bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2424: Conditioned media enhances proliferation and mobility in triple negative breast cancer cells
Authors: Parker-Johnson KiTani A. , Yearby Letitia , Beverly Gabriel , Ochieng Josiah
Published: August 2012

Background. Triple negative breast cancer (TNBC) is one of the most aggressive forms of breast cancer and disproportionally affects African American women. This subtype of breast cancer is characterized by the absence of the estrogen, progesterone, and HER2/neu receptors. Our research has provided insight on understanding that the microenvironment, specifically noncancerous cells, play in enhancing cancer progression and metastasis. However, the role of adjacent noncancerous cells in the metastatic phenomenon is poorly understood. Therefore, the aims of this project were: 1) to determine if conditioned media from MCF-10A cells would enhance proliferation of MDA-MB-231 and MDA-MB-468 cells and 2) to evaluate the ability of the effects of migration of the conditioned media on the MDA-MB-231 and MDA-MB-468 cells. Methods. Crystal violet and alamar blue dye exclusion assays were performed to measure proliferation in the different medias. The trans well migration assay was used to evaluate motility enhancement based on the media used, either conditioned media and the Cellometer was used to evaluate whether the MDA-MB-468 and MCF-10A cells shared the same microenvironment. Results. Conditioned media is made from base medium with a concentration of 1.0 g/L glucose with .5% FBS exposed to non-cancerous MCF-10A cells that have been driven into crisis. This conditioned media encouraged robust and continuous proliferation of the tumorigenic MDA-MB-231 and MDA-MB-468 cell lines. HGCM was extracted in our lab using sterile technique and reused to analyze the proliferative effects on cancerous and non-cancerous cells. MDA-MB-231 cells demonstrated significant proliferation when compared to the control. MDA-MB-468 cells demonstrated a similar response. The trans well migration assay demonstrated that the GFP labeled MDA-MB-468 cells had a higher percentage of motility than with MCF-10A cells in standard media. Conclusions: Taken together, these data indicate that factors secreted into the microenvironment from noncancerous cells may contribute to the mobility of TNBC cells and the conditioned media contains unknown factors that promote the cell mobility of the MDA-MB-231 and MDA-MB-468 cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2424. doi:1538-7445.AM2012-2424
Abstract 2433: Comparisons between an IRDye 800CW-labeled PSMA-targeted small molecule and antibody for preclinical small animal imaging
Authors: Kovar Joy L. , Cheung Lael L. , Simpson Melanie A. , Olive D Michael
Published: August 2012

Prostate cancer continues to be the second leading cause of cancer death in men in 2011. Deciphering the progression and mechanisms contributing to the metastatic spread of this disease is critical to our overall understanding of how to approach treatment and/or therapy. Prostate-specific membrane antigen (PSMA) is a possible therapeutic target for the disease and is the focus of several cancer therapies currently in clinical trials. Near infrared (NIR) fluorescence imaging for cancer diagnosis and treatment is gaining attention for preclinical as well as clinical applications. IRDye 800CW is a NIR fluorophore exhibiting superior target-to-background ratios when conjugated to targeting moieties such as antibodies, peptides, and small molecules. Here we assess two different PSMA-targeted compounds conjugated to IRDye 800CW: the small molecule YC-27 and a PSMA-specific antibody. In vitro binding kinetics for both compounds exhibit expected dose dependent increases with increasing concentrations. Both compounds were successfully blocked with their unlabeled counterpart; however, neither blocked the other suggesting different PSMA epitopes. Although direct comparisons are inappropriate due to differences in molecular structures and labeling density, assessment of their respective pharmacokinetics is possible. Microscopy of prostate tumor cells incubated with each probe revealed a slower internalization of the small molecule when compared to the internalization of the antibody. Specificity of the labeled compounds in vivo was determined in male athymic nu/nu mice implanted with 22Rv1 (PSMA positive) or PC3M-LN4 (PSMA negative) prostate cancer cells (106). Mice received either IRDye 800CW YC27 (1 nmole) or IRDye 800CW PSMA (50 µg) followed by non-invasive fluorescent optical imaging of 800nm signals on the Pearl Impulse Small Animal Imager. At the study endpoint, organs and tumors were excised and imaged to assess residual probe localization. In vivo clearance patterns for these labeled molecules differed with the YC27 clearing via the kidneys and the antibody clearing through the liver. These subtle differences between the two imaging agents provide valuable options to investigators with specific requirements in their animal research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2433. doi:1538-7445.AM2012-2433
Abstract 2442: A precise orthotopic rectal tumor model for evaluating therapeutic response of cancer treatment
Authors: Kikuchi Satoru , Kishimoto Hiroyuki , Tazawa Hiroshi , Hashimoto Yuuri , Uno Futoshi , Nishizaki Masahiko , Kagawa Shunsuke , Urata Yasuo , Hoffman Robert M. , Fujiwara Toshiyoshi
Published: August 2012

