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Biomedical subjects

K Tsuchimoto

Publications and source records attributed to K Tsuchimoto.

16 recordsLinked to original sources
PubMed1991

Proto-oncogene expression in three human hepatoma cell lines, HCC-M, HCC-T and PLC/PRF/5.

Changes of nucleotide sequences and expressions of cellular oncogenes in human hepatoma cell lines, PLC/PRF/5, HCC-M and HCC-T cells, were examined by Southern and Northern blot analyses. The probes used are DNA fragment of myc, N-, H-, K-ras, fos, fms, raf, erb-A, erb-B, and erb-B2 genes and synthetic oligonucleotides corresponding to the part of N-, H-, K-ras genes. The results are as follows. DNA amplification and rearrangement were not detected in these three human hepatoma cell lines. Point mutations at codons 12, 13, and 61 in N- and K-ras genes were not demonstrated in these cell lines. N-, H-, K-ras and myc transcripts were detected in these three cell lines. However, fos gene transcript was detected only in PLC/PRF/5 and HCC-M cells which were derived from hepatitis B related hepatocellular carcinoma and having integrated hepatitis B virus (HBV) DNA. These data showed that there are no specific proto-oncogene expression into RNA except for myc and ras genes, nor DNA rearrangement in these 3 human hepatoma cell lines with regards to at least 10 different oncogenes examined and suggest the relationship between fos gene expression and integration of HBV DNA in host cell DNA.

Blotting, Northern↗
PubMed1991

Serodiagnosis of cancer using porcine carboxypeptidase A as an animal antigen recognized by human monoclonal antibody HB4C5.

Protein from hog which is recognized by human monoclonal antibody (HB4C5), generated from a patient with large cell lung carcinoma, was identified as carboxypeptidase A by comparison of the protein with carboxypeptidase A in enzymatic activity, immunologic reactivity, and amino acid sequence. Carboxypeptidase A activity was also found in human cancer tissue, and purified antigen from cancer tissue recognized by the antibody HB4C5 was reacted with rabbit anti-carboxypeptidase A serum, indicating that carboxypeptidase A is an antigen of HB4C5. Since large amounts of carboxypeptidase A can be obtained from porcine sources, a simple method for its purification was established. The fraction which was most reactive with HB4C5 was obtained from acetone powder of porcine pancreas by successive applications of water extraction, ammonium sulfate precipitation, trypsin treatment, and Mono Q column chromatography. Its apparent molecular weight was 40,000, according to SDS polyacrylamide gel electrophoresis. When the reactivity of IgG in sera with the purified carboxypeptidase A was measured, the detection rates for lung, ovary, larynx, uterus, and liver cancer were more than 50%, while the rates for stomach and breast cancer were around 30%, and pancreatic cancer, benign diseases, and normal controls were minimally detected.

Amino Acid Sequence↗
PubMed1990

Expression of hepatitis B surface antigen in Chang cells transfected with hepatitis B virus DNA.

To investigate hepatitis B virus (HBV) biology in vitro, the transfection of recirculized HBV DNA into Chang cell line was performed. Linear HBV DNA was isolated from recombinant HBV DNA, pHBR105, which includes the whole genome of HBV and was recirculized. Chang cells were transfected with this recirculized HBV DNA by the two different procedures of calcium/phosphate coprecipitation and electroporation. After the transfection, the presence of large nucleated cells with multinuclei and ground-glass cytoplasma were noticed and these cells seemed to proliferate faster than untreated Chang cells. Transient expression of hepatitis B virus surface antigen (HBsAg) was demonstrated in cytoplasma of transfected cells by indirect immunofluorescence. HBsAg was not detected in the culture supernatants by radioimmunoassay. The extra-chromosomal HBV DNA was detected in the transfected cells by both procedures 7 weeks after the transfection by Southern blot analysis but it was lost 4 weeks after that. It was demonstrated that it was possible to transfect Chang cells with HBV DNA and that DNA was functioning to express HBsAg transiently.

Cell Line↗
PubMed1989

Establishment of a human cell line (HCC-T) from a patient with hepatoma bearing no evidence of hepatitis B or A virus infection.

A human hepatoma cell line, designated HCC-T, was established. The tumor was surgically obtained from a Japanese male patient with hepatocellular carcinoma (HCC) arising in a cirrhotic liver that had supposedly developed from nonAnonB (NANB) chronic hepatitis. HCC-T exhibited a typical morphology of epithelial cells in culture. Population doubling time was 24 hours and HCC-T cells had characteristics of malignant cells demonstrated by the ability to grow in a soft agar medium and transplantability to nude mice. The histologic condition of the tumor transplanted to a nude mouse showed similarity to the original tumor. A chromosome analysis showed that there were ten identifiable marker chromosomes and sex chromosomes with its modal number of 64. Alpha-fetoprotein (AFP) production was demonstrated by direct immunofluorescence study, but albumin or hepatitis B surface antigen were not detectable. The integration of hepatitis B viral DNA was not demonstrable in the genome of HCC-T cells or the original hepatoma.

Aged↗
PubMed1989

Decrease of transplantability by the immunopotentiators, OK-432 and interleukin-2: experiments on a human hepatoma cell line in nude mice.

