bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2878: Dietary stearate inhibits tumor development and tumor burden in the N-nitroso-N-methylurea (NMU) rat breast cancer carcinogen model
Authors: Hardy Robert W. , Toline Eric , Evans Lynda M. , Desmond Renee , Ibrahim-Hashim Arig , Siegal Gene P.
Published: February 2011

The goal of the present study was to test the effectiveness of dietary stearate at inhibiting breast cancer development in a carcinogen induced breast cancer model. Three diets were used; a 17% stearate diet, the key being that highly purified stearate was added directly to the diet, a linoleate diet (SF) containing 17% safflower oil as the source of linoleate and a low fat control diet (LF) with a reduced amount of fat (5%) from corn oil. All three diets had adequate essential fatty acids. These 3 diets were initiated 1 week prior to the rats receiving NMU and followed out 100 days. There was no difference in the weight of the rats among groups throughout the study. Approximately 40% fewer animals on the stearate and safflower diets developed palpable tumors compared to the LF (n=30-35 animals/diet; p<0.05). No difference was observed among the three diets as to the time for first tumor appearance. Stearate decreased the average number of tumors per rat compared to the LF (n=30-35 animals per diet; p<0.05) and had less tumors per rat than the SF although this was not statistically significant. Stearate also significantly reduced tumor burden as defined by tumor weight by ∼50% compared to LF and SF (p<0.001) and large tumors compared to the LF (∼47% reduction in tumors over 0.25 g, p= 0.02). In those rats that did develop tumors, the stearate diet group had a similar number of adenocarcinomas compared to other diets; however the stearate and SF groups had lower numbers of DCIS/microinvasive disease as compared to the LF. The dietary groups tended to have similar numbers of the other precursor lesions classified although the dietary stearate group had the least number of “tubular adenomas”. Dietary stearate may be useful as an alternative/complementary therapy or preventative agent against breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2878.
Abstract 2880: Spices suppress oxidative stress during DMBA induced skin carcinogenesis in mice, mimicking human non-melanoma skin cancer
Authors: Das Ila , Acharya Asha , Sengupta Archana , Das Shukta , Bhattacharya Sudin , Saha Tapas
Published: February 2011

Background: Cancer chemoprevention is the use of natural, synthetic or biologic substances to reverse, suppress, or prevent the development of cancer. Spices like cinnamon, cardamom and cumin are the naturally occurring phytoproducts that display an active cancer preventive strategy to inhibit, delay or reverse the human carcinogenesis.

Aims and Objectives: Our aim of this study is to decipher the chemopreventive effect of aqueous infusion of the spices as a diet on DMBA induced skin carcinogenesis, which mimics UV radiation mediated non melanoma skin cancer that has high mortality rate if not diagnosed early.

Research Design and Methodology: Female Swiss Albino Mice have been divided into 5 groups in each case. Normal control (NC) and DMBA treated control (CC) mice received acetone and DMBA/croton oil on it's dorsally shaven skin for eight weeks, respectively. Aqueous suspensions of the spices were orally administered to three groups of mice either before or after or both before and after DMBA applications on the shaved skin during the entire study period. Treated skins were excised after harvesting the mice and H & E staining, immunohistochemistry assays for lipid peroxides, antioxidation enzymes activities, immunoblotting, cell proliferation and apoptosis were performed.

Results: All the spices demonstrate inhibition of the skin papillomagenesis. The best chemopreventive actions of these spices were observed when the spice treatments were performed both before and after the induction of skin carcinogenesis by DMBA. An up-regulation of the phase II detoxification enzymes and induction of non-protein thiol antioxidants were observed in mice treated with the spices. Additionally, cumin and cardamom demonstrate downregulation of COX-2 expression, inhibit cell proliferation and block p53-induced apoptosis. Cardamom stimulates NRF2 and inhibits NF-κB transcription factors to demonstrate its beneficial action against skin carcinogenesis.

Conclusion: Spices inhibit DMBA induced skin carcinoma in mice when treated early and it is believed to be due, at least in part, to the induction of cellular defense systems. We are in a process of identifying unique chemical components of these spices to maximize the benefits.

References:

1. Das, I., and Saha, T.; Nutrition. (2009); 25(4):459-471.

2. Das, I., Das, S. and Saha, T.; Acta Histochem. (2009); (In Press)

3. Das, I., Rana, T., Sengupta, A., and Saha, T.; J. Biol. Chem. 2009; (In Revision)

4. Acharya, A, Das, I., Chandhok, D., and Saha, T.; Oxidative Stress and Cellular Longevity; 2009; (In Press)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2880.
Abstract 2882: Penta-O-galloyl-beta-D-glucose induces DNA replicative S arrest and G1 arrest independent of p21Cip1, p27Kip1 and p53 in human breast cancer cells and is orally active against breast cancer xenograft
Authors: Chai Yubo , Lee Hyo-Jeong , Shaik Ahmad , NKhata Katai , Xing Chengguo , Kim Sung-Hoon , Lü Junxuan
Published: February 2011

