Lichen Secondary Metabolite, Physciosporin, Inhibits Lung Cancer Cell Motility

Lichens produce various unique chemicals that can be used for pharmaceutical purposes. To screen for novel lichen secondary metabolites showing inhibitory activity against lung cancer cell motility, we tested acetone extracts of 13 lichen samples collected in Chile. Physciosporin, isolated from Pseudocyphellaria coriacea (Hook f. & Taylor) D.J. Galloway & P. James, was identified as an effective compound and showed significant inhibitory activity in migration and invasion assays against human lung cancer cells. Physciosporin treatment reduced both protein and mRNA levels of N-cadherin with concomitant decreases in the levels of epithelial-mesenchymal transition markers such as snail and twist. Physciosporin also suppressed KITENIN (KAI1 C-terminal interacting tetraspanin)-mediated AP-1 activity in both the absence and presence of epidermal growth factor stimulation. Quantitative real-time PCR analysis showed that the expression of the metastasis suppressor gene, KAI1, was increased while that of the metastasis enhancer gene, KITENIN, was dramatically decreased by physciosporin. Particularly, the activity of 3’-untranslated region of KITENIN was decreased by physciosporin. Moreover, Cdc42 and Rac1 activities were decreased by physciosporin. These results demonstrated that the lichen secondary metabolite, physciosporin, inhibits lung cancer cell motility through novel mechanisms of action.

Mst2 Controls Bone Homeostasis by Regulating Osteoclast and Osteoblast Differentiation

Mammalian sterile 20-like kinase 2 (Mst2) plays a central role in the Hippo pathway, controlling cell proliferation, differentiation, and apoptosis during development. However, the roles of Mst2 in osteoclast and osteoblast development are largely unknown. Here, we demonstrate that mice deficient in Mst2 exhibit osteoporotic phenotypes with increased numbers of osteoclasts and decreased numbers of osteoblasts as shown by micro-computed tomography (µCT) and histomorphometric analyses. Osteoclast precursors lacking Mst2 exhibit increased osteoclastogenesis and Nfatc1, Acp5, and Oscar expression in response to receptor activator of NF-κB ligand (RANKL) exposure. Conversely, Mst2 overexpression in osteoclast precursors leads to the inhibition of RANKL-induced osteoclast differentiation. Osteoblast precursors deficient in Mst2 exhibit attenuated osteoblast differentiation and function by downregulating the expression of Runx2, Alpl, Ibsp, and Bglap. Conversely, ectopic expression of Mst2 in osteoblast precursors increases osteoblastogenesis. Finally, we demonstrate that the NF-κB pathway is activated by Mst2 deficiency during osteoclast and osteoblast development. Our findings suggest that Mst2 is involved in bone homeostasis, functioning as a reciprocal regulator of osteoclast and osteoblast differentiation through the NF-κB pathway.

Determination of C-Terminal δ-Catenin Responsible for Inducing Dendritic Morphogenesis

δ-Catenin induces dendritic morphogenesis in several cells and it was reported that deletion of C-terminal 207 amino acid of δ-catenin completely abolished the dendritic morphogenesis. However, exact domain responsible for inducing dendritic morphogenesis in C-terminus of δ-catenin was not mapped. Here, we report that expression of ΔC47 (lacking 47 amino acid of C-terminus: 1-1200), ΔC77 (lacking 77 amino acid of C-terminus: 1-1170) deletion mutants of δ-catenin induced the dendritic morphogenesis of HEK293T and NIH3T3 cells as full-length δ-catenin did. In agreement with previous report, ΔC207 deletion mutant did not show the dendritic morphogenesis of the cells. Interestingly, introducing 107 amino acid deletion of C-terminus (ΔC107 mutant: 1-1140) and 177 amino acid deletion of C-terminus (ΔC177 mutant: 1-1070) showed limited primary and secondary dendritic process and notable spine-like process formation. These results suggest that 1140-1170 amino acid of C-terminal δ-catenin is required for primary and secondary dendrite-like process formation.

