bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-174: Use of massively parallel, next-generation sequencing to identify gene mutations beyond ERAS that predict response to panitumumab in a randomized, phase 3, monotherapy study of metastatic colorectal cancer (mCRC)
Authors: Peeters Marc , Oliner Kelly S. , Parker Alex , Huang Jing , Siena Salvatore , Humblet Yves , Van Laethem Jean-Luc , André Thierry , Wiezorek Jeffrey , Reese David , Patterson Scott D. , Van Cutsem Eric
Published: February 2011

Discussant: Sabine Tejpar, Kuleuven Center for Human Genetics, Leuven, Belgium.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-174.
Abstract LB-176: Discovery of CWP232291: A novel and potent small molecule inhibitor of Wnt signaling in hematological malignacies
Authors: Cha Joo Young , Jung Ji-Eun , Emami Kathy , Briaud Isabelle , Tenzin Fnu , Pyon Younghee , Lee Donghee , Chung Jae Uk , Lee Jong Heun , Oh Se-Woong , Jung Kyung Yun , Pai Jin Keon
Published: February 2011

Discussion

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-176.
Abstract LB-177: New temozolomide analogs with activity independent of mismatch repair and alkyltransferase
Authors: Wheelhouse Richard T. , Pletsas Dimitrios , Li Li , Garelnabi Elrashied A.E. , Phillips Roger M.
Published: February 2011

Discussion

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-177.
Abstract LB-185: Decreased LINE-1 methylation in peripheral blood is associated with breast cancer risk in the Sister Study
Authors: Bolick Sophia CE. , Xu Zongli , DeRoo Lisa , Sandler Dale P. , Taylor Jack A.
Published: February 2011

Discussion

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-185.
Abstract LB-186: Genetic variants and risk of lung cancer in never-smokers: A genome-wide association study
Authors: Li Yafei , Sheu Chau-Chyun , Ye Yuanqing , de Andrade Mariza , Wang Liang , Chang Shen-Chih , Aubry Marie-Christine , Aakre Jeremiah , Allen Mark , Chen Feng , Cunningham Julie , Deschamps Claude , Jiang Ruoxiang , Lin Jie , Marks Randolph , Pankratz V. Shane , Su Li , Li Yan , Sun Zhifu , Tang Hui , Vasmatzis George , Wang Renyi , Harris Curtis , Spitz Margaret , Jen Jin , Zhang Zuo-Feng , Christiani David , Wu Xifeng , Yang Ping
Published: February 2011

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-186.
Abstract LB-188: Positive regulation of the Ras oncogene by ubiquitination
Authors: Sasaki Atsuo T. , Cantley Lewis C.
Published: February 2011

Discussion

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-188.
Abstract LB-19: Involvement of aryl hydrocarbon receptor nuclear translocator in EGF-induced c-Jun/Sp1-mediated gene expression
Authors: Chen Ben-Kuen , Huang Wan-Chen
Published: February 2011

Aryl hydrocarbon receptor nuclear translocator (ARNT)/ hydroxia-inducible factor-1β (HIF-1β) is a basic helix-loop-helix Per/AhR/ARNT/Sim (bHLH-PAS) that forms dimeric transcriptional regulatory complexes with other bHLH-PAS proteins to regulate various biological pathways. Our previous report has shown that ARNT is also involved in epidermal growth factor (EGF)-induced COX-2 gene expression. By using pull-down and protein-DNA interaction assays, we herein report that ARNT is associated with transcription factors c-Jun/Sp1, and it regulates gene expression. We find that EGF stimulated the formation of the c-Jun/ARNT/Sp1 complex and the binding of the transcription protein complex to the Sp1 site of the gene promoter in a time-dependent manner. In addition, the promoter activity and the mRNA level of 12(S)-lipoxygenase upon EGF stimulation were inhibited by ARNT small interfering RNA (siRNA). Notably, ARNT cooperated with c-Jun to regulate gene expression. Although both c-Jun and ARNT have a transactivation domain, c-Jun was responsible for the EGF-induced transcriptional activation because a dominant negative c-Jun mutant, TAM-67, blocked ARNT-mediated 12(S) lipoxygenase expression, but not the binding of ARNT to the promoter. ARNT knockdown attenuated the association between c-Jun and Sp1 and the downregulation of gene expression. Furthermore, ARNT siRNA also inhibited other EGF-induced c-Jun/Sp1 mediated gene expression, such as p21WAF1/CIP1. Our results revealed a novel mechanism by which ARNT acts as a modulator to bridge the c-Jun/Sp1 interaction and plays a role in EGF-mediated gene expression under normoxic conditions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-19.
Abstract LB-2: Cullin-2 facilitates EGFR ubiquitination and degradation after trafficking of the receptor to the nucleus
Authors: Kim Jayoung , Freeman Michael R.
Published: February 2011

Objectives of the study: The epidermal growth factor receptor (EGFR) can be overexpressed in bladder cancer and other malignancies and is a molecular risk factor associated with poor prognosis. Surface EGFR is able to traffic to the nucleus, where it can regulate gene expression as a component of transcription complexes. This non-canonical function for the EGFR correlates with tumor aggressiveness and unfavorable clinical outcome. We have identified cullin-2, a ubiquitin E3 ligase cofactor that associates with the Von Hippel-Lindau tumor suppressor protein (pVHL) and elongin B/C, by mass spectrometry as a putative component of an EGFR nuclear trafficking complex in human bladder cancer cells. The goal of the present study was to determine the potential role of cullin-2 in EGFR nuclear trafficking and function.

