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Background Kawasaki Disease (KD), which is mainly characterized by systemic small and medium vasculitis in children, can lead to coronary artery lesions (CALs). Our previous study identified that STAT3 signaling plays essential roles during the acute phase of KD patients. However, whether its interacted protein MDM2 (Murine double minute 2), which functions as an E3 ligase is likewise involved in KD pathogenesis still unknown and remains to be investigated. Methods The role of MDM2 was investigated using the whole-blood samples from KD patients with CALs before and after IVIG treatment. The plasma and peripheral blood mononuclear cells were respectively isolated and collected. Meanwhile, a Candida albicans cell wall extracts (CAWS)‑induced KD mouse model was used to analyze the in vivo functions of MDM2. Real-time PCR, western blotting, and enzyme-linked immunosorbent methods were used respectively in the HCAECs or other cells to investigate the molecular mechanism of MDM2 involved in KD. Results MDM2 levels were downregulated, and STAT3 and VEGFA levels were upregulated in clinical blood samples from KD patients with CAL in the acute stage and in the mouse model. In the mouse model and HCAECs, MDM2 co-located with STAT3 . In vitro, the endogenous STAT3 protein level in HCAECs was upregulated after MDM2knockdown. Overexpression of MDM2 increased STAT3 ubiquitination and endogenous STAT3 and VEGFA levels decreased significantly. Additionally, the E3 ubiquitin ligase MDM2 can target its endogenous substrate STAT3 for ubiquitination. Conclusions Decreased MDM2 levels can reduce STAT3 ubiquitination, leading to STAT3 activation and the induction of VEGFA transcription, which is involved in the vascular endothelial inflammatory injury process of KD.

Background Neuroblastoma (NB) is a common extracranial malignancy with high mortality in children. Recently, super-enhancers (SEs) have been reported to play a critical role in the tumorigenesis and development of NB via regulating a wide range of oncogenes Thus, the synthesis and identification of chemical inhibitors specifically targeting SEs are of great urgency for the clinical therapy of NB. This study aimed to characterize the activity of the SEs inhibitor GNE987, which targets BRD4, in NB. Results In this study, we found that nanomolar concentrations of GNE987 markedly diminished NB cell proliferation and survival via degrading BRD4. Meanwhile, GNE987 significantly induced NB cell apoptosis and cell cycle arrest. Consistent with in vitro results, GNE987 administration (0.25 mg/kg) markedly decreased the tumor size in the xenograft model, with less toxicity, and induced similar BRD4 protein degradation to that observed in vitro. Mechanically, GNE987 led to significant downregulation of hallmark genes associated with MYC and the global disruption of the SEs landscape in NB cells. Moreover, a novel candidate oncogenic transcript, FAM163A, was identified through analysis of the RNA-seq and ChIP-seq data. FAM163A is abnormally transcribed by SEs, playing an important role in NB occurrence and development. Conclusion GNE987 destroyed the abnormal transcriptional regulation of oncogenes in NB by downregulating BRD4, which could be a potential therapeutic candidate for NB.

Recent studies uncovered the emerging roles of SAPCD2 (suppressor anaphase-promoting complex domain containing 2) in several types of human cancer. However, the functions and underlying mechanisms of SAPCD2 in the progression of neuroblastoma (NB) remain elusive. Herein, through integrative analysis of public datasets and regulatory network of GSK-J4, a small-molecule drug with anti-NB activity, we identified SAPCD2 as an appealing target with a high connection to poor prognosis in NB. SAPCD2 promoted NB progression in vitro and in vivo. Mechanistically, SAPCD2 could directly bind to cytoplasmic E2F7 but not E2F1, alter the subcellular distribution of E2F7 and regulate E2F activity. Among the E2F family members, the roles of E2F7 in NB are poorly understood. We found that an increasing level of nuclear E2F7 was induced by SAPCD2 knockdown, thereby affecting the expression of genes involved in the cell cycle and chromosome instability. In addition, Selinexor (KTP-330), a clinically available inhibitor of exportin 1 (XPO1), could induce nuclear accumulation of E2F7 and suppress the growth of NB. Overall, our studies suggested a previously unrecognized role of SAPCD2 in the E2F signaling pathway and a potential therapeutic approach for NB, as well as clues for understanding the differences in subcellular distribution of E2F1 and E2F7 during their nucleocytoplasmic shuttling.

Neuroblastoma is the most common extracranial solid childhood tumor. Despite the availability of advanced multimodal therapy, high-risk patients still have low survival rates. p21-activated kinase 4 (PAK4) has been shown to regulate many cellular processes in cancer cells, including migration, polarization and proliferation. However, the role of PAK4 in neuroblastoma remains unclear. In the present study, we demonstrated that PAK4 was overexpressed in neuroblastoma tissues and was correlated with tumor malignance and prognosis. To investigate the function of PAK4 in neuroblastoma, we used a small-molecule inhibitor that targets PAK4, that is, PF-3758309. Our results showed that PF-3758309 significantly induced cell cycle arrest at the G1 phase and apoptosis in neuroblastoma cell lines. Meanwhile, the inhibition of PAK4 by PF-3758309 increased the expression of CDKN1A, BAD and BAK1 and decreased the expression of Bcl-2 and Bax. In addition, we screened the target genes of PAK4 by PCR array and found that 23 genes were upregulated (including TP53I3, TBX3, EEF1A2, CDKN1A, IFNB1 and MAPK8IP2) and 20 genes were downregulated (including TNFSF8, Bcl2-A1, Bcl2L1, SOCS3, BIRC3 and NFKB1) after PAK4 inhibition by PF-3758309. Moreover, PAK4 was found to regulate the cell cycle and apoptosis via the ERK signaling pathway. In conclusion, the present study demonstrated, for the first time, the expression and function of PAK4 in neuroblastomas and the inhibitory effect of PF-3758309, which deserves further investigation as an alternative strategy for neuroblastoma treatment.

