bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1700: An improved synthesis and mutagenicity studies of O2-[4-(3-pyridyl-4-oxobut-1-yl]thymidine, the major adduct formed by tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in vivo
Authors: Gowdahalli Krishnegowda , Sharma Arun K. , Krzeminski Jacek , Desai Dhimant , Lin Jyh-Ming , Gowda A.S. Prakasha , Spratt Thomas E. , Amin Shantu
Published: February 2011

Among the four pyridyloxobutyl (POB)-DNA adducts formed in the lung and liver of rats treated with tobacco specific nitrosamines [N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL)], the O2-[4-(3-pyridyl)-4-oxobut-1-yl]thymidine (O2-POB-dThd) has been found to be the most persistent. It is an important biomarker to assess the human exposure to these carcinogens and also serves as a useful precursor for the synthesis of site-specifically modified oligomers required for mutagenicity studies. The only synthetic method reported for O2-POB-dThd requires repeated HPLC purifications and could only be used to prepare an analytical standard due to very low yield (0.4%). Our continued efforts have now led to the development of an efficient method for the total synthesis of O2-POB-dThd and its site-specifically adducted oligonucleotides. The synthesis of O2-POB-dThd was achieved by optimizing reaction between O2-5′-anhydrothymidine and sodium salt of 4-(1,3-dithian-2-yl)-4-(3-pyridyl)butan-1-ol, followed by deprotection of the dithiane group. The product was characterized by NMR (1H, 13C, and COSY spectra), MS, and HPLC analysis. This synthetic strategy provided for the first time a reliable method for a gram scale total synthesis of O2-POB-dThd that allowed for solid state site-specifically adducted oligomer synthesis. O2-POB-dThd was converted to its phosphoramidite and subsequently used for the synthesis of the oligomer by standard methods. The oligomer was characterized by MS and HPLC analysis. We examined the in vitro kinetics of the synthesized oligomer with the Klenow fragment of E. Coli DNA polymerase I with the exonuclease activity inactivated (Kf(exo-)) and human DNA polymerasesl eta, kappa, and iota). O2-POB-dThd was replicated in a mutagenic manner with with Kf(exo-)and human pol eta and was unreactive with pol kappa and iota. In summary, highly facile syntheses of O2-POB-dThd and its site-specifically adducted oligonucleotide are developed. The study will facilitate elucidation of mechanistic aspects and mutagenic potential of O2-POB-dThd adduct, and will provide further insight into the role it plays in inducing cancers in smokers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1700.
Abstract 1703: Osteoblastic differentiation induced by PSA: Role of Wif-1 and TGF-β
Authors: Nadiminty Nagalakshmi , Chun Jae Yeon , Lou Wei , Gao Allen C.
Published: February 2011

Introduction: The high prevalence of osteoblastic bone metastases in prostate cancer likely involves the production of osteoblast-stimulating factors by prostate cancer cells. The identity of the factors responsible for the homing of circulating prostate cancer cells to the bone remains unknown. Prostate specific antigen (PSA) is a serine protease produced by prostate cancer cells and is an important serological marker for prostate cancer. Our previous studies suggested that PSA may be involved in the induction of osteoblastic differentiation. In this study, we examined the involvement of Wnt inhibitory factor 1 (Wif-1) and Transforming growth factor β (TGF-β) in osteoblastic differentiation induced by PSA in SaOS-2 human osteosarcoma cells.

Methods: Microarray analysis of RNAs from Saos-2 cells stably expressing PSA and vector controls was performed and the results were validated by northern blotting. The potential role of Wif-1 and TGF-β in osteoblatic differentiation induced by PSA was examined by alkaline phosphatase assays, luciferase assays and northern analysis.

Results: PSA was found to induce bone remodeling in SaOS-2 cells as evidenced by increases in alkaline phosphatase activity, mineral deposition and osteogenic gene expression. Saos-2 cells expressing PSA exhibited markedly upregulated expression of markers of osteoblastic differentiation like collagen type 1, osteocalcin, Runx-2, alkaline phosphatase and bone sialoprotein compared to parental Saos-2 cells and vector controls. Treatment of SaOS cells with exogenous enzymatically active PSA produced similar results, suggesting that osteoblastic differentiation may be regulated by PSA. Among the genes found to be regulated by PSA expression, TGF-β and Wif-1 were examined further. PSA enhanced the expression and activation of TGF-β as shown by higher levels of TGF-β-responsive reporter activity and increase in expression of TGF-β receptors I and II. Overexpression of Wif-1 in SaOS-2 cells enhanced osteogenic gene expression, while inhibition of Wif-1 expression in PSA-expressing cells resulted in reduction of alkaline phosphatase activity, a marker of osteoblastic differentiation.

