bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1641: Targeting developmental regulators of zebrafish exocrine pancreas as a therapeutic approach in human pancreatic cancer
Authors: Yee Nelson S. , Chun Stephen G. , Zhou Weiqiang , Liang I-Chau
Published: June 2012

We aim to test the hypothesis that histone deacetylases (HDACs) and RNA polymerase III (Polr3) cooperatively control exocrine pancreatic growth, and combined inhibition of HDACs and POLR3 produces enhanced growth suppression in pancreatic cancer. This hypothesis is based on the observations that HDACs and POLR3 play vital roles in fundamental cellular processes, and deregulation of these enzymes has been implicated in malignant transformation. Using chemical inhibitors of HDACs and POLR3, we examined the effect on exocrine pancreas during morphogenesis, and then translated the developmental findings to human pancreatic adenocarcinoma cultured cells. Hdacs and Polr3 are required for exocrine pancreatic epithelial proliferation during morphogenesis. In zebrafish larvae, combination of a Hdac inhibitor (Trichostatin A) and an inhibitor of Polr3 (ML-60218) synergistically prohibited expansion of exocrine pancreas. In human pancreatic adenocarcinoma cells, combination of the clinical HDAC inhibitor suberoyl-anilide hydroxamic acid (SAHA) and ML-60218 produced enhanced suppression of colony formation and proliferation, and induction of cell cycle arrest and apoptotic cell death. The enhanced cytotoxicity was associated with supra-additive induction of a pro-apoptotic regulator and the cyclin-dependent kinase inhibitors. tRNAs have been shown to have pro-proliferative and anti-apoptotic roles, and SAHA-stimulated expression of tRNAs was reversed by ML-60218. These findings demonstrate that chemically targeting developmental regulators in zebrafish can be translated into a potential therapeutic approach in human cancer, and suggest that counteracting the pro-malignant side effect of HDAC inhibitors can enhance their anti-tumor activity.

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 1641. doi:10.1158/1538-7445.AM2011-1641
Abstract 1642: TIP-1 regulates sensitivity of glioma cells to radio- and chemotherapeutic agents through modulating p53 stability and activation
Authors: Han Miaojun , Wang Hailun , Han Zhaozhong
Published: June 2012

Malignant gliomas represent one group of tumors that poorly respond to chemo- and radio-therapies because of the intrinsic or acquired resistance. Identification of novel molecules that are involved in the therapeutics resistance is critical to develop new therapeutic modalities. Our previous studies show that TIP-1 involves in tumor cells response to ionizing radiation (IR). In this study, we found that TIP-1 expression level correlates to the clinical staging and overall patient survival time after diagnosis of malignant gliomas. We hypothesized that TIP-1 is one novel predictive biomarker of glioma cell response to treatment, and targeting TIP-1 represents one novel strategy to combat the disease of high mortality. Studies on cell-based models indicated that TIP-1 deficiency resulted in the enhanced sensitivity of D54 and GL261 glioma cell lines to IR and chemotherapeutic agents, whereas ectopic expression of TIP-1 conferred resistance to the therapeutics in the cells. The data also showed that sensitivity of the glioma cell lines to IR correlates to stability and activation of p53 protein after IR treatment. Yeast two-hybrid screening identified C53/LZAP as one TIP-1 interacting protein within glioma cells. PDZ domain within TIP-1 binds to one classic type I PDZ-binding motif at the carboxyl terminus of C53/LZAP protein. C53/LZAP has been studied as one tumor suppressor and modulator of the cancer cell susceptibility to genotoxic stress including IR and several chemotherapeutic agents. C53/LZAP interacts with ARF and protects p53 from Mdm2-mediated protein degradation. Our data demonstrated that, after irradiation, presence of TIP-1 enhanced C53/LZAP interaction with ARF, thus promoted Mdm2-mediated p53 ubiquitination and resulted in less stable p53 protein. On the other hand, with absence of TIP-1 protein, IR treatment resulted in more stabilized and activated p53 protein that drives IR-induced apoptosis of the glioma cells. Taken together, our data suggests that TIP-1 is one novel modulator of p53 tumor suppressor and contributes to chemo- and radio-resistance of glioma cells. Therefore, targeting TIP-1 represents one novel approach for the improved therapy of malignant glioma.

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 1642. doi:10.1158/1538-7445.AM2011-1642
Abstract 1663: Identification of interleukin 4 receptor alpha (IL-4Rα) as a biomarker of advanced stage human bladder carcinoma
Authors: Joshi Bharat H. , Leland Pamela , Puri Raj K.
Published: June 2012

