Intermediate filaments of human trophoblast and choriocarcinoma cell lines

Summary Human term placenta and two human choriocarcinoma cell lines were studied immunohistochemically and by immunoblotting with monoclonal antibodies to keratin polypeptides and vimentin. Four keratin polypeptides (40, 45, 52, 54 K) were detected in both normal and malignant trophoblastic cells. The presence of the 54 K keratin polypeptide distinguishes the benign and malignant trophoblastic cells from human embryonal carcinoma cells and a yolk sac carcinoma cell line.     

Cytogenetic and biological characterization of two new human plasma cell lines

Two new human plasma cell lines designated as ACB-885 and ACB-1085 have been established from a 39-year-old patient with multiple myeloma. These cell lines have definitive plasma cell features by morphologic examination, and essentially all of the cells are positive for cytoplasmic IgG kappa immunoglobulin. These cells are negative for standard T-cell surface markers and mature B-cell markers, such as B1, B2, and HLA-DR, but are strongly positive for the antigen defined by OKT-10. The cells are negative for Epstein-Barr virus. The cell lines have a doubling time of 30-35 hours and a growth fraction approaching 100%. Cytogenetic analysis showed a 2n chromosome number of 45-46 with very similar karyotypic abnormalities in both the plasma cell lines and the original tumor material. One of the chromosomes in each of the pairs of chromosomes number #1, #2, #6, #7, #8, #10, #12, #13, and #22 were consistently missing. These were replaced by eight marker chromosomes that resulted from chromosomal rearrangements involving mainly these missing chromosomes. Almost all of the breakpoints occurring in the marker chromosomes were identified, and eight of these breakpoints have been reported in other studies of myeloma plasma cells. Homogeneously staining regions were observed in two marker chromosomes suggesting gene amplification in these chromosomal regions.     

Chromosomal rearrangement in choriocarcinoma cell lines

Malignant trophoblastic cells from four choriocarcinoma cell lines were evaluated in detail using Q, G, and C banding at various passages. The modal chromosome numbers for BeWo, DoSmi, ElFa, and Jar were 73, 71, 77, and 72, respectively. All the four tumor cell lines exhibited extensive chromosomal rearrangements with several consistent marker chromosomes in each. The majority of these markers have not been previously recognized in this malignancy. Rearrangements of chromosomes 1, 7, 9, 10, and 12 were noted in all four cell lines, but abnormalities of chromosomes 1 and 12 were not consistently present in ElFa and Jar, respectively. Telomeric associations were observed in two cell lines involving chromosomes 11 and 21 as well as chromosomes 3 and 12, resulting in two consistent marker chromosomes. A total of 86 breakpoints were involved in the consistent rearrangements observed in all four cell lines. Most of these breakpoints were located on chromosomes 1, 3, 9, 13, 12, 7, and 21, in order of frequency.     

Cytogenetic characterization of three human and three rat medullary thyroid carcinoma cell lines

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor of the thyroid C-cells. MTC may arise as a sporadic tumor or as a component of one of three autosomal dominant familial cancer syndromes, MEN 2A, MEN 2B, or familial MTC. Recent studies have identified mutations of the RET protooncogene in the proximal long arm of chromosome 10, which are thought to be causative for these syndromes. To facilitate the search for other genes involved in the development of MTC, we characterized cytogenetically three human MTC cell lines and three rat MTC cell lines. The human cell lines studied were TT and RO-H85-1, previously reported, and an uncharacterized cell line, MZ-CRC-1, derived from a malignant pleural effusion from a patient with metastatic MTC. The rat MTC cell lines characterized were CA-77, 6–23C₆, and 44-2. Cytogenetic abnormalities present in the human and rat cell lines were compared with 13 reported cytogenetic studies of human MTC tumors and three other cytogenetically analyzed MTC cell lines. The human 9q/rat 3 and human 3p/rat 15 chromosomes were affected in six of the comparable cell lines and tumors. These findings suggest human chromosome regions 9q and 3p may contain genes involved in the pathogenesis of MTC.     