Chrysin inhibits tumor promoter-induced MMP-9 expression by blocking AP-1 via suppression of ERK and JNK pathways in gastric cancer cells

Cell invasion is a crucial mechanism of cancer metastasis and malignancy. Matrix metalloproteinase-9 (MMP-9) is an important proteolytic enzyme involved in the cancer cell invasion process. High expression levels of MMP-9 in gastric cancer positively correlate with tumor aggressiveness and have a significant negative correlation with patients’ survival times. Recently, mechanisms suppressing MMP-9 by phytochemicals have become increasingly investigated. Chrysin, a naturally occurring chemical in plants, has been reported to suppress tumor metastasis. However, the effects of chrysin on MMP-9 expression in gastric cancer have not been well studied. In the present study, we tested the effects of chrysin on MMP-9 expression in gastric cancer cells, and determined its underlying mechanism. We examined the effects of chrysin on MMP-9 expression and activity via RT-PCR, zymography, promoter study, and western blotting in human gastric cancer AGS cells. Chrysin inhibited phorbol-12-myristate 13-acetate (PMA)-induced MMP-9 expression in a dose-dependent manner. Using AP-1 decoy oligodeoxynucleotides, we confirmed that AP-1 was the crucial transcriptional factor for MMP-9 expression. Chrysin blocked AP-1 via suppression of the phosphorylation of c-Jun and c-Fos through blocking the JNK1/2 and ERK1/2 pathways. Furthermore, AGS cells pretreated with PMA showed markedly enhanced invasiveness, which was partially abrogated by chrysin and MMP-9 antibody. Our results suggest that chrysin may exert at least part of its anticancer effect by controlling MMP-9 expression through suppression of AP-1 activity via a block of the JNK1/2 and ERK1/2 signaling pathways in gastric cancer AGS cells.

Long-Term Outcome of Treatment with Topical Corticosteroids for Severe Dry Eye Associated with Sjögren's Syndrome

This retrospective study was performed to analyze the long-term outcome of topical corticosteroid treatment for severe dry eye associated with Sjögren's syndrome (SS). Patients who had severe dry eye associated with SS were topically treated with loteprednol etabonate 0.5% (group A, n=66) or fluorometholone 0.1% (group B, n=67) twice daily and were followed up for 2 years. Visual acuity (VA), intraocular pressure (IOP), Schirmer test, tear film breakup time (BUT), keratoepitheliopathy, and symptom scores were measured at baseline and 6, 12, 18, and 24 months after treatment. VA and IOP were not changed significantly during follow-up in either group. Schirmer test results, keratoepitheliopathy, and symptom scores at 6, 12, 18, and 24 months (p<0.05) and tear film BUT at 12, 18, and 24 months (p<0.05) significantly improved after treatment compared with baseline in both groups. No significant differences between the groups were found in any parameter during follow-up. At 24 months, the number of patients with IOP elevation of more than 2 mmHg compared with baseline was 4 in group A (6.1%) and 9 in group B (13.4%). The mean IOP in these patients was lower in group A than in group B (15.00±0.82 mmHg versus 16.50±1.12 mmHg; p=0.04). Long-term application of low-dose topical corticosteroids is effective for controlling signs and symptoms of chronic, severe dry eye associated with SS. Loteprednol etabonate 0.5% may have a lower risk for IOP elevation than fluorometholone 0.1%.

Chrysin inhibits cell invasion by inhibition of Recepteur d'origine Nantais via suppressing early growth response-1 and NF-κB transcription factor activities in gastric cancer cells

Cell invasion is one of crucial reasons for cancer metastasis and malignancy. Recepteur d'origine Nantais (RON) has been reported to play an important role in the cancer cell invasion process. High accumulation and activation of RON has been implicated in gastric adenocarcinoma AGS cells. Chrysin is a naturally occurring phytochemical, a type of flavonoid, which has been reported to suppress tumor metastasis. However, the effects of chrysin on RON expression in gastric cancer are not well studied. In the present study, we examined whether chrysin affects RON expression in gastric cancer, and if so, its underlying mechanism. We examined the effect of chrysin on RON expression and activity, via RT-PCR, promoter study, and western blotting in human gastric cancer AGS cells. Chrysin significantly inhibited endogenous and inducible RON expression in a dose-dependent manner. After demonstrating that Egr-1 and NF-κB are the critically required transcription factors for RON expression, we discovered that chrysin suppressed Egr-1 and NF-κB transcription factor activities. Additionally, the phorbol-12-myristate-13-acetate- (PMA) induced cell invasion was partially abrogated by chrysin and an RON antibody. Our results suggest that chrysin has anticancer effects at least by suppressing RON expression through blocking Egr-1 and NF-κB in gastric cancer AGS cells.

