Biomedical subjects

K Noguchi

Publications and source records attributed to K Noguchi.

618 records · Page 35Linked to original sources

PubMedDate not supplied

Augmentation of lymphokine-activated killer cell activity by lentinan.

Lymphokine-activated killer (LAK) activity stimulated by interleukin 2 (IL-2) and/or lentinan was examined in the peripheral blood of 9 healthy subjects and 7 cancer patients. After 4 and 8 days culture, LAK killer activity stimulated by IL-2 and lentinan against autologous tumor and K562 cells was greater than that stimulated by IL-2 alone. The optimal concentration of lentinan for the generation of killer cells ranged from 25-500 ng/ml, a level which can be achieved in vivo by the administration of clinical doses of this agent. The expression of CD25 antigen, the alpha chain of the IL-2 receptor on the activated killer cells was increased by lentinan. Thus it was shown that LAK cells stimulated with IL-2 plus lentinan had strong cytotoxicity and might be useful as effector cells for adoptive immunotherapy.

Cytotoxicity, Immunologic↗

PubMedDate not supplied

In vitro antitumor activity of 4'-O-tetrahydropyranyladriamycin on human gastric cancer cells.

The antitumor activity of 4'-O-tetrahydropyranyladriamycin (THP-ADM) was assessed in established gastric cancer cell lines, including MKN-28, moderately differentiated adenocarcinoma and KATO-III, signet ring cell carcinoma and freshly excised human gastric cancer cells, using the MTT assay. The inhibition rates of THP-ADM were identical to those of adriamycin (ADM) in established gastric cancer cell lines, and the chemosensitivity of MKN-28 was higher than KATO-III. In fresh human gastric cancer cells obtained from 27 patients the inhibition rates of THP-ADM were identical to those of ADM, and there was a significant correlation of inhibition rates ADM and THP-ADM. These results indicate that THP-ADM should be a potent candidate to replace ADM in cancer chemotherapy.

Adenocarcinoma↗

PubMedDate not supplied

Induction of differentiation in embryonic stem cells by 26-kD membrane-bound tumor necrosis factor (TNF) and 17-kD free TNF.

The biological activity of 26-kD membrane-bound tumor necrosis factor (TNF)-a in embryonal development was examined in an in vitro system using embryonic stem (ES) cells. ES cells were seeded on NIH3T3 feeder cells transformed with mouse precursor TNF-a gene to express membrane-bound TNF-a on their cell surface. The proliferation of the ES cells was reduced and differentiation was accelerated. The same effects were also observed when 17-kD free TNF-a was added to the culture medium of the ES cells. Since free TNF-a is not present during embryogenesis, these results suggest that membrane-bound TNF-a may play an important role in embryonal development through cell-cell contact.

3T3 Cells↗

PubMedDate not supplied

Bidirectional feedback regulation on 17 kD tumor necrosis factor (TNF) production by 26 kD membrane-bound TNF precursor.

Based on the hypothesis that 26 kD membrane-bound rumor necrosis factor precursor (proTNF) may act as a principle regulator to maintain homeostasis in an adult, we tried to examine whether proTNF shows bidirectional regulation in specific cellular response. We focused on production of 17 kD mature TNF by acute monocytic leukemia cells THP-1 after stimulation by lipopolysaccharide. ProTNF of primed THP-1 cells had been shown to act as a positive regulator for production of mature TNF by homologous cells (primed THP-1) after LPS stimulation, whereas when THP-1 cells were co-cultivated with NIH3T3 which expressed pro-TNF, production of mature TNF by THP-1 by LPS was significantly suppressed. These results suggested that pro-TNF was really involved in bidirectional feedback regulation for TNF production by THP-1 cells themselves through cell to cell contact.

3T3 Cells↗

PubMedDate not supplied

Etoposide enhances the antitumor effects of cisplatin in gastric cancer cells.

We studied the combination effect of cisplatin(CDDP) plus etoposide(VP-16) in an established gastric cancer cell line, KATO-III, and also highly purified fresh human tumor cells obtained from 55 gastric cancer patients, using MTT assay. The synergistic effects of CDDP plus VP-16 were shown by both the fractional product method and median effect plot analysis in KATO-III cells, and by fractional product method in fresh human gastric cancer cells. The combination with CDDP and VP-16 showed the synergistic antitumor effects in not only KATO-III cells, but also fresh human gastric cancer cells. The antitumor effects of CDDP were enhanced by early exposure of VP-16 in KATO-III cells. The combination effects of CDDP and VP-16 were more potent in poorly differentiated gastric cancer, compared with well-differentiated cell types. Thus, it is suggested that the combination of CDDP plus VP-16 is useful in the anticancer chemotherapy of gastric cancer patients.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Anti-tumor effect of lipopolysaccharide by intradermal administration as a novel drug delivery system.

We examined the antitumor effect of lipopolysaccharide extracted from Pantoea agglomerans, a Gram-negative bacterium, using intradermal administration on murine syngeneic tumors, Meth A fibrosarcoma, MH134 hepatoma and Lewis lung (LL) carcinoma. The latter two tumors are known to be relatively low in immunogenicity, highly metastatic and to have low sensitivity to biological response modifiers. Although the intradermal administration of LPSp had a significantly suppressive effect on the growth of all tumors, including seventy-five percent of complete regression of mice bearing Meth A tumor, no complete regression was observed in MH134 or LL tumors. In combination with cyclophosphamide given once prior to the administration of LPS, however, the antitumor effects by intradermal administration of LPS were significantly augmented and there was complete regression in all types of tumors. Pretreatment by anti-tumor necrosis factor antibody reduced the effect exerted by LPS, suggesting that induced tumor necrosis factor might have a crucial role. Toxicity of intradermal administration of LPS was 230-380 times less than that by the intravenous route. Thus clinical application of LPS administered intradermally in combination with chemotherapeutics such as cyclophosphamide appears promising in terms of its antitumor effect as well as toxicity.

Animals↗