Epithelial Ovarian Carcinoma Cell Lines Research Articles

Macrophage colony-stimulating factor is expressed by an ovarian carcinoma subline and stimulates the c-myc proto-oncogene.

A small, fast-growing and non-differentiated clone (N.1) derived from the heterogeneous human epithelial ovarian carcinoma cell line HOC-7 produces an autocrine/paracrine factor that is secreted into the cell culture supernatant. This factor is capable of enhancing mRNA levels of the proliferation-related oncogene c-myc in the more differentiated clone D3 and in normal human fibroblasts MRC.5, but also in N.1 cells themselves. Supernatants enriched for this paracrine/autocrine factor also confer a mitogenic stimulus as measured by [3H]thymidine incorporation. Trypsin can neutralise the stimulating activity of the secreted factor as well as monoclonal antibodies directed against macrophage colony-stimulating factor (M-CSF). We show that M-CSF and also M-CSF receptor are expressed in N.1 cells and that recombinant M-CSF induces c-myc transcript levels in N.1 cells. This investigation raises the possibility that M-CSF might be an autocrine growth factor in non-differentiated ovarian carcinomas. Inappropriate cytokine production could create a tumour-promoting microenvironment in this cancer type.

Overexpression of the Protein Tyrosine Phosphatase, Nonreceptor Type 6 (PTPN6), in Human Epithelial Ovarian Cancer

Our current understanding of human ovarian tumorigenesis is limited by the lack of a discrete precursor lesion as well as a limited knowledge of the steps in tumor progression. Since the alterations in the regulation of the tyrosyl residues on various cellular proteins appear to be an important pathway in neoplastic transformation, it is possible that changes in the expression of the proteins that control tyrosine phosphorylation (i.e., tyrosine kinases and phosphatases) may play a role in ovarian cancer development. Protein tyrosine phosphatase, nonreceptor type 6 (PTPN6), contains two src homology 2 domains and is expressed primarily in hematopoietic and epithelial cells. Using Northern blot and immunoblotting analysis, we showed that both the PTPN6 transcripts and proteins were overexpressed two- to four-fold in 7 of the 8 ovarian epithelial carcinoma cell lines studied. In addition, we showed that there was also a two- to threefold increase in expression of the PTPN6 transcript in 10 of 11 (91%) invasive ovarian epithelial cancer tissues examined. These observations suggest that the PTPN6 gene is potentially of etiologic relevance to a majority of ovarian cancers.

Inhibition of growth of human ovarian cancer in nude mice by luteinizing hormone-releasing hormone antagonist Cetrorelix (SB-75 )

To report on the in vitro and in vivo inhibitory effects of LH-releasing hormone (LH-RH) antagonist Cetrorelix (SB-75; Asta Medica, Frankfurt-Main, Germany) against a panel of human ovarian carcinomas. the effect of SB-75 was measured using a standardized chemosensitivity assay in the following ovarian cancer cell lines: UCI 101; UCI 107; PA-1; NIH: OVCAR 3; UCLA: 222; A2780, parental; A2780-CR, cisplatin resistant; A2780-DR, doxorubicin resistant; and the human breast cancer cell line, MCF-7. Results were expressed as percent growth inhibition determined by crystal violet photometric analysis. In vivo studies: the antiproliferative effect of this agent was examined using UCI-107, a primary epithelial ovarian carcinoma cell line, in a nude mouse model. On day 0, 10 x 10(6) UCI 107 cells were implanted subcutaneously into 20 intact female athymic nude mice (5 to 6 weeks old). On day 8, the mice were randomly divided into two groups of 10; control mice were implanted with miniosmotic pumps filled with a vehicle solution consisting of 5.2% mannitol in saline; and treated animals received pumps filled to deliver continuous administration of SB-75 at 60 micrograms per mouse per day. direct inhibition of cell proliferation by SB-75 was not observed at concentrations ranging from 1 nM to 100 microM (exposure lasting three to four cell doublings) with the exception of MCF-7, which demonstrated a 33% inhibition at the latter concentration. In vivo studies: on day 16, caliper measurements were taken from subcutaneous tumor nodules in SB-75-treated and untreated mice and a significant difference of 270% in mean tumor volume was observed. End point was determined, on day 30, when control tumor volume approached 10,000 mm3. At that time the difference in mean tumor volumes increased to 600%, indicating a substantial antiproliferative effect had been achieved in the SB-75-treated group. Our in vitro findings show direct inhibition by SB-75 on proliferation of human breast cancer cells. This direct inhibition in vitro was not observed in our ovarian cancer cell lines. However, in vivo SB-75 caused a significant inhibition of growth of human epithelial ovarian cancer. This may be a result of inhibition of the pituitary gonadal axis and gonadotropin secretion. Our results warrant further investigation.