Delineation of the role of glycosylation in the cytotoxic properties of quercetin using novel assays in living vertebrates

Quercetin is a plant-derived flavonoid and its cytotoxic properties have been widely reported. However, in nature, quercetin predominantly occurs as various glycosides. Thus far the cytotoxic activity of these glycosides has not been investigated to the same extent as quercetin, especially in animal models. In this study, the cytotoxic properties of quercetin (1), hyperoside (quercetin 3-O-galactoside, 2), isoquercitrin (quercetin 3-O-glucoside, 3), quercitrin (quercetin 3-O-rhamnoside, 4), and spiraeoside (quercetin 4'-O-glucoside, 5) were directly compared in vitro using assays of cancer cell viability. To further characterize the influence of glycosylation in vivo, a novel zebrafish-based assay was developed that allows the rapid and experimentally convenient visualization of glycoside cleavage in the digestive tract. This assay was correlated with a novel human tumor xenograft assay in the same animal model. The results showed that 3 is as effective as 1 at inhibiting cancer cell proliferation in vivo. Moreover, it was observed that 3 can be effectively deglycosylated in the digestive tract. Collectively, these results indicate that 3 is a very promising drug candidate for cancer therapy, because glycosylation confers advantageous pharmacological changes compared with the aglycone, 1. Importantly, the development of a novel and convenient fluorescence-based assay for monitoring deglycosylation in living vertebrates provides a valuable platform for determining the metabolic fate of naturally occurring glycosides.

Associations between the GNB3 C825T polymorphism and obesity-related metabolic risk factors in Korean obese women

PURPOSE

It is important to identify a 'metabolically unhealthy obese' subset with higher cardiovascular risk among obese individuals. We investigated the associations between the GNB3 C825T polymorphism and obesity-related metabolic risk factors among Korean obese women.

METHODS

This study was a sub-investigation of a double-blind randomized controlled trial that examined the additive effect of or list at on weight loss with sibutramine. A sample of 111 obese women were divided into T-carriers (CT/TT) or a homozygous CC group, according to the presence of the 825T allele at GNB3. These groups were compared to determine their associations with obesity-related metabolic risk factors, i.e., fasting plasma glucose, serum lipids, serum insulin/insulin resistance, and abdominal fat amounts.

RESULTS

The allele frequencies of the GNB3 polymorphism were C allele = 59.5% and T allele = 40.5%. The T allele was found to be significantly associated with greater visceral fat and higher serum lipids, and these significances remained robust after adjusting for potential covariates.

CONCLUSIONS

The GNB3 825T polymorphism is significantly associated with greater visceral fat and higher serum lipids in Korean obese women and it suggests that the GNB3 C825T is a determinant of obesity-related metabolic traits in this population.

Abstract 4431: N-terminal portion of β-catenin is important in ISGylation of β-catenin by 90K glycoprotein in colorectal cancer cells

β-catenin is a major transducer in Wnt signaling pathway, which is highly expressed in colorectal and other cancers. Previously, we have shown that β-catenin is down-regulated in colorectal cancer cells by glycoprotein, 90K, through ISGylation-dependent ubiquitination. The aim of this study is to further clarify a novel mechanism of β-catenin down-regulation pathway by 90K glycoprotein. To identify ISGylation site of β-catenin, deletion mutants of β-catenin lacking N- or C-terminal domain were employed. As only two lysine residues, K19 and K49, are reside in N-terminus of β-catenin, we sequenced cDNA of β- catenin from paired human colorectal cancer tissues to find the mutation and generated arginine point-mutation. As a result, there is no mutation on K19 and/or K49 in examined specimens and did not affect the 90K-mediated ISGylational degradation. To rule out the possibility of involving non-lysine residue in the ISG15 conjugation, such as serine or threonine, we constructed several deletion mutants and found that none are responsible for the ISG15 conjugation. Now, N-terminal portion of β-catenin is under screening for possible interactions with putative E3 ligases, and further detailed studies delineating the complex formation among ISG15 and β-catenin/E3 ligases are under way.

