Drug resistance in cancer, especially in leukemia, creates a dilemma in treatment planning. Consequently, studies related to the mechanisms underlying drug resistance, the molecular pathways involved in this phenomenon, and alternate therapies have attracted the attention of researchers. Among a variety of therapeutic modalities, mesenchymal stem cells (MSCs) are of special interest due to their potential clinical use. Therapies involving MSCs are showing increasing promise in cancer treatment and anticancer drug screening applications; however, results have been inconclusive, possibly due to the heterogeneity of MSC populations. Most recently, the effect of MSCs on different types of cancer, such as hematologic malignancies, their mechanisms, sources of MSCs, and its advantages and disadvantages have been discussed. There are many proposed mechanisms describing the effects of MSCs in hematologic malignancies; however, the most commonly-accepted mechanism is that MSCs induce tumor cell cycle arrest. This review explains the anti-tumorigenic effects of MSCs through the suppression of tumor cell proliferation in hematological malignancies, especially in acute myeloid leukemia.
Cell Cycle Checkpoints ; Cell Proliferation ; Drug Evaluation, Preclinical ; Drug Resistance ; Hematologic Neoplasms ; Leukemia ; Leukemia, Myeloid, Acute ; Mesenchymal Stromal Cells ; Population Characteristics

Acute myeloblastic leukemia (AML) is the most frequent acute leukemia in adulthood with very poor overall survival rates. In the past few decades, significant progresses had led to the findings of new therapeutic approaches and the better understanding of the molecular complexity of this hematologic malignancy. Leukemic stem cells (LSCs) play a key role in the initiation, progression, regression, and drug resistance of different types of leukemia. The cellular and molecular characteristics of LSCs and their mechanism in the development of leukemia had not yet been specified. Therefore, determining their cellular and molecular characteristics and creating new approaches for targeted therapy of LSCs is crucial for the future of leukemia research. For this reason, the recognition of surface maker targets on the cell surface of LSCs has attracted much attention. CD33 has been detected on blasts in most AML patients, making them an interesting target for AML therapy. Genetic engineering of T cells with chimeric antigen receptor (CAR-T cell therapy) is a novel therapeutic strategy. It extends the range of antigens available for use in adoptive T-cell immunotherapy. This review will focus on CAR-T cell approaches as well as monoclonal antibody (mAB)-based therapy, the two antibody-based therapies utilized in AML treatment.

Amniotic fluid represents rich sources of stem cells that can be used in treatments for a wide range of diseases. Amniotic fluid- stem cells have properties intermediate between embryonic and adult mesenchymal stem cells which make them particularly attractive for cellular regeneration and tissue engineering. Furthermore, scientists are interested in these cells because they come from the amniotic fluid that is routinely discarded after birth. In this review we give a brief introduction of amniotic fluid followed by a description of the cells present within this fluid and aim to summarize the all existing isolation methods, culturing, characterization and application of these cells. Finally, we elaborate on the differentiation and potential for these cells to promote regeneration of various tissue defects, including fetal tissue, the nervous system, heart, lungs, kidneys, bones, and cartilage in the form of table.
Adult ; Amniotic Fluid* ; Cartilage ; Female ; Fetus ; Heart ; Humans ; Kidney ; Lung ; Mesenchymal Stromal Cells ; Nervous System ; Parturition ; Regeneration ; Stem Cells* ; Tissue Engineering

BACKGROUND AND OBJECTIVES: Human mesenchymal stem cells (hMSCs) are attractive candidates for cell therapy and regenerative medicine due to their multipotency and ready availability, but their application can be complicated by the factors such as age of the donors and senescence-associated growth arrest during culture conditions. The latter most likely reflects the fact that aging of hMSCs is associated with a rise in intracellular reactive oxygen species, loss of telomerase activity, decrease in human telomerase reverse transcriptase (hTERT) expression and finally eroded telomere ends. Over-expression of telomerase in hMSCs leads to telomere elongation and may help to maintain replicative life-span of these cells. The aim of this study was to evaluate of the effect of L-carnitine (LC) as an antioxidant on the telomerase gene expression and telomere length in aged adipose tissue-derived hMSCs. METHODS: For this purpose, cells were isolated from healthy aged volunteers and their viabilities were assessed by MTT assay. Quantitative gene expression of hTERT and absolute telomere length measurement were also performed by real- time PCR in the absence and presence of different doses of LC (0.1, 0.2 and 0.4 mM). RESULTS: The results indicated that LC could significantly increase the hTERT gene expression and telomere length, especially in dose of 0.2 mM of LC and in 48 h treatment for the aged adipose tissue-derived hMSCs samples. CONCLUSION: It seems that LC would be a good candidate to improve the lifespan of the aged adipose tissue-derived hMSCs due to over-expression of telomerase and lengthening of the telomeres.
Aging ; Carnitine* ; Cell- and Tissue-Based Therapy ; Cytochrome P-450 CYP1A1 ; Gene Expression* ; Humans* ; Mesenchymal Stromal Cells* ; Polymerase Chain Reaction ; Reactive Oxygen Species ; Regenerative Medicine ; Telomerase ; Telomere ; Tissue Donors ; Volunteers