Bone marrow mesenchymal stem cells increase motility of prostate cancer cells via production of stromal cell-derived factor-1α

Mesenchymal stem cells for cartilage regeneration: Insights into molecular mechanism and therapeutic strategies

The use of mesenchymal stem cells (MSCs) in cartilage regeneration has gained significant attention in regenerative medicine. This paper reviews the molecular mechanisms underlying MSC-based cartilage regeneration and explores various therapeutic strategies to enhance the efficacy of MSCs in this context. MSCs exhibit multipotent capabilities and can differentiate into various cell lineages under specific microenvironmental cues. Chondrogenic differentiation, a complex process involving signaling pathways, transcription factors, and growth factors, plays a pivotal role in the successful regeneration of cartilage tissue. The chondrogenic differentiation of MSCs is tightly regulated by growth factors and signaling pathways such as TGF-β, BMP, Wnt/β-catenin, RhoA/ROCK, NOTCH, and IHH (Indian hedgehog). Understanding the intricate balance between these pathways is crucial for directing lineage-specific differentiation and preventing undesirable chondrocyte hypertrophy. Additionally, paracrine effects of MSCs, mediated by the secretion of bioactive factors, contribute significantly to immunomodulation, recruitment of endogenous stem cells, and maintenance of chondrocyte phenotype. Pre-treatment strategies utilized to potentiate MSCs, such as hypoxic conditions, low-intensity ultrasound, kartogenin treatment, and gene editing, are also discussed for their potential to enhance MSC survival, differentiation, and paracrine effects. In conclusion, this paper provides a comprehensive overview of the molecular mechanisms involved in MSC-based cartilage regeneration and outlines promising therapeutic strategies. The insights presented contribute to the ongoing efforts in optimizing MSC-based therapies for effective cartilage repair.

Mesenchymal stem cells and their extracellular vesicles in urological cancers: Prostate, bladder, and kidney

Mesenchymal stem cells (MSCs) are recognized for their remarkable ability to differentiate into multiple cell types. They are also known to possess properties that can fight cancer, leading to attempts to modify MSCs for use in anticancer treatments. However, MSCs have also been found to participate in pathways that promote tumor growth. Many studies have been conducted to explore the potential of MSCs for clinical applications, but the results have been inconclusive, possibly due to the diverse nature of MSC populations. Furthermore, the conflicting roles of MSCs in inhibiting tumors and promoting tumor growth hinder their adaptation to anticancer therapies. Antitumorigenic and protumorigenic properties of MSCs in urological cancers such as bladder, prostate, and renal are not as well established, and data comparing them are still limited. MSCs hold significant promise as a vehicle for delivering anticancer agents and suicide genes to tumors. Presently, numerous studies have concentrated on the products derived from MSCs, such as extracellular vesicles (EVs), as a form of cell-free therapy. This work aimed to review and discuss the current knowledge of MSCs and their EVs in urological cancer therapy.

Extracellular Mechanical Stimuli Alters the Metastatic Progression of Prostate Cancer Cells within 3D Tissue Matrix

This study aimed to understand extracellular mechanical stimuli's effect on prostate cancer cells' metastatic progression within a three-dimensional (3D) bone-like microenvironment. In this study, a mechanical loading platform, EQUicycler, has been employed to create physiologically relevant static and cyclic mechanical stimuli to a prostate cancer cell (PC-3)-embedded 3D tissue matrix. Three mechanical stimuli conditions were applied: control (no loading), cyclic (1% strain at 1 Hz), and static mechanical stimuli (1% strain). The changes in prostate cancer cells' cytoskeletal reorganization, polarity (elongation index), proliferation, expression level of N-Cadherin (metastasis-associated gene), and migratory potential within the 3D collagen structures were assessed upon mechanical stimuli. The results have shown that static mechanical stimuli increased the metastasis progression factors, including cell elongation (p < 0.001), cellular F-actin accumulation (p < 0.001), actin polymerization (p < 0.001), N-Cadherin gene expression, and invasion capacity of PC-3 cells within a bone-like microenvironment compared to its cyclic and control loading counterparts. This study established a novel system for studying metastatic cancer cells within bone and enables the creation of biomimetic in vitro models for cancer research and mechanobiology.

