[Application of adaptive statistical iterative reconstruction V (ASIR-V) in contrast-enhanced abdominal scanning with low-dose for liver cirrhosis].

Objective: To investigate the application of adaptive statistical iterative reconstruction-V (ASIR-V) in contrast-enhanced abdominal CT scanning with low-dose for liver cirrhosis. Methods: From June 2017 to May 2018, a total of 112 liver cirrhosis patients who underwent contrast-enhanced abdominal CT scanning were collected prospectively as the study group. According to Child-Pugh grading of liver function, the study group was divided into A, B and C groups. Thirty examiners with normal liver function who underwent contrast-enhanced abdominal CT scanning no abdominal diseases were collected as the control group. The control group applied 0 pre-ASIR-V. The study group applied 30%, 40% and 50% pre-ASIR-V in plain scanning, arterial and portal vein phase, respectively. The control and study group both combined with 60% post-ASIR-V. The difference of qualitative parameters (contrast to noise ratio of the liver, pancreas, spleen, abdominal aorta and portal vein), image noise and radiation dose were compared by One-way ANOVA. Subjective score of images were compared by Kruskal-Wallis H test. Results: The volume computed tomography dose index (CTDI(vol)), dose length product (DLP) and the effective dose (ED) of study group were lower than the control group in the same phase (F=13.354-28.192, P<0.01). And the ED were decreased by 1.12 (23.9%), 1.54 (33.5%), 2.14 mSv (46.7%). The CNR values of liver and portal vein in Child C group was 0.34-0.42 and 0.43-0.49 lower than that of Child A and control group, respectively (q=2.851-4.658, P<0.05). Image noise had no difference in study and control group. There were no statistical differences between each group of subjective score in arterial and portal vein phase. The mean score of Child C in portal phase was lower than 3, which affected the diagnosis. And there were significant difference among the control, Child A and Child C group(Z=26.734-29.218, P<0.05). Conclusions: According to the classification of liver function, liver cirrhosis combined with ASIR-V can ensure the image quality while reduce the radiation dose. When liver function is Child-Pugh A or B, preset 50%ASIR-V is recommended; 40%ASIR-V is recommended for Child-Pugh C.

Traveling surface acoustic wave (TSAW) microfluidic fluorescence activated cell sorter (µFACS).

We report a microfluidic fluorescence activated cell-sorting (µFACS) device that employs traveling surface acoustic waves (TSAW) to sort cells at rates comparable to conventional jet-in-air FACS machines, with high purity and viability. The device combines inertial flow focusing and sheath flow to align and evenly space cells, improving the sorting accuracy and screening rate. We sort with an interdigital transducer (IDT) whose tapered geometry allows precise positioning of the TSAW for optimal cell sorting. We sort three different cell lines at several kHz, at cell velocities exceeding one meter per second, while maintaining both sorting purity and cell viability at around 90% simultaneously.

[Application of a multi-material artifact reduction algorithm in a wide-detector CT in the evaluation of the portal venous angiography of postoperative TIPS and embolization].

Objective: To assess the effect of monochromatic images and metal artifact reduction (MAR) on the image quality of spectral CT portal venous angiography in patients with operation of after the performing transjugular intrahepatic portosystemic stent shunt(TIPS) and embolization. Methods: From December 2017 to April 2018, the examination data of 28 patients with portal hypertension due to cirrhosis who underwent portal vein angiography 1 month after TIPS and embolization were prospectively collected. After spectral CT scanning in revolution CT, the monochromatic energy levels(60 keV, 120 keV), 60 keV + 120 keV, 120kV-like + 120 keV fused images combined with MAR algorithm were reconstructed. Quantitative parameters such as image artifact index (AI) and qualitative visual evaluation scores were recorded and compared. Results: The 120 keV monochromatic images showed the lowest AI value(30.8±8.5, 18.2±4.3) and highest metal artifacts reduction effect. The 60 keV monochromatic images showed the highest AI value (57.3±15.7, 32.1±7.9) and the lowest metal artifacts reduction effect. The AI value of 60 keV + 120 keV fused images was lower than that of 60 keV images(26.2%, 24.7%). The difference of AI value between each group was statistically significant(all P<0.05). The interobserver agreement in the subjective image scores was moderate with kappa value of 0.824. The overall image quality score of 60 keV + 120 keV fused image and the noise score of 120 kV-like+120 keV were higher than the remaining groups. The differences of the subjective scores among each group were statistically significant(all P<0.05). Conclusion: The spectral CT with MAR algorithm can effectively improve the image quality of portal vein angiography after the TIPS and embolization therapy and the 60 keV + 120 keV fused images can eliminate artifacts and ensure a clear display of blood vessels.