Citation Format: Somy Yoon, Jeong A Bae, Hangun Kim, Kyung-Sub Moon, Kyung Keun Kim. N-terminal portion of β-catenin is important in ISGylation of β-catenin by 90K glycoprotein in colorectal cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4431. doi:10.1158/1538-7445.AM2014-4431

Abstract LB-64: Immune modulatory effects of mesenchymal stem cells on regulatory T cells in mouse glioma model

Objective: Although mesenchymal stem cells (MSCs) have been investigated as a vector in stem cell-based therapy for malignant glioma, there has been a debate about the exact role of MSCs in tumor microenvironment. From an immunnological aspect, MSCs have been reported to inhibit T cell proliferation and to increase CD4+FoxP3+ regulatory T cells (Tregs). They also have been investigated as a potent immune suppressor in several clinical situations including autoimmune diseases. However, whether MSCs have an immune modulatory effect on Tregs in malignant gliomas or not has not been established.

Materials & methods: The author explored the impact of MSCs on freshly sorted CD4+ T cells or already activated Tregs in vitro to determine whether MSCs have different influences on naive T cells and Tregs. Furthermore, using orthotropic mouse glioma model, the author investigated MSC's effect on Tregs during tumor progression.

Results: The authors observed that MSCs decreased Treg conversion from naive T cells and Treg proliferation, without affecting the proportion of natural / induced Treg [nTreg; CD4+FoxP3+Helios+ / iTreg; CD4+FoxP3+Helios-]. When co-cultured with already activated Tregs, however, MSCs did not affect Treg induction and proliferation, but decreased the proportion of iTreg. With an intracranially implanted GL261 cell-based orthotropic mouse model, co-injection of MSCs with tumor cell implantation slightly increased Treg recruit into the tumor and decreased the proportion of iTreg. When MSCs were injected after glioma formation, there was no significant effect of MSCs on Treg recruit and phenotypic changes. Furthermore, there was a lower level of cytokine expressions including TGF-β, INF-γ, IL-2, and IL-1β in Tregs cocultured with MSCs than that in solely cultured Tregs. Increased gene expression of IL-6, CCL17, and TGF-β, or decreased gene expression of CCL2 in MSCs may be relevant to the phenotypic changes of cocultured Tregs.

Conclusions: This study demonstrates that MSCs mainly inhibit iTreg, leading to a relative increase of the proportion of nTregs in mouse glioma model, possibly throughIL-6 signaling pathway. With a better understanding for critical factors and immunological consequences for the altered Treg phenotype in glioma, future experiments will be needed to elucidate the immunological impact of MSCs on Tregs in malignant glioma.

Citation Format: Kyung-Sub Moon, Derek A. Wainwright, Irina V. Balyasnikova, Chung Kwon Kim, Yoo Seung Ko, Kyung Keun Kim, Maciej S. Lesniak. Immune modulatory effects of mesenchymal stem cells on regulatory T cells in mouse glioma model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-64. doi:10.1158/1538-7445.AM2014-LB-64

Cadmium induces urokinase-type plasminogen activator receptor expression and the cell invasiveness of human gastric cancer cells via the ERK-1/2, NF-κB, and AP-1 signaling pathways

Cadmium exposure has been linked to human cancers, including stomach cancer. In this study, the effects of cadmium on urokinase-type plasminogen activator receptor (uPAR) expression in human gastric cancer cells and the underlying signal transduction pathways were investigated. Cadmium induced uPAR expression in a time- and concentration-dependent manner. Cadmium also induced uPAR promoter activity. Additionally, cadmium induced the activation of extracellular signal regulated kinase-1/2 (ERK-1/2), p38 mitogen-activated protein kinase (MAPK), and the activation of c-Jun amino terminal kinase (JNK). A specific inhibitor of MEK-1 (PD98059) inhibited cadmium-induced uPAR expression, while JNK and p38 MAPK inhibitors did not. Expression vectors encoding dominant-negative MEK-1 (pMCL-K97M) also prevented cadmium-induced uPAR promoter activity. Site-directed mutagenesis and electrophoretic mobility shift studies showed that sites for the transcription factors nuclear factor (NF)-κB and activator protein-1 (AP-1) were involved in cadmium-induced uPAR transcription. Suppression of the cadmium-induced uPAR promoter activity by a mutated-type NF-κB-inducing kinase and I-κB and an AP-1 decoy oligonucleotide confirmed that the activation of NF-κB and AP-1 are essential for cadmium-induced uPAR upregulation. Cells pretreated with cadmium showed markedly enhanced invasiveness and this effect was partially abrogated by uPAR-neutralizing antibodies and by inhibitors of ERK-1/2, NF-κB, and AP-1. These results suggest that cadmium induces uPAR expression via ERK-1/2, NF-κB, and AP-1 signaling pathways and, in turn, stimulates cell invasiveness in human gastric cancer AGS cells.

