bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3316: Characterizing mechanisms of resistance to androgen deprivation in prostate cancer
Authors: Botta Ginevra , Jane-Valbuena Judit , Wong Terence , Doench John , Garraway Levi A. 
Published: May 2015

Abstract
Despite significant advances in the treatment of prostate cancer (PCa), this malignancy remains a leading cause of cancer death among men. PCa cells require androgen receptor (AR) signaling for their growth and survival. Androgen deprivation therapy (ADT) constitutes the main therapeutic option for patients with advanced PCa. However, the major cause of death in men with metastatic prostate cancer involves progression to castration-resistant prostate cancer (CRPC). Characterizing mechanisms of resistance to ADT could enable the development of more effective therapeutic strategies. To identify genes whose silencing drives resistance to ADT in androgen-sensitive PCa cells, we performed a systematic genome-wide suppressor RNAi screen in the androgen-sensitive LNCaP cells, using a 98,000-shRNA library, targeting approximately 16,000 human genes. After infection, cells were cultured in absence of androgens for several weeks. Cells showing the ability to proliferate upon androgen deprivation were harvested at different time points and shRNA sequences were identified and quantitated through nextgen sequencing. Hit genes were those with at least 2 shRNAs enriched &gt;4 fold, and whose silencing exerted the most robust effects on cell proliferation. To validate the identified top-tier genes in vitro, we infected LNCaP cells with lentiviruses carrying shRNAs (2 shRNAs/candidate gene) targeting the top ∼30 candidate genes, in parallel with 15 negative control shRNAs. We monitored the ability of each shRNA to increase proliferation under androgen-deprived conditions, using cell viability assays. To determine whether any shRNAs drive castration resistance by reactivating the AR-signaling pathway, we analyzed the expression of known AR effector genes in the presence of candidate shRNAs and also tested their effect on cell proliferation in the presence of the direct AR antagonist MDV3100. In future, we will also validate candidate genes in vivo, using a LNCaP xenograft model. This study has identified several genes whose silencing may modulate resistance to ADT in prostate cancer. Additional functional studies should determine whether a subset of these may promote new therapeutic strategies for men with CRPC.
Citation Format: Ginevra Botta, Judit Jane-Valbuena, Terence Wong, John Doench, Levi A. Garraway. Characterizing mechanisms of resistance to androgen deprivation in prostate 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 3316. doi:10.1158/1538-7445.AM2014-3316
Abstract 3317: The cytosolic domain of a disintegrin and metalloprotease (ADAM)-15 promotes proliferation of non-small cell lung cancer (NSCLC)
Authors: Hou Hsin-Han , Yu Chong-Jen 
Published: May 2015

Abstract
Lung cancer is the leading cause of cancer-related deaths in worldwide, including in Taiwan. Lung cancer can typically be grouped into two large categories: small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), which account for 15% and 85% of lung cancers, respectively. Despite the continuing endeavors by scientists and clinicians, the cure rate remains low and there is urgent to develop a novel target for NSCLC therapy. The a disintegrin and metalloprotease (ADAM)-15 is a transmembrane protease mediating a wide variety of activities including proteolysis, adhesion, cell fusion and signaling. The expression of ADAM-15 is significantly up-regulated in NSCLC compared to normal tissue. However, the mechanisms of ADAM-15-modulated tumorigenesis in NSCLC are remained unclear. The external enzymetic activity of ADAM15 doesn’t involve in the common pathways in tumoregenesis of NSCLC, such as HER3-EGFR signaling. ADAM15 isoforms are different in cytoplasmic tails, which may drive different biological behavior through intracellular signaling. Therefore, we hypothesized that the diverse cytosolic domain of ADAM15 isoforms plays a crucial role in tumoregenesis of NSCLC. In this study, using real-time quantitative PCR measuring the mRNA expression of 22 ADAMs in NSCLC, we identified a correlation of higher expression of ADAM15 in NSCLC of non-smokers (p=0.002, compared with ex- and current smokers) and in adenocarcinoma (p=0.038, compared with squamous cell ca). Comparing to non-invasive CL1-0 cells and matched normal tissue, CL1-5 cells and NSCLC tissue expressed more the longest ADAM-15 isoform with the largest amount of Src homology (SH)3-binding domain. The association ADAM-15 with SH3-motif containing protein, growth factor receptor-bound (Grb) 2, promoted the ability of proliferation in NSCLC in vitro and in vivo. In conclusion, we suggested that the cytosolic domain of ADAM-15 promotes proliferation of NSCLC via enhance of Grb2-associated signaling pathways, and the inhibition of ADAM-15 may be a potential therapeutic target for NSCLC.
