ROR2 Downregulation Activates the MSX2/NSUN2/p21 Regulatory Axis and Promotes Dental Pulp Stem Cell Senescence.

Cellular senescence severely limits the research and the application of dental pulp stem cells (DPSCs). A previous study conducted by our research group revealed a close implication of ROR2 in DPSC senescence, although the mechanism underlying the regulation of ROR2 in DPSCs remains poorly understood so far. In the present study, it was revealed that the expression of the ROR2-interacting transcription factor MSX2 was increased in aging DPSCs. It was demonstrated that the depletion of MSX2 inhibits the senescence of DPSCs and restores their self-renewal capacity, and the simultaneous overexpression of ROR2 enhanced this effect. Moreover, MSX2 knockdown suppressed the transcription of NOP2/Sun domain family member 2 (NSUN2), which regulates the expression of p21 by binding to and causing the 5-methylcytidine methylation of the 3'- untranslated region of p21 mRNA. Interestingly, ROR2 downregulation elevated the levels of MSX2 protein, and not the MSX2 mRNA expression, by reducing the phosphorylation level of MSX2 and inhibiting the RNF34-mediated MSX2 ubiquitination degradation. The results of the present study demonstrated the vital role of the ROR2/MSX2/NSUN2 axis in the regulation of DPSC senescence, thereby revealing a potential target for antagonizing DPSC aging.

Thioether-directed Rh(III)-catalyzed peri-selective acyloxylation of arenes.

A thioether directed acyloxylation of arenes has been realized via Cp*Rh(III)-catalyzed C-H activation and subsequent coupling with carboxylic acids. This new method showed high functional group compatibility and broad substrate scope. Primary mechanistic studies have been conducted and a tentative reaction mechanism was proposed. It represents the first example of a thioether-directed Cp*Rh(III)-catalyzed C(sp2)-H acyloxylation reaction.

Access to acridones by tandem copper(I)-catalyzed electrophilic amination/Ag(I)-mediated oxidative annulation of anthranils with arylboronic acids.

An efficient and practical approach for the synthesis of medicinally important acridones was developed from anthranils and commercially available arylboronic acids by a tandem copper(I)-catalyzed electrophilic amination/Ag(I)-mediated oxidative annulation strategy. This new and straightforward protocol displayed a broad substrate scope (25 examples) and high functional group tolerance. What's more, a possible mechanistic proposal was also presented.

Downregulation of microRNA-149 in retinal ganglion cells suppresses apoptosis through activation of the PI3K/Akt signaling pathway in mice with glaucoma.

Glaucoma represents a major cause of blindness, generally associated with elevated intraocular pressure (EIOP). The aim of the present study was to investigate whether microRNA-149 (miR-149) affects retinal ganglion cells (RGCs) and the underlying mechanism based on a mouse model of chronic glaucoma with EIOP. The successfully modeled mice were administered with mimics or inhibitors of miR-149. Next, the number of RGCs, ultrastructural changes of RGCs, and purity of RGCs in the retinal tissues were detected. Moreover, the RGCs were collected and subsequently treated with 60 mmHg pressure and transfected with a series of plasmids aiding in the regulation of the expression of miR-149 and betacellulin (BTC). The levels of miR-149, BTC, phosphatidylinositol 3-kinase (PI3K), and Akt were subsequently determined. Finally, RGC viability and apoptosis were detected accordingly. Dual luciferase reporter gene assay provided validation, highlighting BTC was indeed a target gene of miR-149. The downregulation of miR-149 is accompanied by an increased number of RGCs and decreased ultrastructural RGC alterations. Additionally, downregulated miR-149 was noted to increase the levels of BTC, PI3K, and Akt in both the retinal tissues and RGCs, whereas the silencing of miR-149 was observed to promote the viability of RGC and inhibit RGC apoptosis. Taken together, the results of the current study provided validation suggesting that the downregulation of miR-149 confers protection to RGCs by means of activating the PI3K/Akt signaling pathway via upregulation of BTC in mice with glaucoma. Evidence presented indicated the promise of miR-149 inhibition as a potential therapeutic strategy for glaucoma treatment.

