Abstract
The importance of apoptosis during the process of inhibiting tumorigenesis has been recognized. The role of BH3-only proapoptotic protein Bcl-2–associated death (BAD) in tumor growth remains controversial. The aim of this study was to explore the role of BAD in lung cancer cells. Our study showed that expression of BAD was upregulated in A549 cells by a recombinant lentivirus overexpressing BAD. In vitro, BAD overexpression significantly inhibited A549 cell proliferation and induced apoptosis in cell proliferation and apoptosis assays, respectively. The effect of BAD on A549 cells was studied in tumor xenograft of nude mice and the results showed that the tumor volume in the experimental group was smaller than the control groups. Further, immunohistochemical technique was used to determine the cell proliferation and apoptosis status of the lung tumor xenograft cells. This demonstrated that the in vivo and in vitro results were consistent. Taken together, our results indicate that overexpression of BAD inhibits the growth of A549 cells in vitro and in vivo, through inhibiting cell proliferation and inducing apoptosis. Thus, BAD could be a potential therapeutic target.
doi:10.1089/cbr.2011.1018
PMCID: PMC3304250
PMID: 22011203
apoptosis; BAD; human A549 lung adenocarcinoma cells; lentiviral vector; overexpression; proliferation
Wang, Yan | Chen, Lei | Huang, Guochang | He, Dongmei | He, Juan | Xu, Wei | Zou, Chunying | Zong, Feng | Li, Yan | Chen, Bo | Wu, Shuanshuan | Zhao, Weihong | Wu, Jianqing | Sarkar, Devanand
Klotho was first identified in 1997 and has been considered as an anti-aging gene. Emerging evidence demonstrates that klotho has a close relationship with cancers, including lung cancer, breast cancer, etc, by inhibiting the proliferation and promoting apoptosis of cancer cells. Cisplatin has been the most widely used drug in the first-line chemotherapy. However, the increase in cisplatin-resistant cancer cells has become a major obstacle in clinical management of cancers. In our study, we for the first time demonstrated that klotho could attenuate the resistance of lung cancer to cisplatin based chemotherapy and the apoptosis of the resistant cells with klotho overexpression was markedly increased. However, klotho knockdown cells showed enhanced resistance to chemotherapy. Further analysis showed that inhibition of PI3K/Akt pathway with specific inhibitor (LY294002) attenuated the promotive effects on cancer growth following interfering with klotho shRNA. Moreover, we demonstrated that klotho modulated the resistance to cisplatin in a xenograft nude mice model. These observations suggested that klotho could improve the resistance of lung cancer cells to chemotherapy and may serve as a potential target for the gene therapy of lung cancers resistant to cisplatin based chemotherapy.
doi:10.1371/journal.pone.0057391
PMCID: PMC3578855
PMID: 23437382
Chen, Bo | Yi, Bing | Mao, Rui | Liu, Haitao | Wang, Jinhua | Sharma, Ashok | Peiper, Stephen | Leonard, Warren J. | She, Jin-Xiong | Bunting, Kevin D.
Activation of signal transducers and activators of transcription (STAT) proteins may be critical to their oncogenic functions as demonstrated by the development of B-cell lymphoma/leukemia in transgenic (TG) mice overexpressing a constitutively activated form of Stat5b. However, low incidence of CD8+ T cell lymphoma was observed in B6 transgenic mice overexpressing a wild-type Stat5b (B6.Stat5bTg) despite of undetectable Stat5b phosphorylation and the rate of lymphomagenesis was markedly enhanced by immunization or the introduction of TCR transgenes [1]. Here, we report that the wild-type Stat5b transgene leads to the acceleration and high incidence (74%) of CD8+ T cell lymphoblastic lymphomas in the non-obese-diabetic (NOD) background. In contrast to the B6.Stat5bTg mice, Stat5b in transgenic NOD (NOD.Stat5bTg) mice is selectively and progressively phosphorylated in CD8+ thymocytes. Stat5 phosphorylation also leads to up-regulation of many genes putatively relevant to tumorigenesis. Treatment of NOD.Stat5bTg mice with cancer chemopreventive agents Apigenin and Xanthohumol efficiently blocked lymphomagenesis through reduction of Stat5 phosphorylation and genes up-regulated in the NOD.Stat5bTg mice. These results suggest that NOD genetic background is critical to the Stat5b-mediated lymphomagenesis through regulation of Stat5 hyperactivation. NOD.Stat5bTg mouse is an excellent model for studying the molecular mechanisms underlying lymphomagenesis and testing novel chemoprevention strategies.
