No abstract

Aberrant expression of transcription factor AP-2α has been functionally associated with various cancers, but its clinical significance and molecular mechanisms in human glioma are largely elusive.Methods: AP-2α expression was analyzed in human glioma tissues by immunohistochemistry (IHC) and in glioma cell lines by Western blot. The effects of AP-2α on glioma cell proliferation, migration, invasion and tumor formation were evaluated by the 3-(4,5-dimethyNCthiazol-2-yl)-25-diphenyltetrazolium bromide (MTT) and transwell assays in vitro and in nude mouse models in vivo. The influence of AP-2α on glioma cell stemness was analyzed by sphere-formation, self-renewal and limiting dilution assays in vitro and in intracranial mouse models in vivo. The effects of AP-2α on temozolomide (TMZ) resistance were detected by the MTT assay, cell apoptosis, real-time PCR analysis, western blotting and mouse experiments. The correlation between AP-2α expression and the expression of miR-26a, Nanog was determined by luciferase reporter assays, electrophoretic mobility shift assay (EMSA) and expression analysis.Results: AP-2α expression was downregulated in 58.5% of glioma tissues and in 4 glioma cell lines. AP-2α overexpression not only reduced the proliferation, migration and invasion of glioma cell lines but also suppressed the sphere-formation and self-renewal abilities of glioma stem cells in vitro. Moreover, AP-2α overexpression inhibited subcutaneous and intracranial xenograft tumor growth in vivo. Furthermore, AP-2α enhanced the sensitivity of glioma cells to TMZ. Finally, AP-2α directly bound to the regulatory region of the Nanog gene, reduced Nanog, Sox2 and CD133 expression. Meanwhile, AP-2α indirectly downregulated Nanog expression by inhibiting the interleukin 6/janus kinase 2/signal transducer and activator of transcription 3 (IL6/JAK2/STAT3) signaling pathway, consequently decreasing O6-methylguanine methyltransferase (MGMT) and programmed death-ligand 1 (PD-L1) expression. In addition, miR-26a decreased AP-2α expression by binding to the 3' untranslated region (UTR) of AP-2α and reversed the tumor suppressive role of AP-2α in glioma, which was rescued by a miR-26a inhibitor. TMZ and the miR-26a inhibitor synergistically suppressed intracranial GSC growth.Conclusion: These results suggest that AP-2α reduces the stemness and TMZ resistance of glioma by inhibiting the Nanog/Sox2/CD133 axis and IL6/STAT3 signaling pathways. Therefore, AP-2α and miR-26a inhibition might represent a new target for developing new therapeutic strategies in TMZ resistance and recurrent glioma patients.

45S5-type bioactive glasses are a promising alternative to established substitutes for the treatment of bone defects. Because the three-dimensional (3D) structure of bone substitutes is crucial for bone ingrowth and formation, we evaluated the osteoinductive properties of different polymer coated 3D-45S5 bioactive glass (BG) scaffolds seeded with human mesenchymal stem cells (hMSC) in vivo. BG scaffolds coated with gelatin, cross-linked gelatin, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) were seeded with hMSC prior to implantation into severe combined immunodeficiency mice. Newly formed bone was evaluated with histomorphometry and micro-computed tomography. Bone formation was detectable in all groups, whereas the gelatin-coated BG scaffolds showed the best results and should be considered in further studies.

Circular RNAs (circRNAs) are reported to play vital roles in tumour process and might be potential prognostic biomarkers and therapeutic targets for tumours. But the expression and function of circRNAs in glioma remain unclear. Here, we performed circRNA microarray analysis of glioma tissues and matched normal brain tissue samples to explore the circRNA profile in glioma. GO analysis, KEGG and Reactom pathway analysis of linear mRNA transcripts corresponding to circRNAs were performed to study the involved biological process and pathways. The clinical significance of the selected circRNA was investigated by Kaplan‐Meier survival analysis. Relevant biological function, such as cell proliferation and metastasis, was detected in vitro and in vivo. And possible mechanism of the regulatory function of the selected circRNA in glioma was explored. We found that circCPA4 (hsa_circ_0082374) up‐regulated the most in glioma tissues and high levels of circCPA4 were positively related to poor outcome of glioma. And knockdown of circCPA4 suppresses cell proliferation and metastasis in glioma. Moreover, circCPA4 interacts with let‐7 and serves as a sponge for let‐7. Through the competitive endogenous RNA (ceRNA) mechanism, circCPA4 sponges let‐7 to regulate the expression of CPA4 and glioma progression. The circCPA4/let‐7/CPA4 axis regulates glioma progression by ceRNA mechanism, and circCPA4 could be a novel prognostic biomarker and target for glioma treatment.