We have previously reported a “true” orthotopic rectal model in which tumors start forming in the rectal mucosal tissue from which tumors actually arise. The model was generated by intrarectal transplantation of mouse rectal cancer cells stably expressing fluorescent protein, followed by disrupting the epithelial cell layer of the rectal mucosa by soaking with an acetic acid solution. Early stage tumor was detected on the rectal mucosa from as early as 6 days after transplantation, which then became invasive into the submucosal tissue. The tumor incidence on the rectal mucosa was 100%, and it was proved that this rectal tumor model reflects the natural course of rectal cancer accurately. Spontaneous lymph node metastasis and lung metastasis were observed 4 weeks after transplantation in over 90% of mice. In the present study, we will report whether this model is useful for evaluating therapeutic response of surgical local resection of tumor with combination of anticancer drugs such as a telomerase-specific replicating adenovirus designed for cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2442. doi:1538-7445.AM2012-2442
Abstract 2452: Tumor detection and measurement of responses to chemotherapy using human phosphatidylserine targeting antibody fragments
Authors: Gong Jian , Archer Rich , Peacock Matthew , Hughes Christopher , Chang Connie , Freimark Bruce
Published: August 2012

Phosphatidylserine (PS) is a phospholipid normally residing in the inner leaflet of the plasma membrane and becomes exposed on tumor vascular endothelial cells and tumor cells in response to chemotherapy, irradiation and oxidative stresses in the tumor microenvironment. Binding of antibodies targeting PS on the tumor endothelial cells and tumors recruit immune cells and engage the immune system to destroy tumor vasculature. The antibodies also enhance anti-tumor immunity by blocking the immunosuppressive action of PS. A chimeric anti-PS antibody, bavituximab, is being used in combination with chemotherapy to treat patients with solid tumors in Phase II trials. In the present study, we characterize the response to chemotherapy of human tumor xenografts in mice using near-infrared dye labeled PGN650, a human F(ab’)2 fragment that targets PS expression. NIR-PGN650 bound human PC-3luc prostate, BT474 breast and A549luc non-small cell lung tumors in SCID or nude mice in the absence of chemotherapy. Docetaxel treatment enhanced tumor targeting of NIR-PGN650 approximately 2-3-fold compared to imaging signals prior to chemotherapy. Peak tumor uptake of NIR-PGN650 was observed when docetaxel was delivered 24 hours prior to injection of NIR-PGN650. Using these parameters, NIR-PGN650 is able to detect responses to chemotherapy in both the primary tumor and metastases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2452. doi:1538-7445.AM2012-2452
Abstract 2548: Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver
Authors: Ross Jeffrey A. , Leavitt Sharon A. , Schmid Judith E. , Nelson Garret B.
Published: August 2012

We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue™ transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclobutanil was not mutagenic under the same conditions. DNA sequencing of the mutants recovered from each treatment group and from untreated control animals revealed that the mutations induced by propiconazole and triadimefon do not result from clonal expansion of background mutations. We hypothesized that these mutations arise from the accumulation of reactive electrophilic metabolic byproducts within the liver in vivo. We therefore measured the spectra of endogenous DNA adducts in the livers of mice from these studies in order to determine if quantitative or qualitative differences in DNA adducts correlated with mutagenicity and tumorigenicity. We resolved and quantitated 16 individual adduct spots by 32P postlabeling and thin layer chromatography using 3 solvent systems. Qualitatively, we observed the same DNA adducts in control mice as in mice receiving conazoles. However, the 13 adducts with the highest chromatographic mobility were, as a group, present at significantly higher amounts in the livers of mice treated with propiconazole and triadimefon than in their concurrent controls, whereas this same group of DNA adducts in the myclobutanil-treated mice was not different from controls. We hypothesize that this treatment-related increase in endogenous DNA adducts may explain the observed increased in vivo mutation frequencies previously reported to be induced by treatment with propiconazole and triadimefon. This abstract does not necessarily reflect EPA policy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2548. doi:1538-7445.AM2012-2548
Abstract 2553: A non-catalytic function of Rev1 in translesion DNA synthesis and mutagenesis is mediated by its stable interaction with Rad5
Authors: Kuang Lisha , Kou Haiping , Xie Zhongwen , Zhou Ying , Wang Zhigang
Published: August 2012

DNA damage tolerance is a major cellular mechanism in response to unrepaired DNA lesions during replication. It allows replication to completion in the presence of DNA lesions that block replicative polymerases. Damage tolerance consists of two major mechanisms: template switching and translesion DNA synthesis. Translesion synthesis directly copies damaged sites of the DNA template during replication. Consequently, error-prone translesion synthesis constitutes the major mechanism of base damage-induced mutagenesis. In eukaryotes, translesion synthesis is carried out by the Rev1-Polα pathway. Rev1 possesses a dCMP transferase activity, and is a member of the Y family of DNA polymerases. Additionally, it is widely believed that Rev1 plays non-catalytic functions in translesion synthesis. However, the non-catalytic function of Rev1 is not clearly defined. Using the yeast model system, we have investigated non-catalytic functions of Rev1 in translesion synthesis and base damage-induced mutagenesis. Specifically, we examined the role of Rev1-Rad5 interaction in translesion synthesis of UV damage and a site-specific 1, N6-ethenoadenine (a DNA lesion of lipid peroxidation products). Although Rad5 is better known for its role in template switching, it stably interacts with Rev1. Interaction domains in the Rev1 and Rad5 proteins were defined. Translesion synthesis and mutagenesis required Rad5 in cells. Disrupting the Rev1-Rad5 interaction by mutating Rev1 did not affect the dCMP transferase of Rev1, but led to inactivation of the translesion synthesis pathway. These results show that Rad5 is an indispensible component of the Rev1-Pol ≤ pathway for translesion synthesis and base damage-induced mutagenesis, and a non-catalytic function of Rev1 in translesion DNA synthesis is mediated by its stable interaction with Rad5.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2553. doi:1538-7445.AM2012-2553
Abstract 2555: Aberrantly expressed AURKC increases tumorigenicity in cancer cells
Authors: Hung Liang-Yi
Published: August 2012