Emerging Roles of Mesenchymal Stem/Stromal-Cell-Derived Extracellular Vesicles in Cancer Therapy

Despite the tremendous efforts of many researchers and clinicians, cancer remains the second leading cause of mortality worldwide. Mesenchymal stem/stromal cells (MSCs) are multipotent cells residing in numerous human tissues and presenting unique biological properties, such as low immunogenicity, powerful immunomodulatory and immunosuppressive capabilities, and, in particular, homing abilities. Therapeutic functions of MSCs are mediated mostly by the paracrine effect of released functional molecules and other variable components, and among them the MSC-derived extracellular vesicles (MSC-EVs) seem to be one of the central mediators of the therapeutic functions of MSCs. MSC-EVs are membrane structures secreted by the MSCs, rich in specific proteins, lipids, and nucleic acids. Amongst these, microRNAs have achieved the most attention currently. Unmodified MSC-EVs can promote or inhibit tumor growth, while modified MSC-EVs are involved in the suppression of cancer progression via the delivery of therapeutic molecules, including miRNAs, specific siRNAs, or suicide RNAs, as well as chemotherapeutic drugs. Here, we present an overview of the characteristics of the MSCs-EVs and describe the current methods for their isolation and analysis, the content of their cargo, and modalities for the modification of MSC-EVs in order for them to be used as drug delivery vehicles. Finally, we describe different roles of MSC-EVs in the tumor microenvironment and summarize current advances of MCS-EVs in cancer research and therapy. MSC-EVs are expected to be a novel and promising cell-free therapeutic drug delivery vehicle for the treatment of cancer.

Osteoid cell-derived chemokines drive bone-metastatic prostate cancer

One of the greatest challenges in improving prostate cancer (PCa) survival is in designing new therapies to effectively target bone metastases. PCa regulation of the bone environment has been well characterized; however, bone-targeted therapies have little impact on patient survival, demonstrating a need for understanding the complexities of the tumor-bone environment. Many factors contribute to creating a favorable microenvironment for prostate tumors in bone, including cell signaling proteins produced by osteoid cells. Specifically, there has been extensive evidence from both past and recent studies that emphasize the importance of chemokine signaling in promoting PCa progression in the bone environment. Chemokine-focused strategies present promising therapeutic options for treating bone metastasis. These signaling pathways are complex, with many being produced by (and exerting effects on) a plethora of different cell types, including stromal and tumor cells of the prostate tumor-bone microenvironment. ​This review highlights an underappreciated molecular family that should be interrogated for treatment of bone metastatic prostate cancer (BM-PCa).

Cancer Therapy Empowered by Extracellular Vesicle-Mediated Targeted Delivery

Extracellular vesicles (EVs) are a class of nanoparticles that mediate signaling molecules delivery between donor and recipient cells. Heterogeneity in the content of EVs and their membrane surface proteins determines their unique targetability. Their low immunogenicity, capability to cross various biological barriers, and superior biocompatibility enable engineering-modified EVs to be ideal drug delivery carriers. In addition, the engineered EVs that emerge in recent years have become a powerful tool for cancer treatment through the selective delivery of bioactive molecules to therapeutic targets, such as tumor cells and stroma. Our review focuses on the various types of EV modifications and their promoting therapeutic capabilities, which provide an innovative means for cancer precision therapy.

Mesenchymal stem cell-derived exosomes for gastrointestinal cancer

Gastrointestinal (GI) malignancies, a series of malignant conditions originating from the digestive system, include gastric cancer, hepatocellular carcinoma, pancreatic cancer, and colorectal cancer. GI cancers have been regarded as the leading cancer-related cause of death in recent years. Therefore, it is essential to develop effective treatment strategies for GI malignancies. Mesenchymal stem cells (MSCs), a type of distinct non-hematopoietic stem cells and an important component of the tumor microenvironment, play important roles in regulating GI cancer development and progression through multiple mechanisms, such as secreting cytokines and direct interactions. Currently, studies are focusing on the anti-cancer effect of MSCs on GI malignancies. However, the effects and functional mechanisms of MSC-derived exosomes on GI cancer are less studied. MSC-derived exosomes can regulate GI tumor growth, drug response, metastasis, and invasion through transplanting proteins and miRNA to tumor cells to activate the specific signal pathway. Besides, the MSC-derived exosomes are also seen as an important drug delivery system and have shown potential in anti-cancer treatment. This study aims to summarize the effect and biological functions of MSC-derived exosomes on the development of GI cancers and discuss their possible clinical applications for the treatment of GI malignancies.

