bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 147: ER-α36 plays an important role in estrogen-dependent growth of gastric cancer cell line BGC823
Authors: Zou Feng , Deng Hao , Zhen Hongyan , Wang Xuming , Liu Lijiang
Published: August 2012

Aims: We aimed to investigate the role of estrogen-development signal in growth of gastric cancer cell, and the expression and location change of new estrogen receptor ER-α36 in gastric cancer cell when dealt with estrogen. Methods: Gastric cancer BGC823 was chosen as research model and 17β- estradiol (E2) was used to deal with cell. Cell growth was examined by WST-1 method and assayed by microplate reader. ER-α36 expression in mRNA and protein level was assayed by RT-PCR and Western-blot methods and was quantitated. The location of ER-α36 in cell was examined by immunofluorenscence methods. Result: The cell numbers significantly increased in all E2 treatment groups compared with control group and the number of the cell was more at 48h than 24h in E2 treatment groups (p<0.05), but with E2 concentration increased, cell growth rate slowed down. ER-α36 mRNA expressions of all E2 treatment groups were more than that of control group at 24h and 48h, and had a concentration-dependent of E2 (p<0.05). ER-α36 protein expression had a concentration-dependent of E2 and was less at 48h than 24h in E2 treatment groups (p<0.05). E2 treatment groups’ protein expression were more than control group's at 24h (p<0.05), and were less than control group's at 48h (p<0.05). ER-α36 is localized on the membrane and cytoplasm of BGC823 cell, and its location did not change dealt with E2. Conclusion: E2 could promote the growth of BGC823 cell, and estrogen in different concentration may play different role in the growth regulation of gastric cancer. ER-α36 could response to estrogen-dependent signaling of growth and may transmit it through a membrane-based pathway in gastric cancer. There were regulations in transcription and translation of ER-α36 in gastric cancer. ER-α36 was an important estrogen receptor in gastric cancer and may be a potential predicted marker of gastric 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 147. doi:1538-7445.AM2012-147
Abstract 1485: The role of angiopoietin family members in the progression of ovarian cancer
Authors: Brunckhorst Melissa K. , Yu Qin
Published: August 2012

Despite advances in surgical debulking, radiation, and chemotherapy over the past few decades, ovarian carcinoma remains the most deadly gynecological malignancy. This is largely due to the lack of early stage detection manifesting in approximately 80% of patients presenting with metastatic disease at the time of diagnosis. Current chemotherapeutic drugs are effective only for a short period as patients with advance disease eventually develop resistance despite significant initial responses. Thus, there is a pressing need for the identification of novel therapeutic targets in ovarian cancer. Mounting evidence suggests that the Angiopoietin/Tie-2 functional axis has wide-ranging effects on tumor angiogenesis and progression of a variety of cancer types, however, the expression profiles and biological effects of the Angiopoietin family members on ovarian cancer remain largely unknown. Our data show for the first time that Ang-1, Ang-2 and Ang-4 are expressed in ovarian cancer cell lines and patient samples from both primary and secondary tumor lesions. More specifically, patient tumors revealed a unique localization pattern of Angiopoietin family members whereby Ang-1 and Ang-2 are robustly expressed in tumor cells and stroma, whereas Ang-4 expression is predominately in the tumor stroma. In addition, we show that overexpression of Ang-4 and Ang-2 and, to a lesser extent, Ang-1, promotes subcutaneous growth of ovarian cancer cells and results in accelerated ascites formation and poor survival in an orthotopic ovarian cancer mouse model. Immunohistochemical analysis of orthotopic tumors suggests the pro-growth effects of Ang-1 and Ang-4 are mediated through increased tumor cell proliferation as determined by positive Ki67 staining. Our results also demonstrated that ovarian cancer cells express Tie-2 receptor tyrosine kinase (RTK), the angiopoietin receptor. The expression of Tie-2, as well as angiopoietin family members, by ovarian cancer cells suggests the potential of an Angiopoietin/Tie-2 autocrine loop. Lastly, further analysis suggests the potential role of angiopoietins in increasing the amount of cancer associated fibroblasts (CAFs) in the tumor microenvironment. Taken together, our data suggest that the Angiopoietin/Tie-2 functional axis is a significant player in ovarian cancer progression and is a potential target for ovarian cancer therapy.

