bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5405: Immuno-phenotyping reveals cell types present in circulation of breast cancer patients and elucidates their funstional potential
Authors: Ramirez Oscar
Published: August 2012

Myeloid derived suppressor cells (MDSC) have an identified role in suppressing anti-tumor immunity through Jak/Stat pathway activation and the generation of reactive oxygen species and arginase -1, thus promoting cancer progression. There is robust data on the identification of functionally suppressive MDSCs in preclinical models. However, such knowledge is underdeveloped in human cancers. Specifically, the clear identification of the true MDSC and their role in tumor immunoevasion, cancer progression and metastasis is undefined. Therefore, comprehensive identification of MDSCs and their ability to augment tumor-induced immune suppression in newly diagnosed early stage breast cancer is warranted to define their potential as a novel immunotherapeutic target. To delineate the role of MDSCs in newly diagnosed, untreated breast cancer and their tumor immunosuppressive effects in comparison to normal hosts, we conducted a prospective trial of stage I-IV breast cancer patients enrolled prior to initiation of systemic therapy and their age-matched normal donors. The following immune cell subsets were analyzed: regulatory T cells (CD3+/CD4+/CD25+/Foxp3+), MDSCs (Linlo/HLA-DR-/CD33+/CD11b+), and DCs (Lin-/CD14-CD4+/CD303+/CD1c+/CD141+). Functional assays of T cell activation and MDSCs mediated-T cell suppression were performed. We identified no significant differences in the percentage of regulatory T cells or mDC2 between breast cancer subjects and normal controls. In contrast, the percent of MDSC, pDCs and conventional DCs detected were suprisingly significantly higher in the healthy donor population as compared to breast cancer subjects. Breast cancer T cells showed reduced capability to respond to external stimulus as measured by up-regulation of CD25 and CD69 as well as T cell proliferation, although not statistically significant relative to normal controls. Breast cancer MDSC were significantly more suppressive of T cell activation relative to normal controls. The granulocytic but not monocyte subset of MDSCs (distinguished by CD15 expression) were identified as the main responders to PMA stimulation. Our results demonstrate immune suppression in newly diagnosed invasive breast cancer is characterized by increased immune suppressive function of MDSCs in the absence of increased cellular levels. When we looked at our cases with the highest MDSC levels, no distinct trend towards advanced stage or poorer prognosis biologic subtype was identified. These data support the identification of MDSCs in breast cancer as a novel therapeutic target to improve treatment outcomes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5405. doi:1538-7445.AM2012-5405
Abstract 5407: The upregulation of BTLA and PD-1 defines a novel subset of dysfunctional tumor antigen-specific CD8+ T cells
Authors: Fourcade Julien , Sun Zhaojun , Pagliano Ornella , Guillaume Philippe , Luescher Immanuel F. , Sander Cindy , Kirkwood John M. , Olive Daniel , Kuchroo Vijay , Zarour Hassane M.
Published: August 2012

Cytotoxic T cells present at the periphery or at tumor sites recognize tumor epitopes presented by melanoma cells but fail to induce tumor rejection in melanoma patients. Inhibitory receptors including PD-1 and Tim-3 expressed by spontaneous CD8+ T cells directed against the cancer-germline antigen NY-ESO-1 play a role in promoting tumor-induced T cell dysfunction. In the present study, we show that BTLA is upregulated on spontaneous NY-ESO-1-specific CD8+ T cells and that BTLA+PD-1+Tim-3− CD8+ T cells represent the largest subset of NY-ESO-1-specific CD8+ T cells in melanoma patients. BTLA+PD-1+Tim-3− CD8+ T cells are partially dysfunctional, producing less IFN-γ than BTLA−PD-1+Tim-3− and BTLA−PD-1−Tim-3− but more IFN-γ, TNF and IL-2 than highly dysfunctional BTLA+PD-1+Tim-3+ NY-ESO-1-specific CD8+ T cells. Unlike PD-1, BTLA expression by NY-ESO-1-specific CD8+ T cells does not increase with higher T cell dysfunction or upon cognate antigen stimulation, suggesting that BTLA upregulation occurs independently of functional exhaustion driven by high antigen load. Finally, BTLA pathway blockade adds to PD-1 and Tim-3 blockades, enhancing NY-ESO-1-specific CD8+ T cell expansion, proliferation and cytokine production. Collectively, our findings support the targeting of BTLA, PD-1 and Tim-3 pathways to reverse tumor-induced T cell dysfunction in patients with advanced melanoma. This work was supported by the National Institutes of Health/National Cancer Institute grants R01CA90360 and R01CA157467 (to H.M. Zarour), an award from the Melanoma Skin Spore grant NCI P50CA121973 (to H.M. Zarour) and a grant from the Cancer Research Institute (to H.M. Zarour).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5407. doi:1538-7445.AM2012-5407
Abstract 5408: CD73 as a target in cancer immunotherapy
Authors: Smyth Mark J. , Beavis Paul , Darcy Phil K. , Loi Sherene , Stagg John
Published: August 2012

