bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2763: Combination therapy of an acid-sensitive albumin-binding prodrug of doxorubicin (INNO-206) and an albumin-binding prodrug of methotrexate (AW054) that is cleaved by cathepsin B and plasmin induces complete remissions against pancreatic cancer in vivo (MiaPaca-2)
Authors: Kratz Felix , Azab Samar S E E A , Zeisig Rainer , Fichtner Iduna , Warnecke Andre
Published: August 2012

Pancreatic cancer is the fourth most common cause of cancer death across the globe. Pancreatic cancer has a poor prognosis. For locally advanced and for metastatic disease, which collectively represent over 80 % of individuals, median survival is approximately 10 and 6 months, respectively. Gemcitabine and 5-fluorouracil that have been approved for this indication have a poor response rate with a benefit in overall survival for a small population of treated patients of up to 2 months on average. Thus there is an unmet medical need for treating this tumor indication more effectively. INNO-206, the (6-maleimidocaproyl)hydrazone of doxorubicin (DOXO-EMCH) is an albumin-binding prodrug of doxorubicin with acid-sensitive properties that has shown objective responses in a phase I study, and phase II studies are scheduled in sarcoma for 2011/2012 (see www.cytrx.com). For treating essentially chemoresistant pancreatic cancer, we preclinically investigated a combination of two albumin-binding prodrugs, i.e. the albumin-binding prodrug INNO-206 and an albumin-binding prodrug of methotrexate, AW054, that is cleaved by two proteases that are over-expressed in solid tumors, cathepsin B and plasmin. In the pancreatic carcinoma xenograft model MiaPaca-2 both INNO-206 and AW054 were administered simultaneously (i.v.) in a three weekly schedule at half the maximum tolerated dose (MTD) of the respective prodrug, i.e. 3 x 12 mg/kg for INNO-206 (doxorubicin equivalents) and 3 x 10 mg/kg (methotrexate equivalents). Compared to doxorubicin (dosed at the MTD of 3 x 6 mg/kg) or methotrexate (dosed at the MTD of 3 x 125 mg/kg) or the combination of the two free drugs (3 x 3 mg/kg for doxorubicin and 3 x 62.5 mg/kg for doxorubicin) which only showed moderate antitumor effects over control animals treated with saline, the combination of the two albumin-binding prodrugs produced complete remissions and an acceptable body weight loss of −13 %. Immunohistochemical staining with CD31 that makes up a large portion of endothelial cell intercellular junctions was moderate to good in control tumors indicating a sufficient vascularity for the albumin-bound forms of the prodrugs to accumulate in the tumor via the EPR effect. This encouraging in vivo result is an impetus for investigating further combinations of albumin-binding prodrugs with other anticancer agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2763. doi:1538-7445.AM2012-2763
Abstract 2765: Combination strategies for management of ovarian cancer using doxorubicin and withaferin A
Authors: Kakar Sham S. , Gupta Ramesh C. , Fong Miranda Y.
Published: August 2012

Ovarian cancer is the 5th cause of cancer death in women with a mortality rate of 70%. Main treatment options include cytoreductive surgery with platinum-based therapy. However, 70% of patients relapse due to the carcinomas becoming platinum-resistant. As an alternative method, doxorubicin (Dox) is used for the treatment of several cancers, including ovarian. However, due to severe side effects, Dox is used as a second-line treatment strategy despite better patient response rates. To overcome this problem, we developed a novel treatment strategy that combines Dox with Withaferin A (WFA). WFA has been used as an anti-inflammatory and anti-bacterial compound in traditional Indian medicine. More recently, it has gained attention as an anti-cancer compound to prevent tumor growth, angiogenesis, and metastasis. We propose that combination of Dox with WFA will enhance the therapeutic effect of Dox so a lower dose of Dox can be used and many side-effects avoided. We used epithelial ovarian cancer cell line A2780 as our in vitro model. Based on our results, combination of Dox with WFA increased cell death over Dox or WFA alone measured by MTT assays. In particular, combination of Dox 200nM with WFA 2μM resulted in 90-95% cell death after 48 hr of treatment. Early apoptosis marker Annexin V-FITC was used to confirm these results as well as TUNEL assay for DNA damage. In addition, we have studied the signaling mechanism responsible for cell death through the inactivation of pro-survival Akt pathway. We demonstrated that down regulation of mTOR/p70S6K leads to autophagy and confirmed this with transmission electron microscopy, autophagy marker LC3B, and cleaved caspase 3. We have also validated this combination therapy in vivo using a xenograft model of ovarian cancer and showed reduction in tumor growth and weight as well as reduced Ki67 and CD31 staining. Mice tolerated receiving low dose of Dox (1 mg/kg) and combination Dox (1mg/kg) + WFA (2 mg/kg), whereas mice receiving high dose of Dox (9 mg/kg) did not tolerate treatment and died within 6 six days of treatment. Three dimensional tumor growth studies showed that treatment of tumors with Dox and WFA suppressed tumors growth by 80% within 3 days of treatment compared to untreated tumors. This work was supported by a grant from NCI CA124630 (SSK).Three dimensional tumor growth studies were performed in association with Vivo Biosciences Inc., Birmingham, AL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2765. doi:1538-7445.AM2012-2765
Abstract 2898: Intracellular dissociation of polymer coating from nanoparticles
Authors: Chen Hongwei , Zou Peng , Paholak Hayley , Sun Duxin
Published: August 2012

