bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4376: Biological, biochemical, and molecular targets for dietary catechin-induced suppression of breast cell chronic carcinogenesis
Authors: Rathore Kusum , Song Xiaoyu , Siriwardhana Nalin , Wang Hwa-Chain R.
Published: February 2011

This study is to identify biological, biochemical, and molecular targets for dietary catechins in early prevention of breast cell carcinogenesis induced chronically by environmental carcinogens. Breast cell carcinogenesis is a multiyear, multistep, and multipath disease process and is the most common type of cancer among women in northern America and northern Europe. Epidemiologic and experimental evidence suggests that dietary constituents in fruits and vegetables prevent human cancers; dietary prevention is a cost-efficient strategy to reduce the risk of this disease. However, the mechanisms for dietary prevention of cellular carcinogenesis induced by chronic exposure to environmental carcinogens remain to be elucidated. To identify dietary components for prevention of chronic human breast cell carcinogenesis, we studied biological, biochemical, and molecular target endpoints that were induced by low doses of carcinogens and suppressed by dietary catechins. Immortalized, non-cancerous human breast epithelial MCF10A cells were repeatedly exposed to carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and/or benzo[α]pyrene (B[α]P), each at picomolar concentrations, to induce cancer-associated biological, biochemical, and molecular properties in cells. We then used these changes as target endpoints to reveal the activity of various dietary catechins in suppression of NNK- and B[α]P-induced cellular carcinogenesis. We identified that cells acquiring the biological properties of reduced dependence on growth factors, anchorage-independent growth, and acinar-conformational disruption were reduced by treatment with dietary catechins. We identified that hydroxysteroid (11-beta) dehydrogenase 2 (HSD11B2) played a novel role in NNK- and B[α]P-induced cellular carcinogenesis, and its expression acted as a molecular target endpoint in catechin-induced suppression of cellular carcinogenesis. The ability of catechins to reduce gene expression of cytochrome P450 enzymes CYP1A1 and CYP1B1, which can bioactivate NNK and B[α]P, may be involved in the preventive mechanism for catechins in suppression of cellular carcinogenesis. Our model system with biological, biochemical, and molecular target endpoints verified the value of dietary catechins for prevention of human breast cell carcinogenesis induced by repeated exposures to low doses of multiple environmental carcinogens.

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 4376.
Abstract 438: Hif-2α expression and radioresistance of cervical cancer
Authors: Kim Min Kyu , Kim Tae Joong , Choi Chel Hun , Lee Jeong Won , Lee Je Ho , Bae Duk Soo , Kim Byoung Gie
Published: February 2011

ABSTRACT

Objective: Hypoxia is now established as a key factor influencing the pathophysiology of malignant growth. Hypoxia-induced changes in gene expression are coordinated mainly by the hypoxia-inducible factor-1(HIF-1α) and HIF-2α. The aim of this study was to determine whether HIF-2α expression is associated with survival and response to radiation in cervical cancer.

Methods: After reviewing the medical records of 119 patients treated in our institution by primary radiotherapy for stage IIB-IVA cervical cancer, we performed a case-control study. Cases (n = 12) were selected from patients with local recurrence or radiation failure after primary radiation therapy with or without concurrent chemoradiation. For each case, we selected two controls from patients who showed no local recurrence. Using pretreatment paraffin-embedded tissues, we evaluated expression of HIF-2α by immunohistochemistry. Staining was scored based on intensity (Intensity Score (IS) 0- 3) and proportion (Proportion Score (PS) 0-100). Results were analyzed by Student t-test, Mann-Whitney U test, Fisher's exact test, and Cox proportional hazards regression model.

Results: HIF-2α expression representing degree of hypoxia has a relationship with poor response to radiotherapy.

Conclusion: HIF-2α expression may have an important role in radioresistance in locally advanced cervical cancer.

Key Words: Cervical neoplasm, Radiation, HIF-2α, Survival, Hypoxia

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 438.
Abstract 4380: Cadmium-induced toxicity in human liver carcinoma (HepG2) cells: Involvement of oxidative stress, phosphatidylserine externalization, and nucleosomal DNA fragmentation
Authors: Skipper Anthony C. , Yedjou Clement , Ndebele Kenneth , Tchounwou Paul B.
Published: February 2011

Human liver carcinoma (HepG2) cells were used as a test model to evaluate the in vitro cytotoxicity of cadmium and to determine whether oxidative stress plays a key role in cadmium induced apoptosis. To achieve this goal, we performed the MTT assay to measure cell viability and lipid peroxidation to determine the level of oxidative cell/tissue damage. The annexin V assay and DNA fragmentation analysis were performed for early and late apoptosis, respectively. The results of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a dose-dependent manner, showing a 24 h-LD50 of 3.6 µg/mL. We detected a significant increase in lipid peroxidation (malondialdehyde) concentrations in cadmium chloride-treated HepG2 cells compared to the control. Similarly, a strong dose-response relationship (p < 0.05) was obtained in connection with cadmium chloride-induced apoptosis. Cadmium chloride-induced apoptosis was characterized by a significant increase in the percentage of annexin-V positive cells (apoptotic cells), as well by the occurrence of nucleosomal DNA fragmentation. In summary, this study indicated cadmium chloride is highly cytotoxic to HepG2 cells. This cytotoxic effect may be mediated at least in part through oxidative cell/tissue damage, phosphatidylserine externalization and occurrence of nucleosomal DNA fragmentation.

