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M Oshimura

Publications and source records attributed to M Oshimura.

At least 163 records · Page 9Linked to original sources
PubMed1993

Restoration of the cholesterol metabolism in 3T3 cell lines derived from the sphingomyelinosis mouse (spm/spm) by transfer of a human chromosome 18.

We searched for a human chromosome that would restore the cholesterol metabolism in 3T3 cell lines (SPM-3T3) derived from homozygous sphingomyelinosis mice (spm/spm). Mouse A9 cells containing a single copy of pSV2neo-tagged chromosomes 9, 11, or 18 derived from normal human fibroblasts served as donor cells for transfer of human chromosomes. Purified A9 microcells were fused with SPM-3T3 cells, and the microcell hybrids were selected in medium containing G418 antibiotics. The microcell hybrids that contained human chromosomes 9, 11, or 18 in a majority of cells were examined. The accumulation of intracellular cholesterol in the microcell hybrids containing a chromosome 18 decreased markedly, whereas in the microcell hybrids containing either chromosomes 9 or 11 it was similar to that in SPM-3T3 cells. The SPM-3T3 cells with an intact chromosome 18 were further passaged and subcloned. Clones which again accumulated intracellular cholesterol had concurrently lost the introduced chromosome 18. The abnormal accumulation was associated with a decrement in the esterification of exogenous cholesterol. These findings suggest that the gene responsible for the abnormal cholesterol metabolism in the spm/spm mice can be restored by a human chromosome 18. The gene was tentatively mapped on 18pter-->18p11.3 or 18q21.3-->qter that was lost during subcloning, thereby resulting in reaccumulation of the intracellular cholesterol.

3T3 Cells↗
PubMed1993

Chromosomal localization and cDNA sequence of human BTEB, a GC box binding protein.

Human BTEB cDNA clones have been isolated, sequenced, and the corresponding gene has been assigned to human chromosome 9, region q13, by fluorescent in situ hybridization and DNA blot analysis using DNAs from hybrid cell clones containing a single human chromosome. The cDNA clone encodes a polypeptide of 244 amino acids whose sequence shows a high sequence similarity with the rat BTEB (98% amino acid identity).

Amino Acid Sequence↗
PubMed1993

Chromosome 7 suppresses indefinite division of nontumorigenic immortalized human fibroblast cell lines KMST-6 and SUSM-1.

Using nontumorigenic immortalized human cell lines KMST-6 (KMST) and SUSM-1 (SUSM), we attempted to identify the chromosome that carries a putative senescence-related gene(s). These cell lines are the only ones that have been established independently from normal human diploid fibroblasts following in vitro mutagenesis. We first examined restriction fragment length polymorphisms on each chromosome of these immortalized cell lines and their parental cell lines and found specific chromosomal alterations common to these cell lines (a loss of heterozygosity in KMST and a deletion in SUSM) on the long arm of chromosome 7. In addition to these, we also found that introduction of chromosome 7 into these cell lines by means of microcell fusion resulted in the cessation of cell division, giving rise to cells resembling cells in senescence. Introduction of other chromosomes, such as chromosomes 1 and 11, on which losses of heterozygosity were also detected in one of the cell lines (KMST), to either KMST or SUSM cells or of chromosome 7 to several tumor-derived cell lines had no effect on their division potential. These results strongly suggest that a gene(s) affecting limited-division potential or senescence of normal human fibroblasts is located on chromosome 7, probably at the long arm of the chromosome, representing the first case in which a specific chromosome reverses the immortal phenotype of otherwise normal human cell lines.

Animals↗
PubMed1993

Deletion mapping of chromosome 3p in human uterine cervical cancer.

