bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 653: Stat3 as a molecular signature and therapeutic target for inflammatory breast cancer
Authors: Thudi Nanda K. , Mandal Pijus K. , McMurray John S. , Robertson Fredika M.
Published: February 2011

Inflammatory breast cancer (IBC) is the most aggressive and lethal of all breast cancers. There is little known about the molecular signatures of IBC with the exception that these breast cancers commonly over-express E-cadherin and Rho C GTPase and exist as tumor emboli within dermal lymphatics. In addition, IBC tumor emboli exhibit characteristics of tumor initiating cells, i.e., cancer stem cells. Another interesting characteristic of IBC tumors is their ability to undergo vasculogenic mimicry, forming tube-like structures that abrogate the need of this very aggressive tumor type to induce the development of angiogenic endothelium. In vitro under low adherence culture conditions, IBC cells readily form tumor spheroids that contain ”label retaining” cells and exhibit self-renewal. In addition, when cultured as tumor spheroids in 3 dimensions, they express high levels of the phosphorylated form of the signal transducer and activator of transcription 3 (phospho-stat3), recently shown to regulate survival of embryonic stem cells. From a panel of newly developed novel stat3-targeted peptidomimetics, we found that the lead compound, designated as PM-73G, inhibited phospho-stat3, which was associated with blockade of the robust invasion, anchorage independent growth in soft agar and vasculogenic mimicry exhibited by IBC tumor cells without a significant anti-proliferative effect. Using array-based PCR and protein analysis, we found a specific pattern of inhibition of genes/proteins within the Jak/Stat pathway by PM-73G. Results of comparative studies using both PM-73G and stat3 shRNA demonstrate a role for stat3 in maintenance of the cancer stem cell phenotype exhibited by IBC tumor spheroids. Taken together, these studies suggest that stat3 may serve both as a molecular signature of IBC and as a target for development of effective therapeutics for this lethal form of breast cancer that contain tumor cells exhibiting a cancer stem cell phenotype. (Funded by The Susan G. Komen For The Cure Promise Grant KGO 81287 (FMR), The State of Texas Rare and Aggressive Breast Cancer Fund (FMR), NIH NCI CA096652 (JSM) and Center for Targeted Therapy at The University of Texas M.D. Anderson Cancer Center and the Texas Institute for Drug and Diagnostic Development at The University of Texas, Austin. (FMR & JSM).

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 653.
Abstract 665: Targeting the pro-apoptotic protein BIM by dexamethasone combined with a MEK inhibitor PD184352 enhances the lethality in acute lymphoblastic leukemia
Authors: Heidari Nastaran , Richardson Amanda , Hicks Mark , Turner Keneshia , Harada Hisashi
Published: February 2011

Glucocorticoids (GC) represent common components of many chemotherapeutic regimens for lymphoid malignancies including acute lymphoblastic leukemia (ALL). Although the effects of GC on lymphocytes have been scrutinized for many years, the molecular mechanisms of sensitivity and resistance need to be elucidated. Since GC-resistant leukemia and myeloma are often associated with GC receptor defects, bypassing the receptor by targeting downstream molecules may develop new therapeutic strategies. We and others have previously shown that BIM (BCL-2 Interacting Mediator of cell death), a pro-apoptotic BCL-2 family protein, is up-regulated by dexamethasone (Dex) treatment in ALL cells and plays an essential role in Dex-induced apoptosis. Furthermore, BIM is inactivated by extracellular signal-regulated kinase (ERK)-mediated phosphorylation by survival/growth factors. We therefore hypothesized that co-treatment with Dex and MEK/ERK inhibitors promote apoptosis in ALL cells through BIM up-regulation and activation, resulting in cell death. We have recently demonstrated that MEK inhibitors synergistically promote Dex lethality in a variety of ALL cell lines, in which BIM is a critical molecule in cell death (Rambal et al., Leukemia 23, 1744-1754, 2009).

In the present study, we examined the therapeutic potential of co-treatment of Dex and MEK inhibitor PD184352 in vivo by severe combined immunodeficiency (SCID) mouse xenograft models of ALL. Minimum doses of Dex (8 mg/kg/day) and PD184352 (50 mg/kg/day) treatment caused BIM up-regulation and ERK dephosphorylation in xenograft tumor samples, respectively. Co-treatment of Dex and PD184352 resulted in an increase of apoptosis determined by caspase-3 cleavage and a significant decrease in size of the tumors. These data show that MEK/ERK inhibition enhances the anti-tumor activity of Dex in vivo. Our study provides a rational foundation for future attempts to improve the effect of GC with clinically relevant pharmacologic MEK inhibitors in the treatment of ALL and possibly other hematological malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 665.
Abstract 672: TumoraseTM: In vivo efficacy data for novel localized proteinase treatment applicable to solid tumors of varied tissue origins
Authors: Qian Yong , Drewe John A. , Shi Jin , McClurg Michael , Li Weidong , Campbell Thomas N.
Published: February 2011

