bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5446: Green tea catechin intervention of reactive oxygen species-mediated ERK pathway activation, DNA damage, and chronically-induced breast cell carcinogenesis
Authors: Wang Hwa-Chain R. , Rathore Kusum , Choudhary Shambhunath
Published: August 2012

Long-term exposure to low doses of environmental carcinogens contributes to sporadic human breast cancers. Epidemiologic and experimental studies indicate that green tea catechins (GTCs) may interfere with breast cancer development. We have been developing a chronically-induced breast cell carcinogenesis model wherein we repeatedly expose non-cancerous, human breast epithelial MCF10A cells to physiologically-achievable pico-molar concentrations of environmental carcinogens 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and benzo[a]pyrene (B[a]P), to progressively induce cellular acquisition of cancer-associated properties, as measurable endpoints. The model is then used as a target to identify non-cytotoxic preventive agents effective in suppressing cellular carcinogenesis. Here, we report a two-step strategy that initially used short-term endpoints that were transiently-induced by a single exposure to NNK and B[a]P. These short-term endpoints were used as targets to detect the ability of individual GTC components to block carcinogenesis. We subsequently used long-term endpoints that were constantly-induced by cumulative exposures to carcinogens as targets to verify and compare the activity of individual GTC components in suppressing carcinogenesis. We detected that a single exposure to NNK and B[a]P resulted in elevation of reactive oxygen species (ROS), leading to ERK pathway activation and induction of cell proliferation and chromosomal DNA damage. GTC components, at non-cytotoxic levels, were able to suppress chronically-induced cellular carcinogenesis by blocking carcinogen-induced ROS elevation, ERK activation, cell proliferation, and DNA damage in each exposure cycle. Our model may help accelerate the identification of agents to prevent carcinogenesis induced by long-term exposure to environmental carcinogens, thereby safely and effectively reducing the health risk of sporadic breast 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 5446. doi:1538-7445.AM2012-5446
Abstract 545: Autocrine growth regulation by PEDF is mediated by ovarian steroid hormones: Implications in the pathogenesis of endometrial carcinoma
Authors: Huang Kuang-Tzu , Pavlides Savvas C. , Mittal Khushbakhat , Blank Stephanie V. , Crawford Susan E. , Gold Leslie I.
Published: August 2012

The angiogenic inhibitor and neurotrophic factor, pigment epithelium-derived factor (PEDF) was first shown in the eye and is now shown to be expressed in a number of tissues and to function in apoptosis and growth inhibition. The importance of PEDF in growth regulation of the endometrium is reflected in PEDF null mice, which develop endometrial hyperplasia. Therefore, we hypothesized that PEDF is decreased in human endometrial carcinoma with loss of growth inhibition. We show by immunostaining (n=44) that PEDF expression is decreased in both stromal and epithelial cells in atypical endometrial hyperplasia (AEH), the precursor to type I endometrial carcinoma (ECA; 80% of all ECAs) and ECA. Whereas PEDF is highly expressed by primary endometrial epithelial cells (EECs) and stromal cells, ECA cells synthesize less protein and stromal cells isolated from malignant endometrium (cancer associated fibroblasts; CAFs) synthesize 80% less PEDF mRNA (n=35) by quantitative real time PCR and less PEDF protein. In addition, whereas exogenous recombinant PEDF inhibits proliferation of ECA cell lines (e.g. HEC-1B by 40%; peak response at 4nM), PEDF antibodies and PEDF siRNA stimulate proliferation suggesting PEDF inhibits cell proliferation in an autocrine manner in the endometrium. Estrogen (E2) stimulates and progesterone (Pg) inhibits proliferation of the endometrium in a cyclical manner. Due to these hormonal growth regulatory effects, E2 induces AEH and Type I ECA and Pg is a successful therapeutic agent for these diseases. Therefore, we further hypothesized that E2 decreases PEDF causing dysreglated growth and conversely, that Pg might inhibit growth by increasing PEDF. Indeed, we show that treatment of the ECA cell lines, HEC-1A, HEC-1B, KLE and primary EECs with E2 decreased PEDF mRNA and protein expression, which was blocked by the estrogen receptor (ER) antagonist, ICI 182,780. In direct contrast, Pg increased PEDF mRNA and protein, which was blocked by the antagonist, RU486. It is notable that the PEDF promoter contains two putative PREs and one ERE thereby justifying these responses. Taken together, our data implicate PEDF as an autocrine hormone-regulated inhibitor of endometrial growth and suggest that the E2-driven decrease in PEDF leads to dysregulated endometrial growth as an important molecular target in the pathogenesis of type I ECA.

