bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 170: Combined mRNA and miRNA profiles in lung cancer cell lines as a tool to screen the targets contributes to cisplatin resistance
Authors: Sun Yunguang , Zheng Siyuan , Zhao Zhongming , Lu Bo
Published: June 2012

microRNAs (miRNAs) are small RNAs average only 22 nucleotides long. miRNA signatures have been associated with histopathological and clinical features, suggesting a potential role of these molecules as prognostic and predictive markers. In this study, we generated a cisplatin resistance cell line. We profiled miRNA and mRNA expression in this cisplatin resistant cells and its parental cells using Exqon miRNA array platform and Affymetrix 1.0 ST array respectively. In order to identify functional regulatory gene-miRNA pairs in cisplatin resistance, we constructed a deregulated miRNA-gene network by incorporating miRNA-target genes information from TargetScan.

The resulting miRNA-gene deregulation network consists of 72 genes and 27 miRNAs. 30 genes were up regulated and 42 were down regulated. Of the miRNAs, 26 were down regulated and 1 was up regulated. The network was further refined by retaining the negative correlated pairs considering that miRNAs predominantly decrease their target mRNA levels. We found several members of has-let-7 family were present in the network. IGF pathway gene, IGF2BP1, was also an important node. In our previous work, this pathway was identified as a promising target for cisplatin resistance treatment.

Our results show that the has-let-7 miRNA family and IGF pathway genes may play important roles in cisplatin resistance. Exploration of the deregulation network can potentially provide more insights to the identification of candidate targets. Our approach also demonstrates the value of systems biology in the analysis of genomic data.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 170. doi:10.1158/1538-7445.AM2011-170
Abstract 1719: Integrative genomic analysis of ovarian cancer cell lines points to EMT involvement in the development of cisplatin resistance
Authors: Haslehurst Alexandria , Koti Madhuri , Vidal Ricardo , Park Paul , Jiang Wenyu , Squire Jeremy , Feilotter Harriet
Published: June 2012

Ovarian cancer is the 5th leading cause of cancer related death in women, and has the highest associated mortality rate of any of the gynecological cancers. Approximately 75-80% of women diagnosed will succumb to the disease. The high mortality rate associated with ovarian cancer is due to poor screening and detection methods, resulting in late stage diagnosis, and also to resistance of the tumours to chemotherapeutic drugs. Primary drug resistance occurs in about 20% of patients during their treatment phase while approximately 70-80% of women that initially respond to chemotherapy will develop drug resistance over the course of treatment or at the time of relapse. Being able to accurately predict which patients will not successfully respond to drugs is the first step in developing personalized medicine and preventing useless chemotherapy treatments. In order to discover biomarkers of cisplatin resistance, a multi-platform integrative approach was taken utilizing data from aCGH as well as miRNA and mRNA microarrays. Data were collected from a drug sensitive and drug resistant ovarian cancer cell line pair (A2780 and A2780cis). Working with the paired cell lines provided a homogeneous population with which to build an integration algorithm. Data analysis using GeneSpring and Nexus software showed an enrichment of genes involved in TGFβ and EGF signaling. These signaling pathways lead us to investigate the involvement of the epithelial to mesenchymal transition (EMT) in drug resistance. Interestingly, many of the key genes involved in the regulation of the EMT process were found to be upregulated in our mRNA expression data. Observations from cell culture work support EMT involvement. We have noted a slower growth rate and a change to a fibroblastic appearance in the resistant cells relative to their drug sensitive parents. Immunohistochemistry has also been utilized to show an increase in mesenchymal markers in the resistant cell line. In order to determine if these findings were representative of drug resistance in human ovarian cancer, expression data from cisplatin sensitive and resistant ovarian cancer tumours were mined specifically for these and other EMT genes. A large number of the same EMT genes were consistently shown to be upregulated in the drug resistant tumour tissues relative to the sensitive tumours. Together, these data suggest the potential involvement of the epithelial to mesenchymal transition in the development of cisplatin resistance in ovarian cancer. Further validation of these results in vitro is currently in progress.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1719. doi:10.1158/1538-7445.AM2011-1719
Abstract 1732: Synthesis and evaluation of NSC23925 isomers to reverse multidrug resistance in cancer
Authors: Duan Zhenfeng , Choy Edwin , Harmon David , Liu Xianzhe , Mankin Henry , Hornicek Francis
Published: June 2012