To facilitate the development of noninvasive solid tumor cancer treatments, BioMedicure reports here the development of a specific proteinase treatment that when injected locally into solid tumors elicits a substantial tumor remission. Reported here is data indicating that intratumoral injection of TumoraseTM (T101, BioMedicure, San Diego, CA), a novel proteinase formulation, into solid tumors of various tissue origin destroys the tumor by digesting the solid-structure, killing cancer cells, including cancer stem cells, locally while not effecting normal tissues. The best route of TumoraseTM biochemical delivery to the tumor is intratumoral injection by a needle with a gauge 20-27. Before TumoraseTM intratumoral delivery, the tumor volume is estimated by 3-dimensional measurement and calculation: L x W X H in mm3, where “L” is the solid-tumor length, “W” solid-tumor width and “H” solid-tumor height. Tumorase works best when intratumorally injected at about 50-80% of solid-tumor volume delivered not by bolus but at about 200 uL per minute. The success rate of eliminating sparsely vascularized solid-tumors 50-400 mm3 in volume is high (over 70%). However, since inhibitory factors in serum diminish the activity of TumoraseTM, the success rate of eliminating a highly vascularized soft or liquid tumor is low (below 30%), though partial tumor mass decrease responses are observed. Multiple treatments can be applied to further diminish tumor mass. Data will be presented for the following tumor models, the human melanoma (CRL-1676 and WM-266-4), the human prostates (CRl-2505 and 22Rv1), human breast ductal carcinomas (HTB-129 and MDA-MB-435S), the human bronchioalveolar carcinomas (HTB-177 and NCI-H460) and the human colon adenocarcinomas (CCL-231 and SW48) xenografts. When a cancerous growth is found early and is accessible by a surgical knife, surgery is still the recommended treatment. However, if not accessible or there are multiple tumors, then, TumoraseTM would be a viable option, a local therapy that can be utilized for multiple tumors elimination. TumoraseTM contains proteases that cleave the extracellular matrix, including vital proteins required for cell survival, leading to cancer cell death. Presented here is in vivo data indicating the efficacy of this novel proteinase preparation for the elimination of solid tumors of multiple tumor classes by destroying tumors’ solid structure and killing cancer cells by cleaving the extracellular domains of vital cell membrane proteins. The wide range of solid cancerous tumors eliminated suggests a potential wide clinical applicability.

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 672.
Abstract 707: Anti-SSTR antibodies can reverse neuroendocrine tumor cellular dedifferentiation induced by neutralizing EMT regulator miR-200c in pancreatic neuroendocrine tumor BON cells while increase cell death
Authors: Leu Frank , Nandi Minesh , Wong Chung
Published: February 2011

Somatostatin receptors (SSTR) are antiproliferative and antisecretory receptors that belong to the Class A of the seven-transmembrane G-protein coupled receptors. SSTR is comprised of five major subtypes namely subtype 1, 2 (A and B), 3, 4 and 5. Recently, we reported that SST signaling serves as a determinant in neuroendocrine-mesenchymal transition (NMT), a process that is dependent on the TGF-beta - SST signaling axis. NMT is similar to the epithelial-mesenchymal transition (EMT), but it has the opposite cellular differentiation outcome in response to the TGF-beta treatment. For instance, TGF-beta promotes cell dedifferentiation in EMT but promotes cell differentiation in NMT. In epithelial cancers, the micro RNA 200c (miR-200c) has been shown to negatively regulate the zinc finger homeodomain enhancer-binding protein (ZEB1) (an E-cadherin's transcriptional repressor) and thus able to keep EMT invasiveness in check. In this study, we found that upon transient transfection of the miR-200c repressor (X-miR-200c made by Oligoengine Inc., designed by Todd Hauser) into BON cells, the X-miR-200c was able to drive NMT forward. In general, the X-miR-200c triggers the expression of tumor metastasis markers to change, such as ZEB1 protein increase coupled with E-cadherin protein decrease, these changes altogether lead to both Vimentin and Twist protein increase. Interestingly, our anti-SSTR 2, 3, and 5 antibodies derived from the extracellular loop 2 ectodomain region were able to reverse BON cells from the mesenchymal state back to the neuroendocrine state. Additionally, the wound gap healing assay demonstrated that the gap closes at a much slower rate (∼2.5x slower) in the presence of either anti-SSTR2 antibody or anti-SSTR5 antibody treatment than the isotype IgG treatment. Our results suggest that similar to EMT, the miR-200c is also involved in controlling the process of NMT and it is reversible in the presence of anti-SSTR2, 3 and 5 antibodies. Furthermore, we also found that these anti-SSTR antibodies examined can increase neuroendocrine tumor cell death that may or may not be dependent on the NMT reversal.

