bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5658: Quercetin induces tumor-selective apoptosis involving downregulation of Mcl-1 and activation of Bax
Authors: Cheng Senping , Chen Gang , Son Young-ok , Luo Jia , Shi Xianglin
Published: February 2011

Quercetin is a promising antitumor agent that induces apoptosis in a variety of tumor cells. However, the underlying mechanisms how this drug works are unclear. Here we report that administration of quercetin in human leukemia cells resulted in marked release of cytochrome c, cleavage of caspase 8, 9, 7 and 3, and apoptosis. Pronounced apoptosis was also noted in diverse primary leukemia cells but not in normal blood peripheral mononuclear cells. These events were accompanied by Mcl-1 down-regulation, most likely through a rapid dephosphorylation of translation initiation factor eIF4E. Following quercetin, Bax protein underwent conformational change and mitochondrial translocation which triggered cytochrome c release. Knockdown Bax by siRNA partially reversed querctin-induced apoptosis. Essentially, knockout of Bax completely abrogated the activation of caspase 9, 7 and 3, PARP cleavage and apoptosis, indicating that Bax is primarily required for quercetin lethality. Ectopic expression of Mcl-1 attenuated quercetin-mediated Bax activation, translocation and cell death. Conversely, interruption of Mcl-1 by siRNA enhanced Bax activation and translocation, as well as lethality induced by quercetin. However, the absence of Bax had no effect on quercetin-mediated Mcl-1 down-regulation. These results suggest that Mcl-1 may operate upstream of Bax. Finally, addition of quercetin increased Bid cleavage. The caspase 8 specific inhibitor prevented Bid cleavage, Bax activation, and subsequent caspase 3 processing. Knockout of Bax had no effect on the processing of caspase 8 and Bid. These observations indicate that Bax activation is also mediated by caspase 8 dependent Bid cleavage upon quercetin treatment. Collectively, these findings demonstrate that quercetin mediates Mcl-1 down-regulation and Bid cleavage which potentiate Bax activation and mitochondrial translocation, events that cooperate to engage the intrinsic and extrinsic apoptotic cascades, and apoptosis.

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 5658.
Abstract 5663: Docosahexaenoic acid protects against UV-induced oxidative stress through upregulation of heme oxygenase-1 and NAD(P)H: Quinone oxidoreductase in mouse epidermal cells
Authors: Park Hyun Jung , Shin Jun-Wan , Surh Young Joon
Published: February 2011

UV radiation is an important environmental factor in the pathogenesis of skin aging and cancer. Exposure of mammalian skin to UV results in oxidative damage, caused by increased cellular levels of reactive oxygen species (ROS). These include DNA breaks, protein inactivation, altered gene expression, loss of membrane lipid-bound essential polyunsaturated fatty acids and apoptosis. Omega-3 fatty acids, which occur at high levels in some fish oils, are known to have ROS scavenging activity and exert protective effects against photoaging and cancer. Their chemopreventive effects against UV-induced carcinogenesis are thought to be mediated through induction of antioxidant / phase 2 detoxifying enzymes, which are involved in elimination of ROS. In our present study, docosahexaenoic acid (DHA), a representative ω-3 fatty acid, significantly up-regulated the expression of two representative antioxidant enzymes, heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase (NQO1) in a time-dependent manner with maximal induction observed at 12 hr and 24 hr, respectively in mouse epidermal JB6 cells. Nuclear factor E2-related factor 2 is a principal transcription factor that plays a pivotal role in the induction of many genes encoding antioxidant and other cytoprotective proteins. DHA (50 μM) treatment enhanced nuclear translocation of Nrf2 and its subsequent binding to antioxidant response element (ARE). DHA treatment increased the activity of mouse HO-1 promoter in JB6 cells as as assessed by the luciferase reporter assay. siRNA knock down of Nrf2 abrogated DHA-induced expression of HO-1 and NQO1. Moreover, DHA pretreatment significantly suppressed intracellular ROS formation in response to UVB. Over expression of HO-1 vector in JB6 cell abolished the ROS generation induced by UVB. These findings, taken together, suggest that DHA exerts protective effects against UVB-induced oxidative stress in mouse epidermal cells through Nrf2-induced expression of HO-1 and NQO1.

