bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5472: Loss of TSC2 function predicts optimal therapeutic response to combinations of MEK and mTOR inhibitors
Authors: Conlon Beth A. , Legrier Marie-Emmanuelle , Rodriguez Gabin Alicia G. , Horwitz Susan Band , McDaid Hayley M.
Published: June 2012

The MAPK-RAS-PI3K signaling network is oncogenic in many human malignancies. The plasticity of cancer cell ‘circuitry’ is an important consideration in the rational design of drug combinations, particularly those targeting this signaling network. Therapies directed at MEK, a downstream RAS effector, have been in various stages of clinical development and shown to exhibit single-agent activity in RAF-mutant tumors. However, there is significant redundancy in the MAPK-PI3K pathway that mediates acute resistance to drugs that target either axis of this network, therefore the optimal use for MEK inhibitors will be in combination.

We have previously demonstrated that the combination of MEK and mTOR inhibitors is synergistic in a broad range of tumor cell lines and xenofrafts and mechanistically this is mediated via potent suppression of cap-dependent translation. To better define which cohort of patients would best benefit from this combination modality, we have evaluated the efficacy of MEK and rapalog combinations in TSC2 defective cells. The TSC1/2 complex integrates AKT/mTOR and MAPK circuitry and normally inhibits mTOR via Rheb. However disruption of the TSC complex occurs by mutational inactivation, LOH and inactivating phosphorylation via various kinases, including ERK. Loss of TSC2 function hyperactivates mTOR signaling and confers increased sensitivity to mTOR-directed therapies, including rapalogs. In spite of the known participation of MAPK signaling in TSC function, pharmacological inhibitors of MAPK or other components have not been evaluated in TSC2 null tumors.

Cells defective in TSC2 had increased sensitivity to both single agent MEK or rapalog therapies, relative to TSC2 WT cells, and had a much more synergistic interaction that was associated with potent dephosphorylation of the translational repressor, 4E-BP1. Synergy was associated with autophagy induction in TSC2 null cells followed by profound growth arrest that did not respond to growth factor stimulation. Cells with intact TSC2 function did not undergo autophagy after combined MEK and rapalog-inhibitor treatment and did not exhibit the same degree of growth arrest. Bioenergetic profiling indicated that TSC2 null cells had increased levels of oxygen consumption relative to WT cells, indicating changes in metabolic output associated with mTOR activation. In conclusion, these data support the use of combined MEK and rapalog-inhibitor therapy in tumors with defective TSC2 signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5472. doi:10.1158/1538-7445.AM2011-5472
Abstract 5503: Anti-proliferative role of MMP-9 and uPAR/cathepsin B knockdown in negative regulation of DNA repair mechanisms in human glioma xenografts
Authors: Ponnala Shivani , Veeravalli Krishna Kumar , Chetty Chandramu , Rao Jasti S.
Published: June 2012

Glioblastoma multiforme (GBM) is one of the most lethal forms of brain tumors. Efficient repair of DNA damage, especially double strand breaks (DSBs) and anti-apoptotic mechanisms associated with GBM, makes treating GBM challenging. In the present study, siRNA-mediated transcriptional silencing of MMP-9 and uPAR (MU) and MMP-9 and cathepsin B (MC) in 4910 and 5310 glioma xenograft cells had significant anti-proliferative effect as assessed by BrdU, MTT and clonogenic assays. FACS analysis revealed cells were in sub-G0-G1 phase after xenograft cells were treated with MU or MC. We also investigated the role of MU or MC knockdown in reducing DNA damage response (DDR), which eventually leads to apoptosis in glioma xenograft cells. RT-PCR and Western blot analyses revealed downregulation of DNA PKcs and Ku70/80 levels, which are responsible for non-homologous end joining (NHEJ) DNA repair. Elevated γH2AX protein expression and increased comet tail length indicated that the reduced NHEJ DNA repair led to accumulation of DSBs in MU and MC knocked down cells. The binding efficiency of Ku70 and Ku80 to DSB was significantly reduced in glioma cells treated with MU or MC. In addition, we noticed a reduced γH2AX and Ku70/Ku80 colocalization at DSBs in MU- and MC-treated xenograft cells. Moreover, MU and MC knockdown in these xenograft cells resulted in the downregulation of several other proteins involved in DNA damage response and the survival pathway (e.g., ATM, Rad 51, CHK2, EGFR, Akt, and ERK). Immunohistochemistry of the brain sections of xenografts injected into nude mice showed a reduced expression of DNA PKcs in animals treated with MU and MC siRNA. Taken together, our results clearly demonstrate that silencing via MU and MC not only negatively regulates DNA damage response, but also downregulates the proteins associated with the survival pathway. Based on these findings, it appears that silencing MU or MC in addition to radiation could be an effective strategy to treat radioresistant high-grade gliomas, where treatment usually fails due to the enhanced repair of DSBs induced by radiation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5503. doi:10.1158/1538-7445.AM2011-5503
Abstract 5524: Generation of cellular immune responses to MUC1-C to target the portion of MUC1 that is most biologically relevant to the transformation process
Authors: Jochems Caroline , Poole Diane J. , Vergati Matteo , Gulley James L. , Schlom Jeffrey , Tsang Kwong Yok
Published: June 2012

