The multiple facets of mesenchymal stem cells in modulating tumour cells’ proliferation and progression

Cancer has become the global health, social, and economic burden that direly needs a revolutionized novel treatment for a broad spectrum of tumors. Among the innovative and promising therapeutic modalities, the use of mesenchymal stem cells (MSCs) as a tool for delivering an antitumorigenic activity via its inherent antiproliferative capability or transportation of proteins or genes that suppress tumor has created a new way to circumvent cancers. MSCs are one of the most studied adult stem cells in the field of regenerative medicine, gene therapy, and immunomodulation due to its unique biological characteristics. Upon an in vivo administration, MSCs are able to migrate and home to the tumor site and exert either stimulatory or inhibitory effects on tumor cell growth, invasion, and metastasis via regulating angiogenesis, altering immune surveillance, modifying signaling pathways, and regulating apoptosis. Nonetheless, the mechanisms involved in the reported inhibition or stimulation are still elusive. Therefore, a better understanding of the biological consequences of MSCs–tumor interaction, prior to a successful MSCs based therapy, should be warranted. In this chapter, a number of previous findings associated with mutual interplays between MSCs and tumor cells are summarized and highlighted

Mesenchymal stem cells inhibit proliferation of lymphoid origin haematopoietic tumour cells by inducing cell cycle arrest

We have previously shown that mesenchymal stem cells (MSC) inhibit tumour cell proliferation, thus promising a novel therapy for treating cancers. In this study, MSC were generated from human bone marrow samples and characterised based on standard immunophenotyping. When MSC were co-cultured with BV173 and Jurkat tumour cells, the proliferation of tumour cells were profoundly inhibited in a dose dependent manner mainly via cell to cell contact interaction. Further cell cycle analysis reveals that MSC arrest tumour cell proliferation in G0/G1 phase of cell cycle thus preventing the entry of tumour cells into S phase of cell cycle

The effect of human Mesenchymal stem cell on neutrophil oxidative burst

Objective: Mesenchymal stem cells (MSC) are multipotent, non-haematopoietic stem cells that are capable of differentiating into different varieties of mature cell types such as osteoblasts, chondrocytes, adipocytes. and myoblasts. There is abundant evidence showing that MSC not only affect the differentiation of haematopoietic progenitors, but also the function of mature cells like lymphocytes and neutrophils. However the effect of MSC on neutrophil function and its responses is not well studied. Therefore, this study was conducted to assess the effect of MSC on neutrophil nitric oxide production. Method: Neutrophils from heparanised venous blood were isolated using Ficoll-Hypaque density gradient centrifugation followed by Dextran sedimentation and red blood cell (RBC) lysis. Isolated neutrophils were on average of 97% purity as determined by morphologic analysis. MSC were generated from human bone marrow and characterised by immunophenotyping (monoclonal antibodies CD1O5, CD73 and CD34) using a flowcytometer. In order to test the effects of MSC on neutrophil function, isolated neutrophils were co-cultured in the presence or absence of MSC at different ratios for 24 and 48 hours. The amount of nitric oxide released was used as an indication of oxidative burst and measured using the Griess assay. Result: The results indicate that MSC neither elevate the NO level when cocultured with resting neutrophils nor alone. However MSC profoundly inhibit the secretion of nitric oxide in PMA stimulated neutrophils after 241w of incubation. Conclusion: MSC exert an immunomodulatory effect on neutrophil by suppressing neutrophil oxidative burst in vitro

Evaluation of metabolic and immunological changes in streptozotocin-nicotinamide induced diabetic rats

Type 2 diabetes is a chronic disease with growing public health concern globally. Finding remedies to assist this health issue requires recruiting appropriate animal model for experimental studies. This study was designated to evaluate metabolic and immunologic changes in streptozotocin-nicotinamide induced diabetic rats as a model of type 2 diabetes. Male rats were induced diabetes using nicotinamide (110 mg/kg) and streptozotocin (65 mg/kg). Following 42 days, biochemical and immunological tests showed that diabetic rats had higher levels of blood glucose, WBC, certain abnormalities in lipid profile and insufficient mitogenic responses of lymphocytes (p < 0.05). However, the status of the total antioxidant, inflammatory biomarkers and other parameters of full blood count (except HCT) were not significantly altered. Phenotyping assay indicated insignificant lymphocyte subtype imbalances excluding a significant rise in the level of CD4+CD25+ marker (p < 0.05). This model of diabetic animals may represent some but not all symptoms of human type 2 diabetes

Metabolic and immunologic alterations of ginger rhizome among streptozotocin-nicotinamide induced diabetic rats

