bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2472: Peritoneal mechanobiology and metastatic success in epithelial ovarian cancer
Authors: Burkhalter Rebecca J. , Liu Yueying , Marszow Michael , Sun Zhe , Meininger Gerald , Wagner Diane , Stack M. Sharon
Published: August 2012

Less than 30% of women diagnosed with epithelial ovarian cancer (EOC) survive for 5 years due to metastatic disease. EOC progression is accompanied by accumulation of ascites (up to 4 liters), changing intraperitoneal (i.p.) fluid pressure from subatmospheric (-5 mmHg) to >20 mmHg with tense ascites. The overall consequence of altered peritoneal mechanobiology on EOC metastatic success is currently unknown. Due to altered i.p. fluid dynamics the peritoneal mesothelium, an elastic soft tissue, may be modified by exposure to tensional force (strain). Mechanical strain (stretching) on intact murine mesothelial explants causes increased tissue stiffness, as determined by atomic force microscopy, and enhances ovarian tumor cell adhesion. To approximate the compressive force environment on EOC cells in tense ascites, cells were seeded in suspension in polystyrene bags and cultured under a compressive load (Instron, 25mmHg, 8h). Increased fluid pressure enhances proliferation in multiple cell lines and increases expression of N-cadherin, a mesenchymal marker, in Dov13 cells. These data suggest that ascites-induced changes in peritoneal mechanobiology may potentiate EOC metastatic success. Support: NIH-R01CA109545, NIH R01CA086984, NIH F31 R01CA086984-12S1.

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 2472. doi:1538-7445.AM2012-2472
Abstract 2621: Relative excess risk due to interactions between GWAS-identified susceptibility loci and other breast cancer risk factors
Authors: Joshi Amit D. , Hüsing Anika , Campa Daniele , Canzian Federico , VanderWeele Tyler J. , Kraft Peter ,   Breast and Prostate Cancer Cohort Consortium.
Published: August 2012

Background: The characterization of the joint effects of multiple susceptibility loci identified in genome wide association studies (GWAS) and known breast cancer risk factors has the potential to inform functional mechanisms of carcinogenesis, public health guidelines and disease risk prediction. Additive interactions- departures from additivity on the absolute risk scale- can have public health and etiologic implications, but are infrequently reported. Methods: We assessed additive interactions among 11,043 non Hispanic White breast cancer cases and 11,665 similar controls within the National Cancer Institute's Breast and Prostate Cancer Cohort Consortium (BPC3). Logistic regression models were used to calculate estimates and confidence intervals for risk excess due to interactions (RERI) between 34 GWAS identified breast cancer susceptibility SNPs and 10 established breast cancer risk factors (age at menarche, parity, age at first full term pregnancy, age at menopause, family history, Gail score, height, body mass index (BMI), alcohol consumption and smoking status). All analyses were adjusted for age (5 year intervals) and cohort. Results and conclusions: After correction for multiple comparisons, we identified a statistically significant RERI (estimate = 0.48, CI=0.24,0.72, uncorrected p-value = 0.0000877) between a SNP in RAD51L1 gene, rs10483813, and BMI (<30 vs. >=30 kg/ m2). Among non-carriers of the risk allele, high BMI was found to significantly protect against breast cancer, but no difference in risks was observed due to BMI among carriers of at least one risk allele. This intriguing result requires replication.

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 2621. doi:1538-7445.AM2012-2621
Abstract 2649: Maternal and offspring folate metabolic genes and the risk of childhood acute lymphoblastic leukemia (ALL)
Authors: Lupo Philip J. , Nousome Darryl , Kamdar Kala Y. , Okcu Mehmet F. , Bondy Melissa L. , Scheurer Michael E.
Published: August 2012