Citation Format: Hsin-Han Hou, Chong-Jen Yu. The cytosolic domain of a disintegrin and metalloprotease (ADAM)-15 promotes proliferation of non-small cell lung cancer (NSCLC). [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 3317. doi:10.1158/1538-7445.AM2014-3317
Abstract 3320: Functional RANK expression is observed in disaggregated primary human lung tumors
Authors: Rossi John M. , Pan Yang , Dougall William C. , Branstetter Daniel , Jacob Allison , Canon Jude , Loberg Robert D. 
Published: May 2015

Abstract
The receptor activator of nuclear factor-κβ (RANK) and its ligand RANKL play a key role in the regulation of bone remodeling. RANK pathway activation has also been implicated in various aspects of lung tumor biology. In mouse models of NSCLC bone metastasis, RANKL inhibition led to decreased skeletal tumor progression and increased survival. By IHC, RANK expression has been reported to occur in approximately 60-70% of NSCLC cases profiled. Expression and function have been observed using human lung cancer cell line models. However, there is a lack of understanding with respect to the role RANK signaling plays in primary human lung tumor cells. To better understand RANK biology in lung cancer a novel platform was employed to measure RANK expression and pathway response to RANKL stimulation in freshly resected human lung tumors.
RANK expression and function were investigated in viable, non-apoptotic disaggregated primary NSCLC samples by flow cytometry using previously described methodology. Cell surface RANK expression was evaluated using a monoclonal antibody (N2B10, Amgen). Evidence of receptor function was investigated by analysis of relevant intracellular signaling pathways using phospho-specific antibodies following ex vivo RANKL stimulation (2.5 pM - 5 µg/mL, 30 minutes). A cocktail of EGF, HGF and IGF1 was also employed as a positive control for functional pathway activation. Molecular profiling of somatic mutations is ongoing to further elucidate the molecular characteristics of tumors that have functional RANK signaling. Table 1 summarizes RANK expression and RANKL response profiles.
This study demonstrates that RANK is expressed and functional in a subset of primary human lung tumors. Data presented here confirms RANK expression on tumor cells of NSCLC and suggests that RANK pathway utilization is restricted to the sub-set of tumors that express detectable RANK.
Table 1SquamousAdenocarcinomaOther# Samples12217RANK Positive373NFκβ p65 Response1pAKT Response1pERK Response2p38 Responsep65 + pAKT Response1p38 + pERK Response1p65 + p38 + pAKT Response1% Responder (Total*)17%19%14%% Responder (RANK positive*)67%57%33%% Responder (EGF/ HGF/ IGF1)75%95%86%Other: large cell (1), carcinoid (1), adenosquamous (3), neuroendocrine (2)*Within Histology subtype
Citation Format: John M. Rossi, Yang Pan, William C. Dougall, Daniel Branstetter, Allison Jacob, Jude Canon, Robert D. Loberg. Functional RANK expression is observed in disaggregated primary human lung tumors. [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 3320. doi:10.1158/1538-7445.AM2014-3320
Abstract 3321: Using NLPs to study EGFR structure, activation, and inhibition
Authors: Scharadin Tiffany M. , Saldana Matthew , Schlein Michael , Hoang-Phou Steven , Trans Denise , Chang Dennis , He Wei , Lam Kit , Carraway Kermit L. , Coleman Matthew A. , Henderson Paul T. 
