表皮生长因子对neu基因表达的诱导作用（简报）

The erb B2/neu oncogene encodes a protein which sequence is closely similar to the epidermal growth factor receptor (EGFR). We have previously found that EGF can induce the expression of erb B1/EGFR gene in normal and 3H-TdR transformed C3H/10T1/2CL8 mouse embryo fibroblast cells i.e. NC3H10 and TC 3H10 respectively, but we do not know whether the neu oncogene expression can be induced by EGF. In this study, the effect of EGF on NC3H10 and TC3H10 has been observed by Northern blot analysis. The result indicated that EGF had a obvious induction effect on neu oncogene expression in these cells. Thus, the expression of both erbB 1/EGFR gene and erbB 2/neu oncogene can be induced by EGF. This result may provide a novel clue to the molecular mechanism of EGF action in cell nucleus.     

表皮生长因子对neu基因表达的诱导作用(简报)

Shih等首次通过NIH/3T3细胞转染试验在乙基亚硝脲(ENU)诱导的大鼠神经胶质纤维瘤中分离鉴定出一种转化基因,称之为neu基因,其表达可导致培养的NIH/3T3细     

Isolation and identification of Triticum aestivum L. em. Thell. cv Chinese Spring-T. peregrinum Hackel disomic chromosome addition lines

Analyses of RFLPs, isozymes, morphological markers and chromosome pairing were used to isolate 12 Triticum aestivum cv Chinese Spring (genomes A, B, and D)-T. peregrinum (genomes S^v and U^v) disomic chromosome addition lines. The evidence obtained indicates that each of the 12 lines contains an intact pair of T. peregrinum chromosomes. One monosomic addition line, believed to contain an intact 6S^v chromosome, was also isolated. A CS-7U^v chromosome addition line was not obtained. Syntenic relationships in common with the standard Triticeae arrangement were found for five of the seven S^v genome chromosomes. The exceptions were 4S^v and 7S^v. A reciprocal translocation exists between 4S¹ and 7S¹ in T. longissimum and evidence was obtained that the same translocation exists in T. peregrinum. In contrast, evidence for syntenic relationships in common with the standard Triticeae arrangements were found for only one U^v chromosome of T. peregrinum.; namely, chromosome 2U^v. All other U^v genome chromosomes are involved in at least one translocation, and the same translocations were found in the U genome of T. umbellulatum. Evidence was also obtained indicating that the centromeric regions of 4U and 4U^v are homoeologous to the centromeric regions of Triticeae homoeologous group-6 chromosomes, that the centromeric regions of 6U and 6U^v are homoeologous to the centromeric regions of group-4 chromosomes, and that 4U and 4U^v are more closely related overall to Triticeae homoeologous group-6 chromosomes than they are to group-4 chromosomes.     

ErbB2 and EGFR are downmodulated during the differentiation of 3T3-L1 preadipocytes

The expression of receptors belonging to the epidermal growth factor receptor subfamily has been largely studied these last years in epithelial cells mainly as involved in cell proliferation and malignant progression. Although much work has focused on the role of these growth factor receptors in the differentiation of a variety of tissues, there is little information in regards to normal stromal cells. We investigated erbB2 expression in the murine fibroblast cell line Swiss 3T3L1, which naturally or hormonally induced undergoes adipocyte differentiation. We found that the Swiss 3T3-L1 fibroblasts express erbB2, in addition to EGFR, and in a quantity comparable to or even greater than the breast cancer cell line T47D. Proliferating cells increased erbB2 and EGFR levels when reaching confluence up to 4- and 10-fold, respectively. This expression showed a significant decrease when growth-arrested cells were stimulated to differentiate with dexamethasone and isobutyl-methylxanthine. Differentiated cells presented a decreased expression of both erbB2 and EGFR regardless of whether the cells were hormonally or spontaneously differentiated. EGF stimulation of serum-starved cells increased erbB2 tyrosine phosphorylation and retarded erbB2 migration in SDS-PAGE, suggesting receptor association and activation. Heregulin-alpha1 and -beta1, two EGF related factors, had no effect on erbB2 or EGFR phosphorylation. Although 3T3-L1 cells expressed heregulin, its specific receptors, erbB3 and erbB4, were not found. This is the first time in which erbB2 is reported to be expressed in an adipocytic cell line which does not depend on non EGF family growth factors (thyroid hormone, growth hormone, etc.) to accomplish adipose differentiation. Since erbB2 and EGFR expression were downmodulated as differentiation progressed it is conceivable that a mechanism of switching from a mitogenic to a differentiating signaling pathway may be involved, through regulation of the expression of these growth factor receptors.     

