Biomedical subjects

H Ishitsuka

Publications and source records attributed to H Ishitsuka.

At least 37 records · Page 2Linked to original sources

PubMed1996

Murine interleukin-12 prevents the development of cancer cachexia in a murine model.

Murine colon 26 carcinoma causes cachexia even when the tumor burden is small. In this tumor model, murine IL-12 suppressed the induction of cancer cachexia and also inhibited tumor growth. IL-12 reduced the serum levels of IL-6, a cachexia mediator in this model, and alleviated the body weight loss and other abnormalities associated with cachexia, such as adipose tissue wasting and hypoglycemia. The anticachectic activity was observed even at low doses of IL-12, insufficient to inhibit tumor growth. IL-12 greatly increased levels of IFN-gamma in the tumor tissue and, to a lesser extent, in the circulation. IFN-gamma given intraperitoneally also prevented cancer cachexia, although it did not reduce IL-6 levels either in the tumor or in the circulation. In athymic mice bearing the same colon 26 tumor, IL-12 was no longer anticachectic and did not induce IFN-gamma. These results indicate that the anticachectic activity of IL-12 is T-cell-dependent and results from at least 2 mechanisms, the down-regulation of IL-6 and the up-regulation of IFN-gamma.

Animals↗

PubMed1996

Preparation of anti-human thymidine phosphorylase monoclonal antibodies useful for detecting the enzyme levels in tumor tissues.

The antitumor activity of cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) depends on its being converted to 5-fluorouracil (5-FUra) by the enzyme thymidine phosphorylase (dThdPase, EC 2.42.4). We prepared mouse anti-human dThdPase monoclonal antibodies to serve as tools for clinical studies with this drug. Partially purified dThdPase obtained form HCT116 human colon cancer cells grown in athymic mice was used as and antigen for the immunization of mice. Six hybridomas were cloned which produced anti-human dThdPase antibodies, as detected by Western blot analysis with human dThdPase. With these antibodies, we developed an ELISA method sensitive enough to measure dThdPase levels, even in tumor tissue samples weighing as little as 10 mg. In addition, one monoclonal antibody was suitable for immunologically staining the enzyme in tumor tissues. Thus, these anti-human dThdPase monoclonal antibodies could be used to measure levels of the enzyme in tumor cells, which is essential for the activation of 5'-dFUrd.

Animals↗

PubMed1995

Selective inhibition of spontaneous pulmonary metastasis of Lewis lung carcinoma by 5'-deoxy-5-fluorouridine.

5'-deoxy-5-fluorouridine (5'-FUdR) is a cytostatic that is biotransformed to 5-fluorouracil (5-FUra) by pyrimidine nucleoside phosphorylase (PyNPase), the expression of which is up-regulated by tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha) and interferon gamma (IFN gamma). In Lewis lung carcinoma (LLC) cell cultures, these inflammatory cytokines up-regulated the expression of type-IV collagenase, metastatic factor, as well as PyNPase and consequently enhanced the antiproliferative activity of 5'-FUdR. However, the activity of 5-FUra was not enhanced. It appears that 5'-FUdR selectively kills highly metastatic cells which are exposed to these intrinsic cytokines in tumor tissues, because of their high PyNPase activity. In fact, 5'-FUdR inhibited the spontaneous metastasis of LLC from the s.c. inoculation site to the lung. When 5'-FUdR was given during the process of metastasis it greatly reduced the number of tumor nodules in the lung even at doses 46 times lower than those inhibiting the primary tumor growth. In addition, 5'-FUdR, but not 5-FUra, lowered type-IV collagenase levels in the tumors at the low dose showing only anti-metastatic activity. On the other hand, 5-FUra showed anti-metastatic activity at doses similar to or only several times lower than those inhibiting the primary tumor growth.

Animals↗

PubMed1995

Establishment and characterization of cachexia-inducing and -non-inducing clones of murine colon 26 carcinoma.