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 545. doi:1538-7445.AM2012-545
Abstract 5452: In utero exposure to bisphenol A promotes mammary tumor development in MMTV-erbB-2 transgenic mice
Authors: Ma Zhi-Kun , Cao Xia , Yang XiaoHe
Published: August 2012

Increasing evidence indicates that environmental exposure plays a critical role in breast cancer etiology. Bisphenol A (BPA), the building block of polycarbonate plastics with estrogenic activity, is one of the most common chemicals exposed in daily life. Recent studies suggest a link between BPA exposure and increased breast cancer risk. However, specific conditions and the underlying mechanisms of BPA exposure associated breast cancer risk remain unclear. This study aimed to investigate the effects of in utero exposure to BPA on mammary tumor development in MMTV-erbB-2 transgenic mice, which exemplifies a scenario of gene-environmental interaction. Since erbB-2 is amplified/overexpressed in approximately 30% of breast cancer, which has been associated with poor prognosis and therapeutic resistance, use of this clinically relevant mammary tumor model is of high translational value. In this study, pregnant MMTV-erbB-2 mice were subcutaneously injected with 0, 25 ng, 250 ng and 250 µg/Kg body weight BPA daily between day 13 and day 19 of gestation. We found that in utero exposed mice in the low dose (25 and 250 ng) groups, but not the high dose group (250 µg), displayed earlier vaginal opening and prolonged estrous phase, suggesting a dose dependent pro-estrogenic effect of in utero exposure to BPA. Whole mount analysis showed that mammary glands of mice with in utero exposure to low dose BPA had a longer ductal extension at 6 weeks and increased lateral branching/alveolar structures at 10 weeks, which was more significant in the 250 ng group but less evident in the high dose group. Molecular analysis of mammary tissues at 10 weeks indicated that in utero exposure to BPA increased phosphorylation/activation of erbB-2, EGFR, erbB-3 Erk1/2 and Akt, and expression of erbB-3 and EGFR. Signaling of estrogen receptor (ER) pathway was upregulated concomitantly, as reflected by increased expression and phosphorylation of ERα and upregulation of cyclin D1 and c-myc. More importantly, mice in the 250 ng group but not the high dose group, developed tumor earlier than the mice in the control group, suggesting that dose is a critical factor affecting the outcomes. These data demonstrated that in utero exposure to BPA may promote mammary tumor development in erbB-2 transgenic mice in a dose dependent manner. Concomitant activation of the erbB-2 and ER pathways in the premalignant tissues suggests that induction of ER-erbB-2 crosstalk may play a critical role in mammary tumorigenesis promoted by in utero exposure to BPA, which underscores the significance of gene-environment interaction in early exposure to BPA associated breast cancer 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 5452. doi:1538-7445.AM2012-5452
Abstract 5464: Genotoxicity of multi-walled carbon nanotubes at occupationally relevant doses
Authors: Sargent Linda M. , Reynolds Steven H. , Lowry David , Kashon Michael L. , Benkovic Stanley A. , Salisbury Jeffery L. , Hubbs Ann F. , Young Shih-Houng , Siegrist Katelyn J. , Keane Michael J. , Mastovich John , Bunker Kristin , Sturgeon Jacqueline , Cena Lorenzo , Dinu Cerasela-Zoica
Published: August 2012

Carbon nanotubes represent a creative alternative for applications in medicine as therapeutic vectors, imaging and controlled release of active molecules. Although the low density and small size of carbon nanotubes makes respiratory exposures to workers likely during the production or use of commercial products, the potential genotoxicity of multi-walled carbon nanotubes has not been investigated. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to single-walled carbon nanotubes (SWCNT). In order to investigate whether genetic damage was unique to SWCNT, we examined mitotic spindle aberrations following dosing of cells to multi-walled carbon nanotubes (MWCNT) at concentrations anticipated in the workplace. Immortalized and primary respiratory epithelial cells were exposed to 0.024, 0.24, 2.4, and 24μg/cm2 carbon nanotubes. The minimal dose of MWCNT considered for this research was based on the permissible exposure limit for particles with an aerodynamic diameter of less than 5 microns (Occupation Safety and Health Administration). MWCNT induced a dose response of disrupted centrosomes, mitotic spindles and aneuploid chromosome number. The data further showed that monopolar mitotic spindles comprised 95% of the disrupted mitoses. The monopolar phenotype of the disrupted mitotic spindles is in sharp contrast to the multi-polar spindle of SWCNT-induced disruption. Three-dimensional reconstructions showed carbon nanotubes integrated with the microtubules, the DNA and within the centrosome structure. The lower doses did not cause cytotoxicity or apoptosis 24 hours after exposure; however, after 72 hours, significant cytotoxicity was observed in the MWCNT-exposed cells. Disruption of the centrosome is common in many solid tumors including lung cancer. The resulting aneuploidy is a key event in the progression of cancer and is correlated with tumor stage. Our results demonstrate significant disruption of the mitotic spindle by MWCNT at occupationally relevant doses. These results suggest caution should be used in the handling and processing of carbon nanotubes.

