Targeted Silencing of NRF2 by rituximab-conjugated nanoparticles increases the sensitivity of chronic lymphoblastic leukemia cells to Cyclophosphamide.

BACKGROUND: Targeting influential factors in resistance to chemotherapy is one way to increase the effectiveness of chemotherapeutics. The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway overexpresses in chronic lymphocytic leukemia (CLL) cells and appears to have a significant part in their survival and chemotherapy resistance. Here we produced novel nanoparticles (NPs) specific for CD20-expressing CLL cells with simultaneous anti-Nrf2 and cytotoxic properties. METHODS: Chitosan lactate (CL) was used to produce the primary NPs which were then respectively loaded with rituximab (RTX), anti-Nrf2 Small interfering RNA (siRNAs) and Cyclophosphamide (CP) to prepare the final version of the NPs (NP-Nrf2_siRNA-CP). All interventions were done on both peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMNCs). RESULTS: NP-Nrf2_siRNA-CP had satisfying physicochemical properties, showed controlled anti-Nrf2 siRNA/CP release, and were efficiently transfected into CLL primary cells (both PBMCs and BMNCs). NP-Nrf2_siRNA-CP were significantly capable of cell apoptosis induction and proliferation prevention marked by respectively decreased and increased anti-apoptotic and pro-apoptotic factors. Furthermore, use of anti-Nrf2 siRNA was corresponding to elevated sensitivity of CLL cells to CP. CONCLUSION: Our findings imply that the combination therapy of malignant CLL cells with RTX, CP and anti-Nrf2 siRNA is a novel and efficient therapeutic strategy that was capable of destroying malignant cells. Furthermore, the use of NPs as a multiple drug delivery method showed fulfilling properties; however, the need for further future studies is undeniable. Video Abstract.

Paediatric pre-B acute lymphoblastic leukaemia-derived exosomes regulate immune function in human T cells.

Exosomes derived from solid tumour cells are involved in immune suppression, angiogenesis and metastasis; however, the role of leukaemia-derived exosomes has less been investigated. Hence, changes in immune response-related genes and human T cells apoptosis co-incubated with exosomes isolated from patients' pre-B cell acute lymphoblastic leukaemia were evaluated in this in vitro study. Vein blood sample was obtained from each newly diagnosed acute lymphoblastic leukaemia (ALL) patient prior any therapy. ALL serum exosomes were isolated by ultrafiltration and characterized using Western blotting and transmission electron microscopy. Exosomes were then co-incubated with T lymphocytes and the gene expressions, as well as functions of human T cells were quantified by qRT-PCR. Apoptosis and caspase-3 and caspase-9 protein expression were also evaluated by flowcytometry and Western blotting analysis, respectively. Exosomes isolated from ALL patients affected T lymphocytes and elevated the apoptosis. Moreover, these exosomes altered the T cells profile into regulatory type by increasing the expression of FOXP3 and Tregs-related cytokines, including TGF-B and IL-10. The expression level of Th17-related transcription factors (RoRγt) and interleukins (IL-17 and IL-23) decreased after this treatment. According to our findings, exosomes derived from ALL patients' sera carry immunosuppressive molecules, indicating the possible effect of exosomes as liquid biomarkers for cancer staging.

The altered expression of homing factors in CD34+ hematopoietic stem cells following G-CSF injection and its effects on transplantation quality in ALL patients.

