Isolation And Identification Of Human Umbilical Cord Mesenchymal Stem Cells And Its Impact On The Malignant Cancer Cell Phenotype Of Human Lung Cancer

Human umbilical cord mesenchymal stem cells (hUC-MSCs) recently get more attention and begin to be carried out at clinical trials as its convinient isolation, rapid proliferation, no ethical conflicts and low viral contamination risks. Accumulated evidence indicate that hUC-MSCs have regenerative potential and tumor tropism, which could suppress growth of cancer cells in vivo and in vitro. In this study, hUC-MSCs were isolated and characterized, and its effect on the malignant cancer cell phenotype were studied.Firstly, hUC-MSCs were isolated by tissue adherent method or collagenase digestion method from human umbilical cord. After subculture, the cells showed typical MSCs morphology that cells were fusiform and growth as radiation or vortex pattern. The cell surface marker of cells isolated by tissue adherent method were analysed by Flow cytometre, results showed that cells were positive for CD29, CD44, CD73, CD90 and CD105, and negative for CD34, CD45 and HLA-DR. After adipogenic induction for 15 days, Oil-Red-O staining showed that induced cells had red oil droplet, RT-PCR showed that PPAR-y was expressed. After osteogenic induction for 21 days, hUC-MSCs were positive for ALP staining and alizarin red staining, RT-PCR showed that Osteocalcin was expressed. The isolated hUC-MSCs had adipogenic and osteogenic ability and could be maintained in long-term subculture in vitro, which indicate that isolated hUC-MSCs had MSC characteristics.Conditioned medium from hUC-MSCs culture was collected and used to treat human lung cancer cell line A549 and H460, results showed that after 24h,48h and 72h of treatment, cell proliferation inhibition rate were 62.1%,57%,43.7% in A549 cell line, and 26.4%,33.4%,59.5% in H460 cell line; anchorage-dependent growth were 1.92%,37.03%,56.41% in A549, and 48.12%,58.31%,83.73% in H460. Cell migrating rate were 64.17%,45.3%,50.78% in A549, and 66.92%,61.90%,56.42% in H460. Invasion inhibition rate were 55.63%,77.06%,59.46% in A549,49.29%, 65.01%,56.34% in H460, respectively. Real-time PCR showed that after 24h,48h and 72h of treatment by conditioned medium, in both A549 and H460 cell lines, Caspase3, Caspase9, and tumor suppressor RUN3 and CDH1 were up-regulated, while Survivin and XIAP were down-regulated.Taken together, results showed that isolated hUC-MSCs maintain MSCs characteristics and multipotent differentiation ability. Treatments of human lung cancer cells with conditioned hUC-MSCs culture medium inhibit the proliferation, anchorage-dependent growth, migration and invasion of lung cancer cells in vitro, the conditioned medium treatment affected the expression of cancer suppressor gene and apoptosis-related genes.