Experimental Study On Effects Of Ultrasound Irradiation Microbubble Agent Combined With Chemotherapy On Biological Effect Of Subcutaneous H22 Hepatoma Of Mice

Purpose:To investigate the therapeutic effects of ultrasound irradiation microbubble agent in the treatment of subcutaneous H22 ascites cells hepatoma of mice and its synergistic effects when combined with chemotherapy and its possible machanism of action.Methods:We established H22 ascites cells hepatoma models by inoculating tumor cells to subcutaneous tissue of mice.Then,mice were randomly allocated into 6 groups(15 mice in each group).Experiment started on the 3th day after the tumor transplantation.The mice of only ultrasound group were treated with ultrasound probe irradiation(output power2W,output time30S);The mice of ultrasound and microbubble group were treated with ultrasound probe irradiation(output power2W,output time30S) soon after injecting microbubble agent into tail vein(0.2ml);The mice of chemotherapy were treated by injecting chemotherapeutic drug cisplatin(DDP)(1mg/kg, 0.2ml) into peritoneal;the mice of chemotherapy combined with only ultrasound group were treated with ultrasound probe irradiation(output power2W,output time30S) 30 minutes after injecting DDP(1mg/kg, 0.2ml) into peritoneal;The mice of chemotherapy combined with ultrasound and microbubble group were treated with ultrasound probe irradiation(output power2W,output time30S) soon after injecting microbubble agent(0.2ml) into vein 30 minutes after injecting DDP(1mg/kg, 0.2ml) into peritoneal.Once every other day for 5 days.From the third day of the tumor model established ,the maximum vertical diameter(a,b)of the tumor were measured with vernier every two days.The tumor volume were calculated according to the fomular V=1/2ab2.Then,the tumor growth curve was got(drew) according to the tumor volume.The rate of tumor inhibition was calculated after sacrificing the animals at the end of experiment.The specimen were immobilized and made into pathological section for HE staining and IHC staining.The necrosis area percentage(NAP) were calculated.The vascular endothelium grow factor(VEGF), microvessel density(MVD) and nuclear associated antigen Ki-67 lebling index (Ki-67LI) were measured immunohistochemically and the apoptotic index was analyzed with terminal deoxynucleotidyl transferase mediated dUTP nick end lebeling(TUNEL) technique.Results:In the controls,the tumor inhibition rate was 0,the NAP was 12.19%±7.93%,the VEGF was 6.19%±1.57%,the MVD was 11.97±2.12,the PI was 41.73%±2.81%,the AI was 0.71%±0.08%,whereas in the ultrasound and microbubble group,they were 33.22%,42.81%±9.04%,2.09%±0.72%,4.24±0.81,24.25%±2.61% and 1.18%±0.16% respectively.When combined with chemotherapy,the findings were 70.50%,59.16%,0.57%,2.06, 12.78% and 2.48% respectively.Compared with control,the groth of tumor in ultrasound and microbubble group was slow and the inhibitory effect of tumor was obvious(p<0.05);Necrosis area and apoptotic cells number at the border of necrosis foci increased obviously compared with that in control group(p<0.05);Ki-67LI,MVD and VEGF expression all were decreased (p<0.05).When combined with chemotherapy,the inhibitory effect of tumor was more prominent(p<0.05);the indicators of NAP and AI were much larger (p<0.05);the indicators of Ki-67LI,MVD and VEGF expression were much more lower(p<0.05).Conclusion:Ultrasound irradiation microbubble agent has good therapeutic effects in the treatment of subcutaneous transplantable H22 ascites cells hepatoma of mice,and can generate synergistic effects to improve therapeutic effects when combined with chemotherapy.the mechanism of action may be due to its antiangiogenetic effect,interrupting blood-supply,inhibiting proliferation,inducing apoptosis and necrosis.