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

Establishment and characterization of a highly tumorigenic human diploid endometrial cancer cell line

A new cell line designated CUME-1 has been established from a poorly differentiated endometrial adenocarcinoma of the uterus. This cell line grew well without interruption for more than 88 months and 110 serial passages were successively carried out. The cells were highly tumorigenic in nude mice (85%). Repeated karyotype analyses from early (4th) to late (55th) passages of this cell line revealed a diploid stable clone in each passages without any noticeable structural or numerical aberrations. But from the 80th passage, a subpopulation with reciprocal translocation between chromosomes 1q and 9q consistently appeared and was observed in about 30% of the cells. This cell line is one of the rare examples of experimentally proved tumorigenic cells of human solid tumor origin that retains the diploid karyotype in vitro. HLA typing indicated the presence of DR4, DR13, DQ3 and DQ6. Cytosol estrogen and progesterone receptors were found both in fresh primary tumor and in this cell line. Gonadotropin-releasing hormone (Gn-RH) receptor mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) in cultured cells. Using the single-strand conformation polymorphism (SSCP) technique, we have screened CUME-1 cells for p53 mutation in exons 4 to 9. No mobility shift was observed. This cell line may be useful in studying the in vitro chromosomal evolution of the cell line and the in vivo properties of human endometrial adenocarcinoma.

Androgen responsiveness of the new human endometrial cancer cell line MFE-296

MFE-296 endometrial cancer cells express androgen receptors in vitro. These cells, which are tumorigenic in nude mice, are derived from a moderately differentiated human endometrial adenocarcinoma. They express vimentin and the cytokeratins 7, 8, 18, and 19. Karyotyping revealed near-tetraploidy for most of the cells. No marker chromosomes were observed. DNA analyses confirmed the genetic identity of the cell line and the patient from whom the cell line was derived. Proliferation of MFE-296 cells was inhibited by the progestin R5020 and the androgen dihydrotestosterone (DHT). The inhibition of proliferation by DHT was antagonized by the antiandrogen Casodex, demonstrating the involvement of the androgen receptor. Androgen binding was determined at 22,000 binding sites per cell using a whole-cell assay (KD = 0.05 nM) and 30 fmol/mg protein with the dextran charcoal method; 7 fmol/mg protein of progesterone receptors were found, whereas estrogen receptors were below 5 fmol/mg protein. The androgen receptor was functionally intact, as demonstrated by transfection experiments with a reporter-gene construct, containing an androgen-responsive element. In MFE-296 cells the content of the androgen receptor was up-regulated by its own ligand.

The EnDA endometrial adenocarcinoma: an oestrogen-sensitive, metastasizing, in vivo tumour model of the rat

A high percentage of endometrial carcinomas contain oestrogen and progesterone receptors. For endocrine therapy of recurrent endometrial carcinoma, only high-dose progestins are in clinical use. As, therefore, the development of new endocrine treatment strategies is of great interest, suitable animal models for this tumour are essential. Up to now, only human tumour xenografts transplanted in immune-deficient nude mice, but no syngeneic in vivo tumour models, have been available. In the present article we describe the hormone sensitivity of the EnDA endometrial adenocarcinoma of the DA/Han rat growing as s.c. implants in DA/Han rats and athymic nude mice in serial passage. In both species, the tumour expresses oestrogen, but no progesterone receptors. Transplanted in DA/Han rats or nude mice, ovariectomy reduced tumour weight by 64% and 46% respectively. In both species substitution of ovariectomized animals with oestradiol restored tumour weights to intact control levels. Oestradiol substitution of intact animals did not further enhance tumour growth. The growth of the primary tumour was inhibited by medroxyprogesterone acetate (MPA) at a dose of 100 mg/kg by 67% and by tamoxifen at a dose of 20 mg/kg by 38%. Lung metastases were regularly seen in both species, although to a lesser extent in nude mice than in DA/Han rats. Tamoxifen treatment did not alter the number of lung metastases, whereas MPA or ovariectomy produced a significant reduction in the number of lung metastases. The EnDA endometrial carcinoma of the DA/Han rat with respect to its oestrogen sensitivity, oestrogen receptor expression, morphology and metastatic growth, grossly resembles a typical endometrial adenocarcinoma and can therefore be regarded as a useful in vivo experimental model for the evaluation of new endocrine treatment strategies.

Development of a preclinical model for hormonal therapy of human endometrial carcinomas

Endometrial carcinoma is the most common gynaecological malignancy. Progestins are widely used in the treatment of advanced and metastatic disease with about 20-40% response rate. Attempts to develop a predictive test for progestin-sensitivity of endometrial cancers are plagued by the problems of steroid receptor instability and the heterogeneous distribution of progesterone receptor. Successful development of a nude mouse model for human endometrial carcinoma has permitted a detailed investigation of the biological behaviour, hormonal modulation and resistance to progestin therapy. Use of this preclinical model should enhance our understanding of the hormonal mechanisms and lead to improved rational treatment strategies for this malignancy.

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.

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.

Marker chromosomes of the long arm of chromosome 1 in endometrial carcinoma

Cytogenetic studies were performed on endometrial specimens of four patients with hyperplasia, six with adenocarcinoma, and one with a mixed mesodermal tumor. Except for one cell, all 65 cells from the hyperplastic specimens had a normal female karyotype. However, a total of 92 cells from the five adenocarcinoma specimens had chromosome abnormalities, though all 20 cells from a specimen of a well differentiated adenocarcinoma showed a normal karyotype. The chromosome number and morphology of the aneuploid cells had minimal changes. The modal number of chromosomes was pseudodiploid in one case and hyperdiploid in four cases. Three kinds of structural abnormalities involving chromosomes #1 were identified to be of clonal origin: del(1p21) in two cases, tdic(1;16)(p21;q24) in one case, and i(1q) markers in two cases. Because the carcinoma cells had two chromosomes #1 of normal morphology, the presence of the marker chromosome led to partial trisomy or tetrasomy of the long arm of chromosome #1. This involvement may be assumed to represent a karyotypic change characteristic of some adenocarcinomas of the endometrium. Complex karyotypes with many rearranged chromosomes were observed in cells from the mixed mesodermal tumor. The karyotypic differences between endometrial carcinoma and the mixed medodermal tumor suggest that the genesis (and its mechanism) of the former may differ from that of the latter.

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.

Müllerian inhibiting substance inhibition of a human endometrial carcinoma cell line xenografted in nude mice

Müllerian inhibiting substance (MIS) is a fetal testicular product which causes regression of the müllerian duct in the male mammalian embryo. This material has been partially purified from a neonatal bovine source and in cruder fractions has shown antitumor effects when tested against the HOC-21 ovarian carcinoma line in monolayer cytotoxicity, in soft agar colony inhibition assay, and in nude mouse xenografts. The glycoprotein used for the present studies was more highly purified by sequential ion exchange, carbohydrate affinity, and dye affinity chromatography. After a 1-hr exposure with 1.0 X 10(6) tumor cells prior to heterotransplantation, this more purified preparation with MIS biological activity as determined by organ culture assay of embryonic urogenital ridges delayed the appearance of palpable tumor nodules. That this response may be specific for tumors derived from the coelomic epithelium of the embryo is further supported by the absence of any antitumor effect when this substance was tested against the SW-48 colon carcinoma line. It is of interest that the antitumor activity followed the biological activity as the preparation was further purified to 30,000-fold.

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.