bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2426: Role of fibroblast growth factor receptor 1 (FGFR1) in liver metastasis of colorectal cancer
Authors: Lee Myung Eun , Shin Yoo Kun , Jeung Hei-Cheul , Shin Sang Joon , Park Young Kyu , Zhao Xue-Feng , Kim Tae Soo , Ahn Joong- Bae , Chung Hyun Cheol , Rha Sun Young
Published: August 2012

Liver metastasis is one of the main cause of death among patients with colorectal cancer (CRC). However, accurate prediction of liver metastasis of CRC is difficult at the inception of diagnosis. Activated receptor tyrosine kinases (RTKs) are the main mediators of the signaling pathway related to cell survival, proliferation, differentiation or apoptosis. To determine if any of these RTKs are involved in liver metastasis from CRC, we performed phospho-receptor tyrosine kinase array with matched 20 colon normal mucosa, primary tumor, metastatic liver tumor, and liver normal tissue proteins using Human Phospho-RTK Array (2009 AACR, #4951). In RTK activation profiling, FGFR1 activation was increased in a high proportion of metastatic liver tumor (p < 0.05). To evaluate the functional roles of FGFR1, DLD-1 and LoVo colon cancer cells were treated with FGFR1 specific siRNA or RTK inhibitor. Inhibition of FGFR1 inhibited phosphorylation of PI3K/AKT and ERK, a downstream cellular signaling molecule of FGFR; whereas, mTOR, p70S6K, JNK and Src activities were not affected. Also, we compared the cell migration and invasion ability by wound healing assay and invasion assay. The invasion capacity and wound closing were significantly delayed by FGFR1 inhibition (p <0.05). To evaluate in vivo anti-metastatic effect of FGFR1, we used an orthotropic liver metastasis model, generated by injecting LoVo colon cancer cells into spleen of BALB/c nu/nu mice. In control group, multiple large metastatic foci were evident, whereas the extent of liver metastasis was dramatically reduced in TKI-258 (50mg/kg/d) treated group (48.9%, p<0.05). Immunoexpression of the p-FGFR1 was much more intense in control than TKI-258 treated tumor tissues. Biological effects were also confirmed that FGFR1 inhibition resulted in a significant reduction of ERK activation and Ki-67 positive cells in tumor tissues. In conclusion, FGFR1 might be a good target for liver metastasis of CRC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2426. doi:1538-7445.AM2012-2426
Abstract 2429: An abdominal imaging window for long-term subcellular visualization of abdominal organs in living mice
Authors: Steller Ernst J. , Ritsma Laila , Rinkes Inne H. Borel , Kranenburg Onno , van Rheenen Jacco
Published: August 2012

Intravital imaging windows are powerful tools for long-term visualization of dynamic cell behaviour in living mice. However, the applications of the current windows are limited because they cannot be used for imaging of organs in the abdomen. In order to overcome this unmet need, we developed the abdominal imaging window (AIW). Using the AIW, we visualized stem cells in the small intestine, lymphocytes in the spleen, transplanted islets of Langerhans under the kidney capsule, and metastatic outgrowth of tumor cells in the liver. We discovered that liver metastases are grown from a single founder cell, and that tumor cells within a growing metastasis are highly motile. Strikingly, this migration appears to be a novel, limiting step during liver metastasis formation. We conclude that the AIW is a powerful tool to visualize distinct biological processes in a variety of abdominal organs with subcellular resolution over a time span of weeks.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2429. doi:1538-7445.AM2012-2429
Abstract 2435: Assessment of vascular disrupting properties of sodium meta-arsenite treatment using Dynamic contrast-enhanced MRI in colon cancer allograft model
Authors: Min Young Joo , Lee Hee-Soon , Cho Wha Ja , Lee Ho Yong , Lee Jong Cheol , Park Sungchan , Cha Hee-jung , Park Hyun Jin , Seo Jin , Lee Young Han , Song Ho Taek , Moon Chang Hoon
Published: August 2012

PURPOSE: Sodium meta-arsenite is an orally bioavailable arsenic compound that currently undergoing clinical evaluation. The sodium meta-arsenite leads to blood vessel congestion, the selective destruction of the vasculature, and extensive necrosis in experimental tumors. The aim of this study is to assess the ability of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to measure the antivascular effects of sodium meta-arsenite in colon cancer allograft model. MATERIALS AND METHODS: Mice CT26 colon cell carcinoma allografts were treated with sodium meta-arsenite or saline. Changes in tumor vascularity were assessed by DCE-MRI. DCE-MRI data were analyzed calculating the k(ep). For histologic analysis, liver, spleen and tumor tissues were taken at 8, 24 and 48 hours after sodium meta-arsenite injection from CT26 tumor allograft models. RESULTS: DCE-MRI results showed comparison between pre-treatment and 24 hr post-treatment Gd-DTPA contrast enhancement T1-weighted MR image. Enhancement has been significantly decreased in sodium meta-arsenite treated group than sham injection group. We also showed extensive central necrosis of tumor by 24 h after treated with sodium meta-arsenite (10 mg/kg, i.p.). CONCLUSION: These results suggest that DCE-MRI could quantitatively visualized the perfusion efficacy of the sodium meta-arsenite acting as a VDA in colon caner allograft model

