bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5577: The role of age-related enhancements of IL-17 in prostate cancer initiation and progression
Authors: De Angulo Alejandra , Faris Robert , Cavazos David , Jolly Christopher , deGraffenried Linda A.
Published: June 2012

Background: Age is the single greatest risk factor for prostate cancer development. As men pass age 40, their chance of developing prostate cancer increases exponentially each year. The mechanism by which age influences the risk of prostate cancer remains largely unknown, hindering the development of effective preventive approaches. While local events are known to contribute to age-related prostate tumorigenesis, the role of the aging immune system in prostate cancer development has been largely understudied. The aging process affects the adaptive cell-mediated immune response and at the same time there is a shift to a more inflammatory cytokine profile. Recent studies have shown that age-related enhancements of Th17 might contribute to changes in immune function and prostate cancer development. The age-related shift in T-lymphocyte cytokine profile and the enhancement of TH17 generation might be significant contributing factors to the association between age and prostate tumorigenesis.

Methods: For our studies we have been using a unique animal model, the glycerol-3-phosphate acyltransferase-1 (GPAT-1) knock out mouse. The GPAT-1 KO young mouse T lymphocyte phenotype mimics old (> 18 m) wild type mice. Preliminary data suggested that cytokines secreted from the GPAT-KO aging mimic T-lymphocytes can promote activation of the STAT3/NF-kB pathways. In order to test if IL-17 was responsible for the strong induction of NF-kB and STAT3, we repeated previous experiments that measured the activation of NF-kB and STAT3, but supplemented the experimental sera and conditioned media with depleting antibodies to IL-17. Successful inhibition of the NF-kB and STAT3 pathways was assessed by Western Blot analysis.

Conclusions: Depleting IL-17 in the GPAT-1 KO sera and conditioned media decreased NF-kB activity to the levels of the cells treated with wild-type sera. Sera from the old and GPAT-1 KO mice induced activation of downstream targets of IL-17. These results suggest that circulating factors from the GPAT-1 KO mice mimic those in aging mice and strongly induced signaling pathways involve in the development of prostate cancer. The age-related enhancements of IL-17 may play a key role in prostate cancer initiation and progression.

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 5577. doi:10.1158/1538-7445.AM2011-5577
Abstract 5579: Selenomethionine does not protect against testosterone plus 17 beta-estradiol-induced prostate carcinogenesis and prostatic oxidative stress in NBL rats
Authors: Ozten Nur , Schlicht Michael J. , Bosland Maarten C.
Published: June 2012

Previous studies with selenium and/or vitamin E in prostate carcinogenesis animal models have been negative, but these models may not involve oxidative stress mechanisms. Selenium and vitamin E have been the subject of one of the largest trials ever conducted, SELECT, which was discontinued because there was no difference between the study arms and there were side effects, including an increased chance of developing diabetes mellitus with the use of selenium. We previously found that selenomethionine supplementation did not prevent prostate cancer in NBL rats treated with testosterone plus 17 beta-estradiol (T+E2), a model that does involve sex-hormone induced oxidative stress mechanisms and prostatic inflammation; this result was fully predictive of the outcome of the SELECT trial. Based on the outcomes of SELECT and our NBL rat study, we hypothesized that selenium has no protective effect against T+E2-induced prostate cancer development because it does not protect against oxidative stress. In the present study, we examined the potential of selenomethionine to modulate prostatic oxidative stress and induction of dysplasia and inflammation in the T+E2-treated NBL rat. Nbl/Crl rats were treated for 16 weeks with T+E2 by Silastic implants and were fed a natural ingredient control diet (NIH-07) with or with L-selenomethionine at a concentration of 1.5 or 3.0 mg/kg (as selenium). These diets were initiated one week post hormone implantation. T+E2 significantly increased immunohistochemical staining for 8-hydroxy-deoxyguanosine (8-OHdG) in prostatic ducts, and in the lateral and dorsal prostate which are the main sites of T+E2-induced inflammation and preneoplasia after 16 weeks of hormone treatment, and in the seminal vesicles. However, selenomethionine did not reduce these effects and did not, by itself, change 8OHdG staining. There was a lobe-specific differential response and modulation of antioxidant enzymes. Glutathione peroxidase activity and protein expression level of manganese superoxide dismutase were induced by T+E2, which effects were counteracted by selenomethionine in the dorsolateral prostate, which is the main site of T+E2-induced inflammation and preneoplasia occurring after 16 weeks of hormone treatment. However, selenomethionine did not influence the induction by T+E2 of marked inflammation and dysplasia in the lateral prostate. These findings partially explain the negative outcome of our previous NBL rat study and is consistent with the negative results of the SELECT trial. (Supported in part by Grant No. CA104334)

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 5579. doi:10.1158/1538-7445.AM2011-5579
Abstract 5583: Differential effect of phenethyl isothiocyanate on expression of antioxidant defense genes between normal and cancerous human prostate cells
Authors: Singh Shivendra V. , Powolny Anna A.
Published: June 2012