Characterization of titanium dioxide and zinc oxide nanoparticles in sunscreen powder by comparing different measurement methods.

Numerous consumer products, such as cosmetics, contain nanoparticles (NPs) of titanium dioxide (TiO2) or zinc oxide (ZnO); however, this raises questions concerning the safety of such additives. Most of these products do not indicate whether the product includes NPs. In this study, we characterized metal oxide NPs according to size, shape, and composition as well as their aggregation/agglomeration characteristics. In order to comprehend quickly the characterization of metal oxide NPs, we employed single particle inductively coupled plasma (SP-ICPMS) to help quantify the size of metal oxide NPs; then, we use transmission electron microscopy (TEM) to corroborate the results. The crystal size and structure was measured by X-ray diffraction (XRD), there are two crystal phase of TiO2 NPs in sunscreen powder showed in XRD. However, SP-ICPMS proved highly effective in determining the size of NPs, the results of which remarkably good agreement with the TEM measurements. Pre-treatment included a conventional copper grid (requiring sample dilution) to evaluate the size, shape and composition of primary particles or plastic embedding (without the need for sample dilution) to evaluate the aggregate/aggregation of native NOAAs. The proposed method is an effective and fast approach to the characterization of oxide NPs in cosmetic sunscreen powder. These findings outline an alternative approach to the analysis of NPs in powder-form matrix.

[Application of preset adaptive statistical iterative reconstruction-V in dual-enhanced abdominal CT].

Objective: To analyze the effect of preset adaptive statistical iterative reconstruction-V (ASIR-V) on image quality and radiation dose in dual-enhanced abdominal CT and to investigate the optimal ASIR-V in clinic use. Methods: From February 13 to April 30 in 2017, one hundred and eighty patients who received up abdominal CT scan in the First Affiliated Hospital of Zhengzhou University were collected prospectively. All patients underwent arterial phase (AP) and portal venous phase (PVP) enhanced abdominal CT(120 kVp, noise index 10) and were randomly divided into 6 groups according to random number table (A-F, 30 cases in each group). In group A-F, 0-50% preset ASIR-V (an interval of 10%) was applied, respectively. Qualitative parameters (subjective image quality, diagnosis confidence and radiation dose) and quantitative parameters[image noise, CT number and contrast to noise ratio (CNR)]were measured and compared among the groups by using one-way analysis of variance or Kruskal-Wallis H test. Results: The CT dose index volume (CTDIvol) decreased with the increasing of preset ASIR-V. The effective radiation dose (ED) was significant different among groups (F=27.598, P<0.05), and the ED of group B-F dropped by 10.8%, 21.7%, 31.2%, 44.9% and 61.9% respectively when compared with that in group A. Group E showed the optimal image quality (Z=18.675, 27.548, 19.761, all P<0.05) and diagnosis confidence(Z=21.387, 17.693, 22.459, all P<0.05) in plain scan, AP and PVP phases. There was no significant differences in image noise and CT value of liver, pancreas and muscle among groups (F=1.468, 0.337, 0.592, 0.284, all P>0.05). There were significant differences in CNRs in liver and portal vein in PVP phase among the groups (F=3.980, 4.681, both P<0.05). Conclusion: In abdominal CT, 40% preset ASIR-V can provides the best image quality and it can reduce radiation dose for 44.9%.

