HNRNPA2B1 stabilizes NFATC3 levels to potentiate its combined actions with FOSL1 to mediate vasculogenic mimicry in GBM cells.

BACKGROUND: Vasculogenic mimicry (VM) is an enigmatic physiological feature that influences blood supply within glioblastoma (GBM) tumors for their sustained growth. Previous studies identify NFATC3, FOSL1 and HNRNPA2B1 as significant mediators of VEGFR2, a key player in vasculogenesis, and their molecular relationships may be crucial for VM in GBM. AIMS: The aim of this study was to understand how NFATC3, FOSL1 and HNRNPA2B1 collectively influence VM in GBM. METHODS: We have investigated the underlying gene regulatory mechanisms for VM in GBM cell lines U251 and U373 in vitro and in vivo. In vitro cell-based assays were performed to explore the role of NFATC3, FOSL1 and HNRNPA2B1 in GBM cell proliferation, VM and migration, in the context of RNA interference (RNAi)-mediated knockdown alongside corresponding controls. Western blotting and qRT-PCR assays were used to examine VEGFR2 expression levels. CO-IP was employed to detect protein-protein interactions, ChIP was used to detect DNA-protein complexes, and RIP was used to detect RNA-protein complexes. Histochemical staining was used to detect VM tube formation in vivo. RESULTS: Focusing on NFATC3, FOSL1 and HNRNPA2B1, we found each was significantly upregulated in GBM and positively correlated with VM-like cellular behaviors in U251 and U373 cell lines. Knockdown of NFATC3, FOSL1 or HNRNPA2B1 each resulted in decreased levels of VEGFR2, a key growth factor gene that drives VM, as well as the inhibition of proliferation, cell migration and extracorporeal VM activity. Chromatin immunoprecipitation (ChIP) studies and luciferase reporter gene assays revealed that NFATC3 binds to the promoter region of VEGFR2 to enhance VEGFR2 gene expression. Notably, FOSL1 interacts with NFATC3 as a co-factor to potentiate the DNA-binding capacity of NFATC3, resulting in enhanced VM-like cellular behaviors. Also, level of NFATC3 protein in cells was enhanced through HNRNPA2B1 binding of NFATC3 mRNA. Furthermore, RNAi-mediated silencing of NFATC3, FOSL1 and HNRNPA2B1 in GBM cells reduced their capacity for tumor formation and VM-like behaviors in vivo. CONCLUSION: Taken together, our findings identify NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors.

EP300 restores the glycolytic activity and anti-tumor function of CD8+ cytotoxic T cells in nasopharyngeal carcinoma.

Competition for glucose may metabolically limit T cells during cancer progression. This study shows that culturing in the condition medium (CM) of NPC c6661 cells restricted glycolytic and immune activities of CD8+ T cells. These cells also exhibited limited tumor-eliminating effects in mouse xenograft tumor models. Glucose supplementation restored glycolysis and immune activity of CD8+ T cells in vitro and in vivo by rescuing the expression of E1A binding protein p300 (EP300). EP300 upregulated bromodomain PHD finger transcription factor (BPTF) expression by catalyzing H3K27ac modification, and BPTF further activated AT-rich interaction domain 1A (ARID1A) transcription. Either BPTF or ARID1A knockdown in CD8+ T cells reduced their glycolytic activity, decreased the secretion of cytotoxic molecules, and blocked the tumor-killing function in mice. Overall, this study demonstrates that EP300 restores the glycolytic and anti-tumor activities of CD8+ T cells in the glucose restriction condition in NPC through the BPTF/ARID1A axis.

Modification of Metal-Organic Framework Nanoparticles Using Dental Pulp Mesenchymal Stem Cell Membranes to Target Oral Squamous Cell Carcinoma.

Engineering a targetable nanoparticle to tumor cell is a challenge issue for clinical application. Our results demonstrated that the chemokine CXCL8 secreted by oral squamous cell carcinoma (OSCC) could act as a chemoattractant to attract dental pulp mesenchymal stem cell (DPSC), which expressed the CXCL8 binding receptor, CXCR2, to the OSCC. Therefore, to create OSCC targetable nanoparticles, we used DPSC membranes to modify nanoparticles of metal-organic framework nanoparticles (MOFs) resulting in a novel MOF@DPSCM nanoparticle. Interestingly, results from in vitro and in vivo experiments illustrated that MOF@DPSCM possessed specificity for the OSCC, and the MOF@DPSCM carried DOX (doxorubicin), MOF-DOX@DPSCM could induce CAL27 cell death in vitro and block CAL27 tumor growth in vivo. Our data suggest that this novel MOF-DOX@DPSCM nanoparticle is a potential targetable drug delivery system for the OSCC in the future clinical application.

Osteopromotive carbon dots promote bone regeneration through the PERK-eIF2α-ATF4 pathway.