Natural herbal compounds with novel actions different from existing breast cancer targeting modalities are attractive for improving treatment and prevention efficacy and safety. We have recently shown that penta-1,2,3,4,6-O-galloyl-beta-D-glucose (PGG), a naturally occurring gallotannin polyphenol compound, induced S-phase arrest in prostate cancer cells through inhibiting DNA replicative synthesis, in addition to the induction of G1 arrest and cell deaths at higher levels of exposure. We and others have shown that PGG through i.p. injection exerts a strong in vivo growth suppression of human prostate cancer xenograft models in athymic nude mice. We hypothesize that the novel DNA replication targeting action and the cellular arrest and death effects of PGG are applicable to breast cancer cells and PGG could be a novel agent for treatment or prevention of breast cancer, especially those without proven drugable targets such as triple-negative breast cancer.

In cell culture studies, exposure to serum achievable level of PGG induced rapid S arrest in p53-wild type ER-dependent MCF-7 breast cancer cells and in p53-mutant ER-/PR- and Her2-negative (triple-negative) MDA-MB-231 breast cancer cells as indicated by the lack of BrdU incorporation into S-phase cells. Higher levels of PGG induced more caspase-mediated apoptosis in MCF-7 than in MDA-MB-231 cells. In addition to S-arrest, PGG induced G1 arrest in both cell lines. Contrary to a study by others with questionable design, we have found no induction of CDK inhibitory proteins p21Cip1 and p27Kip1 with G1 arrest. PGG treatment led to decreased cyclin D1 in both cell lines and over-expressing cyclin D1 abolished G1 arrest and hastened S arrest. In serum-starvation synchronized MCF-7 cells, we observed a close association of down-regulation of cyclin D1 and de-phosphorylation of Rb by PGG shortly before G1-S transition stimulated by serum. Though PGG inhibited estrogen-stimulated cell growth in MCF-7 cells, it had little effect on estrogen receptor-alpha level. To test the in vivo efficacy of PGG, we treated female athymic mice inoculated with MDA-MB-231 xenograft with 10 mg/kg body weight by daily gavage and compared with weekly paclitaxel treatment at the same dosage. Oral administration of PGG led to a better growth inhibitory efficacy than the taxane drug. Together, our in vitro and in vivo data support PGG as a potential chemopreventve or treatment agent for breast cancer with novel targeting actions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2882.
Abstract 2888: Vitamin D inhibits obesity-induced endometrial carcinogenesis in Pten+/− mice
Authors: Yu Wei , Maxwell Larry G. , Cline Mark , Berrigan David , Rodriguez Gustavo , Warri Anni , Hilakivi-Clarke Leena
Published: February 2011

Objectives: A growing body of epidemiologic and experimental evidence suggests that vitamin D may lower the risk of a number of epithelial malignancies. In this study, we sought to determine whether vitamin D exposure reverses endometrial carcinogenesis in an animal model, and further whether it modifies the enhanced risk of endometrial carcinoma associated with obesity. Methods: When 4 weeks of age, Pten+/− and wildtype (WT) mice were each divided into four treatment groups and fed an AIN93G based diet containing either (1) 18% energy from fat (control diet), (2) 18% fat and 25K IU of VD3/kg diet (VD3 supplemented control diet), (3) 58% fat to induce obesity (obesity inducing diet, OID), and (4) 58% fat and 25K IU of VD3/kg diet (VD3 supplemented OID). Mice were kept on these diets until they were sacrificed at 28 weeks of age. Results: Dietary VD3 exposure did it cause any apparent toxicity. VD3 increased the expression of 25-hydroxylase (25-OHase, an enzyme converting VD3 to 25(OH)D3) in the endometrium of WT (p<0.027) and Pten+/− mice (p<0.025). Further, it increased vitamin D receptor (VDR) levels (p<0.006) in the obese Pten+/− mice. Although VD3 did not affect endometrial cancer risk, it inhibited obesity-induced increase in endometrial cancer. Specifically, OID increased focal glandular hyperplasia with atypia and malignant lesions from 58% in the control diet fed Pten+/− mice to 78%. Dietary VD3 supplementation decreased the incidence of endometrial pathology in Pten+/− mice fed OID to 25% (p<0.001). Estrogen receptor (ER)-α mRNA levels were significantly higher (p<0.014) and progesterone receptor (PR) protein levels in the luminal epithelium were significantly lower (p<0.04) in the endometrium of control diet fed Pten+/− mice than in the WT mice, but the expression of ER-α, ER-β or PR mRNA, or epithelial or stromal protein expression were not affected by the dietary exposures. Conclusions: Our data obtained in Pten+/− mice confirm the known association between increased body weight and endometrial cancer risk. Dietary exposure to VD3 inhibited the carcinogenic effect of obesity on the endometrium; the mechanism mediating this protective effect was not linked to changes in the expression of ER-α, ER-β or PR.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2888.
Abstract 2888A: Prevention of MAPK pathway by Brazilian medicinal plant, Tabebuia avellanedae, on peroxynitrite induced carcinogenesis
Authors: Tokuda Harukuni , Kaneko Masafumi , Yamashita Mituaki , Suzuki Nobutaka , Iida Akira
Published: February 2011