Expression of the Activated p185Tyrosine Kinase in Human Epithelial Cells Leads to MAP Kinase Activation but Does Not Confer Oncogenicity

Amplification of thec-erbB2gene and overexpression of p185^erbB2is found in approximately one-third of primary breast and ovarian cancers and also in some colon carcinomas. Moreover, a single point mutation inerbB2(V 664 E)confers transforming potential to erbB2 in NIH3T3 cells, even when expressed at low levels. To examine the transformation potential oferbB2orerbB2(V-E)in colon epithelial cells, we have transfected a nontumorigenic clone of SW 613-S cells with either wild-type p185^erbB2or mutated p185^erbB2(V-E). In contrast to p185^erbB2, p185^erbB2(V-E)associated constitutively with members of the Shc protein family, leading to phosphorylation of Shc and to stimulation of mitogen-activated protein kinase (MAP kinase). However, constitutive activation of MAP kinase activation in p185^erbB2(V-E)expressing cells did not result in a tumorigenic phenotype. In addition, p185^erbB2(V-E)expressing cells displayed a reduced ability to grow in soft agar compared to the parental cell line. In contrast these transfected cells were able to grow in three-dimensional collagen gels, whereas parental cells were not. Thus, expression oferbB2(V-E)in SW 613-S cells induced multiple changes in intracellular signaling and in growth requirement phenotype, particularly in response to the extracellular environment.     

Gene expression is highly correlated on the chromosome level in urinary bladder cancer

Objective: Chromosome correlation maps display correlations between gene expression patterns on the same chromosome. Our goal was to map the genes on chromosome regions and to identify correlations through their location on chromosome regions.

Materials and Methods: Following microarray analysis we used Ingenuity Pathway Analysis (IPA) to construct gene networks of the co-deregulated genes in bladder cancer. Chromosome mapping, mathematical modeling and data simulations were performed using the WebGestalt and Matlab^® softwares.

Results: The top deregulated molecules among 129 bladder cancer samples were implicated in the PI3K/AKT signaling, cell cycle, Myc-mediated apoptosis signaling and ERK5 signaling pathways. Their most prominent molecular and cellular functions were related to cell cycle, cell death, gene expression, molecular transport and cellular growth and proliferation. Chromosome correlation maps allowed us to detect significantly co-expressed genes along the chromosomes. We identified strong correlations among tumors of Tα-grade 1, as well as for those of Tα-grade 2, in chromosomes 1, 2, 3, 7, 12 and 19. Chromosomal domains of gene co-expression were revealed for the normal tissues, as well. The expression data were further simulated, exhibiting an excellent fit (0.7 < R² < 0.9). The simulations revealed that along the different samples, genes on same chromosomes are expressed in a similar manner.

Conclusions: Gene expression is highly correlated on the chromosome level. Chromosome correlation maps of gene expression signatures can provide further information on gene regulatory mechanisms. Gene expression data can be simulated using polynomial functions.     

Nucleolus formation in structurally reconstructed barley karyotypes with six satellite chromosomes

Two structurally reconstructed karyotypes of Hordeum vulgare which, due to appropriate reciprocal translocations, contain three chromosome pairs with nucleolus organizing activity (chromosomes 5⁷, 6 and 7⁷ in translocation line T 21, chromosomes 3⁶, 6³, and 7 in translocation line T 627) have been studied with respect to the position and function of rDNA as inferrred from the pattern of nucleolus formation. The results obtained reveal quantitative relationships between the size of the secondary constriction (the amount of rRNA cistrons) and the number and size of nucleoli being formed. Quantitative and qualitative aspects of rDNA location and expression are being discussed.     