Aurora-C (AURKC) belongs to the Aurora kinase family, which regulates many important events of the cell cycle. Aberrantly expressed Aurora kinases were demonstrated to be correlated with tumorigenesis. Recently, overexpression of AURKC was detected in human primary colorectal cancers, thyroid carcinoma, and several cancer cell lines. However, the regulation of and clinical index for overexpressed AURKC in somatic cancer cells are unclear. Herein, we showed that AURKC has an augmented expression in human cervical cancer with a statistical significance in its development. Overexpressed AURKC increases the proliferation, transformation, and migration activities in cultured cancer cells and in a xenograft model. Importantly, the kinase activity of AURKC is required for its ability of tumorigenesis. A reporter assay and Western blot analysis further demonstrated that PLZF, a transcriptional repressor, serves as a negative regulator for AURKC. The expressions of PLZF and AURKC mRNA in human cervical cancer displayed opposite patterns. Ectopically expressed HA-PLZF specifically repressed the expression of human AURKC, but not other Aurora kinase members, through recruitment to its promoter region. Taken together, our results provide important insights into human cervical cancer and AURKC expression, which may serve as a potential target for human cervical cancer therapy in the future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2555. doi:1538-7445.AM2012-2555
Abstract 2569: Lyc-O-Mato causes cell cycle arrest and apoptosis in human bladder transitional carcinoma cells
Authors: Bhaskaran Natarajan , Shukla Sanjeev , Ponsky Lee E. , Cherullo Edward E. , Gupta Sanjay
Published: August 2012

Approximately two thirds of new bladder cancer cases in the United States are superficial papillary transitional cell carcinoma (TCC), the majority of which are low-grade neoplasms. Data suggest that bladder carcinogenesis is a multi-step, multi-focal (field effect) process, possibly involving the spread of pre-malignant clones-all of which are prerequisites for effective preventive and/or interventional approaches. Epidemiological data suggests an inverse relationship between serum levels of carotenoids and risk of bladder cancer which has encouraged further investigation. In this study, we evaluated the effect of Lyc-O-Mato® (a crude tomato extract containing 10% lycopene and other tomato phytonutrients viz. tocopherols, phytoene, phytofluene, beta-carotene, phospholipids and phytosterols) on human bladder cancer cell growth, cell cycle modulation, induction of apoptosis, and associated molecular alterations. Treatment of bladder cancer cell lines (T-24, high-grade TCC and TCC-SUP, high-grade invasive tumor) with Lyc-O-Mato® at doses of 1-60µM resulted in inhibition of cell growth along with a G1 arrest in T24 cells and G2/M arrest in TCCSUP cells at 24 h post-treatment. In other studies, Lyc-O-Mato® treatment strongly induced the expression of p21/waf1 and p27/kip1, and resulted in a decrease in cyclin-dependent kinases (CDKs) and cyclins involved in G1 and G2/M progression in T24 and TCC SUP cells. Lyc-O-Mato® exposure to these cells showed an increased interaction between cyclin dependent kinase inhibitors (CDKIs)-cyclin-dependent kinases (CDKs) and decrease in the interaction of cyclins and CDKs with their respective stages of the cell cycle. Furthermore, Lyc-O-Mato® treatment significantly reduced the phosphorylation of Retinoblastoma at Serine780, although no significant changes were observed in the total levels of this protein. In additional studies, Lyc-O-Mato® showed a dose- and time-dependent apoptotic death in both T24 and TCC SUP cells which was associated with significant downregulation of survivin along with the enhancement of pro-apoptotic protein, Bax. These observations provide a strong rationale for further evaluating preventive and/or intervention strategies for Lyc-O-Mato® in pre-clinical models of bladder cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2569. doi:1538-7445.AM2012-2569
Abstract 257: PARP inhibitor induces cytotoxicity in primary lung cancer through caspase induction
Authors: Gangopadhyay Nupur N. , Luketich James D. , Opest Amy , Landreneau Rodney , Schuchert Matthew J.
Published: August 2012