Hematopoietic stem cells (HSCs) transplantation is considered a suitable treatment for malignant or nonmalignant hematological diseases. This study aims to investigate the HSCs homing factors in bone marrow (BM) donors of acute lymphoblastic leukemia (ALL) patients following granulocyte colony-stimulating factor (G-CSF) injection, as well as the G-CSF effects on BM transplantation quality in these patients. To mobilize HSCs into peripheral blood, G-CSF was used for ALL patient's BM donors. For HSCs counting, CD34+ cells were evaluated in analogous and autologous donors using flow cytometry. The expression of stem cell homing factors in CD34+ cells and peripheral blood mononuclear cells (PBMCs) were investigated using a real-time polymerase chain reaction. Finally, hematological factors after BM transplantation in ALL patients were assessed. According to our results, after G-CSF injection, the level of CD34+ HSCs was statistically increased. Besides, autologous donors showed a higher level of CD34+ cells compared to analogous donors before and after G-CSF injection. Additionally, a higher number of CD34+ HSCs was achieved in the autologous samples following G-CSF injection. Furthermore, after G-CSF injection, the expression of matrix metalloproteinase (MMP)-2, MMP-9 was increased; while, stromal cell-derived factor 1, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 expression were decreased. Moreover, the expression of C-X-C chemokine receptor type 4, lymphocyte function-associated antigen 1, and very late antigen-4 in CD34+ cells and PBMCs were decreased. BM transplantation on Day 90 also caused an increased level of white blood cells, red blood cells, and platelets as compared to the first day; however, no statistical differences were observed in hemoglobin level. In conclusion, G-CSF by altering the expression of HSCs homing factors in ALL donors improves BM transplantation quality in ALL patients.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles: A novel therapeutic paradigm.

Mesenchymal stem cells (MSCs) have been revealed to hold great potential for the development of new treatment approaches for various diseases. However, the clinical use of these cells is limited due to their tumorigenic effects. The therapeutic benefits of MSCs are largely dependent on paracrine factors including extracellular vesicles (EVs). EVs are nano-sized bilayer membrane structures containing lipids, microRNAs and proteins which play key roles in cell-to-cell communications. Because of their lower immunogenicity, tumorigenicity, and easier management, EVs have emerged as a new promising alternative to whole-cell therapy. Therefore, this paper reviews current preclinical studies on the use of EVs derived from human umbilical cord MSCs (hucMSCs) as a therapeutic approach in treatment of several diseases including neurological, cardiovascular, liver, kidney, and bone diseases as well as the cutaneous wound, inflammatory bowel disease, cancers, infertility, and other disorders.

Novel therapeutic approaches in utilizing platelet lysate in regenerative medicine: Are we ready for clinical use?

Hemoderivative materials are used to treat different diseases. These derivatives include platelet-rich plasma, serum, platelet gel, and platelet lysate (PL). Among them, PL contains more growth factors than the others and its production is inexpensive and easy. PL is one of the proper sources of platelet release factors. It is used in cells growth and proliferation and is a good alternative to fetal bovine serum. In recent years, the clinical use of PL has gained more appeal by scientists. PL is a solution saturated by growth factors, proteins, cytokines, and chemokines and is administered to treat different diseases such as wound healing, bone regeneration, alopecia, oral mucositis, radicular pain, osteoarthritis, and ocular diseases. In addition, it can be used in cell culture for cell therapy and tissue transplantation purposes. Platelet-derived growth factor, fibroblast growth factor, insulin-like growth factor, transforming growth factor ß, and vascular endothelial growth factor are key PL growth factors playing a major role in cell proliferation, wound healing, and angiogenesis. In this paper, we scrutinized recent advances in using PL and PL-derived growth factors to treat diseases and in regenerative medicine, and the ability to replace PL with other hemoderivative materials.

Effects of combination of melatonin and laser irradiation on ovarian cancer cells and endothelial lineage viability.