Introduction: Childhood ALL is the most common type of cancer in children. Although the survival rate is relatively high, there are significant clinical sequelae associated with treatment and little is known about the etiology of this condition. Family studies suggest a genetic component to ALL, and the peak incidence between 2 and 4 years of age indicates factors during pregnancy may influence risk. The folate metabolic pathway is a strong candidate for genetic epidemiologic studies due to its role in DNA synthesis and methylation. Objective: The purpose of this study was to conduct a case-parent triad analysis to assess both maternal and offspring genetic effects of the folate metabolic pathway on childhood ALL risk. Methods: We recruited pediatric ALL case-parent triads (n = 120) from Texas Children's Hospital. DNA samples were genotyped in the Human Genetics Center at The University of Texas School of Public Health using the Sequenom iPLEX MassARRAY for 80 tagSNPs in six folate metabolic pathway genes (MTHFR, MTRR, MTR, DHFR, BHMT, and TYMS). Log-linear modeling was used to examine the associations between ALL and both maternal and offspring genotypes. Results: After controlling for the false discovery rate (<0.10), there were 19 significant maternal effects in the following genes: BHMT (n = 3), MTR (n = 12), and TYMS (n = 4). For instance, maternal genotypes for BHMT rs558133 (RR = 0.51, 95% CI: 0.30-0.88, p = 0.008, q = 0.08), MTR rs2282369 (RR = 0.46, 95% CI: 0.26-0.79, p = 0.003, q = 0.08), and TYMS rs699517 (RR = 1.92, 95% CI: 1.17-3.17, p = 0.006, q = 0.08) were all associated with ALL. There were no significant offspring effects after controlling for the false discovery rate. Conclusions: This is one of the few studies conducted to evaluate maternal genetic effects in the context of pediatric ALL risk. Furthermore, we employed a family-based design (i.e., case-parent triad) that is robust to confounding due to population structure and allows for the evaluation of both maternal and offspring genotypes. These results provide additional evidence that the risk of pediatric ALL is influenced by variation within folate pathway genes and indicate that studies to explore these relationships further are warranted. We plan to extend these analyses to the evaluate folate pathway haplotypes, as well as other relevant genetic pathways (e.g., DNA repair).

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 2649. doi:1538-7445.AM2012-2649
Abstract 2701: RORα suppresses breast tumor progression by inducing cell polarization and inhibiting cell invasion
Authors: Xiong GaoFeng , Xu Ren
Published: August 2012

Background: Disruption of tissue polarity is one of hallmarks of breast cancer development, which is associated with cell invasion and cancer dissemination. Therefore, identifying proteins and pathways that modulate cell polarity is crucial not only to advancing our knowledge of breast cancer, but also to discovering potential therapeutic targets. Methods: To identify potential regulators of tissue polarity, we analyzed over-represented DNA motifs in the promoter regions of the polarization genes that are significantly up-regulated genes in polarized human mammary epithelial cells in a physiologically relevant three-dimensional (3D) culture system. We assessed the protein levels of RORα by immunoblotting and immunohistochemistry in malignant and non-malignant human mammary epithelial cells as well as human breast cancer tissue array. To explore the functional significance of RORα down-regulation the malignance of breast cancer cells, we restored RORα expression in malignant T4-2 cells, MDA231 cells and silenced RORα expression in non-malignant S1 cells. The growth and malignant phenotypes of these cells were examined in 3D culture and xenograft model. Results: Results from promoter analysis suggest that RORα is a potential regulator of mammary tissue polarity and is inactivated in disorganized HMECs. Expression of RORα protein is significantly reduced in malignant breast cancer cell lines and this reduction is associated with disruption of acinar structure in 3D culture. Both mRNA and protein level of RORα were significantly reduced in human breast cancer tissues. Restoring RORα expression in T4-2 and MDA-MB 231 cells significantly suppressed proliferation, invasion and the malignant phenotypes in 3D culture. Silencing RORα expression in non-malignant S1 cells disrupts the polarized acinar morphogenesis. Restoring RORα expression in T4-2 and MDA-MB 231 cells also inhibits the tumor growth in nude mice. Moreover, patients with reduced expression of RORα in cancer tissue have significantly shorter survival. Conclusion: Together these results indicate that inactivation of RORα promotes the breast cancer development and progression by enhancing cell invasion and disturbing normal tissue architecture. RORα provide a potential therapeutic target for 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 2701. doi:1538-7445.AM2012-2701
Abstract 2702: Effects of Src and IGF1R inhibition on acquired endocrine therapy resistant breast cancer
Authors: Liu Shuyling , Meng Xiaolong , Liu Wenbin , Miller Todd , Lu Yiling , Zhang Fan , Arteaga Carlos L. , Mills Gordon B. , Gonzalez-Angulo Ana M.
Published: August 2012