Previously, we have demonstrated that a variety of human and murine cancer cell lines and tumor specimens overexpress Interleukin 4 receptor alpha (IL-4Rα) chain in vitro and in vivo. We have also shown that cancer cell lines and human bladder tumor specimens express high density IL-4Rα at mRNA and protein levels, which sensitized them in vitro and in vivo to a chimeric fusion immunotoxin consisting of circularly permutated IL-4 and a truncated Pseudomonas exotoxin [cpIL-4(38-37)-PE38KDEL]. In the present study, we have examined the expression of two receptor subunits of the IL-4R complex, IL-4Rα and IL-13Rα1, in 60 human bladder carcinoma tissue microarray (TMA) with different pathological grades by IHC and ISH analyses. The TMA consisted of either grade II papillary transitional cell carcinoma or grade I-III transitional cell carcinoma. By IHC analysis for IL-4Rα, we observed that 52/60 (84%) transitional cell carcinoma samples were ≥2+ staining intensity for IL-4Rα. Interestingly, Grade III TCC specimens were most strongly positive (3+) [18/29 (62%)] compared to Grade II specimens [4/26 (15%)]. Grade 1 specimens showed least positivity [5/5 (100%) and showed only 1+ staining intensity]. ISH results corroborated with the IHC findings, which demonstrated that Grade III tumors were more strongly positive (3+) for IL-4Rα mRNA compared to Grade II specimens [19/26 (73%) Grade III versus 4/26 (15%) Grade II, respectively]. 4/5 (80%) Grade I specimens showed 1+ staining and one sample was weakly positive (+/-). All samples expressed IL-13Rα1 at ≤1+ immunostaining intensity by both IHC and ISH analyses. Additional bladder cancer samples and normal or non-cancerous bladder specimens are being studied for IL-4Rα and IL-13Rα1 expression to confirm our observations. Taken together, these results suggest that IL-4Rα may have a role in disease aggressiveness and may serve as a biomarker of advanced stage disease.

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 1663. doi:10.1158/1538-7445.AM2011-1663
Abstract 1686: Effect of echistatin on proliferation, migration, invasion and angiogenesis of integrin αvβ3-expressing human osteosarcoma
Authors: Tome Yasunori , Kimura Hiroaki , Sugimoto Naotoshi , Maehara Hiroki , Tsuchiya Hiroyuki , Kanaya Fuminori , Bouvet Michael , Hoffman Robert M.
Published: June 2012

Expression of integrin αvβ3 has been shown to be associated with tumor progression and metastasis in several types of cancer. To investigate the specific role of integrin αvβ3 expression in human osteosarcoma, we compared integrin αvβ3 expression in a series of osteosarcoma cell sublines (143B parental and LM1-LM4) with increasing metastatic potential. We quantified integrin αvβ3 expression using RT-PCR and Western-blotting. Integrin αvβ3 expression correlated with the metastatic potential of the cells, with the LM4 cells showing the highest expression and highest metastatic capability. LM4 in vitro cell proliferation decreased after treatment with echistatin, which is an antagonist of integrin αvβ3. In vitro migration and invasion of LM4 were also inhibited by echistatin. Tumor-induced angiogenesis by LM4 in the chick chorioallantoic membrane was also inhibited by echistatin. These data indicated that integrin αvβ3 overexpression may play a role in metastasis and that echistatin has potential as an inhibitor of cancer cell migration and invasion.

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 1686. doi:10.1158/1538-7445.AM2011-1686
Abstract 1698: Resveratrol potentiates the cytotoxic profile of docetaxel and doxorubicin via inhibiting the activity and expression of p-glycoprotein molecules
Authors: Al-Abd Ahmed M. , Mahmoud Ali M. , Nofal Salwa M. , El-sherbiny Gamal A. , El-Moselhy Mohammed A. , Ahmed Abdel-Tawab Hekma A. , El-Eraky Wafaa I. , El-Shemy Hany A.
Published: June 2012

P-glycoprotein is membrane protein highly abundant in tumor cells which facilitate the effluxes of several chemotherapeutic agents to the extracellular compartment. Several P-glycoprotein blockers of synthetic origin were suggested as adjuvant therapy for cancer; however, manifested several toxic side effects. Resveratrol was found to block p-glycoprotein with potential use as adjuvant therapy for several p-glycoprotein substrates such as docetaxel and doxorubicin. Herein, we have assessed the interactive characteristics of resveratrol with docetaxel and doxorubicin and further investigated the molecular bases of this interaction in three different solid tumor cell lines (MCF-7, HeLa and HepG2). Resveratrol per se was found to possess anti-cancer properties; however with relatively low potency in all tested cell lines (IC50 ranges from 8.0 to 19.1µg/ml). Doxorubicin and docetaxel showed IC50‘s ranged from 0.28 to 0.42 µg/ml and from 22.3 to 67.1 ng/ml, respectively. Resveratrol combination with doxorubicin and docetaxel significantly increased the potencies of both chemotherapeutic agents showing IC50‘s ranging from 0.07 to 0.2 µg/ml and from 6.2 to 45.7 ng/ml, respectively. The combination index showed synergistic interaction between resveratrol and doxorubicin or docetaxel in MCF-7 cell line, while additive interaction in HeLa and Hep-G2 cell lines. Real time PCR revealed that the expression of BAX and BcL2 were simultaneously elevated due to combination of resveratrol with doxorubicin or docetaxel in all tested cell lines while p-53 showed marginal elevation in MCF-7 and HepG2 cell lines. The p-glycoprotein efflux activity was significantly inhibited with subsequent accumulation of p-glycoprotein substrate within the intracellular compartment of all tested cell lines. Also the expression level of mdr1 gene was down regulated after resveratrol combination with doxorubicin or docetaxel in all tested cell lines. In conclusion, resveratrol potentiates the anti-cancer effects of doxorubicin and docetaxel via increasing their intracellular level due to p-glycoprotein activity inhibition and down regulation of mdr1 gene.

