MicroRNA775 regulates intrinsic leaf size and reduces cell wall pectin levels by targeting a galactosyltransferase gene in Arabidopsis.

Plants possess unique primary cell walls made of complex polysaccharides that play critical roles in determining intrinsic cell and organ size. How genes responsible for synthesizing and modifying the polysaccharides in the cell wall are regulated by microRNAs (miRNAs) to control plant size remains largely unexplored. Here we identified 23 putative cell wall-related miRNAs, termed as CW-miRNAs, in Arabidopsis thaliana and characterized miR775 as an example. We showed that miR775 post-transcriptionally silences GALT9, which encodes an endomembrane-located galactosyltransferase belonging to the glycosyltransferase 31 family. Over-expression of miR775 and deletion of GALT9 led to significantly enlarged leaf-related organs, primarily due to increased cell size. Monosaccharide quantification, confocal Raman imaging, and immunolabeling combined with atomic force microscopy revealed that the MIR775A-GALT9 circuit modulates pectin levels and the elastic modulus of the cell wall. We also showed that MIR775A is directly repressed by the transcription factor ELONGATED HYPOCOTYL5 (HY5). Genetic analysis confirmed that HY5 is a negative regulator of leaf size that acts through the HY5-MIR775A-GALT9 repression cascade to control pectin levels. These findings demonstrate that miR775-regulated cell wall remodeling is an integral determinant of intrinsic leaf size in A. thaliana. Studying other CW-miRNAs would provide more insights into cell wall biology.

Advances of In Vivo Flow Cytometry on Cancer Studies.

Cancer is a big threat to human life. Asia has about 60% of the global population and accounts for half of global cancer incidence and mortality. Circulating tumor cells (CTCs) have been a good biomarker for cancer diagnosis, staging, and prognosis. Conventional detection methods of CTCs require drawing blood. It may disturb the biological environment and limited real-time monitoring. in vivo flow cytometry (IVFC) is a burgeoning technique that allows noninvasive detection of CTCs in vivo. Here, we review the technical development of IVFC based on various contrast principles, including fluorescence IVFC, photoacoustic IVFC, imaging IVFC, and label-free IVFC. This powerful tool has been applied widely in many areas of cancer-related studies, especially the CTC studies. We review applications of IVFC in preclinical studies on prevalent cancers in Asia, including liver cancer, blood cancer, and so forth. Other cancer-related studies in breast cancer, prostate cancer, cancer-related stem cell research and drug studies are also reviewed. © 2019 International Society for Advancement of Cytometry.

In vivo flow cytometry combined with intravital microscopy to monitor kinetics of transplanted bone marrow mononuclear cells in peripheral blood and bone marrow.

Bone marrow mononuclear cells (BM-MNCs) transplantation has evolved as a promising experimental treatment in various regenerative therapy fields, especially in clinical hematopoietic stem cells transplantation (HSCT). In vitro methods have mainly been used to study the pre-clinical kinetics of BM-MNCs in mice after transplantation. And it is difficult to monitor the dynamic homing of BM-MNCs in living mice. The present study obtained the kinetics of transplanted BM-MNCs in the peripheral blood (PB) and the dynamic homing of BM-MNCs in the BM in living mice by a combination of in vivo flow cytometry (IVFC) and calvarium intravital microscopy. We found out that BM-MNCs were cleared rapidly from the PB and mainly localized to various hematopoietic tissues after transplantation. The number of BM-MNCs in the PB decreased over time accompanied by an increase in the BM indeed after transplantation. In addition, a lower number of BM-MNCs were found home to calvaria than long bone, probably indicating long bone marrow might also be an important hematopoietic organ. Clinical studies will benefit from non-invasive measurements to monitor the dynamic homing of transplanted cells. Our pre-clinical kinetics of BM-MNCs in living mice will have important clinical guiding significance in HSCT and other regenerative therapy fields.

A MicroRNA302-367-Erk1/2-Klf2-S1pr1 Pathway Prevents Tumor Growth via Restricting Angiogenesis and Improving Vascular Stability.

