Rational design of a near-infrared fluorescent probe for monitoring butyrylcholinesterase activity and its application in development of inhibitors

Butyrylcholinesterase (BChE) is widely expressed in multiple tissues and has a vital role in several key human disorders, such as Alzheimer's disease and tumorigenesis. However, the role of BChE in human disorders has not been investigated. Thus, to quantitatively detect and visualize dynamical variations in BChE activity is essential for exploring the biological roles of BChE in the progression of a number of human disorders. Herein, based on the substrate characteristics of BChE, we customized and synthesized three near-infrared (NIR) fluorescent probe substrates with cyanine-skeleton, and finally selected a NIR fluorescence probe substrate named CYBA. The CYBA demonstrated a significant increase in fluorescence when interacting with BChE, but mainly avoided AChE. Upon the addition of BChE, CYBA could be specifically hydrolyzed to TBO, resulting in a significant NIR fluorescence signal enhancement at 710 nm. Systematic evaluation revealed that CYBA exhibited exceptional chemical stability in complex biosamples and possessed remarkable selectivity and sensitivity towards BChE. Moreover, CYBA was successfully applied for real-time imaging of endogenous BChE activity in two types of nerve-related living cells. Additionally, CYBA demonstrated exceptional stability in the detection of complex biological samples in plasma recovery studies (97.51%-104.01%). Furthermore, CYBA was used to construct a high-throughput screening (HTS) method for BChE inhibitors using human plasma as the enzyme source. We evaluated inhibitory effects of a series of natural products and four flavonoids were identified as potent inhibitors of BChE. Collectively, CYBA can serve as a practical tool to track the changes of BChE activity in complicated biological environments due to its excellent capabilities.

[Advances on pathogenesis of acquired peritoneal ultrafiltration failure in peritoneal dialysis]

Peritoneal ultrafiltration failure is a common reason for peritoneal dialysis (PD) withdrawal as well as mortality in PD patients. Based on the three-pore system, inter-cellular small pores and trans-cellular ultra-small pores (aquaporin-1) are mainly responsible for water transfer across the peritoneum. Both small and ultra-small pores-dependent water (free water) transport decline accompanied with time on PD, with more significant decrease in free water, resulting in peritoneal ultrafiltration failure. The reduction of free water transport is associated with fast peritoneal solute transfer, reduced crystalloid osmotic gradient due to increased interstitial glucose absorption, and declined osmotic conductance to glucose resulted from impaired aquaporin-1 function and peritoneal interstitial fibrosis. The decline of small pore-based water is mainly because of fast loss of crystalloid osmotic gradient, decrease of hydrostatic pressure mediated by peritoneal vasculopathy, as well as reduced absolute number of small pores. The current review discusses the advance on pathogenesis of acquired peritoneal ultrafiltration failure in long-term PD.

Resveratrol inhibits MUC5AC expression by regulating SPDEF in lung cancer cells

BACKGROUND

MUC5AC was recently identified to play important roles in the proliferation and metastasis of malignant mucinous lung tumor cells. Resveratrol (Res), a natural compound with anticancer effects in lung cancer cells, has been reported to inhibit mucin production in airway epithelial cells. This study aimed to investigate the inhibitory effect of Res on MUC5AC expression in lung mucinous adenocarcinoma cells and the potential mechanisms.

METHODS

Mucus-producing A549 human lung carcinoma cells were used to test the effects of Res on SPDEF and MUC5AC expression. Gene and protein expression was assessed by real-time quantitative PCR (qPCR), immunofluorescence and western blotting assays. SPDEF lentivirus was used to upregulate SPDEF expression levels in mucus-producing A549 human lung carcinoma cells. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay.

