Opportunities and challenges for ribosome-inactivating proteins in traditional Chinese medicine plants.

Ribosome-inactivating proteins (RIPs) are a class of cytotoxic rRNA N-glycosylase, which widely exist in higher plants in different taxonomy, including many traditional Chinese medicinal materials and vegetables and fruits. In this paper, the traditional Chinese medicinal plants containing RIPs protein were sorted out, and their pharmacological effects and clinical applications were analyzed. Since many RIPs in traditional Chinese medicine plants exhibit antiviral and antitumor activities and show great clinical application potential, people's interest in these proteins is on the rise. This paper summarizes the possible mechanism of RIPs's anti-virus and anti-tumor effects, and discusses its potential problems and risks, laying a foundation for subsequent research on how to exert its anti-virus and anti-tumor effects.

USP18 enhances the resistance of BRAF-mutated melanoma cells to vemurafenib by stabilizing cGAS expression to induce cell autophagy.

This study aims to discern the possible molecular mechanism of the effect of ubiquitin-specific peptidase 18 (USP18) on the resistance to BRAF inhibitor vemurafenib in BRAF V600E mutant melanoma by regulating cyclic GMP-AMP synthase (cGAS). The cancer tissues of BRAF V600E mutant melanoma patients before and after vemurafenib treatment were collected, in which the protein expression of USP18 and cGAS was determined. A BRAF V600E mutant human melanoma cell line (A2058R) resistant to vemurafenib was constructed with its viability, apoptosis, and autophagy detected following overexpression and depletion assays of USP18 and cGAS. Xenografted tumors were transplanted into nude mice for in vivo validation. Bioinformatics analysis showed that the expression of cGAS was positively correlated with USP18 in melanoma, and USP18 was highly expressed in melanoma. The expression of cGAS and USP18 was up-regulated in cancer tissues of vemurafenib-resistant patients with BRAF V600E mutant melanoma. Knockdown of cGAS inhibited the resistance to vemurafenib in A2058R cells and the protective autophagy induced by vemurafenib in vitro. USP18 could deubiquitinate cGAS to promote its protein stability. In vivo experimentations confirmed that USP18 promoted vemurafenib-induced protective autophagy by stabilizing cGAS protein, which promoted resistance to vemurafenib in BRAF V600E mutant melanoma cells. Collectively, USP18 stabilizes cGAS protein expression through deubiquitination and induces autophagy of melanoma cells, thereby promoting the resistance to vemurafenib in BRAF V600E mutant melanoma.

BRD4 inhibitor GNE987 exerts anti-cancer effects by targeting super-enhancers in neuroblastoma.

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.

Expression and purification of a recombinant ELRL-MAP30 with dual-targeting anti-tumor bioactivity.

MAP30 (Momordica antiviral protein 30kD) is a single-chain Ⅰ-type ribosome inactivating protein with a variety of biological activities, including anti-tumor ability. It was reported that MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer. To determine whether adding two tumor targeting peptides could improve the antitumor activities of MAP30, we genetically modified MAP30 with an RGD motif and a EGFRi motif, which is a ligand with high affinity for αvß3 integrins and with high affinity for EGFR. The recombinant protein ELRL-MAP30 (rELRL-MAP30) containing a GST-tag was expressed in E. coli. The rELRL-MAP30 was highly expressed in the soluble fraction after induction with 0.15 mM IPTG for 20 h at 16 °C. The purified rELRL-MAP30 appeared as a band on SDS-PAGE. It was identified by western blotting. Cytotoxicity of recombinant protein to HepG2, MDA-MB-231, HUVEC and MCF-7 cells was detected by MTT analysis. Half maximal inhibitory concentration (IC50) values were 54.64 µg/mL, 70.13 µg/mL, 146 µg/mL, 466.4 µg/mL, respectively. Proliferation inhibition assays indicated that rELRL-MAP30 could inhibit the growth of Human liver cancer cell HepG2 effectively. We found that rELRL-MAP30 significantly induced apoptosis in liver cancer cells, as evidenced by nuclear staining of DAPI. In addition, rELRL-MAP30 induced apoptosis in human liver cancer HepG2 cells by up-regulation of Bax as well as down-regulation of Bcl-2. Migration of cell line were markedly inhibited by rELRL-MAP30 in a dose-dependent manner compared to the recombinant MAP30 (rMAP30). In summary, the fusion protein displaying extremely potent cytotoxicity might be highly effective for tumor therapy.

Gadolinium-doped mesoporous calcium silicate/chitosan scaffolds enhanced bone regeneration ability.