Methodology: Various biochemical approaches, including co-IP/Western blotting and fluorescence imaging, were performed to analyze the association of EGFR and ubiquitin E3 ligase components, including cullin-2 and pVHL. Forced expression or silencing of cullin-2 was also performed.

Results: Accumulation of EGFR in nuclei was shown within 30min after treatment of TCCSUP bladder cancer cells with the EGFR ligand HB-EGF. Ubiquitination and degradation of nuclear EGFR were observed 1h after stimulation. Cullin-2 binds to EGFR in the nucleus, leading to recruitment of pVHL upon HB-EGF treatment. The association of nuclear EGFR with the Rpt10/S5a and Rpt1 proteasome subunits implicates the proteasome in nuclear EGFR degradation, which is consistent with data indicating that nuclear EGFR degradation was suppressed by proteasomal inhibition. Silencing of endogenous cullin-2 or pVHL suppressed the degradation of nuclear EGFR. Collectively, these results suggest that cullin-2 is a mediating factor that connects nuclear EGFR to the ubiquitin E3 ligase and the proteasome, leading to proper feedback regulation after EGFR activation. Our findings provide new insight into the diverse intracellular mechanisms in which the EGFR participates and, in particular, its signaling roles in the nucleus in bladder cancer and possibly other cell types.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-2.
Abstract LB-20: Transcriptionally inactive PAX3-FKHR fails to induce ARMS cells differentiation
Authors: Jothi Mathivanan , Keller Charles , Mal Asoke K
Published: February 2011

Alveolar rhabdomyosarcoma (ARMS) is an aggressive muscle cancer of childhood and believed to arise from committed muscle progenitor cells that have arrested during the process of skeletal muscle differentiation. One of the most established genetic signatures in ARMS is the presence of chimeric aberrant transcription factor PAX3-FKHR generated by fusion of PAX3 and FKHR genes. The stronger transcriptional activity of this fusion PAX3-FKHR protein has previously been attributed to the deregulation of genes, which are known to be associated with tumorigenesis and suppression of skeletal muscle differentiation. Currently, we are investigating the relative contribution of PAX3-FKHR's transcriptional activity in abrogating ARMS cells differentiation using mouse ARMS cells as an in vitro model differentiation readout system. Here, we show that transactivation potential of PAX3-FKHR is declined in mouse ARMS cells that have been induced to differentiate by growing these cells in mitogens-deficient in vitro differentiation-permissible condition. Moreover, this diminished activity of PAX3-FKHR is not due to the alteration of its sub-cellular localization or changes in the level of either mRNA or protein in these ARMS cells. Results also show the lack of muscle-specific gene activation in these ARMS cells despite the reduced transcriptional activity of PAX3-FKHR under condition of differentiation. We also observed that decrease in transcriptional activity of PAX3-FKHR is coincided with the activation of PI3/AKT pathway. The results further show that blockade of PI3/AKT pathway sustains the transcriptional activity of PAX3-FKHR whereas forced activation of AKT inhibits this activity. Together, our results signify that transcriptionally inactive PAX3-FKHR by AKT is incompetent to induce mouse ARMS cells differentiation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-20.
Abstract LB-21: Emergence of castration resistant prostate cancer class defined by recurrent ERG fusion
Authors: Rickman David S. , Chen Ying-bei , Banerjee Samprit , Pan Yihang , Moss Benjamin , Sboner Andrea , Yu Jindan , Perner Sven , Lafargue Christopher , VanDoren Vanessa , Mertz Kirsten , Setlur Sunita , Sircar Kanishka , Gerstein Mark , Chinnaiyan Arul , Bismar Tarek , Rubin Mark , Demichelis Francesca
Published: February 2011

The role of recurrent ETS gene fusions in castration resistant prostate cancer (CRPC) is poorly understood. We characterized the transcriptome of CRPC by interrogating a cohort of 54 men with locally advanced or metastatic CRPC using a gene expression profiling method recently established for formalin-fixed paraffin-embedded tissue. We found increased expression of multiple genes in ERG rearranged tumors which suggests a selective growth advantage under oxygen poor conditions. We discovered that trefoil factor 3 (TFF3) is the top differentially regulated gene by both ERG rearrangement and resistance to therapy. Conventional chromatin immunoprecipitation (ChIP)-PCR and ChIP-seq data revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG rearranged prostate cancer cell lines, which was confirmed in ERG rearranged hormone naïve prostate cancer (HNPC) and CRPC tissue samples. In vitro data suggested that ERG has an inhibitory effect on TFF3 expression in hormone naïve cancer, which was relieved in CRPC depending on the level of AR expression. These findings reveal an interplay between ERG rearrangement and AR signaling in CRPC, and provide perspective towards novel therapeutic targets.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-21.
Abstract LB-210: A multiplexed serum biomarker immunoassay panel discriminates clinical lung cancer patients from cancer-free high-risk subjects in a CT-screened cohort
Authors: Bigbee William L. , Gopalakrishnan Vanathi , Dacic Sanja , Hauskrecht Milos , Weissfeld Joel L. , Wilson David O. , Siegfried Jill M. , Lokshin Anna E.
Published: February 2011