It is increasingly being recognised that the tumor microenvironment modulates the effector functions of tumor-infiltrating lymphocytes and consequently suppresses anti-tumor immunity. One immunosuppressive component of the tumor microenvironment is elevated levels of adenosine. The conversion of ATP into adenosine occurs in a stepwise manner essentially through the enzymatic activity of CD39 (NTPDase I) (ATP>AMP) and CD73 (ecto-5′-nucleotidase- AMP>adenosine). CD73 is a glycosylphosphatidyl-inositol (GPI)-linked cell surface enzyme constitutively expressed on endothelial cells, foxp3+ Tregs and subsets of leukocytes, and is considered as the rate-limiting enzyme in the production of extracellular adenosine. We have recently demonstrated that one of the mechanisms contributing to the immunosuppressive accumulation of extracellular adenosine in tumors is the expression of CD73 by tumor cells, but CD73 expression on foxp3+ Tregs is also important for their suppression of anti-tumor immunity. We now report on the role of host-derived CD73 in de novo tumor development in mice. Combinations of anti-CD73 with agonist and T cell checkpoint blockade antibodies demonstrate significant beneficial effects in experimental and de novo models of tumorigenesis. In humans using large cohorts we have shown that CD73 is highest in triple negative breast cancer (TNBC) and expression correlates with an invasion marker and the lack of ER signalling. CD73 expression is also associated with a worse prognosis in TNBC irrespective of treatment and predicts response to anthracycline therapy. The development of CD73 as a target for cancer immunotherapy will be further discussed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5408. doi:1538-7445.AM2012-5408
Abstract 541: Cadmium activates translationally controlled tumor protein (TCTP) and p38 MAPK as possible pathways for prostate cancer cell aggressiveness
Authors: Munirathinam Gnasekar , Kajdacsy-Balla Andre A. , Kaul Sushma , Scumpu Andrei , Kucynda Terrie , Patel Purvi , Zheng Michelle , Lindholm Paul F.
Published: August 2012

Cadmium is a known cause of lung cancer, but in the prostate there is conflicting evidence for the role of cadmium as a causative agent in the prostate. Recent lines of evidence however suggest that cadmium overburden is associated with more aggressive prostate cancer. Since cadmium does not appear to cause direct genotoxic damage, its mechanism of action on cancer progression is not clear. Here we address the hypothesis that cadmium activates two key molecules: p38 MAP kinase and Translationally Controlled Tumor Protein (TCTP). The hypothesis was tested in in vitro with PC-3 prostate cancer cells and clinically relevant, sub micro molar concentrations of cadmium at various time points. Activation of p38 MAPK was analyzed using phospho- specific antibodies against p38 MAPK by western blot analysis. Results of this study showed that p38 MAPK was phosphorylated within 45 minutes following cadmium treatment. This activation of p38 MAPK by cadmium in PC-3 cells was inhibited TCTP in presence of a p38 MAPK inhibitor (SB203580). This inhibitor also markedly attenuated cadmium-induced invasion and migration of PC-3 cells in Boyden chamber experiments. In addition, our mechanistic studies show that treatment of PC-3 cells with cadmium activated a novel stress related gene, namelyTCTP, which was recently identified as an anti-apoptotic protein and target for tumor reversion process. The cadmium- mediated expression of TCTP in PC-3 cells was confirmed by real time PCR and western blot analysis. From our previous experiments, we know that overexpression of TCTP in LNCaP prostate cancer cells enhanced its migratory rates in a Transwell chamber assay and we are now testing the role of TCTP in cadmium-induced PC-3 cells invasion. Thus, results of our study suggest that TCTP and p38 MAPK may have a prominent role in cadmium mediated cell migration and prostate cancer progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 541. doi:1538-7445.AM2012-541
Abstract 5414: Malignant monocytic AML cells trigger apoptosis in anti-leukemic lymphocytes: Role of NADPH oxidase gp91phox expression and PARP-1 activity
Authors: Aurelius Johan , Thoren Fredrik B. , Brune Mats , Palmqvist Lars , Hansson Markus , Hellstrand Kristoffer , Martner Anna
Published: August 2012

The dysfunction of natural killer (NK) cells and T cells in acute myeloid leukemia (AML) determines the course of disease, but only limited information is available on the mechanisms of lymphocyte inhibition. This study aimed to evaluate to what extent malignant AML cells utilize NADPH-oxidase derived reactive oxygen species (ROS) as an immune evasion strategy. We report that a subset of genetically defined malignant monocytic AML cells (FAB class M4/M5), recovered from blood or bone marrow of untreated AML patients at diagnosis, express gp91phox, a component of the NADPH oxidase. These AML cells produced large amounts of ROS upon activation and triggered PARP 1-dependent apoptosis in adjacent natural killer (NK) cells, CD4+ T cells, and cytotoxic T cells. In contrast, myeloblastic (FAB class M2) or immature (FAB class M1) AML cells did not express gp91phox, did not produce ROS, and did not trigger NK or T cell apoptosis. Our data are suggestive of a novel mechanism by which monocytic AML cells evade lymphocyte immunity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5414. doi:1538-7445.AM2012-5414
Abstract 542: Camalexin, the phytoalexin from Cruciferous Plants, decreases cell proliferation and induces apoptosis in prostate cancer cells
Authors: Smith Basil A.
Published: August 2012