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 5464. doi:1538-7445.AM2012-5464
Abstract 5558: Interplay between BRAF, p16, p53, and MIB1 in pediatric low grade gliomas
Authors: Horbinski Craig , Nikiforova Marina N. , Hagenkord Jill , Hamilton Ronald L. , Pollack Ian F.
Published: August 2012

BRAF rearrangements and BRAF V600E point mutations are recurring events in pediatric low-grade gliomas. However, their clinical significance, including possible interactions between these markers and other glioma biomarkers, is unclear. In this study a retrospective cohort of 198 pediatric low-grade gliomas (including 40 treated with adjuvant therapy) was analyzed for BRAF rearrangements, BRAF V600E, p16/CDKN2A deletion, p53 expression, and MIB1 proliferation index. In tumors with BRAF rearrangement, homozygous p16 deletion correlated with shorter PFS (P = 0.04). High MIB1 proliferation index strongly trended toward correlating with worse response to adjuvant therapy (P = 0.06). On multivariate analyses, the two most consistently powerful independent adverse prognostic markers were midline location (P = 0.0001) and p16 deletion (P = 0.03). Tumors with BRAF V600E had a strong trend toward an increased risk for progression (hazard ratio = 2.48, P = 0.07), whereas those with BRAF rearrangement had a milder trend toward reduced risk (hazard ratio = 0.54, P = 0.15). These data suggest that p16 deletion adversely impacts the outcomes of BRAF-driven gliomas; that high proliferation index may be a better marker of progression risk than BRAF; that BRAF rearrangement and BRAF V600E might not necessarily produce comparable outcomes; and that none of these markers is stronger than tumor location in determining prognosis in pediatric low-grade gliomas.

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 5558. doi:1538-7445.AM2012-5558
Abstract 5572: Prognostic significance of TS, TK, OPRT and DPD activities in renal cell carcinoma
Authors: Mizutani Yoichi , Uehara Hiroshi , Fujisue Yutaka , Takagi Shizuko , Nishida Takeshi , Inamoto Teruo , Ubai Takanobu , Nomi Hayahito , Azuma Haruhito
Published: August 2012

Introduction: Thymidylate synthase (TS) and thymidine kinase (TK) are the key enzymes in the de novo and salvage DNA synthetic process, respectively. Orotate phosphoribosyltransferase (OPRT) plays an important role in the de novo pathway of DNA and RNA synthesis. In contrast, dihydropyrimidine dehydrogenase (DPD) is a key enzyme involved in degradation of DNA and RNA. We examined the activities of TS, TK, OPRT and DPD in 83 renal cell carcinomas and normal kidneys and evaluated the clinical significance. Methods: TS, TK, OPRT and DPD activities in non-fixed fresh frozen renal cell carcinomas and normal kidneys were determined enzymatically by the FdUMP binding assay, the DEAE cellulose disc method, the 5-FU phosphorylation assay and the 5-FU degradation assay, respectively. Results: TS activity was 5-fold higher in renal cell carcinoma compared to normal kidney. TS activity in Stage III/IV renal cell carcinoma was 3-fold higher than that in Stage I/II renal cell carcinoma. In addition, the level of TS activity in Grade 3 renal cell carcinoma was 2-fold higher than that in Grade 1 and Grade 2 carcinomas. TK activity was approximately 4-fold higher in normal kidney compared with renal cell carcinoma. TK activity in Stage IV renal cell carcinoma was 2-fold higher than that in Stage I-III renal cell carcinoma. Furthermore, the level of TK activity in Grade 3 renal cell carcinoma was 2-fold higher than that in Grade 1 and Grade 2 carcinomas. OPRT activity was approximately 7-fold higher in renal cell carcinoma compared to normal kidney. OPRT activity in Stage III/IV renal cell carcinoma was 2-fold higher than that in Stage I/II renal cell carcinoma. The level of OPRT activity in Grade 3 renal cell carcinoma was 3-fold higher than those in Grade 1 and Grade 2 carcinomas. DPD activity was approximately 2-fold higher in normal kidney compared to renal cell carcinoma. The higher stage and grade of renal cell carcinoma was, the lower DPD activity was observed. The level of OPRT activity correlated with those of TS and TK activities. However, DPD activity was not associated with TS activity. High TS, TK, OPRT activities and low DPD activity predicted worse prognosis in patients with renal cell carcinoma.Conclusions: The present study has demonstrated that TS, TK, OPRT and DPD activities in renal cell carcinoma correlated with the stage/grade status of renal cell carcinoma. In addition, the levels of TS, TK, OPRT and DPD activities were prognostic parameters in patients with renal cell carcinoma.

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 5572. doi:1538-7445.AM2012-5572
Abstract 5584: Disregulation of phosphorelated Amplified In Breast Cancer3 (AIB3) contributes to poor prognosis and mediates trastuzumab efficacy in breast cancer patients
Authors: Zhang Hao , Dong Hongmei , Chen Yuping , Zhong Xueyun
Published: August 2012

