Decrease in The Telomere Length of Bone Marrow Mesenchymal Stem Cells Co-Cultured with K۵۶۲ Cell Line Along with A Change in The Expression Level of WNT/Β- Catenin Proteins

Background: Chronic myeloid leukemia (CML) is a myeloproliferativedisease characterized by a proliferation of myeloidcell lineage and chromosome translocation t(۹;۲۲), so-calledPhiladelphia chromosome. Without effective therapy, CMLprogresses in three successive phases: chronic (CP), accelerated(AP), and blast crisis (BP). As is the case in all cancers,telomeres play an important role in the progression of CML.Telomere shortening has been reported in each of the threephases of CML, and this shortening is accentuated during progressionof the disease. On the other hand, cell transplantationwith bone marrow derived mesenchymal stem cells (BMSCs) isone of the central therapeutic treatments for hematologic cancers.The assessment of individual telomere length profiles inCML will provide knowledge concerning specific individualtelomere length changes associated with CML. Therefore, theaim of this study is investigation of the effect of BMSCs ontelomere length of co-cultured K۵۶۲ cell line via Wnt/β-cateninsignaling pathway.Materials and Methods: In this study, the bone marrow wasflushed from the femur of rattus norvegicus. Next, mononuclearcells were separated by ficoll hypaque and bone marrow derivedmesenchymal stem cells (BMSCs) were isolated. In addition,immunocytochemistry staining and flow cytometric analysiswere performed to investigate the MSCs-surface markers. Subsequently, K۵۶۲ as chronic myeloid leukemia cell line werecultured in RPMI/۱۶۴۰. After reaching confluency of cells,BMSCs co-cultured with K۵۶۲ cell line for ۷ days (۱:۱۰). Atthe end of co-culture time, K۵۶۲ cell line was collected, DNAand protein were extracted and subjected to Real-time PCR andwestern blotting, respectively. Quantitative real-time PCR andwestern blotting were used to measure the absolute telomerelength and Wnt/β-catenin protein expression, respectively.Results: It was found that BMSCs had the capacity to adhere toculture plastic flasks. Also, immunocytochemistry staining andflow-cytometric analysis showed that BMSCs had high levelsof expression of CD۴۴ (۹۴.۵%) and CD۹۰ (۸۷.۱%) and hematopoieticcell lineage-specific antigens, such as CD۳۱ (۰.۰۷%),and CD۵۶ (۰.۹%) were not expressed in these cells. In addition,quantitative real-time PCR showed that BMSCs cause todecrease telomere length of K۵۶۲ cell line significantly. Alongwith these results, evaluation of Wnt/β-catenin protein expressionindicated the decreased in level of both proteins.Conclusion: Taken together, the data indicated that changes inducedin the absolute telomere length of K۵۶۲ co-cultured withBMSCs via Wnt/β-catenin signaling pathway.

کلیدواژه ها:

Absolute Telomere Length ، Bone Marrow-Derived Mesenchymal Stem Cell ، Wnt/Β-Catenin Signaling Pathway