| INTRODUCTIONMalignant tumors are serious diseases endangering human health. Every year about 1,600,000 patients with cancers were newly increased in our country and about 1,300,000 patients died from tumors. With the growth of population and the accelaration of aging population, the incidence and mortality of tumors are on the rise. So the prevention and treatment of tumors have long been the focal work in the Chinese medicine. It is then an important subject to find medicines both safe and effective in the treatment of tumors. Recently more attentions have been attached to the drugs from animals, and antineoplastics have been developed in using fully the animal sources of our country, which has then become the important content in the research work of tumors. So far, the anti-tumor effect of snake-venom NGF has not been reported in China.Snake venom is full of ingredients with biological activity, including the components possessing the anti-tumor activity. As the snake venom could be got vastly, it was of important value to use as an anti-tumor drug or reagent for clinical treatment after being deprived of its poisonous activity. In the present study snake venom was used to purify its effective component NGF, and was testified to have the anti-tumor potency.Snake venom nerve growth factor (NGF) was a biological reagent purified from snake venom and is a signal component product. Some studies both in vivo and in vitro showed that NGF has the anti-tumor effect on the growth of carcinoma cells. But the exact mechanisms need to be studied further.ET is an active polypeptide distributing widely in nature. It has a very intensive biological effect. In recent years, many reports both at home and abroadhave pointed out that ET has close relationship with the development of tumors, and have verified that tumors including cancers of liver, esophagus, colon, ovary , mammary gland, adrenal gland, etc, can cause the rising of ET. But the relationship between NGF and ET is unknown, and need to be studied further.The present study is of three parts. The first part is mainly screening of the anti-tumor components from snake venom. The second part is to evaluate the anti-tumor potency of NGF on cultured human carcinoma cells in vitro . The third part is to investigate the inhibitory effect of NGF on mice bearing H22 tumor cells and its possible mechanisms.OBJECTIVE1. Experiment was conducted to study on the anti-tumor components of Agkstrodon Halys of Changbai District.2. The anti-tumor potency of snake venom on the 4 kinds of human tumor cells was observed.3. To investigate the inhibitory effect of NGF on mouse H22 ascites tumor to find out the relationship between NGF and ET.METHODSWith chromatography of CMC-Sepharose FF, Sephacryl-200, etc. , the anti-tumor component isolated and purified from the venom of Agkstrod on Halys of Changbai District was found to be the nerve growth factor ( NGF).MTT colorimetric method, trypan blue exclusion and colony formation were adopted. DXR was used as positive control. Four kinds of human tumor cell lines (K562, JF305, AGZY-83a and MG-803) were treated with NGF at different final concentrations of 5,10,15 and 20ug/ml. The effects of NGF on the cells mentioned above were observed at diffenent intervals after the cell were exposed to NGF.The mice bearing H22 were treated with NGF solution at different dosages(5 ug/kg, 10ug/kg and 20ug/kg). The anti - tumor effect of NGF on H22 was observed and the plasma endothelin (ET) content in these mice was measured with radioimmunoassary ( RIA).RESULTSIt is verified from the results of SDS-PAGE experiments that the molecular weight of NGF is 16. 8 KD, and it has inhibitory effect on ascites tumor H22 of mice and can increase living time of mice bearing tumor by 62.2%.The results showed that NGF had obvious cytotoxicity to these cell lines of K562, JF305, AGZY-83a and MG-803. There were obvious dose-response relationship for K562 and JF305 cells ( r = 0. 9726, r = 0. 9768, P < 0. 05). K562 and...
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