bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1643: Withaferin A analogues up-regulate the MAPK and glutathione metabolic pathways prior to activation of apoptosis in pancreatic cancer cells
Authors: Mahadevan Daruka , Liu Xiaobing , Qi Wenqing , Cooke Laurence , Wijevatne Kithsiri , Marron Marilyn , Gunatilaka Leslie 
Published: February 2011

Abstract
Withaferin A is a natural product known to possess anti-cancer activity. Here we studied the effect of Withaferin A and 11 of its analogs on differentiation state-specific pancreatic cancer cell lines. Three pancreatic cell lines Panc-1 (poorly-differentiated), MiaPaca-2 (moderately differentiated) and BxPC-3 (well differentiated) were treated with 11 analogs and cell proliferation was examined by MTS assays. The IC50 of these 11 analogs were &lt;4.0 µM suggesting they have growth inhibitory effects on pancreatic cancer cell proliferation. Two of these 11 analogs, named KW-120-94-1 and KW-120-95-1 were selected for further study. The IC50s of KW-120-94-1 and KW-120-95-1 were 2.25, 0.56 µM (Panc-1); 1.53, 0.52 µM (MiaPaca-2) and 0.45, 0.29 µM (BxPC-3) respectively. Apoptosis was analyzed by morphology (Acridine Orange and Ethidium Bromide staining), flow cytometry (Annexin V-FITC and Propidium Iodide staining) and PARP cleavage. The data showed that apoptosis was induced both in BXPC-3 and MiaPaca-2 cells in a dose-dependent manner. However, Panc-1 cells were in general resistant to apoptosis. In BxPC-3 cells apoptosis was induced as early as 6 hours after KW-120-95-1 treatment at 1.5µM. To determine the Withaferin A analog dependent ‘tumor profile signature’, gene expression profiling by Affymetrix microarrays were performed in the 3 pancreas cancer cell lines. The cells were treated with KW-120-95-1 for 8 hr at 1.5µM. Differential gene expression was analyzed by ANOVA which identified 33 (MiaPaca-2), 54 (Panc-1) and 48 (BXPC-3) gene changes. The Fisher exact test demonstrated that MAPK signaling and glutathione metabolism pathways were over-expressed within the genes that changed with treatment. Western blotting and real-time RT-PCR were utilized to confirm gene expression changes identified in the MAPK pathway (HSPA1A/HSPA1B, c-Jun) and glutathione metabolism pathway (GCLC, GPX2 and GPX3). Taken together, our data indicate that Withaferin A analogs inhibit pancreatic cancer proliferation and induces apoptosis by activating the MAPK and glutathione (stress) pathways. The molecular target(s) of Withaferin A and analogs are likely to function by activating the MAPK signaling and glutathione metabolism pathways.
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 1643.
Abstract 165: MIRA (methylated CpG island recovery assay) assay identifies frequently methylated genes in breast cancer
Authors: Hill Victoria , Hesson Luke , Dansranjavin Temuujin , Dallol Ashraf , Bieche Ivan , Tommasi Stella , Dobbins Timothy , Gentle Dean , Euhus David , Dammann Reinhard , Ward Robyn L. , Minna John , Maher Eammon R. , Pfeifer Gerd , Latif Farida 
Published: February 2011

Abstract
There are several high throughput approaches to identify methylated genes in cancer. We utilized one such recently developed approach, MIRA (methylated-CpG island recovery assay) combined with CpG island arrays to identify novel genes that are epigenetically inactivated in breast cancer. Using this approach we identified numerous CpG islands that demonstrated aberrant DNA methylation in breast cancer cell lines. Using a combination of combined bisulphite restriction analysis (CoBRA) and sequencing of bisulfite modified DNA, we confirmed 5 novel genes frequently methylated in breast tumors; EMILIN2, SALL1, DBC1, FBLN2 and CIDE-A. Methylation frequencies ranged from between 25% and 63% in primary breast tumors, whilst matched normal breast tissue DNA was either unmethylated or demonstrated a much lower frequency of methylation compared to malignant breast tissue DNA. Furthermore expression of the above 5 genes was shown to be restored following treatment with a demethylating agent in methylated breast cancer cell lines. We have expanded this analysis across three other common epithelial cancers (lung, colorectal and prostate). We demonstrate that the above genes show varying levels of methylation in these cancers. Lastly and most importantly, methylation of EMILIN2 was associated with poorer clinical outcome in breast cancer and was strongly associated with estrogen receptor as well as progesterone receptor positive breast cancers. The combination of the MIRA assay with CpG island arrays is a very useful technique for identifying epigenetically inactivated genes in cancer genomes and can provide molecular markers for early cancer diagnosis, prognosis and epigenetic therapy.
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 165.
Abstract 1650: Targeting of compensatory signaling pathways identified in a synthetic lethal screen leads to synergistic growth inhibition in bladder cancer cells
Authors: Axelrod Mark J. , Gioeli Daniel , Weber Michael J. 
Published: February 2011

