bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1759: MK-1775, a novel Wee1 kinase inhibitor, radiosensitizes p53-defective non-small cell lung cancer (NSCLC) cells
Authors: Bridges Kathleen , Hirai Hiroshi , Buser Carolyn , Meyn Raymond E. 
Published: February 2011

Abstract
Wee1 is a tyrosine kinase involved in the S&gt;G2 and G2&gt;M cell cycle transitions. Following DNA damage, Wee1 is phosphorylated by upstream kinases and stabilized. Stabilized Wee1, in turn, phosphorylates and inhibits CDC2, preventing the cells from entering mitosis before repairing their damaged DNA. Abrogation of Wee1 activity, either by decreasing expression using siRNA, or by inhibiting protein activity with selective small molecule inhibitors, sensitizes tumor cells to DNA-damaging agents. This sensitization preferentially takes place in a p53 null or mutant context. We have investigated the ability of a novel, small molecule inhibitor of Wee1, MK-1775, to radiosensitize NSCLC cells treated in vitro. Four NSCLC cell lines were used in the study: A549 and H460 with wild-type p53 status and H1299 and Calu6 with null or mutant p53 status, respectively. A 24 hr pre-irradiation treatment with 200 nM MK-1775 suppressed phosphorylation of CDC2 in both A549 and H1299 cells, however, this treatment did not produce a radiosensitizing effect in either line. An 18 hr post-irradiation treatment slightly radiosensitized the H1299 line but not the A549 line. The optimal treatment of a 1 hr pre-irradiation followed by an 18 hr post-irradiation treatment substantially radiosensitized the H1299 and Calu6 lines, yielding dose-enhancement factors (DEFs) at 10% survival of 1.39 and 1.47 respectively, but did not sensitize the A549 or H460 cells, DEFs of 1.0. To determine the mechanism responsible for the radiosensitizing effect of MK-1775, cells were treated with nocodazole following a dose of 4 Gy and analyzed for phospho-histone H3 as an indication of mitotic index after 4 hrs. Unirradiated cells accumulated in mitosis during the 4 hrs in nocodazole and this accumulation was substantially enhanced by MK-1775 in both p53 wild type A549 and p53 null H1299 cells suggesting that Wee1 inhibition accelerates unirradiated cells into mitosis prematurely. Neither A549 nor H1299 cells, irradiated with 4 Gy, accumulated in mitosis during the 4 hr nocodazole treatment in the absence of MK-1775 indicating a robust G2 block for both lines. However, H1299 cells irradiated with 4 Gy and treated with MK-1775 accumulated in mitosis to a level higher than the unirradiated cells treated with MK-1775 alone. This enhanced entry of irradiated cells into mitosis was not evident to nearly the same degree in the A549 cells. Thus, we conclude that the Wee1 inhibitor, MK-1775, accelerates cells harboring DNA-damage prematurely into mitosis in a p53-dependent manner correlating with its radiosensitizing effects.
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 1759.
Abstract 1761: Class I HDAC expression patterns in gastroenteropancreatic neuroendocrine tumors
Authors: Darb-Esfahani Silvia , Rieger Anja , Pavel Marianne , Kasajima Atsuko , Sasano Hironobu , Dietel Manfred , Denkert Carsten , Wiedenmann Bertram , Weichert Wilko 
Published: February 2011

Abstract
Aims Inhibition of histone deacetylases (HDACs) has been shown to have antiproliferative and proapoptotic effects on gastrointestinal neuroendocrine tumor cells in vitro. While several HDAC inhibitors have entered clinical trials as antineoplastic agents in various tumor entities, information on the expression of HDACs in gastroenteropancreatic neuroendocrine tumors (GEP-NET) in vivo is still lacking.
Methods We investigated expression of class I HDAC1, HDAC2 and HDAC3 in a large cohort of neuroendocrine tumors by immunohistochemistry and correlated our findings with clinicopathologic variables, proliferative activity and patient prognosis.
