bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2423: Development of a validated high throughput ELISA assay for gamma H2AX as a pharmacodynamic marker
Authors: George Jay , Xu Hai 
Published: May 2015

Abstract
Histone H2AX is a 14 kDa ubiquitous member of the H2A histone family that becomes rapidly phosphorylated at Serine 139 by ATM and ATR kinases to yield a form known as γ-H2AX in response to double-strand DNA damage and apoptosis. γ-H2AX is an ideal Pharmacodynamic (PD) surrogate marker to measure molecular responses to a large number of drugs; however, methods such as western blots and immunohistochemistry are widely used but are difficult to validate to regulatory standards, and not suitable for high throughput screening applications. To address this need, we have developed a novel high throughput ELISA assay to measure γ-H2AX levels in cellular extracts and phosphorylation of H2AX in response to therapeutic intervention. This assay documents differences of γ-H2AX levels in PBMC, cultured cells, tissue biopsies, and will be useful in future clinical trials providing one of many needed tools to enable hypothesis-driven preclinical drug design strategies.p
Background
Histone H2AX is a 14 kDa ubiquitous member of the H2A histone family that contains an evolutionarily conserved SQ motif at the C-terminus in eukaryotes. Serine 139 within this motif becomes rapidly phosphorylated by ATM and ATR kinases to yield a form known as γ-H2AX in response to double-strand DNA damage and apoptosis (1). During the past year investigators have confirmed the value of γ-H2AX as an important Pharmacodynamic (PD) marker (2) and genotoxicity endpoint (3). There are over 21 anticancer drugs that are known to result in γ-H2AX formation. As a result, γ-H2AX is an ideal Pharmacodynamic PD surrogate marker to measure molecular responses to a large number of drugs (4,5,6). While many of these drugs have already garnered regulatory approval, and are currently being used to manage various types of cancers, they are the subject of ongoing clinical studies to evaluate their efficacy when used alone or in combination with molecularly targeted drugs.
While methods such as western blots and immunohistochemistry are widely used but are difficult to validate to regulatory standards, the ELISA method is the most quantifiable and easiest to validate, and not suitable for high throughput screening applications. To address this need Trevigen's quantitative pharmacodynamic HT γ-H2AX ELISA assay measures γ-H2AX levels in cellular extracts and phosphorylation of H2AX in response to therapeutic intervention. This assay documents differences of γ-H2AX levels in PBMC, cultured cells, tissue biopsies, and will be useful in future clinical trials providing one of many needed tools to enable hypothesis-driven preclinical drug design strategies.
Citation Format: Jay George, Hai Xu. Development of a validated high throughput ELISA assay for gamma H2AX as a pharmacodynamic marker. [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 2423. doi:10.1158/1538-7445.AM2014-2423
Abstract 2430: Targeting estrogen-related receptor alpha using pyrrole-imidazole polyamide
Authors: Li Yang , Gallagher John , Olenyuk Bogdan , Stiles Bangyan , Kassa Ankeste 
Published: May 2015

