Evodiamine inhibits the proliferation of human osteosarcoma cells by blocking PI3K/Akt signaling.

Osteosarcoma (OS) is the most common non-hematologic primary malignancy of bone, and multiple chemotherapeutic agents have been applied in the treatment of OS for over 40 years. Nevertheless, due to the poor prognosis of OS, it is essential to develop a novel treatment strategy. Evodiamine (EVO), a quinolone alkaloid extracted from the fruit of Evodia rutaecarpa, has been demonstrated to inhibit tumor cell proliferation. Thus, the main aim of the present study was to investigate the anti-proliferative and apoptosis-inducing effects of evodiamine (EVO) on human OS 143B cells, but also the possible mechanisms underlying these effects. The results of crystal violet staining, flow cytometry, western blot analysis and an in vivo experiment demonstrated that EVO exhibits significant inhibitory effects on cell proliferation, exhibits apoptosis-inducing effects and arrests the cell cycle in 143B cells. According to our findings of polymerase chain reaction (PCR), western blot analysis and recombinant adenoviral transfection, we confirmed that EVO upregulates both the protein and gene levels of phosphatase and tensin homolog (PTEN) in a concentration-dependent manner in 143B cells. Overexpression of PTEN reinforced the anti-proliferative effect of EVO in the 143B cells, while knockdown of PTEN upregulated PI3K/Akt signaling transduction and reversed the inhibitory effect of EVO on 143B cell proliferation. Further analysis indicated that EVO upregulated the expression of PTEN by inactivating PI3K/Akt signaling by decreasing phosphorylated Akt1/2. Based on the above results, we conclude that PTEN/PI3K/Akt signaling is involved in the inhibitory effect on human OS 143B cell proliferation by EVO.

Green tea polyphenol epigallocatechin-3-gallate ameliorates insulin resistance in non-alcoholic fatty liver disease mice.

AIM: Epigallocatechin-3-gallate (EGCG) is a major polyphenol in green tea. In this study, we investigated the effects of EGCG on insulin resistance and insulin clearance in non-alcoholic fatty liver disease (NAFLD) mice. METHODS: Mice were fed on a high-fat diet for 24 weeks. During the last 4 weeks, the mice were injected with EGCG (10, 20 and 40 mg·kg(-1)·d(-1), ip). Glucose tolerance, insulin tolerance and insulin clearance were assessed. After the mice were euthanized, blood samples and tissue specimens were collected. Glucose-stimulated insulin secretion was examined in isolated pancreatic islets. The progression of NAFLD was evaluated histologically and by measuring lipid contents. Insulin-degrading enzyme (IDE) protein expression and enzyme activity were detected using Western blot and immunocapture activity assays, respectively. RESULTS: The high-fat diet significantly increased the body weight and induced grade 2 or 3 liver fatty degeneration (steatosis, lobular inflammation and ballooning) accompanied by severe hyperlipidemia, hyperglycemia, hyperinsulinemia and insulin resistance in the model mice. Administration of EGCG dose-dependently ameliorated the hepatic morphology and function, reduced the body weight, and alleviated hyperlipidemia, hyperglycemia, hyperinsulinemia and insulin resistance in NAFLD mice. Furthermore, EGCG dose-dependently enhanced insulin clearance and upregulated IDE protein expression and enzyme activity in the liver of NAFLD mice. CONCLUSION: EGCG dose-dependently improves insulin resistance in NAFLD mice not only by reducing body weight but also through enhancing the insulin clearance by hepatic IDE. The results suggest that IDE be a potential drug target for the treatment of NAFLD.

Oridonin inhibits the proliferation of human osteosarcoma cells by suppressing Wnt/ß-catenin signaling.