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 5663.
Abstract 5667: Identification of chemopreventive agents against dibenzo[a,l]pyrene-induced DNA adducts and potential mechanisms
Authors: Russell Gilandra K. , Vadhanam Manicka V. , Gupta Ramesh C.
Published: February 2011

Intervention with compounds of natural origin with little or no known toxicity is considered an effective means to prevent cancer development. We describe here a microsomal activation system in combination with 32P-postlabeling adduct assay to identify efficacious phytochemicals against the potent lung and breast carcinogen, dibenzo[a,l]pyrene (DBP). Briefly, salmon testes (st)-DNA was incubated with test agents (150 µM), DBP (10 µM), β-naphthoflavone-induced rat liver microsomes, co-factors in Tris. HCl (50 mM, pH 7.4). After incubation for 60 min at 37°C, the reaction was terminated. Analysis of the purified DNA by 32P-postlabeling showed essentially the same spectra of multiple adducts in all samples. However, quantitative differences were observed. Of nine phytochemicals tested, several compounds almost completely abolished the DNA adduct formation, some showed modest inhibition, while others were ineffective: resveratrol (95% reduction), delphinidin (94%), tanshinone I, (84%) tanshinone IIA (78%), diindolylmethane (73%), indole-3-carbinol (49%) and cyanidin (46%) and withaferin A (33%); cucurbitacin B showed insignificant reduction. All adducts were found to be equally inhibited, suggesting that activity of both CYP1A1 and 1B1, the major cytochromes P450s involved in the metabolism of DBP, were similarly affected. Oltipraz included as positive control, as expected, showed over 80-90% inhibition. To determine if the adduct inhibition occurred due to scavenging of electrophilic metabolites of DBP, st-DNA was incubated with the most effective test agents in the presence of anti-dibenzo[a,l]pyrene diolepoxide (anti-DBPDE). Analysis of the resultant adducts showed that only delphinidin, cyanidin and resveratrol showed modest inhibition (30-45%); other compounds were ineffective. Ellagic acid, which is known to scavenge the DBP electrophilic metabolite, almost completely abolished the adduct formation. Together, our data suggest that resveratrol, delphinidin, tanshinones and diindolylmethane are potent inhibitors of microsomal DBP-DNA adduct formation. While, the adduct inhibition for delphinidin and resveratrol may occur, in part, due to scavenging of the electrophilic metabolite of DBP, both these agents, tanshinones and diindolylmethane may also elicit their activity by inhibiting the cytochromes P450 activity. In summary, resveratrol, delphinidin, tanshinones and diindolylmethane, all of which are consumed either in fruits and vegetables or via folklore medicine (tanshinones) may be useful in the prevention of DBP-mediated lung and mammary tumorigenesis (Supported from the USPHS grants CA-118114, ES-011564 and Agnes Brown Duggan Endowment).

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 5667.
Abstract 567: Inhibition of growth and induction of differentiation by apigenin, baicalein and quercetin in colon cancer cells
Authors: Deutsch Jill K. , Lea Michael A.
Published: February 2011

There is considerable data to support the concept that polyphenolic molecules that occur in fruits and vegetables may have beneficial effects as cancer chemopreventive agents. We have shown previously that these polyphenolic molecules can induce enzyme markers of differentiation either alone, or in combination with histone deacetylase (HDAC) inhibitors. These data raise the question whether the induction of enzyme markers for differentiation are due to the anti- or pro-oxidant properties of polyphenols. We have compared the action of three flavonol molecules, apigenin, baicalein, and quercetin on four cell lines derived from human colon cells (Caco-2, SW1116, HT-29, and NCM460). The three polyphenols caused increases in alkaline phosphatase activity but no increase or decrease in aminopeptidase activity in Caco-2 cells. There was no induction of differentiation in the other cell lines by the three polyphenols. Since production of hydrogen peroxide has been reported when some polyphenolic compounds are incubated with serum-containing medium, we examined this phenomenon with the three polyphenols. Production of hydrogen peroxide was greater with baicalein than with quercetin or apigenin. When Caco-2 cells were incubated with hydrogen peroxide, there was some increase in alkaline phosphatase, but the concentrations required were higher than for the polyphenols and the magnitude of the effect was less. Further studies were performed with baicalein because that molecule had resulted in greater production of hydrogen peroxide. To test the significance of the hydrogen peroxide formation, we added catalase, but this addition did not prevent the increase in alkaline phosphatase or the decrease in protein synthesis in Caco-2 cells after incubation with baicalein. In addition, we wanted to determine the potential of the three polyphenols in combination with butyrate to increase the activity of alkaline phosphatase in Caco-2 cells. Synergistic effects were seen for the increase in alkaline phosphatase activity in Caco-2 cells for baicalein and quercetin, but not with apigenin. In conclusion, Caco-2 human colon cancer cells are notably sensitive to growth inhibitory and differentiating effects of apigenin, baicalein, and quercetin. It was evident that these polyphenols can have pro-oxidant effects, but our data suggested that this action was not the sole determinant of growth inhibitory or differentiating effects on colon cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 567.
Abstract 568: Transcriptional repression of SKP2 is impaired in MYCN-amplified neuroblastoma
Authors: Westermann Frank , Henrich Kai-Oliver , Fischer Matthias , Schwab Manfred
Published: February 2011

