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81.
Our laboratory has focused on defining, localizing, and understanding the mode of action of genes involved in fractionated x-irradiation (FXI) leukemia in susceptible and resistant mouse strains. We have described the genetic and molecular evidence suggesting the existence of multiple independent loci involved in FXI-induced leukemogenesis. These studies indicated that one of these, Ril-1, a locus on the distal portion of chromosome 15, is the major locus influencing susceptibility to the disease. Our data unequivocally place Ril-1 in the gene complex Ly-6--Ril-1--Sis--H-30--Pol-5. Ril-1 appears to be closest to Ly-6 and Sis. We report that in FXI-induced leukemias there are hypomethylation changes in the Ly-6 region as compared to normal thymocytes. In contrast, Sis was found to be hypermethylated and not expressed. In addition, we have noted DNA rearrangements in the Ly-6--Pol-5 region in the majority of tumors examined using the Ly-6 and spleen focus-forming virus (SFFLV) molecular probes. Increased expression of Ly-6 and other surface markers encoded in this region has been noted in FXI-induced thymomas.
Address correspondence and offprint request to: N. M. B. Amari. 相似文献
82.
Gene expression of metalloproteinase and its inhibitor in mesangial cells exposed to high glucose. 总被引:3,自引:0,他引:3
M Kitamura A Kitamura T Mitarai N Maruyama R Nagasawa T Kawamura H Yoshida T Takahashi O Sakai 《Biochemical and biophysical research communications》1992,185(3):1048-1054
To clarify the roles of metalloproteinases and their inhibitor (TIMP) in diabetic glomerulopathy, we studied the effect of a high glucose concentration on the gene expression of metalloproteinase transin and TIMP as well as collagen type IV and laminin in cultured rat mesangial cells (MCs). In the high glucose group, collagen type IV, laminin, and TIMP mRNA levels were all elevated in a concentration-dependent manner, whereas transin expression was suppressed. Osmotic control of high glucose with mannitol selectively stimulated TIMP expression. We hypothesize that high glucose decreases matrix-degrading activity as well as increases matrix productivity in MCs. 相似文献
83.
Human hepatocyte growth factor (hHGF) consists of characteristic structural domains. In this study, we prepared mutant proteins lacking each of these domains and examined their biological activities for stimulation of hepatocyte DNA synthesis, inhibition of Meth A cell growth, and induction of MDCK cell dissociation. We also examined their interactions with the c-met/HGF receptor by competition analysis and by analysis of levels of tyrosine phosphorylation. The mutant proteins lacking the N-terminal, the first kringle, or the second kringle domain were not biologically effective and could not compete with hHGF bound to the c-met/HGF receptor. The results indicate that these domains are necessary for the biological activities of hHGF mediated by binding to the c-met/HGF receptor. The mutant proteins lacking the third or fourth kringle domain moderately retained biological activities and the receptor binding. The relative levels of the tyrosine phosphorylation of the c-met/HGF receptor by these mutant proteins correlated well with the relative potencies of the biological activities when compared with that of the wild-type hHGF. The mutant protein lacking the light chain was not effective in the biological activities and tyrosine phosphorylation of the c-met/HGF receptor, but competed with hHGF bound to the c-met/HGF receptor. These results suggest that the heavy chain plays an important role in the interaction of hHGF with the c-met/HGF receptor and that the light chain is further required for the tyrosine phosphorylation of the c-met/HGF receptor. 相似文献
84.
Koichi Rikimaru Hitomi Toda Noriko Tachikawa Nobuyuki Kamata Shoji Enomoto 《In vitro cellular & developmental biology. Plant》1990,26(9):849-856
Summary A novel protein-free synthetic medium has been developed for the culture of human squamous cell carcinoma cells. This medium,
designated PF86-1, supports the serial subcultivation of six out of nine human squamous cell carcinoma cell lines in a protein-free,
chemically defined condition without the adapting culture from serum-containing conditions. These cell lines growing in PF86-1
exhibited nearly equal potency to grow in massive culture without noticeable changes in morphology but presented a significantly
decreased level of colony forming efficiency when compared with the cells cultured in serum-containing media, suggesting the
implication of some autocrine mechanism. Interestingly, this medium supported the growth of normal human squamous cells of
oral mucosa and skin for more than 2 mo. in the primary explant culture in spite of high levels of calcium ion concentration,
where the overgrowth of fibroblasts as contaminant was not observed. These results suggest that PF86-1 supports the growth
of cells derived from epidermal tissues selectively and provides the same defined condition for growth of malignant and nonmalignant
human squamous cells. It seems, therefore, that PF86-1 allows investigations on the products of squamous cell carcinoma cells
or on the differences of growth mechanisms between normal and neoplastic human squamous cells. 相似文献
85.