Published: May 2015

Abstract
The mammalian ErbB receptor tyrosine kinase family is critical for the development and maintenance of a variety of tissues. Though not completely understood, the mechanism of ErbB receptor activation involves the binding of ligand to the extracellular domain leading to a conformational change that allows dimerization and phosphorylation to initiate downstream signaling pathways. Mutations, amplification, and aberrant activation of these receptors lead to oncogenesis and tumor progression in several cancer types, including lung, breast, and colon. Current ErbB-targeted therapies include monoclonal antibodies and tyrosine kinase inhibitors. These treatments are initially effective but many tumors develop resistance, necessitating the discovery of a more specific and efficient drug. Studying the ErbB receptors is often difficult because of their large size and poor water solubility. Here we report success in assembling EGFR into nanolipoprotein particles (NLPs) to study activation and inhibition of the correctly-folded, full-length, and active receptor. NLPs are ∼20 nm cell membrane analogs composed of an apolipoprotein surrounding a lipid bilayer. We produced a homogenous population of EGFR-NLPs, by FLAG-purification of EGFR from mammalian cells, which are of the correct size, phosphorylated, and can be quantified. Furthermore, these EGFR-NLPs can be utilized as a novel target in a one-bead-one-compound (OBOC) screen of small molecules and peptides to identify unique therapeutics. Studies of ligand binding, kinase activity, and EGFR structure are ongoing. Future directions are to incorporate disease-relevant EGFR mutations into NLPs. The T790M mutation is of particular interest because it is a treatment-induced mutation observed in half of all non small cell lung cancers and confers resistance to current ErbB-targeted therapies.
Citation Format: Tiffany M. Scharadin, Matthew Saldana, Michael Schlein, Steven Hoang-Phou, Denise Trans, Dennis Chang, Wei He, Kit Lam, Kermit L. Carraway, Matthew A. Coleman, Paul T. Henderson. Using NLPs to study EGFR structure, activation, and inhibition. [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 3321. doi:10.1158/1538-7445.AM2014-3321
Abstract 3323: PRAF2 regulates Rab5-dependent endocytic trafficking of EGFR in neuroblastoma
Authors: Yco Lisette P. , Bachmann Andre S. 
Published: May 2015

Abstract
Receptor tyrosine kinases, such as the epidermal growth factor receptor (EGFR), mediate extracellular signaling that activates downstream cell proliferation, differentiation, and migration. Through ligand stimulation, clathrin-mediated endocytosis regulates the EGFR signal transduction pathway. Prenylated Rab acceptor 1 domain family, membrane 2 (PRAF2) is a novel 19-kDa protein with a prenylated Rab acceptor 1 (PRA1) motif and four transmembrane-spanning domains. Similar to PRAF1 and PRAF3, PRAF2 belongs to the PRAF family of vesicle transport-associated proteins. Our lab identified PRAF2 as a candidate prognostic marker of neuroblastic tumors. Using RNA interference, we showed that PRAF2 plays an essential role in neuroblastoma tumorigenesis and metastasis. In the present study, we examined the function of PRAF2 in EGFR endocytic trafficking. We generated stable PRAF2-knockdown (SK-shPRAF2) and PRAF2-overexpressing (SK-PRAF2) neuroblastoma SK-N-SH cell lines and stimulated both cell lines with EGF (10 ng/ml) for various time periods in order to determine the role of PRAF2 in EGFR endocytic trafficking. As judged by immunofluorescence microscopy, we detected larger Rab5-positive punctuate structures in PRAF2-overexpressing SK-PRAF2 cells compared to PRAF2-knockdown SK-shPRAF2 cells or control cells, after 15 min EGF stimulation. After EGF treatment, PRAF2 clearly colocalized with Rab5-positive punctae in SK-PRAF2 cells, suggesting that PRAF2 interacts with Rab5, a critical regulator for receptor endocytosis and early endosome fusion. Moreover, using a receptor internalization assay, we observed a delay in the internalization of EGFR in EGF-treated SK-shPRAF2 cells, in contrast to SK-PRAF2 and control cells. This is in support of our immunofluorescence microscopy results in which Rab5-postive punctae distribution is observed mostly along the membrane of the EGF-treated SK-shPRAF2 cells. Notably, the level of phosphorylation of Akt (Ser473) transiently elevated in EGF-treated SK-PRAF2 cells after 15 min and diminished thereafter, suggesting that overexpression of PRAF2 accelerates the EGFR internalization and degradation. Based on our findings, we propose that PRAF2 affects EGFR endocytosis by regulating early endosome trafficking and Akt activation in neuroblastoma.