Conclusions: PSA-induced bone remodeling was mediated by enhanced expression of several markers of osteoblastic differentiation and modulation of TGF-β and the Wnt/β-catenin pathways. These results suggest that PSA produced by metastatic prostate cancer cells may participate in bone remodeling in favor of development of osteoblastic metastases. These findings provide a molecular basis for understanding the high prevalence of osteoblastic bone metastases in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1703.
Abstract 1710: Epigenetic repression of regulator of G-protein signaling 2 promotes prostate cancer progression
Authors: Tu Yaping , Wolff Dennis W. , Gatalica Zoran , Xie Yan , Abel Peter W.
Published: February 2011

Prostate cancer is the most common cancer in American men and acquisition of androgen independence by prostate cancer is the key problem causing prostate cancer progression to highly aggressive form of cancer, leaving limited modalities in its treatment. Recent studies suggest that G protein-coupled receptor (GPCR)-stimulated androgen-independent activation of androgen receptor (AR) contributes to development of androgen independence. We previously reported that RGS2, an inhibitor of GPCR signaling, inhibits androgen-independent AR activation in prostate cancer cells (Cao et al., (2006) Oncogene, 25: 3719-3734). Here, we report that RGS2 protein expression was significantly reduced in human prostate cancer specimens compared to adjacent normal prostate tissues. Interestingly, RGS2 repression in androgen-independent prostate cancer cells and human prostate cancer specimens is not simply due to the loss of the RGS2 gene. Instead, methylation-specific PCR analysis and bisulfite sequencing indicated that methylation of the RGS2 gene promoter correlates with RGS2 down-regulation in prostate cancer cells and human prostate cancer specimens. Hypermethylation of the RGS2 gene promoter abolished its promoter activity and suppressed RGS2 gene expression. Conversely, the DNA methyltransferase inhibitor, 5-aza-2’-deoxycytidine induced re-expression of RGS2 in androgen-independent prostate cancer cells via demethylation of the RGS2 promoter to inhibit androgen-independent prostate cancer growth. Furthermore, ectopic re-expression of RGS2 in androgen-independent prostate cancer cells by RGS2-adenovirus infection suppressed tumorigenicity and growth of xenografts in castrated nude mice. Taken together, our results suggest that RGS2 repression due to hypermethylation of its promoter could unmask a latent pathway for AR activation by various GPCRs, thus contributing to prostate cancer progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1710.
Abstract 1712: Androgen receptor splicing variants promote therapeutic resistance in prostate cancer
Authors: Guo Zhiyong , Yang Xi , Sun Feng , Linn Douglas E. , Jiang Richeng , Chen Hege , Chen Hegang , Kong Xiangtian , Melamed Jonathan , Tepper Clifford G. , Kung Hsing-Jien , Brodie Angela M. H. , Edwards Joanne , Qiu Yun
Published: February 2011

Androgen receptor (AR) plays a key role in progression to incurable castration-resistant prostate cancer. Recently, we and others have identified multiple alternatively spliced AR isoforms in hormone refractory prostate cancer cells. These AR splice variants contain the intact N-terminal transactivation domain and the DNA binding domain, but lack the ligand binding domain. They function as constitutively active transcription factors and their activity is independent of androgen or anti-androgens. Our tissue microarrays analysis on 429 human prostate tissue samples revealed that AR3, one of the major AR splice variants, is significantly up-regulated during prostate cancer progression and AR3 expression level is correlated with the risk of tumor recurrence after radical prostatectomy. Overexpression of AR3 confers castration-resistant growth of prostate cancer cells, whereas specific knockdown of AR3 expression in hormone-resistant prostate cancer cells attenuates their growth under androgen-depleted conditions, suggesting an indispensable role of AR3 in castration-resistant growth of prostate cancer cells. Furthermore, our gene expression microarray analysis showed that AR3 regulates a unique set of target genes which are not regulated by the prototype AR, suggesting that AR3, as an independent transcription factor, utilizes a distinct transcription programs to achieve its distinct and specific biological functions which are important for castration-resistant growth.

In addition to its role in the androgen-ablation resistance, the AR isoforms may also be involved in chemotherapeutic resistance. We found that AR3 is overexpressed in chemotherapeutic resistant prostate cancer cell lines that are more tumorigenic, compared with their parental drug-sensitive lines. Therefore, aberrant expression of AR splicing variants may be a general mechanism underlying the development of multiple therapeutic resistances in prostate cancer.

Taken together, our data suggest that AR3 may potentially serve as a prognostic marker to predict patient outcome in response to hormonal and chemo therapy, and targeting these AR splicing variants may offer more effective treatment for advanced prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1712.
Abstract 1713: Activation of the aryl hydrocarbon receptor and down-regulation of the androgen receptor in prostate cancer cells by the curcumin analog C48
Authors: Fajardo Alexandra M. , Bowles Harmony J. , MacKenzie Debra A. , Vander Jagt David L. , Bisoffi Marco , Thompson Todd A.
Published: February 2011