Trastuzumab (Herceptin) is the first line HER2 (ErbB2)/neu-directed therapy for the treatment of patients with metastatic breast cancer. Although the efficacy of trastuzumab depends on the HER2/neu status of the tumour, the single-agent response rate ranges from 12 to 30% and ew patients respond to trastuzumab monotherapy largely due to various resistance mechanisms. Amplifeid In Breast Cancer3 (AIB3) is a transcriptional coactivator. AIB3 plays an important role in embryonic development, adipocyte differentiation, metabolism. AIB3 was initially found to be amplified in subgroup of breast cancer patients. Our previous data using knockout mouse mode combined cell culture indicate that AIB3 plays important role in breast tumorigenesis. Here we report that AIB3 can be phosphorylated by MAPK at S884 site and phosphorylation at S884 of AIB3 dramatically reduced ligand-dependent AIB3 interactions with estrogen receptors when compared with the wild-type unphosphorylated form, although there was a significant increase of interactions with the unliganded receptor. Misexpression of phosphorylated AIB3 was observed in human breast cancer tissues and disregulation of phosphorylated AIB3 was associated with patients’ poor prognosis. Breast cancer is a heterogeneous disease and intrinsic subtypes play an extremely important role in improve on current standards for breast cancer prognosis and prediction of chemotherapy. Noticeably, phosphorylated AIB3 was highly expressed in Her2-enriched subtype of human breast cancer patients, as well as in the mammary tumor of MMTV-Her2 transgenic mice. Mechanism studies reveal that phosphorylated AIB3 alters trastuzumab efficacy in cultured breast cancer cells. The association between pAIB3 and important clinical outcomes confers pAIB3 a significant prognostic marker in breast cancer. Phosphorylated AIB3 as a modulator in ErbB2-MAPK regulating loop represents a potentially novel mechanism for trastuzumab (herceptin) efficacy. The implied interaction between pAIB3 and Her2 suggests the potential of dual targeting of Her2 and pAIB3 as a promising therapeutic approach for personalized breast 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 5584. doi:1538-7445.AM2012-5584
Abstract 5586: Phase I study of PARP inhibitor ABT-888 and carboplatin with novel imaging in metastatic breast cancer (MBC) (NCI-8609)
Authors: Ramaswamy Bhuvaneswari , Lustberg Maryam B. , Wesolowski Robert , Layman Rachel M. , Mrozek Ewa , Olson Erin M. , Andreopoulou Eleni , Garcia-Villa Alejandra , Chalmers Jeff , Cotrill Jeffrey A. , Nutter Julie , Ledin Jamie , Schaaf Larry J. , Bajestani Saeed , Zhao Weiqiang , Geyer Susan , Chen Alice , Shapiro Charles L. , Villalona-Calero Miguel A. , Knopp Michael , Grever Michael R.
Published: August 2012

Purpose: ABT-888 is an oral inhibitor of PARP 1 and 2 and potentiates activity of platinums in preclinical models. We are conducting a phase I study of ABT-888 on 2 different schedules (7 and 14 day) plus q 3 week carboplatin (C) to identify the recommended phase II dose schedules (RPTD-7and 14 day) for this regimen in patients (pts) with MBC who are: (1) triple negative (TN); or (2) estrogen receptor positive (ER+) with defective Fanconi Anemia (FA) pathway (no FANCD2 foci in tumor). Study design: Eligible pts received C-AUC 5 Q 3weeks (except dose level 1-AUC 6) plus escalating doses of ABT-888 BID on a 7 or 14-day schedule using a 3+3 dose escalation design. Blood samples were collected during cycles 1 and 2 for PAR assay and CTCs isolated to measure gamma H2Ax. We performed 3′-[F-18] Fluoro-3′-deoxythymidine(FLT) PET scans to assess cellular tumor proliferation at baseline, cycle 1 day 7 and 14 and after cycle 3. FDG-PET-CT scans were used to assess response. Results: 22 pts (20-TN, 2-ER+ w/FA defect) with median age of 56.5 yrs (range 31-69) were enrolled on 5 dose levels. Dose level 1 with C at AUC 6 was too toxic with 3 DLTs (Table 1). Further dose escalations were performed with C at AUC-5. Dose reductions in C were made in subsequent cycles for thrombocytopenia, anemia and fatigue. Maximum reduction in thymidine uptake in tumors was seen on day 7 FLT scans. CTCs were isolated using an immunomagnetic negative depletion method on 8 pt samples to date (median-59, range 0-684 CTCs). Gamma H2Ax analysis on sequential samples is ongoing. Four pts have had an unconfirmed partial response (PR) with > 50% tumor shrinkage; 2 of the 4 pts had a defective FA pathway. Conclusions: Thrombocytopenia is the major DLT when ABT-888 is given in combination with C, where lower AUC of C is better tolerated and shows promising activity of this combination. FA deficiency (5/14=27%) seen in this group is consistent with our previous reports. The study is supported U01 CA076576.

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 5586. doi:1538-7445.AM2012-5586
Abstract 5595: ALK mutant-driven cell lines develop crizotinib resistance by secondary mutations and ALK-independent means
Authors: Faber Andrew L. , Johnson Lori J. , Thomas James E.
Published: August 2012