AKT in Bone Metastasis of Solid Tumors: A Comprehensive Review

Simple Summary

Bone metastasis is a frequent complication of solid tumors and leads to a reduced overall survival. Although much progress has been made in the field of tumor therapy in the last years, bone metastasis depicts a stage of the disease with a lack of appropriate therapeutical options. Hence, this review aims to present the role of AKT in bone metastasis of solid tumors to place the spotlight on AKT as a possible therapeutical approach for patients with bone metastases. Furthermore, we intended to discuss postulated underlying molecular mechanisms of the bone metastasis-promoting effect of AKT, especially in highly bone-metastatic breast, prostate, and lung cancer. To conclude, this review identified the AKT kinase as a potential therapeutical target in bone metastasis and revealed remaining questions, which need to be addressed in further research projects.

Abstract

Solid tumors, such as breast cancer and prostate cancer, often form bone metastases in the course of the disease. Patients with bone metastases frequently develop complications, such as pathological fractures or hypercalcemia and exhibit a reduced life expectancy. Thus, it is of vital importance to improve the treatment of bone metastases. A possible approach is to target signaling pathways, such as the PI3K/AKT pathway, which is frequently dysregulated in solid tumors. Therefore, we sought to review the role of the serine/threonine kinase AKT in bone metastasis. In general, activation of AKT signaling was shown to be associated with the formation of bone metastases from solid tumors. More precisely, AKT gets activated in tumor cells by a plethora of bone-derived growth factors and cytokines. Subsequently, AKT promotes the bone-metastatic capacities of tumor cells through distinct signaling pathways and secretion of bone cell-stimulating factors. Within the crosstalk between tumor and bone cells, also known as the vicious cycle, the stimulation of osteoblasts and osteoclasts also causes activation of AKT in these cells. As a consequence, bone metastasis is reduced after experimental inhibition of AKT. In summary, AKT signaling could be a promising therapeutical approach for patients with bone metastases of solid tumors.

Mesenchymal stem/stromal cell-based therapy: mechanism, systemic safety and biodistribution for precision clinical applications

Mesenchymal stem/stromal cells (MSCs) are a promising resource for cell-based therapy because of their high immunomodulation ability, tropism towards inflamed and injured tissues, and their easy access and isolation. Currently, there are more than 1200 registered MSC clinical trials globally. However, a lack of standardized methods to characterize cell safety, efficacy, and biodistribution dramatically hinders the progress of MSC utility in clinical practice. In this review, we summarize the current state of MSC-based cell therapy, focusing on the systemic safety and biodistribution of MSCs. MSC-associated risks of tumor initiation and promotion and the underlying mechanisms of these risks are discussed. In addition, MSC biodistribution methodology and the pharmacokinetics and pharmacodynamics of cell therapies are addressed. Better understanding of the systemic safety and biodistribution of MSCs will facilitate future clinical applications of precision medicine using stem cells.

Antitumor effect of IL-12 gene-modified bone marrow mesenchymal stem cells combined with Fuzheng Yiliu decoction in an in vivo glioma nude mouse model

Background

Glioma is a complex cancer with a high morbidity and high mortality. Bone marrow mesenchymal stem cells (BMSCs) have shown promise as an excellent cell/drug delivery vehicle for gene-targeted therapy; however, maintaining genetic stability and biological activity remains difficult. Furthermore, whether BMSCs support or inhibit tumor growth remains debated. This study investigated whether a traditional Chinese medicine fomular, Fuzheng Yiliu decoction (FYD) had a synergistic antitumor effect with IL-12 gene-modified BMSCs in glioma-bearing nude mice

Methods

The lentivirus-mediated IL-12 gene was transfected into primarily cultured BMSCs. A total of 72 BALB/c nude mice were used to establish xenograft models with glioma U251 cells and were divided into groups (n = 12) including blank control group, nude mouse model group (model group), lentiviral transfection of BMSC group with no gene loading (BMSC group), IL-12 lentivirus-transfected BMSC group (IL-12 + BMSC group), FYD treatment group (FYD group), and FYD treatment in IL-12 lentivirus-transfected BMSC group (FYD + IL-12 + BMSC group).. After treatment for 14 days, all mice were sacrificed to collect tumor tissue and serum for more detection, such as distribution of BMSCs, cell apoptosis in xenograft tumors, serum IL-12 and INF-γ levels, mouse weight and tumor volume were measured

Results

There were significantly more apoptotic cells in tumor tissue in IL-12 gene transfected group, FYD treatment group and FYD combining with IL-12 gene transfected group than that in the model group (P < 0.05). The FYD + IL-12 + BMSC group showed significantly higher Bax and lower Bcl-2 expression (P < 0.05), and serum IL-12 and INF-γ levels (P < 0.05) were higher than that in all other groups. After the intervention, this group also showed a strong inhibitory effect against tumor growth (P < 0.05)

Conclusions

This study suggested FYD treatment combined with IL-12 gene-modified BMSCs shows synergistic antitumor effect in glioma-bearing nude mice.

