bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 663: YK-4-279 inhibits ERG and ETV1 mediated prostate cancer cell invasion
Authors: Rahim Said , Beauchamp Elspeth M. , Kong Yali , Brown Milton L. , Toretsky Jeffrey A. , Üren Aykut
Published: June 2012

Chromosomal translocations involving the ETS family of transcription factors are found in a majority of prostate cancers, including the most clinically aggressive forms. These translocations produce a chimeric gene, which fuses the promoter region of an androgen responsive gene, such as TMPRSS2, to the coding region of ETS factors, most frequently ETV1 or ERG. Over-expression of ETS factors in prostate cancer cells results in a more invasive phenotype. The high prevalence of these rearrangements, and their biological significance represents a novel therapeutic target for the treatment of prostate cancer. We recently reported the development of YK-4-279, a small molecule inhibitor of EWS-FLI1 oncoprotein in Ewing's Sarcoma. ERG and ETV1 belong to the same class of ETS factors as FLI1. Due to the close homology of FLI1 with ERG and ETV1, we tested the ability of YK-4-279 to inhibit ETS biological activity in prostate cell-lines such as VCaP and LNCaP that demonstrate androgen dependent ERG and ETV1 expression, respectively. YK-4-279 inhibited ERG and ETV1 mediated transcription of target genes such as PLAU, PLAT, ADAM19 and MMP-13, which are involved in breakdown of the extracellular matrix and metastasis. YK-4-279 reduced the motility and invasive phenotype of ETV1-fusion positive LNCaP cells and ERG fusion-positive VCaP cells in in vitro invasion assays. However, ETS fusion-negative PC-3 cells were unresponsive to YK-4-279. ERG knockdown in VCaP cells resulted in a loss of drug responsiveness. Transient ERG expression in PC-3 cells resulted in an increased invasive phenotype, which was reduced by YK-4-279. Our results demonstrate that YK-4-279 inhibits ERG and ETV1 biological activity in fusion-positive prostate cancer cells leading to decreased motility and invasion. Therefore, YK-4-279 may have an impact on metastasis in prostate cancer, which is a leading cause of death, and it may be further evaluated for its clinical applications in prostate cancer, in addition to Ewing's sarcoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 663. doi:10.1158/1538-7445.AM2011-663
Abstract 665: Targeting the MluI cell cycle box (MCB) sequence 5’-ACGCGT-3’ in the human Dbf4 promoter using the rationally designed polyamide formamido-imidazole-pyrrole-imidazole (f-IPI)
Authors: Lin Shicai , Kiakos Konstantinos , Lee Moses , Hochhauser Daniel , Hartley John A.
Published: June 2012

Dbf4 is the regulatory subunit of Cdc7 kinase, which is essential for the initiation of DNA replication throughout S-phase. The level of Dbf4 is critical for the activation of Cdc7. Human Cdc7/Dbf4 (HuCdc7/Dbf4) kinase activity is essential for cell proliferation by activating DNA replication. High levels of the Cdc7 kinase activity have been implicated with a large number of aggressive solid cancers. The MluI cell cycle box (MCB) sequence 5’-ACGCGT-3’ is the critical site for transcription factor binding that activates the expression of the HuCdc7/Dbf4 core gene in mammalian cells. HuDbf4 promoter activity has previously been shown to be significantly reduced by a point mutation within the MCB. We have previously shown that the rationally designed simple polyamide formamido-imidazole-pyrrole-imidazole (f-IPI) binds to its cognate sequence 5’-ACGCGT-3’ as a stacked dimer in an anti-parallel conformation (2:1 ligand/DNA complex) with exceptionally high affinity and selectivity, superior to the natural product distamycin A binding to its cognate sequence. DNAse I footprinting experiments indicated selective binding of f-IPI to the MCB sequence in the HuDbf4 promoter at 0.1µM. Eletrophoretic mobility shift assays using the MCB-containing sequence from the HuDbf4 promoter showed dose-dependent inhibition of protein binding by f-IPI which was complete at 0.5µM. RT-PCR showed decreased expression of HuDbf4 mRNA in response to incubation of exponentially growing MDA-MB231 cells with 10 μM f-IPI. Selective effects on protein expression, DNA replication and cell cycle are currently underway. These data demonstrate the potential of small molecule polyamides as modulators of gene expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 665. doi:10.1158/1538-7445.AM2011-665
Abstract 668: Second generation silicon derivatives of indomethacin: Synthesis of potent COX-2 selective agents with improved anticancer activity
Authors: Zakai Uzma I. , Gately Stephen , West Robert
Published: June 2012