The androgen receptor (AR) is a critical player in prostate cancer (CaP) development and progression and is a well-established therapeutic target. Recent studies have shown the aryl hydrocarbon receptor (AhR) is an important modulator of the AR acting as an adaptor for ubiquitin ligases and increasing the degradation of the AR. The natural product curcumin, a known inhibitor of the AR, has been shown to modulate the activity of the AhR. We have identified a curcumin analog, C48, which potently inhibits CaP cell proliferation. The purpose of this study was to identify molecular pathways that contribute to the effects of C48 on CaP cells, which may involve AR down-regulation through an AhR-mediated mechanism. Androgen-sensitive LAPC4, LNCaP and C4-2 CaP cells were used to perform these studies. We have found that C48 potently reduces AR expression levels in CaP cells in a dose- and time-dependent manner. C48 also decreased expression of genes induced by the AR, such as prostate specific antigen. We have found that a potent AhR activator, benzo(a)pyrene, down-regulates AR protein expression in CaP cells. As with benzo(a)pyrene, C48 was found to activate the AhR as determined using an AhR-activated reporter system. In addition, C48 potently induced markers of AhR activation including cytochrome P450 1A1 and aldoketoreductase 1C1 in CaP cells. Previous studies (e.g., Fritz et al., 2007) have shown that the AhR may act as a prostate cancer suppressor. Results from this study may facilitate the identification of safe and effective agents, such as the curcumin analog C48, that target AR down-regulation as a potential therapeutic strategy for prostate cancer without the toxicities associated with agents such as benzo(a)pyrene.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1713.
Abstract 1714: Transcriptional networks downstream of the AR identify clinically relevant prostate cancer targets
Authors: Massie Charlie , Lynch Andy , Stark Rory , Ramos-Montoya Anthony , Fazli Ladan , Warren Anne , Scott Helen , Bon Helene , Sharma Naomi , Zecchini Vinny , Matthews Nik , Osborne Michelle , Hadfield James , Swatton Jane , McArthur Stewart , Adryan Boris , Grigorenko Elena , Watt Carolyn , McEwan Iain , Rennie Paul , Neal David , Mills Ian G.
Published: February 2011

The AR signalling axis is central to Prostate Cancer (PrCa) biology, shown by its use in both screening (PSA) and treatment of the disease (androgen deprivation therapy). Identifying direct target genes of the AR will provide a better understanding the key signalling pathways controlled by the AR in PrCa and could lead to improved biomarkers and future therapeutic targets for the disease. To this end we have performed fine mapping of androgen responsive gene expression in prostate cancer cell lines using Illumina bead-arrays, coupled with AR chromatin-immunoprecipitation and Solexa sequencing technology (ChIP-seq). This approach generated over ten thousand candidate AR target genes. We have then undertaken large scale, cross-platform validation using BioTrove Realtime PCR panels which allow the measurement of >600 transcripts simultaneously. Using this combination of approaches we have identified and validated several hundred AR regulated genes. We found that metabolic enzymes and kinases were significantly enriched in the set of direct AR regulated genes. In nine independent clinical gene expression studies we found that the most consistently up-regulated AR target gene was a calcium regulated kinase. At the protein level this kinase showed increased expression in two independent patient cohorts. A small molecule inhibitor of this kinase reduced the growth of a panel of PrCa cell lines in vitro and tumour growth in xenograft models. Interestingly, we found that the levels of this AR regulated kinase were reduced in clinical PrCa following androgen deprivation therapy, but were raised in Castrate Resistant disease. Therefore, we have identified an AR regulate kinase which contributes to tumour growth and is a potential marker and therapeutic target in both hormone naïve and anti-androgen resistant disease. In summary, these data show that combining expression analysis, ChIP-seq and high through-put validation has identified a framework to understand the oncogenic functions of the AR in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1714.
Abstract 1718: ErbB-2 acts as coactivator of Stat3 in heregulin-induced breast cancer growth
Authors: Béguelin Wendy , Flaqué María C. Díaz , Proietti Cecilia J. , Rivas Martín A. , Tkach Mercedes , Charreau Eduardo H. , Schillaci Roxana , Elizalde Patricia V.
Published: February 2011

We have previously demonstrated that heregulin (HRG), a ligand for ErbB receptors, activates signal transducer and activator of transcription 3 (Stat3) in primary cultures of ErbB-2 overexpressing C4HD cells, from a murine progestin-dependent mammary tumor. ErbB-2 activity is an absolute requirement in the mechanisms of HRG stimulation of Stat3 activity. Recent findings have demonstrated ErbB-2 nuclear migration and its function as a transcription factor. In this work, we studied whether HRG induces ErbB-2 nuclear migration and its interaction with Stat3 in breast cancer cells. We demonstrated that HRG induces ErbB-2 nuclear migration and colocalization with Stat3 in C4HD and human T47D breast cancer cells. Cyclin D1 is a cancer-related gene that contains Stat3 binding sites (GAS sites) but lacks ErbB-2 response elements (HAS sites). By chromatin immunoprecipitation assays (ChIP) and sequential ChIP, we demonstrated that HRG induces in vivo binding of Stat3 and ErbB-2 to the GAS sites of the cyclin D1 promoter. This finding prompted us to evaluate the ability of HRG to regulate cyclin D1 expression. By inhibiting ErbB-2 and Stat3 activation or silencing their expression, we demonstrated that ErbB-2 and Stat3 participate in the mechanism of HRG-induced cyclin D1 protein expression. Next, we explored whether HRG induces cyclin D1 promoter directly via Stat3 binding to its response elements. C4HD and T47D cells transiently transfected with a cyclin D1 promoter luciferase construct showed an enhanced transcriptional activity with HRG treatment. Overexpression of increasing amounts of ErbB-2 wt resulted in a dose-dependent ErbB-2 capacity to enhance Stat3 transcriptional activity induced by HRG. On the other hand, transfection with increasing amounts of an ErbB-2 mutant that is defective in nuclear entry but retains its cell-surface location and functions (ErbB-2ΔNLS) resulted in abrogation of HRG-induced Stat3 activation of cyclin D1 promoter. Finally, we addressed the effect of targeting ErbB-2 in in vivo HRG-dependent growth of C4HD breast tumors. Transfection of C4HD cells with the ErbB-2ΔNLS expression vector significantly inhibited these cells’ ability to form tumors in syngeneic mice. Taken together, these results suggest a new role of ErbB-2 as a coactivator in the mechanism of HRG-induced transcriptional activation of Stat3. We also found nuclear ErbB-2 to be a requisite for HRG stimulation of in vitro and in vivo breast cancer growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1718.
Abstract 1719: Leptin, an obesity-related adipocytokine, promotes accelerated growth of Wnt-1 mammary tumors and modulates basal-like and luminal tumor markers
Authors: Zheng Qiao , Smith Sarah , Zhu Jinling , Hursting Stephen D , Reizes Ofer
Published: February 2011