[Combined use of wide-detector and adaptive statistical iterative reconstruction-V technique in abdominal CT with low radiation dose].

Objective: To investigate the image quality and radiation dose with wide-detector(80 mm) and adaptive statistical iterative reconstruction-V (ASIR-V) technique at abdominal contrast enhanced CT scan. Methods: In the first phantom experiment part, the percentage of ASIR-V for half dose of combined wide detector with ASIR-V technique as compared with standard-detector (40 mm) technique was determined. The human experiment was performed based on the phantom study, 160 patients underwent contrast-enhanced abdominal CT scan were prospectively collected and divided into the control group (n=40) with image reconstruction using 40% ASIR (group A) and the study group (n=120) with random number table. According to pre-ASIR-V percentage, the study group was assigned into three groups[40 cases in each group, group B: 0 pre-ASIR-V scan with image reconstruction of 0-100% post-ASIR-V (interval 10%, subgroups B0-B10); group C: 20% pre-ASIR-V with 20%, 40% and 60% post-ASIR-V (subgroups C1-C3); group D: 40%pre-ASIR-V with 40% and 60% post-ASIR-V (subgroups D1-D2)]. Image noise, CT attenuation values and CNR of the liver, pancreas, aorta and portal vein were compared by using two sample t test and One-way ANOVA. Qualitative visual parameters (overall image quality as graded on a 5-point scale) was compared by Mann-Whitney U test and Kruskal-Wallis H test. Results: The phantom experiment showed that the percentage of pre-ASIR-V for half dose was 40%. With the 40% pre-ASIR-V, radiation dose in the study group was reduced by 35.5% as compared with the control group. Image noise in the subgroups of B2-B10, C2-C3 and D1-D2 were lower (t=-14.681--3.046, all P<0.05) while CNR in the subgroups of B4-B10, C2-3 and D1-D2 were higher(t=2.048-9.248, all P<0.05)than those in group A, except the CNR of liver in the arterial phase (AP) in C2, D1 and D2 and the CNR of pancreas in AP in D1 (t=0.574-1.327, all P>0.05). The subjective image quality scores increased gradually in the range of 0-60% post-ASIR-V and decreased with post-ASIR-V larger than 70%. The overall image quality of subgroup B3-B8, C2-C3 and D1-D2 were higher than that in group A (Z=-2.229--6.533, all P<0.05). Conclusion: Compared with stand-detector together with ASIR technique, wide-detector combined with 40% pre-ASIR-V technique with 60% post-ASIR-V image reconstruction can reduce radiation dose while maintain good overall image quality.

TGFß promotes mesenchymal phenotype of pancreatic cancer cells, in part, through epigenetic activation of VAV1.

The highly homeostasis-resistant nature of cancer cells leads to their escape from treatment and to liver metastasis, which in turn makes pancreatic ductal adenocarcinoma (PDAC) difficult to treat, especially the squamous/epithelial-to-mesenchymal transition (EMT)-like subtype. As the molecular mechanisms underlying tumour heterogeneity remain elusive, we investigated whether epigenetic regulation might explain inter-individual differences in the progression of specific subtypes. DNA methylation profiling performed on cancer tissues prior to chemo/radiotherapy identified one hypermethylated CpG site (CpG6882469) in the VAV1 gene body that was correlated with demethylation of two promoter CpGs (CpG6772370/CpG6772811) in both PDAC and peripheral blood. Transforming growth factor ß treatment induced gene-body hypermethylation, dissociation of DNMT1 from the promoter, and VAV1 expression via SMAD4 and mutant KrasG12D. Pharmacological inhibition of TGFß-VAV1 signalling decreased the squamous/EMT-like cancer cells, promoted nuclear VAV1 localization, and enhanced the efficacy of gemcitabine in prolonging the survival of KPfl/flC mice. Together, the three VAV1 CpGs serve as biomarkers for prognosis and early detection, and the TGFß-VAV1 axis represents a therapeutic target.

