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Brian metastasis, which is diagnosed in 30% of triple-negative breast cancer (TNBC) patients with metastasis, causes poor survival outcomes. Growing evidence has characterized miRNAs involving in breast cancer brain metastasis; however, currently, there is a lack of prognostic plasma-based indicator for brain metastasis. In this study, high level of miR-211 can act as brain metastatic prognostic marker in vivo. High miR-211 drives early and specific brain colonization through enhancing trans-blood–brain barrier (BBB) migration, BBB adherence, and stemness properties of tumor cells and causes poor survival in vivo. SOX11 and NGN2 are the downstream targets of miR-211 and negatively regulate miR-211-mediated TNBC brain metastasis in vitro and in vivo. Most importantly, high miR-211 is correlated with poor survival and brain metastasis in TNBC patients. Our findings suggest that miR-211 may be used as an indicator for TNBC brain metastasis.

Here, we found that STK4 was significantly downregulated in colon cancer and was associated with distal metastasis and poor survival. STK4 colocalized with β‐catenin and directly phosphorylated β‐catenin resulting in its degradation via the ubiquitin‐mediated pathway. This may suggest that STK4 knockdown causes β‐catenin phosphorylation failure and subsequently β‐catenin accumulation, consequently leading to anchorage‐independent growth and metastasis in colon cancer., Mammalian STE20‐like kinase 1 (MST1/STK4/KRS2) encodes a serine/threonine kinase that is the mammalian homolog of Drosophila Hippo. STK4 plays an important role in controlling cell growth, apoptosis, and organ size. STK4 has been studied in many cancers with previous studies indicating an involvement in colon cancer lymph node metastasis and highlighting its potential as a diagnostic marker for colon cancer. However, the role of STK4 defect in promoting colon cancer progression is still understudied. Here, we found that STK4 was significantly downregulated in colon cancer and was associated with distal metastasis and poor survival. Furthermore, STK4 knockdown enhanced sphere formation and metastasis in vitro and promoted tumor development in vivo. We found that STK4 colocalized with β‐catenin and directly phosphorylated β‐catenin resulting in its degradation via the ubiquitin‐mediated pathway. This may suggest that STK4 knockdown causes β‐catenin phosphorylation failure and subsequently β‐catenin accumulation, consequently leading to anchorage‐independent growth and metastasis in colon cancer. Our results support that STK4 may act as a potential candidate for the assessment of β‐catenin‐mediated colon cancer prognosis.

Epithelial and mesenchymal transition mechanisms continue to occur during the cell cycle and throughout human development from the embryo stage to death. In embryo development, epithelial-mesenchymal transition (EMT) can be divided into three essential steps. First, endoderm, mesoderm, and neural crest cells form, then the cells are subdivided, and finally, cardiac valve formation occurs. After the embryonic period, the human body will be subjected to ongoing mechanical stress or injury. The formation of a wound requires EMT to recruit fibroblasts to generate granulation tissues, repair the wound and re-create an intact skin barrier. However, once cells transform into a malignant tumor, the tumor cells acquire the characteristic of immortality. Local cell growth with no growth inhibition creates a solid tumor. If the tumor cannot obtain enough nutrition in situ, the tumor cells will undergo EMT and invade the basal membrane of nearby blood vessels. The tumor cells are transported through the bloodstream to secondary sites and then begin to form colonies and undergo reverse EMT, the so-called “mesenchymal-epithelial transition (MET).” This dynamic change involves cell morphology, environmental conditions, and external stimuli. Therefore, in this manuscript, the similarities and differences between EMT and MET will be dissected from embryonic development to the stage of cancer metastasis.

Cancer metabolic reprogramming promotes tumorigenesis and metastasis; however, the underlying molecular mechanisms are still being uncovered. In this study, we show that the glycolytic enzyme aldolase A (ALDOA) is a key enzyme involved in lung cancer metabolic reprogramming and metastasis. Overexpression of ALDOA increased migration and invasion of lung cancer cell lines in vitro and formation of metastatic lung cancer foci in vivo. ALDOA promoted metastasis independent of its enzymatic activity. Immunoprecipitation and proteomic analyses revealed γ-actin binds to ALDOA; blocking this interaction using specific peptides decreased metastasis both in vitro and in vivo. Screening of clinically available drugs based on the crystal structure of ALDOA identified raltegravir, an antiretroviral agent that targets HIV integrase, as a pharmacologic inhibitor of ALDOA-γ-actin binding that produced antimetastatic and survival benefits in a xenograft model with no significant toxicity. In summary, ALDOA promotes lung cancer metastasis by interacting with γ-actin. Targeting this interaction provides a new therapeutic strategy to treat lung cancer metastasis. Significance: This study demonstrates the role of aldolase A and its interaction with γ-actin in the metastasis of non–small lung cancer and that blocking this interaction could be an effective cancer treatment.

Background Cancer subtype switching, which involves unclear cancer cell origin, cell fate decision, and transdifferentiation of cells within a confined tumor microenvironment, remains a major problem in pancreatic cancer (PDA). Results By analyzing PDA subtypes in The Cancer Genome Atlas, we identified that epigenetic silencing of apoptosis-associated tyrosine kinase (AATK) inversely was correlated with mRNA expression and was enriched in the quasi-mesenchymal cancer subtype. By comparing early mouse pancreatic lesions, the non-invasive regions showed AATK co-expression in cells with acinar-to-ductal metaplasia, nuclear VAV1 localization, and cell cycle suppression; but the invasive lesions conversely revealed diminished AATK expression in those with poorly differentiated histology, cytosolic VAV1 localization, and co-expression of p63 and HNF1α. Transiently activated AATK initiates acinar differentiation into a ductal cell fate to establish apical-basal polarization in acinar-to-ductal metaplasia. Silenced AATK and ectopically expressed p63 and HNF1α allow the proliferation of ductal PanINs in mice. Conclusion Epigenetic silencing of AATK regulates the cellular transdifferentiation, proliferation, and cell cycle progression in converting PDA-subtypes.

Alzheimer's disease (AD) is characterized by a chronic decline in cognitive function and is pathologically typified by cerebral deposition of amyloid-β peptide (Aβ). The production of Aβ is mediated by sequential proteolysis of amyloid precursor protein (APP) by β- and γ-secretases, and has been implicated as the essential determinant of AD pathology. Previous studies have demonstrated that the level of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] in the membrane may potentially modulate Aβ production. Given that PI(4,5)P2 is produced by type 1 phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks), we sought to determine whether the level of PIP5K type Iα (PIP5K1A) can affect production of Aβ by modulating the lipid composition of the membrane. Using a HEK-derived cell line that constitutively expresses yellow fluorescent protein-tagged APP (APP-YFP), we demonstrated that overexpression of PIP5K1A results in significant enhancement of non-amyloidogenic APP processing and a concomitant suppression of the amyloidogenic pathway, leading to a marked decrease in secreted Aβ. Consistently, cells overexpressing PIP5K1A exhibited a significant redistribution of APP-YFP from endosomal compartments to the cell surface. Our findings suggest that PIP5K1A may play a critical role in governing Aβ production by modulating membrane distribution of APP, and as such, the pathway may be a valuable therapeutic target for AD.