Establishment and characterization of four human epithelial ovarian carcinoma cell lines.

To develop in vitro models of human ovarian carcinoma, fresh tumour cells derived from malignant effusions were cultured in vitro in the presence or absence of serum to establish cell lines. Cell lines established were characterized by morphology in culture, surface marker expression, cytogenetic analysis, and growth in anchorage-dependent and anchorage-independent conditions. Four cell lines (MAC-2, RIC-2, SCHM-1, and SIB-1) were established from tumor cells isolated from the malignant effusions of four patients with epithelial ovarian carcinoma. These lines were able to grow in the presence of low concentrations of serum (3%), and two lines grew in the absence of serum (MAC-2 and SIB-1). All cell lines have been grown continuously for longer than 6 months. One cell line (SCHM-1) grew only in liquid medium whereas the other lines grew in both liquid and semi-solid media. Chromosome analysis revealed aneuploidy in three of the four lines. All of the lines stained positively for CA-125 and HMFG-2, consistent with an epithelial origin. The ability of these cells to grow in low concentrations of serum or in serum-free conditions should prove useful for the in vitro study of factors affecting the growth of human ovarian carcinoma. The serum-free medium developed will be of use in the isolation of factors from the conditioned medium of these cell lines and previously established cell lines.

Secretion of extracellular matrix‐degrading proteinases is increased in epithelial ovarian carcinoma

The biochemical events associated with tumor invasion involve localized degradation of the basement membrane by tumor-associated proteinases. In this study, we have characterized the proteinase secretion profiles of 5 ovarian epithelial carcinoma cell lines (DOV 13, OVCA 420, OVCA 429, OVCA 432, OVCA 433) as well as normal ovarian epithelial cells. Immunocapture assays demonstrated that all 5 carcinoma cell lines produce both secreted and surface-associated plasminogen activator. Urinary-type plasminogen activator (u-PA) production was one order of magnitude greater than production of tissue-type plasminogen activator (t-PA). Furthermore, t-PA secretion by normal ovarian epithelial cells was not detectable, whereas u-PA production was 17- to 38-fold lower than in ovarian carcinoma cells. Western-blotting analysis demonstrated that u-PA was secreted as the single chain form (scu-PA) when cells were cultured in serum-free medium. Incubation of plasminogen with ovarian carcinoma cell-conditioned medium resulted in direct activation of the zymogen to plasmin. Furthermore, following incubation of cells with plasminogen, plasmin was eluted from the cell surface, indicating that ovarian carcinoma cells contain binding sites for plasminogen/plasmin which are accessible to surface-associated plasminogen activators. In addition to plasminogen activators, metalloproteinases were also produced by DOV 13, OVCA 429 and OVCA 433 cells. DOV 13 cells produce a 68-kDa metalloproteinase similar to matrix metalloproteinase 2 (MMP-2) whereas a 92-kDa enzyme similar to MMP-9 is secreted by OVCA 429 and 433. Together, ovarian carcinoma-associated plasminogen activators and metalloproteinases catalyze the hydrolysis of the major basement membrane protein components, type-IV collagen, type-IV gelatin, laminin and fibronectin. The enhanced proteolytic capability of ovarian carcinoma cells relative to normal ovarian epithelium suggests a biochemical mechanism by which invasion and spread of ovarian epithelial carcinoma may be mediated.