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 707.
Abstract 709: The fully human IGF-1 receptor antibody, CP-751,871, targets putative colon cancer stem cell populations
Authors: Hart Lori S. , Dicker David T. , Grimberg Adda , Christensen James , El-Deiry Wafik S.
Published: February 2011

The identification of cancer stem cells (CSCs) has the potential to provide answers to questions of tumor pathogenesis, metastasis, and therapeutic resistance. We have previously shown that insulin-like growth factor 1 (IGF-1) enriches putative colon CSC populations, an important finding with the potential to explain the association of colon cancer risk and chemoresistance with the levels of circulating IGF-1 and obesity. Here, we have employed three established methods (side population (SP) analysis, aldehyde dehydrogenase activity (ALDH+), and CD133 expression) to analyze a panel of 8 human colon cancer cell lines for putative cancer stem cell properties. We have found enrichment of SP and/or ALDH+ populations across the panel of 8 colon cancer cell lines, as well as many lines originating from other tissues. The enrichment of SP cells by IGF-1 is independent of altered ABC transporter activity as measured by mitoxantrone efflux. Enrichment of CSCs by IGF-1 does not appear to depend on the activity of MAP kinases (based on inhibition with PD098059 and U0126); therefore, we are currently exploring dependence on alternative IGF signaling pathways downstream of Akt, including NF-κB and mTOR. While we continue our efforts to unravel the mechanism by which IGF-1 enriches CSCs we are also interested in the more immediate clinical implications of our findings. CP-751,871 is a fully human antibody with specificity to the IGF-1 receptor and is currently being tested in clinical trials for a variety of solid malignancies. We have found that CP-751,871 reduces both SP and ALDH+ CSC populations in multiple colon cancer cell lines in vitro, and has promising activity against these populations in pilot experiments in vivo. We are currently repeating these studies to yield conclusions supported by statistics. Interestingly, CP-751,871 blocks IGF-1 enrichment of the side population in DLD1 cells, but not in SW480 cells suggesting a potential role of alternative receptors, such as the insulin receptor in some cell lines, a possibility we are currently analyzing. These studies have the potential to affect clinical oncology treatment strategies as the role of CSCs in tumor growth is delineated. Our results suggest that CP-751,871 has preferential activity against putative CSC populations, and therefore, may benefit current standard chemotherapeutic regimens that target cycling 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 709.
Abstract 711: VEGF121/rGel inhibits prostate cancer-induced osteoblastogenesis by targeting osteoblasts and tumor neovasculature
Authors: Mohamedali Khalid A. , Li Zhi Gang , Starbuck Michael W. , Wan Xinhai , Yang Jun , Kim Sehoon , Zhang Wendy , Navone Nora M. , Rosenblum Michael G.
Published: February 2011

Prostate cancer metastasis to bone usually produces bone-forming lesions although an osteolytic component is present in most cases. We have previously shown excellent efficacy against prostate cancer growth in bone in an osteolytic model (PC-3) with VEGF121/rGel, a chimeric fusion toxin of VEGF121 and the plant toxin gelonin (rGel) that targets VEGFR-1 and VEGFR-2. In the current study, we demonstrate that VEGF121/rGel systemic administration is also effective in a model of prostate cancer that displays the bone-forming phenotype when growing in the femurs of immunodeficient mice. Both murine osteoblast precursor (MC3T3) cells and primary mouse osteoblasts (PMOs) were shown to express VEGFR-1 but not VEGFR-2. VEGFR-1 mRNA expression was shown to down-regulate during osteoblast (MC3T3) differentiation. In vitro, treatment with VEGF121/rGel showed cytotoxicity against osteoblast precursor cells (IC50 = 15 nM) that was substantially reduced (IC50 > 1000 nM) after MC3T3 had been allowed to undergo differentiation. This suggests that the effect of VEGF121/rGel is specifically mediated by VEGFR-1. Furthermore, immunofluorescence microscopy showed that internalization of VEGF121/rGel into PMOs is VEGF121-receptor driven. In an ex vivo model of osteoblastic disease, 100 nM VEGF121/rGel significantly inhibited prostate cancer-mediated new bone formation in neonatal mouse calvaria. In vivo, systemic (iv, tail vein) administration of VEGF121/rGel significantly inhibited growth of the osteoblastic prostate cancer cell line MDA PCa 118b growing intrafemorally. Only 25% of VEGF121/rGel-treated mice showed the development of osteoblastic lesions compared to 90% of saline-treated mice. Micro-CT (µCT) analysis of isolated femurs demonstrated that intrafemoral growth of MDA PCa118b tumors caused a dramatic increase in bone volume and that treatment with VEGF121/rGel restored the bone volume fraction to normalized levels with no changes to the uninvolved contralateral femurs. H&E results confirmed that the osteoblastic growth of 118b cells was severely impeded. Our results clearly demonstrate that VEGF121/rGel administration may suppress the eventual development of skeletal prostate tumors and may have significant therapeutic effect against prostate cancer-mediated osteoblastic lesions in bone. Research conducted, in part, by the Clayton Foundation for Research.

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 711.
Abstract 735: Synthesis of substituted 1,2,3,4-tetrahydroisoquinolines as anticancer agents
Authors: Redda Kinfe Ken , Gangapuram Madhavi NA , Ardley Tiffany W.
Published: February 2011

The 1,2,3,4-tetrahydroisoquinoline moiety is commonly found in biologically active molecules of either natural or synthetic origin, making its derivatives excellent candidates as potential pharmaceutical agents. The tetraydroisoquinoline family of alkaloids includes potent cytotoxic agents that display a range of biological properties such as antitumor and antimicrobial activities studied thoroughly over the past 25 years, starting with the isolation of naphthyridinomycin in 1974. 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTIQ) is considered to be a possible endogenous anti-parkinsonism agent that is present in the mouse, rat, monkey and human brain. Therefore, the discovery of novel and safer anticancer drugs represents a challenging goal for our research program. In the current investigation, we synthesized a few analogs maintaining the tetrahydroisoquinoline moiety with modifications on the phenyl ring by introducing groups with various electronic, steric and lipophilic properties.