Phenethyl isothiocyanate (PEITC) is a promising cancer chemopreventive constituent of cruciferous vegetables (e.g., watercress) as evidenced by efficacy against chemically-induced cancer in experimental rodents. The PEITC is also empowered to inhibit growth of cultured and xenografted human prostate cancer cells, which correlates with apoptotic and autophagic cell death. We have shown previously that reactive oxygen species (ROS) play a critical role in proapoptotic signal transduction by PEITC in human prostate cancer cells. Interestingly, a representative normal human prostate epithelial cell line (PrEC) is significantly more resistant to PEITC-induced apoptosis compared with cancerous prostate cells including PC-3 and LNCaP. However, the mechanism behind this differential response remains elusive. The present study was undertaken to test a hypothesis that differential sensitivity of normal versus cancerous human prostate cells to PEITC-mediated proapoptotic response is determined by differences in ROS production and/or basal or inducible expression of antioxidant defense genes. The PEITC treatment resulted in ROS production in PC-3 human prostate cancer cells as judged by flow cytometry and fluorescence microscopy using a chemical probe (MItoSOX Red) and EPR using a cell permeable sin probe (1-hydroxy-3-methoxy-carbonyl-2,2,5,5-tetramethylpyrrolidine). These effects were not observed in PrEC cells similarly treated with the PEITC. Basal antioxidant defense gene expression signature was strikingly different between PC-3 and PrEC cells. Moreover, PEITC treatment (2.5 μM, 6 h) caused up-regulation of 29 genes and down-regulation of 2 genes in PC-3 cells. Conversely only 4 genes were up-regulated and 10 genes were down-regulated by a similar PEITC treatment in the PrEC cell line. The results of the present study clearly indicate that differential sensitivity of PC-3 versus PrEC cells to proapoptotic effect of PEITC is likely attributable to both differences in ROS production and basal as well as altered expression of antioxidant defense genes. This investigation was supported by the USPHS grant CA101753-07, awarded by the National Cancer Institute.

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 5583. doi:10.1158/1538-7445.AM2011-5583
Abstract 5590: Role of estrogen receptor-beta in colitis-associated cancer
Authors: Saleiro Diana , Murillo Genoveva , Mutreja Karun , Hawthorne Michael , Mehta Rajendra G.
Published: June 2012

Inflammatory bowel disease has been strongly correlated with colitis-associated cancer (CAC) cases, a subtype of colorectal cancer. Previously, we demonstrated that estrogen receptor-beta (ERβ) exerted protective effects against the development of colonic precancerous lesions in the azoxymethane-induced spontaneous colon cancer in vivo model. In the present study, we investigated whether ERβ could also be protective against CAC. Estrogen receptor-β knockout (βERKO) and wild type (WT) mice were exposed to azoxymethane, followed by dextran sodium sulfate (DSS) treatment. Three days after the DSS treatment two βERKO mice died, suggesting that these mice might be more susceptible to inflammatory inducers than WT mice. Furthermore, six weeks after DSS exposure five mice from each group were sacrificed and morphology and RNA analyses of inflammation markers were performed. All βERKO mice presented polyp-like structures in the colon (3.60 ± 0.81) and greater number of cellular infiltration areas (9.00 ± 1.50), whereas only two WT mice presented polyp-like structures (2.40 ± 1.47) and fewer number of cellular infiltration areas (4.00 ± 2.02). βERKO mice showed 9.8 and 5.6 fold increase in mRNA expression of inducible-nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α), respectively, when compared to WT mice. In both βERKO and WT mice a 2.1 fold increase in cyclooxygenase-2 (COX-2) mRNA expression was observed compared to the respective negative control groups. All together these results suggest that ERβ might be protective against CAC. These data will be compared to the group of mice that will be sacrificed 15 weeks post DSS 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 5590. doi:10.1158/1538-7445.AM2011-5590
Abstract 5592: Lack of association between AGTR1 (A168G and T825A) and ACE T5529C polymorphisms with breast cancer among Brazilian women
Authors: Correa-Noronha Silvana A Alves , Ribeiro de Noronha Samuel M. , Geraldo Murilo V. , Carvalho Cristina V. , Linhares Jose J. , Silva Fabricio Colacino , Costa Ana Maria M. , Siufi Adalberto A. , Kimura Edna T. , Shimuta Suma I. , Nakaie Clovis R. , da Silva Ismael D.C.G.
Published: June 2012