Effective standard therapy for hormone receptor-positive (HR+) breast cancer targets the estrogen receptor (ER). However, a significant proportion of women with HR+ breast cancer relapse. Furthermore, the majority of women with metastatic HR+ breast cancer develop resistance to endocrine therapy. Adaptive cross-talk between ER and growth factor receptor pathways including IGF1R and Src is involved in acquired endocrine therapy resistance. To determine effects of adding dasatinib (D), Src inhibitor, and/or anti-IGF1R Ab MK0646 (M) to the ER antagonist fulvestrant (F) in an acquired endocrine therapy resistant breast cancer, we used long-term estrogen-deprived (LTED) derivative of ER+ breast cancer cell lines, MCF-7/LTED and HCC-1428/LTED. Parental and LTED cells were treated with variable combinations of F, D and M, followed by determinations of drug effects on cell growth, migration, and invasion in vitro and tumor growth in vivo. We demonstrated that LTED cells were resistant to F alone, comparing parental cells (P<0.05) in cell growth, migration and invasion. Addition of D to F appeared to be synergistic in all systems including cell growth, cell migration and invasion. However, the addition of M to F or to F+D appeared inhibition on cell growth in monolayer with low-serum medium, but not to significantly add inhibitory effects on cell growth in 3D and cell migration and invasion. The effects of IGF-1R antibody, MK0646, on cells growth in monolayer showed not consistent with 3D, which might be due to growth factors in the matrigel, although we used growth factors decreased matrigel. To verify the effects of the drugs on tumor growth in vivo, we developed xenograft models using MCF-7/LTED cells and treated the mice with F, D, and M along or variable combinations. The study demonstrated that all the combinations of F+D+M, F+D, and F+M (from P< 0.05 to <0.001 in viable time points) show inhibited the tumor growth comparing vehicle or F alone. The inhibitory effect of F+D+M is higher than F+D and F+M. In summary, the addition of dasatinib to fulvestrant appeared to be synergistic in all systems including cell growth, cell migration and invasion and tumor growth in vivo. The addition of MK0646 to fulvestrant mildly inhibited MCF-7/LTED cell growth and xenografts growth, but not cell migration and cell invasion.

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 2702. doi:1538-7445.AM2012-2702
Abstract 2703: Final results of a phase 2 trial using a novel, non-anthracycline neoadjuvant chemotherapy regimen in Her2-positive breast cancer
Authors: O'Regan Ruth M. , Gabram Sheryl , Styblo Toncred , Rizzo Monica , Wood William , Srinivasiah Jayanthi , Jonas William , Schnell Fred , Adams Amy , Nahta Rita , Zelnak Amelia
Published: August 2012

Background: The addition of trastuzumab to preoperative chemotherapy for Her2-positive breast cancers has been shown to increase pCR rate, which correlates with improved outcome. The purpose of this study was to evaluate the efficacy of trastuzumab in combination with dose-dense nab-paclitaxel followed by weekly vinorelbine. Methods: Patients with Stage I (>1.0 cm), II, or IIIA Her2-positive (defined as either immunohistochemical 3+ of fluorescence in situ hybridization-positive) breast cancer received nab-paclitaxel 260 mg/m2 iv every 2 weeks for 4 cycles in combination followed by vinorelbine 25 mg/m2 iv weekly with simultaneous trastuzumab (4 mg/kg loading dose then 2 mg/kg weekly) for 20 weeks. Tissue was collected at baseline, at optional midway biopsy, and post-therapy. Primary endpoint was pCR rate; secondary endpoints included response rate and toxicity. Cardiac evaluation was performed at baseline, after 4 cycles of nab-paclitaxel, after 12 weeks of vinorelbine and every 3 months thereafter per standard practice guidelines. Results: To date, 27 patients have been accrued (3/2008 to 6/2011). 24 patients are currently evaluable for primary endpoint. Patients were accrued from a university center (48.2%), county hospital (11.1%), and community sites (40.7%). Median age was 49.5 years (34-64). Median tumor size was 4.0 cm (1.5-7cm). 14 of 27 patients (51.9%) were clinically node-positive at study entry. 11 patients were African American (40.7%), 16 were Caucasian (59.3%). The regimen was well-tolerated: 3 patients experienced grade 3 neuropathy; 6 patients had grade 3 neutropenia; 1 patient had trastuzumab held for asymptomatic decrease in left ventricular ejection fraction. 18 of 24 patients (75%) had complete clinical response rate. 6 of 24 patients (25%) had partial clinical response. 11 of 24 patients (45.8%) had pCR. Conclusions: The combination of preoperative trastuzumab with dose-dense nab-paclitaxel followed by vinorelbine was well-tolerated and resulted in a high rate of pCR in Her2-positive, early-stage breast cancer. Final results and correlative studies will be reported.