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2435. doi:1538-7445.AM2012-2435
Abstract 2446: Real-time molecular imaging of targeted therapies in patient-derived tumor cells by quantitative immunofluorescence microscopy
Authors: Rothenberg Stephen M. , Wargo Jennifer , Juric Dejan , Corcoran Ryan B. , Winokur Daniel , Flaherty Keith T. , Baselga Jose , Maheswaran Shyamala , Engelman Jeffrey A. , Haber Daniel A.
Published: August 2012

Serial radiographic imaging is the primary means for determining the efficacy of cancer treatments. However, a long time interval is required before changes are appreciated, and the direct effects of therapy on tumor cells cannot be measured. We have utilized highly multiplexed, quantitative immunofluorescence microscopy to monitor multiple signaling proteins simultaneously in direct tumor biopsies and circulating tumor cells obtained serially from patients with BRAF- and PIK3CA-mutant solid cancers undergoing treatment with agents that target these mutated oncogenes. Changes in signaling that accurately predict subsequent clinical response can be determined from small numbers (∼100) of tumor cells and are apparent within days of the first dose of therapy, and weeks before radiographic determination of response. Preliminary results suggest that therapeutic efficacy (or lack thereof) is correlated with both the degree and rapidity of downregulation of tumor cell signaling. The ability to measure the effects of therapy directly in patient-derived tumor cells may permit real time information about efficacy (or lack thereof) to be rapidly incorporated into the decision to continue an ongoing therapy or to switch to a new one, or in the identification of patient populations most likely to respond to a novel class of agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2446. doi:1538-7445.AM2012-2446
Abstract 2448: Development of a red fluorescent labeled agent for assessing HER2 expression in vitro and in vivo
Authors: Narayanan Nara , Cuneo Garry , Morin Jeff , Vasquez Kristine , Rajopadhye Milind , Yared Wael , Peterson Jeffrey D. , Kossodo Sylvie C.
Published: August 2012

Upregulation of tumor HER2 occurs in approximately 25% women with breast cancer and is often associated with poor prognosis. We developed a red fluorescent imaging agent to non-invasively image and quantify tumor-associated HER2 expression in vivo. A red fluorescent dye (VivoTag 645; α=210,000 μ/cm; abs/em max 643/660 nm) was used to label trastuzumab, which is currently used to treat breast and stomach cancer. The red-labeled trastuzumab (VM4003) preferentially labeled HER2+ SKOV-3 human ovarian adenocarcinoma cells over HER2− human colorectal adenocarcinoma Colo-205 cells (10 fold), and the specificity of binding was confirmed by control experiments using free dye, labeled non-specific IgG, and competitive blockade with unlabeled excess trastuzumab. Fluorescence microscopy confirmed the expected membrane localization of fluorescence. In vivo and ex vivo imaging by fluorescence molecular tomography (FMT), showed significantly higher signal within the tumors, peaking at 6-72 hours following intravenous injection of 2 mg/kg VM4003, decreasing thereafter with a tissue half-life of 3 days. In vivo quantification of tumor signal in nude mice showed significantly higher tumor signal in HER2+ than in HER2− tumors (14.36 + 4 versus 2.39+ 0.74 pmol, at 6h imaging time, p=0.007; 18.77 + 4.45 versus 3.50+ 0.98 pmol, at 24h, p=0.001). Specificity of targeting was confirmed by competition with excess intravenous unlabeled trastuzumab, which achieved 70% signal inhibition in the tumors (tumor signal 16.12 + 3.03 versus 4.72 + 1.96 pmol, p=0.022 at 24h). Tumor volumes, as determined by direct measurements of tumor size, were comparable between both groups of mice (p=0.193). Fluorescence microscopy of ex vivo frozen tissue sections confirmed tumor fluorescence and signal localization associated to cell membranes and cytoplasm. In summary, red fluorescent-labeled trastuzumab selectively targets αER2, allowing both imaging in vitro and the non-invasive real-time tomographic imaging and quantification in vivo of HER-2 expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2448. doi:1538-7445.AM2012-2448
Abstract 2457: Laminin receptor cross-talk stimulates receptor internalization and migration of human prostate cancer cells
Authors: Anderson Todd A. , Gard Jaime MC , Sroka Isis C. , Strautman Stephanie R. , Morrissey Colm , Knudsen Beatrice S. , Cress Anne E.
Published: August 2012

