فهرست مطالب hajar nasiri

Acute lymphoblastic leukemia (ALL) is a clonal malignant disorder characterized by an uncontrolled proliferation of immature T or B lymphocytes. Extensive studies have shown that the epigenetic changes, especially modified DNA methylation patterns in the regulatory regions through the DNA methyltransferase (DNMTs), play an important role in the development of genetic disorders and abnormal growth and maturation capacity of leukemic stem cells (LSCs).The aim of this study was to evaluate the changes in DNMT1 promoter methylation and its expression pattern in patients with ALL.
Subjects and In this experimental study, methylation specific PCR (MSP) was used to assess the methylation status of DNMT1 promoter regions in samples collected from ALL patients (n=45) and healthy control subjects. According to this method, un-methylated cytosine nucleotides are converted to uracil by sodium bisulfite and the proliferation of methylated and un-methylated regions are performed using specific primers for target sequences.
None of the patients with B and T-ALL showed methylated promoter regions of the DNMT1 gene, while the methylation pattern of both pre-B ALL patients and the control group showed a relative promoter methylation.
Analysis of promoter methylation patterns in various subgroups of ALL has revealed the importance of DNMT1 in the regulation of gene expression. Likewise, extensive data have also highlighted the methylation-based mechanisms exerted by DNAM1 as one of the main participants regulating gene expression in B-ALL and T-ALL patients. Investigation of the overall DNA methylation pattern offers significant improvements in the prediction of disease prognosis and treatment response.

Stem Cell differentiation is a process composed of vast variety of factors which are controlled by a network of certain mechanisms. This study aims to determine the possible role of DNA methylation, a potent regulator of VHL, ECAD and RUNX3 genes during Erythroid differentiation driven by miR-451.
To determine the methylation status of promoters and the expression levels of VHL, ECAD and RUNX3 genes, Methylation Specific PCR (MSP) and real-time PCR were used, respectively, on both Cord Blood CD34 Hematopoietic Stem Cells and differentiated cells. To measure the expression levels of mir-451, mirna qpcr technique was used.
Our findings demonstrated a similar methylation pattern for the target genes before and after differentiation by miR-451. However, the expression levels were significantly increased after differentiation. Gene expression and surface marker analysis results further confirmed the potential of miR-451 for driving erythroid differentiation from hematopoietic stem cells.
Our findings ruled out DNA methylation effect on the regulation of VHL, ECAD, and RUNX3 genes during miR-451 mediated erythroid differentiation. However, having CpG islands in their promoters, these three genes are candidates to be controlled by methylation which may not able to be detected by MSP method.
Taken together in this study we have shown a successful erythroid differentiation mediated by miR-451 which is at least in part, independent of DNA methylation. Further understanding of the underlying mechanisms driven by eryhtroid differentiation may lead to therapeutic measures to alter disorders of hematopoietic stem cell differentiation.

Iron chelation therapy is used to reduce iron overload development due to its deposition in various organs such as liver and heart after regular transfusion. In this review, different iron chelators implicated in treatment of iron overload in various clinical conditions have been evaluated using more up-to-date studies focusing on these therapeutic agents. Deferoxamine, Deferiprone and Deferasirox are the most important specific US FDA-approved iron chelators. Each of these chelators has their own advantages and disadvantages, various target diseases, levels of deposited iron and clinical symptoms of the afflicted patients which may affect their selection as the best modality. Taken together, in many clinical disorders, choosing a standard chelator does not have an accurate index which requires further clarifications. The aim of this review is to introduce and compare the different iron chelators regarding their advantages and disadvantages, usage dose and specific applications.

Mesenchymal stromal cells (MSCs) are employed in various different clinical settings in order to modulate immune response. Human autologous and allogeneic supplements including platelet derivatives such as platelet lysate (PL), platelet-released factors (PRF) and serum are assessed in clinical studies to replace fetal bovine serum (FBS). The immunosuppressive activity and multi-potential characteristic of MSCs appear to be maintained when the cells are expanded in platelet derivatives.
Platelet-rich plasma was collected from umbrical cord blood (UCB). Platelet-derived growth factors obtained by freeze and thaw methods. CD62P expression was determined by flow cytometry. The concentration of PDGF-BB and PDGF-AB was detemined by ELISA. We tested the ability of a different concentration of PL-supplemented medium to support the ex vivo expansion of Wharton's jelly derived MSCs. We also investigated the biological/functional properties of expanded MSCs in presence of different concentration of PL. The conventional karyotyping was performed in order to study the chromosomal stability. The gene expression of Collagen I and II aggrecan and SOX-9 in the presence of different concentrations of PL was evaluated by Real-time PCR.
We observed 5% and 10% PL, causing greater effects on proliferation of MSCs .These cells exhibited typical morphology, immunophenotype and differentiation capacity. The genetic stability of these derivative cells from Wharton's jelly was demonstrated by a normal karyotype. Furthermore, the results of Real-time PCR analysis showed that the expression of chondrocyte specific genes was higher in MSCs in the presence of 5% and 10% PL, compared with FBS supplement.
We demonstrated that PL could be used as an alternative safe source of growth factors for expansion of MSCs and also maintained similar growing potential and phenotype without any effect on chromosomal stability.