Considering the fact that lung cancer has a high incidental rate among all cancer types, our investigation was aimed to see if PJ34, a PARP inhibitor, could independently exert cytotoxicity in primary lung cancer cells. In the past this PARP inhibitor has been used in combination with other DNA targeted chemotherapeutics or in patients with DNA repair defects (e.g. BRCA mutation), however, based on our published findings we hypothesize that PJ34 can target lung cancer using alternative mechanisms where defects in DNA repair or synthetic lethality are not required. Additionally, we wanted to reveal the specific mechanisms of PARP inhibitor mediated cytotoxicity in lung cancer cells. Anti-cancerous effects of PJ34 were evaluated on six non-small cell lung cancer cell lines developed from surgically resected tissue. Using WST-1 dye and BrdU assay, 30uM (ED50) of PJ34 treatment showed a variable amount of cell survival and DNA synthesis among cultures used herein. Cellular morphological changes in response to the PJ34 treatment were investigated using annexin-V expression, nuclear fragmentation staining, and PARP specific protein in Western blot. Mitochondrial membrane potential changes were measured through JC-1 dye staining and indicated increased stress upon PJ34 treatment. The abundance of Caspase-9 further proves the role of mitochondrial stress in PJ34 treated cells. Immunofluorescent staining for Caspase-3 clearly showed changes towards apoptosis under PJ34 treated vs. untreated conditions. Additionally, a Caspase-3 specific protein band in PJ34 treated cells indicates the possibility of apoptosis through a caspase dependent pathway. Furthermore, lower expressions of PAR in PJ34 treated cells were indicative of PARP inhibition. This study has brought a new paradigm for using PJ34 as a potential therapeutic against lung cancer because of its ability to work regardless of a patient's genetic makeup as well as the possibility of using this group of compounds as independent chemotherapeutic agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 257. doi:1538-7445.AM2012-257
Abstract 2570: Role of PPAR gamma in chemoprevention of renal cell carcinomas by omega-3 fatty acids
Authors: Taub Mary L. , Cutuli Facundo
Published: August 2012

Renal Clear Cell Carcinoma (RCC) is the tenth most prevalent cancer, accounting for 80% of all renal cancers. Recent results of a 15.3 year epidemiological study indicate that a diet of fatty fish offers significant protection against RCC, results which were attributed to omega-3 fatty acids. The question arises as to the molecular mechanisms by which such omega-3 fatty acids exert their protective effect. Our hypothesis is that omega-3 fatty acids exert their protective effects by activating Peroxisome Proliferator-Activated Receptors (PPARs), which in turn reduce the level of expression of Hypoxia Inducible Factor (HIF). The level of HIF increases as a consequence of mutations in the von Hippel Lindau (VHL) gene, which is key to the development of RCCs. In order to begin to examine this hypothesis, primary cultures of renal proximal tubule cells have been examined with regards to their growth responses to PPAR agonists (as the RCC is of renal proximal tubule origin). Fibrate drugs and thiazolidinediones (TZDs) have been identified which have a high affinity for two different classes of PPARs, PPAR alpha and PPAR gamma, respectively. We have observed that troglitazone, a PPAR gamma agonist, caused a 4-fold increase in growth a concentration range of 10-6 to 5 x 10-6 M. A physiologically produced PPAR gamma agonist, Prostaglandin J2 (PGJ2), was also growth stimulatory, albeit to a lesser extent. In contrast, fenofibrate, a PPAR alpha agonist, had no significant affect. In order to examine our hypothesis that PPAR gamma activation affects signaling through HIF, transient transfection studies were conducted with HRE-Luc, a HIF regulatory element/reporter construct. The level of expression of HRE-Luc increases during hypoxia, leading to metabolic changes that promote tumorigenesis. Our studies with HRE-Luc indicate that 5 x 10-6 M troglitazone reduces the increase in HRE-Luc gene expression by over 50%. Similarly, troglitazone prevented the increase in HIF which occurs under normoxia in the presence of the hydroxylase inhibitor dimethyloxalylglycine (DMOG).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2570. doi:1538-7445.AM2012-2570
Abstract 2585: Resveratrol induces autophagy in prostate cancer cells and intervention suppresses the progression of PIN in animals
Authors: Li Guiming , Ghosh Rita , Rivas Paul , Reddick Robert Lee , Kumar Addanki Pratap
Published: August 2012

Resveratrol (3,4′-trihydroxystilbene), a natural product is present in significant concentrations in red wine, peanuts, walnuts etc. Emerging evidence indicates that resveratrol exerts antitumorigenic activity in various tumor models including prostate. Although multiple biological effects on proliferation, apoptosis and activation of SIRT1 have been demonstrated to be associated with resveratrol-induced activities, the precise mechanism associated with resveratrol-induced SIRT1 activation and cancer cell growth inhibition remains unclear. In addition, whether resveratrol intervention suppresses the development and progression of PIN (Prostatic Intraepithelial Neoplasia) is unknown. In this study, we examined the role of SIRT1 and the underlying mechanism involved in resveratrol-mediated biological effects. Our results show that although resveratrol significantly inhibited proliferation of multiple prostate cell lines including RWPE-1, C42B, PC3 and DU145 at higher concentrations (> 50 µM); however, at lower concentrations (< 25 µM), resveratrol prompted cell proliferation. Interestingly androgen responsive LNCaP cells exhibited resistance to resveratrol-mediated inhibition of cell proliferation. Under these experimental conditions, we also observed significant increase in autophagy without remarkable increase in apoptosis. Given the role of Akt/mTOR signaling pathway as a negative regulator of autophagy, we investigated whether resveratrol induce autophagy via modulation of Akt/mTOR signaling. Our data indicate that resveratrol-induced autophagy was associated with decreased levels of mTORC1 activity and increased SIRT1 expression. Knockdown of SIRT1 enhanced prostate cell proliferation and attenuated resveratrol-induced autophagy. Using prostate specific PTEN−/− mice, we found that dietary administration of resveratrol reduced the incidence of high-grade PIN lesions significantly. These findings implicated an important role for mTORC1/SIRT1 signaling axis in mediating resveratrol-induced upregulation of autophagy and inhibition of apoptosis. [Supported by NIH CA137578 (APK)]