Sanguinarine inhibits growth and invasion of gastric cancer cells via regulation of the DUSP4/ERK pathway.

Sanguinarine, a bioactive benzophenanthridine alkaloid extracted from plants of the Papaveraceae family, has shown antitumour effects in multiple cancer cells. But the therapeutic effects and regulatory mechanisms of sanguinatine in gastric cancer (GC) remain elusive. This study was aimed to investigate the correlation of dual-specificity phosphatase 4 (DUSP4) expression with clinicopathologic features and overall survival in patients with GC and explore the effects of sanguinarine on tumour growth and invasion in GC cells (SGC-7901 and HGC-27) and underlying molecular mechanisms. Immunohistochemical analysis showed that decreased DUSP4 expression was associated with the sex, tumour size, depth of invasion and distant metastasis in patients with GC. Functional experiments including CCK-8, Transwell and flow cytometry analysis indicated that sanguinarine or DUSP4 overexpression inhibited GC cell viability and invasive potential, and induced cell apoptosis and cycle arrest in S phase, but DUSP4 knockdown attenuated the antitumour activity of sanguinarine. Further observation demonstrated that sanguinarine up-regulated the expression of DUSP4 and Bcl-2-associated X protein (Bax), but down-regulated phosphorylated extracellular signal-regulated kinase (p-ERK), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP-2) and B-cell lymphoma 2 (Bcl-2) expression. Taken together, our findings indicate that sanguinarine inhibits growth and invasion of GC cells through regulation of the DUSP4/ERK pathway, suggesting that sanguinarine may have potential for use in GC treatment.

VDAC1, as a downstream molecule of MLKL, participates in OGD/R-induced necroptosis by inducing mitochondrial damage.

Ischemia-reperfusion (I/R) injury constitutes a significant risk factor for a range of diseases, including ischemic stroke, myocardial infarction, and trauma. Following the restoration of blood flow post-tissue ischemia, oxidative stress can lead to various forms of cell death, including necrosis, apoptosis, autophagy, and necroptosis. Recent evidence has highlighted the crucial role of mitochondrial dysfunction in I/R injury. Nevertheless, there remains much to be explored regarding the molecular signaling network governing cell death under conditions of oxidative stress. Voltage-dependent anion channel 1 (VDAC1), a major component in the outer mitochondrial membrane, is closely involved in the regulation of cell death. In a cellular model of oxygen-glucose deprivation and reoxygenation (OGD/R), which effectively simulates I/R injury in vitro, our study reveals that OGD/R induces VDAC1 oligomerization, consequently exacerbating cell death. Furthermore, we have revealed the translocation of mixed lineage kinase domain-like protein (MLKL) to the mitochondria, where it interacts with VDAC1 following OGD/R injury, leading to an increased mitochondrial membrane permeability. Notably, the inhibition of MLKL by necrosulfonamide hinders the binding of MLKL to VDAC1, primarily by affecting the membrane translocation of MLKL, and reduces OGD/R-induced VDAC1 oligomerization. Collectively, our findings provide preliminary evidence of the functional association between MLKL and VDAC1 in the regulation of necroptosis.

[Effects of different fluid resuscitations on mesenteric microcirculation in rabbits of acute hemorrhagic shock].

OBJECTIVE: To explore the effects of blood, crystalloid and colloid on mesenteric microcirculation in rabbits of acute hemorrhagic shock. METHODS: Hemorrhagic shock was induced in 28 anesthetized mechanically ventilated rabbits by withdrawing blood to a mean arterial blood pressure (MAP) of 40 mm Hg and maintained for 30 min. The animals were randomized into blank control group, whole blood resuscitation group, Ringer's solution resuscitation (RR) group and volume resuscitation (VR) group (n = 7 each). The data of vital signs, systemic hemodynamic parameters, arterial blood gas analysis and mesenteric microcirculation were collected at baseline, hemorrhagic shock (HS-0), resuscitation 0 min (Res-0) and resuscitation 30 min (Res-30). And side-stream dark field imaging (SDF) was employed to acquire the images of mesenteric microcirculation. RESULTS: No significant difference existed in the basic status between 4 groups. MAP decreased to around 40 mm Hg in all groups. MAP increased significantly after active fluid resuscitation (P < 0.05). In addition to blank control group, total vascular density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV) and microvascular flow index (MFI) significantly increased after active fluid resuscitation in the other three groups. TVD and PVD were significantly lower at Res-0 in VR than in RR (P < 0.05). CONCLUSION: After acute hemorrhagic shock, fluid resuscitation with whole blood and Ringer's solution improves systemic hemodynamics. And the combined regimen of whole blood and Ringer's solution is better at restoring mesenteric microcirculation.