The relationship between nonspecific cytotoxic activity of spleen cells and the resistance against the graft challenge of a human hepatoma cell line (HCC-M) was investigated in nude mice. Two administrations of an immunopotentiator, OK-432 or human interleukin-2, prior to the subcutaneous inoculation of HCC-M cells, which was performed 24 h after the last administration, significantly inhibited the tumor development in terms of rate of tumor take and tumor size. This effect was abrogated by simultaneous administration of an anti-asialo GM1 (ASGM1) antiserum. There was a significant inverse correlation between tumor volume and spleen cell cytotoxicity which was determined at the time of HCC-M cell inoculation against a YAC-1 or HCC-M target. Spleen cell cytotoxicity enhanced by these immunopotentiators could not completely be abolished by in vitro treatment with ASGM1 and complement. This result suggests that effector cells of the enhanced cytotoxicity consist of heterogeneous cells including both ASGM1+ natural killer cells and other nonselective cytotoxic cells. These results suggest that nonspecific cytotoxic cells play crucial roles in the resistance against tumor cell challenge and that the total level of cytotoxic activity of these cells at the time of tumor cell challenge is a key factor which determines tumor development.

Animals↗
PubMed1989

Hepatitis B virus DNA integration in hepatocellular carcinomas and their adjacent non-neoplastic liver tissues.

Hepatitis B virus (HBV) DNA integration was studied in 24 hepatocellular carcinoma (HCC) tissues obtained at operations or autopsies. In 11 cases whose sera were positive for hepatitis B virus surface antigen (HBsAg), HBV DNA integration was demonstrated by Southern blot analysis. Only one of 6 cases whose sera were positive for hepatitis B surface antibody (HBsAb) but negative for HBsAg revealed the integration and the other 5 cases revealed no HBV DNA integration. HBV DNA amplification was noted in 4 of these 6 cases in which HBV DNA integration was found when compared with the adjacent liver tissues. The integration pattern of HBV DNA was different in one case between primary HCC tissue and a metastasized lymph node. It is suggested that HBV DNA amplification is not directly related to the development of HCC and that there are polyclonal tumor cells which have different patterns of virus genome integrations.

Adult↗
PubMed1989

[Effect of combined administration of HBs antigen and anti-HBs antibody on induction of anti-HBs antibody production in vitro and in vivo].

It was considered that nonresponsiveness to hepatitis B surface antigen was in part due to a failure in the antigen recognition (i.e., antigens' phagocytosis, processing and presentation by accessory cells). In order to enhance the capture of antigens, we investigated the effect of simultaneous administration of HBs antigen and anti-HBs IgG on antibody responses in vitro and in vivo. As a result, in vitro sensitization of mononuclear cells from anti-HBs-positive subjects with HBs antigen and anti-HBs IgG induced significant amounts of anti-HBs IgG production in 5 of 6 cases, whereas sensitization with HBs antigen alone failed to induce the antibody production in most cases. In vivo administration of HBs vaccine and anti-HBs immunoglobulin to non-responders to the vaccine triggered active anti-HBs antibody responses in 3 of 7 cases in vivo and in 5 of 7 cases in vitro.

Hepatitis B Antibodies↗
PubMed1987

Transformation of NIH/3T3 cells by DNA from a human hepatoma cell line with integrated hepatitis B virus DNA.

We have studied by means of DNA-mediated gene transfer the transforming activity of the DNA of the human hepatoma cell line HCC-M, which contains genomes of hepatitis B virus (HBV) in integrated form. DNA from HCC-M induced transformed foci on transfection of NIH/3T3 cells. DNAs from primary transformants were capable of inducing secondary transformants. Most of the DNAs of these transformants were demonstrated to contain both human repetitive sequences and HBV DNA, indicating that the transformants had incorporated exogenous human DNA and HBV DNA as well. These results suggest that transformation occurs as the result of the transfer of oncogene which might be closely associated with HBV genome.

Carcinoma, Hepatocellular↗
PubMed1986

New micro-glass-tube leukocyte adherence inhibition assay assessing cell adherence of mononuclear cell subpopulations defined by monoclonal antibodies.

A new micro-glass-tube leukocyte adherence inhibition (LAI) assay which is appropriate for detecting delayed type hypersensitivity in vitro has been developed for human leukocytes. Enumeration of adherent cells is replaced by a cellular radioimmunoassay determining antibody binding of the monoclonal reagents, OKT4, OKT8 and OKM1, to glass-adherent cells, fixed by glutaraldehyde or formaldehyde. An LAI reactivity to purified protein derivative of tuberculin (PPD) was detectable in donors giving a positive PPD skin test with OKT4 reagent, but not with the other two reagents.

Antibodies, Monoclonal↗
PubMed1985

[Systemic chemotherapy with high-dose cisplatin and sodium thiosulfate rescue].

Intravenous bolus injection of an 80- to 120-mg/m2 dose of cisplatin followed by "rescue" with sodium thiosulfate (STS) was tried in the treatment of 7 patients with advanced tumor. STS was given continuously i.v. six hours after cisplatin injection, combined with methylprednisolone and metoclopramide as antiemetics. Four patients were evaluable, consisting of one CR, one PR and two NC. Severe nausea and emesis occurred in two patients and irreversible renal dysfunction occurred in one. The clinical use of the STS rescue regimen was discussed in conjunction with our basic investigation of "STS-rescue" in an animal model.

Adult↗