bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 250: Vinculin is a putative amplification target gene at 10q22 in advanced prostate cancer
Authors: Ruiz Christian , Gonzales Irma M. , Oeggerli Martin , Schneider Sandra , Kiefer Jeffrey A. , Mousses Spyro , Barrett Michael T. , Azorsa David O. , Bubendorf Lukas 
Published: February 2011

Abstract
Patients with advanced prostate cancer are usually treated with androgen withdrawal. Although this therapy is effective at the beginning, nearly all prostate cancers become refractory to it. Approximately 15% of these hormone-refractory prostate cancers contain a genomic amplification at 10q22. Aim of this study was to explore the structure of the 10q22 amplicon and to determine the major driving gene.
We applied high-resolution array-CGH using the 244k Agilent microarrays to cell lines harboring 10q22 amplification. We identified a common amplified region (CAR) and silenced each of the 26 genes in this region by an RNAi screen in the prostate cancer cell lines PC-3 and 22rv1. Genes with a significant growth reduction in the 10q22 amplified cell line PC-3 but not in the non-amplified 22rv1 cells were selected as putative candidate genes of this amplicon. They were further investigated in vivo by functional assays and in vitro by immunohistochemical analysis of the protein expression in more than 500 human prostate cancers on a tissue microarray (TMA).
We could narrow down the CAR to a region of 5.8 Mb. The siRNA screening experiments revealed Vinculin (VCL) as the most promising candidate gene of this amplicon. Immunohistochemical analysis of the Vinculin protein expression on a TMA enriched for 10q22 amplified prostate cancers showed a strong association between VCL gene amplification and overexpression (p &lt; 0.001). Further analysis of 443 specimens from across all stages of prostate cancer progression showed that Vinculin expression was highest in hormone-refractory prostate cancers, but negative or very low in benign prostatic hyperplasia (p &lt; 0.0001). Notably, high tumor cell proliferation measured by Ki67 expression was significantly associated with high Vinculin expression in prostate cancer (p &lt; 0.0001). Although there are countless reports on Vinculin as a cytoskeletal protein, its role in prostate cancer has previously not been investigated. Our data strongly suggest Vinculin as a major driving gene of the 10q22 amplification in prostate cancer and that Vinculin overexpression might contribute to prostate cancer progression by enhancing tumor cell proliferation.
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 250.
Abstract 2513: Arsenic trioxide induces depolymerization of microtubules in an acute promyelocytic leukemia cell line
Authors: Min Young Joo , Cha Seung Joo , Lee Hee-Soon , Baek Jin Ho , Park Min Jae , Kim Hawk , Park Jae-Hoo , Park Keon Uk , Won Jong-Ho 
Published: February 2011

Abstract
Arsenic trioxide (ATO) treatment has been used in recent decades to achieve clinical remission in patients with acute promyelocytic leukemia (APL). The biological basis for ATO treatment has been explained as being mediated through anti-proliferation, anti-angiogenesis, and apoptosis in both APL and solid tumor cells. Arsenic trioxide has been shown to affect microtubules such that dysfunction of the cellular cytoskeleton is induced, which ultimately leads to cell death. In this study, we reported that ATO disrupts tubulin assembly and results in microtubule dysfunction, inducing cell death in an APL cell line. ATO markedly enhanced the depolymerization of microtubules. Analysis of posttranslational modifications of microtubules also revealed that ATO decreased modified forms of the polymerized tubulin portion in adose-dependent manner. Immunocytochemical investigation showed that ATO changed the cellular microtubule network and inhibited the formation of polymerized microtubules. These alterations in microtubules suggest that ATO increases the depolymerized form of tubulin in the cells, potentially through its effect on the attenuation of spindle dynamics.
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 2513.
Abstract 2517: Pharmacodynamic biomarkers for ARQ 736, a small molecule BRAF inhibitor
Authors: Yu Yi , Zhao Xiaolan , Gu Xiubin , Chang Edward , Cousens Laura , Chiesa Erin , Lowe Deirdre , Liu Yanbin , Bull Cathy O. , Waghorne Carol G. , Chan Thomas C.K. 
Published: February 2011