Clinical decision making in the setting of CT screening could benefit from accessible biomarkers that help predict the level of lung cancer risk in high-risk subjects with indeterminate pulmonary nodules commonly found by screening. The specificity and sensitivity needed to improve interpretation of CT images in the setting of a suspicious pulmonary nodule would be less stringent than those needed for lung cancer screening in the general population. As a first step in identifying and characterizing serum protein biomarkers to more accurately identify individuals with lung cancer in populations of high-risk tobacco-exposed individuals, we measured 70 cancer-related proteins by Luminex xMAP® multiplexed immunoassays in a training set of sera from 56 patients with biopsy-proven primary lung cancer diagnosed in a clinical setting and sera from 56 age-, sex- and smoking-matched CT-screened controls. These controls are drawn from a cohort of participants in the Pittsburgh Lung Screening Study (PLuSS) who have undergone CT screening and are known to be cancer-free after a minimum of 3 years follow-up. We found a profile of 8 biomarkers - PRL, TTR, THSP, SELE, CCL5, MIF, and SERPINE1 and ERBB2 - that distinguished lung cancer from controls in the training set with a sensitivity (SN) of 92.9% and specificity (SP) of 87.5%. The balanced accuracy (average of SN and SP) from 20-fold internal cross-validation of the training set was 82.5% ± 4.8%. We then applied this 8 biomarker model to an independent test set of 10 additional clinically detected lung cancer cases and 83 randomly selected PLuSS participants who were known to be cancer-free. These PLuSS controls in the test set included subjects with and without CT-detected pulmonary nodules and a range of airflow obstruction and radiographic emphysema. The biomarker model classified these test set cases and controls with a balanced accuracy of 83.6% (90.0% SN and 77.1% SP). Importantly, the misclassified PLuSS controls in the test set displayed no significant association with airway function variables or level of suspicion of pulmonary nodule. Taken together, these data suggest that the 8 biomarker panel classified lung cancer independently of pulmonary function abnormalities and the presence of non-cancerous pulmonary nodules, and thus may provide clinical utility in ruling out lung cancer in tobacco-exposed individuals screened by CT imaging. [Supported by NCI SPORE in Lung Cancer P50 CA090440 (JMS) and NCI Early Detection Research Network Biomarker Discovery Laboratory U01 CA084968 (WLB)].

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-210.
Abstract LB-213: Plasma soluble VEGFR1 is a potential dual biomarker of response and toxicity for bevacizumab with chemoradiation in locally advanced rectal cancer
Authors: Duda Dan G. , Willett Christopher G. , Ancukiewicz Marek , di Tomaso Emmanuelle , Shah Mira , Czito Brian G. , Bentley Rex , Poleski Martin , Lauwers Gregory Y. , Carroll Madeline , Tyler Douglas , Mantyh Christopher , Shellito Paul , Clark Jeffrey W. , Jain Rakesh K.
Published: February 2011

We explored plasma and urinary concentration of four members of the vascular endothelial growth factor (VEGF) family as potential response and toxicity biomarker of bevacizumab with neoadjuvant chemoradiation in patients with localized rectal cancer.

The levels of VEGF, placental growth factor (PlGF) and soluble VEGF receptors 1 and −2 (sVEGFR1 and sVEGFR2) were measured by multiplex array in plasma and urine at baseline and during treatment. Pre-treatment values and changes over time were analyzed as potential biomarkers of pathological response to treatment (evaluated histologically using ypT, Mandard and N scoring at surgery) as well as for all acute toxicities in patients with locally advanced rectal cancer treated prospectively from 2002 to 2008 with bevacizumab, 5-fluorouracil and radiation therapy prior to surgery in a phase I/II trial (N=32 patients).

Of all biomarkers, the pretreatment plasma sVEGFR1 - an endogenous blocker of VEGF and a factor linked with “vascular normalization” - was strikingly associated with both tumor regression and with the number of adverse events after preoperative (neoadjuvant) bevacizumab and chemoradiation. Thus, plasma sVEGFR1 is a strong candidate as the first biomarker to stratify patients for bevacizumab therapy.

Therefore, future studies of bevacizumab and/or cytotoxics should be further explore sVEGFR1 as biomarker in neoadjuvant setting as well as in metastatic disease.

This study was partially supported by NIH grants R21-CA99237, P01-CA80124, R01-CA115767, R01-CA85140, R01-CA126642 and Federal Share/NCI Proton Beam Program Income grants, and by the National Foundation for Cancer Research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-213.
Abstract LB-216: CSLEX (sialyl LewisX) is an important and useful tumor marker in monitoring breast cancer patients
Authors: Fujita Tomoyuki , Nagura Naoya , Koshikawa Kayoko , Nishimura Hajime , Ito Ken-ichi , Fujimori Minoru
Published: February 2011

Background: CSLEX-1 is one of the monoclonal antibodies for which the structure of the antigen is known. This antigen is called CSLEX (Sialyl Le X). It has been reported that CSLEX may be more useful than CEA in combination with CA15-3 in monitoring breast cancer patients.