The eventual development of multidrug resistance (MDR) during the course of chemotherapy treatment is a fundamental obstacle associated with cancer care. Prior studies have identified NSC23925 ((2-(4-methoxyphenyl)-4-quinolinyl) (2-piperidinyl) methanol)) to be a small molecule agent that reverses MDR in cancer cells. Analysis of the structure of NSC23925 indicates that NSC23925 has two chiral centers which lead to 4 different stereo-isomers (erythro-7a, threo-7b, threo-9a and erythro-9b). Each isomer may or may not have distinct bio-activity from the others. In this study, we synthesized all four isomers of NSC23925 and analyzed by liquid chromatography-mass spectrometry (LCMS, HPLC-MS). Structure and activity relationships for reversing MDR in several MDR human cancer cell lines were evaluated by MTT assay. We observed that compound erythro-9b (NSC23925-9b) is the most potent isomer on reversing drug resistance, threo-7b and threo-9a also showed modest but lesser activity, and Erythro-7a showed the least potency. NSC23925-9b is able to reverse MDR in several drug resistant cell lines expressing Pgp in vitro, including ovarian, breast, colon, and sarcoma cancer cell lines. NSC23925-9b was able to re-sensitize these cell lines to paclitaxel, doxorubicin, vincristine and ET-743 with no effect on cell sensitivity to cisplatin, topotecan and methotrexate. NSC23925-9b was unable to reverse drug resistance in non-Pgp expressing drug resistant cell lines. Furthermore, NSC23925-9b significantly enhanced in vivo antitumor activity of paclitaxel in MDR ovarian cancer cell line SKOV-3TR xenograft models, without significant increasing the level of paclitaxel toxicity. In conclusion, these results demonstrated that NSC23925-9b and derivatives of this compound may hold therapeutic value in the treatment of MDR dependent cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1732. doi:10.1158/1538-7445.AM2011-1732
Abstract 1736: Src inhibitor dasatinib enhances anti-tumor activity of irreversible or T790M-selective epidermal growth factor receptor-tyrosine kinase inhibitors in non-small cell lung cancer cells with T790M gate-keeper mutation
Authors: Yoshida Takeshi , Zhang Guolin , Bai Yun , Edwards Arthur , Fang Bin , Rawal Bhupendra , Okabe Takafumi , Okamoto Isamu , Nakagawa Kazuhiko , Haura Eric B.
Published: June 2012

Despite the therapeutic benefit of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with EGFR mutation, most if not all eventually develop resistance to these drugs. A secondary mutation of EGFR (T790M) accounts for 50% of all cases of acquired resistance to EGFR-TKIs. Although irreversible EGFR-TKIs are thought to be one of the strategies to overcome T790M, the efficacy of these drugs appears limited. To investigate how signal transduction is altered in NSCLC cells with T790M, we generated PC9GR cells with T790M by long term gefitinib exposure of PC9 cells with exon 19 deletion. Global phospho-proteomics approach revealed that Src family kinases were phosphorylated by erlotinib treatment in PC9GR cells, suggesting that Src family kinases compensate EGFR inhibition in NSCLC cells with T790M. Western blot assays demonstrated that BIBW2992, an irreversible EGFR-TKI currently in several clinical trials, also activated Src family kinases in PC9GR and H1975 NSCLC cells with T790M. The Src inhibitor dasatinib combined with BIBW2992 abolished this Src phosphorylation along with complete suppression of phospho Akt and Erk. In addition, significant PARP cleavage was observed in these cells suggesting apoptotic cell death. Consistent with the effects on cell signaling and apoptosis, dasatinib enhances anti-tumor activity of BIBW2992 in both GLO cell proliferation assay and caspase-3 apoptosis assay in PC9GR and H1975 cells. Additional experiments also demonstrated that dasatinib enhanced the effects of T790M selective EGFR-TKI WZ4002, which was recently reported to be another possible strategy to overcome T790M, in PC9GR and H1975 cells. Finally, the combination of BIBW2992 and dasatinib showed significant in vivo tumor suppression (including tumor regression) in PC9GR xenograft studies. These results suggest a role for Src in maintaining downstream signaling despite irreversible EGFR inhibitors and support further studies of irreversible EGFR combined with dasatinib in NSCLC patients who acquired resistance to EGFR-TKI by T790M.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1736. doi:10.1158/1538-7445.AM2011-1736
Abstract 1822: Decision making and cancer clinical trial participation among African Americans
Authors: Nguyen Van T. , Wujcik Debra , Wolff Steven
Published: June 2012

INTRODUCTION: Although the disparity in clinical trial participation is well documented, the main reason why African Americans and the medically underserved do not participate in cancer clinical trials (CCT) has not been agreed upon. It is apparent that new policies and initiatives are required to ensure minority access to CCT and applicability of subsequent results from CCT.

METHODS: In-depth interviews were conducted to explore issues of fear and mistrust in CCT participation. Participants were asked questions regarding their perceptions of cancer, research, cancer clinical trials; attitudes toward participation in clinical trials; and the effect of trust in decision-making. Afterward, participants completed a survey, a modification of the Wake Forest Physician Trust Scale to assess trust in medical research study. One field expert and one medical student independently reviewed the tapes, transcripts, and surveys from the interviews for themes, trends, and congruence. Saturation was achieved at eight interviews.

RESULTS: Eight African Americans, 7 female and 1 male, participated. Three themes emerged related to decision making and CCT participation: 1) Motivation to participate comes from believing what they were doing would help those coming after them; 2) Trusted sources for CCT information include the research team, primary care providers, and trusted individuals; 3) Final decision making, based on all of the advice and information given, would be theirs to make.