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 1485. doi:1538-7445.AM2012-1485
Abstract 1498: Breast adipose mesenchymal stem cells and mammary fibrosis
Authors: Bristol Molly L. , Sachs Patrick , Wang Xu , Zhao Min , Elmore Lynn
Published: August 2012

Introduction: At a biochemical level, the most common symptom of aging and its related pathologies (i.e. cancer) is the accumulation of altered or abnormal proteins. Aberrant proteins can induce oxygen free radical generation and inflammation; additionally an abnormal inflammatory response can lead to over-production and deposition of extracellular matrix (ECM) components, leading to fibrosis. The linkage between fibrosis and cancer is well established in the lung; alternatively breast fibrosis is a less understood phenomenon. Fibrosis is characterized by the excess production and altered composition and crosslinking of the ECM. Myofibroblasts are the principal mediators of fibrosis, producing abundant ECM as well as inflammatory and angiogenic factors; chronic tissue fibrosis is associated with tumor development. Likewise, stromal cells within the breast tumor microenvironment can provide tumor-promoting effects. Yet, very little is known regarding the role of local-adipose mesenchymal stem cells (MSCs) in the development of cancer. Objectives: If breast density and fibrosis are both associated with less fat and more connective tissue, we reason that resident breast MSCs (b-MSCs) are chemoattracted toward mammary glandular elements where they trigger a desmoplastic response characterized by their transdifferentiation into myofibroblasts, rather than differentiating along an adipocytic lineage; thus proposing that b-MSCs, an understudied yet abundant stromal constituent, contribute early in the development of breast cancer. Moreover, if b-MSCs contribute to fibrosis, it is critical to understand and deter this early fibrotic initiation factor. Preliminary Data, Methodology, and Future Directions: Affymetrix data, qRT-PCR, and western blotting results reveal that undifferentiated b-MSCs constitutively express multiple matrix metalloproteinases and chemokine receptors, which could guide these stromal cells from local fat stores into the parenchyma, activating a cascade of events leading to fibrosis. qRT-PCR reveals b-MSCs express multiple members of the epidermal growth factor (EGF) receptor family, most notably HER1. Soluble heparin binding epidermal growth factor (HB-EGF) and EGF modestly effects b-MSC growth, but markedly enhances migration. Moreover, HB-EGF and EGF interfere with adipogenic differentiation. Future studies will analyze the fibrogenic response initiated by b-MSCs in co-culture with normal, pre-malignant and malignant breast epithelial cells and evaluate the effectiveness of the dipeptide, carnosine, on reducing fibrogenesis. Support: This work was supported by a DOD Breast Cancer Research Program Idea Award (BC094734) to L.E.

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 1498. doi:1538-7445.AM2012-1498
Abstract 1510: Blockade of the mTOR/NF-κB signaling axis augments prostate cancer treatment responses through suppression of a microenvironment-derived DNA damage secretory program
Authors: Sun Yu , Coleman Ilsa , Nelson Peter
Published: August 2012

Background/Rationale: Resistance to cytotoxic chemo- and radiotherapy is a common event in advanced prostate cancers. While resistance is established as a consequence of cancer cell intrinsic genetic and epigenetic changes, emerging evidence indicates that therapy failure is also caused by cell extrinsic factors such as cytokines, growth factors, proteases and other soluble ligands generated from damaged stromal cells in the tumor microenvironment (TMEN). We recently reported a unique feature of stromal cells, namely a DNA damage secretory phenotype (DDSP) resulting from genotoxic therapeutics. Thus, anti-cancer therapies that cause DNA damage responses (DDR), unexpectedly, trigger pro-survival signaling in neoplastic or pre-neoplastic cells and may promote subsequent therapy resistance. Results: In this study, we show that molecular inhibition of the mammalian target of rapamycin (mTOR) through genetic or chemical approaches suppresses a cellular secretory program resulting from exposure to genotoxic agents. We identified a physical association between mTOR and the I-kappa-B kinase (IKK) complex which is activated by DNA damage stimuli, and found IKKα to be the major subunit that directly interacts with mTOR while assembling the IKK complex. Rapamycin abrogates IKKα phosphorylation, IαBβ degradation and the central action-p65/p50 nuclear translocation. Thus, IKK catalytic subunits are not equally implicated in propagating damage signals to NF-κB, with IKKα playing the pivotal role. We determined that the mTOR/Raptor complex is activated by genotoxic stress and promotes NF-κB signaling. Suppressing mTOR dramatically abolished transcriptional levels of NF-κB target genes. We also determined that paracrine-acting DDSP factors are regulated through both transcriptional and post-transcriptional mechanisms, as upregulation of S6K and downregulation of 4E-BP1 play essential and synergistical roles in synthesis of DDSP factors. Finally, we determined that mTORC1 is the predominant mediator of the development of the DDSP phenotype, and it receives signals from upstream kinases. Interestingly, PI3K is not required for signal transduction of damage responses in prostate fibroblasts, which occurs through Akt phosphorylation caused by activated p38 MAPK signaling. Conclusions: These studies establish that mTOR is a novel target for therapeutic intervention in the mitigation of resistance mechanisms derived from the tumor microenvironment following genotoxic cancer treatments. These studies suggest that mTOR inhibitors may have efficacy in augmenting tumor responses to ionizing radiation and/or chemotherapy.