Methods: We measured and evaluated the serum levels of some tumor markers, including CSLEX, in a total of 482 breast cancer patients with or without metastasis who consecutively visited the outpatient clinic of the Division of Breast and Endocrine Surgery, Shinshu University Hospital, between April 2007 and September 2007.

Results: All serum levels of tumor markers in a single measurement correlated significantly with the status of metastasis (P < 0.01). All combinations of combined measurements, such as CEA and CA15-3, CEA and NCC-ST439, CEA and CSLEX, CA15-3 and NCC-ST439, and CA15-3 and CSLEX, also correlated significantly with the status of metastasis (P < 0.01). The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy were almost the same between CSLEX and NCC-ST439, which belongs to the type II carbohydrate antigens. The cut-off values of serum CSLEX and NCC-ST439 were 38.8 ± 52.7 U/ml and 22.1 ± 27.8 U/ml, respectively (P = 0.16). Conclusions: These data support there are no differences between CSLEX and NCC-ST439 as diagnostic parameters in single or combined measurements. The cut-off value of serum CSLEX tended to be higher compared with that of NCC-ST439.Patient characteristics Without MetastasisWith MetastasisP-valueNumber363119 Mean Age ± SD (years)56.5 ± 11.758.9 ± 12.60.06CEA2.5 ± 6.311.9 ±34.50.008CA15-311.9 ± 11.166.4 ± 162.50.001BCA22561.0 ±51.5139.4 ± 228.60.001NCCST-4392.0 ± 2.234.2 ± 108.20.003CSLEX3.4 ± 3.765.6 ± 223.10.005Diagnostic parameters for the detection of breast cancer metastasis using tumor markers (%) SensitivitySpecificityPPVNPVAccuracySingle measurement     CEA3095688179CA15-33498828282BCA2251698707878NCC-ST4392497727979CSLEX2397697978Combined measurement     CEAandCA15-34893698482CEA and NCC-ST4394392648380CEA and CSLEX4392658380CA15-3 and NCC-ST4394595758483CA15-3 and CSLEX4495738482

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-216.
Abstract LB-220: Molecular predictors of sensitivity to an IGF1R inhibitor in pre-clinical models of lung and colon cancers
Authors: Lira Maruja E. , Pavlicek Adam , Lee Nathan V. , Ching Keith O. , Ye Jingjing , Cao Joan , Garza Scott , Hook Kenneth , Ozeck Mark , Shi Stephanie , Yuan Jing , Zheng Xianxian , Rejto Paul , Gualberto Antonio , Kan Julie , Christensen James G.
Published: February 2011

Targeting the insulin like growth factor receptor (IGF1R) signaling pathway is a promising approach against a variety of cancers and several clinical trials are now underway designed to evaluate the efficacy of IGF1R inhibitors singly or in combination with chemotherapeutic agents. Identification of the optimal patient population likely to respond is critical to the success of this class of targeted agents. To identify potentially predictive biomarkers, we sought to correlate response to figitumumab (CP-751,871), a fully human monoclonal antibody against IGF1R with molecular characteristics across a panel of cell lines. Growth inhibition to CP-751,871 was assessed in a panel of non-small cell lung carcinoma (NSCLC) (n=27) and colon cancer cell lines (n=21) cultured in anchorage and anchorage-independent conditions. Mutation status, whole-genome mRNA expression and DNA copy number were correlated to drug sensitivity. In addition, RNA expression of key genes in relevant signaling pathways was also interrogated via real time PCR. In the present studies, the frequency of response was greater in colon cancer cell lines than in NSCLC. Tissue or cell origin-specific expression levels of insulin-like growth factor binding proteins (IGFBPs) were associated with sensitivity. Low IGFBP3 expression [p=0.0035] correlated with response in NSCLC cell lines whereas low IGFBP6 [p=0.013] and IGF2BP3 [p=0.038] expression correlated with response in colon cancer lines. Increased IGF1R mRNA [p=0.045] levels, microsatellite stability, and PIK3CA wild-type status were also correlated with sensitivity in colon cancer lines. In addition, high expression of erbB2 [p=0.04] and erbB3 [p=0.04] were also associated with sensitivity of colon cancer lines. Collectively, findings from these studies are of potential value to identify patient populations with increased probability of benefit from IGF1R targeted agents. Our results further indicate that molecular predictors associated with the IGF1R pathway are potentially distinct between lung and colon cancer lines and additional studies to extend to other tumor types are warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-220.
Abstract LB-229: PTEN modulates EGFRvIII-mediated SHP-2 activation and translocation to affect glioblastoma sensitivity to tyrosine kinase inhibitors (TKI)
Authors: Kapoor Gurpreet Singh , O'Rourke Donald M.
Published: February 2011