Based on the protein kinase A (PKA)/GSK3&beta, interaction protein (GSKIP)/glycogen synthase kinase 3&beta, (GSK3&beta, ) axis, we hypothesized that these might play a role in Tau phosphorylation. Here, we report that the phosphorylation of Tau Ser409 in SHSY5Y cells was increased by overexpression of GSKIP WT more than by PKA- and GSK3&beta, binding defective mutants (V41/L45 and L130, respectively). We conducted in vitro assays of various kinase combinations to show that a combination of GSK3&beta, with PKA but not Ca2+/calmodulin-dependent protein kinase II (CaMK II) might provide a conformational shelter to harbor Tau Ser409. Cerebrospinal fluid (CSF) was evaluated to extend the clinical significance of Tau phosphorylation status in Alzheimer&rsquo, s disease (AD), neurological disorders (NAD), and mild cognitive impairment (MCI). We found higher levels of different PKA&ndash, Tau phosphorylation sites (Ser214, Ser262, and Ser409) in AD than in NAD, MCI, and normal groups. Moreover, we used the CRISPR/Cas9 system to produce amyloid precursor protein (APPWT/D678H) isogenic mutants. These results demonstrated an enhanced level of phosphorylation by PKA but not by the control. This study is the first to demonstrate a transient increase in phosphor-Tau caused by PKA, but not GSK3&beta, in the CSF and induced pluripotent stem cells (iPSCs) of AD, implying that both GSKIP and GSK3&beta, function as anchoring proteins to strengthen the cAMP/PKA/Tau axis signaling during AD pathogenesis.

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 β treatment induced gene-body hypermethylation, dissociation of DNMT1 from the promoter, and VAV1 expression via SMAD4 and mutant KrasG12D. Pharmacological inhibition of TGFβ-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 TGFβ-VAV1 axis represents a therapeutic target.

Aberrant Wnt signaling appears to play an important role in the onset of diabetes. Moreover, the insulin signaling pathway is defective in the nucleus tractus solitarii (NTS) of spontaneously hypertensive rats (SHRs) and fructose-fed rats. Nevertheless, the relationships between Wnt signaling and the insulin pathway and the related modulation of blood pressure (BP) in the central nervous system have yet to be established. The aim of this study was to investigate the potential signaling pathways involved in Wnt-mediated BP regulation in the NTS. Pretreatment with the LDL receptor–related protein (LRP) antagonist Dickkopf-1 (DKK1) significantly attenuated the Wnt3a-induced depressor effect and nitric oxide production. Additionally, the inhibition of LRP6 activity using DKK1 significantly abolished Wnt3a-induced glycogen synthase kinase 3β (GSK-3β)S9, extracellular signal–regulated kinases 1/2T202/Y204, ribosomal protein S6 kinaseT359/S363, and AktS473 phosphorylation; and increased insulin receptor substrate 1 (IRS1)S332 phosphorylation. GSK-3β was also found to bind directly to IRS1 and to induce the phosphorylation of IRS1 at serine 332 in the NTS. By contrast, administration of the GSK-3β inhibitor TWS119 into the brain decreased the BP of hypertensive rats by enhancing IRS1 activity. Taken together, these results suggest that the GSK-3β-IRS1 pathway may play a significant role in Wnt-mediated central BP regulation.

Type 2 diabetes are at a high risk of complications related to hypertension, and reports have indicated that insulin levels may be associated with blood pressure (BP). Fructose intake has recently been reported to promote insulin resistance and superoxide formation. The aim of this study is to investigate whether fructose intake can enhance superoxide generation and impair insulin signaling in the NTS and subsequently elevate BP in rats with fructose-induced hypertension. Treatment with fructose for 4 weeks increased the BP, serum fasting insulin, glucose, homeostatic model assessment-insulin resistance, and triglyceride levels and reduced the serum direct high-density lipoprotein level in the fructose group. The Tempol treatment recovered the fructose-induced decrease in nitric oxide production in the NTS. Immunoblotting and immunofluorescence analyses further showed that fructose increased the p38- and fructose-induced phosphorylation of insulin receptor substrate 1 (IRS1S307) and suppressed AktS473 and neuronal nitric oxide synthase phosphorylation. Similarly, fructose was able to impair insulin sensitivity and increase insulin levels in the NTS. Fructose intake also increased the production of superoxide in the NTS. The results of this study suggest that fructose might induce central insulin resistance and elevate BP by enhancing superoxide production and activating p38 phosphorylation in the NTS.

Upregulation of Pin1 was shown to advance the functioning of several oncogenic pathways. It was recently shown that Pin1 is potentially an excellent prognostic marker and can also serve as a novel therapeutic target for prostate cancer. However, the molecular mechanism of Pin1 overexpression in prostate cancer is still unclear. In the present study, we showed that the mRNA expression levels of Pin1 were not correlated with Pin1 protein levels in prostate cell lines which indicated that Pin1 may be regulated at the post-transcriptional level. A key player in post-transcriptional regulation is represented by microRNAs (miRNAs) that negatively regulate expressions of protein-coding genes at the post-transcriptional level. A bioinformatics analysis revealed that miR-296-5p has a conserved binding site in the Pin1 3′-untranslated region (UTR). A luciferase reporter assay demonstrated that the seed region of miR-296-5p directly interacts with the 3′-UTR of Pin1 mRNA. Moreover, miR-296-5p expression was found to be inversely correlated with Pin1 expression in prostate cancer cell lines and prostate cancer tissues. Furthermore, restoration of miR-296-5p or the knockdown of Pin1 had the same effect on the inhibition of the ability of cell proliferation and anchorage-independent growth of prostate cancer cell lines. Our results support miR-296-5p playing a tumor-suppressive role by targeting Pin1 and implicate potential effects of miR-296-5p on the prognosis and clinical application to prostate cancer therapy.

Background and Purpose Oxidative stress is an important pathogenic factor in the development of hypertension. Resveratrol, the main antioxidant in red wine, improves NO bioavailability and prevents cardiovascular disease. The aim of this study was to examine whether resveratrol decreases the generation of reactive oxygen species (ROS), thereby reducing BP in rats with fructose-induced hypertension. Experimental Approach Rats were fed 10% fructose with or without resveratrol (10 mg·kg−1·day−1) for 1 week or for 4 weeks with resveratrol treatment beginning at week 2; systolic BP (SBP) was measured by tail-cuff method. Endogenous in vivo O2− production in the nucleus tractus solitarii (NTS) was determined with dihydroethidium. Real-time PCR and immunoblotting analyses were used to quantify RNA and protein expression levels. Key Results In fructose-fed rats, ROS levels in the NTS were higher, whereas the NO level was significantly decreased. Also, RNA and protein levels of NADPH oxidase subunits (p67, p22-phox) were elevated, superoxide dismutase 2 (SOD2) reduced and AMP-activated PK (AMPK) T172 phosphorylation levels in the NTS were lower in fructose-fed rats. Treatment with the AMPK activator resveratrol decreased levels of NADPH oxidase subunits and ROS, and increased NO and SOD2 levels in the NTS of fructose-fed rats. Administration of resveratrol, in combination with fructose at week 0 and later at week 2, significantly reduced the SBP of fructose-fed rats. Conclusions and Implications Collectively, resveratrol decreased BP through the phosphorylation of AMPK, Akt and neuronal NOS in fructose-fed rats. These novel findings suggest that resveratrol may be a potential pharmacological candidate for the treatment of hypertension.

The transcriptional network of the SRY (sex determining region Y)-box 17 (SOX17) and the prognostic impact of SOX17 protein expression in human cancers remain largely unclear. In this study, we evaluated the prognostic effect of low SOX17 protein expression and its dysregulation of transcriptional network in esophageal squamous cell carcinoma (ESCC). Low SOX17 protein expression was found in 47.4% (73 of 154) of ESCC patients with predicted poor prognosis. Re-expression of SOX17 in ESCC cells caused reduced foci formation, cell motility, decreased ESCC xenograft growth and metastasis in animals. Knockdown of SOX17 increased foci formation in ESCC and normal esophageal cells. Notably, 489 significantly differential genes involved in cell growth and motility controls were identified by expression array upon SOX17 overexpression and 47 genes contained putative SRY element in their promoters. Using quantitative chromatin immunoprecipitation-PCR and promoter activity assays, we confirmed that MACC1, MALAT1, NBN, NFAT5, CSNK1A1, FN1 and SERBP1 genes were suppressed by SOX17 via the SRY binding-mediated transcriptional regulation. Overexpression of FN1 and MACC1 abolished SOX17-mediated migration and invasion suppression. The inverse correlation between SOX17 and FN1 protein expression in ESCC clinical samples further strengthened our conclusion that FN1 is a transcriptional repression target gene of SOX17. This study provides compelling clinical evidence that low SOX17 protein expression is a prognostic biomarker and novel cell and animal data of SOX17-mediated suppression of ESCC metastasis. We establish the first transcriptional network and identify new suppressive downstream genes of SOX17 which can be potential therapeutic targets for ESCC.