Polymer-coated nanoparticles are widely used for drug delivery in cancer therapy. However, it is not known whether the polymer coating will be disrupted in the lipid bilayer or intracellular space. Our current work suggests that the polymer coating of inorganic nanoparticles is disrupted after internalization by cancer cells. Single dispersed red quantum dots (QDs) labeled with 5-FAM (green) (D = 28 nm) were incubated with cancer cells (PC-3) and imaged via fluorescence microscopy. Initially the 5-FAM-labeled polymer coating was attached to the QDs and its green fluorescence was quenched when the nanoparticles were internalized from 2 to 4 hrs, but 5-FAM-labeled polymer became separated from the QDs once they are inside lysosome of cells and its fluorescence suddenly visible from 8 hrs. The fluorescence ratio (5-FAM/QDs) were increased by 29-fold after 8 h incubation compared to 2 h. The fluorescence quenching effect was compared to free PEG-5-FAM mixed with QDs, which only exhibited a 44% decrease in 5-FAM quenching. In addition, the intracellular dissociation of polymer coating from QD loaded micelles (D = 300 nm) was also observed. Furthermore, when labeled amphiphilic polymeric micelles encapsulate hydrophobic iron oxide nanoparticles (IONPs) with the hydrophobic dye BODIPY-TMR (red), double quenching was observed by encapsulated nanoparticles and the hydrophobic region inside the micelles by 8-fold fluorescence reduction. The BODIPY-TMR-labeled nanoparticles also showed polymer dissociation inside of cancer cells after 24 h incubation. These results suggest that polymer coating is stable in the lipid bilayer and it is dissociated from nanoparticles in the lysosome of cancer cells. These data will provide guidance for intracellular drug delivery using polymer coated nanoparticles.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2898. doi:1538-7445.AM2012-2898
Abstract 2899: Doxorubicin-mitomycin co-loaded polymer lipid nanoparticle enhanced efficacy against breast tumor and decreased toxicity as compared to Doxil
Authors: Prasad Preethy , Shuhendler Adam , Cai Ping , Sun Mei , Liu Peter , Bistrow Rob , Rauth Andrew , Wu Xiao
Published: August 2012

Background: Multidrug resistance acquired by cancer cells and the dose-limiting toxicity of anti-cancer drugs are contributing factors to the failure of cancer chemotherapy. Doxorubicin (Dox) -Mitomycin C (MMC) co-loaded stealth polymer lipid hybrid nanoparticles (DMsPLN) was developed to overcome these problems and demonstrated anti-cancer synergy in vitro. The purpose of the study is to evaluate in vivo efficacy and safety of DMsPLN in a breast cancer model. Method: The efficacy and systemic toxicity of DMsPLN were evaluated against clinically used Doxil in mice bearing murine or human mammary carcinomas. DMsPLN were administered intravenously at 50 mg/m2 doxorubicin single dose or once every 4 days for 4 cycles. Tumor size was measured as function of time to determine therapeutic efficacy of the treatment and systemic toxicity was monitored by repeated measurement of body weight. Results: Significant difference in the efficacy of DMsPLN relative to Doxil was observed in both sensitive and resistant tumor models. A clear enhancement of tumor growth delay (TLD) was evident with both single and 4 times doses of DMs PLN. In single dose and 4x dose DMsPLN groups, the TGD were significantly improved to 100% and 300% in the sensitive tumor model. In the resistant tumor model, the TGD ranged from 30%-130% for the single dose and the 4x dose DMsPLN, respectively. 10% of the mice showed complete tumor disappearance in DMs PLN and 25% complete tumor disappearance was observed in DMs PLN 4x group in the sensitive tumor model. 11% of the mice showed complete tumor disappearance in both DMs PLN and in DMs PLN 4x group in the resistant tumor model. In addition to enhanced efficacy, none of the toxicity associated with Doxil treatment were observed in single or 4x DMsPLN treatment. Conclusions: DMsPLN demonstrated enhanced efficacy and reduced toxicity over Doxil in aggressive mouse models of sensitive and resistant breast cancers. Therefore, DMsPLN may provide clinically relevant, more aggressive anti-cancer interventions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2899. doi:1538-7445.AM2012-2899
Abstract 2912: Development of potent SHP2 inhibitors for in vivo studies
Authors: Ge Yiyu , Lawrence Harshani R. , Chen Liwei , Scott Latanya M. , Sebti Said M. , Lawrence Nicholas J. , Wu Jie
Published: August 2012

