Resveratrol augments ER stress and the cytotoxic effects of glycolytic inhibition in neuroblastoma by downregulating Akt in a mechanism independent of SIRT1

Cancer cells typically display increased rates of aerobic glycolysis that are correlated with tumor aggressiveness and a poor prognosis. Targeting the glycolytic pathway has emerged as an attractive therapeutic route mainly because it should spare normal cells. Here, we evaluate the effects of combining the inhibition of glycolysis with application of the polyphenolic compound resveratrol (RSV) in neuroblastoma (NB) cancer cell lines. Inhibiting glycolysis with 2-deoxy-D-glucose (2-DG) significantly reduced NB cell viability and was associated with increased endoplasmic reticulum (ER) stress and Akt activity. Administration of 2-DG increased the expression of the ER molecular chaperones GRP78 and GRP94, the prodeath protein C/EBP homology protein (CHOP) and the phosphorylation of Akt at S473, T450 and T308. Combined treatment with both RSV and 2-DG reduced GRP78, GRP94 and Akt phosphorylation but increased CHOP and NB cell death when compared with the administration of 2-DG alone. The selective inhibition of Akt activity also decreased 2-DG-induced GRP78 and GRP94 expression and increased CHOP expression, suggesting that Akt can modulate ER stress. Protein phosphatase 1α (PP1α) was activated by RSV, as indicated by a reduction in PP1α phosphorylation at T320. Pretreatment of cells with tautomycin, a selective PP1α inhibitor, prevented the RSV-mediated decrease in Akt phosphorylation, suggesting that RSV enhances 2-DG-induced cell death by activating PP1 and downregulating Akt. The RSV-mediated inhibition of Akt in the presence of 2-DG was not prevented by the selective inhibition of SIRT1, a known target of RSV, indicating that the effects of RSV on this pathway are independent of SIRT1. We propose that RSV inhibits Akt activity by increasing PP1α activity, thereby potentiating 2-DG-induced ER stress and NB cell death.

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Post Traumatic Lymphangioma in a Young Adult Male

The authors report the case of a 34-year-old male, who underwent a fluorine-18 fluoro deoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) scan 7 years after trauma for the evaluation of multifocal masses in the right iliac and right inguinal areas. CT findings showed multifocal low density masses and ¹⁸F-FDG PET revealed slightly increased uptake (maximum standardized uptake value [SUVmax] 3.1). These findings did not exclude the possibility of a benign or malignant lesion. To achieve differential diagnosis, partial surgical excision was performed and a pathologic examination subsequently revealed lymphangioma. Here, the authors describe the ¹⁸F-FDG PET/CT findings of a rare case of lymphangioma resulting from trauma.

miR-181c inhibits glycolysis by targeting hexokinase 2 in cancer-associated fibroblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of miR-181c in glycolysis of cancer-associated fibroblasts (CAFs) and explore the mechanism.</p><p><b>METHODS</b>Human lung CAFs and normal fibroblasts (NFs), isolated from fresh human lung adenocarcinoma tissue specimens by primary culture of tissue explants, were transfected with a miR -181c mimics, a miR-181c inhibitor, a siRNA siRNA-HK2 or the vector HK2-vector via Lipofectamine(TM) 2000. Quantitative real-time PCR was used to analyze the changes in miR-125b expression in the transfected cells; hexokinase-2 (HK2) protein expression in the cells was detected using Western blotting, and the cellular glucose uptake was assessed with 2-NBDG. Lactate production in the cells was examined and expression of HK2 mRNA was detected with dual luciferase reporter gene assay.</p><p><b>RESULTS</b>No obvious difference was found in the cell morphology between CAFs and NFs. Compared with the NFs, the CAFs showed obviously increased glucose uptake, lactate production and HK2 protein expression with decreased expressions of the miR-181 family (P<0.05). Transfection with the miR-181 inhibito- rsignificantly increased glucose uptake, lactate production and HK2 protein expression in the NFs. In CAFs, transfection with the miR-181 mimics caused significantly lowered glucose uptake, lactate production and HK2 protein expression of. Knockdown of endogenous HK2 by siRNA abolished miR-181 mimics-mediated decrease of glucose uptake and lactate production in CAFs, while transfection with miR-181 mimics suppressed HK2 overexpression-induced enhancement of glucose uptake and lactate production in NFs.</p><p><b>CONCLUSION</b>Transfection with miR-181 mimics can suppress glycolysis in CAFs by inhibiting HK2 expression.</p>