Camalexin, the phytoalexin produced in the model plant Arabidopsis thaliana, accumulates in various cruciferous plants upon exposure to environmental stress and plant pathogens. Besides moderate antibacterial and antifungal activity, camalexin was reported to also exhibit antiproliferative and cancer chemopreventive effects. We studied the effects of camalexin treatment on viability of several prostate cancer (PCa) cell lines and whether cytostatic/cytotoxic effects of camalexin-treated prostate cancer cells were due to reactive oxygen species (ROS) generation. As models, we utilized LNCaP and its aggressive subline, C4-2, as well as ARCaP cells stably transfected with empty vector (Neo) control or constitutively active Snail cDNA that represents an EMT model. Previous studies have shown that C4-2 and ARCaP-Snail cells express more ROS than LNCaP and ARCaP-Neo, respectively. We hypothesized that camalexin would decrease cell proliferation and increase apoptosis in PCa cell lines and that the more aggressive cell lines expressing more ROS would be more sensitive to camalexin. Our results showed that camalexin treatments led to higher ROS as shown spectrofluorometrically by the oxidation of H2DCFDA, and this was decreased by co-treatment with NAC. Cell viability using MTS proliferation assay indicated that camalexin treatments decreased cell proliferation more significantly in C4-2 and ARCaP-Snail cells, as compared to LNCaP and ARCaP-Neo cells, respectively, while PrEC normal prostate epithelial cells were unaffected. Conversely, camalexin treatments increased apoptosis and mitocasp activity, which assesses caspase3/7 activity. This was associated with increased p21 and p27 anti-proliferative markers and cleaved PARP apoptotic marker as shown by western blot analysis. NAC reduced camalexin-induced ROS in ARCaP-Snail cells and abrogated camalexin-mediated cell proliferation decrease and apoptosis increase, showing that camalexin is mediating its effects through ROS. In conclusion, camalexin retarded prostate cancer cell proliferation and induced apoptosis via increased ROS generation. Interestingly, it was more potent in aggressive PCa cells expressing higher levels of ROS and did not affect normal cells. Hence, this phytoalexin has a strong potential as a novel therapeutic agent for the treatment of especially metastatic prostate cancer cells that express high levels of ROS. Supported by grants P20MD002285-01 & G12RR003062-22.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 542. doi:1538-7445.AM2012-542
Abstract 5422: Verification of the preventive effects of Lactobacillus casei Shirota and soymilk on breast cancer in animal model
Authors: Kano Mitsuyoshi , Kaga Chiaki , Takagi Akimitsu , Kado Shoichi , Nanno Masanobu , Sakai Masashi , Miyazaki Kouji , Toi Masakazu , Ohashi Yasuo
Published: August 2012

Breast cancer is the most prevalent cancer among women, and the incidence rate is increasing in Japan. There is a growing public awareness toward prevention and detection of breast cancer in Japan. We have previously shown in a case-control study that consumption of either soy isoflavone or fermented milk drink containing Lactobacillus casei strain Shirota (LcS) decreases the risk of developing breast cancer. To investigate the preventive effects of LcS and soy isoflavone against breast cancer, we next conducted an animal study. Female SD rats were treated with the heterocyclic amine PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine) under a diet containing LcS, soymilk, both LcS and soymilk or LcS-fermented soymilk (L-FSM), and changes were observed for 17 weeks. As a result, decrease in adenocarcinoma and tumor multiplicity was observed in the soymilk, LcS + soymilk and L-FSM groups. Suppression of tumor volume was observed in the LcS, LcS + soymilk and L-FSM groups. Results indicate the possibility that soymilk prevents adenocarcinoma formation, while LcS suppresses tumor growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5422. doi:1538-7445.AM2012-5422
Abstract 5427: EGCG prevents hepatocellular carcinoma development in a diethylnitrosamine-induced rat model
Authors: Yamada Suguru , Fujii Tsutomu , Wei Lan , Hoshida Yujin , Lauwers Gregory Y. , Schmitt Anthony D. , Lanuti Michael , Tanabe Kenneth K. , Fuchs Bryan C.
Published: August 2012