Evidence for a novel HLA antigen found on human extravillous trophoblast and a choriocarcinoma cell line

We describe the characterization of a novel HLA Class I molecule, which we have isolated from chorionic cytotrophoblast cell membranes, and from a trophoblast-derived choriocarcinoma cell line, BeWo; classical HLA Class I antigens are not expressed on these cells. This antigen is an electrophoretically non-polymorphic glycoprotein of approximately 40,000 molecular weight, which is found in association with beta 2 microglobulin, and which is detected by monoclonal antibodies recognizing monomorphic determinants of HLA Class I. Elucidation of the nature and origin of this molecule may provide valuable information regarding the immune barrier that exists between mother and fetus.     

Serological analysis of cell surface antigens in choriocarcinoma cell lines

Major histocompatibility complex (MHC) antigens as well as blood group related antigens were investigated in four newly established gestational choriocarcinoma cell lines (NaUCC-1, -2, -3, and -4) using protein A and immune adherence assays. Antibodies to both monomorphic determinants of HLA class I antigens and beta 2 microglobulin reacted with all of the choriocarcinoma cell lines at levels equal to or much greater than SCH, which was teratoid choriocarcinoma cell line. Antibodies to polymorphic determinants not only of the patient's HLA type, but also of the husband's type, reacted to NaUCC-1 and -2. These results indicated that all four newly established choriocarcinoma cell lines express class I HLA antigens. However, we could not demonstrate expression of class II antigens. No expression of blood group A and B antigens could be established, and binding of antibody to Rho(D) antigens was only positive in the NaUCC-1 cell line. These results suggest that some choriocarcinoma cell lines actually express alloantigens and that choriocarcinomas have the character of transplanted tumors that have activities to induce transplantation immunity of the patients.     

Cytogenetic studies of esophageal carcinoma cell lines

Although the incidence of cancer of the esophagus is low in the United States, the prognosis of patients with this malignancy is poor, especially when metastases exist. More research concerning the biological characteristics of this tumor is necessary to permit more effective treatment and to determine the etiology. We successfully studied cytogenetically 14 short- and long-term cell lines derived from esophageal carcinoma to determine whether these tumors have nonrandom, unique chromosomal abnormalities. Our results showed that the tumor cells had chromosome numbers clustering around a modal number that varied according to the cell line. The presence in the primary explant of extensive numerical and structural abnormalities involving every chromosome including the sex chromosomes indicate that these abnormalities occur early in the malignant cells. The chromosomes most frequently involved in the structural abnormalities were 1, 9, and 11, each occurring in 13 of the 14 lines, and of three found in 12 of the 14 lines. The major aberrations resulted in deletions of portions of these chromosomes. The most frequent breakpoints for these abnormalities occurred at 3p14, 11q11q12; and 9q11q12 as well as in the centromeric regions of all the acrocentric chromosomes. Another unusual chromosomal marker found in three lines (HCE-1, HCE-3, and HCE-5) was a homogeneously staining region (HSR) that occurred as an extension on 11q12.     

Cytogenetic characterization of a BCR-ABL transduced mouse cell line

Most patients with Philadelphia (Ph)-positive acute lymphoblastic leukemia (ALL) show evidence of secondary chromosome aberrations that may influence the course of disease and response to treatment. To better understand how these secondary chromosomal aberrations occur and to investigate whether the p185/p190 BCR-ABL fusion protein may directly induce an increased chromosomal instability and subsequently the appearance of clonal chromosome aberrations, three BRC-ABL (p185/ p190)-transduced mouse pre-B cell lines were analyzed by spectral karyotyping and fluorescence in situ hybridization. The human wild-type BCR-ABL gene was expressed at a level comparable with that in human Ph-positive leukemias at diagnosis. All BCR-ABL-transduced cell lines acquired similar clonal chromosomal aberrations. Trisomy 5 was always present, followed by loss of the Y chromosome, trisomy of chromosomes 12 and 18, and an unbalanced translocation between chromosomes X and 12. Thus, ectopic p185/p190 BCR-ABL expression, such as p210 BCR-ABL, PML-RARA, or C-MYC transduction, may induce an increased chromosomal instability leading to clonal karyotypic evolution, which may mimic secondary chromosome aberrations in human Ph-positive ALL.     

