zinostatin and Necrosis

Liver metastases are the major cause of death for patients with colorectal cancer. Surgical resection is at present the only curative option. Styrene maleic acid neocarzinostatin [SMANCS/Lipiodol (S/L)] targets the unique vascular architecture of tumor blood vessels, which are hyperpermeable and lack a well-developed lymphatic system. Here we report changes in the microvascular architecture of liver metastases by scanning electron microscopy (SEM) following the administration of S/L.. Liver metastases were induced by the intrasplenic injection of dimethylhydrazine induced colon cancer cells in mice. In this model tumor angiogenesis occurs at day 10, while exponential tumor growth occurs at day 16. Changes in the tumor microvasculature were observed at 3 weeks following treatment with S/L at these time points by SEM of corrosion casts.. Tumors treated with S/L at day 10 appear similar to day 10 controls. Tumor vessels, 50 +/- 18 microm in diameter, are easily identified from hepatic vessels. Within the hepatic sinusoids are avascular spaces, 144 +/- 60 microm in diameter, which correspond to tumor cell aggregates at the initial stages of growth. Similarly, day 16 treated tumors appear comparable to day 16 controls. These vessels are narrower (84 +/- 32 microm vs. 150 +/- 70 microm) than their control counterparts. This is in contrast to vessels (216 +/- 36 microm in diameter) of a complex nature at 3 weeks.. S/L exerts a marked and immediate effect on the tumor microvessels at both the angiogenic and the exponential phases of tumor growth. This agent is effective at the microvascular level during inhibition of metastatic growth.

Topics: Animals; Antineoplastic Agents; Colorectal Neoplasms; Contrast Media; Corrosion Casting; Iodized Oil; Liver Circulation; Liver Neoplasms, Experimental; Male; Maleic Anhydrides; Mice; Mice, Inbred CBA; Microcirculation; Microscopy, Electron, Scanning; Necrosis; Neovascularization, Pathologic; Polystyrenes; Zinostatin

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

Combination therapy consisting of Lipiodol (Laboratoire Guerbet, Villepinte, France) containing styrene maleic acid neocarzinostatin and transcatheter arterial embolization (L-TAE) has been an important conservative therapy for hepatocellular carcinoma (HCC). We examined the clinical and pathologic characteristics of 14 HCC cases that achieved total tumor necrosis in response to L-TAE. The HCCs of all cases were resected 45 +/- 17 days after L-TAE and were confirmed to be totally necrotic. Ultrasonography showed a mean tumor size of 2.5 +/- 1.0 cm, often with a halo formation around the tumor. Angiographically, neovascularity and clear tumor stains were observed in all cases. Computed tomography portography showed nodular perfusion defects in all the cases examined. There were portal invasions in two cases. On Lipiodol-computed tomography, Lipiodol was densely and homogeneously retained within the whole tumor. The number of tumors was single in all diagnostic images. Macroscopic view of HCCs were single nodular type in nine cases and single nodular type with extra growth in four cases. Clear capsular formation was seen in each HCC nodule. Soft x-rays were taken to observe the exact distribution of Lipiodol in the operative specimens. Microscopic intrahepatic metastases were found histologically in four cases. Histologic examination showed the trabecular pattern with broad blood spaces in which Lipiodol was positive with Sudan III staining. Necrosis was seen not only in the main tumor, but also in the capsular invasions and microscopic metastases with Lipiodol deposition. The characteristics of the cases with total tumor necrosis were as follows. Deposition of Lipiodol throughout the tumor was essential, and clinically the cases showed a single HCC tumor with a diameter of more than 5 cm and arterial hypervascularity. The pathologic findings included expansive growth with capsular formation and trabecular-type HCC with abundant blood spaces. These findings are important for evaluating the radical efficacy of L-TAE.

Topics: Aged; Antineoplastic Agents; Carcinoma, Hepatocellular; Chemoembolization, Therapeutic; Combined Modality Therapy; Female; Humans; Infusions, Intra-Arterial; Iodized Oil; Liver Neoplasms; Male; Maleic Anhydrides; Middle Aged; Necrosis; Polystyrenes; Tomography, X-Ray Computed; Zinostatin