[Clinical study of combined treatment of remifemin and paroxetine for perimenopausal depression].

OBJECTIVE: To explore the efficacies and safety of combined treatment of remifemin and paroxetine for perimenopausal depression. METHODS: A total of 120 patients with perimenopausal depression were digital randomly divided into the treatment and control groups (n = 60 each). The treatment group received oral remifemin one tablet twice daily and paroxetine 20 mg once daily for 2 months while the control group oral paroxetine 20 mg once daily for 2 months. The Hamilton depression scale (HAMD) and Kupperman scale were used to assess the therapeutic efficacies. Blood and urine routine, electrocardiography, liver function, kidney function and blood pressure before and after treatment were examined to assess the side effects. RESULTS: For the improvement of perimenopausal depression on HAMD, the total effective rates of the treatment and control groups were 88.3% and 78.3% respectively. The therapeutic efficacy of the treatment group was significantly higher than that of the control group (P < 0.05). After 8-week treatment, Kupperman menopausal indices of the treatment and control groups were 9.89 ± 3.76 and 15.75 ± 5.84 respectively. There was also significant difference (P < 0.01). No significant changes existed in blood routine, urine routine, liver function, kidney function, blood pressure, ECG or blood pressure before and after treatment (P > 0.05). CONCLUSION: The combined treatment of remifemin and paroxetine for perimenopausal depression can improve the efficacies. It is easily accepted by patients for its higher safety and fewer side-effects. It is worthy of a wider application and further researches.

A New Paradigm in Spinal Cord Injury Therapy: from Cell-free Treatment to Engineering Modifications.

Spinal cord injury (SCI) is an intractable and poorly prognostic neurological disease, and current treatments are still unable to cure it completely and avoid sequelae. Extracellular vesicles (EVs), as important carriers of intercellular communication and pharmacological effects, are considered to be the most promising candidates for SCI therapy because of their low toxicity and immunogenicity, their ability to encapsulate endogenous bioactive molecules (e.g., proteins, lipids, and nucleic acids), and their ability to cross the blood-brain/cerebrospinal barriers. However, poor targeting, low retention rate, and limited therapeutic efficacy of natural EVs have bottlenecked EV-based SCI therapy. A new paradigm for SCI treatment will be provided by engineering modified EVs. Furthermore, our limited understanding of the role of EVs in SCI pathology hinders the rational design of novel EVbased therapeutic approaches. In this study, we review the pathophysiology after SCI, especially the multicellular EVs-mediated crosstalk; briefly describe the shift from cellular to cell-free therapies for SCI treatment; discuss and analyze the issues related to the route and dose of EVs administration; summarize and present the common strategies for EVs drug loading in the treatment of SCI and point out the shortcomings of these drug loading methods; finally, we analyze and highlight the feasibility and advantages of bio-scaffold-encapsulated EVs for SCI treatment, providing scalable insights into cell-free therapy for SCI.

Inhibition of mitochondrial VDAC1 oligomerization alleviates apoptosis and necroptosis of retinal neurons following OGD/R injury.