Elevated tumor cyclooxygenase-2 is associated with poor overall survival in patients with a variety of cancers. Patients with elevated COX-2 that receive a COX-2 inhibitor have demonstrated improved survival. Indomethacin (IM) is a COX-non-selective inhibitor with demonstrated anticancer activity in patients. The anticancer effects of IM are related to inhibition of COX-2 as well as COX-independent targets. We now report the improved synthesis and activity of IM-sila- amide derivatives where strategic silicon addition results in COX-2 selective IM derivatives that demonstrate activity in mouse models of human cancers and are devoid of the COX-1 associated toxicities. The sila-IM compounds demonstrated improved inhibition of purified human COX-2, IC50 0.2 uM and limited inhibition of COX-1 up to 10 uM. Sila-IM derivatives were also found to be potent inhibitors of NF-κB transcription activating function at concentrations below 1.0 UM. A sila-IM derivative Silexsyn was tested in various animal models of human cancer following oral administration. Significant activity was observed in models of non-small cell lung cancer and pancreas cancer. Potent synergism was observed for Silexsyn in combination with EGFR inhibitors. A synthetic methodology incorporating a heteroatom in the amino-functional silane has been developed and used to generate second-generation sila-IM derivatives that could have improved pharmacological properties. The introduction of silicon into an approved scaffold represents an efficient strategy for the rapid production of biologically relevant therapeutics for the treatment of cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 668. doi:10.1158/1538-7445.AM2011-668
Abstract 684: The difference between gefitinib and serum deprivation in cancer cells
Authors: Suenaga Mitsuhiro , Yamamoto Masatatsu , Furukawa Tatsuhiko , Tei Chuwa
Published: June 2012

Gefitinib is a selective inhibitor of epidermal growth factor receptor tyrosine kinase. The serum free condition could resemble to gefitinib exposure since it blocks EGF stimuli. In this study, we examined distinction between gefitinib exposure and serum deprivation in cultured cancer cells. At first, we verified that ERK phosphorylation was downregulated by gefitinib exposure in A431 and A549 cells. We examined the phosphorylation status of ERK under the serum deprivation condition. The phosphorylation of ERK in A431 cells was downregulated after 1hr culture in serum free medium, while after 3-6hr ERK was phosphorylated again. We hypothesized that an auto- or paracrine mechanism would work to phosphorylate ERK. In the cells cultured with the conditioned serum free medium from the dish in which A431 cultured for 24hr, the downregulation of ERK phosphorylation was weaker than with the fresh serum free medium. We confirmed that gefitinib could inhibit the ERK phosphorylation under the serum free condition. Exogenous EGF attenuated the inhibitory effect on ERK phosphorylation with serum free medium. These results suggest EGF may be one of the auto- or paracrine substance that induces ERK phosphorylation. Since the ERK phosphorylation status affects the stability of c-MYC, we also examined whether “gefitinib” and “serum deprivation” affect the expression of c-MYC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 684. doi:10.1158/1538-7445.AM2011-684
Abstract 690: Selection of resistance by anticancer drugs is not responsible for alterations in membrane micro-fluidity: A study by Fluorescence Correlation Micro-Spectroscopy
Authors: Winckler Pascale , Cailler Aurélie , Jaffiol Rodolphe , Royer Pascal , Jeannesson Pierre , Morjani Hamid
Published: June 2012

Expression of P-glycoprotein (P-gp), the multidrug resistance (MDR) 1 gene product, can lead to MDR in tumors. Previous studies on multidrug-resistant cells have suggested changes in membrane fluidity associated with P-gp expression in drug-selected resistant cells. However, Aleman and co-workers have shown that, in MDR1 transfected cells, expression of P-gp has little effect on membrane fluidity and the changes in this parameter observed in drug-selected cells must reflect other host adaptations to drug selection. In this study and the other reported on drug-selected resistant cells, membrane fluidity has been measured using fluorescent membrane probes and fluorescence anisotropy or electron spin resonance on cell population samples (Aleman et al. Cancer Res. 2003 63:3084-91).

Here, we propose to explore the plasma membrane microfluidity by using the fluorescent membrane probe DiA and fluorescence correlation micro-spectroscopy (FCM-S) on a single living cell and nanometer scale. By using the fluorescent membrane probe DiA and FCM-S to explore the plasma membrane micro-fluidity, we have previously shown a decrease in plasma membrane micro-fluidity in LR73R cells (the Chinese hamster ovarian LR73 cells transfected with MDR1 cDNA; Boutin et al., J Biomed Opt. 2009 14: 034030). Moreover, a strategy using flow cytometry and calcein-AM functional fluorescence-activated cell sorting permitted us to select two cell populations from LR73R cells expressing distinct levels of P-gp function. In this case, we were able to observe distinct level of membrane micro-fluidity in the two populations. Cells showing high level of calcein-AM uptake presented a higher membrane micro-fluidity. In contrast, the FCM-S yielded opposite data when we compared the membrane micro-fluidity of several parental cell lines (MCF7, KB3.1, LR73, ME-SSA) and their resistant counterparts which have been selected in the presence of anticancer drugs.