It has been reported that oridonin (ORI) can inhibit proliferation and induce apoptosis in various types of cancer cell lines. However, the exact mechanism for this function remains unclear. In this study, we investigated the proliferation inhibitory effect of ORI on human osteosarcoma (OS) 143B cells and dissected the possible molecular mechanism(s) underlying this effect. We demonstrated that ORI can inhibit proliferation, induce apoptosis and arrest the cell cycle in 143B cells. Using luciferase reporter assay, we found that the Wnt/ß-catenin signaling was inhibited in 143B cells by ORI. Accordingly, the total protein levels and nuclear translocation of ß-catenin were reduced by ORI treatment. ORI increased glycogen synthase kinase 3ß (GSK3ß) activity and upregulated Dickkopf-1 (Dkk-1) expression. We found that Dkk-1 overexpression or ß-catenin knockdown can potentiate the proliferation inhibitory effect of ORI in 143B cells, while ß-catenin overexpression attenuated this effect. Using the xenograft tumor model of human OS, we demonstrated that ORI effectively inhibited the growth of tumors. Histological examination showed that ORI inhibited cancer cell proliferation, decreased the expression of PNCA and ß-catenin. Our findings suggest that ORI can inhibit 143B OS cell proliferation by downregulating Wnt/ß-catenin signal transduction, which may be mediated by upregulating the Dkk-1 expression and/or enhancing the function of GSK3ß. Therefore, ORI can be potentially used as an effective adjuvant agent for the clinical management of OS.

The PTEN/PI3K/Akt and Wnt/ß-catenin signaling pathways are involved in the inhibitory effect of resveratrol on human colon cancer cell proliferation.

Colon cancer is one of the most common malignancies and the treatments for colon cancer have been developed substantially in the last decades, but there is still a great clinical need to explore new treatment regimens due to the undesirable prognosis. In this investigation, we demonstrated the anti-proliferative and apoptosis-inducing activities of resveratrol (Res) in human colon cancer cells, and the possible mechanisms underlying these effects. We used crystal violet staining, flow cytometry and western blotting to validate the anti-proliferative and apoptosis-inducing effects of Res on HCT116 cells. A xenograft tumor model was used to confirm the anti-proliferative effects of Res. We employed polymerase chain reaction, western blotting, recombinant adenovirus and luciferase reporter assay to explore the possible mechanism(s) of action. We found that Res inhibits significantly the proliferation and promotes apoptosis in HCT116 cells, as well as inhibits the xenograft tumor growth of colon cancer. Res upregulates the expression of phosphatase and tensin homolog (PTEN) and decreases the phosphorylation of Akt1/2. The exogenous expression of PTEN inhibits the PI3K/Akt signal and promotes the anti-proliferative effects of Res in HCT116 cells, while knockdown of PTEN increases PI3K/Akt signal but reduces the anti-proliferative function of Res. The protein and mRNA expression of ß-catenin are all decreased by Res concentration-dependently. Thus, our findings strongly suggest that the anti-proliferative effects of Res in human colon cancer cells may be mediated by regulating separately the PTEN/PI3K/Akt and Wnt/ß-catenin signaling.

Experimental validations of in vivo human musculoskeletal tissue conductivity images using MR-based electrical impedance tomography.

Magnetic resonance (MR)-based electrical impedance tomography (MREIT) is a widely used imaging technique that provides high-resolution conductivity images at DC or below the 1 kHz frequency range. Using an MR scanner, this technique injects imaging currents into the human body and measures induced internal magnetic flux density data. By applying the recent progress of MREIT techniques, such as chemical shift artifact correction, multi-echo pulse sequence, and improved reconstruction algorithm, we can successfully reconstruct conductivity images of the human body. Meanwhile, numerous studies reported that the electrical conductivity of human tissues could be inferred from in vitro or ex vivo measurements of different species. However, in vivo tissues may differ from in vitro and/or ex vivo state due to the complicated tissue responses in living organs. In this study, we performed in vivo MREIT imaging of a human lower extremity and compared the resulting conductivity images with ex vivo biological tissue phantom images. The human conductivity images showed unique contrast between two different types of bones, muscles, subcutaneous adipose tissues, and conductive body fluids. Except for muscles and adipose tissues, the human conductivity images showed a similar pattern when compared with phantom results due to the anisotropic characteristic of muscle and the high conductive fluids in the adipose tissue.

