Screening And Pharmacodynamic Evaluation Of Tumor Vas-cular Disrupting Agent From Ocean

Tumor blood vessels play an important role in the development of solid tumors, it provides oxygen, nutrients and transports the waste, meanwhile providing the main transfer route.Targeting tumor vascular system as a treatment strategy for cancer has achieved inspiring clinical results. Currently most of the available drugs of this kind are targeting tumor angiogenesis. As the estabolished tumour blood vessels are characterized of irregular, confusion and so on, which makes it possible for targeting the established tumor vascular. Low molecular vascular disrupting agents cause marked and selective disruption of the established tumour blood vessel network, resulting in tumour necrosis, which provide a new strategy for the treatment of cancer. Vascular Disrupting Agent (VDA) is a kind of drug which can cause marked and selective disruption of the established tumour blood vessel network. Currently there is a variety of VDA drug candidates in the research and development, many of which have entered clinical research.Marine resources is the most complete and ample resources, and it's the most promising areas of new drug development.Nowadays, development of innovative and challenging new drugs from marine resources has been listed as a national priority for most countries. Lamellarins are a large family of alkaloids which are isolated from sea sponges, sea squirts, the structure character is that a multi-hydroxy pyrrole center was replaced by one or more methoxy benzene ring. Many experiments show that Lamellarins have strong cytotoxic activity against a variety of tumor cell lines. Therefore, we choose LamellarinD as the leading compound for its simple structure and significant anti-tumor activity. We use this structure as the guide and get a series of compounds similar to CA4 with a lot of structure modification and structure-activi-ty relationship optimization.We screened a series of compounds using a model established on human umbilical vein endothelial cells (HUVEC), with confluence state and nonconfluence state cells in vitro to mimic the normal blood vessels and tumor blood vessels. The results show that MDS-11 has good effects as well as CA4. First of all, in molecular level, we use SPR binding assay,microtubule polymerization experiments. The results show that: MDS-11 have a higher affinity with tubulin and can inhibite the cell-free tubulin polymerization dose-dependently.Then, at cellular level, laser confocal evaluation,P, S microtubule protein separation assay, HUVEC luminal damage assay, results show that:MDS-11 can quickly disrupt the formed HUVEC luminal. Endothelial cell morphology change is very important in the destructive effects of these compounds. Laser confocal result shows that MDS-11 could disrupt tubulin cytoskeleton to induce morphological changes in HUVEC,with appeared membrane foaming and stress fibers, which is consistent with the in vitro tubulin polymerization experiment. P, S tubulin separation experiment also shows MDS-11P can reduce the P type tubulin in a dose-dependent manner within cell. Finally, we use MDA-MB-231 nude mice transplanted tumor model, carrying out a series of pharmacological evaluations with HE staining, CD31 and PCNA immunohistochemical staining.Experiment results show that:24 hours after administration the mice were killed, HE staining shows large area of tumor necrosis within tumor, while little effect on normal tissues; CD31, and PCNA immunohistochemistry proved that MDS-11P caused vascular damage and tumor necrosis within tumor in a dose-dependent manner. Tumor proliferation slow down and blood vessel numbers reduce.In the end, based on molecular, cellular and animal experimental data, we concluded that:MDS-11 can affect the tumor endothelial cell skeleton system, selectively destruct tumor blood vessels.It implies that MDS-11 is a candidate for further development of the vascular disrupting agent.