Early diagnosis and treatment of leukemia patients remains a fundamental aim in clinical oncology, especially in developing country. Present study highlights the basic requirements of these patients in Iran. Better understanding of these issues may lead to improve the healthcare standards toward leukemia diagnosis and treatment. This descriptive study included 101 specialists in hematology-oncology and pathology serving in oncology centers. The participants were then asked to fill out a standard questionnaire on the issues around diagnosis and treatment of blood malignancies. According to specialists, unfair distribution of facilities across the country, delayed diagnosis of disease, absence of psychological support for patients, and insufficient financial support were the main reasons of inappropriate diagnosis and treatment in leukemia patients. Our results show that making an amendment to health policies by preparing well-equipped medical centers in all provinces, improving the morale of patients through consultation during the process of treatment, and above all, subsiding leukemia patients'' financial problems will promote the health standard regarding the leukemia diagnosis and treatment in Iran.

The use of stem cells is considered as an appropriate source in cell therapy and tissue engineering. Differentiation of human induced Pluripotent Stem Cells (hiPSCs) to Hepatocyte-like Cells (HLCs) on mouse embryonic fibroblasts (MEFs) feeders is confronted with several problems that hinder the clinical applications of these differentiated cells for the treatment of liver injuries. Safe appropriate cells for stem cell-based therapies could create new hopes for liver diseases. This work focused on the determination of a capacity/efficiency for the differentiation of the hiPSCs into Hepatocyte-like Cells on a novel human adult bone marrow mesenchymal stem cells (hMSCs) feeder. Undifferentiated human iPSCs were cultured on mitotically inactivated human adult bone marrow mesenchymal stem cells. A three-step differentiation process has been performed in presence of activin A which added for 3 days to induce a definitive endoderm formation. In the second step, medium was exchanged for six days. Subsequently, cells were treated with oncostatin M plus dexamethasone for 9 days to generate hepatic cells. Endodermic and liver-specific genes were assessed via quantitative reverse transcription-polymerase chain reaction and RT-PCR, moreover, immunocytochemical staining for liver proteins including albumin and alpha-fetoprotein. In addition, functional tests for glycogen storage, oil red examination, urea production and alpha-fetoprotein synthesis, as well as, cells differentiated with a hepatocyte-like morphology was also performed. Our results show that inactivated human adult bone marrow mesenchymal stem cell feeders could support the efficient differentiation of hiPSCs into HLCs. This process induced differentiation of iPSCs into definitive endocrine cells that expressed sox17, foxa2 and expression of the specific genes profiles in hepatic-like cells. In addition, immunocytochemical analysis confirmed albumin and alpha-fetoprotein protein expression, as well as, the hiPSCs-derived Hepatocyte-like Cells on human feeder exhibited a typical morphology. we suggested a successful and efficient culture for differentiation and maturation of hepatocytes on an alternative human feeders; this is an important step to generate safe and functional hepatocytes that is vital for regenerative medicine and transplantation on the cell-based therapies.

Non- Hodgkin lymphoma (NHL) and acute lymphoblastic leukemia (ALL) are two main hematological malignances which have been driven from lymphoid tissue. Genetic polymorphisms in tumor necrosis factor-α (TNF-α) -308 and lymphotoxin-α (LT-α) +252 may affect their transcription and expression which leads to their high plasma level. The frequency of the TNF-α (-308) and LT-α (+ 252) polymorphisms are different for NHL and ALL cases in various populations with different ethnicity. This research is designed to investigate the prevalence and association of TNF-α (-308) and LT-α (+ 252) polymorphisms from NHL and ALL in Azarian patients and healthy individuals from Northwestern part of Iran. Seventy subjects with ALL and 68 NHL, along with another 130 healthy subjects as control group took part in this study. Genomic DNA was extracted, then genetic polymorphisms in TNF-α and LT-α genes were analyzed with the PCR-RFLP and NCOI as restriction enzyme. A statistical analysis was performed by chi-square test using SPSS software. A P-value of <0.05 was considered statistically significant. A statistically significant difference of LT-α polymorphism was in NHL patients and control (P-value= 0.008) but there was not any association of TNF-α polymorphism between NHL patients and control group. A significant association for TNF-a variant was in ALL and control (P-value =0.005), however, there was no relationship about LT variant between ALL and control. The results show that there are significant differences between TNF-α (-308) and LT-α (+252) genetic polymorphisms respectively in ALL and NHL patients with control group from Northwestern part of Iran.