Our data are not in agreement with previous published data and demonstrates clearly that alterations that can affect drug-selected cells do not induce any changes in membrane fluidity. Moreover, micro-analysis of cell membrane could allow to more precise measurements of membrane fluidity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 690. doi:10.1158/1538-7445.AM2011-690
Abstract 700: ICAM-3 endows anti-cancer drug resistance against microtubule-damaging reagents via modulation of caspases activities and Bcl-2
Authors: So Kwangsup , Kang Sung Wook , Kim Jae-Sung , Hwang Sang-Gu , Um Hong-Duck , Park Jong Kuk
Published: June 2012

We have previously reported that intercellular adhesion molecule-3 (ICAM-3) is associated with various cancer cell physiologic responses including developing cellular radio-resistance. In this report, we studied whether ICAM-3 exerts an additional effect on development of resistance against anti-cancer drug because drug/radiation resistance of cancer usually displays cross-resistance. We treated several anti-cancer drugs including, paclitaxel (Ptxl), 5-fourouracil (5-FU), and etoposide (Eto), to an ICAM-3 over-expressing stable transfectant or empty vector- transfected control NCI-H1299 non-small cell lung cancer (NSCLC) cell line (p53 and PTEN null cell). Ratios of cell survival against each drug were detected with microculture tetrazolium (MTT) assay. ICAM-3 stable transfectants showed less cell death compared with empty vector-transfected cells by Ptxl treatment. The ICAM-3 stable transfectants also showed a resistance against cell death induced by vincristine (VCS), another microtubule-damaging reagent. In clonogenic assay and cell counting assay, we also observed significant drug-resistance against microtubule-damaging reagents in ICAM-3 stable transfectant cell line. Ptxl/VCS-treated control control transfectant cells showed more apoptotic cell death and activation of caspase-3/-8 than those of ICAM-3 stable transfectant cell line at 96 hour after drugs treatments. Blockage of p44/42 MAPkinase and PI3-kinase/Akt pathway by treatment of pharmaceutical inhibitors increased Ptxl/VCS-induced apoptotic cell death. However, in same condition, ICAM-3 stable transfectant cell line showed relatively less cell death. We also detected ICAM-3 inhibited Ptxl/VCS-induced degradation of mitochondrial anti-apoptotic molecules including Bcl-2, Bcl-XL, and Mcl-1 in dose-dependent manner. These results indicate that ICAM-3 endowed drug-resistance of cancer cells against microtubule-damaging reagent via modulation of apoptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 700. doi:10.1158/1538-7445.AM2011-700
Abstract 711: Understanding the mechanisms of resistance to BRAF inhibitors in melanoma
Authors: Villanueva Jessie , Krepler Clemens , Vultur Adina , Chen Yuhao , He Xu , Wubbenhorst Bradley , Nathanson Katherine L. , Herlyn Meenhard
Published: June 2012

The presence of activating BRAF mutations in approximately 50% of melanomas, the majority of which are BRAFV600E, has prompted the development of selective BRAF inhibitors for targeted therapy. Pre-clinical data using multiple BRAF inhibitors and results from recent clinical trials using PLX4032 validate the effectiveness of this treatment strategy and offers hope to patients suffering from this deadly disease. However, similar to other malignancies, therapy with BRAF inhibitors is effective in only a subset of patients and even if an initial effective response is observed, tumors eventually develop resistance and patients relapse. We recently reported that acquired resistance to BRAF inhibitors can be mediated by non-genetic mechanisms through rewiring of their signaling pathways and this is mediated by a RAF kinase switch and increased PI3K-dependent survival. However, as melanoma is a highly heterogeneous disease, we anticipate that multiple mechanisms can be associated with acquired resistance to BRAF and/or MEK inhibitors. Also, the mechanisms of intrinsic resistance can be different from those underlying acquired resistance.

Here we report that melanoma cells which harbor the BRAFV600E mutation and express PTEN have low levels of phospho-AKT and are sensitive to BRAF inhibitors. In contrast, BRAFV600E mutant melanoma cell lines that do not express PTEN have higher levels of phospho-AKT and are less sensitive to BRAF inhibitors. Co-targeting PI3K and mutant BRAF in melanoma cells that lack functional PTEN sensitizes them to the combination strategy. Our studies suggest that the presence or absence of functional PTEN can modulate response to inhibitors of the MAPK pathway and warrant further evaluation of combination strategies to treat melanomas refractory to BRAF inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 711. doi:10.1158/1538-7445.AM2011-711
Abstract 720: Mechanism of resistance to trastuzumab and molecular sensitization via ADCC activation by exogenous expression of HER2 extracellular domain in human breast cancer cells
Authors: Yoshida Ryosuke , Tazawa Hiroshi , Hashimoto Yuuri , Uno Futoshi , Kagawa Shunsuke , Fujiwara Toshiyoshi
Published: June 2012