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2585. doi:1538-7445.AM2012-2585
Abstract 2590: A novel use of E2f and Cdk inhibitors to prevent RB-null tumours in genetically engineered models of retinoblastoma
Authors: McCurdy Sean R. , Aman Ahmed , Livne-Bar Izhar , Sangwan Monika , Chen Danian , Al-awar Rima , Bremner Rod
Published: August 2012

Over the past few decades, extensive mouse and human genetics have implicated deregulated E2f and Cdk activity in cell exit escape and tumorigenesis. In flies, activating E2f or Cdk causes temporary abnormal division, but both must be induced for long-term aberrant proliferation - a hallmark in benign tumor-prone lesions. Almost invariably, defects in the Rb-E2f or Cip/Kip Cdk inhibitor (CKI)-Cdk2/1 cell cycle regulatory pathways occur together in human cancer. Despite this, little is known in regards to whether dual activation is an obligate feature for tumor susceptibility at initiation in vivo. In human retinoblastoma, homozygous RB1 inactivation is sufficient to initiate the disease. However, mouse retinoblastoma requires inactivation of both Rb1 and one of its family members (p107 or p130). Like pRb, p107 and p130 are best known as E2f inhibitors. Unexpectedly, the additional loss of p107 does not elevate E2f targets follow Rb loss. Instead, Rb/p107-deficient cells induce the E3 ubiquitin ligase Skp2 and activate Cdk2 in vivo. Strikingly, Cdk2 activity tightly correlates with susceptibility to retinoblastoma in our mouse models. Compiling this data, tumorigenesis may have two distinct steps: (1) Rb loss initiates abnormal division, and (2) the additional loss of p107 or, as we have found, p27kip1, both of which lead to Cdk2 activation is required to engender cancer susceptibility. Together, E2f and Cdk dual axes activity is essential for retinoblastoma initiation. To test this notion pharmaceutically, we treated retinoblastoma-prone mice with a Cdk or E2f small molecule inhibitor during the birth period of suspected cancer cell-of-origin. Strikingly, one-week exposure to an inhibitor of either axes curtailed retinoblastoma in Rb/p107- null and Rb/p27-null retinas. These therapeutic successes were achieved without disrupting normal proliferation. Thus, E2f inhibitors, untested in vivo, or Cdk inhibitors, largely unproven as therapeutics, may be ideal chemopreventative agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2590. doi:1538-7445.AM2012-2590
Abstract 2656: Predictors of bloodstream infection associated with permanently implantable venous port in solid cancer patients
Authors: Chen I-Chun , Hsu Chiun , Chien Shu-Fen , Kao Hsiang-Fong , Chang Sin-Yuan , Hu Fu-Chang , Chen Yee-Chun , Yeh Kun-Huei
Published: August 2012

Background There is no literature for stratification of permanent implantable venous ports (Port-A) related bloodstream infection (BSI) in solid cancer patients. We conduct this study to characterize the risk factors of BSI associated with the use of Port-A (PABSI) in solid cancer patients. Methods The study is done in a teaching hospital in Taiwan. Solid cancer patients who were implanted with a Port-A for systemic anti-cancer therapies were prospectively followed for the occurrence of PABSI, defined as BSI without other identifiable infection foci. Patients with PABSI during the follow-up period constitute the case cohort (N = 58) and 174 patients were randomly selected from those without BSI as the control cohort. PABSI risk score was developed by Cox proportional hazards model. Results 416 patients were registered (Table 1). Eighty-eight PABSI episodes occurred in 58 patients, with an incidence of 1.05 per 1000 catheter-days. All but one patient had stage 4 cancer. Independent predictors of PABSI occurrence included neutropenia (HR = 3.86, 95% CI = 1.75-8.50), total parental nutrition (TPN) (HR = 3.51, 95% CI = 1.86-6.63), chronic steroid use (HR = 7.01, 95% CI = 2.78-17.65), invasive procedure (HR = 3.00, 95% CI = 1.29-6.98), postoperative antibiotics (HR = 2.61, 95% CI = 1.43-4.75), and preoperative antibiotics (HR = 0.38, 95% CI = 0.17-0.83). A PABSI risk score, with a cut-off value of 0 (sensitivity 88.5%, specificity 64.3%), was defined for stage 4 cancer patients as follows: neutropenia, +1.350; TPN, +1.256; chronic steroid use, +1.947; preoperative antibiotics, –0.970; postoperative antibiotics, +0.959; and invasive procedure, +1.098. The median PABSI-free survival was 4.47 months for patients with score β0 but not reached for patients with score < 0 (p < 0.0001). Conclusions The PABSI risk score can help define high-risk groups in solid cancer patients and may help design future preventive strategies. Presence of any risk factor would render patients as high risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2656. doi:1538-7445.AM2012-2656
Abstract 2675: CXCL12 (SDF-1) and its truncation products in patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) receiving ON 01910.Na (Rigosertib) in phase I trials
Authors: Cho Sool Y. , Navada Shyamala C. , Silverman Lewis R. , Holland James F. , Roboz John
Published: August 2012

