MicroRNA-34b inhibits pancreatic cancer metastasis through repressing Smad3

Pancreatic cancer is characterized by extremely poor prognosis because of early recurrence and metastasis, and increasing evidence supports the critical role of microRNA in cancer progression. Here we identified that microRNA-34b functioned as a tumor-suppressing microRNA by targeting oncogenic Smad3 in pancreatic cancer. As a hypovascular tumor with a potential endoplasmic reticulum stress microenvironment, miR-34b was silenced after ER stress inducer thapsigargin (Tg) treatment and negatively regulated by ER stress chaperone glucose regulated protein 78 (GRP78) in pancreatic cancer cells. In human specimens, we found that miR-34b was down-regulated in pancreatic cancer tissues and low level of miR-34b expression was positively correlated with tumor-node-metastasis (TNM) stage, lymph-node metastasis and overall survival. Functional assays showed that over-expression of miR-34b inhibited pancreatic cancer progression in vitro and in vivo. In addition, Smad3 was demonstrated as a direct target of miR-34b and negatively regulated by miR- 34b at mRNA and protein levels. Luciferase assays confirmed that miR-34b could directly bind to the 3'untranslated region of Smad3. An inverse correlation between miR-34b and Smad3 was observed in 64 pancreatic cancer tissues. Our findings indicate that miR-34b acts as a tumor metastasis suppressor through negatively modulating Smad3, which may provide a potential therapeutic strategy for pancreatic cancer.

Profilin 1 potentiates apoptosis induced by staurosporine in cancer cells

The correlation between the loss of Profilin 1 (Pfn1) with tumor progression indicated that Pfn1 is a tumor suppressor in human carcinoma. The molecular mechanisms underlying Pfn1 tumor suppression has yet to be elucidated. In this study, we showed that Pfn1 overexpression sensitizes cancer cells to apoptosis through the typical intrinsic apoptotic pathway. Mechanistically, the increased Pfn1 expression mediated the upregulation of p53R273H, one of the most common tumor-associated hotspot mutations of p53, with transactivation deletion in tumorigenesis and increased localization of p53R273H in cytoplasm. Further studies showed that mutant p53R273H was involved in apoptosis induced by Staurosporine (STS) via transcription-independent mitochondrial functions. We observed (i) the increased cytosolic localization of p53R273H, (ii) the activation of phosphorylation at Ser15, (iii) its mitochondrial localization; Pfn1 acted as a positive regulator of these processes. We also found that Pfn1 interacted with p53R273H and thus facilitated its exertion over the transcription-independent activity in the cytoplasm during drug action. Our results define a new function and mechanism of Pfn1 demonstrating that the combined effect with apoptotic agents led to a synergistic increase in apoptosis. In addition, p53R273H abrogating DNA binding was found to play a major role in the Pfn1- sensitized apoptosis through a transactivation-independent and cytosolic activity.

Up-regulation of MBD1 promotes pancreatic cancer cell epithelial-mesenchymal transition and invasion by epigenetic down-regulation of E-cadherin

Methyl-CpG binding domain protein 1 (MBD1) has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell-cycle progression and development. It is also predicted that MBD1 might be involved in tumor development and progression. However, whether and how MBD1 is involved in tumorigenesis, especially in pancreatic cancer (PC), is currently unknown. We found that MBD1 was significantly up-regulated in PC tissues compared with the surrounding normal tissues according to RT-PCR data. Tissue microarray (TMA) based immunohistochemical study from 58 surgically resected PC specimens indicated that higher MBD1 expression correlated with lymph node metastasis and poor survival in PC patients. Gain- and loss-of-function studies in vitro validated MBD1 as a potent oncogene promoting PC cell invasion as well as epithelial-mesenchymal transition (EMT). Mechanistically, MBD1 is associated with Twist and NAD-dependent deacetylase sirtuin-1 (SIRT1), thereby forming the Twist-MBD1-SIRT1 complex on the CDH1 promoter, which resulted in reduced E-cadherin transcription activity and increased cell EMT ability. Significantly, targeting MBD1 reversed the EMT phenotype of PC and restored sensitivity to chemotherapy. Taken together, the results of our study revealed a novel function of MBD1 in PC invasion and metastasis by providing a molecular mechanism underlying MBD1-promoted EMT. Thus MBD1 may serve as a potential therapeutic target for PC.

