The research on the immuno-modulatory defect of mesenchymal stem cell from Chronic Myeloid Leukemia patients

Biology and Therapeutic Properties of Mesenchymal Stem Cells in Leukemia

This comprehensive review delves into the multifaceted roles of mesenchymal stem cells (MSCs) in leukemia, focusing on their interactions within the bone marrow microenvironment and their impact on leukemia pathogenesis, progression, and treatment resistance. MSCs, characterized by their ability to differentiate into various cell types and modulate the immune system, are integral to the BM niche, influencing hematopoietic stem cell maintenance and functionality. This review extensively explores the intricate relationship between MSCs and leukemic cells in acute myeloid leukemia, acute lymphoblastic leukemia, chronic myeloid leukemia, and chronic lymphocytic leukemia. This review also addresses the potential clinical applications of MSCs in leukemia treatment. MSCs' role in hematopoietic stem cell transplantation, their antitumor effects, and strategies to disrupt chemo-resistance are discussed. Despite their therapeutic potential, the dual nature of MSCs in promoting and inhibiting tumor growth poses significant challenges. Further research is needed to understand MSCs' biological mechanisms in hematologic malignancies and develop targeted therapeutic strategies. This in-depth exploration of MSCs in leukemia provides crucial insights for advancing treatment modalities and improving patient outcomes in hematologic malignancies.

Detection of endogenously circulating mesenchymal stem cells in human cancer patients

Mesenchymal stem cells (MSCs) can play a vital role in tumor progression and anticancer therapy response, as demonstrated by various in vitro and in vivo model systems. Their ability to home to developing tumors and modulate the tumor microenvironment, by suppressing T-cell responses and contributing to the tumor stroma, is suggested to have a significant impact on disease progression, metastasis formation, and therapy response. Most evidence, however, is derived from artificial models using exogenously administered MSCs. The contribution of endogenous MSCs to tumor progression is currently unclear. Furthermore, few studies have been conducted in humans. A prospective biomarker study was therefore undertaken in 40 human cancer patients and 10 healthy controls of similar age, aimed at (i) exploring and quantifying circulating MSC levels in healthy volunteers and patients with advanced malignancies, (ii) determining the variability of MSC levels between healthy volunteers and cancer patients with different histologic tumor types, and (iii) exploring biomarkers associated with MSC levels. Significantly increased levels of circulating MSC-like cells were observed in cancer patients when compared to healthy individuals (1.72 fold difference, 95% CI 1.03-2.81%, p = 0.03). In addition, prior systemic therapy was associated with a significant increase in MSC-like cells (1.73 fold difference, 95% CI 1.02-2.95, p = 0.04). These results indicate that the amount of endogenously circulating MSCs in humans is increased in response to cancer, and that systemic anticancer treatment can influence MSC levels. Further research is needed to determine whether MSCs have a predictive value.

Mesenchymal Stem Cells (MSC) Regulate Activation of Granulocyte-Like Myeloid Derived Suppressor Cells (G-MDSC) in Chronic Myeloid Leukemia Patients

It is well known that mesenchymal stem cells (MSC) have a role in promotion of tumor growth, survival and drug-resistance in chronic myeloid leukemia (CML). Recent reports indicated that a subpopulation of myeloid cells, defined as granulocyte-like myeloid-derived suppressor cells (G-MDSC) is increased in these patients. So far, the role of MSC in MDSC expansion and activation into the BM microenvironment remains unexplored. To address this question, here we use a specific experimental model in vitro, co-culturing MSC with peripheral blood mononucleated cells (PBMC) from normal individuals, in order to generate MSC-educated G-MDSC. Although MSC of healthy donors (HD) and CML patients were able to generate the same amount of MDSC, only CML-MSC-educated G-MDSC exhibited suppressive ability on autologous T lymphocytes. In addition, compared with HD-MSC, CML-MSC over-expressed some immunomodulatory factors including TGFβ, IL6 and IL10, that could be involved in MDSC activation. CML-MSC-educated G-MDSC expressed higher levels of ARG1, TNFα, IL1β, COX2 and IL6 than G-MDSC isolated from co-culture with HD-MSC. Our data provide evidence that CML-MSC may play a critical role in tumor microenvironment by orchestrating G-MDSC activation and regulating T lymphocytes-mediated leukemia surveillance, thus contributing to CML immune escape.