RATIONALE: Angiogenic hypersprouting and leaky vessels are essential for tumor growth. MicroRNAs have unique therapeutic advantages by targeting multiple pathways of tumor-associated angiogenesis, but the function of individual miRNAs of miR302-367 cluster in angiogenesis and tumors has not yet been fully evaluated. OBJECTIVE: To investigate the functions of miR302-367 in developmental angiogenesis and tumor angiogenesis and explore the molecular mechanisms of microRNA for the treatment of pathological neovascularization-related diseases. METHODS AND RESULTS: Here, we show that miR302-367 elevation in endothelial cells reduces retinal sprouting angiogenesis and promotes vascular stability in vivo, ex vivo, and in vitro. Erk1/2 is identified as direct target of miR302-367, and downregulation of Erk1/2 on miR302-367 elevation in endothelial cells increases the expression of Klf2 and in turn S1pr1 and its downstream target VE-cadherin, suppressing angiogenesis and improving vascular stability. Conversely, both pharmacological blockade and genetic deletion of S1pr1 in endothelial cells reverse the antiangiogenic and vascular stabilizing effect of miR302-367 in mice. Tumor angiogenesis shares features of developmental angiogenesis, and endothelial specific elevation of miR302-367 reduces tumor growth by restricting sprout angiogenesis and decreasing vascular permeability via the same Erk1/2-Klf2-S1pr1 pathways. CONCLUSIONS: MiR302-367 regulation of an Erk1/2-Klf2-S1pr1 pathway in the endothelium advances our understanding of angiogenesis, meanwhile also provides opportunities for therapeutic intervention of tumor growth.

Monitoring circulating prostate cancer cells by in vivo flow cytometry assesses androgen deprivation therapy on metastasis.

It remains controversial whether surgical castration prolongs survival rate and improves therapy prospects in patients suffering from prostate cancer. We used PC3 cell line to establish prostate tumor models. In vivo flow cytometry and ultrasonic imaging were used to monitor the process of prostate cancer growth, development and metastasis. We found out that the number of circulating tumor cells (CTCs) in orthotopic tumor model was higher than that in subcutaneous tumor model. The CTC number in orthotopic tumor model was due to burst growth, while CTC number in subcutaneous tumor model showed a gradual increase with tumor size. After androgen deprivation therapy (ADT) through testicular extraction, we constructed GFP-PC3 subcutaneous tumor models and orthotopic tumor models. We found dramatically decreased CTC number, relieved symptoms caused by the tumor, and significantly prolonged survival time after testicular extraction in orthotopically transplanted prostate tumor model, while the carcinogenesis process and metastases were little influenced by ADT in subcutaneous tumor model. ADT treatment can restrict tumor growth, decrease the CTC number significantly and inhibit distant invasion through inhibition of tumor proliferation and tumor angiogenesis in orthotopical prostate tumor model. © 2018 International Society for Advancement of Cytometry.

Proportion of circulating tumor cell clusters increases during cancer metastasis.

Circulating tumor cell (CTC) clusters are found among CTCs and show significantly greater potential for an important role in cancer metastasis than single CTCs, which have been traditionally believed as the majority of CTCs. The accurate proportion and dynamics of CTC clusters remain unclear due to the fact that CTCs in blood flow are very difficult to detect in vivo and in vitro. CTC clusters are even more difficult to be distinguished from CTCs without perturbation by state-of-the-art detection methods. Here, we demonstrate that by using in vivo flow cytometry (IVFC), we can reliably measure the proportion and dynamics of CTC clusters in two murine tumor models. CTC clusters are easily identified by their unique fluorescent pattern with multiple peaks and wider time duration. We find that the proportion of CTC clusters increases significantly during cancer metastasis in both mouse models, the orthotopic liver cancer and the subcutaneous prostate cancer models. Our results suggest that CTC clusters account for a much larger proportion of CTCs than previously anticipated. Hence this report might provide a new-level of understanding of CTCs during cancer development and progression. © 2016 International Society for Advancement of Cytometry.

Simultaneous two-color stimulated Raman scattering microscopy by adding a fiber amplifier to a 2 ps OPO-based SRS microscope.

Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technique. Two-color imaging is often necessary to determine the distribution of chemical species in SRS microscopy. Current multi-color SRS imaging methods involve complicated instrumentation or longer data acquisition time or are limited to transmission imaging. In this Letter, we show that by adding a simple fiber amplifier to a 2 ps laser source and optical-parametric-oscillator-based SRS setup, one can achieve simultaneous two-color or frequency modulation SRS microscopy. The fiber amplifier can generate a wavelength tunable laser of ±10 nm around the Stokes laser wavelength at 1031 nm with average power greater than 200 mW. In vivo and ex vivo lipid-protein imaging of mouse brain and skin is demonstrated. To further demonstrate the potential of this technique in high-speed in vivo imaging, white blood cells in a blood stream are imaged in a live mouse.

Morphological change of CD4(+) T cell during contact with DC modulates T-cell activation by accumulation of F-actin in the immunology synapse.

BACKGROUND: The changes in T-cell morphology during immunological synapse (IS) formation are essential for T-cell activation. Previous researches have shown that T cell changed from spherical to elongated and/or flattened during in contact with B cell. As most powerful antigen presenting cell, dendritic cell (DC) has a strong ability to activate T cells. However, the morphological change of T cell which contacts DC and the relationship between morphological change and T-cell activation are not very clear. Thus, we studied the morphological change of CD4(+) T cell during contact with DC. RESULTS: Using live-cell imaging, we discovered diversity in the T-cell morphological changes during contact with DCs. The elongation-flattening of CD4(+) T cells correlated with a low-level Ca(2+) response and a loss of T-cell receptor (TCR) signalling molecules in the IS, including zeta-chain associated protein kinase 70 (ZAP-70), phospholipase C-γ (PLC-γ) and protein kinase C-θ (PKC-θ), whereas rounding-flattening correlated with sufficient CD4(+) T-cell activation. Different morphological changes were correlated with the different amount of accumulated filamentous actin (F-actin) in the IS. Disruption of F-actin by cytochalasin D impaired the morphological change and the localisation of calcium microdomains in the IS and decreased the calcium response in CD4(+) T cells. CONCLUSION: Our study discovered the diversity in morphological change of T cells during contacted with DCs. During this process, the different morphological changes of T cells modulate T-cell activation by the different amount of F-actin accumulation in the IS, which controls the distribution of calcium microdomains to affect T-cell activation.

The bullseye synapse formed between CD4+ T-cell and staphylococcal enterotoxin B-pulsed dendritic cell is a suppressive synapse in T-cell response.

The immunological synapse (IS) is a supermolecular activation cluster formed between T cells and antigen-presenting cells. Although diverse IS structures have been reported, the function of the IS in T-cell activation remains unclear. Here, we found that the bullseye IS, one of IS types at the interface of CD4(+) T cells and staphylococcal enterotoxin B-pulsed dendritic cells, suppressed CD4(+) T-cell activation, whereas multifocal IS, another synapse type, stimulated CD4(+) T-cell activation. Consistent with these results, bullseye IS formation was accompanied by a low-level calcium response in T cells and a loss of T-cell receptor signalling molecules from the synapse, whereas multifocal IS exhibited the opposite. Furthermore, we found that CD4(+)CD25(+) regulatory T cells (T(regs)) more efficiently formed bullseye IS and promoted bullseye IS formation in CD4(+) CD25(-) T cells. Cytotoxic T-lymphocyte antigen-4 (CTLA-4), an inhibitory molecule expressed continuously on T(regs), was localised in bullseye IS. Moreover, blocking CTLA-4 reduced the percentage of bullseye IS formation and promoted T-cell activation. Our data thus indicate that bullseye IS formation is mediated by CTLA-4, and may negatively control T-cell activation as a suppressive synapse.

Near infrared in vivo flow cytometry for tracking fluorescent circulating cells.

The in vivo flow cytometry (IVFC) is now a powerful technique in biomedical research, especially for tracking specific cells in circulatory system. The current fluorescence-based IVFC is limited to visible spectrum, while near infrared (NIR) dyes have their advantages, such as deeper penetration, less absorption and less scattering for NIR fluorescence. Here, using an NIR in vivo flow cytometer with a 785 nm laser excitation, the measurement of fluorescent dye IR-780 labeled circulating cells is demonstrated. Representative peaks corresponding to NIR fluorescent circulating cells are detected and quantified. In addition, blood flow information, including the blood flow velocity and flow volume per unit time, is obtained. By simultaneous detection of IR-780 and enhanced green fluorescent protein (EGFP) signals from dual labeled cells, the IR-780 is shown to be a suitable fluorescent dye for multicolor detection by IVFC, including NIR. Thus, the IVFC is extended to the NIR range and shows potential application in biomedical research.