Abstract
Despite promising preclinical results, monotherapies that target deregulated signal transduction pathways often are insufficient to slow or shrink tumors in human patients. We hypothesize that multiple pathways within the cellular signaling network are altered in cancer cells, and that these pathways are acting in a redundant or compensatory manner to provide resistance against drugs targeting a single protein. A treatment plan consisting of multiple small molecules that inhibit these compensatory and redundant pathways should overcome this resistance. To discover pathways that act in a redundant or compensatory manner, we performed a screen that allows us to examine the cellular effects of blocking pathways both individually and in combination. We found that the combination of the epidermal growth factor receptor (EGFR) inhibitor lapatinib in combination with the phosphoinositol-3-kinase (PI3K) inhibitor LY294002 produced synergistic growth inhibition in UMUC-6 bladder cancer cells. In order to confirm that this effect was due to inhibition of the putative targets of these compounds, we substituted structurally distinct EGFR and PI3K inhibitors for lapatinib and LY294002 and obtained similar results. Cell cycle analysis of cells treated with this combination revealed an arrest in the G1 phase, which could explain the synergistic inhibition observed in the screen. In order to find a molecular mechanism for this synergistic effect, we performed Western blotting analysis of the cells treated with each drug individually and in combination. We found that treatment with LY294002 caused an increase in levels of phosphorylated SHC, and ERK, indicating that receptor tyrosine kinase signaling, and possibly EGFR signaling is activated to compensate for PI3K pathway inhibition. Inhibition of ERK activity with PD325901 produced the same effect as EGFR inhibition, confirming the role of ERK as a compensatory signaling molecule for PI3K inhibition. Parallel RNAi experiments against SHC are currently ongoing. These data suggest that synthetic lethal screening with a library of targeted inhibitors of signaling proteins can be used to search for combinatorial effects and functionally identify compensatory and redundant relationships between different signaling components. This work paves the way for the development of rational combinatorial therapies for the effective treatment of bladder 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 1650.
Abstract 1652: Global proteomics analysis by SILAC (stable isotope labelling with amino acid in cell culture) in hepatocellular carcinoma treated by sorafenib: identification of phospho-AKT activation as a resistant mechanism
Authors: Feng Wen-Chi , Hsu Chih-Hung , Lin Shiou-Der , Gao Ming , Yeh Pei-Yen , Chow Lu-Ping , Cheng Ann-Lii 
Published: February 2011