MUC1 is overexpressed in diverse human carcinomas and hematological cancers, and therefore serves as a potential target for immunotherapy. The MUC1 molecule has two distinctive subunits, formed by autocleavage with a SEA domain. The N-terminal (MUC1-N) is the large extracellular domain, and the C-terminal (MUC1-C) has three subunits: a small extracellular domain that is covalently bound to MUC1-N, a single transmembrane domain and a cytoplasmic tail. It has been reported by Kufe et al that the MUC1-C subunit transduces signals that confer growth and survival responses. The MUC1-C cytoplasmic tail located downstream of the SEA domain is sufficient for the induction of anchorage independent growth and tumorigenicity. MUC1-C overexpression is also highly associated with poor prognosis in patients with lung cancer and breast cancer. We and others have previously reported on HLA-A2 binding agonist epitopes to MUC1-N. The objective of this investigation is to identify and characterize HLA-A3 binding cytotoxic T-lymphocyte (CTL) epitopes and agonist epitopes of the MUC1-C subunit. The intention is to add these peptides to vaccines against MUC1 positive carcinomas, as well as using them for monitoring patients’ immune responses in clinical MUC1 vaccine trials. The generation of cellular immune responses to MUC1-C would thus target the portion of MUC1 that is most biologically relevant to the transformation process.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5524. doi:10.1158/1538-7445.AM2011-5524
Abstract 5553: Low-dose carcinogenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in rats: Evidence for the existence of no-effect levels and a mechanism involving p21Cip/WAF1
Authors: Wei Min , Kakehashi Anna , Yamano Shotaro , Fukushima Shoji , Wanibuchi Hideki
Published: June 2012

The carcinogenicity of the low amounts of genotoxic carcinogens present in food is of pressing concern. The purpose of the present study was to determine the carcinogenicity of low doses of the dietary genotoxic carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and to investigate mechanisms by which IQ exerts its carcinogenic effects. A total of 1595 male F344 rats were divided into 7 groups and administered IQ at doses of 0, 0.001, 0.01, 0.1, 1, 10 and 100 ppm in the diet for 16 weeks. We found that IQ doses of 1 ppm and below did not induce preneoplastic lesions in either the liver or the colon, while IQ doses of 10 and 100 ppm induced preneoplastic lesions in both these organs. These results demonstrate the presence of no effect levels of IQ for both liver and colon carcinogenicity in rats and indicate that the dose-response relationship for IQ carcinogenicity is nonlinear. The finding that p21Cip/WAF1 was significantly induced in the liver at doses well below those required for IQ mediated carcinogenic effects, suggests that induction of p21Cip/WAF1 is one of the mechanisms responsible for the observed no-effect of low doses of IQ. Furthermore, IQ administration caused significant induction of CYP1A2 at doses of 0.01 to 10 ppm, but administration of 100 ppm IQ induced CYP1A1 rather than CYP1A2. This result indicates the importance of dosage when interpreting data on the carcinogenicity and metabolic activation of IQ. Overall, our results argue for the existence of a practical carcinogenic threshold for this genotoxic compound.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5553. doi:10.1158/1538-7445.AM2011-5553
Abstract 5556: Role of the aberrant intracellular iron metabolism in rat liver carcinogenesis
Authors: Shpyleva Svitlana I. , Muskhelishvili Levan , Tryndyak Volodymyr , Beland Frederick A. , Pogribny Igor
Published: June 2012

Intracellular iron homeostasis in normal cells is tightly regulated by the coordination of several proteins that are responsible for the uptake, intracellular storage, and removal of iron from cells. Cancer cells, including liver cancer cells, are characterized by profound abberations in intracellular iron metabolism. Dysregulated iron homeostasis has been found not only in rodent and human hepatocellular carcinomas, but also in several preneoplastic pathological states associated with liver cancer development; however, the precise mechanistic role of iron metabolic disturbances in the initiation and early progression of liver carcinogenesis has remained unexplored. In the present study, using an in vivo model of rat hepatocarcinogenesis induced by 2-acetylaminofluorene, we found extensive alterations in cellular iron metabolism at preneoplastic stages of liver carcinogenesis characterized by a substantial decrease in the levels of cytoplasmic non-heme iron in initiated hepatocytes and altered expression of the major genes responsible for the proper maintenance of accurate intracellular homeostasis. Specifically, analysis of the gene expression patterns revealed prominent up-regulation of the ferroportin (Fpn) gene and down-regulation of the hepcidin (Hamp) gene in the preneoplastic livers. This indicates that the decreased intracellular levels of non-heme iron in preneoplastic foci may be attributed to increased iron export from the cells driven by the loss of an inhibitory effect of hepcidin on Fpn. This suggestion is supported by a substantial up-regulation of Fpn (3-fold) compared to transferrin receptor (Tfrc) gene, (1.6 fold), the latter of which is responsible for the iron intake into cell. These data indicate that in preneoplastic livers there is a disruption in the balance of regulatory networks controlling cellular iron uptake and export. Interestingly, we detected similar gene expression changes in initiated preneoplastic liver cells that were transformed by culturing of non-tumorigenic TRL-1215 rat liver cells in the presence of iron. In conclusion, our results demonstrate the significance of altered intracellular iron metabolism in the progression of liver carcinogenesis and suggest that correction of these alterations may affect liver cancer development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5556. doi:10.1158/1538-7445.AM2011-5556
Abstract 5565: Differential changes of proteome profiles in the dorsal-lateral vs. ventral prostate of during TRAMP carcinogenesis
Authors: Zhang Jinhui , Wang Lei , Zhang Yong , Lu Junxuan
Published: June 2012