CONCLUSION: Potential African American participants in CCT have many trusted sources to turn to and receive advice regarding their decision to participate or not. However, they will listen to the CCT research team and their primary care providers, especially if what they perceive is a trusting and open relationship is established. Given that these potential participants are the ones who make the final decisions, just as much of an effort should be placed on making sure that they have all of the information that they want, whether these conversations are with researchers or primary care providers who know about CCT. An emphasis on how potential African American participants can contribute to CCT and positively affect the lives of other African Americans with the same diagnoses should also be made. Results from this study and a previous study will form the basis for an intervention study.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1822. doi:10.1158/1538-7445.AM2011-1822
Abstract 1825: Sustained aerobic exercise alone does not counteract the tumor-promoting effects of a westernized diet on prostate cancer progression in vivo
Authors: Vandersluis Avi D. , Venier Natalie A. , Kiss Alex , Colquhoun Alexandra J. , Fleshner Neil E. , Klotz Laurence H. , Venkateswaran Vasundara
Published: June 2012

Introduction: The influence of lifestyle behaviors on prostate cancer (PCa) is well established. Our lab has previously reported that diets high in both fat and carbohydrates – the “Westernized” diet – promote PCa tumor growth in vivo. Numerous studies have also found an inverse relationship between exercise and PCa progression. However, the exact relationships between diet, exercise and PCa, as well as their underlying mechanisms, are unclear. Herein we aim to investigate the effect of sustained aerobic exercise on PCa tumor growth in animals fed a “Westernized” diet or a normal diet.

Methods: Athymic nude mice (n=46) were inoculated subcutaneously with LNCaP cells. Mice were fed ad libitum with either a high-fat/high-carbohydrate diet (HFHC) or a standard normal diet (Normal), and randomized into exercising (Ex) and non-exercising groups (No-Ex). Exercise was undertaken 3 days per week (3 × 15 mins; 2-min breaks between cycles; 2.0-7.0 m/min) for 8 weeks, using a forced exercise wheel. Body weights, tumor volumes, and food consumption were recorded tri-weekly. Comparisons between groups over time were performed using RANOVA Type 3 Tests of Fixed Effects.

Results: There were no significant differences in body weight between the groups over time. The HFHC-Ex group (n=10) had the highest rate of tumor growth compared to all other groups (p<=0.0007). No significant differences were observed between the rate of tumor growth of the HFHC-No Ex group (n=11) and the Normal-No Ex group (n=12) or between the Normal-No Ex group and the Normal-Ex group (n=10). However, the rate of tumor growth of the Normal-Ex group was reduced compared to the HFHC-No Ex group (p<=0.0008). Food consumption analysis revealed significant differences (p<=0.012) in energy consumption (kcal) between each of the groups over time. Mice in HFHC-Ex group consumed the most energy compared to all other groups followed by HFHC-No Ex>Normal-Ex>Normal-No Ex groups.

Conclusions: The results indicate that exercise stimulated an increase in food consumption. In mice fed a tumor-promoting “Westernized diet,” this enhanced the rate of tumor growth. However, in mice placed on a normal diet, this increase in energy consumption did not correspond with increased tumor growth over time, emphasizing the importance of both exercise and healthy diet in the progression of PCa. Further studies to examine the relationship between diet and exercise with respect to PCa progression are currently underway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1825. doi:10.1158/1538-7445.AM2011-1825
Abstract 1839: Improving colorectal cancer screening rates in minority and underserved populations: A tailored community approach
Authors: Darwish-Yassine May
Published: June 2012

Disparities in colorectal cancer screening rates continue to be observed across population groups in Michigan. In 2008, screening rates were below the general population for each of the minority population groups except Asian Americans (63.7% + 15.0%); rates were exceptionally low for Hispanics (46.5% + 15.4%) and Arab Americans (45.6% + 21.9%).

Four special projects were conducted that focused on increasing awareness of colorectal cancer (CRC) screening in Michigan's underserved populations. We present a summary of each project methodology and highlight the outcomes of each intervention type as it relates to awareness of colorectal cancer risk and behavioral changes within the selected populations.

Generally, community-wide interventions, particularly those using media, seek to increase preventive behaviors within a community by targeting a large part of the population in a defined area. The evaluations presented in this report were designed to include all community members 50 years of age or older living in the campaign geographical area and did not necessarily target individuals who were touched by every type of intervention offered. This was primarily due to the timeline and resources surrounding the interventions. However, our evaluation results show signs of improvement in CRC awareness within the study communities, and suggest that tailored and culturally-appropriate approaches are effective in health promotion at the community level.

Reducing disparities in cancer outcomes undoubtedly requires repeated and sustained efforts for achieving optimal outcomes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1839. doi:10.1158/1538-7445.AM2011-1839
Abstract 1848: Decursin derivatives with increased in vivo stability suppress androgen receptor signaling and prostate cancer cell growth: Structure-bioactivity relationship
Authors: Zhang Yong , Shaik Ahmad , Chai Yubo , Li Li , Zhang Jinhui , Zhang Wei , Xing Chengguo , Kim Sung-Hoon , Lü Junxuan , Jiang Cheng
Published: June 2012