2-deoxy-D-glucose modified supermagnetic iron oxide nanoparticles enhance the contrasting effect on MRI of human lung adenocarcinoma A549 tumor in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the role of 2-deoxy-D-glucose (2-DG) modified supermagnetic iron oxide nanoparticles (SPIO) (γ-Fe2O3@DMSA-DG NPs) in tumor detection as a magnetic resonance imaging (MRI) contrast agent.</p><p><b>METHODS</b>γ-Fe2O3@DMSA-DG NPs was prepared. The degree of A549 cells targeted absorption of γ-Fe2O3@DMSA-DG NPs was detected by Prussian blue staining, colorimetric assay, T2W and multi-echo sequence MRI. γ-Fe2O3@DMSA NPs was used as a control agent, and free D-glucose as a competitive inhibitor. Human lung adenocarcinoma A549 xenograft tumor was prepared in nude mice. Sterile aqueous suspension of γ-Fe2O3@DMSA NPs or γ-Fe2O3@DMSA-DG NPs was injected into the tail vein of nude mice. Before and 6, 12, 24, 48 h after injection, MRI imaging of the mice was performed. T2 signal intensity of the tumor, brain, liver and thigh skeletal muscles, and T2 values of the tumors were measured.</p><p><b>RESULTS</b>The average diameter of the particles was about 10 nm, and there were no significant differences between the diameters of γ-Fe2O3@DMSA NPs and γ- Fe2O3@DMSA-DG NPs. The IR spectra showed the C-N retractable vibration peak at γ-Fe2O3@DMSA-DG NPs surface, indicating that 2-DG was conjugated to the γ-Fe2O3@DMSA NPs. The Prussian blue staining, colorimetric assay, MRI T2 signal intensity and T2 values revealed that γ-Fe2O3@DMSA-DG NPs were significantly more absorbed by A549 cells at growth peak than γ-Fe2O3@DMSA NPs, and the absorption of γ-Fe2O3@DMSA-DG NP was inhibited by free D-glucose. The results of in vivo examination showed that before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA-DG NPs, the mean T2 signal intensities of the tumors were (326.00 ± 16.26)s, (276.40 ± 5.13)s, (268.40 ± 30.58)s, (240.40 ± 25.93)s, (262.20 ± 30.04)s, respectively, and the T2 values of the tumors were (735.80 ± 20.93) ms, (645.80 ± 69.58) ms, (615.00 ± 124.61) ms, (570.60 ± 67.78) ms, and (537.80 ± 105.29) ms, respectively. However, before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA NPs, the mean T2 signal intensities of the tumors were (335.60 ± 4.93)s, (290.80 ± 5.93)s, (273.40 ± 15.08)s, (327.40 ± 16.65)s, and (313.20 ± 20.45)s, respectively, and T2 values were (686.00 ± 21.44)ms, (617.80 ± 69.93)ms, (645.20 ± 85.89)ms, (669.40 ± 13.72)ms, and (608.80 ± 61.90)ms, respectively. The T2 signal intensity and T2 value of the tumors were not declined generally after injection. The liver T2 signal intensity was decreased after injection of both γ-Fe2O3@DMSA-DG NPs and γ-Fe2O3@DMSA NPs, and T2 signal intensity of the brain and muscle did not show significant changes.</p><p><b>CONCLUSIONS</b>γ-Fe2O3@DMSA-DG NPs has an ability to target glucose receptors overexpressed in tumors, and may serve as a MRI contrast agent for tumor detection.</p>