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 1510. doi:1538-7445.AM2012-1510
Abstract 1519: Peroxisome proliferator-activated receptor ≤ promotes colonic inflammation and inflammation-associated tumorigenesis
Authors: Wang Dingzhi , Guo Lixia , Ning Wei , Wu Hong , Chaturved Rupesh , Wilson Keith , DuBois Raymond N.
Published: August 2012

Although epidemiologic and experimental evidence strongly indicates chronic inflammation as a risk factor for cancer, it remains unclear how chronic inflammation contributes carcinogenesis. Peroxisome proliferator-activated receptor ≤ (PPARδ) is one member of PPAR family that belongs to the nuclear hormone receptor superfamily and is also ligand-dependent transcription factor. Although PPARδ has been shown to be involved in chronic inflammation and the progression of hereditary and sporadic CRC, its role in inflammation-induced carcinogenesis is not defined. The aim of our present study was to determine whether PPARδ contributes to the pathogenesis of colonic inflammation and inflammation-associated carcinogenesis. Here we present genetic evidence demonstrating that deletion of PPARδ diminishes colonic inflammation accompanied with reducing infiltration of immune cells and the expression of pro-inflammatory chemokines and cytokines in a mouse model of colitis. These PPARδ-dependent chemokines are responsible for recruitment of leukocytes from the circulation to local inflammatory sites and the tumor microenvironment. Our results further reveal that activation of PPARδ induces COX-2 expression in colonic epithelial cells. Importantly, COX-2-derived PGE2 stimulates macrophages to produce pro-inflammatory chemokines and cytokines. More intriguingly, loss of PPARδ attenuated colonic chronic inflammation and colitis-associated adenoma growth via PGE2 signaling in two mouse models of colitis-associated tumorigenesis. Collectively, our results demonstrate that PPARδ promotes colonic chronic inflammation and colitis-associated tumor growth via a PGE2 signaling which mediates the crosstalk between tumor epithelial cells and macrophages. Our data further supports the notion that the existence of crosstalk between PPARδ and COX-2 signaling in CRC progression. These findings indicate that PPARδ plays a pivotal role in connecting colonic inflammation to cancer progression and may represent a potential therapeutic target for prevention or treatment of colorectal 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 1519. doi:1538-7445.AM2012-1519
Abstract 1520: Estrogen modulates angiogenic factors of thyroid tumor microenvironment
Authors: Rajoria Shilpi , George Andrea , Suriano Robert , Shin Edward J. , Geliebter Jan , Tiwari Raj K.
Published: August 2012

Thyroid cancer is the most common endocrine related cancer with the incidences occurring three to four times higher in women than in men, thus suggesting that estrogen plays a critical role in thyroid cancer progression. We have previously demonstrated that thyroid cancer cells express functionally active estrogen receptors (ER), ER-α and ER-α and that estrogen enhances the metastatic propensity of thyroid cancer cells by increased migration, adhesion and invasion, potentially mediated by enhanced secretion of matrix metalloproteinases (MMP), MMP-2 and MMP-9. However, to successfully grow and metastasize, thyroid cancer cells must initiate endothelial cell induced neo-vascularization such that adequate blood supply is maintained within the tumor. In an effort to define the interacting factors between endothelial cells and thyroid cancer epithelial cells, we developed an in vitro cell culture based system using three thyroid cancer cell lines (a papillary thyroid carcinoma cell line B-CPAP, and two follicular thyroid carcinoma cell lines, CGTH-W-1 and ML-1) and human umbilical vein endothelial cell (HUVECs). We observed that conditioned medium from estrogen treated thyroid cancer cells induced prolific tubulogenesis of endothelial cells which was abrogated in presence of the anti-estrogen, fulvestrant or neutralizing antibody to vascular endothelial growth factor (VEGF). We also observed that conditioned medium from thyroid cancer cells was able to induce migration of endothelial cells, again a phenomenon which was abrogated by fulvestrant and VEGF neutralizing antibodies. We further demonstrate that estrogen acts as a modulator of endothelial-epithelial cell interaction by modulating angiogenic factors that include VEGF and MMPs, which in turn induce mitogenic signaling and help promote and maintain cellular tumor heterogeneity. Estrogen modulated tumor modulating factors are viewed as novel therapeutic targets and provide evidence that the higher incidence of thyroid cancer in females is potentially attributed to the presence of a functional ER that mediates upregulation of pro-angiogenic factors and thus anti-estrogens can be potentially used to treat and/or prevent thyroid 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 1520. doi:1538-7445.AM2012-1520
Abstract 1527: CD44v9 involving in multiple myeloma cells adhesion to bone marrow stromal cell promotes bone erosion by augmenting the activation of HGF-receptor/cMet
Authors: Lee Chansu , Ahn Kwang-Sung , Ryu JIyeon , Park Soyoung , Jung Woo June , Park Juwon , Bae Eunkyung , Yoon Sung-Soo
Published: August 2012