The transgenic adenocarcinoma of mouse prostate (TRAMP) model is being widely used in the field of prostate cancer chemoprevention. As is understood today, the TRAMP represents at least two models of prostate carcinogenesis in the dorsal-lateral prostate (DLP, epithelial) and ventral prostate (VP, neuroendocrine). However, the molecular basis for the two lobe-specific lineages of carcinogenesis is poorly defined. To this end, we profiled concurrently the proteomes of DLP and VP lobes from the prostate of both TRAMP and wild type littermate C57BL/6 mice at the age of 17-18 weeks by 2D LC-MALDI-TOF/TOF with iTRAQ labeling. Totally 748 proteins were identified. In wild-type mice, 84 proteins were found to have different expression levels (cut-off 20%) between DLP and VP, including experimental autoimmune prostatitis antigen 2 (EAPA2), beta-tropomyosin, heat shock protein 5 (GRP78) and clusterin. In TRAMP mice, 118 proteins were found to be significantly changed in DLP and/or VP during TRAMP carcinogenesis. Among these 118 proteins, 55 and 36 proteins were uniquely changed in DLP or VP lobe, respectively, and 27 proteins in both DLP and LP lobe. 24 of the 27 proteins shared the same trend, albeit the extent of change was not exactly the same. Those shared changes such as up-regulation of HMGB 1&2 and down-regulation of calponin-1 indicated possible common molecular events associated with TRAMP carcinogenesis. The other three proteins, clusterin, polymeric immunoglobulin receptor and aldose reductase went in opposing directions in DLP versus VP during carcinogenesis. Those three proteins, as well as other proteins changed only in DLP or VP (e.g. EAPA2 in DLP and alpha-2-macroglobulin in VP), are more likely related to lobe-specific mechanisms of carcinogenesis. The lobe-specific and TRAMP-related expression patterns of GRP78 and clusterin were further validated by western blot. Ingenuity Pathway Analysis identified 14-3-3 zeta/delta (up-regulated only in DLP), epidermal growth factor (EGF, up-regulated only in DLP) and NF-κB as distinct inferred network nodes in TRAMP carcinogenesis in DLP lobe, whereas ERK1/2 and FGF2 were recognized as network nodes in VP lobe during carcinogenesis. Additional experiments confirmed lobe-specific expression patterns of NF-κB p65 and FGF2 in both wild type and TRAMP mice. Overall our data-sets highlight different mechanisms were likely involved in modifying carcinogenesis in DLP and VP.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5565. doi:10.1158/1538-7445.AM2011-5565
Abstract 5584: Green tea polyphenols inhibit histone deacetylases and modulate p53 transcriptional activities in human prostate cancer cells
Authors: Gupta Karishma , Thakur Vijay S. , Bhaskaran Natarajan , Gupta Sanjay
Published: June 2012

Inhibitors of histone deacetylases (HDACs) are emerging as a promising class of anticancer drugs. HDAC inhibitors have been demonstrated to induce cellular activities similar to p53-mediated responses such as induction of cell cycle arrest and apoptosis in various malignant cells. Green tea polyphenols (GTP) have shown protective effects against development and progression of various human cancers. GTP-mediated cellular responses include p53 activation, cell cycle arrest and induction of apoptosis in cancer cells. In the present study, we sought to determine whether GTP-mediated cellular responses are similar to that elicited by HDAC inhibitors. For these studies, we used human prostate cancer LNCaP cells, possessing wild-type p53, infected with short hairpin (sh) RNA vector and sh-p53 RNA vector to generate isogenic cell lines. Knockdown of p53 in LNCaP cells caused an increase in the activity of class I HDACs with specific increase in the protein expression of HDAC viz. 1 and 8, respectively. Treatment of both cell lines with 20, 40 and 80 mcg/mL doses of GTP for 24 h resulted in dose-dependent decrease in the total HDAC activity and protein expression of HDAC 2, 3 and 8 and HDAC 1, albeit at highest GTP dose. Similar dose-dependent responses were achieved by trichostatin A (TSA), a well known pharmacological inhibitor of class I and II HDACs in these cells. Interestingly, chemosensitization by GTP was more pronounced in the cells expressing p53 than the isogenic cell lines lacking p53 as observed by cell cycle analysis and annexin V flow cytometric analysis. Furthermore, GTP treatment resulted in marked increase in acetylation of p53 at its C-terminal amino acid positions K373 and K382, other than K305 along with increase in the acetylated forms of histone H3 and H4 which correlated with increased p53 expression, cell cycle arrest and apoptosis. Taken together, these results suggest that interaction of HDACs with p53 probably results in p53 deacetylation, thereby reducing the transcriptional activity; whereas GTP has the ability to cause deacetylation of p53 by reducing the levels of class I HDACs. This seems likely to be, in part, the mechanism for GTP-mediated p53 activation, a similar response elicited by HDAC inhibitors, which are developed as a promising class of drugs for the treatment of various human malignancies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5584. doi:10.1158/1538-7445.AM2011-5584
Abstract 5593: Are variants in the syndecan-1 gene associated with breast cancer risk in older women
Authors: Madeleine Margaret M. , Resler Alexa J. , Johnson Lisa G. , Malkki Mari , Petersdorf Effie W. , McKnight Barbara , Malone Kathleen E.
Published: June 2012