Background: Hepatocellular carcinoma (HCC) is increasing in incidence and treatment is often unsuccessful. Thus, prevention in high-risk patients with established cirrhosis has been proposed as an alternative strategy. It has been suggested that the increased inflammation and fibrogenesis observed during cirrhosis predisposes the liver to future malignant transformation to HCC through a “field effect”. A growing body of evidence indicates that the green tea polyphenol, (-)-epigallocatechin gallate (EGCG), can reduce inflammation and fibrogenesis during chronic liver injury. Here, we test the hypothesis that physiological concentrations of EGCG administered in the setting of cirrhosis can prevent future HCC development. Methods: A rat model of diethylnitrosamine (DEN)-induced cirrhosis was used to examine the efficacy of EGCG for inhibition of HCC formation in these cirrhotic livers. DEN (50 mg/kg) was administered weekly throughout the study while 0.02% EGCG was given in drinking water beginning at the onset of cirrhosis. At the end of the study, rats were sacrificed, livers were sectioned and stained to analyze disease progression and tumor nodules were counted. Liver function tests were performed to determine liver injury and overall liver function. Finally, genome-wide gene expression profiling on the surrounding, non-tumoral liver tissue was used to monitor the “field effect” in response to EGCG. Results: EGCG significantly (p < 0.01) prevented the development of HCC tumor nodules from on average 18.8 in vehicle controls to on average 9.1 in EGCG-treated animals. EGCG also reduced liver injury and improved liver function as assessed by serum chemistry tests. Finally, a gene expression signature predictive of poor survival and HCC development in human cirrhosis patients was reversed in response to EGCG. Conclusions: Our data are consistent with the growing body of evidence suggesting that EGCG has protective effects in liver disease. Further, our results suggest that EGCG is a potentially effective HCC prevention strategy that can be monitored using gene expression signatures.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5427. doi:1538-7445.AM2012-5427
Abstract 5428: Consumption of S-allylcysteine inhibits tumor growth and progression in a mouse xenograft model of oral cancer
Authors: Tang Feng-Yao , Wang Fu-Yu , Pai Man-Hui
Published: August 2012

Oral cancer is a prevalent type of cancer in many countries. Although studies indicated that garlic extracts such as diallyl disulfide and diallyl trisulfide have anti-cancer effects, the chemopreventive effects of aqueous garlic extracts, S-allylcysteine (SAC), on oral cancer have not been studied yet. To this specific aim, we investigated the inhibitory effects of SAC on the proliferation and progression of oral cancer cells in both in vitro and in vivo models. In the present study, our results demonstrated that SAC dose-dependently inhibited the proliferation of human oral squamous cancer CAL-27 cells in vitro. The results indicated that SAC stabilized the adherent junction complex of E-cadherin/β-catenin and suppressed epithelial-mesenchymal transition (EMT) in oral cancer cells through suppression of MAPK/ERK signaling pathways. By study end (4th week), consumption of SAC (at doses of 5 and 40 mg / kg of body weight per day) significantly prevented tumor growth of oral cancer in a mouse xenograft model. Histopathological and immunohistochemical (IHC) staining results indicated that SAC could effectively suppress tumor progression including EMT of oral cancer in vivo. The chemopreventive effects of SAC were associated with decreases in cyclin D1 expression and suppression of Akt, mTOR, IκBα, and ERK 1/2 signaling cascades in tumor tissues. SAC consumption could inhibit the expression of cyclooxygenase-2 (COX-2), Vimentin, and nuclear NF-κB p65 (RelA) proteins. These results suggested that SAC could act as an effective agent to prevent tumor growth, progression, and EMT of oral cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5428. doi:1538-7445.AM2012-5428
Abstract 5436: The role of reactive oxygen species in (-)-epigallocatechin-3-gallate (EGCG)-induced cell growth inhibition and apoptosis in oral cancer cells
Authors: Tao Ling , Forester Sarah C. , Lambert Joshua D.
Published: August 2012

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea (Camellia sinensis L.). Recently, it has been reported to have cancer chemotherapeutic and chemopreventive effects. However, the mechanisms are incompletely understood. We found that EGCG induced both extracellular and intracellular reactive oxygen species (ROS) in SCC-25 and SCC-9 human oral squamous carcinoma cells. Extracellular ROS was produced rapidly in the DMEM/F12 (1:1) cell culture medium, but was also quenched very rapidly (t1/2 = 1.7 h). By contrast, the level of intracellular ROS increased more slowly and was increasing even after EGCG could no longer be detected in either the cytosol or the cell culture medium. We observed that EGCG treatment decreased the mitochondrial membrane potential suggesting that EGCG induced dysfunction of electron transport chain in the mitochondria of treated cells. This may explain the continuous ROS production in the cells even after EGCG levels have dropped to below the limit of detection. EGCG treatment for 72 hr reduced cell viability significantly (IC50=127 µM in SCC-25 cells and IC50=83 µM in SCC-9 cells). Effects on cell viability were modulated by inclusion of N-acetylcysteine, a thiol-antioxidant, indicating a role for EGCG-induced ROS in the reduction of cell viability. EGCG treatment also arrested cell cycle progression in the G2/M phase of cell cycle, and induced apoptosis (increased TUNEL positivity and annexin V staining). Based on the present studies, it appears that EGCG-induced oxidative stress and mitochondrial dysfunction play a role in its anti-oral cancer effects in cell culture. Ongoing studies in our laboratory are focused on the mechanism by which EGCG induces mitochondrial dysfunction, and the relevance of this mechanism to oral cancer prevention in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5436. doi:1538-7445.AM2012-5436
Abstract 5440: Upregulation of prostaglandin E2 and TGF-alpha by linoleic acid enhances pro-oncogenic signaling in models of human lung and breast cancer
Authors: Martins Clarissa R. , Pardini Ronald S. , Kikawa Keith D.
Published: August 2012