The main aim of our study is to determine the significance of the stromal microenvironment in the malignant behavior of multiple myeloma cells. The stroma-derived growth factors/cytokines and hyaluronan act in autocrine/paracrine ways with their receptors, including receptor-tyrosine kinases and CD44 variants (CD44v), to potentiate and support multiple myeloma cell survival. In this study, we found that CD44s and CD44 variants were differentially expressed between fraction of CD138+ fraction and CD138- fraction. Expression levels of CD44v6, CD44v9, and CD44v10, respectively, correlated with bone erosion (p=0.029, p=0.013, p=0.032), suggesting that CD44 variant molecules are involved in multiple myeloma progression. Binding studies using CD44 isoform specific reagents showed that CD44v6 and CD44v9 were involved in binding to bone marrow stromal cells, but not to in vitro synthesized ECM. In 3D culture, CD44v6 and CD44v9-mediated plasma cell binding resulted in a significant induction of HGF secretion by bone marrow stromal cells. CD44v6 and CD44v9-mediated plasma cell binding significantly induces PI3K/Akt via activation the Src-kinase Lyn. In bone marrow serum of MM patients, the expression levels of IL-6, OPN, and hepatocyte growth factor (HGF), respectively, statistically correlated with bone erosion of MM patients (p=0.021, p=0.001, p=0.036). HGF derived from bone marrow stromal cells with multiple myeloma cells stimulates CD44 signaling via activation of HGF-receptor/cMet. Specific CD44 shRNA suppresses HGF-mediated CD44 signaling. Taken together, the role of CD44 variants in adhesion induced HGF- secretion may explain the previously observed correlation between CD44 variants expression and adverse prognosis in multiple myeloma.

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 1527. doi:1538-7445.AM2012-1527
Abstract 1537: Combined Tbet and IL-12 gene therapy elicits and recruits superior anti-tumor immunity in vivo
Authors: Taylor Jennifer L. , Qu Yanyan , Chen Lu , Lowe Devin B. , Storkus Walter J.
Published: August 2012

We have recently shown that intra-tumor (i.t.) injection of syngenic dendritic cells (DC) engineered to express the transcription factor Tbet (TBX21) promotes protective Type-1 T cell-mediated immunity via a mechanism that is largely interleukin (IL)-12p70-independent. Since IL-12 is a classical promoter of Type-1 immunity, the current study was undertaken to determine whether gene therapy using combined Tbet and IL-12 cDNA would yield improved anti-tumor efficacy based on the complementary/synergistic action of these biologic modifiers. Mice bearing established s.c. tumors injected with DC concomitantly expressing ectopic Tbet and IL-12 (i.e. DC.Tbet/IL12) displayed superior i.) rates of tumor rejection and extended overall survival, ii.) cross-priming of Tc1 reactive against antigens expressed within the tumor microenvironment, and iii.) infiltration of CD8+ T cells into treated tumors in association with elevated locoregional production of CXCR3 ligand chemokines. In established bilateral tumor models, i.t. delivery of DC.Tbet/IL12 into a single lesion led to slowed growth or regression at both tumor sites. Furthermore, DC.Tbet/IL12 pulsed with tumor antigen-derived peptides and injected as a therapy distal to the tumor site prevented tumor growth and activated robust antigen-specific Tc1 responses. These data support the translational use of combined Tbet and IL-12p70 gene therapy in the cancer setting. In order to target multiple gene pathways which should provide a more beneficial clinical outcome, we have begun combinational immunotherapy with DC.Tbet/IL12 and chemotherapeutic drugs targeting multiple receptor tyrosine kinases (i.e. sunitinib).

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 1537. doi:1538-7445.AM2012-1537
Abstract 1540: Inhibition of SDF production by brain tumor cells reduces brain tumor bed effect
Authors: Chiang Chi-Shiun , Ling Chi-Ming , Wang Shu-Chi , Hong Ji-Hong
Published: August 2012

Previous study on a murine prostate tumor model, TRAMP-C1, has shown that tumor transplants in preirradiated (pre-IR) tissues have longer growth delay and lower microvascular density (MVD) than in nonirradiated tissues, a phenomenon known as the tumor bed effect (TBE) that is associated with less responsive to salvage radiotherapy or chemotherapy and higher risk of metastasis. This study further demonstrates that a murine astrocytoma, ALTS1C1, grown from pre-IR brain tissues also have obvious TBE. This indicates that there is also a brain TBE that may affect the therapeutic efficacy of recurrent brain tumor after radiotherapy. Additional study shows that the inhibition of SDF expression in ALTS1C1 by specific siRNA reduces pre-IR-induced tumor growth delay and TAM association with hypoxia. The vessel formation mechanism is also altered into more mature form. This indicates that SDF production by brain tumor cells plays significant roles on the response of recurrent brain tumors after radiotherapy to salvage therapy.

