| It has been demonstrated that angiogenesis (new blood vessel development) is vital to the growth and metastasis of cancers, thus it represents a potential therapeutic target and has become a new spotlight in tumor study fields. Vessel of tumor is the morphology foundation for growth and metastasis of malignant tumor. The vessel of tumor not only provides tumor with nutrients, but also it delivers tumor cells to other places. To develop angiogenesis inhibitor may be an important way to control the growth and matastasis of tumor. It has been proved that angiogenesis of malignant tumor is strictly modulated by angiogenatic factors and inhibitor factors. There are more than 30 kinds of fators which promote angiogenesis. VEGF (vascular endothelial growth factor), bFGF (basic fibroblast growth factor) are the most important factors. Studies indicate that MMPs also plays important role in angiogenesis.Colorectal tumor is one of the most common malignant tumors, and the present therapeutic methods such as surgery, chemotherapy and other adjuvant methods have their own limits. Previous studies showed that the growth and metastasis of colorectal tumor intimately depend on the angiogenesis as well, thus it is important to explore a potential way of inhibiting angiogenesis to increase its cure rate. Docetaxel, which is derived from Taxus baccata, is a cytoskeleton toxic chemotherapeutical agent. It can break the dynamic equilibrium of mitosis and cell division, hence it can induce apoptosis by preventing microtubule disassembly after binding to tubulin. It has been proved to have positive effects on the treatment of tumors such as non small cell lung cancer (NSCLC), breast cancer, ovarian cancer and some other refractory and metastatic cancerous diseases. Recently, docetaxel has been proved to hold antiangiogenic activity, but whether its antiangiogenic properties are linked to its cytotoxic role remain unclear, and we knew little about its mechanism as yet. In this communication, we aim to explore the effects of the non-cytotoxic concentrations docetaxel on angiogenesis of LS174T Cells in vitro and subcutaneous tumor in nude mice. Part I In VitroObjective 1. To study the antiangiogenesis effect of docetaxel on cell and organ levels. 2. To study the effects of non-cytotoxic concentrations of docetaxel on some important angiogenic factors of LS174T cells Methods 1. The non-cytotoxic concentrations of docetaxel were determined with MTT and Comas blue. MTT experiment was adopted to evaluate the effect of docetaxel on Human umbilial vein endothelial cell (HUVEC) function of proliferation. All experiments were classified into blank, docetaxel solvent control, 0.05, 0.1, 0.2, 0.5, 1.0ng/ml groups. 2. Endothelial cell migration and capillary formation experiments were adopted to evaluate the effect of docetaxel on Human umbilial vein endothelial cell function of proliferation.3. Rat aortic ring culture methods were adopted to evaluate the effect of docetaxel on neovascularization of rat aortic ring.4. The activity of gelatinase was evaluated by gelatin zymography.5. The expression of VEGF (vascular endothelial growth factor), bFGF (basic fibroblast growth factor), MMP (matrix metalloproteinase) 2 and 9 were investigated with RT-PCR and Western blot. Results 1. The mean MTT A value of all groups were 0.307±0.07, 0.305±0.08, 0.301±0.05, 0.298±0.06, 0.251±0.04, 0.224±0.05, 0.205±0.02 respectively, there were no significant differences between the first four groups(P>0.05), there were significant differences between other groups(P<0.01); 0.2ng/mL and 1.0ng/mL were determined as the maximum non-cytotoxic concentration of docetaxel on HUVEC and LS174T cell.2. The migrated number cell of above groups were 44.36±4.8, 42.28±5.2, 37.75±4.6, 28.65±3.6, 15.59±2.1, 10.82±1.3, 7.43±0.6, respectively; The mean capillary length of them were 192.36±11.54, 188.89±7.59, 175.53±11.54, 166.78±12.35, 151.62±16.38, 118.65±11.58, 78.93±3.67μm respectively; there were no signif...
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