Androgen receptor (AR) signaling is crucial for the genesis and progression of prostate cancer (PCa). Targeting AR signaling remains an attractive approach for PCa chemoprevention and therapy. Our previous studies suggest that decursin, which is isolated from the Korean medicinal herb Angelica gigas Nakai, has novel anti-androgen attributes in comparison to that of AR antagonist drug bicalutamide (Casodex) and stronger anti-proliferative and pro-apoptotic activities in cell culture models. However, decursin quickly de-esterifies to decursinol in vivo, which lacks the anti-androgen and anti-proliferative activities. We report here that a novel prototype derivative (decursinol thiocarbamate, DTC) shows in vivo stability in single dose pharmacokinetic studies, with no detection of decursinol. Molecular docking with the wild type AR ligand binding domain (LBD) suggested that its AR-binding energy is inferior to DHT, but higher than decursin. Mechanistically DTC retains all the desirable properties of decursin, including inhibiting AR nuclear translocation, decreasing cellular AR protein abundance by promoting its 26S proteasomal-mediated degradation and lacking agonist activity. Dose-response comparisons showed that DTC was half as potent as decursin to inhibit AR signaling and androgen sensitive LNCaP PCa cell growth. In animal studies with mice, daily i.p. injection of DTC (2 mg per mouse) decreased AR transcriptional targets such as probasin and NKX3.1 in the mouse prostates. Chemical deposits on the surface of liver and other organs were observed suggesting poor solubility. Additional derivatives aimed to improved solubility had been synthesized and are being investigated for structure-activity relationship. Overall, the data suggest that DTC is a prototype stable decursin derivative retaining the novel AR antagonist activity for PCa chemoprevention or treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1848. doi:10.1158/1538-7445.AM2011-1848
Abstract 1849: Chemopreventive efficacy of naproxen, sulindac, and their nitric oxide-derivatives in the hydroxylbutyl(butyl)nitrosamine induced model of urinary bladder cancer
Authors: Grubbs Clinton J. , Boring Daniel , Steele Vernon E. , Verney Zoe M. , Lu Yian , You Ming , Lubet Ronald A.
Published: June 2012

A variety of studies were performed with naproxen (a standard NSAID with a good cardiovascular profile), sulindac, and their nitric oxide (NO)-derivatives. In Fisher 344 rats, OH-BBN (2x/week for 8 weeks by gavage) induced invasive urinary bladder cancers. When treatment was initiated one week following the final dose of OH-BBN, both naproxen (400 ppm) and sulindac (400 ppm) were highly effective preventive agents at these human equivalent doses. The NO-derivatives of each compound (NO-naproxen, 550 ppm and NO-sulindac, 520 ppm) were similarly effective. When the dose of naproxen was decreased from 400 ppm to 75 ppm a strong preventive effect was still observed. This activity was observed even when treatment with naproxen was started 12 weeks after the last OH-BBN treatment; microcarcinomas already existed at this time. In an attempt to make a more direct comparison between the human and rat data, animals were treated with 40 mg/kg BW/day of naproxen by gavage. Similar to the dietary dose of 400 ppm, the agent was highly effective; however, gavaging the rats permitted more direct comparison of the pharmacokinetics observed in the rat with known results in humans. In contrast to the naproxen data, reducing the dose of sulindac from 400 to 150 ppm, a dose comparable to the human dose employed by Meyskens, et al. (Cancer Prevention Res. 1:32-38, 2008), resulted in only limited activity. Finally, the effects of naproxen and NO-naproxen on modulation of gene expression in the livers of treated rats were determined. Limited, but similar, gene expression changes induced by both agents were observed. Interestingly, neither agent induced the antioxidant response element genes [e.g., GST Pi, quinone oxidoreductase, aldo keto reductase A37 (aflatoxicol)] that one might have expected to be highly induced by free NO. Supported by the NCI contract number HHSN261200433001C.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1849. doi:10.1158/1538-7445.AM2011-1849
Abstract 2151: Characterization of a novel anti-apoptotic signaling pathway downstream of FGFR4 in rhabdomyosarcoma
Authors: Wachtel Marco , Schaefer Beat
Published: June 2012

FGFR4 is highly overexpressed in Rhabdomyosarcoma tumors and contains activating mutations in eight percent of the cases. These data strongly suggest that FGFR4 plays an important role in the tumorigenesis of this cancer type. However, the molecular mechanisms behind the benefit of active FGFR4 for Rhabdomyosarcoma cells are largely unknown.

Here, we describe a survival pathway activated by FGFR4 in Rhabdomyosarcoma cells. Active FGFR4 is able to block apoptosis induced by inhibition of other central signaling pathways with small molecule inhibitors, such as the IGF1R pathway with AEW541 and PI3K-controlled pathways with BEZ235. Using different biochemical and genetic approaches, we could locate the apoptotic block upstream of the pro-apoptotic BH3-only proteins bmf and bim. To further elucidate the mechanism of this prosurvival signaling, we then performed proteomic studies to define the complete interactome of FGFR4 in Rhabdomyosarcoma cells. These analyses revealed a strong interaction of FGFR4 with PLCγ, linking FGFR signaling to PKCs. Indeed, activation of PKCs strongly inhibits AEW541/BEZ253-induced apoptosis, suggesting that PKCs are central for FGFR4-activated survival signaling. In contrast, the classical survival pathways via Akt and Erk are not or only marginally involved in the rescue mechanism.