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 1698. doi:10.1158/1538-7445.AM2011-1698
Abstract 17: Bcl-2 is a downstream target of ATF5 that mediates ATF5's pro-survival function in a cell type-dependent manner
Authors: Dluzen Douglus , Li Guangfu , Tacelosky Diana , Moreau Matthew , Liu David X.
Published: June 2012

The activating transcription factor 5 (ATF5) is a member of the ATF/CREB family of basic zipper (bZIP) proteins. Recent reports showed that ATF5 loss-of-function causes apoptotic cell death in glioblastoma and breast cancer cells but not in non-transformed astrocytes and human breast epithelial cells. The mechanism for ATF5's cell type-dependent survival function is unknown. We report here that the anti-apoptotic factor Bcl-2 is a downstream target that mediates ATF5-promoted cancer-cell survival in C6 glioma cells and MCF-7 breast cancer cells. ATF5 binds to an ATF5-specific regulatory element (ARE) that is downstream of and adjacent to the negative regulatory element (NRE) in the Bcl-2 P2 promoter, stimulating Bcl-2 expression. Highlighting the importance of Bcl-2 in ATF5-dependent cancer-cell survival, expression of Bcl-2 blocks death of C6 and MCF-7 cells induced by d/nATF5 and depletion of Bcl-2 impairs ATF5-promoted cell survival. Moreover, we found that Bcl-2 expression is not regulated by ATF5 in non-transformed rat astrocytes, MEFs, and human breast epithelial cells (HBEC), where knock-down of Bcl-2 but not that of ATF5 evokes cell death. These findings identify Bcl-2 as an essential mediator for ATF5's cancer-specific cell survival function in glioblastoma and breast cancer cells and provide direct evidence that the cell type-specific function of ATF5 derives from the differential regulation of downstream targets by ATF5 in different types of 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 17. doi:10.1158/1538-7445.AM2011-17
Abstract 1715: Induction of CYP1B1 expression in non-small cell lung carcinoma cells treated with B(a)P inhibits cisplatin-induced apoptosis
Authors: Park Juwon , Kim Kyungseon , Chae Yang Seok , Ahn Kwang-Sung , Won Nam Hee
Published: June 2012

Cytochrome P450 1B1 (CYP1B1) is a key enzyme involved in metabolizing environment pollutants and whose expression is often significantly increased in human malignancies. In the past years, several studies focused on the possible role of CYP1B1 in tumor progression, invasion and drug resistance. CYP1B1 gene polymorphisms have been associated with the risk of lung and other cancer. However, there is no a evidence that induction of CYP1B1 by B(a)P has relevance to anticancer drug resistance. In this study, we found that CYP1B1 expression was increased by exposure of B(a)P in A549 cells and H1299 cells, respectively. Both A549 cells and H1299 cells prolonged exposed to B(a)P [A549-B(a)P and H1299-B(a)P] were resistant to cisplatin treatments. MTT assay showed that IC50 of A549-B(a)P and H1299-B(a)P was 2.3 folds and 3.2 folds higher than IC50 of parental cells. Results of immuocytostain revealed that induction of CYP1B1 and AhR was detected in A549-B(a)P and H1299-B(a)P. Reduction of CYP1B1 by shRNA of CYP1B1 in A549-B(a)P and H1299-B(a)P became to be sensitized to cisplatin treatments. The similar result was found in A549 cells and H1299 cells transfected with shRNA of AhR. Our data suggested that AhR-mediated CYP1B1 expression affected the response of cisplatin treatments on non-small cell lung cancer cells (NSCLCs). It suggested that, in exposure of B(a)P on lung cancer cells, AhR can modulate CYP 1B1 expression resulting in producing BPDE to form a bulk of DNA adducts. Exposure of B(a)P is committed to controlling proliferative/apoptotic balance, which has obvious and important implications in tumor progression and drug resistance.

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 1715. doi:10.1158/1538-7445.AM2011-1715
Abstract 1794: A novel combination therapeutic approach for targeting murine cancers with IL-13 receptor alpha 2 DNA vaccine and an immunotoxin
Authors: Nakashima Hideyuki , Joshi Bharat H. , Husain Syed R. , Puri Raj K.
Published: June 2012

Iinterleukin-13 receptor α2 (IL-13Rα2), a cancer testis antigen, is frequently over-expressed on human solid tumors and can be effectively targeted by a recombinant fusion immunotoxin composed of IL-13 and a mutated form of Pseudomonas exotoxin (IL13-PE). We have previously demonstrated that cDNA vaccine to IL-13Rα2 or IL13-PE alone can cause regression of established murine cancer. Here, we demonstrate that combination therapy with DNA vaccine and IL13-PE can cause a remarkable antitumor effect in advanced tumor metastasis models induced by 4T1 breast carcinoma and MCA304 sarcoma. Murine metastatic tumor models were developed by i.v. injection of either 1×105 4T1 or 1×106 MCA304 cells. Mice with established 4T1 metastasis received twice daily i.p. injections of IL13-PE (50 ug/kg/injection) on five consecutive days beginning day 7 followed by i.m. DNA vaccination (100 μg/day) on day 18, 23, 28 and 33. The combination therapy significantly (p<0.01) prolonged overall survival (56 days) of animals compared to control (32 days), IL-13PE alone (43 days) or DNA vaccine alone (40 days). Similar results were observed in MCA304 sarcoma tumor model. Mice treated with combination therapy showed higher CTL activity and IFN-γ release from splenocytes in vitro compared to the controls in both tumor models. Immunofluorescence analyses exhibited infiltration of CD4+ and CD8+ T cells in lung tissues of immunized mice. The role of CD4+ and CD8+ T cells in tumor immunity was further confirmed by similar treatment of tumor-bearing RAG2 KO mice (deficient in T and B cells), which showed no response to therapy. Interestingly, tumor bearing mice treated with combination therapy recruited much lower number of myeloid-derived suppressor cells (MDSC) in lungs than PBS treated controls. These results indicate that combination therapy with IL13-PE followed by DNA vaccine may be a new therapeutic approach of treating human 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 1794. doi:10.1158/1538-7445.AM2011-1794
Abstract 18: Deep-sequencing of ovarian cancer stem cells
Authors: Zehir Ahmet , Ertem Server Adil , Moore Malcolm AS
Published: June 2012