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 4380.
Abstract 4384: Differential expression and function of peroxiredoxin genes in normal vs. cancerous breast epithelial cell lines
Authors: Gongalves Kevin , Sullivan Katie , Phelan Shelley A.
Published: February 2011

Peroxiredoxins are thiol-specific antioxidants that reduce a wide variety of cellular peroxides and protect cells from oxidative stress-induced damage and death. These proteins have been implicated in numerous disease processes associated with increased oxidative stress, including cancer. We sought to compare peroxiredoxin expression between the normal MCF10A and cancerous MCF7 breast epithelial cell lines and examine the effect of Prdx1 and Prdx6 suppression in each line. Prdx1 and Prdx6 suppression was achieved through transient transfection of siRNA, and the relative expression of all six mammalian peroxiredoxin genes was determined by real time PCR and western blotting. We also examined the effect on peroxide-induced reactive oxygen species (ROS) accumulation and cytotoxicity. We demonstrated that MCF7 cells express significantly higher levels of Prdxs 1-5, while Prdx6 levels are comparable in the two lines. We achieved approximately 90% mRNA suppression of Prdx1 and Prdx6 in both lines using siRNA. Interestingly, Prdx1 suppression in both lines led to a marked reduction in Prdx2 expression and significant induction of Prdx4 expression. In addition, several Prdx genes were upregulated in MCF10 cells when either Prdx1 or Prdx6 were suppressed. We further demonstrated that Prdx1 and Prdx6 suppression caused a differential increase in peroxide-induced ROS levels and cytotoxicity in the two lines, and that simultaneous knock-down of both genes in MCF10 cells leads to a much more pronounced effect than in MCF7 cells. Together, these data suggest coordinated and complex regulatory interactions between the peroxiredoxin genes, and implicate a potentially different function for these proteins in transformed vs. untransformed cells. The elevated expression of peroxiredoxins in MCF7 cells may also represent a cellular adaptation to the cancerous state.

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 4384.
Abstract 4386: Androgen Receptor Requires JunD as a Co-activator to Switch on an Oxidative Stress Generation Pathway in Prostate Cancer Cells
Authors: Mehraein-Ghomi Farideh , Basu Hirak S. , Church Dawn R. , Wilding George
Published: February 2011

The relatively high oxidative stress in the prostate is postulated to be one of the major factors for prostate carcinogenesis and prostate cancer (CaP) progression. We focused on elucidating metabolic pathways of oxidative stress generation in CaP cells. Previously, we have shown that the transcription factor JunD is essential for the androgen-induced reactive oxygen species (ROS) production in androgen-dependent LNCaP human prostate cancer cells. We have also recently demonstrated that androgen induces the first and the regulatory enzyme spermidine/spermine N1-acetyl transferase (SSAT) in a polyamine catabolic pathway that produces copious amounts of metabolic ROS. Here, we present co-immunoprecipitation and Gaussia luciferase reconstitution assay data that show that JunD forms a complex with activated AR in situ. Our chromatin immnoprecipitation (ChIP) assay data demonstrate that JunD binds directly with a specific SSAT promoter sequence only in androgen-treated LNCaP cells. Using a vector containing a luciferase reporter gene connected to the SSAT promoter and a JunD silenced LNCaP cell line, we show that JunD is an essential co-activator of androgen-induction of SSAT gene expression. As there is no Androgen Response Element (ARE) in the SSAT promoter, we hypothesize that JunD mediates binding of androgen-activated AR to the SSAT promoter for the induction of SSAT that leads to polyamine oxidation and ROS production in prostate cells. Elucidation of this pathway may help the design of inhibitors of oxidative stress generation specifically in prostate cells to prevent prostate cancer occurrence and progression.

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 4386.
Abstract 4393: ASG-5ME is a novel antibody drug conjugate (ADC) for treating prostate cancers
Authors: Gudas Jean M. , An Zili , Morrison Robert Kendall , Morrison Karen J. , Jia Xiao-Chi , Raitano Arthur B. , Duniho Steven , Smith Leia , Hayes Dawn , Senter Peter , Benjamin Dennis , Jakobovits Aya
Published: February 2011