Background: Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with poor prognosis. We aimed to identify a panel of CpG methylation biomarkers for prognosis prediction of ESCC patients. Methods: Illumina's GoldenGate methylation array, supervised principal components, Kaplan-Meier survival analyses and Cox regression model were conducted on dissected tumor tissues from a training cohort of 40 ESCC patients to identify potential CpG methylation biomarkers. Pyrosequencing quantitative methylation assay were performed to validate prognostic CpG methylation biomarkers in 61 ESCC patients. The correlation between DNA methylation and RNA expression of a validated marker, SOX17, was examined in a validation cohort of 61 ESCC patients. Results: We identified a panel of nine CpG methylation probes located at promoter or exon1 region of eight genes including DDIT3, FES, FLT3, NTRK3, SEPT5, SEPT9, SOX1, and SOX17, for prognosis prediction in ESCC patients. Risk score calculated using the eight-gene panel statistically predicted poor outcome for patients with high risk score. These eight-gene also showed a significantly higher methylation level in tumor tissues than their corresponding normal samples in all patients analyzed. In addition, we also detected an inverse correlation between CpG hypermethylation and the mRNA expression level of SOX17 gene in ESCC patients, indicating that DNA hypermethylation was responsible for decreased expression of SOX17. Conclusions: This study established a proof-of-concept CpG methylation biomarker panel for ESCC prognosis that can be further validated by multiple cohort studies. Functional characterization of the eight prognostic methylation genes in our biomarker panel could help to dissect the mechanism of ESCC tumorigenesis.

We have synthesized certain indeno[1,2-c]quinolin-11-one derivatives for antiproliferative evaluation. Among them, 9-methoxy-6-{4-[(oxiran-2-yl)methyl]piperazin-1-yl}-11H-indeno[1,2-c]quinolin-11-one O-(oxiran-2-yl)methyl oxime (12) exhibited strong antiproliferative activities against the growth of Hela, SKHep, MDA-MB-231, and H1299 cells with IC50 values of 0.54, 0.99, 0.79, and 1.18 μM respectively. Compound 12 was also found to be a potent DNA intercalating agent. Mechanism studies indicated that DNA damage was strongly induced by 12-treated cells even at a low concentration of 5.0 μM. Our results demonstrated that 12 significantly increased Bax expression, activation of caspase-3 and -7, enhanced the cleavage of PARP, and decreased Bcl-2 expression in H1299 cells. Compound 12 also significantly decreased the HDAC6, SIRT1, FOXO3a, p-Akt, and PTEN expression in H1299 cells.

Heat shock proteins (HSPs), which are members of the chaperone family of proteins, are essential factors for cellular responses to environmental stressors, such as hyperthermia, and are antiapoptotic. The transcription of HSPs is mainly controlled by heat shock transcription factor 1 (HSF1). In response to environmental stress, HSF1 forms a trimer, undergoes hyperphosphorylation, and is translocated to the nucleus. In this study, we show that upon heat shock treatment of cells, a WW domain-containing propyl-isomerase, PIN1, is able to colocalize to and associate with phospho-HSF1 at Ser(326) in the nucleus via its WW domain. This interaction is required for the DNA-binding activity of HSF1 and is consistent with the lower induction of HSPs in PIN1-deficient cells. This function of PIN1 is further demonstrated by in vivo refolding and survival assays, which have shown that PIN1-deficient cells are temperature sensitive and develop apoptosis upon exposure to an environmental challenge. Moreover, the reduced levels of HSPs in PIN1-deficient cells resulted in less efficient refolding of denatured proteins. Based on our results, we propose a novel role for PIN1 whereby it acts as a stress sensor regulating HSF1 activity in response to stress on multiple levels through the transcriptional activation of stress response elements in embryonic fibroblast cells, tumor cells, and neurons.

Background and Purpose Clinical studies indicate that statins have a BP-lowering effect in hypercholesterolemic individuals with hypertension. Specifically, statins modulate BP through the up-regulation of endothelial NOS (eNOS) activation in the brain. However, the signalling mechanisms through which statins enhance eNOS activation remain unclear. Therefore, we examined the possible signalling pathways involved in statin-mediated BP regulation in the nucleus tractus solitarii (NTS). Experimental Approach To investigate the involvement of Ras and other signalling pathways in simvastatin-induced effects on BP, BP and renal sympathetic nerve activity (RSNA) were determined in spontaneously hypertensive rats (SHRs) before and after i.c.v. administration of simvastatin in the absence and presence of a Ras-specific inhibitor (farnesyl thiosalicylic acid, FTS), a geranylgeranyltransferase inhibitor (GGTI-2133), a PI3K inhibitor (LY294002) or a MAPK-ERK kinase (MEK) inhibitor (PD98059). Key Results FTS significantly attenuated the decrease in BP and increased NO evoked by simvastatin and reversed the decrease in basal RSNA induced by simvastatin. Immunoblotting and pharmacological studies showed that inhibition of Ras activity by FTS significantly abolished simvastatin-induced phosphorylation of ERK1/2, ribosomal protein S6 kinase (RSK), Akt and decreased eNOS phosphorylation. Likewise, administration of Akt and ERK1/2 signalling inhibitors, LY294002 and PD98059, attenuated the reduction in BP evoked by simvastatin. Furthermore, i.c.v. simvastatin decreased Rac1 activation and the number of ROS-positive cells in the NTS. Conclusions and Implications Simvastatin modulates central BP control in the NTS of SHRs by increasing Ras-mediated activation of the PI3K-Akt and ERK1/2-RSK signalling pathways, which then up-regulates eNOS activation.

\((E)\)-6-Hydroxy-9-methoxy-6-(piperazin-1-yl)-11\(H\)-indeno[1,2-\(c\)]quinolin-11-one \(O\)-2-(pyrrolidin-1-yl)ethyl oxime (2c) was identified as a potential dual topo I/II inhibitor in our previous paper. In continuation for the search of more potent compounds, we describe herein the preparation of certain indeno[1,2-\(c\)]quinoline derivatives and evaluation of their antiproliferation, DNA binding affinity, and topoisomerases (topo I and topo II) inhibitory activities. Among them, \((E)\)-9-[3-(dimethylamino)propoxy]-11\(H\)-indeno[1,2-\(c\)]quinolin-11-one \(O\)-3-(dimethylamino)propyl oxime (11b) and its analog 11c exhibited approximately equal activity to the lead compound 2c against the growth of HeLa and A549 cancer cells. Both compounds 11b and 11c were more active than 2c in the inhibition of topo I and topo II. However, none of them exhibited significant DNA binding affinity while 2c was a very strong DNA binding agent. Compound 11b exhibited a high oral bioavailability of 39.8 % while the oral bioavailability of 2c and 11c was only 10.9 and 8.6 %, respectively. The in vivo anti-tumor evaluation of 11b in nude mice bearing subcutaneous breast cancer tumors revealed that treatment with low (10 mg/kg) or high (30 mg/kg) doses of 11b dramatically diminished tumor growth. Therefore, compound 11b is identified as a potential non-DNA intercalating dual topo I/II inhibitor.