CXCL12 (stromal cell-derived factor, SDF-1), is an 8 kDa peptide chemokine. The interaction between CXCL12 and its receptor, CXCR4, plays a pivotal role in the trafficking of hematopoietic stem cells between bone marrow and peripheral blood. The CXCL12/CXCR4 axis may play a role in the pathogenesis of myeloid neoplasms. We developed a technique for the determination of intact (full length) CXCL12 and its protease(s)-induced truncation products in plasma from patients with myeloproliferative neoplasms (Cancer Res., 70, 3402, 2010). In the present work, we are extending our observations to the myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). CXCL12 concentrations in normal subjects were 16.6 ± 9.4 ng/mL (n=10). In primary myelofibrosis (PMF), the concentrations were 5.8 ± 4.0 ng/mL (n=15), and in polycythemia vera (PV) 7.9 ± 3.6 ng/mL (n=21). Now we report that in MDS/AML, the concentrations are 2.2 ± 2.1 ng/mL (n=8). In normal subjects, truncation products, due to proteolysis, were not detectable (≥ 1.0 ng/mL). The loss of 2, 3, 4, and 5 amino acids (aa) from CXCL12 were confirmed by molecular masses measured using electrospray ionization mass spectrometry. Quantification was completed with synthetic standards. In MDS/AML patients the concentration of the truncation product corresponding to −2 aa (KP removed),-3 aa (KPV removed), −4 aa (KPVS removed) and −5 aa (KPVSL removed) were 2.7 ± 3.2 ng/mL, 2.4 ± 2.1 ng/mL, 3.8 ± 3.0 ng/mL, and 2.5 ± 2.4 ng/mL, respectively. The total concentration of all truncation products was 11.3 ± 5.8 ng/mL. For comparison, the concentration of total truncation products was 28.7 ± 19.9 for PMF, and 31.1 ± 7.8 for PV. Patients with these myeloid malignancies have lower CXCL12 concentrations compared to normal controls and high concentrations of proteolytic truncation products which are absent in normal plasma. Of the 8 patients with MDS (n=3) and AML (n=5), treated with continuous infusion of ON 01910.Na (rigosertib), 650 - 1,700 mg/m2, in a Phase I dose escalation study, 4 patients attained a partial or complete bone marrow remission according to International Working Group criteria. The concentration of intact CXCL12 rose at 72 h in responding patients, whereas those who failed to respond had a decrease. These data suggest that monitoring intact CXCL12 and its truncation products may provide a marker of response to treatment with ON 01910.Na, as well as insight into the role of the CXCL12/CXCR4 axis in the pathobiology of these bone marrow diseases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2675. doi:1538-7445.AM2012-2675
Abstract 268: Regulation of the UDP-glucuronosyltransferases (UGTs) by UV exposure in human melanocytes
Authors: Dellinger Ryan W. , Ahmed Amelia S. , Duong Priscilla H. , Meyskens Frank L.
Published: August 2012

The UDP-glucuronosyltransferase (UGT) family of enzymes catalyzes the glucuronidation of a variety of endogenous compounds such as bilirubin and steroid hormones, as well as xenobiotics including chemotherapeutic agents and environmental carcinogens. Glucuronidation of these substrates inactivates them by making them more hydrophilic and easily excreted. UGTs are expressed primarily in the liver, but are also expressed in several extra-hepatic tissues including prostate, breast, colon, lung, brain, kidney, bladder and ovary. We have demonstrated that three UGT family members (UGT2B7, UGT2B10 and UGT2B15) are normally expressed in human melanocytes isolated form neonatal foreskin. Further, we screened several primary and metastatic melanoma cells lines for UGT expression. Interestingly, of all the melanoma cell lines screened only WM115, a primary melanoma, had UGT expression. Again, only UGT2B7, UGT2B10 and UGT2B15 were detected. UGT expression was not detected in another primary melanoma cell line, WM3211, or in any of the four metastatic melanoma cell line assayed suggesting that loss of UGT expression occurs during melanoma progression. To elucidate if ultraviolet (UV) light could be the underlying cause to the disappearance of UGTs in melanoma progression, human melanocytes were subjected to UV-B radiation at low and high (sunburn) doses. Melanocytes were collected at 1, 5 and 24 Hrs post UV-B treatment and UGT expression was analyzed by quantitative real-time PCR. Expression of UGT2B7, UGT2B10 and UGT2B15 all was significantly reduced in response to both low and high dose UV-B. In general, loss of UGT expression was observed even at 1 hour after exposure, reached maximal low levels at 5 hours and started to return to normal levels at 24 hours post exposure. We hypothesize that reduction of UGT expression in melanocytes following a sunburn would increase an individuals risk for melanoma since the UGTs detoxify environmental carcinogens. This hypothesis is consistent with a causative role for UV in melanoma in which ‘classical’ UV-induced DNA damage is not observed; a problem that has long puzzled investigators.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 268. doi:1538-7445.AM2012-268
Abstract 2682: New diagnostic and therapeutic target KU-MEL9 for chronic myeloid leukemia (CML)
Authors: Matsushita Maiko , Suzuki Takuma , Tsutsumida Naoya , Iijima Shiro , Tsukamoto Nobuo , Kawakami Yutaka , Matsuki Eri , Okamoto Shinichiro , Hattori Yutaka
Published: August 2012