The clinical success of crizotinib against mutant ALK-expressing cancers has generated great interest; however, the emergence of drug resistance is limiting its durability in some patients. In NSCLC, crizotinib resistance is linked to secondary mutations within EML4-ALK at amino acids L1196M, C1156Y, L1152R. A mutation at amino acid F1174L reduced the sensitivity to criozotinib in a patient with an inflammatory myofibroblastic tumor harboring a RANBP2-ALK translocation. The goal of our studies was to evaluate mechanisms of crizotinib resistance in a range of ALK-mutant expressing cell lines. Cells from ALCL (Karpas299), NSCLC (NCI-H3122 and NCI-H2228) or neuroblastoma (SKNSH and KELLY) developed resistance to crizotinib after being exposed to incremental increases in the compound over several weeks. NPM-ALK expressing Karpas299 cells independently acquired point mutations in ALK at amino acids N1178H and I1171N. As the concentration of drug was increased, cells that harbored the NPM-ALK N1178H mutation also expressed a mutation at G1269A. Each mutation enhanced the temperature dependent auto-phosphorylation activity of the kinase and diminished the inhibitory effect of crizotinib on downstream ALK signaling. Mutations in Karpas299 cells were also accompanied by up regulation of a drug efflux transporter, BCRP, whose heightened expression level was dependent on the presence of the compound. In contrast no additional mutations were discovered in ALK in crizotinib resistant NCI-H3122 and NCI-H2228 (EML4-ALK) or SKNSH and KELLY (ALK F1174L) cell lines. Instead both NCI-H3122 and NCI-H2228 resistant cell lines displayed increased levels of phospho-HER2 and HER3 and activation of AKT and ERK that may be due to autocrine secretion of a growth factor. NSCLC resistant lines also displayed an apparent change in phenotype with a mesenchymal-to-epithelial transition. SKNSH and KELLY are inherently less sensitive to crizotinib. We found that these cells may survive exposure to high levels of the compound by altering RET expression. Our observations represent potential mechanisms of resistance demonstrated in a small number of cell lines. It will be important to align these results with emerging data from drug-resistant patients to understand the multiple mechanisms by which resistance might develop.

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 5595. doi:1538-7445.AM2012-5595
Abstract 5604: Targeting survivin (BIRC5) with YM155 for the treatment of head and neck squamous cell carcinoma
Authors: Kumar Bhavna , Yadav Arti , Teknos Theodoros N. , Kumar Pawan
Published: August 2012

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer worldwide and five-year survival rate (<50%) is among the lowest of the major cancers. Treatment of advanced head and neck tumors remains a challenging clinical problem, due to the persisting high rate of local and distant failure. Currently, many advanced stage head and neck tumors are being treated with concurrent chemoradiation therapy but this treatment regimen is often associated with significant toxicity. Recent research efforts have attempted to develop targeted tumor-specific therapies to minimize normal tissue toxicity but maximize therapeutic benefits. One such potential target for HNSCC is survivin (a member of the inhibitor of apoptosis protein family), which is often overexpressed in HNSCC. Our results demonstrate that survivin is significantly upregulated in HNSCC cell lines as compared to normal oral keratinocytes. In this study, we used two cisplatin resistant cell lines; one naturally occurring cisplatin resistant cell line (UM-SCC-74A) and a second cell line (CAL27-PT) that was developed in the laboratory by subjecting a sensitive HNSCC cell line (CAL-27) to multiple rounds of cisplatin treatment. Interestingly, acquisition of cisplatin resistance by CAL27-PT resulted in further increase of survivin expression as compared to the parental cell line. Therefore, we hypothesize that targeting of survivin protein in advanced HNSCC could reverse the resistant phenotype in tumor cells thereby enhancing the therapeutic efficacy cisplatin treatment. We used both in vitro and in vivo models to test the efficacy of YM155, a small molecule survivin inhibitor, either as a single agent or in combination with cisplatin treatment. YM155 treatment significantly decreased survivin expression in a dose-dependent manner and significantly inhibited cell proliferation, migration and colony formation ability of UM-SCC-74A and CAL27-PT cells. In addition, YM155 markedly enhanced the anti-proliferative and anti-migratory effects of cisplatin. This combination treatment was very effective in inducing tumor cell apoptosis as measured by Annexin V staining. In a SCID mouse xenograft model, YM155 significantly enhanced the anti-tumor and anti-angiogenic effects of cisplatin treatment with no added systemic toxicity. Taken together, our results suggest a potentially novel strategy to use YM155 to overcome the resistance in tumor cells thereby enhancing the effectiveness of the chemotherapy in HNSCC.

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 5604. doi:1538-7445.AM2012-5604
Abstract 5609: Mechanisms of acquired resistance to selective PI3K inhibitors in breast cancer cell lines
Authors: O'Brien Carol Lynn , Spoerke Jill , Lackner Mark , Sproul Scott , Haverty Peter , Hampton Garret
Published: August 2012

GDC-0941 is a class I PI3 kinase inhibitor of all 4 isoforms currently in phase II clinical trials in multiple indications, including ER+ breast cancer. The PI3 kinase pathway plays an important role in proliferation and survival and is known to be one of the most altered pathways in cancer. These alterations include PI3 kinase amplification, PI3 kinase mutations and PTEN loss, as well as numerous others. We have previously shown in-vitro and in-vivo data that alterations in this pathway can potentially help identify patients that are more likely to respond to a PI3 kinase inhibitor. A major outstanding question is mechanisms of intrinsic and acquired resistance to PI3K inhibitors. To address these questions we have selected multiple breast cancer cell lines harboring different pathway alterations (HER2, PIK3K mutations, PTEN loss) for resistance to PI3 kinase inhibition. Some of the resistant lines show cross resistance to inhibitors of mTOR and AKT (ie general pathway resistance), while others show specific resistance to PI3K or PI3K/mTOR inhibitors. We have characterized these resistant cell lines in detail at the molecular level and in terms of signaling pathway activation. Analyses performed include deep sequencing, reverse phase protein arrays, as well as focused Western blots and RTK arrays. We will discuss these results in detail and comment on candidate resistance mechanisms.