[Application of half-dose spectral CT based on the automatic spectral imaging mode selection and adaptive statistical iterative reconstruction in the CT examination of upper abdomen in obese patients.]

Objective: To investigate the value of combined use of half-dose spectral CT based on the automatic spectral imaging mode selection (GSI Assist) and adaptive statistical iterative reconstruction (ASIR) in the CT examination of upper abdomen in obese patients as compared with conventional CT. Methods: Eight-two obese patients (body mass index≥29 kg/m(2)) were prospectively selected from October to December 2016, and contrast-enhanced CT during arterial phase (AP) and portal venous phase (PVP) were carried out in those patients.The patients were randomly assigned to the study group and control group with random number table (41 cases in each group). In the study group, half-dose spectral CT based on GSI Assist was applied and monochromatic images (40 to 70 keV, 10 keV as increment) were reconstructed using 50% ASIR (group A). In the control group, the fixed tube potential of 120 kVp was done with images reconstruction using 30% ASIR (group B). Quantitative parameters of radiation dose, CT value, contrast to noise ratio (CNR) and image noise were compared between the two groups by using two sample t test, while qualitative visual parameters (overall image quality as graded on a 5-point scale) were compared with Mann-Whitney U test. Results: There was significant difference in effective radiation dose between the two groups[(5.2±0.8) vs (10.4±1.7) mSv, t=-17.822, P<0.001], and it was decreased for 50% in group A. During the arterial phase (AP) and portal venous phase (PVP), at the energy level of 40 keV and 50 keV, higher CT values, higher or similar CNRs, higher image noise and lower overall image quality scores were found in group A when compared with group B. At the energy level of 60 keV, group A had higher CT values, higher or similar CNRs, similar overall image quality scores with higher or similar image noise as compared with group B. At the energy level of 70 keV, the two groups had similar CT values, CNRs and image noise, and higher overall image quality scores were found in group A. Conclusions: In obese patients, combined use of half-dose spectral CT based on GSI Assist and ASIR can reduce effective radiation dose up to 50% when compared with conventional upper abdominal CT.Monochromatic images at 70 keV can maintain CNR and improve overall image quality.

Characterizing titanium dioxide and zinc oxide nanoparticles in sunscreen spray.

OBJECTIVE: Numerous commercial products contain titanium dioxide (TiO2 ) and zinc oxide (ZnO) nanoparticles (NPs); however, many of these are not labelled as containing NPs. This study sought to develop an effective means of characterizing TiO2 and ZnO NPs in sunscreen sprays, including the size, shape and composition of the particles as well as their aggregation/agglomeration characteristics. METHODS: Transmission electron microscopy (TEM) coupled with a window-type microchip K-kit/copper grid and X-ray diffraction (XRD) was used to characterize the oxide NPs. RESULTS: TME pre-treatment was performed using two approaches: using a conventional copper grid (requiring dilution) and using a K-kit (not requiring dilution). The use of K-kit in conjunction with XRD makes it possible to obtain direct measurements from samples that have not undergone pre-treatment, which could otherwise alter the nature of the samples, such as the degree of agglomeration. XRD was used to obtain information related to particle size and crystal structure. A strong correlation was observed between XRD and TEM measurements. CONCLUSION: The proposed measurement methods were shown to be highly effective in the characterization of oxide NPs in sunscreen sprays, providing consistent information related to NPs and their interactions in the formulations.

Involvement of two distinct signalling pathways in IGF-1-mediated central control of hypotensive effects in normotensive and hypertensive rats.