Overall survival of patients with chronic myeloid leukemia (CML) has dramatically changed over past ten years by the introduction of targeted therapy with tyrosine kinase inhibitors (TKIs). However, it has been reported that more than half of patients eventually relapse after the cessation of TKIs, suggesting that CML cells including leukemic stem cell (LSC) cannot be completely eradicated by TKIs. To this end, the identification of targets expressed in LSC is crucial for developing highly effective therapies for CML. In this study, we evaluated the gene expression of cancer testis antigen KU-MEL9, which was found in melanoma research, in a variety of human cell lines. This gene was highly expressed in several cell lines of hematological malignancies including CML and multiple myeloma (MM). We then investigated the gene expression of KU-MEL9 in bone marrow samples from 20 CML patients by standard RT-PCR method. Gene expression of KU-MEL9 were found in 17 patients (85%), and correlated with the expression of BCR-ABL fusion gene in most of the cases. On the other hand, 6 samples from normal donors didn't express this gene. In 2 CML patients who achieved a molecular remission with imatinib, the expression of KU-MEL9 gene was still observed, although BCR-ABL gene was not detected. It suggested that KU-MEL9 was expressed in residual CML cells including LSC and could be a more sensitive biomarker for CML patients. We also examined the possibility of KU-MEL9 being as a target of cytotoxic T cells (CTL) for immunotherapy to eradicate remaining LSCs after TKI treatment. Although this study had limited number of patient sample, KU-MEL9 may be a useful target for diagnosis and treatment for CML patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2682. doi:1538-7445.AM2012-2682
Abstract 2684: Imaging lung colony formation by osteosarcoma cells expressing αv integrin-GFP in nude mice
Authors: Tome Yasunori , Sugimoto Naotoshi , Yano Shuya , Momiyama Masashi , Maehara Hiroki , Tsuchiya Hiroyuki , Tomita Katsuro , Kanaya Fuminori , Bouvet Michael , Hoffman Robert M.
Published: August 2012

We report here imaging the behavior of αv integrin linked to GFP in osteosarcoma cells which are colonizing the lung of nude mice. 143B osteosarcoma cells expressing αv integrin-GFP were generated by transfection of an αv integrin-GFP vector. Confocal microscopy with the FV1000 (Olympus Corp., Tokyo, Japan) demonstrated that αv integrin immunofluorescence staining colocalized with αv integrin-GFP fluorescence. To generate pulmonary colonies, osteosarcoma cells, stably expressing αv integrin-GFP, were injected intravenously (1×106) via the tail vein of nude mice. Eight weeks after injection, both lungs were harvested and observed by confocal microscopy within 1 hour after harvesting. Scattered-expression of αv integrin-GFP was observed in the pulmonary osteosarcoma colonies. In contrast, osteosarcoma cells strongly expressed αv integrin-GFP when aligned along the edge of colonies and around blood vessels. Expression of αv integrin-GFP can be imaged in lung metastasis which will allow further understanding of its role in this process.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2684. doi:1538-7445.AM2012-2684
Abstract 2686: Methioninase S-phase block of cancer cells imaged in real time by cell-cycle-specific fluorescence reporters
Authors: Yano Shuya , Li Shukuan , Han Qinghong , Tan Yuying , Fujiwara Toshiyoshi , Hoffman Robert M.
Published: August 2012

A general feature of cancer cells is their elevated requirement for methionine compared to normal cells, which may be due to excessive methylation reactions in cancer cells since methionine is the global source of cellular methyl groups. When deprived of methionine, cancer cells undergo a cell-cycle arrest in late S-phase. The recombinant bacterial enzyme, methionine β, α-lyase (methioninase or METase) degrades methionine very efficiently and effects an S-phase block selectively in cancer cells. In order to image the kinetics of cell cycle arrest of cancer cells due to deprivation of methionine by METase, cancer cells were engineered to express cell cycle-dependent fluorescent proteins using fluorescent ubiquitination-based cell cycle indicator (FUCCI) whereby cancer cells express Azami-green only in S-phase and Kusabira-orange only in G1. Thus, each cancer could be followed in real time as it becomes blocked in S-phase after METase treatment. FUCCI imaging demonstrated that cancer cells could remain in S-phase for 5 days before starting to die which indicates a new type of cancer cell dormancy. The use of METase treatment and cell-cycle specific fluorescent reporters provide a unique opportunity to image and study the cancer cell cycle and the consequences and advantages of an S-phase block in cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2686. doi:1538-7445.AM2012-2686
Abstract 2744: Identification of synergistic effect of autophagy inhibitors and resveratrol on BRCA1 mutant cancer cells
Authors: Vazquez-Ortiz Guelaguetza , Chisholm Cristine L. , Huang Ruili , Li Cuiling , Xu Xiaoling , Rui-Hong Wang , Deng Chuxia
Published: August 2012