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 2703. doi:1538-7445.AM2012-2703
Abstract 2704: Tetraspanin CD151 drives mammary tumor onset and metastasis by coordinating integrin-dependent cell adhesion, motility, survival and signaling
Authors: Deng Xinyu , Hoff John , Novak Marian , Kaetzel David , Hemler Martin E. , Yang Xiuwei H.
Published: August 2012

The ErbB2+ subtype of human breast tumors remains a significant threat to women's health, as they are highly prone to recurrence or metastasis, and development of drug resistance. Here we report that CD151, a member of the tetraspanin family and a close partner of the laminin-binding (LB) integrins (≥3α1 and α6β4), contributes to the onset and malignancy of ErbB2-induced mammary tumors. By crossing gene-targeted mice onto a clinically-relevant MMTV-ErbB2 transgenic model, we demonstrated that deletion of CD151 significantly impaired the onset and metastasis of mammary tumors in mice. Our subsequent analyses of cell lines derived from mouse primary tumors showed that loss of CD151 decreased integrin-mediated cell-ECM adhesion and cell-cell contacts. Also, for ErbB2-overexpressing MCF-10A cells cultured in 2D or 3D, ablation of CD151 markedly reduced tumor cell motility, invasion and survival. However, only MAPK and FAK kinases among an array of signaling molecules downstream of integrins and ErbB receptors, exhibited a decreased activation in response to CD151 disruption. Importantly, there were corresponding changes in the activation and signaling of α6β4 integrin, as reflected by decreased phosphorylation of multiple serine residues at its cytoplasmic domain. Also, the cross-talk between integrins and ErbB receptors was strongly inhibited. Meanwhile, our analyses of clinical dataset revealed a strong correlation between CD151 gene expression and patients’ metastasis-free survival. Taken together, our results demonstrate that tetraspanin CD151 drives ErbB2-induced mammary tumorigenesis by coordinating the function and signaling of LB integrins. This newly-identified crucial role of CD151 offers a strong therapeutic potential for the treatment of breast cancer 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 2704. doi:1538-7445.AM2012-2704
Abstract 279: Small interfering RNA targeting CD44 blocks EGFR signaling in head and neck squamous cell carcinoma (HNSCC)
Authors: Perez Aymee , Jacobs Mark , Wen Judy , Pereira Lutecia , Neskey David M. , Franzmann Elizabeth J.
Published: August 2012

INTRODUCTION: Head and Neck Squamous Cell Carcinoma (HNSCC) is a disease that accounts for 90% of the 600,000 new diagnoses of head and neck cancers worldwide each year. CD44 is a purported cancer stem cell (CSC) marker, and its colocalization with EGFR has been proposed to activate tyrosine kinase (TK) and mitogen-activated protein kinase (MAPK). Therapies tend to have dismal cure rates. Understanding the interaction between CD44 and EGFR may result in improved therapies for HNSCC. METHODS: To evaluate the effect of CD44 on EGFR, we inhibited CD44 expression in a CD44-overexpressing HNSCC cell line, CAL27, using the siRNA method. The cell line was stably transfected with a DNA plasmid designed to knock down the expression of CD44. We then performed western blots examining CD44 and phosphorylated EGFR (Y1068) in siRNA knockdown clones and in scrambled sequence, followed by implantation of the CD44siRNA clones and scramble controls in nude mice. The mice were sacrificed, and the tumors were embedded in paraffin for IHC analysis. CD44 and EGFR colocalization was examined in 5 HNSCC cases and in CAL 27 xenografts by immunohistochemistry (IHC) and laser scanning confocal microscopy (LSCM). RESULTS: Downregulation of CD44 by siRNA in CAL 27 cells inhibited constitutive EGFR phosphorylation in vitro and in vivo. Knocking down of CD44 by siRNA reduced the tumor growth in mice compared to CAL 27 and scrambled siRNA. CD44 and EGFR coexpression and colocalization were observed in 80% (4/5) of HNSCC cases and in CAL 27 xenografts. CONCLUSION: Based on these studies, targeting CD44 may provide an additional therapeutic option for HNSCC that does not respond favorably to other treatments. Anti- CD44 therapy in HNSCC may target the cancer stem cell population and alter EGFR signaling.

