bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4859: Ultra-sensitive detection of rare mutants by droplet digital PCR with conventional TaqMan assays
Authors: Hindson Benjamin , So Austin , Koehler Ryan , Troup Camille , Heredia Nick , Karlin-Neumann George , Saxonov Serge , White Helen 
Published: August 2012

Abstract
Molecular tests for genetic mutations play an important role in the diagnosis of cancer. Somatic mutations that drive the pathological features of most tumors have increasing promise as biomarkers for cancer prognosis and therapeutic efficacy. The detection of somatic mutations poses an analytical challenge due to the heterogeneous nature of most samples, where a gene carrying a mutation may differ from the highly abundant wild type sequence by only a single nucleotide. Although a variety of methods exist for mutation analysis, many have poor selectivity and fail to detect mutant sequence below 1 in 100 wildtype sequences. Methods that provide better discrimination and quantitation of somatic mutations are desirable. Here we present a simple strategy using droplet digital™ PCR (ddPCR™) for the detection of somatic mutations with high selectivity and sensitivity. Based on the simple principle of sample partitioning into water-in-oil microdroplets, this ddPCR method increases the abundance of a mutant DNA sequence up to 20,000 times compared to an equivalent bulk PCR reaction. Using conventional TaqMan chemistries and workflow, selectivities of up to 1/100,000 can readily be achieved in any laboratory. Here we present results on the use of ddPCR for the detection and quantitation of several clinically important mutations, including KRAS, c-KIT D816V and JAK2 from clinical samples such as bone marrow aspirates and FFPE. Results from ddPCR are compared to those of conventional approaches including allele specific real-time PCR and sequencing. This ddPCR method may play an important role in the earlier detection of cancer, monitoring the progress of disease and response to therapeutics.
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 4859. doi:1538-7445.AM2012-4859
Abstract 4860: Exon capture analysis of G-protein coupled receptors reveals activating mutations in GRM3 in melanoma
Authors: Prickett Todd D. , Wei Xiaomu , Cardenas-Navia Isabel , Teer Jamie , Lin Jimmy C. , Walia Vijay , Gartner Jared , Jiang Jiji , Cherukuri Praveen , Molinolo Alfredo , Davies Michael A. , Stamke-Hale Katherine , Margulies Elliott H. , Rosenberg Steven A. , Samuels Yardena 
Published: August 2012

Abstract
An important feature of cellular signaling involves the activation of plasma membrane-bound receptor complexes via endogenous ligands. G protein-coupled receptors (GPCRs), the largest human gene family, are known to be activated by ligands such as, thrombin, chemokines or glutamate, and have been shown to be important regulators of signaling pathways. Dysregulation via overexpression of diverse GPCRs has been well documented in primary and metastatic tumors cells such as breast, lung, prostate and gastric tumors, head and neck squamous cell carcinoma, and melanoma (1), however, knowledge of their genetic alterations is limited especially in malignant melanoma. Thus, further analysis of this gene family is warranted to determine if GPCR proteins play a role in melanomagenesis. In our current study, we used exon capture and illumina sequencing methods to analyze the mutational status of all the GPCRs in melanoma. This investigation revealed that one family member, GRM3 was frequently mutated in melanoma and that one of its mutations clustered within one position (Glu870Lys). Biochemical analysis of GRM3 alterations revealed that mutant GRM3 selectively regulated the phosphorylation of MEK leading to increased anchorage-independent growth and migration. In vivo studies revealed that overexpression of mutant forms of GRM3 result in increased lung macrometastases; whereas depletion of GRM3 in cells expressing mutant forms of GRM3 resulted in reduced xenograft tumor formation compared to equivalently treated wild type GRM3 cells. Furthermore, melanoma cells expressing mutant forms of GRM3 had reduced cell growth and reduced cellular migration after shRNA-mediated knockdown of GRM3 or treatment with a selective MEK inhibitor, AZD-6244, which is currently being used in phase II clinical trials. Our study yields a comprehensive map of genetic alterations in the GPCR gene family and suggests a potential novel therapeutic target for melanoma patients.
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 4860. doi:1538-7445.AM2012-4860
Abstract 486A: Biological characterization of recombinant maspin in breast cancer cells
Authors: Bodenstine Thomas M. , Seftor Richard E. B. , Seftor Elisabeth A. , Khalkhali-Ellis Zhila , Pemberton Philip A. , Hendrix Mary J. C. 
Published: August 2012