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/ß-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.

Continuous hypoxia regulates the osteogenic potential of mesenchymal stem cells in a time-dependent manner.

The effects of hypoxia on the osteogenic potential of mesenchymal stem cells (MSCs) have been previously reported. From these studies, possible factors affecting the association between hypoxia and the osteogenic differentiation of MSCs have been suggested, including hypoxia severity, cell origin and methods of induction. The effect of the duration of hypoxia, however, remains poorly understood. The aim of the present study was to investigate the effect of continuous hypoxia on the induced osteogenesis of MSCs. Rat MSCs were isolated and cultured in vitro. Once the cells had been cultured to passage three, they were switched to 1% oxygen and cultured either with or without osteogenic medium, while cells in the control groups were cultured under normoxia in corresponding conditions. Four osteogenic differentiation biomarkers, runt-related transcription factor 2, osteopontin, osteocalcin and alkaline phosphatase, were analyzed by quantitative polymerase chain reaction and western blotting at defined intervals throughout the culture period. In addition, Alizarin Red staining was used to assess changes in mineralization. The results showed that 1% hypoxia was able to enhance and accelerate the osteogenic ability of the MSCs during the initial phases of differentiation, and the protein expression of certain associated biomarkers was upregulated. However, continuous hypoxia was shown to impair osteogenesis in the latter stages of differentiation. These findings suggest that hypoxia can regulate the osteogenesis of MSCs in a time-dependent manner.

Injury-to-surgery interval does not affect postfracture osteonecrosis of the femoral head in young adults: a systematic review.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common and severe complication following femoral neck fractures in young adults. Despite significant advances in surgical techniques, radiological evaluation and comprehensive treatment for the prevention of ONFH, the incidence of traumatic ONFH has remained unchanged at approximately 20% in recent decades. The injury-to-surgery interval is considered as a principal factor affecting the occurrence of ONFH, and traditionally, femoral neck fractures are treated emergently. However, the relationship between the injury-to-surgery interval and ONFH occurrence is poorly understood, and previous reviews have not provided a precise explanation due to the lack of strict selection criteria for studies. METHODS: We reviewed previously published articles and included in current systematic review those studies with accurate multivariate analyses that included age, fracture type, operation method, follow-up, ONFH occurrence and injury-to-surgery interval. RESULTS: Six case studies were included and reevaluated. The studies included 263 hips for final analysis, with an overall incidence of postfracture ONFH of 17.5%. Patients were categorized into groups of less/more than 8 h, less/more than 24 h, less/more than 48 h and less/more than 3 weeks based on the individual injury-to-surgery interval. The postfracture ONFH incidence ranged from 13.3% (<8 weeks) to 21.7% (>3 weeks). Operations performed within 3 weeks of injury resulted in a lower ONFH incidence compared with operations performed after 3 weeks; however, this difference was not statistically significant. The ONFH incidence remained relatively stable when the operations were performed within 3 weeks of injury. CONCLUSIONS: The injury-to-surgery interval did not significantly affect the incidence of postoperative ONFH.

[The effect and mechanism of Yiqi Tongluo Jiedu capsule against cerebral ischemia reperfusion injury].

To observe the effect and mechanism of Yiqi Tongluo Jiedu capsule aganist cerebral ischemia reperfusion injury, the SD rats were randomly divided into following groups: sham-operated group, model group, the group of low, medium and high dose of Yiqi Tongluo Jiedu capsule, and nimodipine group. Using focal middle cerebral artery embolization (MCAO) model, following items were observed: symptoms of neurological deficit score; infarct volume; activity of SOD, content of MDA and NO, activity of NOS of ischemic brain tissue; Bcl-2 and Bax protein expression; content of IL-1beta, IL-6 and TNFalpha in serum; IL-1beta mRNA expression of ischemic brain tissue. Results showed that Yiqi Tongluo Jiedu capsule could significantly reduce the symptoms of neurological deficits, promote the recovery symptoms of neurological deficits; narrow infarct volume of brain tissue obviously, reduce the percentage of infarct volume; raise activity of SOD, reduce content of MDA and NO, reduce activity of NOS; increase Bcl-2 protein, reduce Bax expression; reduce content of IL-1beta, IL-6 and TNFa in serum; reduce IL-1beta mRNA expression of ischemic brain tissue. Yiqi Tongluo Jiedu capsule has significant protective effects against ischemic brain injury, it has significant anti-apoptotic, antioxidant and anti-inflammatory effects.