Treatment approaches targeting the IGF1R/PI3K axis in Rhabdomyosarcoma are under intensive investigation. Our data suggest that rescue mechanisms via FGFR4 and PKCs should be taken into account when applying such treatment strategies. A combination of IGF1R- and FGFR4/PKC-inhibitors therefore might be superior compared to single treatments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2151. doi:10.1158/1538-7445.AM2011-2151
Abstract 2160: Critical BRCA1 role as a transcriptional regulator in prostate cancer DNA damage response
Authors: De Luca Paola , Moiola Cristian , Zalazar Florencia , Gueron Geraldine , Cotignola Javier , Vazquez Elba , Gardner Kevin , De Siervi Adriana
Published: June 2012

Loss or mutation of the BRCA1 gene is associated with nearly 5% of all breast cancers. Since many cases of sporadic cancers that also show decreased BRCA1 expression are often associated with higher grade tumors, significant interest has developed in defining mechanisms of BRCA1 regulation at the level of transcription. BRCA1 plays numerous roles in regulating genome integrity. It interacts with crucial proteins and is considered a gene-specific transcriptional co-regulator; however, BRCA1's role in the transcriptional response to DNA damage is poorly understood. In this study we show that BRCA1 plays a central role in the transcriptional response to genotoxic stress in prostate cancer. Using BRCA1-depleted or BRCA1-overexpressing human prostate cancer cell lines, we found that BRCA1 mediates apoptosis, cell cycle arrest and decreased viability in response to doxorubicin treatment. Furthermore, xenograft studies using human prostate carcinoma PC3 cells demonstrate that BRCA1 depletion results in increased tumor growth. In addition, genome-wide screens using the combined application of chromatin immunoprecipitation and microarray technology (ChIP-chip) reveals that BRCA1 is highly enriched at the promoters of greater than 1300 genes. Gene Ontology (GO) analysis of this “BRCA1 ChIP signature” reveals a significant enrichment in genes that function in cell cycle regulation and the response to DNA damage including “M phase”’ and “Mitotic checkpoint” terms, suggesting a specific role for BRCA1 in controlling mitotic events following genotoxic stress. We have validated multiple members of this BRCA1 ChIP signature including: BLM, FEN1, DDB2, H3F3B, BRCA2, CCNB2, MAD2L1, GADD153 and ATM. Further focused analysis reveals that BRCA1 occupancy at the ATM promoter increases its transcription and H2AX phosphorylation. Notably, following doxorubicin exposure, BRCA1 is released from the ATM promoter and redistributed to other genes like GADD153 where it induces expression, apoptosis and cell cycle arrest. RNAi depletion of GADD153 blocks BRCA1-dependent apoptosis and cell cycle arrest in response to doxorubicin, suggesting that GADD153 is required for BRCA1 mediated drug sensitivity. These findings define a novel mechanism through which BRCA1 influences cell fate decisions in response to genotoxic insult through direct transcriptional control of genes, including GADD153 and ATM. Thus, tumors with absent or reduced expression of BRCA1 are likely to show a marked resistance to chemotherapy for prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2160. doi:10.1158/1538-7445.AM2011-2160
Abstract 2175: Role of p38 MAPK in regulating Cripto-1 expression and signaling in human embryonal carcinoma cells
Authors: Held Natalie , Rangel Cristina , Castro Nadia , Gonzales Monica , Nagaoka Tadahiro , Karasawa Hideaki , Salomon David S. , Bianco Caterina
Published: June 2012

Cripto-1 (CR-1) is a cell-membrane protein that is overexpressed in several different types of human carcinomas. We have previously shown that TGFβ1 and Activins can enhance CR-1 expression while BMP2 and BMP4 can inhibit CR-1 expression in NTERA-2 embryonal carcinoma cells and in LS174T colon cancer cells. Nevertheless, there is still a very incomplete picture as to the nature of the epigenetic, transcriptional and hormonal factors that might be involved in regulating Cripto-1 expression under different conditions. Previous studies have demonstrated that activation of p38 MAPK can regulate expression of Nodal, a Cripto-1 ligand, during early embryogenesis and is necessary for the specification of mouse cardiomyocytes from embryonic stem cells, which depends upon a Nodal-dependent signaling pathway involving Cripto-1. We therefore evaluated if activation of p38 MAPK might be involved in regulating Cripto-1 expression and Cripto-1 dependent signaling in human embryonal carcinoma cells. In undifferentiated NTERA-2 and NCCIT embryonal carcinoma cells two p38 MAPK inhibitors PD169316 and SB20358 completely inhibited the basal levels of CR-1 mRNA and protein expression in both cell lines. A JNK inhibitor SP600125 had only minor effects on CR-1 mRNA and protein expression whereas the p44/42 MAPK inhibitor U0126 showed no effect. Transfection of specific siRNA against p38 MAPK was also able to significantly interfere with CR-1 mRNA and protein expression in NTERA2 and NCCIT embryonal carcinoma cells. In contrast, knockdown of p44/42 MAPK or JNK with specific siRNA did not significantly affect CR-1 expression in embryonal carcinoma cells. We therefore evaluated whether CR-1 might trigger activation of p38 MAPK in embryonal carcinoma cells and in mouse mammary epithelial cells. Recombinant CR-1 protein was found to stimulate in a delayed fashion (after 50-60 minutes) p38 MAPK phosphorylation in mouse mammary epithelial cells and in embryonal carcinoma cells suggesting a feed-forward activation loop. Whether p38 MAPK functions in undifferentiated embryonal carcinoma cells to regulate CR-1 expression and/or signaling involving regulation of invasion, migration and epithelial to mesenchymal transition in human embryonal carcinoma cells and in mouse mammary epithelial cells is under investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2175. doi:10.1158/1538-7445.AM2011-2175
Abstract 2182: IGFBP-6 in nasopharyngeal carcinoma is a candidate tumor suppressor gene by regulating the expression of EGR-1
Authors: Kuo Yuan-Sung , Lin Chin-Tarng , Wu Han-Chung
Published: June 2012