AGS-5 is a novel transmembrane antigen discovered by Agensys using transcriptional profiling that is highly expressed in a variety of epithelial tumors. A fully human IgG2k monoclonal antibody that binds to AGS-5 with high affinity was conjugated with the anti-microtubulin drug, monomethyl auristatin E (MMAE), via a conditionally labile valine-citrulline (vc) maleimidocaproyl linker to yield an average drug: antibody ratio of 3.7. Following cell surface binding, ASG-5ME is internalized and trafficked through the endocytic pathway, where proteolytic cleavage releases free active drug that subsequently binds and disrupts microtubules. We evaluated the expression of AGS-5 protein in a large number of prostate patient tumors using IHC. ASG-5ME was evaluated for its cell cytoxicity in vitro, and its anti-tumor activity was investigated on different established xenograft tumors, using both patient-derived and cell line models of prostate cancer. The pharmacokinetics of ASG-5ME in mice was also evaluated. Our studies indicated AGS-5 protein was expressed in more than 95% of primary prostate cancer specimens and distant metastases, and on more than 90% and 80% of pancreatic and gastric cancer specimens, respectively. ASG-5ME, bound with high affinity (Kd = 0.5 nM) to both human and cynomolgus monkey AGS-5 and mediated potent dose dependent cell cytotoxicity in vitro. ASG-5ME showed significant long term tumor regression and eradication of multiple established prostate cancer xenografts, including those grown orthotopically. Phamacokinetic (PK) analysis of ASG-5ME in mice indicated that the ADC was stabile with long T1/2 of ∼12 days. When considered together these data indicate that ASG-5ME is a promising therapeutic ADC for the treatment of prostate and other AGS-5 expressing cancers.

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 4393.
Abstract 4398: Maytansinoid release from thioether linked antibody maytansine conjugates (AMCs) under oxidative conditions: Implication for formulation and for ex vivo sample analysis in pharmacokinetic studies
Authors: Fishkin Nathan , Maloney Erin , Chari Ravi , Singh Rajeeva
Published: February 2011

Several antibody—maytansinoid conjugates (AMCs) are in various stages of clinical testing, with the most advanced being trastuzumab-DM1 (T-DM1) in Phase III testing. In T-DM1, the maytansinoid, DM1, is linked to the trastuzumab antibody via a non-reducible (“non-cleavable”) thioether bond using the SMCC (N-succinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxylate) linker. It has been reported that T-DM1 shows evidence of maytansinoid loss in circulation over time based on ex vivo analysis (Liepold, AACR 2009 abstract #2914), and it has been assumed that a slow retro-Michael reaction is the cause of some linker cleavage.

In the present study, however, we demonstrate that a more likely source of observed maytansinoid release is a reaction generated ex vivo. In our study, we used a model synthetic compound, DM1-MCC, which has the DM1 maytansinoid linked via a thioether bond like that in T-DM1, and also a thioether-linked AMC. When incubated in human plasma ex vivo, these were found to release maytansinoid sulfonate (DM1-SO3-) under physiological conditions (37°C, pH 7.4) at a slow rate. The formation of an initial sulphenic acid intermediate (RSOH) during β-elimination was confirmed with trapping experiments using dimedone (5,5-dimethyl-1,3-cyclohexanedione). Oxidatively-stressed AMCs and a model substrate with a more hindered thioether made with the maytansinoid DM4 showed a 3-fold increase in rate of sulfoxide formation, but an 8-fold lower rate of β-elimination compared to unhindered thioethers. DM1-MCC and thioether-linked AMCs were incubated at 37°C with thiol-trapping agents, such as 2,2′-dipyridyldisulfide. No release of DM1-thiol was detected under these conditions. In contrast, greater than 20% of conjugated maytansinoid was cleaved from a thioether-linked AMC under oxidative stress conditions (10−6 M H2O2 1 hr, 4°C dialysis, then incubation 18 h at pH 7.4, 37 °C).

The present observations suggest that ex vivo thioether oxidation may lead to maytansinoid release from conjugates. This sulfoxide elimination is noted at 37 °C under aqueous conditions and is likely facilitated by the mildly acidic β-hydrogen on the maleimide (pKa ∼ 25). Oxidation of thioethers (such as methionine) is common during protein extraction and concentration, and the present studies underscore the importance of reducing autooxidation of thioether-linked AMCs with regard to sample handling during pharmacokinetic analyses and conjugate formulation.

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 4398.
Abstract 4400: A novel bispecific antibody with high-affinity to DOTA-metal haptens for pretargeted radioimmunotherapy
Authors: Orcutt Kelly Davis , Frangioni John V. , Wittrup K Dane
Published: February 2011

In an effort to reduce background and at the same time maintain hapten retention in the tumor for pretargeted radioimmunotherapy (PRIT) applications, we recently engineered a high-affinity single chain variable fragment (scFv) to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) metal chelates. This scFv displays ∼100 pM affinity to Lu and Y chelates of DOTA, ∼1 nM affinity to In chelates of DOTA-aminobenzene (DOTABn), and ∼10 nM affinity to In chelates of DOTA. A bispecific antibody (bsAb) construct was then engineered as a fusion of this scFv to the C-terminus of an IgG light chain.

We present a three-step method for PRIT using the IgG-scFv bsAb, a dextran-based clearing agent, and radiolabeled DOTA. Biodistribution and tumor uptake were evaluated in mice with LS174T carcinoembryonic antigen (CEA)-positive tumors using this anti-CEA bsAb and 177Lu-DOTA, 111In-DOTABn, or 111In-DOTA after pretargeting with the bsAb at time t = −25 h, and clearing of residual bsAb with a dextran-based compound at t = −1 h. The bsAb exhibited tumor uptake of 19 ± 3 %ID/g at 24 h post injection resulting in approximately 10^5 DOTA binding sites per cell. The PRIT approach resulted in 177Lu-DOTA tumor uptake of ∼14 %ID/g at 24 h and 48 h, tumor to kidney ratios of ∼20 at 24 h and 48 h and tumor to blood ratios greater than 300 at 24 h and 48 h.

