The Experimental Study On Rubus' Inhibition To The Activity Of MMP And Anti-tumor Mechanism Of Rubus

Malignancy is one serious kind of common diseases harm human health.According to statistics data of the World Health Organization,there are 1000 million falled ill in cancer per year in the world,and 700 million died. The cancer has been second killer second only the angiocardiopathy.And the cancer incidence rate is increasing year by year. So how to prevent and cure cancer still is a big problem for human in 21st century, and exploitation and manufacture of antitumor drugs has aiso been an important topic in recent years. The course of tumor invasion and metastasis is a process of which primary tumor cells transfer to surrounding or distant tissues, involving tumor cells through extracellular matrix barriers, vascular basement membrane wall and entering into the host micro-environment. A large number of experiments show that the capacity of invasion and metastasis of tumor cells is closely related to protease degrading its extracellular matrix, basement membrane. Matrix metallo- proteinases can degrade almost all ECM components, which is the most important to tumor invasion and metastasis.Many studies show, metallo- proteinases played its role mainly through three aspects in tumor biological actions :(1)to degradate extracellularmatrix: Extracellular matrix (ECM) is an important internal environment for survival of cells, especially the basement membrane among the total, which is physiological barrier overcame in the course of tumor metastasis. Many studies confirmed that MMP is the most important Erzymes to degradate ECM, It can degradate almost all ingredient in the ECM besides polysaccharide, and activate other MMP , forming waterfall effect. (2) to play a role in neovascularization: The neovascularization include the degradation of basement membrane under the capillary endodermis, endothelial cells migration and proliferation, neovascularization and formation of new basement membrane. Vitro experiments show that vascular endothelial cells and tumor cells can secrete matrix metalloproteinases to degradate ECM, in the process of neovascularization and tumor metastasis, which play a significant role in tumor metastasis. While tumor neovascularity, many cytokines interaction as autocrine or paracrine's form, participate in the formation process of blood capillary. These cytokines can raise uPA's expression in endothelial cells, and the uPA can activate the fibrinolytic enzyme and then activate MMP. At the same time these cytokines can directly induce MMP gene transcription in cells.(3) to adjust cell adhesion: the adhesion between tumor cells and the host cell and tumor cell plays an important role in tumor invasion and metastasis, for example, melanoma cells can express intercellular adhesion molecule-1(ICAM-1), adhere to leukocyte, which is beneficial for tumor cell to gather in intravascular and to wear a tumor cells.And also integrin are important in cells invasion. It can adjust the cell's transition in ECM directly, also can adjust MMP's expression. Recognized the important role of MMP in tumor invasion and metastasis, the research of MMP's inhibitor has also been paid attention to. MMP's inhibitor consist of nonspecific inhibitors, organization specific inhibitors (TIMPs) and synthetic inhibitors.Of the total, TIMPs is MMPs'specific inhibitors, playing the most important role in regulation of the MMPs'activity. TIMPs are endogenic organization specific inhibitors, which are secreted by cells in the body, can inhibit the activity of MMPs, and combine with MMPs'enzyme precursor in activated form. TIMPs could be expressed in tumor cells and cell of Leydig. At present, there are not strong evidence whether or not surgery, chemotherapy and radiation therapy can control tumor metastasis. Chinese Medicine possess unique advantages in improving patients'subsistence quality and prolonging live time and reducing distant metastasis and so on.Modern pharmacology study shows that Rubus chingii Hu has strong function of antitumor, bacteriostasis, central nervous system inhibition, anti-aging, anti-mutagenesis, preventing plymphocyte proliferation lesions. In recent years, with the deepening of the research of Rubus chingii Hu, Rubus chingii Hu's medicinal value has been paid more and more attention. In addition, Rubus chingii Hu, woody plants, distributed in east China area, easily cultivated and bred., which provides rich plant resources for further research development and utilization. So we think, Rubus chingii Hu is plant resources worthy of exploitation and utilization, and have very good development prospect, especially in the research on antitumor drugs. Rubus chingii Hu has definite antitumor effect through clinical pharmacology study. The writer wants to through the experiment prove whether its inhibiting tumor therapy is concerned with MMPs activity.Experimental Methods:Put MMP-13 of 1μl and different density of the Rubus chingii Hu extract of 1μl into buffer solution of 48μl and make eventually volume 50μl. Rubus chingii Hu solution should not be joined in control group. After that, put solution of all the group into 96 hole enzyme plate, and incubate in incubator in 37 degrees Celsius for 30 minutes. Then 50μl buffer solution containing 0.2μg DQ-gelatin was added and makes two groups of final reaction system for 100μl. Immediately they were detected by Bio-Red FLx-800 fluorescence enzyme reader for 10 minutes, in the excitation wavelength of 460nM and emission wavelength of 520nM. Detection of changes in the fluorescence intensity on behalf of the substrate enzyme degradation dynamic strength. By inhibiting the activity of Rubus chingii Hu extract calculated observation of MMP-13 in vitro. When the inhibition percentage of 50%,compared with Rubus chingii Hu extract inhibited the activity of IC50.Experimental Results:The Rubus chingii Hu extract have the effect of inhibiting MMP-13 in vitro, IC50=0.036μg/ml. And the function depends on the density . That is to say , the Rubus chingii Hu extract's inhibition on the MMP-13 enhances with the increase in drug concentration . Conclusion:The Rubus chingii Hu extract can inhibit the activity of the MMP-13, and the inhibition are relatively strong. Its concentration is proportional to the inhibition effect of MMP-13,which confirms it has bright prospects further to search the new drugs targeted to MMPs/TIMPs from the natural medicine.