Human epidermal growth factor receptor 2 (HER2) is a member of a family of receptors associated with tumor cell proliferation, apoptosis, adhesion, migration, and differentiation. According to numerous preclinical and clinical studies, HER2 can be immunogenic and antibodies against this transmembrane receptor have become in use in individuals with HER2-overexpressing tumors. Trastuzumab, a monoclonal antibody that targets HER2, induces antibody-dependent cellular cytotoxicity (ADCC) and inhibits HER2-mediated signaling. Numerous randomized trials have confirmed the utility of trastuzumab in HER2-overexpressing breast cancer in various clinical scenarios; however, HER2-overexpression has been identified only in approximately 25-30% of primary breast cancers. Moreover, it has been reported that the majority of metastatic breast cancer patients treated with trastuzumab develop acquired resistance within a year. In this study, we analyzed the mechanism of resistance to trastuzumab and examined for molecular sensitization by exogenous expression of HER2 extracellular domain in human breast cancer cells. A long-term exposure to trastuzumab induced its resistance in HER2-positive breast cancer cells. We found that trastuzumab-resistant cells exhibited down-regulation of HER2 expression in cell surface and impaired ADCC activity, suggesting that trastuzumab-resistant cells could be re-sensitized to trastuzumab by exogenous induction of extracellular domain (ECD) of HER2.We constructed the expression vector with HER2-ECD and stably transfected into low HER2-expressing human breast cancer cell line, MCF7. HER2-ECD expression had no apparent effect on the growth and signaling pathway in MCF7 cells; however, ADCC activity was strongly enhanced in HER2-ECD-expressing MCF7 cells compared to parental MCF7 cells. These results suggest that exogenous expression of HER2-ECD might be an appropriate strategy to sensitize HER2-negative or trastuzumab-resistant human breast cancer cells to trastuzumab. The modification of the tumor-specific replication-competent adenovirus (OBP-301, Telomelysin) to contain the HER2-ECD gene for exogenous expression is currently under the investigation. We will further examine the antitumor effects of this virus in the combination with trastuzumab.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 720. doi:10.1158/1538-7445.AM2011-720
Abstract 742: Mechanisms of resistance to small molecule inhibition of anaplastic lymphoma kinase in human neuroblastoma
Authors: Carpenter Erica L. , Haglund Elizabeth A. , Chow Adrian K. , Christensen James G. , Maris John M. , Mosse Yael P.
Published: June 2012

The purpose of this study was to identify therapeutically targetable mechanisms of resistance to anaplastic lymphoma kinase (ALK) inhibition in neuroblastoma. ALK is a receptor tyrosine kinase (RTK) frequently activated in neuroblastoma, a malignancy of the autonomic nervous system representing almost 10% of pediatric cancers. ALK aberrations, including mutation and amplification, lead to increased autophosphorylation and activation in neuroblastoma. PF-02341066, an orally available small-molecule inhibitor of the ALK tyrosine kinase, has shown dramatic activity in non-small lung cancers harboring an ALK translocation, and is currently in phase 1 trials in pediatrics. Although pharmacological inhibition of kinases in diseases such as chronic myelogenous leukemia has significantly improved survival, resistance inevitably develops. Mechanisms of resistance to tyrosine kinase inhibitors have included mutation of the targeted receptor as well as up-regulation and dependence switch to other RTKs. We hypothesize that patients with neuroblastoma who successfully respond to ALK inhibition will eventually relapse and that in vitro models can be used to predict the underlying mechanisms of resistance. To mimic the development of resistance, we treated ALK-expressing human neuroblastoma-derived cell lines in vitro with PF-02341066 for several months. Once resistance was established, serial dilutions were used to generate clonal populations of PF-02341066-resistant cells. Western blotting was used to confirm inhibition of phospho-ALK and rule out drug efflux as a resistance mechanism. DNA analysis revealed no additional PF-02341066-induced mutations or copy number variations within ALK. We next used Western blot and phoshpho-array technology to evaluate changes in the activation state of a panel of RTKs as well as their downstream signaling molecules. Interestingly, in comparison to the untreated parental line, PF-02341066-resistant cells had up-regulated activated epidermal growth factor receptor (EGFR) as well as other downstream signaling molecules. Dependence of the PF-02341066-resistant cells on these pathways was verified by showing increased sensitivity of the resistant versus parental cell lines to inhibition of these up-regulated pathways. Taken together, these data suggest that ALK inhibition in neuroblastoma leads to a dependence switch to EGFR and implies the need to develop therapeutic strategies to target this receptor when ALK inhibition is used clinically.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 742. doi:10.1158/1538-7445.AM2011-742
Abstract 761: Comparison of different classes of CpG-ODNs to augment generation, proliferation and specific cytotoxicity of human epitope-peptide specific CTLs in vitro
Authors: Katsuda Masahiro , Iwahashi Makoto , Matsuda Kenji , Miyazawa Motoki , Nakamori Mikihito , Nakamura Masaki , Ojima Toshiyasu , Iida Takeshi , Hayata Keiji , Yamaue Hiroki
Published: June 2012

Three distinct classes of CpG- oligonucleotides (ODN) (CpG-A, CpG-B and CpG-C) have been identified based on differences in their structures and immune effect. So far, CpG-B is only applied for clinical treatments; however, it is still unknown which of the different CpG-ODN classes is most useful as adjuvant of human cancer vaccine therapy. In the present study, we examined the activity of these 3 types of CpG-ODNs to enhance the induction of human peptide-specific CTLs. In addition, we elucidated the effect of CpG-ODNs on tumor antigen epitope peptide-specific CTL clones to investigate the adjuvant mechanism of CpG-ODNs on peptide vaccine therapy. Our data showed that PDC activated by CpG-ODNs augmented induction of peptide specific CTLs. Importantly, CpG-A is superior to CpG-B and CpG-C in augmenting the generation, proliferation and cytotoxic activity of human peptide specific CTLs in vitro. Moreover, type-1 IFNs produced by PBMCs that were stimulated with CpG-ODNs accelerated the proliferation of peptide-specific CTL clones, and also directly augmented the peptide specific cytotoxicity of CTL clones through the up regulation of Granzyme-B. These data showed that IFN-α might play an important role for CpG-ODNs to induce the adjuvant effects in peptide vaccine therapy. In addition, because CpG-A induced high amount of type-1 IFNs, CpG-A might be the superior candidate for vaccine adjuvant than CpG-B or CpG-C.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 761. doi:10.1158/1538-7445.AM2011-761
Abstract 763: Cranberry juice constituents as an adjuvant for protein vaccination against malignant lymphoma
Authors: Hochman Jacob , Braitbard Ori , Roniger Maayan , Bar-Sinai Allan , Weiss Ervin I. , Hochman Nira
Published: June 2012