Discovery and mapping of wheat Ph1 suppressors

Pairing between wheat (Triticum turgidum and T. aestivum) homeologous chromosomes is prevented by the expression of the Ph1 locus on the long arm of chromosome 5B. The genome of Aegilops speltoides suppresses Ph1 expression in wheat x Ae. speltoides hybrids. Suppressors with major effects were mapped as Mendelian loci on the long arms of Ae. speltoides chromosomes 3S and 7S. The chromosome 3S locus was designated Su1-Ph1 and the chromosome 7S locus was designated Su2-Ph1. A QTL with a minor effect was mapped on the short arm of chromosome 5S and was designated QPh.ucd-5S. The expression of Su1-Ph1 and Su2-Ph1 increased homeologous chromosome pairing in T. aestivum x Ae. speltoides hybrids by 8.4 and 5.8 chiasmata/cell, respectively. Su1-Ph1 was completely epistatic to Su2-Ph1, and the two genes acting together increased homeologous chromosome pairing in T. aestivum x Ae. speltoides hybrids to the same level as Su1-Ph1 acting alone. QPh.ucd-5S expression increased homeologous chromosome pairing by 1.6 chiasmata/cell in T. aestivum x Ae. speltoides hybrids and was additive to the expression of Su2-Ph1. It is hypothesized that the products of Su1-Ph1 and Su2-Ph1 affect pairing between homeologous chromosomes by regulating the expression of Ph1 but the product of QPh.ucd-5S may primarily regulate recombination between homologous chromosomes.     

Transfer of the human X chromosome to human--Chinese hamster cell hybrids via isolated HeLa metaphase chromosomes.

Evidence is presented for the uptake of the human X chromosome by human-Chinese hamster cell hybrids which lack H P R T activity, following incubation with isolated human HeLa S3 chromosomes. Sixteen independent clonal cell lines were isolated in H A T medium, all of which contained a human X chromosome as determined by trypsin-Giemsa staining. The frequency of H A T-resistant clones was 32 x 10(-6) when 10(7) cells were incubated with 10(8) HeLa chromosomes. Potential reversion of the hybrid cells in H A T medium was less than 5 x 10(-7). The 16 isolated cell lines all contained activity of the human X-linked marker enzymes H P R T, P G K,alpha-Gal A, and G6PD, as determined by electrophoresis. The phenotype of G6PD was G6PD A, corresponding to G6PD A in HeLa cells. The human parental cells used in the fusion to form the hybrids had the G6PD B phenotype. The recipient cells gave no evidence of containing human X chromosomes. These results indicate that incorporation and expression of HeLa X chromosomes is accomplished in human-Chinese hamster hybrids which lack a human X chromosome.     

Chromosomal rearrangements and their effects in spontaneous immortalization and transformation of rat embryo cells in vitro

G-banding analysis of LRec-1 and LRec-3, spontaneously immortalized cell lines from rat embryo fibroblast, revealed diploid karyotypes with specific clonal structural rearrangements of chromosomes 7 and 19 - del(7)(q11.2q22.1), t(7;19)(q11.1;q12) in malignant stage. Both clonal abnormalities of chromosomes 7 and 19 were also revealed in LRec-1k clone and LRec-1 sf cell line. Previous study of LRec-1 and LRec-3 cells showed the presence of karyotypes with pseudodiploid modal chromosome number, partial trisomy of chromosome 7 and same clonal structural rearrangements of chromosomes 7 and 19 in immortalized stage. In malignant stage, the trisomy 6 and new clonal structural rearrangements of chromosomes 1, 2, 11, 15, 18, 19 and of chromosomes 10, 20 were also found in LRec-1 sf and LRec-1 cells, accordingly. There were no new clonal structural chromosome rearrangements in LRec-1 k and LRec-3 cells. We compared locies of chromosomes involved in rearrangements with mapped genes on these chromosomes according to RATMAP. Supposedly these genes are involved in spontaneous immortalization of rat embryo fibroblast and malignant transformation of LRec-1 and LRec-3 cells and rearrangements of chromosomes 1, 2, 11, 15 and 18 facilitate expression of growth factors of LRec-1 sf cells.     