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 1540. doi:1538-7445.AM2012-1540
Abstract 1555: Epigenetic modulation enhances the therapeutic effect of anti-IL13 receptor β2 antibody in human mesothelioma xenografts
Authors: Kato Kazunori , Takenouchi Makoto , Sakuragi Naoya , Yagita Hideo
Published: August 2012

Purpose: Interleukin-13 receptor β2 (IL13Rα2) is known as a cancer antigen and high expression of this receptor is found in various human cancers, such as glioma, renal cell carcinoma and prostate carcinoma. Immunotoxin or cytotoxin therapy for malignant glioma targeting IL13Rα2 has already been investigated in preclinical and clinical trials. Here, we have examined the constitutive surface expression and the epigenetic regulation of IL13Rα2 by human mesothelioma. We have also investigated the therapeutic effect of the DNA methylation inhibitor, 5-aza-2′-deoxycytidine (5-aza-dC), and anti-IL13Rα2 monoclonal antibody on mesothelioma xenografts. Experimental Design: Cell surface expression of IL13Rα2 by various lung carcinomas was analyzed using flow cytometry. Therapeutic effects of anti-IL13Rα2 and 5-aza-dC were investigated using antibody-dependent cellular cytotoxicity and proliferation assays, and by monitoring the survival of mesothelioma-bearing mice. Results: We found that human malignant mesotheliomas expressed surface IL13Rα2 on their surface and that it was up-regulated by treatment with 5-aza-dC. This augmented expression of IL13Rα2 resulted in growth inhibition of the mesothelioma cells when co-cultured with anti-IL13Rα2 and effector cells, such as splenocytes and peritoneal exudate cells. The growth inhibition of mesothelioma cells was mediated by interferon-α that was only detected in the supernatant when effector cells were exposed to 5-aza-dC-treated tumors in the presence of anti-IL13Rα2. Compared with the control or either regimen alone, in vivo administration of anti-IL13Rα2 in combination with 5-aza-dC significantly prolonged the survival of mice with mesothelioma xenografts. Conclusion: These observations indicate a promising role for IL13Rα2 as a target for antibody treatment in malignant mesothelioma, and, in combination with epigenetic regulation by a DNA methylation inhibitor, suggest the potential for a novel strategy to enhance therapeutic potency.

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 1555. doi:1538-7445.AM2012-1555
Abstract 1565: Mesoporous silicon particle mediated dendritic cell based vaccine formulation showed stronger immunoresponse for the presentation of tumor antigens and adjuvant
Authors: Meraz Ismail M. , Gu Jianhua , Serda Rita
Published: August 2012

Dendritic cell (DC) based immunotherapy is being used for cancer therapy in various clinical trials. During evaluation of recent clinical studies, it became apparent that efficient DC-based immunotherapy is dependent on a number of factors, such as the mode of antigen presentation, maturation of DC, injection site, and vaccination dosing. Major limiting factors for DC-based vaccines are insufficient loading of antigens by DC and poor migratory capacity of DC to lymph nodes. Nanotechnology provides tools to load large payloads of antigens and adjuvants in particles for uptake by DC. Toll-like receptor (TLR) ligands have been proposed as vaccine adjuvants for boosting adaptive immunity in cancer therapy. TLR signaling induces DC activation that is characterized by enhanced expression of costimulatory molecules and increased secretion of cytokines necessary for activation and differentiation of naive T cells. In this study, we have used porous silicon (pSi) microparticles to create a novel vaccine. We have demonstrated that porous silicon particles can be decorated with TLR-ligands using lipopolysaccharide (LPS) or monophosphoryl lipid (MPL). This decorated particles are substrates for bone marrow-derived DC internalization, leading to cellular uptake and activation and enhanced migration of DC to lymph nodes. Confocal and scanning electron microscopy, as well as flow cytometry studies supported higher uptake of LPS and MPL conjugated particles as compared to unlabeled particles. TLR ligands induced morphological changes in GM-CSF-stimulated bone marrow cells during particle uptake consistent with classical DC dentron formation. Stimulated antigen presenting cells also expressed elevated levels of costimulatory (e.g. CD80, CD86) and major histocompatibility molecules (MHC), and secreted pro-inflammatory cytokines both in vitro and in vivo. Ex-vivo processed DC loaded with TLR ligand coated pSi showed enhanced migration to lymph node as compared with empty DC when injected mice subcutaneously. As expected, LPS conjugation to particles showed toxicity towards DC whereas MPL conjugated pSi showed little or no toxicity.

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 1565. doi:1538-7445.AM2012-1565
Abstract 1811: Antitumor activity of lapatinib in combination with the dual mTORC1/2 inhibitor INK-128 in breast tumors resistant to anti-HER2 therapy
Authors: Garcia-Garcia Celina , Ibrahim Yasir H. , Serra Violeta , Calvo Maria Teresa , Guzman Marta , Grueso Judit , Aura Claudia , Perez Jose , Jesen Katti , Liu Yi , Rommel Christian , Tabernero Josep , Baselga Jose , Scaltriti Maurizio
Published: August 2012

