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BACKGROUND: Umbilical cord blood has been used for transplantation in regenerative medicine of hematological disorders. MicroRNAs are important regulators of gene expression that control both physiological and pathological processes such as development and cancer. Some studies have shown that miR-33, p53 and c-myc have critical roles in control of self-renewal cells. OBJECTIVE: To understand the effect of adipose-derived mesenchymal stem cells (ADSCs), as a feeder layer, on expansion of HSCs, the expression of p53 and miR-33a were evaluated. METHODS: Isolated human ADSCs in passage 3 were cultured as a feeder layer. Ex vivo cultures of cord blood CD34+ cells were performed in three culture conditions for 7 days: cytokines with ADSCs feeder layer, cytokines without ADSCs feeder layer, and co-culture with ADSCs without cytokine. Expression of genes p53, c-myc and miR-33 were analyzed by real-time PCR. RESULTS: The expression of p53 was significantly down-regulated in HSCs directly cultured on ADSCs feeder layer compared to that cultured without feeder layer. The expression of miR-33a was significantly up-regulated in HSCs directly cultured on feeder layer compare to that cultured without feeder layer. CONCLUSION: Defining the role of ADSCs in controlling the HSC self-renewal through miR-33, p53 and c-myc may lead to the treatment and prevention of hematopoietic disorders.
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BACKGROUND: Derivation of induced pluripotent stem cells (iPSCs) from various adult somatic cells through over-expression of pluripotent genes could allow for the unlimited autologous supply in regenerative medicine. On the other hand the generation of various progenitors from bone-marrow mesenchymal stem cells (MSCs) is justly well established. OBJECTIVE: In this study we compared the expression level of pluripotent genes oct4, c-myc, sox-2, nanog, klf4 and lin28 in iPSCs and MSCs derived from bone marrow. Also the potential of osteogenesis of iPSCs and bone-marrow MSCs were compared. METHODS: We analyzed the expression level of oct4, sox-2, c-myc, klf4, nanog and lin28 genes in human MSCs derived from iPSCs and MSCs by cell culture and real-time PCR. Also the expression level of osteocalcin and osteopontin in both groups were evaluated. RESULTS: We found that the expression of osteogenic markers in differentiated iPSCs to osteoblast were higher than bone-marrow MSCs. While the levels of pluripotency genes oct4, c-myc and klf4 in iPSCs were significantly (p<0.05) higher than bone-marrow MSCs, MSCs showed higher expression of sox-2, nanog and lin28 compared with iPSCs (p=NS). CONCLUSION: It seems that the higher expression of osteopontin and osteocalcin in MSCs compared to iPSCs may be due to other factors (besides pluripotency) required for differentiation of stem cells to osteoblast.
RESUMEN
BACKGROUND: In regenerative medicine, use of each of the mesenchymal stem cells derived from bone marrow, cord blood, and adipose tissue, has several cons and pros. Mesenchymal stem cells derived from cord blood have been considered the best source for precursor transplantation. Direct reprogramming of a somatic cell into induced pluripotent stem cells by over-expression of 6 transcription factors Oct4, Sox2, Klf4, lin28, Nanog, and c-Myc has great potential for regenerative medicine, eliminating the ethical issues of embryonic stem cells and the rejection problems of using non-autologous cells. OBJECTIVE: To compare reprogramming and pluripotent markers OCT4, Sox-2, c-Myc, Klf4, Nanog, and lin28 in mesenchymal stem cells derived from cord blood and induced pluripotent stem cells. METHODS: We analyzed the expression level of OCT4, Sox-2, c-Myc, Klf4, Nanog and lin28 genes in human mesenchymal stem cells derived from cord blood and induced pluripotent stem cells by cell culture and RT-PCR. RESULTS: The expression level of pluripotent genes OCT4 and Sox-2, Nanog and lin28 in mesenchymal stem cells derived from cord blood were significantly higher than those in induced pluripotent stem cells. In contrast to OCT-4A and Sox-2, Nanog and lin28, the expression level of oncogenic factors c-Myc and Klf4 were significantly higher in induced pluripotent stem cells than in mesenchymal stem cells derived from cord blood. CONCLUSION: It could be concluded that mesenchymal stem cells derived from human cord blood have lower oncogenic potential compared to induced pluripotent stem cells.