EGFRvIII, a constitutively active truncated mutant of epidermal growth factor receptor (EGFR), has been associated with increase neoplastic transformation and poor overall survival (OS). An earlier report showed that expression of EGFRvIII in gliomas provides resistance to chemotherapy. Co-expression of EGFRvIII and PTEN in a small subset of recurrent GBMs has been shown to increase sensitivity to tyrosine kinase inhibitors (TKI), including Erlotinib (tarceva) and Geftinib. However, the exact mechanism of EGFRvIII and PTEN interaction in response to TKI is still unresolved. Our recent reports showed that SHP-2 PTPase and its phosphatase activity are required for the EGFRvIII-mediated transformation. The aim of the present work was to investigate the molecular interaction between EGFRvIII/SHP-2 activation complex and PTEN in response to tarceva treatment and its effect on glioblastoma transformation. Our recent report demonstrated an increased SHP-2 phosphorylation in U87MG. EGFRvIII (PTEN-deficient) when compared to PTEN-intact LN229.EGFRvIII cells. In the present study, we show that tarceva treatment abolished EGFRvIII, EGFR, SHP-2 and Erk1/2, but Src family kinase (SFK), phosphorylation in LN229.EGFRvIII cells at all time intervals ranging from 30 minutes to 6 hours. On the contrary, phosphorylation of EGFRvIII, Src and Erk1/2 in U87MG. EGFRvIII cells was inhibited in early time points, but was restored in 2 to 6 hours. Surprisingly, phosphorylation of SHP-2 at Tyr542 residue was unaffected by tarceva treatment, but EGFR phosphorylation was inhibited in a time-dependent manner. PTEN deficiency resulted in resistance to tarceva treatment as assessed by MTT proliferation and soft agar transformation assays. Immunofluorescent labeling of U87MG. EGFRvIII cells with anti-phospho-SHP-2 (Tyr542) antibody showed perinuclear localization of SHP-2, whereas LN229.EGFRvIII cells exhibited membrane staining of phosphorylated SHP-2 (Tyr542). Our results showed that tarceva increased perinuclear SHP-2 Tyr542 in U87MG. EGFRvIII cells. Interestingly, stable expression of PTEN in U87MG. EGFRvIII cells conferred relocalization of phospho-SHP-2 to the membrane, a phenotype resembling LN229.EGFRvIII cells. Moreover, PTEN-expressing U87MG. EGFRvIII clones grew slower and showed a partially untransformed phenotype. These results suggest that SHP-2 is downstream effectors of PTEN and that PTEN deficiency may lead to SHP-2 activation and perinuclear localization by EGFRvIII, which may results in increased resistance to TKIs. Therefore, targeting SHP-2 may provide a new and effective therapeutic approach for treatment of glioblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-229.
Abstract LB-231: p 190RhoGAP-B is required for rho down-regulation and ductal morphogenesis of breast epithelial cells in compliant collagen gels
Authors: Suzanne Ponik , Wozniak Michele , Keely Patricia J.
Published: February 2011

Breast epithelial cells cultured in compliant (floating), but not stiff (attached), 3-dimensional collagen gels differentiate into tubules. While the mechanisms of breast ductal morphogenesis are not well understood, we have previously shown that this process requires down-regulation of the small GTPase Rho in compliant collagen gels. In this study we sought to better define the signaling pathways regulating Rho activity when epithelial cells are cultured in compliant vs. stiff 3D collagen gels. Of the known Rho regulators, expression of p190RhoGAP has been detected at the terminal end buds in the mouse mammary gland, suggesting that proper breast development in vivo requires Rho down-regulation through this protein. Therefore, we specifically investigated the role of p190RhoGAP in ductal morphogenesis. We found that shRNA against p190RhoGAP-B, but not p190RhoGAP-A, blocked down-regulation of Rho activity and inhibited tubule formation in T47D cells cultured in compliant 3D collagen gels. Additionally, both Rho and p190RhoGAP-B co-localized with the adherens junction protein, p120-catenin at sites of cell-cell adhesion when cultured in 3D collagen gels. Similar to our results with p190B knockdown, shRNA against p120-catenin resulted in disruption of ductal morphogenesis and disregulation of Rho activity in cells cultured in compliant 3D collagen gels. Interestingly, we found that the association between p190RhoGAP-B and p120-catenin, which has been shown by others to play a role in Rho regulation, increases in compliant vs. stiff collagen gels. Interaction between p190RhoGAP-B is not mediated by Rho, as it does not require the Rho binding domain of p120-catenin. Together these results demonstrate that p190RhoGAP-B is required for Rho regulation and ductal morphogenesis of breast epithelial cells in floating collagen gels through a mechanism that may involve p 120-catenin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-231.
Abstract LB-232: MEK2 signaling pathway alone is sufficient but not necessary for melanoma cell proliferation
Authors: Lee Chih-Shia , Dykema Karl J. , Hawkins Danielle M. , Furge Kyle A. , Duesbery Nicholas S.
Published: February 2011