KITENIN-targeting microRNA-124 suppresses colorectal cancer cell motility and tumorigenesis

MicroRNAs are increasingly implicated in the modulation of the progression of various cancers. We previously observed that KAI1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in sporadic human colorectal cancer (CRC) tissues and hence the functional KITENIN complex acts to promote progression of CRC. However, it remains unknown that microRNAs target KITENIN and whether KITENIN-targeting microRNAs modulate CRC cell motility and colorectal tumorigenesis. Here, through bioinformatic analyses and functional studies, we showed that miR-124, miR-27a, and miR-30b negatively regulate KITENIN expression and suppress the migration and invasion of several CRC cell lines via modulation of KITENIN expression. Through in vitro and in vivo induction of mature microRNAs using a tetracycline-inducible system, miR-124 was found to effectively inhibit the invasion of CT-26 colon adenocarcinoma cells and tumor growth in a syngeneic mouse xenograft model. Constitutive overexpression of precursor miR-124 in CT-26 cells suppressed in vivo tumorigenicity and resulted in decreased expression of KITENIN as well as that of MYH9 and SOX9, which are targets of miR-124. Thus, our findings identify that KITENIN-targeting miR-124, miR-27a, and miR-30b function as endogenous inhibitors of CRC cell motility and demonstrate that miR-124 among KITENIN-targeting microRNAs plays a suppressor role in colorectal tumorigenesis.

P42 Ebp1 regulates the proteasomal degradation of the p85 regulatory subunit of PI3K by recruiting a chaperone-E3 ligase complex HSP70/CHIP

The short isoform of ErbB3-binding protein 1 (Ebp1), p42, is considered to be a potent tumor suppressor in a number of human cancers, although the mechanism by which it exerts this tumor-suppressive activity is unclear. Here, we report that p42 interacts with the cSH2 domain of the p85 subunit of phosphathidyl inositol 3-kinase (PI3K), leading to inhibition of its lipid kinase activity. Importantly, we found that p42 induces protein degradation of the p85 subunit and further identified HSP70/CHIP complex as a novel E3 ligase for p85 that is responsible for p85 ubiquitination and degradation. In this process, p42 couples p85 to the HSP70/CHIP-mediated ubiquitin–proteasomal system (UPS), thereby promoting a reduction of p85 levels both in vitro and in vivo. Thus, the tumor-suppressing effects of p42 in cancer cells are driven by negative regulation of the p85 subunit of PI3K.

Helicobacter pylori and interleukin-8 in gastric cancer

Helicobacter pylori (H. pylori) is a major etiological factor in the development of gastric cancer. Large-scale epidemiological studies have confirmed the strong association between H. pylori infection and both cancer development and progression. Interleukin-8 (IL-8) is overexpressed in gastric mucosa exposed to H. pylori. The expression of IL-8 directly correlates with a poor prognosis in gastric cancer. IL-8 is multifunctional. In addition to its potent chemotactic activity, it can induce proliferation and migration of cancer cells. In this review, we focus on recent insights into the mechanisms of IL-8 signaling associated with gastric cancer. The relationship between IL-8 and H. pylori is discussed. We also summarize the current therapeutics against IL-8 in gastric cancer.

Quality indicators for initial licensure and discipline in nursing laws in South Korea and North Carolina

BACKGROUND

The Korean regulatory framework of nursing licensure reflects that of the USA, but its content differs in some of the powers related to quality assurance.