The PRIT system was used to analyze in vivo the effect of small molecule affinity on tumor uptake. 177Lu-DOTA with an affinity of ∼100 pM for the bsAb resulted in 9-fold higher tumor uptake at 24 h than 111In-DOTABn (∼1 nM), and 28-fold higher tumor uptake than 111In-DOTA (∼10 nM). In addition, haptens with higher affinity resulted in higher tumor to kidney and tumor to blood ratios.

We present here a PRIT approach with the highest yet reported 48 h tumor to blood and tumor to kidney ratios for CEA targeting. In addition, we report for the first time a systematic study of the effect of small molecule affinity on tumor uptake with affinities spanning a range of two orders of magnitude.24 h biodistribution of DOTA haptens with varying affinities Affinity for bsAb24 h tumor uptake24 h tumor/kidney ratio24 h tumor/blood ratio177Lu-DOTA∼100 pM13.8 ± 2.1 %ID/g18.0 ± 2.2324 ± 56111In-DOTABn∼1 nM1.6 ± 0.3 %ID/g5.6 ± 1.774 ± 4111In-DOTA∼10 nM0.5 ± 0.1 %ID/g1.2 ± 0.4not measurable

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 4400.
Abstract 4401: Antibody-mediated targeting of the uPA proteolytic activity neutralizes uPA functions in vivo
Authors: Lund Ida K. , Jögi Annika , Rønø Birgitte , Rasch Morten G. , Lund Leif R. , Almholt Kasper , Gårdsvoll Henrik , Behrendt Niels , Rømer John , Høyer-Hansen Gunilla
Published: February 2011

Urokinase-type plasminogen activator (uPA) plays a central role in tissue remodeling processes, during both normal physiological conditions and cancer progression. Most of our understanding of the role of uPA in vivo is derived from studies using gene-targeted uPA-deficient mice. To enable in vivo studies on the acute and specific interference with uPA functionality in adult mice, we have now developed murine monoclonal antibodies (mAbs) directed against murine uPA by immunization of uPA-deficient mice with the recombinant protein. Guided by ELISA, Western blotting, SPR and enzyme kinetic analyses, we have selected two highly potent and inhibitory anti-uPA mAbs (mU1 and mU3). Both mAbs recognize epitopes located on the B-chain of uPA that encompasses the catalytic site. In activity assays in vitro, mU1 blocked uPA-catalyzed plasminogen activation as well as plasmin-mediated pro-uPA activation, whereas mU3 only was directed against the first of these reactions.

We provide evidence that acute disruption of uPA activity in the adult mouse was effective with mU1, but not mU3, because only mU1 rescued mice treated with a uPA-activable anthrax pro-toxin. Moreover, systemic administration of mU1 (i) delayed wound healing in tissue-type plasminogen activator (tPA)-deficient mice, and (ii) impaired uPA-mediated hepatic fibrinolysis in tPA-deficient mice, resulting in a phenotype mimicking that of uPA;tPA double-deficient mice. Importantly, these results demonstrate the specific antagonist-directed targeting of mouse uPA at the enzyme activity level in normal physiological processes in vivo. Preliminary results indicate that wild-type mice, which have been transplanted with murine Lewis lung carcinoma cells, display significant reduction in primary tumour growth, when treated with mU1 as compared to placebo-treated (i.e. PBS-treated) littermates. We thus suggest that mU1 is an excellent mAb candidate for therapeutic intervention studies in mouse cancer models.

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 4401.
Abstract 4407: Neutralizing monoclonal antibody to periostin (PN) inhibits ovarian tumor metastatic growth in animal models
Authors: Zhu Min , Saxton Romaine E. , Ramos Lillian , Chang David D. , Karlan Beth Y. , Gasson Judith C. , Slamon Dennis J.
Published: February 2011

Periostin (PN), an extracellular matrix protein, is reported to be overexpressed in a variety of human cancers and its functions appear to be linked to tumor angiogenesis and metastasis. Our previous results show that engineered PN overexpression promotes ovarian tumor growth and dissemination in vivo. In the present study, we developed a neutralizing monoclonal antibody to PN, named MZ-1, and have investigated its effects on human ovarian tumor cell metastasis and progression. MZ-1 markedly reduced tumor metastatic growth in orthotopic ovarian tumor models derived from two PN-expressing ovarian cancer cell lines A2780 and TOV-112D. These in vivo antitumor effects of MZ-1 were attributed to its specific inhibition of anchorage-independent growth and survival of PN-expressing cells, as well as its neutralization on PN-induced migration. The data suggests that blocking PN expression may be a novel approach for treatment of ovarian 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 4407.
Abstract 441: Temporal profiling of a breast cancer cell line MCF-7 in response to reoxygenation
Authors: Chen Kuo Chin , Tsai Mong Hsun , Chuang Eric Y. , Hsiao Chuhsing Kate , Lai Liang Chuan
Published: February 2011