Ischemia-reperfusion (I/R) injury is a common pathological mechanism in many retinal diseases, which can lead to cell death via mitochondrial dysfunction. Voltage-dependent anion channel 1 (VDAC1), which is mainly located in the outer mitochondrial membrane, is the gatekeeper of mitochondria. The permeability of mitochondrial membrane can be regulated by controlling the oligomerization of VDAC1. However, the functional mechanism of VDAC1 in retinal I/R injury was unclear. Our results demonstrate that oxygen-glucose deprivation and re-oxygenation (OGD/R) injury leads to apoptosis, necroptosis, and mitochondrial dysfunction of R28 cells. The OGD/R injury increases the levels of VDAC1 oligomerization. Inhibition of VDAC1 oligomerization by VBIT-12 rescued mitochondrial dysfunction by OGD/R and also reduced apoptosis/necroptosis of R28 cells. In vivo, the use of VBIT-12 significantly reduced aHIOP-induced neuronal death (apoptosis/necroptosis) in the rat retina. Our findings indicate that VDAC1 oligomers may open and enlarge mitochondrial membrane pores during OGD/R injury, leading to the release of death-related factors in mitochondria, resulting in apoptosis and necroptosis. This study provides a potential therapeutic strategy against ocular diseases caused by I/R injury.

Targeting Necroptosis: A Novel Therapeutic Option for Retinal Degenerative Diseases.

The discovery of the necroptosis, a form of regulated necrosis that is mediated by receptor-interacting protein kinase 1 (RIPK1), RIPK3, and mixed-lineage kinase domain-like pseudokinase (MLKL), represents a major breakthrough that has dramatically altered the conception of necrosis - traditionally thought of as uncontrolled cell death - in various human diseases. Retinal cell death is a leading cause of blindness and has been identified in most retinal diseases, e.g., age-related macular degeneration, glaucoma, retinal detachment, retinitis pigmentosa, etc. Increasing evidence demonstrates that retinal degenerative diseases also share a common mechanism in necroptosis. Exacerbated necroptotic cell death hinders the treatment for retinal degenerative diseases. In this review, we highlight recent advances in identifying retinal necroptosis, summarize the underlying mechanisms of necroptosis in retinal degenerative diseases, and discuss potential anti-necroptosis strategies, such as selective inhibitors and chemical agents, for treating retinal degenerative diseases.

Targeting Programmed Cell Death to Improve Stem Cell Therapy: Implications for Treating Diabetes and Diabetes-Related Diseases.

Stem cell therapies have shown promising therapeutic effects in restoring damaged tissue and promoting functional repair in a wide range of human diseases. Generations of insulin-producing cells and pancreatic progenitors from stem cells are potential therapeutic methods for treating diabetes and diabetes-related diseases. However, accumulated evidence has demonstrated that multiple types of programmed cell death (PCD) existed in stem cells post-transplantation and compromise their therapeutic efficiency, including apoptosis, autophagy, necroptosis, pyroptosis, and ferroptosis. Understanding the molecular mechanisms in PCD during stem cell transplantation and targeting cell death signaling pathways are vital to successful stem cell therapies. In this review, we highlight the research advances in PCD mechanisms that guide the development of multiple strategies to prevent the loss of stem cells and discuss promising implications for improving stem cell therapy in diabetes and diabetes-related diseases.

Self-perceived burden and influencing factors in patients with cervical cancer administered with radiotherapy.

BACKGROUND: Cervical cancer is the fourth commonest malignancy in women around the world. It represents the second most commonly diagnosed cancer in South East Asian women, and an important cancer death cause in women of developing nations. Data collected in 2018 revealed 5690000 cervical cancer cases worldwide, 85% of which occurred in developing countries. AIM: To assess self-perceived burden (SPB) and related influencing factors in cervical cancer patients undergoing radiotherapy. METHODS: Patients were prospectively included by convenient sampling at The Fifth Affiliated Hospital of Sun Yat-Sen University, China between March 2018 and March 2019. The survey was completed using a self-designed general information questionnaire, the SPB scale for cancer patients, and the self-care self-efficacy scale, Strategies Used by People to Promote Health, which were delivered to patients with cervical cancer undergoing radiotherapy. Measurement data are expressed as the mean ± SD. Enumeration data are expressed as frequencies or percentages. Caregivers were the spouse, offspring, and other in 46.4, 40.9, and 12.7%, respectively, and the majority were male (59.1%). As for pathological type, 90 and 20 cases had squamous and adenocarcinoma/adenosquamous carcinomas, respectively. Stage IV disease was found in 12 (10.9%) patients. RESULTS: A total of 115 questionnaires were released, and five patients were excluded for too long evaluation time (n = 2) and the inability to confirm the questionnaire contents (n = 3). Finally, a total of 110 questionnaires were collected. They were aged 31-79 years, with the 40-59 age group being most represented (65.4% of all cases). Most patients were married (91.8%) and an overwhelming number had no religion (92.7%). Total SPB score was 43.13 ± 16.65. SPB was associated with the place of residence, monthly family income, payment method, transfer status, the presence of radiotherapy complications, and the presence of pain (P < 0.05). The SPB and self-care self-efficacy were negatively correlated (P < 0.01). In multivariate analysis, self-care self-efficacy, place of residence, monthly family income, payment method, degree of radiation dermatitis, and radiation proctitis were influencing factors of SPB (P < 0.05). CONCLUSION: Patients with cervical cancer undergoing radiotherapy often have SPB. Self-care self-efficacy scale, place of residence, monthly family income, payment method, and radiation dermatitis and proctitis are factors independently influencing SPB.