Syndecans are transmembrane proteins on the cell surface that act as receptors for ligands from a number of protein families. These proteoglycans are involved in a large number of important normal cell functions, including signaling, proliferation, and cell-matrix adhesion; they are also involved in aberrant cell functions such as inflammation, angiogenesis, and carcinogenesis. In a recent pathway directed re-analysis of GWAS data (Menashe, Cancer Research, 2010), variants in the syndecan-1 (SDC1) gene on chromosome 2p were found to be associated with excess risk of breast cancer. We sought to extend this finding by investigating the association between tagging SNPs in the SDC1 gene and risk of breast cancer in our case-control study (The PACE study) in older women. This population-based study includes 845 women who were 65-79 years old at diagnosis of incident breast cancer and 807 age-matched unaffected controls from the Seattle area. The analysis was restricted to Caucasian women. A total of 11 SNPs were chosen to represent 10 bins using Snagger, with double coverage of one large bin. Five SNPs failed genotyping, leaving six SNPs for analysis. At the gene level, a P-min permutation test was not significant for SDC1 (p=0.10). Three SNPs, rs10495704, rs2002090, and rs3771240, were in high linkage disequilibrium in our controls (r2 0.81-0.87) and all three were separately associated with marginally increased risks of breast cancer (OR 1.2, 95% CI 1.0-1.4). One of these SNPs, rs10495704, is in the 5’UTR and thus could be associated with protein processing. No excess risk of breast cancer was associated with the other three SDC1 variants: rs4432408, rs2348478, or rs2015110. A similar pattern of marginally increased risk for the three polymorphisms in high LD (rs10495704, rs2002090, and rs3771240) was found in two subsequent analyses restricted to women with ductal histology and luminal type tumors. We are currently assessing other genes related to inflammation that may be related to breast cancer risk in this study population. The data for SDC1 in the PACE study cannot rule out a modest association with breast cancer risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5593. doi:10.1158/1538-7445.AM2011-5593
Abstract 5599: Screening for large genomic rearrangements in the FANCA and FANCJ genes reveals extensive genomic FANCA deletion in a Finnish breast cancer family
Authors: Solyom Szilvia , Winqvist Robert , Nikkilä Jenni , Pylkäs Katri
Published: June 2012

A portion of familial breast cancer is accounted for by mutations in the same genes that are inactivated in Fanconi anemia (FA). In the current study we set out to evaluate the role of large genomic rearrangements in the FANCA and FANCJ/BRIP1 genes in Finnish breast cancer families. Mutations in the upstream FANCA gene account for the majority of FA patients, and about one-third of all FANCA mutations are large intragenic deletions. Based on the gene's hypermutable nature, the protein's interaction with BRCA1 and its involvement in genomic integrity maintenance, we considered FANCA as a candidate for breast cancer susceptibility. In FANCJ, which is a downstream FA and known breast cancer susceptibility gene, early truncating mutations have been reported, but no large deletions have been recognized so far.

For the present study, blood DNA from affected index persons of 100 Northern Finnish breast cancer families were assessed for possible constitutional exonic deletions or amplifications in FANCA and FANCJ by using the multiplex ligation-dependent probe amplification (MLPA) method.

We identified a novel large heterozygous FANCA deletion in one of the studied breast cancer families, removing the promoter region and the first 12 exons of the gene. The defective allele was absent from all of the tested 124 controls as well as 540 unselected breast cancer cases, but was present in the father of the index patient having pancreatic cancer. No large deletions in FANCJ were uncovered.