Kenji Takeuchi Sayumi Shibamoto Makio Hayakawa Takamitsu Hori Keiji Miyazawa Naomi Kitamura Fumiaki Ito 《Experimental cell research》1996,223(2):420
Hepatocyte growth factor (HGF) stimulated cell migration of human gastric carcinoma cell lines MKN1, MKN7, and MKN28. Epidermal growth factor (EGF) also stimulated the cell migration of these three cell lines. In MKN7 cells, HGF-stimulated cell migration was rather reduced in the presence of EGF, whereas such an observation was not made with MKN1 and MKN28 cells. Therefore, we compared the effect of EGF on HGF-stimulated HGF receptor phosphorylation in these cell lines. HGF induced a rapid tyrosine phosphorylation of the HGF receptor in all these cell lines. In MKN7 cells, the increased phosphorylation was further enhanced by EGF, although EGF alone did not affect tyrosine phosphorylation of the HGF receptor. In MKN1 and MKN28 cells, EGF did not influence tyrosine phosphorylation of the HGF receptor, whether HGF was present or not. The data presented here suggest that EGF negatively modulates the cellular response to HGF by increasing tyrosine phosphorylation of the HGF receptor in certain types of epithelial cells, e.g., MKN7 cells. 相似文献
86.
Akira Nomura Yuko Yamazaki Takashi Tsuji Yukishige Kawasaki Shoji Tanaka 《Experimental cell research》1996,227(2):256
For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification ofin situmechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space. 相似文献
87.
Yuriko Osakabe Kazuya Nanto Hiroko Kitamura Shinya Kawai Yuki Kondo Tomoyuki Fujii Keiji Takabe Yoshihiro Katayama Noriyuki Morohoshi 《Planta》1996,200(1):13-19
The polypeptide encoded by the partial fragment of cDNA of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), PALcDNAl (Osakabe et al., 1995, Plant Sci. 105: 217–226), isolated from Populus kitakamiensis (P. sieboldii x P. grandidentata), was expressed in Escherichia coli cells. The polypeptide was purified and an antiserum raised against it. The antiserum recognized a protein of 77 kDa on nitrocellulose blots after sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of total protein and the partially purified PAL protein from P. kitakamiensis. Moreover,the antiserum recognized a protein on the blot after non-denaturing polyacrylamide gel electrophoresis of P. kitakamiensis proteins and this protein had PAL activity. Furthermore, the antibody inhibited PAL activity of extracts from stem tissues. These results showed that the antiserum against the partial PAL peptide recognized only the PAL subunits in extracts of P. kitakamiensis. Immunolocalization studies of P. kitakamiensis tissues revealed that the PAL protein was specifically localized in the xylem and the phloem fibers and no immunogold signal was found in the epidermis, the cortex, the pith, or the cambium of either stems or leaves.Abbreviations IgG
immunoglobulin G
- IPTG
isopropylthio--d-galactoside
- PAL
phenylalanine ammonia-lyase
The authors thank Dr. Kunio Hata of Nippon Paper Industries Co., Ltd. (Japan) for supplying P. kitakamiensis. This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (No. 07406008). 相似文献
88.
Shuji Nakamura David W. Stock Karen L. Wydner Jacques A. Bollekens Kenichi Takeshita Brian M. Nagai Shigeru Chiba Toshio Kitamura Thomas M. Freeland Zhiyong Zhao Jun Minowada Jeanne B. Lawrence Kenneth M. Weiss Frank H. Ruddle 《Genomics》1996,38(3):314
We have cloned a new Dlx gene (Dlx7) from human and mouse that may represent the mammalian orthologue of the newt geneNvHBox-5.The homeodomains of these genes are highly similar to all other vertebrate Dlx genes, and regions of similarity also exist between mammalian Dlx7 and a subset of vertebrate Dlx genes downstream of the homeodomain. The sequence divergence between human and mouse Dlx7 in these regions is greater than that predicted from comparisons of other vertebrate Dlx genes, however, and there is little sequence similarity upstream of the homeodomain both between these two genes and with other Dlx genes. We present evidence for alternative splicing of mouseDlx7upstream of the homeodomain that may account for some of this divergence. We have mapped humanDLX7distal to the 5′ end of the HOXB cluster at an estimated distance of between 1 and 2 Mb by FISH. Both the human and the mouse Dlx7 are shown to be closely linked to Dlx3 in a convergently transcribed orientation. These mapping results support the possibility that vertebrate distal-less genes have been duplicated in concert with the Hox clusters. 相似文献
89.
CD45-AP is a recently identified phosphorylated protein that specifically associates with the leukocyte-specific transmembrane glycoprotein CD45. The gene for CD45-AP,Ptprcap(protein tyrosine phosphatase, receptor type c polypeptide associated protein), was mapped in mouse by typing the progeny of two multilocus crosses using the mouse CD45-AP cDNA as a Southern hybridization probe. The CD45-AP gene mapped to the centromeric region of Chr 19 proximal to the genesFth, Cd5,andPcna-rs.The gene for the human CD45-AP homologue,PTPRCAP,was localized to chromosome band 11q13.1–q13.3 by fluorescencein situhybridization using human genomic CD45-AP DNA as a hybridization probe. The genetic mapping of thePtprcap/PTPRCAPgenes extends the previously defined synteny conservation of various genes that have been assigned to these regions of the mouse and the human chromosomes. 相似文献
90.
Anti-human immunodeficiency virus type 1 activity of phosphorothioate analogs of oligodeoxynucleotides: penetration and localization of oligodeoxynucleotides in HIV-1-infected MOLT-4 cells. 总被引:1,自引:1,他引:0
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H Nakashima Y Shoji S G Kim J Shimada Y Mizushima M Ito N Yamamoto H Takaku 《Nucleic acids research》1994,22(23):5004-5010