RESULTS

Res decreased MUC5AC expression in an SPDEF-dependent manner in mucus-producing A549 human lung carcinoma cells, and this change was accompanied by decreased ERK expression and AKT pathway activation. Moreover, SPDEF was found to be overexpressed in lung adenocarcinoma (LUAD), especially in mucinous adenocarcinoma. In-vitro functional assays showed that overexpression of SPDEF reduced the chemosensitivity of A549 cells to cisplatin (DDP). In addition, Res treatment increased A549 cell chemosensitivity to DDP by inhibiting the SPDEF-MUC5AC axis.

CONCLUSION

Our results indicate that the SPDEF-MUC5AC axis is associated with DDP sensitivity, and that Res decreases SPDEF and MUC5AC expression by inhibiting ERK and AKT signaling in A549 cells, which provides a potential pharmacotherapy for the prevention and therapeutic management of mucinous adenocarcinoma.

[Efficacy comparison of primary percutaneous coronary intervention by drug-coated balloon angioplasty or drug-eluting stenting in acute myocardial infarction patients with de novo coronary lesions]

Objective: To compare the safety profile, angiographic and clinical outcomes between drug-coated balloon(DCB) only strategy versus drug eluting stent(DES) implantation in primary percutaneous coronary intervention(PCI) for acute myocardial infarction(AMI) patients. Methods: A total of 380 AMI patients who underwent primary PCI in Beijing Chaoyang Hospital from January 2016 to May 2019 were enrolled. They were allocated into DEB group(n=180) or DES group(n=200). The Primary endpoint was the major adverse cardiac events(MACE) in hospital and within 3 months after discharge, the composite event of cardiac death, non-fatal myocardial infarction(MI), target vessel revascularization(TVR) and in stent thrombosis. The secondary endpoints included: (1)TIMI blood flow grade and myocardial perfusion grade (TMP grade) of infarct-related vessels before and after PCI. (2)The degree of ST segment resolution(STR) between half hour and two hours after PCI, and STR was represented by percentage of summed ST-segment reduction between baseline and post-PCI. Using the most significant lead of ST segment elevation, calculating the rate of decline in the ST segment after treatment; or the most significant lead of the ST segment depression, to calculate the rate of recovery in the ST segment after treatment. STR<50% was defined as incomplete STR. (3)The occurrence of coronary artery dissection during operation. (4)The peak value of myocardial enzymes. (5)The incidence of bleeding in hospital and within 3 months after discharge. The inverse probability weighting method based on propensity score (IPTW) was used to compare the effects of the two treatments on MACE occurrence in the logistic regression model. Results: There was no significant difference in sex, age, risk factors of coronary heart disease, type and site of AMI, interventional therapy data(P>0.05) between the two groups. The ratio of bifurcation lesions in DCB group was significantly higher than that in DES group, and the diameter of the DCB was smaller while the length was longer than that of DES (all P<0.05). One death occurred in each group during hospitalization. Compared with the DES group, the incidence of MI ［2.8%(5/180) vs. 0.5% (1/200), P=0.10］ and TVR ［2.8%(5/180) vs. 0.5%(1/200), P=0.10］ in the DCB group during hospitalization showed an increasing trend, and were mostly associated with delayed coronary dissection. The incidence of MACE was similar between the two groups (3.3%(6/180) and 1.0%(2/200), P=0.15) during hospitalization. There was no MACE occurred in the two groups within 3 months after discharge. There was no significant difference between the two groups in TIMI grade, TMP grade, incomplete STR rate and peak value of myocardial enzyme (all P>0.05). The incidence of coronary artery dissection was significantly higher in DCB group than in DES group (8.3%(15/180) and 3.0%(6/200), P=0.02), but most of them were type B or A dissection and did not need special treatment. There was no significant difference in bleeding event between the two groups(P=0.91). Logistic regression analysis showed that there was no difference in the risk of MACE during hospitalization between DES and DCB groups for AMI patients receiving PCI (compared with DCB, OR=0.35, 95%CI 0.08-1.43, P=0.13). Conclusions: The initial safety and efficacy profiles of DCB are similar with those of DES for the AMI patients during PCI. The study highlights that the incidence of coronary dissection (type A or B) is higher post DCB treatment than post DES, but it does not affect blood flow. However, the incidence of in-hospital MI due to delayed coronary dissection trends to be higher post DCB. So we should pay close attention to the risk of delayed coronary dissection after DCB in AMI patients with de novo lesion.