Oxygen fluctuation resulting from hyper-proliferation of tumor cells, abnormal metabolism and disorganized tumor neovasculature characterizes the microenvironment of many cancers, which influences tumor development and angiogenesis. Furthermore, this condition increases chemo-resistance and radio-resistance of tumor cells, and also associates with increased invasion and metastatic potential accompanied with a poor prognosis. Hypoxia/ reoxygenation induce oxidative stress, which leads to DNA damage and genomic instability. It is known that multiple cellular responses were activated in order to survive under this microenvironment, but little is known about the dynamic response upon reoxygenation. To investigate the dynamic response of signalling pathways in tumor adaptation, a breast cancer cell line MCF-7 was cultured under 0.5% oxygen condition 24 hours followed by reoxygenation, and was harvested at various time points during reoxygenation. Genome-wide microarray results revealed that 274 genes were differentially expressed during reoxygenation; 47.4% of them were up-regulated and 52.3% down-regulated. Furthermore, pathway analysis, including canonical pathway and gene network, were performed using Ingenuity Pathway Analysis. Selected genes of interest were validated by quantitative real-time PCR, such as hexokinase 2 (HK2) and cyclin D3 (CCND3). Survival analysis using clonogenic assay showed little effect of reoxygenation on MCF-7 cells, but proliferation was inhibited upon reoxygenation. Our result showed dynamic changes of MCF-7 gene expression and molecular pathways unpon reoxygenation, which shed some light on understanding of tumor adaptation.

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 441.
Abstract 4413: STX140 is an orally bioavailable microtubule targeting agent with no associated peripheral neuropathy and potent anti-metastasis efficacy in vivo
Authors: Newman Simon P. , Foster Paul A. , Day Joanna M. , Leese Mathew P. , Potter Barry VL , Reed Michael J. , Purohit Atul
Published: February 2011

There is a continued need for orally bioavailable anti-cancer compounds that exhibit good efficacy and with a more favourable toxicity profile than current ‘traditional’ cytotoxics. The microtubule disruptor, STX140 has previously been shown to have excellent oral bioavailability and significantly reduce tumor growth in vivo. These data presented here show STX140 to: lack significant neuropathy in a validated in vivo behavioural model and to significantly reduce metastasis in a highly aggressive orthotopic model of breast cancer.

To assess the potential for neurotoxicity animals were dosed with, vehicle (0.5% methlycellulose), STX140 (20 mg/kg p.o. 5/7 × 4) or Taxol (15 mg/kg i.v weekly x 4). Thermal hyperalgesia, as assessed by paw withdrawal latency, was measured every 3-4 days using Hargreaves Plantar equipment. The 4T1 murine tumor cell line was used to establish orthotopic tumors in the mammary fad pads of nude mice. After 28 days dosing, as above, tumor size, number of lung and liver metastasises were recorded. Additionally relative levels of circulating tumor cells (CTCs) were assessed by quantifying the number of viable tumor cell colonies grown from 30 µL of blood taken by cardiac puncture at day 28.

In the thermal hyperalgesia model of neuropathy Taxol caused a significant decrease in paw withdrawal latency from day 14 till the end of study, in contrast there were no significant changes in withdrawal times in either the vehicle or STX140 dosed groups. In the 4T1 xenograft study both Taxol and STX140 reduced, tumor volume, extent of lung metastasis and number of viable CTCs in the blood relative to vehicle. In a separate study STX140 but not Taxol caused a significant improvement in survival.

These studies highlight the excellent efficacy of the orally bioavailable anti-cancer agent STX140 in a highly aggressive model of breast cancer. STX140 may offer a major additional advantage over existing drugs as the most common dose limiting toxicity of neuropathy, is negated / minimised.

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 4413.
Abstract 4417: Uptake of the new paclitaxel-derivative (ANG1005) by the low-density lipoprotein receptor-related protein1 (LRP1) is related to the aggressive phenotype of glioblastoma cells
Authors: Bertrand Yanick , Currie Jean-Christophe , Demeule Michel , Régina Anthony , Stanimirovic Danica , Castaigne Jean-Paul , Béliveau Richard
Published: February 2011

The most common primary brain tumour is glioblastoma multiforme (GBM). Despite latest cancer researches to improve the outcome of patients with GBM, this highly aggressive tumour remains one of the most difficult tumors to treat. Angiochem's Engineered Peptide Compounds (EPiC) provides a non-invasive and flexible platform for small and large molecules to treat brain diseases. Based on these properties, we have created a portfolio of new drug entities composed of siRNA, peptides and mAbs, The most advanced, ANG1005, is a new taxane derivative currently completing two Phase ½ clinical trials for the treatment of primary and secondary brain tumors. This EPiC drug is comprised of one Angiopep-2 peptide conjugated to three molecules of paclitaxel. Recently, Angiopep-2 has been shown to use the low-density lipoprotein related protein 1 (LRP1) has a gateway across the blood-brain barrier. Interestingly, LRP1 seems to be required in many tumours for the aggressive behaviour and is overexpressed in GBM. Here, we show an increase uptake of Angiopep-2 in implanted brain tumour using in vivo imaging when compared to the contralateral normal brain region. In these tumors, ANG1005 could be detected by LC/MS/MS analysis and immunohistochemistry. We next characterized Angiopep-2 and ANG1005 uptake in human U87 glioblastoma cell line. The transfection of U87 cells with siRNA LRP1 decreased the uptake of both Angiopep-2 and ANG1005 indicating that LRP1 is involved in their internalization in glioblastoma cells. Furthermore, we measured an increase in the uptake of both Angiopep-2 and ANG1005 in glioblastoma (U87) cells under three experimental conditions that mimic the aggressive cancer cell microenvironment: acidic pH, serum deprivation and hypoxia. Interestingly, under these conditions LRP1 expression was also increased. The increase of ANG1005 uptake and LRP1 expression indicates that the aggressive cancer microenvironment phenotype favors the entry of this anticancer drug into glioblastoma cells. Overall these results demonstrate that the EPiC drug ANG1005 can be an effective therapeutic strategy to target brain cancer cells and aggressive tumors such as GBM.