Nasopharyngeal carcinoma (NPC) is one of the common cancers in South-Eastern Asia, particularly southern China, Singapore and Taiwan. It has been proposed to be closely associated with Epstein-Barr virus (EBV), but other researches also show that EBV can enhance the NPC proliferation but not related with initiation or promotion of NPC carcinogenesis. The aim of this study was to identify the pivotal genes that may be altered during NPC progression. Using cDNA microarray analysis, we compared the expression of 18 genes between NPC and normal nasomucosal cells. Q-RT-PCR analysis found the expression of IBFBP-6 in NPC cell lines and immunolocalization of IGFBP-6 in NPC cells and biopsy specimens to be very weak. To explore the effects of IGFBP-6 on NPC tumor growth, we constructed inducible plasmids containing full-length IGFBP-6 cDNA (pBIG2i-IGFBP-6) and established pBIG2i-IGFBP-6-transfected NPC stable cell lines (NPC-TW01-pBIG2i-IGFBP-6). We then performed in vitro and in vivo functional analysis of the IGFBP-6 in these cell lines. Over-expression of IGFBP-6 significantly suppressed the proliferation, invasion and metastatic activity of NPC cells and increased their apoptosis. We found the EGR-1, caspase-1 and TSP-1 genes to be markedly up-regulated when NPC-TW01-pBIG2i-IGFBP-6 was treated with doxycycline. Knocking down EGR-1 with EGR-1 siRNA resulted in a decrease in expression of caspase-1, TSP-1 and EGR-1 but not the expression of IGFBP-6. However, in knockdown cells the unchanged expression of IGFBP-6 did not inhibit the migration of NPC cells. Chromatin immunoprecipitation and luciferase reporter assay experiments showed that IGFBP-6 bound the EGR-1 promoter regions and activated EGR-1 promoter. We conclude that IGFBP-6 can regulate the progression of NPC by regulating the expression of EGR-1. These results suggest that IGFBP-6 could be used as a new target for NPC therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2182. doi:10.1158/1538-7445.AM2011-2182
Abstract 2185: DLEU7 is a putative tumor suppressor in glioblastoma
Authors: Efanov Alexey A. , Palamarchuk Alexey , Zanesi Nicola , Nazaryan Natalia , Croce Carlo M. , Pekarsky Yuri
Published: June 2012

DLEU7 was first identified as a tumor suppressor in B-CLL. We previously showed that Dleu7 functions as a potent NF-kappaB and NFAT inhibitor. To investigate possible function of Dleu7 in brain tumorigenesis we carried out the real-time PCR of RNAs isolated from different parts of human brain, brain tumors and brain tumor cell lines and found that expression of DLEU7 significantly decreased in brain tumor cell lines and brain tumors (glioblastoma) in comparison with normal brain tissues. We further investigated the effect of DLEU7 expression in HTB-15 glioblastoma cell line. Our results showed that Dleu7 overexpression resulted in apoptosis and cell cycle halt. In addition, adenovirus-mediated DLEU7 expression resulted in 100 percent increase of caspase 3/7 activation compared to AdenoGFP control in HTB-15 cells. Our data indicate that DLEU7 may play a tumor suppressor role in glioblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2185. doi:10.1158/1538-7445.AM2011-2185
Abstract 235: Beyond KRAS mutation status: Influence of KRAS copy number alteration and microRNAs in response to cetuximab in metastatic colorectal cancer patients
Authors: Mekenkamp Leonie J.M , Tol Jolien , Dijkstra Jeroen , De Krijger Inge , Vink-Borger M Elisa , Teerenstra Steven , Verwiel Eugene , Koopman Miriam , Meijer Gerrit A. , van Krieken J. Han J.M. , Kuiper Roland , Punt Cornelis J.A. , Nagtegaal Iris D.
Published: June 2012

Introduction: KRAS mutation is a negative predictive factor for treatment with anti-epidermal growth factor receptor (EGFR) antibodies in metastatic colorectal cancer (mCRC). Novel predictive markers are required to further improve the selection of patients for this treatment. We assessed the influence of modification of KRAS by gene copy number aberration (CNA) and microRNAs (miRNAs) in correlation to clinical outcome in mCRC patients treated with cetuximab in combination with chemotherapy and bevacizumab.