Abstract
Sorafenib, a multikinase inhibitor against Raf kinase and vascular endothelial growth factor receptor (VEGFR), was recently approved for the treatment of advanced hepatocellular carcinoma (HCC). However, the majority of HCC are inherently resistant to sorafenib. A global proteomic approach was applied to delineate the molecular mechanisms affecting the effectiveness of sorafenib in HCC cells. HCC cells (Huh7, SKHep1, and PLC5) were treated with sorafenib and analyzed by the SILAC (Stable Isotope Labeling with Amino acids in Cell culture) methodology. A total of 354 phosphoproteins were identified from untreated Huh7 cells (labeled with light amino acid, designated as L) and sorafenib-treated cells (labeled with heavy amino acid, designated as H). Forty-five proteins with high L/H ratio, indicating decreased expression after sorafenib treatment, were recognized. Among them, downstream proteins of Raf kinase, which are expected to be downregulated by sorafenib, were found. On the other hand, 30 proteins with low L/H ratio, indicating increased expression after sorafenib treatment, were recognized. Biological interaction network analysis of the phosphoproteome using IPA (ingenuity pathway analysis) method revealed that several signaling pathways including PI3K/AKT were significantly altered in sorafenib-treated Huh7 cells. To validate the relevance of these pathway alterations, the expression of p-AKT (Ser 473) was examined and was found significantly upregulated by sorafenib. Downregulation of AKT by siRNA attenuated the upregulation of p-AKT induced by sorafenib and enhanced the cytotoxicity of sorafenib in Huh7 cells. Combination of MK-2206, an allosteric inhibitor of AKT, abolished sorafenib-induced p-AKT upregulation, and resulted in a synergistic anti-proliferative effect in HCC cells. In conclusion, an unbiased and global phosphoproteomic approach by SILAC proves useful in identifying molecules altered by sorafenib in HCC cells; and by using this approach we showed that targeting AKT is a potentially useful strategy to improve the efficacy of sorafenib in advanced HCC. (The study was supported by the grant NSC 97-2628-B-002-004-MY3 from National Science Council of Taiwan and a research grant from Merck & Co., Inc.)
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 1652.
Abstract 1653: Highly effective treatment of HER2-amplified breast cancers through the complete inactivation of the HER2-HER3 tumorigenic driver
Authors: Amin Dhara N. , Sergina Natalia , Ahuja Deepika , McMahon Martin , Wang Donghui , Hann Byron , Shokat Kevan , Moasser Mark M. 
Published: February 2011

Abstract
Approximately 25% of breast cancers are driven by amplification of the HER2 oncogene and over-activity of the HER2-HER3 signaling complex. It is a promising hypothesis that the pharmacologic inactivation of HER2-HER3 signaling with tyrosine kinase inhibitors (TKIs) in patients will be a highly effective treatment for this disease. Treatment of HER2 amplified breast cancers with HER2 targeting agents shows that the HER2-HER3 complex is endowed with a two-log signal buffering capacity, making drug potency a critical and potentially limiting variable. The buffering capacity is mediated through Akt driven negative feedback signaling, which has the ability to amplify HER2-HER3 signaling and protect it against incomplete inhibition of HER2 kinase. The concomitant use of downstream inhibitors induces compound sensitizing and desensitizing mechanisms and incremental anti-tumor effects. The HER2-HER3 signal buffering mechanisms cannot ultimately compensate for the total loss of HER2 catalytic activity, and at fully inactivating doses of TKI, the failure to phosphorylate HER3 and the dual loss of MAPK and Akt pathway signaling leads to apoptotic tumor cell death. Such HER2-inactivating dosing is not tolerable in vivo using continuous schedules but is feasible and highly effective using intermittent dosing. We show that continuous dosing of the HER2 TKI, lapatinib, at its maximum tolerated dose in mice bearing HER2-amplified tumors produces modest growth inhibitory effects. However, a five day repeated intermittent schedule allows eight fold higher dosing and produces much more profound tumor regression and durable anti-tumor effects. Therefore high dose intermittent TKI therapy is an imminently testable clinical treatment hypothesis that can fully inactivate HER2-HER3 signaling by overpowering its signal buffering capacity, revealing a monotherapy potential in HER2-targeting TKIs that may surpass many of the combination therapy approaches currently being explored.
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 1653.
Abstract 1656: Id1, inhibitor of differentiation, is a key protein mediating anti-tumor responses of gamma-tocotrienol in breast cancer cells
Authors: Yap Wei Ney , Zaiden Norazean , Tan Yee Ling , Chang Piek Ngoh , Zhang Xue Wu , Wong Y.C , Ling M.T , Yap Yee Leng 
Published: February 2011