Results While 58 (59.2%) out of 98 neuroendocrine foregut and midgut tumors did not display any nuclear expression of HDAC1, HDAC2 or HDAC3, 38 (38.8%) were partially positive, i.e. showed nuclear staining for at least one of the three HDAC isoforms. Only 2 (2.0%) tumors were positive for all of the three HDACs.
Nuclear expression of HDAC isoforms correlated strongly (p&lt;0.006) with each other and also correlated with proliferative capacity as determined by expression of Ki67 (p=0.003). Consequently, expression of HDAC1 in foregut tumors was correlated with grading (p=0.009) and a similar tendency was seen for HDAC2 (p=0.077). No correlation was seen between HDAC expression in primary tumors and tumor stage, nodal status or state of metastasis. However, HDAC expression was lower in nodal foregut and midgut lesions when compared to the corresponding primary tumors (p&lt;0.023). HDAC expression was not associated with disease specific survival in stage IV midgut tumors.
Conclusion Our observation of a tight association of HDAC positivity and proliferative activity in GEP-NETs mirror the fact that overexpression of HDACs promote cancer cell growth in these neoplasms in vivo. We additionaly hypothesize that differences in HDAC expression might predict response to HDAC inhibitors which should be taken into account when future clinical trials with these substances are being planned.
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 1761.
Abstract 1764: Horizontal and vertical signal pathway inhibition in human tumor primary culture micro-spheroids
Authors: Nagourney Robert Alan , Bernard Paula J. , Francisco Federico R. , Evans Steven S. 
Published: February 2011

Abstract
Introduction: Signal transduction pathways are targets for small molecule tyrosine and serine-threonine kinase inhibitors. Redundancy and cross talk between pathways can complicate the application of genomic signatures but proteomic and functional platforms may more closely approximate tumor phenotypes. We used EVA/PCD (ex vivo analysis of programmed cell death), a functional platform measuring both apoptotic & non-apoptotic events to examine the PI3K and EGFr pathways in human 1° culture micro-spheroids. Methods: 337 tumor specimens provided from the OR were mechanically and enzymatically disaggregated and exposed to EGFr (Gefitinib), AKT (B-15), PI3K (LY294002) & mTOR (Rapamycin) inhibitors with LC50 values interpolated from 5-point dose response curves. Synergy was assessed by median effect and correlation coefficients by Pearson Moment. Results: Parallel Pearson Moment analyses in 51 specimens by 2-tailed T, revealed LY vs. B15 (NS); LY vs. Rapa (P&lt;0.02); B15 vs. Rapa (P&lt;0.0025); Rapa vs. Gefitinib (P &lt;0.001). Synergy analyses for Rapa & Gefitinib revealed synergy in 29%, additivity in 41%, sub-additivity in 13% and antagonism in 17%. Exploratory synergy analyses that combined Gefitinib & LY and Gefitinib & B-15, favored the Gefitinib& B-15 combination with 100% synergy in this small series. Conclusions: EVA/PCD analyses provide insights into cellular response to targeted therapies, alone and in combination. Correlative analyses identify points of commonality and/or disparity in downstream signaling that can be exploited in drug development and therapy. Synergy analyses reveal potentially important drug combinations. The EVA/PCD human tumor micro-spheroid platform provides a functional tool capable of streamlining drug development and cancer therapy. Supported by The Vanguard Cancer Foundation and the Nagourney Institute.
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 1764.
Abstract 1765: Preclinical optimization of the Chk1/2 inhibitor AZD7762 in combination with gemcitabine in pancreatic cancer
Authors: Parsels Leslie A. , Morgan Meredith A. , Tanska Daria M. , Parsels Joshua D. , Davis Mary A. , Hassan Maria C. , Arumugarajah Sankari , Hylander-Gans Linda , Morosini Deborah , Zhao Lili , Simeone Diane M. , Canman Christine E. , Normolle Daniel P. , Zabludoff Sonya D. , Lawrence Theodore S. , Maybaum Jonathan 
Published: February 2011

Abstract
Pancreatic cancer remains among the most lethal cancers with an overall 5-year survival of less than 5%. Chk1 inhibition has emerged as a promising approach to sensitize pancreatic cancer to gemcitabine (Gem), the current standard therapy for both local control and metastatic disease. Here, we characterized the ability of AZD7762, a small molecule Chk1/2 inhibitor currently in Phase I trials, to sensitize pancreatic cancer cells to Gem both in vitro and in vivo.
