Effects of the angiogenesis inhibitor angiostatin on the growth of CC531 colon carcinoma cells in vitro and in a laparoscopic animal model of peritoneal carcinomatosis

As angiogenesis is one of the key steps in tumor growth, invasion, and metastasis, antiangiogenic therapy is supposed to be an attractive approach for antitumor treatment. We investigated the cytotoxic, anti-adhesive, and anti-invasive effects of angiostatin in vitro and on intraperitoneal tumor growth in a laparoscopic rat model of peritoneal carcinomatosis using CC531 colon adenocarcinoma cells. The in vitro adhesion and cytotoxicity assays were performed with microtiter plates, and the invasion assay with Transwell dual chambers. Normal saline was used as control. In in vivo experiments, CC531 adenocarcinoma cells were intraperitoneally given to Wistar Albino Glaxo rats after the establishment of a pneumoperitoneum. The animals received angiostatin in different doses intraperitoneally, and in some, angiostatin was additionally administered subcutaneously. Saline was used as control. After 21 days, the animals were euthanized to determine the intra-abdominal tumor weight. In in vitro experiments, there was no effect of angiostatin on the viability of tumor cells in the cytotoxicity assay, but there was a significant inhibition of tumor cell adhesion and invasion (p