Detection of BCR/ABL Translocation in Bone Marrow Derived Mesenchymal Stem Cells in Egyptian CML Patients

BACKGROUND:

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder of hematopoietic stem cells. It is characterized at the cytogenetic level by Philadelphia (ph) chromosome and at the molecular level by the BCR/ABL gene rearrangement. Bone marrow derived mesenchymal stem cells (MSCs) are pluripotent stem cells that can differentiate into several mesenchymal tissues.

AIM:

To observe the biological characteristics of MSCS from CML patients and to determine whether MSCs harbor the abnormal BCR/ABL translocation similar to CML bone marrow cells.

SUBJECTS AND METHODS:

Characterized MSCs were isolated from 12 newly diagnosed Philadelphia positive untreated CML patients.

RESULTS:

MSCs can be readily isolated from CML marrow and exhibit major expansion. Flow cytometry analysis revealed the typical MSC phenotype. Moreover; MSCs do not harbor the BCR/ABL translocation confirmed by karyotype and real time PCR.

CONCLUSION:

MSCs from CML patients express the typical MSC phenotype; and do not express the BCR/ABL gene. Since; MSCs are able to support engraftment of hematopoietic stem cells in stem cell transplantation(SCT) as well as suppress alloreactive T cells causing graft versus –host disease, this current study provides evidence that in a SCT setting of CML patients, autologous MSCs could be a source of stem cell support in future cell therapy applications.

Bone marrow mesenchymal stem cells altered the immunoregulatory activities of hepatic natural killer cells

We explored the biological characteristics of bone marrow-derived mesenchymal stem cells (BMSCs) and their immunological effects in vivo. To establish the characteristics of BMSCs, we first examined their morphology, differentiation ability, phenotype, and growth patterns. We further explored the effects of intravenous infusion of BMSCs on the immunological activities in vivo and the possible mechanism involved in it. The results showed that BMSCs displayed a fibroblast-like morphology and could differentiate into bone, fat and cartilage cells. Phenotypic analysis indicated the cells were negative for CD34 and CD31 but positive for Flk1, CD29, CD44 and CD105. In addition, BMSC culture supernatants could not improve the resistance against H2O2-induced apoptosis in L02 cells. We also found that infusion of BMSCs suppressed the activity of intrahepatic natural killer T cells. In summary, BMSCs are an ideal candidate for therapeutic application because they are relatively easy to harvest, easily expandable in vitro, and can be isolated from adult bone marrow while retaining their differentiation potential. BMSCs have stem cell properties, and BMSC therapy is an alternative treatment for acute liver disease.

Mouse Flk-1+Sca-1- mesenchymal stem cells: functional plasticity in vitro and immunoregulation in vivo

OBJECTIVES

Mesenchymal stem cells (MSCs) represent a powerful tool in regenerative medicine because of their differentiation and migration capacities. Moreover, the immunomodulatory ability of MSCs may be used to develop therapies for the treatment of autoimmune diseases.

METHODS

In this study, we isolated Flk-1Sca-1 MSCs from bone marrow (bMSCs). Next, we studied their biological characteristics and immunologic functions. We also investigated their effects on graft-versus-host disease (GVHD) associated with allogeneic bone marrow transplantation in mice.

RESULTS

Flk-1Sca-1 bMSCs were able to differentiate into fat and cartilage cells, indicating that the isolated cells had stem cell properties. They could also suppress alloantigen-induced T cell proliferation in vitro in a dose-dependent manner. Infusion of bMSCs into allogeneic bone marrow-transplanted mice alleviated the lethal GVHD that occurred in control recipient mice. There was significantly lower mortality among the recipients of the Flk-1Sca-1 bMSCs that also ameliorated the clinical symptoms and GVHD histopathology. Beneficial effects on GVHD by Flk-1Sca-1 bMSCs were also observed when MSCs were engineered to express anti-inflammatory cytokines IL-4 and IL-10 and decrease expression of proinflammatory cytokines IFN-γ, TNF-α, and IL-2.

CONCLUSION

Flk-1Sca-1 bMSCs have stem cell properties and can efficiently ameliorate the GVHD associated with allogeneic bone marrow transplantation in mice.