Downregulation of ROR2 promotes dental pulp stem cell senescence by inhibiting STK4-FOXO1/SMS1 axis in sphingomyelin biosynthesis.

Dental pulp stem cells (DPSCs) play a vital role in tooth restoration, regeneration, and homeostasis. The link between DPSC senescence and tooth aging has been well-recognized. ROR2 plays an important role in aging-related gene expression. However, the expression and function of ROR2 in DPSC aging remain largely unknown. In this study, we found that ROR2 expression was significantly decreased in aged pulp tissues and DPSCs. The depletion of ROR2 in young DPSCs inhibits their self-renewal capacity, while its overexpression in aged DPSCs restores their self-renewal capacity. Interestingly, we found that sphingomyelin (SM) is involved in the senescence of DPSCs regulated by ROR2. Mechanistically, we confirmed that ROR2 inhibited the phosphorylation of STK4, which promoted the translocation of Forkhead Box O1 (FOXO1) to the nucleus. STK4 inhibition or knockdown of FOXO1 markedly increased the proliferation of DPSCs and upregulated the expression of SMS1, which catalyzed SM biogenesis. Moreover, FOXO1 directly bound to the SMS1 promoter, repressing its transcription. Our findings demonstrated the critical role of the ROR2/STK4-FOXO1/SMS1 axis in the regulation of SM biogenesis and DPSC senescence, providing a novel target for antagonizing tooth aging.

Investigation of a Novel LRP6 Variant Causing Autosomal-Dominant Tooth Agenesis.

BACKGROUND: The low-density lipoprotein receptor-related protein 6 (LRP6) gene is a recently defined gene that is associated with the autosomal-dominant inherited tooth agenesis (TA). In the present study, a family of four generations having TA was recruited and subjected to a series of clinical, genetic, in silico, and in vitro investigations. METHODS: After routine clinical evaluation, the proband was subjected to whole-exome sequencing (WES) to detect the diagnostic variant. Next, in silico structural and molecular dynamics (MD) analysis was conducted on the identified novel missense variant for predicting its intramolecular impact. Subsequently, an in vitro study was performed to further explore the effect of this variant on protein maturation and phosphorylation. RESULTS: WES identified a novel variant, designated as LRP6: c.2570G > A (p.R857H), harbored by six members of the concerned family, four of whom exhibited varied TA symptoms. The in silico analysis suggested that this novel variant could probably damage the Wnt bonding function of the LRP6 protein. The experimental study demonstrated that although this novel variant did not affect the LRP6 gene transcription, it caused a impairment in the maturation and phosphorylation of LRP6 protein, suggesting the possibility of the disruption of the Wnt signaling. CONCLUSION: The present study expanded the mutation spectrum of human TA in the LRP6 gene. The findings of the present study are insightful and conducive to understanding the functional significance of specific LRP6 variants.

[Clinical observation on treatment of active rheumatoid arthritis with Chinese herbal medicine].