Over 2/3 of the US population is obese or overweight, a condition associated with increased risk and decreased survival of various cancers including breast cancer. There is a large unmet medical need to identify mechanisms underlying the link between obesity and cancer. The purpose of these studies is to elucidate the obesity-dependent mechanisms promoting aggressive mammary tumor growth. Circulating levels of leptin, an adipocyte-secreted cytokine that regulates body weight, are elevated in obese and overweight individuals. We orthotopically transplanted tumor cells derived from primary spontaneous MMTV-Wnt-1 tumors into morbidly obese leptin-deficient (ob/ob; lack wild-type leptin) and leptin receptor-deficient (db/db; hyperleptinemic) mice. The MMTV-Wnt-1 tumors, like many human breast tumors, are mixed lineage giving rise to tumors expressing both basal and luminal tumor markers. We determined that orthotopic transplant of MMTV-Wnt-1 tumor cells into obese db/db mice, with high serum leptin, leads to accelerated tumor growth. In contrast, transplant into obese ob/ob mice leads to small, disorganized tumors. More importantly, tumors from leptin-deficient ob/ob mice are predominantly comprised of differentiated epithelial (E-cadherin) and myoepithelial (α—SMA and keratin 14) tumors cells and surprisingly lack basal (keratin 5 and 6) and luminal (keratin 8) lineage tumor cells. Indeed, we determined that AKT cell survival/proliferation pathway was suppressed in the tumors from leptin-deficient mice. The phospho-AKT (p-AKT) immunopositive cells were primarily also expressing keratin 6, and not αSMA or keratin 8, indicating that AKT is activated in the keratin 6 basal-like tumor cells. These studies are highly significant because they indicate leptin, elevated in obese patients, promotes aggressive tumor growth by targeting survival, proliferation, and/or differentiation of subpopulations of mammary tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1719.
Abstract 1721: A steroid-based drug that binds estrogen receptor beta can inhibit cancer cell proliferation by blocking chromosome replication
Authors: Weitman Steven D. , Bittner Michael , Hershberger Pamela , Babine Robert E. , Nye Steven , Yarger James
Published: February 2011

Our approach for developing a cancer therapeutic is based on the notion that the estrogen receptors alpha (ER-alpha) and beta (ER-beta) function in opposing manners towards events involved in controlling cell growth and proliferation. If the proposed inhibitory function of ER-beta is accurate, we predict that treatment of cancer cells with an ER-beta agonist may lead to cessation of cell division and potentially to cell death. Towards that end, we have discovered a family of first-in-class compounds for treating cancer that function by blocking chromosome replication in rapidly dividing cells. NDC-1022 and NDC-1308 are estradiol analogs which vary only in the length of the 6-alkoxyalkyl group at the carbon 6 position. Importantly, the length of the 6-alkoxyalkyl group may impact the function of the compounds since in silico modeling studies predict a difference in how the side-chains of NDC-1022 and NDC-1308 are bound within the ligand binding sites of ER-alpha and ER-beta. To understand the mechanism of action for these compounds, competitive binding studies were carried out with either recombinant human ER-alpha or ER-beta in the presence of labeled estradiol. The results show that the NDC compounds preferentially bind to the ER-beta receptor compared to the ER-alpha receptor. To determine how the NDC compounds affect cell growth, 201T NSCLC cells were incubated with 100 µm of NDC-1022. After 48 hours, NDC-1022 caused a reversible cell cycle arrest at G0/G1 for the majority of cells. The level of cytotoxicity was determined by treating 14 different human tumor cell lines with a serial dilution of the NDC compounds. The EC50 data suggests that NDC-1308 (10-20 uM) is about 3 to 8.5-fold more potent than NDC-1022 (30-85 uM). We propose that this difference in potency is due to NDC-1308 making additional non-polar interactions within the receptor ligand binding sites compared to NDC-1022. Finally, gene expression studies were carried out using microarray to identify the mechanism of action for cytotoxicity. Three human tumor cell lines (A549-lung, SKOV-3-ovary, and Panc-1- pancreatic) were treated with the NDC compounds for 24 hours. Both NDC-1022 and NDC-1308 exhibit a substantial reduction in the transcription of 27 genes critical for chromosome replication, a cellular process exaggerated in most cancer cells and therefore a relevant therapeutic target. We conclude that NDC-1022 and NDC-1308 impact all rapidly growing cells without regard to any underlying mutation and therefore could be used to treat a wide range of cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1721.
Abstract 1725: Neuroendocrine modulation of anoikis
Authors: Armaiz-Pena Guillermo N. , Halder Jyotsnabaran , Nick Alpa M. , Stone Rebecca L. , Spannuth Whitney A. , Deavers Michael T. , Allen Julie K. , Han Liz Y. , Kamat Aparna A. , Shahzad Mian M.K. , McIntyre Bradley W. , Diaz-Montero Claudia M. , Jennings Nicholas B. , Lin Yvonne G. , Merritt William M. , DeGeest Koen , Mejias Pablo E. Vivas , Berestein Gabriel Lopez , Schaller Michael D. , Cole Steven W. , Lutgendorf Susan K. , Sood Anil K.
Published: February 2011