We conclude that large FANCA deletions might contribute to breast cancer susceptibility, therefore more extensive studies on their involvement in the disease are needed. To our knowledge, this is the first report on the existence of a large-size genomic deletion in an upstream FA gene in association with familial breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5599. doi:10.1158/1538-7445.AM2011-5599
Abstract 5614: Associations of common variants at 1p11.2 and 14q24.1 (RAD51L1) with breast cancer risk and heterogeneity by tumor subtype: Findings from the Breast Cancer Association Consortium
Authors: Figueroa Jonine D. , Garcia-Closas Montserrat ,   Studies from the Breast Cancer Association Consortium (BCAC), Easton Douglas , Spurdle Amanda
Published: June 2012

A recent genome-wide association study identified single-nucleotide polymorphisms (SNPs) at 1p11.2 and 14q24.1 (RAD51L1) as markers of susceptibility for breast cancer. Using case-control studies from the Breast Cancer Association Consortium (BCAC), we sought to estimate more precisely the breast cancer risk associated with these loci, and investigate if these risks differ by breast tumor characteristics. Analyses included genotyping data from rs11249433 (1p.11.2) and two highly correlated SNPs at 14q24.1 (RAD51L1) (rs999737or rs10483813, r2=0.98) on up to 46,748 breast cancer cases and 47,048 controls from 39 studies. Odds ratios (ORs) were estimated by logistic regression, adjusted for study. Heterogeneity by tumor characteristics was assessed using polytomous logistic regression models for multiple level outcomes, and tested using case-only analyses with tumor characteristics as the outcome. Tumor characteristics evaluated were estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), grade, node status, tumor size, and histopathological type. We confirmed that both rs11249433 (per allele OR and 95%CI 1.10, 1.08-1.12 P=3.2×10−22) and 14q24.1 SNPs rs999737/ rs10483813 (per allele OR and 95%CI 0.92, 0.90-0.94, P=9.21×10−14) are associated with invasive breast cancer risk. SNP rs11249433 was associated with ER-positive but not ER-negative breast cancer (P-heterogeneity =0.00008) and PR-positive but not PR-negative breast cancer (P-heterogeneity=0.007). SNP rs11249433 showed stronger associations with ER-positive tumors of lower grade (P-heterogeneity =6.67 x103) and lobular compared to ductal tumors (P-heterogeneity =0.01). In contrast, there was no evidence that the OR for rs999737/ rs10483813 differed by ER, PR, HER2, grade, node status, tumor size, or histopathological type, and in particular was associated with both ER-positive and ER-negative disease. Further studies aimed at identifying the causal variants in these regions and the biological mechanisms underlying these associations are warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5614. doi:10.1158/1538-7445.AM2011-5614
Abstract 57: Integrating transcriptome profiling and in silico pathway analysis toward reduction of therapeutic dimensionality in nasopharyngeal carcinoma
Authors: Bao Ying-Na , Dai Yilin , Yan Yongpan , Lu Wen-Hua , Peng Li-Xia , Zheng Fang-Jing , Li Xin-Jian , Kang Tie-Bang , Zeng Yi-Xin , Trent Jeffrey M. , Qian Chao-Nan
Published: June 2012

Nasopharyngeal carcinoma (NPC) has its highest incidence in southern China and Southeast Asia. In order to obtain deeper insights into the molecular mechanism of NPC tumorigenesis, we performed genome expression profiling combined with computerized pathway analyses on 18 NPC tissues and 18 age-matched tissues of non-cancerous nasopharyngeal mucosa from individuals in the endemic area, Guangdong province, China, between Dec 2007 and Oct 2010. Gene expression profiling was performed using an Agilent gene expression kit and Agilent 4×44K microarray gene chips. One-way analysis of variance was used to identify the genes differentially expressed between cancer and non-cancerous tissues. Genes with a false discovery rate of less than 0.001 and a fold-change larger than 2 or less than 0.5 were selected for in silico network mapping combined with pathway analysis using GeneGo software. Pathways were prioritized based on the gene enrichment analysis. The genes’ connectivity was also integrated to identify the regulatory hotspots in the key pathways. Genes within or surrounding these hotspots constitute potential therapeutic targets. Genes previously known to be up-regulated in NPC that were detected in our study included CCND1, CDKN1A, STAT1, BCL2A1, SGK1, RAI14, FOXM1, EPHB2, PMAIP1, COL1A1, GADD45A, ICAM1, FANC1, ZWINT, LAMB3, CKAP4, ISG15, and MMP3; known down-regulated genes included ATM and INPP5D. However, what was of interest was the identification of a series of previously unrecognized genes: those up-regulated more than 10-fold included MMP1, HOXC8, KREMEN2, and HOXA1, and those down-regulated more than 10-fold included LTF, C7, SHISA3, SKLC26A7, and C16orf89. Although the deregulated pathways in NPC encompass many cytological functions, pathway analysis has been helpful in ranking a series of the most significant deregulated pathways, which include ECM remodeling pathways; alternative complement pathway; plasmin signaling pathway; the TGF, WNT, and cytoskeletal remodeling pathways; leukocyte chemotaxis pathway; and the BAFF and PLAU signaling pathways. Results will be presented on key genetic changes within these pathways that have been verified by biologically. In conclusion, we are beginning to recognize key genes and pathways, prioritized by pathway analysis, that appear likely to identify possible novel mechanisms of NPC tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 57. doi:10.1158/1538-7445.AM2011-57
Abstract 572: Suppression of urokinase plasminogen activator receptor blocks recruitment of endothelial cells by inhibiting irradiation-induced monocyte chemo-attractant protein-1 in meningioma
Authors: Nalla Arun Kumar , Gogineni Venkateswara Rao , Gupta Reshu , Rao Jasti S.
Published: June 2012