The main goal of anti-cancer therapeutic approaches is to induce apoptosis in tumor masses but not in the normal tissues. Nevertheless, the combination of photodynamic irradiation with complementary oncostatic agents contributes to better therapeutic performance. Here, we applied two different cell lines; SKOV3 ovarian carcinoma cells and HUVECs umbilical cord cells as in vitro models to pinpoint whether pharmacological concentration of melatonin in combination with photodynamic therapy induces cell cytotoxicity. The cells were separately treated with various concentrations of melatonin (0 to 10 mM) and photodynamic irradiation alone or in combination. Cells were preliminary exposed to increasing concentrations of melatonin for 24 h and subsequently underwent laser irradiation for 60 s with an output power of 80 mW in continuous mode at 675 nm wavelength and a total light dose of 13.22 J/cm2. Cell viability, apoptosis/necrosis rates, and reactive oxygen species levels as well as heat shock protein 70 expression were monitored after single and combined treatments. A statistical analysis was performed by applying one-way analysis of variance (ANOVA) and post hoc Tukey's test. Combination treatment of both cell lines caused a marked increase in apoptosis/necrosis rate, reactive oxygen species generation, and heat shock protein 70 expression compared to incubation of the cells with each agent alone (p < 0.05). SKOV3 cancer cells expressed higher level of heat shock protein 70 under experimental procedure as compared to HUVECs (p < 0.05). Our results introduce melatonin as a potent stimulus for enhancing the efficacy of laser on induction of apoptosis in tumor cells.

Cord blood stem cell-generated KIR+NK cells effectively target leukemia cell lines.

Acute lymphoid (ALL) and myeloid leukemia (AML) are known to be invasive and highly lethal hematological malignancies. Because current treatments are insufficient and have a variety of side effects, researchers are looking for new and more effective therapeutic methods. Interestingly, ongoing efforts to find the best approach to optimize NK cell anti-leukemia potential shed light on the successful treatment of cancer. Mature KIR+NK cells ability to remove HLA Class-I deficient cells has been exploited in cancer immunotherapy. Here, we generated KIR+NK cells from cord blood stem cells using IL-2 and IL-15 cytokines. Our finding underlined the importance of KIR expression in the cytotoxic function of NK cells. Taken together, this study presented an effective in vitro method for the expansion and differentiation of KIR+NK cells using cytokines without any feeder cells. Furthermore, the presented culture condition could be useful for the generation of mature and pure NK cells from limited numbers of CD34+ cord blood cells and might be used as a novel method to improve the current state of cancer therapy.

Platelet Microparticle Controversial Role in Cancer.

Platelet-derived microparticles (PMPs) are a group of micrometer-scale extracellular vesicles released by platelets upon activation that are responsible for the majority of microvesicles found in plasma. PMPs' physiological properties and functions have long been investigated by researchers. In this regard, a noticeable area of studies has been devoted to evaluating the potential roles and effects of PMPs on cancer progression. Clinical and experimental evidence conflictingly implicates supportive and suppressive functions for PMPs regarding cancer. Many of these functions could be deemed as a cornerstone for future considerations of PMPs usage in cancer targeted therapy. This review discusses what is currently known about PMPs and provides insights for new and possible research directions for further grasping the intricate interplay between PMPs and cancer.

The role of CD44 in cancer chemoresistance: A concise review.

CD44 is a cell surface adhesion molecule, which is overexpressed on cancer stem cells. The interaction of CD44 with hyaluronan is responsible for tumor development, metastasis, and expression of the chemoresistant phenotype. The overexpression of CD44 impedes the cytotoxic effect of chemotherapy medications in various cancers. Therefore, the high expression of CD44 is associated with a poor prognosis in affected patients. This high expression of CD44 in various cancers has provided an ample opportunity for the treatment of patients with chemoresistant malignancy. This review aims to demonstrate the various cross-talk between CD44 and intracellular and extracellular factors and highlight its role in developing chemoresistant tumors in some troublesome cancers.

WT-1, BAALC, and ERG Expressions in Iranian Patients with Acute Myeloid Leukemia Pre- and Post-chemotherapy.