Abstract
Mammary serine protease inhibitor (maspin) is a non-inhibitory member of the serine protease inhibitor (serpin) superfamily and is involved in mammary gland development. Loss of maspin expression is commonly observed during breast cancer progression while re-expression of maspin confers tumor suppressive capabilities. Cellular localization of maspin within the cytosol, nucleus, and association in complexes at the plasma membrane confer different properties in cancer cells adding to the complexity of maspin function. The recombinant form of maspin (rMas) when added to growth media of maspin-null cancer cells recapitulates many of the effects of exogenous maspin re-expression including inhibition of invasion through 3D matrices. These effects highlight the potential of rMas for therapeutic development as a novel adjuvant therapy. The aim of this study was to characterize the uptake, processing and distribution of wild-type and mutated forms of rMas in cancer cells. Using the MDA-MB-231, BT549 and Hs578T breast cancer cell lines we demonstrate that rMas is directly internalized by cancer cells and degraded rapidly. Time-lapse confocal microscopy using Alexa Fluor 594 labeled rMas and nuclear/cytoplasmic extraction of rMas following cellular uptake demonstrate that rMas is predominantly localized and processed in the cytosol. Wild-type rMas inhibited cancer cell invasion through collagen based matrices and this effect was independent of nuclear localization. Interestingly, site-directed mutagenesis of rMas to induce reported polymorphisms (Ile to Val 66, Pro to Ser 176, Leu to Val 187, Ile to Val 319) abrogated the ability of rMas to inhibit invasion. These preliminary experiments contribute to the characterization of rMas following internalization by cancer cells and aid in the therapeutic development of rMas as a potential therapy. Additionally, mutational data from this study support growing evidence that mutations in the maspin gene alter functionality in vitro, and may correlate to clinical outcomes in patients in which maspin is expressed in tumors.
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 486A. doi:1538-7445.AM2012-486A
Abstract 4885: mTOR complex 2 is involved in regulation of c-FLIP stability and sensitization of TRAIL-induced apoptosis
Authors: Zhao Liqun , Yue Ping , Khuri Fadlo R. , Sun Shi-Yong 
Published: August 2012