2-Deoxy-D-glucose combined with Taxol inhibits VEGF expression and induces apoptosis in orthotopically transplanted breast cancer in C3H mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the antineoplastic effects of 2-Deoxy-D-glucose (2-DG) combined with Taxol on orthotopically transplanted breast cancer in C3H mice and explore the mechanism.</p><p><b>METHODS</b>C3H mice bearing orthotopically transplanted breast cancer xenograft were randomly divided into 4 groups, namely the control group, 2-DG group, Taxol group, and 2-DG+Taxol group. The corresponding drugs were administered intraperitoneally every 3 days for 18 consecutive days, and the tumor volume was measured every 3 days to draw the tumor growth curve. The mice were then sacrificed to measure the tumor weight on day 19 and examine tumor cell apoptosis with TUNEL assay and VEGF expression using immunohistochemistry.</p><p><b>RESULTS</b>2-DG combined with Taxol obviously suppressed the tumor growth with a tumor inhibition rate of 66.06% as compared to the rate of 36.97% in Taxol group. The combined treatment also caused more obvious cell apoptosis and significantly reduced VEGF expression in the tumor cells as compared with the other groups.</p><p><b>CONCLUSION</b>2-DG can enhance the inhibitory effect of Taxol on orthotopically transplanted breast cancer xenograft in C3H mice probably by inducing tumor cell apoptosis and lowering VEGF expressions.</p>

Serial Positron Emission Tomography Findings and Neuropsychological Assessments in Limbic Encephalitis

OBJECTIVE: Limbic encephalitis (LE) is characterized by rapid development of impaired cognitive function, seizure and psychiatric symptoms. Brain 18fluoro labelled deoxyglucose (18FDG)-positron emission tomography (PET) typically showed glucose hypermetabolism in the temporomesial region in the acute stage. Although several studies about brain 18FDG-PET in LE have been reported, serial 18FDG-PET findings during the course of the disease are limited. The purpose of this study is to analyze serial 18FDG-PET findings in LE and to compare them with the results of neuropsychological test. METHODS: We studied prospectively two patients diagnosed as LE using clinical criteria. They underwent serial brain magnetic resonance imaging (MRI) and 18FDG-PET scans. They also received detailed neuropsychological tests. RESULTS: Initial 18FDG-PET presented glucose hypermetabolism in unilateral temporomesial region without obvious abnormalities in brain MRI. Follow-up 18FDG-PET images obtained three month later displayed hypometabolism in both temporomesial region. Correspondingly, neuropsychological studies revealed prominent visuospatial and verbal memory deficits. CONCLUSION: The initial 18FDG-PET was very sensitive in visualizing the disease process compared with MRI and suggesting more markedly functional impairment than structural damage in early stage of LE. This was well correlated with cognitive dysfunction measured by neuropsychological test such as anterograde episodic memory loss involving both verbal and non-verbal materials.

Glycosylation inhibitor 2-deoxy-D-glucose sensitizes oral cancer cells to TRAIL-induced apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of 2-deoxy-D-glucose (2-DG) in enhancing the sensitivity of oral cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis.</p><p><b>METHODS</b>The oral cancer cell line KB was incubated in the presence of different concentrations (0, 0.625, 1.25, 2.5, 5, and 10 mmol/L) of 2-DG with or without TRAIL (200 ng/ml). The cell viability was measured using MTT assay and cell apoptosis was detected using flow cytometry with propidium iodide (PI) staining. KB cells treated with 5 mmol/L 2-DG with or without TRAIL for 0, 6, 16, or 24 h were examined with Western blotting for protein expressions of death receptor 5 (DR5) and caspase-3.</p><p><b>RESULTS</b>Treatment of the cells with 5 mmol/L 2-DG for 24, 48 and 72 h resulted in a cell viability of 25.25%, 69.06%, and 59.19%, respectively. Combined treatment with 5 mmol/L 2-DG with TRAIL for 24 significantly enhanced the cell apoptotic rate (72.5%) as compared to the rate induced by TRAIL alone (45.3%) and by 2-DG (15.9%) alone. 2-DG treatment markedly up-regulated DR5 and caspase-3 expression and enhanced the inhibitory effect of TRAIL on cell colony formation.</p><p><b>CONCLUSION</b>2-DG sensitizes oral cancer cells to TRAIL- induced apoptosis by up-regulating DR5 and caspase-3 expressions.</p>

