zinostatin and Body-Weight

Immunoconjugate targeting of solid tumors has not been routinely successful because the endo-thelial cells of blood vessels act as a physical barrier against the transport of macromolecules, such as antibodies. In the present study, we attempted to achieve tumor vascular targeting with an anti-tumor tissue endothelium-specific monoclonal antibody (TES-23). TES-23, an IgG1 monoclonal antibody raised against rat KMT-17 fibrosarcoma-derived endothelial cells, was covalently conjugated with neocarzinostatin (NCS) in a previous study. The TES-23-NCS conjugate induced tumor hemorrhagic necrosis, and showed marked anti-tumor effects against rat KMT-17 fibrosarcoma. This result prompted us to investigate whether this approach would be applicable to various other types of solid tumors. One hour after injection of (125)I-labeled TES-23 into BALB / c mice bearing Meth-A fibrosarcoma and Colon 26 adenocarcinoma, the tumor accumulation of TES-23 was greater than that of the control IgG. In the present study, we report the anti-tumor effects of this monoclonal antibody in mice bearing Meth-A fibrosarcoma. Mice treated with the immunoconjugate showed improved survival with no side effects. This result indicates that common antigens may be found in different kinds of tumor endothelial cells, and that TES-23 might recognize these antigens.

Topics: Animals; Antibodies, Monoclonal; Antibody Specificity; Body Weight; Endothelium, Vascular; Female; Fibrosarcoma; Hemorrhage; Immunoglobulin G; Iodine Radioisotopes; Mice; Mice, Inbred BALB C; Necrosis; Radioimmunotherapy; Rats; Tissue Distribution; Zinostatin

We assessed the efficacy of "two-route chemotherapy (TRC)" using neocarzinostatin (NCS) given ip and its antidote, N-(2-mercaptopropionyl)-glycine (tiopronin), given iv for peritoneally disseminated tumors in mice. Whether or not the single iv administration of tiopronin (800 mg/kg) at various times after NCS ip would decrease the lethal toxicity induced by NCS ip was given attention. When compared with the LD50 (4.4 mg/kg) of NCS ip alone, simultaneous or postadministration of tiopronin together with NCS ip increased the LD50 of NCS ip by 2.8 to 7.6 fold in a time-dependent manner. Chemotherapy experiments on ip disseminated tumors in mice were done to compare the antitumor effects of the following treatments, at two dose levels (75 and 100% of LD10) of NCS, with or without tiopronin: treatment with NCS ip alone and combined chemotherapy using NCS ip plus tiopronin iv, simultaneously or postadministered. Based on the survival time of the treated mice, the groups given NCS plus tiopronin (postadministration, 15 or 25 min later) showed a significantly superior survival time to that of the group given NCS ip alone. The side effects, evaluated in terms of the changes in body weight and number of WBC of the mice, were not significantly different among the groups treated with 100% of LD10 of NCS.

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Body Weight; Injections, Intraperitoneal; Injections, Intravenous; Leukocyte Count; Male; Mice; Peritoneal Neoplasms; Tiopronin; Zinostatin

The cytotoxicity and antitumor effects of zinostatin (NCS) were examined under various conditions of pH using cultured HeLa cells and a transplantable tumor line of WKA rats. The cytotoxicity of NCS against HeLa cells was highly dependent on the pH at ranges of 6-8. When HeLa cells were treated with 0.075 microgram/ml of NCS, the survival rate was about 1% at pH 6.0, while it was near 90% at pH 7.4 and pH 8.0. Even at pH 6.5-6.75, the survival rate was about 50% lower than that seen with pH 7.4 and pH 8.0. The ratio of the dose of NCS for a 90% cell mortality at pH 6.0 to that at pH 7.4 was less than one-seventh. Antitumor effects were assessed by local intra-arterial infusion against tumors 4 or 9 days after inoculation of 10(6) RBT-1 tumor cells into the thigh of rats. When NCS (0.7 mg/kg) in phosphate-buffered saline (PBS) (pH 7.4) or 5 mM lactate (about pH 3.0) was administered, the ratio of average tumor weight about 2 weeks after treatment (tumor weight of the rats given NCS in PBS/tumor weight of the rats given NCS in lactate) was 3.2 or 1.7 for the rats treated 4 or 9 days after tumor inoculation, respectively. Lactate or PBS alone had no effect on the growth of tumor. After treatment there was no difference in body weight change between the group treated with NCS in lactate and the group treated with NCS in PBS. We conclude that the cytotoxicity of NCS was potentiated under acidic conditions, both in vitro and in vivo.

Topics: Animals; Antibiotics, Antineoplastic; Body Weight; Carcinoma, Transitional Cell; Cell Survival; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Drug Synergism; Female; HeLa Cells; Humans; Hydrogen-Ion Concentration; Rats; Rats, Inbred Strains; Urinary Bladder Neoplasms; Zinostatin

We studied the effect of "two-route chemotherapy" (TRC) with intra-arterial (IA) neocarzinostatin (NCS) and IV N-(2-mercaptopropionyl)-glycine (tiopronin), its antidote, on rat limb tumors. Chemotherapy experiments were carried out on day 9 after the inoculation of 10(6) syngeneic transitional carcinoma cells into the hind limb in female Wistar King A rats. In the group given TRC, 3500 units/kg NCS and 800 mg/kg tiopronin were given via the femoral artery and the femoral vein, respectively. The antitumor effect was evaluated by the tumor weight on day 12 after the treatment. Compared with the weight of tumors in untreated controls, TRC reduced tumor weight to one-tenth, while 700 units/kg IA NCS alone reduced tumor weight to one-third and 700 units/kg systemic NCS alone reduced tumor weight to three-fourths of the control weight. In the group given TRC, WBC and nucleated bone marrow cells were completely protected and loss of body weight was slight.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Body Weight; Bone Marrow; Carcinoma, Transitional Cell; Female; Infusions, Intra-Arterial; Infusions, Parenteral; Leukocytes; Mice; Mice, Inbred Strains; Rats; Rats, Inbred Strains; Tiopronin; Zinostatin

Distribution, excretion and toxicity of an antitumor protein, neocarzinostatin (NCS) were examined in mice after oral administration. The oral LD50 1 g/kg after intravenous injection. After oral administration of 200 mg/kg of NCS, the tissue level was low but detectable in lung, skin and pancreas in addition to the tissues of the gastrointestinal tract. The NCS level in lung and skin remained constant through 6 hours. In gastrointestinal tissues after oral administration the level was higher in the stomach than the large intestine or small intestine. The total recovery of orally administered NCS in feces of mice was 26.5% of the given dose during the first 12 hours. Inactivation of NCS by homogenates of small and large intestines (about 50%) was found in in vitro experiments.

Topics: Administration, Oral; Animals; Antibiotics, Antineoplastic; Body Weight; Feces; Gastric Mucosa; Injections, Intravenous; Intestine, Large; Intestine, Small; Lung; Mice; Pancreas; Rabbits; Skin; Zinostatin