A ROS-responsive loaded desferoxamine (DFO) hydrogel system for traumatic brain injury therapy.

Traumatic brain injury (TBI) produces excess iron, and increased iron accumulation in the brain leads to lipid peroxidation and reactive oxygen species (ROSs), which can exacerbate secondary damage and lead to disability and death. Therefore, inhibition of iron overload and oxidative stress has a significant role in the treatment of TBI. Functionalized hydrogels with iron overload inhibiting ability and of oxidative stress inhibiting ability will greatly contribute to the repair of TBI. Herein, an injectable, post-traumatic microenvironment-responsive, ROS-responsive hydrogel encapsulated with deferrioxamine mesylate (DFO) was developed. The hydrogel is rapidly formed via dynamic covalent bonding between phenylboronic acid grafted hyaluronic acid (HA-PBA) and polyvinyl alcohol (PVA), and phenylboronate bonds are used to respond to and reduce ROS levels in damaged brain tissue to promote neuronal recovery. The release of DFO from HA-PBA/PVA hydrogels in response to ROS further promotes neuronal regeneration and recovery by relieving iron overload and thus eradicating ROS. In the Feeney model of Sprague Dawley rats, HA-PBA/PVA/DFO hydrogel treatment significantly improved the behavior of TBI rats and reduced the area of brain contusion in rats. In addition, HA-PBA/PVA/DFO hydrogel significantly reduced iron overload to reduce ROS and could effectively promote post-traumatic neuronal recovery. Its effects were also explored, and notably, HA-PBA/PVA/DFO hydrogel can reduce iron overload as well as ROS, thus protecting neurons from death. Thus, this injectable, biocompatible and ROS-responsive drug-loaded hydrogel has great potential for the treatment of TBI. This work suggests a novel method for the treatment of secondary brain injury by inhibiting iron overload and the oxidative stress response after TBI.

Lung cancer in young adults aged 35 years or younger: A full-scale analysis and review.

Objectives: Lung cancer in young adults is a distinct disease with particular socioeconomic implications. This study aimed to clarify the clinicopathological characteristics, best interventions, and outcomes of this distinctive entity. Methods: A retrospective review of patients with lung cancer was performed in our institute from January 2010 to June 2017. Young adults were defined as between 18 and 35 years old. Demographic, clinicopathological, therapeutic, and prognostic data were systematically analyzed. Results: From a total of 8734 patients, 120 (1.37%) were young adults, of which 82 with complete hospital records were included in this study. A high proportion had adenocarcinoma (45%) and late-stage disease (49.21% stage IV at diagnosis). Pleura (38.71%) were the most common metastatic site, followed by bone (35.48%) and lung (25.81%). The majority (68%) had single organ metastasis. Young patients had an increased frequency of gene mutations. Among the 18 patients for whom epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) status was determined, 10 had sensitive EGFR mutations while 5 had ALK rearrangement; only 3 patients were driver gene mutation-negative. The 1-year overall survival (OS) rate was 62.31% and the 3- and 5-year survival rates were both 53.31%; median OS was not achieved (range, 3-86 months). Male sex, negative or unknown gene mutation status, stage IV, and squamous or small cell lung cancer were associated with poor prognosis (OS) in early-onset lung cancer. Conclusions: Lung cancer in young adults is distinctive, with adenocarcinoma and stage IV at presentation being predominant characteristics. Gene mutation assessment should be mandatory in this subgroup due to the increased likelihood of positive driver gene alterations, as individualized targeted therapy may achieve superior outcomes.

Platelets enhance the ability of bone-marrow mesenchymal stem cells to promote cancer metastasis.