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 5609. doi:1538-7445.AM2012-5609
Abstract 5623: Eliminating pancreatic cancer metastases through inhibition of hedgehog and RAS signaling
Authors: Gu Dongsheng , Zhang Xiaoli , Xie Jingwu
Published: August 2012

Pancreatic cancer is arguably one of the most challenging human malignancies, with the five year survival rate below 5%. Pancreatic cancer is often found in advanced stages, and is unresponsive to conventional cancer therapy. Thus, the need to develop novel treatment strategies targeting metastasis of pancreatic cancer has never been greater. The molecular hallmark of pancreatic cancer is an activating mutation in the small GTPase KRAS. Unfortunately, efforts to target RAS signaling are not very successful for pancreatic cancer treatment. Recently, inhibition of hedgehog (Hh) signaling emerges as a new cancer therapeutic option, but the available data from several current clinical trials in pancreatic cancer show only modest activity. At present, gemcitabine is the standard chemotherapy for metastatic pancreatic cancer but the response rate is less than 10%, with the median survival of only 6-7 months. A new chemotherapy combination of 5-fluorouracil, irinotecan and oxaliplatin (FOLFIRINOX) was recently studied in Europe with a response rate of 30% and median survival of 11 months, but at a cost of significant toxicity. In order to design treatment strategies based on the molecular changes critical for cancer metastasis, we took the advantage of the knowledge recently generated in our laboratory and the newly developed molecularly targeted drugs currently in clinical trials. We compared primary pancreatic tumors with metastatic liver tumors for molecular alterations in an orthotopic mouse model, and discovered elevated expression of Indian hedgehog (Ihh) and ERK1/2 phosphorylation in liver metastases. Inhibition of Hh signaling or MEK activity alone reduced primary tumor size but did not significantly affect distal tumor metastases. In contrast, targeting Hh signaling and MEK activity in the orthotopic mouse model dramatically decreased the primary tumor size and nearly eliminated lung and liver metastases. Mice treated with two inhibitors lived two weeks longer than those in other groups. While MEK inhibition mainly interefered with cell proliferation, suppression of ligand-dependent Hh signaling affected the tumor microenvironment. These data indicate that simultaneous suppression of RAS and Hh signaling will be more effective in future pancreatic cancer treatment.

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 5623. doi:1538-7445.AM2012-5623
Abstract 5626: FKBP51 is a crucial modulator of melanoma plasticity and promising molecular target for preventing melanoma metastasis
Authors: Romano Maria Fiammetta , Romano Simona , Staibano Stefania , Greco Adelaide , Brunetti Arturo , Ilardi Gennaro , Mascolo Massimo , Bisogni Rita , Alfano Bruno
Published: August 2012

FKBP51, a protein with a relevant role in developmental stages in mammals and other organisms, is highly expressed in melanoma and correlates with tumor aggressiveness and resistance to therapy. We found that FKBP51 positively regulates melanoma cancer stem cell (CSC) phenotype at the transcriptional level. We also found that melanoma CSCs are endowed with epithelial to mesenchimal transition (EMT) traits. The immunochemistry study of 10 primitive cutaneous and 20 brain melanoma metastases showed that melanocytic cells capable of extravasation and subverting the architecture of metastatic tissue display intense FKBP51 nuclear signal and cytoplasmic positivity for the CSC marker nestin. These findings support the conclusion that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program. To confirm the role of FKBP51 in melanoma invasion, we utilized an experimental metastasis model. Animal studies were performed in accordance with NIH recommendations and the approval of the local institutional animal research committee. Injecting SAN melanoma cells into the tail vein of IL2γ-NOD-SCID mice produced prominent multifocal lesions in lungs and liver. We systemically administered two separate doses of FKBP51 siRNA to mice after the injection of melanoma cells. Organ colonization was evaluated both in live animals and post mortem. Qualitative PET/CT image analysis demonstrated low FDG uptake limited to small areas in lungs and liver. By contrast, untreated mice had diffuse metastatic liver and lung lesions and high FDG uptake in the same organs. Quantitative analysis performed on PET/CT images revealed that mean standardized uptake values (SUV) in treated mice were significantly lower than in untreated mice, both for lungs and liver. High Frequency Ultrasound examination revealed few or no liver metastases in treated mice versus untreated mice. Post-mortem organ examination showed a dramatic difference between the morphologically preserved organs dissected from treated mice, and severely compromised organs from untreated mice. The histological examination confirmed these findings. Most interestingly, invading cells co-expressed FKBP51 and nestin. Our study suggests a prominent role for FKBP51 in the pathogenesis of metastatic melanoma; we envision that targeting this protein for melanoma metastasis prevention may produce a successful outcome.