Ovarian cancer remains to be one of the most fatal cancer types in women due to a lack of proper identification of therapies that will completely eradicate tumor cells in patients. Cancer stem cell (CSC) hypothesis states that there is a sub-population of cells in tumors that can self-renew and give rise to a differentiated tumor tissue. CSCs are also postulated to be resistant to conventional therapies, which might explain the recurrent nature of some of the cancer types. We have recently identified a novel cellular structure consisting of a chain of 4-72 cells with a pericellular glycocalyx, free-floating in the ascites of NOD/SCIDIL2Rγ-/- mice with intraperitoneal human serous ovarian adenocarcinoma (OvCa) xenografts. We have termed these “catenae” (Latin for “chains”). While the catena has the features of conventional CSCs, such as self-renewal, resistance to chemotherapy and ability to generate tumors in mice with as few as one cell; it also presents with unusual phenotypes. To elucidate the molecular mechanisms responsible for these phenotypes, as well as to get a transcriptional snapshot of pure CSCs; we performed SOLID deep-sequencing of catena on both whole cell RNA sample and polysomal RNA sample. We obtained 80millions and 60millions reads respectively. By comparing whole RNA sample to polysomal RNA sample, we have identified transcripts that are abundant in numbers but are not translated preferentially. We also identified alternative splicing events that might lead to the CSC phenotypes that catena have. Using public databases, we compared our data to differentiated cell states and generated comparative GO analysis of catena deep-sequencing data. The power of deep sequencing methodology will allow a deeper understanding of how CSCs might operate and will enable us to generate new therapies for eradicating CSCs.

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 18. doi:10.1158/1538-7445.AM2011-18
Abstract 1809: Stimulation of antibody dependent cell-mediated cytotoxicity by interleukin-15 is equivalent to interleukin-2
Authors: McDowell Kimberly A. , Hank Jacquelyn A. , Sondel Paul M.
Published: June 2012

An important strategy for the treatment of cancer involves administration of tumor-specific antibodies that target tumor cells for destruction by the individual's leukocytes via antibody dependent cell-mediated cytotoxicity (ADCC). However, ADCC is frequently depressed in individuals with cancer. Interleukin-2 (IL-2), a pro-inflammatory cytokine, enhances ADCC and is used clinically for this purpose. Interleukin-15 (IL-15) is a cytokine that shares many functions with IL-2, including stimulation of ADCC and proliferation and activation of natural killer cells. In contrast to IL-2, IL-15 supports the survival of CD8+ memory T cells, does not produce T cell activation-induced cell death and has no marked effects on Treg cells. Since these different functions may prove beneficial when using a cytokine to stimulate ADCC in vivo in cancer immunotherapy, we compared the in vitro effect of IL-15 (generously provided by Dr. Stephen Creekmore, NCI-Frederick) versus IL-2 to enhance ADCC. Using a standard 51Cr release assay, M21 human melanoma cells were loaded with 51Cr and incubated for four hours at 37° with human peripheral blood mononuclear cells (PBMC), hu14.18K322A, (generously provided by Dr. Fariba Navid of St. Jude Children's Research Hospital) a monoclonal antibody specific for GD2 (disialoganglioside) that is overexpressed on M21 cells (5 ng/ml), and either media, IL-2 (10 ng/ml) or IL-15 (10 ng/ml). The ratio of effectors (PBMCs) to targets (M21) was 10:1 or 30:1 and % cytotoxicity was determined from which lytic units were calculated. Incubation with IL-2 augmented ADCC from 163±39 to 230±40 lytic units (n=6, mean±SEM) while incubation with IL-15 enhanced ADCC from 148±27 to 229±36 lytic units (n=6). ADCC response was comparable for IL-2 and IL-15 (p=0.4857) and similar results were obtained using higher and lower concentrations of hu14.18K322A (0.1 – 100 ng/ml) and IL-2 and IL-15 (5 – 25 ng/ml), and after pre-incubation of PBMCs with IL-2 or IL-15 (4 – 44 hours). These experiments indicate that IL-2 and IL-15 demonstrate comparable stimulation of ADCC in vitro. If IL-15 produces equivalent enhancement of ADCC compared to IL-2 in vivo, it may be a potential immunotherapeutic for 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 1809. doi:10.1158/1538-7445.AM2011-1809
Abstract 1810: The effects of adoptive T cell transfer on the population of regulatory T cells in the mouse colorectal cancer transplant model
Authors: Okajima Manabu , Kokura Satoshi , Matsumoto Tsuguhiro , Ishikawa Takeshi , Matsuyama Ryuichi , Funaki Jun , Adachi Satoko , Matsuura Yuko , Sakamoto Naoyuki , Naito Yuji , Yosikawa Toshikazu
Published: June 2012