2-DG enhances TRAIL-induced apoptosis of leukemia HL-60 cells / 中国实验血液学杂志

This study was purposed to investigate the effects of 2-deoxy-D-glucose (2-DG) on sensitizing HL-60 cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis and its possible mechanism. The proliferative inhibition of HL-60 cells treated with different concentrations of 2-DG and TRAIL was measured by MTT assay. The cells were treated with 2-DG, TRAIL, and 2-DG combined with TRAIL at the concentration < IC50 value, i.e. 10 mmol/L for 2-DG and 100 ng/ml for TRAIL. Apoptosis was analyzed by flow cytometry with PI staining; the expression of RIP1, GRP78, and PARP was analyzed by Western blot; the activity of caspase-3 was detected by special detection kit. The results showed that the combined treatment of HL-60 cells for 48 h induced an apoptotic rate of (45.1 ± 4.3)%, which was significantly higher than that of treated with 2-DG or TRAIL alone; at the same time, the combined treatment potentiated the expression of GRP78 and caspase-3 activity, and down-regulated the expression of RIP1. It is concluded that 2-DG can sensitize HL-60 cells to TRAIL-induced apoptosis, which may be correlated with excessive endoplasmic reticulum stress response, down-regulation of RIP1, and increase of caspase-3 activity.

Comparison of the targeting properties of 2-deoxy-D-glucose-conjugated nanoparticles to breast cancer MDA-MB-231 cells and breast fibroblasts cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To compare the differences in uptake of 2-deoxy-D-glucose (2-DG)-conjugated nanoparticles between breast carcinoma MDA-MB-231 cells with high metabolism and breast fibroblasts with normal metabolism, and investigate the feasibility of using the coated nanoparticles as a MRI-targeted contrast agent for highly metabolic carcinoma cells.</p><p><b>METHODS</b>The γ-Fe2O3@DMSA-DG was prepared. The glucose metabolism level of both cell lines was determined. The targeting efficacy of γ-Fe2O3@DMSA-DG and γ-Fe2O3@DMSA NPs to breast carcinoma MDA-MB-231 cells and breast fibroblasts at 10 min, 30 min, 1 h and 2 h was measured with Prussian blue staining and UV colorimetric assay. MRI was performed to visualize the changes of T2WI signal intensity.</p><p><b>RESULTS</b>Prussian blue staining showed more intracellular blue granules in the MDA-MB-231 cells of γ-Fe2O3@DMSA-DG NPs group than that in the γ-Fe2O3@DMSA NPs group, and the γ-Fe2O3@DMSA-DG uptake was greatly competed by free D-glucose. As revealed by UV colorimetric assay, MDA-MB-231 cells also showed that the cellular iron amount of γ-Fe2O3@DMSA-DG group was significantly higher than that of the γ-Fe2O3@DMSA group and γ-Fe2O3@DMSA-DG + D-glucose group, statistically with a significant difference between them. MRI showed that the signal intensity of γ-Fe2O3@DMSA-DG group was decrease significantly, the T2 signal intensity was decreased by 10.5%, 37.5%, 72.9%, 92.0% for 10 min, 30 min, 1 h and 2 h, respectively. In contrast, the signal intensity did not show obvious decrease in the γ-Fe2O3@DMSA-DG group, the T2 signal intensity was decreased by 8.5%, 11.4%, 32.0%, 76.7% for 10 min, 30 min, 1 h and 2 h, respectively. However, HUM-CELL-0056 cells did not produce apparent difference for positive staining in the γ-Fe2O3@DMSA-DG group, γ-Fe2O3@DMSA group and γ-Fe2O3@DMSA-DG+D-glucose group, and the signal intensity also did not produce apparent difference.</p><p><b>CONCLUSIONS</b>γ-Fe2O3@DMSA-DG has good targeting ability to highly metabolic breast carcinoma (MDA-MB-231) cells. It is feasible to serve as a specific MRI-targeted contrast agent for highly metabolic carcinoma cells, and deserves further studies in vivo.</p>

Random Synchronous Malignancy in Male Breast: A Case Report / 한국유방암학회지

We report here a case of a random synchronous male breast malignancy in a patient with a known base of tongue malignancy that was incidentally detected on a whole body 18-fluorine deoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT). Patient was referred to us for PET/CT staging and radiotherapy planning for a poorly differentiated squamous cell carcinoma of base of tongue. Histopathologically, the incidentally detected breast lesion was proven to be an invasive ductal carcinoma. 18F-FDG PET/CT being a whole body imaging modality is known to detect a considerable number of synchronous primaries. Synchronous malignancies in the head and neck area and the upper aerodigestive tract are well established. However, synchronous malignancy in male breast is reportedly uncommon. Our case is unique for the fact that a random synchronous dual malignancy of base of tongue and breast in a male patient was detected during a whole body 18F-FDG PET/CT imaging.