Cranberry fruit and juice have been reported to exert a multitude of health-related benefits. NDM is a 12-30K molecular weight fraction, which we have derived from cranberry juice and which, as we have previously reported, impairs in vitro growth and invasion through extracellular matrix of murine lymphoma cells [N.Hochman et al. Nutrition and Cancer 60(4), 511-517,2008]. Furthermore, intraperitoneal inoculation of NDM inhibited the in vivo growth of these tumors in syngeneic hosts, demonstrating its in vivo efficacy as an anti-tumorigenic agent.

MMTV-p14 (p14 for short) is the signal peptide of the env-precursor of Mouse Mammary Tumor Virus. This peptide was found by us to localize in the nucleoli of every MMTV-containing lymphoma or mammary carcinoma tested, (as well as in some cases of human breast cancer).

Here we report that priming and boosting of mice with purified recombinant p14 +NDM results in enhanced generation of anti-p14 antibodies in the sera of inoculated mice. Furthermore, mice primed and boosted with p14+NDM are immunized against a subsequent challenge with malignant lymphoma cells that contain MMTV. Mice, primed and boosted separately with p14 or NDM were not immunized against a lymphoma challenge.

These findings demonstrate that NDM can be used as adjuvant in a protein vaccination protocol against malignant lymphoma cells that harbor the virus MMTV.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 763. doi:10.1158/1538-7445.AM2011-763
Abstract 765: Costimulatory SA-4-1BBL and monophosphoryl lipid A as novel adjuvant system for the development of cancer vaccines with robust therapeutic efficacy
Authors: Srivastava Abhishek , Sharma Rajesh , Zhao Hong , Yolcu Esma , Shirwan Haval
Published: June 2012

Subunit vaccines based on tumor-associated antigens (TAAs) represent an attractive alternative to conventional treatments for cancer due to their safety profile and ability to control recurrences by establishing long-term immunological memory. However, the efficacy of TAA-based therapeutic vaccines is limited by weak immunogenic nature of these antigens and various immune evasion mechanisms employed by the progressing tumor. To overcome these limitations, we herein used SA-4-1BBL costimulatory molecule and toll-like receptor 4 agonist monophosphoryl lipid A (MPL) as two immunomodulators with distinct mechanisms of action as a novel adjuvant system for the development of HPV16 E7 and survivin TAA-based therapeutic vaccines against TC-1 cervical and 3LL pulmonary carcinoma mouse models, respectively. A single immunization with a vaccine formulation containing E7 protein plus SA-4-1BBL and MPL resulted in the eradication of established E7 expressing TC-1 tumors in 100% of mice. Similarly, a single vaccination with survivin, as a bona fide self-TAA, resulted in control and/or eradication of established 3LL pulmonary metastases and the efficacy of the vaccine was further improved by a booster injection. Combined adjuvants had better therapeutic efficacy over the individual agents while SA-4-1BBL significantly performed better than MPL. The therapeutic efficacy achieved with the combinatorial use of both adjuvants and SA-4-1BBL as monotherapy was correlated with elevated levels of IFN-γ+TNF-α+IL-2+ triple positive antigen-specific CD8+ T cells, cytotoxic response, long-term immune memory, and most importantly an increase in the intratumoral number of CD8+ T effector cells with simultaneous decrease in the number of CD4+FoxP3+ T regulatory cells, resulting in a favorable T effector/T regulatory cell ratio. In marked contrast, although MPL as monotherpay improved the effector function of CD8+ T cells, it did not increase the infiltration of these cells into the tumor. Surprisingly, MPL as monotherapy increased the number of CD4+FoxP3+ T regulatory cells infiltrating into the tumor, resulting in an unfavorable T effector/T regulatory cell ratio. Taken together, these data demonstrate the utility of using SA-4-1BBL and MPL as a novel adjuvant system for the development of therapeutic TAA-based subunit cancer vaccines with strong clinical implications.