Chemokines, a common outcome of inflammatory reaction, play a vital role in recruiting various cell types during tissue repair. Radiation, a major therapeutic modality in cancer treatment, has been described to induce inflammatory response, which might lead to the expression of several chemokines. In the present study, we investigated the mechanisms underlying radiation-induced monocyte chemo-attractant protein (MCP-1) in meningioma cell lines and the paracrine effect on human microvascular endothelial cells (HMEC). Upon radiation, meningioma cell lines (IOMM Lee and SF 3061) showed an increased expression of MCP-1. In addition, irradiated meningioma cancer cell culture conditioned medium (CM) demonstrated an increased ability to attract HMEC and stimulated MCP1-induced protein (MCPIP), VEGF and angiogenin expression in HMEC as compared to HMEC grown in non-irradiated cancer cell CM. This chemotactic activity and angiogenic stimulator effect in HMEC was nearly abrogated by depleting MCP-1 from the irradiated cancer cell CM using a neutralizing anti-MCP-1 monoclonal antibody. Inhibition of ERK activation and NF-κB nuclear translocation hindered irradiation-induced MCP-1 expression in both meningioma cell lines. Considering that radiation induces uPA/uPAR expression and stimulates the ERK signaling pathway, we correlated the role of irradiation-induced uPA/uPAR in MCP-1 regulation. Supplementing cancer cells with exogenous ATF-uPA (with and without radiation) activated ERK phosphorylation, nuclear translocation of the NF-κB p65 sub-unit (Rel-A), and MCP-1 expression. Downregulation of uPA and uPAR by transfecting the cancer cells with a siRNA-expressing plasmid (pU) inhibited irradiation-induced ERK activation, nuclear translocation of Rel-A, NF-κB DNA binding activity, and MCP-1 expression. Further, pU-transfected cancer cells (with or with radiation) reduced the potential to attract and stimulate angiogenic signaling in HMEC under in vitro conditions. Under in vivo conditions, we observed that pU transfected cancer cells (with and without irradiation) showed a significant reduction in number of CD31+ endothelial cells and CD14+ monocytes present in the tumor regions compared to tumor formed from irradiated cancer cells. In conclusion, we demonstrated that blockade of uPA/uPAR expression inhibits irradiation-induced MCP-1, thereby inhibiting the chemo-attractant ability of cancer cells to recruit other cells during the inflammatory process induced by radiation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 572. doi:10.1158/1538-7445.AM2011-572
Abstract 588: Silencing of MnSOD attenuates ATRA-induced neurofilament expression in neuroblastoma cells
Authors: Silvis Anne M. , Kiningham Kelley
Published: June 2012

Differentiation therapy with retinoids is a means to treat high-risk neuroblastoma patients when the tumor has recurred after initial attempts of removal by surgery, radiation, and/ or chemotherapy. A metabolite of Vitamin A, all-trans retinoic acid (ATRA) is the main signaling retinoid in vivo and one of the most potent differentiation inducers for human neuroblastoma in vitro. Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that converts the superoxide anion to hydrogen peroxide. Previously we have reported that ATRA increased MnSOD expression and activity in SK-N-SH neuroblastoma cells. However, our current study suggests that this upregulation may limit the ability of ATRA to induce differentiation. Treatment with ATRA upregulated the expression of neurofilament (an early marker of neuronal differentiation) as early as 48 hrs. Although MnSOD activity was not significantly increased by ATRA until 72 hrs, silencing of the MnSOD gene with siRNA enhanced neurofilament expression over that of cells infected with a control siRNA construct at 48 hrs. This suggests that even basal levels of MnSOD activity can attenuate an early marker of differentiation. We also demonstrated that ATRA decreased catalase expression and increased dichlorofluoroscein fluorescence, suggesting an increase in hydrogen peroxide. Therefore, these data suggest that rather than being scavenged by catalase, hydrogen peroxide may remain present in the cell after ATRA treatment to also limit the differentiation potential of the cells. Taken together, it is apparent that the alteration of redox status by retinoids may contribute to the modulation of genes which are involved in differentiation. (Funding: Centers for Biomedical Research Excellence 1P20RR020180 (KKK) and 5P20RR016477; WV-INBRE 5P20RR016477; WV-NASA 91-175B).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 588. doi:10.1158/1538-7445.AM2011-588
Abstract 591: Expanding the therapeutic window through pharmacological activation of the RB pathway in breast cancer treatment
Authors: McClendon Kathleen , Dean Jeffry L. , Rivadeneira Dayana , Reed Christopher A. , Witkiewicz Agnieszka , Gao Erhe , Koch Walter J. , Force Thomas , Knudsen Erik S.
Published: June 2012