Comparative fasting bioavailability and pharmacokinetic properties of 2 formulations of glucosamine hydrochloride in healthy Chinese adult male volunteers

Glucosamine (CAS 66-84-2) hydrochloride is an amino monosaccharide indicated for the treatment of arthrosis, especially osteoarthritis of the knee joint. This study was conducted to assess and compare the pharmacokinetic (PK) properties, bioavailability of a newly developed dispersible tablet formulation (test) of glucosamine hydrochloride with those of an established branded capsule formulation (reference) in healthy Chinese adult male volunteers.This single-dose, randomized, open-label, 2-period crossover study was conducted in 18 healthy Chinese adult male volunteers under fasting condition. Plasma samples were collected at pre-specified times over a 12-h period following administration in each period and analyzed the plasma glucosamine concentrations by Liquid Chromatography coupled with Tandem Mass Spectrometry (LC/MS/MS) method. The mean (SD) PK parameters of Cmax, Tmax, AUC0-12, and AUC0-∞ after administration of the test and reference formulations were, respectively, as follows: Cmax, 907.01 (444.22) vs. 944.40 (429.89) ng/mL, Tmax, 3.03 (0.95) vs. 3.30 (0.99) hours, AUC0-12, 2891.41 (1352.30) vs. 2889.69 (925.48) ng/mL/h, and AUC0-∞, 3029.90 (1321.36) vs. 3091.87 (870.36) ng/mL/h. The mean (SD) t1/2 was 1.10 (0.52) hours for the test formulation and 1.50 (1.17) hours for the reference formulation. On ANOVA, neither period nor sequence effects were observed for any PK properties. The relative bioavailability of the test formulation was 98.3% assessed by AUC0-12. The 90% CIs of glucosamine for the log-transformed ratios of Cmax, AUC0-12, and AUC0-∞ were 78.4-113.9%, 80.8-108.5% and 80.8-105.8%, respectively, meeting the predetermined criteria for bioequivalence of SFDA.

SU-E-J-205: Modeling Fiducial Marker Movement in Prostate

PURPOSE

To understand fiducial marker movement in prostate and to improve prostate patient positioning with fiducial markers.

METHODS

Patient planning CT and positioning CBCT were retrospectively analyzed. CBCT images were automatically registered to the corresponding CT ones based on their bony structures in Eclipse. The coordinates of the markers in the CT and CBCT were recorded. The status of bladder and rectum fillings, and gas in rectum were indexed into four levels and recorded. An algorithm was developed to optimally register the (three) fiducial markers in CBCT with those in the CT so that only the information on prostate deformation and marker migration remained. A mathematical model was built to estimate the marker migration and the relative contribution to the deformation from the status change of bladder and rectum.

RESULTS

The registration error from our optimal registration algorithm indicates the minimal patient setup error by using fiducial markers. The results from our analyzed 3 patients were average(standard deviation) = 1.10(0.40), 1.27(0.67) and 0.62(0.38) mm, but there were some fractions when the registration errors were over 2 mm. From our mathematical model, it was found that the marker migration could be as large as 2.9 mm. If 2 mm tolerance is required in such as SBRT, then soft tissue based registration may be more appreciated when the optimal registration error is greater than 2 mm or from the date when the migration is greater than 2 mm because the migrated marker may not change the location thereafter. In addition, for one investigated patient, the relative contribution to the deformation from the bladder, rectum filling and gas in the rectum is 0.43:0.31:0.26. More patient data are in analysis, and other interesting results will be reported.

CONCLUSIONS

Fiducial marker migration can be over 2 mm. The migration will Result in a conclusion that small registration error does not mean good patient positioning.

Physiological responses of Egeriadensa to high ammonium concentration and nitrogen deficiency

High ammonia (i.e. the total of NH(3) and NH(4)(+)) concentration or nitrogen deficiency in water can exert stress on growth and health of many aquatic plants. To investigate the physiological impacts of high ammonia-N (NH(4)Cl) concentration and nitrogen deficiency on plant physiology, apical shoots of submerged macrophyte Egeriadensa were first treated with five levels of nitrogen: 0, 1, 10, 30, 60 mg L(-1) ammonia-N (NH(4)Cl) for 5d. After having explored the stress range of ammonia-N, its effect on E. densa was further examined at three levels of ammonium (0, 1, 30 mg L(-1) ammonia-N) and at six exposure times (0, 1, 2, 3, 5 and 7d). In testing the concentration-dependent stress, the increase of ammonia-N reduced the amounts of total chlorophyll (chl a and b), soluble proteins and soluble carbohydrates, but increased the activity levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase and peroxidase in E. densa. In the N-free medium, total chlorophyll, soluble proteins, soluble carbohydrates and the activities of SOD and peroxidase in E. densa decreased significantly compared with the control (1 mg L(-1) ammonia-N). When comparing the ammonia-N impacts over time, the plants showed a declining trend in total chlorophyll, soluble proteins and soluble carbohydrates, but an rising trend in MDA, SOD, peroxidase and catalase in 30 mg L(-1) ammonia-N over 7d. Compared with the control, the N-free medium significantly decreased the amounts of total chlorophyll, soluble proteins, soluble carbohydrates, SOD and peroxidase in E. densa over time. Our study indicates that high ammonium (ammonia-N ≥ 10 mg L(-1)) affects the growth of E. densa through inducing oxidative stress and inhibiting photosynthesis, and nitrogen deficiency can also induce an abiotic stress condition for the E. densa growth by reducing photosynthetic pigments, soluble proteins, soluble carbohydrates, and the activity of antioxidant enzymes.

