Study On The Inhibitory Effect Of Adinbitor, A Disintegrin From The Snake Venom Of Gloydius Brevicaudus, On The Growth Of The Hepatocarcinoma 22 In Mice

Hepatocellular carcinoma(HCC)is one of the common types of malignant tumors in China.It is high mortality and the second rank in city, and it is the first place of death induced by cancer in some rural areas,HCC five-year survival rate has not improved.But various means of the treatment of HCC have arrived. Disintegrins is one of the treatment of HCC.Disintegrins are a kind of highly homologous polypeptide abstracted from snake venom, which contain an Arg-Gly-Asp (RGD) or Lys-Gly-Asp (KGD) sequence and plentiful cysteines, and the molecular weight is 5～9kD, and inhibit the function of integrins in biological activity.The research proves different integrin have different expression on tumor cells and perform different function in the different process of tumorigenesis. So integrins regulate the events such as tumor cells adhesion, proliferation, invasion and metastasis, apoptosis and the formation of tumoral blood vessel by delivering specific signal or inducing gene expression. Because all disintegrins contain an RGD distinctive recognition sequence which is essential for their biological activity and then become the strong antagonists to many integrin receptor by force of the sequence, they inhibit the function of integrins in the tumorigenesis.Adinbitor, a disintegrin cloned from Gloydius brevicaudus venom in Lushun, China. As a novel disintegrin, Adinbitor is composed of 73 amino acid residues including 12 cysteine residues and an RGD three-peptide disintegrin characteristic recognition sequence and its relative molecular weight is 9kD. So it has the inhibitory effect on tumor as the strong antagonists to many integrin receptors. So far, my work was to resuscitate and express the frozen E.coli BL21, which had completed transformation with recombinant plasmid pET23b-adinbitor and identification, for recovery and IPTG induction of expression, in order to obtain soluble and efficient expression of the recombinant protein Adinbitor. And then Adinbitor as a novel disintegrin with 9kD molecular weight was purified and obtained by using His-Bind Column chromatography. Then my work was to Study on the inhibitory effect of Adinbitor, a disintegrin from the Snake Venom of Gloydius brevicaudus, on the growth of the hepatocarcinoma 22 in miceMethods:the hepatocarcinoma 22 model was established in 40 BALb/C mice. After 24h of postoperation, The 40 mice were distributed randomly into 5 groups:each group had 8 mice, on the day 2 after implantation of the hepatocarcinoma 22 Cells, respectivel. Adinbitor at doses of Low dose Group,Moderate dose Group and High dose Group was given i. P. once a day.Negative control group Was given i.p. normal saline for 20 day once a day, in same volum,and positive control group was given i.p. Recombinant human endostatin once a day. The therapy effect was observed and the tumor inhibitory rate was calcu lated after killing the animals on the 20th day after administering.The result showed:the tumor inhibitory rate of Low dose group was 44.21%, the tumor inhibitory rate of Moderate dose group was 64.80%, the tumor inhibitory rate of High dose group was 70.38%, the tumor inhibitory rate of Recombinant human endostatin group was 71.67%, the difference is obviously significant compared with the NS group (P<0.01).High dose group(70.8%)was the same than in Recombinant human endostatin group(71.67%), the difference is not significant(P>0.05). High dose group is identical in antitumor activity with Recombinant human endostatin.In brief, these results of my work points to Adinbitor, the disintegrin was obtained by inducing expression and purifying, could inhibit tumor proliferation in vivo. So disintegrins, the biological factors, as a new antitumor matter will provide a new thought and method for clinical therapy of malignant tumors, reveal new prospects for human defeating cancers.