doi:10.1371/journal.pone.0056600
PMCID: PMC3572980
PMID: 23457589
Kelpke, Stacey S. | Chen, Bo | Bradley, Kelley M. | Teng, Xinjun | Chumley, Phillip | Brandon, Angela | Yancey, Brett | Moore, Brandon | Head, Hughston | Viera, Liliana | Thompson, John A. | Crossman, David K. | Bray, Molly S. | Eckhoff, Devin E. | Agarwal, Anupam | Patel, Rakesh P.
Renal injury induced by brain death is characterized by ischemia and inflammation and limiting it is a therapeutic goal that could improve outcomes in kidney transplantation. Brain death resulted in decreased circulating nitrite levels and increased infiltrating inflammatory cell infiltration into the kidney. Since nitrite stimulates nitric oxide signaling in ischemic tissues, we tested whether nitrite therapy was beneficial in a rat model of brain death followed by kidney transplantation. Nitrite, administered over 2 hours of brain death, blunted the increased inflammation without affecting brain death-induced alterations in hemodynamics. Kidneys were transplanted after 2 hours of brain death and renal function followed over 7 days. Allografts collected from nitrite-treated brain dead rats showed significant improvement in function over the first 2 to 4 days post transplantation compared to untreated brain dead animals. Gene microarray analysis after 2 hours of brain death without or with nitrite therapy showed the latter significantly altered the expression of about 400 genes. Ingenuity Pathway analysis indicated multiple signaling pathways were affected by nitrite, including those related to hypoxia, transcription and genes related to humoral immune responses. Thus, nitrite-therapy attenuates brain death-induced renal injury by regulating responses to ischemia and inflammation, ultimately leading to better post-transplant kidney function.
doi:10.1038/ki.2012.116
PMCID: PMC3412933
PMID: 22534964
inflammation; nitric oxide; kidney; transplantation
Chen, Bo | Guizar-Sicairos, Manuel | Xiong, Gang | Shemilt, Laura | Diaz, Ana | Nutter, John | Burdet, Nicolas | Huo, Suguo | Mancuso, Joel | Monteith, Alexander | Vergeer, Frank | Burgess, Andrew | Robinson, Ian
Artificially structured coatings are widely employed to minimize materials deterioration and corrosion, the annual direct cost of which is over 3% of the gross domestic product (GDP) for industrial countries. Manufacturing higher performance anticorrosive coatings is one of the most efficient approaches to reduce this loss. However, three-dimensional (3D) structure of coatings, which determines their performance, has not been investigated in detail. Here we present a quantitative nano-scale analysis of the 3D spatial structure of an anticorrosive aluminium epoxy barrier marine coating obtained by serial block-face scanning electron microscopy (SBFSEM) and ptychographic X-ray computed tomography (PXCT). We then use finite element simulations to demonstrate how percolation through this actual 3D structure impedes ion diffusion in the composite materials. We found the aluminium flakes align within 15° of the coating surface in the material, causing the perpendicular diffusion resistance of the coating to be substantially higher than the pure epoxy.
doi:10.1038/srep01177
PMCID: PMC3558722
PMID: 23378910
Chen, Bo | Tao, Zhengxian | Zhao, Yingming | Chen, Hongwu | Yong, Yonghong | Liu, Xiang | Wang, Hua | Wu, Zuze | Yang, Zhijian | Yuan, Li | Zheng, Yi
Background
Hepatocyte growth factor (HGF) is one of the major angiogenic factors being studied for the treatment of ischemic heart diseases. Our previous study demonstrated adenovirus-HGF was effective in myocardial ischemia models. The first clinical safety study showed a positive effect in patients with severe and diffused triple coronary disease.
Methods
12 Pigs were randomized (1∶1) to receive HGF, which was administered as five injections into the infarcted myocardium, or saline (control group). The injections were guided by EnSite NavX left ventricular electroanatomical mapping.