Over 200,000 new breast cancer cases are diagnosed in the US each year, with 5% of cases caused by mutations in BRCA1 (Breast cancer associated gene 1). Mutation carries have a lifetime risk of up to 80% for developing breast cancer. Current treatment options are limited and often do not lead to cure. We showed previously that treatment with resveratrol, although initially reduced more the tumor size in BRCA1 mutant (mt) tumors, with respect to BRCA1 wild-type (wt) in mice, tumors continued to grow after prolonged treatment. To identify small molecules that can be repurposed and synergize the killing effect of resveratrol in BRCA1-mt tumors, we screened the NCGC Pharmaceutical Collection in which, more than 52% are drugs approved for human or animal use by FDA, and the rest are drugs approved in other countries or in clinical trial. Using a high-throughput cell viability assay by measuring intracellular ATP content, we identified the inhibitory effect of 43 compounds that exhibited synergy with resveratrol (Res) with efficacy>50% and potency <35uM. We further analyzed 4 of them, cantharidin, chloroquine, amodiaquin and colchicine for in vivo study. Utilizing BRCA1-mt breast tumor implant models in aythymic mice reveal that mice treated with combination therapy (Drug + Res) exhibit significantly reduced tumor volumes and increased survival rate compared with mice on monotreatment and this effect was even more significant when compared to wt-BRCA1. Also, some mammary tumors developed in the BRCA1 mammary tissue specific mutant mice exhibited a total regression with combination therapy. In order to identify a shared molecular and biochemical change which make BRCA1-mt cancer cells more susceptible to the combination treatment, we found that these compounds inhibit autophagy at different levels, targeting the mTOR/AKT pathway at different levels and/or inhibiting the fusion between the lysosome and the phagosome producing strong vacuolization in the cytoplasm during treatment, increasing LC3-II in a Beclin independent manner, followed by a faster induction of apoptosis on the BRCA mutant cells. This approach offers the potential to combat breast cancer cells and sensitize BRCA1 deficient cells to more effective treatments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2744. doi:1538-7445.AM2012-2744
Abstract 2751: Protective effects of phenylaminoethyl selenide (PAESe) on doxorubicin-induced cardiotoxicity in vitro and in vivo
Authors: Kang Jeong Yeon , Costyn Leah J. , Nagy Tamas , Cowan Elizabeth A. , Oldham Charlie D. , May Sheldon W. , Arnold Robert D.
Published: August 2012

Anthracyclines are potent anticancer agents that are effective in the treatment of acute leukemia, non-Hodgkin's lymphomas, breast, ovarian and lung cancers, but their clinical use is hampered by dose-limiting cardiotoxicity mediated by free radicals generation. We determined the ability of phenyl-2-aminoethyl selenide (PAESe), a novel antioxidant, to reduce doxorubicin (DOX)-induced cardiotoxicity. Growth inhibitory effects of PAESe on human breast carcinoma (BT-474) and prostate adenocarcinoma (PC-3) cells were determined alone and in combination with two clinically used anticancer agents, DOX, a topoisomerase-2 antagonist known to generate reactive oxygen species (ROS), and vincristine (a tubulin binding agent) and a known oxidant, tert-butylhydroperoxide (TBHP). Conventional growth inhibitory assays, i.e., sulforhodamine B (SRB) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) staining, were used to determine in vitro activity. Treatment effect on intracellular formation of ROS was also determined by quantifying the oxidation of a cell-permeant indicator H2DCFDA. The effect of PAESe on cardiomyocytes was determined in NCr (nu/nu) mice with DOX (5 mg/kg), PAESe (10 mg/kg), concomitant (DOX & PAESe) therapy, and saline controls were administered by tail vein injections weekly over 12 weeks. Histopathological examination was performed to look for evidence of cardiotoxicity. PAESe did not alter the growth of BT-474 or PC-3 cells up to 10 uM. However, co-administration of PAESe decreased the oxidative-mediated cytotoxicity of TBHP in a dose-dependent manner, but had limited to no effect on vincristine or DOX antitumor activity. Further, PAESe decreased the formation of intracellular ROS from TBHP and DOX in a dose-dependent manner. Histological examination showed PAESe decreased short-term DOX-mediated infiltration of neutrophils and macrophages into the myocardium and more chronic evidence of necrotic foci, suggesting PAESe decreased early and late myocardial damage following initial and prolonged DOX treatments, unlike other antioxidants. Concomitant administration of PAESe did not alter the antitumor activity of DOX in vivo, nor did it reduce treatment mediated weight-loss associated with DOX. These data suggest that PAESe may be used in combination with DOX to preserve its antitumor activity, but decrease free radical generation and cardiotoxicity associated with use of anthracyclines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2751. doi:1538-7445.AM2012-2751