Background: Angiotensin II (AngII) exerts promitotic, pro-proliferative and angiogenic effects and the administration of angiotensin I-converting enzyme (ACE) inhibitors reduces tumor growth in animal models of cancer. AngII type 1 receptor (AGTR1) is found in a wide variety of normal tissues, increased expression is often found in the corresponding neoplastic tissues, suggesting that its overexpression is involved in carcinogenesis. In a previous study we observed that the ID genotype might be protective against breast cancer and also that the ACE (I/D) polymorphism is a possible target for developing genetic markers for breast cancer. Other authors have also observed the association of the ACE with breast cancer risk. To further test the hypothesis that AngII participates in breast carcinogenesis through AGTR1 and ACE, we examined genetic polymorphisms in the 5’-region of the AGTR1 gene (A-168G and T-825A) and in the ACE (T5529C) in relation to risk of breast cancer among Brazilian women. Methods: Genotyping was performed through Real Time PCR (A168G and T825A) or PCR-RFLP (T5529C) using genomic DNA extracted from buccal cells of subjects with or without breast cancer.Results: Patients with (case) or without (control) breast cancer aging from 30 to 90 years old were genotyped for A168G (n=516), and the following frequencies obtained for AA, AG and GG in % were, among cases: 63, 30, 07 and among controls: 64, 32, 04 (p = 0.89). For T825A (n=562), we determined the frequency of TT, TA and AA (in %, cases: 62, 33, 05; controls: 59, 33, 08; p = 0.68). At last, for ACE (T5529C) (n=272) these are the obtained frequencies for TT, TC and CC genotypes in %, among cases: 65, 23, 12 and among controls: 55, 29, 15 (p = 0.39).

Conclusion: Our results suggest a lack of significant association between AGTR1 polymorphisms (A168G and T825A) with breast cancer risk in the Brazilian population, in contrast to a previous result among Chinese women, where an association of the AGTR1 polymorphisms with breast cancer has been reported. Regarding the ACE T5529C polymorphism, it also did not show any association with breast cancer risk in the present study, differently from the observed for another polymorphism of the same gene, the ACE (I/D). Therefore, the AGTR1 (A168G and T825A) and ACE (T5529C) variant genotypes do not appear to be related to risk of breast cancer among Brazilian women. Support: FAPESP.

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 5592. doi:10.1158/1538-7445.AM2011-5592
Abstract 5597: Evaluation of functional genetic variants for breast cancer risk: Results from the Shanghai Breast Cancer Study
Authors: Zhang Ben , Beeghly-Fadiel Alicia , Zheng Wei
Published: June 2012

In previous studies among 1,144 cases and 1,256 controls recruited in the Stage I Shanghai Breast Cancer Study (SBCS-I), 18 known or potentially functional single nucleotide polymorphisms (SNPs) in 16 genes were found to be associated with breast cancer risk. The authors evaluated these associations among 1,918 cases and 1,819 controls recruited in the Stage II SBCS (SBCS-II) using genetic effect models and subgroup analyses pre-determined from SBCS-I results. Five SNPs showed generally consistent results in SBCS-I and SBCS-II and statistically significant associations with breast cancer risk in combined analyses (AHR rs2066853, ATM rs1003623, ESR1 rs2234693, GSTP1 rs1695, and SHBG rs6259), mostly in subgroups defined by age or menopausal status. Further, the relation between breast cancer risk and SHBG rs6259 was found to vary by body mass index (BMI) (P-value for interaction = 0.003). The strongest reduction in risk associated with SHBG rs6259 was found for postmenopausal lean (BMI<23) minor allele carriers (Odds Ratio=0.6; 95% Confidence Interval: 0.5, 0.8; P-value = 4.6×10−4). This biologically plausible and highly significant finding provides strong evidence for a true association among Asian women. This study also highlights the value of gene-environment interaction analyses in evaluating genetic factors for complex diseases.

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio; SBCS, Shanghai Breast Cancer Study; SNP, single nucleotide polymorphism.

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 5597. doi:10.1158/1538-7445.AM2011-5597
Abstract 5609: Characteristics of triple-negative breast cancer in patients with a BRCA1 mutation, results from a population-based study of young women
Authors: Lee Eunjung , McKean-Cowdin Roberta , Ma Huiyan , Spicer Darcy , Berg David Van Den , Bernstein Leslie , Ursin Giske
Published: June 2012

BACKGROUND: Triple-negative breast cancers (TNBC) are tumors with low or no expression of estrogen receptor, progesterone receptor, or human epidermal growth factor receptor-2. These tumors have a poor prognosis, remain a clinical challenge, and are more common among women with BRCA1 mutations. We tested whether there are distinguishing features of TNBC after BRCA1 mutation status has been taken into account. METHODS: We sequenced BRCA1/2 genes in a population-based sample of 1,469 incident breast cancer patients aged 20-49 years from Los Angeles County. Information on tumor receptor status was available for 1,167 women. Clinical, pathologic and hormone-related lifestyle characteristics were compared across patient subgroups defined by BRCA1-mutation status and triple-negative receptor status. RESULTS: Forty-eight percent of BRCA1 mutation carriers had TNBC in contrast with only 12% of non-carriers. Within BRCA1 mutation carriers, as well as within non-carriers, triple-negative receptor status was associated with younger age at diagnosis and higher tumor grade. Among women without a BRCA1 mutation we observed that women with TNBC had higher premenopausal body mass index and earlier age at first full-term pregnancy than those with non-TNBC. Age at menarche and other reproductive factors were not associated with triple-negative status regardless of BRCA1 mutation status. Within BRCA1 mutation carriers, Ashkenazi Jewish women were about 5 times more likely to have TNBC than non-Ashkenazi Jewish women. CONCLUSIONS: Our results suggest that among BRCA1 mutation carriers, as among non-carriers, there are unique characteristics associated with the triple-negative subtype. The finding in Ashkenazi Jewish BRCA1 mutation carriers should be confirmed.