Numerical simulations of MREIT conductivity imaging for brain tumor detection.

Magnetic resonance electrical impedance tomography (MREIT) is a new modality capable of imaging the electrical properties of human body using MRI phase information in conjunction with external current injection. Recent in vivo animal and human MREIT studies have revealed unique conductivity contrasts related to different physiological and pathological conditions of tissues or organs. When performing in vivo brain imaging, small imaging currents must be injected so as not to stimulate peripheral nerves in the skin, while delivery of imaging currents to the brain is relatively small due to the skull's low conductivity. As a result, injected imaging currents may induce small phase signals and the overall low phase SNR in brain tissues. In this study, we present numerical simulation results of the use of head MREIT for brain tumor detection. We used a realistic three-dimensional head model to compute signal levels produced as a consequence of a predicted doubling of conductivity occurring within simulated tumorous brain tissues. We determined the feasibility of measuring these changes in a time acceptable to human subjects by adding realistic noise levels measured from a candidate 3 T system. We also reconstructed conductivity contrast images, showing that such conductivity differences can be both detected and imaged.

[Clinical survey and analysis of persistent submacular fluid on optical coherence tomography after surgery for rhegmatogenous retinal detachment].

OBJECTIVE: To investigate the incidence, duration and consequences of persistent submacular fluid after pars plana vitrectomy (PPV) and scleral buckling surgery (SB) in rhegmatogenous retinal detachment, thus to explore the clinical association between persistent SMF and different surgical methods, and simultaneously, to study the effect of persistent submacular fluid on visual outcome. METHODS: It was a retrospective case-series study. Ninety-two qualified eyes including 54 eyes of males and 38 eyes of females with rhegmatogenous retinal detachment which had been performed PPV or SB were recruited. The average age of the patients was (45.8 ± 15.3) years with a age-range from 15 to 76 years. The inclusion criteria was as follows, the macula-off rhegmatogenous retinal detachments without macular hole and obvious proliferative vitreoretinopathy, the retina was completely reattached 1 month after operation and no redetachment was found by ophthalmoscope and B scan till the last follow-up, the minimal follow-up time was 1 year and the submacular fluid must have been dissolved for at least 6 months. All patients underwent thorough ophthalmologic examinations before and after operation, Those patients in whom a persistent submacular fluid was seen on optical coherence tomography (OCT) at 1 month after operation performed follow-up with repeat of the investigations at 3, 6 and 12 months after surgery, If the abnormality resolved, further observations were continued to undertake for 6 months or more till the last follow-up.Rank-sum test, χ²-test and Fisher exact test were applied respectively to analyze for statistical analysis. RESULTS: The incidence of persistent submacular fluid at 1 month after surgery in the PPV and SB group was 13.9% (5/36) and 48.2% (27/56).Six months later however, the figure expressed as percentage was 2.8% (1/36) and 23.2% (18/28) correspondingly. Persistent submacular fluid was more frequent in eyes with inferior breaks (64.3%) than that with superior ones (13.9%), making a significant differences (χ² = 17.38, P < 0.01) . The persistent submacular fluid group showed worse best-corrected visual acuity than no persistent submacular fluid group 6 and 12 months after surgery (t = 2.525, t = 2.254, both P < 0.05). Comparing the visual acuity (VA) between the eyes with or without persistent submacular fluid 6, 12 months after surgery and the latest followed-up among the ever suffered eyes, a statistically significant differences presented in late stages(average VA: 0.47 ± 0.29, 0.30 ± 0.16; 0.44 ± 0.28, 0.27 ± 0.15;0.42 ± 0.22, 0.27 ± 0.19; t = 2.114, 2.207, 2.068; all P < 0.05), though there were no significant differences in the first three months (average VA: 0.70 ± 0.33, 0.63 ± 0.37; 0.50 ± 0.25,0.45 ± 0.22; t = 0.556, 0.601; both P > 0.05). CONCLUSIONS: Persistent submacular fluid presents in both surgical procedures but it is more frequent after buckling surgery than vitrectomy, the selection of patients, the location of retinal breaks and the duration of detachment may be the potential influencing factors. Persistent submacular fluid after retinal detachment surgery is responsible for delayed recovery, and may affect the final visual outcome. The longer it lasts, the more harm may it do.