Enhancing Electric Field Distribution in the Pancreas for Improved TTFields Therapy: A Computational Modeling Investigation.

BACKGROUND: Tumor treating fields (TTFields) therapy has shown effectiveness in glioblastoma treatment and holds potential for other cancers. However, its application in pancreatic cancer and the distribution of electric fields in pancreas remain unexplored. This study aims to investigate the electric field distributions in pancreatic regions using different array configurations for TTFields therapy. METHODS: Computational modelling was employed to simulate electric field distributions, and quantitative analysis was conducted. Human body impedance measurements were used to optimize the electric properties of the model. Various array configurations were examined to assess their impact on the electric field distributions. RESULTS: The study revealed that well-positioned arrays, specifically the combination of 20-piece transducer arrays in anterior-posterior orientation and 13-piece transducer arrays in left-right orientation, consistently achieved electric fields exceeding the 1V/cm threshold in over 99.4% of the pancreas. Even with a reduced number of transducers (13 pieces for both orientations), sufficient electric field coverage was achieved, exceeding the threshold in over 92.9% of the pancreas. Additionally, different array placements within the same orientation were explored to address clinical challenges such as skin rash and patient anatomical variations. CONCLUSIONS: This research lays the groundwork for understanding TTFields distribution within the abdomen, offering insights into optimizing array configurations for improved electric field delivery. The findings have the potential to guide practical designs of TTFields devices, enhance treatment efficacy, and improve patient outcomes. These results offer promises of advancing TTFields therapy for pancreatic cancer towards clinical applications, and potentially enhancing treatment efficacy and patient outcomes.

Single Nucleus Total RNA Sequencing of Formalin-Fixed Paraffin-Embedded Gliomas.

Gliomas, the predominant form of brain cancer, comprise diverse malignant subtypes with limited curative therapies available. The insufficient understanding of their molecular diversity and evolutionary processes hinders the advancement of new treatments. Technical complexities associated with formalin-fixed paraffin-embedded (FFPE) clinical samples hinder molecular-level analyses of gliomas. Current single-cell RNA sequencing (scRNA-seq) platforms are inadequate for large-scale clinical applications. In this study, automated snRandom-seq is developed, a high-throughput single-nucleus total RNA sequencing platform optimized for archival FFPE samples. This platform integrates automated single-nucleus isolation and droplet barcoding systems with the random primer-based scRNA-seq chemistry, accommodating a broad spectrum of sample types. The automated snRandom-seq is applied to analyze 116 492 single nuclei from 17 FFPE samples of various glioma subtypes, including rare clinical samples and matched primary-recurrent glioblastomas (GBMs). The study provides comprehensive insights into the molecular characteristics of gliomas at the single-cell level. Abundant non-coding RNAs (ncRNAs) with distinct expression profiles across different glioma clusters and uncovered promising recurrence-related targets and pathways in primary-recurrent GBMs are identified. These findings establish automated snRandom-seq as a robust tool for scRNA-seq of FFPE samples, enabling exploration of molecular diversities and tumor evolution. This platform holds significant implications for large-scale integrative and retrospective clinical research.

A Pilot Study of Near-Infrared Light Treatment for Alzheimer's Disease.

BACKGROUND: Laboratory investigations have demonstrated that near-infrared (NIR) light treatment can reduce amyloid-ß burden in models of Alzheimer's disease (AD). However, previous clinical studies are rather insufficient. OBJECTIVE: Before starting a large-scale clinical trial, we performed a pilot study to characterize the efficacy of NIR light for AD patients. METHODS: Twenty participants with mild to moderate AD were assigned randomly to the intervention (1060-1080 nm and 800-820 nm NIR light treatment for 12 weeks) or control group (without sham treatment). Safety and efficacy were evaluated at baseline, week 4, 8, and 12, and 4 weeks after treatment. RESULTS: In the intervention and control groups at week 12, mean changes from baseline on the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) were -3.1 and -1.3 (p = 0.5689). Mean changes from baseline on the Activities of Daily Living (ADL) were -3.6 versus 3.1 (p = 0.0437). Mean changes from baseline on the Mini-Mental State Examination (MMSE) were 4.4 versus 1.0 (p = 0.0253). The percentage of participants who exhibited a change larger than 4 points from baseline to week 12 was determined for the intervention and control groups on the ADAS-Cog (57% versus 29%), ADL (29% versus 0%), and MMSE (57% versus 14%). Treatment with NIR light did not increase the incidence of adverse events in participants. CONCLUSION: NIR light treatment appears to be safe and potentially beneficial for AD patients. It improved cognitive function and activities of daily living. The preliminary data encouraged us to launch a large-sample, multicenter, double-blind clinical trial.