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 5609. doi:10.1158/1538-7445.AM2011-5609
Abstract 564: Resistant to Erlotinib, epidermal growth factor receptor tyrosine kinase inhibitor, is involved in epithelial to mesenchymal transition, cell migration and inflammation in A549, a non-small cell lung cancer cell line
Authors: Yang Seok-Chul , Lee Kyu-Hwa , Lee Sang-Min , Yim Jae-Jun , Yoo Chul-Gyu , Han Sung Koo , Kim Young Whan
Published: June 2012

Background: In recent years, a number of novel agents have been investigated that target specific molecular pathways in non-small cell lung cancer (NSCLC). A great deal of effort has been focused on identifying specific markers that predict treatment response. The epidermal growth factor receptor (EGFR) pathway has emerged as a key regulator of cancer cell proliferation and invasion, and several specific EGFR inhibitors have been examined. Erlotinib, a selective EGFR tyrosine kinase inhibitor (EGFR-TKI) is clinically used to treat patients with NSCLC. In this study, we investigated the mechanisms for the drug-resistance of Erlotinib and the cytotoxic effects in NSCLC cell lines treated with Erlotinib.

Methods: In this study, we established an Erlotinib resistant subline (A549/ER) from parental A549 cell line. MTT assay and western blot analysis were used to measure the cell sensitivity to drugs. A549 and A549/ER cells were grown in chamber slide and stained with H&E to observe the cell morphology. The migration ability of A549 and A549/ ER cells was evaluated by transwell experiment. In addition, cDNA microarray was used to analyze gene expression patterns in transcript level, and secretory cytokine patterns were evaluated with multiplex enzyme-linked immunosorbent assay (ELISA) from A549 and A549/ER cell lines.

Results: In the EGFR-TKI-resistant cell line A549/ER, cell growth inhibition by Erlotinib was only mild, and the phosphorylation of this leading target such as EGFR was not inhibited. Phenotypic changes such as a spindle-cell shape and increased pseudopodia formation suggesting epithelial to mesenchymal transition (EMT) was found in A549/ER cells. These changes were accompanied by decreased expression of E-cadherin (ECAD) and cytokeratin-8, which are mesenchymal transition markers. Moreover, the ability of migration was increased in A549/ER cells. Different pattern of gene expression in cDNA microarray reflects changes during resistant progression in A549 cells. In experiment using multiplex ELISA, the secretory cytokines including vascular endothelial growth factor (VEGF), interleukin-6, interleukin-8 known to contribute to pathological inflammation were increased in the medium of A549/ER compared to that of A549 cells.

Conclusions: These results suggest that the mechanism of upstream receptor tyrosine kinase inhibitor, Erlotinib, resistance may be related with EMT, cell migration and inflammation in NSCLC.

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 564. doi:10.1158/1538-7445.AM2011-564
Abstract 573: Ionizing radiation activates IFN signaling in tumor cells
Authors: Khodarev Nikolai , Pitroda Sean , Sood Ravi , Khan Sajid , Filippo Matthew , Gutt Ruchika , Perakis Samantha , Darga Thomas , Malik Renuka , Pederson Aaron , Weichselbaum Ralph
Published: June 2012

Ionizing radiation (IR) uses multiple pathways to mediate killing in tumor cells. We found that fractionated irradiation leads to the constitutive overexpression of Interferon Stimulated Genes (ISGs) which are controlled by Signal Transducer and Activator of Transcription 1 (Stat1). Stat1 mediated IFN signal transduction and at the same time was involved in the production of Type I and Type II IFNs. IR-induced ISGs represent the following groups: 1) mitochondrial-related genes with pro- and anti-apoptotic functions, 2) cell cycle control and regulators of transcription, 3) protein modification and degradation, 4) cytoplasmic sensors of nucleic acids, and 5) anti-viral defense. Fractionated or single-dose IR induced the IFN pathway mediated by activation of Stat1 in breast, colon, prostate and head and neck tumor xenografts. Depletion of tumor-derived IFNs led to the suppression of IR response indicating that IFN production/signaling is a component of anti-tumor IR action. Cell-autonomous experiments indicated that tumor cells up-regulate Stat1 and ISGs and produce IFNα in response to single dose IR (3Gy). Up-regulated Stat1 in irradiated tumor cells was not phosphorylated at Tyr701 position compared to Stat1 activation following interferon stimulation. In a syngeneic tumor model of B16F1, IR-induced activation of IFN signaling in tumors (assessed both by up-regulation of the Stat1-dependent pathway and induction of Type I and Type II IFNs) was dependent on TNFα signaling in the host and was impaired in TNFR1,2-/- mice. We therefore conclude that IR induces IFN signaling in tumor cells as a component of the cytotoxic response. This interferon induction depends on TNFα signaling in host cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 573. doi:10.1158/1538-7445.AM2011-573
Abstract 59: Identification of RNA editing events in cancer using high-throughput sequencing data
Authors: Radenbaugh Amie , Sanborn John Z. , Zerbino Daniel , Wilks Chris , Stuart Joshua M. , Haussler David
Published: June 2012

RNA editing is a post-transcriptional modification of pre-mRNA that has recently been identified as an additional epigenetic mechanism relevant to cancer development and progression. With projects like The Cancer Genome Atlas (TCGA) providing high-throughput sequencing datasets measuring both DNA and RNA from the same patients across multiple cancers, it is now possible to search for RNA editing events at a genome-wide scale.