Abstract
Estrogen-related receptor α (ERRα), an orphan nuclear receptor, is a prominent regulator of mitochondrial biogenesis and function. We previously showed that liver-specific PTEN deletion and the subsequent activation of PI3K/AKT pathway lead to tumorigenesis. Here we show that Pten-null hepatocytes established from Pten-null mice exhibit dramatically increased ERRα expression, accompanied by elevated mitochondrial mass, cellular oxygen consumption and reactive oxygen species production. Silencing ERRα by siRNA in Pten-null hepatocytes not only suppresses mitochondrial biogenesis and respiration but also attenuates hepatocytes' proliferation and colony-forming potential. Cohort analyses of clinical datasets from liver tissues revealed a negative correlation between expressions of PTEN and ERRα in patients with liver cancer. Therefore, targeting ERRα might provide therapeutic implication for treating tumors bearing abnormal PTEN-ERRα signaling. ERRα exerts transcriptional activity towards its target genes via binding to consensus DNA sequences named estrogen-related receptor α response elements (ERRE). The DNA-binding activity of ERRα could be modulated by polyamides, a class of synthetic amino acid oligomers capable of binding to DNA minor groove with sequence specificity. By designing and employing polyamide that specifically targets ERRE in Pten-null hepatocytes, we found the mRNA levels of two ERRα target genes, cytochrome c (cyt c) and ATP synthase β (ATP5b), are reduced. Biochemical gel-shift assay showed the binding between ERRα and ERRE is significantly diminished by polyamides in vitro. Moreover, polyamide treatment in hepatocytes reduced mitochondrial respiration and colony-forming ability. In conclusion, our findings show that ERRα is significantly induced via PTEN-AKT signaling pathway and in turn activates mitochondrial bioenergetics, which likely provides growth and survival advantages. The crucial role in mitochondrial metabolism and the association with PTEN signaling make ERRα a useful target for cancer therapy. Synthetic polyamide that disrupts transcription factor-DNA interaction can be utilized to modulate ERRα's activity, highlighting its potential as a future therapeutic target.
Citation Format: Yang Li, John Gallagher, Bogdan Olenyuk, Bangyan Stiles, Ankeste Kassa. Targeting estrogen-related receptor alpha using pyrrole-imidazole polyamide. [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 2430. doi:10.1158/1538-7445.AM2014-2430
Abstract 2432: Phosphorylation of Raptor by pemetrexed-activated AMPK is sufficient to suppress mTORC1 activity promoted by loss of p53 and TSC2
Authors: Agarwal Stuti , Bell Catherine M. , Moran Richard G. 
Published: May 2015

Abstract
The key sensor of energy status, AMP-dependent kinase (AMPK), can be activated by intracellular ZMP generated directly from the aminoimidazolecarboxamide ribonucleoside (AICAR) or from inhibition of purine synthesis by the antifolate pemetrexed (PTX). In spite of this common mechanism, signaling from AMPK activated by PTX or AICAR differed: PTX-activated AMPK phosphorylated the mTORC1 component Raptor but not tuberin (TSC2), whereas AICAR-activated AMPK phosphorylated both targets. This dichotomy proved to be due to p53 function: although p53 accumulated after either treatment, AICAR robustly activated the transcriptional profile of p53, including expression of p53 target genes TSC2 and sestrin2 whereas, in PTX-treated cells, p53 was virtually inactive as a transcriptional activator. Accordingly, activation of AMPK by PTX initiated a cell growth inhibition that was p53 and TSC2 independent, whereas p53 and TSC2 wild-type HCT116 colon carcinoma cells were more sensitive to AICAR than isogenic cells null for p53 or both p53 and TSC2. Furthermore, in cells null for p53, mTORC1 was hyperactive, apparently caused by lower TSC2 function, higher Rheb bound to mTORC1, and a concomitantly lower inhibition of mTORC1 by PRAS40. Although TSC2 was deficient and mTORC1 activity enhanced in the absence of p53 function, Raptor phosphorylation by AMPK following PTX was robust and independent of both p53 and TSC2. This provides insight into the therapeutic activity of PTX against human lung cancers lacking p53 function and with hyperactive mTORC1, a feature atypical of other antifolates. We concluded that phosphorylation of Raptor by AMPK after PTX treatment was both necessary and sufficient to suppress the kinase activity of mTORC1, even under conditions of limited TSC2 and enhanced mTORC1 function, suggesting the use of pemetrexed for treatment of Tuberous Sclerosis.
Citation Format: Stuti Agarwal, Catherine M. Bell, Richard G. Moran. Phosphorylation of Raptor by pemetrexed-activated AMPK is sufficient to suppress mTORC1 activity promoted by loss of p53 and TSC2. [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 2432. doi:10.1158/1538-7445.AM2014-2432
Abstract 2463: Suppression of hepatocyte nuclear factor 4α by nuclear factor κB in hepatoma cells
Authors: Ning Bei-Fang , Zhang Xin , Xie Wei-Fen 
Published: May 2015