Introduction: This study was conducted to determine immunological and metabolic effects of different concentrations of ginger rhizome (Zingiber officinale Roscoe) in streptozotocin (STZ)-nicotinamide (NA) induced diabetic rats. Methods: Forty-eight fasted male Sprague-Dawley rats were induced diabetes using a single intraperitoneal injection of NA(110 mg/kg b.w.) and STZ (65 mg/kg b.w, 15 min after NA). Diabetic rats orally received either different concentrations (250, 500 and 750 mg/kg body weight) of ginger rhizome suspension or glibenclamide (10 mg/kg body weight) for 6 weeks. Two control diabetic and normal groups were gavaged with only distilled water as a vehicle. Results: The results indicated that the lower concentrations of ginger modulated body weight, fasting blood glucose, level of triglyceride and tumor necrosis factor-α (TNF-α) (p0.05). Conclusion: Ginger indicated better impact on metabolic and immunologic parameters in lower doses of supplementation compared with high doses of treatment

Human mesenchymal stem cells inhibit the differentiation and effector functions of monocytes

Although monocytes represent an essential part of the host defence system, their accumulation and prolonged stimulation could be detrimental and may aggravate chronic inflammatory diseases. The present study has explored the less-understood immunomodulatory effects of mesenchymal stem cells on monocyte functions. Isolated purified human monocytes were co-cultured with human umbilical cord-derived mesenchymal stem cells under appropriate culture conditions to assess monocytes’ vital functions. Based on the surface marker analysis, mesenchymal stem cells halted monocyte differentiation into dendritic cells and macrophages and reduced their phagocytosis functions, which rendered an inability to stimulate T-cell proliferation. The present study confers that mesenchymal stem cells exerted potent immunosuppressive activity on monocyte functions such as differentiation, phagocytosis and Ag presentation; hence, they promise a potential therapeutic role in down-regulating the unwanted monocyte-mediated immune responses in the context of chronic inflammatory diseases

Human mesenchymal stem cells-mediated transcriptomic regulation of leukemic cells in delivering anti-tumorigenic effects

Treatment of leukemia has become much difficult because of resistance to the existing anticancer therapies. This has thus expedited the search for alternativ therapies, and one of these is the exploitation of mesenchymal stem cells (MSCs) towards control of tumor cells. The present study investigated the effect of human umbilical cord-derived MSCs (UC-MSCs) on the proliferation of leukemic cells and gauged the transcriptomic modulation and the signaling pathways potentially affected by UC-MSCs. The inhibition of growth of leukemic tumor cell lines was assessed by proliferation assays, apoptosis and cell cycle analysis. BV173 and HL-60 cells were further analyzed using microarray gene expression profiling. The microarray results were validated by RT-qPCR and western blot assay for the corresponding expression of genes and proteins. The UC-MSCs attenuated leukemic cell viability and proliferation in a dose-dependent manner without inducing apoptosis. Cell cycle analysis revealed that the growth of tumor cells was arrested at the G0/G1 phase. The microarray results identified that HL-60 and BV173 share 35 differentially expressed genes (DEGs) (same expression direction) in the presence of UC-MSCs. In silico analysis of these selected DEGs indicated a significant influence in the cell cycle and cell cycle-related biological processes and signaling pathways. Among these, the expression of DBF4, MDM2, CCNE2, CDK6, CDKN1A, and CDKN2A was implicated in six different signaling pathways that play a pivotal role in the anti-tumorigenic activity exerted by UC-MSCs. The UC-MSCs perturbate the cell cycle process of leukemic cells via dysregulation of tumor suppressor and oncogene expression

Generation and characterization of human osteoarthritis cartilage-derived mesenchymal stem cells by modified sample processing and culture method

Introduction: Mesenchymal stem cells (MSCs) can be isolated from different tissue sources, and show a high differentiation capacity towards osteogenic, adipogenic, chondrogenic, neurogenic and myogenic lineages upon a specific induction. Although the retrieval of MSCs from normal tissues is very straightforward, yet it could be challenging in degenerative conditions that limit the expansion of stem cells such as osteoarthritis. Thus, this study aimed to establish human MSCs culture from osteoarthritic cartilage (OA hC-MSCs) by optimising the sample processing and culture techniques. Methods: Human osteoarthritis knee cartilage samples were obtained (2-4 g) from 8 patients with a mean age of 62.75 years old during the joint replacement surgery. A conventional culture method carried along with the modified method where the period of enzyme digestion and serial plating culture procedure were incorporated. Results: The modified culture method has significantly increased the number of single cells twice after the sample processing. The time taken to form colonies and achieve confluence was also reduced when samples subjected to the modified method. The number of cell yields after passage 0 for the conventional and modified methods were 3.05±0.31 and 6.10±0.42 million cells, respectively. The adherent cells generated under these two conditions comply with criteria for MSCs in term of immunophenotyping and mesodermal differentiation. Conclusions: The current modified method enhances the production of MSCs and could be opted for samples that known to have reduced or defective stem cell pool which may impede the in vitro cell expansion

Global gene profiling and anti-tumour activity of human mesenchymal stem cells on BV173 B leukaemia cell line