A maize epimerase modulates cell wall synthesis and glycosylation during stomatal morphogenesis.

The unique dumbbell-shape of grass guard cells (GCs) is controlled by their cell walls which enable their rapid responses to the environment. The molecular mechanisms regulating the synthesis and assembly of GC walls are as yet unknown. Here we have identified BZU3, a maize gene encoding UDP-glucose 4-epimerase that regulates the supply of UDP-glucose during GC wall synthesis. The BZU3 mutation leads to significant decreases in cellular UDP-glucose levels. Immunofluorescence intensities reporting levels of cellulose and mixed-linkage glucans are reduced in the GCs, resulting in impaired local wall thickening. BZU3 also catalyzes the epimerization of UDP-N-acetylgalactosamine to UDP-N-acetylglucosamine, and the BZU3 mutation affects N-glycosylation of proteins that may be involved in cell wall synthesis and signaling. Our results suggest that the spatiotemporal modulation of BZU3 plays a dual role in controlling cell wall synthesis and glycosylation via controlling UDP-glucose/N-acetylglucosamine homeostasis during stomatal morphogenesis. These findings provide insights into the mechanisms controlling formation of the unique morphology of grass stomata.

In vivo flow cytometry reveals a circadian rhythm of circulating tumor cells.

Circulating tumor cells (CTCs) is an established biomarker of cancer metastasis. The circulation dynamics of CTCs are important for understanding the mechanisms underlying tumor cell dissemination. Although studies have revealed that the circadian rhythm may disrupt the growth of tumors, it is generally unclear whether the circadian rhythm controls the release of CTCs. In clinical examinations, the current in vitro methods for detecting CTCs in blood samples are based on a fundamental assumption that CTC counts in the peripheral blood do not change significantly over time, which is being challenged by recent studies. Since it is not practical to draw blood from patients repeatedly, a feasible strategy to investigate the circadian rhythm of CTCs is to monitor them by in vivo detection methods. Fluorescence in vivo flow cytometry (IVFC) is a powerful optical technique that is able to detect fluorescent circulating cells directly in living animals in a noninvasive manner over a long period of time. In this study, we applied fluorescence IVFC to monitor CTCs noninvasively in an orthotopic mouse model of human prostate cancer. We observed that CTCs exhibited stochastic bursts over cancer progression. The probability of the bursting activity was higher at early stages than at late stages. We longitudinally monitored CTCs over a 24-h period, and our results revealed striking daily oscillations in CTC counts that peaked at the onset of the night (active phase for rodents), suggesting that the release of CTCs might be regulated by the circadian rhythm.

A label-free, fast and high-specificity technique for plant cell wall imaging and composition analysis.

BACKGROUND: New cell wall imaging tools permit direct visualization of the molecular architecture of cell walls and provide detailed chemical information on wall polymers, which will aid efforts to use these polymers in multiple applications; however, detailed imaging and quantification of the native composition and architecture in the cell wall remains challenging. RESULTS: Here, we describe a label-free imaging technology, coherent Raman scattering (CRS) microscopy, including coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy, which can be used to visualize the major structures and chemical composition of plant cell walls. We outline the major steps of the procedure, including sample preparation, setting the mapping parameters, analysis of spectral data, and image generation. Applying this rapid approach will help researchers understand the highly heterogeneous structures and organization of plant cell walls. CONCLUSIONS: This method can potentially be incorporated into label-free microanalyses of plant cell wall chemical composition based on the in situ vibrations of molecules.

Microglia modulation with 1070-nm light attenuates Aß burden and cognitive impairment in Alzheimer's disease mouse model.