AIM

This article compares regulatory quality indicators and describes core standards in nursing regulations that are related to both initial licensure and discipline for three groups: the National Council of State Boards of Nursing, the North Carolina and the South of Korea.

METHODS

A descriptive, comparative law design is used to examine the differences and similarities in the quality indicators and core standards found in three documents: the National Council of State Boards of Nursing Model Act, the North Carolina Nursing Practice Act and the Korean Medical Service Act for registered nurses.

RESULTS

The findings indicate that ten quality indicators and two standards appear in study objects. Although most of the quality indicators are common to all documents, some differences are found in terms of the scope of criminal background checks and the range of grounds for disciplinary action.

LIMITATIONS

These findings cannot be generalized in the USA because although the North Carolina nursing act was selected as an example of US nursing laws, nursing laws differ somewhat across states.

CONCLUSIONS

This comparative study shows a clear opportunity to develop indicators that acknowledge the important areas of competence and good moral character and how they can improve patient safety in Korea.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

This study provides recommendations for Korean nursing legislative redesign and pointers for other jurisdictions to consider.

(-)-Epigallocatechin-3-gallate blocks nicotine-induced matrix metalloproteinase-9 expression and invasiveness via suppression of NF-κB and AP-1 in endothelial cells

Cigarette smoke, specifically the nicotine contained within, has been shown to correlate closely with cell invasion and strategies to downregulate their expression may ultimately be of clinical utility. Matrix metalloproteinase-9 (MMP-9) is critically involved in the cell invasion and metastasis processes. Since nicotine plays a crucial role in the regulation of MMP-9 expression, the investigation of plant-derived compounds capable of modulating nicotine-induced signaling is an issue of concern. In this study, the effects of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on nicotine-induced cell invasion and MMP-9 activity in ECV304 human endothelial cells were examined. EGCG treatment was found to reduce the MMP-9 expression and transcriptional activity in a dose-dependent manner. EGCG inhibited nicotine-activated production of reactive oxygen species (ROS), which are known as important signaling molecules to activate MMP-9. To further study the mechanisms for the EGCG-mediated regulation of MMP-9, the transcription factors NF-κB and AP-1 activities were examined. EGCG suppressed the nicotine-induced NF-κB and AP-1 activation. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated MMP-9 expression. EGCG also abrogated the nicotine-induced activation of AP-1 subunits c-fos and c-jun. The above studies demonstrate that EGCG may exert at least part of its anti-invasive effect in ECV304 human endothelial cells by controlling MMP-9 expression through the suppression of ROS, NF-κB and AP-1.

Abstract 4201: miR-124 suppresses colorectal tumor progression in a mouse xenograft model via targeting KITENIN

MicroRNAs (miRNAs) are increasingly implicated in modulating the progression of various cancers. Although there is emerging evidences that some miRNAs can function as oncogenes or tumour suppressors, the regulation of colorectal cancer (CRC) progression by miRNA is not fully understood. KITENIN (KAI1 C-terminal interacting tetraspanin, Vangl1) is not only a major component of PCP pathway but also a functional protein promoting CRC cell motility and invasiveness. Previously, we observed that KITENIN acts as a metastasis-enhancing protein in a mouse model of colon cancer and that KITENIN is highly expressed in sporadic human CRC tissues. But the underlying regulation mechanisms of aberrant expression of KITENIN in CRC are not clearly understood. Here we tried to identify the miRNAs, which modulate the expression of KITENIN, using luciferase assay and with computational prediction of miRNA targeting KITENIN. We identified several miRNAs and one of them is miR-124. miR-124 negatively regulated KITENIN expression through binding to the 3′-untranslated region of KITENIN. We further examined whether increased expression of miR-124 affects colorectal tumor progression via targeting KITENIN. Ectopic expression of miR-124 was found to suppress the migration and invasiveness of various CRC cells. miR-124 also inhibited tumor growth in a mouse xenograft model. These findings provide the experimental evidence to a possible therapeutic effect of miR-124 on suppressing colorectal tumor progression and identification of miR-124-mediated regulation of KITENIN might provide a promising therapeutic target in treating CRC.