Karyotypic analysis and chromosome polymorphisms in four choriocarcinoma cell lines

Four choriocarcinoma cell lines were karyotyped and examined for genetic homozygosity or heterozygosity using chromosomal polymorphisms. The BeWo, Jar, and ElFa lines had modal chromosomes in the hypertriploid range, while the DoSmi line was hypotetraploid. A number of chromosomal rearrangements were seen in all lines but there was no common rearrangement. The BeWo and Jar cell lines, derived from tumors following term births, were shown to be heterozygous by the presence of both X and Y chromosomes. The ElFa and DoSmi lines, established following molar pregnancies, were shown to be heterozygous; the ElFa line by the presence of both X and Y chromosomes and the DoSmi line by the examination of Q-band polymorphisms. Thus, all four lines, whatever their origin, were shown to be genetically heterozygous.     

Cytogenetic characterization of a nasopharyngeal carcinoma cell line and its subline

Cytogenetic results of a nasopharyngeal carcinoma (NPC) cell line NPC-TW039 and its subline NPC-TW039-N1, established from the nude mouse transplant, were reported. This is the third case of NPC presented with banded karyotype, to date, in the literature. A 3q + marker chromosome, with involvement of band q25 similar to that present in the two previously reported cases, was detected in most tumor cells from both cell lines. The structural chromosome abnormalities of NPC-TW039-N1 were similar to its original cell line, NPC-TW039, except that the subline lost one marker chromosome and gained a new one.     

Expression of melatoninergic receptors in human placental choriocarcinoma cell lines

BACKGROUND: Melatonin crosses the placenta and enters the fetalcirculation. Moreover, experimental data suggest a possibleinfluence of melatonin on placental function and fetal developmentin humans. To date, the expression and role of melatonin receptorsin human placenta choriocarcinoma cell lines and in human termplacental tissues remain to be elucidated. METHODS AND RESULTS:Results from RT–PCR, western blotting and confocal microscopydemonstrated that the MT1, MT2 and ROR1 melatonin receptorsare expressed in the human term placental tissues and in choriocarcinomacell lines JEG-3 and BeWo. Furthermore, enzyme-linked immunosorbentassay showed that 6-chloromelatonin (a melatonin agonist) inhibits,in a dose-dependent manner, forskolin-stimulated hCG- secretionin JEG-3 (P < 0.001) and BeWo (P < 0.05) cells but hadno effect on basal human chorionic gonadotrophin (hCG-) levels.This effect of 6-chloromelatonin on forskolin-stimulated HCG-secretion was abolished by pertussis toxin (PTX), suggestingthat melatonin regulates hCG- production by an action involvingan inhibitory Gi/o protein. In PTX-treated BeWo cells, 6-chloromelatoninstimulated basal hCG- secretion (P < 0.001). CONCLUSION:These results demonstrate, for the first time, the expressionof melatonin receptors in human term placental tissues and inchoriocarcinoma cells and suggest a possible paracrine/autocrinefunction for melatonin in human placenta.     

Cytogenetic and molecular study of two human neuroblastoma cell lines

Long-term cell cultures (GI-LA-N and GI-ME-N) were established from the metastases of two disseminated neuroblastomas (NB). The first was obtained from a lymph node biopsy of a stage III NB after 7 months of chemotherapy, and the second from a bone marrow specimen of a stage IV NB after 6 months of chemotherapy. Cytogenetic investigation revealed several structural and numerical alterations in both cell cultures, but the only common chromosomal aberration was partial monosomy of 1p. Moreover, at the 5th in vitro passage, GI-LA-N displayed a high number of double minutes, not seen in GI-ME-N even after 33 subcultures. Molecular analysis revealed N-myc oncogene amplification in GI-LA-N cells, whereas, only one copy was found in GI-ME-N. No structural N-myc rearrangement was detected in either cell culture.     