Citation Format: Lisette P. Yco, Andre S. Bachmann. PRAF2 regulates Rab5-dependent endocytic trafficking of EGFR in neuroblastoma. [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 3323. doi:10.1158/1538-7445.AM2014-3323
Abstract 3324: The endocannabinoid system inhibits non-small cell lung cancer tumorigenesis by modulating the EGF/EGFR pathway
Authors: Ravi Janani , Sneh Amita , Shilo Konstantin , Nasser Mohd , Ganju Ramesh 
Published: May 2015

Abstract
Non-small cell lung cancer (NSCLC) is a leading form of cancer with limited treatment regimens and is a major cause of cancer related mortality in the United States. The endocannabinoid system composed of two cannabinoid receptors- CB1 and CB2, their endogenous ligands and the enzymes for their metabolism has been implicated in several pathophysiological conditions. They have been extensively studied in various cancers as inhibitors of tumor cell growth by modulating key cell survival pathways. Anandamide (AEA), a well characterized neurotransmitter is an endogenous cannabinoid and agonist for the cannabinoid receptor CB1. One way to enhance the effect of endocannabinoid signaling is to inhibit the enzyme fatty acid amide hydrolase (FAAH), which metabolizes AEA by using the selective FAAH inhibitor URB597. To understand the physiological role of the endocannabinoid system, the NSCLC cell lines A549 and H460 were treated with either Met-F-AEA, URB597 or in combination and subjected to further analysis. Cells which were incubated in combination with Met-F-AEA and URB597 showed reduced proliferative and chemotactic activities in vitro when compared to AEA alone, which were confirmed by reduced MMP2 secretion and stress fiber formation. Also, we have shown that the combination treatment modulates activation of epidermal growth factor receptor (EGFR) and its downstream targets. In response to EGFR pathway activation, cells treated with Met-F-AEA in combination with URB597 underwent GO/G1 cell cycle arrest, ultimately leading to apoptosis via activation of caspase-9 and PARP. Furthermore, these results were validated in vivo in a xenograft nude mouse model system. Mouse xenografts treated with both Met-F-AEA and URB597 underwent reduction in tumor growth when compared to Met-F-AEA or URB597 alone. In summary, our results presented here show that Met-F-AEA in combination with URB597 inhibits the EGFR pathway, resulting in cell cycle arrest and apoptosis. Our findings suggest a novel perspective for the antitumorigenic activity of the endocannabinoid Met-F-AEA when used in combination with URB597 in NSCLC.
Citation Format: Janani Ravi, Amita Sneh, Konstantin Shilo, Mohd Nasser, Ramesh Ganju. The endocannabinoid system inhibits non-small cell lung cancer tumorigenesis by modulating the EGF/EGFR pathway. [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 3324. doi:10.1158/1538-7445.AM2014-3324
Abstract 3328: Novel regulation of HER2 degradation and breast cancer cell proliferation by junctional adhesion molecule-a (JAM-A)
Authors: Brennan Kieran , McSherry Elaine A. , Hudson Lance , Kay Elaine W. , Young Leonie S. , Hill Arnold DK , Hopkins Ann M. 
Published: May 2015

Abstract
Background: We have previously shown that the adhesion protein Junctional Adhesion Molecule-A (JAM-A) is over-expressed in a population of aggressive and metastatic breast tumours, and that it regulates the migration of breast cells. JAM-dependent regulation of migration could contribute to the likelihood of metastatic disease, since migration is an early event in metastasis. Our objective was to further interrogate the links between JAM-A signalling and markers of disease progression in breast cancer.