Abstract
BACKGROUND & AIMS: HCC predominantly arises from cirrhotic liver where there usually has been repeated wound-healing response upon chronic inflammation. However, the mechanistic link between hepatic inflammation and carcinogenesis remains largely unknown.
METHODS: Expression of HNF4α, RelA(p65) or microRNAs in human HCCs was determined by Real-time PCR, western blot or immunohistochemistry. 3′UTR reporter assay was conducted to determine the regulation of HNF4α by microRNAs. The recombinant adenoviruses carrying HNF4α gene were injected into diethylinitrosamine(DEN)-administrated Wistar rats through tail vein. Tissue microarray was utilized to assess the expression of HNF4α and RelA HCC tissues.
RESULTS: Overexpression or interference of RelA remarkably decreased or increased HNF4α expression in hepatoma cells respectively, suggesting a negative regulation of HNF4α by NF-κB. Interestingly, ecotopic RelA expression dramatically reduced the activation of HNF4α-3′UTR indicating microRNA could be involved in the feedback regulation. MiR-21 was predicted to be regulated by NF-κB using Targetscan analysis, and overexpression of RelA evidently enhanced the miR-21 expression. Delivery of miR-21 mimic notably suppressed HNF4α-3′UTR activity and HNF4α expression. Moreover, treatment of miR-21 inhibitor increased HNF4α levels and attenuated the down-regulation of HNF4α by RelA. Consistently, downregulation of HNF4α and upregulation of RelA was detected during DEN-induced rat hepatocarcingenesis, negative correlation of HNF4α and RelA was also observed in human HCCs. CONCLUSIONS: These findings not only broaden the knowledge on hepatic inflammation and cancer initiation, but also indicates novel strategy in HCC prevention.
Note: This abstract was not presented at the meeting.
Citation Format: Bei-Fang Ning, Xin Zhang, Wei-Fen Xie. Suppression of hepatocyte nuclear factor 4α by nuclear factor κB in hepatoma 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 2463. doi:10.1158/1538-7445.AM2014-2463
Abstract 2543: Circulating s100a9 myeloid-derived suppressor cells are predictive for poor pfs in patients with egfr mutation positive lung adenocarcinoma treated with gefitinib
Authors: Feng Po-Hao , Yu Chih-Teng , Lee Kang-Yun 
Published: May 2015

Abstract
Introduction: Around 10-30% of patients with EGFR-mutation positive lung adenocarcinoma do not have objective response to EGFR-TKI, whilst the majority of the EGFR-mutation positive patients eventually develop acquired resistance. We have recently demonstrated that the distinct S100A9+ myeloid derived suppressor cells (MDSC) predicted poor outcome in response to cisplatin-based chemotherapy in patients with advanced NSCLC. In this study, we tested whether numbers of circulating S100A9+ MDSC, among other potential factors, could be a predictor for treatment response to EGFR-TKI.
Methods: Between 2010-2012, thirty-four patients with pathologically proved, stage IIIB-IV lung adenocarcinoma with sensitizing EGFR-mutations, were prospectively enrolled. Gefitinib was used as the first line treatment. Pretreatment S100A9 MDSC was determined by FACS analysis and serum HGF by ELISA.
Results:
Among the patients, 47.1% (16/34) had Ex19Del and 50.0% (17/34) had L858R mutations. The objective response rate was 84.4% and the median progression-free survival (PFS) 10.16 months (95% CI 8.18-12.14 months). In univariate analysis, body weight loss, brain metastasis and S100A9 MDSC (p = 0.008, 0.022 and 0.014, respectively), but not gender, smoking, type of EGFR mutation, or serum HGF, were significant factors for PFS. Multivariate Cox regression analysis revealed brain metastasis (HR=3.924, 95% CI 1.449-10.627, p=0.007) and S100A9+ MDSC (HR=4.944, 95% CI 1.578-15.490, p=0.006) were both independent factors for PFS. When the medium number of S100A9 MDSC, e.g. 17.9% of the PBMC, was chosen as a cut off level, patients with high MDSC had shorter PFS compared with those with low MDSC (median 7.2 months (95% CI, 5.5-8.9 months) vs. 12.7 months (95% CI, 8.1-17.2 months), respectively, p=0.014 by Log-Rank Test).
Conclusions: Pretreatment S100A9+ MDSC and brain metastasis are independent predictors for shorter PFS to EGFR TKI in EGFR-mutation positive patients. This MDSC might potentially play some roles in treatment response to EGFR-TKI.
Keyword: NSCLC, S100A9+ MDSC, EGFR mutation, EGFR-TKI
Citation Format: Po-Hao Feng, Chih-Teng Yu, Kang-Yun Lee. Circulating s100a9 myeloid-derived suppressor cells are predictive for poor pfs in patients with egfr mutation positive lung adenocarcinoma treated with gefitinib. [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 2543. doi:10.1158/1538-7445.AM2014-2543
Abstract 3117: BET bromodomain inhibition triggers apoptosis of NF1-associated malignant peripheral nerve sheath tumors through Bim induction
Authors: Patel Amish J. , Liao Chung-Ping , Chen Zhiguo , Liu Chiachi , Wang Yong , Le Lu Q. 
Published: May 2015

