Explore The Ability Of Mesenchymal Stem Cell Homing To Malignant Melanoma Tissue

Objective: Malignant melanoma is a highly malignant tumor, and it’sincidence is third in the tumor of Department of Dermatology, and this trendwas increasing year by year. Malignant melanoma has a high malignantdegree, and easily metastasis, patients prognosis usually bad. Patient’smortality increases with the depth of tumor’s invasion. At present, exceptearly detection and operation, there is no effective treatment. But at presentmany tumors as found the metastasis has occurred, so the operation is difficultto achieve cure goals. Treatment with radiotherapy and chemotherapy, asauxiliary means for malignant melanoma have little effect. So to find a highefficient, safe means of adjuvant therapy is becoming an urgent human needs,In recent years, with the deep research of stem cell, mesenchymal stem cellsgradually step into people’s vision. Because of mesenchymal stem cells isabundant, easy amplification in vitro and has the ability of migration to thedamage and tumor tissu. So the mesenchymal stem cell is a kind of idealcarrier, can carry antineoplastic drugs or anticancer genes into tumor tissue, inorder to achieve the effect of tumor therapy. But mesenchymal stem cellsmigration to tumor is affected by many factors, the number of the cells rechedthe target tissue for treatment will play a decisive role. Transplantation path isa primary factor in determining the mesenchymal stem cell homing. Celltransplantation approach now is mainly three path: intravenous transplantation,artery transplantation and local transplantation. Through the intravenoustransplantation is safe, and also conducive to the stem cell migration in vivo,but the block of pulmonary capillary became the primary factor affectingmesenchymal stem cells into tumor tissue. In this experiment, throughestablishment the model of melanoma in mice, and through the intravenousroute to the tumor and normal mice transplanted PKH26labeled mesenchymal stem cells. By counting the number of fluorescence positive cells in tumortissue and lung tissue of two groups, in order to explore the ability ofmesenchymal stem homing to melanoma tissue, and the effect of pulmonarycapillary block on the homing. I hope through this experiment will provide aguidance to the target treatment by mesenchymal stem cells for tumor.Methods：1By density gradient centrifugation method for the separation andpurification of rat bone marrow mesenchymal stem cells.2By induction, let the mesenchymal stem cells differentiation into bone cellsand neuron cells, to validate weather the cell have the ability of multipotentialdifferentiation.3Melanoma animal model prepartion: subcutaneous injection the mousemelanoma B16cells to the hind limbs of mice, preparation of melanomaanimal models.4PKH26labeled bone marrow mesenchymal stem cells, and calculate thelabeling rate.5Animal experimental: randomly divided the4week old female mice into A,B two groups with10rats in each group, group A by subcutaneous injectionof B16melanoma cells to establish the models of melanoma in mice.2weekslater after group A mice’s tumor formed, through rat tail vein of the twogroups of mice transplanted PKH26labeled mesenchymal stem cells. Let themouse free feed food and water, observe and record the group A mice’s tumordiameter and the state of the two group mice.6Two weeks later, put all the mice to death, take out the group A mice’stumor tissue, as well as A, B two groups of mice’s lung tissue. Count thenumber of fluorescence positive cells in tissue sections under the fluorescentmicroscope.7Use statistical software SPSS statistical analysis the data.Results：1By density gradient centrifugation method for the separation andpurification of the cells, gradually acquired the fusiform shape and radially arranged cells.2By induction, the mesenchymal stem cells can differentiation intoosteoblasts and neurons.3One week after injected the melanoma cells, tumor was formde,2weeksafter, tumor’s largest diameter1cm minimum0.6cm, group A mice just a littlethiner than before, energetic normal.4PKH26labeled mesenchymal stem cell’s membrane can uniform expressionred fluorescence, mark rate was100%, and the offspring can also expressionfluorescence. The PKH26labeled cells growth and proliferation were notaffected.5Two weeks after transplantation mesenchymal stem cell for the two groupsof mice,the2group mice were all alive, group A mice’s subcutaneous fatdisappeared, presentation cachexia state, group A mice’s tumor maximumdiameter is2.4cm, minimum1.2cm, part of the tumor tissues the apicalappear different degree of ulceration. Group B mice showed no abnormality.6The fluorescence positive cells in group A mice’s tumor tissue sections wereaverage9.9, and the group A mice’s tumor diameter is linear correlation withthe number of the fluorescence positive cells, the correlation coefficient was0.976,(P=0.00<0.05) with statistical significance. The number offluorescence positive cells in group A mice’s lung tissue slice were average3.1, the number of fluorescence positive cells in group B mice’s lung tissueslice were average3.2, two group of data compared statistically are nodifferences (P=0.813>0.05).Conclusion: Through intravenous transplantation the mesenchymal stemcells, it’s capable migration to the tumor tissue in vivo. Tumor’s diametereffected the number of mesenchymal stem cells migration to the tumor tissue,and the both was linearly related. Due to the blocking of pulmonary capillary,part of the cells will remain in the lungs, and both have no difference, nomatter with the effect of tumor.