Results
The catheter-based injections caused no pericardial effusion, malignant arrhythmia or death. During mapping and injection, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, serum creatinine and creatine kinase-MB levels have no significant increase as compared to those before and after the injection in HGF group(P>0.05). HGF group has high HGF expression with Western blot, less myocardial infarct sizes by electroanatomical mapping (HGF group versus after saline group, 5.28±0.55 cm2 versus 9.06±1.06 cm2, P<0.01), better cardiac function with Gated-Single Photon Emission Computed Tomography compared with those in saline group. Histological, strongly increased lectin–positive microvessels and microvessel density were found in the myocardial ischemic regions in HGF group.
Conclusion
Intramyocardial injection guided by NavX system provides a method of feasible and safe percutaneous gene transfer to myocardial infarct regions.
doi:10.1371/journal.pone.0053007
PMCID: PMC3536803
PMID: 23301013
Objective. To evaluate the effectiveness of Tuina-focused integrative Chinese medical therapies (TICMT) on inpatients with low back pain (LBP). Methods. 6 English and Chinese databases were searched for randomized controlled trials (RCTs) of TICMT for in-patients with LBP. The methodological quality of the included RCTs was assessed based on PEDro scale. And the meta-analyses of TICMT for LBP on pain and functional status were conducted. Results. 20 RCTs were included. The methodological quality of the included RCTs was poor. The meta-analyses' results showed that TICMT had statistically significant effects on pain and functional status, especially Tuina plus Chinese herbal medicine (standardised mean difference, SMD: 1.17; 95% CI 0.75 to 1.60 on pain; SMD: 1.31; 95% CI 0.49 to 2.14 on functional status) and Tuina plus acupuncture (SMD: 0.94; 95% CI 0.38 to 1.50 on pain; SMD: 0.53; 95% CI 0.21 to 0.85 on functional status). But Tuina plus moxibustion or hot pack did not show significant improvements on pain. And the long-term evidence of TICMT was far from sufficient. Conclusions. The preliminary evidence from current studies suggests that TICMT might be effective complementary and alternative treatments for in-patients with LBP. However, the poor methodological quality of the included RCTs means that high-quality RCTs with long follow-up are warranted.
doi:10.1155/2012/578305
PMCID: PMC3543824
PMID: 23346207
Summary
Membrane-associated guanylate kinases (MAGUKs) are the major family of scaffolding proteins at the postsynaptic density. The PSD-MAGUK subfamily, which includes PSD-95, PSD-93, SAP97 and SAP102, is well accepted to be primarily involved in the synaptic anchoring of numerous proteins, including N-methyl-D-aspartate receptors (NMDARs). Notably, the synaptic targeting of NMDARs depends on the binding of the PDZ ligand on the GluN2B subunit to MAGUK PDZ domains as disruption of this interaction dramatically decreases NMDAR surface and synaptic expression. We recently reported a secondary interaction between SAP102 and GluN2B, in addition to the PDZ interaction. Here, we identify two critical residues on GluN2B responsible for the non-PDZ binding to SAP102. Strikingly, either mutation of these critical residues or knock-down of endogenous SAP102 can rescue the defective surface expression and synaptic localization of PDZ binding-deficient GluN2B. These data reveal an unexpected, non-scaffolding role for SAP102 in the synaptic clearance of GluN2B-containing NMDARs.
doi:10.1016/j.celrep.2012.09.024
PMCID: PMC3513525
PMID: 23103165
Chen, Bo | Friedman, Beth | Whitney, Michael A. | Van Winkle, Jessica A. | Lei, I-Farn | Olson, Emilia S. | Cheng, Qun | Pereira, Benedict | Zhao, Lifu | Tsien, Roger Y. | Lyden, Patrick D.