Patients and methods: Formalin-fixed paraffin-embedded primary tumor tissue was used of 34 mCRC patients from a phase III trial (CAIRO2), who were selected based upon their good (n=17) and poor (n=17) progression-free survival (PFS) upon treatment with cetuximab in combination with capecitabine, oxaliplatin, and bevacizumab. Gene CNA at the KRAS locus was assessed using a high resolution genome-wide array CGH and the expression levels of 17 miRNAs targeting KRAS were determined by real-time PCR.

Results: Copy number loss of the KRAS locus was observed in the tumor of 5 patients who were all good responders including patients with a KRAS mutation. Copy number gains in two wild type-KRAS tumors were associated with a poor PFS. Increased expression of several miRNAs (presented at the meeting) targeting KRAS correlated with PFS of patients treated with cetuximab, bevacizumab and chemotherapy.

Conclusion: Our results indicate that the assessment of KRAS CNA and miRNAs targeting KRAS further optimize the selection of mCRC eligible for anti-EGFR therapy, in addition to KRAS mutation status.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 235. doi:10.1158/1538-7445.AM2011-235
Abstract 2385: Activated Kras and INK4a/Arf deficiency cooperate to produce pancreatic cancer involved with Notch and NF-κB pathways
Authors: Wang Zhiwei , Banerjee Sanjeev , Ahmad Aamir , Azmi Asfar S. , Bao Bin , Ali Shadan , Mohammad Ramzi M. , Miele Lucio , Korc Murray , Sarkar Fazlul H.
Published: June 2012

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the United States. Therefore, novel strategies for the prevention and treatment are urgently needed. Kras mutations are observed in 80%-90% of pancreatic cancer. Oncogenic Kras is involved with the initiation or early phase of PDAC. To understand the molecular mechanisms, several mouse models of PDAC have been generated by targeting a conditionally mutated KrasG12D to recapitulate the progression of PDAC. It was previously shown that one mouse model which activated Kras and Ink4a/Arf deficiency cooperate to produce metastatic PDAC. However, the molecular mechanism(s) by which Kras and Ink4a/Arf deficiency contribute to PDAC has not been fully elucidated. Here, we assessed the molecular alterations in mice which are activated Kras and Ink4a/Arf deficiency. For the first time, we demonstrated that deletion of Ink4a/Arf in Kras expressing mice leads to PDAC partly through Notch and NF-κB signaling pathways. Moreover, we show that several miRNAs, such as miR-200 family and miR-34 could partially play roles in tumorigenesis in activated Kras and Ink4a/Arf deficiency mice.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2385. doi:10.1158/1538-7445.AM2011-2385
Abstract 2457: Nestin regulates pancreatic cancer stem cell functions
Authors: Matsuda Yoko , Yamahatsu Kazuya , Kawahara Kiyoko , Suzuki Taeko , Fujii Takenori , Yamamoto Tetsushi , Korc Murray , Naito Zenya , Ishiwata Toshiyuki
Published: June 2012

Background: Nestin, a class VI intermediate filament protein, was originally described as a neuronal stem cell/progenitor cell marker. Nestin expression has also been shown to be up-regulated in progenitor cells in muscle, testis, teeth and pancreas. In the pancreas, lineage-tracing experiments have indicated that exocrine cells are derived from Nestin-expressing progenitor cells. Moreover, activation of K-ras in the nestin cell lineage is sufficient for the initiation of premalignant pancreatic intraepithelial neoplasia lesions in mice. To examine cancer stem cell (CSC) functions, floating cultures in plates with a low-attachment surface have been widely employed. CSCs are reported to be able to grow in floating spheres in serum-free culture medium supplemented with epidermal growth factor (EGF) and/or fibroblast growth factor-2 (FGF-2), whereas non-CSCs, more differentiated non-CSCs cannot form spheres. In this study, we examined nestin expression in spheres and clarified whether nestin regulates sphere forming activity. Methods: Human pancreatic ductal adenocarcinoma (PDAC) cell lines, PANC-1, KLM-1, MIAPaCa-2 and PK-45H were used to perform sphere-forming assay in ultra-low attachment plates supplemented with EGF and FGF-2. Expression of CSC markers including CD133, CD44, CD24, epithelial specific antigen (ESA), and nestin in spheres were determined by real time RT-PCR and immunocytochemistry. Sphere-forming cells were dispersed with trypsin, and then cell growth and migration were assessed. Next, short hairpin RNA (shRNA) targeting nestin was stably transfected into PANC-1 and PK-45H, human PDAC cells, which express high levels of nestin, in order to assess the effects of decreased nestin expression on sphere-forming ability. Conversely, KLM-1 cells which express low level of nestin were stably transfected with a nestin expression vector and their sphere forming ability was then determined. Results: All the PDAC cell lines formed spheres, and all CSC markers examined were expressed in the spheres. The sphere cells showed low cell growth rates and increased cell migration as compared to non-sphere cells. Expression levels of nestin in the spheres of PDAC cells were higher than those of non-sphere cells. Nestin shRNA transfected PANC-1 and PK-45H cells showed a marked decrease in sphere number and diameter. By contrast, nestin-gene-transfected KLM-1 cells exhibited increased sphere formation. Conclusion: Nestin is a pancreatic CSC marker that promotes the sphere-forming ability of CSCs. Therefore, nestin may represent a novel therapeutic target for CSCs in PDAC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2457. doi:10.1158/1538-7445.AM2011-2457
Abstract 2500: Radiosensitizing effects of neem leaf extract in human neuroblastoma xenograft is through modulation of apoptotic pathway
Authors: Veeraraghavan Jamunarani , Aravindan Sheeja , Natarajan Mohan , Awasthi Vibhudutta , Herman Terence S. , Aravindan Natarajan
Published: June 2012