The Raf-MEK-ERK signaling pathway plays a critical role in survival of many types of cancers, including melanoma. Targeting this pathway by using MEK inhibitors is a rational therapeutic strategy for melanoma treatment. Despite their success in pre-clinical studies, MEK inhibitors have failed to obtain satisfactory responses in clinical cancer trials. An improved understanding of MEK signaling in melanoma survival will facilitate the design of more effective therapeutics. There are two isoforms of MEK; MEK1 and MEK2. Although they are thought to be functionally redundant, recent studies have suggested that these two signaling molecules have non-overlapping cellular functions. To test this we developed a novel experimental system to allow signaling through individual MEK pathway in human melanoma SK-MEL-28 cells. In this system, multiple MEK/MKK pathways are inhibited by anthrax lethal toxin (LeTx), a Bacillus anthracis-secreted toxin which specifically and proteolytically inhibits members of MEK/MKK proteins. MEK1 or MEK2 signaling is rescued by expressing a cleavage-resistant MEK mutant (MEK1cr or MEK2cr) able to actively signal in the presence of LeTx. Using this approach, we determined that MEK2 signaling, and not MEK1, is sufficient for melanoma cell proliferation and anchorage-independent growth. To explain this we hypothesized that MEK1 and MEK2 signaling differentially regulate downstream effectors to control cell survival. To test this and to identify the non-overlapping effectors downstream to MEK1 and MEK2, we compared gene expression profiles using Agilent 60-mer Whole Human Genome Microarrays. We found that global suppression of MKK signaling by LeTx treatment significantly altered expression of 20% of represented genes. These mainly include genes involved in survival pathways such as the pathways of DNA replication, E2F transcription factors, rRNA processing, and cell proliferation, as well as oncogenic pathways such as Myc and Ras. Of these genes, approximately half were rescued by expression of one of MEK1cr or MEK2cr. Whereas MEK2cr had a more pronounced effect on expression and predominantly rescued signaling associated with cell proliferation, MEK1cr rescued signaling normally associated with epithelial to mesenchymal transition. Our findings demonstrate that MEK1 and MEK2 have non-redundant cellular functions and differentially regulate downstream effectors in SK-MEL-28 cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-232.
Abstract LB-235: SUMO-1 modification represses CPAP transcriptional co-activator activity in TNFα-induced NF-κB signaling pathway
Authors: Yang Shu-Ting , Hung Liang-Yi
Published: February 2011

The transcription factor nuclear factor-κB (NF-κB) is an important regulator in inflammation, immune responses, apoptosis, cell proliferation and differentiation. CPAP (Centrosomal protein P4.1-associated protein), which plays important roles on centrosomal functions, is previously identified as the transcriptional coactivator for NF-κB. Here, we have demonstrated that decreased expression of CPAP by siRNA can attenuate NF-κB-mediated genes expression under TNFα stimulus. On the contrary, overexpressed CPAP contributes to the NF-κB-driven transcriptional activation. Immunoflourescence data showed that the nuclear localization of CPAP is induced by TNFα stimulus. Chromatin immunoprecipitation assay further indicated that CPAP was recruited to COX-2 promoter region under TNF treatment. We found that the NF-κB signaling pathway is activated by CPAP through recruiting more IKKß to the inactivated NF-κB complex to enhance the degradation of IκB and the phosphorylation of p65. Importantly, CPAP was covalently modified by small ubiquitin-related modifier-1 (SUMO-1) protein under TNFα stimulus, and the specific acceptor sites were located in the C-terminal of CPAP. Interestingly, when overexpressing SUMO-deficient CPAP in A549 cells, the TNFα-induced NF-κB-mediated genes expression was up-regulated. Co-immunoprecipitation assay showed that the association of IKKß to NF-κB complex was augmented by SUMO-deficient CPAP than wild type CPAP. Taken together, these results suggest that there might be a mechanism for the SUMOylation of CPAP in modulating the activity of NF-κB. The detailed machinery for SUMOylated CPAP in the TNFα-induced NF-κB activation is currently under investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-235.
Abstract LB-243: Discovery of single amino acid changes that confer constitutive activation of mTOR in human cancer
Authors: Tamanoi Fuyuhiko
Published: February 2011