The omega-6 polyunsaturated fatty acid (PUFA), linoleic acid (LA), has been reported to have adverse affects in the growth and metastasis of a variety of cancer cell models. However, there has been some controversy over how much these models relate to human disease. In the current study, a novel cascade of actions behind the LA-induced upregulation of cell proliferation has been identified. It is well established that PUFAs serves as precursors for eicosanoids, and LA supplementation was found to significantly increase the levels of Prostaglandin E2 (PGE2) in a variety of lung and breast cancer cell lines. These increases in PGE2 are associated with elevations in the activity of Cyclooxygenase-2 (COX-2), increased levels of Tumor Growth Factor-alpha (TGF-alpha) and specific pro-proliferative signaling pathways. These findings were corroborated in animal xenografts derived from the same cell lines used for the in vitro studies, with serum levels of PGE2 showing significant increases in PGE2 in animals fed diets high in LA. Moreover, the omega-3 PUFA, docosahexaenoic acid (DHA), was found to have an opposing affect on PGE2 production by upregulating Thromboxane B2 (TXB2), a stable metabolite of Thromboxane A2 (TXA2), which inhibits COX-2 activity. These findings present specific mechanisms behind the upregulation of cancer cell growth due to LA supplementation that may contribute to a resolution in determining its role in human disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5440. doi:1538-7445.AM2012-5440
Abstract 5444: In vitro modeling for breast cancer prevention - omega-3 ethyl esters functioning as preventive agents in 21T series models
Authors: Chen Ching Hui , Fabian Carol , Hursting Stephen , deGraffenried Linda
Published: August 2012

Over the past few decades, multiple trials have warranted the benefits of using prevention as an effective strategy for lowering breast cancer incidence. The Breast Cancer Prevention Trial (BCPT) and Study of Tamoxifen and Raloxifene (STAR) conducted by National Cancer Institute demonstrated the effectiveness of tamoxifen and raloxifene as preventive agents in reducing diagnoses of invasive breast cancer. Another prevention study the VITAL cohort study demonstrated that omega-3 supplementation reduces breast cancer incidence in postmenopausal women. In vivo studies have produced results that demonstrated a delay in onset of breast cancer in transgenic mice model. However, current in vitro effort did not have a system that closely resembles the linear progression of breast cancer and therefore stalls the molecular investigation of breast cancer prevention. Majority of in vitro preventive studies have been conducted using cancer cell lines that do not represent precancerous status of mammary tissues and do not mirror the observation of delayed onset or reduced incidence in in vivo and clinical trials. A recent report has suggested the use of a new series of mammary cells that represent hyperplasia, ductal carcinoma in situ (DCIS) and invasive carcinoma in nude mice. In this study we propose the use of 21T series breast cancer cells as a model for breast cancer prevention study using omega-3 ethyl esters. Preliminary data using this model has shown that omega-3 ethyl esters derived from Omacor® reduce proliferation only in 21NT (DCIS) and 21MT-1 (Invasive Carcinoma) and not in 21PT cells (hyperplasic). Suppression of proliferation is most optimal in the presence of estrogen. Survival of cells is inhibited in all cell lines and Ki67 index is reduced in the presence of treatments. Targets of omega-3 ethyl esters may include Akt, ER and NF-kB. Current studies are conducted to investigate the effect of omega-3 ethyl esters on these targets.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5444. doi:1538-7445.AM2012-5444
Abstract 5445: Polyphenolic phytochemical curcumin suppresses HER-2 protein phosphorylation and gene expression in breast cancer cells
Authors: Thomas T. J. , Venkiteswaran Sripriya
Published: August 2012

Curcumin (diferuloylmethane) is the major pigment ingredient of turmeric, a plant native to South Asia, belonging to ginger family. Turmeric is used in Oriental cuisine and is believed to exert anti-inflammatory, anti-oxidant and anti-carcinogenic properties. Curcumin has apoptotic activity against different types of cancer, including colon cancer, stomach and skin tumors, breast cancer and prostate cancer, and has been the subject of several clinical studies. Curcumin disrupts different stages of carcinogenesis, including cell proliferation, survival, angiogenesis and metastasis in preclinical models. In order to understand the mechanism of action of curcumin in HER-2 positive breast cancer, we investigated the effects of different concentrations of curcumin on SK-BR-3, an HER-2 positive human breast cancer cell line. Curcumin inhibited the growth of SK-BR-3 cells in a concentration- and time-dependent manner, with an IC50 value of 5 ± 1 µg. A significant 80% cells underwent apoptosis in the presence of 25 µM curcumin at the 24 hour of treatment, as determined by APO-BRDU assay. At 25 µM concentration, curcumin suppressed the expression of HER-2 gene by a significant 70% (P ≤ 0.005, compared to untreated control) at 24 hours of treatment, as measured by real-time qPCR assay. In addition, curcumin suppressed the expression of cyclin A, cyclin B1, cyclin D1 and cyclin E by 30 to 70%. In contrast, 10, 25 and 50 µM concentrations of curcumin increased the expression of p21 by 4-, 3-, and 2-fold, respectively, at 16 hours of treatment. Comparable increase in p21 level was evident at 24 hours of treatment also. Curcumin arrested cells in the G2/M phase (38 ± 3% compared to 22 ± 2 % control at the same time point; P < 0.001; n = 3). Curcumin suppressed HER-2 phosphorylation in a concentration- and time-dependent manner, suggesting a possible mechanism of action. Pre-treatment of cells with an anti-oxidant, glutathione partially reversed apoptosis induced by curcumin, and restored HER-2 and cyclin D1 protein levels. These results suggest the involvement of redox pathway also in the action of curcumin. Taken together, our data indicate multiple pathways in the mechanism of action of curcumin in HER-2 positive breast cancer cells, and suggest possible preventive strategies with this natural plant product.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5445. doi:1538-7445.AM2012-5445
Abstract 5447: Breast cancer chemoprevention by ‘Jamun’, the Indian blackberry: Potential mechanisms
Authors: Aqil Farrukh , Jeyabalan Jeyaprakash , Munagala Radha , Ravoori Srivani , Sharma Ramjee , Sidana Jasmeen , Singh Inder P. , Gupta Ramesh C.
Published: August 2012