Background and Aim: Recent evidence has demonstrated that regulatory T cells (Tregs) mediated immunosuppression is one of the most crutial tumor immune-evasion mechanisms. We clinically demonstrated that the number of peripheral Tregs in the patients with variety of cancer which received ACT, which is non-specific CD3-LAK significantly decreased and that the clinical outcome of the patients of which peripheral Tregs decreased was better. ACT, which contains even only the non-specific lymphocytes might have the potential to not only directly kill malignant cells but also manipulate the population of Tregs in tumor bearing hosts in strong immunosuppressive states. The aim of this study is to investigate the effect of ACT which is composed of non-specific T lymphocytes on the population of Tregs in local tumor, draining lymph nodes and spleen in the mice colorectal cancer transplant model. We have also investigated the effect of activated T cells on the induction of Tregs from CD4+ T cells by IL-2 and TGF-β.

Materials and Methods: In vivo study: Male Balb/c mice were injected s.c. with colon26. The population of Treg in the tumor, the lymph node, and the spleen was analyzed after ACT(non-specific CD3-LAK) administration via a tail vein. In vitro study: The inducible system of Tregs was established. CD4+cells sorted from murine splenocytes were expanded for 72 hours in culture media containing IL-2 and TGFβ. LAK cells were co-cultured non-contactly with CD4+cells. Then we investigated the changes in the system after the co-culture. We also measured the concentration of IFN-γ in the culture solution to reveal the mechanism.

Results: The accumulation of Tregs in the draining LNs and tumor was significantly suppressed by ACT. The induction of Tregs in vitro was inhibited by co-culture with LAK cells. The concentration of IFN-γ in the culture solution increased in LAK+ group.Conclusions: We have demonstrated that ACT has the potential to reduce the number of Tregs in tumor and draining lymph nodes in the mouse colorectal cancer transplant model. As one of the mechanisms of this phenomenon, IFN-γ secreted from LAK cells might blockade the conversion of CD4+ cells into Tregs. These findings suggest a novel therapeutic position of ACT in variety of cancer immunotherapies.

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 1810. doi:10.1158/1538-7445.AM2011-1810
Abstract 1818: Identification of men with a genetic predisposition to prostate cancer: Targeted screening of BRCA1/2 mutation carriers and controls; The IMPACT study
Authors: Bancroft Elizabeth K. , Castro Elena , Dalby Elizabeth C. ,   The IMPACT Study Steering Committee & Collaborators, Eeles Rosalind A.
Published: June 2012

Introduction: Men with a mutation in either the BRCA1 or BRCA2 gene have an increased risk of prostate cancer, estimated as 3-5% for BRCA1 and up to 20% for BRCA2 by age 70. It has been demonstrated that men with BRCA2 develop aggressive disease but the real incidence and prevalence of cancer in mutation carriers remains unknown. IMPACT is a multi-national targeted prostate cancer screening study of men with a known germline mutation which is thought to predispose to the disease. The study is recruiting male BRCA1/2 mutation carriers and a control group who have tested negative for a mutation present in their family from 37 centres in 14 countries.

The aims of the study are to establish an international targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers; to determine the sensitivity and specificity of PSA screening for prostate cancer in this group; to determine the incidence of abnormal biopsy as a result of PSA screening in this group and to determine whether the pathology of tumours is different from screen-detected disease in controls.

Method: Eligible men aged 40-69 years are offered annual serum PSA testing for five years. The PSA threshold used to determine prostate biopsy is >3ng/ml. All men are offered a biopsy irrespective of PSA level after 5 years of screening. Men are also invited to take part in a Quality of Life sub-study.

Results: To date 1000/1700 men have been recruited, 77 have undergone biopsy and 30 men have been diagnosed with prostate cancer (18 BRCA2 carriers, 7 BRCA1 carriers and 5 controls). 80% of cases diagnosed in BRCA1/2 carriers were Gleason score ≥7 and T2 or higher (in the intermediate/high risk group for immediate radical treatment and not active surveillance, according to NICE guidelines) while in the general population (ERSPC study), 72% had a Gleason ≤6 and 61% were T1 (low risk group, suitable for active surveillance). The estimated positive predictive value for PSA screening in BRCA carriers is 44% vs 24% in the general population (ERSPC study).

Conclusions: Our preliminary results show that annual PSA screening using a cut-off of 3.0ng/ml detects aggressive prostate cancer in BRCA1/2 carriers. The higher risk of PrCa observed in BRCA1 and BRCA2 carriers will need to be confirmed with further data. Early data indicate that a larger proportion of gene carriers have developed clinically significant prostate cancers (those that would need radical treatment on UK treatment guidelines) compared with the control group.