The cell cycle regulator, SKP2, is overexpressed in various cancers, and plays a key role in p27 degradation, which is involved in tumor cell dedifferentiation. Little is known about the mechanisms leading to impaired SKP2 transcriptional control in tumor cells. We used neuroblastoma as a model to study SKP2 regulation because SKP2 transcript levels gradually increase with aggressiveness of neuroblastoma subtypes. Highest SKP2 levels are found in neuroblastomas with amplified MYCN. Accordingly, we found 5.5-fold (range 2-9.5) higher SKP2 core promoter activity in MYCN-amplified cells. Higher SKP2 core promoter activity in MYCN-amplified cells is mediated through a defined region at the transcriptional start site (TSSR). This region includes a specific E2F-binding site that makes SKP2 activation largely independent of mitogenic signals integrated through the SP1/ELK-1 site. We demonstrate by chromatin immunoprecipitation that SKP2 activation through the TSSR in MYCN-amplified cells is associated with low abundance of pRB-E2F1 complexes bound to the SKP2 promoter. Transcriptional control of SKP2 via this regulatory mechanism can be re-established in MYCN-amplified cells by restoring pRB activity using selective small compound inhibitors of CDK4. In contrast, doxorubicin or nutlin-3 treatment - both leading to p53-p21 activation - or CDK2 inhibition had no effect on SKP2 regulation in MYCN-amplified cells. Together, this implies that deregulated MYCN protein levels in MYCN-amplified neuroblastoma cells activate SKP2 through CDK4 induction, abrogating repressive pRB-E2F1 complexes bound to the SKP2 promoter.

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 568.
Abstract 5698: MicroRNA-31 acts as an oncomir in lung cancer by repressing specific tumor suppressors
Authors: Liu Xi , Sempere Lorenzo F. , Ouyang Haoxu , Memoli Vincent A. , Andrew Angeline S. , Luo Yue , Demidenko Eugene , Korc Murray , Shi Wei , Preis Meir , Dragnev Konstantin H. , Liu Hua , DiRenzo James , Bak Mads , Kauppinen Sakari , Freemantle Sarah J. , Dmitrovsky Ethan
Published: February 2011

MicroRNAs (miRNAs) encode small RNAs that regulate gene expression. The expression profiles of miRNAs have proven useful to improve classification, diagnostic and prognostic information for human cancers. We sought to uncover miRNAs preferentially over-expressed in lung cancers versus adjacent normal lung tissues. We comprehensively interrogated miRNA array expression profiles conducted on lung cancers versus adjacent normal lung tissues isolated from murine transgenic cyclin E models that were engineered. Notably, miR-136, miR-376a and miR-31 were each significantly over-expressed in murine lung cancers as compared to adjacent normal lung tissues. Real-time RT-PCR and in situ hybridization assays independently confirmed these miRNA expression profiles in paired normal-malignant lung tissues from transgenic mice as well as from a well characterized panel of paired human normal-malignant lung tissues. Knock-down of miR-31, but not other highlighted miRNAs, using a synthetic antagonist significantly repressed lung cancer cell growth and in vivo tumorigenicity. Bioinformatically predicted miR-31 target genes were identified and studied. These included two tumor suppressors: large tumor suppressor 2 (LATS2) and PP2A regulatory subunit B alpha isoform (PPP2R2A) that were each substantially increased by miR-31 knock-down and repressed by miR-31 over-expression. Engineered repression of either LATS2 or PPP2R2A significantly antagonized miR-31-mediated growth inhibition. Luciferase binding assays confirmed that miR-31 directly suppressed LATS2 and PPP2R2A through binding to their respective 3′-untranslated regions (UTRs). Interestingly, miR-31 was inversely expressed relative to these identified target genes in both murine and human lung cancers. Clinical relevance was uncovered using miR-31 in situ hybridization and cyclin E immunohistochemistry assays performed on tissue arrays from the population-based New Hampshire Lung Cancer Registry. As expected, cyclin E expression was significantly associated with miR-31 levels. Real-time RT-PCR assays validated LATS2 and PPP2R2A repression in lung cancers versus adjacent normal lung tissues. Thus, these findings implicate miR-31 as an oncogenic miRNA (oncomir) that exerts its effects by repressing specific tumor suppressors. Taken together, miR-31 is proposed as a novel molecular target for lung cancer therapy and chemoprevention.

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 5698.
Abstract 5709: Prevention of colitis-induced carcinogenesis with TNF-α antibody, infliximab; top-down strategy for colitic cancer prevention
Authors: Hahm Ki-Baik , Choi Seok Ryeol , Kim Yoon Jae , Hong Kyung Sook , Chung Joon Won
Published: February 2011

Prevention of colitis-induced carcinogenesis with TNF-α antibody, infliximab; top-down strategy for colitic cancer prevention