GnRH Agonist Therapy in Human Ovarian Epithelial Carcinoma (OVCAR-3) Heterotransplanted in the Nude Mouse Is Characterized by Latency and Transience

We have previously documented the responsiveness of a cell line of human ovarian epithelial carcinoma (Bowman Gray 1) heterotransplanted in nude mice to treatment with the GnRH agonist Lupron-SR. In this study we used another human ovarian epithelial carcinoma cell line, OVCAR-3, and the human endometrial carcinoma cell line HEC-1A. After a latent period, OVCAR-3 tumors showed significant inhibition of growth on Days 17, 21, and 24 ( P < 0.03) compared to controls. The effect was transient and did not persist beyond Day 24. HEC-1A tumors showed no inhibition of growth. Radioreceptor assay studies utilizing native radiolabeled GnRH and [ d-Lys 6]-GnRH revealed no specific GnRH receptors in any of the tumor samples (BG-1, OVCAR-3, HEC-1A, University of Nebraska cell line, and two fresh human ovarian epithelial tumor samples) compared to male rat anterior pituitary cells. Binding studies and the latency and transience of effect would suggest that the mechanism of action in this animal model may be indirect. This activity may be via altered circulating steroids, gonadotropins, cell-cycle regulatory events, or some other as-yet-undefined action related to GnRH agonist administration or indirectly via effects of the metabolic products of degraded GnRH agonist such as d -amino acids, which are incorporated into the cells by constitutive or adsorptive pinocytosis. This study confirms latency and transience of effect of GnRH agonist therapy on an in vivo model of ovarian cancer.

Characterization of a Human Ovarian Carcinoma Cell Line: UCI 101

A new epithelial ovarian carcinoma cell line (UCI 101) has been established from the ascitic fluids and solid tumor of a patient with progressive papillary adenocarcinoma of the ovary shown previously to be refractory to combination chemotherapy consisting of cyclophosphamide, Adriamycin, and cisplatin as well as single-agent chemotherapy of taxol and high-dose cisplatin. The UCI 101 cell line grows well with an in vitro doubling time of 24 hr. The cell line expresses the B 72.3 (Tag 72), CA125, MH99 (ESA), and E29 (EMA) cell surface antigens and AE1/AE3 cytokeratins. This cell line overexpresses (as determined by immunocytochemistry) both p-glycoprotein and the epidermal growth factor receptor. The in vitro drug response to single agents including Adriamycin, cisplatin, dequalinium chloride, etoposide, 5-fluorouracil, taxol and tumor necrosis factor was examined. Intraperitoneal transplantation of the cells into athymic mice resulted in foci of tumor on all peritoneal surfaces including the viscera and diaphragm ultimately leading to solid bulky disease with massive production of ascites. High levels of CA125 (>500 units/ml) were detected in the serum of tumor-bearing mice. Cytogenetic analysis of cultured cells shows several marker chromosomes containing deletions, duplications, and translocations. Cytologic and histologic evaluation of the xenograft revealed morphological characteristics identical to those of the original tumor.

Comparison of a rabbit heteroantiserum and a murine monoclonal antibody raised against a human epithelial ovarian carcinoma cell line

An ovarian carcinoma cell line (OVCA 432) and a B-lymphocyte line (LAZ 446) were established from the same donor. A heteroantiserum (D-100) was prepared in rabbits against OVCA 432 and absorbed with LAZ 446, human AB erythrocytes, and the CX-1 colorectal cell line. After absorption, D-100 reacted by indirect immunofluorescence with six of six epithelial ovarian carcinoma cell lines and cryostat sections of 18 of 18 epithelial ovarian tumors but bound to zero of 12 nonovarian tumor cell lines. Despite a lack of reactivity with nonovarian tumor cell lines, D-100 reacted with epithelial components of normal ovary, fallopian tube, endometrium, endocervix, breast, colon, and epididymis. A murine monoclonal antibody (OC 133) was also raised against OVCA 432 and selected for lack of reactivity with the autologous B-lymphocyte line LAZ 446. OC 133 reacted with six ovarian carcinoma cell lines and cryostat sections of seven of 19 ovarian tumors, but it also reacted with five of five nonovarian tumor cell lines. Of 12 normal tissues examined, OC 133 reacted with endometrium and endocervix only. Whereas D-100 bound to serous, mucinous, endometrioid, and clear cell ovarian neoplasms, OC 133 bound only to serous tumors. In developing monoclonal reagents, cell lines may provide a useful source of antigen, but promising antibodies should be screened for reactivity with sections of normal and malignant human tissues.