| Background:hepatocellular carcinoma (HCC) is one of the most common alimentary canal malignancy,according to epidemiological survey, HCC is the fifth most common cancer worldwide, the third most common cause of cancer mortality.the second most common cause of cancer mortality in chinese urban and rural residents,300thousands people die from Hcc.It has the characteristic of most difficult to feel,most difficult to diagnose,most difficult to cure,evolve the fastest,the worst result.even after radical excision,the5-year recurrence-rate still can reach up to70%,threat humen life safety.For finding lately,change quickly.pathogenesis complexly,recurrence early,it has a very high mortality rate.With the development of medical imaging, anesthesiology and surgery, hepatocellular carcinoma (HCC) treatment in our country achieved advanced development. Surgical resection, survival and quality of life has improved tremendously. But contrast to other tumor, the curative effect of hepatocellular carcinoma is far not completely satisfied.That beacase many facts can influence it,not only wih the selection of treatment, but also with HCC biological characteristics, stages are closely related. Liver cancer foundation research has entered the platform, thus establishing a animal model of liver cancer for basic and clinical research appears very important,45%peole who die from Hcc in the world are Chinese.At present.we are far from satisfied with the treatment results of Hcc,and studies have showed that main treatments to cancer now only have satisfactory effect to some special mold,but suppressed cytotoxic effects under hypoxic circumstance and the process of operation may breed even more malignant、more easily to metastasize cancer cell;may breed cancer cells that is resistant to radiotherapy and chemotherapy,and these therapies may even promote metastasizing.so it is pressing to develop new antitumot therapies. Pseudomonas Aeruginosa mannose sensitive hamemagglutination vaccine(PA-MSHA) is made of killed organism of ordinary Pseudomonas Aeruginosa expressing mannose sensitive hamemagglutination pili,can be used as large molecule antigen to stimulate human body,generally improve and regulate humoral immunity and cell-mediated immunity,And its pili can specificly conjugate with tumor cells which express high mannose,and transform the structure and function of tumor cell membrane,change its biological behavior.PA-MSHA is one of the hot topic of bacteria antitumor therapy.People ofen have to surrend when cancer have metastasized,drugs have little effects, complete excision can not implement.whereas bacteria therapy showed therapeutical effects to metastatic tumor,the real mechanism is still not clear.thus studying and promoting bacteria therapy have great meaning to conquer cancer.The VX2tumor is cancerized by the Shope virus from rabbit apilloma,so it is Epithelium of the source,can be transplanted in big animal’s body,Its growing、invasion style and lymphaden、blood metastasizing are quite similar to head and neck epidermoid carcinoma,it has great superiority over small experimental animal tumor model,so often used to sudy PCI and RF therapy to cancer,to study iconography and establishing of experimental animal models.Percutaneous intratumor injection treatment (PIT)is one of the main treatments HCC now, anhydrous alcohol、acetic acid can be injected into tumors or perform RFA. Previous Study Reveal that PA-MSHA inhibit the growth of tumor cells significantly,and it is safe to human body. This Experiment use PA-MSHA to treat rabbit liver cancer model so as to study its effect to tumor tissue and cells,there is no related reports domestic and overseas.Aim:1.study the effects of PA-MSHA to liver cancer tissue and cells through rabbit VX2liver Tumor model;2. Percutaneous intratumor inject PA-MSHA to rabbit liver cancer mode under the ultrasound guidance;3.after injection, use Immunohistochemical staining to detect apoptosis and necrosis.evalue PA-MSHA’s effects to tumor tissue and cells.Method:1.establish babbit liver tumor model.resect the tumor from the hind leg of the rabbit.and cut it intolmm3tissues,transplant one into left lobe of the rabbit liver by operation. 2. ultrasound monitering rabbit VX2liver cancer.the growth of rabbit liver cancer will be test by ultrasound2weeks after tansplant,the position of tumor is located.after measure the volume first time,inject PA-MSHA,and inject at the same place every other day,ultrasound detect and measure the volume every8days,total24days.3. experimental groups and dosing method:3weeks after transplant VX2liver cancer,forty new Zealand white rabbits are divided into four groups randomly,10rabbits in each group:Group A:the physiological saline control group; Group B:small doses of PA-MSHA; Group C:moderate doses of PA-MSHA; Group D:large dose of PA-MSHA.4. Observation index and methods:(1) experimental animals in each group are detect by ultrasound before treatment,8day、16day,24day after treatment, measuring the liver tumor size, tumor long and short diameter, the volume (V) according to the formula:V=1/2ab2(including a for long diameter, b for short diameter), and calculate tumor growth rate (tumor volume after treatment/before treatment×100%).(2) after ultrasound detect liver tumors for the last time, execute4rabbits model each5groups, make tumor tissue samples fixed in10%formalin, paraffin embedded,do biopsy, the slice is4μm thick,and perform immunohistochemical staining and test tumor necrosis rate, tumor necrosis rate=tumor necrosis area (cm2)/tumor area (cm2)×100%.(3) stained Sections in step(2) were examined by Light microscopes to observed apoptosis,calculate tumor cell apoptosis exponent, apoptosis exponent=the number of apoptosis tumor cell/total cellsResults:1, successfully established rabbit VX2hepatic tumor model by directly transplant tumor tissue into rabbit liver,transplantation succeed100%,3weeks later, ultrasound examining preexperimental rabbits show that liver tumor are round hypoechoic areas0.7cm off the skin,able to inject,.autopsy demonstrate tumor cut surface is gray,fish surface, quality hardware, Hemorrhagic necrosis of the tumor was observed.2, ultrasound examine the size of tumor in rabbit model in3weeks after planted VX2tumor before injection and8th day、16th day、24th day, the results show the size of experimental groups is smaller than control group(P<0.05).(2)necrosis areas in experimental groups are larger than control group(P<0.05).(3). apoptosis exponent in each experimental groups is higher than control group,(P<0.05).Conclusion:1, Experimental Rabbit VX2liver tumor model is a good to study growth and metastasis of tumor,and it is easy to establish.2, PA-MSHA is safe to rabbit,no animal die of drug overdose.3, PA-MSHA can significantly inhibit the growth of tuinor,promote cancer cells apoptosis,result in tumor necrosis. |
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