Using fully-sequenced tumor and matched-normal genomes and RNA-Seq data from TCGA project, we will identify RNA editing events in acute myeloid leukemia (AML) patients. We have analyzed the tumor and matched normal genomes to identify SNPs, mutations (both germline and somatic), and heterozygosity across the entire genome. By comparing the patient's genomic data to the RNA transcripts assembled by the UCSC RNA-Seq pipeline, we can identify any bases that were transcribed abnormally. All putative RNA editing events will be assessed according to the most common types of RNA editing, such as the deamination of adenosine into inosine (A-to-I) or the conversion of cytosine into uracil (C-to-U). Local phasing information inferred from the genomic sequence will be used to disambiguate potential RNA editing events found at heterozygous locations.

As a positive control, we will confirm RNA-editing events previously discovered experimentally in AML patients, such as an A-to-I conversion in the protein tyrosine phosphatase PTPN6 gene. The PTPN6 gene is recognized as a tumor suppressor gene and is important for the down-regulation of growth-promoting receptors. The A-to-I conversion of adenosine 7866 causes the splicing mechanism to ignore a splicing junction, leading to a non-functional PTPN6 protein via the inclusion of an intron in the mature RNA transcript. Using the TCGA sequencing data, we will identify all AML samples that exhibit this particular A-to-I conversion as well as the inclusion of the intron with the RNA-Seq data. In addition, we will report novel RNA editing events in AML and other cancer types and look for patterns that may be cancer specific or globally relevant to cancer development.

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 59. doi:10.1158/1538-7445.AM2011-59
Abstract 592: Novel IAP antagonist (822B) induces apoptosis through degradation of IAP proteins which have a BIR3 domain in human pancreatic cancer cells
Authors: Shin Jae Sik , Hong Seung-Woo , Jin Dong-Hoon , Bae In-Hwan , Kim Maeng-Sup , Na Young-Soon , Lee Jae-Lyun , Hong Yong Sang , Kim Tae-Won
Published: June 2012

Several companies recently began to develop inhibitor of apoptosis (IAP) antagonist ‘Smac/Diablo mimetic’ compounds for the treatment of cancer. IAP antagonist compounds (IACs) was, therefore, designated as being able to induce apoptosis through the inhibition of IAP proteins in cancer cells. In our study we demonstrated that the novel-in what sense is it synthetic IAP antagonist, 822B, induces apoptotic cell death through proteasomal-dependent degradation of the inhibitor of apoptosis proteins (IAPs) with a BIR3 domain. We first found that apoptotic cell death is induced by exposure of pancreatic cancer cells to 822B. This apoptotic effect increased after the knockdown of endogenous IAPs using RNA interference. Moreover, 822B-induced apoptosis results from degradation of the inhibitor of apoptosis proteins (IAPs). 822B was preferable to Samc/Diablo for binding to IAPs and it induced ubiquitination. However, we also found that degradation of XIAP is not induced in several pancreatic cancer cell types in response to 822B. Interestingly, resistance to 822B was related to phosphorylation at the ser-87 site of XIAP. This resistant effect was eliminated using the (or “an” if there's more than one . . .) XIAP mutant that was replaced with alanine at 87 amino acid site. AKT CA (constitutive active) mutant and wild type-AKT that can induce phosphorylation at the ser-87 site of XIAP also suppressed the resistant effect to 822B. In addition, mutation in the RING domain of XIAP was not observed. Mutation in the RING domain of XIAP cannot induce XIAP ubiquitination, thus suggesting that the level of phospho-XIAP and phospho-AKT may be used as an indicator for cancer therapy using 822B. These results suggest that a novel synthetic inhibitor of the apoptosis (IAP) antagonist induces apoptosis through ubiquitination of IAPs with a BIR3 domain.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 592. doi:10.1158/1538-7445.AM2011-592
Abstract 6: S1, a Bid-like BH3 mimetic, induces apoptosis by dynamic change of Mcl-1 and dependent on Bak, not Bax
Authors: Ting Song , Chao Zhang Zhi , Long Chang Xi
Published: June 2012