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 4417.
Abstract 4420: ABI-013: A novel nanoparticle albumin-bound (nab) docetaxel analog with superior antitumor activity over docetaxel
Authors: D'Cruz Osmond , Piacente Marit , Trieu Vuong , Tao Chunlin , Desai Neil
Published: February 2011

Background: Docetaxel-based chemotherapy is currently used to treat patients with a variety of tumors. A critical challenge has been to improve its chemotherapeutic levels without systemic toxicity. We developed ABI-013, a novel analog of docetaxel (Taxotere®) as a solvent (polysorbate 80/ethanol)-free, nanoparticle albumin-bound 70-nm (nab) form with improved stability in vivo as a tumor-targeting chemotherapeutic agent. In this study, we evaluated the comparative antitumor activity of ABI-013 versus Taxotere® in human tumor xenografts.

Methods: Subcutaneous human breast (MDA-MB-231), colon (HT29 and HCT-116), and lung (H358) tumors were grown in athymic nude mice and treated intravenously (IV) with ABI-013 (15, 30, 60, 90, 120 or 150 mg/kg) or Taxotere (MTD of 15 mg/kg) on a q4dx3 schedule. Evaluations of anti-tumor activity were based on the number of partial and complete regressions, the median number of days for tumors in each group to reach one tumor mass doubling (T-C) or the percentage tumor growth inhibition (%TGI).

Results: Significant dose-dependent TGI was observed with complete or partial tumor regressions in all xenograft models treated with ABI-013. In the MDA-MB-231 breast tumor model, ABI-013 effectively delayed the tumor growth with T-C values of 83.1, 80.7, and >84.8 days at dosages of 120, 90, and 60 mg/kg, respectively, with >96% TGI compared to vehicle control (P < 0.0001 vs. saline). In contrast, Taxotere delayed the tumor growth with a T-C value of 49.5 days and decreased tumor growth by 88% (P < 0.0001 vs. saline). In the HT 29 colon tumor model, Taxotere revealed dose-limiting toxicity with a 27% body weight loss (BWL) despite 86 to 91% TGI (P < 0.01 vs. saline). In contrast, ABI-013 (90 mg/kg) caused complete tumor regression with a maximum BWL of 19% (P < 0.0001 vs. saline). Treatment with Taxotere delayed the growth of HCT-116 colon tumor with a T-C value of 14.9 days with a maximum BWL of 21%. In contrast, complete tumor regression was achieved in 40% of ABI-013-treated mice. In the H358 human non-small cell lung cancer model, unlike Taxotere, ABI-013 (60 mg/kg) caused partial tumor regression with minimal toxicity.

Conclusion: ABI-013, a solvent-free nanoparticle albumin-bound 70-nm particle form of a novel docetaxel analog, had superior antitumor activity in human breast, colorectal, and lung cancer xenograft models compared with equitoxic doses of solvent-based formulation of docetaxel. The nab form of the novel docetaxel analog shows promise in cancer therapy.

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 4420.
Abstract 4432: Discovery of novel Pin1 inhibitors by structure-guided fragment evolution that downregulate cyclin D1 expression in PC-3 prostate cancer cells
Authors: Moore Jonathan D. , Potter Andrew , Ray Stuart , Oldfield Victoria , Nunns Claire L. , Fromont Christophe , Northfield Christopher J. , Gueritz Louisa , Bryant Christopher J. , Scrace Simon F. , Robinson David , Matassova Natalia , Baker Lisa , Surgenor Allan E. , Dukurno Pawel , Davis Ben , Richardson Christine M. , Murray James B.
Published: February 2011

Pin1 is a peptidyl-prolyl isomerase (PPIase) that is specialized for catalysing isomerization around pSer/Thr-Pro bonds. As isomerisation around such bonds can promote major conformational changes within proteins, Pin1 is able to influence signaling dynamics and outcomes within pathways regulated by proline-directed kinases such as: MAP kinases, cyclin-dependent kinases and GSK-3β. Pin1 overexpression is only weakly oncogenic in itself, but enhances transformation by ErbB2 or activated Ras alleles. Remarkably however, cells from Pin1 deficient mice are resistant to transformation by Ras and ErbB2. As Pin1-deficient mice have a mild phenotype, there are considerable grounds for hope that Pin1 inhibitors will have value for the therapy of cancer and also inflammatory disorders.

