Cytotoxicity On Paravertebral Metastatic Tumor By Different Bone Cements: A Experimental Study

ObjectiveTo investigate the anti-tumor effect of two kinds of bone cements(CPC and PMMA) in rabbit paravertebral metastatic tumors. To research the feasibility of the paravertebral me-tastatic tumor model to replace the spine tumor model.Methods and methods1. Transplantable tumor model were constructed by paracentesis under the CT guiding. The rabbits were checked after 15 days by MRI. 2. The rabbit models were randomly divided into 3 groups: Control Group-nothing was injected with the rabbits, PMMA Group-PMMA 1 ml was injected to the center of the tumor, CPC Group-CPC 1 ml was injected to the center of the tumor. 3. The rabbits were executed at 1d,7d and 14d after bone cement were injected. The tissues of tumor were washed,dehydrated,permeabilized,embeded and cut into section after tumor tissue dissection. 4.â‘ The model rabbits were observed every day after operation;â‘¡The morphological change and necrosis of tumor cells near and away from the bone cements were observed by HE stainâ‘¢Apoptotic feature and apoptotic rate were analyzed by TUNEL apoptosis measurement. The data were statistically analyzed by SPSS13.0 statistical bag.Resultsâ‘ All model animals can tolerate the operation well. Bone cement was agglomerate in tumor, and was not found cement leakage. Physiological discomfort, psychical dispirited, drowsiness and fastidium were not observed after operation on rabbits;â‘¡HE stain results suggested that there was typical nuclei concentration,nuclei cleavage,nuclei dissolution and necrosis of tumor cells near the PMMA bone cements. Few of tumor cells could found in necrosis tissues. Until at 7 days and 14 days after operation, the tumor cells near bone cement were significantly proliferated. But tumor cells significantly proliferated were found on control group and CPC group at all time.â‘¢TUNEL apoptosis examination showed that PMMA could induce apoptosis on tumor cells near bone cements,and the PMMA's apoptotic effect was reduced gradually. At the different time after treatment, the apoptosis index (AI, %) of tumor tissue in the PMMA group was higher than that of in control group and CPC group. The difference of apoptosis index PMMA group compared with other two group has statistical significance (p<0.001). There is no statistical signifi-cance of CPC group and control group (p>0.001).Conclusion:The results suggest that PMMA has a significantly cytotoxic and anti-tumor effect, and CPC haven't the effect. The method establishing rabbit paravertebral metastatic tumor model is easy, which can replace the spine tumor model partially.