RNA interference suppression of A100A4 reduces the growth and metastatic phenotype of human renal cancer cells via NF-kB-dependent MMP-2 and bcl-2 pathway

BACKGROUND AND AIM

S100A4 is a well established marker and mediator of metastatic disease, but the exact mechanisms responsible for the metastasis promoting effects are less well defined. We tested a hypothesis that the S100A4 gene plays a role in the proliferation and invasiveness of human renal cancer cells (RCC) and may be associated with its metastatic spread.

MATERIALS AND METHODS

The small interference RNA vector pcDNA3.1-S100A4 siRNA was transfected in to the human renal cancer cell lines ACHN, Ketr-3, OS-RC-2, CaKi-2 and HTB-47, then treated with ABT-737 or BB94. Cell apoptosis and cell viability was detected by flow cytometry and MTT assay. Matrigel was used for cell motility and invasion assay. MMP-2, bcl-2 and S100A4 was detected by RT-PCR and western blot assay. NF-kB subunit p65 activity was detected by confocal microscopy assay. We then determine the effect S100A4 sliencing on tumor growth, lung metastasis development in vivo. Immunohistochemistry was used to detected the expression of S100A4, bcl-2, MMP-2, p65 and CD31.

RESULTS

S100A4 silencing in ACHN cells by RNA interference significantly inhibited NF-kB and NF-kB-mediated MMP-2 and bcl-2 activation and cellular migration, proliferation, and promoted apoptosis. Furthermore, re-expression of S100A4 in S100A4-siRNA-transfected ACHN cells by transient S100A4 cDNA transfection restored the NF-kB and NF-kB-mediated MMP-2 and bcl-2 activation and their high migratory and cellular proliferative ability. An inhibitor ABT-737 (the Bcl-2 antagonist targets Bcl-2) against Bcl-2 suppressed cellular proliferation and promoted apoptosis induced by S100A4 re-expression in S100A4-siRNA-transfected ACHN cells. A inhibitor BB94 against MMPs to neutralize MMP-2 protein suppressed cellular invasion and migration induced by S100A4 re-expression in S100A4-siRNA-transfected ACHN cells. In the prevention model, S100A4 silencing inhibited primary tumor growth by (tumor weight) (76 ± 8%) and (tumor volum) (78 ± 4%) respectively and promoted apoptosis and the formation of lung metastases was inhibited by 89% (p < 0.01). Microvascular density was reduced by 70% (p < 0.01). In addition, S100A4 sliencing inhibited the expression of S100A4 in vivo, followed by the NF-kB, MMP-2 and bcl-2 suppression.

CONCLUSIONS

We conclude that S100A4 plays a crucial role in proliferation and migratory/invasive processes in human RCC by a mechanism involving activation of NF-kB-bcl-2 and NF-kB-MMP-2 pathway.

EpCAM is an endoderm-specific Wnt derepressor that licenses hepatic development

Mechanisms underlying cell-type-specific response to morphogens or signaling molecules during embryonic development are poorly understood. To learn how response to the liver-inductive Wnt2bb signal is achieved, we identify an endoderm-enriched, single transmembrane protein, epithelial-cell-adhesion-molecule (EpCAM), as an endoderm-specific Wnt derepressor in zebrafish. hi2151/epcam mutants exhibit defective liver development similar to prt/wnt2bb mutants. EpCAM directly binds to Kremen1 and disrupts the Kremen1-Dickkopf2 (Dkk2) interaction, which prevents Kremen1-Dkk2-mediated removal of Lipoprotein-receptor-related protein 6 (Lrp6) from the cell surface. These data lead to a model in which EpCAM derepresses Lrp6 and cooperates with Wnt ligand to activate Wnt signaling through stabilizing membrane Lrp6 and allowing Lrp6 clustering into active signalosomes. Thus, EpCAM cell autonomously licenses and cooperatively activates Wnt2bb signaling in endodermal cells. Our results identify EpCAM as the key molecule and its functional mechanism to confer endodermal cells the competence to respond to the liver-inductive Wnt2bb signal.