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BM-MSCs) have been identified to be closely associated with cancer progression. Our previous experimental results showed that BM-MSCs promote tumor growth and metastasis of gastric cancer through paracrine-soluble cytokines or exosomes. However, the elements that affect the role of BM-MSCs in promoting tumor metastasis are not clear. It is known that thrombocytosis in cancer patients is very common. Recently, platelets are recognized to play a critical role in tumor progression. PURPOSE: This study aims to observe the effect of BM-MSCs which were co-cultured with platelets on tumor cell metastasis. METHODS: Platelet aggregation rate and the expression of P-selectin of platelets co-incubated with conditioned medium of SGC-7901 cells and BM-MSCs were detected by flow cytometry and platelet aggregometer. We also analyzed the change of BM-MSCs after co-incubation with platelets or platelets which were treated with SGC-7901 cells using transwell assay and Western blot analysis. The proliferation and migration ability and expression of VEGF, c-Myc, and sall-4 in SGC-7901 cells treated with medium of BM-MSCs which were co-cultured with platelets were detected. SGC-7901 cells were injected into Balb/c nude mice and the extent of lung metastasis was observed. Both in vitro and in vivo assays were used to analyze the effect of platelets on enhancing the ability of BM-MSCs to promote cancer metastasis. RESULTS: Results suggested that BM-MSCs and tumor cells can promote platelet aggregation rate and the expression of P-selectin. The protein levels of α-smooth muscle actin, vimentin, and fibroblast activation protein in BM-MSCs were higher after co-incubation with platelets, and SB431542 was used to confirm the effect of TGF-ß on transdifferentiation of BM-MSCs into cancer-associated fibroblasts. Medium of BM-MSCs treated with platelets enhanced the proliferation and migration ability of SGC-7901 cells. More lung metastases were found in mice which were injected with SGC-7901 cells treated with conditioned medium from BM-MSCs co-incubated with platelets. CONCLUSION: Tumor cells and BM-MSCs activate platelets which can change the characteristics of BM-MSCs through secretion of TGF-ß. Moreover, we found that platelets enhanced the effect of BM-MSCs on tumor metastasis, which suggested a potential target and approach for gastric cancer therapy.

Gastric cancer mesenchymal stem cells derived IL-8 induces PD-L1 expression in gastric cancer cells via STAT3/mTOR-c-Myc signal axis.

The expression of PD-L1 in tumor cells is one of the main causes of tumor immune escape. However, the exact mechanism for regulating PD-L1 expression in gastric cancer (GC) cells remains unclear. Our previous studies have shown that mesenchymal stem cells (MSCs) exert broad immunosuppressive potential, modulating the activity of cells either in innate or adaptive immune system to promote tumor progress. This study aims to investigate whether GCMSCs regulate the PD-L1 expression in GC cells and explore the specific molecular mechanism. The results have shown that GCMSCs enhanced PD-L1 expression in GC cells resulting in the resistance of GC cells to CD8+ T cells cytotoxicity. However, this resistance was attenuated with IL-8 inhibition. Further studies proved that IL-8 derived from GCMSCs induced PD-L1 expression in GC cells via c-Myc regulated by STAT3 and mTOR signaling pathways. Our data indicated that blocking IL-8 derived from GCMSCs may overcome the immune escape induced by PD-L1 in GC cells and provide a potential strategy to enhance the immunotherapy efficiency in GC.

Human Bone Marrow Mesenchymal Stem Cells Promote Gastric Cancer Growth via Regulating c-Myc.

The clinical application of human bone marrow mesenchymal stem cells (hBM-MSCs) has generated a great deal of interest because of their potential use in regenerative medicine and tissue engineering. However, safety concerns over hBM-MSCs limit their clinical application. In this study, we observed that hBM-MSC-conditioned medium (hBM-MSC-CM) promotes gastric cancer development via upregulation of c-Myc. Our results showed that c-Myc was upregulated in MGC-803 and BGC-823 cells after hBM-MSC-CM treatment. Moreover, we found that the c-Myc inhibitor JQ1 and c-Myc siRNA decreased the expression of c-Myc in hBM-MSC-CM-treated tumor cells in vitro. Additionally, hBM-MSC-CM enhanced the migration and glucose uptake of gastric cancer cells. In vivo studies showed that JQ1 inhibited hBM-MSC-CM-induced gastric cancer growth. These results indicated that hBM-MSC-CM induced gastric cancer growth via upregulation of c-Myc, which may be a potential risk factor and/or a therapeutic target for clinical applications.

Human Gastric Cancer Mesenchymal Stem Cell-Derived IL15 Contributes to Tumor Cell Epithelial-Mesenchymal Transition via Upregulation Tregs Ratio and PD-1 Expression in CD4+T Cell.