We first evaluated the in vitro schedule-dependence of AZD7762-mediated Gem sensitization by clonogenic assay. We found that AZD7762 effectively sensitized pancreatic cancer cell lines to Gem-induced loss of clonogenicity, with shifts in IC50 from 3- to 38-fold, compared to cells treated with Gem alone. At low concentrations of Gem (≤IC50), AZD7762 was most effective when present during Gem treatment. At higher concentrations of Gem, however, giving AZD7762 24 h after Gem resulted in the greatest sensitization. We next assessed the molecular mechanisms of AZD7762-mediated chemosensitization in one of these cell lines, MiaPaCa2, by immunoblot, flow cytometry and immunofluorescent staining. Gemcitabine sensitization was associated with inhibition of Chk1, rather than Chk2 and abrogation of the S-M and G2-M checkpoints. Despite checkpoint abrogation, we found that Gem/AZD7762-treated cells were unable to exit S-phase and, over time, AZD7762 inhibited DNA synthesis, as measured by BrdUrd incorporation. This inhibition was associated with pan γ-H2AX staining in Gem-treated cells, in addition to disruption of Rad51 foci and inhibition of homologous recombination repair activity.
We next evaluated the effects of AZD7762 in two different human pancreatic cancer xenograft models; MiaPaCa2, and a patient-derived early passage pancreatic cancer xenograft, EPX-J. AZD7762 had anti-tumor activity both as a single agent, and in combination with Gem in both MiaPaCa2 and EPX-J, with average times to tumor doubling of 37 and 49 days, respectively, in tumors treated with both Gem/AZD7762, compared to 18 and 29 days for tumors treated with Gem alone (*p≤0.05). Chk1 inhibition, as determined by S296- and S345-Chk1 phosphorylation status, correlated with in vivo response. Finally, we found increased S345-Chk1 phosphorylation in normal tissues from mice treated with Gem/AZD7762, suggesting this may be a useful surrogate marker for AZD7762 activity in vivo.
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 1765.
Abstract 1770: Overexpression of fibroblast growth factor receptor 2 (FGFR2) in gastric cancer and basis for future FGFR2-targeted cancer therapy
Authors: Yeh Kun-Huei , Shun Chia-Tung , Kao Chiu-Hua , Lin Yu-Lin , Shen Ying-Chun , Cheng Ann-Lii 
Published: February 2011

Abstract
Introduction: Fibroblast growth factors (FGFs) are potent mitogens and inducers of angiogenesis. FGF signalling pathway is closely associated with cancer development and progression. Fibroblast growth factor receptor 2 (FGFR2) gene, located at human chromosome 10q26, encodes FGFR2b and FGFR2c isoforms functioning as distinct FGF receptors. Gene amplification or missense mutation of FGFR2 occurs in gastric cancer (GC). Genetic alterations of FGFR2 may induce aberrant activation of FGFR2 signalling pathway, thereafter induce proliferation and survival of GC cells. FGFR2 plays an important role in gastric carcinogenesis.
Patients and Methods: A total of 33 gastric cancer tissues with formalin-fixed, paraffin-embedded tumor slides were investigated by immunohistochemical staining with primary antibody against FGFR2. By Lauren's classification, there are 9 diffuse-type, 23 intestinal-type, and 1 mixed-type GC patients, respectively.