Integrin cell adhesion receptors are internalized and recycled to the plasma membrane during cellular migration. The laminin binding A3B1 and A6B1 integrin receptors are differentially expressed on prostate tumor cells in Gleason grades 3-5 as detected in biopsy and prostatectomy specimens. The A6 integrin exists as a full length form or as a pro-metastatic variant, A6pB1, a receptor form missing the extracellular laminin binding domain via the action of the serine protease, uPA. The objective of this study is to determine whether internalization of the A6 integrin occurs in human bone metastatic lesions and whether cross-talk between the laminin receptors A6B1, A6pB1 and A3B1 modifies their respective internalization rates. In a tissue microarray of 185 metastatic prostate cancers from 45 patients, approximately 70% of bone metastases expressed A6B1 on tumor plasma membrane and/or within the cytoplasm. The A6 and A6p integrins in DU145 cells are constitutively internalized with a biological half life of approximately 30 minutes as compared to 60 minutes for A3 or 20 minutes for the unrelated transferrin receptor. Increasing production of A6pB1 by supplying exogenous uPA stimulated A3 internalization. Conversely, blockage of A6pB1 production using an A6 specific antibody (J8H) decreased A3 internalization. Targeted depletion of the A3 integrin increased DU145 cell migration that was dependent upon A6 integrin as detected by antibody blocking experiments using J8H (A6 specific) and AIIB2 (B1 specific). Analysis of transcriptomic data from prostate cancer xenografts, revealed three different candidate receptor recycling genes that significantly correlated with the loss of membrane and increase in cytoplasmic expression. Taken together, these data indicate that cross-talk between A6B1 and A3B1 modifies their internalization rates and prostate tumor cell migration. This suggests that successful therapeutic targeting of metastasizing prostate cancer cells may depend upon coordinated targeting of both receptors and the recycling machinery. Current work is to determine the involvement of candidate recycling genes in the biological control of laminin binding integrins in human prostate cancer. (Supported in part by NIH grants P30CA023074, 1RO1 CA159406 and the TACMASS core service of the University of Arizona Cancer Center).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2457. doi:1538-7445.AM2012-2457
Abstract 2539: The PARP inhibitor AZD2281 induces autophagy and complete cell death in BRCA mutant breast cancer cell lines
Authors: Akar Ugur , Barrera Angelica Gutierrez , Hortobagyi Gabriel N , Arun Banu
Published: August 2012

BRCA1 and BRCA2 are well-known DNA repair proteins that are usually mutated or deleted in breast tumors. According to the literature, 5 (12%) of 41 breast cancer cell lines have BRCA mutations and 28 (68%) of the 41 cell lines have BRCA1 allelic loss. PARP inhibitors are known to inhibit tumor growth in BRCA mutant tumors. The purpose of this study was to investigate the effects of PARP inhibitors in BRCA mutant breast cancer cell lines. We found that AZD2281 as a single agent induced complete cell death in BRCA1 mutant (HCC-1937, MDA-MB-436, and SUM-149PT) and BRCA2 mutant (HCC-1428) cell lines. AZD2281 induced an average growth inhibition of 33% in BRCA wild-type cell lines with BRCA1 allelic loss. Downregulation of BRCA1 or BRCA2 by shRNA sensitized the triple-negative breast cancer cell lines BT-20 and MDA-MB-231 to AZD2281 treatment. We also investigated whether autophagy is induced in response to PARP inhibition. AZD2281 treatment induced LC3-II expression, an indication of autophagy. Transmission electron micrographs demonstrated autophagosome formation after AZD2281 treatment. On transmission electron micrographs, we observed a decrease in mitochondria related to autophagosome formation after AZD2281 treatment. To show AZD2281 induced autophagy is targeting mitochondria, we labeled mitochondria with yellow fluorescein protein using lentiviral stable transfection. Flow cytometry measurement demonstrated a decrease in fluorescein-labeled mitochondria after AZD2281 treatment. Inhibition of autophagy in a AZD2281-treated BRCA mutant breast cancer cell line rescued mitochondrial degradation and partially inhibited apoptosis. In conclusion, we showed that autophagy plays an important role in AZD2281-induced cell death in BRCA mutant breast cancer cell lines by degradation of mitochondria besides DNA degradation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2539. doi:1538-7445.AM2012-2539
Abstract 2540: Identification of factors governing sensitivity of NSCLC cell lines to inhibition of Poly (ADP-Ribose) Polymerase (PARP)
Authors: Kommajosyula Naveen , Moreau Lisa , D'Andrea Alan D. , Shapiro Geoffrey I.
Published: August 2012