Citation Format: So-Yeon Park, Jeong A Bae, Somy Yoon, Hangun Kim, Kyung Keun Kim. miR-124 suppresses colorectal tumor progression in a mouse xenograft model via targeting KITENIN. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4201. doi:10.1158/1538-7445.AM2013-4201

Effect of the G-protein β3 subunit 825T allele on the change of body adiposity in obese female

No clinical studies on the lipolytic effect of guanine nucleotide-binding protein β3 subunit gene (GNB3) 825T polymorphism have been performed. This study was a subinvestigation of a 12-week randomized controlled trial (NCT01184560) for the additive effect of orlistat on sibutramine treatment. The analysis involved 101 obese females aged 18-49 years, genotyped at the GNB3 825 locus. To exclude any influence from potential confounders, we used an analysis of covariance model. After the intervention, fat mass proportion in total weight loss was significantly lower in subjects with a T allele than in those without a T allele (p = 0.034). GNB3 825T allele was associated with blunted fat mass reduction in obese females.

A guide to facilitate the early treatment of patients with idiopathic demyelinating disease (multiple sclerosis and neuromyelitis optica)

Definite diagnosis of inflammatory demyelinating disease (multiple sclerosis (MS) and neuromyelitis optica (NMO)) may require time, but early treatment offers the opportunity to maximize patient outcomes. The purpose of this report is to provide guidance to facilitate early treatment decisions for patients with inflammatory demyelinating disease, before definitive diagnosis. Neurology experts reviewed the existing literature and clinical evidence. A treatment decision pathway was developed, defining patients for whom first-line MS disease-modifying therapies (a) are unlikely to be effective, (b) may be effective but require careful monitoring and (c) are likely to provide benefit. This algorithm seeks to ensure that patients, particularly those in Asia, receive appropriate treatment early in inflammatory demyelinating disease.

Expression of KITENIN and its association with tumor progression in oral squamous cell carcinoma

OBJECTIVE

KAI1 COOH-terminal interacting tetraspanin (KITENIN) contributes to tumor invasion and metastasis in various cancers. The aim of this study was to investigate expression of KITENIN in patients with oral cavity squamous cell carcinoma (SCC) and to determine whether KITENIN affects tumor cell behavior in oral cavity SCC cell line.

METHODS

Western blotting and immunohistochemistry was used to assess alteration of KITENIN expression in human oral cavity SCC and normal oral cavity mucosa. To evaluate the impact of KITENIN knockdown, the cell invasion assay and cell migration assay using small-interfering RNA were performed.

RESULTS

KITENIN protein expression was significantly increased in human oral cavity SCC tissues than in normal oral cavity mucosa by Western blotting. KITENIN immunoreactivity was strongly identified in human oral cavity SCC relative to adjacent normal tissue. Knockdown of KITENIN resulted in significantly reduced cell invasion in human oral cavity SCC cells (p=0.001). Cell migration showed a marked decrease in KITENIN knockdown oral cavity SCC cells compared to the negative control oral cavity SCC cells (p=0.01).

CONCLUSION

KITENIN is associated with tumor invasiveness and metastasis in human oral cavity SCC.

Abstract 4006: Biochemical characteristics of functional domain of KITENIN: Its implication in AP-1 signal activation and colorectal cancer cell motility

