggest that Kisspeptin regulates endometrial cancer cell motility via FAK and Src expression and the ERK1/2, N-Cadherin, E-Cadherin, beta-Catenin, Twist, and matrix metalloproteinase signaling pathways. We expect these molecules could be candidates for the development of new approaches and therapeutic targets.

Expression of cell adhesion molecule 1 in human and murine endometrial glandular cells and its increase during the proliferative phase by estrogen and cell density

AIMS

Cell adhesion molecule 1 (CADM1) mediates interepithelial adhesion and is upregulated in crowded epithelial monolayers. This study aimed to examine CADM1 expression in the human endometrium of proliferative and secretory phases, and its transcriptional regulation in terms of estrogen stimuli and higher cellularity.

MAIN METHODS

CADM1 immunohistochemistry was conducted on endometrial tissues from women in their 40s and adult mice subcutaneously injected with estradiol following ovariectomy. Dual-luciferase reporter assays were conducted using human endometrial HEC-50B and HEC-1B cells and reporter plasmids harboring the human CADM1 3.4-kb promoter and its deleted and mutated forms. Cells were transfected with estrogen receptor α cDNA and reporter plasmids, and treated with estradiol before luciferase activity measurement.

KEY FINDINGS

Immunohistochemistry revealed that CADM1 was clearly expressed on the lateral membranes of the simple columnar glandular cells in the proliferative phase, but not in the secretory phase, from both women and the mouse model. The glandular cell density increased two-fold in the proliferative phase. Reporter assays identified three Sp1-binding sites as estradiol-responsive elements in the proximal region (from -223 to -84) of the transcription start site (+1) in HEC-50B cells. When the cell culture was started at eight-fold higher cell density, the CADM1 3.4-kb promoter was transactivated at a two-fold higher level in HEC-50B cells. This cell density effect was not detected for the CADM1 2.3-kb or 1.6-kb promoter.

SIGNIFICANCE

Two (proximal and distal) promoter regions are suggested to function additively to transactivate CADM1 in endometrial glandular cells that crowd in the proliferative phase.

Effect of p53 gene transfection on vascular endothelial growth factor expression in endometrial cancer cells

It has been reported that tumor suppressor gene p53 regulates vascular endothelial growth factor (VEGF) expression, but the relation between them in endometrial carcinoma remains unclear. We investigated VEGF expression in 11 endometrial carcinoma cell lines and the effect of p53 gene transfection on VEGF expression in the p53-mutated endometrial carcinoma cell line, HEC-50B. Immunoblotting for detecting VEGF, p53, and beta-actin was performed. Wild type p53 gene was transfected using the SuperFect method. The mean VEGF value of 0.8 +/- 0.3 (n = 6) in p53 wild-type group was significantly lower than the 1.6 +/- 0.8 (n = 5) that was found in the p53 mutant group (P < 0.05). Levels of VEGF in the culture medium were measured by enzyme immunoassay (EIA). VEGF levels in the p53 gene-transfected HEC-50B cells and the conditioned medium were decreased at 48 h after p53 gene transfection. VEGF expression was downregulated by p53 in endometrial carcinoma cells.

VEGF expression and its reguration by p53 gene transfection in endometrial carcinoma cells

Vascular endothelial growth factor (VEGF) that activates endothelial cell growth induces angiogenesis, which is indispensable to tumor igenesis and tumor progression. On the other hand, tumor suppressor gene p53 has been considered to regulate VEGF expression, but the detailed relationship between them remains unclear. In this study, we aimed to study VEGF expression in endometrial carcinoma cells and the effect of p53 gene transfection on VEGF expression using p53-mutated endometrial carcinoma cell line, HEC-50B. Immunoblotting for detecting VEGF protein, p53 protein and beta-actin was performed using 11 endometrial carcinoma cell lines. Levels of VEGF in the cultured media were measured by Enzyme immunoassay(EIA). Transfection of wild p53 gene was carried out by SuperFect method in HEC-50B cells, which had mutant p53 gene and did not express p53 protein. The results of immunoblotting were analyzed by NIH image and expressed as values. The results of EIA were expressed as the relative value. The VEGF value was 0.8 +/- 0.3 (n = 6) in p53-wild group, whereas in p53-mutant group it was 1.6 +/- 0.8 (n = 5). VEGF expression was correlated significantly with p53 status (P < 0.05). VEGF levels in p53 gene-transfected cells and the conditioned medium were decreased in 48 hours after p53 gene transfection. VEGF expression was down-regulated by p53 in endometrial carcinoma cells.