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 1818. doi:10.1158/1538-7445.AM2011-1818
Abstract 182: Novel hydroxamic acid-derivative, MHY218, induces apoptosis and cell cycle arrest in HCT116 human colon cancer cells
Authors: Kim Dong Hwan , Kang Yong Jung , Kim Min Young , Hossain Mohammad Akbar , Jang Jung Yoon , Mon Hyung Ryong , Chung Hae Young , Choi Yung H. , Kim Nam Deuk
Published: June 2012

In this study, we investigated the anti-proliferative and pro-apoptotic properties of novel hydroxamic acid-derivative, MHY218, in HCT116 human colon cancer cells. We found that treatment of cells with MHY218 resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner. The induction of apoptosis was showed by decreased viability, cleavage of poly(ADP-ribose) polymerase (PARP), alteration in the ratio of Bax/Bcl-2 protein expression, and activation of caspase-8 and -9 together with caspase-3. In addition, MHY218 induced G2/M phase cell cycle arrest which was related to a decrease in the protein expression of cyclin B1 and its activating partners Cdc25c and Cdc2. MHY218 also caused an increase in the expression levels of p21WAF1/CIP1 in a p53-independent pathway. Nuclear transcription factor-kappa B (NF-κB) has been reported to be an implicated factor in apoptotic cell death of various cancer cells. Therefore, we found the effect of MHY218 on NF-κB signaling pathway. Treatment of cells with MHY218 resulted in inhibition of the expression levels of NF-κB and IκBα in a dose-dependent manner. These results suggest that MHY218 may have potential as a chemotherapeutic agent for prevention against colon 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 182. doi:10.1158/1538-7445.AM2011-182
Abstract 1827: Height, obesity and colorectal adenomatous polyps: The Minnesota Cancer Prevention Research Unit case-control study
Authors: Tu Huakang , Bostick Roberd M.
Published: June 2012

Background: Several observational studies found greater height and obesity to be associated with increased risk for colorectal cancer; however, there have been few studies of their associations with adenomatous polyps, precursors to most colorectal cancers.

Methods: We investigated the association of body size characteristics with risk of incident, sporadic colorectal adenomatous polyps using data from the Minnesota Cancer Prevention Research Unit case-control study of 566 colonoscopy-positive adenomatous polyp cases, 687 colonoscopy-negative controls, and 535 community controls conducted 1991-1994. Self-administered measurements of height, weight, and waist and hip circumferences were collected at recruitment. From these measurements, waist-to-hip ratio (WHR) and body mass index (BMI; kg of weight/height in m2) were calculated as indicators of obesity.

Results: In the multivariate analyses using the colonoscopy-negative controls, the adjusted odds ratios (OR) for adenomas across the upper three quartiles relative to the lowest quartile of height were 1.25 (95% confidence interval [CI]: 0.89, 1.76), 1.31 (95% CI: 0.93, 1.85), and 1.42 (95% CI: 0.96, 2.10), respectively; for WHR, the corresponding ORs were 0.82 (95% CI: 0.57, 1.18), 1.71 (95% CI: 1.15, 2.54), and 1.06 (95% CI: 0.75, 1.50); and for BMI they were 1.01 (95% CI: 0.70, 1.47), 1.28 (95% CI: 0.89, 1.82), and 1.20 (95% CI: 0.84, 1.70). For the combined effects of height and WHR and height and BMI, height, WHR, and BMI were dichotomized based on the median values among the community controls. Relative to those with shorter height and who also had a smaller WHR, those who were taller and also had a larger WHR were more likely to have adenomas (OR=1.71, 95% CI: 1.18, 2.48); the p-value for a multiplicative interaction was 0.68. Relative to those with shorter height and who also had a smaller BMI, those who were taller and also had a larger BMI were more likely to have adenomas (OR=1.50, 95% CI: 1.03, 2.19); the p-value for a multiplicative interaction was 0.72.

Conclusions: These data suggest that being taller and/or overweight may be associated with increased risk for colorectal adenomatous polyps.

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 1827. doi:10.1158/1538-7445.AM2011-1827
Abstract 184: HIPK2 downregulates Nox1 that is involved in p53Lys382 deacetylation and suppression of p53 oncosuppressor function
Authors: Puca Rosa , Nardinocchi Lavinia , D'Orazi Gabriellla
Published: June 2012

.HIPK2 is a stress-induced kinase and a transcriptional co-repressor that functionally cooperates with p53 to suppress cancer. Activation of the p53 proapoptotic function requires a cascade of phosphorylations and acetylations, and HIPK2 takes part in both modifications in that it phosphorylates Ser46 and allows Lys382 acetylation. In a cDNA microarray analysis we have found that depletion of HIPK2, that strongly affects p53 transcriptional function, induces Nox1 upregulation. Nox1, a homologue of the catalytic subunit of the superoxide-generating NADPH-oxidase is often overexpressed in tumors where triggers the angiogenic switch and induces genome instability by producing oxygen reactive species (ROS). However, the involvement of Nox1 in p53 regulation has never been addressed. We found that HIPK2 downregulated Nox1-luc promoter activity and that Nox1 upregulation, following HIPK2 silencing or Nox1 overexpression, inhibited drug-induced p53 Lys382 acetylation that strongly affected p53 apoptotic activity. P53Lys382 is a target of SirT1, a NAD-dependent deacetylase that is often upregulated in tumors and inhibits p53 apoptotic function. By the use of either small interfering RNAs to target SIRT1 or the SirT1 inhibitor nicotinamide we found that Nox1-dependent inhibition of p53 transcriptional activity was SirT1-dependent. Thus, Nox1 was unable to inhibit p53 when coexpressed with a SirT1 deacetylase-defective mutant (SIRT1HY) suggesting a link between Nox1 and SirT1 activity and a novel mechanism of SirT1 activation. Finally, recovery of HIPK2 function, by the use of Doxicyclin-induced conditional interference, downregulated Nox1 expression and reduced ROS production with rescue of p53Lys382 acetylation and p53 apoptotic activity. These findings suggest that Nox1 is a novel target of HIPK2 repressor function and is linked to p53 inactivation involving SirT1 activation and probably ROS production.

