bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2283: β-catenin silencing induces both apoptotic and autophagic cell death through LKB1/AMPK signal in head and neck cancer cells
Authors: Chang Hyo Won , Moon So Young , Kim Hyo Jung , Lee Myung Jin , Kim Mi Ra , Park Jung Je , Seo Ji Hyun , Kim Seong Who , Kim Sang Yoon 
Published: August 2012

Abstract
β-Catenin, a multifunctional protein involved in key molecule of Wnt signaling transduction, has been well known to regulate cell proliferation, differentiation, cell-cell adhesion, survival, and apoptosis as well as plays an important role in human tumorigenesis. Our previous report showed that Wnt/β-catenin pathway controls radiosensitivity of head and neck caner (HNC) cell via cyclooxygenase-2-mediated Ku expression. However, the specific molecular mechanisms of β-catenin in tumor cell survival and death are still not fully understood, so in the present study we attempted to elucidate the mechanism of cell death in HNC cell by studying how β-catenin silencing regulates cell death through KB1/AMPK signaling. We performed β-catenin knockdown in HNC cell by using small interfering RNA. Its effect on the cell viability was confirmed by observation of cell morphologic change, electron microscopy, MTT and FACS analysis. Also, we confirmed the expression of several proteins corresponding signal pathway by western blot analysis. β-catenin silencing significantly induced G1 cell-cycle arrest and also increased the expression of Bax and the active form of caspase-3, and decreased the expression of Bcl-2, demonstrating the sequential activation of apoptotic cascades following treatment with β-catenin siRNA in HNC cell. Interestingly, β-catenin silencing induced autophagy as well as apoptosis. We confirmed that the numbers of autophagic vacuoles and the expression of LC3-II increased in cells treated with β-catenin siRNA. This is probably because LKB1-dependent AMPK is activated by β-catenin silencing in HNC cell. Activated AMPK, in β-catenin silenced AMC-HN-3 cells, causes a G1 cell cycle arrest by phosphorylated p53 as well as inhibited protein synthesis by suppressing mTOR activity. Also, Treatment with LKB1 siRNA or compound C in AMC-HN-3 cells preserved cell viability against β-catenin silencing-induced cytotoxicity. Taken together, our data show that β-catenin silencing induces cell death through LKB1/AMPK signal, and as a result, apoptosis and autophagy are induced together in HNC cell, suggesting that a novel interaction between β-catenin and LKB1/AMPK signaling pathway occurs. Our study provides new insights into understanding the cellular and molecular mechanisms involving β-catenin silencing-induced cell death.
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 2283. doi:1538-7445.AM2012-2283
Abstract 2285: Inhibition of autophagy and tumor growth in colon cancer by miR-502
Authors: Zhai Haiyan , Song Bo , Xu Xiao , Zhu Wei , Ju Jingfang 
Published: August 2012

Abstract
Autophagy is a catabolic process that allows cellular macromolecules to be broken down and recycled as metabolic precursors. The influence of non-coding microRNAs (miRNAs) in autophagy has not been explored in colon cancer. In this study, we discovered a novel mechanism of autophagy regulated by hsa-miR-502-5p (miR-502) by suppression of Rab1B, a critical mediator of autophagy. A number of other miR-502 suppressed mRNA targets (e.g. DHODH) were also identified by microarray analysis. Ectopic expression of miR-502 inhibited autophagy, colon cancer cell growth, and cell cycle progression of colon cancer cells in vitro. miR-502 also inhibited in vivo colon cancer growth in a mouse tumor xenografts model. In addition, the expression of miR-502 was regulated by p53 via a negative feedback regulatory mechanism. The expression of miR-502 was down-regulated in colon cancer patient specimens compared to the paired normal control samples. These results suggest that miR-502 may function as a potential tumor suppressor and therefore be a novel candidate for developing miR-502 based therapeutic strategies.
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 2285. doi:1538-7445.AM2012-2285
Abstract 2288: Genetic and epigenetic inactivation of miR-31 in EBV-associated nasopharyngeal carcinoma
Authors: Cheung Chartia Ching-Mei , Chung Grace Tin-Yun , Lun Samantha Wei-Man , Choy Kwong-Wai , To Ka-Fai , Lo Kwok-Wai 
Published: August 2012