Triple negative breast cancer (TNBC) is a highly aggressive disease that is most often treated with cytotoxic chemotherapies, such as anthracyclines and platinum compounds. While effective for certain tumors, these therapies are known to cause severe toxicities in numerous tissues. Thus, targeting pathways to both exploit therapy-sensitive tumors and ameliorate tissue toxicity is of utmost significance. Loss of the retinoblastoma tumor suppressor (RB) protein is a frequent event in TNBC, and is expected to alter therapeutic sensitivity by perturbing cell cycle checkpoints and yielding a predilection towards cell death. Conversely, it is possible that the same principles that drive sensitivity to cytotoxic agents in an RB-deficient setting could be used to prevent toxicities in an RB-proficient setting (i.e. normal tissues). Thus, modulation of the RB pathway could be critical for expanding the therapeutic window in the treatment of breast cancer. To address this hypothesis, combination studies of pharmacological activation of the RB pathway and cytotoxic chemotherapies commonly used to treat TNBC were performed in vitro and in vivo. Results indicate that activation of the RB pathway can modulate the efficacy of cytotoxic compounds in the treatment of TNBC. The mechanisms behind these observations were attributed directly to RB-mediated regulation of DNA damage and repair signaling pathways, as well as apoptosis. RB-deficiency resulted in bypass of these mechanisms and thus enhanced sensitivity to cytotoxic therapies. These results were supported by in silico data demonstrating that RB-deficient TNBC is associated with better clinical outcome in response to chemotherapy. Importantly, functional studies indicated that RB pathway activation can provide protection against the toxicity of frequently used chemotherapeutic compounds in normal tissue. Combined, these studies suggest that RB pathway status could be utilized in the clinic to direct combination treatments that would exploit the sensitivity of RB-deficient tumors to cytotoxic chemotherapies while simultaneously providing protection for normal tissues.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 591. doi:10.1158/1538-7445.AM2011-591
Abstract 598: Characterization of biological activity in colorectal cancer cells to anticancer regimens
Authors: Roh Seon Ae , Choi Eun Young , Lee Kang Hong , Kim Jin Cheon
Published: June 2012

There have been significant advances in the use of chemotherapy in the treatment of colorectal cancer (CRC) patients over the last 20 years. A goal of cancer therapy is to predict patient response and toxicity to drugs in order to facilitate the individualization of patient treatment. Identification of subgroups of patients that differ in their prognosis and response to treatment could help to identify the best available chemotherapy according the biological activity. In metastatic CRC, novel molecular targeted agents are being developed as the pathways that characterize cell growth, the cell cycle, apoptosis, angiogenensis and invasion provide novel targets for cancer therapy. The purpose of this study was to evaluate the efficacy of monotherapy and combination chemotherapy with targeted drugs in the CRC cell death pathway. The chemosensitivities of 12 CRC cell lines to established regimens [FX (5-FU + leucovorin + oxaliplatin) and FR (5-FU + leucovorin + irinotecan)], two biologically targeted drugs (bevacizumab + cetuximab) were comparatively evaluated through various cell death pathways; apoptosis, angiogenesis, invasion and autophagy. In this study, the cell deaths by apoptosis and invasion were associated with the respective chemotherapeutic regimens. Monotherapy using bevacizumab and cetuximab did not induce significant tumor inhibition, but treatment with combination of FX and FR led to significantly higher response rates than those to FX and FR alone. SW480 cell was expressed significantly higher apoptotic cell death and activasion of caspase-3 to the all drugs. Additionally, the MMP-9 activity remarkably reduced in the drug-treated SW480 cell compared with other cells. The SW480 cell shows the microsatellite-stable, functionally p53-deficient, hMLH1-proficient and kras mutation. These molecular and genentic profiling were associated with the chemosensitivity of SW480 cell to respective regimens. In future studies, it will important to combine these genetic profiling with the various CRC cancer cell death pathways to identify the tumor response to chemotherapy and finally realize an individualized treatment regimen to each patient.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 598. doi:10.1158/1538-7445.AM2011-598
Abstract 617: Small molecule that simultaneously inhibits Myc oncoprotein and activates HIF1A
Authors: Xue Chengyuan , Cheung Leanna , Norris Murray D. , Haber Michelle , Burkhart Catherine , Fedtsova Natalia , Gudkov Andrei , Makarov Sergei S.
Published: June 2012

