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Hybrid Cell Lines (hybrid + cell_line)
Selected AbstractsEndotoxin-stimulated macrophages decrease bile acid uptake in WIF-B cells, a rat hepatoma hybrid cell lineHEPATOLOGY, Issue 1 2000Ekkehard Sturm Endotoxemia leads to cytokine-mediated alterations of the hepatocellular sodium-taurocholate-cotransporting polypeptide (ntcp). We hypothesized that stimulated macrophages are essential transducers for down-regulating hepatocellular bile salt uptake in response to endotoxin (lipopolysaccharide [LPS]) exposure. Using an in vitro model, we exposed mouse macrophages (IC-21 cell line) to LPS for 24 hours. Concentrations of cytokines tumor necrosis factor-, (TNF-,), interleukin (IL)-1,, and IL-6 increased 10.6-fold, 12.5-fold, and 444-fold, respectively, in LPS-conditioned IC-21 medium (CM) versus unconditioned IC-21 medium (UM). WIF-B rat hepatoma hybrid cells were incubated with either CM or UM or treated directly with medium containing recombinant TNF-,, IL-1,, and IL-6. [3H]Taurocholate ([3H]TC) uptake decreased in WIF-B cells exposed to either TNF-, (54% of control), IL-1, (78%), IL-6 (55%) as single additives, or in triple combination (TCC) (43%). A virtually identical decrease was observed after exposing WIF-B cells to CM (52%, P < .001). LPS had no direct effect on [3H]TC uptake. CM treatment did not decrease L-alanine transport in WIF-B cells. Blocking antibodies against TNF-,, IL-1,, and IL-6 restored the diminished [3H]TC uptake in cells exposed to TCC and CM to 87% and 107% of controls, respectively. Northern blotting revealed that ntcp messenger RNA (mRNA) expression was significantly reduced in WIF-B cells after exposure to CM, and in primary rat hepatocytes exposed to CM or TNF-, (68%, 14%, and 29% of control, respectively). We conclude that macrophages and their ability to secrete the cytokines TNF-,, IL-1,, and IL-6 may be essential in mediating the endotoxin-induced cholestatic effect of decreased hepatocellular bile salt uptake. [source] Characterization and gene expression profiling in glioma cell lines with deletion of chromosome 19 before and after microcell-mediated restoration of normal human chromosome 19GENES, CHROMOSOMES AND CANCER, Issue 10 2009Kristen L. Drucker Nearly 10% of human gliomas are oligodendrogliomas. Deletion of chromosome arm 19q, often in conjunction with deletion of 1p, has been observed in 65,80% of these tumors. This has suggested the presence of a tumor suppressor gene located on the 19q arm. Chromosome 19 deletion is also of interest due to the better prognosis of patients with deletion, including longer survival and better response to chemotherapy, compared with patients without deletion. Two glioma cell lines with deletion of 19q were used for chromosome 19 microcell-mediated transfer, to assess the effect of replacing the deleted segment. Complementation with chromosome 19 significantly reduced the growth rate of the hybrid cells compared with the parental cell lines. Affymetrix U133 Plus 2.0 Gene Chip analysis was performed to measure and compare the expression of the chromosome 19 genes in the chromosome 19 hybrid cell lines to the parental cell line. Probes were considered significantly different when a P value <0.01 was seen in all of the cell line comparisons. Of 345 probes within the commonly deleted 19q region, seven genes (APOE, RCN3, FLJ10781, SAE1, STRN4, CCDC8, and BCL2L12) were identified as potential candidate genes. RT-PCR analysis of primary tumor specimens showed that several genes had significant differences when stratified by tumor morphology or deletion status. This suggests that one or more of these candidates may play a role in glioma formation or progression. © 2009 Wiley-Liss, Inc. [source] Homozygous deletions within the 11q13 cervical cancer tumor-suppressor locus in radiation-induced, neoplastically transformed human hybrid cellsGENES, CHROMOSOMES AND CANCER, Issue 4 2004Marc S. Mendonca Studies on nontumorigenic and