Approach and Results: Immunohistochemical analysis of JAM-A in two breast cancer tissue microarrays (TMA) revealed that high JAM-A expression correlated significantly with HER2 protein expression, ERnegativity, high grade breast cancers and aggressive luminal B, HER2 and basal subtypes of breast cancer. Using LCC1 and MCF7-HER2 cells which co-express high levels of JAM-A and HER2, we silenced the gene expression of each one in order to examine potential consequences for protein expression of the other. Knockdown of HER2 had no effect on JAM-A protein levels, but knockdown of JAM-A significantly reduced the protein expression of HER2 and its downstream pro-survival effector pAkt. Accordingly, JAM-A knockdown increased apoptosis via a pathway involving Akt activation, as evidenced by apoptosis normalisation upon pharmacological inhibition of Akt. The expressional regulation of HER2 and pAkt by JAM-A was sensitive to inhibition by the proteasomal inhibitor MG132, suggesting that JAM-A regulates the proteasomal degradation of HER2. Finally, over-expression of wild-type JAM-A was sufficient to significantly enhance proliferative and migratory behaviour in breast cell lines.
Conclusions: Our results are consistent with a model whereby JAM-A expression inhibits the proteasomal degradation of HER2, facilitating a pro-survival phenotype through increased Akt activity. Therefore JAM-A antagonists may have future therapeutic value in the treatment of breast tumours overexpressing HER2.
Citation Format: Kieran Brennan, Elaine A. McSherry, Lance Hudson, Elaine W. Kay, Leonie S. Young, Arnold DK Hill, Ann M. Hopkins. Novel regulation of HER2 degradation and breast cancer cell proliferation by junctional adhesion molecule-a (JAM-A). [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 3328. doi:10.1158/1538-7445.AM2014-3328
Abstract 3329: Investigations into the tumor specific regulation of HER2 by Grp94 in breast cancer
Authors: Yan Pengrong , Patel Hardik , Yang Chenghua , Taldone Tony , Chiosis Gabriela 
Published: May 2015

Abstract
Background: Grp94 is the Endoplasmic Reticulum (ER) paralog of the Hsp90 family of chaperones. Overexpression of Grp94 in tumors correlates with advanced stage and poor survival in various cancers and is closely linked to cancer growth and metastasis. Until recently, the major focus of cancer related studies on Grp94 was on the involvement of this protein in the secretion of IGF-II and the regulation of Toll-Like Receptors (TLRs) and integrins.
Objective/Hypothesis: Our group combined compound library screening with computational tools to develop potent and selective inhibitors of Grp94 and of Hsp90, the cytosolic HSP90 paralog. We hypothesize that these small molecules are important pharmacologic tools to investigate, in a tumor-by-tumor manner, Grp94 and Hsp90 associated oncogenic mechanisms.
Approach/Results: Using the Hsp90 paralog specific inhibitors we produce preliminary evidence for an unanticipated role for Grp94 in maintaining the architecture of high density HER2 formations at the plasma membrane, particularly in cancer cells where HER2 is required to channel an amplified signaling through the receptor. Our data indicate that under conditions in which stress is imposed on the cell by proteome alterations (i.e. HER2 overexpression), the chaperoning function of Grp94 is vital for proper HER2 functioning. In these cells Grp94 translocates to the plasma membrane where it functions to maintain an active conformation of HER2 and to stabilize downstream signaling through the receptor. Our data show that inhibition of Grp94 in these cells is sufficient to destabilize membrane HER2, inhibit its signaling properties and target HER2 towards a degradative pathway. These effects are associated with cancer cell viability loss and induction of apoptosis.
Significance: These findings reveal a novel mechanism of HER2-regulation at the plasma membrane, where Grp94 is implicated in HER2 regulation at this location in the specific case of HER2 positive tumors. They also provide a strong rationale for the use of these inhibitors in the investigation of Grp94 associated oncogenic mechanisms. Further, this study proposes the development of Grp94-based cancer therapeutics for HER2 overexpressing breast cancer.
Citation Format: Pengrong Yan, Hardik Patel, Chenghua Yang, Tony Taldone, Gabriela Chiosis. Investigations into the tumor specific regulation of HER2 by Grp94 in breast 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 3329. doi:10.1158/1538-7445.AM2014-3329