The starting material, 2-aminoisoquinoliniumiodide was obtained by the reaction of hydroxylamine-O-sulfonic acid, water, and isoquinoline after heating at 90 oC for 2 h. The reaction mixture was cooled to room temperature, potassium carbonate added, and the water was evaporated. Ethanol was added to the solid residue and the insoluble potassium sulfate was filtered out. Hydroiodic acid was added to the filtrate, and the resulting solution was placed in a freezer for overnight. The precipitate was filtered out, washed with ethanol, and dried in vacuo. The crude product was used for the next step without further purification. Reaction of the 2-aminoisoquinoliniumiodide with substituted benzoyl chlorides/benzenesulfonyl chlorides in anhydrous tetrahydrofuran containing triethylamine gave stable benzoyl/benzenesulfonyl imino ylides. This was followed by reduction with sodium borohydride in absolute ethanol, which furnished the target compounds, 1-(substituted benzoyl/benzenesulfonylamino)-1,2,3,4-tetrahydroisoquinolines. These compounds were evaluated for their in vitro anti cancer activity on MCF-7, MDA-MB-231 and Ishikawa breast cancer cell lines. The cytotoxicity activities of the compounds were tested using tomaxifen as a control. The 1-benzoyl amino-1,2,3,4-tetrahydroisoquinoline showed most potent cytotoxicity with an IC50 values 0.23, 0.63, 0.74 µg/mL on Ishikawa, MCF-7 and MDA-MB-231, respectively.

This research was supported by NIH/RCMI Grant # G12 RR03020 and Pharmaceutical Research Center NIH/NCRR Grant 1 C06 RR12512-01.

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 735.
Abstract 737: Modeling of σ2 selective agonists for the development of new anticancer agents that utilize the celecoxib scaffold
Authors: Kinder David H. , Rhoades Derek J. , Mahfouz Tarek
Published: February 2011

Celecoxib has proved to be an enigma as a potential anticancer agent. COX-2 inhibition is not necessarily involved in its mechanism of cytotoxicity, and it induces a non-classical apoptotic pathway leading to cell death in some cell culture models. Because the classical pathways are not always induced by celecoxib, we hypothesized that celecoxib might be working as a σ2 receptor agonist as part of its cytotoxicity. In addition, published research has supported the therapeutic potential of σ2 receptor agonists in cancer chemotherapy. We have determined that celecoxib will inhibit the CRL-1620 cell line with an IC50 of 32 μM, and the 9L rat glioma model with an IC50 of 60 μM. Using a group of 41 high affinity σ2 receptor selective agonists and following a ligand-based drug design approach, we have developed a four-site pharmacophore model for σ2 receptor agonists. Upon aligning celecoxib to this model, it matched three of the four sites, further supporting our hypothesis that celecoxib might be working as a σ2 receptor agonist as part of its cytotoxicity. Additional compounds have been developed utilizing the celecoxib scaffold as σ2 receptor agonist anticancer agents. From the pharmacophore model we also developed an in silico model for the σ2 receptor binding pocket as it has not been cloned nor has its three dimensional structure been determined.

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 737.
Abstract 739: Targeting pancreatic cancers with a quadruplex-binding small molecule
Authors: Hampel Sonja , Gunaratnam Mekala , de la Fuente Maria , Schatzlein Andreas , Neidle Stephen
Published: February 2011

We have previously reported on a novel series of tetra-aminoalkyl substituted naphthalene diimide compounds that bind to quadruplex nucleic acids and have high potency against a panel of human cancer cell lines. We now report on a further sub-set of derivatives with piperidino end-groups, which show high selectivity for human telomeric quadruplexes and only low-level binding to duplex DNA. These compounds are similarly potent in the cancer cell line panel, and also show potency against several pancreatic cancer cell lines, with typical IC50 values < 0.1μM. Telomerase activity is decreased in these cells on compound exposure, together with long-term growth arrest; this behaviour is consistent with a telomere targeting mechanism of action. These compounds also have > 40-fold selectivity over several normal fibroblast cell lines.

We report on preliminary in vivo studies in this series, using the pancreatic cancer MiaPaCa-2 xenograft model. Starting doses for the compounds have been established in a dose ranging study. The compounds are relatively well-tolerated at doses well above the IC50 values, suggesting a sufficient therapeutic window exists to explore their therapeutic potential. The compounds show evidence of anticancer activity in the form of growth delay when established MiaPaCa-2 xenografts were dosed once daily by intraperitoneal injection.

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 739.
Abstract 741: Lactic acid, hyperacidic media, and hypoxia diminish 4-hydroxyanisole-induced toxicity in melanoma cell lines
Authors: Moridani Majid , Kudugunti Shashi , Samala Rama Krishna
Published: February 2011

Lack of in-vitro in-vivo correlation in drug efficacy is a major problem in anticancer drug discovery, which may be attributed to hypoxia and lactic acid production in tumor. In current work, we evaluated the effect of hypoxia, lactic acid and hyper-acidic condition on efficacy of 4-hydroxyanisole (4-HA) as an anti-melanoma prodrug in human SK-MEL-28 cells. Lactic acid concentrations and pH were determined in tumor and compared with liver, lung, kidney and serum in skin melanoma tumor model in mice.