Mechanisms of ischemic neuronal and vascular injury remain obscure. Here we test the hypothesis that thrombin, a blood-borne coagulation factor, contributes to neurovascular injury during acute focal ischemia. Stroke was induced in adult Sprague Dawley rats by occluding the middle cerebral artery. Intra-arterial thrombin infusion during ischemia significantly increased vascular disruption and cellular injury. Intravenous infusion of argatroban, a direct thrombin inhibitor, alleviated neurovascular injury. Immunostaining showed thrombin on neurons in the ischemic core. Using an activatable cell penetrating peptide engineered to detect thrombin activity, we discovered that thrombin proteolytic activity was specifically associated with neuronal damage during ischemia. Protease activated receptor-1, the presumptive thrombin receptor, appeared to mediate ischemic neurovascular injury. Furthermore, rats receiving thrombin during ischemia showed cognitive deficit whereas rats receiving argatroban retained intact learning and memory. These results suggest a potential role for thrombin contributing to neurovascular injury and several potential avenues for neuroprotection.
doi:10.1523/JNEUROSCI.0369-12.2012
PMCID: PMC3383068
PMID: 22649241
Streptococcus suis serotype 2 (SS2), a major swine pathogen and an emerging zoonotic agent, has greatly challenged global public health. The encoding proteins with unknown functions the bacterium encodes are an obstruction to studies of the pathogenesis. A novel surface protective antigen HP0197 is one of these proteins which have no sequence homology to any known protein. In the present study, the protein was determined to be involved in bacterial virulence through an evaluation of the isogenic mutant (Δhp0197) in both mice and pigs. The experimental infection also indicated that Δhp0197 could be cleared easily during infection, which could be attributed to the reduced thickness of the capsular polysaccharides (CPS) and the significantly reduced phagocytotic resistance. Microarrays-based comparative transcriptome analysis suggested that the suppressed expression of the operon responsible for CPS synthesis might be reversed by CcpA activity, which controlled global regulation of carbon catabolite through the binding of the CcpA and HPr-Ser-46-P to the catabolite-responsive elements (cre) of the target operons. The hypothesis was approved by the fact that the purified FLAG-tagged HPr from WT stain exhibited a higher binding activity to cre with CcpA compared to the Δhp0197 by the Electrophoretic Mobility Shift Assay, suggesting lower level of phosphorylation of the phosphocarrier protein HPr at residue Ser-46 (HPr-Ser-46P) in Δhp0197. These indicated that HP0197 could enhance CcpA activity to control the expression of genes involved in carbohydrate utilization and CPS synthesis, thus contributing to the virulence of S. suis.
doi:10.1371/journal.pone.0050987
PMCID: PMC3511442
PMID: 23226442
Quiescent cells are considered to be dormant. However, recent studies suggest that quiescent fibroblasts possess active metabolic profile and certain functional characteristics. We previously observed that serum-starved quiescent fibroblasts respond to proinflammatory stimuli by robust expression of cyclooxygenase-2 (COX-2), which declines after the quiescent fibroblasts are driven to proliferation. In this study, we elucidated the underlying signaling and transcriptional mechanism and identified by microarray genes with similar differential expression. By using pharmacological inhibitors coupled with gene silencing, we uncovered the key role of protein kinase C δ (PKCδ) and extracellular signal regulated protein kinase 1/2 (ERK1/2) signaling in mediating COX-2 expression in quiescent cells. Surprisingly, COX-2 expression in proliferative cells was not blocked by PKCδ or ERK1/2 inhibitors due to intrinsic inhibition of PKCδ and ERK1/2 in proliferative cells. Restrained COX-2 transcription in proliferative cells was attributable to reduced NF-κB binding. Microarray analysis identified 35 genes whose expressions were more robust in quiescent than in proliferative cells. A majority of those genes belong to proinflammatory cytokines, chemokines, adhesive molecules and metalloproteinases, which require NF-κB for transcription. Quiescent fibroblasts had a higher migratory activity than proliferative fibroblasts as determined by the transwell assay. Selective COX-2 inhibition reduced migration which was restored by prostaglandin E2. As COX-2 and inflammatory mediators induce DNA oxidation, we measured 8-hydroxydeoxyguanosine (8-OHdG) in quiescent vs. proliferative fibroblasts. PMA-induced 8-OHdG accumulation was significantly higher in quiescent than in proliferative fibroblasts. These findings indicate that quiescent fibroblasts (and probably other quiescent cells) are at the forefront in mounting inflammatory responses through expression of an array of proinflammatory genes via the PKCδ/ERK1/2 signaling pathway.