Among enterovirus 71 infections, brainstem encephalitis progressing abruptly to cardiac dysfunction and pulmonary edema causes rapid death within several hours. However, no currently known early indicators and treatments can monitor or prevent the unexpectedly fulminant course. We investigate the possible mechanisms and treatment of fatal enterovirus 71 infections to prevent the abrupt progression to cardiac dysfunction and pulmonary edema by using an animal model.Treatment study.Research laboratory.Sprague-Dawley rats.We microinjected 6-hydroxydopamine or vitamin C into nucleus tractus solitarii of the rat and evaluated the cardiopulmonary changes after treatment with ganglionic blocker.The time course of changes in the heart and lungs of rats with brainstem lesions were investigated. Rats were administered 6-hydroxydopamine to induce brainstem lesions, causing acute hypertension in 10 minutes and acute elevations of catecholamines accompanied by acute cardiac dysfunction and increased strong expressions of connexin 43 gap junction protein in heart and lung specimens by immunohistochemical staining within 3 hours. Severe pulmonary hemorrhagic edema was produced within 6 hours, and the rats expired rapidly within 7 hours. After hexamethonium treatment, it was found that the acute hypertension induced by 6-hydroxydopamine lesions was immediately reversed and the acute high rise of catecholamine serum level was significantly attenuated within 3 hours, accompanied by preserved cardiac output and decreased expressions of connexin 43 in the heart and lungs. No pulmonary edema occurred and the rats survived for more than 14 hours.Early hexamethonium treatment attenuates acute excessive release of catecholamines to prevent cardiac dysfunction and pulmonary edema for increasing survival rate.

Deciphering the network of signaling pathways in cancer via protein-protein interactions (PPIs) at the cellular level is a promising approach but remains incomplete. We used an in situ proximity ligation assay to identify and quantify 67 endogenous PPIs among 21 interlinked pathways in two hepatocellular carcinoma (HCC) cells, Huh7 (minimally migratory cells) and Mahlavu (highly migratory cells). We then applied a differential network biology analysis and determined that the novel interaction, CRKL-FLT1, has a high centrality ranking, and the expression of this interaction is strongly correlated with the migratory ability of HCC and other cancer cell lines. Knockdown of CRKL and FLT1 in HCC cells leads to a decrease in cell migration via ERK signaling and the epithelial-mesenchymal transition process. Our immunohistochemical analysis shows high expression levels of the CRKL and CRKL-FLT1 pair that strongly correlate with reduced disease-free and overall survival in HCC patient samples, and a multivariate analysis further established CRKL and the CRKL-FLT1 as novel prognosis markers. This study demonstrated that functional exploration of a disease network with interlinked pathways via PPIs can be used to discover novel biomarkers.

The synthesis and degradation of hBora is important for the regulation of mitotic entry and exist. In G 2 phase, hBora can complex with Aurora A to activate Plk1 and control mitotic entry. However, whether the post-translational modification of hBora is relevant to the mitotic entry still unclear. Here, we used the LC-MS/MS phosphopeptide mapping assay to identify 13 in vivo hBora phosphorylation sites and characterized that GSK3β can interact with hBora and phosphorylate hBora at Ser274 and Ser278. Pharmacological inhibitors of GSK3β reduced the retarded migrating band of hBora in cells and diminished the phosphorylation of hBora by in vitro kinase assay. Moreover, as well as in GSK3β activity-inhibited cells, specific knockdown of GSK3β by shRNA and S274A/S278 hBora mutant-expressing cells also exhibited the reduced Plk1 activation and a delay in mitotic entry. It suggests that GSK3β activity is required for hBora-mediated mitotic entry through Ser274 and Ser278 phosphorylation.

BACKGROUND AND PURPOSE Neuropeptide Y (NPY) is a 36-amino acid polypeptide found abundantly in the central and peripheral nervous systems. NPY exerts a potent depressor effect via the activation of both Y1 and Y2 receptors in the nucleus tractus solitarii (NTS) of rats. However, the precise mechanisms involved in this NPY-mediated action remained unclear. EXPERIMENTAL APPROACH Effects of a selective antagonist of Y1 receptors, a PKC inhibitor, a PI3 kinase inhibitor, a NOS inhibitor, an endothelial NOS (eNOS)-selective inhibitor, a neuronal NOS (nNOS)-specific inhibitor or a MAPK inhibitor, on responses to microinjection of NPY into the NTS of Wistar-Kyoto rats were studied to determine the underlying mechanisms. Blood pressure and heart rate were measured and, in NTS, protein phosphorylation assessed by immunohistochemical techniques. KEY RESULTS Unilateral microinjection of exogenous NPY (4.65 pmol/60 nL) into the NTS of urethane-anesthetized Wistar-Kyoto rats markedly decreased blood pressure and heart rate. Microinjection of the Y1 receptor antagonist BIBP3226 or the Gi/Go-protein inhibitor, Pertussis toxin, into the NTS attenuated these NPY-induced hypotensive effects. A selective Y1 receptor agonist increased expression of ERK1/2, ribosomal protein S6 kinase (RSK) and the phosphorylation of eNOS. RSK also bound directly to eNOS and induced its phosphorylation at Ser1177. Pretreatment of the NTS with an eNOS inhibitor, but not a nNOS inhibitor, attenuated the NPY-induced hypotensive effects. CONCLUSIONS AND IMPLICATIONS Together, these results suggested that NPY-induced depressor effects were mediated by activating NPY Y1 receptor-PKC-ERK-RSK-eNOS and Ca2+-eNOS signalling pathways, which are involved in regulation of blood pressure in the NTS.

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed. Lipopolysaccharides (LPS) are surface glycolipids found on the outer membrane of gram-negative bacteria, including EHEC, and LPS biosynthesis has long been considered as potential anti-bacterial target. Here, we demonstrated that the EHEC rfaD gene that functions in the biosynthesis of the LPS inner core is required for the intestinal colonization and pathogenesis of EHEC in vivo. Disruption of the EHEC rfaD confers attenuated toxicity in Caenorhabditis elegans and less bacterial colonization in the intestine of C. elegans and mouse. Moreover, rfaD is also involved in the control of susceptibility of EHEC to antimicrobial peptides and host intestinal immunity. It is worth noting that rfaD mutation did not interfere with the growth kinetics when compared to the wild-type EHEC cells. Taken together, we demonstrated that mutations of the EHEC rfaD confer hypersusceptibility to host intestinal innate immunity in vivo, and suggested that targeting the RfaD or the core LPS synthesis pathway may provide alternative therapeutic regimens for EHEC infection.

Growth factor receptor bound protein-7 (Grb7) is a multi-domain adaptor protein that is co-opted by numerous tyrosine kinases involved in various cellular signaling and functions. The molecular mechanisms underlying the regulation of Grb7 remain unclear. Here, we revealed a novel negative post-translational regulation of Grb7 by the peptidyl-prolyl cis/trans isomerase, Pin1. Our data show that phosphorylation of Grb7 protein on the Ser194-Pro motif by c-Jun N-terminal kinase facilitates its binding with the WW domain of Pin1. Subsequently, Grb7 is degraded by the ubiquitin- and proteasome-dependent proteolytic pathway. Indeed, we found that Pin1 exerts its peptidyl-prolyl cis/trans isomerase activity in the modulation of Grb7 protein stability in regulation of cell cycle progression at the G2-M phase. This study illustrates a novel regulatory mechanism in modulating Grb7-mediated signaling, which may take part in pathophysiological consequences.