The pH of tumor and blood was measured using pH meter. The lactic acids were measured by a microdialysis analyzer. Modular incubator chamber was used to maintain hypoxic condition. MTT assay was used for IC50 (48h) determination and cell viability measurement. Male C57BL/6 mice (n=3) were inoculated s.c. at right flank with 1×106 B16-F0 melanoma cells.

The pH of tumor and serum was 6.8-6.9 and 7.4-7.6, respectively, indicating that pH was significantly lower in tumor. The lactic acid concentrations in tumor increased from 10.8 to 19.4mM during day 8 through 13 post melanoma cell inoculation, whereas in serum, liver, lung and kidney remained within 5.5-7.8mM, 11.1-14.4mM, 3.5-6.9mM and 6.6-7.5mM, respectively. Normoxia results: The IC50 (48h) of 4-HA in SK-MEL-28 was 50µM. Lactic acid demonstrated a concentration dependent toxicity towards melanoma cell lines with an IC50 (48h) of 20mM. 4-HA (50µM) led to 50% toxicity in the presence of lactic acid (5-20mM) as well. A decrease in pH of the media was observed with an increase in lactic acid concentration. Hypoxia results: The IC50 (48h) of 4-HA remained 50µM in hypoxia. Lactic acid was less toxic to the cells under hypoxia. 4-HA (50µM) showed no toxicity in presence of lactic acid (5-20mM) under hypoxic condition. The effect of pyruvic acid, HCl and NaCl on 4-HA toxicity were also investigated in normoxia and hypoxia conditions.

Our results suggest that lactic acid, hyper-acidic media and hypoxia may play major roles in diminishing 4-HA toxicity in melanoma cells, however, the role of hypoxia was found to be more prominent. Lactic acid provided protective effect against 4-HA induced toxicity under hypoxic condition.

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 741.
Abstract 75: Electron transport chain-dependent oxygen consumption in metastatic breast cancer cells
Authors: Al-Mehdi Abu-Bakr , Patel Mita , Reed Darla
Published: February 2011

Although mitochondrial ATP-production deficiency has been historically implicated to account for the Warburg effect or “aerobic” glycolysis in cancer cells, recent observations indicate the presence of functionally competent mitochondria in cancer cells. We hypothesized that a lung-metastatic breast cancer cell line with intact mitochondrial membrane potential would exhibit mitochondria-dependent oxygen consumption. A murine breast cancer cell line (4T1) was used to evaluate mitochondrial membrane potential by JC-1 fluorescence microscopy. Oxygen consumption by cancer cells in suspension was determined using a dissolved oxygen meter. Fluorescence microscopy of JC-1 red aggregates indicated the presence of highly polarized mitochondria in 4T1 cells, suggesting that these cells are capable of oxidative phosphorylation. Oxygen consumption rate of 4T1 cells suspended in 10 mM glucose-containing medium equilibrated with 21% oxygen (258 µM dissolved oxygen) at 25°C was 2.98 nmol/min/million cells (Control). Oxygen consumption was significantly enhanced by carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), a mitochondrial uncoupler (7.88 nmol/min/million cells, p<0.05 vs. Control). Myxothiazol (a respiratory chain complex III inhibitor) inhibited the oxygen consumption (0.75 nmol/min/million cells; p<0.05 vs. Control), indicating the presence of a functional electron transport chain. A nitric oxide donor also inhibited oxygen consumption (0.84 nmol/min/million cells; p<0.05 vs. Control). These data indicate the presence of oxidative phosphorylation-competent mitochondria in breast cancer cells. We conclude that cancer cells possess respiration-capable mitochondria and their “aerobic” glycolysis may not reflect a compensatory mechanism for ATP generation.

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 75.
Abstract 753: Novel, potent and selective small molecule inhibitors of 3-phosphoinositide-dependent kinase (PDK1)
Authors: Murphy Sean T. , Alton Gordon , Bailey Simon , Baxi Sangita , Burke Ben , Ermolieff Jacques , Greasley Samantha , Kablaoui Natasha , Kath John , Kohls Darcy , Kothe Michael , Kupchinsky Stan , Lingardo Laura , Marx Matthew A. , Richter Dan , Tran Khanh , Vernier William , Yin Min-Jean
Published: February 2011