doi:10.1371/journal.pone.0049232
PMCID: PMC3498339
PMID: 23155470
Glutamate-induced neuronal damage is mainly caused by overactivation of N-methyl-D-aspartate (NMDA) receptors. Conversely, normal physiological brain function and neuronal survival require adequate activation of NMDA receptors. Studies have revealed that NMDA receptor-induced neuronal death or survival is mediated through distinct subset of NMDA receptors triggering different intracellular signaling pathways. Here we discuss recent advances in the characterization of NMDA receptors in neuronal protection, emphasizing subunit-specific role, which contributes to temporal-spatial distribution, subcellular localization and diverse channel properties of NMDA receptors.
doi:10.1007/s11515-011-1187-6
PMCID: PMC3491906
PMID: 23144645
NMDA receptors; glutamate; excitotoxicity; ischemia; neuroprotection
The structure of a recombinant pineapple cystatin (AcCYS) was determined by NMR with the RMSD of backbone and heavy atoms of twenty lowest energy structures of 0.56 and 1.11 Å, respectively. It reveals an unstructured N-terminal extension and a compact inhibitory domain comprising a four-stranded antiparallel β-sheet wrapped around a central α-helix. The three structural motifs (G45, Q89XVXG, and W120) putatively responsible for the interaction with papain-like proteases are located in one side of AcCYS. Significant chemical shift perturbations in two loop regions, residues 45 to 48 (GIYD) and residues 89 to 91 (QVV), of AcCYS strongly suggest their involvement in the binding to papain, consistent with studies on other members of the cystatin family. However, the highly conserved W120 appears not to be involved in the binding with papain as no chemical shift perturbation was observed. Chemical shift index analysis further indicates that the length of the α-helix is shortened upon association with papain. Collectively, our data suggest that AcCYS undergoes local secondary structural rearrangements when papain is brought into close contact. A molecular model of AcCYS/papain complex is proposed to illustrate the interaction between AcCYS and papain, indicating a complete blockade of the catalytic triad by AcCYS.
doi:10.1371/journal.pone.0047865
PMCID: PMC3490968
PMID: 23139757
Zheng, Qinxiang | Ren, Yueping | Tzekov, Radouil | Zhang, Yuanping | Chen, Bo | Hou, Jiangping | Zhao, Chunhui | Zhu, Jiali | Zhang, Ying | Dai, Xufeng | Ma, Shan | Li, Jia | Pang, Jijing | Qu, Jia | Li, Wensheng | Ohlmann, Andreas
Leber congenital amaurosis (LCA) is one of the most severe forms of inherited retinal degeneration and can be caused by mutations in at least 15 different genes. To clarify the proteomic differences in LCA eyes, a cohort of retinal degeneration 12 (rd12) mice, an LCA2 model caused by a mutation in the RPE65 gene, were injected subretinally with an AAV vector (scAAV5-smCBA-hRPE65) in one eye, while the contralateral eye served as a control. Proteomics were compared between untreated rd12 and normal control retinas on P14 and P21, and among treated and untreated rd12 retinas and control retinas on P42. Gene therapy in rd12 mice restored retinal function in treated eyes, which was demonstrated by electroretinography (ERG). Proteomic analysis successfully identified 39 proteins expressed differently among the 3 groups. The expression of 3 proteins involved in regulation of apoptosis and neuroptotection (alpha A crystallin, heat shock protein 70 and peroxiredoxin 6) were investigated further. Immunofluorescence, Western blot and real-time PCR confirmed the quantitative changes in their expression. Furthermore, cell culture studies suggested that peroxiredoxin 6 could act in an antioxidant role in rd12 mice. Our findings support the feasibility of gene therapy in LCA2 patients and support a role for alpha A crystallin, heat shock protein 70 and peroxiredoxin 6 in the pathogenetic mechanisms involved in LCA2 disease process.
doi:10.1371/journal.pone.0044855
PMCID: PMC3432120
PMID: 22953002
In the title complex, {[CaZn(C10H2O8)(H2O)2]·H2O}n, the ZnII ion is coordinated by four O atoms from four benzene-1,2,4,5-tetracarboxylate anions in a distorted tetrahedral geometry. The CaII ion is eight-coordinated by six O atoms from four benzene-1,2,4,5-tetracarboxylate anions and by two water molecules in a distorted square-antiprismatic geometry. The CaII and ZnII ions and the lattice water molecule are located on twofold rotation axes; the centroid of the benzene-1,2,4,5-tetracarboxylate anion is located on a centre of inversion. The μ8-bridging mode of the anion results in the formation of a three-dimensional structure with channels extending along [100] in which lattice water molecules are situated. Intermolecular O—H⋯O hydrogen bonds involving the coordinating and lattice water molecules as donors and the carboxylate O atoms and lattice water molecules as acceptors are present in the structure.