Since colitis-associated cancers arise in the setting of chronic inflammation, during which “inflammation-dysplasia-carcinoma” sequence prevails, we investigated whether infliximab can prevent the development of inflammation-associated colon cancer in rat models, for which 6 week old C57BL/6J mice were exposed to 15 cycles of dextran sulfate sodium (DSS) with each cycle consisting of 0.7% DSS for 1 week followed by distilled water for 10days. Infliximab, 4mg/kg, was given intravenously on 1st, 3rd, and 7th week or 25th, 27th, and 31th week after commencement of repeated bouts of colitis to compare cancer preventing effect of “step-up” versus “top-down” strategy. Additionally, molecular changes regarding inflammation and carcinogenesis were compared between colitis cancer group and colitis cancer group treated with infliximab in addition to in vitro documentation of molecular changes in cells. Multiple colorectal tumors developed in 75-80% of control mice, whereas only 16.7% of mice treated with infliximab at 1st, 3rd, and 7th weeks developed colon tumors. This significant reduction in tumor development with earlier administration of infliximab was correlated with significant decreases in serum NO levels, serum and tissue levels of TNF-α, iNOS, and COX-2. The expressions and activities of matrix metalloprotease (MMP)-3, MMP-9, and MMP-11 were significantly decreased in mice treated with infliximab in accordance with attenuated expression of β-catenin accumulated crypts in infliximab treated mice group. However, in repeated set of colitis-induced carcinogenesis experiment, where infliximab was administered at later stage of 25th, 27th, and 31th weeks, no reduction in colon tumor was noted compared to control group. In conclusion, potent anti-inflammatory treatment in the early stage of inflammation could reduce colitis-associated cancer, stratifying the rationale that earlier and intensive therapy with infliximab should be considered for either ameliorating clinical course or preventing colitic cancer in high risk 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 5709.
Abstract 5714: Screening of some tropical Indian plants for their anticancer activity
Authors: Nawab Akbar , Gupta Sanjay
Published: February 2011

Carcinoma of the breast, colon and prostate are highly prevalent malignancies in the Western nations. Although much innovation in diagnosis and treatment of these cancers has been done but no satisfactory treatment options are currently available. New agents are required which can be developed as anticancer drugs. Despite major scientific and technological progress in combinatorial chemistry, plant derived drugs still make an enormous contribution to drug discovery. Tropical plant species namely Artemisia vulgaris (Compositae), Cichorium intybus (Compositae), Smilax glabra (Liliaceae), Solanum nigrum (Solanaceae) and Swertia chirayata (Gentianaceae) are commonly used for medicinal purposes in traditional forms of Indian medicine. Extracts derived from various parts have shown anti-inflammatory and anti-pyretic properties. However, the anticancer property has not been elucidated. We used human cancer cell lines derived from breast (T47-D), colon (RKO) and prostate (PC-3), to conduct our work. Aqueous freeze dried extracts were prepared from inflorescence (Artemisia vulgaris), seeds (Cichorium intybus), rhizome (Smilax glabra), berries (Solanum nigrum) and whole plant (Swertia chirayata) at the doses ranging from 1-1000μg/mL used to determine EC50 value by performing MTT assay. Exposure of aqueous extract obtained from berries of Solanum nigrum for 24-72h caused 40-87% growth inhibition of PC-3 cells and EC50 value determined to be 220μg/mL after 24 h of treatment. Similarly T47-D cells demonstrated 48-79% inhibition (EC50 550μg/mL) and RKO cells exhibited 40-76% inhibition of cell growth and EC50 value determined to be >1000 μg/mL. Furthermore, aqueous extracts of Artemisia vulgaris, Cichorium intybus, Smilax glabra and Swertia chirayata exhibited cell growth inhibition in all three cell lines but the EC50 values determined were >1000μg/mL. Treatment of cells with 500μg/mL doses of various plant extract for 48h exhibited DNA laddering in all three cell lines with Solanum nigrum. To further verify the apoptotic effect Solanum nigrum we investigated changes in the activity of the apoptotic-related proteins: poly (ADP-ribose) polymerase and caspase 3, which were cleaved in all three cell lines suggesting induction of apoptosis through perturbation of apoptotic signal pathway. A mechanistic understanding of the anti-proliferative and anticancer effects of Solanum nigrum remains to be elucidated.

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 5714.
Abstract 5739: Lifetime recreational physical activity, hormone therapy use and breast cancer risk in postmenopausal women
Authors: Dieli-Conwright Christina , Sullivan-Halley Jane , Patel Alpa , Press Michael , Malone Kathi , Ursin Giske , Burkman Ronald , Strom Brian , Simon Michael , Bernstein Leslie
Published: February 2011

Studies consistently demonstrate that physical activity is inversely associated with postmenopausal breast cancer. Whether the strength of this association varies with exposure to menopausal hormone therapy (HT) is clearly important given the marked decline in HT use since 2002. The Women's Contraceptive and Reproductive Experiences Study, a multi-center population-based case-control study of invasive breast cancer recruited white women and black women ages 35-64 years, and collected histories of lifetime exercise activity and HT use. Unconditional logistic regression models assessed possible associations between lifetime exercise activity measures (hr/wk/yr and metabolic equivalents of energy expenditure [MET]-hrs/wk/yr) and breast cancer among postmenopausal women (1908 case patients, 2013 control subjects) stratified by duration of HT use (never, ≤5 years of use, or ≥5 years of use), and current HT-use status (current use of estrogen-alone therapy [ET], current use of estrogen plus progestin therapy [EPT], or past HT use). Breast cancer risk decreased as level of physical activity increased among women who had never used HT, among women who used HT for fewer than 5 years, and among current ET users; Ptrend values ranged from 0.004 to 0.019. Despite the lack of association among long-term HT users, current EPT users, and past HT users, no statistical heterogeneity of trends was observed across duration-of-use categories or by current-use status. Although the inverse association between physical activity and breast cancer was limited to women with no HT use, short duration of HT use or current ET use, this study did not demonstrate effect modification by HT use.