Work is in part funded by NIH 2R44 AI071618-02, R43 AI074176, R41 CA121665, KLCP, the W.M. Keck Foundation, and the Commonwealth of Kentucky Research Challenge Trust Fund.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 765. doi:10.1158/1538-7445.AM2011-765
Abstract 768: Lymphokine activated killer cell conditioned media induces monocytes to differentiate into a dendritic cell-like/activated monocyte phenotype with cytotoxic potential against glioblastoma
Authors: Cornforth Andrew N. , Lee Gregory , Fan Eric , Fowler Abner , Alldredge Jessica , Carbonell Denysha , Dillman Robert O.
Published: June 2012

Background: Despite advances in surgery and multimodal treatment regimens, Glioblastoma (GBM) continues to have poor overall survival outcomes and associated treatment morbidity. Cell-based immunotherapy is being explored as an option in the treatment of GBM. Treatment of GBM with lymphokine activated killer cells (LAK) generated by interleukin-2 (IL-2) stimulation has been associated with encouraging overall survival rates (Dillman RO et al. J Immunotherapy 2009 32:914-919). Since it has been reported that IL-2-activated lymphocytes can produce cytokines that may influence the differentiation and activation of monocytes (Kirsch M et al. J Neurooncol 1994 20:35-45), we explored the generation of activated monocytes and/or dendritic cells (DC) in LAK cell therapy products. Methods: Magnetic cell isolation of major histocompatibility complex II positive cells (HLA-DR) from LAK cell preparations revealed a small subpopulation of cells expressing CD80 and CD86 which also retained some CD14 expression. We then explored the possibility of generating activated monocytes and/or DC by incubating elutriated monocytes in the conditioned media of LAK cell preparations (LAK-CM) and examining their characteristics in comparison to standard GM-CSF/IL-4 DC or LAK cells. Results: The resulting LAK-CM incubated monocytes showed high levels of expression of CD80 (65.3%), CD86 (72.3%), HLA-DR (83.6%), comparable to the standard GM-CSF/IL-4 DC. The LAK-CM treated monocytes also retained their CD14 expression at (58.2% vs. 58.4%) and had similar levels of phagocytic ability compared to DC (14.7% vs. 12.7%) and demonstrated higher cytotoxicity levels against a model GBM cell line, U251, compared to either LAK cells themselves or the standard GM-CSF/IL-4 generated DC (85.6% vs. 55.9% vs. 60.9%, respectively). Conclusions: Combining lymphocytes and monocytes from elutriated lymphocyte fractions under LAK cell generation conditions (1000 IU/mL IL-2 in AIMV) also yielded similar dendritic cell/activated monocyte phenotypes suggesting that new combinations of cell therapy could be produced using this method with higher tumor cytotoxicity potentials as well as antigen cross presentation capabilities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 768. doi:10.1158/1538-7445.AM2011-768
Abstract 773: Inhibition of HIF-1 impairs TGF-β-mediated immunosuppression
Authors: Teramoto Koji , Kawaguchi You , Hori Tetsuo , Ohshio Yasuhiko , Kitamura Shoji , Hanaoka Jun , Tezuka Noriaki , Kontani Keiichi
Published: June 2012

Hypoxia is one of distinctive features of the tumor microenvironment. In the tumor tissues under hypoxia, a transcription factor, hypoxia-inducible factor-1 (HIF-1) plays a critical role in regulating expressions of various genes associated with tumor growth. In order to understand the immunobiology of hypoxic tumor microenvironment, it is of great interest to elucidate the anti-tumor immune responses regulated by HIF-1. From these viewpoints, we focused on a relationship between HIF-1 and transforming growth factor-beta (TGF-β). TGF-β which is derived from either tumor cells or tumor stromal cells may be regulated by HIF-1 and suppress anti-tumor immune responses in tumor-bearing hosts. In this report, we hypothesized that eliminated expression of TGF-β by inhibition of HIF-1 in tumor tissue would contribute to augmentation of anti-tumor immune responses. We examined the possibilities in tumor-bearing mice models. C57BL/6 mice bearing mouse lymphoma E.G7 were administrated HIF-1 siRNA into the tumor tissue four times at 2-day interval. Seven days after the last administration of HIF-1 siRNA, anti-tumor immune responses elicited in the mice were examined. As results, inhibition of HIF-1 in tumor tissue led to low expression of TGF-β mRNA as well as low level of TGF-β protein there. In tumor-draining lymph nodes where TGF-β derived from tumor tissue would affect anti-tumor immune responses, the numbers of CD4+CD25+Foxp3+ cells (regulatory T cells) as well as CD11b+Gr-1+ cells (myeloid-derived suppressor cells) were decreased. Meanwhile, tumor antigen-specific CD8+ as well as CD4+ cells producing IFN-γ were increased. In spleen, production of reactive oxygen species by CD11b+Gr-1+ cells was recovered to the same level as that from normal mouse. Tumor antigen-specific CD8+ as well as CD4+ cells producing IFN-γ were increased and cytotoxic activity against target E.G7 cells were enhanced in spleen. Subsequently, tumor growth was effectively suppressed by inhibition of HIF-1. Inhibition of HIF-1 in tumor tissue can reduce expression of TGF-β there. This contributes to weakening suppressor cells in tumor-draining lymph nodes, which elicits enhanced anti-tumor immune responses systemically. These results demonstrate that hypoxia and immunosuppression in tumor microenvironment are linked by HIF-1and TGF-β, respectively. Inhibition of HIF-1 can improve anti-tumor immune responses, and provides a new rationale with the cancer immunotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 773. doi:10.1158/1538-7445.AM2011-773
Abstract 780: Immune escape in colorectal carcinoma: role of the IFN-γ pathway
Authors: Britzen-Laurent Nathalie , Naschberger Elisabeth , Rau Tilman , Schneider-Stock Regine , Hartmann Arndt , Croner Roland S. , Stürzl Michael
Published: June 2012