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 5626. doi:1538-7445.AM2012-5626
Abstract 5641: Dual roles for ganoderic acid A in inducing apoptosis and enhancing HLA class II presentation in leukemia and lymphoma cells
Authors: Haque Azizul , Radwan Faisal F.Y. , Hossain Azim , God Jason M.
Published: August 2012

Ganoderic acid A (GA-A), a natural extract isolated from the medicinal mushroom Ganoderma lucidum, was found to induce a remarkable cytotoxicity in various leukemia and lymphoma cell lines and primary tumors, with a minor toxicity to nonmalignant B-cells. The GA-A cytotoxicity and growth inhibitory effects resulted from an induction of apoptosis, which was characterized by a dose-dependent increase in expression and activity of activated caspases 3, 8, and 9. Mechanistic studies showed that GA-A treatment upregulated pro-apoptotic protein Bax proteins while downregulating anti-apototic proteins Bcl-2 and survivin. Data also demonstrated that cytochrome c and apoptotic protease activating factor-1 (Apaf-1) were significantly elevated in the cytoplasmic fractions of GA-A-treated cells, which may have activated caspases for cell death. Despite GA-A's notable cytotoxic effects on leukemia and lymphoma cells, GA-A treatment enhanced HLA class II antigen (Ag) presentation and CD4+ T cell recognition of both malignant and nonmalignant B-cells. These data suggest that GA-A administration may play dual roles in inducing apoptosis and enhancing HLA class II Ag presentation, and could be used as novel adjunctive therapy for the treatment of hematological malignancies.

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 5641. doi:1538-7445.AM2012-5641
Abstract 5642: Wound-healing drainages contribute to triple negative breast cancers aggressiveness
Authors: Bianchi Francesca , Sasso Marianna , Turdo Federica , Agresti Roberto , Ghirelli Cristina , Cremona Mattia , Orlandi Rosaria , Tagliabue Elda , Campiglio Manuela
Published: August 2012

The triple negative breast cancers (TNBC) is an extremely aggressive cancer subtype that although account for only 10-17% of breast cancers carries the higher rate of distant recurrence and death than women with other breast cancer subtypes and, unfortunately has limited treatment options. The TNBC pattern of recurrence present a distant recurrence peak at approximately 3 years and then declines rapidly thereafter. It's now well known that growth-factors released during the healing process can accelerate the early recurrences in breast cancer patients. We speculate that wound healing drainages (WHD) stimulation may specifically contribute to TNBC early relapse. To this aim, a panel of TNBC cell lines (BT-549; HCC1937, MDA-MB-157; MDA-MB-231; MDA-MB-468; SUM159; SUM149) and the luminal cell lines MCF7 were treated with WHD. All breast carcinoma cell lines are induced to proliferate in response to more than 20 drainage fluids obtained from breast cancer patients, but median proliferation level was 3-folds higher in TNBC- compared to luminal-cell line. To identify which receptors/pathways can be activated and play a driving role in TNBC progression, a reverse phase protein microarray (RPMA) experiment on TNBC cells WHD stimulated was performed. We revealed a specific activation of PDGFR, VEGFR and their downstream pathways, whereas no significant changes were observed in other receptors, such as EGFR, IRS, Met and ERB3. Conversely, PDGFR and VEGFR pathways were not activated in MCF7. The type of activated receptors suggested the involvement of angiogenic properties, besides canonical proliferation pathways, upon WHD stimulation. To prove whether the receptors found activated by WHD play a key role in in vitro and in vivo TNBC progression, we targeted PDGFR, VEGFR and other receptors possibly involved in proliferation and angiogenic capabilities with sunitinib (targeting PDGFR, VEGFR, FGF and c-kit), anti-bFGF antibody (targeting the ligand bFGF) and bevacizumab (targeting the VEGF) in TNBC cells WHD-stimulated. Sunitinib and anti-bFGF antibody halved the proliferation of TNBC cell lines, whereas bevacizumab modestly affect proliferation. Notably, sunitinib and anti-bFGF antibody strongly inhibited MDA-MB-231 and MDA-MB-468 xenografts tumor growth (sunitinib: 80%, and 70% Growth Index (GI), respectively; anti-bFGF antibody 70% and 60% GI, respectively) whereas bevacizumab determined no more than 30% decrease of tumor volume. In conclusion, WHD promotes TNBC progression probably by sustaining both proliferation and angiogenic.

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 5642. doi:1538-7445.AM2012-5642
Abstract 5650: Targeting siRNA to tumors and their stroma as a dual anticancer and anti-angiogenic therapy
Authors: Ofek Paula , Fischer Wiebke , Calderon Marcelo , Haag Rainer , Satchi-Fainaro Ronit
Published: August 2012