Dark-colored berries are gaining increasing attention lately for their chemopreventive and chemotherapeutic activities. Jamun (Syzygium cumini L.), the Indian blackberry is perhaps the only berry that has the diversity of anthocyanins of blueberry and abundance of ellagic acid present in black raspberry. We previously reported chemoprotective activities in jamun pulp extract and powder in vitro and short-term in vivo studies (Aqil et al. AACR 2010, Vol. 51, Abst. # 5688). Here we report anti-cancer potential of jamun pulp powder against estrogen mediated breast cancer and the role of miRNAs and other targets in the disease inhibition. Groups of female ACI rats were given AIN-93M diet or diet supplemented with jamun pulp powder (5%, w/w). Two weeks later, animals from each group were treated with subcutaneous silastic implants of 17β-estradiol (1.2 cm; 9 mg). Additional groups of animals received control or experimental diet in the absence of estrogen. Diet and water were provided ad libitum. Twelve weeks later animals were palpated weekly for the mammary tumors, and all groups were euthanized when tumors incidence reached over 90% in control group. Compared to control, jamun-supplemented diet delayed the first tumor appearance by 21 days, and significantly reduced the tumor incidence (65% vs 96%), tumor burden (313±95 vs 661±123 mm3) and tumor multiplicity (1.8±0.3 vs 4.2±0.4 tumors/rat). The experimental diet also significantly reduced the estrogen-associated growth of pituitary prolactinomas, circulating prolactin and estradiol levels and the mammary cell proliferation (PCNA) markers. Mechanistically, the jamun diet significantly offset estrogen-associated increases in mammary cell proliferation, ER-α and cyclin D1 as determined by western blot analysis. We have recently identified ‘miRNA signature’ associated with estrogen treatment (Munagala et al. AACR 2011, Vol. 52, Abst. # 155). All miRNAs that were either significantly overexpressed (miR-182 and miR-375) or underexpressed (miR-127 and miR-206) as a result of estrogen treatment were significantly protected by intervention with the jamun diet. Targets for these miRNAs remain to be identified. Together, our data show that jamun significantly offset estrogen-mediated alterations in i) mammary cell proliferation; ii) ER-α; iii) cyclin D1, and iv) candidate miRNAs, and that the modulation of these biomarkers correlated with the reduction in mammary carcinogenicity. (Supported by CA-125152, CA-118114 and Agnes Brown Duggan Endowment).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5447. doi:1538-7445.AM2012-5447
Abstract 5448: Common targets of epigenetic dysfunction in distinct target tissues of arsenic and cadmium induced malignant transformation
Authors: Severson Paul L. , Tokar Erik J. , Vrba Lukas , Waalkes Michael P. , Futscher Bernard W.
Published: August 2012