Background and aim Low expression of cyclin-dependent kinase 2-associated protein (CDK2AP1) is associated with tumour progression in oral and oesophageal carcinomas, but is not well studied in patients with head and neck cancer and nasopharyngeal carcinoma (NPC). Methods A rabbit anti-human CDK2AP1 polyclonal antibody was prepared. Immunoblotting of CDK2AP1 was examined in three cell lines and immunoexpression was retrospectively assessed in biopsies of 124 consecutive NPC patients without initial distant metastasis and treated with consistent guidelines. Results Higher CDK2AP1 expression level was identified in dysplastic oral keratinocytes, compared with two NPC-derived HONE-1 and TW01 cell lines. Low expression of CDK2AP1 (50.8%) was correlated with advanced nodal status (p=0.002) and American Joint Committee on Cancer (AJCC) stage (p=0.004). In multivariate analyses, low CDK2AP1 expression emerged as an independent prognosticator for worse disease-specific survival (DSS; p=0.037) and local recurrence-free survival (LRFS; p=0.042), along with AJCC stage III–IV (p=0.034, DSS; p=0.029, LRFS). Conclusions Low CDK2AP1 expression is common and associated with adverse prognosticators, conferring tumour aggressiveness through cycle cycle, cell growth or apoptosis cellular processes.

Background and purpose The renin-angiotensin system (RAS) is critical for the control of blood pressure by the CNS. Recently, direct renin inhibitors were approved as antihypertensive agents. However, the signalling mechanism of renin, which regulates blood pressure in the nucleus tractus solitarii (NTS) remains unclear. Here we have investigated the signalling pathways involved in renin-mediated blood pressure regulation, at the NTS. Experimental approach Depressor responses to renin microinjected into the NTS of Wistar-Kyoto rats were elicited in the absence and presence of the endothelial nitric oxide synthase (eNOS)-specific inhibitor, N(5)-(-iminoethyl)-L-ornithine, Akt inhibitor IV and LY294002, a PI3K inhibitor and GP antagonist-2A [G(q) inhibitor]. Lisinopril (angiotensin converting enzyme inhibitor), losartan, valsartan (angiotensin AT(1) receptor antagonists), D-Ala7-Ang-(1-7) (angiotensin-(1-7) receptor antagonist) were used to study the involvement of RAS on renin-induced depressor effects. Key results Microinjection of renin into the NTS produced a prominent depressor effect and increased NO production. Pretreatment with G(q) -PI3K-Akt-eNOS pathway-specific inhibitors significantly attenuated the depressor response evoked by renin. Immunoblotting and immunohistochemical studies further showed that inhibition of PI3K significantly blocked renin-induced eNOS-Ser ¹¹⁷ and Akt-Ser⁴⁷³ phosphorylation in situ. In addition, pre-treatment of the NTS with RAS inhibitors attenuated the vasodepressor effects evoked by renin. Microinjection of renin also increased Ras activation in the NTS. Conclusions and implications Taken together, these results suggest renin modulated blood pressure at the NTS by AT₁ and Mas receptor-mediated activation of G(q) and Ras to evoke PI3K-Akt-eNOS signalling.

Three classes of kojic acid derivatives were synthesized and examined for their antiproliferative activity against HeLa cells. Both 8b and 11 co-treated with copper ion exhibited synergistic effect on the HeLa cell growth inhibition with GI50 values of 11.9 and 7.1 μM, respectively. Flow cytometric analysis of HeLa cells revealed that 11-Cu co-treatment induced the sub-G1 arrest in a dose-dependent manner, suggesting that the growth-inhibitory effect is attributed to DNA fragmentation. Moreover, western blot of HeLa cells cytosolic extracts displayed the cleavage of the 116-kDa protein poly(ADP-ribose) polymerase and activation of caspase-3 by the reduced level of the 32-kDa proenzyme, indicating that the caspase-dependent apoptotic pathway was involved. We further demonstrated that MAPK pathway regulators such as ERK and p38 were activated in response to 11-Cu co-treatment, suggesting that the intracellular oxidative stress was dramatically stimulated by the copper ion. Taken together, we have successfully synthesized kojic acid-derived copper-induced apoptotic agents.

Recent studies have reported that the activation of AMP-activated protein kinase (AMPK) suppressed oxidative stress. The aim of this study was to examine whether the activation of AMPK in the brain decreased Rac1-induced ROS generation, thereby reducing blood pressure (BP) in rats with fructose-induced hypertension. The inhibition of ROS by treatment with an AMPK activator (oral resveratrol, 10 mg/kg/day) for 1 week decreased the BP and increased the NO production in the rostral ventrolateral medulla (RVLM) of fructose-fed rats but not in control Wistar-Kyoto (WKY) rats. In addition, resveratrol treatment abolished the Rac1-induced increases in the activity of the NADPH oxidase subunits p22-phox and reduced the activity of SOD2, while treatment with an AMPK inhibitor (compound C, 40 μM/day) had the opposite effect, in the fructose-fed rats. Interestingly, the activation of AMPK abolished Rac1 activation and decreased BP by inducing the activities of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and ribosomal protein S6 kinase (RSK) and nNOS phosphorylation in the fructose-fed rats. We conclude that the activation of AMPK decreased BP, abolished ROS generation and enhanced ERK1/2-RSK-nNOS pathway activity by negatively regulating Racl-induced NADPH oxidase levels in the RVLM during oxidative stress–associated hypertension.

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 3β (GSK3β) 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 GSK3β-binding FXXXLI/VXRLE motifs. Immunofluorescence, immunoprecipitation and molecular modelling showed that WWOX interacts physically with GSK3β. We demonstrated biochemically that WWOX can bind directly to GSK3β through its short-chain alcohol dehydrogenase/reductase domain. Moreover, the overexpression of WWOX inhibited GSK3β-stimulated S396 and S404 phosphorylation within the microtubule domains of Tau, indicating that WWOX is involved in regulating GSK3β activity in cells. WWOX repressed GSK3β 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 GSK3β 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.

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.

BACKGROUND AND PURPOSE Recent evidence has suggested that nicotine decreases blood pressure (BP) and heart rate (HR) in the nucleus tractus solitarii (NTS), indicating that nicotinic acetylcholine receptors (nAChRs) play an important role in BP control in the NTS. However, the signalling mechanisms involved in nAChR-mediated depressor effects in the NTS are unclear. Hence, the aim of this study was to investigate these signalling mechanisms. EXPERIMENTAL APPROACH Depressor responses to nicotine microinjected into the NTS of Wistar-Kyoto rats were elicited in the absence and presence of an antagonist of α7 nAChR, the calcium chelator ethylene glycol tetraacetic acid, a calmodulin-specific inhibitor, nitric oxide (NO) synthase (NOS) inhibitor, endothelial NOS (eNOS)-selective inhibitor or neuronal NOS (nNOS)-specific inhibitor. KEY RESULTS Microinjection of nicotine into the NTS produced a dose-dependent decrease in BP and HR, and increased nitrate levels. This depressor effect of nicotine was attenuated after pretreatment with a nAChR antagonist or blockers of the calmodulin-eNOS pathway. In contrast, N5-(1-Imino-3-butenyl)-L-ornithine (vinyl-L-NIO), nNOS-specific inhibitor, did not diminish these nicotine-mediated effects. Calmodulin was found to bind eNOS after nicotine injection into NTS. However, nicotine did not affect the eNOS phosphorylation level or eNOS upstream extracellular signal-regulated kinases (ERK)1/2 and Akt phosphorylation levels. Furthermore, pretreatment with an ERK1/2 or Akt inhibitor did not attenuate nicotine-induced depressor effects in the NTS. CONCLUSIONS AND IMPLICATIONS These results suggest that the nAChR-Ca2+-calmodulin-eNOS-NO signalling pathway, but not nNOS, plays a significant role in central BP regulation, and neither the ERK1/2 nor Akt signalling pathway are significantly involved in the activation of eNOS by nAChRs in the NTS.