New targets for RNA interference (RNAi)-based cancer therapy are constantly emerging from the increasing knowledge on the molecular pathways involved in carcinogenesis. Nevertheless, in vivo delivery of small interfering RNA (siRNA) remains a crucial challenge for its therapeutic success. SiRNAs on their own are not taken-up by most mammalian cells in a way that preserves their activity. In order to circumvent these limitations, we developed a cationic carrier system, which can strongly improve its stability, intracellular trafficking and silencing efficacy. We have recently developed a polyglycerol (PG)-Amine, a water-soluble polyglycerol-based dendrimer that accumulates in the tumor environment due to the enhanced permeability and retention (EPR) effect, and therefore, represents an ideal delivery vehicle for antitumor biological agents. PG-Amine entrapment of siRNA neutralized its negative charge in a dose-dependent manner and significantly improved its cellular uptake. The luciferase gene, ectopically overexpressed in U87 human glioblastoma cell line was used as a model system and its silencing efficacy was extensively evaluated both in vitro and in vivo. Following encouraging results obtained from several cancer cell lines, the silencing efficiency of the nanocarrier luciferase-siRNA polyplexes was followed-up in vivo by non-invasive intravital bioluminescence imaging. A significant gene silencing effect was accomplished in vivo in both human glioblastoma and murine mammary adenocarcinoma mouse models following intravenous administration of our polyplexes. We further characterized the effect of silencing a few selected key proteins (e.g. Notch1) in vitro and achieved significant effects on the proliferation and migration of glioblastoma and neuroblastoma cell lines. In conclusion, we predict that specific delivery of siRNA to tumor epithelial and endothelial cells in vivo, and silencing of an important cell growth and angiogenesis regulator will warrant this approach as a successful anticancer 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 5650. doi:1538-7445.AM2012-5650
Abstract 5658: Engineered Salmonella effectively produce and preferentially deliver bacterial cytotoxins to solid tumors
Authors: Jean Adam T. St. , Swofford Charles A. , Brentzel Zachary J. , Forbes Neil S.
Published: August 2012

To effectively treat cancer, therapeutics must specifically target tumor tissue and impart minimal toxicity to healthy tissues. Bacterial toxins, such as Pseudomonas aeruginosa Exotoxin A (PEA) and Staphylococcus aureus Alpha-Hemolysin (SAH), are highly cytotoxic and are promising moieties for cancer treatment. Due to their high toxicity and non-specificity towards all cells types, systemic effects limit their effectiveness as a therapeutic. While efforts have been made to impart cancer-cell specificity to these potent molecules, especially through immunotoxin technology, systemic toxicities still prove to be a challenge. Genetically engineered bacteria, such as Salmonella typhimurium, are known to target cancer by preferential accumulation within tumors and thus can be exploited as tumor-specific drug delivery vectors. By using cellular engineering techniques, the genetic machinery of bacteria can be used to produce exogenous bacterial toxins in situ. In addition to the specificity of bacterial accumulation, inducible promoter systems such as the arabinose-inducible system can be used to minimize systemic toxin levels by controlling the timing of protein expression. By coupling these strategies, we have been able to develop an effective bacterial therapy for targeted tumor treatment. PEA and SAH expressed in Salmonella under the PBAD promoter was secreted into the culture medium following arabinose induction. Monolayer cultures of MCF7 human breast carcinoma cells treated with secreted PEA and SAH for three days were depleted by 82% and 99%, respectively. Mechanism of delivery studies in a murine tumor model showed co-localization of salmonella, toxins and cell death within tumors following arabinose induction, while minimizing the localization of toxins to the healthy organs. Survival studies indicate that bacterial delivery of PEA and SAH can minimize systemic toxicities while decreasing tumor growth and increasing survival. Overall, these data indicate that by using bacteria to produce toxins in situ, we were able to overcome the delivery challenges inherent with non-specific toxin moieties and create a highly efficacious drug delivery system for use in the treatment of solid tumors.

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 5658. doi:1538-7445.AM2012-5658
Abstract 5661: Pharmaceutically controlled replication of adenoviruses in mesenchymal stem cell-based cell carriers improves oncolytic virotherapy for advanced human renal cell carcinoma
Authors: Hsiao Wan-Chi , Liao Chia-Hui , Sung Shian-Ying , Hsieh Chia-Ling
Published: August 2012

Cell-based carriers were recently exploited as a tumor-targeting tool to improve systemic delivery of oncolytic viruses for cancer therapy. However, the slow clearance of carrier cells from normal organs indicates the need for a controllable system which allows viral delivery only when the carrier cells reach the tumor site. In this communication, we sought to develop a pharmaceutically-inducible cell-based oncolytic adenovirus delivery strategy for effective targeting and treatment of renal cell carcinoma (RCC), which is one of the most malignant tumor types with an unfavorable prognosis. Herein, we demonstrated the intrinsic tumor homing property of human bone marrow-derived mesenchymal stem cells (hMSCs) to specifically localize primary and metastatic RCC tumors after systemic administration in a clinically relevant orthotopic animal model. PDGF-AA secreted from RCC was identified as a chemoattractant responsible for the recruitment of hMSCs. Like endogenous osteocalcin whose barely detectable level of expression was dramatically induced by vitamin D3, the silenced replication of human osteocalcin promoter-directed Ad-hOC-E1 oncolytic adenoviruses loaded in hMSCs was rapidly activated and the released viral progenies sequentially killed co-cultured RCC cells upon vitamin D3 exposure. Moreover, systemic treatment of RCC tumor-bearing mice with Ad-hOC-E1-loaded hMSCs had very limited effect on tumor growth, but when it combined with vitamin D3 treatment induced effective viral delivery to RCC tumors and significant tumor regression. Therapeutic effects of hMSC-based Ad-hOC-E1 delivery were confirmed to be significantly greater than those of injection of carrier-free Ad-hOC-E1. Our results presented the first pre-clinical demonstration of a novel controllable cell-based gene delivery strategy that combines the advantages of tumor tropism and vitamin D3-regulatable human osteocalcin promoter-directed gene expression of hMSCs to improve oncolytic virotherapy for advanced RCC.

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 5661. doi:1538-7445.AM2012-5661