Chronic stress and associated hormones are known to affect multiple systems including immunological and endocrinological functions, but the effects on cancer growth and progression are not fully understood. Here, we demonstrate that chronic stress and associated increases in catecholamines, protect tumor cells from anoikis and promote growth by activating focal adhesion kinase (FAK). These effects involve phosphorylation of FAKY397 associated with actin-dependent Src interaction with membrane-associated FAK. In human ovarian cancer patients, behavioral states related to greater adrenergic activity were associated with higher levels of pFAKY397, which was in turn linked to substantially accelerated mortality. These data suggest that FAK modulation by stress hormones, especially norepinephrine and epinephrine, can contribute to tumor progression in ovarian cancer patients. These findings further point at potential new therapeutic targets for cancer management.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1725.
Abstract 1736: Skewed usage of TCRVbeta repertoire and predictive role of CD60 and CD49d expression in the survival rate of patients with Sézàry Syndrome
Authors: Scala Enrico , Pomponi Deborah , Narducci Maria Grazia , Lombardo Giuseppe Alfonso , Caprini Elisabetta , Liso Marina , Mari Adriano , Russo Giandomenico
Published: February 2011

Background: Sézary Syndrome (SS) is a rare and aggressive leukemic variant of Cutaneous T-Cell Lymphoma (CTCL) characterised by erythroderma and the presence of a malignant circulating memory CD4+ T cell clone with skin homing characteristics, lack of CD26 and CD49d and over-expression of CD60. The availability of a large panel of monoclonal antibodies to CDR3 Vß epitopes, allows the study of the TCR repertoire by flow cytometry and a more precise identification of the malignant clone phenotypic characteristics.

Objective: The aim of this study was to evaluate both the distribution of TCR-Vß family and CD60/CD49d expression within the clonal T cell population in patients affected by SS.

Methods: We studied, by five-color flow cytometry analysis, TCR-Vß repertoire in 62 patients affected by SS, in 180 patients with MF, 6 cases of B cell Lymphomas (BCL), 19 with chronic Eczema (CE) recruited and followed from 1998 to 2008. A sequential gating strategy was used in order to examine the CD60 and CR49d expression within the neoplastic clonal population identified through the TCR-Vß repertoire analysis.

Results and Conclusion: A skewed usage of only 4 out of 25 TCR-Vß subfamilies was observed in circulating T cell clone in 61.9% of patients affected by SS. TCR-Vß 2 and 5.1 were the most frequently represented (42.8% of TCR-Vß reactive patients), followed by TCR-Vß 12 and 13.1. In 20 cases the TCR-Vß panel was unable to identify the neoplastic clone, recognizing less than 5% of T cells, thus representing an indirect proof for the presence of a clonal population. CD60 was over expressed and CD49d down regulated within clonal T lymphocytes. This phenotype of the dominant T cell clone in the peripheral blood of patients with SS was significantly associated with a lower survival rate (chi-square 5.467, p <0.019).

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1736.
Abstract 1738: Significance of thymidylate synthase expression in prostate cancer
Authors: Mizutani Yoichi , Edagawa Yu , Fujisue Hiroshi , Uchimoto Shinya , Koyama Kohei , Ibuki Naokazu , Inamoto Teruo , Ubai Takanobu , Nomi Hayahito , Azuma Hruhito , Katsuoka Yoji
Published: February 2011

Introduction :

Thymidylate synthase (TS) is an important rate-limiting enzyme in the pathway of de novo DNA synthesis. Several reports demonstrated that TS expression was up-regulated in various cancers. 5-fluorouracil (5-FU) is an anti-cancer agent used clinically against a variety of cancers including prostate cancer. TS is a target enzyme for 5-FU. 5-FU inhibits DNA synthesis by binding TS and folic acid. We then investigated the expression of TS in prostate cancer and investigated its prognostic significance.

Materials and Methods :

Total 100 prostate cancer tissue specimens were obtained from patients who underwent radical prostatectomy for prostate cancer. Fifty-two patients did not received neoadjuvant hormonal therapy, and the rest 48 patients received neoadjuvant hormonal therapy. We examined prostate cancer tissues and normal prostate tissues for TS expression by immunohistochemistry. TS expression was regarded as positive, when more than 25% cells showed positive staining. If less than 25% were positive staining, TS expression was regarded as negative.