Purpose: Acute myeloid leukemia (AML) is the most prevalent acute leukemia in adults. It possesses different cytogenetic and molecular features. The expression of Wilms tumor-1 (WT1), brain and acute leukemia, cytoplasmic (BAALC) and ETS-related gene (ERG) might be considered as prognostic factors in AML patients. The aim of this study was to determine the mRNA expressions of WT-1, BAALC and ERG genes in bone marrow of mononuclear cells and their effects on complete remission in the Iranian AML patients, pre- and post- chemotherapy. Methods: Forty AML patients with normal karyotype were evaluated. The mRNA gene expressions were measured with quantitative real-time PCR in bone marrow of mononuclear cells of AML patients at the baseline and after chemotherapy. The subtypes of AML and flow cytometry panel were also assessed. Complete remission (CR) after the treatment was addressed for all patients. Results: The mRNA expressions of WT-1, BAALC and ERG were significantly decreased after the treatment (p = 0.001, 0.017, 0.036). WT-1 mRNA expression was inversely correlated with CR after chemotherapy (P =0.024). There was also significant correlation between baseline expression of BAALC and CR (P =0.046). No significant correlation was observed between ERG and CR pre- and post- chemotherapy (P =0.464 and 0.781). There was also significant correlation between BAALC mRNA expression and CD34+ (P <0.001). Conclusion: The present study showed that WT-1 decreased significantly after standard chemotherapy which could have favorable effects on CR. Also, the high expression of BAALC could have a poor prognostic role in AML patients. The identification of these gene expressions can be an efficient approach in targeted therapy among AML patients.

Exosome: From leukemia progression to a novel therapeutic approach in leukemia treatment.

Exosomes, as small vesicles, are released by tumor cells and tumor microenvironment (cells and function as key intercellular mediators and effects on different processes including tumorigenesis, angiogenesis, drug resistance, and evasion from immune system. These functions are due to exosomes' biomolecules which make them as efficient markers in early diagnosis of the disease. Also, exosomes have been recently applied in vaccination. The potential role of exosomes in immune response toward leukemic cells makes them efficient immunotherapeutic agents treating leukemia. Furthermore, variations in exosomes contents make them beneficial to be used in treating different diseases. This review introduces the role of exosomes in the development of hematological malignancies and evaluates their functional role in the treatment of these malignancies.

Low-Level Laser Irradiation Modulated Viability of Normal and Tumor Human Lymphocytes In Vitro.

Introduction: Laser radiation is a promising strategy against various malignancies. Recent studies have shown that the application of low-power laser therapy (LPLT) at different doses and exposure times could modulate the growth dynamic of tumor cells. Based on the type of laser, LPLT could potentially trigger cell proliferation, differentiation, and apoptosis in different cell lines. Methods: In this study, MTT assay was used to monitor the effect of low and high laser intensities on the viability of normal and cancer lymphocytes. The protein levels of Ki-67 (a proliferation marker) and Caspase-3 (an apoptosis factor) were measured in human peripheral mononuclear cells (PBMCs) and the B-lymphoblastic cell line (Nalm-6) using flow cytometry after being-exposed to 630-nm LPLT at low (2, 4, 6, and 10 J/cm2 ) and high (15, 30, 60, and 120 J/cm2) energy densities in a continuous mode for 48 and 72 hours. Results: By using higher energy densities, 60 and 120 J/cm2 , a significant decrease was shown in the viability of Nalm-6 cells, which reached 6.6 and 10.1% after 48 hours compared to the control cells (P<0.05). Notably, Cell exposure to doses 30, 60, and 120 J/cm2 yielded 7.5, 12.9, and 21.6 cell viability reduction after 72 hours. The collected data showed that the high-intensity parameters of LPLT (15 to 120 J/cm2) promoted significant apoptotic changes in the exposed cells coincided with the activation of Caspase-3 compared to the none-treated control cells (P<0.05). The data further showed the stimulation of the Ki-67 factor both in primary PBMCs and the lymphoblastic cell line treated with LPLT at energy densities of 4 and 6 J/cm2 (P<0.05), indicating enhanced cell proliferation. Similar to Nalm-6 cells, primary PBMCs showed apoptosis after 48 hours of being exposed to doses 60, and 120 J/cm2 , indicated by increased Caspase-3 levels (P<0.05). As expected, the Nalm-6 cells were resistant to cytotoxic effects of laser irradiation in the first 48 hours (P>0.05) compared to normal PBMCs. The exposure of Nalm-6 cells to low-intensity laser intensities increased a proliferation rate compared to the PBMCs treated with the same doses. Conclusion: We showed the potency of LPLT in the induction of apoptosis and proliferation in human primary PBMCs and Nalm-6 cells in a dose and time-dependent manner after 72 hours.