Novel EDA p.Ile260Ser mutation linked to non-syndromic hypodontia

Hypodontia, a tooth developmental disease, can affect chewing and pronunciation. Mutations in the ectodysplasin-A (EDA) gene can lead to both X-linked hypohidrotic ectodermal dysplasia (XLHED) and non-syndromic hypodontia (NSH). However, the mechanism by which these 2 related but different disorders are caused by the distinct mutations in EDA is unknown. In this study, we identified a novel missense mutation (c.779 T>G) in a Chinese family with NSH via a direct sequencing approach. This mutation results in an Ile260Ser substitution in the tumor necrosis factor (TNF) homology domain. Homology modeling suggests that this alteration may induce a conformational change in the hydrophobic center of the TNF homology domain. Furthermore, by exploring systematic 3D conformation analysis and calculation of residue relative solvent accessibility (RSA) for all the reported mutated amino acid sites on EDA's TNF homology domain, we found that the site mutations at the interior may be linked to XLHED, while those at the surface are more likely to be associated with NSH. These findings may aid in the discovery of unidentified functionally significant mutation sites in the EDA gene and provide a new way to clarify the mechanisms by which the XLHED and NSH phenotypes arise from mutations in the same gene.

Abstract P2-09-06: The structure design and biological activities of inhibitory peptides, which block the interactions among polycomb repressive complex 2

Polycomb repressive complex (PRC2) contains several proteins, including embryonic ectoderm development (EED), suppressor of zeste 12 (SUZ12) and enhancer of zeste homolog 2 (EZH2). Excessive EZH2 concentrations have been reported as a marker of aggressive breast cancer and associated with invasion and cancer progression. EZH2 levels were elevated in patients with invasive breast carcinoma relative to normal or atypical hyperplasia. Except for the C-terminal SET domain, which functions as a histone-lysine N-methyltransferases, EZH2 has an N-terminal alpha helix region, which forms tight complex with EED protein. The in vivo enzymatic activity of EZH2 relies on and be tightly regulated by the interaction with EED. We designed series of artificial peptides trying to block the interaction between EZH2 and EED. By using label-free surface plasmon resonance (SPR) technology, the dynamic binding capacities of these peptides were tested. There were 3 leading structures standing out from the screening of more 80 peptides. After several round of co-crystal structure based optimization, the binding capacity of one inhibitor was reached to several nM levels, which indicated the availability for being a drug candidate. Finally, the biological activities of the inhibitory peptides were tested in several breast cancer cell lines. The PRC2 inhibitory peptides in this study are the first time reported PRC2 targeting epigenetic molecules with biological activity in breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-09-06.

320-detector row CT angiography for detection and evaluation of intracranial aneurysms: comparison with conventional digital subtraction angiography

AIM

To compare the diagnostic performance of 320-detector row computed tomographic angiography (CTA) with digital subtraction angiography (DSA) for the detection and characterization of intracranial aneurysms.

MATERIALS AND METHODS

Fifty-two consecutive patients with non-traumatic subarachnoid haemorrhage (SAH) and suspected intracranial aneurysms were evaluated from January 2009 to October 2011. All underwent both 320-detector row volume CTA examination and DSA. CTA volume data were transmitted to a VITREA workstation and two physicians with experience in diagnostic imaging of the nervous system independently carried out image post-processing and assessed the results. The three-dimensional (3D) CTA and DSA images were assessed using intraoperative findings as the reference standard.

RESULTS

In 52 patients, 54 aneurysms were detected; 48 patients underwent surgery for 50 aneurysms. The overall sensitivity, specificity, and accuracy of 3D CTA were 96.3, 100, and 94.6%, respectively. Meanwhile, the overall sensitivity, specificity, and accuracy of DSA were 98.1, 98.1, and 95.1%, respectively. For aneurysms less than 3 mm, the sensitivity, specificity, and accuracy of 3D CTA were 81.8, 100, and 93.3%, respectively. The sensitivity, specificity, and accuracy of DSA for small aneurysms were 90.9, 100, and 96.2%, respectively. 3D CTA was superior to DSA in demonstrating aneurysmal calcification, parent artery, and surrounding vascular anatomy.