In 2013, there were 8.2 million cancer deaths worldwide and cancers were the second leading cause of death after cardiovascular diseases. Thus, it represents one of the major health issues all over the world. Current therapies such as the conventional methods of targeting the tumour cells by non-specific chemotherapy and radiotherapy have not yielded satisfactory outcomes as seen in many cancer remission cases, and an efficient treatment for cancer cells has yet to be identified. The recent development in mesenchymal stem cell research promises an efficient anti-cancer therapy via a possible mode of cell cycle arrest, apoptosis and immunosuppressive activity. Umbilical cord mesenchymal stem cells (UC-MSCs) are considered as post- natal stem cells present in the Wharton’s jelly of the umbilical cord tissue and are considered as an appealing source of adult stem cells for the cell therapy and tissue engineering as they are easily obtained and expanded while maintaining their multi-lineage differentiation potential. The past research studies have shown that UC-MSCs profoundly inhibited the growth of various tumour cells, however, the molecular mechanisms that execute this inhibition have yet to be identified. Although MSCs contribute to the haematopoiesis and support the growth of blood cells but also able to inhibit highly proliferating cells. Therefore, this study aims to investigate the inhibitory effect of UC-MSCs on haematopoietic tumour cells proliferation at in vitro by elucidating the molecular mechanisms and the relevant gene expression profiles. Wharton’s jelly from human umbilical cord was subjected to the collagenase digestion and the single cells were cultured to generate UC-MSCs. The adherent cells were characterized based on a universally accepted immunophenotyping and mesodermal differentiation. Haematopoietic origin tumour cell lines HL-60, K562, Jurkat and BV173 cell lines were purchased from ATCC and maintained in 10% foetal bovine serum supplemented RPMI media. Umbilical cord MSCs and tumour cells were co-cultured and the effect of UC-MSCs on tumour cell proliferation, apoptosis, cell cycle arrest, gene expression, biological process and signalling pathways were evaluated. Finally, the six selected genes were validated using SYBER GREEN qPCR. The results demonstrated that in the presence of UC-MSCs, tumour cell proliferation were profoundly inhibited in dose dependent manner as measured by 3H-thymidine uptake and MTS Assay. Transwell assays indicated that UC-MSCs mediated inhibition was mainly attributed to the cell- to-cell contact mode. Umbilical cord MSCs did not induce apoptosis as their mode of anti-proliferative activity. Further investigation on the tumour cell cycle revealed that UC-MSCs induced an arrest in Go/G1 and S phase of cell cycle. A subsequent microarray analysis showed that out of 3019 differentially expressed genes, 2000 and 1019 genes were up and down- regulated respectively in BV173 tumour cell line that were co-cultured with UC-MSCs. Besides, the microarray results also highlighted 380 altered genes with unknown function or unrelated association in BV173 cell line. When these dysregulated genes were analysed based on biological processes, the physiological functions such as cell adhesion, vasculature development, regulation of cell proliferation and regulation of cell migration processes were over-represented. In addition, the microarray analysis showed the most significant signalling pathways such as focal adhesion, ECM-receptor interaction, cytokine-cytokine receptor interaction, MAPK, p53 and TGF-§ signalling pathway were dysregulated by UC-MSCs in BV173. The qPCR result confirmed the mRNA level some of the selected genes. The present study indicated that UC-MSCs inhibit tumour cells proliferation by arresting in Go/G1 phase of cell cycle and this effect is mediated by cell-to- cell contact. Further gene profiling and signalling pathways revealed that anti- proliferative activity of UC-MSCs on tumour cell proliferation is associated with genes which are involved in cell cycle (CDK6, CCNE2 and CDKN1A), cell adhesion (TGF§I, MYO7A and CD82), metastasis (CCL2, TFPI2 and CXCR3), angiogenesis (PDGF, CXCL1 and PTX3) and regulation of cell proliferation (HECW1, SCIMP and ANXA1). The generalized tumour cells inhibition by UC-MSCs could be potentially exploited to treat various tumours. However, this anti-proliferative activity needs to be tested in in-vivo model and at protein level for their better understandings and validation

Magnetic exposure using Samarium Cobalt (SmCO5) increased proliferation and stemness of human Umbilical Cord Mesenchymal Stem Cells (hUC-MSCs)

Despite the extensive reports on the potential hazard of magnetic field (MF) exposures on humans, there are also concurrently reported on the improved proliferative property of stem cells at optimum exposure. However, the effect on mesenchymal stem cells (MSCs) remains unknown. Therefore, we aimed to investigate the impact of induced static MF (SMF) on human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) using Samarium Cobalt (SmCO5). At passage 3, hUC-MSCs (1 × 104) were exposed to 21.6 mT SMF by a direct exposure (DE) showed a significantly higher cell count (p < 0.05) in the growth kinetics assays with the shortest population doubling time relative to indirect exposure and negative control. The DE group was committed into the cell cycle with increased S phase (55.18 ± 1.38%) and G2/M phase (21.75 ± 1.38%) relative to the NC group [S-phase (13.54 ± 2.73%); G2/M phase (8.36 ± 0.28%)]. Although no significant changes were observed in the immunophenotype, the DE group showed an elevated expression of pluripotency-associated markers (OCT4, SOX2, NANOG, and REX1). These results suggest that the MFs could potentially induce proliferation of MSCs, a promising approach to promote stem cells propagation for clinical therapy and research without compromising the stemness of hUC-MSCs