Recently, Poly (ADP Ribose) Polymerase-1 (PARP-1) has been shown to be an important target in subsets of breast and ovarian cancers. PARP inhibitors are emerging as important new anticancer agents, especially in cancers defective in homologous recombination (HR) repair, such as those lacking BRCA1 or BRCA2. To date, the potential role of PARP inhibition in NSCLC has not been extensively studied. BRCA1 or BRCA2 promoter hypermethylation and ATM mutation have been described in primary NSCLCs, alterations that may sensitize cells to PARP inhibition. We have examined a panel of 26 genotypically-defined NSCLC cell lines for sensitivity to the PARP-1 inhibitor AG014699 using colony formation assays. We have identified 5cell lines that are exquisitely sensitive (IC50 ≤ 50nM), 9 cell lines that are moderately sensitive (IC50 ≤ 60-500nM) and 12 cell lines that are resistant (IC50 > 5 µM). To determine whether sensitive cell lines have defective HR compared to resistant cell lines, we examined the formation of Rad51 foci following exposure to PARP inhibition, as well as to gamma-irradiation and cisplatin. Both sensitive and resistant cell lines demonstrated efficient formation of Rad51 foci as well as gamma-H2AX foci in response to DNA damaging treatments, suggesting correct initiation of HR. In resistant cell lines, the repair process following PARP inhibition is completed within 24 hours, with resolution of Rad51 and gamma H2AX foci. No alterations in cell cycle distribution were detected in these cell lines, suggesting that the efficiency of repair allows proliferation to continue largely unabated. However, in sensitive cell lines, these foci persist greater than 30 hours following DNA damaging treatments. These results suggest that although sensitive lines are able to initiate HR repair, they are unable to complete the process, so that Rad51 foci are not resolved. The persistence of DNA damage in these cell lines is confirmed by persistent gamma H2AX focus formation as well as S/G2 arrest, the latter representing intact checkpoint control. We are currently investigating whether PARP inhibitor-sensitive cell lines have a deficiency in one of the helicases or resolvases required for resolution of the complex Holliday junctions formed during HR repair. Our results may define a novel subset of NSCLCs with a late-step defect in HR that can be approached with PARP inhibition as a novel treatment strategy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2540. doi:1538-7445.AM2012-2540
Abstract 2541: Effect of carcinogen acrolein on DNA repair and mutagenic susceptibility.
Authors: Wang Hsiang-Tsui
Published: August 2012

Lung cancer death is the number one cause of cancer death in the United States. Cigarette smoking is the major cause of lung cancer. Cigarette smoke (CS) contains more than 60 human carcinogens. Our early work has demonstrated that acrolein (Acr), one of the most abundant aldehydes in CS, reacts with DNA to form α- and α-hydroxy-1, N2-cyclic propano-dG adducts (α-Acr-dG and α-Acr-dG). The distribution of Acr-dG in the p53 gene coincides with lung cancer p53 mutational spectrum. Acr-dG adducts induce mainly G to T and G to A mutations that are similar to the mutation signature found in the p53 gene in lung cancer. We have also found that Acr inhibits DNA repair. Therefore, we concluded that Acr is a major etiological agent for CS related lung cancer. In this study, we found that Acr-dG adducts are poorly repaired in Acr treated normal human bronchial epithelial (NHBE) cells. Intriguingly, NHBE cell lysates are competent in carrying out in vitro repair synthesis assay using Acr-modified as well as UV-irradiated DNA as substrates. These results indicate that Acr treatment impairs DNA repair function. We found that Acr not only inhibits nucleotide excision repair (NER), it also inhibits base excision repair (BER) and mismatch repair (MMR). Acr does not change the expression of XPA, XPC, hOGG1, PMS2 or MLH1 genes. However, Acr causes a reduction of XPA, XPC, hOGG1, PMS2 and MLH1 proteins and that this effect can be neutralized by the proteosome inhibitor, MG132. We further found that Acr treatment enhances both bulky and oxidative DNA damage-induced mutagenesis. These results indicate that Acr not only damages DNA, but can also modify DNA repair proteins and further cause degradation of these modified repair proteins. We propose that these two detrimental effects contribute to Acr mutagenicity and carcinogenicity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2541. doi:1538-7445.AM2012-2541
Abstract 2544: Associations between RET/PTC rearrangements, BRAF and RAS mutations and radiation dose, age at exposure, and latency in post-Chernobyl thyroid cancer
Authors: Leeman-Neill Rebecca J. , Brenner Alina V. , Little Mark P. , Bouville Andre C. , Bogdanova Tetyana I. , Hatch Maureen , Mabuchi Kiyohiko , Tronko Mykola D. , Nikiforov Yuri E.
Published: August 2012

Introduction: Childhood exposure to I-131 from the Chernobyl accident was associated with a dramatic increase in incidence of papillary thyroid cancer (PTC). PTCs are characterized by several genetic alterations including RET/PTC rearrangements and point mutations of BRAF and RAS. Association between mutations and radiation doses has not been studied in post-Chernobyl tumors. Design: We analyzed 70 PTCs diagnosed in a Ukrainian-American cohort who were < 18 y.o. at the time of Chernobyl and received 0.008-8.6 Gy of I-131 to the thyroid. Thyroid doses were estimated based on radioactivity measurements taken shortly after the accident, environmental transport models, and interview data. BRAF and RAS mutations were identified by melting curve analysis and RET/PTC1 and RET/PTC3 by real-time RT-PCR. All mutations were confirmed by sequencing. Results: Identified mutations and patient characteristics are shown in Table 1. Logistic regression analysis demonstrated a significant decrease in I-131 dose for both BRAF and RAS mutations (p=0.005 and 0.026). There were highly statistically significant (p<0.001) differences between the trends with dose for BRAF and RAS vs RET/PTC. Comparing with BRAF and RAS mutations, the age at exposure was lower in cases with RET/PTC (p=0.001). RET/PTC3 was associated with a shorter latency period as compared to other mutations (p<0.02). Table 1. Genetic alterations and corresponding patient characteristics Conclusions: Our results demonstrate for the first time that prevalence of BRAF or RAS point mutations in post-Chernobyl tumors significantly decreases with increasing radiation dose, in contrast to the lack of decrease for RET/PTC. RET/PTC rearrangements are associated with younger age at exposure than point mutations of BRAF and RAS. These data provide support for the potential relationship between chromosomal rearrangements, but not point mutations, and radiation exposure.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2544. doi:1538-7445.AM2012-2544
Abstract 2545: FLT3-driven redox signalling in acute myeloid leukemia
Authors: Corcoran Aoife , Cotter Thomas G.
Published: August 2012