IL-17 and IL-23 levels in patients with early-stage chronic lymphocytic leukemia

OBJECTIVE:

Cytokines produced by bone marrow mesenchymal stem cells are important components of the tumor microenvironment in chronic lymphocytic leukemia (CLL). The roles of IL-17 and IL-23 in both autoimmune diseases and tumor growth have been demonstrated. The role of the IL-17/23 axis in apoptosis has also been demonstrated in studies. Autoimmune cytopenias are common in CLL. In this study, we aimed to compare IL-17/IL-23 levels in early-stage CLL patients with healthy controls.

METHODS:

After obtaining ethical approval from the local ethics committee, 22 patients with early-stage chronic lymphocytic leukemia and 21 healthy control groups were included in this study. IL-17 and IL-23 were analyzed using the enzyme-linked immunosorbent assay method.

RESULTS:

The findings showed that the median IL-23 level was lower in men in the chronic lymphocytic leukemia group than women. There was a positive correlation between IL-17 and IL-23 levels in both the control group and the chronic lymphocytic leukemia group. There was no significant correlation between stage and IL-17 and IL-23 levels in chronic lymphocytic leukemia patients.

CONCLUSION:

Results of studies conducted on IL-17 and/or IL-23 in chronic lymphocytic leukemia in the literature are not consistent. These inconsistent results can be explained by the fact that the immune system develops differently in each individual due to environmental factors, past infections, intestinal flora, vaccines, ethnicity, and even gender. Therefore, it can be hypothesized that the development and application of personalized immunotherapy strategies instead of standard therapy in chronic lymphocytic leukemia may increase therapeutic success rates.

Suppression of PTBP1 signaling is responsible for mesenchymal stem cell induced invasion of low malignancy cancer cells

Mesenchymal stem cells (MSCs) hold great promise as attractive vehicles to deliver therapeutic agents against cancer, while the cross-talk between MSCs and cancer cells remains controversial. Here in an indirect co-culture system we observed that MSCs induced the malignancy transformation of low malignancy cancer cells HT29 and MCF7, whereas MSCs were reprogrammed by high malignancy cancer cells HCT116 and MDA-MB-231 without exerting an obvious influence on them. We further demonstrated that the RNA-binding protein polypyrimidine tract-binding protein 1 (PTBP1) was suppressed in low malignancy cancer cells co-cultured with MSCs. Moreover, shRNA mediated silencing of PTBP1 could promote the invasiveness of HT29 cells while over-expression of PTBP1 attenuate the MSC-induced invasion of HT29 cells. Our results suggested that differential effects of MSCs on the invasion of cancer cells partially corresponded to PTBP1 expression in cancer cells and the maintenance of biological characteristics in MSCs, which insight could provide a theoretical basis for evaluating the safety of MSC application and PTBP1 targeting in cancer treatment.

Human renal angiomyolipoma cells of male and female origin can migrate and are influenced by microenvironmental factors

Background

Improving the knowledge of angiomyolipoma physiopathology might help in refining its pharmacological treatment. We investigated if angiomyolipoma cells have migratory properties, how their growth and motility can be influenced by the hormonal milieu, and if this can be related to a specific gender.

Methods

Primary cells were isolated from angiomyolipomas surgically resected for therapeutical reasons in a female and in a male patient. The genetic control demonstrated no TSC2 deletion. Bi- (wound healing) and three-dimensional (transwell assay) migration were analyzed in vitro in basal conditions and under the influence of 17- β-estradiol and SDF-1α.

Results

Treatment up to 72 hours with 17-β-estradiol (0.1–100 nM), tamoxifen (0.2–20 μM) or with both, does not modify angiomyolipoma cells proliferation. On the other hand, SDF-1α and 17-β-estradiol treatment induce a significant motility increase (both bi- and three-dimensional) which becomes evident already after 2 hours of incubation. Angiomyolipoma cells express mRNA coding for SDF-1α and 17-β-estradiol receptors and secrete both the metalloproteases principally involved in malignant phenotype acquisition, i.e. MMP-2 and MMP-9.