Deletion mapping of chromosome 3p was performed on 47 cases of human uterine cervical cancer using 24 polymorphic DNA markers including five inter-Alu DNA markers and two NotI-boundary cosmid markers obtained in our laboratory. The most likely order of these 24 polymorphic DNA markers was determined as being cen-[D3S4, H8]-D3S693-D3S659-D3S30-D3S687-[D3S2, UR9, UR47]-J36-J17-GNAI2B-D3F15S2-D3S643- D3S32-D3S23-D3S686-H35-UR189-D3S685-D3S 11 - D3S12-THRB-D3S22-pter, based on the data from radiation hybrid mapping genetic linkage analysis and in situ hybridization. Loss of heterozygosity (LOH) at one or more loci on chromosome 3p was detected in 21 of 47 cases (45%). Four tumors showed partial or interstitial deletions, and the common region of LOH in these tumors was 3p13-p21.1 between the D3S30 marker and the D3S2 marker. Candidates for tumor-suppressor genes, APEH, D8, GNA12B, ZNF35, RARB, THRB and RAFI, were all mapped outside of the common region in uterine cervical cancer. However, this region is commonly deleted in carcinoma of the lung, breast and kidney, and encompasses the breakpoint of the (3;8) translocation in hereditary renal cell carcinoma. This result indicates the presence of a novel tumor-suppressor gene in the region of 3p13-p21.1, which is involved in the development of several human cancers.

Base Sequence↗
PubMed1993

Suppression of tumourigenicity in human colon carcinoma cells by introduction of normal chromosome 1p36 region.

Development of colon carcinomas appears to be associated with inactivation of multiple tumour suppressor genes. Cytogenetic and DNA analyses of colon carcinomas have detected a high frequency of chromosome 1p deletion, which suggests the presence of a tumour suppressor gene. We therefore introduced normal human chromosome 1 into colon carcinoma COKFu cells, through microcell hybridization. Six clones of hybrid cells containing normal chromosome 1 were obtained, four of which had a small fragment of the introduced chromosome 1, including 1p36-34. The morphology of hybrid cells with chromosome 1 markedly altered to a flat shape. The cloning efficiency of all six hybrid cells in soft agar was significantly reduced, and the tumourigenicity in athymic nude mice was completely suppressed. Hybrid cells containing only the region of 1p36-34, as well as those containing intact chromosome 1, showed suppressed transformed phenotype. Furthermore, several tumourigenic revertant cells were obtained from the hybrid cells. These revertant cells had a morphology similar to that of COKFu cells, and were found to have lost the 1p36 region from the introduced chromosome 1. These results indicate that a normal chromosome 1p36 carries a tumour suppressor gene for colon carcinogenesis.

Adenocarcinoma↗
PubMed1993

Chromosome 3p deletion in a renal cell carcinoma cell line established from a patient with von Hippel-Lindau disease.

von Hippel-Lindau disease (VHL) is an autosomal dominant inherited disease, frequently accompanied by occurrences of renal cell carcinoma (RCC). Both the VHL gene and tumor suppressor genes for RCC have been mapped to the short arm of chromosome 3, although the genes have not yet been identified. An RCC cell line, KC12, was established from a VHL patient. Molecular genetic analyses in conjunction with cytogenetic studies revealed that the short arm of chromosome 3 distal to the D3S4 locus at 3p11 was lost in the RCC cell line as a result of an unbalanced translocation between chromosomes 3p and 5q. Structural and numerical aberrations, including those on chromosome 3p, were not detected in T-lymphocytes from the patient, suggesting that the inherited mutation of the VHL gene at 3p25-26 in this patient was too subtle to be detected by either Southern blot or karyotype analysis. Since no permanent RCC cell line has been established from a VHL patient, this cell line will be a useful source for analyzing the VHL gene at 3p25-26 and tumor suppressor gene(s) at 3p13-21.

Adult↗
PubMed1993

[Telomere, cellular senescence and transformation].

Telomere is the structure which is located on both ends of individual chromosomes in eukaryotes. The DNA sequence of the telomere consists of Guanine-rich tandem repeat, i.e., (TTAGGG)n in man. Telomere protects the end of the chromosome from fusion or deletion and maintains the stability of the chromosome and is synthesized by telomerase, a ribonucleoprotein. Telomere reduction is observed with cell senescence and immortalization, both in vivo and in vitro. Thus, telomere is considered to be a "clock" which measures the life span of cells, and its length is altered by cellular senescence and immortalization.

Aging↗
PubMed1993

Gene rearrangement and truncated mRNA in cell lines with 11q23 translocation.