Abstract
Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignant cancer prevalent in Southern China and South-eastern Asia. In this study, we aim to elucidate the fundamental role of aberrant expressed microRNAs (miRNA) in NPC tumorigenesis. By comparison of miRNA expression profiles in NPC tumor lines with non-malignant nasopharyngeal epithelial cell, 119 differentially expressed miRNAs were identified in EBV-associated NPC. Among the 58 microRNAs downregulated in NPC, transcriptional silencing of miR-31 was consistently found in both NPC tumor lines and primary tumors. Expression of miR-31 was detected in none of 6 EBV-positive tumor lines and 38 microdissected primary tumors, but in all normal nasopharyngeal epithelia. Interestingly, miR-31 is located at 0.5 Mb telomeric to CDKN2A at 9p21.3, which is commonly homozygous deleted in NPC. Homozygous deletion of both miR-31 and CDKN2A locus was confirmed in 2 tumor lines. In the 4 tumor lines with intact miR-31, hypermethylation of 5′CpG islands was detected by bisulfate sequencing and MSP analysis. Re-expression of miR-31 was demonstrated in the EBV-positive NPC cell line C666-1 treated with 5-aza-2′-deoxycytidine. The findings suggested that homozygous deletion and promoter methylation are the major mechanisms for transcriptional silencing of miR-31 in NPC. By microarray and bioinformatic analysis, we have identified a number of putative targets of miR-31. Among these candidates, we have proven that miR-31 targeted FIH1 and MCM2 expression in NPC. Ectopic expression of miR-31 in NPC cells resulted in repression of FIH1 and MCM2 protein. Finally, we have demonstrated that restoration of miR-31 or knockdown of FIH1 expression significantly suppressed cell proliferation of C666-1. Our findings indicated that miR-31 is a NPC-associated microRNA which negatively regulates cell growth by repressing FIH1 expression.
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 2288. doi:1538-7445.AM2012-2288
Abstract 2300: MicroRNA-101 (miR-101) posttranscriptionally regulates the expression of EP4 receptor in colon cancers
Authors: Onyeagucha Benjamin C. , Chandramouli Anupama , Mercado-Pimentel Melania E. , Shahin Nisreen Abu , LaFleur Bonnie J. , Heimark Ronald L. , Bhattacharyya Achyut K. , Nelson Mark A. 
Published: August 2012

Abstract
The predominant product of cyclooxygenase (COX-2) in the colon, prostaglandin (PG) E2 promotes carcinogenesis. Expression of the PGE2 receptor EP4 is upregulated during colorectal carcinogenesis. However the mechanism leading to deregulation of the EP4 receptor is not known. The present study was conducted to investigate the regulation of EP4 receptor by miRNAs. A bioinformatics search revealed a conserved target site for miR-101 within the EP4 receptor-3′ UTR. In both colorectal cancer cell lines and human specimens, we observed an inverse correlation between miR-101 and EP4 receptor protein. Transfection of LS174T cells with miR-101 significantly suppressed a luciferase reporter containing the EP4 receptor-3′-UTR. In contrast, a mutant EP4 receptor-3′-UTR was unaffected. Ectopic expression miR-101 markedly reduced cell proliferation and motility. Co-transfection of EP4 receptor could rescue colon cancer cells from the tumor suppressive effects of miR-101. Moreover, pharmacologic inhibition of EP4 receptor signaling or silencing of EP4 receptor phenocopied the effect of miR-101. This is the first study to show that the EP4 receptor is negatively regulated by miR-101.
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 2300. doi:1538-7445.AM2012-2300
Abstract 2304: MicroRNA-7 functions as antimetastic microRNA in gastric cancer by targeting insulin-like growth factor 1 receptor
Authors: Zhao Xiaodi , Dou Weijia , Nie Yongzhan , Fan Daiming 
Published: August 2012