doi:10.1107/S1600536812034113
PMCID: PMC3435579
PMID: 22969452
PLoS ONE
2012;7(8):10.1371/annotation/8d7e5659-d669-4794-9fb8-40a7e8267a48.
doi:10.1371/annotation/8d7e5659-d669-4794-9fb8-40a7e8267a48
PMCID: PMC3414534
Bian, Fei | Xie, Bin-Bin | Qin, Qi-Long | Shu, Yan-Li | Zhang, Xi-Ying | Yu, Yong | Chen, Bo | Chen, Xiu-Lan | Zhou, Bai-Cheng | Zhang, Yu-Zhong
Yu et al. (Polar Biol. 32:1539–1547, 2009) isolated 199 Pseudoalteromonas strains from Arctic sea ice. We sequenced the genomes of six of these strains, which are affiliated to different Pseudoalteromonas species based on 16S rRNA gene sequences, facilitating the study of physiology and adaptation of Arctic sea ice Pseudoalteromonas strains.
doi:10.1128/JB.06427-11
PMCID: PMC3272954
PMID: 22275105
Jin, Wei | Chen, Bo-bin | Li, Ji-yu | Zhu, Hua | Huang, Mark | Gu, Sheng-mei | Wang, Qiao-qiao | Chen, Jia-ying | Yu, Sanjian | Wu, Jiong | Shao, Zhi-ming
TIEG1 can induce apoptosis of cancer cells, but its role in inhibiting invasion and metastasis has not been reported and is unclear. In this study, we find that decreased TIEG1 expression is associated with increased human epidermal growth factor receptor (EGFR) expression in breast cancer tissues and cell lines. TIEG1 plays an important role in suppressing transcription of EGFR by directly binding to the EGFR promoter. While overexpression of TIEG1 attenuates EGFR expression, knockdown of TIEG1 stimulates EGFR expression. Furthermore, TIEG1 and HDAC1 form a complex, which binds to Sp1 sites on the EGFR promoter and inhibits its transcription by suppressing histone acetylation. TIEG1 significantly inhibits breast cancer cell invasion, suppresses mammary tumorigenesis in xenografts in mice, and decreases lung metastasis by inhibition of EGFR gene transcription and the EGFR signaling pathway. Therefore, TIEG1 is an antimetastasis gene product; regulation of EGFR expression by TIEG1 may be part of an integral signaling pathway that determines and explains breast cancer invasion and metastasis.
doi:10.1128/MCB.06152-11
PMCID: PMC3255702
PMID: 22025675
Accurate determination of renal function in mice is a major impediment to the use of murine models in acute kidney injury. The purpose of this study was to determine whether early changes in renal function could be detected using dynamic gamma camera imaging in a mouse model of ischemia-reperfusion (I/R) injury. C57BL/6 mice (n = 5/group) underwent a right nephrectomy, followed by either 30 min of I/R injury or sham surgery of the remaining kidney. Dynamic renal studies (21 min, 10 s/frame) were conducted before surgery (baseline) and at 5, 24, and 48 h by injection of 99mTc-mercaptoacetyltriglycine (MAG3; ~1.0 mCi/mouse) via the tail vein. The percentage of injected dose (%ID) in the kidney was calculated for each 10-s interval after MAG3 injection, using standard region of interest analyses. A defect in renal function in I/R-treated mice was detected as early as 5 h after surgery compared with sham-treated mice, identified by the increased %ID (at peak) in the I/R-treated kidneys at 100 s (P < 0.01) that remained significantly higher than sham-treated mice for the duration of the scan until 600 s (P < 0.05). At 48 h, the renal scan demonstrated functional renal recovery of the I/R mice and was comparable to sham-treated mice. Our study shows that using dynamic imaging, renal dysfunction can be detected and quantified reliably as early as 5 h after I/R insult, allowing for evaluation of early treatment interventions.