The Zuo Jin Wan Formula increases chemosensitivity of human primary gastric cancer cells by AKT mediated mitochondrial translocation of cofilin-1

Resistance to cisplatin (DDP)-based chemotherapy is a major cause of treatment failure in human gastric cancer (GC). It is necessary to identify the drugs to re-sensitize GC cells to DDP. In our previous research, Zuo Jin Wan Formula (ZJW) has been proved could increase the mitochondrial apoptosis via cofilin-1 in a immortalized cell line, SGC-7901/DDP. Due to the immortalized cells may still difficult highly recapitulate the important molecular events in vivo, primary GC cells model derived from clinical patient was constructed in the present study to further evaluate the effect of ZJW and the underlying molecular mechanism. Immunofluorescent staining was used to indentify primary cultured human GC cells. Western blotting was carried out to detect the protein expression. Cell Counting Kit-8 (CCK-8) was used to evaluate cell proliferation. Flow cytometry analysis was performed to assess cell apoptosis. ZJW inhibited proliferation and induced apoptosis in primary DDP-resistant GC cells. Notably, the apoptosis in GC cells was mediated by inducing cofilin-1 mitochondrial translocation, down-regulating Bcl-2 and up-regulating Bax expression. Surprisingly, the level of p-AKT protein was higher in DDP-resistant GC cells than that of the DDP-sensitive GC cells, and the activation of AKT could attenuate ZJW-induced sensitivity to DDP. These data revealed that ZJW can increase the chemosensitivity in DDP-resistant primary GC cells by inducing mitochondrial apoptosis and AKT inactivation. The combining chemotherapy with ZJW may be an effective therapeutic strategy for GC chemoresistance patients.

Expression and biological function of rhotekin in gastric cancer through regulating p53 pathway

Background/aim

Gastric cancer (GC) is one of a most threatening cancer globally. Rhotekin (RTKN), a Rho effector, has been reported to be upregulated in GC tissues. This study aimed to investigate the underlying regulatory roles of RTKN in the biological behavior of GC.

Methods

Real-time PCR and Western blotting were carried out to detect the mRNA and protein expression, respectively. Cell Counting Kit-8 and xenograft nude mice model were used to evaluate cell proliferation. Flow cytometry analysis was performed to assess cell cycle distribution and cell apoptosis.

Results

RTKN had high expression level in GC compared with normal tissues. RTKN expression strongly associated with tumor size, TNM stage, lymphnode metastasis and the poor prognosis of patients with GC. Downregulation of RTKN significantly repressed GC cell proliferation, but increased cell population in G1/S phase and induced cell apoptosis. Moreover, the RTKN expression level was related to the p53 signaling pathway and histone deacetylase (HDAC) Class I pathway. RTKN knockdown caused a notable increment in the acetylation level of p53 (Lys382), and the expression of p53-target genes (p21, Bax, and PUMA), as well as a reduction in the expression of a potential deacetylase for p53, HDAC1. Notably, downregulation of HDAC1 had similar effects as RTKN knockdown, and RTKN overexpression could hardly abrogate the effects of HDAC1 knockdown on GC cells.

Conclusion

RTKN could work as an oncogene via regulating HDAC1/p53 and may become a promising treatment strategy for GC.