Results :

TS in prostate cancer tissues expressed at higher levels in patients without neoadjuvant hormonal therapy, compared with normal prostate tissues. TS expression was positive in approximately 70% prostate cancer tissues. In contrast, TS expression was observed in about 10% normal prostate tissues. The positive rate of TS expression in Stage T3 prostate cancer was higher than that in Stage T2 prostate cancer. In addition, the rate of positive TS expression in Gleason score 7 or greater prostate cancer was higher than that in Gleason score less than 7 prostate cancer. Patients with prostate cancer with negative TS expression without neoadjuvant hormonal therapy had a longer postoperative recurrence-free rate than those with positive expression in the 5 year follow-up. The rate of positive TS expression in prostate cancer tissues was significantly down-regulated in patients who received neoadjuvant hormonal therapy, compared with no neoadjuvant hormonal therapy. Especially, the rate of positive TS expression in stage T2 prostate cancer tissues was decreased by neoadjuvant hormonal therapy.

Conclusions :

The present study has demonstrated for the first time that TS expression may be a prognostic parameter for prostate cancer patients undergoing radical prostatectomy, and that TS may be a molecular therapeutic target for prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1738.
Abstract 1742: Evaluating the prognostic value of EGFR by p16/HPV status in patients with squamous cell carcinoma of the head and neck treated with concurrent chemoradiation
Authors: Hao Desirée , Lau Harold Y. , Eliasziw Michael , Klimowicz Alexander C. , Suzuki Keiko , Petrillo Stephanie K. , Box Alan , Diaz Roman , Banh Alice , Le Quynh-Thu , Magliocco Anthony M.
Published: February 2011

Background: Overexpression of the epidermal growth factor receptor (EGFR) has been correlated with a worse prognosis in patients with squamous cell carcinoma of the head and neck (SCCHN), however the prognostic value of EGFR has not been fully evaluated in the context of human papillomavirus (HPV) status. Methods: Records from 91 consecutive SCCHN patients treated with concurrent chemoradiation at the Tom Baker Cancer Centre between August 2000 and March 2005 were reviewed. Triplicate 0.6 mm cores from available pre-treatment formalin-fixed paraffin-embedded (FFPE) biopsies were assembled into a tissue microarray. Immunofluorescence combined with automated quantitative analysis (AQUA™) was used to evaluate EGFR and p16 protein expression. Phosphorylated EGFR (pEGFR) was assessed by proximity ligation assay. HPV infection status was determined by colorimetric in-situ hybridization using the INFORM HPV Family 16 Probe (CISH). PCR was used to detect HPV DNA. EGFR and pEGFR were correlated with clinical outcomes according to p16-status and HPV-status. Results: FFPE biopsies were available from 49 patients (54%). Patient characteristics were as follows: mean age 55 years, 82% male, 49% oropharyngeal primaries. The complete response rate was 88%. With a median follow-up of 42 months (range 3 to 60), the 5 year overall survival (OS) was 54%. EGFR and pEGFR protein expression were classified as high in 14 (29%) and 13 (27%) tumours respectively. 27 tumours were p16 positive; 30 were HPV positive by either PCR or CISH. p16 was strongly correlated with HPV status (Spearman r=0.80). In univariate analyses, tumours with high EGFR, low p16, and HPV negative were associated with significant 3-, 7-, and 5-fold increases, respectively, in locoregional recurrence, recurrence at any site, disease-specific mortality and worse OS. pEGFR did not predict outcome. Neither EGFR nor pEGFR predicted response. After adjusting for age, smoking status, T- and N-stage, p16, and HPV there was no relationship between EGFR and outcome. p16 and EGFR were inversely related (Spearman r=-0.3). Conclusions: In our small cohort of patients, EGFR did not have prognostic value after correction for p16 / HPV status.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1742.
Abstract 1749: The downregulated expression of adiponectin receptors (AdipoR1, R2) in human colorectal cancer
Authors: Hiyoshi Masaya , Kitayama Joji , Tsuno Nelson H. , Sunami Eiji , Kawai Kazusige , Otani Kensuke , Nishikawa Takeshi , Shuno Yasutaka , Yasuda Koji , Hongo Kumiko , Kikkawa Yoshiko , Sasaki Kazuhito , Kaneko Manabu , Takahashi Koki , Nagawa Hirokazu
Published: February 2011

[Background] Adiponectin is 30 kDa adipocytokine hormone secreted by the adipose tissues, which mediates antineoplastic as well as anti-angiogenic effects after binding to its receptors, Adipo-R1 and Adipo-R2, which has been reported to be expressed in colorectal cancer tissue and cell lines. Recent studies have shown decreased levels of adiponectin in sera of patients with various types of cancer, including colorectal. And a recent study demonstrated that adiponectin expression is significantly associated with high histological grade tumors and low microvessel density count in colorectal cancer, suggestive of an anti-angiogenic role for adiponectin in colorectal cancer. However, presently, the expression and function of adiponectin receptors in tumor tissue have not been well characterized. Thus, in the present study, we aimed to study the expression of adiponectin receptors in colorectal cancer tissues, and investigate on their clinicopathological implications.