Cytogenetic studies of four human lung adenocarcinoma cell lines

G-banded karyotypes were analyzed on four human lung adenocarcinoma cell lines, AGZY83-a, LTEP-a1, LTEP-a2, and GLC-82. More than 50 cells were counted and 20-40 cells were karyotyped for each cell line at different passages. The chromosome numbers of cell line AGZY83-a, LTEP-a1, LTEP-a2, and GLC-82 were 53-69, 100-110, 51-56, and 61-63, respectively. Each cell line had a number of markers involving complex chromosome rearrangements. Chromosomal analysis at different passages showed the stability of these cell lines in vitro. It was revealed that the marker chromosomes involving deletions or rearrangements of the short arm of chromosome #1 were present in all the four cell lines with breakpoints at 1p12-1p22.     

Cytogenetic analysis of four human ovarian carcinoma cell lines

Four cell lines derived from adenocarcinomas of the ovary, including three recently established cell lines, have been karyotyped. Chromosomes #1, #3, and #6 were found to be frequently involved in translocations with various other chromosomes, in agreement with results of other investigators, strongly implicating genes on these chromosomes in ovarian tumorigenesis.     

Anti-peroxidase antibody-secreting hybrid lines. I. Identification, cloning and cell characterization.

Anti-peroxidase antibody (Ab)-secreting hybrids have been produced by fusion of peroxidase (PO)-immunized mouse lymph node cells and immunoglobulin (Ig)-secreting P3-X63-Ag8 (X63) myeloma cells. Identification of Ab-secreting hybrids can be performed as early as day 5 after cell fusion by the hemolytic plaque assay. Immediately after identification, hybrids were directly isolated, by means of a micropipette, into Terasaki microchambers containing nutrient medium and a thymocyte filler layer. The yield of secreting hybrids is improved by using this procedure. All the cells of the PO 772 C2 clone show the same ultrastructural pattern and immunocytological properties; they are proplasmocytes, as are the parental X63 cells; they present intracisternae Ab and show no Ig or Fc receptors at the cell surface. Over 90% of viable PO 772 C2 cells form specific plaques. Isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis show that the cells of this clone secrete Ab; the secreted Ig are formed with chi and gamma 1 chains from the parental X63 cells and specific L and H chains from the lymphoid parent. These biological investigations demonstrate the relative stability of the PO 772 C2 clone secreting anti-peroxidase antibody.     

Wide-ranging DNA methylation differences of primary trophoblast cell populations and derived cell lines: implications and opportunities for understanding trophoblast function

Difficulties associated with long-term culture of primary trophoblasts have proven to be a major hurdle in their functional characterization. In order to circumvent this issue, several model cell lines have been established over many years using a variety of different approaches. Due to their differing origins, gene expression profiles and behaviour in vitro, different model lines have been utilized to investigate specific aspects of trophoblast biology. However, generally speaking, the molecular mechanisms underlying functional differences remain unclear. In this study, we profiled genome-scale DNA methylation in primary first trimester trophoblast cells and seven commonly used trophoblast-derived cell lines in an attempt to identify functional pathways differentially regulated by epigenetic modification in these cells. We identified a general increase in DNA promoter methylation levels in four choriocarcinoma (CCA)-derived lines and transformed HTR-8/SVneo cells, including hypermethylation of several genes regularly seen in human cancers, while other differences in methylation were noted in genes linked to immune responsiveness, cell morphology, development and migration across the different cell populations. Interestingly, CCA-derived lines show an overall methylation profile more similar to unrelated solid cancers than to untransformed trophoblasts, highlighting the role of aberrant DNA methylation in CCA development and/or long-term culturing. Comparison of DNA methylation and gene expression in CCA lines and cytotrophoblasts revealed a significant contribution of DNA methylation to overall expression profile. These data highlight the variability in epigenetic state between primary trophoblasts and cell models in pathways underpinning a wide range of cell functions, providing valuable candidate pathways for future functional investigation in different cell populations. This study also confirms the need for caution in the interpretation of data generated from manipulation of such pathways in vitro.