Enhanced Radiosensitivity and Chemosensitivity of Breast Cancer Cells by 2-Deoxy-D-Glucose in Combination Therapy / 한국유방암학회지

Breast cancer is the most common malignancy, and it is also the major cause of cancer-related deaths of women worldwide. Breast cancer treatment involves surgery, chemotherapy, radiation therapy, or combination therapy, and novel strategies are needed to boost the oncologic outcome. The non-metabolizable glucose analogue, 2-deoxy-D-glucose (2-DG) which inhibits glucose synthesis and adenosine triphosphate production, is one of the important discoveries involving the disturbances that can be caused to the process of the metabolism. The glucose analogue, 2-DG, is known as a tumor sensitizer to irradiation (IR) and chemotherapy, which help improve the treatment rates. It enhances the cytotoxicity via oxidative stress, which is more redundant in tumor cells than in normal ones. This article provides a brief summary on studies related to 2-DG chemo-/radio-sensitization effects by combination therapy of 2-DG/IR or 2-DG/doxorubicin.

Review of the Potential Glycemic Markers Glycated Albumin and 1,5-anhydroglucitol / 임상당뇨병

The measure of HbA1c is the gold standard index of glycemic control in clinical practice for diabetes treatment and is well known as a risk marker for diabetes complications. However, HbA1C does not accurately reflect glucose fluctuations or the actual status of glycemic control for several days or weeks. HbA1c measurement can be confounded in the anemia, hemoglobinopathy, or renal impairment. In comparison, glycated albumin (GA), a ketoamine formed by binding of albumin and glucose, more accurately reflects short-term changes in plasma glucose and postprandial plasma hyperglycemia (PPH). GA is not affected by hemoglobin or dialysis. 1,5-Anhydroglucitol (1,5-AG), another glycemic marker, structurally resembles glucose and decreases with spikes of hyperglycemia exceeding the average renal threshold for glucose. Especially, 1,5-AG level is reflective of PPH or glycemic variability and becomes an increasingly important contributor in a moderately controlled glycemic state, even when HbA1c level is within the target range. Herein, the usefulness of and recent studies on GA and 1,5-AG are summarized. Further investigations about the associations between these glycemic markers and diabetes complications are needed.

The Roles of Glycated Albumin as Intermediate Glycation Index and Pathogenic Protein

The conventional glycemic indices used in management of diabetic patients includes A1c, fructosamine, 1,5-anhydroglucitol, and glycated albumin (GA). Among these indices, A1c is currently used as the gold standard. However, A1c cannot reflect the glycemic change over a relatively short period of time, and its accuracy is known to decrease when abnormalities in hemoglobin metabolism, such as anemia, coexist. When considering these weaknesses, there have been needs for finding a novel glycemic index for diagnosing and managing diabetes, as well as for predicting diabetic complications properly. Recently, several studies have suggested the potential of GA as an intermediate-term glycation index in covering the short-term effect of treatment. Furthermore, its role as a pathogenic protein affecting the worsening of diabetes and occurrence of diabetic complications is receiving attention as well. Therefore, in this article, we wanted to review the recent status of GA as a glycemic index and as a pathogenic protein.