The Src homology-2 domain-containing protein tyrosine phosphatase-2 (SHP2) is a positive transducer of growth factor, cytokine, integrin, and hormone signaling pathways which regulates processes such as cell proliferation, differentiation, adhesion, migration, and apoptosis and plays a pivotal role in growth factor and cytokine signaling. Gain-of-function SHP2 mutations are associated with various kinds of leukemia, and solid tumors. This makes SHP2 an attractive target for anticancer therapy. We are developing SHP2 inhibitors as novel anticancer drugs. Previously, we have reported on SPI-112 and its methyl ester prodrug SPI-112Me. However, the poor solubility of SPI-112Me has become an obstacle for in vivo studies. In ongoing study, we generate SPI-112 analogs to further improve physicochemical properties of these SHP2 inhibitors, such as solubility and cell permeability. To this aim, we synthesized SPI-112 derivatives containing various phosphotyrosine mimics and their prodrugs. SPI-112 derivatives of SHP2 inhibitors having improved properties have been obtained in this effort.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2912. doi:1538-7445.AM2012-2912
Abstract 294: Sox2 remodels the tumor microenvironment via recruitment of Tregs
Authors: Xu Yingxi , Mou Wenjun , Chen Yanan , Wang Lina , Xiang Rong , Li Na
Published: August 2012

Recent study showed that Sox2 gene, a key stem cell gene that maintains the pluripotency properties of embryonic stem cell (ESC) and cancer stem cell (CSC) plays an important role in the tumorigenesis and metastasis process of various types of tumor, however its regulatory effect on tumor microenvironment (TME) is still elusive. In this study, we established a BALB/c mice model xenografted with a mice breast cancer cell line-4T1 with down-regulation of Sox2 gene (4T1-shRNA-Sox2). We found that down-regulation of Sox2 inhibits the growth of tumors with a modulated immunomicroenvironment, which was reflected by the increased number of CD3+CD8+ T cells and expression level of Th1 cytokines, such as TFN-γ and decreased number of Foxp3+ Tregs and expression level of Th2 cytokines such as IL4, IL6 and IL10. In addition, the reduced expression level of vascular endothelial cell marker CD31 and lymphatic vessel marker Lyve-1 was also revealed in the 4T1-shRNA-Sox2 xenografted tumors. We further demonstrated that Sox2 modulates the TME by recruiting Tregs. By using real-time RT-PCR, we found the cytokines contributing to recruitment of Tregs, such as CCL1, CCL22, CCL28 and Cxcl12 reduced after Sox2 downregulation. In addition, the mRNA expression level of transcriptional factor NF-κB and its co-transcriptional factor RelA which controlled the expression of CCL1, CCL22 and CCL28 were also reduced. Consequently, our study revealed the functional interaction between tumor cells and the immunocytes in TME by demonstrated that Sox2 gene in tumor cells recruited Tregs to influence the tumor microenvironment thus promotes the growth of tumor.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 294. doi:1538-7445.AM2012-294
Abstract 2941: Inhibition of proteasome deubiquitinating activity as a novel cancer therapy
Authors: D'Arcy1 Pádraig , Brnjic1 Slavica , Olofsson Maria H. , Fryknas Marten , Larsson Rolf , Linder Stig T.
Published: August 2012

Tumor cells display enhanced sensitivity to disruptions in the ubiquitin-proteasome system making this an attractive target for the development of anti-cancer therapies. Ubiquitin-tagged substrates are degraded by the 26S proteasome; a multisubunit complex comprising a proteolytic 20S core particle (20S CP) capped by 19S regulatory particles (19S RP). The 20S CP has evolved as an important target for anti-cancer drug development, resulting in the approval of bortezomib (Velcade®) for the treatment of multiple myeloma. We have identified the small molecule b-AP15 as a novel class of proteasome inhibitor that functions by abrogating the deubiquitinating (DUB) activity of the 19S RP (D'Arcy, Brnjic et al., Nature Medicine Epub Nov 6 2011). b-AP15 inhibits the activity of two 19S RP-associated DUBs, UCHL5 and USP14. Consistent with DUB inhibition, treatment with b-AP15 caused the accumulation of polyubiquitinated proteins with higher molecular weight compared to bortezomib treatment and induced a stronger proteotoxic response. Short exposures were sufficient for induction of apoptosis by the compound. Importantly, apoptosis induction by b-AP15 differed from that of bortezomib by being insensitive to disruptions of the p53 tumor suppressor and insensitive to overexpression of the intrinsic apoptotic suppressor Bcl-2. b-AP15 shows strongest activity on colon and glioma tumor cell lines and is less active on non-transformed cells. Treatment with b-AP15 inhibited tumor progression in human and mouse tumor in vivo models of breast, lung, colon, head & neck carcinoma and inhibited organ infiltration in an acute myeloid leukemia (AML) model. Our results suggest that inhibiting the DUB activity of the 19S RP may be a novel target for the treatment of cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2941. doi:1538-7445.AM2012-2941
Abstract 297: Effect of hypoxia on the expression of the T cell co-inhibitory ligands B7-H3 and B7-H1 in cancer
Authors: Smallwood Chelsea A. , Barsoum Ivraym B. , Graham Charles H.
Published: August 2012