Abstract
Metastasis is a major clinical obstacle in the treatment of gastric cancer (GC) and accounts for the majority of cancer-related mortality. MicroRNAs (miRNAs) have been recently emerged as regulators of metastasis through acting on multiple signaling pathways. In this study, we found that miR-7 is significantly down-regulated in high-metastatic GC cell lines and metastatic tissues. Both gain-of-function and loss-of-function studies showed that increased miR-7 expression significantly reduced migration and invasion of GC cells, while decreased miR-7 expression dramatically enhanced cell migration and invasion. In vivo metastasis assays also shown that overexpression of miR-7 remarkably inhibits GC metastasis. Moreover, the IGF1R oncogene, which is often mutated or amplified in human cancers and has been shown to function as an important regulator of cell growth and tumor invasion, was identified as a direct target of miR-7. RNA interference silencing of IGF1R recapitulated the antimetastic function of miR-7, whereas restoration of IGF1R expression attenuated the function of miR-7 in GC cells. Furthermore, we found that suppression of Snail by miR-7 through targeting IGF1R increased E-cadherin expression and partly reversed the epithelial-mesenchymal transition (EMT). Finally, analyses of the miR-7 and IGF1R level in human primary GC with matched lymph node metastasis tissue arrays revealed that miR-7 is inversely related to the increase of IGF1R expression. The present study provides an insight into the specific biological behavior of miR-7 in EMT and tumor metastasis. This novel miR-7/IGF1R/Snail axis would be helpful in the therapeutic application to block GC metastasis.
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 2304. doi:1538-7445.AM2012-2304
Abstract 2306: Overexpression of microRNA-223 regulates the ubiquitin ligase FBXW7 in esophageal squamous cell carcinoma
Authors: Kurashige Junji , Watanabe Masayuki , Iwatsuki Masaaki , Baba Yoshifumi , Baba Hideo 
Published: August 2012

Abstract
Background: F-box and WD repeat domain-containing 7 (FBXW7) is a cell cycle regulatory gene whose protein product ubiquitinates positive cell cycle regulators such as c-Myc, cyclin E and c-Jun, thereby acting as a tumor-suppressor gene. This study focused on microRNA-223 (miR-223), which is a candidate regulator of FBXW7 mRNA. The aim of this study was to clarify the clinical significance of miR-223 and FBXW7 in esophageal squamous cell carcinoma (ESCC) patients and to elucidate the mechanism by which FBXW7 is regulated by miR-223. Methods: The expression levels of miR-223 and the expression of FBXW7 protein was examined using 109 resected specimens to determine the clinicopathological significance. The expression levels of miR-223 were determined by qRT-PCR. The immunohistochemical studies for FBXW7 were performed on formalin-fixed paraffin-embedded surgical sections obtained from 109 patients with ESCC. We also investigated the role of miR-223 in the regulation of FBXW7 expression in ESCC cell lines in an in vitro analysis. Results: We found that the mean expression levels of miR-223 in cancerous tissue specimens were significantly higher than those in non-cancerous tissues (p &lt;0.001). We divided the 109 ESCC patients into two groups according to the ratio of their cancer/normal tissue expression levels of miR-223, as α1.0 or &lt;1.0 for the cancer/noncancerous tissues expression levels of miR-223. There were 74 cases (67.9%) in the high miR-223 group and 35 cases (32.1%) in the low miR-223 expression group. There were significant differences in gender (p = 0.008), tumor size (p = 0.042), and depth of tumor invasion (p = 0.030) between the groups. There was a significant inverse relationship between the expression levels of miR-223 and FBXW7 protein. High levels of miR-223 were associated with low FBXW7 expression (Pearson correlation, r = −0.336; p&lt;0.01). Moreover, patients with high miR-223 expression demonstrated a significantly poorer prognosis than those with low expression (p=0.034). Based on a series of gain-of-function and loss-of-function investigation in vitro, we found that these effects may be due to the downregulation of the tumor-suppressor FBXW7, which was targeted by miR-223. Conclusions: Our present study indicates that high expression of miR-223 had a significant adverse impact on the survival of esophageal squamous cell carcinoma patients through repression of the function of FBXW7.
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 2306. doi:1538-7445.AM2012-2306
Abstract 231: Development of an ELISA for quantification of in vitro and cellular PTEN phosphatase activity
Authors: Landward Michael B. , Ehrmantrout Kimberly K. , Morrow Xin Chen , Branch Angie M. , Ferguson Colin G. 
Published: August 2012