HEC-1 cells

HEC-1 cell line was the first in vitro cell line of a human endometrial adenocarcinoma which enabled us to perform research work on the endometrium and endometrial carcinoma at a simplified cellular system, contributing cell and molecular biological studies on endometrial carcinoma. Once a cell line is established, it provides a stable experimental system that facilitates and progresses in the study of the tissues and/or neoplasias from which they are derived. In this article we report how HEC-1 cells have been established and cleared the proposed requirements to characterize the established cell line. Also to show the usefulness of the cell line for research work, once it was established, we illustrate these concepts by recalling results obtained with HEC-1 cells and reviewing the literature on what has been achieved by using these cells.

Growth, morphologic, and invasive characteristics of early and late passages of a human endometrial carcinoma cell line (RL95-2)

Two in vitro passages of a human endometrial adenocarcinoma continuous cell line (RL95-2), an early (subcultured less than 30 times) and a late passage (subcultured greater than 200 times) have provided an interesting model to study the growth, morphologic, and invasive properties of endometrial tumors. The early passage, which has been shown to be estrogen-receptor positive, has characteristics closely resembling a primary tumor, whereas the estrogen receptor negative late passage exhibits several features of the metastatic phenotype. Compared to the early passage cells, the late passage cells were less serum dependent, formed foci, demonstrated a faster rate of growth (due to their shorter doubling times), and attained higher saturation densities. The late passage cells also displayed an altered morphology which was accompanied by alterations in the distribution of F-actin. Even though early and late passages showed similar invasive potential in an in vitro invasion assay, the late passage cells, by virtue of their several transformed characteristics, maintain distinctive properties compared with their early passage counterparts.

Establishment and characterization of CA 125 producing cell line (OMC-2) originating from a human endometrial adenocarcinoma

A new human endometrial carcinoma cell line, designated OMC-2, was established from the endometrial adenocarcinoma of a 59-year-old woman. This cell line has grown well for 51 months and has been subcultured more than 50 times. Monolayer cultured cells are polygonal in shape, showing a pavement-like arrangement and a piling up tendency without contact inhibition. The chromosomal number shows aneuploidy and the modal chromosomal number is in the diploid range. The cells were transplanted into the subcutis of nude mice and produced tumors resembling the original tumor. 1 X 10(5) OMC-2 cells produced CA 125 (184-682 U) during 19 days in culture media. CA 125 was demonstrated immunohistochemically in the original tumor, heterotransplanted tumor, and OMC-2 cells. The cells contain no estrogen or progesterone receptors. Twenty-nine other reports of endometrial carcinoma cell lines are reviewed.

A monoclonal antibody (MSN-1) against a newly established uterine endometrial cancer cell line (SNG-II) and its application to immunohistochemistry and flow cytometry

To determine a phenotypic difference between normal endometrium and endometrial adenocarcinoma, a new monoclonal antibody (MSN-1) was produced by immunizing a new endometrial cancer cell line (SNG-II), which was established in 1981 from a 43-year-old Japanese woman with stage II uterine endometrial cancer. MSN-1 recognized the Lewis-b carbohydrate moiety on the cell surface glycolipid and seldom reacted immunohistochemically with normal endometrium but with about 90% of endometrial cancer cases. By application of MSN-1 to flow cytometry, the possibility of differentiating endometrial normal cells from cancer cells was demonstrated.

A simple immunofiltration assay for mucins secreted by a human colonic epithelial cell line

An enzyme-linked immunosorbent assay for the quantitative detection of mucins secreted in culture by a human colonic epithelial cell line has been developed. Dilutions of mucin standards and culture media were applied to nitrocellulose membranes by vacuum filtration through a specially designed immunofiltration manifold. Sequential incubation of the nitrocellulose with blocking buffer, anti-mucin polyclonal antibodies and horseradish peroxidase-conjugated goat anti-rabbit IgG permitted quantitation of mucins. Linear and reproducible standard curves were obtained with mucins purified by gel filtration chromatography using a gel of large pore size. The assay was found to be simple, sensitive, reproducible, rapid and not influenced by contaminating proteins up to a concentration of 500 micrograms/ml. This assay has been used to monitor column fractions obtained during the analysis of mucin preparations, and to study the effects of cholera toxin on the secretion of mucins by cultured cells.