Conclusion

Angiomyolipoma cells behave similarly, despite their different source. Primary angiomyolipoma cells migrate in response to hormonal milieu and soluble factors, and produce active metalloproteases, both aspects being consistent with the theory claiming they can migrate to the lungs (and/or other organs) and colonizing them. No main feature, among the aspects we analyzed, seems to be referable to the gender of origin.

Self-assembling nanoparticles encapsulating zoledronic acid inhibit mesenchymal stromal cells differentiation, migration and secretion of proangiogenic factors and their interactions with prostate cancer cells

Zoledronic Acid (ZA) rapidly concentrates into the bone and reduces skeletal-related events and pain in bone metastatic prostate cancer (PCa), but exerts only a limited or absent impact as anti-cancer activity. Recently, we developed self-assembling nanoparticles (NPS) encapsulating zoledronic acid (NZ) that allowed a higher intratumor delivery of the drug compared with free zoledronic acid (ZA) in in vivo cancer models of PCa. Increasing evidence suggests that Bone Marrow (BM) Mesenchymal stromal cells (BM-MSCs) are recruited into the stroma of developing tumors where they contribute to progression by enhancing tumor growth and metastasis.

We demonstrated that treatment with NZ decreased migration and differentiation into adipocytes and osteoblasts of MSCs and inhibited osteoclastogenesis. Treatment with NZ reduced the capability of MSCs to promote the migration and the clonogenic growth of the prostate cancer cell lines PC3 and DU145. The levels of Interleukin-6 and of the pro-angiogenic factors VEGF and FGF-2 were significantly reduced in MSC-CM derived from MSCs treated with NZ, and CCL5 secretion was almost totally abolished. Moreover, treatment of MSCs with supernatants from PC3 cells, leading to tumor-educated MSCs (TE-MSCs), increased the secretion of IL-6, CCL5, VEGF and FGF-2 by MSCs and increased their capability to increase PC3 cells clonogenic growth. Treatment with NZ decreased cytokine secretion and the pro-tumorigenic effects also of TE-MSCS. In conclusion, demonstrating that NZ is capable to inhibit the cross talk between MSCs and PCa, this study provides a novel insight to explain the powerful anticancer activity of NZ on PCa.

Targeting the CXCL12/CXCR4 pathway and myeloid cells to improve radiation treatment of locally advanced cervical cancer

Cervical cancer is the fourth most commonly diagnosed cancer and the fourth leading cause of cancer death in women worldwide. Approximately half of cervical cancer patients present with locally advanced disease, for which surgery is not an option. These cases are nonetheless potentially curable with radiotherapy and cisplatin chemotherapy. Unfortunately, some tumours are resistant to treatment, and lymph node and distant recurrences are major problems in patients with advanced disease at diagnosis. New targeted treatments that can overcome treatment resistance and reduce metastases are urgently needed. The CXCL12/CXCR4 chemokine pathway is ubiquitously expressed in many normal tissues and cancers, including cervical cancer. Emerging evidence indicates that it plays a central role in cervical cancer pathogenesis, malignant progression, the development of metastases and radiation treatment response. Pre-clinical studies of standard-of-care fractionated radiotherapy and concurrent weekly cisplatin plus the CXCR4 inhibitor Plerixafor (AMD3100) in patient-derived orthotopic cervical cancer xenografts have shown improved primary tumour response and reduced lymph node metastases with no increase in early or late side effects. These studies have pointed the way forward to future clinical trials of radiotherapy/cisplatin plus Plerixafor or other newly emerging CXCL12 or CXCR4 inhibitors in women with cervical cancer.

Autocrine signals increase ovine mesenchymal stem cells migration through Aquaporin-1 and CXCR4 overexpression

Sheep is a relevant large animal model that is frequently used to test innovative tissue engineering (TE) approaches especially for bone reconstruction. Mesenchymal stem cells (MSCs) are used in TE applications because they represent key component of adult tissue repair. Importantly, MSCs from different species show similar characteristics, which facilitated their application in translational studies using animal models. Nowadays, many researches are focusing on the use of ovine mesenchymal stem cells (oMSCs) in orthopedic preclinical settings for regenerative medicine purposes. Therefore, there is a need to amplify our knowledge on the mechanisms underlying the behaviour of these cells. Recently, several studies have shown that MSC function is largely dependent on factors that MSCs release in the environment, as well as, in conditioned medium (CM). It has been demonstrated that MSCs through autocrine and paracrine signals are able to stimulate proliferation, migration, and differentiation of different type of cells including themselves. In this study, we investigated the effects of the CM produced by oMSCs on oMSCs themselves and we explored the signal pathways involved. We observed that CM caused an enhancement of oMSC migration. Furthermore, we found that CM increased levels of two membrane proteins involved in cell migration, Aquaporin 1 (AQP1), and C-X-C chemokine receptor type 4 (CXCR4), and activated Akt and Erk intracellular signal pathways. In conclusion, taken together our results suggest the high potential of autologous CM as a promising tool to modulate behaviour of MSCs thus improving their use in therapeutically approaches.