The presence of a Th1 adaptive immune response in colorectal carcinoma (CRC) has been associated with improved clinical outcome and survival of patients. The Th1 adaptive immune response is mediated by IFN-γ, a known anti-proliferative, pro-apoptotic and pro-immunogenic cytokine. We have previously identified the guanylate-binding protein 1 (GBP-1), one of the proteins the most highly induced by IFN-γ, as a sensitive marker for the detection of this immune response in CRC in vivo. In a tissue microarray study with 388 CRC tumors, 30% showed GBP-1 expression. Interestingly, in these tumors the expression of GBP-1 was only induced in the cells of the desmoplastic stroma and not observed in adjacent tumor cells. This suggested that CRC tumor cells might undergo an immune escape from the Th1 adaptive immune response, characterized by the loss of IFN-γ responsiveness. Therefore, we investigated the responsiveness to IFN-γ in sixth different CRC cell lines and in normal colon epithelial cells. After treatment with IFN-γ, three of the sixth CRC cell lines (DLD-1, SW480 and HCT116) failed to express GBP-1 as well as other IFN-induced proteins such as caspase-1 and MxA. On the contrary, a robust GBP-1 induction was present in normal colon epithelial cells, in T84, WiDr and HT29 cells.

We then investigated whether the loss of expression of IFN-γ target genes was associated with phenotypic changes in CRC cells. In fact, we found that DLD-1, HCT116 and SW480 were resistant to IFN-γ-induced apoptosis. Furthermore, the loss of IFN-γ responsiveness correlated in SW480 and HCT116 with the absence of expression of the IFN-γ receptor alpha chain (IFNγRα).

Tumor xenotransplant experiments using DLD-1 cells with reconstituted GBP-1 expression resulted in significantly reduced tumor growth as compared to xentotransplants with control vector transfected DLD-1 cells. This indicated that GBP-1 expression may mediate the anti-tumorigenic effects of the Th1 response.

Overall, these data suggested that loss of IFN-γ responsiveness may be a common event in CRC and may protect tumor cells against the anti-tumorigenic (e.g. pro-apoptotic) effects of IFN-γ. The presence of an immune escape from the Th1 adaptive immune response may have important repercussions for prognosis and patients recruitment for immune-based therapy in CRC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 780. doi:10.1158/1538-7445.AM2011-780
Abstract 79: Role of histone deacetylase expression in intrahepatic cholangiocarcinoma
Authors: Morine Yuji , Shimada Mitsuo , Utsunomiya Tohru , Imura Satoru , Ikemoto Tetsuya , Mori Hiroki , Hanaoka Jun , Iwahashi Syuichi , Saito Yu , Yamada Shinichiro , Asanoma Michihito , Kanamoto Mami
Published: June 2012

Introduction: Histone deacetylase (HDAC) plays an important role in chromatin remodeling, gene expression and in regulating cell cycle progression and differentiation. Furthermore, HDAC inhibitors have recently been found to repress the function of hypoxia inducible factors (HIF) through inducing hyperacetylation of histones. However, few studies have been conducted regarding the role of HDAC in IHCC. The aim of this study was to elucidate the role of HDAC in IHCC.

Methods: Thirty-five patients with IHCC who underwent hepatic resection were evaluated. The expressions of HDAC1 and HIF-1α were determined immunohistochemically, and the patients were divided into two groups: HDAC1 positive group (n=21); and HDAC1 negative group (n=14). Clinicopathological variables including HIF-1α expression were compared between the two groups.

Results: The HDAC1 expression correlated significantly with higher stage carcinoma, lymph node metastasis, and vascular invasion. The prognosis in the HDAC1 positive group was poorer than in the HDAC1 negative group (5-year survival: 77.9% vs. 7.9%, p=0.001). In the multivariate analysis, HDAC1 positive expression was identified as the only independent prognostic factor for disease free survival (Hazard Ratio: 7.194, p=0.0018). Furthermore, there was a significant correlation between HDAC1 expression and HIF-1α expression (p=0.007), and co-expressions of these markers in same cancer cells were proven by immunofluorescent stainings in the serial section

Conclusions: The findings suggested that a positive expression of HDAC1 is a new prognostic indicator of IHCC, and that HDAC1 might be a possible promising molecular target of IHCC, through the regulation of HIF-1α.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 79. doi:10.1158/1538-7445.AM2011-79
Abstract 795: Patterns of T-cell distribution at the invasive margin of colorectal cancer liver metastases: Downstream recruitment of T cells and spatial heterogeneity
Authors: Halama Niels , Zoernig Inka , Spille Anna , Schirmacher Peter , Brand Karsten , Falk Christine , Grabe Niels , Jäger Dirk
Published: June 2012