Mammalian target of rapamycin (mTOR), a serine/threonine kinase that belongs to the PI3K related kinase family, plays critical roles in a variety of cellular processes including protein synthesis, growth, cell cycle and autophagy in response to growth factor, nutrient and energy conditions. Overactivation of the mTOR signaling is observed in a number of human cancer. Inhibitors of mTOR such as rapamycin and its derivatives are being evaluated in clinical trials. Despite these developments that point to the significance of mTOR in human cancer, no mutations in mTOR have so far been identified in human cancer. Here we report novel mTOR mutations identified in human cancer by mining human cancer genome database. Of 889 cancer samples mined, we identified 14 amino acid changes in mTOR. Characterization of the mTOR signaling after expressing some of these mutants led to the identification of two single amino acid changes (S2215Y and R2505P) that confer constitutive activation of mTOR as detected by the phosphorylation of S6K, 4E-BP1 and S6 under nutrient starvation conditions. The mutation directly affects mTOR complex 1 (mTORC1), as the complex isolated from cells expressing the mutant mTOR after nutrient starvation still retained the activity to phosphorylate 4E-BP1 in vitro. On the other hand, we did not observe significant effects on the activity of mTORC2. The cells expressing the mTOR mutant exhibited resistance to cell size decrease by amino acid starvation and showed increased percentage of S-phase cells. The cells expressing the activated mutant were resistance to 1-butanol treatment and partially resistant to hydrogen peroxide treatment. However, they were sensitive to rapamycin. The mutations are located within the kinase domain at positions that correspond to regions where oncogenic mutations of PI3 kinase were identified. It is interesting to point out that the mTOR S2215Y mutation was identified in large intestine adenocarcinoma together with K-rasG13D mutation, while the mTOR R2505P mutation was identified in renal cell carcinoma together with CDC25A F218I mutation, raising the possibility that the mTOR mutations may cooperate with mutations in other signaling proteins. Since “we are moving into an era in which it will be possible to obtain the complete DNA sequence of large numbers of cancer genomes” (Stratton et al., Nature 458, 719), our study points to the idea that mTOR activating mutations can be identified in a wide range of human cancer yielding valuable information on the significance of mTOR in human cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-243.
Abstract LB-246: Identification of novel direct targets of miR-19a in MCF-7 breast cancer cells
Authors: Kanzaki Hirotaka , Ouchida Mamoru , Ito Sachio , Tamaru Seiji , Hanafusa Hiroko , Jitsumori Yoshimi , Oka Takashi , Shimizu Kenji
Published: February 2011

Background: MicroRNAs (miRNAs) are small non-cording RNAs (20-23 nucleotides) that negatively regulate gene expression at post-transcriptional level by interacting with 3′UTRs of their target mRNAs. Aberrant expression of miRNAs in cancer indicates that miRNAs play key roles in human cancers acting as either oncogenes or tumor suppressor genes depending on their targets. The miR-17-92 cluster, including miR-17-5p, -17-3p, -18a, -19a, -20a, -19b and -92-1, located on C13orf25 is well known as oncogenic miRNA, which is overexpressed in lung cancer, malignant lymphoma and breast cancer. However, few data have been collected about the targets of miRNAs, including miR-17-92 cluster, and their roles in tumorigenesis. By using a proteomic approach, we identify novel direct targets of miR-19a.

Methods and Results: MiR-17-92 expression profiling was performed in a subset of 32 of cancer cell lines by TanqMan Real-time PCR, and MCF-7 breast cancer cell line was identified as a miR-17-92 cluster overexpressed cell line. To detect candidate target proteins for miR-17-92 cluster, we transfected MCF-7 cell with antisense oligonucleotides against miR-19a, -20a and -92-1 and then performed two-dimensional protein electrophoresis (2-DE) and differential display analysis in protein extracts of MCF-7 which was knocked down of endogenous miR-17-92 by antisense oligonucleotides. Of the 1455 defined valid protein spots, 146 distinct proteins changed 1.5-fold their expression. 135 proteins were identified as candidate target proteins for miR-17-92 cluster by LC-MS/MS. To determine direct targets of miR-17-92, bioinformatics analysis, luciferase assay and western blotting analysis were performed as validation studies.

Conclusions: Our results of exhaustive analysis revealed significant differences in the proteomic profile between anti-miR-LNA treated and non-treated MCF-7 breast cancer cell line. Among these candidate target proteins of miR17-92 cluster, we identified novel direct target of miR-19a. To better evaluate the role of miR-19a and the target gene, further studies of gene function are being performed now.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-246.
Abstract LB-28: Regulation of FOXM1 by NADPH oxidases in malignant mesothelioma cells
Authors: Newick Kheng , Mossman Brooke , Hillegass Jedd , Beuschel Stacie , Shukla Arti , Arbiser Jack , Pass Harvey , Heintz Nicholas
Published: February 2011