Several studies show that mesenchymal stem cells (MSCs) homing to tumors not only provide the microenvironment for tumor cells but also promote tumor growth and metastasis. However, the exact mechanism remains unclear. Our study aims to investigate the role of gastric cancer MSCs (GCMSCs)-derived IL15 during GC progression. The effects of IL15 secreted by GCMSCs on GC development were evaluated by detecting the stemness, epithelial-mesenchymal transition (EMT), and migration abilities of GC cell lines. The expression of IL15 in serum and tissues of GC patients was also assessed. We found that IL15 derived from GCMSCs enhanced stemness, induced EMT and promoted migration of GC cell lines. The level of IL15 was higher in GC patients both in serum and tissues compared with that in healthy donors, which was associated with lymph node metastasis. In addition, the results have shown that IL15 in GC microenvironment was mainly produced by GCMSCs. Moreover, IL15 upregulated Tregs ratio through activation of STAT5 in CD4+T cells was accompanied by elevated expression of programmed cell death protein-1 (PD-1). Our data proved that the high concentration of IL15 in tumor microenvironment, which was mainly secreted by GCMSCs, may contribute to tumor cell metastasis and offer a new opportunity to develop effective therapeutics for intercepting tumor progression.

Exosomes derived from human umbilical cord mesenchymal stem cells improve myocardial repair via upregulation of Smad7.

It has been previously reported that exosomes derived from human umbilical cord mesenchymal stem cells (hucMSC)­exosomes exhibit cardioprotective effects on the rat acute myocardial infarction (AMI) models and cardiomyocyte hypoxia injury models in vitro, however the exact mechanisms involved require further investigation. The present study aimed to investigate the repair effects of hucMSC­exosomes on myocardial injury via the regulation of mothers against decapentaplegic homolog 7 (Smad7) expression. Compared with sham or normoxia groups (in vivo and in vitro, respectively), western blotting demonstrated that Smad7 expression was significantly decreased in the borderline area of infraction myocardium and in H9C2(2­1) cells following hypoxia­induced injury. Additionally, microRNA (miR)­125b­5p expression was markedly increased using reverse transcription­quantitative polymerase chain reaction, but was reversed by hucMSC­exosomes. Trypan blue staining and lactate dehydrogenase release detection demonstrated that cell injury was significantly increased in the AMI + PBS and hypoxia group compared with in the sham and normoxia groups and was inhibited by hucMSC­exosomes. A dual luciferase reporter gene assay confirmed that Smad7 is a target gene of miR­125b­5p. In addition, miR­125b­5p mimics promoted H9C2(2­1) cell injury following 48 h exposure to hypoxia. Downregulation of Smad7 expression under hypoxia was increased by miR­125b­5p mimics compared with the mimic negative control, and hucMSC­exosomes partially alleviated this phenomenon. In conclusion, hucMSC­exosomes may promote Smad7 expression by inhibiting miR­125b­5p to increase myocardial repair. The present study may provide a potential therapeutic approach to improve myocardial repair following AMI.

Enhanced gastric cancer growth potential of mesenchymal stem cells derived from gastric cancer tissues educated by CD4+ T cells.

OBJECTIVES: Gastric cancer mesenchymal stem cells (GC-MSCs) can promote the development of tumour growth. The tumour-promoting role of tumour-associated MSCs and T cells has been demonstrated. T cells as the major immune cells may influence and induce a pro-tumour phenotype in MSCs. This study focused on whether CD4+ T cells can affect GC-MSCs to promote gastric cancer growth. MATERIALS AND METHODS: CD4+ T cells upregulation of programmed death ligand 1 (PD-L1) expression in GC-MSCs through the phosphorylated signal transducer and activator of transcription (p-STAT3) signalling pathway was confirmed by immunofluorescence, western blotting and RT-PCR. Migration of GC cells was detected by Transwell migration assay, and apoptosis of GC cells was measured by flow cytometry using annexin V/propidium iodide double staining. CD4+ T cell-primed GC-MSCs promoted GC growth in a subcutaneously transplanted tumour model in BALB/c nu/nu mice. RESULTS: Gastric cancer mesenchymal stem cells stimulated by activated CD4+ T cells promoted migration of GC cells and enhanced GC growth potential in BALB/c nu/nu xenografts. PD-L1 upregulation of GC-MSCs stimulated by CD4+ T cells was mediated through the p-STAT3 signalling pathway. CD4+ T cells-primed GC-MSCs have greater GC volume and growth rate-promoting role than GC-MSCs, with cancer cell-intrinsic PD-1/mammalian target of rapamycin (mTOR) signalling activation. CONCLUSIONS: This study showed that GC-MSCs are plastic. The immunophenotype of GC-MSCs stimulated by CD4+ T cells has major changes that may influence tumour cell growth. This research was based on the interaction between tumour cells, MSCs and immune cells, providing a new understanding of the development and immunotherapy of GC.