To investigate the mechanism causing cachexia and its association with shorter patient survival, we cloned weight-loss-inducing and -non-inducing sublines of murine colon 26 carcinoma (colon 26). One clone, clone 20, induced substantial weight loss, wasting of adipose tissue and muscle, and hypoglycemia in mice with a minimum tumor burden of 0.3 g (2 g per 100 g body weight). Clone-20-bearing mice had a median survival of 24.5 days with average tumor weight of 0.4 g. In contrast, clone 5 induced neither severe weight loss, wasting of adipose tissue and muscle, nor hypoglycemia; clone-5-bearing mice survived for a median of 70 days with average tumor weight of 12 g. These results clearly indicate that shorter survival is associated with the degree of cachexia and is independent of tumor size. Using this pair of colon 26 clones, we examined mediators of cachexia. Neither TNF alpha, IL-1 alpha nor IFN gamma was detected in the serum of mice bearing either clone, while IL-6 was detected in mice bearing both clones by ELISA and a bioassay. Administration of anti-IL-6 monoclonal antibody (MAb) partially but significantly suppressed cachexia induction in clone-20-bearing mice. These results point to the involvement of IL-6 in experimental cachexia. However, our finding of the presence of IL-6 in the serum of mice bearing clone 5, which does not induce weight loss, clearly indicates that IL-6 is not solely responsible for the induction of cachexia.

Animals↗

PubMed1995

Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in human breast cancer.

We have investigated the expression of platelet-derived endothelial-cell growth factor/thymidine phosphorylase (PD-ECGF/dThdPase) in human breast-cancer tissues by the immunocytochemical method using anti-PD-ECGF/dThdPase monoclonal antibody. Out of 100 invasive-ductal-carcinoma tissue samples, 39 (39%) were evaluated as PD-ECGF/dThdPase-positive. The expression of PD-ECGF/dThdPase was identified mainly in the cytoplasma of tumor cells. The expression of PD-ECGF/dThdPase was significantly associated with the microvessel density assessed by immunostaining to factor-VIII-related-antigen (p < 0.05). However, there was no correlation between expression of PD-ECGF/dThdPase and menopausal status, tumor size, axillary lymph-node metastases, hormone-receptor status, epidermal-growth-factor receptor, or erb-B-2-protein and p53-protein expression. We suggest that expression of PD-ECGF/dThdPase plays an important role in the promotion of angiogenesis in human breast cancer.

Antibodies, Monoclonal↗

PubMed1995

Involvement of human interleukin 6 in experimental cachexia induced by a human uterine cervical carcinoma xenograft.

A human tumor xenograft model for cancer cachexia was established by growing a uterine cervical carcinoma, Yumoto, in nude mice. The tumor transplanted into the mice induced severe body weight loss (30% of body weight) when the tumor weight was only 1 g. In addition, other indicators for cachexia, such as adipose tissue and muscle wasting and hypoglycemia, were also observed in the tumor-bearing mice, suggesting that this is a proper model for experimental cachexia induced by a human tumor. We then examined the association of this model with various cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1alpha, IL-1beta, IFN-gamma, IL-6, and leukemia inhibitory factor, and identified human IL-6, which was produced by the tumor cells, as a mediator of cachexia. A neutralizing antibody against hIL-6 administered to the mice after the development of cachexia symptoms significantly improved body weight loss, adipose tissue wasting, hypoglycemia, acute phase reaction, and leukocytosis, although it did not suppress the tumor growth. These results demonstrate that the hIL-6 produced by the tumor cells is an essential mediator of the cachexia induction in this model.

Animals↗

PubMed1993

Cytokines induce thymidine phosphorylase expression in tumor cells and make them more susceptible to 5'-deoxy-5-fluorouridine.