ETN-1: a new human endometrial carcinoma cell line producing ascites and distant metastases in nude mice

A human carcinoma cell line (ETN-1) has been established from a skin metastasis of a moderately differentiated adenocarcinoma of endometrial origin. The cell line has been so far maintained for 27 months through 55 passages, growing as a monolayer as well as in 3-dimensional clusters with a population doubling time of 72 hr. The number of chromosomes per cell varied from 39 to 107 (average number 61.0 +/- 19.8), with a modal number of 46-48. Seven clonal marker chromosomes were detected. Flow cytometric analysis revealed a population of pseudo-tetraploid cells (DNA index 2.1) next to a pseudo-diploid population (DNA index 1.1). The epithelial character of the cells was confirmed by a positive immunocytochemical reaction using monoclonal antibodies (MAbs) to different keratins, the epithelial cell markers BW 495/36 and HMFG-2, as well as by the presence of many junctional complexes. The tumour cells retained a positive reaction with the anti-ovarian carcinoma OV-TL 3, OV-TL 10 and OC 125 MAbs, although the reaction was markedly diminished in comparison with the original tumour. Tumour cells inoculated subcutaneously in nude mice produced well differentiated adenomatous tumour nodules with formation of glandular lumina and basal lamina. Tumour cells injected intraperitoneally produced malignant ascites and regional as well as distant metastases of adenomatous character.

Establishment and characterization of a human cell line from a serous papillary endometrial carcinoma

The cell line SPEC-1, derived from a human serous papillary endometrial carcinoma (SPEC), has been established and repetitively subcultured for over 18 months. SPEC is a clinically aggressive histologic variant of endometrial adenocarcinoma with a significantly poorer prognosis. The SPEC cells exhibit morphologic and ultrastructural characteristics of transformed epithelial cells. The cells were further characterized with regard to growth kinetics, histochemistry, karyotype, and tumorigenicity. These studies indicate that several properties of the SPEC cells in culture contrast markedly with those of both typical endometrial adenocarcinoma cell lines and normal endometrial epithelia, as described in the literature. The most significant of these differences concern cytogenetic and ultrastructural features. The implications of these unique characteristics are discussed with regard to the relationship they may have to the unusually aggressive biological behavior of this tumor cell type in vivo. This SPEC cell line should prove useful in future studies designed to determine important factors in the biological behavior of human tumor cells.

Neuron-specific enolase as a serum marker for immature teratoma and dysgerminoma

Neuron-specific enolase (NSE) was measured with an enzyme-immunoassay in sera from 54 patients with malignant (24 cases) and benign (30 cases) germ cell tumors of ovarian origin. Serum NSE contents were clearly raised above control value (greater than 10 ng/mg) in 4 of 8 patients with immature teratomas and 5 of 6 with dysgerminomas. NSE was also measured in nine cell lines of germ cell tumors. Among these cell lines, high NSE contents were detected in the cell extracts and culture supernatants from PA-1 and Tera-II lines. In immunohistochemical study, widespread positive staining for NSE was shown in dysgerminomas, whereas the immunostaining was confined to neural elements in both an immature teratoma and xenograft tumors derived from PA-1 and Tera-II lines in nude mice. These findings suggest that serum NSE measurements are of diagnostic value not only for immature teratomas but also for dysgerminomas.

Oestradiol is effective in stimulating 3H-thymidine incorporation but not on proliferation of breast cancer cultured cells

The growth of numerous human oestrogen target cell lines is said to have been stimulated by oestradiol. We studied the action of this hormone on the growth of two human cancer cell lines originating from endometrium (GUS), and from breast (FAM). Oestradiol was inactive on endometrial cell multiplication as well as on their tritiated thymidine uptake, but in FAM breast cancer cells, we noticed a discrepancy between tritiated thymidine uptake and actual cell proliferation: there was a 40% increase in DNA precursor uptake, but no change in either the number of cells or in their DNA content, both of which were verified by two different methods. Therefore, an actual increased nuclear (autoradiographic) uptake of thymidine did take place in oestrogenized cells, associated with an increase of incorporation into DNA (a rise of radioactivity in the acid-insoluble materials), but finally there was no greater total DNA increase in the whole treated population than in control cells. Then we examined the metabolism of tritiated thymidine in oestradiol-treated FAM cells. We extracted the radioactive thymine nucleotides and characterized them chromatographically: the oestradiol caused an increase in the labelling of deoxythymine monophosphate (TMP). How these results are consistent with both unmodified cell count and whole DNA content is discussed.