Mcl-1 is a unique anti-apoptotic member of Bcl-2 family. Its expression has been demonstrated to seriously impede the most authentic BH3 mimetic ABT-737-induced apoptosis in multiple cancer cell lines. S1, which has been previously identified as a pan-Bcl-2 inhibitor and pure BH3 mimetic by our group, was investigated here to challenge Mcl-1's protection. Cell viability assay and apoptosis assay showed S1 exhibits robust anticancer effectiveness in three selected ABT-737-resistant cancer cell lines, SMMC-7721, HCT116 and K562 cells. In contract with ABT-737, S1-induced apoptosis is regardless of the baseline of Mcl-1 expression. Interestingly, it dynamically modulates Mcl-1 through a combination of proteasome and caspase-mediated pathway and this dynamical change is associated well with the resistance, apoptosis onset, and apoptosis burst out induced by S1. To investigate how Mcl-1 dynamics is related with apoptosis at molecular level, we performed time-sequence and dose-dependent analysis of cell viability, western blot, and co-immunoprecipitation experiments. We found the trafficking of Bcl-2 family members determines Mcl-1 dynamical change and in turn apoptosis. First of all S1 untethers Bax and Bim from Bcl-2, but Bim shifts to Mcl-1 which stabilizes Mcl-1 and enforces the binding with Bak. Only when Bak is released by enough dose of S1 or enough exposure time is Mcl-1 downregualted to allow apoptosis occur. Using shRNA, we identified both S1-induced apoptosis and Mcl-1 dynamical modulation depend on Bak, not Bax. As such, much distinct function of Bax and Bak in the S1-induced pathway was illustrated. While Bax can be fully compensated for by Bak, Bak could be partly compensated for by Bax. Consistently, Bax-deficient DU145 cell is sensitive to S1, whereas Bak-mutant MKN-28 cells is much more resistant. NMR analyses revealed that S1 highly mimic tBid to target the BH3-binding pocket of Mcl-1. Cytochrome c release assay in purified DU145 mitochondrial testified a nicely structural-to-functional mimic of tBid, but not Bim. The Bid-like property is also consistent with its Bak-dependent apoptosis induction. The in vitro model could be extended to an in vivo mouse xenograft model that S1 induces apoptosis through Mcl-1 dynamical modulation and released Bak is the biomarker of apoptosis. In conclusion, S1 could be a highly potent therapeutic molecule for the treatment of Mcl-1-driven cancer cells with a mechanism-based model. Bak could serve as a biomarker to specify cancer cells sensitive to S1. In addition, the highly tBid/Mcl-1 binding mimic property could be used to probe the sophisticated network of Bcl-2 family.

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 6. doi:10.1158/1538-7445.AM2011-6
Abstract 601: Macitentan (ACT-064992), a tissue-targeting endothelin receptor antagonist enhances therapeutic efficacy of paclitaxel by modulating survival pathways in orthotopic models of metastatic human ovarian cancer
Authors: Kim Sun Jin , Kim Jang Seong , Kim Seung Wook , Brantley Emily C. , Yun Seok Joong , He Junqin , Marva Maya K. , Zhang Fahao , Wu Qiuyu , Lehembre Francois , Regenass Urs , Fidler Isaiah J.
Published: June 2012

Introduction: In 2009, ovarian cancer was the leading cause of death from gynecologic cancer in the United States. Efforts to develop tools for early detection and therapeutic regimens to overcome drug resistance of the ovarian cancer have not made a significant achievement to prolong the median survial of the patients. Potential treatments for ovarian cancers that have become resistant to standard chemotherapies include modulators of tumor cell survival, such as endothelin receptor (ETR) antagonist. We investigated the therapeutic efficacy of the dual ETR antagonist, macitentan, on human ovarian cancer cells, SKOV3ip1 and IGROV1, growing orthotopically in nude mice.

Materials and Methods: Mice were injected with one million cells of SKOV3ip1 or IGROV1. Ten days later, mice with established disease were randomized into vehicle (control), paclitaxel (weekly, intraperitoneal injections), macitentan (daily oral administrations) or a combination of paclitaxel and macitentan treatment groups. After 4 weeks of treatment, mice were necropsied and tumor incidence, tumor weight, and incidence of ascites were recorded. Tumor tissues were processed for immunohistochemical analyses.

Results: Treatment with paclitaxel decreased tumor weight and volume of ascites. Combination therapy with macitentan and paclitaxel reduced tumor incidence and further reduced tumor weight and volume of ascites when compared with paclitaxel alone. Macitentan alone occasionally reduced tumor weight but alone had no effect on tumor incidence or ascites. Immunohistochemical analyses revealed that treatment with macitentan and macitentan plus paclitaxel inhibited the phosphorylation of ETRs and suppressed the survival pathways of tumor cells by decreasing the levels of pVEGFR2, pAkt, and pMAPK. The dose of macitentan necessary for inhibition of phosphorylation correlated with the dose required to increase antitumor efficacy of paclitaxel.

Conclusion: Treatment with macitentan enhanced the cytotoxicity mediated by paclitaxel as measured by the degree of apoptosis in tumor cells and tumor-associated endothelial cells. Collectively, these results show that administration of macitentan in combination with paclitaxel prevents the progression of ovarian cancer in the peritoneal cavity of nude mice in part by inhibiting survival pathways of both tumor cells and tumor-associated endothelial cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 601. doi:10.1158/1538-7445.AM2011-601
Abstract 607: Restoration of p53 pathway signaling and apoptotic induction by prodigiosin and its structurally-related compound (NSC247562) in p53-deficient human colon carcinoma cells
Authors: Hong Bo , Chen Fang , Dicker David T. , El-Deiry Wafik S.
Published: June 2012

