The role of the genetic abnormalities, epigenetic and microRNA in the prognosis of chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is increased proliferation of B-cells with peripheral blood and bone marrow involvement, which is usually observed in older people. Genetic mutations, epigenetic changes and miRs play a role in CLL pathogenesis. Del 11q, del l17q, del 6q, trisomy 12, p53 and IgVH mutations are the most important genetic changes in CLL. Deletion of miR-15a and miR-16a can increase bcl2 gene expression, miR-29 and miR-181 deletions decrease the expression of TCL1, and miR-146a deletion prevents tumor metastasis. Epigenetic changes such as hypo- and hypermethylation, ubiquitination, hypo- and hyperacetylation of gene promoters involved in CLL pathogenesis can also play a role in CLL. Expression of CD38 and ZAP70, presence or absence of mutation in IgVH and P53 mutation are among the factors involved in CLL prognosis. Use of monoclonal antibodies against surface markers of B-cells like anti-CD20 as well as tyrosine kinase inhibitors are the most important therapeutic approaches for CLL.

Co-transplantation of autologous bone marrow mesenchymal stem cells and Schwann cells through cerebral spinal fluid for the treatment of patients with chronic spinal cord injury: safety and possible outcome.

STUDY DESIGN: This is a clinical trial (phase 1). OBJECTIVES: The objective of this study was to asses the safety and feasibility of bone marrow mesenchymal stem cell (MSC) and Schwann cell (SC) co-injection through cerebral spinal fluid (CSF) for the treatment of patients with chronic spinal cord injury. METHODS: Six subjects with complete spinal cord injury due to trauma according to International Standard of Neurological Classification for Spinal Cord Injury (ISNCSCI) developed by the American Spinal Injury Association were enrolled. They received autologous co-transplantation of MSC and SC through lumbar puncture. Neurological status of the patients was determined by ISNCSCI, as well as by assessment of functional status by Spinal Cord Independent Measure. Before and after cell transplantation, magnetic resonance imaging (MRI) was performed for all the patients. Before the procedure, all the patients underwent electromyography, urodynamic study (UDS) and MRI tractograghy. After transplantation, these assessments were performed in special cases when the patients reported any changes in motor function or any changes in urinary sensation. RESULTS: Over the mean 30 months of follow-up, the radiological findings were unchanged without any evidence of neoplastic tissue overgrowth. American Spinal Injury Association class in one patient was changed from A to B, in addition to the improvement in indexes of UDS, especially bladder compliance, which was congruous with axonal regeneration detected in MRI tractography. No motor score improvement was observed among the patients. CONCLUSION: No adverse findings were detected at a mean of 30 months after autologous transplantation of the combination of MSCs and SCs through CSF. It may suggest the safety of this combination of cells for spinal cord regeneration.

Comparison of osteogenic differentiation potential of human adult stem cells loaded on bioceramic-coated electrospun poly (L-lactide) nanofibres.

OBJECTIVES: To compare potential of four types of stem cell in tissue engineering and regenerative medicine applications, osteogenic capacity of newly introduced mesenchymal stem cells (MSCs) derived from buccal fat pads (BFP) (an adipose-encapsulated mass of the oral cavity), was compared to those isolated from bone marrow (BM-MSCs), adipose tissue (AT-MSCs) and unrestricted somatic stem cells (USSCs). Cells were cultured on poly (L-lactide) (PLLA) nanofibres, Bio-Oss(®)-coated PLLA (PLLA-Bio), and culture plates (TCPS) as control. MATERIALS AND METHODS: Capacity of proliferation and osteogenic differentiation of the stem cells was investigated by MTT assay and common osteogenic markers, alkaline phosphatase activity, calcium mineral deposition and bone-related genes. RESULTS: Highest proliferation level was observed in cells cultured on PLLA-Bio, but with no significant difference between proliferation levels of the four types of stem cell. Over the period of study, BM-MSCs cultured on PLLA-Bio scaffolds exhibited greatest alkaline phosphatase (ALP) activity and mineralization with BFP-MSCs having the next closest results. However, AT-MSC had the lowest capacity for ALP activity and mineralization during osteogenic differentiation. Gene expression evaluation revealed that highest expression of three important bone-related genes was observed in stem cells cultured on bioceramic-coated nanofibrous scaffolds. CONCLUSIONS: Results indicated Bio-Oss-coated PLLA to compose most appropriate substrates to support proliferation and osteogenic differentiation of stem cells in vitro. BFP-MSCs demonstrated the same osteogenic differentiation capacity as other stem cells tested and thus hold very promising potential for applications in bone tissue engineering and regenerative medicine.

Bypassing the maturation arrest in myeloid cell line U937 by over-expression of microRNA-424.

Micro RNAs are a class of small non-coding RNAs which has been recently shown to play a crucial role in major cellular processes such as development and differentiation through post-transcriptional regulation. The role of these epigenetic elements has also been demonstrated in hematopoietic lineage differentiation and there is a large body of evidence that miR-424 is responsible for monocyte differentiation. Our goal was to examine the effect of miR-424 over-expression on defeating the maturation blockage in monoblastic cell line U937. The permanent over-expression of miR-424 was established using a retroviral vector construct containing the precursor of miR-424 sequence. Induction of differentiation process was monitored by assaying changes in cell morphology, and expression of cell surface markers using light microscopy, quantitative RT-PCR, and flow cytometry for monocyte markers such as CD11b and CD14. The cells showed monocytic characteristics 14 days after transduction, and CD11b and CD14 expression were significantly increased, confirmed by flow cytometry QRT-PCR and RT-PCR results. In conclusion, miR-424 over-expression is an effective factor in maturation of the monoblastic U937 cells and it has the ability of directing them into cells, expressing monocyte/macrophage characteristics.

Nanofibrous poly(epsilon-caprolactone)/poly(vinyl alcohol)/chitosan hybrid scaffolds for bone tissue engineering using mesenchymal stem cells.

In the present study, based on a biomimetic approach, novel 3D nanofibrous hybrid scaffolds consisting of poly(epsilon-caprolactone), poly(vinyl alcohol), and chitosan were developed via a multi-jet electrospinning method. The influence of chemical, physical, and structural properties of the scaffolds on the differentiation of mesenchymal stem cells into osteoblasts, and the proliferation of the differentiated cells were investigated. Osteogenically induced cultures revealed that cells were well-attached, penetrated into the construct and were uniformly distributed. The expression of early and late phenotypic markers of osteoblastic differentiation was upregulated in the constructs cultured in osteogenic medium.