Abstract
Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are highly aggressive sarcomas that develop sporadically or in Neurofibromatosis type 1 (NF1) patients. MPNSTs are typically fatal, and effective treatments remain limited. To gain insights into MPNST pathogenesis, we utilized a novel MPNST mouse model that allowed us to study the evolution of these tumors at the transcriptome level. Strikingly, in MPNSTs we found upregulation of chromatin regulator Brd4, and show that BRD4 inhibition profoundly suppresses both growth and tumorigenesis. Our findings reveal new roles for BET bromodomains in MPNST development, and report a novel mechanism by which bromodomain inhibition induces apoptosis through induction of pro-apoptotic Bim, which may represent a paradigm shift in therapy for MPNST patients. Moreover, these findings indicate novel epigenetic mechanisms underlying the balance of anti-/pro-apoptotic molecules, and suggest that bromodomain inhibition can shift this balance in favor of cancer cell apoptosis.
Citation Format: Amish J. Patel, Chung-Ping Liao, Zhiguo Chen, Chiachi Liu, Yong Wang, Lu Q. Le. BET bromodomain inhibition triggers apoptosis of NF1-associated malignant peripheral nerve sheath tumors through Bim induction. [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 3117. doi:10.1158/1538-7445.AM2014-3117
Abstract 3166: Rab11 regulates E-cadherin expression and induces cell transformation in colorectal carcinoma
Authors: Chung Yuan-Chiang , Wei Wan-Chen , Huang Shin-Han , Shih Chi-Min , Hsu Chih-Ping , Chang King-Jen , Chao Wei-Ting 
Published: May 2015

Abstract
In the process of epithelial mesenchymal transition EMT, the disassembly of junctional adhesion complexes such as E-cadherin is a remarkable sign during changes in cell morphology and polarity. However, E-cadherin expression is dynamic, and is regulated by the cellular endocytic system; it is also involved in cell signaling mechanisms. In this study, we investigated the role of E-cadherin in colorectal tumors and the relationship with recycling endosome protein Rab11 in colon cell transformation. For tissue screening, the expressions of E-cadherin and Rab11 in colorectal tumors were identified by immunohistochemistry in 113 patients with colorectal carcinoma. For the in vitro cell experiment, GFP-tagged Rab11 plasmid was transfected into HT29 colon cells, E-cadherin expression and cell transformation were monitored by Western blot and confocal microscopy. In immunohistochemistry, the mean score of E-cadherin in tumor and normal tissues was 1.41 ± 0.06 and 1.08 ± 0.06 (p &lt; 0.05). The mean score of Rab11 in tumor and normal tissues was 0.51 ± 0.05 and 0.18 ± 0.02 (p &lt; 0.05). Synchronous overexpression of E-cadherin and Rab11 was noted in 74 patients (66.5%) with colorectal carcinoma. When GFP-tagged Rab11 plasmid was overexpressed in cultured colon cell line HT-29, the E-cadherin expression was up-regulated, and a fibroblast-like cell polarity was induced, which resulted in cell transformation. This study demonstrated the importance of the overexpression of Rab11 and E-cadherin in colorectal cancer. The results indicated that Rab11 together with E-cadherin might be potential markers for colorectal cancer progression and treatment.
Citation Format: Yuan-Chiang Chung, Wan-Chen Wei, Shin-Han Huang, Chi-Min Shih, Chih-Ping Hsu, King-Jen Chang, Wei-Ting Chao. Rab11 regulates E-cadherin expression and induces cell transformation in colorectal carcinoma. [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 3166. doi:10.1158/1538-7445.AM2014-3166
Abstract 3177: Hepatitis C virus transcriptionally downregulates miR-181c for promotion of hepatocyte growth towards hepatocellular carcinoma
Authors: Ray Ratna B. , Mukherjee Anupam , Shrivastava Shubham , Ray Ranjit 
Published: May 2015