Purpose: The PI3K/Akt/mTOR pathway is an attractive target in HER2 positive breast cancer refractory to anti-HER2 therapy. The hypothesis is that suppression of this pathway results in sensitization to anti-HER2 agents. However, this combinatorial strategy has not been comprehensively tested in models of trastuzumab and lapatinib resistance. Experimental Design: We analyzed in vitro cell viability and induction of apoptosis in five different cell lines resistant to trastuzumab and lapatinib. Inhibition of HER2/HER3 phosphorylation, PI3K/Akt/mTOR and ERK signaling pathways was evaluated by western blot. Tumor growth inhibition following treatment with lapatinib, INK-128 or the combination of both agents was evaluated in three different animal models: two cell-based xenograft models refractory to both trastuzumab and lapatinib and a xenograft derived from a patient who relapsed to trastuzumab-based therapy. Results: The addition of lapatinib to INK-128 prevented both HER2 and HER3 phosphorylation induced by INK-128, resulting in inhibition of both PI3K/Akt/mTOR and ERK pathways. This dual blockade synergistically enhanced cell death in five different HER2 positive cell lines resistant to trastuzumab and lapatinib. In vivo, both cell line-based and patient-derived xenografts showed exquisite sensitivity to the antitumor activity of the combination of lapatinib and INK-128, causing durable tumor shrinkage in the absence of any sign of toxicity. Conclusions: The simultaneous blockade of PI3K/Akt/mTOR and ERK pathways achieved by combining lapatinib with INK-128 acts synergistically in inducing cell death and tumor regression in breast cancer refractory to anti-HER2 therapy.

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 1811. doi:1538-7445.AM2012-1811
Abstract 182: Tumor suppressor microRNA-493 decreases cell motility and migration ability in human bladder cancer cells by down-regulating RhoC and FZD4
Authors: Ueno Koji , Hirata Hiroshi , Majid Shahana , Yamamura Soichiro , Shahryari Varahram , Tabatabai Z. Laura , Hinoda Yuji , Dahiya Rajvir
Published: August 2012

Introduction and Objective: The purpose of this study was to identify new tumor suppressor microRNAs in bladder cancer to carry out functional analysis of their suppressive role and identify their specific target genes. Methods: To identify tumor suppressor microRNAs in bladder cancer, microRNA microarray was performed using SV-HUC-1, T24, J82 and TCCSUP cells. Based on the microRNA microarray, 10 microRNAs were selected and expression levels confirmed using real-time PCR. The function of miR-493 was measured by MTS, cell cycle, migration, and wound healing assays using T24 and J82 cells. Based on the observation that miR-493 affects cell motility and migration, we searched for target genes of miR-493 related to motility and migration using a target scan algorithm, identified RhoC and FZD4 and performed 3′UTR luciferase assays. To examine whether RhoC and FZD4 affects T24 and J82 cell migration, RhoC siRNA, FZD4 siRNA or control siRNA was transfected into T24 and J82 cells and migration, and wound healing assays were performed. We also analyzed whether over-expression of miR-493 affects the binding of RhoC to Rock-1by immunoprecipitation at 72 hr after transfection in T24 cells. Results: Expression of miR-493 in bladder cancer (T24, J82 and TCCSUP) cells was down-regulated compared to normal SV-HUC-1 cells. Also the expression of miR-493 was significantly lower in human bladder cancer tissues than in their corresponding non-cancerous tissues. Transfection of miR-493 into T24 and J82 cells decreased cell growth and migration abilities. To identify potential miR-493 target genes, we used target scan algorithms to identify target oncogenes (FZD4 and RhoC) related to invasion and migration. MiR-493 decreased 3′UTR luciferase activity and protein expression of FZD4 and RhoC. Cell migration was significantly decreased by 35 to 50% in RhoC and FZD4 siRNA transfectants compared with control cells. MiR-493 also decreased binding of RhoC and Rock-1. Conclusions: MiR-493 is a new tumor suppressor microRNA in bladder cancer and inhibits cell motility through down-regulation of RhoC and FZD4.

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 182. doi:1538-7445.AM2012-182
Abstract 1824: Functional characterization of DOG1 in Gastrointestinal Stromal Tumors (GIST)
Authors: Simon Susanne , Fererra Loretta , Galietta Luis , Grabellus Florian , Breitenbücher Frank , Schuler Martin , Fletcher Jonathan , Bauer Sebastian
Published: August 2012