Targeting the IL-17/IL-6 axis can alter growth of Chronic Lymphocytic Leukemia in vivo/in vitro

The tumor microenvironment (TME) is critical to the longevity of tumor B cells in chronic lymphocytic leukemia (CLL). Bone marrow mesenchymal stem cells (BMMSCs) and the cytokines they produce including IL-6 are important components of the TME in CLL. We found BMMSCs supported the survival of CLL cells in vitro through an IL-6 dependent mechanism. IL-17 which induces IL-6 generation in a variety of cells increased production of IL-6 both in CLL cells and BMMSCs in vitro. In a xenograft CLL mouse model, BMMSCs and the culture supernatant of BMMSCs increased engraftment of CLL cells through an IL-6 mediated mechanism with human recombinant IL-6 showing similar effects in vivo. Human recombinant IL-17 treatment also increased CLL engraftment in mice through an IL-6 mediated mechanism. Plasma of CLL patients showed elevated levels of both IL-6 and IL-17 by ELISA compared with healthy controls, with levels of IL-6 linearly correlated with IL-17 levels. CLL patients requiring fludarabine based chemotherapy expressed higher levels of IL-6 and IL-17, while CLL patients with the lowest levels of IgA/IgM had higher levels of IL-6, but not IL-17. These data imply an important role for the IL-17/IL-6 axis in CLL which could be therapeutic targets.

Inflammation fires up cancer metastasis

Metastatic disease is the major challenge of cancer that accounts for over 90% of total cancer lethality. Mounting clinical and preclinical data now indicate that inflammation, a potent immune and repair response, is indispensable for metastasis. In this review we describe our current understanding of how major inflammatory cells contribute to metastatic cascade with a focus on the primary tumour. We also discuss exciting new directions for future research and novel therapeutic approaches to tackle metastatic disease through targeting inflammation.

Mouse models of metastasis: progress and prospects

Metastasis is the spread of cancer cells from a primary tumor to distant sites within the body to establish secondary tumors. Although this is an inefficient process, the consequences are devastating as metastatic disease accounts for >90% of cancer-related deaths. The formation of metastases is the result of a series of events that allow cancer cells to escape from the primary site, survive in the lymphatic system or blood vessels, extravasate and grow at distant sites. The metastatic capacity of a tumor is determined by genetic and epigenetic changes within the cancer cells as well as contributions from cells in the tumor microenvironment. Mouse models have proven to be an important tool for unraveling the complex interactions involved in the metastatic cascade and delineating its many stages. Here, we critically appraise the strengths and weaknesses of the current mouse models and highlight the recent advances that have been made using these models in our understanding of metastasis. We also discuss the use of these models for testing potential therapies and the challenges associated with the translation of these findings into the provision of new and effective treatments for cancer patients.

Therapeutic interactions between mesenchymal stem cells for healing medication-related osteonecrosis of the jaw

Background

Mesenchymal stem cells (MSCs) have been isolated from a variety of tissues, including bone marrow, adipose, and mucosa. MSCs have the capacity for self-renewal and differentiation. Reports have been published on the systemic administration of MSCs leading to functional improvements by engraftment and differentiation, thus providing a new strategy to regenerate damaged tissues. Recently, it has become clear that MSCs possess immunomodulatory properties and can therefore be used to treat diseases. However, the therapeutic effect mechanisms of MSCs are yet to be determined. Here, we investigated these mechanisms using a medication-related osteonecrosis of the jaw (MRONJ)-like mouse model.

Methods

To generate MRONJ-like characteristics, mice received intravenous zoledronate and dexamethasone two times a week. At 1 week after intravenous injection, maxillary first molars were extracted, and at 1 week after tooth extraction, MSCs were isolated from the bone marrow of the mice femurs and tibias. To compare “diseased MSCs” from MRONJ-like mice (d-MSCs) with “control MSCs” from untreated mice (c-MSCs), the isolated MSCs were analyzed by differentiation and colony-forming unit-fibroblast (CFU-F) assays and systemic transplantation of either d-MSCs or c-MSCs into MRONJ-like mice. Furthermore, we observed the exchange of cell contents among d-MSCs and c-MSCs during coculture with all combinations of each MSC type.