OBJECTIVE: To study the efficacy and safety of Chinese drugs for expelling evil-wind, removing dampness, promoting blood circulation and invigorating yin in treating active rheumatoid arthritis (RA). METHODS: Sixty-seven patients with active RA were randomized into 3 groups, the Group A, B and C. They were made coequal in terms of age, sex and condition of disease and treated respectively with basic treatment (non-steroid anti-inflammation drug combined with immune inhibitor) only, basic treatment + small dose prednisone, and basic treatment + Chinese herbal medicine, all for 8 weeks. The efficacy and adverse effects of treatment were analyzed by scoring. RESULTS: The total effective rate was 20.0% (4/20) in Group A, 810% (17/21) in Group B and 85.7% (18/21) in Group C, the latter two were superior to the former one (P <0.01). Before treatment, comparison of disease activity score (DAS) among the three groups showed no significant difference (P > 0.05). After treatment, improvements of Ritchie arthritis index (RAI), number of swollen joint, erythrocyte sedimentation rate (ESR), general health (GH), and DAS were shown in Group B and C (P <0.05), while in Group A, improvement was only shown in GH (P <0.05). The difference of DAS between pre- and post-treatment was 0.25 +/- 0.77 in Group A, 0.87 +/- 0.60 in Group B and 0.92 +/- 0.59 in Group C, showing statistical significance between Group A vs B and A vs C (P = 0.0000). The total accumulative score of adverse reaction was 3.76 +/- 2.72 in Group C, 9.10 +/- 6.01 in Group A and 14.38 +/- 9.36 in Group B, also showing statistical significance among groups (P < 0.05). CONCLUSION: The combination of Chinese and Western medicine for active RA is effective and safe.

Downregulation of microRNA­182 inhibits cell viability, invasion and angiogenesis in retinoblastoma through inhibition of the PI3K/AKT pathway and CADM2 upregulation.

Retinoblastoma (RB) is a well­vascularized tumor dependent on angiogenesis. The present study aimed to explore whether microRNA (miR)­182 regulates cell viability, invasion and angiogenesis in RB via the phosphatidylinositol­3­OH kinase (PI3K)/protein kinase B (AKT) signaling pathway and by targeting cell adhesion molecule 2 (CADM2). The expression levels of miR­182 and CADM2 were initially detected in RB tissues from patients with RB who underwent ophthalmectomy, and normal retinal tissues collected from other trauma patients who underwent eye enucleation. To determine whether CADM2 was targeted by miR­182, a dual luciferase reporter assay was conducted. Subsequently, Y79 and WERI­Rb­1 RB cells were transfected with a miR­182 mimic or miR­182 inhibitor, or small interfering RNA against CADM2, in order to investigate the effects of miR­182 on viability and invasion, which were detected using MTT and Transwell assays, respectively. In addition, to determine whether the regulatory mechanism underlying the effects of miR­182 was associated with the PI3K/AKT signaling pathway, the expression levels of associated genes were detected by reverse transcription­quantitative polymerase chain reaction and western blot analysis. A xenograft tumor model in nude mice was also established, in order to evaluate the effects of miR­182 on tumor growth and angiogenesis. The results indicated that miR­182 expression was increased and CADM2 expression was reduced in RB tissues; CADM2 was confirmed to be targeted and negatively regulated by miR­182. When the expression of miR­182 was downregulated, cell viability, invasion, tumor volume and angiogenesis were significantly decreased. Furthermore, the expression levels of PI3K/AKT signaling pathway­associated genes were increased in response to miR­182 overexpression or CADM2 silencing. Taken together, these results suggested that inhibition of miR­182 may suppress cell viability, invasion and angiogenesis in RB through inactivation of the PI3K/AKT pathway and CADM2 upregulation. This mechanism may reveal a novel potential therapeutic target.

Upregulation of PD-L1 predicts poor prognosis and is associated with miR-191-5p dysregulation in colon adenocarcinoma.