Abstract
Phosphatase and Tensin Homolog deleted on Chromosome 10 (PTEN) is a 3′ phosphoinositide phosphatase that converts PI(3,4,5)P3 to PI(4,5)P2 thus opposing PKB/Akt activation by PI 3-Kinase. PTEN is involved in neuronal stem cell proliferation and self-renewal, cardiac myocyte hypertrophy and contractility, and a wide range of developmental processes. However, PTEN is best known for its role as a tumor suppressor. Loss of PTEN activity results in accumulation of PI(3,4,5)P3, abnormal activation of PKB/Akt, unregulated cell growth, suppression of apoptosis, and increased tumorigenesis in a number of human tissues. It has also been proposed that PTEN is a candidate for targeted chemotherapy because certain anti-cancer agents preferentially destroy tumors with PTEN mutations. In addition to this direct role in cancer, PTEN has recently been shown to regulate cancer-associated pathways including VEGF-mediated angiogenesis and others. Consequently interest in PTEN as a cancer target is still high. Traditionally, quantification of PTEN phosphatase activity has required the use of radioactivity, organic solvents, and chromatography. In addition, detection of free phosphate released from the PTEN activity is commonly used for quantification. However, this latter method has limited sensitivity and dynamic range, and is susceptible to contamination from other sources of inorganic phosphate which can give incorrect results. To address the need for a better quantification method, we have developed a PTEN activity assay using a standard competitive ELISA format. Rather than detecting free phosphate, the assay detects the PTEN product, PI(4,5)P2, giving much more accurate quantification, improved sensitivity, and eliminates possible errors from phosphate contamination. We have shown that the assay can successfully quantify PTEN activity using both recombinant and immunoprecipitated enzyme. Several cell lines were tested for PTEN activity including the human breast cancer cell lines MDA-MB-231 and MDA-MB-468 (PTEN deficient).
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 231. doi:1538-7445.AM2012-231
Abstract 2310: Identification of signaling pathways involved in the regulation of let-7 in ovarian cancer
Authors: Guo Rong , Morin Patrice 
Published: August 2012

Abstract
miRNAs represent a class of small non-coding RNAs that can regulate the stability and translation of specific mRNA targets. Several members of the let-7 miRNA family are down-regulated in ovarian and other cancers and are thought to act as tumor suppressors, possibly through their ability to target growth-promoting genes (RAS, HMGA2), cell cycle genes (CDK6, CDK7, STK6, STK12), and anti-apoptotic genes (Bcl-2, casp3). However, the exact mechanisms regulating their expression and activity are not clearly known. In order to address this issue, we have developed a reporter assay for let-7 activity. We have made several reporter constructs containing the luciferase gene attached to different site combinations and sequences of let-7 in its 3′ UTR, and have identified a reporter that is extremely sensitive to let-7 activity. Ovarian cancer cell lines BG1 and UCI101 were transfected with the let-7 reporter and treated with 80 different kinase inhibitors in order to identify upstream pathways that can affect let-7 activity. We found nine inhibitors which caused consistent, dose-dependent changes on endogenous let-7 activity. The nine drugs can be categorized into three classes of inhibitors and further validation is currently underway through knockdowns of specific kinases. Our findings suggest novel molecular pathways involved in the regulation of let-7 family and, considering the important role of let-7 family members in ovarian cancer, these pathways may further our understanding of ovarian tumorigenesis and provide new targets for therapy.
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 2310. doi:1538-7445.AM2012-2310
Abstract 2316: Itraconazole, an antifungal drug with anti-angiogenic activity, inhibits VEGFR2 trafficking, glycosylation, and signaling in endothelial cells
Authors: Nacev Benjamin A. , Grassi Paola , Dell Anne , Haslam Stuart M. , Liu Jun O. 
Published: August 2012