Changes in cortical bone response to high-fat diet from adolescence to adulthood in mice

Diabetic obesity is associated with increased fracture risk in adults and adolescents. We find in both adolescent and adult mice dramatically inferior mechanical properties and structural quality of cortical bone, in agreement with the human fracture data, although some aspects of the response to obesity appear to differ by age.

INTRODUCTION

The association of obesity with bone is complex and varies with age. Diabetic obese adolescents and adult humans have increased fracture risk. Prior studies have shown reduced mechanical properties as a result of high-fat diet (HFD) but do not fully address size-independent mechanical properties or structural quality, which are important to understand material behavior.

METHODS

Cortical bone from femurs and tibiae from two age groups of C57BL/6 mice fed either HFD or low-fat diet (LFD) were evaluated for structural and bone turnover changes (SEM and histomorphometry) and tested for bending strength, bending stiffness, and fracture toughness. Leptin, IGF-I, and non-enzymatic glycation measurements were also collected.

RESULTS

In both young and adult mice fed on HFD, femoral strength, stiffness, and toughness are all dramatically lower than controls. Inferior lamellar and osteocyte alignment also point to reduced structural quality in both age groups. Bone size was largely unaffected by HFD, although there was a shift from increasing bone size in obese adolescents to decreasing in adults. IGF-I levels were lower in young obese mice only.

CONCLUSIONS

While the response to obesity of murine cortical bone mass, bone formation, and hormonal changes appear to differ by age, the bone mechanical properties for young and adult groups are similar. In agreement with human fracture trends, adult mice may be similarly susceptible to bone fracture to the young group, although cortical bone in the two age groups responds to diabetic obesity differently.

Encoding a superantigen by Staphylococcus aureus does not affect clinical characteristics of infected atopic dermatitis lesions

BACKGROUND

Bacterial infection with Staphylococcus aureus is a known trigger for the worsening of atopic dermatitis (AD). Staphylococcal superantigens have been theorized to make a potential contribution to this worsening of AD seen with infection.

OBJECTIVES

We sought to assess whether encoding a superantigen by S. aureus affects the inflammatory characteristics of impetiginized AD skin lesions.

METHODS

Fifty-two children with clinically impetiginized lesions of AD which were positive for S. aureus were enrolled in this study. A lesion was graded clinically using the Eczema Area and Severity Index (EASI), and then wash fluid was obtained from the lesion for quantitative bacterial culture, and measurement of bacterial products lipoteichoic acid and staphylococcal protein A and cytokines. The staphylococcal isolate was tested for antibiotic susceptibilities and the presence of a superantigen.

RESULTS

Fifty-four per cent (28 of 52) of the staphylococcal isolates encoded a superantigen. The presence of a superantigen had no significant effect on EASI score, amounts of bacterial products or inflammatory cytokines in the AD lesion.

CONCLUSIONS

These studies suggest that the expression of a superantigen by S. aureus alone does not play an important role in the increased skin inflammation associated with staphylococcal infection in childhood AD.

Two HTS options for a 600 MHz insert of a 1.3 GHz LTS/HTS NMR magnet: YBCO and BSCCO

In 2008, the Phase 3 program to complete a 1.3 GHz (30.5 T) NMR magnet started at the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology. It comprises two sub-phases, 3A and 3B. In Phase 3A, a 600 MHz high temperature superconductor (HTS) insert magnet (H600) will be designed, constructed, and operated in the bore of a 500 MHz low temperature superconductor (LTS) background magnet. This will be followed by Phase 3B, in which the H600 will be combined with a 700 MHz LTS background magnet to complete a 1.3 GHz NMR LTS/HTS magnet. This paper presents and discusses design issues for two conductor options for H600: BiSCCO-2223 (Bi2223) and coated-YBCO or its variants, here designated as YBCO. For each conductor option, we focused on the following issues: 1) elastic and thermal properties; 2) critical current vs. field performance; 3) splice and index heat dissipations; 4) mechanical and thermal stresses; and 5) protection.