Results

d-MSCs were inferior to c-MSCs in differentiation and CFU-F assays. Moreover, the d-MSC-treated group did not show earlier healing in MRONJ-like mice. In cocultures with any combination, MSC pairs formed cell–cell contacts and exchanged cell contents. Interestingly, the exchange among c-MSCs and d-MSCs was more frequently observed than other pairs, and d-MSCs were distinguishable from c-MSCs.

Conclusions

The interaction of c-MSCs and d-MSCs, including exchange of cell contents, contributes to the treatment potential of d-MSCs. This cellular behavior might be one therapeutic mechanism used by MSCs for MRONJ.

Tumor Mesenchymal Stem-Like Cell as a Prognostic Marker in Primary Glioblastoma

The isolation from brain tumors of tumor mesenchymal stem-like cells (tMSLCs) suggests that these cells play a role in creating a microenvironment for tumor initiation and progression. The clinical characteristics of patients with primary glioblastoma (pGBM) positive for tMSLCs have not been determined. This study analyzed samples from 82 patients with pGBM who had undergone tumor removal, pathological diagnosis, and isolation of tMSLC from April 2009 to October 2014. Survival, extent of resection, molecular markers, and tMSLC culture results were statistically evaluated. Median overall survival was 18.6 months, 15.0 months in tMSLC-positive patients and 29.5 months in tMSLC-negative patients (P = 0.014). Multivariate cox regression model showed isolation of tMSLC (OR = 2.5, 95% CI = 1.1~5.6, P = 0.021) showed poor outcome while larger extent of resection (OR = 0.5, 95% CI = 0.2~0.8, P = 0.011) has association with better outcome. The presence of tMSLCs isolated from the specimen of pGBM is associated with the survival of patient.

Probable impact of age and hypoxia on proliferation and microRNA expression profile of bone marrow-derived human mesenchymal stem cells

Decline in the therapeutic potential of bone marrow-derived mesenchymal stem cells (MSC) is often seen with older donors as compared to young. Although hypoxia is known as an approach to improve the therapeutic potential of MSC in term of cell proliferation and differentiation capacity, its effects on MSC from aged donors have not been well studied. To evaluate the influence of hypoxia on different age groups, MSC from young (<30 years) and aged (>60 years) donors were expanded under hypoxic (5% O₂) and normal (20% O₂) culture conditions. MSC from old donors exhibited a reduction in proliferation rate and differentiation potential together with the accumulation of senescence features compared to that of young donors. However, MSC cultured under hypoxic condition showed enhanced self-renewing and proliferation capacity in both age groups as compared to normal condition. Bioinformatic analysis of the gene ontology (GO) and KEGG pathway under hypoxic culture condition identified hypoxia-inducible miRNAs that were found to target transcriptional activity leading to enhanced cell proliferation, migration as well as decrease in growth arrest and apoptosis through the activation of multiple signaling pathways. Overall, differentially expressed miRNA provided additional information to describe the biological changes of young and aged MSCs expansion under hypoxic culture condition at the molecular level. Based on our findings, the therapeutic potential hierarchy of MSC according to donor’s age group and culture conditions can be categorized in the following order: young (hypoxia) > young (normoxia) > old aged (hypoxia) > old aged (normoxia).

Nanoparticles and mesenchymal stem cells: a win-win alliance for anticancer drug delivery

Schematic illustration of the combination of NPs and MSCs drug delivery systems for cancer therapy.

Cell therapy for liver diseases: current medicine and future promises

Liver diseases are a major health problem worldwide since they usually represent the main causes of death in most countries, causing excessive costs to public health systems. Nowadays, there are no efficient current therapies for most hepatic diseases and liver transplant is infrequent due to the availability of organs, cost and risk of transplant rejection. Therefore, alternative therapies for liver diseases have been developed, including cell-based therapies. Stem cells (SCs) are characterized by their self-renewing capacity, unlimited proliferation and differentiation under certain conditions into tissue- or organ-specific cells with special functions. Cell-based therapies for liver diseases have been successful in experimental models, showing anti-inflammatory, antifibrogenic and regenerative effects. Nowadays, clinical trials using SCs for liver pathologies are increasing in number, and those that have reached publication have achieved favorable effects, encouraging us to think that SCs will have a potential clinical use in a short time.