Nonvolatile Memory Based on Molecular Ferroelectric/Graphene Field Effect Transistor

Ferroelectric thin films are extensively attractive as next-generation nonvolatile memories. Recently, molecular ferroelectrics (MFe), as an emerging new class, have been a new research focus because of their desirable characteristics such as good solution processability, tunable chemical properties, and bio-friendly compositions. However, traditional uniaxial MFe only possess one polar axis which greatly limits their application, as it requires restricted orientational control in single crystal. To achieve macroscopic ferroelectricity and thus fully realize technological advantages of MFe, development of multiaxes is imperative to maximize effective polarization in specific crystallographic orientations. Herein, we present an early exploration on polycrystalline multiaxial MFe thin films of [Hdabco][ReO₄] with a two-dimensional graphene hybrid nonvolatile memory device. The polarization switching of MFe is experimentally realized by the nonvolatile modulation of two current states in graphene. Such a hybrid device can exhibit large memory window ∼35 V implying its great potential in memory applications. Hence, by taking the advantages of multiple polarization axes of MFe, the low cost and large area MFe/graphene hybrid memory manifests new possibilities for the integration of these materials as flexible next generation memory devices.

[Feasibility and safety of paclitaxel-eluting balloon for the treatment of de novo coronary lesions]

Objective: To evaluate the safety and feasibility of treating de novo coronary lesions with paclitaxel-eluting balloon. Methods: This is a retrospective study, which enrolled 76 patients with 80 de novo coronary lesions treated with paclitaxel-eluting balloons(<30% residual stenosis and there was no blood flow limited dissection after pretreatment) from April 2015 to November 2016 in Guangdong general hospital. The data of basic characteristics,procedures,devices and follow-up information were retrieved and analyzed. The primary endpoint was the composite of cardiac death, recurrent myocardial infarction and target lesion revascularization. Results: (1)The age was (63.3±10.3) years. There were 68.4%(52/76) acute coronary syndrome patients, prevalence of type 2 diabetes was 36.8%(28/76), and 64.5%(49/76)patients with at least one high bleeding risk. (2)The lesion length was (17.4±7.6)mm, and the stenosis was (88.1±8.2)%.The reference vessel diameter≥2.75 mm accounted for 51.2% (41/80), and bifurcation stenosis accounted for 67.5%(54/80). (3)53.7%(43/80) lesions were pretreated with scoring balloon to optimize plaque modification. The paclitaxel-eluting balloon length and diameter were (22.3±5.5)mm and (2.74±0.52)mm.The residual stenosis was (12.3±10.3)%. Procedural success was 88.8%(71/80).Bail-out stenting rate was 5.0%(4/80). (4)The median follow-up duration was 12(6, 25) months. Primary endpoint occurred in 3 cases (3.9%), including 2 cardiac deaths(1 patient died of recurrent myocardial infarction, and 1 patient died of acute heart failure induced by severe mitral insufficiency), and one patient receivedtarget lesion revascularization. Conclusion: In case of no more than 30% residual stenosis and no blood flow limited dissection after lesion pretreatment,it is safe and feasible to treat de novo coronary lesionsusing paclitaxel-eluting balloon.

Advance of antioxidants in asthma treatment

Asthma is an allergic disease, characterized as a recurrent airflow limitation, airway hyperreactivity, and chronic inflammation, involving a variety of cells and cytokines. Reactive oxygen species have been proven to play an important role in asthma. The pathogenesis of oxidative stress in asthma involves an imbalance between oxidant and antioxidant systems that is caused by environment pollutants or endogenous reactive oxygen species from inflammation cells. There is growing evidence that antioxidant treatments that include vitamins and food supplements have been shown to ameliorate this oxidative stress while improving the symptoms and decreasing the severity of asthma. In this review, we summarize recent studies that are related to the mechanisms and biomarkers of oxidative stress, antioxidant treatments in asthma.

[Diatoms Distribution in Ningbo Three-river Watershed during Summer]

OBJECTIVES

To explore the species, quantity and distribution of diatoms in Ningbo three-river watershed during summer and to provide scientific basis for forensic examination of drowning cases in the waters of Ningbo.

METHODS

Water samples were collected in July and August of 2015. Fourteen water sampling points were selected from the Yao River, the Fenghua River and the Yong River. The morphological features of diatom species and dominant diatoms were distinguished by microscope.