Bone defects are still an unsolved clinical issue that must be overcome. Carbon dots have shown very promising effects in biological therapy. In the current study, we explored their effects on osteogenesis. Furthermore, we revealed the mechanisms in order to develop novel therapeutic approaches to manage the bone defect. For this study, ascorbic acid carbon dots (CDs) were created by a one-step microwave-assisted method. Results showed that the CDs effectively enhanced matrix mineralization, promoted osteogenic differentiation in vitro, and promoted new bone regeneration in the skull defect model in vivo. Furthermore, our data demonstrated that the ER stress and PERK-eIF2α-ATF4 pathway were activated by the CD-induced increase in intracellular calcium. Taken together, our findings suggest that the PERK pathway plays a critical role in CD-induced osteogenic differentiation, and the CDs created herein have the potential to be used to repair bone defects in clinical practice.

Bone mesenchymal stem cells are recruited via CXCL8-CXCR2 and promote EMT through TGF-ß signal pathways in oral squamous carcinoma.

OBJECTIVES: Bone mesenchymal stem cells (BMSCs) play critical roles in tumour microenvironment. However, molecular mechanisms of how BMSCs to be recruited and effect subsequent tumour progression are poorly understood in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: The distribution of CXCL8 was detected by immunohistochemical staining in OSCC tissues. The chemotaxis of conditioned media from different epithelial cells to BMSCs was examined by trans-well assay. Real-time quantitative PCR (qPCR) and ELISA were used to detect the expression of related cytokines and chemokine receptors. The migration of BMSCs was observed in BALB/c nude mice. The roles of BMSCs in proliferation, migration and invasion of OSCC were detected by CCK-8, flow cytometry and trans-well assay. Epithelial-mesenchymal transition (EMT)-related markers were analysed by qPCR and Western blot in vitro, and growth was evaluated in BALB/c nude mice using subcutaneously implanted OSCC in nude mouse model in vivo. RESULTS: Using OSCC, we show CXCL8, secreted by OSCC, binds to exclusively CXCR2 in BMSCs to facilitate migration of BMSCs to OSCC. TGF-ß secreted by BMSCs subsequently induces EMT of OSCC to promote their proliferation, migration and infiltration. We also showed that the Ras/Raf/Erk axis plays a critical role in tumour progression. CONCLUSIONS: Our results provide the molecular basis for BMSC recruitment into tumours, and how this process leads to tumour progression and leads us to develop a novel OSCC treatment target.

Chemotherapy Modulates Endocrine Therapy-Related Resistance Mutations in Metastatic Breast Cancer.

PURPOSE: Accumulation of PIK3CA, ESR1, and GATA3 mutations results in resistance to endocrine therapy in breast cancer patients; however, the response of these genes to chemotherapy is unclear. Therefore, we sought to evaluate the genetic response of circulating tumor DNA (ctDNA) to chemotherapy in metastatic breast cancer patients. METHODS: The mutation frequency of 1021 genes was examined prior to chemotherapy in ctDNA of 44 estrogen receptor-positive metastatic breast cancer patients. These genes were evaluated again in a subset of patients (n=24) following chemotherapy. Mutation frequency was defined as the percentage of mutations found in ctDNA compared to total cell-free DNA. RESULTS: Prior to chemotherapy, PIK3CA was the most commonly mutated gene, with mutation found in 22 of the metastatic breast cancer patients. Following chemotherapy, 16 patients exhibited progressive disease (PD), and 8 patients experienced no progression (non-PD). PIK3CA mutation frequency increased in 56.25% (9/16) of the PD patients but decreased in 62.5% (5/8) of the non-PD patients. As a result, more PD patients exhibited increased PIK3CA mutation frequency than non-PD patients (56.25% vs 0%, P=.002). Further, ESR1 and GATA3 mutations correlated with PIK3CA mutation. Interestingly, patients receiving the mTOR inhibitor everolimus exhibited a lower progression rate (0% vs 62.5%, P=.001), and the combination of everolimus and chemotherapy effectively suppressed PIK3CA, ESR1, and GATA3 gene mutations. CONCLUSION: Together, these results suggest that mTOR inhibition may be a useful chemotherapy adjuvant to suppress chemotherapy-induced gene mutations that render tumors resistant to endocrine therapy in metastatic breast cancer patients with PD.

MRI compatibility of several early transition metal based alloys and its influencing factors.

Magnetic resonance imaging (MRI) compatibility of three early transition metal (ETM) based alloys was assessed in vitro with agarose gel as a phantom, including Zr-20Nb, near-equiatomic (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr, together with pure tantalum and L605 Co-Cr alloy for comparison. The artifact extent in the MR image was quantitatively characterized according to the maximum area of 2D images and the total volume in reconstructed 3D images with a series of slices under acquisition by fast spin echo (FSE) sequence and gradient echo (GRE) sequence. It was indicated that the artifacts extent of L605 Co-Cr alloy with a higher magnetic susceptibility (χv ) was approximately 3-fold greater than that of the ETM-based alloys with χv in the range of 160-250 ppm. In the ETM group, the MRI compatibility of the materials can be ranked in a sequence of Zr-20Nb, pure tantalum, (TiZrNbTa)90 Mo10 and Nb-60Ta-2Zr. In addition, using a rabbit cadaver with the implanted tube specimens as a model for ex vivo assessment, it was confirmed that the artifact severity of Nb-60Ta-2Zr alloy is significantly reduced in comparison with the L605 alloy. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 377-385, 2018.