Chromosomal changes in cell lines from mouse tumors induced by nickel sulfide and methylcholanthrene

Rhabdomyosarcomas were induced in mice by intramuscular injections of crystalline nickel sulfide and 3-methylcholanthrene. At early passage, karyotypes were performed by G-banding for four nickel sulfide cell lines and for three 3-methylcholanthrene cell lines. Six cell lines were near-diploid and one nickel sulfide line was near-tetraploid. Three of the nickel sulfide cell lines were characterized by a rearranged marker chromosome which was present in a majority of the cells of each line. The rearrangements leading to the formation of marker chromosomes were different in each nickel sulfide cell line but involved chromosome 4 in two of the nickel sulfide cell lines. Extra copies of chromosome 15 were present in two nickel sulfide cell lines. Possible rearrangement and/or gene activation was examined for the c-mos oncogene on chromosome 4 and the c-myc oncogene on chromosome 15, but no alteration or activation was observed. None of the 3-methylcholanthrene cell lines contained rearranged marker chromosomes; however, one MCA cell line did contain large numbers of double minutes. In all cell lines, minichromosomes (small atypical acrocentric chromosomes) were observed that contained distinct centromeric regions but no other G-positive bands.Abbreviations DHFR dihydrofolate reductase - MCA 3-methylcholanthrene - NS nickel sulfide     

A chimeric EGF-R-neu proto-oncogene allows EGF to regulate neu tyrosine kinase and cell transformation.

The neu oncogene, characterized by Weinberg and colleagues, is a transforming gene found in ethylnitrosourea-induced rat neuro/glioblastomas; its human proto-oncogene homologue has been termed erbB2 or HER2 because of its close homology with the epidermal growth factor receptor (EGF-R) gene (c-erbB1). Expression of the rat neu oncogene is sufficient for transformation of mouse NIH 3T3 fibroblasts in culture and for the development of mammary carcinomas in transgenic mice, but the neu proto-oncogene has not been associated with cell transformation. We constructed a vector for expression of a chimeric cDNA and hybrid protein consisting of the EGF-R extracellular, transmembrane and protein kinase C-substrate domains linked to the intracellular tyrosine kinase and carboxyl terminal domain of the rat neu cDNA. Upon transfection with the construct, NIH 3T3 cells gave rise to EGF-R antigen-positive cell clones with varying amounts of specific EGF binding. Immunofluorescence and immunoprecipitation using neu- and EGF-receptor specific antibodies demonstrated a correctly oriented and positioned chimeric EGF-R-neu protein of the expected apparent mol. wt on the surface of these cells. EGF or TGF alpha induced tyrosine phosphorylation of the chimeric receptor protein, stimulated DNA synthesis of EGF-R-neu expressing cells and led to a transformed cell morphology and growth in soft agar. In contrast, the neu proto-oncogene did not show kinase activity or transforming properties when expressed at similar levels in NIH 3T3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative study of pig-rodent somatic cell hybrids

The pig chromosome complement of six different types of pig-rodent hybrid cell lines was examined by means of fluorescence in situ hybridization with a porcine SINE probe. The cell lines were obtained by fusing pig lymphocytes with cells of the Chinese hamster cell lines wg3h, BK14-150 and E36, and of the mouse cell lines NSO, PU and LMTK^-. The hybrids were analysed with respect to: (1) the number of pig chromosomes, (2) the type of pig chromosomes, (3) the occurrence of pig-rodent chromosome trans-locations, and (4) the presence of pig chromsome fragments. The results show that the number of pig chromosomes varied within and among hybrid cell lines. The pig-hamster hybrids mainly retained nontelocentric pig chromosomes, whereas the pig-mouse hybrids also retained telocentric pig chromosomes. Pig-rodent chromosome translocations were found in all types of hybrids, but the incidence was in general low. Chromosome fragments were abundant in BK14-150 hybrids, and rare in most other hybrid cell lines. It is concluded that the SINE probe is a useful tool to make a preliminary characterization of the porcine chromosome complement of pig-rodent somatic cell hybrids. The results of this characterization can be used to select hybrids for further cytogenetic analysis. Furthermore, our data show that different rodent cell lines will have to be used as fusion partners for the production of hybrids when constructing a panel informative for all pig chromosomes.     