RESULTS

A total of 16 species of diatoms were detected in the Yao River, the Fenghua River and the Yong River. Melosira was the dominant species in the Yao River, and the quantity and richness were higher than in other rivers. The richness of Cyclotella in the Yong River was higher than in other rivers. The richness of Pinnularia and Licmophora were higher in the Fenghua River than in the Yao River and the Yong River.

CONCLUSIONS

The species and proportion of diatom is different in each river. Database of the species and relative composition for the diatoms in corresponding river is established, which may provide data support for forensic examination of drowning cases in Ningbo three-river watershed.

[The effect and safety of tirofiban on acute ST segment elevation myocardial infarction patients receiving no early reperfusion therapy]

OBJECTIVE

To study the efficacy and safety of tirofiban on acute ST segment elevation myocardial infarction (STEMI) in patients who do not receive early reperfusion therapy.

METHODS

A total of 153 STEMI patients without early reperfusion therapy were randomly distributed into tirofiban group (therapeutic group, n=78) and non-tirofiban group (control group, n=75). Coronary angiography was performed on the 5(th) and 10(th) day after treatment, and percutaneous coronary intervention (PCI) was conducted when necessary. The differences of initial patency of the infarct related artery (IRA), bleeding complication and clinic events within 30 days between these two groups were compared.

RESULTS

Tirofiban did not increase the percentage of patients with initial patency of IRA (60.3% vs 64.0%, P=0.63). The percentage of patients with thrombolysis in myocardial infarction (TIMI) 3 after PCI was 100.0% in tirofiban group and 97.1% in the control group (P=0.09). However, application of tirofiban significantly decreased poor myocardial perfusion rate after PCI (1.4% vs 8.8%, P=0.04). No significant differences were observed in major adverse cardiovascular events (MACE) (3.8% vs 2.7%, P=0.68) between therapeutic and control group. The same is true for mild (5/78 vs 4/75 cases, P=0.78) and severe hemorrhage (2/78 vs 1/75 cases, P=0.58), and severe thrombocytopenia (2/78 vs 0/75 cases, P=0.10) between these two groups within 30 days.

CONCLUSIONS

Tirofiban did not increase initial patency in STEMI patients without early reperfusion therapy. However, it can improve myocardial perfusion after PCI.

Resveratrol inhibits mucus overproduction and MUC5AC expression in a murine model of asthma

Previous in vitro studies have demonstrated that resveratrol is able to significantly inhibit the upregulation of mucin 5AC (MUC5AC), a major component of mucus; thus indicating that resveratrol may have potential in regulating mucus overproduction. However, there have been few studies regarding the resveratrol‑mediated prevention of MUC5AC overproduction in vivo, and the mechanisms by which resveratrol regulates MUC5AC expression have yet to be elucidated. In the present study, an ovalbumin (OVA)‑challenged murine model of asthma was used to assess the effects of resveratrol treatment on mucus production in vivo. The results demonstrated that resveratrol significantly inhibited OVA‑induced airway inflammation and mucus production. In addition, the mRNA and protein expression levels of MUC5AC were increased in the OVA‑challenged mice, whereas treatment with resveratrol significantly inhibited this effect. The expression levels of murine calcium‑activated chloride channel (mCLCA)3, an important key mediator of MUC5AC production, were also reduced following resveratrol treatment. Furthermore, in vitro studies demonstrated that resveratrol significantly inhibited human (h)CLCA1 and MUC5AC expression in a dose‑dependent manner. These results indicated that resveratrol was effective in preventing mucus overproduction and MUC5AC expression in vivo, and its underlying mechanism may be associated with regulation of the mCLCA3/hCLCA1 signaling pathway.

Improving diet recipe and cooking methods attenuates hyperphosphatemia in patients undergoing peritoneal dialysis

BACKGROUND AND AIMS

Hyperphosphatemia is an independent predictor for cardiovascular and all-cause mortality in patients undergoing peritoneal dialysis (PD). The study aimed to investigate the effect of dietary intervention on reducing serum phosphate concentration in hyperphosphatemic PD patients.