Photobiomodulation, by utilizing low-power light in the visible and near-infrared spectra to trigger biological responses in cells and tissues, has been considered as a possible therapeutic strategy for Alzheimer's disease (AD), while its specific mechanisms have remained elusive. Here, we demonstrate that cognitive and memory impairment in an AD mouse model can be ameliorated by 1070-nm light via reducing cerebral ß-amyloid (Aß) burden, the hallmark of AD. The glial cells, including microglia and astrocytes, play important roles in Aß clearance. Our results show that 1070-nm light pulsed at 10 Hz triggers microglia rather than astrocyte responses in AD mice. The 1070-nm light-induced microglia responses with alteration in morphology and increased colocalization with Aß are sufficient to reduce Aß load in AD mice. Moreover, 1070-nm light pulsed at 10 Hz can reduce perivascular microglia and promote angiogenesis to further enhance Aß clearance. Our study confirms the important roles of microglia and cerebral vessels in the use of 1070-nm light for the treatment of AD mice and provides a framework for developing a novel therapeutic approach for AD.

Critical Role of Regulatory T Cells in the Latency and Stress-Induced Reactivation of HSV-1.

Herpes simplex virus 1 (HSV-1) spreads in populations through a latency entry and reactivation cycle. The role of host immune-suppressive factor regulatory T cells (Treg cells) in controlling latency establishment and reactivation is not completely understood. Here, using an HSV-1 ocular infection murine model, we observe a positive correlation between the level of Treg cells and viral infectivity and demonstrate the requirement for Treg cells in latency establishment. Furthermore, we show that host stress leads to HSV-1 reactivation via increased Treg cell control of CD8+ T cells, permitting viral replication under diminished immune surveillance. Together, we propose that Treg cell regulation may serve as a key target for controlling HSV infection.

Noninvasive monitoring of nanoparticle clearance and aggregation in blood circulation by in vivo flow cytometry.

Nanoparticles have been widely used in biomedical research as drug carriers or imaging agents for living animals. Blood circulation is crucial for the delivery of nanoparticles, which enter the bloodstream through injection, inhalation, or dermal exposure. However, the clearance kinetics of nanoparticles in blood circulation has been poorly studied, mainly because of the limitations of conventional detection methods, such as insufficient blood sample volumes or low spatial-temporal resolution. In addition, formation of nanoparticle aggregates is a key determinant for biocompatibility and drug delivery efficiency. Aggregation behavior of nanoparticles in blood is studied using dynamic light scattering in serum or serum protein solutions, which is still very different from in vivo condition. In this work, we monitored the dynamics of nanoparticle concentration and formation of nanoparticle aggregates in the bloodstream in live animals using in vivo flow cytometry (IVFC). The results indicated that nanoparticles in smaller size could stay longer in the bloodstream. Polyethylene glycol (PEG)-modification could prolong circulating time and reduce the formation of aggregates in the blood circulation. Our work shows that IVFC can be a powerful tool for pharmacokinetic studies of nanoparticles and other drug carriers, assessing cell-targeting efficiency, as well as potentially measuring cardiac output and hepatic function in vivo.

Systemically Infused Mesenchymal Stem Cells Show Different Homing Profiles in Healthy and Tumor Mouse Models.

Bone marrow-derived mesenchymal stem cells (MSCs) can localize in injured, inflamed, and cancerous tissues after systemic infusion. However, the dynamic homing profile of MSCs in the peripheral blood is not well characterized. Here, using in vivo flow cytometry to noninvasively monitor the dynamics of fluorescence-labeled cells, we found different clearance kinetics of systemically infused MSCs between healthy and tumor mouse models. The circulation times of MSCs in healthy mice and mice with subcutaneous tumors, orthotopically transplanted liver tumors, or metastatic lung tumors were 30, 24, 18, and 12 hours, respectively, suggesting that MSCs actively home to tumor environments. MSCs infiltrated into hepatocellular carcinoma (HCC) sites and preferentially engrafted to micrometastatic regions both in vivo and in vitro. The expression of epidermal growth factor, CXCL9, CCL25, and matrix metalloproteinases-9 by HCC cells differed between primary tumor sites and metastatic regions. By characterizing the homing profiles of systemically perfused MSCs under physiological and cancerous conditions, these findings increase our understanding of the migration of MSCs from the circulation to tumor sites and constitute a basis for developing MSC-based anti-cancer therapeutic strategies. Stem Cells Translational Medicine 2017;6:1120-1131.