To grab the stroma by the horns: from biology to cancer therapy with mesenchymal stem cells

Mesenchymal stem or stromal cells (MSCs) are precursor cells that play important roles in tumorigenesis. MSCs are recruited to tumors from local and distant sources to form part of the tumor microenvironment. MSCs influence tumor progression by interacting with cancer cells, endothelial cells, immune cells, and cancer stem cells, in a context-dependent network. This review aims to synthesize this emerging yet controversial field to identify key questions regarding the mechanisms of MSC mobilization and survival in blood; homing to tumors, metastases, and premetastatic sites; spatiotemporal organization and differentiation; and interaction with immune cells and cancer stem cells. Understanding the fundamental biology underlying mesenchymal stem cell and tumor interactions has the potential to inform our knowledge of cancer initiation and progression as well as lead to novel therapeutics for cancer. Furthermore, knowledge of endogenous mechanisms can be used to “program” exogenous MSCs for targeted chemotherapeutic delivery to tumors and metastases. Emerging studies will provide crucial insight into the mechanisms of tumor interactions with the whole organism including MSCs.

The uncertain role of unmodified mesenchymal stem cells in tumor progression: what master switch?

Mesenchymal stem cells (MSCs) are emerging as promising gene vectors for cancer therapy because of their unique characteristics, including the ease of their expansion and genetic modification and their remarkable tumor-tropic properties. However, there remains a concern that MSCs may promote cancer progression. Surprisingly, there are conflicting reports within the literature describing both the promotion and inhibition of cancer progression by MSCs. The reasons for this discrepancy are still unknown. The surface markers, differentiation ability, and tumorigenic roles of MSCs, as well as their effect on immunoregulation, produce heterogeneity. In this review, we describe the heterogeneity of MSCs by the species from which they are derived, the methodology for their isolation and the context of their interactions with cancer cells. The conflicting roles of MSCs in tumor progression may be attributable to the bimodal effect of unmodified MSCs on immunoregulation. MSCs have been reported to suppress T-cell function and inhibit graft-versus-host disease (GVHD). On the other hand, MSCs elicit the graft-versus-tumor (GVT) effect in some cases. Selective allodepletion may be used to dissociate GVHD from the GVT effect. Understanding the conditions that balance GVHD and the GVT effect of MSCs may be crucial to advance cancer therapy research with respect to MSCs.

Comparison of the effects of human adipose and bone marrow mesenchymal stem cells on T lymphocytes

Mesenchymal stem cells (MSCs) are multipotent cells that can be derived either from the bone marrow (bMSCs) or adipose tissue (aMSCs). We have compared the immune regulatory properties of cells derived from bone marrow and adipose tissue to provide a theoretical basis for the choice of stem cell source for transplantation. The phenotypes of bMSCs and aMSCs are similar, differing only in the expression of CD106. aMSCs proliferate faster than bMSCs, but aMSCs suppressed T-lymphocyte proliferation and activation more poorly than bMSCs. Thus cell origin and abundance are important factors in determining the suitability of MSCs for transplantation. Adipose tissue offers a more promising source of cells for such an application.

Effects of transplanted bone-marrow-derived mesenchymal stem cells in animal models of acute hepatitis

Our aim was to evaluate the therapeutic effects of bone-marrow-derived mesenchymal stem cells (BMMSCs) on ConA-induced hepatitis and to elucidate the possible mechanism involved. MSCs were isolated from bone marrow and their characteristics and anti-apoptotic effects on the L02 cell line were analyzed. The effect of intravenous infusion of BMMSCs on liver damage was also tested. Furthermore, the recruitment of donor BMMSCs to the liver of recipient animals and their effects on the activity of intrahepatic natural killer T (NKT) cells were investigated. BMMSCs ameliorated liver damage in a time- and dose-dependent manner. Donor BMMSCs were detected in the livers of recipient animals, suggesting that tissue damage stimulated the migration of BMMSCs. Transplanted BMMSCs also suppressed the activity of intrahepatic NKT cells, not only in the liver but throughout the body. The general infusion of BMMSCS ameliorated immunoregulatory activities by the suppression of intrahepatic NKT cells.