TGFβ signaling in myeloid cells regulates mammary carcinoma cell invasion through fibroblast interactions

Metastasis is the most devastating aspect of cancer, however we know very little about the mechanisms of local invasion, the earliest step of metastasis. During tumor growth CD11b+ Gr1+ cells, known also as MDSCs, have been shown to promote tumor progression by a wide spectrum of effects that suppress the anti-tumor immune response. In addition to immunosuppression, CD11b+ Gr1+ cells promote metastasis by mechanisms that are currently unknown. CD11b+ Gr1+ cells localize near fibroblasts, which remodel the ECM and leave tracks for collective cell migration of carcinoma cells. In this study we discovered that CD11b+ Gr1+ cells promote invasion of mammary carcinoma cells by increasing fibroblast migration. This effect was directed by secreted factors derived from CD11b+ Gr1+ cells. We have identified several CD11b+ Gr1+ cell secreted proteins that activate fibroblast migration, including CXCL11, CXCL15, FGF2, IGF-I, IL1Ra, Resistin, and Shh. The combination of CXCL11 and FGF2 had the strongest effect on fibroblast migration that is associated with Akt1 and ERK1/2 phosphorylation. Analysis of subsets of CD11b+ Gr1+ cells identified that CD11b+ Ly6Chigh Ly6Glow cells increase fibroblast migration more than other myeloid cell populations. Additionally, tumor-derived CD11b+ Gr1+ cells promote fibroblast migration more than splenic CD11b+ Gr1+ cells of tumor-bearing mice. While TGFβ signaling in fibroblasts does not regulate their migration toward CD11b+ Gr1+ cells, however deletion of TGFβ receptor II on CD11b+ Gr1+ cells downregulates CXCL11, Shh, IGF1 and FGF2 resulting in reduced fibroblast migration. These studies show that TGFβ signaling in CD11b+ Gr1+ cells promotes fibroblast directed carcinoma invasion and suggests that perivascular CD11b+ Ly6Chigh Ly6Glow cells may be the stimulus for localized invasion leading to metastasis.

The multiple functional roles of mesenchymal stem cells in participating in treating liver diseases

Mesenchymal stem cells (MSCs) are a group of stem cells derived from the mesodermal mesenchyme. MSCs can be obtained from a variety of tissues, including bone marrow, umbilical cord tissue, umbilical cord blood, peripheral blood and adipose tissue. Under certain conditions, MSCs can differentiate into many cell types both in vitro and in vivo, including hepatocytes. To date, four main strategies have been developed to induce the transdifferentiation of MSCs into hepatocytes: addition of chemical compounds and cytokines, genetic modification, adjustment of the micro-environment and alteration of the physical parameters used for culturing MSCs. Although the phenomenon of transdifferentiation of MSCs into hepatocytes has been described, the detailed mechanism is far from clear. Generally, the mechanism is a cascade reaction whereby stimulating factors activate cellular signalling pathways, which in turn promote the production of transcription factors, leading to hepatic gene expression. Because MSCs can give rise to hepatocytes, they are promising to be used as a new treatment for liver dysfunction or as a bridge to liver transplantation. Numerous studies have confirmed the therapeutic effects of MSCs on hepatic fibrosis, cirrhosis and other liver diseases, which may be related to the differentiation of MSCs into functional hepatocytes. In addition to transdifferentiation into hepatocytes, when MSCs are used to treat liver disease, they may also inhibit hepatocellular apoptosis and secrete various bioactive molecules to promote liver regeneration. In this review, the capacity and molecular mechanism of MSC transdifferentiation, and the therapeutic effects of MSCs on liver diseases are thoroughly discussed.

The osteoblastic and osteoclastic interactions in spinal metastases secondary to prostate cancer

Prostate cancer (PC) is one of the most common cancers arising in men and has a high propensity for bone metastasis, particularly to the spine. At this stage, it often causes severe morbidity due to pathological fracture and/or metastatic epidural spinal cord compression which, if untreated, inevitably leads to intractable pain, neurological deficit, and paralysis. Unfortunately, the underlying molecular mechanisms driving growth of secondary PC in the bony vertebral column remain largely unknown. Further investigation is warranted in order to identify therapeutic targets in the future. This review summarizes the current understanding of PC bone metastasis in the spine, highlighting interactions between key tumor and bone-derived factors which influence tumor progression, especially the functional roles of osteoblasts and osteoclasts in the bone microenvironment through their interactions with metastatic PC cells and the critical pathway RANK/RANKL/OPG in bone destruction.