Results: The FGFR2 immunohistochemical staining was classified as 0, 1+, 2+, and 3+ according to percentage of immunoreactive positive-staining FGFR2 cells in &lt;10%, 10-25%, 25-50%, and &gt;50% tumor cells, respectively. The relationship between the FGFR2 expression and the clinicopathological characteristics were analyzed. Among 33 GC patients, 13 patients (39.4%; 23-57%, 95% C.I.) had FGFR2 expression (1+, 2+, and 3+), and 11 patients (33.3%; 17-52%, 95% C.I.) had FGFR2 overexpression (2+ and 3+), respectively. FGFR2 expression was not correlated with diffuse-type versus intestinal-type GC patients (p=0.427, Fisher exact test).
Conclusions: Overexpression of FGFR2 in gastric cancer forms the basis of the rational clinical application of future FGFR2-targeted cancer therapy for treatment of advanced GC.
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 1770.
Abstract 1771: Therapeutic management of pancreatic cancer using a novel drug, Minnelide
Authors: Chugh Rohit , Patil Satish , Sangwan Veena , Vickers Selwyn , Georg Gunda , Saluja Ashok K. 
Published: February 2011

Abstract
Background: Pancreatic cancer, the fourth-leading cause of cancer-related deaths in the United States, is one of the most malignant and aggressive forms of cancer, with a 5-year survival of &lt;5%. We have previously shown that triptolide, a diterpenoid isolated from Tripterygium wilfordii, inhibits HSP70 expression leading to cell death in pancreatic cancer cells and reduces the growth as well as loco-regional spread of pancreatic tumors in an orthotopic model. The drawback of the use of triptolide in the clinic is its insolubility in water, requiring the presence of organic solvents. We therefore developed a prodrug of triptolide named Minnelide which is water soluble and converts to the parent compound both in vitro and in vivo.
Aim: To evaluate the efficacy of Minnelide as a potential therapeutic agent for pancreatic cancer.
Methods: Pancreatic cancer cells of varying metastatic potential (MIA PaCa-2/S2-VP10/S2-013) were incubated with different concentrations of Minnelide (100-200 nM) or vehicle (control). Cell viability was measured using an MTT-based assay, and apoptosis assessed using annexin V staining and caspase 3/9 activation at different time intervals. HSP70 expression was measured in lysates from Minnelide-treated cells by western blot. In vivo efficacy of the drug was measured by implanting tumor cells into the pancreas of nude mice which were then treated with either vehicle or Minnelide for different periods of time, and at different stages of tumor formation.
Results: Minnelide decreased the cell viability of the three different human pancreatic cancer cell lines tested in a dose- and time-dependent manner. Furthermore, cell death was associated with annexin V positivity and activation of caspase 3/9. Minnelide repressed HSP70 protein expression at 100nM, supporting our previous results which show that HSP70 plays an important role in tumor progression. In the in vivo orthotopic mouse model, Minnelide dramatically decreased tumor size, loco-regional spread of tumor and extended survival, both in the early (7 days post-inoculation) and late (28 days post-inoculation) stages of pancreatic cancer. Importantly, toxic studies have shown that Minnelide at the concentrations required for tumor regression is not toxic to the animal.
Conclusion: Minnelide is a potent anti-cancer agent, both in vitro and in vivo, causing cell death via apoptosis and tumor regression in vivo. It holds great promise as a novel single-agent therapeutic strategy against pancreatic cancer. We are currently in the process of initiating Phase I clinical trials for this drug.
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 1771.
Abstract 1772: Calcium activated nucleotidase 1 (CANT1) promotes progression of prostate carcinomas
Authors: Gerhardt Josefine , Steinbrech Corinna , Fritzsche Florian , Tischler Verena , Müntener Michael , Sulser Tullio , Stephan Carsten , Jung Klaus , Moch Holger , Kristiansen Glen 
Published: February 2011

Abstract
Aims:
Previously, we identified Calcium-activated nucleotidase 1 (CANT1) mRNA to be overexpressed in human prostate cancer, however, so far no involvement of CANT1 in the progression of human tumours was reported. Therefore the protein expression level of CANT1 in prostate tumours was determined, followed by the elucidation of a functional implication of CANT1 overexpression in prostate cancer progression.