Here we report the discovery of our second series of cell active Pin1 inhibitors. Screening of a 700 member fragment library at high concentrations in a PPIase assay revealed 37 potential novel hits. Only two of these hits could be verified to bind Pin1 by 2D NMR, and we were able to obtain a crystal structure of just one of the novel hits bound to Pin1, a pyridyl pyrazole acid. After examining a number of 6-5 unfused ring system acids, we selected a phenyl-imidazole acid as a start point. A program of structure-guided medicinal chemistry led to the discovery of a series of ligands that occupied a novel combination of surfaces within the Pin1 active site, distinct from that occupied by our previously published amino acid-derived inhibitors. This effort culminated in VER-158197, a sub-micromolar (∼750 nM) inhibitor of Pin1 that exhibits high permeability in a CaCo-2 permeability assays and inhibits the growth of Pin1-dependent PC-3 prostate cancer cells (GI50 ∼ 13 uM). Mode of action studies indicated that VER-158197 downregulated cyclin D1 expression and prevented the phosphorylation of p70 S6 Kinase on Thr389 that is normally observed in repsonse to insulin stimulation.

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 4432.
Abstract 4434: Combined targeting of Aurora B (AZD1152) and MEK1/2 (AZD6244) kinases leads to enhancement of anti-tumour effects in vivo.
Authors: Odedra Rajesh , Heaton Simon , Logie Armelle , Mundt Kirsten E. , Anderson Elizabeth , Smith Paul D. , Wilkinson Robert W.
Published: February 2011

Future cancer treatment regimes may involve novel drug combinations aimed at targeting different pathways involved in tumour proliferation and survival. Understanding the mechanisms involved in such combinations and identifying the optimum schedule/sequence will be key to guiding clinical development.

The Aurora kinases play a critical role in mitosis and have been suggested as promising targets for therapy due to their frequent over expression in a variety of tumours. AZD1152 is a selective Aurora B kinase inhibitor, with a novel anti-tumour mechanism of action, inducing endoreduplication, apoptosis and inhibition of cytokinesis. The MAPK signaling pathway is implicated in uncontrolled cell proliferation and cell survival in many cancers. AZD6244 (ARRY-142886), a selective, ATP non-competitive inhibitor of MEK1/2, has demonstrated G1 arrest and anti-tumour activity in a range of preclinical models.

In the present study, we dosed AZD1152 and AZD6244 in combination to nude mice bearing human NSCLC tumour (Calu-6) xenografts. Pharmacodynamic analysis of Calu-6 xenografts treated with either AZD1152 or AZD6244 as monotherapies (MonTx) indicated downstream biomarker effects in accordance with their targets (for e.g. suppression of phosphorylation of histone H3 and ERK, respectively). When the same doses of AZD1152 (150mg/Kg/day s.c. for 2 days via osmotic minipumps) or AZD6244 (25mg/kg/BID p.o.) were dosed in a chronic disease setting, both drugs significantly suppressed Calu-6 tumour growth (versus respective vehicle groups, p<0.005). In combination, the two drugs were dosed in sequence, either AZD1152 → AZD6244 or AZD6244 → AZD1152. Whilst both sequences proved superior to the vehicle arms, only AZD1152

→ AZD6244 proved superior to both MonTx arms in terms of apoptosis induction and tumour growth inhibition. These data indicate a promising therapeutic strategy for combining AZD1152 and AZD6244, and suggest that the sequence of drug administration may be critical when combining these inhibitors. Both AZD1152 and AZD6244 are currently in clinical trials.

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 4434.
Abstract 4439: Anti-cancer actions of omega-3 polyunsaturated fatty acids in human cervical cancer
Authors: Jing Kaipeng , Shin Soyeon , Song Kyoung-Sub , Kim Nayeong , Jeong Soyeon , Kim Jong-Seok , Park Hae-Duck , Han Chang , Wu Tong , Kang Jing X. , Park Jong-Il , Park Seung-Kiel , Kweon Gi-Ryang , Yoon Wan-Hee , Hwang Byung-Doo , Lim Kyu
Published: February 2011