The concept of reactive oxygen species (ROS) being produced via the activation of specific oncogenes provides a basis for generating genomic instability and pro-survival signalling in tumor cells. The purpose of this study was to identify downstream targets of NADPH oxidase (Nox)-derived ROS signalling in acute myeloid leukemia cells, by performing a proteomic analysis utilizing two-dimensional phosphotyrosine immnoblotting. The majority of the targets identified were cytoskeletal-associated proteins including Ezrin, a known regulator of the cytoskeleton, which was examined further. The study demonstrated that inhibition of Nox enzymes, using diphenyleneiodonium chloride in the acute myeloid leukemia cell line MOLM-13, resulted in a decrease in Ezrin tyrosine phosphorylation and also triggered a shift in Ezrin sub-cellular localization as detected by immunofluorescence. The change in Ezrin localization coincided with altered cell morphology, observed using scanning electron microscopy and a decreased ability to migrate through a polycarbonate transwell membrane. Similar effects were observed upon inhibition of the oncogenic receptor tyrosine kinase FLT3 using the staurosporine derivate PKC412, implicating a role for FLT3 as an upstream regulator of Ezrin. Our results indicate that FLT3 drives production of ROS by Nox, which stimulates changes in Ezrin tyrosine phosphorylation and localization via redox regulation of Src. Furthermore, the modulation of Ezrin by FLT3 leads to subsequent alterations of MOLM-13 cell morphology and a significant influence on cell motility.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2545. doi:1538-7445.AM2012-2545
Abstract 2552: Detection of PIGO-deficient cells using proaerolysin: a valuable tool to investigate mechanisms of mutagenesis in the DT40 cell system
Authors: Nakamura Jun , Tian Xu , Bultman Scott , Swenberg James A.
Published: August 2012

A DNA damage response analysis makes use of the chicken DT40 isogenic cell line and its dozens of available mutants knocked out in various DNA repair and cell cycle pathways. While this DT40 cell system is valuable for understanding the DNA damage response to genotoxic agents, no convenient mutation assay for mutagens currently exists for this reverse-genetic system. Here we establish a proaerolysin (PA) selection-based mutation assay in DT40 cells to identify glycosylphosphatidylinositol (GPI)-anchor deficient cells. Using PA, we detected an increase in the number of PA-resistant DT40 cells exposed to MMS for 24 hours followed by a 5-day period of phenotype expression. GPI anchor synthesis is catalyzed by a series of phosphatidylinositol glycan complementation groups (PIGs). The PIG-O gene is on the sex chromosome (Chromosome Z) in chicken cells and is critical for GPI anchor synthesis at the intermediate step. We identified that all PA-resistant DT40 cells analyzed have mutations in the PIG-O gene. This novel assay for DT40 cells provides a valuable tool to investigate the mode of action of mutations caused by reactive agents using a series of isogenic mutant DT40 cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2552. doi:1538-7445.AM2012-2552
Abstract 2554: HSP90 inhibition induced cytotoxicity via downregulation of Rad51 expression and DNA repair capacity in non-small cell lung cancer cells
Authors: Lin Yun-Wei , Weng Shao-Hsing , Ko Jen-Chung , Chen Huang-Jen , Tseng Sheng-Chieh , Huang Yu-Ching , Tsai Min-Shao , Chiou Robin Y.-Y.
Published: August 2012

Heat shock protein 90 (HSP90) is an exciting target in cancer therapy. Our previous studies indicated that repair protein Rad51 involved in protecting non-small lung cancer (NSCLC) cell lines against chemotherapeutic agents induced cytotoxicity. In this study, the role of Rad51 expression in HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) induced cytotoxicity in two NSCLC cell lines, A549 and H1975, were investigated. 17-AAG treatment decreased cellular Rad51 protein and mRNA levels and phosphorylated MKK1/2-ERK1/2 protein levels. 17-AAG treatment disrupted the HSP90 and Rad51 interaction and triggered Rad51 protein degradation through 26S proteasome pathway. Moreover, 17-AAG treatment decreased DNA repair capacity in NSCLC cells, which could restore by enforced expression of Flag-Rad51 vector. Specific inhibition of Rad51 expression by siRNA could further enhance the 17-AAG-induced cytotoxicity. Enhancement of ERK1/2 activation by constitutively active MKK1/2 (MKK1/2-CA) vector significantly restored the 17-AAG-reduced Rad51 protein levels as well as cell viability. Moreover, arachidin-1, antioxidant stilbenoids, has demonstrated beneficial effects on human health. It could further decrease Rad51 expression and augment the cytotoxic effect and growth inhibition by 17-AAG. Moreover, 17-AAG and arachidin-1-induced synergistic cytotoxic effect and DNA repair capacity decrease could be abrogated in lung cancer cells with MKK1/2-CA or Flag-Rad51 expression vector transfection. Our results suggested that HSP90 inhibition induced cytotoxicity via downregulation of Rad51 expression and DNA repair capacity in NSCLC cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2554. doi:1538-7445.AM2012-2554
Abstract 2557: Exploring the contribution of ubiquitin binding domain of Bcr-Abl in chronic myelogenous leukemia
Authors: Chen Ru , Mahon Gwen , Tala Ilona , Chen Qing , Hu Tinghui , Li Dan , Ozer Harvey , Whitehead Ian
Published: August 2012