We have previously demonstrated that the breakpoints of t(11;19)(q23;p13) leukemias are within 360 kb of the CD3 gene. One of the phage clones, 6n, which was isolated from the yeast artificial chromosome clone yB22B2 containing CD3, was found to be within 60 kb of t(11;19) breakpoints. In this study, gene walking was conducted and two phage clones (lambda Hp8-3 and lambda Hp23-13) were isolated from a human placenta genomic library. Southern blot analysis with a genomic probe from lambda Hp8-3 detected gene rearrangements in t(4;11) and t(11;19) cell lines with BamHI digestion. Subsequently, using reiterated sequence-free probes from both ends of 6n that detected transcriptional units in various hematopoietic cells, we isolated cDNA clones. These cDNA clones were classified into two groups (designated MLL-a and MLL-b), which do not hybridize to each other. Northern blot analysis with MLL-a cDNA detected 15-, 14- and 12-kb mRNAs, while MLL-b detected the additional 9.7- and 5-kb mRNAs in peripheral blood lymphocytes. MLL-b cDNA detected a truncated form of 12.5-kb mRNA in t(4;11) cell lines and a truncated form of 10-kb or 9.2-kb mRNA in t(11;19) cell lines. MLL-a did not demonstrate a truncated form of mRNA, but the stronger 14-kb signal was noted in t(4;11) cells, while this signal was very weak in t(11;19) cells. By Southern blot analysis, MLL-b cDNA detected gene rearrangement in cell lines with t(4;11) and t(11;19), whereas MLL-a did not. Furthermore, chimeric cDNA clones were isolated from cDNA libraries of t(4;11) and t(11;19) cell lines with a MLL-b cDNA probe. These results indicate that the MLL-b cDNA is derived from the common target gene involved in 11q23 translocation with 4q21 or 19p13.

Adult↗
PubMed1992

Localization of metastasis suppressor gene(s) for prostatic cancer to the short arm of human chromosome 11.

Previous studies using somatic cell hybridization of highly metastatic and nonmetastatic rat prostatic cancer cells demonstrated that the resultant hybrids were nonmetastatic if all of the parental chromosomes were retained. Somatic hybrid segregants which underwent nonrandom chromosomal losses reexpressed high metastatic ability. These results demonstrated that there are gene(s) the expression of which can suppress metastatic ability of prostatic cancer cells. To identify the location of homologous gene(s) in the human, specific human chromosomes were introduced into highly metastatic rat prostatic cancer cells using the microcell-mediated chromosome transfer. Introduction of human chromosome 11 into highly metastatic rat prostate cancer cells results in suppression of metastatic ability without suppression of the in vivo growth rate or tumorigenicity of the hybrid cells. Spontaneous deletion of portions of human chromosome 11 in some of the clones delineated the minimal portion of human chromosome 11 capable of suppressing prostatic cancer metastases as the region between 11p11.2-13 but not including the Wilms' tumor-1 locus.

Animals↗
PubMed1992

Human chromosome 11 contains two different growth suppressor genes for embryonal rhabdomyosarcoma.

The identification of acquired homozygosity in human cancers implies locations of tumor suppressor genes without providing functional evidence. The localization of a defect in embryonal rhabdomyosarcomas to chromosomal region 11p15 provides one such example. In this report, we show that transfer of a normal human chromosome 11 into an embryonal rhabdomyosarcoma cell line elicited a dramatic loss of the proliferative capacity of the transferrants. Indeed, the majority of the viable microcell hybrids had either eliminated genetic information on the short arm of the transferred chromosome 11 or increased the copy number of the rhabdomyosarcoma-derived chromosomes 11. Cells that possessed only the long arm of chromosome 11 also demonstrated a decreased growth rate. In contrast, all microcell hybrids retained the ability to form tumors upon inoculation into animals. These functional data support molecular studies indicating loss of genetic information on chromosome 11p15 during the development of embryonal rhabdomyosarcoma. In addition, our studies demonstrate the existence of a second gene on the long arm, previously unrecognized by molecular analyses, which negatively regulates the growth of embryonal rhabdomyosarcoma cell lines.

Cell Division↗
PubMed1992

Structure of the human pituitary adenylate cyclase activating polypeptide (PACAP) gene.

The human gene encoding pituitary adenylate cyclase activating polypeptide (PACAP) was isolated and its nucleotide sequence was determined. By comparison with a human PACAP cDNA, the exon/intron organization of PACAP gene was determined. The last exon encoded the longer form of PACAP, PACAP38 and 3'-untranslated sequences, suggesting that the shorter form of PACAP, PACAP27 is not generated by alternative splicing mechanisms. The 5'-flanking region of the PACAP gene contains several sequence motifs homologous to CRE, TRE, and GHF-1. On the basis of DNA isolated from mouse A9 microcell hybrid clone containing a single human chromosome, the PACAP gene was assigned to human chromosome 18. Furthermore, we determined the locus of the gene to be 18p11 by the chromosomal in situ hybridization technique.