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 5739.
Abstract 5749: Birth weight and sex hormones in adolescent girls: Results from the Dietary Intervention Study in Children (DISC)
Authors: Ruder Elizabeth H. , Hartman Terryl J. , Rovine Michael J. , Dorgan Joanne F.
Published: February 2011

The purpose of the present study is to explore the association of birth weight and concentrations of sex hormones (serum estrogens, progesterone, androgens and sex hormone blinding globulin (SHBG)) among girls participating in the Hormone Ancillary Study (HAS) of the Dietary Intervention Study in Children (DISC), a randomized controlled clinical trial to evaluate the effect of a reduced fat diet intervention on serum hormones. Serum was collected at 5 points during the study and captured the participants’ before, during, and after puberty. Of the 301 girls in DISC, 263 participated in the HAS and had a reported birth weight. Hormones were measured by radioimunnoassay and SHBG was measured by an immunoradiometric assay. Mixed linear regression models were used to calculate hormone concentrations during follow-up after controlling for potential covariates including DISC intervention assignment. Preliminary results for 203 participants suggest an inverse association of birth weight and concentration of DHEAS throughout the 7 years of follow-up after adjusting for years until/ since menarche and other covariates (P ≤ 0.05). An inverse association between birth weight and pre-menarche concentration of androstenedione was observed (P ≤ 0.05), but the relationship did not maintain statistical significance after adjusting for years until menarche (P ≤ 0.24); suggesting that effect of birth weight on pre-menarche androstenedione concentrations may occur in part via the association of birth weight and age at menarche. Post-menarche concentrations of SHBG were positively associated with birth weight, independent of years since menarche (P ≤ 0.05) and other covariates. Luteal phase estradiol, free estradiol and estrone concentrations were positively associated with birth weight, independent of years since menarche and other covariates (P = 0.04, 0.03, 0.05 respectively). No association was found among the other hormones under investigation or the follicular phase estrogens. In conclusion, these data suggest that pre-menarche androstenedione concentration may be inversely associated with birth weight, but this association is likely mediated by the relationship of birth weight and age at menarche. Conversely, the relationships between birth weight and DHEAS, post-menarche SHBG, and certain luteal phase estrogens appear to be independent of the effect of birth weight on age at menarche. Although untested, it is possible that birth weight, as a proxy for in utero hormone exposure, could potentially influence breast cancer risk via long-term effects on pubertal sex hormones on breast tissue development.

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 5749.
Abstract 5778: Fragment-based drug discovery of selective inhibitors of fibroblast growth factor receptor (FGFr)
Authors: Saxty Gordon , Squires M S. , Murray C W. , Berdini V , Ward G A. , Miller D , Rich S J. , Cleasby A , Saalau-Bethell S M. , Coyle J , Madin A , Carr M G. , O'Brien M A. , Jones C Griffiths , Vickerstaff E , Nijjar R K. , Graham B , Pike A , Lewis E J. , Perera T , Angibaud P , Newell H
Published: February 2011

Recent data in a number of tumour types has implicated Fibroblast Growth Factor (FGF) and Fibroblast Growth Factor receptor (FGFr) signalling as being key to the molecular pathology of cancer. This poster will describe fragment based drug discovery using biophysical screening to identify initial fragments. Subsequently, in the fragments-to-leads stage a detailed structural understanding of the binding interactions between the fragment and its target protein utilised X-ray crystallography and NMR. Starting with different fragments allows several lead series to be identified, often by synthesizing only small numbers of compounds.

A fragment screening campaign was conducted against the FGFr-1 to detect very low molecular weight compounds that bound to the hinge region of the kinase. The screening produced several fragment molecules (Molecular Weight <250 Da) which were in the micromolar range and confirmed binding mode in X-ray crystallography. One X-ray hit series that was 120 uM verse FGFr-3 will be described. Several iterations of structure-guided medicinal chemistry led to the identification of a lead compound with 3 nM affinity for FGFr-3, good cell activity and 30-fold selectivity verse VEGFr-2 with good oral activity. The lead was optimised to afford a compound that showed good PK/PD and efficacy.

This poster represents first disclosure of the structure of the lead series and illustrates how a fragment-based drug discovery approach can be efficiently used to discover compounds advanced nanomolar compounds with oral bioavailability.