Abstract
The mammalian target of rapamycin (mTOR), a serine-threonine kinase related tightly to the phosphoinositide 3-kinase family, acts as a central molecule in regulation of cell proliferation and survival through forming two complexes primarily with raptor (mTOR complex 1; mTORC1) or rictor (mTOR complex 2; mTORC2). Compared with the mTORC1, relatively little is known about the biological functions of mTORC2. However, it is clear that both of the mTOR signaling pathways are dysregulated in human cancers, including lung cancer. Accordingly, novel ATP-competitive mTOR kinase inhibitors such as PP242 that inhibit both mTORC1 and mTORC2 have been developed for cancer therapy. In this study, we focus on addressing whether mTORC2 regulates apoptosis, particularly induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a potential cancer therapeutic protein tested in clinical trials. We found that PP242 synergized with TRAIL to augment apoptosis in human lung cancer cells. PP242 reduced the level of the short form of c-FLIP (FLIPS) and survivin with minimal effects on the expression of DR4 and DR5. Enforced expression of FLIPS, but not survivin, attenuated PP242/TRAIL-induced apoptosis; this suggests that FLIPS downregulation contributes to synergistic induction of apoptosis by the PP242 and TRAIL combination. Mechanistic studies revealed that PP242 decreased FLIPS stability, increased FLIPS ubiqutination and facilitated FLIPS degradation, suggesting that PP242 decreases FLIPS levels through promoting its degradation via an ubiqutination and proteasome-dependent mechanism. Interestingly, knockdown of rictor, but not raptor, mimicked PP242 in decreasing FLIPS levels and sensitizing cells to TRAIL. Moreover, rictor knockdown decreased the stability of FLIPS. These data together suggest that it is mTORC2 inhibition that mediates FLIPS downregulation and subsequent sensitization of TRAIL-induced apoptosis. Our findings hence provide the first evidence showing that mTORC2 positively regulates FLIPS expression, thereby, connecting mTORC2 signaling to regulation of the death receptor-mediated apoptosis pathway. (This study was supported by the Georgia Cancer Coalition Distinguished Cancer Scholar award and NIH/NCI R01 CA118450. FR Khuri and SY Sun are Georgia Cancer Coalition Distinguished Cancer Scholars)
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 4885. doi:1538-7445.AM2012-4885
Abstract 4891: Radiation enhances the efficacy of Bcl-2 and Bcl-XL inhibition in small cell lung cancer: A new concept of using radiation for targeted therapy through contextual oncogene addiction
Authors: Loriot Yohann , Mordant Pierre , Dugué Delphine , Gombos Andrea , Opolon Paule , Vozenin Marie-Catherine , Bourhis Jean , Geneste Olivier , Kraus-Berthier Laurence , Pierré Alain , Depil Stéphane , Soria Jean-Charles , Deutsch Eric 
Published: August 2012

Abstract
Purpose: Radiotherapy has a critical role in the treatment of small cell lung cancer (SCLC). Effectiveness of radiation in SCLC remains limited as resistance results from defects in apoptosis. Experimental Design: We investigated whether using a new Bcl-2/Bcl-XL inhibitor, S44563, can enhance radiosensitivity of SCLC cells in vitro and in vivo. We also explored the mechanisms of the potential interaction. Results: In vitro studies confirmed that S44563 induce apoptosis in SCLC cells by inducing hallmarks of apoptosis (cleaved caspase-3, sub-G1 fraction induction and induction of the mitochondrial caspase activation pathway). S44563 markedly enhanced sensitivity of H146 and H69 cells to radiation in clonogenic assay. In vitro experiments demonstrated a greater induction of apoptosis (sub-G1 fraction and cleaved caspase-3) with the combination as well as in vivo caspase-3 immunostaining. This positive interaction between S44563 and radiation was greater when S44563 was given during and after the completion of the radiation, which was explained by the radiation-induced over expression of anti-apoptotic proteins (Bcl-2 and Bcl-XL). in vitro studies based on gene expression and immunoblotting indicated that radiation activates NF-κB pathways which results in anti-apoptotic expression. In addition, S44563 combined with cisplatin-based chemo-radiation showed a dramatic tumor growth delay and increased overall survival in mouse xenograft models.Conclusion: This study underlines the critical role of sequence administration of targeted therapies with conventional therapies such as radiation and chemotherapy. SCLC cells which survive to IR highly rely on the induction of anti apoptotic proteins for their survival therefore yielding to the concept of “contextual oncogene addiction” to the Bcl-2/Bcl-XL pathway. These results suggest that radioresistance results in part from resistance to apoptosis in SCLC mediated by up regulation of Bcl-2/Bcl-XL. The inhibition of Bcl-2 and Bcl-XL leads to the induction of radiation-induced apoptosis and enhances radiation therapy both in vitro and in SCLC xenograft models. Our data suggest that targeting radiation induced survival pathways may constitute an efficient strategy to potentiate IR.
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 4891. doi:1538-7445.AM2012-4891
Abstract 4898: Methylseleninic acid potentiates multiple types of cancer cells to ABT-737-induced apoptosis involving Mcl-1, AKT-Bad, and mitochondrial cascade
Authors: Yin Shutao , Dong Yinhui , Li Jinghua , Lü Junxuan , Hu Hongbo 
Published: August 2012