Correlation between 1,5-anhydroglucitol and glycemic excursions in type 2 diabetic patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The accurate and comprehensive assessment of glycemic control in patients with diabetes is important for optimizing glycemic management and for formulating personalized diabetic treatment schemes. This study aimed to analyze the correlation between 1,5-anhydroglucitol (1,5-AG) and glycemic excursions in type 2 diabetic patients.</p><p><b>METHODS</b>Seventy-one outpatients with type 2 diabetes mellitus were randomly recruited from Chinese People's Liberation Army General Hospital. Using a continuous glucose monitoring system (CGMS), these patients' blood glucose levels were monitored for three consecutive days to obtain mean blood glucose (MBG) data. Intraday glycemic excursions were evaluated using the mean amplitude of glycemic excursions (MAGE), the largest amplitude of glycemic excursions (LAGE), standard deviation of blood glucose (SDBG) and the M-value. Interday glycemic excursion was assessed by absolute mean of daily difference (MODD). Postprandial glycemic fluctuations were evaluated using postprandial glucose excursions (PPGE) and postprandial incremental area under the curve (iAUC). Fasting venous blood samples were collected to measure serum 1,5-AG, whole-blood hemoglobin A1c (HbA1c) and serum glycated albumin (GA). Clinical markers of glycemia and parameters of glycemic excursions from CGMS were analyzed using the Pearson correlation coefficient and multivariate stepwise regression.</p><p><b>RESULTS</b>Pearson correlation analysis revealed that 1,5-AG was significantly correlated with MAGE, SDBG, M-value, LAGE, PPGE and iAUC (r values were -0.509, -0.430, -0.530, -0.462, -0.416 and -0.435, respectively, P < 0.01), especially in moderately and well-controlled patients, based on defined HbA1c levels. Multivariate stepwise regression analysis revealed a negative correlation between 1,5-AG and the above parameters, but not HbA1c and GA. Finally, HbA1c and GA were positively correlated with MBG and fasting blood glucose (FBG).</p><p><b>CONCLUSIONS</b>1,5-AG was much better than HbA1c and GA as a marker of glycemic excursions in type 2 diabetic patients. Based on these results 1,5-AG is the best metric for assessing postprandial glucose levels in moderately and well-controlled patients, while HbA1c and GA were superior to 1,5-AG for monitoring MBG and FBG.</p>

Adventitial Fibroblast Abormality in Thoracic Aortic Aneurysms and Aortic Dissections

BACKGROUND: Development of thoracic aortic aneurysms and aortic dissections (TAAD) is attributed to unbearable wall tension superimposed on defective aortic wall integrity and impaired aortic repair mechanisms. Central to this repair mechanisms are well-balanced and adequately functional cellular components of the aortic wall, including endothelial cells, smooth muscle cells (SMCs), inflammatory cells, and adventitial fibroblasts. Adventitial fibroblasts naturally produce aortic extracellular matrix (ECM), and, when aortic wall is injured, they can be transformed into SMCs, which in turn are involved in aortic remodeling. We postulated the hypothesis that adventitial fibroblasts in patients with TAAD may have defects in ECM production and SMC transformation. MATERIALS AND METHODS: Adventitial fibroblasts were procured from the adventitial layer of fresh aortic tissues of patients with TAAD (Group I) and of multi-organ donors (Group II), and 4-passage cell culture was performed prior to the experiment. To assess ECM production, cells were treated with TNF-alpha (50 pM) and the expression of MMP-2 / MMP-3 was analyzed using western blot technique. To assess SMC transformation capacity, cells were treated with TGF-beta1 and expression of SM alpha-actin, SM-MHC, Ki-67 and SM calponin was evaluated using western blot technique. Fibroblasts were then treated with TGF-beta1 (10 pM) for up to 10 days with TGF-beta1 supplementation every 2 days, and the proportion of transformed SMC in the cell line was measured using immunofluorescence assay for fibroblast surface antigen every 2 days. RESULTS: MMP-3 expression was significantly lower in group I than in group II. TGF-beta1-stimulated adventitial fibroblasts in group I expressed less SM alpha-actin, SM-MHC, and Ki-67 than in group II. SM-calponin expression was not different between the two groups. Presence of fibroblast was observed on immunofluorescence assay after more than 6 days of TGF-beta1 treatment in group I, while most fibroblasts were transformed to SMC within 4 days in group II. CONCLUSION: ECM production and SMC transformation are compromised in adventitial fibroblasts from patients with TAAD. This result suggests that functional restoration of adventitial fibroblasts could well be a novel approach for the prevention and treatment of TAAD.