Arsenic and cadmium are known human carcinogens and rank as number one and seven respectively on the Agency for Toxic Substances and Disease Registry (ATSDR) substance priority list. Accumulating evidence suggests that long-term exposure to arsenic or cadmium induces epigenetic dysfunction and this effect may be an important aspect of their carcinogenic activity. To this end we analyzed the epigenetic dysfunction associated with arsenic or cadmium induced malignant transformation of immortalized urothelial and prostate epithelial cells. Using methyl-DNA immunoprecipitations coupled to human promoter microarrays as well as Sequenom MassArray, we found that arsenic and cadmium mediated malignant transformation of immortalized urothelial and prostate epithelial cells produced thousands of DNA methylation changes. Many of the DNA hypermethylation events appear to be localized to individual genes whereas others cluster into groups that are within large genomic regions on the order of 100kb. Significant aggregates of DNA hypermethylation events occur within the protocadherin and HOX gene clusters. Intersecting the arsenic induced hypermethylation events from the two distinct models results in an overlap of 113kb of DNA which represents roughly 100 genes. This overlap is significantly more than expected by chance, suggesting these genes are targeted for aberrant DNA methylation in both models of arsenic induced malignant transformation. A similar result is seen in the cell lines transformed by cadmium, and the cadmium induced DNA hypermethylation events are highly concordant with the hypermethylation profiles induced by arsenic. Most of the DNA hypermethylated regions found in the arsenic or cadmium transformed cells are also targets of aberrant DNA hypermethylation in human bladder tumors. Comparing the hypermethylated regions from our models to publicly available H3K27me3 ChIP-seq data from embryonic stem cells revealed that the targets of DNA hypermethylation fall disproportionately within H3K27me3 domains of human stem cells. H3K27me3 chromatin immunoprecipitations coupled to real-time PCR confirmed that the promoters of candidate genes NPR3 and LTK are marked with H3K27me3 in normal and immortalized cells before becoming DNA hypermethylated in the arsenic transformed cells. This H3K27me3 data supports the previously discovered association between H3K27me3 marked regions of normal cells and DNA hypermethylation in malignant cells. All together, these observations suggest commonality in the mechanisms of epigenetic change induced by carcinogenic metals.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5448. doi:1538-7445.AM2012-5448
Abstract 5453: The effect of ovarian hormones on the induction of mammary tumors induced by the environmental pollutant 6-nitrochrysene
Authors: Sun Yuan-Wan , Krzeminski Jacek , Aliaga Ceser , Manni Andrea , Amin Shantu , El-Bayoumy Karam
Published: August 2012

Exposure to ovarian hormones is the most widely recognized risk factors for breast cancer. However, hormones alone do not fully address the majority of the risk for this disease. Increasing data have linked environmental factors such as radiation, chemical pollutants and diet to the incidence of breast cancer. Humans are often exposed to a combination of multiple risk factors. Thus, the potential of the interaction between the environment and hormones is critical to assess the risk of breast cancer. The goal of the present study is to examine the role of ovarian hormones on the induction of mammary tumors by 6-nitrochrysene (6-NC), a representative environmental pollutant. We have previously demonstrated that 6-NC is one of the most potent mammary carcinogen in the rat. Thus, 6-NC (25 µmol in 500 µL trioctanoin) was administered orally to both female intact and ovariectomized (ovax) Sprague-Dawley rats at age of 30 days once a week for 8 weeks. Tumors in the intact animals was first detected at week 4 (incidence 8%) and tumor incidence reached 50% at week 18 after the last administration of 6-NC. On the contrary, in the group of ovax rats tumors were first observed at week 8 (4% incidence) and the incidence remained the same at week 22 after the last dose of 6-NC administration. Further evidence to support this hormone dependence is also observed in a separate group of ovax rats which received both 6-NC at the same dose described above and estradiol (E2) pellet implantation (twice, 5 mg/90 days); mammary tumor incidence was comparable to that observed in intact animals treated with 6-NC. No tumors were found in vehicle (trioctanoin) treated intact and ovax control groups. In this study, we showed for the first time that ovarian hormones are essential in the development of mammary tumors induced by this environmental pollutant; the molecular mechanisms are being explored. Support: NCI RO1 35519.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5453. doi:1538-7445.AM2012-5453
Abstract 5454: Genotoxic consequences of exposure to mixtures of food-derived chemical carcinogens
Authors: David Rhiannon M. , Gooderham Nigel J.
Published: August 2012

It has been shown that mutagenic chemicals can form naturally in foods during cooking. Examples include Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon generated by incomplete combustion of organic substances such as lipids, leading to contamination of numerous foodstuffs (Lijinski and Shubik, Science 1964, 145, 53), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a heterocyclic amine that is formed during the cooking of meat (Murray, et al. J Chromatog 1993, 616, 211), and glycidamide (GA) is the ultimate genotoxic metabolite of acrylamide (AC), which forms when foods, such as potatoes and cereals, are cooked at temperatures exceeding 100°C, in a reaction between the amino acid asparagine and reducing sugars that are naturally present in these foods (Tornqvist, Adv Exp Biol Med 2005, 561, 1). These chemicals have individually been shown to be genotoxic but the biological consequences of exposure to mixtures of these chemicals have not been systematically examined. The aim of the current study was to examine the biological response of MCL-5 cells (a metabolically competent human lymphoblastoid cell line) to mixtures of these genotoxic chemicals at concentrations that are relevant to human exposure (mM to sub-nM). Cells were exposed to the chemicals individually or in mixtures for 24h and mutagenicity was assessed through resistance to trifluorothymidine at the thymidine kinase (TK) locus and 6-thioguanine at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus. The mixture exposures gave modified dose-response curves from the individual chemicals, with increased mutation frequency (MF) at some low concentration combinations that were not mutagenic individually, and decreased MF at some combinations of higher concentrations that did produce a mutation response individually. Responses also differed between the TK and HPRT loci, with a higher MF observed for high concentration combinations at HPRT compared to TK. Ethoxyresorufin-O-deethylase (EROD) activity was measured and was found to correspond to the MF at the TK locus suggesting the involvement of CYP1A family in the mutation response. These data suggest that mixtures of genotoxic chemicals produce different mutation responses to the individual chemicals. The increase in MF at some low concentration combinations where the individual chemicals are not genotoxic is of significance when considering the carcinogenic potential of food.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5454. doi:1538-7445.AM2012-5454
Abstract 5457: Chlorinated drinking water alters carcinogenesis in a mice model of colon cancer
Authors: Sasada Tatsunari , Hinoi Takao
Published: August 2012