Escape from adaptive immunity is important for malignant progression. B7-H3 and B7-H1 ligands provide co-inhibitory signals to T cells resulting in T cell anergy or apoptosis. Their expression has been shown to increase in cancer cells and to correlate with disease progression. Tumour hypoxia is a major contributor to the spread of cancer and resistance to radiation and chemotherapy. We proposed that hypoxia results in the up-regulation of the B7 molecules B7-H3 and B7-H1, thus contributing to immune escape. Using breast and prostate cancer cell lines, we investigated whether hypoxia increases the expression of these ligands and, if so, whether the transcription factor hypoxia-inducible factor-1 (HIF-1) is required for this hypoxic effect. We incubated MDA-MB-231 breast cancer cells and DU145 prostate cancer cells in standard culture conditions (20% O2, 37°C, 5% CO2), hypoxic conditions (0.5% O2, 37°C, 5% CO2), or with 100μM CoCl2 (known to stabilize HIF-1α) for 24 hours. Our findings revealed that B7-H3 expression is not increased in hypoxia. However, hypoxia and exposure to CoCl2 increased B7-H1 expression, which correlated with the levels of HIF-1α accumulation. Furthermore, HIF-1α knockdown attenuated B7-H1 mRNA levels. These results indicate a role for hypoxia in the up-regulation of B7-H1 on cancer cells, thus potentially contributing to immune escape of cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 297. doi:1538-7445.AM2012-297
Abstract 2973: Adhesion of tumor cells to ECM microarrays identifies novel ECM interactions in metastasis
Authors: Reticker-Flynn Nathan E. , Malta David F. Braga , Winslow Monte M. , Xu Mary J. , Lamar John M. , Hynes Richard O. , Jacks Tyler E. , Bhatia Sangeeta N.
Published: August 2012

Extracellular Matrix (ECM) interactions play an essential role in all phases of tumorigenesis and metastasis. Here, we report a novel ECM microarray platform for investigating the combinatorial effects of ECM adhesion on cancer metastasis. This platform is composed of micropatterned spots of nearly 800 unique ECM combinations, and can be used to measure cellular adhesion, proliferation, marker expression, or any other phenotypic responses that can be queried by microscopy. Using a genetic model of lung adenocarcinoma (KrasLSL-G12D/+;p53flox/flox), we tested the adhesion of cell lines derived from tumors throughout the stages of tumor progression. We found that the adhesion profiles of primary tumors and their metastases could be distinguished by Euclidian clustering whereas gene expression profiles of the same cells could not. In particular, we identified combinations of ECM molecules that exhibited preferential adhesion to either the metastatic or primary tumor cell lines. Histological examination of tissues from mice bearing the autochthonous tumors confirmed that the primary tumor-associated molecules are present in the lungs but not the sites of metastases. Conversely, metastasis-associated ECM molecules were not present in the primary tumors, but were expressed at the metastatic sites. From the known integrin-ECM interactions, we then identified several integrins as playing a functional role in ECM interactions during lung cancer metastasis. Flow cytometry confirmed higher expression of these candidates on the cell surface of the metastatic lines than the primary lines. Knockdown of integrin expression in the metastatic cells by shRNAs reduced the adhesion of the cells to the cognate ECM molecules in vitro, confirming a functional role in our phenotypic assay. Additionally, abrogation of cell-ECM interactions through inhibition of contact between the metastasis-associated molecules and the receptors on the metastatic cells prevented metastases from seeding in vivo. Thus, ECM microarrays offer a novel platform for the phenotypic characterization of tumor cells from different stages of tumor progression, identification of key ECM interactions, and the identification of potential therapeutic targets in cancer metastasis. In the future, we will apply the ECM Microarrays for the stratification of patients to assist in diagnostics and treatment guidance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2973. doi:1538-7445.AM2012-2973
Abstract 2975: Transgenic mouse model of Twist1-induced metastasis reveals genes highly prognostic for human hepatocellular carcinoma
Authors: Bellovin David I. , Tran Phuoc T. , Adam Stacey J. , Gentles Andrew J. , Wang Xin W. , Felsher Dean W.
Published: August 2012

Hepatocellular carcinoma (HCC) is a top global cancer health concern due to its high rate of mortality and increasing incidence. HCC lethality is largely attributable to its poor response to existing therapy and frequent diagnosis at late stage of disease, consequently resulting in HCC that progresses to local invasion and distant metastasis. Expression of Twist1 has been correlated with cancer invasion and metastasis, but a causal role has yet to be established for autochthonous tumors. Here, we report a new conditional transgenic mouse model of Twist1- and MYC-induced primary hepatocellular carcinoma (HCC). Expression of MYC alone produced primary tumors, but failed to induce metastasis, while Twist1 co-expression with MYC caused extra-hepatic metastases to the lymph nodes, spleen, peritoneum, and lungs. Moreover, Twist1 expression caused an increase in circulating tumor cells (CTCs). Combined Twist1 and MYC inactivation resulted in sustained regression of both primary and metastatic HCC as shown by X-ray computed tomography (micro-CT) and bioluminescence imaging (BLI) and the suppression of metastasis as measured by a loss of CTCs. Importantly, gene expression profiling illustrated that our mouse model of Twist1/MYC-induced liver cancer was representative of human HCC. Moreover, we exploited the Twist1-induced progression to identify a gene signature in Twist1/MYC tumors that is highly predictive of metastasis in human HCC patients, as well as prognostic for overall survival. Hence, we show that Twist1 expression can causally induce stepwise disease progression to metastasis in primary HCC, allowing for the identification of a gene signature that is highly predictive of clinical outcome in human liver cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2975. doi:1538-7445.AM2012-2975
Abstract 2979: Epithelial-mesenchymal gene expression signature defines clinically relevant subtypes in epithelial ovarian cancer
Authors: Huang Ruby YJ , Tan Tuan Zea , Wong Meng Kang , Matsumura Noriomi , Lai Hung Cheng , Chung Vin Yee , Ye Jieru , Mori Seiichi , Thiery Jean Paul
Published: August 2012