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 5778.
Abstract 578: Combination of 4-HPR and EGCG induces apoptosis and inhibits angiogenesis and tumorigenesis of neuroblastoma SH-SY5Y and SK-N-DZ cells
Authors: George Joseph , Banik Naren L. , Ray Swapan K.
Published: February 2011

Neuroblastomas are extracranial, malignant solid tumors in childhood with a dismal prognosis. N-(4-Hydroxyphenyl) retinamide (4-HPR) is a synthetic retinoid that induces apoptosis in tumor cells. (-)-Epigallocatechin-3-gallate (EGCG) is a potent antioxidant abundant in green tea with anticancer properties. In the present investigation, we have studied the combined effect of 4-HPR and EGCG to induce apoptosis and to inhibit angiogenesis and tumor progression of human neuroblastoma malignant SH-SY5Y and SK-N-DZ cells in vivo. The cells were treated with 1 μM 4-HPR, 10 μM EGCG, or combination of both and subjected to MTT assay and TUNEL staining. Western blotting was performed for molecules involved in both receptor and mitochondria mediated apoptotic pathways. Angiogenesis and subcutaneous tumor growth studies were performed in immunocompromised mice. Treatment with combination of 4-HPR and EGCG resulted in more than 70% apoptosis and 80% inhibition in cell proliferation in both cell lines. Apoptosis was associated with induction of both receptor and mitochondria mediated pathways. Our in vivo angiogenesis studies demonstrated significant inhibition of neovascularization after treatment with either agent alone and complete inhibition after treatment with combination of both agents. Studies also demonstrated marked suppression of subcutaneous tumorigenesis and solid tumor formation after treatment with combination of 4-HPR and EGCG. In conclusion, our studies demonstrated that treatment with combination of 4-HPR and EGCG effectively induced apoptosis and inhibited cell proliferation, angiogenesis, and growth of neuroblastomas in vivo. Therefore, the combination of 4-HPR and EGCG could be used as a potential therapeutic regimen for effectively controlling the growth of human malignant neuroblastomas. This investigation was supported in part by the R01 grants (NS-57811 and CA-91460) from the National Institutes of Health (Bethesda, MD).

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 578.
Abstract 599: Development of poly(Asp-DET) cationic polymers for nonviral gene delivery
Authors: Mirosevich Janni , Cardoen Gregoire , Sill Kevin , Burke Brian
Published: February 2011

Cationic polymers have received much attention as promising non-viral vectors for gene transfer. However, identification of polymers able to systemically deliver nucleic acids continues to be a significant hurdle to the success of this methodology. The purpose of this study was to develop a new biocompatible and biodegradable cationic polymer system as a non-viral gene delivery agent for plasmid DNA.

Poly-aspartate-diethylene triamine (“P(Asp-DET)”) polymers were synthesized and utilized to complex plasmid DNA. The resulting polymer/DNA complexes, also known as “polyplexes,” were further modified by covalent coupling with polyethylene glycol (PEG), known as “PEGylation,” and characterized. Polyplexes were evaluated for efficiency of encapsulation, particle size, zeta potential and morphology by TEM. Stability of the complexed plasmid DNA was assessed by challenging polyplexes with nucleases. Efficacy of DNA delivery and gene expression was examined by performing transfection experiments using HCT-116 cells. In vivo DNA delivery was also investigated using tumor-bearing nude mice.

Asp-DET polymers were found to bind to plasmid DNA with polymer to DNA (+/-) charge ratios of above 1.5. In addition, these polymers formed polyplex particles of approximately 50-150 nm with zeta potentials between neutral and +40 mV. TEM showed that the polyplexes were uniform and spherical in shape. It was also demonstrated that the polyplexes maintained the structural integrity of DNA following incubation in nucleases. The polyplexes were also capable of transfecting HCT-116 culture cells, with non-PEG complexes having significantly higher GFP and luciferase expression. Tail vein injections of post-PEGylated polyplexes into tumor bearing nude mice did not reveal any observable toxicities. Notably, nucleic acid accumulation was found in tumors with expression detected in lymph nodes.

P(Asp-DET) cationic polymers show enormous potential as non-viral drug delivery agents. Further, the surface modification of described polyplexes with PEG allowed for systemic delivery of nucleic acids to tumors. The characterization of post-PEGylated Asp-DET/DNA polyplexes provides insights that can be used to design vectors for targeted nucleic acid delivery.