CONCLUSIONS

3D CTA is a highly sensitive, specific, and non-invasive imaging method for diagnosis and evaluation of intracranial aneurysms. It also allows for precise depiction of aneurysm morphology. Therefore, 320-detector row CTA may be used as an alternative to DSA as a first-line imaging technique in patients with SAH.

[Cryosurgery Combined with Radioactive Seeds and Release-controlled Chemical Drugs Implantation for the Treatment of Lung Carcinoma.]

BACKGROUND

It is very difficult for cryosurgery to ablate all tumors because of its large volume and irregular shape. It is a complementary method for chemo-radioactive concurrent therapy to treat tumor remains. The aim of this study is to evaluate the application, security and effectiveness of Argon-Helium cryosurgery combined with radioactive seeds/release-controlled drugs implantation for percutaneous treatment of pulmonary neoplasma by CT guidance.

METHODS

Lung cryosurgery and radioactive seeds and release-controlled drugs implantation were sequentially performed in 20 cases with 16 primary lung cancer and 4 secondary lung cancer. Side effects were observed during cryosurgery and seeds implantation.

RESULTS

(3.4+/-0.2) cryoprobes were inserted into a nodule which is average (5.8+/-0.5) cm in diameter in 20 cases with 21 tumors. 85.6%+/-2.4% of tumor size had been ablated for each procedure. Haemoptysis occurred in 80% patients after cryosurgery, and disappeared in a week. Pneumothroax happened in 15% patients and recovered in a short time without special treatment. Absorption fever occurred in 20% patients and returned to normal in a week. (23.4+/-1.4) radioactive seeds and (8.3+/-1.2) drug-released drugs were percutaneously inserted into the 21 remaining tumors in a week after cryosurgery and 4 tumors (<2 cm in diameter) without cryosurgery. There were no severe side effects directly related to the procedures except 3 had slight nausea. The medium survive time was 16 months and average survive time was (14.0+/-2.6) months. More than 60% of patients survived more than 1 year.

CONCLUSIONS

Cryosurgery is a rapid modality for the debulking of pulmoanry tumor and concurrent therapy of radioactive seeds and release-controlled drugs implantation could effectively treat the remaining tumor. It is a rapid and effective method for the treatment of advanced stage lung cancer.

A 3D Static Heart Model From a MSCT Data Set

Dynamic Computed Tomography (CT) imaging aims to access the kinetics of the moving organs. In cardiac imaging, the interest lies in the possibility of obtaining anatomic and functional information on the heart and the coronaries during the same examination. However, segmentation, reconstruction and registration algorithms need to be developed for diagnostic purposes. We propose thus to built a 3D heart model from Multi-slice Spiral Computed Tomography (MSCT) dynamic sequences to facilitate the evaluation of these algorithms. The model building relies on semi-automatic segmentation techniques based on deformable models such as Fast Marching and active contours. Shape-based interpolation and Marching Cube algorithms are then used for the 3D surface reconstruction.

Estimation and Removal of Physiological Noise from Undersampled Multi-slice fMRI data in Image Space

The signal variations induced by respiration and cardiac motion decrease the statistical significance in functional MRI data analysis. Significant components of these fluctuations are aliased into the activation spectrum in standard multi-slice imaging protocols. A method of estimation and removal physiological noise in image space is reported. Based on reordering the data from slice ordering to time ordering, the aliased physiological information is available in multi-slice magnitude images. Then physiological noise can be estimated and removed adaptively using signal projecting technique with the actual functional signal preserved.

Femtosecond population inversion and stimulated emission of dense Dirac fermions in graphene

We show that strongly photoexcited graphene monolayers with 35 fs pulses quasi-instantaneously build up a broadband, inverted Dirac fermion population. Optical gain emerges and directly manifests itself via a negative conductivity at the near-infrared region for the first 200 fs, where stimulated emission completely compensates absorption loss in the graphene layer. Our experiment-theory comparison with two distinct electron and hole chemical potentials reproduce absorption saturation and gain at 40 fs, revealing, particularly, the evolution of the transient state from a hot classical gas to a dense quantum fluid with increasing the photoexcitation.