AIMS: Insulin-like growth factor-1 (IGF-1) is abundantly expressed in the nucleus tractus solitarii (NTS). In a previous study, we revealed that the induction of nitric oxide (NO) production in the NTS reduces blood pressure (BP). It is well known that both acute administration and chronic administration of IGF-I reduce BP. The aim of this study was to evaluate the short-term hypotensive effect of IGF-1 in the NTS and to delineate the underlying molecular mechanisms of IGF-1 in the NTS of normotensive WKY rats and spontaneously hypertensive rats (SHRs). METHOD: Microinjections of the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and the MAP kinase-ERK kinase (MEK) inhibitor PD98059 into the NTS in WKY rats and SHRs were used to study the involvement of IGF-1-induced depressor effects. RESULT: An IGF-1 (7.7 pmol) injection into the NTS resulted in a significant decrease in BP and HR in WKY rats and SHRs. Immunoblotting and immunohistochemical analysis showed that the microinjection of LY294002 (0.6 pmol) or PD98059 (3.0 pmol) into the NTS attenuated the IGF-1-induced depressor effects and Akt or ERK phosphorylation in WKY rats. An attenuation effect of LY294002, but not PD98059, was found in the SHRs. However, the mRNA and protein expression levels of the IGF-1R showed no significant differences in the NTS of the WKY rats and the SHRs. CONCLUSION: These results suggest that distinct Akt and ERK signalling pathways mediated the IGF-1 control of the central depressor effects in WKY rats and SHRs. ERK signalling defects may be associated with the development of hypertension.

MicroRNA-18a is elevated in prostate cancer and promotes tumorigenesis through suppressing STK4 in vitro and in vivo.

MicroRNAs (miRNAs) comprise a class of short, non-coding RNAs that regulate protein synthesis through posttranscriptional modifications. In this study, we found significant upregulation of miR-18a in prostate cancer specimens and prostate cancer cell lines compared with the normal controls. MiRNAs can be separated into two groups based on whether they regulate tumor suppressors or oncogenes. In our previous study, we found that miR-18a, which belongs to the miR17-92 cluster, is upregulated in prostate cancer; the objective of this study was to investigate the associated regulatory mechanisms. We found that miR-18a is upregulated in clinical tumor specimens and cancer cell lines. Our bioinformatics analysis showed that the serine/threonine-protein kinase 4 (STK4) 3' untranslated region contains a highly conserved binding site for the miR-18a seed region. Luciferase reporter assays were performed to indicate that STK4 is a direct target of miR-18a. Interestingly, miR-18a knockdown decreased cell growth in prostate cancer cells and significantly decreased prostate tumor growth in in vivo nude mice experiments through STK4-mediated dephosphorylation of AKT and thereby inducing apoptosis. Our results suggest that miR-18a acts as an oncomiR targeting STK4 in prostate cancer, and inhibition of miR-18a expression may offer therapeutically beneficial option for prostate cancer treatment.

Endoplasmic reticulum ribosome-binding protein 1 (RRBP1) overexpression is frequently found in lung cancer patients and alleviates intracellular stress-induced apoptosis through the enhancement of GRP78.

Lung cancer is the leading cause of cancer deaths and is the most occurring malignancy worldwide. Unraveling the molecular mechanisms involved in lung tumorigenesis will greatly improve therapy. During early tumorigenesis, rapid proliferating tumor cells require increased activity of endoplasmic reticulum (ER) for protein synthesis, folding and secretion, thereby are subjected to ER stress. Ribosome-binding protein 1 (RRBP1) was originally identified as a ribosome-binding protein located on the rough ER and associated with unfolding protein response (UPR). In this report, we investigated the role of RRBP1 in lung cancer. RRBP1 was highly expressed in lung cancer tissue, as compared with adjacent normal tissues as assessed by immunohistochemistry (IHC) using lung cancer tissue array (n=87). Knockdown of RRBP1 by short-hairpin RNAs caused ER stress and significantly reduced cell viability and tumorigenicity. This effect was associated with a significant reduction in the expression of glucose-regulated protein 78 (GRP78). UPR regulator GRP78, an anti-apoptotic protein that is widely upregulated in cancer, has a critical role in chemotherapy resistance in some cancers. According to our results, cells with a higher level of RRBP1 were more resistant to ER stress. Ectopic expression of RRBP1 alleviated apoptosis that was induced by the ER-stress agent tunicamycin, 2-deoxy-D-glucose (2DG) or doxorubicin via enhancing GRP78 protein expression. A strong correlation was observed between the expression of RRBP1 and GRP78 in tumor biopsies using the database GSE10072. Our results also indicated that RRBP1 may involve in the regulation of mRNA stability of UPR components including ATF6 and GRP78. Taken together, RRBP1 could alleviate ER stress and help cancer cell survive. RRBP1 is critical for tumor cell survival, which may make it a useful target in lung cancer treatment and a candidate for the development of new targeted therapeutics.