Abstract
The MAPK/ERK pathway is a cascade of serine/threonine protein kinases activated by various extracellular factors to control cell growth, differentiation, migration and death. A number of somatic mutations occur that lead to constitutive activation of this pathway in multiple human cancers. BRAF mutations were detected in over 60% of melanomas and may account for a significant proportion of colon cancer patients whose tumors are resistant to anti-EGFR therapy. ARQ 736 is a novel inhibitor of BRAF and is selectively potent in killing cancer cell lines harboring at least one mutated BRAF allele. The objective of this study is to identify potential protein biomarkers for use in connection with ARQ 736 treatment. A number of proteins released by BRAF (V600E) mutant A375 human melanoma cells into conditioned media detected by antibody arrays (R&D human angiogenesis array ARY007 and human cytokine array ARY005) are reduced following exposure to ARQ 736. These effects were not seen in the ARQ 736-resistant cell line DLD1, a k-ras mutant colon carcinoma line. Potential protein biomarkers identified include GM-CSF, Serpin E1, VEGF, amphiregulin, IGFBP-2, IGFBP-3, pentraxin-3 and IL-8. To investigate whether changes in secreted proteins observed in vitro in response to ARQ 736 treatment could be recapitulated in vivo, a similar analysis of plasma was performed at the termination of an A375 human tumor xenograft study. In this study, ARQ 736 administered intraperitoneally at 300 mg/kg on a Q1Dx13 schedule resulted in a 54% inhibition of growth of A375 human melanoma tumor xenografts. Constant administration of ARQ 736 by Alzet osmotic mini-pumps resulted in a 77% inhibition of tumor growth. Pharmacodynamic evidence of BRAF inhibition by ARQ 736 was demonstrated by a reduction in p-ERK staining of tumors via immunohistochemistry. Plasma from the ARQ 736 treated mice showed a reduction in human angiogenesis and cytokine related proteins relative to the control group. These include GM-SCF, Serpin E1, sICAM, and IL-8. The markedly reduced plasma IL-8 levels in response to ARQ 736 treatment detected by the antibody array were subsequently confirmed with a quantitative ELISA for human IL-8 (6-8 fold reduction). These results provide a basis for future clinical biomarker studies.
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 2517.
Abstract 2531: The selective CCR9 antagonist CCX8037 inhibits CCL25-CCR9-STAT3 mediated proliferation of pancreatic cancer cells
Authors: Lu Jianming , Shen Xiaoming , Mailey Brian , Lowy Andrew M. , Kim Joseph 
Published: February 2011

Abstract
Introduction: We previously reported the expression of CCR9 in pancreatic intraepithelial neoplasia (PanIN) and invasive pancreatic cancer tissues. Here, our objective was to investigate signaling downstream of CCR9 and to determine the anti-proliferative effects of the candidate therapeutic CCR9 antagonist CCX8037.
Methods: PanIN and corresponding invasive pancreatic cancer (5143PDA) and liver metastasis (5143LM) cell lines were derived from Pdx-1-Cre;LSL-K-rasG12D and Pdx-1-Cre;LSL-K-rasG12D/p53R172H mice. In culture, murine and human pancreatic cancer cells (PANC-1) were exposed to CCL25, the specific CCR9 ligand. The phosphorylation of STAT3, an established regulator of pancreatic cancer proliferation, was measured by Western blot assay and proliferation assays were performed with the small molecule CCX8037 and the JAK/STAT inhibitor AG490.
Results: First, we verified that exposure to CCL25 enhanced cell proliferation (20%-40%) in both murine and human pancreatic cancer cells. To investigate CCL25/CCR9 signaling, we exposed cells to CCL25 and observed increased phosphorylation of STAT3 in the cells. Blockade of STAT3 signaling with AG490 abrogated CCL25/CCR9-mediated proliferation in both murine and human pancreatic cancer cells. Pre-treatment of PanIN and pancreatic cancer cells with CCX8037 blocked CCL25-mediated phosphorylation of STAT3 and inhibited CCL25-mediated cell proliferation.
Conclusion: Our study demonstrates for the first time that the CCL25/CCR9 axis activates downstream STAT3 signaling to mediate proliferation in murine and human PanIN and pancreatic cancer cells. Additionally, our data shows that the candidate therapeutic agent CCX8037 effectively blocks CCL25/CCR9-mediated proliferation in pancreatic cancer and warrants investigation 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 2531.
Abstract 2534: Suppression of prostate cancer growth by the Src signaling inhibitor, KXO1 (KX2-391)
Authors: Bu Yahao , Gao Lingqiu , Hangauer David , Gelman Irwin H. 
Published: February 2011