The present study was carried out to examine the chemopreventive activity of natural Brazilian medicinal plant, Tabebuia avellanedae ext. and its components on peroxynitrite(PN) induced carcinogenesis. Tabebuia avellanedae,(TA) which is a plant that has been used for herbal medicine in South America and from Brazil to northern Argentina, is well known in traditional folk medicne used for the treatment of various disease during five hundred years. The inner bark of this plant produced in Brazil is distributed in Asia as a herb tea and healthy purpose. On the fundamental findings, this substance was observed the inhibitory effects against chemical carcinogenesis induced tumor initiating and promoting activity using two-stage mouse skin model.

In the course of these studies, female SENCAR mouse

(6 weeks of age) were treated topically with single dose of PN solution, followed by TPA twice a weekly for 20 weeks. Tumor incidences were 100% with 6 to 7 paillomas per mouse at end of experiment as positive control group. TA powder were orally fed with drinking water for only 2 weeks, before and after initiation and following promoting treatment with drinking water only, as test compounds. In our observations, TA and its components treated group cause about 60-70 % reduction in the average number of tumors per mouse after 20 weeks of experiment, respectively. Topical administration of TA and its components had much influence against PN induced expression stage. We postulate that these data suggeste possible role of a regulatory mechanism of chemopreventive activity in PN induced carcinogenesis. Employing Western blot analysis studies, we found that H-Ras, MEK-2 and p38 levels observed the effects against PN induced activation, and more detail Western blot analysis indicated a active decrease in p38 expression in the skin after TA treatment. Summary of our findings, we suggest that one target of TA and its component effects in mouse skin is the modulation or regulation of the MAPK signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2888A.
Abstract 2896: Effects of Calcium and Vitamin D Supplementation on the Inflammation Marker Cyclooxygenase-2 (COX-2) in Normal Colon Mucosa: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial
Authors: Chen Vincent , Bostick Roberd M.
Published: February 2011

To investigate whether calcium and vitamin D reduce the expression of the inflammation marker COX-2 in the normal-appearing colorectal mucosa of sporadic colorectal adenoma patients, we conducted a pilot, randomized, double-blind, placebo-controlled, 2 × 2 factorial clinical trial (n=92) of 2.0 g elemental calcium daily and vitamin D3 800 IU/day, alone and in combination, versus placebo over 6 months. COX-2 expression and colorectal crypt distribution in biopsies of normal-appearing colorectal mucosa were detected by automated immunohistochemistry and quantified by image analysis. COX-2 expression along the entire crypt increased by 4% (p=0.73) in the calcium group and decreased by 3% (p=0.86) and 4% (p=0.73) in the vitamin D3 and joint calcium and vitamin D3 supplementation groups, respectively, relative to the placebo group. The distribution of COX-2 in the colorectal crypts overall or in various regions of the crypt (proliferative zone, differentiation zone, and area closest to contact with colon lumen contents) did not substantially change over follow-up. Our findings did not support the hypothesis that calcium and/or vitamin D3 supplementation can substantially decrease COX-2 expression in the normal appearing colorectal mucosa of sporadic adenoma patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2896.
Abstract 2898: Prognostic value of postoperative alpha-fetoprotein level on recurrence after curative resection for hepatocellular carcinoma
Authors: Nobuoka Daisuke , Kato Yuichiro , Gotohda Naoto , Takahashi Shinichiro , Konishi Masaru , Kinoshita Taira , Nakatsura Tetsuya
Published: February 2011

Background: The high incidence of recurrence after curative resection is a major challenge in hepatocellular carcinoma (HCC) treatment. Although serum alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) are well known as tumor markers of HCC, the clinical usefulness for early detection of HCC recurrence remains controversial. In this retrospective study, we evaluated the clinical value of AFP and DCP levels in predicting HCC recurrence after curative resection, with a focus on the time course as surveillance tools.

Methods: A total of 165 consecutive HCC patients who had undergone curative hepatectomy at the National Cancer Center Hospital East from 2005 to 2007 and whose serum AFP and DCP had been measured before and after hepatectomy were included in this study. The minimum postoperative levels within a 4-month period were used for analysis. In this study, the cut-off levels for AFP and DCP were set to 10 ng/ml and 40 mAU/ml, respectively.