2-Deoxy-D-glucose regulates dedifferentiation through beta-catenin pathway in rabbit articular chondrocytes

2-deoxy-D-glucose (2DG) is known as a synthetic inhibitor of glucose. 2DG regulates various cellular responses including proliferation, apoptosis and differentiation by regulation of glucose metabolism in cancer cells. However, the effects of 2DG in normal cells, including chondrocytes, are not clear yet. We examined the effects of 2DG on dedifferentiation with a focus on the beta-catenin pathway in rabbit articular chondrocytes. The rabbit articular chondrocytes were treated with 5 mM 2DG for the indicated time periods or with various concentrations of 2DG for 24 h, and the expression of type II collagen, c-jun and beta-catenin was determined by Western blot, RT-PCR, immunofluorescence staining and immunohistochemical staining and reduction of sulfated proteoglycan synthesis detected by Alcain blue staining. Luciferase assay using a TCF (T cell factor)/LEF (lymphoid enhancer factor) reporter construct was used to demonstrate the transcriptional activity of beta-catenin. We found that 2DG treatment caused a decrease of type II collagen expression. 2DG induced dedifferentiation was dependent on activation of beta-catenin, as the 2DG stimulated accumulation of beta-catenin, which is characterized by translocation of beta-catenin into the nucleus determined by immunofluorescence staining and luciferase assay. Inhibition of beta-catenin degradation by inhibition of glycogen synthase kinase 3-beta with lithium chloride (LiCl) or inhibition of proteasome with z-Leu-Leu-Leu-CHO (MG132) accelerated the decrease of type II collagen expression in the chondrocytes. 2DG regulated the post-translational level of beta-catenin whereas the transcriptional level of beta-catenin was not altered. These results collectively showed that 2DG regulates dedifferentiation via beta-catenin pathway in rabbit articular chondrocytes.

Uptake of 2-NBDG by human breast cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The purpose of this study was to assess the feasibility of fluorescent 2-deoxyglucose analog, 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG), that could be taken up by breast cancer cells highly expressing glucose transporter 1 (GLUT-1). The purpose of this study was to clarify if a fluorescent 2-deoxyglucose analog, 2-[N-(7-nitrobenz-2-oxa-1, 3-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG), can be taken up by breast cancer cells highly expressing glucose transporter 1 (GLUT-1), and to assess whether it can be used as a targeting imaging agent.</p><p><b>METHODS</b>The expressions of GLUT-1 mRNA and protein in breast cancer MDA-MB-231 cells were detected by RT-PCR and immunohistochemistry, respectively. The difference of GLUT-1 protein expression between breast cancer MDA-MB-231 cells and MCF-7 cells was compared by Western blot. Secondly, MDA-MB-231 cells which were grown in 6-well plates were incubated with 2-NBDG, and the result of 2-NBDG uptake was analyzed by fluorescence microscopy and flow cytometry. The difference of 2-NBDG absorption in MDA-MB-231 and MCF-7 cells was compared by flow cytometry.</p><p><b>RESULTS</b>The results of RT-PCR and immunohistochemistry confirmed that MDA-MB-231 cells highly expressed GLUT-1. Furthermore, Western blot revealed that GLUT-1 expression of MDA-MB-231 cells (0.946 ± 0.007) was higher than that in the MCF-7 cells (0.833 ± 0.010). Fluorescence microscopic and flow cytometric analysis showed that 2-NBDG was uptaken rapidly by MDA-MB-231 cells. Addition of 50 mmol/L D-glucose to the media with 2-NBDG reduced its uptake by 46.0%. Moreover, flow cytometry indicated that the fluorescence intensity of MDA-MB-231 cells (25.10 ± 0.57) was higher than that of MCF-7 cells (10.12 ± 0.62) when incubated with 2-NBDG for 20 minutes.</p><p><b>CONCLUSION</b>The preliminary data clearly demonstrate that 2-NBDG is taken up and accumulated in breast cancer cells that highly express GLUT-1, and may be used as an optical probe for glucose uptake in hypermetabolic malignant cells.</p>