Gastric cancer tissue-derived mesenchymal stem cells impact peripheral blood mononuclear cells via disruption of Treg/Th17 balance to promote gastric cancer progression.

Gastric cancer tissue-derived mesenchymal stem cells (GC-MSCs) are important resident stromal cells in the tumor microenvironment (TME) and have been shown to play a key role in gastric cancer progression. Whether GC-MSCs exert a tumor-promoting function by affecting anti-tumor immunity is still unclear. In this study, we used GC-MSC conditioned medium (GC-MSC-CM) to pretreat peripheral blood mononuclear cells (PBMCs) from healthy donors. We found that GC-MSC-CM pretreatment markedly reversed the inhibitory effect of PBMCs on gastric cancer growth in vivo, but did not affect functions of PBMCs on gastric cancer cell proliferation, cell cycle and apoptosis in vitro. PBMCs pretreated with GC-MSC-CM significantly promoted gastric cancer migration and epithelial-mesenchymal transition in vitro and liver metastases in vivo. Flow cytometry analysis showed that GC-MSC-CM pretreatment increased the proportion of Treg cells and reduced that of Th17 cells in PBMCs. CFSE labeling and naïve CD4+ T cells differentiation analysis revealed that GC-MSC-CM disrupted the Treg/Th17 balance in PBMCs by suppressing Th17 cell proliferation and inducing differentiation of Treg cells. Overall, our collective results indicate that GC-MSCs impair the anti-tumor immune response of PBMCs through disruption of Treg/Th17 balance, thus providing new evidence that gastric cancer tissue-derived MSCs contribute to the immunosuppressive TME.

Molecularly Imprinted Solid Phase Extraction using Bismethacryloyl-ß-cyclodextrin and Methacrylic Acid as Double Functional Monomers for Selective Analysis of Glycyrrhizic Acid in Aqueous Media.

In this work, a new molecularly imprinted solid phase extraction protocol was developed for the selective extraction and purification of glycyrrhizic acid from liquorice roots in aqueous media. The molecularly imprinted polymers (MIPs) for glycyrrhizic acid were prepared by using bismethacryloyl-ß-cyclodextrin and methacrylic acid as double functional monomers and characterized by Fourier transform infrared spectroscopy, scanning electron microscope, thermo gravimetric analysis, nitrogen adsorption and elemental analysis. In aqueous media, the adsorption properties of MIPs including adsorption kinetics, adsorption isotherms and selectivity adsorption were investigated. The characterization of imprinted polymers indicated that the prepared MIPs had good stability and many cavity structures. The results of adsorption experiments illustrated the MIPs had high adsorption capacity of glycyrrhizic acid (69.3 mg g-1) with the imprinting factor 3.77, and it took ~5 min to get adsorption equilibrium. The MIPs could be used as an solid phase extraction sorbent absorbent for enrichment and purification of glycyrrhizic acid from the crude extraction of licorice roots, and the results showed promising practical value.

Lefty A protein inhibits TGF-ß1-mediated apoptosis in human renal tubular epithelial cells.

This study aimed to examine the effects of Lefty A protein on transforming growth factor-ß1 (TGF-ß1)-mediated apoptosis in human renal tubular epithelial cells (HK-2). HK-2 cells were transfected with the human Lefty gene to induce the secretion of endogenous Lefty A protein. Following exposure of the HK-2 cells to recombinant human TGF-ß1 (10 ng/ml), p-Smad2/3 protein levels were examined by western blot analysis, and cellular apoptosis was detected by flow cytometry 6, 12, 24 and 48 h following TGF-ß1 treatment. Coculture of renal tubular epithelial cells with TGF-ß1 resulted in a significant increase in p-Smad2/3 protein levels and the rate of cell apoptosis, which were attenuated by liposome-mediated transfection with the Lefty gene. Lefty A protein was able to inhibit the TGF-ß1/Smad signaling pathway and markedly attenuate TGF-ß1-mediated apoptosis in human renal tubular epithelial cells. Taken together, these results indicated that the TGF-ß1/Smad signaling pathway most likely mediates apoptosis in renal tubular epithelial cells. In addition, Lefty A protein is capable of inhibiting the TGF-ß1/Smad pathway to reduce TGF-ß1/Smad-mediated apoptosis in renal tubular epithelial cells. This study may provide novel insights into the prevention and treatment of urinary tract obstruction disease using Lefty A protein.