RUNX3-mediated transcriptional inhibition of Akt suppresses tumorigenesis of human gastric cancer cells.

Activation of Akt signaling pathway has been suggested involving in chemoresistance, metastasis and tumorigenesis of gastric cancer. However, the mechanism of Akt regulation in gastric cancer is not fully understood. RUNX3, which was first identified as a transcription factor, suppresses gastric tumorigenesis through regulating expression of target genes. Here, we found that restoration of RUNX3 significantly downregulates the protein and mRNA expression of Akt1 in gastric cancer cell lines, AGS and SNU-1. Knockdown of RUNX3 upregulates protein and mRNA expression of Akt1 in normal gastric epithelial cell line, GES-1. The negative correlation of RUNX3 and Akt expression and downstream ß-catenin/cyclin D1 effectors was further confirmed in AGS and GES-1 cell lines, as well as clinical specimens of gastric cancer. We identified two RUNX3-binding sites in Akt1 promoter and the binding of RUNX3 on Akt1 promoter significantly inhibits Akt1 expression. The RUNX3-mediated inhibition of Akt1 caused ß-catenin protein degradation and then cyclin D1 downregulation. Restoration of cyclin D1 reverses cell growth inhibition and G1 phase arrest induced by RUNX3 in gastric cancer cells. Our results show that loss of RUNX3 expression can enhance the Akt1-mediated signaling pathway and promote the tumorigenesis process in human gastric cancer.

TOPK/PBK promotes cell migration via modulation of the PI3K/PTEN/AKT pathway and is associated with poor prognosis in lung cancer.

We integrated four gene expression profile data sets, namely two different pair-matched stage I lung adenocarcinoma data sets, secondary metastatic tumors vs benign tumors and lung tumor metastasizes to the brain, and we identified one kinase, T-LAK Cell-Originated Protein Kinase (TOPK), as a putative gene that promotes metastasis. To delineate the role of TOPK in lung cancer, we showed that overexpression of TOPK, but not a catalytically inactive form of TOPK, can enhance the migration and invasion of lung fibroblasts or cells with low TOPK expression. In addition, TOPK-induced cell migration was shown to be a PI3K/AKT-dependent event. TOPK concurrently promoted AKT phosphorylation at Ser(473) and decreased the phosphatase and tensin homolog (PTEN) levels, whereas TOPK knockdown had the reverse effects. LY294002, a PI3K inhibitor, did not inhibit the TOPK-induced decrease in PTEN, and co-expression of PTEN significantly reduced TOPK-induced AKT phosphorylation in a dose-dependent manner; these results indicate that the TOPK-mediated PTEN decrease has an upstream role in regulating PI3K/AKT-stimulated migration. Using immunohistochemical analysis of lung cancer tissue samples, we showed that a high TOPK expression level correlates strongly with reduced overall and disease-free survivals. Moreover, an inverse correlation between TOPK and PTEN expression was present and is consistent with the biochemical findings. Finally, a combination of high TOPK and low PTEN expression was inversely correlated with overall and disease-free survivals, independent of other pathologic staging factors. Our results suggest that TOPK is a potential therapeutic target in lung cancer that promotes cell migration by modulating a PI3K/PTEN/AKT-dependent signaling pathway; they also suggest that high TOPK expression, either alone or in combination with a low level of PTEN, may serve as a prognostic marker for lung cancer.

WW domain-containing oxidoreductase promotes neuronal differentiation via negative regulation of glycogen synthase kinase 3ß.