Introduction: DOG1, a calcium-dependent chloride channel, has been shown to be strongly and specifically expressed in GIST and is commonly used as diagnostic marker. Notably, KIT-negative GIST cell lines do not express DOG1. We have therefore sought to investigate the role of DOG1 for KIT expression and GIST growth and its potential as therapeutic target. Methods: GIST cell lines (GIST882: K642E, IM-sensitive, GIST-T1: del558-614, IM-sensitive, GIST48: V560D/D820A, IM-resistant) were transduced with lentiviral particles containing DOG1 sh-RNA. Expression of KIT and DOG1 was measured by immunoblotting. Effects of DOG1 knock-down on proliferation (with/without imatinib) were studied by BrdU incorporation assays and effects on chloride currents using patch clamp technique. Xenografts from transduced cells (and scrambled control) were generated and evaluated for tumor growth and expression of DOG1, KIT and Ki-67. Expression profiles from cell lines and xenograft tumors were compared using microarrays. Results: Lentiviral knock-down of DOG1 resulted in a near-complete inhibition of DOG1 while expression of KIT or the KIT-depending signalling pathways were not affected. Patch clamp measurements showed a strong inhibition of chloride currents in the majority of cells (DOG1-knock-down) tested compared to scrambled control. No difference was found in the growth rate of cells with DOG1-knockdown alone or in the presence of imatinib compared to cells transduced with scrambled sh-RNA. Xenografts generated from transduced cell lines retained DOG-1 knockdown as well as strong KIT-expression. Notably, xenografts with knock-down of DOG1 showed a lower proliferative activity (Ki-67: immunoreactivity score 12 (strongly positive) versus 6 (moderately positive)) with a reduction of tumor size of 43% after 19 days of tumor growth (n=8; p=0.003) when compared with the scrambled control. Expression analyses revealed MNK1 (MAP kinase-interacting serine/threonine-protein kinase 1) to be down-regulated in DOG1 negative GIST xenografts compared to scrambled control. Conclusion: DOG1 knock-down results in a reduction of intracellular chloride currents but does not affect KIT-expression or sensitizes cells to imatinib treatment. Proliferation is not affected by DOG1 knock-down in vitro but DOG1 appears to contribute to 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 1824. doi:1538-7445.AM2012-1824
Abstract 1833: A large-scale synthetic lethal RNAi screening identifies unique sensitizing targets for anti-inflammatory CDDO-Me in metastatic melanoma
Authors: Ekmekcioglu Suhendan , Qin Yong , Deng Wuguo , Grimm Elizabeth A.
Published: August 2012

Metastatic melanoma is the most lethal form of skin cancer strongly associated with the inflammatory process by secreting high levels of proinflammatory cytokines and producing reactive oxygen and nitrogen species. Chronic inflammation is considered as a major factor to promote the tumor microenvironment in advantage of resistance to radiation, chemotherapy, and biotherapy for metastatic melanoma. CDDO-Me, a novel synthetic triterpenoid, has been shown to exert potent anti-inflammatory and antitumor activity by decreasing oxidative stress and the production of pro-inflammatory molecules, such as Nrf2 and iNOS, in several tumor models. CDDO-Me is presently under evaluation in clinical studies for chronic kidney disease and pancreatic cancer. Here, we used CDDO-Me as a primary agent to inhibit metastatic melanoma growth. In order to improve CDDO-Me response in melanoma cells, we utilized a large-scale synthetic lethal RNAi screen with 24,000 siRNAs targeting ∼6,000 human druggable genes to identify targets that when silenced would sensitize melanoma cells to CDDO-Me. Results from the screens identified twenty of siRNA pools that significantly potentiated the growth inhibitory effects of CDDO-Me in A375 cells. We selected five unique genes, GNPAT, SUMO1, SPUNT2, FLI1, and SSX1, which have not been addressed as drug targets in melanoma before, for target validation and functional analysis in four metastatic melanoma and control cell lines. Specific siRNA against each of these five genes could substantially sensitize four tested melanoma cells to CDDO-me by increasing the growth inhibition and induction of apoptosis, while treatment with nontarget siRNA resulted in no change compared to the treatment with CDDO-Me only. Further studies of downstream signaling revealed that these five genes involved in regulating melanoma cell proliferation and cell death. We identified for the first time that the levels of phosphorylated Erk1/2, Akt, GSK-2, and PRAS40, were dramatically decreased by individual siRNA against GNPAT, SUMO1, SPUNT2, FLI1, and SSX1. Our findings indicate that GNPAT, SUMO1, SPUNT2, FLI1, and SSX1 may play critical roles in synergy with inflammation pathways in modulating melanoma cell survival, which could serve as sensitizing targets to enhance CDDO-Me efficacy in melanoma. Supported by MDACC SPORE in Melanoma P50CA093459.

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 1833. doi:1538-7445.AM2012-1833
Abstract 1847: SNRPE is involved in cell proliferation and the progression of high-grade prostate cancer through the regulation of AR expression
Authors: Anchi Takashi , Tamura Kenji , Furihata Mutsuo , Satake Hirofumi , Kamei Maiko , Shimamoto Tsutomu , Fukuhara Hideo , Ashida Shingo , Karashima Takashi , Nishikawa Hiroshi , Yamasaki Ichiro , Yasuda Masaharu , Kamada Masayuki , Inoue Keiji , Shuin Taro
Published: August 2012