Cord blood stem cell derived CD16+ NK cells eradicated acute lymphoblastic leukemia cells using with anti-CD47 antibody.

Acute lymphoblastic leukemia (ALL) is an aggressive cancer in children and adults which possess higher CD47 expression than normal cells. ALL chemotherapy has a lot of side effects and in most cases is ineffective. However arrival of Natural killer (NK) cell immunotherapy raised hopes for successful treatment of cancers, tailoring NK cells to meet clinical requirements is still under investigation. Of note, CD16+ (FCγIIIa) NK cells eliminate tumor cells with antibody dependent cell cytotoxicity (ADCC) mechanism. Therefore, we evaluated ADCC effect of cord blood stem cell derived CD16+ NK cells with using anti CD47 blocking antibody. CD16+ NK cells generated efficiently from CD34 positive cord blood cells in vitro using IL-2, IL-15 and IL-21 cytokines, although it was not dose dependent. CD16+ cells derived from CD34+ cells in day 14 of culture efficiently increased apoptosis in ALL cells, produced INFγ and increased CD107-a expression when used anti CD47 antibody (increased around 30-40%). Interestingly, CD16+ NK cell cytotoxicity slightly increased in combination with macrophages against ALL cells (around 10%). Taken together, our findings induced this hope that cord blood stem cell derived CD16+ NK cells exploit antitumor immune response in cancer therapy with using anti-CD47 antibody.

Human umbilical cord mesenchymal stem cells derived-exosomes in diseases treatment.

Exosomes are extracellular vesicles with the size of 40-100 nm in diameter and a density of 1.13-1.19 g/mL, containing proteins, mRNAs, miRNAs, and DNAs. Exosomes change the recipient cells biochemical features through biomolecules delivery and play a role in cellular communication. These vesicles are produced from body fluids and different cell types like mesenchymal stem cells (MSCs). Evidence suggests that mesenchymal stem cells-derived exosome (MSC-EXO) exhibit functions similar to MSCs with low immunogenicity and no tumorization. MSCs can also be isolated from a variety of sources including human umbilical cord (HUC). Because of the non-invasive collection method, higher proliferation and lower immunogenicity, HUCMSC-EXO has been frequently used in regenerative medicine and various diseases treatment compared to the other MSC-EXO resources. This review aimed to investigate the applications of HUCMSC-EXO in different diseases.

The Effect of Mesenchymal Stem Cell-Derived Microvesicles on Erythroid Differentiation of Umbilical Cord Blood-Derived CD34+ Cells.

Purpose: Mesenchymal stem cells (MSCs) play an important role in the proliferation and differentiation of hematopoietic stem cells (HSCs) in the bone marrow via cell-to-cell contact, as well as secretion of cytokines and microvesicles (MVs). In this study, we investigated the effect of mesenchymal stem cell-derived microvesicles (MSC-MVs) on erythroid differentiation of umbilical cord blood-derived CD34+ cells. Methods: In this descriptive study, CD34+ cells were cultured with mixture of SCF (10 ng/ml) and rhEPO (5 U/ml) cytokines in complete IMDM medium as positive control group. Then, in MV1- and MV2-groups, microvesicles at 10 and 20 µg/ml concentration were added. After 72 hours, erythroid specific markers (CD71 and CD235a) and genes (HBG1, GATA1, FOG1 and NFE2) were assessed by flow cytometry and qRT-PCR, respectively. Results: The expression of specific markers of the erythroid lineages (CD71 and GPA) in the presence of different concentration of microvesicles were lower than that of the control group (P<0.001). Also, the expression of specific genes of the erythroid lineages (NFE2, FOG1, GATA1, and HBG1) was investigated in comparison to the internal control (GAPDH). Among all of them, HBG1 and FOG1 genes were significantly decreased to the control group (P<0.0001) but GATA1 and NFE2 gene expressions was not significant. Conclusion: The results of this study showed that MSC-MVs decrease the erythroid differentiation of umbilical cord blood-derived CD34+ cells. Therefore, MSC-MVs play a key role in the regulation of normal erythropoiesis.