WW domain-containing oxidoreductase (WWOX), a putative tumour suppressor, is suggested to be involved in the hyperphosphorylation of Alzheimer's Tau. Tau is a microtubule-associated protein that has an important role in microtubule assembly and stability. Glycogen synthase kinase 3ß (GSK3ß) has a vital role in Tau hyperphosphorylation at its microtubule-binding domains. Hyperphosphorylated Tau has a low affinity for microtubules, thus disrupting microtubule stability. Bioinformatics analysis indicated that WWOX contains two potential GSK3ß-binding FXXXLI/VXRLE motifs. Immunofluorescence, immunoprecipitation and molecular modelling showed that WWOX interacts physically with GSK3ß. We demonstrated biochemically that WWOX can bind directly to GSK3ß through its short-chain alcohol dehydrogenase/reductase domain. Moreover, the overexpression of WWOX inhibited GSK3ß-stimulated S396 and S404 phosphorylation within the microtubule domains of Tau, indicating that WWOX is involved in regulating GSK3ß activity in cells. WWOX repressed GSK3ß activity, restored the microtubule assembly activity of Tau and promoted neurite outgrowth in SH-SY5Y cells. Conversely, RNAi-mediated knockdown of WWOX in retinoic acid (RA)-differentiated SH-SY5Y cells inhibited neurite outgrowth. These results suggest that WWOX is likely to be involved in regulating GSK3ß activity, reducing the level of phosphorylated Tau, and subsequently promoting neurite outgrowth during neuron differentiation. In summary, our data reveal a novel mechanism by which WWOX promotes neuronal differentiation in response to RA.

MicroRNA-330 acts as tumor suppressor and induces apoptosis of prostate cancer cells through E2F1-mediated suppression of Akt phosphorylation.

MicroRNAs (miRNAs) make up a novel class of gene regulators; they function as oncogenes or tumor suppressors by targeting tumor-suppressor genes or oncogenes. A recent study that analysed a large number of human cancer cell lines showed that miR-330 is a potential tumor-suppressor gene. However, the function and molecular mechanism of miR-330 in determining the aggressiveness of human prostate cancer has not been studied. Here, we show that miR-330 is significantly lower expressed in human prostate cancer cell lines than in nontumorigenic prostate epithelial cells. Bioinformatics analyses reveal a conserved target site for miR-330 in the 3'-untranslated region (UTR) of E2F1 at nucleotides 1018-1024. MiR-330 significantly suppressed the activity of a luciferase reporter containing the E2F1-3'-UTR in the cells. This activity could be abolished with the transfection of anti-miR-330 or mutated E2F1-3'-UTR. In addition, the expression level of miR-330 and E2F1 was inversely correlated in cell lines and prostate cancer specimens. After overexpressing of miR-330 in PC-3 cells, cell growth was suppressed by reducing E2F1-mediated Akt phosphorylation and thereby inducing apoptosis. Collectively, this is the first study to show that E2F1 is negatively regulated by miR-330 and also show that miR-330 induces apoptosis in prostate cancer cells through E2F1-mediated suppression of Akt phosphorylation.

Neuronal nitric oxide synthase activation is involved in insulin-mediated cardiovascular effects in the nucleus tractus solitarii of rats.

Neuronal nitric oxide synthases (nNOS) is distributed throughout the central nervous system (CNS) and has been proposed to modulate neuronal activity in the nucleus tractus solitarii (NTS). Here, we investigated whether the activation of nNOS is involved in insulin-induced cardiovascular responses in the NTS. Insulin (100 IU/ml) was unilaterally microinjected into the NTS, and the cardiovascular effects were evaluated before and after microinjection of the nNOS inhibitors 7-nitroindazole (7-NI) (5 pmol) and N(5)-(1-imino-3-butenyl)-l-ornithine (vinyl-L-NIO) (600 pmol). Western blot and immunohistochemical analyses were performed to determine nNOS phosphorylation levels after insulin or phosphoinositide 3-kinase (PI3K) inhibitor LY294002 microinjection into the NTS. Unilateral microinjection of insulin into the NTS produced prominent depressor and bradycardic effects in WKY rats. Pretreatment with the nNOS inhibitors 7-NI and Vinyl-L-NIO attenuated the cardiovascular response evoked by insulin in Wistar-Kyoto (WKY) rats. Moreover, Western blot analysis showed a significant increase in nNOS (16.5+/-0.4-fold; P<0.05; n=4) phosphorylation after insulin injection, whereas the PI3K inhibitor LY294002 abolished the insulin-induced effects. In situ nNOS phosphorylation was found to be increased in the NTS after insulin injection. Furthermore, co-immunoprecipitation assay showed Akt and nNOS can bind to each other as detected by phospho-Akt(S473) and phospho-nNOS(S1416) antibodies. In vitro kinase assay showed insulin activated Akt can directly phosphorylate nNOS(S1416). These results demonstrated that nNOS may couple with the activation of the insulin receptor, via the liberation of NO, in order to participate in central cardiovascular regulation of WKY rats.