Chronic myelogenous leukemia (CML) is invariably associated with the expression of the p210 Bcr-Abl fusion protein. Although the Abl-encoded tyrosine kinase activity is important for leukemogenesis, the emerging problems of acquired resistance and minimal residual disease highlight the need for new complementary targets for pharmacological intervention. In our previous studies, we had identified a non-classical ubiquitin binding domain (UBD) within the NH2-terminal of p210 Bcr-Abl. Deletion of the UBD (p210 Bcr-Abl(≥UBD)) impairs the interaction between p210 Bcr-Abl and p-β-catenin (ser33). Over-expression of p210 Bcr-Abl, but not p210 Bcr-Abl(≥UBD), leads to an accumulation of phosphorylated β-catenin, and at least two of its known transcriptional targets, cyclin D1 and c-Myc. The interaction between p210 Bcr-Abl and β-catenin is ubiquitination dependent. β-catenin is a central component of the Wnt pathway which plays a critical role in the regulation of hematopoiesis. In a murine bone marrow transplantation model for CML, mice transplanted with hematopoietic cells that express p210 Bcr-Abl(≥UBD) have significantly increased life spans compared to mice transplanted with p210 Bcr-Abl expressing cells. Delayed disease progression is associated with decreased levels of β-catenin, and reduced numbers of granulocyte macrophage progenitors (GMPs), in the bone marrow. Deletion of UBD also impairs the transplantability of CML cells. Based on these observations we propose a model in which p210 Bcr-Abl may influence the Wnt signaling pathway, and leukemic expansion, by binding ubiquitinated β-catenin, and stabilizing it against degradation. Stabilized β-catenin leads to increased self-renewal of CML stem cells and progenitors. Importantly, this activity is contained within Bcr sequences, and is independent of tyrosine kinase activity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2557. doi:1538-7445.AM2012-2557
Abstract 2560: IKKα inactivation predisposes to spontaneous lung squamous cell carcinomas
Authors: Xiao Zuoxiang , Jiang Qun , Willette-Brown Jami , Zhu Feng , Young Howard A. , Lin Fanching , Burkett Sandra , Datla Mahesh , Xi Sichuan , Schrump David S. , Wiltrout Robert H. , Hu Yinling
Published: August 2012

Lung cancer is the leading cause of cancer deaths worldwide. To advance the understanding of this disease, various genetically engineered and chemical induced mouse models have been established. However, most animal models resemble human lung adenocarcinoma, and spontaneous lung squamous cell carcinomas (SCCs) mouse models are very rare. Here, we generated Ikkα-KA/KA knock-in mice (KA/KA) in which an ATP binding site of IKKα, Lys 44 was replaced by alanine. The knock-in mice develop severe skin lesions and begin to die after 6 months. We found lung SCCs in some of the mice. To study lung SCC development, we decided to stabilize the skin condition by reintroducing transgenic IKKα by crossing KA/KA with Lori.IKKα transgenic mice to generate KA/KA/Lori.IKKα (KA/KAL) mice. Almost all the KA/KAL (100%) mice at 4 to 6 months of age developed spontaneous lethal lung SCCs. The endogenous IKKα protein level generally markedly declined in an age dependent manner in these IKKα mutant mice. Progenitor cell related markers Sox2, OCT3/4 and Nanog were only increased in the lung SCC tissue but not in the tumor adjacent tissues, implying the involvement of cancer stem cells in lung SCC. Furthermore, we detected substantial increases in Ras and CyclinD1 levels and EGFR, ERK and p38 activities in lung SCCs. On the other hand, we detected reduction in tumor suppressor gene Rb and IαBβ accompanying with reduced IKKα levels in KA/KAL lungs as well as in lung SCCs. Importantly, we observed a similar alteration pattern in mouse and human lung SCCs. Finally, reintroducing IKKα into lung epithelial cells prevented lung SCC development in mice. Collectively, our study supports the tumor suppressing role of IKKα in lung tumorigenesis. This novel lung SCC mouse model may facilitate investigations in pathogenesis, diagnosis, and treatment of human lung SCC disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2560. doi:1538-7445.AM2012-2560
Abstract 2561: IKKα links inflammation and tumorigenesis in a mouse model of lung squamous cell carcinoma
Authors: Jiang Qun , Xiao Zuoxiang , Willette-Brown Jami , Back Timothy , Wiltrout Robert H. , Hu Yinling
Published: August 2012