Baculovirus expression and antigenic characterization of classical swine fever virus E2 proteins

Genes encoding a major structural glycoprotein, E2, of classical swine fever viruses (CSFV) Brescia (subgroup 1.2), Paderborn (subgroup 2.1) and Kanagawa (subgroup 3.4) were constructed by removing the transmembrane domain and adding a C-terminal 6 histidine (His) tag. All the E2 constructs were efficiently expressed in a baculovirus system as 53-kDa glycosylated proteins that were identified in Western blots by their reaction with anti-His and CSFV-specific antibodies. These proteins were used as ELISA antigens to confirm the existence of an antigenic relationship between the viruses using group-specific polyclonal antisera. Antigenic differences were identified by Western blot and ELISA reactivity of the E2 proteins with a panel of monoclonal antibodies. Specifically, one monoclonal antibody (WH303) reacted with all three proteins, two monoclonal antibodies (M1660 and M1665) reacted with only the Brescia E2 protein, and three monoclonal antibodies (M1654, M1664 and M1669) reacted equally well with only Brescia and Kanagawa E2 proteins. Therefore, antibody reactivity profiles, established using recombinant E2 proteins, could be used to quickly identify novel CSFV strains as illustrated in this report with only a limited number of monoclonal antibodies. These proteins could also have added utility in the production of monoclonal antibodies and as critical reagents in diagnostic assays.

[Radioactive seed implantation for the treatment of mediastinal malignant tumors and lymph node metastases in 43 cases]

背景与目的

纵隔内恶性肿瘤位置深邃、隐匿, 手术切除可能性极小。由于其紧邻心包、主气管、大血管等重要解剖结构, 氩氦刀冷冻及热消融同样受到限制。本文比较43例放射性¹²⁵Ⅰ粒子植入患者的影像复查资料和生存质量, 探讨其操作安全性和临床疗效。

方法

2010年7月-2011年7月经病理证实并完成随访的43例患者, 其中原发纵隔型肺鳞癌21例, 原发食管癌9例, 淋巴结转移癌13例。合并主气道50%以上狭窄18例, 食管梗阻9例, 上腔静脉回流障碍6例。每个病灶植入¹²⁵Ⅰ粒子10枚-60枚, 平均(30.79±14.23)枚。治疗后2个月、4个月、6个月及12个月复查CT观察局部病灶控制情况, 并对患者生存质量及生存期进行随访。

结果

全部操作技术成功率100%, 最长随访时间12个月, 6个月生存37例, 6个月生存率为85.0%, 局部病灶PR 30个, NC 7个, 临床有效率为81.08%, 临床受益率为100%。12个月生存31例, 1年生存率为60.5%, 局部病灶CR 16个, PR 7个, NC 2个, PD 6个, 临床有效率为74.19%, 临床受益率为80.65%。6个月、12个月KPS评分提高且差异明显。穿刺导致气胸3例(6.98%), 无大血管、主气管、喉返神经及心包损伤等严重并发症。

结论

放射性¹²⁵Ⅰ粒子植入治疗纵隔内恶性肿瘤, 技术成功率高且相对安全, 临床疗效肯定。

Efficient doping and energy transfer from ZnO to Eu3+ ions in Eu(3+)-doped ZnO nanocrystals

Successful doping of Eu3+ ions into ZnO nanocrystals has been realized by using a low temperature wet chemical doping technique. The substitution of Eu3+ for Zn2+ is shown to be dominant in the Eu-doped ZnO nanocrystals by analyzing the X-ray diffraction patterns, transmission electron microscopy images, Raman and selectively excited photoluminescence spectra. Measurement of the luminescence from the samples shows that the excited ZnO transfers the excited energy efficiently to the doped Eu3+ ions, giving rise to efficient emission at red spectral region. The red emission quantum yield is measured to be 31% at room temperature. The temperature dependence of photoluminescence and the photoluminescence excitation spectra have also been investigated, showing strong energy coupling between the ZnO host and Eu3+ ions through free and bound excitons. The result indicates that Eu3+ ion-doped ZnO nanocrystals are promising light-conversion materials and have potential application in highly distinguishable emissive flat panel display and LED backlights.