The Effect of Bone Marrow Mesenchymal Stem Cells on the Granulocytic Differentiation of HL-60 Cells.

OBJECTIVE: Mesenchymal stem cells (MSCs) are multipotent stromal cells that can differentiate into a variety of cell types. They control the process of hematopoiesis by secreting regulatory cytokines and growth factors and by the expression of important cell adhesion molecules for cell-to-cell interactions. This investigation was intended to examine the effect of bone marrow (BM)-derived MSCs on the differentiation of HL-60 cells according to morphological evaluation, flow cytometry analysis, and gene expression profile. MATERIALS AND METHODS: The BM-MSCs were cultured in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum (FBS). After the third passage, the BM-MSCs were irradiated at 30 Gy. To compare how the HL-60 cells differentiated in groups treated differently, HL-60 cells were cultured in RPMI-1640 and supplemented with 10% FBS. The HL-60 cells were seeded into six-well culture plates and treated with all-trans-retinoic acid (ATRA), BM-MSCs, or BM-MSCs in combination with ATRA, while one well remained as untreated HL-60 cells. The expression levels of the granulocyte subset-specific genes in the HL-60 cells were assayed by real-time polymerase chain reaction. RESULTS: Our results revealed that BM-MSCs support the granulocytic differentiation of the human promyelocytic leukemia cell line HL-60. CONCLUSION: Based on the results of this study, we concluded that BM-MSCs may be an effective resource in reducing or even preventing ATRA's side effects and may promote differentiation for short medication periods. Though BM-MSCs are effective resources, more complementary studies are necessary to improve this differentiation mechanism in clinical cases.

Rapamycin Inhibits Expansion of Cord Blood Derived NK and T Cell.

BACKGROUND: The mammalian target of rapamycin (mTOR) is important in hematopoiesis. Despite the central role of mTOR in regulating the differentiation of immune cells, the effect of mTOR function on cord blood mononuclear cells is yet to be defined. OBJECTIVES: To evaluate the effect of mTOR inhibition, using rapamycin on the proliferation and apoptosis of cord blood mononuclear cells, as well as on the B and T cell expansion. METHODS: Cord blood mononuclear cells were cultured in the presence of IL-2, IL-7 and IL-15 cytokines and inhibited by rapamycin for 14 days. The harvested cells were evaluated at distinct time points by flow cytometry. RESULTS: The mTOR expression decreased in the presence of rapamycin on day 14. Inhibition of mTOR reduced the proliferation of the cord blood mononuclear cells, yet did not influence apoptosis. Moreover, the number of T and NK cells was significantly reduced in the presence of rapamycin, while no change was observed in the B cell expansion. CONCLUSION: mTOR signaling plays a crucial part in cord blood derived NK and T cells expansion.

The Effect of Mesenchymal Stem Cell-Derived Extracellular Vesicles on Hematopoietic Stem Cells Fate.