Abstract
Hepatitis C virus (HCV) induced chronic liver disease is one of the leading causes for hepatocellular carcinoma (HCC). The molecular events leading to HCC following HCV infection remains poorly defined. MicroRNAs (miRNAs) have been implicated in the control of many biological processes and their deregulation associate with different viral infections. In this study, we have identified a mechanism by which HCV suppresses miR-181c in human hepatocytes and target pathways involved in cell proliferation. Our results suggested that HCV infection transcriptionally downregulates miR-181c expression by modulating C/EBP-β. In silico prediction suggests that HOXA1 is a direct target of miR-181c. Homeobox A1 (HOXA1) is a member of homeodomain containing transcription factor family, and possesses pivotal roles in normal growth, development and differentiation of mammalian tissues. We have observed that HOXA1 expression is enhanced in HCV infected hepatocytes, and overexpression of mimic miR-181c inhibits HOXA1. Subsequently, exogenous expression of miR-181c inhibited HOXA1 downstream molecules STAT3 and STAT5, important transcription factors involved in HCV mediated cell survival and proliferation. Taken together, our results suggested that miR-181c is downregulated during HCV infection, which in turn, enhanced HOXA1 signaling pathway and promoted hepatocyte growth towards HCC.
Citation Format: Ratna B. Ray, Anupam Mukherjee, Shubham Shrivastava, Ranjit Ray. Hepatitis C virus transcriptionally downregulates miR-181c for promotion of hepatocyte growth towards hepatocellular carcinoma. [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 3177. doi:10.1158/1538-7445.AM2014-3177
Abstract 3200: The effect of a sesquiterpenoid from Tussilago farfara on cellular proliferation via the Wnt/β-catenin signaling pathway in colon cancer
Authors: Ryu Jae-Ha , Li Hua , Lee Hwa Jin , Kim Woo-Young 
Published: May 2015

Abstract
The β-catenin, a major transcriptional modulator in Wnt signaling, plays a key role in embryogenesis, stem cell renewal and organ regeneration.
Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. Therefore, the modulation of Wnt/β-catenin signaling pathway has been regarded as a guaranteed target for the treatment of cancer. In the past decade, various pharmacological inhibitors of β-catenin have been identified from medicinal plants. Most of the plant-derived inhibitors are flavonoids such as quercetin, fisetin, silibene and so on. In the present study, we identified tussilagone (TSL), a sesquiterpenoid isolated from the flower buds of medicinal plant Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity in a dose dependent manner (2, 10, 30 μM), and also down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were activated by Wnt3a or 20 mM LiCl, an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not affected by TSL up to 30 μM, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, the levels of cytosolic and nuclear β-catenin were decreased significantly by the treatment with 10 μM TSL in Western blot and immunofluorescence analysis. Moreover, TSL also decreased the expression of cyclin D1 and c-myc, the representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, tussilagone from T. farfara may be a new lead compound for the development of therapeutic agents against colon cancer through modulating Wnt/β-catenin signaling pathway. Acknowledgements: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Ministry of Science, ICT & Future Planning (Project No 2011-0030699 and 2012R1A1A3013645).
Citation Format: Jae-Ha Ryu, Hua Li, Hwa Jin Lee, Woo-Young Kim. The effect of a sesquiterpenoid from Tussilago farfara on cellular proliferation via the Wnt/β-catenin signaling pathway in colon cancer. [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 3200. doi:10.1158/1538-7445.AM2014-3200