Microwave irradiation enhances gene and oligonucleotide delivery and induces effective exon skipping in myoblasts.

Microwave (MW) energy consists of electric and magnetic fields and is able to penetrate deep into biological materials. We investigated the effect of MW (2450 MHz) irradiation on gene delivery in cultured mouse myoblasts and observed enhanced transgene expression. This effect is, however, highly variable and critically dependent on the power levels, duration and cycle conditions of MW exposure. MW irradiation greatly enhances delivery of 2'O methyl-phosphorothioate antisense oligonucleotide (AON) targeting mouse dystrophin exon 23 and induces specific exon skipping in cultured myoblasts. Effective delivery of AON by MW irradiation is able to correct the dystrophin reading frame disrupted by a nonsense point mutation in the H2K mdx myoblasts, resulting in the restoration of dystrophin expression. MW-mediated nucleic acid delivery does not directly link to the increase in system temperature. The high variability in gene and oligonucleotide delivery is most likely the result of considerable irregularity in the distribution of the energy and magnetic field produced by MW with the current device. Therefore, achieving effective delivery of the therapeutic molecules would require new designs of MW devices capable of providing controllable and evenly distributed energy for homogenous exposure of the target cells.

Gravitational compression of colloidal gels.

We study the compression of depletion gels under the influence of a gravitational stress by monitoring the time evolution of the gel interface and the local volume fraction, φ, inside the gel. We find φ is not constant throughout the gel. Instead, there is a volume fraction gradient that develops and grows along the gel height as the compression process proceeds. Our results are correctly described by a non-linear poroelastic model that explicitly incorporates the φ-dependence of the gravitational, elastic and viscous stresses acting on the gel.

FLJ10540-elicited cell transformation is through the activation of PI3-kinase/AKT pathway.

A significant challenge in the post-genomic era is how to prioritize differentially expressed and uncharacterized novel genes found in hepatocellular carcinoma (HCC) microarray profiling. One such category is cell cycle regulated genes that have only evolved in higher organisms but not in lower eukaryotic cells. Characterization of these genes may reveal some novel human cancer-specific abnormalities. A novel transcript, FLJ10540 was identified. FLJ10540 is overexpressed in HCC as examined by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. The patients with higher FLJ10540 expression had a poor survival than those with lower FLJ10540 expression. Functional characterization indicates that FLJ10540 displays a number of characteristics associated with an oncogene, including anchorage-independent growth, enhanced cell growth at low serum levels and induction of tumorigenesis in nude mice. FLJ10540-elicited cell transformation is mediated by activation of the phosphatidylinositol 3'-kinase (PI3K)/AKT pathway. Moreover, FLJ10540 forms a complex with PI3K and can activate PI3K activity, which provides a mechanistic basis for FLJ10540-mediated oncogenesis. Together, using a combination of bioinformatics searches and empirical data, we have identified a novel oncogene, FLJ10540, which is conserved only in higher organisms. The finding raises the possibility that FLJ10540 is a potential new therapeutic target for HCC treatment. These findings may contribute to the development of new therapeutic strategies that are able to block the PI3K/AKT pathway in cancer cells.