Epithelial ovarian cancer (EOC) represents a broad and heterogeneous entity which includes different invasive behavior as well as distinct histopathological subtypes. The heterogeneity of EOC is further complicated by the fact that EOC is characterized by a high degree of genetic damages and multiple genetic alterations resulting from different mechanisms. Even within the seemingly similar histo-pathological group, molecular subtypes with different gene/pathway activations have been identified. In this study, we described a classification scheme based on in silico meta-analysis of gene expression profiling of 1,538 EOC microarray data. and identified five major robust subtypes termed Epithelial-A, Epithelial-B, Mesenchymal, Stem-A, and Stem-B that were distinctive in gene expression patterns. The epithelial subtype is hallmarked by genes known to confer epithelial characteristics, such as Keratin genes (KRT17, 14, 19, and 7), E-cadherin (CDH1), and Ep-CAM (EPCAM) and show the second best prognosis in Kaplan-Meier analysis. On the other hand, the mesenchymal subtype consists of genes such as fibronectin (FN1) and known EMT inducers ZEB1 and TWIST1. The Stem-A subtype consists of genes which confer stemness (LGR5, NCAM1). The Mesenchymal and Stem-A subtypes are linked with poorer outcomes. We further utilized a panel of 42 ovarian cancer cell lines to model EMT in vitro by performing phenotypic EMT characterization. Four EMT subgroups (epithelial, intermediate epithelial, intermediate mesenchymal, mesenchymal) representing different epithelial-mesenchymal compositions on the EMT spectrum were identified. We also demonstrated that this EMT spectrum can be used to refine the analysis of data generated in cell-based functional studies. By performing EMT-related functional assays, we found that ovarian cancer cells harbouring intermediate phenotypes are more migratory, invasive, anoikis resistant, and more spheroidogenic. We further utilized this cell line model to apply a cell line-based EMT scoring system to re-classify the 1,538 EOC microarray data. It revealed that the Mesenchymal and Stem-A subtypes were both enriched in higher mesenchymal scores. This supported the hypothesis of EMT's contribution to the aggressiveness of solid tumors. In conclusion, our results showed that EOC is sub-classified into distinct molecular subtypes correlated with clinical outcomes that are linked to EMT.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2979. doi:1538-7445.AM2012-2979
Abstract 299: Modulation of the leptin receptor in pancreatic cancer cells mediates tumor growth
Authors: Mendonsa Alisha , Chalfant Madeleine , Nagathihalli Nagaraj , Merchant Nipun , Gorden Lee , VanSaun Michael N.
Published: August 2012

Background: Pancreatic cancer is the fourth leading cause of cancer death with a five year survival rate around 5%, which has not changed in 30 years. Obesity and increased abdominal adipose tissue independently correlate with an increased relative risk for the development of pancreatic cancer. These conditions have been associated with altered levels of adipokines, or adipose secreted cytokines. Circulating serum levels of the adipokine leptin are increasesddramatically in obese patients as well as in high fat diet induced obese mice. Leptin has been shown to induce oncogenic signaling in breast and prostate cancer. We have previously shown an increase in orthotopic pancreatic tumor size in high fat diet induced obese mice compared with regular diet control mice. We hypothesize that leptin signaling mediates pancreatic tumorigenesis. Methods: Leptin receptor status was determined in human as well as murine pancreatic cell lines. Leptin stimulated cell proliferation was determined using a modified BrdU assay. Leptin receptor levels were knocked down in human and murine pancreatic tumor cells using a shRNAmir approach. Leptin receptor shRNA Panc02 knockdown cells were injected orthotopically into the pancreas of C57/Bl6J mice on regular or high fat diet to determine the contribution of leptin to pancreatic tumor growth. Results: We have detected the long form of the leptin receptor in five human and four murine pancreatic cancer cell lines. In vitro administration of leptin stimulated proliferation of Panc1 and CFPAC1 cell lines, which was abrogated with co-incubation of a leptin antagonist. To better understand the mechanism of leptin-mediated signaling, we studied downstream targets and identified a significant increase in phosphorylation of STAT3 in Panc1, BXPC3 and CFPAC1 cell lines after leptin treatment. Orhtotopic injection of leptin receptor shRNA Panc02 cells into normal and obese mice showed a markedly diminished tumor growth in obese mice when compared to the nonsilencing control Panc02 cell growth in obese mice. Conclusion: These results implicate leptin as a mediator of pancreatic tumorigenesis and suggest that leptin activation is mediated in part through STAT3 signaling. Knockdown of the leptin receptor results in inhibition of high fat diet associated tumor growth in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 299. doi:1538-7445.AM2012-299
Abstract 3005: Characterization of a lung cancer growth factor, LASEP1 as a serological and prognostic biomarker and a therapeutic target
Authors: Takano Atsushi , Nakamura Yusuke , Daigo Yataro
Published: August 2012