[Methods] Surgically resected specimens from 48 patients with colorectal cancer, receiving surgical operation in our surgical department in the period between November 2008 and July 2009, were analyzed. The study was approved by the Human Ethics Committee of the University of Tokyo. The messages and protein expressions of AdipoR1 and AdipoR2 were evaluated by real-time RT-PCR and immunohistochemistry, respectively, in cancer tissues and the matched normal counterparts.

[Results] The mean age of the patients was 66.79±11.85 years. The levels of expression of both AdipoR1/AdipoR2, normalized with the internal control (beta-actin), were significantly lower in cancer specimens compared with normal mucosa (0.966±0.392, vs1.366±0.408, p<0.001 and 0.918±0.309, vs1.596±0.459, p<0.001, respectively for AdipoR1 and Adipo R2). The mRNA levels of AdipoR1 and AdipoR2 showed a tendency of decrease in tumors with nodal metastases and the difference was significant with AdipoR2 (p<0.05). Immunohistochemistry with polyclonal Abs showed a consistent reduction in protein expression of both receptors in cancer tissues in comparison with the normal counterparts.

[Conclusion] Both receptors were downregulated in colorectal cancer, as confirmed by the mRNA and the protein expressions, and AdipoR2 seemed to be associated with nodal metastases. This downregulation seems to be associated with poorer prognosis of colorectal cancer, and may be an escape mechanism of cancer cells from the suppressive effects of adiponectin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1749.
Abstract 1755: Utility of anti-p53 antibody in blood as a predictive marker for the detection of early recurrence in postoperative patients with esophageal carcinoma
Authors: Hagiwara Nobutoshi , Takahashi Ken , Uchida Eiji , Makino Hiroshi , Nomura Tsutomu , Okawa Keiichi , Akagi Ichiro , Fujita Itsuro , Fujita Itsuro , Sakurazawa Nobuyuki , Onodara Hiroyuki , Yamashita Naoyuki , Miyashita Masao
Published: February 2011

Background: Circulating anti-p53 antibody(p53-Ab) in blood can be detected in various cancers. Serum p53-Ab has been applied as a tumor marker in detecting esophageal squamous cell carcinoma (ESCC). However, little is known about prognostic value for postoperative patients with ESCC. We evaluate the significance of preoperative serum p53-Ab as a potential marker of early recurrence after curative resection for ESCC.

Methods: Anti-p53 antibodies in serum was measured with Enzyme-linked immunosorvent assay (ELISA) to analyze serum p53-Ab before treatment in 44 patients with ESCC. Squamous cell carcinoma antigen(SCC-Ag) and Carcinoembryonic antigen (CEA) as popular tumor markers for ESCC were measured simultaneously by immunoradiometric assay to compare with the p53-Ab results. Clinicopathological characteristics were also examined. Kaplan-Meier survival analyses were used to analyze the association with prognosis.

Results: The recurrence-free rate was significantly higher in patients negative for p53-Ab in serum than those strongly positive for p53-Ab (p=0.0002). The patients positive for p53-Ab in serum were more likely to have early recurrence after curative resection than patients negative for p53-Ab (p=0.05). On the other hand there were no significant correlations between CEA, SCC-Ag positivity and early recurrence. Conclusions: This study suggests that p53-Ab in serum is a promising tumor marker to predict a risk of early recurrence after curative surgical resection for ESCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1755.
Abstract 176: The presence of RNA polymerase II, active or stalled, predicts epigenetic fate of promoter CpG islands
Authors: Takeshima Hideyuki , Yamashita Satoshi , Shimazu Taichi , Niwa Tohru , Ushijima Toshikazu
Published: February 2011

Aberrant DNA methylation of promoter CpG islands (CGIs) is deeply involved in cancers and other disorders. Contrary to our initial expectations, aberrant methylation is now recognized to possess several unique characteristics different from mutations [Ushijima and Asada, Cancer Sci, 2010]. One of the remarkable differences is target gene specificity. Specific cancers have aberrant methylation of specific genes, and specific inducers of methylation, such as Helicobacter pylori infection, induce methylation of specific genes [Nakajima et al, Int J Cancer, 2009]. As the mechanism of target gene specificity (namely, instructive mechanism), low transcription levels and trimethylation of histone H3 lysine27 (H3K27me3) in precursor cells are known to promote methylation induction. However, factors that protect genes from aberrant methylation are unknown.

To identify protective factors, we first isolated 5,510 and 521 genes resistant and susceptible, respectively, to aberrant methylation induction by methylated DNA immunoprecipitation (MeDIP)-on-chip analysis of nucleosome-free regions of promoter CGIs in normal prostatic epithelial cells and four prostate cancer cell lines. Then, by gene expression analysis, the susceptible genes were shown to have low transcription levels in normal prostatic epithelial cells. Finally, by ChIP-on-chip analysis in normal prostatic epithelial cells, we revealed that, even among the genes with low transcription, genes with high active histone modifications and binding of RNA polymerase II (Pol II) had marked resistance to aberrant methylation induction, and confirmed that genes with high H3K27me3 had marked susceptibility to aberrant methylation induction. On the other hand, another repressive histone modification, trimethylation of histone H3 lysine9 (H3K9me3), was not associated with resistance or susceptibility. By multivariate analysis, Pol II binding showed stronger influence on the resistance than active histone modifications, and H3K27me3 showed independent influence on the susceptibility. The same was true in normal mammary epithelial cells for 5,430 and 733 genes resistant and susceptible, respectively, to aberrant methylation in breast cancers [Takeshima et al, Genome Res, 2009].