Targeting of the programmed cell-death 1 ligand 1 (PD-L1) signal pathway is a promising treatment strategy in several cancers. The purpose of this study was to evaluate the clinical significance of PD-L1 in patients with colon adenocarcinoma (COAD). A total of 240 patients who were diagnosed with COAD from The Cancer Genome Atlas (TCGA) RNA-sequencing data and another cohort for pair-matched COAD samples (n = 40) in tissue microarray (TMA) were enrolled in this study. The correlation of PD-L1 or miR-191-5p expression with clinicopathological features and prognosis in patients with COAD was further analyzed using TCGA data and TMA. The Cox proportional hazard regression model was used to evaluate the association of PD-L1 or miR-191-5p expression with overall survival (OS) and tumor recurrence in patients with COAD. The microRNAs (miRNAs) that target PD-L1 gene were identified by bioinformatics and Spearman correlation analysis. We found that PD-L1 expression was increased in COAD tissues and was correlated with poor survival and tumor recurrence in patients with COAD. The increased expression of PD-L1 was attributed to the dysregulation of miR-191-5p expression rather than its genetic or epigenetic alterations. Moreover, the expression of miR-191-5p presented the negative correlation with PD-L1 expression and acted as an independent prognostic factor of OS in patients with COAD. Therefore, PD-L1 may predict poor prognosis and is negatively associated with miR-191-5p expression in patients with COAD.

Toosendanin suppresses oncogenic phenotypes of human gastric carcinoma SGC­7901 cells partly via miR­200a­mediated downregulation of ß-catenin pathway.

Aberrant activation of ß-catenin signaling due to low expression of miR­200a is found in gastric carcinoma (GC) tissues promoting GC evolution. Toosendanin (TSN) has exhibited antitumor effects on various human cancer cells, but its influence on GC is largely unidentified. The potential roles of TSN on GC cells were examined and it was found that TSN inhibited growth, migration, invasion and TGF­ß1-induced epithelial-mesenchymal transition (EMT) and induced cell cycle arrest and apoptosis in SGC­7901 cells which were most sensitive to TSN among various GC cell lines. TSN also inactivated ß-catenin pathway in SGC­7901 cells and the above effects were reversed following induction of ß-catenin overexpression. Moreover, TSN facilitated the level of miR­200a which targets ß-catenin and miR­200a silencing attenuated the antitumor effects of TSN on SGC­7901 cells. Nonetheless, knockdown of miR­200a did not relieve the suppressive effects of TSN on p­AKT, p­ERK and p­GSK3ß which were upstream regulators of ß-catenin. In addition, TSN administration inhibited growth and liver metastasis of orthotopically implanted SGC­7901 tumors in vivo through miR­200a­mediated ß-catenin pathway. Our data suggest that TSN may suppress oncogenic phenotypes of human GC cells partly via miR­200a/ß-catenin axis. Hence, TSN may have a promising chemotherapeutic activity for GC therapy.

[The mechanism of accumulative oxidative injury by hydrogen peroxide on human retinal pigment epithelial cells].

OBJECTIVE: To explore the effects of oxidative injury induced by hydrogen peroxide on human retinal pigment epithelial (RPE) cells. METHODS: Cultured human RPE cells were treated by 600 micromol/L hydrogen peroxide (H2O2) for 1, 6, 12, 24 and 72 hours. Cell viability was assessed by the MTT assay. Apoptosis was assessed by Annexin V-fluorescein isothiocyanate/Propidium iodium (Annexin V-FITC/PI) staining. The expression of clusterin was assessed by Western blot. RESULTS: (1) The treatment of RPE cells with 600 micromol/L H2O2 caused a time-dependent decrease of cellular viability. (2) Apoptosis was detected in cultured human RPE cells treated with 600 micromol/L H2O2 for 6 hours. The number of apoptotic cells reached a maximum at 24th hour after being exposed to 600 micromol/L H2O2 (P < 0.05). (3) Western blot showed the expression of clusterin protein was demonstrated in 6 hours exposure to 600 micromol/L H2O2, a significantly increasing of clusterin expression was observed overtime (P < 0.01). Thereafter the expression of clusterin protein decreased at 24th hour after being exposed to 600 micromol/L H2O2. At 72nd hour, the expression of clusterin protein was quite weak. CONCLUSION: Hydrogen peroxide can inhibits RPE proliferation and induces apoptosis and aging gene expression;the result suggest that accumulative oxidative injury induced by hydrogen peroxide in RPE in vitro may be similar to the aging changes in vivo.