Abstract
KXO1 (KX2-391), developed as a Src tyrosine kinase signaling inhibitor, exhibits anti-proliferative activity against broad range of human cancer types in vitro, and has shown low toxicity in completed Phase I trials. We tested whether human and mouse prostate cancer (CaP) cell lines, which display activated levels of Src-family tyrosine kinases such as Src, Fyn and Lyn, could be inhibited by KXO1 compared to the broad tyrosine kinase inhibitor, Dasatinib (BMS-354825). Low nanomolar concentrations (9-75 nM) of KXO1 potently inhibited the proliferation of human CaP cell lines LNCaP, LNCaP-C4-2, PC3-LN4, LAPC-4 and DU145, and the CaP cell line, C2H, isolated from a castration-recurrent lesion in TRAMP mice. In contrast, whereas the GI50 of Dasatinib was equal to KXO1 for PC3-LN4 cells (9 nM), the GI50 for Dasatinib in LNCaP and DU145 cells was 10- and 2.7-fold higher than for KXO1, and Dasatinib failed to inhibit the proliferation of LNCaP-C4-2 cells at 10 μM. KXO1 exhibited a dose-dependent ability to inhibit anchorage-independent growth (AIG) of PC3-LN4, LNCaP and LNCaP-C4-2 cells. In contrast, Dasatinib caused less than 15% inhibition of AIG (compared to vehicle controls) in these CaP lines. Cell death, as measured by DNA fragmentation (Promega Cell Death ELISA kit), was induced after 24 h of KXO1 treatment (2-10X the GI50) of LNCaP and PC3-LN4 cells, but not induced by Dasatinib at 10X GI50 levels. We then tested the efficacy of KXO1 (vs. vehicle) in immunocompetent mice (C57BL/6) bearing small (∼150 mm3) syngeneic TRAMP C2H tumors using several treatment regimens that delivered 10 mg/kg/mouse/day. Mice receiving constant oral dosing (drinking water containing KXO1 in 5% sucrose) showed a 35-40% decrease in tumor growth rate, whereas mice dosed by oral gavage once or twice daily showed initial tumor growths followed by regression. Data will be shown comparing the efficacy of KXO1 against C2H tumors in immunocompetent versus SCID mice. Thus, KXO1 shows anti-CaP activity n vitro and in vivo irrespective of p53, AR or androgen-responsive status. Taken together, these data demonstrate strong preclinical evidence for the treatment of androgen-responsive and castration-recurrent CaP with KXO1.
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 2534.
Abstract 2544: Analysis of the mechanism for acquiring resistance to 5-FU in gastric cancer cell lines
Authors: Nakamura Ayako , Hayashi Kazuhiko , Nakajima Go , Kuramochi Hidekazu , Okuyama Ryuji , Kamikozuru Hirotaka , Yamamoto Masakazu 
Published: February 2011