The local immunological cancer microenvironment influences the clinical course of colorectal cancer. The interface between colorectal cancer liver metastases and adjacent normal liver represents a clear border. Typically, T cells in the vicinity of the tumor are located on the stromal compartment of the tumor and only few cells are in direct contact with the tumor epithelium. Patterns of T cell distribution at the invasive margin are heterogeneous and have not been analyzed systematically. Using high-throughput whole slide imaging technology, tissue areas of 1 mm2 size were analyzed for precise T cell density and localization, showing distinct density patterns of localization in relation to the malignant tissue across the invasive margins of samples from different patients. Unsupervised clustering revealed distinct patterns: regions with T cells in close contact to the tumor usually had significantly elevated T cell numbers further away from the tumor, whereas the other groups showed limited enrichment. Additionally, in the distance of around 20 to 40 µm from the tumor a decrease in T cells was found. The distribution of the cells in the tissues could be accounted for by cell-matrix interactions, immune cell – immune cell interactions or chemotactic fields potentially generated by tumor or other cells. Direct T cell – tumor interaction however leads to subsequent far-reaching attraction and activation of T cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 795. doi:10.1158/1538-7445.AM2011-795
Abstract 802: Cytokine profiles in bone marrow supernatant and peripheral blood of patients with multiple myeloma and Waldenström's macroglobulinemia
Authors: Plyler Ryan J. , Wang Weixin , Ghobrial Irene M. , Roccaro Aldo M. , Korde Neha , Zingone Adriana , Landgren Ola , Calvo Katherine R.
Published: June 2012

Cytokines serve vital roles in the regulation of immune responses. In patients diagnosed with hematologic malignancies, cytokines may play a role in the tumor-host microenvironment affecting tumor survival and progression. Previous studies have quantified the variation in cytokine concentrations between malignant and normal states in patients’ serum. However the research is sparser in relation to measurement of cytokine concentrations in the bone marrow microenvironment. Multiple myeloma (MM) and Waldenström's macroglobulinemia (WM) are two such malignancies that arise in the B-lymphoid lineage and proliferate within the bone marrow (BM) microenvironment. In this study, an ultra-sensitive IL-6 and a human TH1/TH2 multiplex ELISA system were utilized to determine protein concentrations of the following cytokines: IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, IL-13, IFN-gamma, and TNF-alpha, in the BM supernatant and peripheral blood (PB) of 20 patients with WM, 16 patients with MM, and 7 controls. The BM supernatant concentration of TNF-alpha was significantly increased in MM compared to controls (10.650 pg/ml vs. 4.980 pg/ml, p=0.0158). IL-1beta was significantly decreased in the bone marrow supernatant of MM (0.038 pg/ml vs. 2.352 pg/ml, p=0.0469) and WM (0.046 pg/ml vs. 2.352 pg/ml, p=0.0435). IL-8 was also significantly decreased in the BM supernatant of patients with MM (11.520 pg/ml vs. 43.590 pg/ml, p=0.0158) and WM (7.348 pg/ml vs. 43.590 pg/ml, p=0.0036). Differences in BM supernatant concentrations of IL-6 were not significant in MM, WM, and normal controls. Analysis of PB showed IL-2, IL-5, IL-6, IL-8, IL-10, and TNF-alpha were significantly increased in both MM and WM versus controls, and IFN-gamma was significantly increased in WM. Hierarchical clustering analysis of the cytokine profiles suggested two distinct subgroups existed within both MM and WM. TNF-alpha was the only cytokine in our study that was increased in both the bone marrow and serum of MM patients. The discordant results obtained in the BM supernatant vs. PB for IL-6 and IL-8 in both MM and WM indicate that cytokine profiles vary somewhat between the PB and BM compartments. The BM supernatant and PB cytokine profiles in patients with MM and WM highlight the important role cytokines may play in the microenvironment and biology of MM and WM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 802. doi:10.1158/1538-7445.AM2011-802
Abstract 805: mTORC protein levels affect class switch recombination, somatic hypermutation, and antibody production
Authors: Zhang Shuling , Pruitt Margaret , Tran Dena , DuBois Wendy , Robinson Richard , Mock Beverly A.
Published: June 2012

Mammalian target of rapamycin (mTOR) regulates cell growth, cell cycle, and survival through two main complexes, mTORC1 and mTORC2. In our previous studies, striking decreases in both size and number of B cells were seen in mice with constitutive reductions in protein levels of both mTOR complexes. In addition, there were alterations in B cell differentiation with partial blocks in B cell development in the bone marrow. In our current studies, we have focused on their defect in antibody production. When challenged with either NP-CGG (T-dependent antigen) or NP-LPS (T-independent antigens), reduced IgG antibody titers to NP antigens were seen in mice with constitutive reductions in mTOR protein levels, despite equivalent levels of total antibody production; high affinity antibody production was also less. The numbers of germinal centers were reduced in the spleens of the mTORC1/2-compromised mice compared to their wild-type littermates. Fewer B cells from the mTORC1/2-compromised mice were able to undergo class switching from IgM to IgG. In addition, germinal center B cells from these mice exhibited reductions in somatic hypermutation rates of their immunoglobulin loci. Studies are currently underway to evaluate the ability of these mice to respond to an in vivo challenge of live bacteria.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 805. doi:10.1158/1538-7445.AM2011-805