Cytogenetic and immunological study of mammalian hybrid cell lines

Two hybrid cell lines, KS-RL-3 (hybrid between TK^? sheep kidney cells and rabbit lymphocytes) and CR-KS TK^? (hybrid between rabbit β-cells and TK^? sheep kidney cells), were assayed cytogenetically. It was shown that these hybrid cell lines were characterized by the presence of both sheep and rabbit chromosomes, with a number and structure which varied depending on the cell type and the number of passages. In some cases aberrant chromosomes were identified. The modal chromosome number was 121–135 (40.7%) in the KS-RL-3 cell line and 106–120 (51.6%) in the CR-KS TK^? cell line. CR-KS TK^? and KS-RL-3 cells were identified in the testicles and ear lobes of experimental animals during periods of 7 to 28 days after cell inoculation. Partial immunological tolerance of the hybrid cell lines was suggested.     

Assignment of the human gene for hexosaminidase B to chromosome 5

Mouse-human somatic cell hybrids between different mouse and human cells were studied for the expression of human hexosaminidases A and B activities. The expression of human hexosaminidase B in the hybrids was found to segregate concordantly with the presence of the human chromosome 5. Mouse-human hybrid clones containing either the human chromosomes 5 and 7 only or the human chromosome 7 only were also included in this study. Expression of human hexosaminidase B activity was detected only in those clones containing human chromosome 5. These results indicate that the gene(s) for human hexosaminidase B is located on chromosome 5. No hexosaminidase A activity was detected in clones which contained either human chromosomes 5 and 7 or chromosome 7.     

erbB-2与胃癌细胞恶性表型及其增殖调控的关系

应用基因重组、基因转染、Ｓｏｕｔｈｅｒｎ杂交、Ｎｏｒｔｈｅｒｎ杂交、细胞生长曲线测定及裸鼠成瘤观察了反义ｅｒｂＢ－２逆转录病毒重组载体的转染对人胃癌细胞中ｅｒｂＢ－２过度表达的影响及其对ＥＧＦ的反应性．研究结果显示,ｅｒｂＢ－２的表达被其反义重组子特异抑制,伴有细胞增殖能力的下降及致瘤性的下降;在ＥＧＦ的刺激下,ｅｒｂＢ－２高表达肿瘤细胞生长速度提高的幅度显著大于ｅｒｂＢ－２反义重组载体转染细胞;ＥＧＦ促细胞增殖及促基因表达的功能在ｅｒｂＢ－２反义重组子转染后受到抑制,提示ｅｒｂＢ－２在细胞增殖调控中具有重要功能．     

Localization of amplified CAD genes on rearranged chromosomes of Chinese hamster cells

Chinese hamster cell lines carrying an amplified CAD region were selected from V79,B7 cells by their resistance to N-phosphonacetyl-L-aspartate (PALA). In one of the selected cell lines, SP PALA _inf1 ^supR L, an acrocentric chromosome with abnormally elongated q arms was identified as a marker for the PALA-resistant phenotype. The marker chromosome carried a homogeneously staining region close to a telomeric nucleolar organizer region. In the same region, localization of amplified CAD sequences was demonstrated by in situ hybridization. The marker chromosome was found to undergo extensive rearrangements. In particular, dicentric chromosomes, occurring with an unusually high incidence, were found to originate from end-fusion of two homologous marker chromosomes.Abbreviations ATCase Aspartate Transcarbamylase - CAD Carbamyl-phosphate synthetase-Aspartate transcarbamylase-Dihydroorotase - MTX Methotrexate - NOR Nucleolar Organizer Region - PALA N-phosphonacetyl-L-Aspartate