METHODS AND RESULTS

In this single-center clinical trial, 97 prevalent PD patients with serum phosphate concentration ≥ 1.6 mmol/l were allocated to the intervention (n = 48) or control (n = 49) group and followed up for 1 year. In addition to phosphate binder (calcium carbonate) therapy, patients in the intervention group were intensively educated to reduce phosphate-rich food intake and improve cooking methods. While stable in the control group (1.97 ± 0.20 to 1.94 ± 0.35 mmol/l, p > 0.05), the serum phosphate concentration decreased significantly in the intervention group (1.98 ± 0.28 to 1.65 ± 0.33 mmol/l, p = 0.015) concurrently with the drop in dietary phosphate intake (13.03 ± 3.39 to 10.82 ± 3.00 mg/kg ideal body weight/day, p = 0.001). Moreover, after 6 months of intervention, fewer patients needed to use calcium carbonate (from 64.6% to 41.5%, p = 0.029) and the medicine dose reduced significantly (from 2.25 (0, 3.94) to 0 (0, 1.50) g/day, p < 0.001).

CONCLUSIONS

Our data indicated that intensive dietary intervention of reducing phosphate-rich food intake and improving cooking methods attenuated hyperphosphatemia in PD patients. It suggests that regular assessment of dietary phosphate intake and modification of diet recipe and cooking methods are essential for hyperphosphatemia treatment in PD patients in addition to phosphate binder therapy.

Prohibitin induces apoptosis in BGC823 gastric cancer cells through the mitochondrial pathway

Prohibitin (PHB), an evolutionarily-conserved protein, has been found to be over-expressed in gastric cancer and be closely related with tumor malignancy. In this study, to investigate the relationship between PHB expression and cell apoptosis in the BGC823 gastric cancer cell line, low and high expression PHB in BGC823 cells was accomplished using RNA interference technology and gene transfer techniques. Cell proliferation, cell cycling, apoptosis, Bax, Bcl-2 and Cyt.c protein expression and the activation of Caspase-3,9 were assessed after 48 h. Over-expression of PHB gene in BGC823 cells resulted in slow cell growth, cell arrest in G2 phase, and an increased apoptosis ratio while the opposite was found for PHB under-expressing cells. In PHB over-expressing cells, the expression of Bax gene was increased, the expression of Bcl-2 was decreased, the activation level of Caspase-3, 9 was increased, but the activation level of Caspase-8 demonstrated no change. These results indicate that PHB induced apoptosis through the mitochondrial pathway.

Multiple variants of TERT and CLPTM1L constitute risk factors for lung adenocarcinoma

Recent studies have shown that 5p15.33 is one of the chromosomal regions that is most consistently altered in lung cancer; common variants that are located in this region have been genotyped in various populations. However, the genetic contribution of these variants to carcinogenesis is relatively unknown. A clinic-based case-control study in Shanghai was undertaken on 196 patients with lung cancer and 229 healthy individuals. TERT rs2736100 and CLPTM1L rs401681 and rs402710 were genotyped using the ABI TaqMan Allelic Discrimination assay. For rs2736100, the G variant and the GG genotype were more frequent, whereas the TT genotype was less frequent in patients with lung adenocarcinoma than in controls. The CT genotype at rs401681 was more common and the TT genotype was rare in patients, and the differences were significant between lung adenocarcinoma patients and controls. This was also true for rs402710. Moreover, the frequency of the GGCTCT haplotype was higher and the TTTTTT frequency was lower in patients, especially those with lung adenocarcinoma. Aberrant linkage disequilibrium among the three SNPs was found in patients with lung adenocarcinoma. We conclude that multiple variants at 5p15.33 contribute to susceptibility to lung adenocarcinoma.

