On The Impact Of Mesenchymal Stem Cells On Mouse Melanoma Experimental Research

Objective: malignant melanoma (malignant melanoma, MM) from themelanin cell, is a kind of high malignant degree has the melanin celldifferentiation of malignant tumor, accounting for1%-2%of all malignanttumors, most occurred in skin[1-2], genital, followed by the rectum, anus,genital tract, the digestive tract, sinuses, throat and lung, can also occur in thechoroid and piamater[3-5]. Malignant melanoma accounts for7%-20%of skincancer, its incidence was significantly higher trend in recent years. Melanomaoccurrence of related factors such as heredity, ultraviolet (uv), pigmentednevus. Due to malignant melanoma pathological histology and cytology in theform of diversity, some tumors do not contain melanin, easy to misdiagnosisand Jane. Current surgical treatment often USES, biological, radiation andchemotherapy, but the effect is not very ideal. Therefore seeking good potencyand less side effects of treatment is to the present research hot spot problems.Mesenchymal stem cells (mesenchymal stem cells, MSCs) the earliestdiscovered isolated from bone marrow, has the plastic stick wall, fibrous, ableto differentiate into fat cells, in vivo and in vitro of osteoblasts andchondrocytes, can also be used to other reproductive system differentiation.Due to the differentiation characteristics of MSCs has more potential, is usedto repair tissue at the earliest. In recent years, studies have shown that it alsohas antiproliferative and anti-inflammatory effect. MSCs have highself-renewal ability and multi-directional differentiation potential, has the verygood ability to migrate and tumor tropism. In microenvironment of tumorgrowth, tumor cells and the surrounding the fiber matrix can secrete variouscytokine, can promote the migration of MSCs to the tumor site concentration,proliferation, differentiation, and then affect the growth of tumor. Therefore,pay attention to and study the effect of MSCs on the tumor microenvironment, MSCs for clinical antitumor therapy research has an important role.Methods:1with density gradient centrifugation separation and purification of ratbone marrow mesenchymal stem cells, and MSCs cells cultured in DMEMmedium containing10%fetal bovine serum (including100u/ml, penicillinstreptomycin100u/ml, PH7.2), in37℃and5%CO2incubator for regularsubculture.2Induced by, made of mesenchymal stem cells into osteoblast andneurons through the sample cell differentiation, to verify it as the potential ofstem cells with multidirectional differentiation.3to develop malignant melanoma B16cells in DMEM mediumcontaining10%fetal bovine serum (including100u/ml, penicillinstreptomycin100u/ml, PH7.2), in37℃and5%CO2incubator for regularsubculture.4Preparation: the animal model of the melanoma B16melanomacells in mice to mice with hind limbs subcutaneous injection, and preparationof melanoma animal model.5Animal model after completion of preparation, mice were randomlydivided into A (control group) and B (experimental group) in the two groups,each group of six.6animal experiment mice injected with normal saline group A, group Binjection of mesenchymal stem cells in mice. Let mice eat free water, observeand record the growth of tumor.7mesenchymal stem cell transplantation mice all executed after twoweeks, to remove the A and B two groups of mice tumor, doing routinehistopathologic examination.8statistical analysis using the statistical software SPSS to data forstatistical analysis.Results:1by density gradient centrifugation separation and purification of cells,can gradually get a long spindle radial arrangement of the cells. 2through induction of mesenchymal stem cells to the osteoblast andneuronal cell differentiation.3Three mice after subcutaneous injection of mice B16melanoma cells,into a tumor after1week,2weeks tumor increases obviously, vitality ofnormal mice.4mesenchymal stem cell transplantation after two weeks, the vitality ofnormal mice and mice and all put to death. Group A portion of the tumor inmice appeared different degree of burst at the top of the organization. Group Bdid not see obvious abnormalities in mice.5A group (control group) in mice tumor tissues average length is0.28cm in diameter, the average width of0.18cm and the average wet weight0.65g; B group (experimental group) mice subcutaneous fat disappeared basically,tumor diameter and average diameter of2.35cm length, average width of0.71cm; The average wet weight7.90g, the top of the part of the tumor tissueappeared different degree of burst and bleed.6A group (control group) were observed under microscope: most,dermis of normal structure, A large number of tumor cells has hit belowleather group. Tumor cell sizes and larger, staining deep, violet black, morenuclear fission. Area of the tumor tissue, densely packed nest tendency and itsvisible fibrous tissue around the interval, blood vessels distribution, less tumorcells were polygonal; Portion of the tumor tissue shows diffuse distribution,less tumor stroma, rich blood vessels, tumor cells is larger, a circle or oval.Rich between tumor blood vessels, pipe cavity expansion, full of red bloodcells, tumor tissue area, densely packed some tumor cells invade the bloodvessel walls, tube wall damage, into the lumen. Interstitial lymphocytes andneutrophils, plasma cells, fat necrosis. B group (experimental group) wereobserved under microscope, the tumor has invaded cuticular, close to thebasement membrane zone, like nuclear fission. Vascular volume increasedsignificantly between tumor tissue, blood vessel diameter increasedsignificantly. Inflammatory cells visible lymphocyte compared with group A(control group)(more), neutrophils (medium), and plasma cells (less). More visible fat necrosis.7B mice tumor average weight7.90g,0.659mm3, average volumeand tumor in mice of group A average weight0.65g, compared to the averagetumor volume0.009mm3have obvious difference, statistical analysis (P<0.001, with statistical significance.Conclusions：1tumor volume are increased, the weight increased significantly, MSCscan produce significant influence on the growth of melanoma.2Between tumor tissue vascular volume increased significantly.3MSCs more visible between tumor tissue lymphocytes, plasma cells,neutrophils and nuclear dust, MSCs have obvious immune regulatory.