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Background and Aim: Bone sialoprotein (BSP) is a specific marker of osteoblastic differentiation. In this research, the effect of Zoledronic Acid on BSP expression and methylation status during osteoblastic differentiation of mesenchymal stem cells (MSCs) was evaluated.

Materials and Methods: In this experimental study, MSCs were isolated from human bone marrow. For osteogenic differentiation, hMSCs were pulse treated with zoledronic acid, and were incubated in osteogenic differentiation medium for 3 weeks. The DNA and RNA were extracted after the first, second and third weeks of culture and also from undifferentiated MSCs. After Sodium bisulfate (SBS) treatment, gene specific methylation analysis for BSP was carried out using Methylation Specific PCR technique.

Results: BSP expression was observed in osteoblastic differentiated cells whereas it was not seen in MSCs. MSP showed that BSP was unmethylated during osteoblastic differentiation.

Conclusion: BSP was expressed from the first week of differentiation. This confirms that zoledronic acid accelerates osteoblastic differentiation. Unmethylation status of BSP indicates that zoledronic acid does not have any effect on BSP methylation status. Other genetic or epigenetic mechanisms may control BSP expression during osteoblastic differentiation induction by zoledronic acid.

Background and Aim: Different regulation processes have an effect on osteoblastic differentiation of mesenchymal stem cells (MSCs), and among them Wnt signaling pathway is particularly desirable. In Wnt signaling pathway, Adenomatous Polyposis Coli (APC) bind to β-catenin and induce its degradation, thereby acting as a negative regulator of canonical Wnt pathway. In this study, gene expression and DNA methylation of APC gene during osteoblastic differentiation were determined.

Materials and Methods: In this experimental study, after the isolation of MSCs, the induction of osteoblastic differentiation was done. To confirm osteoblastic differentiation, alizarin red staining together with the expression of Alkaline Phosphatase (ALP) and osteocalcin as specific osteoblastic markers was performed. APC gene methylation status by MSP (Methylation Specific PCR) and gene expression status of APC gene using Real-Time PCR technique during different times were evaluated.

Results: The results of alizarin red staining and the expression of ALP and osteocalcin confirmed osteoblastic differentiation. In addition, the results showed a significant decrease in the expression of APC gene on the 7^th day of osteoblastic differentiation (P<0.05). Also, the results revealed hypermethylation status of APC gene promoter during osteoblastic differentiation.

Conclusion: It seems that the decreased expression APC gene will play an important role in Wnt signaling pathway regulation in different stages during osteoblastic differentiation of bone marrow-derived MSC. Also, according to the results, APC gene promoter methylation will play an important role in controlling gene expression.

Background and Aim: Chronic myeloid leukemia (CML) is a myeloprolifrative neoplasm that is characterized by an expansion of myeloid, erythroid cells and platelets in peripheral blood and myeloid hyperplasia in bone marrow. Secreted frizzled-related protein family is a negative regulator of the Wnt signaling pathway that suppresses this signaling pathway in healthy individuals. Aberrant regulation of the Wnt signaling pathway is a prevalent theme in cancer biology, and methylation in promoter of SFRP family has been shown to cause uncontrolled cell proliferation in cancer. Chronic myeloid leukemia was the first malignancy in which the important role of Wnt signaling pathway has been described. 
In the present study, we examined the methylation status of SFRP1 and SFRP2 genes in patients with CML.
Materials and Methods: Blood samples were obtained from 25 healthy individuals and 33 patients whit chronic meyloied leukemia (23 male, 10 female) Then Isolated DNA was treated with sodium bisulfite and analyzed by methylation-specific polymerase chain reaction (MSP) with primers specific for methylated and unmethylated promoter sequences of the SFRP1 & -2 genes. We used Mann-Whitney u-tests to investigate the correlation between SFRP-1 and SFRP-2 genes hypermethylation and clinical parameters.
Results: In CML patient hypermethyleation frequency of SFRP-1 and SFRP-2 genes were 16.1℅ and 27.2% respectively. In control group SFRP-1 and SFRP-2 genes were unmethylated.
Conclusion: The present study showed that, methylation of SFRP genes also occurs in CML like other solid tumors. Therefore, the methylation of these genes may play a role in the initiation of malignant disease.