Surviving Inhibition Induces Cell Cycle Arrest and Disrupts Multipotency in Haemangioma Stem Cells.

OBJECTIVE: To explore the potential therapies for infantile haemangiomas by targeting survivin, a member of the inhibitor of apoptosis protein family, using its specific small molecule inhibitor YM155. METHODS: The expression of survivin in human haemangioma tissue was explored using immunohistochemistry and immunohistofluorescence. Cell cycle analysis and EdU assays were used to measure cell proliferation. Heochst33342 and Annexin V/PI double staining were performed to measure cell apoptosis. The capacity for self-renewal and multilineage differentiation potential of haemangioma stem cells (HemSCs) were measured by clone formation assays and multiple differentiation assays. Murine haemangioma models were established to explore the therapeutic efficacy of YM155 in vivo. RESULTS: Strong staining of survivin in stromal cells was observed in the proliferative haemangioma tissue. In vitro studies demonstrated that YM155 induced cell cycle arrest and proliferation suppression of HemSCs, and also caused cell apoptosis at a higher concentration. YM155 impaired the self-renewal capacities and damaged multiple differentiation potentials of HemSCs. Importantly, YM155 suppressed blood vessel formation and cell proliferation, and induced cell apoptosis in murine haemangioma models. CONCLUSION: The present study demonstrated that targeting survivin using its specific suppressant, YM155, prevented the progression of infantile haemangioma by suppressing cell proliferation, inducing cell apoptosis and disrupting the differentiation potential of HemSCs. These results indicate a novel and promising therapeutic approach for the treatment of infantile haemangioma.

Lymphotoxin-α promotes tumor angiogenesis in HNSCC by modulating glycolysis in a PFKFB3-dependent manner.

Tumor angiogenesis is critical for tumor progression as the new blood vessels supply nutrients and facilitate metastasis. Previous studies indicate tumor associated lymphocytes, including B cells and T cells, contribute to tumor angiogenesis and tumor progression. The present study aims to identify the function of Lymphotoxin-α (LT-α), which is secreted by the activated lymphocytes, in the tumor angiogenesis of head and neck squamous cell carcinoma (HNSCC). The coculture system between HNSCC cell line Cal27 and primary lymphocytes revealed that tumor cells promoted the LT-α secretion in the cocultured lymphocytes. In vitro data further demonstrated that LT-α promoted the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) by enhancing the PFKFB3-mediated glycolytic flux. Genetic and pharmacological inhibition of PFKFB3 suppressed the enhanced proliferation and migration of HUVECs. We further identified that LT-α induced PFKFB3 expression was dependent on the TNFR/NF-κB signaling pathway. In addition, we proved that PFKFB3 blockade decreased the density of CD31 positive blood vessels in HNSCC xenografts. Finally, the results from the human HNSCC tissue array revealed that the expression of LT-α in HNSCC samples positively correlated with microvessel density, lymphocytes infiltration and endothelial PFKFB3 expression. In conclusion, infiltrated lymphocyte secreted LT-α enhances the glycolysis of ECs in a PFKFB3-dependent manner through the classical NF-κB pathway and promotes the proliferation and migration of ECs, which may contribute to the aberrant angiogenesis in HNSCCs. Our study suggests that PFKFB3 blockade is a promising therapeutic approach for HNSCCs by targeting tumor angiogenesis.

Cyclic Stretch Enhances Osteogenic Differentiation of Human Periodontal Ligament Cells via YAP Activation.