Decreased autophagy is accompanied by the development of a myeloproliferative state or acute myeloid leukemia (AML). AML cells are often sensitive to autophagy‑inducing stimuli, prompting the idea that targeting autophagy can be useful in AML cytotoxic therapy. AML NB4 cells overexpressing microtubule-associated protein 1 light chain 3-green fluorescent protein were screened with 69 inhibitors to analyze autophagy activity. AML cells were treated with the polo-like kinase 1 (PLK1) inhibitors RO3280 and BI2536 before autophagy analysis. Cleaved LC3 (LC3-II) and the phosphorylation of mammalian target of rapamycin (mTOR), adenosine monophosphate-activated protein kinase, and Unc-51-like kinase 1 during autophagy was detected with western blotting. Autophagosomes were detected using transmission electron microscopy. Several inhibitors had promising autophagy inducer effects: BI2536, MLN0905, SK1-I, SBE13 HCL and RO3280. Moreover, these inhibitors all targeted PLK1. Autophagy activity was increased in the NB4 cells treated with RO3280 and BI2536. Inhibition of PLK1 expression in NB4, K562 and HL-60 leukemia cells with RNA interference increased LC3-II and autophagy activity. The phosphorylation of mTOR was reduced significantly in NB4 cells treated with RO3280 and BI2536, and was also reduced significantly when PLK1 expression was downregulated in the NB4, K562 and HL-60 cells. We demonstrate that PLK1 inhibition induces AML cell autophagy and that it results in mTOR dephosphorylation. These results may provide new insights into the molecular mechanism of PLK1 in regulating autophagy.

Background: Kawasaki disease (KD) is a self-limiting illness with acute systematic vascular inflammation. It causes pathological changes in mostly medium and small-sized arteries, especially the arteria coronaria, which adds the risk of developing coronary heart disease in adults. Materials and methods: We detected the miR-223-3p expression in 30 KD patients combined with 12 normal controls using miRNA microarrays and RT-PCR. A KD mouse model was constructed using Candida albicans water insoluble substance (CAWS). We also checked the miR-223-3p's expression using qRT-PCR. The Luciferase reporting system was implemented to validate the correlation between miR-223-3p and Interleukin-6 receptor subunit beta (IL-6ST). TNF-α was used to stimulate human coronary artery endothelial cells (HCAECs), and miR-223-3p activator or inhibitor and KD serum were used to treat HCAECs. A Western blotting automatic quantitative analysis protein imprinting system was used to test the expression of signal transducer and the activator of transcription 3 (STAT3), phosphorylated-signal transducer and the activator of transcription 3 (pSTAT3) and NF-κB p65. Results: Clinical trials found that miR-223-3p expressions were markedly different (more than 2-fold) between the acute KD group and the control group. E-selectin and intercellular cell adhesion molecule-1 (ICAM-1) levels were also significantly higher (about 2-fold) in KD especially with coronary artery lesions. MiR-223-3p could alleviate vascular endothelial damage in KD mice, and IL-6 (Interleukin-6), E-selectin and ICAM-1 were simultaneously negative. The values of IL-6, E-selectin, and ICAM-1 mRNA expressions decreased, while the value of IL-6ST was increased between the agonist treated mice and KD mice. The RT-qPCR consequences displayed that miR-223-3p explored the highest expression on the third day in both the KD mice as well as the agonist group. MiR-223-3p can directly combine with IL-6ST 3' untranslatable regions (UTR) and held back the IL-6's expression. Overexpression of miR-223 down regulated IL6ST expression and decreased the expression of p-STAT3 and NF-κB p65, while the miR-223 inhibitor could reverse the above process. Conclusion: MiR-223-3p is an important regulatory factor of vascular endothelial damage in KD and could possibly become a potential target of KD treatment in the future.

A series of signal transduction pathways have been found to regulate the polarity establishment and formation of animal primary body axis. Among them, Wnt signaling pathway is extremely conserved and several key components in the pathway have been identified in the demosponge lineage. This implies that it is one of the earliest pathways involved in the ancestral metazoan axis development and might play an important role in specification and development of posterior and ventral fate of animal axis. Recently, with the establishment of functional experiments in vitro, the body plan formation has been found to be affected, in varying degrees, by many genes in the Wnt signaling pathway, such as members of wnt gene family, maternal gene beta-catenin and some transcription factor encoding genes. In this review, we analyzed the evolutionary origin of the wnt gene family involved in development of metazoan body plans, and then made a brief review on the roles of canonical Wnt/beta-catenin signaling in the polarity establishment and formation of primary body axis in diverse deuterostomes including sea urchin, amphioxus, zebrafish, frog, and mouse.

A series of signal transduction pathways have been found to regulate the polarity establishment and formation of animal primary body axis. Among them, Wnt signaling pathway is extremely conserved and several key components in the pathway have been identified in the demosponge lineage. This implies that it is one of the earliest pathways involved in the ancestral metazoan axis development and might play an important role in specification and development of posterior and ventral fate of animal axis. Recently, with the establishment of functional experiments in vitro, the body plan formation has been found to be affected, in varying degrees, by many genes in the Wnt signaling pathway, such as members of wnt gene family, maternal gene beta-catenin and some transcription factor encoding genes. In this review, we analyzed the evolutionary origin of the wnt gene family involved in development of metazoan body plans, and then made a brief review on the roles of canonical Wnt/beta-catenin signaling in the polarity establishment and formation of primary body axis in diverse deuterostomes including sea urchin, amphioxus, zebrafish, frog, and mouse.