The present study shows that various cytokines such as tumor necrosis factor (TNF alpha), interleukin-1 alpha (IL-1 alpha), and interferon-gamma (IFN gamma) make tumor cells much more susceptible to the cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) than to 5-fluorouracil (5-FUra) and other cytostatics. These three cytokines increased the susceptibility of human cancer cell lines (COLO201, MKN45 and WiDr) but did not affect that of normal fibroblast WI38 cells. The cytokine mixture induced a 50-fold increase in the susceptibility of COLO201 to 5'-dFUrd, whereas a 12-fold increase and a less than 5-fold enhancement in the susceptibility to 5-FUra and other cytostatics, respectively, were observed. The increased susceptibility would be a result of the induction of thymidine phosphorylase (TdR Pase), which is the essential enzyme for the conversion of 5'-dFUrd to 5-FUra. The cytokine mixture increased TdR Pase activity by up to 47 times and greatly induced its mRNA expression in the cancer cell lines. These results suggest that the therapeutic benefit of 5'-dFUrd would be improved by its use in combination with the cytokines.

Antineoplastic Agents↗

PubMed1993

Cytokines induce uridine phosphorylase in mouse colon 26 carcinoma cells and make the cells more susceptible to 5'-deoxy-5-fluorouridine.

The antiproliferative activity of 5-fluorouracil (5-FUra) and 5'-deoxy-5-fluorouridine (5'-dFUrd), used in combination with typical cytokines and growth factors, was investigated in mouse colon 26 carcinoma cells. Tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha), and interferon gamma (IFN gamma) at low doses showing < 50% inhibition of cell growth by themselves enhanced the susceptibility of the cells to the activity of 5'-dFUrd. In particular, a mixture of these cytokines greatly enhanced the activity of 5'-dFUrd and 5-FUra by up to 12.4- and 2.7-fold, respectively, whereas the activity of other cytostatics was only slightly changed (< 1.5-fold). Basic fibroblast growth factor also increased the susceptibility, but only to 5'-dFUrd. This preferential enhancement of the activity of 5'-dFUrd would be due to induction by the cytokines of uridine phosphorylase (Urd Pase), by which 5'-dFUrd is converted to 5-FUra. TNF alpha, IL-1 alpha, IFN gamma, and a mixture of these factors increased the enzyme activity by up to 3.7-fold in colon 26 cells. Consequently, the anabolism of 5'-dFUrd to fluoronucleotides and the incorporation of 5-FUra into RNA in colon 26 cells were increased by TNF alpha treatment. In addition, the increase by the cytokine mixture in the susceptibility to 5'-dFUrd was abolished by an inhibitor of Urd Pase, 2,2'-anhydro-5-ethyluridine. These results indicate that induction of Urd Pase activity by cytokines is a critical event that increases the susceptibility to 5'-dFUrd.

Animals↗

PubMed1993

[Antitumor activity of various cytostatics in mice bearing murine advanced tumors].

Antitumor activities of cytostatics such as 5-FU, 5'-DFUR, cyclophosphamide (CPA), ACNU, CDDP, mitomycin C (MMC) and doxorubicin (DXR) were compared in mice bearing four different murine-tumor models at two different stages of the tumor growth. All cytostatics tested suppressed the tumor growth in most of the four tumors, colon 26 carcinoma, UV 2237 fibrosarcoma, Ehrlich carcinoma and Meth A fibrosarcoma, when the tumor sizes were small (early transplant). When given to mice bearing advanced tumors, 5-FU, CDDP, MMC and DXR were effective only at the higher doses, showing toxicity. In contrast, 5'-DFUR was equally effective against both most of early and advanced tumors except for advanced Meth A against which higher doses of 5'-DFUR were needed. CPA and ACNU equally suppressed the growth of early transplant and advanced tumors of Meth A, although higher doses were needed against advanced tumors of three others. 5'-DFUR was also effective against tumor cachexia (colon 26) and spontaneous metastasis (Lewis lung carcinoma), which are characteristically observed in mice bearing advanced tumors. CPA also showed an anticachectic activity, though the activity was weaker than that of 5'-DFUR. These results suggest that 5'-DFUR and CPA can be used in both intensive and adjuvant chemotherapies.

Animals↗

PubMed1991

5'-Deoxy-5-fluorouridine improves cachexia by a mechanism independent of its antiproliferative action in colon 26 adenocarcinoma-bearing mice.