p53 deficiency occurs commonly in human tumors, and contributes to radio- and chemo-resistance as well as an aggressive phenotype. It is believed that specific restoration of p53 will be beneficial in the treatment of aggressive or resistant tumors. Using a p53 mutant cell line (SW480) stably integrated p53-responsive reporter, we sought to identify small molecules with p53 rescue activity by screening of the NCI drug library. We found prodigiosin and its structurally related compound (NSC247562) can activate p53-dependent transcriptional activity in SW480, DLD1 as well as HCT116 p53−/− colon tumor cells. The induction of p53-dependent transcriptional activity by prodigiosin and its related compound (NSC247562) is stronger than that induced by CP31398 or ellipticine, which were previously reported as p53 function-restoring drugs. Furthermore, prodigiosin and its related compound (NSC247562) are found to induce the expression of p53 target genes (p21, Puma, DR5 and DR4) in mutant-p53 containing or p53-null human colon cancer cells. The restoration of p53 transcriptional activity by prodigiosin and its related compound (NSC247562) is accompanied by apoptotic induction as indicated by an increase of sub-G1 population and PARP cleavage. More importantly, prodigiosin and its related compound (NSC247562) induced tumor cell death, but have little or no detectable cytotoxicity towards normal human fibroblasts. Thus prodigiosin and its related compound may serve as promising compounds for the development of anticancer drugs which rescue p53 activity and induce cell death.

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 607. doi:10.1158/1538-7445.AM2011-607
Abstract 628: Functional characterization of a diverse set of ERBB3 inhibitory antibodies
Authors: Vincent Sylvie , Weiler Solly , Fleet Christina , Bottega Steve , Prima Michael Di , Wang Fang , McIntosh Donna , Breault Lyne , Tyler Steven , Meetze Kristan , Winston William , Gyuris Jeno
Published: June 2012

One important manifestation of the plasticity of cancer is the rapid escape from the effect of anti-cancer agents following initial therapeutic response. ERBB3, a kinase inactive member of the epidermal growth factor (EGFR) receptor family, which also includes EGFR, HER-2 and ERBB-4, has been linked to the development of resistance to multiple cancer therapies. The reactivation of ERBB3 following treatments with EGFR or HER-2 inhibitors has been observed in multiple tumor types following initial responses. The reactivation of ERBB3 signaling is thought to be the consequence of the formation of kinase active heterodimers of ERBB3 with EGFR, HER-2 and c-Met. ERBB3 heterodimer formation is consequence of a conformational change in the ErbB3 ECD (extracellular domain) in response to increased presence of the ERBB3 ligand NRG (neuregulin) or increased membrane concentrations of ERBB3 partners or ERBB3 itself which is often due overexpression or increased membrane localization.

To understand the role of NRG dependent and independent ERBB3 activation mechanisms in the development of resistance to EGFR and/or HER-2 inhibitors, we set out to identify a diverse set of ERBB3 specific inhibitory monoclonal antibodies with different mechanisms of action. Immunizations with a mixture of tethered and opened ERBB3 ECD antigens allowed us to identify a large variety of potent ERBB3 inhibitors. Competition binding experiments have identified at least 5 independent binding sites for these antibodies on ERBB3. Some of these antibodies inhibited NRG binding (ligand neutralizers) while others did not interfere with ligand binding. Since a few of these antibodies bound to the dimerization domain (domain II) of ERBB3, we have inferred that they most likely inhibit the formation of ERBB3 heterodimers (dimerization inhibitors). In vivo activity of these antibodies was tested in tumor models driven by ligand independent and dependent activation of ERBB3 to identify the most promising candidate for the development of a highly potent ERBB3 therapeutic antibody with superior activity against both ligand dependent and independent ERBB3 heterodimers.

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 628. doi:10.1158/1538-7445.AM2011-628
Abstract 633: Target therapy of glioblastoma by gene transfer of a monovalent antibody against the MET oncogene
Authors: Pacchiana Giovanni , Chiriaco Cristina , Fontani Lara , Comoglio Paolo M. , Vigna Elisa
Published: June 2012

Glioblastoma multiforme is a severe brain tumor refractory to conventional radio-and chemotherapy. The tumor often relies on an autocrine-loop between HGF and its receptor, the product of the met oncogene. Recently we demonstrated that the monovalent form of the DN-30 anti-Met monoclonal antibody (MvDN-30), acting trough a mechanism of receptor shedding, is a potent Met inhibitor (Pacchiana et al., J Biol Chem. 2010; 285:36149-57). We now report its therapeutic effect on glioblastoma, delivering the MvDN-30 to U-87MG cells by mean of gene transfer through a Tet inducible lentiviral vector. Upon doxycicline (Dox) treatment U-87MG correctly express and secret MvDN-30, inhibiting Met receptor expression. Antibody gene transfer results in impairment of U-87MG invasive growth in vitro and tumorigenic properties in vivo. In a preclinical model of “prevention trial” nude mice transplanted with U87-MG were treated with Dox from the day of tumor cell injection. MvDN30 severely impaired tumor onset as, after 16 weeks of treatment, 80% of the mice were still tumor free. Dox treatment was then removed and after 12 weeks mice didn't develop tumors, indicating that MvDN-30 treatment was curative. In a preclinical model of “regression trial” mice bearing tumors of 50 mm3 were treated with Dox. 55% of the mice showed strong slow down of tumor growth or tumor regression that, in the 22% of the cases, took to complete tumor remission. This data highlights MvDN-30 as a candidate for glioblastoma target 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 633. doi:10.1158/1538-7445.AM2011-633
Abstract 651: Insulin-like growth factor 1 receptor antibody induces rhabdomyosarcoma cell death via a process involving AKT and Bcl-xL
Authors: Mayeenuddin Linnia , Yu Yunkai , Kang Zhigang , Helman Lee , Cao Liang
Published: June 2012