Background: Osteopontin (OPN) is involved in the gastric cancer progression. The study validated whether OPN expressions correlate with Helicobacter pylori-related chronic gastric inflammation and the precancerous change as intestinal metaplasia (IM). Methods: This study included 105 H. pylori-infected patients (63 without and 42 with IM) and 29 H. pylori-negative controls. In each subject, the gastric OPN expression intensity was evaluated by immunohistochemistry, and graded from 0 to 4 for the epithelium, lamina propria, and areas with IM, respectively. For the H. pylori-infected subjects, the gastric inflammation was assessed by the Updated Sydney System. Forty-nine patients received follow-up endoscopy to assess OPN change on gastric mucosa after H. pylori eradication. The in vitro cell-H. pylori coculture were performed to test the cell origin of OPN. Results: The H. pylori-infected patients had higher gastric OPN expression than the noninfected controls (p

Background. We investigated the relationship of the immunohistochemical expression status of manganese superoxide dismutase (MnSOD), catalase, glutathione peroxi- dase (GPx), and myeloperoxidase (MPO) in buccal mucosal squamous cell carcinoma (SCC) with clinicopathologic parame- ters and prognosis. Methods. The expression status of MnSOD, GPx, catalase, and MPO was evaluated by immunohistochemistry in a series of 216 surgically resected buccal mucosal SCC specimens, using tissue microarray slides. Results. MnSOD, GPx, catalase, and MPO were commonly expressed in buccal mucosal SCC. The high expression level of MnSOD was associated with better disease-specific survival (p ¼ .009), especially for patients in moderate or poor cell differentiation (p ¼ .045), pathologic stage I (p ¼ .002) and postoperative radiotherapy (p ¼ .048). The high expres- sion level of GPx was also correlated with better disease-specific survival (p ¼ .042), especially for patients in pathologic stage IV (p ¼ .010) and postoperative radiotherapy (p ¼ .018). Conclusions. MnSOD and GPx are significant prognostic factors for favorable survival in patients with buccal mucosal SCC. V C 2011 Wiley Periodicals, Inc. Head Neck 33: 1606- 1615, 2011

Sprouty protein is a novel feedback regulator involved in downstream inactivation of several growth factor receptor pathways. Sprouty2 (Spry2) protein was shown to be downregulated in human cancers. High levels of microRNA-21 (miRNA-21) expression have been associated with poor survival and poor response to adjuvant chemotherapy in cancer patients. But the effect of Spry2 in human colon cancer remained unknown. Paired tumor and normal mucosa samples from patients were examined for their expression of Spry2 mRNA and miRNA-21 by real-time quantitative RT-PCR analysis. Our results show that Spry2 was downregulated in human colon cancer, and its expression levels were lower in advanced-stage tumors than in early-stage tumors. There was a negative correlation between the expression levels of Spry2 and miRNA-21. Furthermore, overexpression of Spry2 suppressed the growth and migration of colon cancer cells with a concomitant increase in PTEN expression and reduction of Akt and MAPK phosphorylation. Spry2 inhibited the growth and tumorigenesis of colon cancer cells in vivo. Conclusively, we show for the first time that Spry2 expression is downregulated and miRNA-21 is upregulated in the clinical samples of colon cancer, which correlates with clinical stage of disease. Thus, Spry2 functions as a tumor suppressor in colon cancer.

Certain indeno[1,2-c]quinoline derivatives were synthesized and evaluated for their antiproliferation, DNA binding affinity, and topoisomerases (topo I and topo II) inhibitory activities. The preliminary results are the following: (1) substituent of the aminoalkoxyimino side chain at C11 is important for antiproliferative activities in which the terminal amine preferred to be a tertiary or the cyclic five-membered pyrrolidino ring; (2) among the indeno[1,2-c]quinoline derivatives evaluated, (E)-6-hydroxy-9-methoxy-11H-indeno[1,2-c]quinolin-11-one O-2-(pyrrolidin-1-yl)ethyl oxime (8c) was found to be one of the most cytotoxic agents with a GI50 value of 0.84, 0.89, and 0.79 microM against SAS, A549, and BT483, respectively, which is more active than camptothecin; (3) substituent at C6 is crucial for the selective cytotoxicity in which the OH group is the most preferred while hydrogen or piperazine exhibited cytotoxicity on both cancer cells and Detroit-551; (4) a positive correlation of antiproliferative activity, DNA binding affinity, and topo I and topo II inhibitory activities has been observed for indeno[1,2-c]quinoline derivatives; (5) compound 8c induced DNA fragmentation may through caspase-3 activation, phosphorylation of the histone protein H2AX at Ser139 (gamma-H2AX), and PARP cleavage; (6) compound 8c demonstrated significant tumor regression in the human breast xenograft model; (7) indeno[1,2-c]quinoline derivatives are a new class of molecules that have the potential to be developed as dual topo I and topo II inhibitory agents.

The scaffold of 3,5-diaryl-1H-pyrazole was selected as a molecular template to synthesize novel growth-inhibitory agents in the present study. Our findings suggested that analogs bearing electron-withdrawing groups on one ring while electron-donating groups on another reveal significant activities. In particular, 26 bearing a 1,1'-biphenyl moiety displayed the most potent activity against OVCA, SW620, H460 and AGS cells with GI(50) values of 0.67, 0.89, 0.73 and 0.79 microM, respectively. The mechanistic study revealed that 26-mediated apoptosis-inducing effect on OVCA cells was, in part, attributed to the inhibition of protein kinase B/Akt activity, accompanied by the mitochondrial apoptotic pathway through the activation of caspase-9, caspase-3, as well as the cleavage of protein poly(ADP-ribose) polymerase (PARP) and DNA fragmentation. Further structure-activity relationship study employed by Comparative Molecular Field Analysis (CoMFA) was carried out with q(2) and R(2) values of 0.671 and 0.846, respectively.

Rationale : Angiotensin (Ang) II exerts diverse physiological actions in both the peripheral and central neural systems. It was reported that the activity of Ang II is higher in the nucleus tractus solitarii (NTS) of spontaneously hypertensive rats (SHRs) and that angiotensin type-1 receptors are colocalized with NAD(P)H oxidase in the neurons of the NTS, resulting in the induction of local reactive oxygen species production by Ang II. However, the signaling mechanisms of Ang II that induce hypertension remain unclear. Objective : The aim of this study was to investigate the possible signaling pathways involved in Ang II–mediated blood pressure regulation in the NTS. Methods and Results : Male SHRs were treated with losartan or tempol for 2 weeks, after which systolic blood pressure was observed to decrease significantly. Dihydroethidium staining showed many cells with high reactive oxygen species in the NTS of SHRs. The addition of losartan or tempol decreased the numbers of reactive oxygen species–positive cells in the NTS. The systemic administration of losartan or tempol reduced the systolic blood pressure and increased NO production. Immunoblotting and immunohistochemical analysis further showed that inhibition of Ang II activity by losartan or tempol significantly increased the expression extracellular signal-regulated kinase (ERK)1/2, ribosomal protein S6 kinase (RSK), and also increased neuronal NO synthase (nNOS) phosphorylation. RSK was also found to bind directly to nNOS and induce phosphorylation at the Ser1416 position. Conclusions : Taken together, these results suggest that the ERK1/2-RSK-nNOS signaling pathway may play a significant role in Ang II–mediated central blood pressure regulation.