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 599.
Abstract 624: Synergistic effects of combining the Akt inhibitor triciribine with erlotinib in EGFR TKI-resistant NSCLC
Authors: Gills Joell J. , Morrow Betsy , Kawabata Shigeru , Mercado Jose , Hennessy Bryan , Kunnumakkara Ajaikumar B. , Pao William , Dennis Phillip A.
Published: February 2011

EGFR tyrosine kinase inhibitors (TKIs) are clinically useful agents for the treatment of NSCLC, yet resistance ultimately develops. In an effort to develop strategies to combat resistance and prolong patient benefit, EGFR TKIs were combined with the Akt inhibitor triciribine in a panel of EGFR TKI-resistant NSCLC cell lines. The combination synergistically reduced proliferation in cells that expressed a variety of resistance mechanisms, including intrinsic EGFR T790M mutations, K-Ras mutations, and Met amplification. The combination of erlotinib and triciribine significantly increased apoptosis in H1975 and H1650 cells. It also decreased the phosphorylation of Akt and PRAS40, C-Raf, MEK, and ERK to a greater extent than either drug alone. Unbiased analysis using reverse phase lysate arrays confirmed decreased activation of PI3K/Akt pathway components as well as ERK. The effect of the combination appeared to depend on downregulation of Akt, since a constitutively active form of Akt abrogated the decreased proliferation and increase in cell death caused by the combination. In vivo, the combination inhibited the growth of H1975 xenografts to a greater extent than either drug alone. When tested in an invariably progressive, transgenic model of EGFR-driven lung tumorigenesis (EGFR L858R/T790M), the combination did not cause regression of tumors but stabilized disease in approximately 80% of mice. We conclude the combination of triciribine with EGFR TKIs is promising and should be explored clinically, and that combining inhibitors of the PI3K/Akt pathway with EGFR TKIs may be a useful strategy to overcome EGFR TKI 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 624.
Abstract 647: Xenograft Models of Breast Cancer: the Link between Characteristics of Biomarker Expression and the Anti-tumor Effect of the Representative Therapies
Authors: Zhang Juan , Guan Ziqiu , Song Xiaoming , Chen Taiping , Wery Jean-Pierre , Chen Yiyou
Published: February 2011

Gene expression analysis has led to the identification of 5 subtypes of breast cancer (basal-like, HER2-like, luminal A and B, and normal-like) that have distinct biological features, clinical outcomes, and responses to conventional chemotherapy and targeted therapy. Animal models possessing genetic and other biomarker abnormalities similar to each subtype of the human counterpart are thus of crucial importance in the development of new therapeutic strategies. Human breast cancer xenograft model is one of the more difficult models with transplantation of either established cell lines or primary tumors. We have successfully established 6 xenograft models derived from established cell lines and 2 xenograft models by transplanting primary human tumor fragments. The immunohistochemical results classified the 9 models into 4 major groups: ER negative and HER2 negative (MX-1, MDA-MB-231, MCF-7-CB1, and SKBR3-CB1), ER negative and HER2 positive (BT-474-CB1), ER positive and HER2 negative (MCF-7), and ER positive and HER2 positive (BT-474), which well resembled basal-like/normal-like, HER2-like, luminal A, and luminal B breast cancer types in human. The mutation status of TP53, BRCA1, BRCA2 and EGFR was investigated, and compared with the in vivo efficacy results by using various test drugs including cytotoxic agents, paclitaxel and doxorubicin; ER antagonist, tamoxifen; anti-HER2 monoclonal antibody, trastuzumab; HER2 inhibitor, HKI-272 and EGFR inhibitor, erlotinib. These data closely mimicked the heterogeneity in clinical outcomes of the human disease. Therefore, these models provide valuable platform for the development of personalized therapy for breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 647.
Abstract 660: Clinical significance of FGFR2 amplification in gastric cancer
Authors: Park Joon Oh , Lee Jeeyun , Jang Hye-Lim , Jang Jiryeon , Park Se Hoon , Park Young Suk , Lim Ho Yeong , Kang Won Ki
Published: February 2011

Background: The fibroblast growth factor receptor (FGFR) tyrosine kinase family, which is comprised of four kinases that differentially respond to 18 FGF ligands, has long been implicated in cancer. Among them, activating somatic mutations in FGFR2 have been recently identified in several types of human cancer and are shown to be sensitive to FGFR2 kinase inhibition in the cell lines bearing such FGFR2 mutations, implicating FGFR2 as a novel therapeutic target. Therefore, we undertook this study to understand the clinical impact of FGFR2 amplification on gastric cancer patients. Patients and Methods: FGFR2 amplification was tested by qPCR using TaqMan probe and dual-color FISH in a panel of 37 gastric cancer cell lines and tumor specimens from 482 gastric cancer patients. Results: Of the 482 patients, 119 (24.8%) of the patients had FGFR2 copy number greater than 3.0 copies. FGFR2 amplification was not associated with clinicopathological parameters such as age, sex, histology, Bormann type, Lauren Classification, tumor location and TNM staging. Patients with FGFR2 amplification showed a trend toward shorter DFS (5-year DFS; 49.6% vs. 59.6%; FGFR2 amplification (+) vs. FGFR2 amplification (-); P=.065) and poorer survival (5-year OS; 47.9% vs. 58.41%; P=.084). We are currently performing preclinical study to investigate FGFR2-correlated sensitivity to several types of molecular-targeted agents. Conclusion: These results suggest that the FGFR2 amplification plays an important role in determining prognosis in gastric cancer patients. However, this study did not cover a predictive role of the FGFR2 amplification for the treatment response to FGFR2 kinase inhibitors, which should be further explored as a novel therapeutic target in upcoming clinical trials.