The cytostatic agent 5'-deoxy-5-fluorouridine (5'-dFUrd) improves cachexia and prolongs survival, suppressing tumor growth in mice bearing large burdens of colon 26 adenocarcinoma. To investigate the mode of this anticachectic action, we isolated colon 26 variants that were resistant to the anticachectic activity in vivo in tumor-bearing mice that initially responded to 5'-dFUrd in terms of tumor growth and cachexia but again became cachectic and refractory to the drug after prolonged treatment. The original line and variants were equally susceptible to the antiproliferative action of 5'-dFUrd, and their growth was stopped. However, 5'-dFUrd given to cachectic mice exhibiting large burdens of these variants could not reverse wasting and only slightly prolonged the survival period. These results indicate that the anticachectic activity of 5'-dFUrd is independent of its antiproliferative action and that the survival of colon 26-bearing mice is shorter when the size of the tumors is not reduced to levels below those that cause cachexia.

Adenocarcinoma↗

PubMed1991

[Comparative studies on the antitumor activity of fluorinated pyrimidine derivatives against human bladder, cervical and ovarian cancer xenografts in nude mice].

Fluorinated pyrimidines given orally were examined for their antitumor activity with 11 human cancer xenograft models (4 bladder, 4 cervical and 3 ovarian cancers). The drugs were evaluated to be effective when they inhibited tumor growth over 58%. UFT was not effective against all of 11 cancer xenografts tested. 5-Fluorouracil (5-FU) was effective against only one bladder cancer xenograft among 6 cancer xenografts tested. On the other hand, 5'-deoxy-5-fluorouridine (5'-DFUR) was effective against one bladder, 3 cervical and one ovarian cancer xenografts. The Antitumor activity of 5'-DFUR was correlated with the enzyme activity of pyrimidine nucleoside phosphorylase, which is an essential enzyme for phosphorolysis of 5'-DFUR to 5-FU.

Administration, Oral↗

PubMed1990

Anticachectic activity of 5'-deoxy-5-fluorouridine in a murine tumor cachexia model, colon 26 adenocarcinoma.

Murine colon 26 adenocarcinoma causes a progressive weight loss and physiological changes associated with cachexia when it grows to a certain size. By the use of this tumor model several types of cytostatics were examined for their ability to alleviate cachexia. Among them, 5'-deoxy-5-fluorouridine could reverse a progressive weight loss and improve hypoglycemia, hyperglucocorticism, and hepatic malfunctions, as well as inhibiting the tumor growth. Cyclophosphamide, nimustine, and 2'-deoxy-5-fluorouridine were only slightly effective in reversing the wasting, while 5-fluorouracil, tegafur, mitomycin C, cis-platinum, and doxorubicin were not active. Within 3 days after 5'-deoxy-5-fluorouridine was administered to cachectic mice with large tumor burdens, the wasting was immediately reversed even at doses in which there was increase or no significant reduction in tumor growth. These results indicate that the anticachectic activity of 5'-deoxy-5-fluorouridine is independent of its antiproliferative activity.

Acute-Phase Proteins↗

PubMed1990

Experimental cancer cachexia induced by transplantable colon 26 adenocarcinoma in mice.

The present study investigates a tumor model for cachectic mice. Among various murine transplantable tumors, used for assessing cytostatics, we identified colon 26 adenocarcinoma (colon 26) as capable of causing cachexia. Fifteen days after inoculation, the tumor grew to about 6% of the body weight causing substantial carcass weight loss of 3.4 g (14.5% of the carcass weight). When the tumor size was 2.7 g at 3 weeks after the inoculation, the carcass weight was 12 g less than the age-matched control. The tumor continued to grow while the mice maintained this weight, surviving for an average of 45 days. This extensive weight loss was essentially the wasting of adipose and muscle tissues. Hypoglycemia and hypercorticism occurred during the time of the weight loss. In addition, the colon 26 caused disorders of hepatic functions: the concentration of acute phase proteins in serum increased; the number of hepatic glucocorticoid-cytosol receptors decreased; and activities of hepatic catalase and drug-metabolizing enzymes decreased. On the other hand, noncachectic mice with Meth A fibrosarcoma gained weight, which was somewhat less than the control, and had neither hypoglycemia nor hypercorticism, although some mild disorders of hepatic functions were found. Mice bearing colon 26 is an appropriate model for elucidating the mechanism that causes cachexia.