Malignant mesothelioma (MM) is linked to the occupational exposure to asbestos with an estimated median survival of less than two years; effective therapy is lacking. Due to long latency periods, incidence is expected to rise in regions where asbestos use has been banned, as well as where worker protection is lacking. MM cells exhibit changes in oxidant and energy metabolism, with elevated expression of the NADPH oxidase NOX4. We hypothesize that NOX4 produces reactive oxygen species (ROS) that promote uncontrolled growth through redox-dependent signaling to core cell cycle factors such as FOXM1 and FOXO3a, transcription factors involved in responses in oxidative stress and cell cycle progression. Targeted microarrays were used to assess the expression levels of 96 genes involving redox metabolism in four human MM cell lines and one control mesothelial line (LP9) immortalized with hTERT. Gene expression profiles from MM cell lines indicate tumorigenesis commonly results in elevated expression of NOX activity and adaptation to constitutive production of ROS, including up-regulation of antioxidant enzymes and cytoprotective factors. mRNA for FOXM1, a transcription factor that regulates the G2/M transition in the cell cycle, was up-regulated in all four MM cell lines, and FOXM1 continued to be expressed in MM cells, but not LP9 cells, in the absence of growth factors. Inhibitors of NOX activity markedly reduced expression of FOXM1, which correlated with dose-dependent effects on MM cell proliferation and viability. In the HM MM cell line, thiostrepton (TS), a thiazole antibiotic that inhibits the expression of FOXM1 via an unknown mechanism, increased the rate of oxidation of DCF, hyper-activated ERK1/2, and showed dose-dependent effects on MM cell viability in vitro and MM tumor growth in Fox Chase SCID mice. N-acetyl-L-cysteine blocked activation of ERK1/2 and cell death by TS, indicating the cytotoxic effects of TS in MM cells may be dependent on induction of intolerable levels of oxidative stress. In support of this possibility, inhibitors of p38 MAPK accentuated the cytotoxic effects of TS on cell viability. Our studies indicate that altered oxidant metabolism that supports expression of cell cycle factors such as FOXM1 is a common property of MM cells, and suggest that either inhibiting or accentuating the production of ROS in MM cells may be useful therapeutic approaches in the treatment of MM.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-28.
Abstract LB-288: MPI-0486348: A novel inhibitor of nicotinamide phosphoribosyltransferase (Nampt) induces tumor regression in a preclinical model
Authors: Fleischer Tracey C. , Baichwal Vijay R. , Bradford Chad L. , Demie Lynn , Green Jeremy P. , Hess Mark A. , Lockman Jeffrey W. , McKinnon Rena , Ostanin Kirill , Papac Damon I. , Reeves Leslie F. , Terry-Lorenzo Ryan T. , Willardsen J Adam
Published: February 2011

Background: Nicotinamide phosphoribosyltransferase (Nampt) catalyzes the first step in the recycling of nicotinamide into NAD. Cancer cells develop dependence on Nampt due to increased energy requirements and the elevated activity of NAD consuming enzymes such as sirtuins and mono and poly(ADP-ribose) polymerases (PARPs). Identification of Nampt as the target of an orphan cytotoxic compound using chemical proteomics spawned a Nampt drug discovery program at Myriad. We have developed a potent and selective inhibitor of Nampt that inhibits the growth of cancer cells in culture and induces tumor regression in a mouse xenograft model.

Materials and Methods: In vitro Nampt activity was measured in a coupled biochemical assay based on the production of fluorescent resorufin. Viability was determined by measuring cellular ATP levels at 72 hrs following addition of compound. Nampt cellular activity was assayed by measuring levels of NAD and NAD-dependent poly (ADP)-ribosylation (PAR). Pharmacokinetic studies were conducted in female CD-1 mice. Anti-tumor activity was evaluated in an HCT116 human colon carcinoma xenograft in nu/nu mice.

Results: MPI-0486348 inhibited Nampt activity in vitro with an average IC50 value of 40 pM. Depending upon the time of compound exposure, MPI-0486348 showed TC50 values of 180 pM to 20 nM in HCT116 cells. MPI-0486348 treatment also reduced cellular NAD levels and nuclear PAR levels, with IC50 values of 170 pM and 120 pM, respectively. These cellular effects of MPI-0486348 were prevented by coadministration of nicotinic acid, demonstrating on target mechanism of action. In mouse pharmacokinetic studies, absolute oral bioavailability of 47% was determined using 40% Captisol as the vehicle at an oral dose of 10 mg/kg. The same dose in rats gave an absolute oral bioavailability of 46%. Finally, in HCT116 tumor-bearing mice, a single oral dose of MPI-0486348 (50 or 75 mg/kg) resulted in 31% and 67% regression, respectively.

Conclusions: MPI-0486348 is an orally bioavailable small molecule inhibitor of Nampt and shows promising preclinical results in a human xenograft model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-288.
Abstract LB-293: Indirubins decrease glioma growth and invasion in vivo: A novel treatment paradigm combining antimigratory and antiangiogenic effects
Authors: Williams Shante’ P. , Nowicki Michal O. , Chiocca E. Antonio , Lawler Sean E.
Published: February 2011

The invasive nature of gliomas is a major obstacle to their effective treatment. We demonstrated in a recent report that lithium blocks glioma cell migration and that this involved the inhibition of glycogen synthase kinase-3 (GSK-3). Here we report that treatment of glioma cells with GSK-3 inhibitors of the indirubin family leads to a potent and specific blockade of glioma cell migration. Indirubins inhibited GSK-3 to a greater extent than lithium in glioma cells as assessed by ß-catenin TCF/LEF luciferase reporter assays and were effective at much lower concentrations than other GSK-3 inhibitors so far tested. When examined in intracranial xenograft models in nude mice, 6-bromo-indirubin acetoxime (BIA) led to a significant reduction of invasion of normal, both in terms of diffuse invasion around the tumor, and the number of tumor foci. Interestingly treatment with BIA also led to decreased tumor proliferation and significantly improved survival of tumor-bearing animals. Histological examination of tumors showed a substantial decrease in blood vessel density in tumors. Finally we showed that indirubins block motility of endothelial cells in vitro, and also cause increased production of anti-angiogenic proteins in BIA treated glioma cells. This data suggests that anti-invasive glioma therapy with indirubins, and potentially other GSK-3 inhibitors, not only inhibits invasion of tumor cells, but also blocks angiogenesis providing a novel treatment paradigm for invasive gliomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-293.