Background & aims: KITENIN (KAI1 C-terminal interacting tetraspanin) is not only a membrane-associated protein but also a functional protein promoting the invasiveness of colorectal cancer (CRC) cells. Recent studies about the mechanism of KITENIN function in the CRC cells indicate that KITENIN plays a pivotal role in tumor initiation and promotion through activating the activator protein-1 (AP-1) signaling. However, the contribution of each functional domain of KITENIN to AP-1 signaling is still unknown and the biochemical properties of C-terminal region of KITENIN were investigated. Methods: To compare the biochemical and functional properties of KITENIN deletion mutants with wild-type KITENIN, the various mutant constructs of C-terminal region (238-512 aa) were generated and being expressed in the 293T and Caco2 cells. AP-1 activity was measured via AP-1 luciferase reporter assays, and the cellular phenotypes of these cells expressing KITENIN mutants were examined via in vitro cell invasion and wound-healing assays. Results: KITENIN mutant with deletion of C-terminal 63 amino acids (DCKIT) markedly increased the AP-1 activity in contrast to other deletion mutants and wild-type KITENIN. Also, DCKIT increased the degradation of Dvl2 and stability of c-Jun, which are responsible for AP-1 activation by KITENIN. The C-terminal fragment of KITENIN (KICD, roughly 30 kDa) was generated and preferentially translocated to the nucleus after PMA treatment, but its functional significance is under investigation. A mutant construct of 408ALRA411-KITENIN was obtained by mutation of YXXΨ motifs, which directs the clathrin-dependent endocytosis of membrane-spanning proteins. This mutation did not influence the AP-1 activity, cell invasiveness, and cell migration by KITENIN but disrupted the interaction of KITENIN with Dvl2. Moreover, co-expression of this mutant with ErbB4 exhibited more attenuated AP-1 activity than that of forced expression of wild-type KITENIN and ErbB4. These results indicate that endocytosis of KITENIN and subsequent interaction with Dvl2 is essential to activating AP-1 signal and modulating cell motility by KITENIN. Conclusion: These biochemical properties of deletion mutants of KITENIN suggest that the C-terminal region of KITENIN is an important component for modulating AP-1 signal and CRC cell motility by KITENIN.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4006. doi:1538-7445.AM2012-4006

δ-Catenin promotes E-cadherin processing and activates β-catenin-mediated signaling: implications on human prostate cancer progression

δ-Catenin binds the juxtamembrane domain of E-cadherin and is known to be overexpressed in some human tumors. However, the functions of δ-catenin in epithelial cells and carcinomas remain elusive. We found that prostate cancer cells overexpressing δ-catenin show an increase in multi-layer growth in culture. In these cells, δ-catenin colocalizes with E-cadherin at the plasma membrane, and the E-cadherin processing is noticeably elevated. E-Cadherin processing induced by δ-catenin is serum-dependent and requires MMP- and PS-1/γ-secretase-mediated activities. A deletion mutant of δ-catenin that deprives the ability of δ-catenin to bind E-cadherin or to recruit PS-1 to E-cadherin totally abolishes the δ-catenin-induced E-cadherin processing and the multi-layer growth of the cells. In addition, prostate cancer cells overexpressing δ-catenin display an elevated total β-catenin level and increase its nuclear distribution, resulting in the activation of β-catenin/LEF-1-mediated transcription and their downstream target genes as well as androgen receptor-mediated transcription. Indeed, human prostate tumor xenograft in nude mice, which is derived from cells overexpressing δ-catenin, shows increased β-catenin nuclear localization and more rapid growth rates. Moreover, the metastatic xenograft tumor weights positively correlate with the level of 29kD E-cadherin fragment, and primary human prostate tumor tissues also show elevated levels of δ-catenin expression and the E-cadherin processing. Taken together, these results suggest that δ-catenin plays an important role in prostate cancer progression through inducing E-cadherin processing and thereby activating β-catenin-mediated oncogenic signals.

Specific mechanism of use-dependent channel block of calcium-permeable AMPA receptors provides activity-dependent inhibition of glutamatergic neurotransmission

This study examined the blocking action of the selective channel blocker of calcium-permeable (CP) AMPA receptors, N1-(1-phenylcyclohexyl)pentane-1,5-diaminium bromide (IEM-1925), on excitatory postsynaptic currents in rat neostriatal and cortical neurons and in fly neuromuscular junctions. In both preparations, the blocking of CP-AMPA receptor currents increased along with the stimulation frequency. The continuous presence of kainate, which activates AMPA receptors, in the external solution also caused an enhanced blocking effect. Likewise, decrease of the synaptic release by lowering calcium concentration resulted in significant reduction of the blocking action. The activity dependence of the block is explained using the guarded receptor model. The drug molecule can only bind if the channel is open. After the channel has closed, the drug molecule remains trapped inside. However, the trapped molecule slowly egresses from closed channels to the cytoplasm. The total block effect is determined by the equilibrium between accumulation of the drug in the open channels and relief from the closed channels. Therefore, the conditions that favour the open state result in enhanced inhibition. This significant finding reveals a new way to modulate CP-AMPAR-mediated transmission using a physiologically relevant approach. Moreover, it allows the involvement of CP-AMPARs in the physiological and pathological processes – such as high-frequency synaptic activity or increase of the steady-state glutamate concentration – to be examined.