Results: Until the end of follow-up, tumor recurrence was identified in 114 patients (69.1%). Among the patients with a positive level of AFP before operation, the number of patients whose AFP level did not change from positive to negative after operation in the group with recurrence exceeded that in the group without recurrence (48/60, 80.0% vs. 4/23, 17.4%), and the difference was significant (P < 0.001). In contrast, there was no significant difference between two groups in DCP (14/72, 19.4% vs. 2/29, 6.9%; P=0.118). Minimum postoperative AFP level was found to be a significant independent risk factor for recurrence by univariate and multivariate analysis (P < 0.001). There was no statistically significant correlation between AFP level and grade of hepatitis activity (P = 0.599).

Conclusions: Postoperative AFP level is a useful predictor of recurrence after curative hepatectomy. A positive level of AFP after operation might suggest a site of residual viable cancer. The need for effective adjuvant therapy and close follow-up is suggested in patients with a positive postoperative AFP level.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2898.
Abstract 2908: Promyelocytic leukemia-retinoic acid receptor α forms complexes with Fas and FLIP and impairs Fas-mediated apoptosis
Authors: Tao Rong-Hua , Berkova Zuzana , Wise Jillian , Daniluk Urszula , Samaniego Felipe
Published: February 2011

Fas plays a critical role in cell proliferation and in the selective killing of autoreactive lymphocytes and abnormal cells, including infected cells. To explain the common expression of Fas and the resistance to the Fas-induced apoptosis observed in some normal and cancer cells, we have screened cells for potential regulators of the Fas death receptor. By using mass spectroscopy analysis of Fas-associated proteins, we identified peptides derived from promyelocytic leukemia (PML).

PML enhances pro-apoptotic signaling, while the promyelocytic leukemia-retinoic acid receptor α (PMLRARα) activates pro-survival pathways. Given these opposing functions, we tested whether PMLRARα, which typically operates in a dominant-negative manner, blocks Fas-mediated apoptosis.

Co-immunoprecipitation analysis demonstrated that PMLRARα interacts with Fas in acute promyelocytic leukemia (APL)-derived NB4 cells, U937-PR9 cells and in APL primary cells. The binding of PMLRARα to Fas was mapped to the B-box domain of PMLRARα. Flow cytometry analysis of propidium iodide-stained and Annexin-V-stained cells challenged with Fas ligand (FasL) or agonistic anti-Fas antibody (CH-11) indicated that the presence of PMLRARα was associated with blocked Fas-mediated apoptosis at early and late stages. The knockdown of PMLRARα with shRNA sensitized the NB4 cells to Fas-mediated apoptosis. Expression of PMLRARα in U937-PR9 cells prevented Fas-mediated cleavage of procaspase-8 and also prevented procaspase-8 from binding to the Fas complex upon stimulation with the agonistic anti-Fas antibody (CH-11). Further analysis indicated that PMLRARα bound to FLIPL/S and forms a complex with Fas associated with suppression of Fas signaling.

These data suggest that cancer-specific inhibitors of Fas such as PMLRARα block Fas-mediated apoptosis and thus can contribute to cancer development and resistance to therapy. Our results may provide an explanation for the long-known role of PMLRARα and PML in the regulation of Fas signaling, which we have shown to occur by direct regulation. We have identified an attractive potential target to the regulation of apoptosis at the PMLRARα-Fas and PML-Fas interfaces. By neutralizing the effect of death receptor inhibitors such as PMLRARα and other potential inhibitors, we can improve on the success of the many chemotherapeutic treatments that depend on activation of death receptors for effective elimination of cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2908.
Abstract 2915: p53 isoforms Δ133p53 and p53β are endogenous regulators of replicative cellular senescence
Authors: Fujita Kaori , Mondal Abdul M. , Horikawa Izumi , Nguyen Giang H. , Kumamoto Kensuke , Sohn Jane J. , Bowman Elise D. , Mathe Mathe A. , Schetter Aaron J. , Pine Sharon R. , Ji Helen , Vojtesek Borivoj , Bourdon Jean-Christophe , Lane David P. , Harris Curtis C.
Published: February 2011