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 184. doi:10.1158/1538-7445.AM2011-184
Abstract 1851: Dietary mixed tocopherols inhibit cell proliferation in mammary hyperplasia, suppress the expression of inflammatory markers, and upregulate PPARγ
Authors: Smolarek Amanda K. , So Jae Young , Thomas Paul E. , Lee Hong Jin , Paul Shiby , Dombrowski Anne , Wang Chung-Xiou , Kong Ah-Ng Tony , Reuhl Kenneth , Lee Mao-Jung , Yang Chung S. , Suh Nanjoo
Published: June 2012

Dietary intake of vitamin E, a fat-soluble vitamin, has been suggested to reduce cancer risk because of antioxidant properties. There are eight different forms of vitamin E which include four tocopherols (with a saturated phytyl tail) and four tocotrienols (with an unsaturated isoprenoid side chain) designated as α, β, γ, and Δ variants. Previous clinical and epidemiological studies on vitamin E and cancer have focused on α-tocopherol. However, γ-tocopherol has demonstrated greater anti-inflammatory and anti-tumor activity than α-tocopherol. This study assessed the potential chemopreventive activities of a tocopherol mixture containing 58% γ-tocopherol (γ-TmT) in an established rodent model of mammary carcinogenesis. Female ACI rats were utilized due to their sensitivity to 17β-estradiol to induce mammary hyperplasia and eventually mammary tumors. The rats were implanted subcutaneously with estradiol (E2) pellets containing 2.5 mg of E2 and given 0.3% or 0.5% γ-TmT in the diet for 2 or 10 weeks. Serum E2 levels were significantly reduced by the treatment with 0.5% γ-TmT. Serum levels of anti-inflammatory markers, prostaglandin E2 and 8-isoprostane, were suppressed by γ-TmT treatment. Histology of mammary glands showed evidence of epithelial hyperplasia in E2 treated rats. Immunohistochemical analysis revealed a decrease in estrogen receptor α (ERα) and proliferating cell nuclear antigen (PCNA), and an increase in cleaved-caspase3 and peroxisome proliferator-activated receptor γ (PPARγ) in the γ-TmT treated rats, indicating that tocopherol treatment inhibits cell proliferation and induces apoptosis. Treatment with γ-TmT resulted in a decrease in the expression of ERα mRNA, while ERβ and PPARγ mRNA levels were increased. These data suggest that γ-TmT inhibits the cell proliferation in mammary hyperplasia, suppresses the expression of inflammatory markers, and upregulates PPARγ. In conclusion, γ-TmT may be a promising agent for human breast cancer prevention.

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 1851. doi:10.1158/1538-7445.AM2011-1851
Abstract 2157: Cell cycle dependent regulation of c-Myb target gene specificity
Authors: Quintana Anita M. , Ness Scott A.
Published: June 2012

The c-Myb transcription factor is a critical regulator of proliferation and stem cell differentiation, and mutated alleles of c-Myb are oncogenic, but little is known about changes in c-Myb activity during the cell cycle. Previous studies have shown that the specificity of c-Myb depends in part on its DNA binding domain, but also on protein-protein interaction motifs in the C-terminal regulatory domains of the protein. These interactions are likely subject to regulation by post-translational modifications and are modified in oncogenic derivatives of c-Myb, which regulate different sets of target genes than the normal c-Myb protein. The analysis of cell cycle regulated target genes provides an ideal means of following the regulation of c-Myb activity in different subsets of cells that are in distinct cell cycle phases. Using Chromatin Immunoprecipitation (ChIP) assays, we found that c-Myb associated with some target genes only in specific cell cycle stages. For example, with the Cyclin E1 gene promoter only in G2/M phase cells. However, we also found that the levels of c-Myb protein were dramatically affected by treating with some cell cycle blocking agents. To map the association of c-Myb with specific target genes during the cell cycle, we developed a novel Fix-Sort-ChIP approach, in which asynchronously growing cells were fixed with formaldehyde, stained with Hoechst 33342 and separated into different cell cycle fractions by flow sorting, then processed for ChIP assays. This approach showed that the specificity of c-Myb is dramatically different in small subpopulations of cells, for example cells in the G2/M phase of the cell cycle, than in the bulk population. The repositioning of c-Myb during the cell cycle is not due to changes in its expression and also occurs with ectopically expressed, epitope-tagged versions of c-Myb. The repositioning occurs in established cell lines, in primary human CD34+ hematopoietic progenitors and in primary human acute myeloid leukemia cells. Our results suggest that c-Myb specificity is actively regulated during the cell cycle, probably through changes in protein-protein interactions. This sheds new light on the dynamic nature of gene regulation during the cell cycle and on the importance of post-translational modifications and/or oncogenic mutations that can dramatically alter the activity and the specificity of transcription factors like c-Myb.