Effect of Chaihu Shugan Tang on excitability in different brain regions of pentylenetetrazole-kindled chronic epileptic rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of the Chinese compound prescription Chaihu Shugan Tang (CHSGT) on the excitability in the cerebral cortex and hippocampus (different brain regions) of pentetrazole (PTZ)-kindled chronic epileptic rats.</p><p><b>METHOD</b>To establish the model of chronic kindling rats intraperitoneal injected with pentylenetet. Fully kindled rats were randomized into control and experimental groups for intragastric administration of normal saline (control, model), Sodium Valproate and CHSGT at the high, medium and low doses for 4 consecutive weeks. The content of 2-NBDG, the glutamate (Glu) and the aspartate (Asp) in different brain regions of rats were detected by fluorescence imaging techniques and HPLC assay respectively.</p><p><b>RESULT</b>CHSGT at the high, medium and low doses all significantly decreased the content of 2-NBDG, the Glu and the Asp in different brain regions of chronic epileptic rats (P < 0.01).</p><p><b>CONCLUSION</b>CHSGT can inhibit the excitability in different brain regions of PTZ-induced epileptic rats, by decreasing the level of excitatory neurotransmitter maybe one of its antiepileptic mechanisms.</p>

Endoplasmic reticulum stress (ER-stress) by 2-deoxy-D-glucose (2DG) reduces cyclooxygenase-2 (COX-2) expression and N-glycosylation and induces a loss of COX-2 activity via a Src kinase-dependent pathway in rabbit articular chondrocytes

Endoplasmic reticulum (ER) stress regulates a wide range of cellular responses including apoptosis, proliferation, inflammation, and differentiation in mammalian cells. In this study, we observed the role of 2-deoxy-D-glucose (2DG) on inflammation of chondrocytes. 2DG is well known as an inducer of ER stress, via inhibition of glycolysis and glycosylation. Treatment of 2DG in chondrocytes considerably induced ER stress in a dose- and time-dependent manner, which was demonstrated by a reduction of glucose regulated protein of 94 kDa (grp94), an ER stress-inducible protein, as determined by a Western blot analysis. In addition, induction of ER stress by 2DG led to the expression of COX-2 protein with an apparent molecular mass of 66-70kDa as compared with the normally expressed 72-74 kDa protein. The suppression of ER stress with salubrinal (Salub), a selective inhibitor of eif2-alpha dephosphorylation, successfully prevented grp94 induction and efficiently recovered 2DG-modified COX-2 molecular mass and COX-2 activity might be associated with COX-2 N-glycosylation. Also, treatment of 2DG increased phosphorylation of Src in chondrocytes. The inhibition of the Src signaling pathway with PP2 (Src tyrosine kinase inhibitor) suppressed grp94 expression and restored COX-2 expression, N-glycosylation, and PGE2 production, as determined by a Western blot analysis and PGE2 assay. Taken together, our results indicate that the ER stress induced by 2DG results in a decrease of the transcription level, the molecular mass, and the activity of COX-2 in rabbit articular chondrocytes via a Src kinase-dependent pathway.

Relationship between expressions of serum amyloid A and insulin resistance in 3T3-L1 adipocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between the expression of serum amyloid A (SAA) and insulin resistance in 3T3-L1 adipocytes.</p><p><b>METHODS</b>3T3-L1 adipocytes were incubated with different concentrations of dexamethasone (10, 100, and 1000 nmol/L) for 48 h to establish cell models of insulin resistance at different resistant levels (models 1, 2, and 3, respectively). The degree of insulin resistance of 3T3-L1 adipocytes was assayed by 2-deoxy-[(3)H]-D-glucose uptake. Semi- quantitative RT-PCR was performed for quantification of SAA mRNA expression. SAA concentrations in the culture medium were determined by ELISA.</p><p><b>RESULT</b>Dexamethasone did not affect the basal glucose transport (P>0.05). Insulin-stimulated glucose uptake was significantly decreased by 15% (P<0.05), 40% (P<0.01), and 55% (P<0.01) in models 1, 2, and 3 in comparison with the untreated group, respectively; the expressions of SAA mRNA were upregulated by 2.5 (P<0.01), 3.33 (P<0.01), and 4.08 folds (P<0.01) and SAA concentrations increased by 2.05, 3.13, and 4.23 folds, respectively. The expressions of SAA mRNA were positively correlated to the degree of insulin resistance (r=0.773, P<0.01) and SAA concentration (r=0.832, P<0.01).</p><p><b>CONCLUSION</b>A cell model of insulin resistance has been established in 3T3-L1 adipocytes by dexamethasone exposure. SAA is closely associated with insulin resistance and may serve as a marker of insulin resistance.</p>