The finite proliferative potential of normal human cells leads to replicative cellular senescence, which is a critical barrier to tumor progression in vivo. The p53 signaling pathway plays central roles in the regulation of cellular senescence. Humans, as well as Drosophila and zebrafish, have p53 isoforms; however, their regulation and function are poorly understood. We here examine the expression profiles of two human p53 isoforms, p53β (lacking the C-terminal oligomerization domain due to an alternative mRNA splicing) and Δ133p53 (lacking the N-terminal transactivation and proline-rich domains due to the transcription from an alternative promoter in intron 4), during in vitro and in vivo cellular senescence and their biological activities in regulating cellular senescence. Induced p53β and diminished Δ133p53 were associated with replicative senescence, but not oncogene-induced senescence, in normal human fibroblasts. The replicatively senescent fibroblasts also expressed increased levels of miR-34a, a p53-induced microRNA, the antisense inhibition of which delayed the onset of replicative senescence. The siRNA-mediated knockdown of endogenous Δ133p53 induced cellular senescence, which was attributed to the regulation of p21WAF1 and other p53 transcriptional target genes. In overexpression experiments, while p53β cooperated with full-length p53 to accelerate cellular senescence, Δ133p53 repressed miR-34a expression and extended cellular replicative lifespan, providing a functional connection of this microRNA to the p53 isoform-mediated regulation of senescence. The senescence-associated signature of p53 isoform expression (i.e., elevated p53β and reduced Δ133p53) was observed in vivo in colon adenomas with senescent phenotypes. The decreased p53β and increased Δ133p53 expression found in colon carcinomas might signal an escape from the senescence barrier during the progression from premalignant to malignant tumors in vivo. This study shows that natural p53 isoforms constitute an endogenous regulatory mechanism for p53-mediated replicative senescence and may open up a new p53-based, senescence-mediated strategy to manipulate carcinogenesis and aging. The molecular details of the senescence-associated Δ133p53 repression and p53β induction are currently under investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2915.
Abstract 2922: NDC-1308 inhibits growth of lung and pancreatic tumors in vivo by blocking chromosome replication of cancer cells
Authors: Yarger James G. , Weitman Steven , Weitman Steven , Meibohm Bernd , Gately Stephen , Nye Steven
Published: February 2011

Identification of the cellular mechanisms that alter normal cell growth may be exploited for creating new drugs that treat cancers with unmet needs. For example, recent evidence by our group, and others, suggests that proliferation of lung and pancreatic cancer cells may be controlled by the estrogen receptors alpha (ER-alpha) and beta (ER-beta). If accurate, designing drugs that enhance the proposed inhibitory function of ER-beta versus the stimulatory function of ER-alpha, should lead to cessation of cell division and potentially to cell death. We previously demonstrated that an estradiol-like compound, NDC-1308, is cytotoxic to 14 different tumor cell lines in vitro with an EC50 of 10-20 uM. As predicted, receptor binding studies confirmed that NDC-1308 binds preferentially to ER-beta compared to ER-alpha. A more detailed in vitro analysis showed that NDC-1308 causes a substantial reduction in the transcription of 27 genes involved in chromosomal replication, likely disrupting the cell cycle of the cancer cells. To determine the efficacy of NDC-1308 to kill tumor cells in vivo, xenograft studies were carried out using SCID mice injected with A549 (lung) and BxPC3 (pancreas) tumor cell lines. Mice (N=15 per treatment group) were administered either 8, 16 or 24 mg/kg of NDC-1308 via tail vein injection. Depending on the schedule, the mice were dosed every other day or every third day and the tumor weights followed for two additional weeks after ending treatment. The results show that tumor size was substantially smaller (2 to 3-fold) in NDC-1308 treated animals versus untreated controls. We conclude that intravenous administration of NDC-1308 can cause a cessation of tumor growth in a mouse model of lung and pancreatic cancer. Consistent with the proposed mechanism of action and recent rat pharmacokinetic data (t1/2=120min), increasing the dose or decreasing the time between doses enhanced the effect of NDC-1308 on tumor growth in the xenograft model. Future studies will include large animal safety and toxicity studies leading to IND submission and Phase I clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2922.
Abstract 2923: Estrogen signaling modulates cisplatin resistance in the treatment of human non-small cell lung cancer
Authors: Márquez-Garbán Diana C. , Patel Amitkumar D. , Chen Hsiao-Wang , Goodglick Lee , Fishbein Michael C. , Garon Edward B. , Garbán Hermes J. , Pietras Richard J.
Published: February 2011

Lung cancer is the most common cause of cancer mortality in male and female patients in the US. Non-small cell lung cancer (NSCLC) accounts for more than 85% of lung cancers. Standard initial chemotherapy for patients with advanced NSCLC is a platinum-based regimen, with data showing that these therapies elicit a modest improvement in patient survival. However, a major limitation to cisplatin therapy is development of drug resistance, leading to cancer progression and reduced patient survival. Cisplatin acts by interacting with DNA to form adducts that, in turn, activate signaling pathways for cell death (apoptosis). DNA damage-mediated apoptotic signals, however, can be blocked, and the resistance that ensues is a major drawback of cisplatin therapy. Resistance mechanisms, such as increased DNA adduct repair, may be modulated by interactions with other signaling pathways for cell survival, and emerging data suggest that estrogens may play a role in this process. To understand how estrogens modulate cisplatin resistance in vitro, we used two models of human NSCLC, A549 and H23 cells, that proliferate in response to estradiol-17β (E2) and express estrogen receptors and aromatase (enzyme that produces estrogens locally). Cisplatin markedly reduces tumor cell growth and enhances apoptosis in both models. However, the antitumor action of cisplatin is significantly blocked when cells are treated with estrogen in vitro. Using qRT-PCR and Western immunoblot analysis of excision repair cross-complementing-1 (ERCC1) protein (repairs cisplatin-induced DNA damage), we find that ERCC1 mRNA and protein levels are significantly increased in the presence of estrogen, thereby suggesting a potential mechanism for estrogen-induced cisplatin resistance. Analyses of the 5’-regulatory region of the human ERCC1 gene revealed putative half-estrogen responsive elements in close proximity with sp1 and AP1 sites. Chromatin immunoprecipitation assays showed binding of estrogen receptors to these promoter sites. Furthermore, treatment of human NSCLC xenografts in vivo with an aromatase inhibitor (exemestane) alone or combined with standard cisplatin chemotherapy elicits a significant reduction in tumor progression as compared to paired controls. A new strategy to block NSCLC progression may be use of cisplatin with simultaneous suppression of estrogen signaling (such as use of aromatase inhibitors). [Supported by NIH Lung Cancer SPORE, National Lung Cancer Partnership and Stiles Program funds].