Abstract
ABT-737, a novel small-molecule inhibitor of select Bcl-2 family survival proteins, holds excellent promise to complement current cytotoxic therapies for cancer, especially B-cell malignancies. However many types of solid cancer cells are resistant to ABT-737. One practical approach to improving its therapeutic efficacy is to combine with agents that can overcome such resistance to restore the sensitivity. In the present study, we sought to test the hypothesis that the cancer chemopreventive selenium compound methylseleninic acid (MSeA), known to suppress the expression of some Bcl-2 family members and AKT survival signaling, could synergistically sensitize cancer cells to ABT-737-induced apoptosis. Our results show that serum achievable levels of MSeA increased apoptosis induction by ABT-737 in several aggressive malignant cell lines: MDA-MB-231 human breast cancer cells, HT-29 human colon cancer cells and DU145 human prostate cancer cells, as evidenced by greater than additive enhancement of annexin V/FITC positive (apoptotic) cells and activation of multiple caspases and PARP cleavage. Mechanistic investigation demonstrated that MSeA significantly decreased the basal expression of Mcl-1 and ABT-737-induced Mcl-1 expression. Knocking down of Mcl-1 with RNAi increased ABT-737-induced apoptosis. More importantly, we identified activation of AKT phosphorylation and AKT-mediated inactivation of Bad by ser-136 and ser-112 phosphorylation as a novel mechanism involved in ABT-737 resistance which could be overcome by MSeA. In addition, we found that expression of Bax was required for the efficient execution of synergistic sensitization. These mitochondria-related apoptosis findings, to our knowledge for the first time, provide a strong mechanistic rationale for developing MSeA as a novel sensitizing agent of ABT-737 for cancer chemotherapy.
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 4898. doi:1538-7445.AM2012-4898
Abstract 4899: Altered receptor glycosylation confers cisplatin resistance in ovarian and colon cancer cells
Authors: Schultz Matthew J. , Swindall Amanda F. , Bellis Susan L. 
Published: August 2012

Abstract
Chemotherapy resistance is a significant clinical obstacle in the treatment of cancer. Platinum-based drugs are a mainstay of treatment in many solid cancers; however, tumor resistance to these drugs hampers long term efficacy. Resistance is multi-factorial, and theories to explain resistance are incomplete. In this study we report a novel mechanism for resistance to cisplatin involving changes in receptor glycosylation. Previous work in our lab has demonstrated enhanced colon cancer cell survival in cells expressing ST6Gal-I, a Golgi glycosyltransferase that adds the negatively-charged sugar, alpha2-6-linked sialic acid, to selected membrane proteins. We showed that sialylation of the Fas death receptor by ST6Gal-I decreases apoptotic signaling in response to Fas agonists by blocking DISC formation and receptor internalization. Elevated ST6Gal-I expression has been reported in many cancers, including ovarian and colon, and its expression is negatively correlated with patient prognosis. Interestingly, cisplatin has been demonstrated to mediate its cytotoxic effects, in part, through Fas receptor upregulation and activation, although the mechanism is not currently understood. Combining these results and observations, we investigated whether ST6Gal-I-mediated sialylation of the Fas receptor inhibits apoptotic signaling in response to cisplatin treatment, contributing to intrinsic cisplatin resistance. We determined the extent of cisplatin-induced apoptotic cell death by blotting for cleaved caspase-3, a terminal caspase, and detected decreased levels of activated caspase in ST6Gal-I expressing ovarian and colon cell lines. This result was observed in both a low endogenous ST6Gal-I cell model with forced ST6Gal-I expression, as well as a high endogenous ST6Gal-I expression cell model with shRNA ST6Gal-I knockdown. We also show sustained viability in cells expressing ST6Gal-I after cisplatin treatment by measuring a peptide protease substrate which is cleaved in live cells. Conversely, we detected a decrease in viability in non-ST6Gal-I expressing counterpart cell lines indicating that cells lacking ST6Gal-I expression are more sensitive to cisplatin-mediated cell death. Finally, we observed that cisplatin-mediated cell death is attenuated by treating cells with blocking antibodies to Fas, consistent with other studies implicating this receptor in cisplatin efficacy. Our findings suggest a novel mechanism contributing to platinum drug resistance in cancer cell populations and identify ST6Gal-I as a promising target for therapeutic intervention.
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 4899. doi:1538-7445.AM2012-4899
Abstract 4900: Bortezomib induces G2-M arrest through ROS-inducible phosphorylation of ATM independent on genotypes of KRAS in human colon cancer cells
Authors: Kim Seung-Mi , Hong Yong Sang , Hong Seung-Woo , Jin Dong-Hoon , Kim Tae Won 
Published: August 2012