Adenocarcinoma↗

PubMed1990

Comparative studies on the antirhinovirus activity and the mode of action of the rhinovirus capsid binding agents, chalcone amides.

Studies of various analogs related to the antirhinovirus agent 4'-ethoxy-2'-hydroxy-4,6'-dimethoxychalcone (Chalcone Ro 09-0410) led to the identification of amide analogs that are 4.5 to 10 times more active against human rhinovirus (HRV) in tissue culture as measured by chemotherapeutic indices. Chalcone amides Ro 09-0535, Ro 09-0696 and Ro 09-0881 inhibited viral replication at concentrations as low as less than 2-3 ng/ml and were cytotoxic between 30 to 50 micrograms/ml. These compounds bind to HRV and reduce the virus infectivity titers by 3 log10 or greater at 0.5 micrograms/ml for 60 min similar to Ro 09-0410. These amide analogs competitively inhibited the binding of [3H]Ro 09-0410 to the viral capsid similar to capsid binding antirhinovirus agents, Ro 09-0410, 4',6-dichloroflavan and WIN-51711. Furthermore, strains of HRV type 2 resistant to each of the above agents showed cross-resistance to all other agents. These results indicate that the chalcone amides also bind to the same or close-proximity site for the capsid binding antirhinovirus agents, which is on the specific site within the viral capsid protein. However, differences in the degree of the inhibition of [3H]Ro 09-0410 binding, cross-resistance of strains of HRV resistant to the agents and HRV serotype specificity were observed not only between the chalcone amides and the other antivirus agents (Ro 09-0410, 4',6-dichloroflavan and WIN-51711) but also among the chalcone amides, particularly between Ro 09-0535 and Ro 09-0696. These differences are presumably due to alterations in the binding affinities of compounds as a consequence of variations in the shape and size of the hydrophobic pocket that exists between serotypes including resistant strains.

Amides↗

PubMed1990

Comparative antitumor activity and intestinal toxicity of 5'-deoxy-5-fluorouridine and its prodrug trimethoxybenzoyl-5'-deoxy-5-fluorocytidine.

N4-Trimethoxybenzoyl-5'-deoxy-5-fluorocytidine (Ro 09-1390), a prodrug of the cytostatic 5'-deoxy-5-fluorouridine (5'-DFUR), was synthesized with the aim of reducing of the dose-limiting toxicity of 5'-DFUR, which is diarrhea. In mice bearing Lewis lung carcinoma, 5'-DFUR given po produced a substantial amount of 5-fluorouracil (5-FU) in the intestinal tract as well as tumors, where the enzyme pyrimidine nucleoside phosphorylase, essential for conversion of 5'-DFUR to 5-FU, is predominantly located. With the oral administration of Ro 09-1390 only a small amount of 5-FU was formed in the intestine; however, the administration of Ro 09-1390 and 5'-DFUR at the same dose produced similar amounts of 5-FU in tumor tissues. These differences in metabolism were reflected in their toxicity and antitumor efficacy. The administration of 5'-DFUR resulted in damage to the intestinal mucosal membrane and diarrhea in normal mice, whereas Ro 09-1390 was much less toxic to the intestinal tract. As regards antitumor activity, Ro 09-1390 and 5'-DFUR at equivalent doses inhibited the growth of Lewis lung carcinoma to similar extents. Since Ro 09-1390 was much less toxic to the intestinal tract than 5'-DFUR, mice bearing Lewis lung carcinoma could be given Ro 09-1390 daily over a longer period and at a higher dose, resulting in a longer survival time.

Animals↗

PubMed1990

Comparative studies on the antitumor and immunosuppressive effects of the new fluorouracil derivative N4-trimethoxybenzoyl-5'-deoxy-5-fluorocytidine and its parent drug 5'-deoxy-5-fluorouridine.