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2923.
Abstract 293: Regulation of inhibitor of differentiation 1 (Id1) by PKC signaling in the intestinal epithelium
Authors: Hao Fang , Pysz Marybeth A. , Haas Kristin N. , Curry Kathryn J. , Vollmer Thomas R. , Black Adrian R. , Black Jennifer D.
Published: February 2011

Increasing evidence supports a role for protein kinase C (PKC) signaling in regulation of intestinal epithelial self-renewal, and alterations in PKC isozyme expression/activity have been broadly linked to intestinal carcinogenesis. PKCα, which exhibits growth inhibitory and tumor suppressor properties in the intestine, is lost early during intestinal tumor development. To gain further insight into the tumor suppressive effects of PKCα signaling, we explored the consequences of restoration of PKCα expression in DLD-1 human colon cancer cells by microarray analysis. The most downregulated known gene in PKCα-expressing DLD-1 cells was inhibitor of differentiation 1 (Id1), a member of the Id family of dominant negative antagonists of bHLH transcription factors that has cell cycle stimulatory functions and has been associated with tumorigenesis in a number of systems. Suppression of Id1 protein by PKCα in colon cancer cells was confirmed by Western blot analysis in a panel of cell lines including DLD-1, HCT116, FET, FET/DNR, and GEO. Notably, activation of PKC/PKCα in non-transformed IEC-18 intestinal crypt cells also resulted in rapid and profound downregulation of Id1 mRNA and protein, pointing to a role for PKCα in Id1 regulation in the normal intestinal epithelium. PKC-induced suppression of Id1 was found to occur via an ERK/MAPK-dependent, PI3K-independent mechanism. Manipulation of Id1 levels in normal and transformed intestinal cells demonstrated its ability to affect two key cell cycle targets of PKCα, the potent mitogen cyclin D1 and the cdk inhibitor p21Waf1/Cip1. Knockdown of Id1 consistently decreased steady-state levels of cyclin D1, while overexpression of the factor resulted in reduced levels of p21Waf1/Cip1. Thus, Id1 appears to control the expression of important cell cycle regulators in intestinal cells. Immunohistochemical analysis of normal intestinal mucosa further demonstrated that PKCα activation, which occurs precisely at the point of growth arrest in the mid/upper crypt, coincides with marked downregulation of Id1 in vivo. Conversely, loss of PKCα in intestinal tumors is associated with Id1 overexpression. Ongoing studies are focused on delineating the link between the tumor suppressor functions of PKCα and its inhibitory effects on Id1 expression in intestinal cells. Supported by NIH grants DK54909, DK60632, CA16506, and CA113048.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 293.
Abstract 2941: Rapid changes in chromatin structure in response to extracellular signals
Authors: Fernandez Alfonso G. , Di Lijun , Byun Jung , Fufa Temesgen , Gardner Kevin
Published: February 2011