The phosphatidylinositol 3-kinase (PI3K) signaling pathway plays a crucial role in cell growth, proliferation and survival. Genomic aberrations in the PI3K pathway, such as mutational activation of PI3Kα or loss-of-function of the tumor suppressor PTEN, have been closely linked to the development and progression of a wide range of cancers. Inhibition of the key targets in the pathway, PI3K, AKT, mTOR & PDK1, may provide an effective treatment of cancer. In an effort to discover compounds that inhibit PDK1, we have developed a series of 3-Carbonyl-4-Amino-Pyrrolopyrimidine (CAP) compounds that are selective and potent PDK1 inhibitors. Early screening led to a viable starting point, PF-03772304, (4-amino-7-isopropyl-7H-pyrrolo[2,3-d]pyrimidin-5-yl)-(6-methylamino-pyrazin-2-yl)-methanone, which has an IC50 of 94 nM for PDK1 and a ligand efficiency of 0.42. While potent, this lead was not selective against PI3K. Using structure-based drug design, this lead was modified to expand into the selectivity pocket of PDK1 (under the G-Loop), leading to the identification of a potent and pathway-selective compound, PF-05017255 ((4-Amino-7-isopropyl-7H-pyrrolo[2,3-d]pyrimidin-5-yl)-{6-[(3S,4R)-4-(4-fluoro-phenyl)-tetrahydro-furan-3-ylamino]-pyrazin-2-yl}-methanone). PF-05017255 has a Ki of 0.6 nM for PDK1 and is more than 400-fold selective against other PI3K pathway kinases: PI3Kα, AKT, S6K and mTOR. For even greater kinase selectivity, we sought to lower the clogP of our lead (clogP for PF-05017255 is 3.0) to reduce the contribution from the hydrophobic effect. These efforts led to PF-05168899 (1-{(2R,3R)-3-[6-(4-Amino-7-isopropyl-7H-pyrrolo[2,3-d]pyrimidine-5-carbonyl)-pyrazin-2-ylamino]-2-phenyl-pyrrolidin-1-yl}-ethanone) with a Ki of 0.4 nM for PDK1, a clogP of 2.1, and greater than 1000-fold selectivity against PI3Kα, AKT, S6K, mTOR, CDK2, CHK1 and PAK4. PF-05168899 also showed little inhibitory effect (<50% at 1 uM) against 33 of 35 kinases in a broader panel, demonstrating significant inhibition only against CHK2 (94%) and AuroraB (54%). In addition, the most potent analogs (e.g. PF-05168889) inhibited the phosphorylation of AKT at the residue threonine 308 (IC50 40-200 nM) in a variety of cancer cell lines (e.g. H460, A549). The design, synthesis and SAR of this chemical series will be described.

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 753.
Abstract 766: Downregulation of MUC4 in pancreatic cancer cells by thymoquinone: A promise for pancreatic cancer therapies
Authors: Torres Maria P. , Ponnusamy Moorthy P. , Chakraborty Subhankar , Arafat Hwyda A. , Batra Surinder K.
Published: February 2011

Pancreatic cancer remains one of the most lethal cancers in the world. Currently, the existing therapies have not been optimized and the survival of pancreatic cancer patients remains under 5% after being diagnosed. The high molecular weight glycoprotein Mucin-4 (MUC4) contributes to the regulation of differentiation, proliferation, and metastasis of pancreatic tumor cells. As it is not expressed in normal pancreatic epithelial cells, MUC4 is a promising target for novel cancer therapeutics. Among the natural derived drugs that are being investigated, the extracts from the seeds of the plant Nigella sativa, particularly thymoquinone (TQ), possess multiple benefits, including anti-tumorigenic properties. The main objective of this study was to evaluate the effect of TQ on pancreatic cancer cells and determine the role of the drug on MUC4 expression by analyzing the cytotoxicity, protein and gene expression, and metastatic properties on the MUC4-expressing pancreatic cancer cell line FG/COLO357. Experimental techniques used included western blot, polymerase chain reaction (PCR), transient gene silencing, confocal, and flow cytometry analyses, among other functional assays. The results indicated a decrease in cell viability at increasing concentrations of TQ that correlated with MUC4 downregulation, which occurred thru the proteasomal degradation pathway. The genes that were regulated in FG/COLO357 cells after treatment with TQ were determined by microarray analysis and the results were confirmed by functional assays. It was found that TQ activated the Jun N-terminal Kinase (JNK) and p38 Mitogen-Activated Protein Kinase (MAPK) pathways. As the activation of these pathways is directly related to a decrease in proliferation, survival, and invasion of cancer cells, these results indicate the direct involvement of TQ on the induction of apoptosis of pancreatic cancer cells. The results present evidence that TQ induces the apoptosis of pancreatic cancer cells and the downregulation of MUC4 is related to the apoptotic effect of the drug. In conclusion, TQ, which has a role in downregulation of MUC4 among other anti-tumorigenic properties, represents promise for the development of novel therapies against pancreatic 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 766.
Abstract 783: High microsatellite instability predicts good prognosis in intestinal type gastric cancers
Authors: Song Meiying , An Ji Yeong , Noh Sung Hoon , Shin Sung Kwan , Lee Yong Chan , Kim Hoguen , Hyunki Kim
Published: February 2011