Methods:
Two tissue microarrays including 1100 prostate samples from two different institutions were constructed to examine the protein expression level of CANT1. The role of CANT1 in tumour progression was assessed in two prostate cancer cell lines in an RNA interference based approach. Cell number and DNA synthesis rate were determined by in vitro assays to measure cell proliferation, further cell migration was studied in transwell chamber assays.
Results:
A recurrent overexpression of CANT1 protein in human prostate cancers was confirmed on the tissue microarrays. Functionally, CANT1 knockdown induced a reduction of LNCaP as well as PC-3 cell number, which was caused by a diminished DNA synthesis rate. Moreover, a considerable decrease of cell migration towards a fibronectin gradient was observed in both cell lines upon CANT1 knockdown. This decreased cell mobility was also accompanied by morphological cell changes.
Conclusions:
Two cellular processes that are directly linked to tumour progression are markedly impaired upon CANT1 knockdown in prostate cancer cell lines, demonstrating for the first time a tumourbiological relevance of CANT1 expression. In future experiments the mechanism how CANT1 exerts its effects on proliferation and migration will be elucidated as well as the pathways that lead to CANT1 overexpression in prostate cancer. This will contribute to a better understanding of prostate carcinogenesis and to the evaluation of the potential of CANT1 as a therapeutic target.
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 1772.
Abstract 1773: The addition of Reolysin, an oncolytic reovirus, to irinotecan shows synergistic anticancer activity in colorectal cancer cell lines
Authors: Seetharam Raviraja N. , Coffey Matthew C. , Klampfer Lidija , Mariadason John , Goel Sanjay 
Published: February 2011

Abstract
Recent clinical data suggests that the anti EGFR antibodies, cetuximab and panitumumab, are ineffective in patients with colorectal cancer whose tumors harbor a mutation in the kras oncogene. Currently, for these patients, the only option after failure of front line therapy is irinotecan, and there is no drug that can be combined with it to improve clinical outcomes. We studied in vitro, the combination of Reolysin and irinotecan to develop a novel therapeutic approach for these patients.
Reolysin (reovirus Serotype 3) has been shown to replicate specifically in tumors bearing an activated ras pathway. This specificity coupled with its relatively nonpathogenic nature in humans makes it an attractive anti-cancer therapy candidate. We have performed in vitro studies of Reo (multiplicity of infection 1 to 10), iri (0.5-10 µM), as single agents and in combination in human colorectal cancer cells to study the role of kras mutation.
Reolysin was obtained from Oncolytics Biotech Inc. and irinotecan was obtained commercially. A panel of 8 colorectal cancer cell lines were infected with Reolysin (multiplicity of infection 1 to 10), irinotecan (0.5-10 µM), as a single agent or in combination. The cells were exposed to Reolysin for 6-8 hours and to irinotecan for 72 hours. Viable cells were determined 72 hours post treatment using MTT assay. The effect of Reolysin and irinotecan combination on cell viability was assessed using CalcuSyn software (Biosoft, UK) that generates combined cytotoxic effect by calculating combination indices (CIs). A CI of &lt;1 indicates synergy, 1 denotes additive effect, and &gt;1 denotes antagonism.
We found that Reolysin and irinotecan as single agents were cytotoxic to all colon cell lines studied. Further, when Reolysin was combined with irinotecan, there was evidence of synergistic cytotoxicity in all (HT29, HCT116, DLD, KM12, SKCO-1, SW620, LIM2405) except one (SW948) cell line. There appears to be no association between kras mutation status and synergism. To further explore these findings and understand the mechanistic basis of drug synergism we are studying the effect of Reolysin and irinotecan in isogenic HCT116 (kras mutant) and Hke3 (kras WT) cell lines.
In summary, the combination of Reolysin and irinotecan is synergistic in colorectal cancer cell lines including those with kras mutation and is worthy of exploration in human patients.
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 1773.