Abstract
Background 5-Fluorouracil (5-FU) still remains the key drug for the treatment of gastric cancer. Thus, analysis of the mechanism for acquiring resistance of gastric cancer cells to 5-FU and the development of effective chemotherapy for 5-FU-resistant gastric cancer are important.
Methods From the parent human gastric cancer cell lines (MKN45, MKN74, KATOIII and NCI-N87), we established several 5-FU-resistant cell lines (MKN45/5FU, MKN74/5FU, KATOIII/5FU and NCI-N87/5FU) by continuous exposure of the cells to progressively increasing concentrations of 5-FU over a year. We then compared the sensitivity of the parent cell lines to 5-FU-resistant cell lines by MTT assay. We also quantitatively evaluated the mRNA expression levels of four genes known to be associated with 5-FU metabolism, namely, thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), thymidine phosphorylase (TP), and orotate phosphoribosyltransferase (OPRT), by real-time RT-PCR assay.
Results The IC50 ratio of each 5-FU resistant cell line to its parent cell line was as follows; MKN45/5FU: 10.0; MKN74/5FU: 5.5; KATOIII/5FU: 2.2; NCI-N87/5FU: 4.8. Comparing with the corresponding parent cell lines, the 5-FU resistant cell lines, MKN45/5FU, MKN74/5FU, KATOIII/5FU and NCI-N87/5FU, showed a 0.62, 0.40, 0.37 and 0.56-fold decrease in TS gene expression, respectively. In addition, three of the four resistant cell lines showed a tendency towards increase in the gene expression level of DPD and decrease in that of TP. No significant changes in the expression level of the gene encoding OPRT was noted in any of the 5-FU-resistant cell lines.
Conclusion We established four 5-FU-resistant lines from the corresponding parent gastric cancer cell lines and demonstrated the various changes in the expression profiles of the genes known to be associated with 5-FU metabolism. These results suggest that the mechanism of acquiring resistance to 5-FU may vary among gastric tumors. To identify the genetic characteristics of these resistant cell lines, we propose to analyze the gene expression profiles at several time-points from the beginning of establishment of 5-FU-resistance, using microarray-based technology.
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 2544.
Abstract 2554: Copper transporter 2 (CTR2) is able to transport cisplatin and/or oxaliplatin in drug-resistant cell lines
Authors: Komlodi-Pasztor Edina M. , Murphy Robert , Wilkerson Julia , Fojo Tito 
Published: February 2011

Abstract
The clinical use of platinum (Pt) agents is often compromised by the occurrence of drug resistance. Studies have shown reduced intracellular Pt accumulation in cells resistant to Pt drugs. Copper transporters have been reported to have a role in Pt influx and efflux. While the first member of this family, CTR1, has been shown to transport Pt, the role of the structurally similar CTR2 in Pt transport is unclear. The aim of this study was to assess the role of CTR2 in Pt based drug-transport using KB-3.1 cervical carcinoma cells and its cisplatin (KB-CP20) or oxaliplatin (KB-OX60) resistant subclones. In previous studies we reported that compared to parental cells the resistant cell lines have lower levels of intracellular Pt following cisplatin (CIS) or oxaliplatin (OX) exposure. We transfected parental KB-3.1 cells and its drug resistant sublines with CTR1, CTR2 or both transporters, and incubated cells with either CIS or OX. Intracellular Pt accumulation was not increased in any of the transfected parental KB-3.1 cells. In contrast, KB-CP20 cells transfected with CTR1, CTR2 or both trasnporters accumulated more CIS but not more OX compared to non-transfected KB-CP20 cells; while transfected KB-OX60 cells accumulated higher levels of both CIS and OX compared to non-transfected KB-OX 60 cells. In both resistant cell lines, the increased intracellular Pt observed after transtfection of the transporters was accompanied by increased DNA platination. Given the clinical utility of OX in colon carcinoma we next determined intracellular CIS and OX levels, the expression of proteins involved in copper transport (ATP7A, ATP7B, CTR1 and CTR2), and the IC50 for CIS and OX of six colon carcinoma cell lines. We found an inverse correlation between intracellular Pt levels and the IC50 of both drugs, and correlations between: (1) the IC50 of CIS and expression levels of CTR1, (2) intracellular CIS levels and expression levels of ATP7A, (3) expression levels of ATP7B and CTR2, and (4) OX accumulation and expression levels of ATP7A. In summary, we have shown CTR2 is able to transport Pt-containing drugs and increases intracellular Pt accumulation that is accompanied by greater DNA-platination. In unselected colon cancer cells, we have shown that the IC50 of a Pt based drug is determined by the intracellular accumulation of that drug, and to varying extent by the expression of copper transporters.
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 2554.
Abstract 2557: GSTP1 is a determinant of temozolomiode resistance in human glioblastoma cells
Authors: Singh Simendra , Ali-Osman Francis 
Published: February 2011