CD44 and osteopontin (OPN) are functionally related molecules that, alone or in combination, play miscellaneous biological and pathophysiologic roles. CD44 cleavage, one unique feature of CD44, occurs in human cancers, but its function remains unclear. This study aimed to assess the clinicopathologic significance and mechanism of CD44 cleavage in gastrointestinal stromal tumor (GIST) with respect to OPN and OPN/CD44 interaction.CD44 cleavage was evaluated by immunoblotting in 31 primary GIST tumor specimens with paired normal tissues. OPN/CD44 interaction was examined by in situ proximity ligation assay. The associations of CD44 cleavage activity with clinicopathologic parameters, cyclin D1 expression, beta-catenin expression, OPN expression, and OPN/CD44 interaction were analyzed.CD44 cleavage activity was demonstrated in 87.1% of GIST, in contrast to its absence in normal tissues. Increased CD44 cleavage activity was significantly associated with enhanced mitosis by multivariate analysis, in addition to being related to tumor size, recurrence, high-risk status, and poor survival by univariate analysis. Mitosis was significantly higher in GIST with increased CD44 cleavage activity, which also positively correlated with tumor-specific beta-catenin and cyclin D1 overexpression, indicating a mitotic effect through aberrant cell cycle. Both OPN and OPN/CD44 interactions were significantly associated with CD44 cleavage.Our study demonstrates the clinicopathological significance of CD44 cleavage in GIST. There is a significantly increased mitosis associated with CD44 cleavage in relation to OPN/CD44 interaction and dysregulated cell cycle in GIST.

Acute tubular necrosis is followed by regeneration of damaged renal tubular epithelial cells, and renal stem cells are supposed to contribute to this process. The purpose of our study is to test the hypothesis that renal stem cells isolated from adult mouse kidney accelerate renal regeneration via participation in the repair process. A unique population of cells exhibiting characteristics consistent with renal stem cells, mouse kidney progenitor cells (MKPC), was isolated from Myh9 targeted mutant mice. Features of these cells include (1) spindle-shaped morphology, (2) self-renewal of more than 100 passages without evidence of senescence, and (3) expression of Oct-4, Pax-2, Wnt-4, WT-1, vimentin, α-smooth muscle actin, CD29, and S100A4 but no SSEA-1, c-kit, or other markers of more differentiated cells. MKPC exhibit plasticity as demonstrated by the ability to differentiate into endothelial cells and osteoblasts in vitro and endothelial cells and tubular epithelial cells in vivo. The origin of the isolated MKPC was from the interstitium of medulla and papilla. Importantly, intrarenal injection of MKPC in mice with ischemic injury rescued renal damage, as manifested by decreases in peak serum urea nitrogen, the infarct zone, and the necrotic injury. Seven days after the injury, some MKPC formed vessels with red blood cells inside and some incorporated into renal tubules. In addition, MKPC treatment reduces the mortality in mice after ischemic injury. Our results indicate that MKPC represent a multipotent adult stem cell population, which may contribute to the renal repair and prolong survival after ischemic injury.

Background: The relationship between cytokine gene polymorphisms and susceptibility to Kawasaki diseases (KD) is still controversial, so the aim of the present study was to investigate the association of 14 various polymorphisms of 9 cytokine genes (interleukin (IL)-1A, IL-1B, IL-1RN, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor-A and transforming growth factor-B) with KD risk. Methods and Results: A total of 211 KD children and 221 adult controls were recruited. All controls were frequency matched to KD patients on sex and ethnicity. PCR and TaqMan assays were used for genotyping. There were no significant differences between KD children and adult controls in the genotype or allelic type frequencies of the 14 polymorphisms. No significant associations were found between haplotypes, constructed by IL-1B, IL-4, IL-8, and IL-10 cytokine genes, and risk of KD. Additionally, a linear trend was observed when these single nucleotide polymorphisms were combined, as evidenced by an increasing risk of KD as the number of at-risk genotypes increased (Plinear trend=0.002). In the stratification analysis of age and sex, there was a linear trend of KD risk as the number of at-risk genotypes increased among those aged >12 months (P=0.014) or female (P=0.001), respectively. Conclusions: No associations between individual cytokine genetic polymorphisms and susceptibility of KD were observed, but a gene-dosage effect on the risk of KD was found, especially for older or female subjects. (Circ J 2010; 74: 2726-2733)

The inflammatory effects of glycogen synthase kinase-3 (GSK-3) have been identified; however, the potential mechanism is still controversial. In this study, we investigated the effects of GSK-3-mediated interleukin-10 (IL-10) inhibition on lipopolysaccharide (LPS)-induced inflammation. Treatment with GSK-3 inhibitor significantly blocked LPS-induced nitric oxide (NO) production as well as inducible NO synthase (iNOS) expression in BV2 murine microglial cells and primary rat microglia-enriched cultures. Using an antibody array and enzyme-linked immunosorbent assay, we found that GSK-3-inhibitor treatment blocked LPS-induced upregulation of regulated on activation normal T-cell expressed and secreted (RANTES) and increased IL-10 expression. The time kinetics and dose-response relations were confirmed. Reverse transcription-polymerase chain reaction showed changes on the messenger RNA level as well. Inhibiting GSK-3 using short-interference RNA, and transfecting cells with dominant-negative GSK-3beta, blocked LPS-elicited NO and RANTES expression but increased IL-10 expression. In contrast, GSK-3beta overexpression upregulated NO and RANTES but downregulated IL-10 in LPS-stimulated cells. Treating cells with anti-IL-10 neutralizing antibodies to prevent GSK-3 from downregulating NO and RANTES showed that the anti-inflammatory effects are, at least in part, IL-10-dependent. The involvement of Akt, extracellular signal-regulated kinase, p38 mitogen-activated protein kinase and nuclear factor-kappaB that positively regulated IL-10 was demonstrated. Furthermore, inhibiting GSK-3 increased the nuclear translocation of transcription factors, that all important for IL-10 expression, including CCAAT/enhancer-binding protein beat (C/EBPbeta), C/EBPdelta, cAMP response binding element protein and NF-kappaB. Taken together, these findings reveal that LPS induces iNOS/NO biosynthesis and RANTES production through a mechanism involving GSK-3-mediated IL-10 downregulation.

A series of 2-styrylchromone analogs were synthesized and examined for their antiproliferative effects on a panel of carcinoma cells. Among the tested agents, only 4m exhibited a moderate activity with an IC 50 value of 28.9 μM against PC-3 cells which indicates the selectivity of PC-3 cells in response to 2-styrylchromones. In addition, 4q demonstrated the most antiproliferative effect with an IC 50 value of 4.9 μM against HeLa cells. Flow cytometric analysis and DAPI staining revealed that HeLa cells exposed to 4q as low as 5 μM induced cell death through sub-G1 arrest and DNA fragmentation. Furthermore, CoMFA analysis of tested 2-styrylchromones resulted in a q 2 of 0.459 to generate a 3D-QSAR model on BT483 cell line. Together, these results suggest a potential structural optimization and pharmacological study of 2-styrylchromones.

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 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.

This study identifies a novel mechanism by which thiazolidinediones mediate cyclin D1 repression in prostate cancer cells. Based on the finding that the thiazolidinedione family of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists mediated PPARgamma-independent cyclin D1 degradation, we developed a novel PPARgamma-inactive troglitazone derivative, STG28, with high potency in cyclin D1 ablation. STG28-mediated cyclin D1 degradation was preceded by Thr-286 phosphorylation and nuclear export, which however, were independent of glycogen synthase kinase 3beta. Mutational analysis further confirmed the pivotal role of Thr-286 phosphorylation in STG28-induced nuclear export and proteolysis. Of several kinases examined, inhibition of IkappaB kinase alpha blocked STG28-mediated cytoplasmic sequestration and degradation of cyclin D1. Pulldown of ectopically expressed Cul1, the scaffold protein of the Skp-Cullin-F-box E3 ligase, in STG28-treated cells revealed an increased association of cyclin D1 with beta-TrCP, whereas no specific binding was noted with other F-box proteins examined, including Skp2, Fbw7, Fbx4, and Fbxw8. This finding represents the first evidence that cyclin D1 is targeted by beta-TrCP. Moreover, beta-TrCP expression was up-regulated in response to STG28, and ectopic expression and small interfering RNA-mediated knock-down of beta-TrCP enhanced and protected against STG28-facilitated cyclin D1 degradation, respectively. Because cyclin D1 lacks the DSG destruction motif, mutational and modeling analyses indicate that cyclin D1 was targeted by beta-TrCP through an unconventional recognition site, (279)EEVDLACpT(286), reminiscent to that of Wee1. Moreover, we obtained evidence that this beta-TrCP-dependent degradation takes part in controlling cyclin D1 turnover when cancer cells undergo glucose starvation, which endows physiological relevance to this novel mechanism.