There is growing evidence to suggest that epigenetic tags, especially DNA methylation, are critical regulators of fruit ripening. To examine whether this is the case in sweet pepper (Capsicum annuum) we conducted experiments at the transcriptional, epigenetic, and physiological levels. McrBC PCR, bisulfite sequencing, and real-time PCR demonstrated that DNA hypomethylation occurred in the upstream region of the transcription start site of some genes related to pepper ripening at the turning stage, which may be attributed to up-regulation of CaDML2-like and down-regulation of CaMET1-like1, CaMET1-like2, CaCMT2-like, and CaCMT4-like. Silencing of CaMET1-like1 by virus-induced gene silencing led to DNA hypomethylation, increased content of soluble solids, and accumulation of carotenoids in the fruit, which was accompanied by changes in expression of genes involved in capsanthin/capsorubin biosynthesis, cell wall degradation, and phytohormone metabolism and signaling. Endogenous ABA increased during fruit ripening, whereas endogenous IAA showed an opposite trend. No ethylene signal was detected during ripening. DNA hypomethylation repressed the expression of auxin and gibberellin biosynthesis genes as well as cytokinin degradation genes, but induced the expression of ABA biosynthesis genes. In mature-green pericarp, exogenous ABA induced expression of CaDML2-like but repressed that of CaCMT4-like. IAA treatment promoted the transcription of CaMET1-like1 and CaCMT3-like. Ethephon significantly up-regulated the expression of CaDML2-like. Treatment with GA3 and 6-BA showed indistinct effects on DNA methylation at the transcriptional level. On the basis of the results, a model is proposed that suggests a high likelihood of a role for DNA methylation in the regulation of ripening in the non-climacteric pepper fruit.

The principal nucleus of the bed nucleus of the stria terminalis (BNSTp) is a sexually dimorphic nucleus, and the male BNSTp is larger and has more neurons than the female BNSTp. To assess the roles of neuroestrogen synthesized from testicular androgen by brain aromatase in masculinization of the BNSTp, we performed morphometrical analyses of the adult BNSTp in aromatase knockout (ArKO), estrogen receptor-α knockout (αERKO), and estrogen receptor-β knockout (βERKO) mice and their respective wild-type littermates. In wild-type littermates, the BNSTp of males had a larger volume and greater numbers of neuronal and glial cells than did that of females. The volume and neuron number of the BNSTp in ArKO and αERKO males and glial cell number of the BNSTp in αERKO males were significantly smaller than those of wild-type male littermates, and they were not significantly different from those in female mice with either gene knockout. In contrast, there was no significant morphological difference in the BNSTp between βERKO and wild-type mice. Next, we examined the BNSTp of ArKO males subcutaneously injected with estradiol benzoate (EB) on postnatal days 1, 2, and 3 (1.5 µg/day). EB-treated ArKO males had a significantly greater number of BNSTp neurons than did oil-treated ArKO males. The number of BNSTp neurons in EB-treated ArKO males was comparable to that in wild-type males. These findings suggested that masculinization of the BNSTp in mice involves the actions of neuroestrogen that was synthesized by aromatase and that this estrogen mostly binds to ERα during the postnatal period.

We examined the effect of bilateral radiofrequency lesions in the lateral septum (LS) or medial preoptic area (MPOA) on olfactory preference (time spent sniffing odors derived from either a stud or castrated male) and pacing behavior (paracopulatory behavior in a cage with a compartment inaccessible to males) in ovariectomized rats following different hormonal regimes. Sham-operated and LS-lesioned females, but not MPOA-lesioned females, preferred odors from the stud males to the castrated males. MPOA lesions significantly decreased total nose-poking time, compared to that of sham-operated females. When mounted by stud males, both LS- and MPOA-lesioned females showed significantly higher lordosis quotients than sham-operated females. On the other hand, LS-lesioned females spent a significantly longer time in the male compartment, and stayed with the males even after they were mounted. These results suggest that the LS and MPOA play different roles in the sociosexual activity in female rats, and that the two regions exert an inhibitory influence on lordosis.

The pharmacokinetics of small interfering RNAs (siRNAs) is a pivotal issue for siRNA-based drug development. In this study, we comprehensively investigated the behavior of siRNAs in vivo in various tissues and demonstrated that intravenously-injected naked siRNA accumulated remarkably in the submandibular gland, bulbourethral gland, and pancreas, with a respective half-life of ~22.7, ~45.6, and ~30.3 h. This was further confirmed by gel separation of tissue homogenates and/or supernatants. In vivo imaging and cryosectioning suggested that delivery carriers significantly influence the distribution and elimination profiles of siRNA. Gene-silencing assays revealed that neither naked nor liposome-formulated siRNA resulted in gene knockdown in the submandibular and bulbourethral glands after systemic administration, suggesting that these glands function as drug reservoirs that enable slow siRNA release into the circulation. But robust gene-silencing was achieved by local injection of liposome-encapsulated siRNA into the submandibular gland. Our results enhance understanding of the pharmacokinetic properties of siRNAs and we believe that they will facilitate the development of siRNA therapy, especially for the submandibular gland.