Abstract 1778: Anticancer activities and regulatory effects on apoptotic gene expression of Bufalin in the orthotopic transplantation model of human colorectal cancer in nude mice

Background: Bufalin, a natural small-molecule compound from the Traditional Chinese Medicine “Chansu”, shows inhibitory effects on many human cancer cells. However, whether or not Bufalin has anticancer activity in human colorectal cancer (CRC), and its possible underlying mechanism, remains unclear.

Objectives: 1) To investigate anticancer activities of Bufalin in human CRC using an orthotopic transplantation model in nude mice and 2) to study possible underlying mechanisms related to apoptosis.

Materials and methods: An orthotopic transplantation tumor model was established by implanting human CRC HCT-116 cells into the colon of nude mice. Sixty mice were randomly divided into five treatment groups (12 mice in each group): normal saline group, 5-FU group, and 3 Bufalin groups with low (BL), medium (BM), and high (BH) doses. After cell transplantation, 0.2 ml normal saline, 25 mg/kg 5-Fu, or 0.5 mg/kg, 1 mg/kg, 1.5 mg/kg Bufalin was injected intraperitoneally in mice in each corresponding group, daily for 7 days (days 15 to 21). Six mice in each group were sacrificed on day 24. Tumor size, growth inhibition rate, and morphological changes of tumor cell under microscopy were recorded. Apoptosis was determined by TUNEL staining, mRNA and protein expressions of Bcl-xl and Bax were evaluated with real-time RT-PCR and immunohistochemical staining, respectively. The overall survival (OS) was determined in the remaining 6 mice in each group.

Results: The tumor size in mice treated with 5-Fu, BL, BM, or BH was significantly smaller than that in mice treated with normal saline (p&lt;0.05), with the tumor inhibitor rates of 64.3%, 51.4%, 48.7%, and 36.3%, respectively. Under microscopy, increased tumor necrosis was observed in the 5-Fu, BM and BH groups. The tumor apoptotic rate in each of 3 Bufalin treated groups was significantly higher than that in the normal saline group (p&lt;0.05). Real time RT-PCR and immunohistochemical staining showed both mRNA and protein expressions of Bcl-xl were decreased, whereas the expression of Bax increased, in tumor treated with Bufalin. The OS was prolonged in groups of BL and BM (p&lt;0.05).

Conclusion: Bufalin has significant anticancer activity in a human CRC orthotopic transplantation model in nude mice, and induces tumor cell apoptosis, which may be associated with the down-regulation of Bcl-xl and up-regulation of Bax in tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1778. doi:10.1158/1538-7445.AM2011-1778

A new pathway of glucocorticoid action for asthma treatment through the regulation of PTEN expression

Background

"Phosphatase and tensin homolog deleted on chromosome 10" (PTEN) is mostly considered to be a cancer-related gene, and has been suggested to be a new pathway of pathogenesis of asthma. The purpose of this study was to investigate the effects of the glucocorticoid, dexamethasone, on PTEN regulation.

Methods

OVA-challenged mice were used as an asthma model to investigate the effect of dexamethasone on PTEN regulation. Immunohistochemistry was used to detect expression levels of PTEN protein in lung tissues. The human A549 cell line was used to explore the possible mechanism of action of dexamethasone on human PTEN regulation in vitro. A luciferase reporter construct under the control of PTEN promoter was used to confirm transcriptional regulation in response to dexamethasone.

Results

PTEN protein was found to be expressed at low levels in lung tissues in asthmatic mice; but the expression was restored after treatment with dexamethasone. In A549 cells, human PTEN was up-regulated by dexamethasone treatment. The promoter-reporter construct confirmed that dexamethasone could regulate human PTEN transcription. Treatment with the histone deacetylase inhibitor, TSA, could increase PTEN expression in A549 cells, while inhibition of histone acetylase (HAT) by anacardic acid attenuated dexamethasone-induced PTEN expression.

Conclusions

Based on the data a new mechanism is proposed where glucocorticoids treat asthma partly through up-regulation of PTEN expression. The in vitro studies also suggest that the PTEN pathway may be involved in human asthma.