NF-kB plays critical roles in linking inflammation and carcinogenesis. The activation of NF-kB is regulated by the IkB Kinase Complex (IKK), composed of IKKα, IKKα, and NF-κB essential modulator (NEMO). We have established a mouse model of lung squamous cell carcinoma (SCC) by inactivating IKKα in vivo. However, IKKα's attributes relating to linkage between inflammation and lung SCC have not yet been well-defined. We now show that inactivation of IKKα in mice causes systemic chronic inflammation, which consequently promotes lung SCC initiation and progression. In mice with mutated IKKα, CD4 T cells, dendritic cells, and macrophages are all significantly increased in the spleen and lung. Proinflammatory cytokines and chemokines are also remarkably elevated in the lungs of these mice. An M2 macrophage phenotype is observed only in the lungs of old IKKα mutant mice, not in younger mice, suggesting the M1/M2 polarization may be driven by the proinflammatory microenvironment in these mice. Production of Th2 cytokines and IL-10 are elevated in CD4 T cells from the lungs of mice with mutated IKKα, and may contribute to M2 polarization during the chronic inflammation. In addition, depletion of macrophages in these mice can significantly reduce Th2 cytokine production, oxidative DNA damage, and shut down SCC development in the lungs, suggesting their important roles in inflammation-associated lung carcinogenesis. Together, our data suggest that IKKα may play important roles in linking inflammation and lung SCC tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2561. doi:1538-7445.AM2012-2561
Abstract 258: Development of death receptor agonists - A novel therapy for breast cancer
Authors: Srivastava Rakesh , Shankar Sharmila
Published: August 2012

Binding of TRAIL to death receptors (TRAIL-R1/DR4 and TRAIL-R2/DR5) induces apoptosis in cancer cells without affecting normal cells. The purpose of this study was to identify and characterize TRAIL-death receptor agonist (DRA) that induces apoptosis in breast cancer cells. DRA is a small organic molecule. The pharmacokinetics of the DRA with a single oral dose was also characterized in nude mice. Blood was collected over 72-hour period after DRA administration, and analyzed by HPLC-MS/MS for plasma drug concentration. The Cmax, tmax, and AUC of DRA were measured. DRA inhibited cell viability and colony formation, and induced apoptosis in estrogen-dependent (MCF-7) and independent (MDA-MB-231 and MDA-MB-468) human breast cancer cell lines, but had no effect on human normal mammary epithelial cells and hepatocytes. The combination of DRA with paclitaxel or doxorubicin had synergistic effects on apoptosis in breast cancer cell lines. DRA formed active TRAIL-DISC (death-inducing signaling complex) similar to that of TRAIL. DRA inhibited the growth of orthotopically implanted MDA-MB-231 and MDA-MB-468 tumors in nude mice. Histological examination of tumor tissues derived from DRA-treated nude mice revealed massive caspase-3 activation and apoptosis. Pharmacokinetic data demonstrate that DRA possesses a long terminal half-life, which is acceptable for further clinical development. In conclusion, we have identified DRA that can be used either alone or in combination with chemotherapeutic drugs for the treatment of human breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 258. doi:1538-7445.AM2012-258
Abstract 2655: Esophagectomy with extended 2-field lymph node dissection for patients with thoracic esophageal carcinoma
Authors: Xue Hengchuan , Wu Changrong , Zhu Zonghai , Zhang Zhenbin , Ma Zhenkai , Gao Jie
Published: August 2012

Objective: To summarize the surgical effect and clinical application of esophagectomy with extended 2- field lymph node dissection for patients with thoracic esophageal carcinoma. Methods: From June, 1987 to December, 2008, 1690 patients with thoracic esophageal cancer underwent esophagectomy with extended 2-field (thoracic and abdominal) dissection of lymph nodes were recruited and followed up. Patients with the middle and lower thoracic esophageal cancer underwent Ivor-Lewis esophagectomy, while patients with upper thoracic esophageal cancer underwent Akiyama esophagectomy. Both thoracic and abdominal lymph node metastases were recorded. Survival rates on 1, 3, 5, and 10 years were analyzed respectively. Results: Totally, 1690 eligible patients were recruited and successfully followed. Lymph node metastases were found in 713 patients, with the proportion of 42.2%(713/1690). Thoracic lymph node metastasis rate was 39.3%(665/1690), of which 20.7%(349/1690) were found in the right apical pleural para-tracheal triangle, 26.3%(444/1690) were found in the posterior upper mediastinum, and 18.2%(307/1690) were found in the lower mediastinum. Abdominal lymph node metastasis rate was 20.1%(339/1690). Out of 1690 patients underwent esophagectomy, 278 patients were reported postoperative complications, among which the pulmonary complication was ranked as the first one (43.6%). The death rate due to operation was 0.2%.The l-year, 3-year, 5-year and 10-year survival rates were 88.2%, 63.5%, 54.8% and 30.8%, respectively. Patients without lymph node metastasis had higher 5-year survival rate (76.2%), as compared to those with lymph node metastases (36.8%). Conclusion: Findings from this study demonstrated that Ivor-Lewis and Akiyarna esophagectomy with 2-field lymph node dissection could expose the operation fields clearly and make radical lymphadenectomy thoroughly, which was useful for observing the lymph nodes in the posterior upper mediastinum around the recurrent laryngeal nerve and in the right pleural apical para-tracheal triangle. We believe that esophageal cancer patients with potential lymph node metastases could benefit from esophagectomy with extended 2-field dissection of lymph nodes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2655. doi:1538-7445.AM2012-2655
Abstract 2659: Cilastatin attenuates cisplatin-induced proximal tubular cell damage without compromising antitumoral activity
Authors: Humanes Blanca , Blanco-Codesido Montserrat , Lazaro Alberto , Camaño Sonia , Tejedor Alberto
Published: August 2012