These results indicated that the presence of Pol II, active or stalled, protects promoter CGIs from aberrant DNA methylation, independently of transcription levels.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 176.
Abstract 1762: Clinical relevance of plasma IL-6 and IL-6 levels in chronic lymphocytic leukemia (CLL)
Authors: Johnston James B. , Yoon Ju-Yoon , Lakhi Sunjay , Kuschak Brenda , Hewitt Donna , Gibson Spencer B.
Published: February 2011

It has been suggested that cytokines play an important role in the survival and proliferation of chronic lymphocytic leukemia (CLL) cells and these growth factors may be derived from a variety of cell types, including CLL cells. The plasma levels of the inflammatory cytokines, IL-6 and IL-8, vary in CLL and increased levels have been associated with a poor prognosis. This phenomenon has been related to the inhibition of apoptosis of CLL cells by the cytokines. In the present study, plasma IL-6 levels were measured by an ELISA assay in 193 CLL patients (107 males, 86 females; ages, 37-92 yr (median, 67.6 yr)) and the plasma IL-8 levels in 66 patients (31 males, 35 females; ages, 37-92 yr (median, 69 yr)). Samples were obtained from patients followed in the CLL Clinic at CancerCare Manitoba. Among the patients, plasma IL-6 levels ranged from < 0.01 to 1058 pg/mL, with a median value of 5.23 pg/mL. The median plasma IL-6 level in 37 age- and sex-matched controls was significantly lower at 0.83 pg/mL (range, 0.06-8.11 pg/mL)). Plasma IL-8 levels in the patients ranged from <0.01 to 1058 pg/mL, with a median value of 5.23 pg/mL. There were 22 normal age- and sex-matched controls for IL-8 levels, and the median IL-8 level here was 3.86 pg/mL (range, 1.42-11.60 pg/mL). A significant correlation was observed between plasma levels of IL-6 and IL-8 (Spearman r = 0.4810, p-value <0.0001), and the levels of both cytokines correlated positively with age and β2-microglobulin. There was also a trend between cytokine levels and RAI stage. There was no correlation between cytokine levels and CD38, IgVH mutation status or the Zap-70 level. For patients aged ≥65 yrs, approximately 22% had increased levels of plasma IL-6 (>3 pg/mL, 8% in normals) and 25% had increased IL-8 (>10 pg/mL, 8% in normals). Plasma from CLL patients with high IL-6 levels was able to induce IL-6 expression in CLL cells whereas plasma from CLL patients with low IL-6 levels failed to induce IL-6 expression in CLL cells. This indicates that factor(s) within the microenvironment are contributing to increased IL-6 levels in CLL.

We have previously shown that the relative survival decreases in CLL after age 65 yrs. The present study suggests that this may be related to a potentiation in the age-related increase in IL-6/IL-8 that is observed in the normal population. Whether the increase in mortality in elderly CLL patients is related to frailty/cardiovascular disease or to CLL progression is being investigated.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1762.
Abstract 1763: Quantitative gamma-H2AX immunoassay for pharmacodynamic monitoring anticancer cytotoxic agents
Authors: Zhang Yiping , Parchment Ralph , Tomaszewski Joseph , Doroshow James , Ji Jay
Published: February 2011

Phosphorylated H2AX (gamma-H2AX) has been reported as a biomarker for DNA double-strand breaks and programmed cell death. We have developed a 96-well plate based ELISA test for quantifying gamma-H2AX with the lowest limit quantiation at 16 pg/mL. The gamma-H2AX immunoassay is a cell- free assay with chemiluminescence readout using one unique pair of anti- gamma-H2AX antibodies as a sandwich bracketing the gamma-H2AX antigen from cell lysis extracts. The high affinity antibodies used in the assay provide high sensitivity and specificity allowing simple cell lysis procedures for antigen capture from crude extracts. The gamma-H2AX quantitation is normalized based on either cell numbers or total protein through BCA assay. We have performed gamma-H2AX quantitation in selected NCI60 cell lines from nine groups of human cancers. The gamma-H2AX levels among the NCI60 cell lines ranged from undetectable (< 16 pg/ml) to 6325 pg/10 million cells with an average of 711 pg. The gamma-H2AX quantitation results from ionic radiation and topotecan treated cell lines, topotecan treated human PBMC and selected patient specimens will be reported. The applications of the assay include target discovery and drug screening with selected human cancer cell lines, preclinical development and pharmacodynamic evaluation with xenograft tumors and animal models under treatment of investigational drugs, as well as clinic testing for patient enrollment, regiment selection and therapy monitoring of anti-cancer agents involving in DNA replication, repair, cell cycle and apoptosis.

Funded by NCI Contract No. HHSN261200800001E

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1763.