Immediate early genes (IEGs) are well known to be rapidly and transiently induced at high levels of expression in response to various extracellular signals such as growth factors. These rapid changes in the transcriptional state of this class of genes raised questions regarding the role of higher order chromatin structure in this transient event of inducible gene expression. In these studies, we compared the degree of chromatin condensation in Jurkat cells before and after mitogen stimulation of c-fos, a well-known IEG. Soluble chromatin obtained from unstimulated and stimulated cells were collected for a sucrose gradient sedimentation assay in order to separate chromatin fibers by means of size and more importantly by the extent of structural condensation of the chromatin. Real time-PCR analysis of c-fos was then used as a tool to quantify the distribution of open and closed chromatin fibers across the collected fractions obtained from the sucrose gradients. The results suggested a major decondensation of the chromatin fiber at the c-fos gene upon stimulation. The unfolding of the chromatin structure upon stimulation is paired with a dramatic increase in histone acetylation as detected by chromatin immunoprecipiation (ChIP) at the promoter region. Histone hyperacetylation is known to cause destabilization of the higher order chromatin structure leading to an increase in chromatin accessibility as clearly shown in our DNase hypersensitivity studies. Taken together, we have detected a rapid decondensation of the chromatin fiber, which is believed to facilitate the rapid transcriptional response to extracellular signals. Our current interest lies in obtaining further information regarding the molecular events that are more directly related to destabilization of the higher order chromatin structure upon mitogen stimulation. Testing of various molecular candidates involved in chromatin destabilizing events include phosphorylation of linker histone H1, recruitment of histone variants and dramatic histone modications such as ADP-polyribosylation at the c-fos promoter region. A more detailed understanding on the rapid decondensation of the chromatin fiber would provide valuable information regarding the cascade of events that must take place in response to stress or extracellular signals.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2941.
Abstract 2943: Aurora kinase A induces miR-17-92 cluster through regulation of E2F1 transcription factor
Authors: He Shun , Yang Shangbin , Deng Guohua , Zhu Hongxia , Liu Mei , Zhang Wei , Quan Lanping , Bai Jinfeng , Xu Ningzhi
Published: February 2011

Aurora Kinase A (AURKA) encodes an evolutionally conserved serine/threonine kinase that plays a pivotal role in centrosome cycling during mitosis. Abnormal expression of AURKA has been observed in many malignancies, yet the exact role for AURKA in tumorigenesis still remains elusive. Here through a transcription factor array, we show that the transcription activity of E2F1 was increased by AURKA overexpression. Meanwhile, E2F1 protein level was found to be upregulated upon AURKA induction and the correlation between AURKA and E2F1 expression was also observed in breast cancer specimens. Further analysis revealed that AURKA increased E2F1 protein stability by inhibiting proteasome-dependent degradation of this protein. Additionally, a microRNA cluster, miR-17-92 was found to be upregulated upon AURKA overexpression, and this stimulation was largely repressed by small interfering RNA (siRNA) against E2F1. Chromatin immunoprecipitation further demonstrates that AURKA enhanced the in vivo occupancy of E2F1 to the promoter of the miR-17-92 cluster. These data reveal a novel link between AURKA and microRNAs via the regulation of E2F1, providing new clues for understanding the role of AURKA in tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2943.
Abstract 2944: Genome-wide transcriptional modulation screening in non-smoking female lung cancer in Taiwan
Authors: Lu Tzu-Pin , Chen Pei-Chun , Lee Jang-Ming , Hsu Chung-Ping , Chen Shin-Kuang , Tsai Mong-Hsun , Hsiao Chuhsing K. , Chuang Eric Y. , Lai Liang-Chuan
Published: February 2011

Lung cancer has become the leading cause of cancer death in Taiwan and in most countries. Although smoking has been the major risk factor for lung cancer, less than 20% smokers develop lung cancer. In Taiwan, only about 50% of lung cancer cases were related to smoking, while more than 90% lung cancer females were non-smokers. In this study, we collected gene expression microarrays to investigate the pathogenesis process. One hundred and twenty lung tumor samples and their normal counterparts from non-smoking females were collected from National Taiwan University Hospital and Taichung Veterans General Hospital. RNAs from 60 paired samples were examined using Affymetrix Human U133 plus2.0 microarray. Paired t-tests were used to identify differentially expressed genes between tumor and normal tissues. The preliminary results showed there were 791 differentially expressed genes (p-value < 10−14). Ingenuity Pathway Analysis (IPA) was utilized for further functional and pathway analyses on these genes, and the axon guidance signaling pathway was the most significantly enriched pathway. Among genes in the axon guidance signaling pathway, SEMA5A was chosen for further investigation because it was the most significant down-regulated gene in tumor tissue. Its down-regulation was validated by both real-time PCR and immunohistochemistry (IHC). Furthermore, Kaplan-Meier survival analysis showed that patients with low SEMA5A expression had poor overall survival as compared to those who had high SEMA5A expression. This significant association was also observed in two published studies. Therefore, these results indicated that the SEMA5A may play an important role in the carcinogenesis and can be a potential prognosis biomarker for non-smoking lung cancer females in Taiwan.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2944.
Abstract 2951: Nicotine induced EMT involves β-arrestin-1 mediated regulation of E2F1 target genes
Authors: Pillai Smitha R. , Damit Michael , Chellappan Srikumar
Published: February 2011