Abstract
Background: Gamma-tocotrienol has demonstrated anti-proliferative effect on breast cancer (BCa) cells, but mechanisms involved are largely unknown. This study aimed at deciphering the molecular pathways responsible for its activity. Methods: MTT cell proliferation, DNA fragmentation, TUNEL assay and flow cytometry were performed to investigate gamma-tocotrienol induced cell cytotoxicity and cell cycle arrest. Western blotting was used to characterize multiple signaling pathways associated with gamma-tocotrienol in BCa. Docetaxel, a chemotherapeutic drug that is able to provide significant survival advantage in metastatic BCa, was used in the chemosensitization studies. Results: Our results showed that treatment of BCa cells with gamma-tocotrienol resulted in induction of apoptosis as evidenced by activation of pro-caspases (cleaved caspase-3, −7, −8, −9 and cleaved PARP), accumulation of sub-G1 cells and DNA fragmentations. Examination of the pro-survival genes revealed that the gamma-tocotrienol-induced cell death was associated with suppression of Id1 and NF-κB through modulation of their upstream regulators (Src, Smad1/5/8, Fak and LOX). Meanwhile, gamma-tocotrienol treatment also resulted in the induction of JNK signaling pathway and inhibition of JNK activity by specific inhibitor partially blocked the effect of gamma-tocotrienol. Furthermore, synergistic effect was observed when cells were co-treated with gamma-tocotrienol and Docetaxel. Interestingly, in cells that treated with gamma-tocotrienol, alpha-tocopherol or ß-aminoproprionitrile were found to partially restore Id1 expression. Meanwhile, this restoration of Id1 was found to protect the cells from gamma-tocotrienol induced apoptosis. Consistent outcome was observed in cells ectopically transfected with the Id-1 gene. Conclusion: Our results suggested that the anti-proliferative and chemosensitization effect of gamma-tocotrienol on BCa cells may be mediated through downregulation of Id1 protein.
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 1656.
Abstract 1657: HSP90 inhibition down regulates EGFR and its effector signaling proteins in pancreatic cancer cell lines
Authors: Chandana Sreenivasa R. , Leece Cheryl , Bhutani Manisha , Conley Barbara A. 
Published: February 2011

Abstract
Rationale: Currently approved therapies, including EGFR inhibitors, have minimal effect on survival in pancreatic cancer (PC). HSP90 is a molecular chaperone that specifically enables activity of numerous protein kinases, including EGFR and other signaling proteins. We have reported that simultaneous inhibition of EGFR and HSP90 may be additive in inhibiting cell viability in PC cell lines. Here we report possible molecular mechanisms underlying HSP90 and EGFR inhibition. Methods: MiaPaCa-2 and PANC-1 were treated with EGFR inhibitor, compound 56 (CMP56) (5 − 35 μmol), and HSP90 inhibitor geldanamycin (250 nmol − 1μmol). Growth inhibition was evaluated using the MTT assay, and apoptosis was evaluated by caspase-3 and PARP cleavage. The effect on relevant cell signaling proteins was assessed by immunoblotting with specific antibodies directed against EGFR and effectors such as AKT, STAT-3 and JNK. Results: Growth inhibition was significantly (p &lt; 0.05) higher in both MiaPaCa-2 and PANC1 cells treated with CMP56 and geldanamycin than in cells treated with either agent at various concentrations. The molecular effects are shown in table 1. There was a decrease in phosphorylation of EGFR in bothe cell lines after treatment with CMP56. Concomitant inhibition of EGFR and HSP90 was associated with decreased phosphorylation of ERK, JNK and AKT and with an increase in caspase-3, PARP cleavage in MiaPaCa-2 cells, but not in PANC-1 cells. Conclusions: These results suggest that HSP90 inhibition in MiaPaCa-2 cells induces down regulation of EGFR, STAT-3 and AKT, but not in PANC-1 cells. Higher concentrations of geldanamycin may be required in PANC-1cells. Combined inhibition of EGFR and HSP90 induced apoptosis additively. We are studying further to understand the other potential molecular pathways involved in this strategy.Table.Molecular effects of EGFR and HSP90 inhibition in PC Cell lines ↘ - Decrease, - No change, GEL - Geldanamycin (500 nmol), CMP-56 - Compound 56 (10 μmol)Protein of interest MiaPaCa-2 PANC-1 GELCMP56GEL + CMP56 GELCMP56GEL + CMP56EGFR↘-↘↘ --↘AKT↘-↘↘ --↘STAT-3↘-↘↘ --↘
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 1657.
Abstract 1661: Effect of thalidomide and liposomal doxorubicin on human osteoclastogenesis
Authors: Chen Yu-Jen , Chen Yu-Yawn , Liao Hui-Fen , Chi Chih-Wen 
Published: February 2011