Establishment of human endometrial adenocarcinoma cell line containing estradiol-17 beta and progesterone receptors

The cell line designated HHUA was established from a well-differentiated endometrial adenocarcinoma (grade 1) of a 54-year-old female on December 10, 1980. The cell line grew well without interruption for 22 months and was subcultivated more than 56 times. The cells were spindle or polygonal in shape, formed multilayers, and did not show contact inhibition. The chromosome number varied widely and showed aneuploidy. The modal number was 46 and no marker chromosome was identified. The cells were transplanted into the subcutis of BALB/C nude mice and produced tumors which were interpreted as adenocarcinoma. The cells contained estradiol-17 beta and progesterone receptors. Administration of estradiol-17 beta successfully depleted cytoplasmic estrogen receptors and brought about increased progesterone receptor levels.

KLE: a cell line with defective estrogen receptor derived from undifferentiated endometrial cancer

KLE is a cell line derived from a poorly differentiated endometrial carcinoma that is aneuploid with chromosome numbers ranging from 51 to 66 and 6-8 marker chromosomes demonstrated by G banding. Tumors harvested from five of five nude mice bearing an inoculum for more than a month resemble the original specimen, and electron microscopy shows microvilli, many junctional processes, glycogenation, and a prominent nucleolonema. The cell cytosol contains a specific binder for estradiol, but there is no estrogen receptor in the nucleus and in a study reported elsewhere (Raam et al., Breast Cancer Res. Treat. 2, 277 (1982) ) translocation to the nucleus fails to occur. The enzyme phenotype of this cell is human, non-HeLa.

Characterization of a new human endometrial carcinoma (RL95-2) established in tissue culture

A new human endometrial cell line, RL95-2, derived from a Grade 2 moderately differentiated adenosquamous carcinoma of the endometrium has been passaged successfully in cell culture for more than 2 yr. The cells are characteristically epithelioid with well-defined junctional complexes, tonofilaments, filopodialike extensions, and surface microvilli. Nuclei are large, irregular, and invaginated frequently with multiple, prominent, lamellar nucleoli. The cells have a log phase doubling time of 22 to 34 h followed by continued growth at a reduced rate with no apparent plateau phase. They exhibit a strong tendency for piling up as well as for the formation of glandlike dome structures. Karyotypically the line is trisomic 8 (47,XX,+8) and has an 8% frequency of polyploidization. Both cytoplasmic and nuclear estrogen receptors are present. Antihuman alpha-keratin characterizes the cell line as epithelial, nonstromal. The RL95-2 cell line may provide a useful in vitro system for the investigation of the endocrine regulation of endometrial neoplasia.

The establishment and morphologic characterization of finite cell lines from normal human endometrium

Twenty-nine samples of normal human endometrium have been initiated in tissue culture. Twenty cultures (69%) demonstrated sufficient growth in vitro to allow establishment of finite cell lines. Morphologic characterization by means of conventional light microscopy as well as scanning and transmission electron microscopy was performed. Differences between stromal and epithelial cell lines indicated several similarities with in vivo observations. Ultrastructural studies of stromal cell lines revealed cells virtually devoid of microvilli and exhibiting poorly specialized cell junctions. Epithelial cell lines were characterized by numerous microvilli and highly specialized "junctional complexes" typical of glandular epithelium. Cytogenetic analysis utilizing a variety of banding techniques revealed no karyotypic alterations through several subpassages. Our observations suggest that simple explant tissue culture of human endometrium can be manipulated in order to achieve separation of stromal from epithelial elements, allowing critical examination of each.

Establishment and characterization of a new endometrial cancer cell line (SCRC-1)

A new human endometrial cell line, SCRC-1, has been established from a uterine adenocarcinoma. During a period of 57 weeks in culture, the SCRC-1 cells have been passaged over 100 times. Cultures have an epitheloid morphology, high mitotic activity, and a tendency to form multiple cell layers. The cells are polygonal and are arranged in pavement-like fashion. Most have multiple nucleoli, some are multinucleated, and all have heavily vacuolated cytoplasm. Pretreatment with iododeoxyuridine did not reveal viral markers by cocultivation or immunofluorescence techniques. Karyologic studies indicate that the SCRC11 cell line is essentially diploid with a small subpopulation of tetraploid cells. Over a period of 20 weeks, 1 of 14 athymic nude mice inoculated with SCRC-1 cells developed a tumor which histologically closely resembled the original human tumor. Cells were subsequently propagated from this tumor and the resulting epitheloid-like cell line was designated SCRC-1, Tu 1.