To identify molecules that might serve as biomarkers or targets for the development of novel molecular therapies, we have been screening genes encoding transmembrane/secretory proteins that are up-regulated in lung cancers, using cDNA microarrays. During this process, we identified a secreted protein, LASEP1 (lung cancer-associated serum protein 1) as a candidate. Immunohistochemical staining using tumor tissue microarrays consisting of 374 non-small cell lung cancers (NSCLC) revealed that LASEP1 protein was frequently over-expressed in lung cancers; positive staining of LASEP1 was observed in 210 (56.1%) of 374 NSCLC, while that was observed in 9 (69.2%) of 13 small cell lung cancers (SCLC). In addition, a strong LASEP1 positivity was associated with poor prognosis for patients with NSCLC (P<0.001 by log-rank test), and multivariate analysis confirmed its independent prognostic value. Serum LASEP1 levels were higher in NSCLCs as well as SCLCs patients than in healthy volunteers. The proportion of serum LASEP1-positive cases was 127 (38.6%) of 329 lung cancers, while 4 (3.9%) of 102 healthy volunteers were falsely diagnosed. Furthermore, treatment of lung cancer cells with siRNAs against LASEP1 suppressed its expression and resulted in growth suppression of the lung cancer cells; on the other hand, induction of exogenous expression of LASEP1 conferred growth-promoting activity and enhanced the cell mobility in vitro. Interestingly, the growth activity of the LASEP1-positive cells was neutralized by addition of originally developed anti-LASEP1 monoclonal antibodies into their culture media. The systemic administration of the anti-LASEP1 antibody to LASEP1-positive tumor-implanted mice significantly suppressed tumor growth without any adverse events. We found a receptor (LASEPR) which interacts with LASEP1 on lung cancer cell surface and is essential for the growth of cancer cells. The data suggest that the LASEP1-LASEPR interaction could promote the cancer cell growth in an autocrine manner. LASEP1 is a potential serological and prognostic biomarker and a therapeutic target for lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3005. doi:1538-7445.AM2012-3005
Abstract 3010: IL-6 enhances migration and ICAM-1 expression of human oral squamous cell carcinoma involves IL-6 receptor signaling pathway
Authors: Yen Wei-Lin , Chuang Jing-Yuan , Tang Chih-Hsin
Published: August 2012

Oral squamous cell carcinoma(SCC) has a striking tendency to migration and metastasize. Interleukin-6(IL-6) has been implicated in the promotion of many cancers proliferation and migration. Intercellular adhesion molecule-1(ICAM-1), a member of the immunoglobulin supergene family, is an inducible surface glycoprotein that mediates adhesion-dependent cell-to-cell interactions. However, the effects of IL-6 in migration and ICAM-1 expression in human oral cancer cells are largely unknown. We found that IL-6 increased migration and ICAM-1 expression in human oral cancer cells. Using a specific inhibitor and genetic inhibition of IL-6 receptor, we discovered that the IL-6 receptor is involved in migration and ICAM-1 expression of human oral cancer cells. IL-6-mediated migration and ICAM-1 up-regulation were attenuated by inhibitor of Syk, JNK and AP-1. Activation of the Syk, JNK and AP-1 signaling pathway occurred after IL-6 stimulation. IL-6 induced AP-1 activity was inhibited by Syk and JNK inhibitor. Our results indicated that IL-6 enhances the migration of human oral cancer cells by increasing ICAM-1 expression through the IL-6 receptor, Syk, JNK and AP-1 signal transduction pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3010. doi:1538-7445.AM2012-3010
Abstract 3070: Activated EGFR and PPARδ regulate MUC1 expression in human uterine and pancreatic cancer cell lines
Authors: Dharmaraj Neeraja , Carson Daniel D.
Published: August 2012

The high molecular weight, transmembrane mucin, MUC1 is expressed at high levels in many epithelial tumors including endometrial and pancreatic cancers. Aberrant glcosylation and overexpression of MUC1 make tumor cells poorly adherent, protect tumor cells from the host immune system, promote metastases from primary sites and enhance resistance to chemotherapeutic drugs. MUC1 has three distinct domains: an extracellular domain (ECD) composed of a tandem repeat region rich in serine, threonine and proline; a transmembrane domain (TM) and; a short cytoplasmic tail domain (CT) involved in a variety of signal transduction events. Epidermal Growth Factor Receptor (EGFR/erbB) family members regulate cell growth and survival in both normal and cancer cells. MUC1 interacts with erbB receptors and also affects downstream signaling pathways in a EGFR-ligand dependent manner. We previously demonstrated that the Peroxisome Proliferator Activated Receptor ≤ (PPARδ) agonist rosiglitazone severely inhibits progesterone stimulated MUC1 expression (Wang et al. 2010. Mol. Endocrinol. 24: 1368-1379). Two independent approaches were used to determine if rosiglitazone as well as EGFR tyrosine kinase inhibitor, AG1478 reduced MUC1 expression in a high MUC1-expressing cell line, HES; the uterine adenocarcinoma cell line, HEC-1A; and in the human pancreatic adenocarcinoma cell lines, HPAFII and CAPAN2. EGFR activation by Epidermal Growth Factor (EGF) stimulated MUC1 protein expression (1.5-2 fold) in both uterine and pancreatic cancer cells. The PPARδ agonist, rosiglitatzone, markedly (> 90%) reduced EGFR-driven MUC1 expression detected by antibodies directed against the MUC1 ECD and CT. Preliminary studies indicate that rosiglitazone effects on EGFR-driven MUC1 expression is indirect. Furthermore, rosiglitazone treatments enhanced EGFR degradation via the lysosomal degradation pathway in the presence of EGF-family ligands in both uterine and pancreatic cancer cell lines. A combination of biochemical and molecular biological assays have been used to identify the transcriptional and signal transduction pathways activated by EGFR, leading to increased MUC1 expression and the impact of AG1478 and rosiglitazone on these events. Understanding the molecular basis of how these agents reduce MUC1 expression may offer novel therapeutic avenues to improve cancer chemotherapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3070. doi:1538-7445.AM2012-3070
Abstract 3072: HER2 signaling affects SRC-3 phosphorylation and gene regulatory potential within the cistrome
Authors: Nikolai Bryan C. , Smith Carolyn L. , O'Malley Bert W.
Published: August 2012