Abstract
Background: Thalidomide has been reported capable of inhibiting angiogenesis and growth of multiple myeloma. Liposomal doxorubicin is known to be mainly absorbed and degraded in reticuloendothelial system, especially the monocyte-macrophage lineage. Since osteoclasts (OCs) are derived from precursors of monocyte-macrophage lineage, we aimed to examine the effect of thalidomide, liposomal doxorubicin and their combination on human osteoclastogenesis.
Materials and Methods: We isolated CD14+ cells from peripheral blood mononuclear cells of healthy subjects and generated OCs under stimulation with macrophage-colony forming factor and receptor activator of NK-κB ligand. Cell viability, surface CD51/61 expression, and tartrate-resistant acid phosphatase (TRAP) activity were assessed by using MTT, flow cytometry and immunohistochemical staining, respectively.
Results: In comparison with control differentiated OCs, combination of thalidomide (purchased from TTY Biopharm, Taiwan) and liposomal doxorubicin (purchased from TTY Biopharm, Taiwan) profoundly inhibited the amount of harvested viable OCs. By treatment with each drug alone, thalidomide increased and liposomal doxorubicin decreased the amount of viable OCs. The expression of osteoclast-specific surface antigen CD51/61 was greatly inhibited by each drug and their combination. Furthermore, the amount of multinucleated TRAP-positive cells characteristics of OCs, was suppressed by each drug and, the mostly, their combination. Elucidation of cellular and molecular mechanisms of action has been undergoing.
Conclusion: Thalidomide, liposomal doxorubicin and their combination may effectively inhibit human osteoclastogenesis.
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 1661.
Abstract 1668: Pharmacodynamic biomarker development for INK128, a potent and selective inhibitor of TORC1/2 for the treatment of cancer
Authors: Jessen Katayoun , Wang Shunyou , Guo Xin , Kessler Linda , Kucharski Jeff , Staunton Jocelyn , Lan Lucy , Elia Marikka , Stewart Josh , Brown Jolene , Li Liansheng , Chan Katrina , Martin Michael , Ren Pingda , Rommel Christian , Liu Yi 
Published: February 2011

Abstract
Pharmacokinetic / pharmacodynamic (PK/PD) modeling is a valuable strategy to achieve target inhibition as well as predictable and meaningful therapeutic efficacy. The mammalian target of rapamycin (mTOR) comprises two protein complexes, TORC1 and TORC2, which together regulate cell growth, metabolism, angiogenesis, and cell survival. Because TORC1 and TORC2 play a crucial role in several pathways that are frequently dysregulated in human cancer, the mTOR kinase is a compelling target for oncology drug development. Through rational drug design we have identified INK128, a potent and selective small molecule, ATP-competitive, active-site TORC1/2 kinase inhibitor with excellent drug-like properties. Inhibition of phosphorylation of S6 and 4EBP1, downstream markers of TORC1 signaling, was selected for PD analysis in peripheral blood cells (PBCs), skin tissue, and tumor tissue biopsy in mice xenograft tumor models. Time- and dose-dependent inhibition of S6 and 4EBP1 was demonstrated in PBCs by phospho-flow (FACS) analysis. Immunohistochemistry and immunoblot analysis demonstrated a correlation between S6 and 4EBP1 inhibition in tumors or skin tissue and antitumor effect. Additionally, site-selective inhibition of AKT phosphorylation at Ser473, the downstream substrate of TORC2, was also demonstrated in tumors and skin biopsies in mouse xenograft models. Our results demonstrate that daily, oral administration of INK128 selectively inhibits PI3K/AKT/mTOR signaling at the level of TORC1/2, and show that INK128 inhibits growth, and in some cases induces regression, of various tumor xenograft models. Results from these studies display a clear pharmacokinetic and pharmacodynamic relationship. Moreover, the activity of several of these downstream markers can be reproducibly measured in human peripheral blood cells and may permit development of a PK/PD model that might assist to predict PBC and skin tissue PD marker inhibition time-profiles in patients. In summary, INK128 presents a compelling, biomarker-guided approach for the treatment of a variety of cancer by targeting TORC1/2 signaling.
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 1668.