Abstract
Temozolomide (TMZ) is a methylating agent used in first-line treatment of malignant gliomas and melanomas. Unfortunately, its use is limited by multifaceted resistance mechanisms. Although, the glutathione S-transferase P1 (GSTP1) protein metabolizes several alkylating and free radical generating anticancer agents, its role in TMZ metabolism and/or tumor resistance to TMZ are not known. In this study, we investigated the potential role of GSTP1-based metabolic detoxification of TMZ in glioma resistance to TMZ. The ability of GSTP1 to metabolize TMZ was assessed indirectly by measuring changes in the level of residual (free, un-metabolized) TMZ in a cell-free system containing TMZ, reduced glutathione (GSH) and human placental GSTP1 protein. We observed a time- and both GSH and GSTP1 concentration-dependent decrease in residual TMZ levels in reaction mixtures containing GSTP1 and after a 6 hr incubation, the level of free TMZ in GSTP1-containing reaction mixtures was decreased to 40% of controls without GSTP1. Presence of GSH alone resulted in only a 10% decrease in residual TMZ. Using three GSTP1 expressing glioma cell lines, viz, MGR1, MGR3 and U87, we examined the effect of siRNA-mediated knockdown of GSTP1 expression on tumor survival to TMZ and the level of TMZ-induced apoptosis using caspase-3/7 activation as endpoint. The TMZ IC50 values for MGR1, MGR3 and U87 of 1.31, 0.91 and 1.06 mM, respectively, were reduced significantly to 0.78, 0.6 and 0.69 mM at 48hrs following GSTP1 knockdown. Similarly, siRNA-mediated knockdown of GSTP1 increased TMZ-induced caspase-3/7 activation, significantly, in all three cell lines when exposed to TMZ for 48 hrs. Experiments evaluating the effect of combined knockdown of GSTP1 and O6-methylguanine-DNA methyltransferase (MGMT) on cellular sensitivity of TMZ suggest synergism between the two strategies. Overall, these results provide support for a pivotal role that GSTP1 may play in glioma cell resistance to TMZ-based chemotherapy and the potential of targeting GSTP1 as part of strategies to reverse this resistance.
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 2557.
Abstract 256: Distinct roles for gain and loss of function p53 mutations in medullary thyroid cancer
Authors: Akeno Nagako , Ma Xiaolan , Wikenheiser-Brokamp Kathryn A. 
Published: February 2011

Abstract
Medullary thyroid carcinoma (MTC) accounts for 5-10% of all thyroid cancers and presents as metastatic diseases in ∼50% of patients. Patients with metastatic MTC are typically incurable because of the poor tumor response to current chemotherapeutics and radiation treatment. MTC occurs as sporadic tumors in ∼75% of cases. The remaining cases are familial and associated with either multiple neuroendocrine neoplasia syndromes or familial MTC syndrome. The Rearranged during Transfection (RET) proto-oncogene plays a key role in MTC development: however, the absence of RET mutations in ∼50% of sporadic cases and the variable clinical manifestations in patients with the same RET mutation provide compelling evidence that other genetic alterations are involved in MTC pathogenesis. Recent studies in human tumors and mouse models suggest that the Rb and p53 pathways cooperate to suppress MTC evolution. Although some p53 mutations cause a loss of function, most p53 mutations detected in human cancers result in expression of a mutant p53 protein which may exhibit gain of function properties. The objective of this study was to identify the function of p53 mutant proteins commonly expressed in human cancers in MTC pathogenesis. A conditional mouse model was generated in which MTC is initiated by Rb inactivation. Using this model, the consequences of p53 mutant protein expression on MTC initiation and progression were compared to p53 deletion. Loss of a single copy of p53 led to accelerated medullary thyroid tumor progression resulting in decreased survival. Loss of both p53 alleles resulted in a markedly more severe phenotype leading to a median survival of 4 months. Expression of the structural p53R172H mutant, but not the DNA contact p53R270H mutant, resulted in accelerated death compared with p53 deletion demonstrating that p53R172H has a gain of function property. Interestingly, mice heterozygous for p53R172H/+ and p53R270H/+ showed similar survival as mice with loss of a single p53 allele providing evidence that neither p53 mutant protein functions in a dominant negative fashion to promote MTC initiated by Rb loss. These results clearly demonstrate that p53 suppresses the progression of MTC initiated by Rb loss and indicate that gain of function p53 mutations confer poorer prognosis than p53 loss. Given the critical roles played by the Rb and p53 pathways in tumor response to therapy, identifying key Rb and p53 functions in MTC pathogenesis is important for future design of therapies to combat these currently treatment resistant malignancies.
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 256.