Aberrant expression of Myc oncoproteins is a major causal factor in a large proportion of human cancer. In particular, MYCN oncogene amplification is one of the most powerful prognostic markers identified in the childhood cancer neuroblastoma and, as such, represents a valuable therapeutic target for the development of novel treatment approaches. A diverse chemical library of small molecules was screened using a cell-based assay to identify inhibitors of MYCN. Among a number of molecules identified as potential Myc inhibitors, M606 was found to reduce protein expression of MYCN and its downstream target genes in the MYCN-amplified neuroblastoma cell line BE(2)-C. A similar effect was also observed in a number of c-Myc over-expressing tumor cell lines. Analysis of signalling pathways affected by M606 using FACTORIAL™ technology (Attagene Inc.) indicated that this small molecule inhibited Myc mediated transcription in a dose-dependent manner. Interestingly, hypoxia inducible factor 1 alpha (HIF1A) was induced ∼100 fold. Consistently, we observed HIF1A protein accumulation and nuclear translocation post-M606 treatment under normoxic conditions accompanied by activation of transcription of the HIF1A target, VEGF. siRNA-mediated knockdown of c-Myc or HIF1A in HepG2 cells followed by M606 treatment demonstrated that downregulation of c-Myc and upregulation of HIF1A by M606 are two independent events. Furthermore, inhibition of HIF1A prolyl hydroxylases by dimethyloxalylglycine (DMOG) resulted in downregulation of c-Myc protein independent of any HIFA upregulation. These results suggest that the same molecular mechanism, targeted by M606 and presumably involving inhibition of prolyl hydroxylases, can affect both HIF1A and Myc but in opposite ways. Further development of this compound may be useful in the treatment of cancers in which Myc oncoproteins are overexpressed as well as in the treatment or prevention of ischemic injury since recent studies suggest HIF1A activation may protect against ischemia-reperfusion injury.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 617. doi:10.1158/1538-7445.AM2011-617
Abstract 631: Monovalency unleashes the full therapeutic potential of the DN-30 anti-Met antibody
Authors: Pacchiana Giovanni , Chiriaco Cristina , Stella Maria C. , Petronzelli Fiorella , De Santis Rita , Galluzzo Maria , Carminati Paolo , Comoglio Paolo M. , Michieli Paolo , Vigna Elisa
Published: June 2012

Met, the high affinity receptor for Hepatocyte Growth Factor (HGF), is one of the most frequently activated tyrosine kinases in human cancer and a validated target for cancer therapy. We previously developed a mouse monoclonal antibody directed against the extracellular portion of Met (DN-30) that induces Met proteolytic cleavage (receptor ‘shedding’) followed by proteasome-mediated receptor degradation, leading to inhibition of HGF/Met-mediated biological activities. However, DN-30 binding to Met also results in partial activation of the Met kinase due to antibody-mediated receptor dimerization. To safely harness the therapeutic potential of DN-30, its shedding activity must be disassociated from its agonistic activity. We have generated a DN-30 Fab fragment that maintains high affinity Met binding, elicits efficient receptor shedding and down-regulation, and does not promote kinase activation. In Met-addicted tumor cell lines, DN-30 Fab displays potent cytostatic and cytotoxic activity in a dose-dependent fashion. DN-30 Fab also inhibits anchorage-independent growth of several tumor cell lines. In mouse tumorigenesis assays using Met-addicted carcinoma cells, intra-tumor administration of DN-30 Fab or systemic delivery of a chemically stabilized form of the same molecule results in reduction of Met phosphorylation and inhibition of tumor growth. These data provide proof-of-concept that monovalency unleashes the full therapeutic potential of the DN-30 antibody and point at DN-30 Fab as a promising tool for Met-targeted therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 631. doi:10.1158/1538-7445.AM2011-631
Abstract 632: The efficacy of IGF-I receptor monoclonal antibody for human gastrointestinal carcinomas is independent for mutation status of k-ras
Authors: Adachi Yasushi , Yamamoto Hiroyuki , Ii Masanori , Li Hua , Ohashhi Hirokazu , Arimura Yoshiaki , Endo Takao , Imai Kohzoh , Carbone David P. , Shinomura Yasushisa
Published: June 2012

Background & Aims: Insulin-like growth factor (IGF)-I receptor (IGF-IR) signaling is required for carcinogenicity and proliferation of many tumors, including gastrointestinal cancers. We have previously shown successful therapy for colorectal, pancreatic, gastric, and esophageal carcinomas using recombinant adenoviruses expressing dominant negative IGF-IR. Mutation in k-ras is one of key factors in the patients with gastrointestinal cancers. In this study, we sought to evaluate the effect of a new monoclonal antibody for IGF-IR, figitumumab (CP-751,871), on the progression of human gastrointestinal carcinomas with/without k-ras mutation. Methods: We assessed the effect of figitumumab on signal transduction, proliferation, and survival in 6 gastrointestinal cancer cell lines with or without k-ras mutation, colon and pancreatic adenocarcinoma, esophageal squamous cancer; and hepatoceller carcinoma. Combination effects of figitumumab and chemotherapy were studied. Then figitumumab was evaluated in the treatment for human gastrointestinal. cancer xenografts in nude mice. Results: Figitumumab blocked autophosphorylation of IGF-IR and the downstream signals. The antibody suppressed proliferation and tumorigenicity in all cell lines. The drug inhibited survival by itself and up-regulated chemotherapy (5-FU and gemcitabine) induced apoptosis in all cell lines. Moreover, the combination of the monoclonal antibody and chemotherapy was effective against tumors on mice. The effect of figitumumab is not influenced by the mutation stasis of k-ras. Figitumumab reduced expression of IGF-IR but not insulin receptor in tumors on mice. The drug did not affect on neither murine body weight nor blood concentrations of glucose, insulin, IGFBP-3, and growth hormone. Conclusions: IGF-IR might be a good molecular therapeutic target and figitumumab may thus have therapeutic utility in human gastrointestinal carcinomas even if k-ras mutated types.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 632. doi:10.1158/1538-7445.AM2011-632