Periodontal remodeling and alveolar bone resorption and formation play essential roles during orthodontic tooth movement (OTM). In the process, human periodontal ligament cells (HPDLCs) sense and respond to orthodontic forces, contributing to the alveolar bone formation. However, the underlying mechanism in this process is not fully elucidated. In the present study, cyclic stress stimulus was applied on HPDLCs to mimic the orthodontic forces during OTM. Our results demonstrated that cyclic stretch promoted the osteogenic differentiation of HPDLCs. Moreover, our data suggested that yes-associated protein (YAP), the Hippo pathway effector, which also involved in mechanical signaling transduction, was activated as we found that the nuclear translocation of YAP was significantly increased in the cyclic stress treated HPDLCs. The mRNA expression of CTGF and CYR61, the target genes of YAP, was also remarkably increased. Furthermore, knockdown of YAP suppressed the cyclic stretch induced osteogenesis in HPDLCs, while overexpression of YAP in HPDLCs enhanced osteogenesis. We also noticed that YAP activities could be suppressed by the ROCK and nonmuscle myosin II inhibitors, Y-27632 and Blebbistatin. The inhibitors also significantly inhibited the cyclic stretch induced osteogenesis in HPDLCs. Finally, in the murine OTM model, our results revealed that YAP was upregulated and nuclearly translocated in the PDLCs at the tension side. In summary, our present study demonstrated that cytoskeleton remodeling induced activation of YAP signaling pathway was crucial for the cyclic stretch-induced osteogenesis of HPDLCs, which might play important roles during OTM.

Wnt5a mediated canonical Wnt signaling pathway activation in orthodontic tooth movement: possible role in the tension force-induced bone formation.

Orthodontic tooth movement (OTM) is associated with bone remodeling mediated by orthodontic mechanical loading. Increasing studies reported that Wnt signaling played crucial roles in mechanical stimuli induced bone remodeling. However, little is known about the involvement of Wnt signaling in orthodontic force-induced bone formation during OTM. In virtue of the OTM mice model as we previously reported, where new bone formation was determined by micro-CT and immunoreactivity of osteocalcin and osterix, we explored the activation of Wnt signaling pathway during OTM. Our results proved the nuclei translocation of ß-catenin, suggesting the activation of canonical Wnt signaling pathway in the periodontal ligament cells (PDLCs) near the alveolar bone at the tension site (TS). Moreover, the immunoreactivity of Wnt5a, but not Wnt3a in PDLCs indicated the activation of canonical Wnt pathway might be mediated by Wnt5a, but not Wnt3a as in most cases. The co-location of Wnt5a and ß-catenin that was evidenced by double labeling immunofluorescence staining further supported the hypothesis. In addition, the high expression of FZD4 and LRP5 in PDLCs at TS of periodontium suggested that the activation of Wnt signaling pathway was mediated by these receptors. The negligible expression of ROR2 also indicated that canonical but not non-canonical Wnt signaling pathway was activated by Wnt5a, since previous studies demonstrated that the activation of canonical/non-canonical Wnt signaling pathway was largely dependent on the receptors. In summary, we here reported that Wnt5a mediated activation of canonical Wnt signaling pathway might contribute to the orthodontic force induced bone remodeling.

Gold-nanorods-siRNA nanoplex for improved photothermal therapy by gene silencing.

Nanomaterials-mediated photothermal therapy (PTT) often suffers from the fundamental cellular defense mechanism of heat shock response which leads to therapeutic resistance of cancer cells and reduces the therapeutic efficacy. Herein, a gold nanorods (GNRs)-siRNA platform with gene silencing capability is produced to improve the PTT efficiency. After surface modification, the GNRs show the ability to deliver siRNA oligos targeting BAG3 which is an efficient gene to block the heat-shock response. The synthesized GNRs-siRNA nanoplex exhibits excellent ability in the delivery of siRNA into cancer cells with high silencing efficiency which is even better than that of commercial Lipofectamine 2000. The in vitro and in vivo studies demonstrate the ability of the GNRs-siRNA nanoplex to sensitize the cancer cells to PTT under moderate laser irradiation by down-regulating the increased BAG3 expression and enhancing apoptosis. The GNRs-siRNA mediated PTT has large potential in clinical cancer therapy due to the elimination of therapeutic resistance and enhanced photothermal therapeutic efficacy by means of gene silencing. It also suggests an efficient platform for gene delivery and controllable gene therapy.