[Posterior vitreous detachment induced by intravitreal injection of the combination of chondroitinase ABC and matrix metalloproteinase-3].

OBJECTIVE: To investigate the occurrence of enzymatic induction of posterior vitreous detachment (PVD) by the combination of Chondroitinase ABC (CA) and matrix metalloproteinase-3 (MMP-3), so as to seek a noninvasive and effective pharmacologic approach to facilitate and eventually replace the present mechanical vitreous surgery. METHODS: Twenty-four pigmented rabbits were randomly assigned to two groups of twelve each, the experimental group was treated with CA (0.2 U) and MMP-3 (10 ng) combination, the control group was received equivalent dose of balanced salt solution (BSS). Clinical examinations and electroretinography were performed before and after injection. Over a different period of time, the rabbits were euthanized and killed and their eyes were examined histologically. RESULTS: The foci of partial synchisis and clinically named PVD were recognized for the first time three days after injection. Complete liquefaction was found in every eye of experimental group, and in which, 5/8 eyes developed clinically detected PVD one week after injection Histologic section showed PVD with various extent in 3/7, 7/7, 7/7 eyes of experimental group 30 minutes, 60 minutes and one week after injection respectively, and complete PVD in 0/7, 1/7, 5/7 eyes of experimental group at the same periodic intervals as above. By contrast, no vitreous liquefaction was found and only one eye showed confined partial PVD in the control group. Clinic, electrophysiologic and histologic evaluation in all rabbits revealed no evidence of ocular toxicity. CONCLUSIONS: Vitreous 1iquefaction and PVD can be produced shortly after intravitreal injection using a combination of CA and MMP-3, and the two enzymes were cooperative. Synchisis and weakening of vitreoretinal adherence were almost simultaneously. The dose of 0.2 U CA and 10 ng MMP-3 combination proved to be safe and ideal selection to induce PVD.

[Study of retinal damage in rabbit eyes induced by air infusion during vitrectomy].

OBJECTIVE: To investigate the histologic and physiologic changes in rabbit retina damaged by infusion air and to explore the mechanism of vision defects after vitreoretinal surgery. METHODS: Twenty four pigmented rabbits were randomly divided into three groups of eight each, a standard three port vitrectomy followed by fluid-air exchange was performed in 16 eyes, humidified air was infused with an air pressure of 25 or 40 mm Hg and then the vitreous cavity was refilled with balanced salt solution. As a control, vitrectomy without fluid-air exchange was performed in the remaining eight eyes. Clinical examinations and electroretinography were performed before and after the operation. Six weeks after the operation, the rabbits were sacrificed, their eyes were enucleated and examined by light and electron microscopy. RESULTS: One day postoperatively, the value of bA ratio of group A and group B decreased significantly. Six weeks later, the physiologic function of eyes in group A seemed to have a tendency to recover while that of group B not. With light microscopy, the retina opposite the infusion location in eyes of group B was disorganized, with loss of some layers of sensory retina, and the thickness of total retina and the outer layer of the retina was sharply reduced, the changes in the latter appeared more prominently. With electron microscopy, marked lesions were observed in the nerve fiber layer and photoreceptor cells in eyes of group B, the pathologic changes in group A were slighter than that of group B. In contrast, no morphologic change was present in the control eyes. CONCLUSION: Irreversible changes were produced in rabbit retina by air infusion during vitrectomy. The damages are more serious in the eyes perfused with higher air pressure. Air infusion during vitrectomy may be one of the main factors producing vision defects.