Purpose: The gastrointestinal tract is constantly exposed to vast numbers of commensal bacteria and inflammatory product. The diet and enteric environment has been implicated in the pathogenesis of enterocolitis and colon cancer. Probiotic Lactbacilli modify the enteric microflora and are thought to have a beneficial effect on enterocolitis, eventually on colon cancer. We conducted this study to evaluate the effects of chlorinated drinking water which was used in general institutions. Experimental design: Mouse stains carrying colon epithelium-preferential Apc mutation (CPC;Apc mice), that show sporadic colorectal adenomas and carcinomas are used in this study. Nine of Eighteen CPC;Apc mice were consumed chlorinated drinking water (chlorinate concentrations of 10.0 mg/L) and 9 consumed tap water (chlorinate concentrations of 0.7 mg/L) for 25 week. Body weight was measured weekly. Faecal microbial analysis was performed. At sacrifice, the small and large bowel were histologically assessed. Results: Chlorinated drinking water strongly prevented intestinal tumorigenesis in terms of polyps formation in distal portion of small intestine. However, in colon we observed an increase in numbers and volumes of tumors. Body weight gain was more favorable by chlorine treated. Conclusions: These results show for the first time the efficacy and associated mechanisms of chlorinated drinking water feeding against spontaneous intestinal tumorigenesis in the CPC;Apc mice suggesting its chemopreventive potential against intestinal cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5457. doi:1538-7445.AM2012-5457
Abstract 5460: Effects of ethanol exposure during involution on mouse mammary gland
Authors: Garofalo Jennifer-Marie , Bowers Dawn , Browne Richard , MacQueen Brian , Mashtare Terry , Masso-Welch Patricia A.
Published: August 2012

Mammary gland involution represents a discrete developmental time point when the breast may be particularly susceptible to risk factors associated with mammary carcinogenesis. One dietary carcinogen which has been shown to affect breast cancer risk in women is ethanol; as little as one drink per day can increase breast cancer risk by 10%. The purpose of the current study was to determine if ethanol exposure during involution affects mammary tumor development or progression in the FVB-MMTV-Her2/Neu transgenic mouse. Dams were fed isocaloric liquid diets containing 0, 0.5, 1 or 2% ethanol from day 1 of involution (weaning at day 21 of lactation) until day 4, 9 or 14 post-weaning. Short-term effects of ethanol on the progression of involution were assessed. No significant difference in mouse weight, or organ weights (spleen, liver or kidney), was seen between groups. Lobular regression (decrease in ducts per lobule) occurred similarly in all dietary groups, in parallel with an increase in average adipocyte size. No difference in leukocyte infiltration was seen between dietary groups. Proteomic analysis and tumor studies are ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5460. doi:1538-7445.AM2012-5460
Abstract 5461: Role of the NLRP3 inflammasome in the development and drug resistance of malignant mesothelioma
Authors: Shukla Arti , Miller Jill M. , Hillegass Jedd M. , MacPherson Maximilian B. , Beuschel Stacie L. , Pass Harvey I. , Mossman Brooke T.
Published: August 2012

Inflammation plays an important role in development of various cancers including malignant mesothelioma (MM). We have shown that asbestos activates NOD-like receptor protein 3 (NLRP3), a component of the inflammasome in human macrophages. As chronic asbestos exposure is a key risk factor for the development of MM, we hypothesized that inflammasome-mediated inflammation might underlie the pathogenesis of this cancer. To show the involvement of NLRP3 in asbestos-induced mesothelioma, we demonstrated that exposure of asbestos to immortalized human mesothelial cells (LP9/hTERT), a cell type responsible for origin of MM, caused mRNA increase and activation of NLRP3 as measured by caspase-1 activation and IL-1β release. Inhibition of NLRP3 by siRNA caused significant decreases in NLRP3 mRNA levels as well as asbestos-induced IL-1β release in medium. On the other hand, human MM lines and tumor tissues showed significantly decreased levels of NLRP3 and caspase-1 as compared to LP9 or matching normal tissues respectively. Our findings suggest that initial exposure to asbestos causes increased mRNA levels and activity of NLRP3, which may help in MM development by promoting mesothelial cell transformation. However, tumor development culminates in MM with decreased NLRP3 protein and increased drug resistance which may be due to caspase-1 inactivation. Thus NLRP3 may be an appropriate target for therapy of MM, especially in combination with cytotoxic chemotherapeutic drugs and IL-1 receptor antagonists. This study is supported by a Meothelioma Applied Research Foundation (MARF) grant (AS) and by NIEHS grants T32 ES07122 (BM).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5461. doi:1538-7445.AM2012-5461