doi:10.1152/ajprenal.00083.2007
PMCID: PMC3373432
PMID: 17634403
acute kidney injury; nuclear imaging; mice models of acute renal failure
Differential cell migration and growth drives the organization of specific tissue forms and plays a critical role in embryonic development, tissue morphogenesis, and tumor invasion. Localized gradients of soluble factors and extracellular matrix have been shown to modulate cell migration and proliferation. Here we show that in addition to these factors, initial tissue geometry can feedback to generate differential proliferation, cell polarity, and migration patterns. We apply layer by layer polyelectrolyte assembly to confine multicellular organization and subsequently release cells to demonstrate the spatial patterns of cell migration and growth. The cell shapes, spreading areas, and cell-cell contacts are influenced strongly by the confining geometry. Cells within geometric ensembles are morphologically polarized. Symmetry breaking was observed for cells on the circular pattern and cells migrate toward the corners and in the direction parallel to the longest dimension of the geometric shapes. This migration pattern is disrupted when actomyosin based tension was inhibited. Cells near the edge or corner of geometric shapes proliferate while cells within do not. Regions of higher rate of cell migration corresponded to regions of concentrated growth. These findings demonstrate the multicellular organization can result in spatial patterns of migration and proliferation.
doi:10.1016/j.yexcr.2011.02.009
PMCID: PMC3096689
PMID: 21338603
differential migration; differential proliferation; microscale; cell patterning
The potential influence of mechanical loading on transvascular transport in vascularized soft tissues has not been explored extensively. This experimental investigation introduced and explored the hypothesis that dynamic mechanical loading can pump solutes out of blood vessels and into the surrounding tissue, leading to faster uptake and higher solute concentrations than could otherwise be achieved under unloaded conditions. Immature epiphyseal cartilage was used as a model tissue system, with fluorescein (332 Da), dextran (3, 10 and 70 kDa) and transferrin (80 kDa) as model solutes. Cartilage disks were either dynamically loaded (±10% compression over a 10% static offset strain, at 0.2 Hz) or maintained unloaded in solution for up to 20 hours. Results demonstrated statistically significant solute uptake in dynamically loaded (DL) explants relative to passive diffusion (PD) controls for all solutes except unbound fluorescein, as evidenced by the DL:PD concentration ratios after 20 hours (1.0 ± 0.2, 2.4 ± 1.1, 6.1 ± 3.3, 9.0 ± 4.0, and 5.5±1.6 for fluorescein, 3, 10, and 70 kDa dextran, and transferrin). Significant uptake enhancements were also observed within the first 30 seconds of loading. Termination of dynamic loading produced dissipation of enhanced solute uptake back to PD control values. Confocal images confirmed that solute uptake occurred from cartilage canals into their surrounding extracellular matrix. The incidence of this loading-induced transvascular solute pumping mechanism may significantly alter our understanding of the interaction of mechanical loading and tissue metabolism.
doi:10.1016/j.jbiomech.2011.03.026
PMCID: PMC3124764
PMID: 21481875
vascular transport; solute pumping; cartilage canals; active transport
Bian, Fei | Qin, Qi-Long | Xie, Bin-Bin | Shu, Yan-Li | Zhang, Xi-Ying | Yu, Yong | Chen, Bo | Chen, Xiu-Lan | Zhou, Bai-Cheng | Zhang, Yu-Zhong
Glaciecola nitratireducens strain FR1064T was isolated from seawater and described as a new species by Baik et al. in 2006. The genome size is about 1.01 to 1.26 Mb smaller than two reported Glaciecola genomes, indicating the gain or loss of large genome segments in the evolution of Glaciecola strains.
doi:10.1128/JB.06296-11
PMCID: PMC3232840
PMID: 22123761
Malignant tumors in the tonsils are usually primary. Metastases to the tonsils are extremely rare, with nearly one hundred cases reported. Herein we present an unusual case of palatine tonsillar metastasis of non-small cell lung cancer during chemotherapy. The patient was a 39-year-old man who was diagnosed as non-small lung cancer with IIIA4 staging and poor differentiated histology. After two cycles of vinorelbine and cisplatin based chemotherapy, a big mass was developed in the right palatine tonsil which was pathologically confirmed as the metastasis from the lung. There was no hemorrhage and complains except moderate foreign body sensations. No cervical lymphadenopathy and distal metastases to other organs such as brain and liver was found. Because of poor overall performance status, no radiotherapy was given. The disease progressed after docetaxel treatment. To the best of our knowledge, this is the first case with palatine tonsillar metastasis from non-small lung cancer during induction chemotherapy.