Hematopoietic stem cells (HSCs) are multipotent stem cells, with self-renewal ability as well as ability to generate all blood cells. Mesenchymal stem cells (MSCs) are multipotent stem cells, with self-renewal ability, and capable of differentiating into a variety of cell types. MSCs have supporting effects on hematopoiesis; through direct intercellular communications as well as secreting cytokines, chemokines, and extracellular vesicles (EVs). Recent investigations demonstrated that some biological functions and effects of MSCs are mediated by their EVs. MSC-EVs are the cell membrane and endosomal membrane compartments, which are important mediators in the intercellular communications. MSC-EVs contain some of the molecules such as proteins, mRNA, siRNA, and miRNA from their parental cells. MSC-EVs are able to inhibit tumor, repair damaged tissue, and modulate immune system responses. MSC-EVs compared to their parental cells, may have the specific safety advantages such as the lower potential to trigger immune system responses and limited side effects. Recently some studies demonstrated the effect of MSC-EVs on the expansion, differentiation, and clinical applications of HSCs such as improvement of hematopoietic stem cell transplantation (HSCT) and inhibition of graft versus host disease (GVHD). HSCT may be the only therapeutic choice for patients who suffer from malignant and non-malignant hematological disorders. However, there are several severe side effects such GVHD that restricts the successfulness of HSCT. In this review, we will discuss the most important effects of MSCs and MSC-EVs on the improvement of HSCT, inhibition and treatment of GVHD, as well as, on the expansion of HSCs.

NF-Kß Activation in U266 Cells on Mesenchymal Stem Cells.

Purpose: Mesenchymal Stem Cells (MSCs) are one of the essential members of Bone Marrow (BM) microenvironment and the cells affect normal and malignant cells in BM milieu. One of the most important hematological malignancies is Multiple Myeloma (MM). Numerous studies reported various effects of MSCs on myeloma cells. MSCs initiate various signaling pathways in myeloma cells, particularly NF-kß. NF-kß signaling pathway plays pivotal role in the survival, proliferation and resistance of myeloma cells to the anticancer drugs, therefore this pathway can be said to be a vital target for cancer therapy. This study examined the relationship between U266 cells and MSCs. Methods: U266 cells were cultured with Umbilical Cord Blood derived-MSCs (UCB-MSCs) and Conditioned Medium (C.M). Effect of UCB-MSCs and C.M on proliferation rate and CD54 expression of U266 cells were examined with MTT assay and Flowcytometry respectively. Furthermore, expression of CXCL1, PECAM-1, JUNB, CCL2, CD44, CCL4, IL-6, and IL-8 were analyzed by Real Time-PCR (RT-PCR). Moreover, status of p65 protein in NF-kß pathway assessed by western blotting. Results: Our findings confirm that UCB-MSCs support U266 cells proliferation and they increase CD54 expression. In addition, we demonstrate that UCB-MSCs alter the expression of CCL4, IL-6, IL-8, CXCL1 and the levels of phosphorylated p65 in U266 cells. Conclusion: Our study provides a novel sight to the role of MSCs in the activation of NF-kß signaling pathway. So, NF-kß signaling pathway will be targeted in future therapies against MM.

The Study of Extracellular Protein Fractions of Probiotic Candidate Bacteria on Cancerous Cell Line.

INTRODUCTION: Probiotics are live microorganisms, habituated in the human intestine, which have a beneficial effect on our health. In spite of many reports about the anticancer effect of these bacteria in in-vivo and in-vitro, their mechanisms of action are not completely understood. The goal of this study was to compare the extracellular fractions of Lactobacillus casei and L. paracasei on the anti proliferation and apoptosis induction in K562 cell line. MATERIALS AND METHODS: L. casei and L. paracasei were cultured in MRS broth medium. Then extracellular secretions were collected and after enrichment, analyzed by electrophoresis. Fractionation were determined by gel filtration chromatography using sephadex G100 column, and the anticancer properties were evaluated. RESULTS: The results of SDS-PAGE showed various molecular weight of fractionated proteins of L. casei and L. paracasei. Bioactivity assessment illustrated that anti proliferative effects on K562 cells is dose and time dependent and the cytotoxic effects was parallel with protein concentration and the increase of time from 36 to 72 hours. CONCLUSION: Regarding the cell cytotoxicity results, the fractionated extracellular proteins of L. casei and L. paracasei have significant effects in inhibition of cancer cell proliferation. However, more study is needed to  better elucidate the  mechanisms of extracted proteins, and its effect on other human cancer cell lines.