Clinically high-grade prostate cancers (PC) with high Gleason scores of 8-10 tend to grow quickly and are more likely to spread beyond the prostate. They show a poor response to androgen deprivation therapy and eventually acquire a castration-resistant phenotype. To identify novel molecular cancer drug targets, we previously analyzed the gene expression profiles of high-grade PC using a cDNA microarray combined with laser microbeam microdissection and found a number of genes that are transactivated in high-grade PC. Among them, we report the identification of a novel molecular target, small nuclear ribonucleoprotein polypeptide E (SNRPE). Semi-quantitative RT-PCR confirmed that SNRPE is overexpressed in high-grade PC cells compared with normal prostatic epithelial cells (NP). Knockdown of SNRPE expression by short interfering RNA (siRNA) resulted in the marked suppression of PC cell proliferation. In contrast, SNRPE overexpression promoted PC cell proliferation, indicating its oncogenic effects. Furthermore, we demonstrated that SNRPE regulates androgen receptor (AR) mRNA expression in PC cells. Knockdown of SNRPE expression by siRNA resulted in the marked suppression of AR and its downstream target genes at the mRNA level. We suggest that the regulation of AR expression by SNRPE is essential for the cell proliferation and progression of high-grade PC and that it could be a novel molecular target for cancer drugs.

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 1847. doi:1538-7445.AM2012-1847
Abstract 1851: A role for heat-shock protein 40 YDJ1 in the protection from anthracycline exposure
Authors: Flores-Rozas Hernan , Mazu Tryphon
Published: August 2012

Doxorubicin is an anthracycline antibiotic commonly used as an antineoplastic agent for the treatment of both solid tumors and hematological cancers. Although there is a dose-dependent response in the use of anthracyclines, there is also a dose-related toxicity associated to them, namely chronic cardiotoxicity. To increase our knowledge of the pathways that protect cells from the cytotoxic effects of anthracyclines, we carried out a genetic screening in the eukaryotic model organism S. cerevisiae, to identify gene defects that generate cells hypersensitive to doxorubicin. Our findings indicate that inactivation of the heat-shock protein 40 encoded by the genes YDJ1 and ZUO1, as well as the heat-shock protein 70 encoded by the gene SSZ1, render cells highly sensitive to the toxicity of doxorubicin. Further analysis of the YDJ1 defective strain revealed that it is also sensitive to daunorubicin and cisplatin, but not to other DNA damaging agents such as alkylating agents, the topoI inhibitor campthotecin or replication blocks from hydroxyurea. YDJ1 mutant displayed different sensitivity to DNA-double-strand breaks and oxidative damage, both of which are generated by anthracyclines. Complementation of the ydj1 mutation with the human DNAJA2 gene rescues the sensitivity of the deletion strain, suggesting a potential role of DNAJA2 in the protection to doxorubicin and implying that this mechanism also applies to higher eukaryotes.

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 1851. doi:1538-7445.AM2012-1851
Abstract 1867: Gene expression profiles obtained from ex vivo human scalp hair to determine the effects of drug response following exposure to HDAC inhibitors.
Authors: Reed Benjamin J. , Forslund Ann , Casneuf Tineke , Miele Gino , Grimes Emma , Mefo Tim , Harrison Elliott , Meyer-Turkson Lydia , Brady Ged , McClue Steve , Winkler Hans
Published: August 2012

Background Plucked human scalp hair represents an ideal surrogate tissue to enable non-invasive monitoring of drug response in clinical trials. Congruence of patterns of transcriptome activity within the bulb region of plucked scalp hair show high concordance and to that of primary target tumour tissues. The ex vivo plucked scalp hair culture technique involves exposing healthy normal volunteer hair to different concentrations of a number of HDAC inhibitors and ascertain the effects that they have on gene expression. This technique is an ideal approach to identifying desirable non-invasive transcriptional biomarkers to demonstrate target engagement and define a PK/PD relationship, as well as enabling the monitoring of a well tolerated dose schedule with maximal biological effect. Materials and Methods In this study, we deployed our proprietary ex vivo culture technique to ascertain the effects that three different HDAC inhibitors had on gene expression in plucked hair. Three different concentrations of each HDAC inhibitor were incubated in culture for a period of 18 hours. RNA was extracted from the hair bulb following the culture technique and gene expression was assessed following microarray analysis. Statistically significant biomarkers (p<0.05) were identified along with genes with a greater than 2 fold change from the vehicle group. Direct comparisons in the profiles obtained following exposure to the three different HDAC inhibitors were conducted to evaluate differences in the mechanism of action of each compound. Results We were able to demonstrate from the ex vivo plucked hair study, a panel of transcriptional markers that exhibited a similar response to drug treatment following exposure to the three different HDAC inhibitors. The differentially expressed genes identified were biologically relevant as they are consistent with pathways that are known to be associated with HDAC inhibition. The results also demonstrated the potency of each of the HDAC inhibitors and provided an insight into the different mechanisms of action of each compound. The differentially expressed biomarkers identified in this study may be used in clinical settings to monitor pharmacodynamic responses in plucked scalp hair obtained from patients. Conclusions We conclude that plucked human scalp hair represents an ideal minimally invasive surrogate tissue to monitor drug response in patients receiving treatment with HDAC inhibitors.

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 1867. doi:1538-7445.AM2012-1867