Amino Acid Sequence↗
PubMed1992

Growth and transformation suppressor genes for BHK Syrian hamster cells on human chromosomes 1 and 11.

To map putative tumor suppressor genes for the near-diploid baby hamster kidney fibrosarcoma cell line BHK, we transferred five different normal human chromosomes (1, 3, 7, 11, and 12) into these tumor cells by microcell-mediated chromosome transfer. Transfer of human chromosome 1 into BHK cells resulted in suppression of cell growth both on plastic and in soft agar, indicating that chromosome 1 has a generalized effect on cell growth and thereby suppresses anchorage-independent growth. Selection against cells with an intact chromosome 1 was observed. In contrast, the introduction of chromosome 11 into BHK cells resulted in suppression of anchorage independence but not growth on plastic. Most chromosome-11 growth-suppressed BHK hybrids retained intact copies of human chromosome 11. Tumorigenic derivatives of chromosome 11 hybrids had lost this chromosome. Transfer of human chromosome 3, 7, or 12 into BHK cells did not correlate with growth suppression of BHK cells on plastic or in soft agar. Thus, we conclude that genes that suppress BHK-cell growth in general or in agar reside on human chromosomes 1 and 11, respectively.

Animals↗
PubMed1992

Complementation of a DNA repair deficiency in six human tumor cell lines by chromosome 11.

Human tumor cells, after x-irradiation during the G2 phase of the cell cycle, show an abnormally high frequency of persistent chromatid breaks and gaps resulting from deficient DNA repair. Addition of a single human chromosome 11 from normal fibroblasts by micro-cell fusion to cell lines from six different tumors resulted in efficient repair of the radiation-induced damage to the level in normal cells. For one of the cell lines, addition of the long arm of chromosome 11 was sufficient to restore repair efficiency. In four of the six tumor lines, restoration of efficient DNA repair by chromosome 11 was associated with tumor suppression in nude mice. These results suggest that chromosome 11 carries a DNA repair gene or genes that complement the repair deficiency of tumor cells and that this gene for at least one tumor is localized to the long arm.

Carcinoma, Renal Cell↗
PubMed1992

Assignment of a human DNA double-strand break repair gene (XRCC5) to chromosome 2.

The Chinese hamster ovary (CHO-K1) cell mutant XRS-6 is defective in rejoining of DNA double-strand breaks and is hypersensitive to X-rays, gamma-rays, and bleomycin. Radiation resistance or sensitivity of somatic cell hybrids constructed from the fusion of XRS-6 cells with primary human fibroblasts strongly correlated with the retention of human chromosome 2 isozyme and molecular markers. Discordancies between some chromosome 2 markers and the radiation resistance phenotype in some of the hybrid cells suggested the location of the X-ray repair cross complementing 5 (XRCC5) gene on the p arm of chromosome 2. Introduction of human chromosome 2 by microcell-mediated chromosome transfer into the radiation-sensitive XRS-6 cells resulted in hybrid cells in which the radiation sensitivity was complemented. The chromosome 2p origin of the complementing human DNA in the microcell hybrids was supported by fluorescent in situ hybridization analysis of human metaphases using human DNA amplified from the hybrids by inter-Alu-PCR as chromosome-painting probes. XRCC5 is therefore provisionally assigned to human chromosome 2p.

Animals↗
PubMed1992

Isolation and mapping of 88 new RFLP markers on human chromosome 8.

To obtain new RFLP markers for construction of a high-resolution map of human chromosome 8, a cosmid library was constructed from a somatic hybrid cell that contained chromosome 8 as the only human component in mouse genomic background. Eighty-eight new RFLP markers were isolated and characterized, and 71 of them were sublocalized to chromosomal bands by fluorescent in situ hybridization (FISH). Of these, 36 were localized to the short arm, 34 to the long arm, and 1 to the centromeric region. Five markers defined VNTR loci. This work represents the first extensive isolation and physical mapping of RFLP markers on human chromosome 8. These new markers will serve as useful resources for linkage mapping of loci for inherited diseases and for efforts to identify a putative tumor suppressor gene(s) on chromosome 8.

Autoradiography↗