A subset of gastric cancers shows high microsatellite instability (MSI-H). The reported clinicopathologic features of MSI-H gastric cancers are heterogeneous, and specific factors associated with prognosis have not been identified. We analyzed the clinicopathologic characteristics and prognostic factors in a large series (161 cases) of MSI-H gastric cancers, and compared the results to 315 cases of microsatellite stable or low MSI gastric cancers. The frequency of MSI-H gastric cancers was 9.0% (161/1786). MSI-H gastric cancers have distinct clinicopathologic features including female gender, older age, antral location, protruded gross type (Borrmann typeIand type II), well to moderate differentiation, intestinal type of Lauren classification, expanding type of Ming classification, non signet ring cell component, presence of mucinous component, moderate to severe lymphoid stromal reaction, and lower tumor stage. The MSI-H phenotype was associated with better prognosis (P = .044), and male gender (P = .035, HR: 0.23), intestinal/mixed type of Lauren classification (P <.001, HR: 0.09) and lower tumor stage (1 and 2) (P = .001, HR: 0.08) were independently favorable prognostic factors. With unique clinicopathologic features, the intestinal type MSI-H gastric cancers are associated with good prognosis and can be classified as a different subset of gastric 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 783.
Abstract 808: Intrinsic gene expression profiles of gliomas are a better predictor of survival than histology
Authors: Gravendeel Lonneke , Kouwenhoven Mathilde , Gevaert Olivier , de Rooi Johan , Stubbs Andrew , Duijm Elza , Daemen Anneleen , Bleeker Fonnet , Bralten Linda , Kloosterhof Nanne , de Moor Bart , Eilers Paul , van der Spek Peter , Kros Johan M. , Smitt Peter Sillevis , van den Bent Martin , French Pim
Published: February 2011

Gliomas are the most common primary brain tumors with heterogeneous morphology and variable prognosis. Treatment decisions in patients rely mainly on histological classification and clinical parameters. However, differences between histological subclasses and grades are subtle, and classifying gliomas is subject to a large inter-observer variability. To improve current classification standards, we have performed gene expression profiling on a large cohort of glioma samples of all histological subtypes and grades. We identified seven distinct molecular subgroups that correlate with survival. These include two favorable prognostic subgroups (median survival >4.7 years), two with intermediate prognosis (median survival 1-4 years), two with poor prognosis (median survival <1 year), and one control group. The intrinsic molecular subtypes of glioma are different from histological subgroups and correlate better to patient survival. The prognostic value of molecular subgroups was validated on five independent sample cohorts (TCGA, REMBRANDT, GSE12907, GSE4271, and Li et al.). The power of intrinsic subtyping is demonstrated by its ability to identify a subset of prognostically favorable tumors within an external dataset that contains only histologically confirmed glioblastomas. Specific genetic changes (EGFR amplification, IDH1 mutation, 1p/19q LOH) segregate in distinct molecular subgroups. We identified a subgroup with molecular features associated with secondary glioblastoma, suggesting that different genetic changes drive gene expression profiles. Finally, we assessed response to treatment in molecular subgroups. Our data provides compelling evidence that expression profiling is a more accurate and objective method to classify gliomas than histological classification. Molecular classification therefore may aid diagnosis and can guide clinical decision making.

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 808.
Abstract 836: In vivo PET imaging of MET receptor in human cancer using [11C]SU11274
Authors: Ma Patrick C. , Wu Chunying , Tang Zhe , Fan Weiwen , Zhu Wenxia , Wang Changning , Somoza Edurado , Owino Norbert , Li Ruoshi , Wang Yanming
Published: February 2011

The mesenchymal-epithelial transition (MET) receptor plays prominent role in human tumorigenesis, tumor progression and metastasis. Overexpression or mutation of MET results in activation of oncogenic signaling pathways and leads to upregulation of diverse tumor cell functions. Mounting evidence has validated MET receptor as novel target for anticancer therapy. For efficacy evaluation of various MET-targeted anticancer therapies currently under development, it is critical to develop an imaging tool that permits detection and quantification of MET expression in vivo. To date, a number of small molecule MET inhibitors have been developed, including SU11274, which is a specific, reversible MET inhibitor that induces apoptosis in cells transformed by activated MET kinase. Here, we report the radiosynthesis and evaluation of a molecular imaging probe, [11C]SU11274, for quantification of MET receptors in human cancers in vivo. The radiolabeling with C-11 was accomplished through radiomethylation using 3-[3,5-Dimethyl-4-(piperazine-1-carbonyl)-1H-pyrrol-2-ylmethylene]-2-oxo-2,3-dihyro-1H-indole-5-sulfonic acid (3-chlorophenyl)-methyl amide hydrochloride as a key precursor. Following the synthesis of the precursor that was achieved in 10 steps with a total yield of 9.7%, [11C]SU11274 was obtained through radiomethylation in a range of 5-10 % radiochemical yield and over 95% radiochemical purity. For in vivo PET studies, two human lung adenocarcinoma cancer xenograft models were established using MET-positive H1975 and MET-negative H520 cell lines. The time-radioactivity curves showed that the uptake of [11C]SU11274 in the H1975 xenograft was significantly higher than in the H520 xenograft (p = 0.00019). Compared to H520, the H1975 xenograft mice exhibited an increased tumor uptake of [11C]SU11274 throughout the entire measurement period of 90 min. At 65 min post-injection, the radioactivity concentration ratio of H1975/H520 reached a statistically significant and enhanced ratio of 2.1, and peaked at 2.6 at 80 min. The PET imaging results were consistent with their corresponding immunohistochemical tissue staining patterns of MET receptors from the same animals. Hence, our results suggest that [11C]SU11274-PET is a specific imaging marker that can differentiate and quantify MET receptor expression in vivo. These studies demonstrated that [11C]SU11274-PET can facilitate the clinical development of MET-targeted cancer therapeutics.