Steroid Receptor Coactivator-3 (SRC-3/AIB1) is a potent transcriptional coregulator for nuclear receptors and other transcription factors and is often amplified or overexpressed in tumors. The growth promoting effects of SRC-3 involve its ability to integrate extracellular signals into discrete patterns of gene expression. SRC-3 is regulated by various post-translational modifications, including multiple phosphorylations that define a combinatorial code that tailors SRC-3 activity in response to specific signaling stimuli. HER2 is a member of the ErbB receptor tyrosine kinase family of growth factor receptors and is often associated with cancer. Clinical studies show that breast cancer patients with tumors expressing high levels of both HER2 and SRC-3 have reduced disease-free survival, and SRC-3 phosphorylation is influenced by HER2. The current study seeks to define the effect of HER2 signaling events on SRC-3 activity in breast cancer cells. HER2 knock down using siRNA affects multiple kinase pathways, as evidenced by decreased AKT and c-Raf phosphorylation. HER2 knockdown causes the isoelectric point of SRC-3 to shift, suggesting that post-translational modification of SRC-3 is actively altered by HER2 signaling. Reduction of SRC-3 phosphorylation in HER2-depleted cells also was evident using a phospho-specific antibody to SRC-3. Expression microarray analysis revealed that many genes are altered by HER2 knockdown. Parsing the microarray with SRC-3 ChIP-seq data identified genes that are coordinately regulated by a HER2/SRC-3 signaling axis. Collectively, this work describes transcriptomic and cistromic mechanisms for oncogenic cooperation between HER2 and SRC-3 and identifies key genes that contribute to proliferation of breast cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3072. doi:1538-7445.AM2012-3072
Abstract 3076: p53 homologue p63 trans-activates epidermal growth factor (EGF) receptor and 14-3-3α and thus promotes tumorigenesis and chemoresistance in pancreatic cancer
Authors: Danilov Alexey V. , Srivastava Amitabh , Feofanova Elena V. , Humphries Leigh Ann , Direnzo James , Korc Murray
Published: August 2012

Pancreatic cancer is the 4th leading cause of cancer-related mortality in the United States. Despite these statistics, progress in therapy of pancreatic cancer has been slow. p53 tumor suppressor pathway is altered in 50-75% of pancreatic cancer tumors. However, the role of p53 homologs p63 and p73 has not been well studied. We previously reported that p63 is expressed in pancreatic cancer cell lines and contributes to their motility and invasion. Here we tested expression of p63 in resected tumors and investigated its role as a transcription factor in pancreatic cancer. Expression of p63 was determined by immunohistochemistry in 20 resected tumor samples (15 - adenocarcinoma, 5 - squamous) using pan-p63 (clone 4A4) and ΔNp63-specific antibodies; and by immunoblotting, real-time quantitative and semi-quantitative PCR in 5 pancreatic cancer cell lines. p63 levels were manipulated employing transient overexpression and lentiviral approaches. We studied cell doubling times, motility in a wound assay and invasiveness in Matrigel chambers in the presence or absence of epidermal growth factor (EGF). Functional reporter and chromatin immunoprecipitation assays were performed to study the effects of p63 on selected promoters. We found that the p53 homolog p63 was expressed in resected pancreatic cancer samples. Pancreatic tumors with squamous differentiation showed strong diffuse expression of p63, whereas adenocarcinomas without squamous component had a focal expression of p63 (ΔNp63). In pancreatic cancer cell lines, p63 protein levels were high in 3/5 tested cell lines and ΔNp63α was the predominantly expressed variant. By contrast, TAp63 was not detected while p73 was barely detectable in 2/5 cell lines. Ectopic expression of ΔNp63α in PANC-1 cells (which had low endogenous p63) and shRNA-mediated knockdown in T3M4 cells (with high endogenous p63) indicated that ΔNp63α promoted anchorage-dependent and independent growth, motility and invasion, and enhanced resistance to cisplatin-induced apoptosis. Motogenic effects of ΔNp63α were augmented in presence of EGF. ΔNp63α augmented the EGF receptor expression in pancreatic cancer cells via transcriptional regulation and potentiated EGF-mediated activation of ERK, Akt and JNK signaling. 14-3-3α transcription was also positively regulated by ΔNp63α and we have previously shown that 14-3-3α contributes to chemoresistance in pancreatic cancer. Thus, p53 homolog ΔNp63α is expressed in pancreatic cancer, where it enhances tumor progression and chemoresistance via trans-activation of EGF receptor and 14-3-3α.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3076. doi:1538-7445.AM2012-3076
Abstract 308: Tumor hypoxia promotes tolerance and angiogenesis via CCL28 and Treg cells
Authors: Facciabene Andrea , Coukos George
Published: August 2012