Potential role of soluble B7-H3 in liver immunopathogenesis during chronic HBV infection

Immune-mediated mechanisms have been implicated in liver pathogenesis and subsequent progression in hepatitis B virus (HBV) infection. Costimulatory molecules, the important regulators of immune responses, participate in the regulation of liver pathology in HBV infection. However, the role of B7-H3 (CD276, a new member of B7 family) in this process has not been investigated. In this study, we detected abundant soluble B7-H3 (sB7-H3) in the plasma of patients with chronic HBV infections. The increase of the plasma B7-H3 was associated with the progression of liver cirrhosis and accompanied by decreased expression of B7-H3 on hepatocytes. The identification analysis suggests that the plasma B7-H3 might be derived from the membrane-bound B7-H3 on hepatocytes. A functional study showed that immobilized (4Ig) B7-H3Ig fusion protein could inhibit TCR-induced proliferation and IFN-γ secretion of T cells, which could be partially blocked by soluble B7-H3flag fusion protein. These results suggest that the reduced expression of B7-H3 in the livers might temper the inhibition of T-cell responses mediated by B7-H3 expressed on hepatocytes and thus promote the hepatic inflammation and hepatitis progression in the chronic HBV-infected patients.

[Sealing of airway fistulas for metallic covered z-type stents]

背景与目的

气道瘘包括食管气管瘘、支气管胸膜瘘和气管纵隔瘘，临床治疗较为棘手。本文旨在探讨被膜金属支架封堵气道瘘的疗效和安全性。

方法

回顾性分析32例食管气管瘘、5例支气管胸膜瘘和1例气管纵隔瘘患者在气管镜和/或X线透视下放置被膜金属支架。原发病为食管肿瘤26例，肺癌11例，甲状腺癌1例。

结果

38例患者共有46个瘘口，口径0.5 cm-7.0 cm。放置Z型气管被膜金属支架40枚(其中Y形24枚，L形8枚和I形8枚)。食管放置被膜金属支架24枚。46个瘘口封堵疗效：治愈2例(4.3%)，临床完全缓解28例(60.9%)，部分缓解11例(23.9%)，无效5例(10.9%)，有效率为89.1%，中位生存时间为5个月。

结论

被膜金属支架能有效封堵食管气管瘘、支气管胸膜瘘和气管纵隔瘘。应首选气管支架封堵ERF，无效的患者可同时放置食管支架。分叉型气管支架尤其适于隆突周围瘘口。

Retinoic acid signaling sequentially controls visceral and heart laterality in zebrafish

During zebrafish development, the left-right (LR) asymmetric signals are first established around the Kupffer vesicle (KV), a ciliated organ generating directional fluid flow. Then, LR asymmetry is conveyed and stabilized in the lateral plate mesoderm. Although numerous molecules and signaling pathways are involved in controlling LR asymmetry, mechanistic difference and concordance between different organs during LR patterning are poorly understood. Here we show that RA signaling regulates laterality decisions at two stages in zebrafish. Before the 2-somite stage (2So), inhibition of RA signaling leads to randomized visceral laterality through bilateral expression of nodal/spaw in the lateral plate mesoderm, which is mediated by increases in cilia length and defective directional fluid flow in KV. Fgf8 is required for the regulation of cilia length by RA signaling. Blockage of RA signaling before 2So also leads to mild defects of heart laterality, which become much more severe through perturbation of cardiac bmp4 asymmetry when RA signaling is blocked after 2So. At this stage, visceral laterality and the left-sided Nodal remain unaffected. These findings suggest that RA signaling controls visceral laterality through the left-sided Nodal signal before 2So, and regulates heart laterality through cardiac bmp4 mainly after 2So, first identifying sequential control and concordance of visceral and heart laterality.