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 836.
Abstract 852: Prognostic value of circulating endothelial and progenitor cells in advanced cancer patients enrolled in phase 1 in association with clinical prognostic scores
Authors: Massard Christophe , Deley Marie-Cecile Le , Roca Carlos Gomez , Borget Isabelle , Soria Jean-Charles , Farace Françoise
Published: February 2011

Background

New surrogate biomarkers such as circulating endothelial cell (CEC) and progenitor cell (CEP) have been proposed to monitor anti-vascular drug activity. During anti-angiogenic therapy, dramatic changes in both CEC and CEP levels were observed. Moreover, these biomarkers may also be used as a candidate prognostic and predictive biomarker in patients with advanced cancer.

Methods

Medical charts of patients treated in one centre and enrolled into five Phase I trials with anti-vascular therapies between October 2005 and April 2009 were reviewed for clinical characteristics and validated clinical prognostic factors (albumin, lactate dehydrogenase, number of metastatic sites)(Arkenau et al, JCO 2009).

Overall 70 patients had CEC or CEP evaluation at baseline. CECs were measured in one ml erythocyte lysed whole blood by four color flow cytometry (FCM) and identified by a CD45-CD31+CD146+ 7-amino-actinomycin (7AAD)- phenotype… CEPs were measured in 10ml blood after progenitor cell enrichment and were identified by FCM as extremely rare events with a CD45dimCD34+VEGFR2+7AAD- phenotype.

We studied the impact of CEC and CEP values on the overall survival (OS) adjusted on the clinical prognostic score.

Results

The median age was 50 years (range, 21 to 78 years).

Median baseline CEC value was 12/ml (range, 0 to 154).

The CEPs were measured in 57 patients; the median CEP value was 1.3% of hematopoietic stem cells, with range from 0% to 32.5% (absolute counts: 12/ml, range, 0 to 392/ml). 31/57 had CEP values greater than 1% of HSC.

Median follow-up was 23 months. The risk of death was significantly increased in patients with prognostic score greater than 0 as compared to patients with score equal to 0 (Median OS 9.2 versus 24.2 respectively) as well as in patients with increased CEP (>1%) as compared to those with lower values (Median OS 9.0 versus 13.3). Both factors remained significant in multivariate analysis (HR=3.9, 95%CI, 0.95-16.6, p=0.02 and HR=2.1, 95%CI, 1.0-4.3, p=0.04, respectively). We did not observe any relationship between the CEC level and the outcome.

Conclusion

This analysis suggests that a prognostic score based on CEP level combined with clinical characteristics could be a helpful tool to determine the prognosis of patients with advanced cancers enrolled into phase 1 trials. Further studies are requested to confirm these findings.

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 852.
Abstract 868: Regular aspirin use and risk of multiple myeloma: A prospective analysis
Authors: Birmann Brenda M. , Giovannucci Edward , Colditz Graham A.
Published: February 2011

Multiple myeloma (MM) is a lethal malignancy with a poorly understood etiology and no prevention strategies. Aspirin inhibits nuclear factor (NF)-κB, a transcription factor that mediates growth factors important to MM pathogenesis. We undertook the present analysis to evaluate whether regular aspirin use is associated with MM risk and thus may offer opportunities for MM chemoprevention. We conducted prospective analyses of regular aspirin use and MM risk in the Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS) populations. Questions on regular aspirin use were first asked of women in 1980 and of men in 1986, and were updated thereafter on biennial follow-up questionnaires. Participants reported height and weight at enrollment (1976 in NHS, 1986 in HPFS), and updated weight biennially. We followed participants from the year of first aspirin use questions through the earliest among a cancer diagnosis, death, or June 2006 (NHS) or January 2006 (HPFS). We excluded persons with missing baseline exposure data or a baseline history of cancer. We imposed a 4-year lag on aspirin use classification to minimize the influence of preclinical MM-related bone pain on use; exposures were updated biennially. We identified 164 women and 110 men with MM during follow-up (i.e., 1,586,035 NHS and 593,489 HPFS person-years). We obtained hazard ratios (HR) and 95% confidence intervals (CI) from Cox proportional hazard models stratified by age and adjusted for body mass index, to assess the association of updated quantity and duration of aspirin use with MM. In men, cumulative average aspirin tablets/week (tab/wk) was inversely associated with MM risk. Compared to non-users, the HR (95% CI) was 0.60 (CI=0.36-0.98) for <3 tab/wk, 0.33 (0.12-0.92) for 3-<6 tab/wk, and 0.22 (0.03-1.56) for 6-<10 tab/wk. Duration of continuous aspirin use was also inversely associated with MM in men: compared to non-users, the HR (95% CI) was 0.62 (0.38-0.99) for ≤5 years, 0.54 (0.30-0.95) for 6-10 years, and 0.39 (0.12-1.25) for 11-20 years continuous use. Preliminary findings among women were suggestive of an inverse association of regular aspirin use with MM risk, but were not statistically significant. Analyses stratified by duration of use and BMI are ongoing. This prospective analysis offers evidence that regular aspirin use is associated with a diminished risk of MM. Thus, NF-κB dysregulation may contribute to MM etiology as well as to pathogenesis. However, the utility of aspirin for MM chemoprevention requires further clarification.

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 868.