Insulin-like growth factors (IGFs) and their receptor, IGF-1 receptor (IGF1R), have important roles in growth, development, stress response, aging and cancer. There are many agents that inhibit IGF1R in oncology clinical development, and in some cases, they have been associated with rapid tumor regression. However, it is not clear by which process these targeted agents induce cancer cell death and how to predict such tumor responses. Here, we showed that IGF1R antibody led to rapid cell death and tumor regression in some rhabdomyosarcoma (RMS) cells. Mechanistic analysis revealed a rapid onset of mitochondrial-dependent apoptosis, including mitochondrial depolarization, cytochrome C release and the activation of specific caspases. The antibody sensitive cells had greater dependence on AKT for maintaining downstream signaling and the expression of a constitutively active AKT, which restored AKT-signaling in these cells, inhibited anti-IGF1R induced cell death. Further analysis showed IGF1R antibody-induced hypophosphorylation of BAD and activation of downstream BAX. Interestingly, the examination of RMS cell lines and tumors revealed an inverse correlation between elevated IGF1R and Bcl-2 level (P=0.033), with the sensitive cells lacking Bcl-2 expression. The overexpression of BAD specific target, Bcl-xL, conferred resistance, whereas Bcl-xL knockdown sensitized cells lacking Bcl-2 to anti-IGF1R-induced cell death. We propose that RMS pathogenesis involves increased IGF1R expression that enhances AKT and Bcl-xL-mediated cell survival, and the blockage of IGF1R results in inhibition of survival signal from Bcl-xL and cell death in the sensitive Bcl-2 negative cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 651. doi:10.1158/1538-7445.AM2011-651
Abstract 660: Inhibition of centrosomal clustering suppresses tumor growth in vivo
Authors: Raab Marc S. , Breitkreutz Iris , Leber Blanka , Weitz Ludmila , Hayden Patrick J. , Larsen Thomas O. , Cllausen Mads H. , Fruehauf Johannes , Nissen Felix , Mier Walter , Haberkorn Uwe , Podar Klaus , Ho Anthony D. , Goldschmidt Hartmut , Anderson Kenneth C. , Kraemer Alwin
Published: June 2012

Tumor cells frequently contain multiple centrosomes, associated with the formation of multipolar mitotic spindles and chromosome segregation defects. To allow for bipolar mitotic division, supernumerary centrosomes are clustered into two functional spindle poles (centrosomal clustering). We recently described a phenotype-based small molecule screening strategy directed to induce tumor cells with supernumerary centrosomes to undergo multipolar mitoses, thereby resulting in apoptotic cell death (Rebacz et al., Cancer Res 2007; 67: 6342-6350). We here describe the novel small molecule GF-15, a derivative of griseofulvin and a potent inhibitor of centrosomal clustering, thereby inducing multipolar spindles followed by apoptosis. We tested more than 25 cancer cell lines from hematologic malignancies (including acute and chronic leukemias, lymphomas), solid tumors (including glioblastoma, colon, cervix, and pancreatic cancers) and a wide array of myeloma cell lines. We found mean inhibitory concentrations (IC50) for proliferation and survival in the range of 1-5μM GF-15, associated with activation of caspases 8, 9, and 3. As expected, tumor cell lines displaying only limited centrosomal aberrations or microsatellite instability were less sensitive to treatment with GF-15. Importantly, non-malignant cells without supernumerary centrosomes including PBMCs, immortalized hepatocytes, and bone marrow stromal cells, did not reach their IC50 even at 30μM GF-15. Specifically, cell cycle analysis of synchronized myeloma cells showed marked G2/M arrest, followed by a dramatic increase of the sub-G1 fraction, after treatment with GF-15. In addition, treatment with GF-15 was associated with inhibition of VEGF- and IGF1-triggered myeloma cell migration. Pharmakodynamic studies in vivo revealed rapid renal clearance of GF-15 and metabolites within 6 hours p.i. No acute or chronic toxicity was observed. Finally, both intraperitoneal and oral GF-15 treatment of murine xenograft models of human multiple myeloma resulted in tumor growth inhibition and significantly prolonged survival associated with significant increase of aberrant mitoses in vivo. Taken together, our results demonstrate the in vitro and in vivo anti-tumor efficacy of the first in class small molecule inhibitor of centrosomal clustering with specificity for tumor cells, and strongly support its clinical evaluation to improve patient outcome in both hematologic malignancies and solid tumors.

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 660. doi:10.1158/1538-7445.AM2011-660