Induction of apoptosis is directly correlated with the biological effectiveness of radiation (IR). Recently we have shown in neuroblastoma (NB) cells that IR modulates apoptotic signaling cascade and further demonstrated that fractionation relatively impede IR-induced cell death. It is therefore important to identify bioactive compounds that enhance IR-induced cell death and potentiate the use of radiotherapy in NB patients. In this study, we investigated the efficacy of neem leaf extract (NLE) on IR-associated apoptotic transcriptional modulation and cell death. NB xenografts developed in athymic NCr-nu/nu nude mice with human SK-N-MC cells were exposed to SDR (10Gy) or FIR (2Gy/Day for 5days) with or without NLE. IR exposures were limited to the tumor in flank region, while rest of the animal was protected by a specially designed cerrobend shield. Transcriptional activation of 84 apoptotic pathway focused genes was assessed using QPCR profiling. Cell death was measured using TdT nick end labeling. The results revealed that FIR significantly induced 55 genes and suppressed 10 genes, while SDR induced 49 and suppressed 5 genes. Of these, 46 genes were upregulated and 4 genes were downregulated after FIR and SDR, respectively. NLE inhibited 14 FIR-induced and 15 SDR-induced genes in human NB xenograft. To that end, NLE significantly inhibits anti-apoptotic NAIP, Birc6, Birc8, NOL3 after both SDR and FIR. Conversely, NLE significantly enhanced FIR- and SDR-induced pro-apoptotic BAK1, BAX, BCL10, Casp1, Casp10 CARD8 and CRADD in this setting. Furthermore, compared to mock-IR, DNA fragmentation analysis revealed that FIR and SDR significantly increased cell death. More importantly, NLE robustly and significantly conferred FIR- and SDR-induced cell death. Together, these data imply that NLE may exert radiosensitization mutually by activating pro-apoptotic signaling and negating survival signaling and, may thus serve as a potential “deliverable” to further potentiate radiotherapy in mitigating NB progression and relapse.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2500. doi:10.1158/1538-7445.AM2011-2500
Abstract 2585: Snail-p53 interaction inhibitor GN25 and its combination with Oxaliplatin targets both hedgehog signaling and K-ras pathway in pancreatic cancer
Authors: Azmi Asfar S. , Park Bum-Joon , Mohammad Ramzi M.
Published: June 2012

Activation of hedgehog (Hh) signaling is widely observed in human cancers including pancreatic cancer (PC). Similarly, mutations in K-Ras gene is found in >80% of PC. Constitutive activation of Hh signaling component Gli in turn enhances p53 suppressor Snail. Studies from our group have revealed that p53 is further suppressed by direct binding with oncogenic K-Ras-induced Snail. Therefore in order to target combined suppressive effects of Hh signaling and K-Ras-induced snail on p53 pathway, a specific inhibitor of the p53-Snail binding (GN25) was developed. This inhibitor can induce p53 expression and functions in K-Ras-mutated cells, with no toxicity to normal cells (Oncogene 2010). Here we show that GN25 when combined with Oxaliplatin induces synergistically (combination index CI<1) enhanced growth inhibition (MTT) and apoptosis (Histone DNA ELISA and Annexin V FITC) in multiple PC cell lines (AsPC-1, Capan-2, BxPC-3 and Colo-357) irrespective of the mutational or functional status of both p53 and K-Ras. Interestingly, we found that some of the above cell lines have hyper activation of Hh signaling that results in constitutively over activation of Gli. Western blot analysis demonstrated that GN25/oxaliplatin re-activated the p53 protein and downstream effector molecules such as pro-apoptotic Bax and cell cycle regulator p21. Further analysis showed that GN25/oxalipltin interferes with the Hh signaling and suppresses Snail. In SCID mice studies in vivo, the maximum tolerated dose of GN25 was found to be 35 mg/kg i.v. In addition, it can be given in combination with oxaliplatin at 5 mg/kg i.p twice a week for two weeks. The combination studies of GN25/oxaliplatin in multiple tumor xenografts (wt-k-Ras BxPC-3 and AsPC-1 mut-p53 k-Ras) are ongoing. So far our results suggest that GN25/oxaliplatin is a strong combination against hyper activated Hh and mutant K-Ras-initiated human pancreatic cancer irrespective of mutational status of p53.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2585. doi:10.1158/1538-7445.AM2011-2585