Although immune mechanisms can suppress tumor growth, tumors establish potent and overlapping mechanisms that mediate immune evasion. Emerging evidence suggests a link between tumor immune tolerance and angiogenesis. Hypoxia, a condition known to drive tumor angiogenesis, results in release of damage-associated molecular pattern molecules, which can trigger tumor immune rejection. Thus, counter-activation of tolerance mechanisms at the site of tumor hypoxia would be a critical condition to maintain immunologic escape of tumors. However, a direct link between tumor hypoxia and tolerance through the recruitment of regulatory cells has not been established. We hypothesized that tumor hypoxia induces expression of chemotactic factors promoting tolerance. Here we show that tumor hypoxia promotes T regulatory (Treg) cell recruitment via the CCL28 chemokine, which in turn promotes tumor tolerance and angiogenesis. Thus, peripheral immune tolerance and angiogenesis are intimately connected and cooperate to sustain tumor growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 308. doi:1538-7445.AM2012-308
Abstract 3096: ICAD deficiency in human colon cancer and predisposition to colon tumorigenesis in mice: Linkage to resistance to apoptosis and susceptibility to genomic instability
Authors: Errami Youssef , Brim Hassan , Naura Amarjit , Kim Hogyoung , Jihang Ju , Xu Ming , Zhang Jianhua , Valle Luis Del , Boulares Hamid
Published: August 2012

We previously showed that DNA fragmentation factor, which comprises a caspase-3-activated DNase (CAD) and its inhibitor (ICAD), may influence the rate of cell death by generating PARP-1-activating DNA breaks. Here we tested the hypothesis that ICAD-deficient colon epithelial cells (CECs) exhibiting resistance to death stimuli may accumulate additional genetic modifications, leading to a tumorigenic phenotype. We show that ICAD deficiency is highly associated with colon malignancy in humans. Upon DNA damage caused by a low dose of irradiation, ICAD-/- cells acquire a tumorigenic phenotype. CECs derived from ICAD-/- mice showed a marked resistance to death induced by the colon carcinogen dimethylhydrazine (DMH) in vitro and in mice. Such resistance was associated with a decrease in PARP-1 activation. In an animal model of DMH-induced colon tumorigenesis, ICAD-/- mice developed significantly higher numbers of tumors with markedly larger sizes than the wild-type counterparts. Interestingly, the phenotype of the ICAD-/- mice was not associated with a significant increase in the precancerous aberrant crypt foci suggesting a link to tumor progression rather than initiation. More importantly, ICAD deficiency was associated with severe genomic instability, constituting most prominently of amplifications but with sizable deletions as compared to the wild-type counterparts affecting several cancer-related genes including RAF-1, GSN, LMO3, and Fzd6 independently of p53. Our results present a strong case for involvement of ICAD deficiency in colon carcinogenesis and show that apoptosis and genomic instability may comprise the means by which such deficiency may contribute to the process of increasing susceptibility to carcinogen-induced tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3096. doi:1538-7445.AM2012-3096
Abstract 3104: Genome-wide screen for modulators of cell death induced by the NEDD8-activating enzyme inhibitor MLN4924
Authors: Cosmopoulos Kat , Blank Jonathan , Liu Xiaozhen , Bouck David , Garcia Khristofer , Liao Hua , Bernard Hughes , Tayber Olga , Hather Greg , Liu Ray , Lightcap Eric
Published: August 2012

The NEDD8-activating enzyme (NAE) is an E1 involved in the activation of a large family of ubiquitin E3 ligases termed the cullin-RING ligases (CRLs) through conjugation of the cullin proteins with the ubiquitin-like modifier NEDD8. Polyubiquitination of CRL substrate proteins targets them for degradation by the proteasome. In this way, NAE regulates the stability of proteins required for cancer cell growth and survival. MLN4924 is an investigational small molecule that is a potent and selective inhibitor of NAE in Phase I clinical trials. In order to investigate the primary genetic determinants that confer sensitivity of cells to NAE inhibition, we have performed a genome-wide synthetic lethal RNAi screen using MLN4924 in the A375 melanoma cell line. We have also investigated the biological consequences of NAE inhibition by studying the regulation of protein and transcript levels in MLN4924-treated A375 cells using large-scale quantitative proteomics and gene expression profiling, respectively. The RNAi screen has identified 123 genes whose down-regulation modulates MLN4924-induced cell death, and approximately one-third of these interfere with components of the NEDD8 pathway itself, the cell cycle and apoptotic machinery, and DNA damage-response pathways. Of these genes, 99 were subsequently assessed using high throughput FACS analysis for their contribution to the major phenotype induced by MLN4924. The results emphasize replication, p53, BRCA1/BRCA2, and transcription-coupled repair as being particularly important for MLN4924-induced cell death. In addition, the interactions of 80 genes with roles in cell cycle and DNA damage repair were explored with proteasome inhibitors and 12 DNA damaging agents, demonstrating that MLN4924 induces DNA damage by a distinct mechanism.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3104. doi:1538-7445.AM2012-3104