Injury-to-surgery interval does not affect the occurrence of osteonecrosis of the femoral head: a prospective study in a canine model of femoral neck fractures.

BACKGROUND: It is controversial whether an early reduction and internal fixation can reduce the occurrence of femoral neck fracture-induced osteonecrosis of the femoral head (ONFH). This prospective study was designed to reflect the relationship between injury-to-surgery interval (ISI) and traumatic ONFH based on a canine model of femoral neck fractures. MATERIAL/METHODS: Twenty-four dogs were equally divided randomly into 3 groups. A lateral L-shape approach centered left great trochanter was used for exposure of the femoral neck. A low-speed drill was used for making displaced fractures in the narrow femoral neck, with the femoral head kept in situ with ligamentum teres intact. In Group A, the fracture was immediately reduced and fixed with 3 parallel pins; while the operation was done 3 days later in Group B, and 3 weeks later in Group C. Another 2 dogs had their fractures untreated. Postoperatively, all dogs were fed separately and received regular x-ray examination. Left femoral heads were harvested for histological examination with a postoperative follow-up of 3.5 months. RESULTS: The canine model of femoral neck fractures could be achieved successfully. Radiological signs of post-fracture ONFH could not be detected at intervals of 2 weeks, 4 weeks, 1 month and 2 months. Histologically, there were 2 cases with ONFH in Group A, 1 case in Group B, and 2 cases in Group C. The difference had no statistical significance. For untreated fractures, obvious ONFH could be found radiologically. CONCLUSIONS: A shorter ISI may not reduce the incidence of fracture-induced ONFH, which suggests that intrinsic factors play an important role in the occurrence of ONFH.

Pain relief following osteonecrosis of the femoral head treated by free vascularized fibular grafting.

BACKGROUND: Pain is the core and basic problem in the treatment of osteonecrosis of the femoral head (ONFH). However, it is unclear about the status of pain relief following ONFH treated by free vascularized fibular grafting (FVFG) and the level of pain relief contributed to clinical results. Therefore, we designed a consecutive and prospective study to investigate post-operative pain relief in the treatment of osteonecrosis of the femoral head by FVFG. METHODS: One hundred and fifty-one patients with unilateral osteonecrosis of the femoral head were enrolled consecutively for current prospective study from January to August of 2006. Patients were managed by modified technique of free vascularized fibular grafting. Pre-operative, post-operative Harris hip score (HHS) and Harris pain score (HPS) were recorded and compared statistically, meanwhile, correlation between disease severity and Harris hip score, Harris pain score were revealed. RESULTS: All patients had an average follow-up of 54.3 months. Post-operative Harris hip score could be improved from 73.7 to 83.5 averagely in stage-II patients, 64.6 to 78.9 in stage-III, and 53.6 to 72.4 in stage-IV. As for Harris pain score, it was elevated from 28.8 to 38.6 in stage-II patients, 25.5 to 36.6 in stage-III, and 21.8 to 34.2 in stage-IV. Taken together, HHS was improved from 67.7 to 80.3 (ΔHHS = 12.6), and HPS was improved from 26.6 to 37.3 (ΔHPS = 10.7) averagely. CONCLUSIONS: Harris pain score could be employed to monitor prognosis of osteonecrosis of the femoral head treated by free vascularized fibular grafting. Improvement of HPS was the heaviest contributor to elevation of HHS, and both of them conceived of a close relationship with disease severity.

The effect of dexamethasone and hypoxic stress on MC3T3-E1 cells.

Osteonecrosis of the femoral head (ONFH) can be caused by a decrease in the activity or numbers of osteoblasts, a process in which apoptosis may play an essential role. We investigated the effect of dexamethasone (Dex) combined with hypoxic stress on murine osteoblastic MC3T3-E1 cells. Flow cytometry, western blot and real-time quantitative PCR analyses revealed that hypoxia significantly enhanced Dex-induced apoptosis. Further data demonstrated that both the death receptor and the mitochondria-mediated pathway were involved in Dex-induced apoptosis under hypoxic conditions. However, the death receptor pathway had only a minor effect on this process. The expression levels of Bcl-2 and Bax, which regulate the mitochondria-initiated apoptotic cascade signaling pathway, were significantly different in response to Dex and hypoxia. The mitochondrial membrane potential collapsed, and the inhibitor brain- derived neurotrophic factor (BDNF) conferred effective protection against apoptosis. In summary, the mitochondria-mediated apoptotic pathway functions in osteoblast apoptosis that is induced by Dex in a hypoxic environment, and the present study may help us to gain further insight into the molecular mechanisms of steroid-induced ONFH.