Cigarette smoking is strongly correlated with the onset of non-small cell lung cancer. Nicotine, an active component of tobacco smoke has been found to induce proliferation, invasion and epithelial-mesenchymal transition in NSCLC cell lines. While nicotine by itself is not carcinogenic, it can induce cell proliferation utilizing a scaffolding protein, β-arrestin-1 which translocates to nucleus and associates with E2F1 transcription factor. In addition, nicotine induces changes in gene expression consistent with epithelial-mesenchymal transition characterized by increase in the levels of mesenchymal proteins like vimentin and fibronectin. In this study we demonstrate that mesenchymal markers such as vimentin and fibronectin are E2F1 regulated and β-arrestin-1 is involved in regulating their expression in response to nicotine stimulation. Analysis of vimentin and fibronectin promoters revealed the presence of potential E2F binding sites. Transient transfection experiments in A549 cells using vimentin and fibronectin promoter constructs showed that these promoters were induced significantly by E2F1 and repressed by Rb. Depletion of E2F1 using siRNAs resulted in down regulation of vimentin and fibronectin as seen by Real-Time PCR. Chromatin immunoprecipitation assays on quiescent as well as nicotine stimulated A549 cells showed a robust recruitment of E2F1 and β-arrestin-1 to vimentin and fibronectin promoters. In addition, depletion of β-arrestin-1 resulted in down regulation of vimentin and fibronectin expression as revealed by western blot and Real-Time PCR. Nicotine stimulation resulted in the induction of vimentin and fibronectin promoters when A549 cells were transfected with reporter constructs while β-arrestin-1 depleted cells did not show promoter induction with nicotine stimulation. Boyden chamber assays conducted on β-arrestin-1 knocked down cells showed that ablation of β-arrestin-1 resulted in the inhibition of nicotine induced migratory and invasive potential of cells. Taken together, these data suggest that β-arrestin-1 contributes to nicotine induced epithelial-mesenchymal transition by regulating E2F1 mediated vimentin and fibronectin expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2951.
Abstract 2952: Gene expression profiling in gastric adenomas and carcinomas
Authors: Kim Won Kyu , Koh Kwi Hye , Nam Suk Woo , Rhee Hwanseok , Kim Hoguen , Hyunki Kim
Published: February 2011

A subset of gastric carcinogenesis is a multistep process, which progresses from chronic gastritis, atrophy, intestinal metaplasia, adenoma and finally leads to gastric carcinoma. To explore the transcriptomic change during the gastric adenoma-carcinoma sequence, a total 26 snap-frozen samples (8 paired normal mucosa, adenoma and carcinoma cases and additional 2 carcinomas) were analyzed by oligonucleotide microarrays. We identified 60 gradually up and down regulated genes according to normal, adenoma and carcinoma sequence. Twenty one genes were gradually decreased from normal mucosa to adenoma to carcinoma and 39 genes were gradually increased. We validated the expression of hydroxyprostaglandin dehydrogenase 15 (HPDG15), follistatin-like 1 (FSTL1), trefoil factor 1 (TFF1) and trefoil factor 2 (TFF2) by real time RT-PCR. The identified gene sets according to adenoma-carcinoma sequence might play critical roles in gastric carcinogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2952.
Abstract 2955: LSm1 over expression contributes to an increase in alternative splicing in lung cancer cells
Authors: Watson Patricia M. , Boylan Alice , Watson Dennis K.
Published: February 2011

RNA splicing is a key molecular event that allows for substantial protein diversity. Through this process, a single gene magnifies its coding capacity by expressing several related proteins with diverse and often antagonistic functions leading to cell or tissue specific changes in mRNA through changes in splice site choice. Alternative splicing, which represents the suppression of constitutive splice sites and/or the use of suboptimal sites, is elevated in cancer and many other disease states. Pre-mRNA splicing is coordinated by the spliceosome, a macromolecular ribonuclear complex that assembles on the pre-mRNA as it is transcribed. Due to the number of proteins involved in splicing, the diversity of pre-mRNA substrates and the multi-step process of spliceosome assembly and catalysis, regulation of splicing can occur at any point in the pathway. The LSm proteins are a family of eight RNA binding proteins that form two seven membered ring structures and contribute to mRNA stability and splicing. LSm1 forms a complex with LSm2-7 that targets mRNA for degradation in P bodies. LSm8 also forms a complex with LSm2-7 that binds the U4 U5 U6 tri-SNRP, an integral part of the spliceosome. Previously, it was shown that LSm1 was elevated in many different types of cancer and contributed to the malignant phenotype. Recently, alternative splicing has been shown to contribute to the activation of oncogenes and the inactivation of tumor suppressor genes. To determine if the over expression of LSm1 could contribute to alternative splicing, a well differentiated lung cancer cell line was infected with adenovirus expressing the open reading frame of LSm1 or GFP. The RNA from these cells was analyzed for alternative splicing using Agilent SpliceArray™ microarray slides. Significant differences were seen between the cells treated with control virus and the LSm1 expressing virus in the splicing patterns of several genes that could contribute to the cancer phenotype, including hepatoma derived growth factor (HDGF), CD44 and c-myc. Thus, over expression of LSm1 leads to changes in alternative splicing that impacts the malignant phenotype of cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2955.