N4-Trimethoxybenzoyl-5'-deoxy-5-fluorocytidine (Ro 09-1390), a new prodrug of 5'-deoxy-5-fluorouridine (5'-dFUrd), was synthesized for the purpose of finding a drug with less intestinal toxicity than the parent compound. The present study compared the antitumor activity and immunotoxicity of Ro 09-1390 with those of 5'-dFUrd, 5-fluorouracil (5-FUra) and tegafur in various transplantable tumor models. The antitumor efficacy of Ro 09-1390 was comparable to 5'-dFUrd and these two agents were much more effective than the others. However, Ro 09-1390 was much less toxic to the intestinal tract and less immunosuppressive in both humoral and cellular immune reactions than 5'-dFUrd. Consequently, Ro 09-1390 showed higher therapeutic indices and higher efficacy than 5'-dFUrd at high dosages. The antitumor spectrum of Ro 09-1390 was somewhat different from that of 5'-dFUrd, though it shows the efficacy after it converts to 5'-dFUrd. The activity of Ro 09-1390 was partly associated with cytidine deaminase in the tumors treated. Ro 09-1390 appeared to be more effective against tumors with a high concentration of the enzyme by which the major metabolite 5'-deoxy-5-fluorocytidine (5'-dFCyd) is metabolized to 5'-dFUrd.

Animals↗

PubMed1989

Antitumor activity of indomethacin in mice bearing advanced colon 26 carcinoma compared with those with early transplants.

The antitumor activity of indomethacin (IND) was investigated in mice bearing advanced colon 26 adenocarcinoma compared with its early transplants. Treatment with 0.001% IND in drinking water retarded the growth of tumor when commenced at Day 1 after the tumor inoculation. The suppression of the tumor growth by IND continued up to 4 to 5 weeks as long as the size of the tumor remained small. On the other hand, IND given to mice bearing a large burden of the tumor at 2 weeks after the inoculation had facilitated the tumor growth. IND reduced tumor-associated PGE2 production in mice bearing either small or large burdens of the tumors. These results indicate that the antitumor activity of IND depends on tumor size and therefore is not simply associated with the reduction of PGE2 levels. We found that colon 26 caused changes in parameters reported for tumor cachexia, such as weight loss, wasting of muscle and adipose tissues and hypoglycemia, when it grew to around 1 g at 2-3 weeks after the tumor inoculation. IND given to the mice with large burdens of colon 26 alleviated the cachexia of the mice, resulting in the increase of the survival time even though the growth of the tumor had been facilitated. It is possible that IND affects the tumor growth and survival by reversing tumor-induced disorders in homeostasis.

Adenocarcinoma↗

PubMed1989

Comparative antitumor activity of 5-fluorouracil and 5'-deoxy-5-fluorouridine in combination with radiation therapy in mice bearing colon 26 adenocarcinoma.

The present study compared the antitumor activities of chemotherapy with 5-fluorouracil (5-FU) and with its prodrug 5'-deoxy-5-fluorouridine (5'-DFUR) in combination with radiotherapy on a solid colon 26 adenocarcinoma in the mouse. A single administration of 5'-DFUR immediately after local irradiation on day 10 after tumor inoculation produced more than additive antitumor effects, while only an additive effect was observed in the combined treatment with 5-FU and radiation. This over-additive effect of 5'-DFUR was more obvious in a fractionated-dose treatment schedule, where the same combined modality treatment was given three times on days 6, 10 and 14 after inoculation of the tumor cells. 5'-DFUR enhanced the radiation effects on the tumor in terms of the delay in tumor growth as well as the increase in the survival time. 5-FU produced only a marginal additive antitumor effect. Furthermore, radiation damage to normal tissues (skin damage by local irradiation and bone marrow and spleen damage by whole-body irradiation) was not enhanced by 5'-DFUR, though radiation damage to the thymus was additive. On the other hand, 5-FU produced toxic effects that were additive for all normal tissues tested. Thus, at doses that were the most effective against tumors, relative therapeutic gain factors (the ratio of the effect on tumors to that on the bone marrow) of 5'-DFUR and 5-FU were 1.24 and 0.49, respectively. These results suggest that 5'-DFUR will have a greater potential than 5-FU in combined modality treatment of cancer patients.

Adenocarcinoma↗