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 2157. doi:10.1158/1538-7445.AM2011-2157
Abstract 2168: Detections of olfactomedin 4 gene expression by qRT-PCR in human prostatic samples and cell lines
Authors: Li Hongzhen , Liu Wenli , Zhu Jianqiong , Rodriguez-Canales Jaime , Hanson Jeffrey C. , Emmert-Buck Michael R. , Rodgers Griffin P.
Published: June 2012

The human olfactomedin 4 gene (OLFM4) encodes an olfactomedin-related glycoprotein. OLFM4 gene is normally expressed in a limited number of tissues, including the prostate, but the regulation of OLFM4 gene expression in prostate are largely unknown. We have previously reported that reduced or lost expression of OLFM4 protein is correlated with higher Gleason scores in prostate cancer and loss of gene expression is due to deletions within the OLFM4 gene in about 36.7% (11/30) of prostate cancer patient samples studied. In this study, we investigated the regulation of OLFM4 gene expression in human prostate cancer pathogenesis.

We have investigated the mRNA expression levels using quantitative RT-PCR analysis in 144 human prostate cDNA samples (OriGene). We found that the average expression level of OLFM4 gene is significantly reduced in cancer tissues compared with normal tissues. The expression level of OLFM4 mRNA is inversely corrected with higher Gleason Score in prostate cancer. Interestingly, we also found higher expression of OLFM4 gene within small subset of samples with inflammation including prostatitis, hyperplasia and well differentiated tumor tissue.

We have also screened the expression of OLFM4 mRNA level using qRT-PCR in primary cultured human normal prostate epithelial cells (PREC), benign immortalized prostate epithelial cell (RWPE1), androgen-responsible cancer cells (LNCaP and VCaP), androgen-independent cancer cells (PC-3 and DU145). We found lower expression of OLFM4 in RWPE1 cells. We also confirmed our previous results that OLFM4 mRNA was not expressed in cancer cell lines, LNCaP, VCaP, PC-3 and DU145.

We have reported previously that deletions within the OLFM4 gene were present in about 40% in human prostate cancer samples studied. To test whether methylation is also involved in the loss of OLFM4 gene expression in human prostate cancer, the methylation status of CpG sites in OLFM4 promoter region has been analyzed in primary prostate tissues obtained by Laser Capture Microdissection. Hypermethylation of CpG sites at -91, -486 and -681 were detected in higher Gleason score of cancer samples. We further treated PC-3 cells (in which the OLFM4 gene is intact) using the demethylation reagent, 5-aza-2’-deoxycytidine and found restoration of OLFM4 mRNA expression. The results suggest that methylation status of OLFM4 gene promoter region may affect OLFM4 gene expression in prostate cancer 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 2168. doi:10.1158/1538-7445.AM2011-2168
Abstract 2184: Complex formation between the DLC1 START domain and Cav1 contributes to the tumor suppressor function of DLC1
Authors: Du Xiaoli , Qian Xiaolan , Papageorge Alex , Vass William C. , Braverman Richard , Lowy Douglas R.
Published: June 2012

Deleted in live cancer (DLC1), a tumor suppressor gene with Rho GTPase-activating (RhoGAP) activity, is frequently inactivated in a variety of cancers. DLC1 encodes a 1091 amino acid multi-domain protein whose RhoGAP catalytic domain (aa 609-878) is flanked by an amino-terminal sterile alpha motif (SAM; aa 17-76) and a carboxy-terminal steroidogenic acute regulatory (StAR)-related lipid transfer (START; aa 879-1080) domain. Caveolin-1 (Cav1), a key constituent of caveolae, plays an important role in signal transduction, endocytosis, and cholesterol transport, behaves as a tumor suppressor in most contexts, and is reported to form a complex with DLC1. Here, we have sought to assess the biological relevance of the DLC1-Cav1 interaction and to determine the region of DLC1 that interacts with Cav1.

After confirming that endogenous DLC1 and Cav1 co-localize with each other by immunomicroscopy and form a complex in vivo as assessed by co-immunoprecipitation, we determined the DLC1 sequences that were required for complex formation. Using GST-Pull down of a GST-Cav1 fusion protein that had been co-transfected with a series of GFP-DLC1 fragments, we identified a polypeptide of DLC1 (aa 899-996), composed of residues from the START domain that was necessary and sufficient for complex formation. A full-length GFP-DLC1 mutant lacking some of these START residues (aa 929-957) was deficient for complex formation with endogenous Cav1. When stably expressed in a human lung cancer cell line that did not express endogenous DLC1, the mutant was severely compromised in suppressing cell migration, colony formation, and anchorage-independent growth in soft agar compared to cells stably expressing the wild type GFP-DLC1. We conclude that the START domain of DLC1 is required for its complex formation with Cav1, and that this interaction contributes to the tumor suppressor activity of DLC1. To our knowledge, this is the first identified function for the DLC1 START domain.

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 2184. doi:10.1158/1538-7445.AM2011-2184