tumorigenic human cell hybrids derived from the fusion of HeLa (a cervical cancer cell line) with GM00077 (a normal skin fibroblast cell line) have demonstrated "functional" tumor-suppressor activity on chromosome 11. It has been shown that several of the neoplastically transformed radiation-induced hybrid cells called GIMs (gamma ray induced mutants), isolated from the nontumorigenic CGL1 cells, have lost one copy of the fibroblast chromosome 11. We hypothesized, therefore, that the remaining copy of the gene might be mutated in the cytogenetically intact copy of fibroblast chromosome 11. Because a cervical cancer tumor suppressor locus has been localized to chromosome band 11q13, we performed deletion-mapping analysis of eight different GIMs using a total of 32 different polymorphic and microsatellite markers on the long arm (q arm) of chromosome 11. Four irradiated, nontumorigenic hybrid cell lines, called CONs, were also analyzed. Allelic deletion was ascertained by the loss of a fibroblast allele in the hybrid cell lines. The analysis confirmed the loss of a fibroblast chromosome 11 in five of the GIMs. Further, homozygous deletion (complete loss) of chromosome band 11q13 band sequences, including that of D11S913, was observed in two of the GIMs. Detailed mapping with genomic sequences localized the homozygous deletion to a 5.7-kb interval between EST AW167735 and EST F05086. Southern blot hybridization using genomic DNA probes from the D11S913 locus confirmed the existence of homozygous deletion in the two GIM cell lines. Additionally, PCR analysis showed a reduction in signal intensity for a marker mapped 31 kb centromeric of D11S913 in four other GIMs. Finally, Northern blot hybridization with the genomic probes revealed the presence of a novel >15-kb transcript in six of the GIMs. These transcripts were not observed in the nontumorigenic hybrid cell lines. Because the chromosome 11q13 band deletions in the tumorigenic hybrid cell lines overlapped with the minimal deletion in cervical cancer, the data suggest that the same gene may be involved in the development of cervical cancer and in radiation-induced carcinogenesis. We propose that a gene localized in proximity to the homozygous deletion is the candidate tumor-suppressor gene. © 2004 Wiley-Liss, Inc. [source] Construction of a Primary RH Panel of Italian Ryegrass Genome via UV-Induced Protoplast FusionPLANT BIOLOGY, Issue 5 2006A. Cheng Abstract: Symmetric and asymmetric somatic hybrids were produced via protoplast fusion between common wheat (Triticum aestivum L.) cv. "Jinan 177" and Italian ryegrass (Lolium multiflorum Lam.). The ryegrass without or with UV irradiation was used as a donor, providing a small amount of chromatin. In these somatic hybrids, most ryegrass chromosomes have been confirmed preferential elimination and the somatic hybrid calli and plants showed wheat-like morphology. Some of the hybrid lines were used for the analysis of distribution and heredity of donor DNA in the hybrid genome and the possibility of establishing a radiation hybrid (RH) panel of the ryegrass in the present experiment. These hybrids, subcultured for two and three years, retained the ryegrass DNA examined by RFLP and GISH analysis, respectively. Distribution of the ryegrass DNA in the wheat genomes of 20 single-cell individuals, randomly selected from hybrid cell lines produced, were analyzed by 21 ryegrass genome specific SSR markers. The average frequencies of molecular marker retention in symmetric hybrid lines (UV 0), as well as asymmetric hybrid lines from UV 30 s and 1 min were 10.88, 15.48 and 33.86, respectively. It was suggested that the UV dose increased the introgression of donor DNA into wheat genome. The ryegrass SSR fragments in most asymmetric hybrid cell lines remained stable over a period of 2 , 3 years. This revealed that those asymmetric somatic hybrids are suitable for the introgression of ryegrass DNA into wheat, and for RH panel and RH mapping. [source] | ||||||||||