PMCID: PMC3396057
PMID: 22808302
Tonsil neoplasm; metastasis; lung neoplasm; computed tomography; histopathology
Su, Chun-Hui | Zhao, Ruiying | Zhang, Fanmao | Qu, Changju | Chen, Bo | Feng, Yin-Hsun | Phan, Liem | Chen, Jian | Wang, Hua | Wang, Huamin | Yeung, Sai-Ching J. | Lee, Mong-Hong
COP1 is a p53-targeting E3 ubiquitin ligase that is downregulated by DNA damage through mechanisms that remain obscure. Here we report that COP1 is not downregulated following DNA damage in 14-3-3σ null cells, implicating 14-3-3σ as a critical regulator in the response of COP1 to DNA damage. We also identified that 14-3-3σ, a p53 target gene product, interacted with COP1 and controlled COP1 protein stability after DNA damage. Mechanistic studies revealed that 14-3-3σ enhanced COP1 self-ubiquitination, thereby preventing COP1-mediated p53 ubiquitination, degradation, and transcriptional repression. Additionally, we found that COP1 expression promoted cell proliferation, cell transformation, and tumor progression, manifesting its role in cancer promotion, whereas 14-3-3σ negatively regulated COP1 function and prevented tumor growth in a mouse xenograft model of human cancer. Immunohistochemical analysis of clinical breast and pancreatic cancer specimens demonstrated that COP1 protein levels were inversely correlated with 14-3-3σ protein levels. Together, our findings define a mechanism for posttranslational regulation of COP1 after DNA damage that can explain the correlation between COP1 overexpression and 14-3-3σ downregulation during tumorigenesis.
doi:10.1158/0008-5472.CAN-10-2518
PMCID: PMC3358120
PMID: 21135113
14-3-3σ; COP1; p53; ubiquitination
Background
Caspases are important regulators and executioners in apoptosis pathway and have been defined as either tumor suppressors or oncogenes. Polymorphisms in promoter and exon of caspase 9 were shown to confer genetic susceptibility to multiple cancers, but the results were inconsistent. To accomplish a more precise estimation of the relationship, a meta-analysis was performed.
Methodology/Principal Findings
We assessed published studies of the association between caspase 9 polymorphisms and cancer risk from nine studies with 5,528 subjects for rs4645978, six studies with 2,403 subjects for rs105276 and two studies for rs4645981. Overall meta-analysis indicated that no evidence of an association between rs4645978 and cancers was found. Through the stratified analysis, statistically significant reduced cancer risks were observed among Caucasians (AG vs AA: OR = 0.81, 95% CI = 0.66–0.99, Pheterogeneity = 0.150 and the dominant model: OR = 0.86, 95% CI = 0.75–0.99, Pheterogeneity = 0.290) and prostate cancer. As for rs105276, Ex5+32G>A polymorphism was found with protective effect in overall meta-analysis (AA vs GG: OR = 0.75, 95% CI = 0.60–0.92, Pheterogeneity = 0.887; A vs G: OR = 0.85, 95% CI = 0.77–0.95, Pheterogeneity = 0.739 and the recessive model: OR = 0.68, 95% CI = 0.56–0.82, Pheterogeneity = 0.309) and Asians group. While for rs4645981, a statistically significant increase in risk of lung cancer was shown in Asians (T vs C: OR = 1.23, 95% CI = 1.07–1.42, Pheterogeneity = 0.399 and the dominant model: OR = 1.22, 95% CI = 1.04–1.43, Pheterogeneity = 0.660).
Conclusions/Significance
Our meta-analysis suggests that the caspase 9 rs4645978 most likely contributes to decreased susceptibility to cancer in Caucasians and prostate cancer. The A allele of rs105276 might be a protective factor for cancer, especially for Asians. However, it seems that rs4645981 confers increased susceptibility to lung cancer in Asians.
doi:10.1371/journal.pone.0037443
PMCID: PMC3355128
PMID: 22616010