Abstract
The use of cetuximab (CET) as an inhibitor of EGFR for treatment of colorectal cancer (CRC) has revolutionized. However, a number of CRC patients exhibits resistance to CET. In this report, we suggest the possibility of using bortezomib as a proteasome inhibitor in human colon cancer cells. Although bortezomib has been known to induce apoptosis and cell cycle arrest in various human cancer cells, the inhibitory mechanism of it was not clear. First, bortezomib induced G2-M arrest independent on genotype of KRAS in all of tested human colon cancer cells. Its treatment causes an increase of intracellular ROS levels and activation of ATM-CHK1 pathway, but not ATR. Also, activation of that pathway led to inactivation of cdc2. Moreover, treatment with NAC, Reactive Oxygen Species (ROS)scavenger, inhibited phosphorylation of ATM and subsequent to decrease of cell number at G2-M phase in response to bortezomib indicating that the increased level of ROS after exposure to bortezomib is a result of ATM phosphorylation. In addition, knockdown of endogenous ATM by RNA interference induced the decreased sensitivity to bortezomib. Therefore, these results suggest that bortezomib induces G2-M arrest through ROS-inducible ATM phosphorylation and responses to colon cancer cells independent on genotype of KRAS, implying a potential possibility of it in the treatment of CRC patients.
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 4900. doi:1538-7445.AM2012-4900
Abstract 4906: Tamoxifen-mediated apoptosis relationship with ERα36 in gastric cancer cell BGC823
Authors: Li Yan , Deng Hao , Fan Jun , Zhou Diwei , Chen Ying , Wang Chengxin 
Published: August 2012

Abstract
Aim: The growth, apoptosis and estrogen receptor α36 (ERα36) expression and location changes in gastric cancer cell line BGC823 were observed, when dealt with different concentrations Tamoxifen (TAM), to characterize the role of TAM in gastric cancer growth and apoptosis and the mechanism of it. Materials and Methods: BGC823 cell was dealt with 10-6M and 10-5M TAM for 24h and 48h. Cell growth was assessed by WST1 assay. The mRNA and protein expressions of ERα36 were examined by RT-PCR and Western blot methods. Average optical densities were detected and processed using Student's t test analysis. Immunofluorescence assay was used to examine ER-α36 location in BGC823 cell. Hoechest33258 assay was used to examine apoptosis. Results: TAM could promote apoptosis and inhibit growth of BGC823 cell, and this effect had concentration dependant (P&lt;0.05). TAM could promote ERα36 mRNA expression, and the increase level of ERα36 mRNA expression had concentration dependent of E2β(P&lt;0.05). TAM could promote ERα36 protein expression, and the increase level of ERα36 protein expression had concentration dependent of E2β(P&lt;0.05). The location of ERα36 had no change, when BGC823 cell dealt with TAM.Conclusions: TAM could promote apoptosis and inhibit growth of BGC823 cell, and the effect had concentration dependant. TAM could promote ERα36 expression in BGC823 cell, and the effect had concentration dependant. ERα36 may participate apoptosis mediated by Tamoxifen in Gastric Cancer Cell Line BGC823
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 4906. doi:1538-7445.AM2012-4906