On resonant scatterers as a factor limiting carrier mobility in graphene

We show that graphene deposited on a substrate has a non-negligible density of atomic scale defects. This is evidenced by a previously unnoticed D peak in the Raman spectra with intensity of ∼1% with respect to the G peak. We evaluated the effect of such impurities on electron transport by mimicking them with hydrogen adsorbates and measuring the induced changes in both mobility and Raman intensity. If the intervalley scatterers responsible for the D peak are monovalent, their concentration is sufficient to account for the limited mobilities currently achievable in graphene on a substrate.

Induction treatment of proliferative lupus nephritis with leflunomide combined with prednisone: a prospective multi-centre observational study

To evaluate the efficacy and safety of leflunomide in the treatment of proliferative lupus nephritis, a prospective multi-centre observational study was conducted. Patients with biopsy proven proliferative lupus nephritis were assigned to receive either leflunomide or cyclophosphamide with concomitant prednisone. Leflunomide was given orally with a loading dose of 1 mg/kg/day for 3 days followed by 30 mg/day. Intravenous cyclophosphamide was administered monthly at a dose of 0.5 g/m2 of body-surface area. A total of 110 patients were enrolled, 70 in the leflunomide group and 40 in the cyclophosphamide group. The complete remission rate in the leflunomide group was 21% and partial remission rate 52%, as compared with 18% and 55%, respectively, in the cyclophosphamide group. Renal parameters and systemic lupus erythematosus disease activity index improved significantly and similarly in both groups. Serum creatinine decreased or stabilized in both treatment groups. No significant difference was noted with respect to clinical outcome between groups. Repeat biopsy also showed a significant reduction of active lesions in kidney pathology after 6 months of leflunomide treatment. Major adverse events, similar in both treatment groups, included infection, alopecia and hypertension. Leflunomide, compared with cyclophosphamide, in combination with prednisone was effective in the induction therapy of proliferative lupus nephritis and was generally well-tolerated.

Graphene thickness determination using reflection and contrast spectroscopy

We have clearly discriminated the single-, bilayer-, and multiple-layer graphene (<10 layers) on Si substrate with a 285 nm SiO2 capping layer by using contrast spectra, which were generated from the reflection light of a white light source. Calculations based on Fresnel's law are in excellent agreement with the experimental results (deviation 2%). The contrast image shows the reliability and efficiency of this new technique. The contrast spectrum is a fast, nondestructive, easy to be carried out, and unambiguous way to identify the numbers of layers of graphene sheet. We provide two easy-to-use methods to determine the number of graphene layers based on contrast spectra: a graphic method and an analytical method. We also show that the refractive index of graphene is different from that of graphite. The results are compared with those obtained using Raman spectroscopy.

Strong green luminescence of Mg-doped ZnO nanowires

The ZnO nanowires doped with Mg (Mg-ZnONWs) were produced by thermally oxidizing Zn and Mg powders. TEM and XRD patterns indicated that Mg-ZnONWs were crystalline with a wurzite structure. The Mg doping was confirmed with XPS measurements. The green emission band at 500 nm in the photoluminescence spectrum of Mg-ZnONWs and peaks at 366 nm in low intensity were observable. Raman spectrum indicated that oxygen deficiency was not the dominant factor for the green emission. The green emission was further directly observed with a digital camera.

Raman spectroscopic investigation of carbon nanowalls

Two-dimensional carbon nanowalls (CNWs) were prepared by microwave plasma-enhanced chemical-vapor deposition and scanning electron microscopy was used to observe their morphologies. The Raman observations of different sample orientations and polarizations show that CNWs are well crystallized. Micro-Raman scattering measurements were also carried out with different excitation laser lines (325, 488, 514, 532, and 633 nm). The D band shows a very strong shift of 46.19 cm(-1)eV with excitation laser energy and this has been explained by the double resonance effect. The decreasing intensity ratios IDIG and ID'/IG with increasing laser excitation energy were detected and discussed.