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 660.
Abstract 695: LA480, a c-Met antibody with neutralization and internalization properties, inhibits HGF-dependent and HGF-independent c-Met pathway activation and tumor growth
Authors: Wortinger Mark A. , Zeng Wei , Yang Wei Jennifer , Peek Victoria , Yan Lei , Lu Jirong , Chow Chi-Kin , Vaillancourt Peter , Davies Julian , Denning Irene , Weir Spring , Wooldridge James , Liu Ling
Published: February 2011

c-Met is a receptor tyrosine kinase that binds hepatocyte growth factor (HGF) and has been implicated in human cancer. Inappropriate activation of c-Met can be induced by ligand-independent mechanisms such as gene amplification, specific genetic mutations, and transcriptional upregulation, or by ligand-dependent autocrine or paracrine mechanisms. Indeed, amplification of the c-Met gene, with consequent protein overexpression and constitutive kinase activation, has been reported in a number of human cancers, including gastric, esophageal and non-small-cell lung carcinomas. Activating mutations of the c-Met gene have been found in a subset of patients with hereditary and sporadic papillary renal cancer, lung cancer, childhood hepatocellular carcinoma and gastric carcinoma. Another common constitutive c-Met activation in human tumors is increased protein expression as a consequence of transcriptional upregulation, in the absence of gene amplification. c-Met expression level has been correlated with poor prognosis in multiple tumor types. In addition, cMet activation by an elevated level of HGF has also been described in gliobastoma, breast carcinomas, rhabdomyosarcoma and osteosarcoma. We report here that LA480, a humanized monoclonal c-Met antibody, inhibits HGF-dependent and HGF-independent c-Met pathway activation and tumor growth. Our data demonstrate that LA480 blocks binding of HGF to c-Met as shown by ELISA, blocks HGF stimulation of phospho-Met in HCT116 cells, and blocks HGF stimulation of primary human hepatocyte proliferation. Moreover, LA480 internalizes and depletes cell surface c-Met, significantly reduces phospho-c-Met and total c-Met in multiple tumor cell lines, and inhibits proliferation of tumor cell lines that have c-Met gene amplification. In addition, LA480 does not stimulate biological activities that are elicited by HGF. Furthermore, LA480 reduces total c-Met and phospho-Met in xenograft tumors and significantly inhibits tumor growth in both ligand-independent and ligand-dependent mouse xenograft models. These findings suggest that LA480 may be a promising therapy for treatment of cancers driven by ligand-dependent and ligand-independent c-Met activation.

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 695.
Abstract 702: RON receptor tyrosine kinase: A potential therapeutic target in malignant pleural mesothelioma
Authors: Gray Steven G. , Easty David , Nonaka Daisuke , Soltermann Alex , Murer Bruno , Kennedy M John , O'Donnell Dearbhaile M. , Mutti Lucciano , Pass Harvey I. , O'Byrne Kenneth J.
Published: February 2011

BACKGROUND: Expression of receptor tyrosine kinases (RTK) and their cognate ligands has been described in mesothelioma, leading to the hypothesis that autocrine growth pathways could be therapeutic targets of tyrosine kinase inhibitors (TKIs).

METHODS: Phospho-RTK arrays were used to evaluate phosphorylation of 42 RTKs in 4 mesothelioma cell lines and 11 mesothelioma surgical specimens. Western Blot analysis, IHC, cellular migration and invasion assays were performed.

RESULTS: Tumours contained 14 phospho-RTKs. RON emerged as a frequently identifed kinase which has not been previously reported in mesothelioma. An extended panel of sixteen mesothelioma tumour and five benign pleural tissue samples were characterised by western blot analysis. The presence of RON message was confirmed by RT-PCR with specific primers in mesothelioma cell lines Western blot analysis detected RON in 16 tumours and 4 cell lines but not in the SV-40 transformed normal mesothelial MET-5A cells. Mesothelioma expressed different isoforms of RON compared to benign pleural plaques: both benign pleural plaques and mesotheliomas expressed the shortform of RON (sf-RON), whereas, the larger RON variants, Δ160 and Δ165, were seen in mesothelioma samples.

IHC was subsequently carried out on a large series of FFPE samples (n>400), with clinical followup to determine if RON expression correlates with prognosis or response to therapy. Scratch assays using antibodies directed against RON prevented MPM cell line migration

CONCLUSIONS: Mesothelioma contains multiple activated RTKs including RON. Previously, RON was shown to mediate epithelial mesenchymal transition (EMT). This may be significant given the epithelioid to sarcomatoid spectrum of mesothelioma. Expression of Δ160 and Δ165 was previously reported in gastric and colorectal cancers and may be associated with oncogenesis. RON has been identified as a therapeutic target in pancreatic cancer and this may also apply in mesothelioma. Functional studies on targeting RON in mesothelioma are ongoing.

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 702.