Over 90% of human cervical carcinoma is associated with high risk human papillomavirus (HPV), and a number of biological effects that could contribute to cancer suppression by ω3-polyunsaturated fatty acids (ω3-PUFAs) have been reported. However, the anti-cancer effect of ω3-PUFAs on cervical cancer has been not known yet. In this study, we report inhibitory mechanisms of ω3-PUFAs on cell growth and invasion in cervical cancer. DHA inhibited the cell growth in a dose- and time-dependent manner. In flow cytometry analysis, cell cycle of DHA-treated HeLa cells was arrested in G2/M phase and SubG1 cells also increased. Moreover, apoptotic cell death was confirmed by TUNEL assay, the induction of PARP cleavage and down-regulation of Bcl-2. The invasiveness of cells was significantly inhibited by DHA treatment in vitro transwell assay as well. The MMP-9 and MMP-2 promoter activities were decreased after DHA treatment. Cox-2 and VEGF promoter activities were also inhibited by DHA. Furthermore, DHA decreased the levels of reporter activity of NF-κB, which is transcription factor that regulates MMPs, Cox-2 and VEGF expression. In in vivo experiments, when human papillomavirus type 16 (HPV16)-transformed mouse TC-1 cells were injected into the tail vein of Fat1 mice (Fat1 transgenic mice express a Caenorhabditis elegans ω3-desaturase converting ω6- to ω3-PUFAs endogenously.) and WT (wild type) mice, lung metastasis of TC-1 cells was dramatically inhibited in Fat1 transgenic mice compared to WT mice. Taken together, these findings provide evidence that ω3-PUFAs may inhibit metastasis as well as cell growth and invasion through suppression of MMPs/COX-2/VEGF expression by inhibition of NF-κB expression in cervical cancer cells, indicating that the utilization of ω3-PUFAs may represent a potential effective therapy for the chemoprevention and treatment of human cervical cancer.[This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government(MEST) (#E00026) and by the Infection Signaling Network Research Center (R13-2007-020-01000-0) at Chungnam National University].

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 4439.
Abstract 4440: Using nanocurcumin to treat medulloblastoma and glioblastoma
Authors: Lim Kah Jing , Maitra Anirban , Bisht Savita , Eberhart Charles , Bar Eli
Published: February 2011

We attempted to treat medulloblastoma and glioblastoma, malignant tumors of the central nervous system, with curcumin, a polyphenolic compound derived from the Indian spice turmeric. Curcumin was delivered in a nanoparticle-encapsulated formulation (nanocurcumin) to increase its solubility and bioavailability. Nanocurcumin caused a dose-dependent decrease in cell growth as measured by MTT in multiple brain cancer cell lines, including the embryonal tumor derived cultures DAOY, D283, and PFSK, and the glioblastoma neurosphere line HSR-GBM1. Notably, doses used in these studies did not cause a comparable inhibition in the growth of NIH 3T3 cells or non-neoplastic human fetal cortical neurospheres. The reductions in viable cell mass observed were associated with a combination of G2/M arrest and apoptotic induction. The proportion of G2/M cells increased between 25% and 106% in the various lines, while the percentage of apoptotic cells increased at least two-fold. Nanocurcumin was also found to reduce the CD133+ stem-like cancer cell population in medulloblastoma and glioblastoma cells. In the primary glioblastoma culture JHH-GBM14, the CD133+ population decreased from 7.7% to 0.6%. In addition, 10uM nanocurcumin suppressed clonogenicity of our brain tumor cell lines by more than 97%. Curcumin has been shown to target multiple pathways in different tumor types. We found that Stat3 activity was reduced by nanocurcumin in the DAOY medulloblastoma cell line, via reductions in phospho-Tyr705 and phospho-Ser727. Nanocurcumin also reduced the expression of Hes 5, one of the target genes in the Notch pathway. However, we did not find significant changes in protein expression of Bcl2, MEK, ERK and Akt following nanocurcumin treatment. In conclusion, our results suggest that nanocurcumin can inhibit malignant brain tumor growth, at least in part due to reduction in Stat activity.

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 4440.
Abstract 4441: Stichoposides induce apoptosis through the generation of ceramide in human leukemia cells
Authors: Park Joo-In , Yun Seong-Hoon , Shin Sung-Won , Park Eun-Seon , Lee Seon-A , Han Jin-Yeong , Jeong Jin-Sook , Stonik Valentin A , Kwak Jong-Young
Published: February 2011

Marine triterpene glycosides are physiologically active natural compounds, isolated from sea cucumbers (holothurians) and demonstrate a wide spectrum of biological effects. Stichoposides are extracted from Thelenota anax (family Stichopodidae). Previous studies demonstrated that stichoposides had antifungal, cytotoxic, and antitumor activities. However, the specific molecular mechanisms underlying this effect remain to be elucidated. Stichoposide-induced apoptosis was examined in human leukemia cells in relation to mitochondrial injury and perturbations in signaling pathways. Stichoposide C (STC) induces apoptosis in these cells in a dose-dependent manner and leads to the activation of FAS, recruitment of FADD, activation of caspase-8, cleavage of Bid, mitochondrial damage and activation of caspase-3. In contrast, stichoposide D (STD) induces apoptosis in these cells in a dose-dependent manner and causes to activation of extrinsic pathway, not to activation of intrinsic pathway. In addition, STC- and STD-induced apoptosis are mediated by ER stress pathway, showing that Salubrinal, ER pathway inhibitor, inhibits apoptosis by STC and STD. STD activated acid sphingomyelinase (SMase) and neutral SMase, resulting in the generation of ceramide, but STC slightly activated them. By using specific inhibitor for acid SMase or neutral SMase and siRNA knockdown experiments, stichoposides-induced apoptosis was blocked. Thus, these results indicate that ceramide generation by stichoposides may contribute to stichoposides-induced apoptosis. Thus, these data suggest that stichoposides may have therapeutic relevance in the treatment of human leukemia.

This study was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MEST) through the Medical Research Center for Cancer Molecular Therapy at Dong-A University (R13-2002-044-05002-0).

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 4441.