Introduction: Cisplatin (CDDP) is a very effective and common treatment in solid malignancies. One of the most important side effects of CDDP is the nephrotoxicity. Nephrotoxicity is a limitating side effect on treatment with CDDP, preventing patients with limit kidney function of receiving the drug and stopping treatment once kidney function has worsened. Cilastatin (Cls) is a specific inhibitor of renal dedydrodipeptidase I (DHP-I) which prevents hydrolysis of imipenem and its accumulation in the proximal tubule. In this work we hypothesized that Cls acts as a nephroprotector against CDDP-induced damage without compromising antitumor activity. Methods: Primary cultures of proximal tubular cells (PTCs) and cell lines of different malignancies (colon, breast, ovarian, bladder) were cultured with different concentrations of CDDP (1, 10 and 30 μM) in the presence or absence of Cls. Cell viability was assessed with MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) assay. Raft staining was measured with toxine B choleric and FasL by confocal microscopy. Results: Cls interfered with CDDP-induced FasL signalling at raft level on PTCs brush border. Concomitant treatment with Cls reduced CDDP-induced changes. Several tumoral cell lines were tested with CDDP and Cls together. Cls did not increase or decreased tumor growth alone or in combination with CDDP. CDDP sensitivity was not affected by Cls. Conclusion: By binding a DHP-I, Cls blocks CDDP-induced PTCs apoptosis but it does not affect the CDDP antitumoral activity. Our findings suggest that the affinity of Cls for renal DHP-I make this effect specific for proximal tubular cells and may be related to a reduction in intracellular drug accumulation. Cls administration might represent a novel strategy in the prevention of CDDP-induced acute renal injury. Cls treatment could potentially increase the number of patients undergoing CDDP treatment or maintaining treatment. Further clinical trials for renal function preservation in cancer patients are warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2659. doi:1538-7445.AM2012-2659
Abstract 2662: Racial disparities in the surgical outcomes after esophagectomy for esophageal cancer
Authors: Akateh Clifford , Zhao Lili , Orringer Mark B. , Chang Andrew C. , Lin Jules , Reddy Rishindra M.
Published: August 2012

Introduction: Despite advances in the management of esophageal cancer, African American patients continue to have poorer outcomes following esophagectomy for esophageal cancer. The reasons for this are multifactorial, including access to care and cultural perceptions of treatments. For those patients who underwent esophagectomy, we sought to evaluate if there were disparities in outcomes for African American patients. Method: We identified African American and Caucasian patients who underwent esophagectomy for esophageal cancer at a single, high volume institution. from 1974 to 2011. Using Chi-square and Fisher's exact test, we evaluated for differences in perioperative risk factors, postoperative complications and long term survival. Results: 2090 (2.7% African Americans, 97.3% Caucasians) patients were included in the study. No significant difference was seen in anastomotic leaks, chylothoraces, hoarseness, or other postop complications. However, more African Americans were sent to the intensive care unit during their postop hospitalization (62% versus 46%, p= 0.02). In addition, African Americans had a significantly longer hospitalization compared to their Caucasian counterparts (19 versus 12 days, p<0.0001). This difference persisted even after adjusting for histology, preoperative staging, age, gender, alcohol and tobacco use. Squamous cell cancer was more likely to be seen in African Americans than in Caucasians (79% versus 20% respectively, p<0.0001). Adenocarcinoma was more often seen in Caucasians than African Americans (78% vs 21%, p<0.0001) as were Barrett's changes (33% versus 10%, p=0.003). Despite the longer hospitalizations, there was no significant difference in the long term survival (weeks) between African Americans and Caucasians. Conclusion: African Americans have equal survival to Caucasians after esophagectomy for esophageal cancer at single, high volume institution. Despite having longer hospitalizations with more ICU admissions after surgery, there were no significant differences in postoperative complications or long term survival based on race. Differences in outcomes in patients with esophageal cancer may be related to initial access to care, but there doesn't appear to be a difference in outcomes once patients proceed to surgery at an experienced center.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2662. doi:1538-7445.AM2012-2662