We have previously discovered that star fruit can induce oliguric acute renal failure. To investigate the mechanisms of star fruit-associated acute oxalate nephropathy, the nephrotoxic effect of star fruit was examined in both cellular experiments and animal models. We evaluated renal function, pathological changes in kidney tissues and apoptotic effects using terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay in four groups of rats – a control group (CG), fed with tap water (1); a star fruit group (SG), fed with star fruit juice naturally containing 0.2 M oxalate (2); and oxalate groups (OxG), fed with 0.2 M (3) or 0.4 M (4) oxalate solution. The effects of both star fruit juice and oxalate on MDCK cells were also analyzed by flow cytometry. We found that the mean creatinine clearance was significantly lower in the SG, 0.2 M OxG and 0.4 M OxG. Dose-dependent apoptotic effects were evident from the TUNEL assay, and flow cytometry analysis of treated MDCK cells showed dose- and time-dependent effects. Our findings suggest that star fruit juice produces acute renal injury, not only through the obstructive effect of calcium oxalate crystals, but also by inducing apoptosis of renal epithelial cells, which may be caused by the levels of oxalate in the fruit.

Neuropathological hallmarks of Alzheimer's disease are extracellular senile plaques and intracellular neurofibrillary lesions. The neurofibrillary lesions mainly consist of the hyperphosphorylated microtubule-associated protein Tau predominantly expressed in the axon of CNS neurons. Hyperphosphorylation of Tau negatively affects its binding to tubulin and decreases the capacity to promote microtubule assembly. Among a number of proline-directed kinases capable of phosphorylating paired helical filament-Tau, glycogen synthase kinase 3beta (GSK3beta) was first identified as a Tau protein kinase I and has been demonstrated to phosphorylate Tau both in vivo and in vitro. However, the phosphorylation mechanism of Tau by GSK3beta remained unclear. In this study, we show that the T231 is the primary phosphorylation site for GSK3beta and the Tau227-237 (AVVRTPPKSPS) derived from Tau containing T231P232 motif is identified as the GSK3beta binding site with high affinity of a Kd value 0.82 +/- 0.16 mumol/L. Our results suggest that direct binding and phosphorylation of T231P232 motif by GSK3beta induces conformational change of Tau and consequentially alters the inhibitory activity of its N-terminus that allows the phosphorylation of C-terminus of Tau by GSK3beta. Furthermore, hyperphosphorylation reduces Tau's ability to promote tubulin assembly and to form bundles in N18 cells. T231A mutant completely abolishes Tau phosphorylation by GSK3beta and retains the ability to promote tubulin polymerization and bundle formation. Taken together, these results suggest that phosphorylation of T231 by GSK3beta may play an important role in Tau's hyperphosphorylation and functional regulation.

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.

WW domain-containing oxidoreductase (WWOX) has been reported to be a tumor suppressor in multiple cancers, including prostate cancer. WWOX can induce apoptotic responses to inhibit tumor progression, and the other mechanisms of WWOX in tumor suppression have also been reported recently. In this study, we found significant down-regulation of WWOX in prostate cancer specimens and prostate cancer cell lines compared with the normal controls. In addition, an ectopically increased WWOX expression repressed tumor progression both in vitro and in vivo. Interestingly, overexpression of WWOX in 22Rv1 cells led to cell cycle arrest in the G1 phase but did not affect sub-G1 in flow cytometry. GFP-WWOX overexpressed 22Rv1 cells were shown to inhibit cell cycle progression into mitosis under nocodazole treatment in flow cytometry, immunoblotting and GFP fluorescence. Further, cyclin D1 but not apoptosis correlated genes were down-regulated by WWOX both in vitro and in vivo. Restoration of cyclin D1 in the WWOX-overexpressed 22Rv1 cells could abolish the WWOX-mediated tumor repression. In addition, WWOX impair c-Jun-mediated cyclin D1 promoter activity. These results suggest that WWOX inhibits prostate cancer progression through negatively regulating cyclin D1 in cell cycle lead to G1 arrest. In summary, our data reveal a novel mechanism of WWOX in tumor suppression.

Background In lung cancer, uPA, its receptor (uPAR), and the inhibitors PAI-1 and PAI-2 of the plasminogen activator family interact with MMP-2 and MMP-9 of the MMP family to promote cancer progression. However, it remains undetermined which of these markers plays the most important role and may be the most useful indicator to stratify the patients by risk. Methods We determined the individual prognostic value of these 6 markers by analyzing a derivation cohort with 98 non-small cell lung cancer patients by immunohistochemical staining. The correlation between the IHC expression levels of these markers and disease prognosis was investigated, and an immunohistochemical panel for prognostic prediction was subsequently generated through prognostic model analysis. The value of the immunohistochemical panel was then verified by a validation cohort with 91 lung cancer patients. Results In derivation cohort, PAI-2 is the most powerful prognostic factor (HR = 2.30; P = 0.001), followed by MMP-9 (HR = 2.09; P = 0.019) according to multivariate analysis. When combining PAI-2 and MMP-9, the most unfavorable prognostic group (low PAI-2 and high MMP-9 IHC expression levels) showed a 6.40-fold increased risk of a poor prognosis compared to the most favorable prognostic group (high PAI-2 and low MMP-9 IHC expression levels). PAI-2 and MMP-9 IHC panel could more precisely identify high risk patients in both derivation and validation cohort. Conclusions We revealed PAI-2 as the most powerful prognostic marker among PA and MMP protease family even after considering their close relationships with each other. By utilizing a combination of PAI-2 and MMP-9, more precise prognostic information than merely using pathological stage alone can be obtained for lung cancer patients.

We have shown that Sp1 phosphorylation at Thr739 decreases its DNA-binding activity. In this study, we found that phosphorylation of Sp1 at Thr739 alone is necessary, but not sufficient for the inhibition of its DNA-binding activity during mitosis. We demonstrated that Pin1 could be recruited to the Thr739(p)-Pro motif of Sp1 to modulate the interaction between phospho-Sp1 and CDK1, thereby facilitating CDK1-mediated phosphorylation of Sp1 at Ser720, Thr723 and Thr737 during mitosis. Loss of the C-terminal end of Sp1 (amino acids 741-785) significantly increased Sp1 phosphorylation, implying that the C-terminus inhibits CDK1-mediated Sp1 phosphorylation. Binding analysis of Sp1 peptides to Pin1 by isothermal titration calorimetry indicated that Pin1 interacts with Thr739(p)-Sp1 peptide but not with Thr739-Sp1 peptide. X-ray crystallography data showed that the Thr739(p)-Sp1 peptide occupies the active site of Pin1. Increased Sp1 phosphorylation by CDK1 during mitosis not only stabilized Sp1 levels by decreasing interaction with ubiquitin E3-ligase RNF4 but also caused Sp1 to move out of the chromosomes completely by decreasing its DNA-binding activity, thereby facilitating cell cycle progression. Thus, Pin1-mediated conformational changes in the C-terminal region of Sp1 are critical for increased CDK1-mediated Sp1 phosphorylation to facilitate cell cycle progression during mitosis.