Abstract
Itraconazole is a widely used antifungal drug that has been recently shown to inhibit angiogenesis in vivo and to block non-small cell lung cancer growth in animal models. Based on these and other results, itraconazole is currently being evaluated in four clinical trials as a cancer therapeutic. Angiogenesis, one of the hallmarks of cancer, is required for tumor growth and is driven by tumor-secreted growth factors including vascular endothelial growth factor (VEGF). We now report that in endothelial cells, itraconazole inhibits signaling of VEGF through the VEGF receptor 2 (VEGFR2) (80% inhibition; p &lt; 0.05) and subsequently through a downstream substrate, PLCϒ1 (60% inhibition; p &lt; 0.05). Mechanistically, we show that this was due to a nearly complete loss of VEGF binding to VEGR2 that was secondary to a loss of cell surface expression of the receptor. After itraconazole treatment, VEGFR2 was retained in a perinuclear aggregate which partially overlapped with the cis-Golgi marker GM130. Correlated with this loss of VEGFR2 signaling and trafficking, was a dramatic change in VEGFR2 mobility on SDS-PAGE which resulted from incomplete N-glycosylation. Itraconazole globally reduced poly-LacNAc and tetra-antennary glycans in endothelial cells and induced hypoglycosylation of EGFR in a renal cell carcinoma line, suggesting that the effects of itraconazole apply to multiple cell types and receptors. Importantly, small molecule inducers of lysosomal accumulation and mTOR inhibition, two previously known itraconazole-induced effects, did not interfere with VEGFR2 glycosylation. Similarly, glycosylation inhibitors did not affect cholesterol trafficking or inhibit mTOR. However, increasing cellular cholesterol levels, which was known to rescue the effects of itraconazole on mTOR and cholesterol trafficking, restored VEGFR2 glycosylation and signaling. Thus, the newly described properties of itraconazole occur in parallel to inhibition of cholesterol trafficking and mTOR but appear downstream of a single target. Taking these findings together, we propose a model in which itraconazole inhibits intracellular trafficking. This model could explain the loss of VEGFR2 signaling, incomplete VEGFR2 glycosylation, as well as disruption of cholesterol trafficking and mTOR signaling. Importantly, the effects of itraconazole we report here may significantly contribute to the in vivo efficacy of itraconazole and are relevant to ongoing clinical trials.
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 2316. doi:1538-7445.AM2012-2316
Abstract 2318: Azadirachta indica leaf extract attenuates angiogenesis in endothelial cells
Authors: Mahapatra Saswati , Young Charles Y.F , Tindall Donald J. , Donkena Krishna Vanaja 
Published: August 2012

Abstract
Azadirachta indica (common name: neem) leaves have been found to possess immunomodulatory, anti-inflammatory and anti-carcinogenic properties. Neem leaves contain multiple bioactive compounds that could target multiple signaling pathways dysregulated in cancer. The present study evaluates anti-angiogenic potential of ethanol extract of neem leaves (EENL) in human umbilical vein endothelial cells (HUVECs). Treatment of HUVECs with EENL inhibited VEGF induced angiogenic response, assessed by the formation of tubes in vitro and the formation of vascular structure in the angioreactor in vivo. The in vitro proliferation, invasion and migration of HUVECs were suppressed with EENL. Nuclear fragmentation and abnormally small mitochondria with dilated cristae were observed in EENL treated HUVECs by transmission electron microscopy. Genome-wide mRNA expression profiling after treatment with EENL revealed differentially regulated genes. Expression changes for the 30 up-regulated and 30 down-regulated genes were validated by quantitative real-time polymerase chain reaction. Additionally, increase in the expression of HMOX1, ATF3 and EGR1 proteins were determined by immunoblotting. Analysis of the compounds in the EENL by mass spectrometry with mobile phase containing sodium acetate suggests the presence of nimbolide, 2′, 3′-dehydrosalannol, 6-desacetyl nimbinene and nimolinone. We further confirmed antiproliferative activity of nimbolide and 2′, 3′-dehydrosalannol in HUVECs. Our results suggest that EENL by regulating the genes involved in cellular development and cell death functions could control cell proliferation, attenuate the stimulatory effects of VEGF and exert antiangiogenic effects. EENL treatment could have a potential therapeutic role during cancer progression.
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 2318. doi:1538-7445.AM2012-2318