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 279. doi:1538-7445.AM2012-279
Abstract 2814: Potent and selective small molecule inhibitors of polo-like kinase 1: Biological characterization
Authors: Frame Sheelagh , Aspinall Claire , O'Neil Robert , Hollick Jonathan , Taylor Stephen , Hupp Ted , Blake David , Zheleva Daniella I.
Published: August 2012

Polo-like kinase 1 (Plk1) is one of the emerging new generation of anti-mitotic targets. Plks are a family of serine-threonine kinases involved in the regulation of mitosis and maintenance of DNA integrity. Plk1 is required for almost every step of mitosis: promotes mitotic entry, contributes to centrosome maturation, regulates kinetochore assembly, contributes to spindle assemble checkpoint and initiates mitotic exit. Besides promoting proliferation, Plk1 overexpression contributes to oncogenesis by promoting chromosome instability and aneuploidy. Overexpression of Plk1 is associated with tumor development and many cancers have elevated Plk1 levels compared to surrounding normal tissues. Numerous studies have shown that Plk1 expression levels correlate with disease progression, invasiveness and poor patient prognosis. Furthermore, pre-clinical studies have demonstrated that cancer cell proliferation is blocked in vitro and in vivo via inhibition of Plk1 using siRNA or small molecule inhibitors. Collectively, these observations support the selection of Plk1 as an attractive target for cell cycle-directed cancer therapy and several small molecule inhibitors are currently being investigated in clinical trials. Using a de novo ligand design approach we have identified pyrimidodiazepinone small molecules, which are ATP-competitive, highly selective and potent Plk1 inhibitors. These molecules have good drug-like properties, oral bioavailability and efficacy in mouse xenograft models. To characterize the cell sensitivity toward the Plk1 inhibitors we have used washout and outgrowth assays in a panel of oesophageal, lung and colon cancer cell lines. The anti-proliferative activity of Plk1 inhibitors was correlated with the Plk1 expression level, p53 and Ras mutational status. Generally, we found that cell lines harbouring p53 mutations are more sensitive towards these inhibitors. Time-lapse microscopy and flow cytometry studies of RKO cell line (WT p53) treated with Plk1 inhibitors demonstrated that a proportion of cells arrested just before the G2-/-M transition and were able to resume normal proliferation upon compound removal. These results suggest that Plk1 inhibitors should have better therapeutic window when used for treatment of tumors with mutant p53, p53 mutational status could be used as a patient stratification marker, and tumor types with high frequency of p53 mutations, such as oesophageal cancer, could be suitable therapeutic indications for Plk1 inhibitors.

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 2814. doi:1538-7445.AM2012-2814
Abstract 2817: Preclinical studies of the PI3K/mTOR dual inhibitors in endometrial cancer cell lines
Authors: Yuan Jing , Garza Scott J. , Cao Joan , Fisher Timothy S. , Lee Nathan V. , Eisele Koleen , Pasis Angela , Hook Kenneth , Christensen James G. , Kan Julie L.
Published: August 2012

The PI3K pathway plays a pivotal role in many cellular functions that include regulation of cell proliferation, survival, growth, angiogenesis, and motility. Dysregulation of the PI3K/AKT pathway is a common occurrence in cancer and could be a result of mutations in PIK3CA and PTEN, as well as loss of heterozygosity of PTEN. In endometrial cancer patients, the most frequent aberration is the activation of the PI3K/mAKT pathway with; (1) 80% loss of PTEN function and 30% PIK3CA mutations in type I endometrial cancer and (2) 20% PIK3CA mutation and 46% PIK3CA amplification in type II endometrial cancer. In this study, we investigated the functional consequences of the dual PI3K/mTOR inhibitors PF-04691502 and PF-05212384 in endometrial cancer cell lines for antiproliferative effects, pathway signaling inhibition and tumor growth inhibition. Both compounds had antiproliferative activity in vitro that translated to tumor growth inhibition in vivo. Moreover, in the MFE-280 xenograft model that harbors a PIK3CA mutation (P1047R), the dual PI3K/mTOR inhibitors showed tumor regression. These studies support the use of the dual PI3K/mTOR inhibitors for endometrial 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 2817. doi:1538-7445.AM2012-2817
Abstract 2818: Aurora B kinase inhibitor barasertib (AZD1152) and cytarabine in combination exert more than additive cytotoxicities against cytarabine-resistant acute myeloid leukemia cells in vitro
Authors: Yamauchi Takahiro , Ueda Takanori
Published: August 2012

The majority of patients with acute myeloid leukemia (AML) initially achieve complete remission by cytarabine (ara-C)-based chemotherapy, but many relapse with resistant disease. Aurora B kinase is involved in the spindle assembly checkpoint component of the mitotic process. Barasertib (formerly AZD1152), a selective inhibitor of aurora B kinase, provided an overall hematological response rate of 25% in AML patients in a phase I/II study, which warrants further investigation. To see the feasibility of the incorporation of this new agent to the standard induction chemotherapy, we evaluated the combination effect of barasertib with ara-C against leukemic cells in vitro. Cultured human leukemia HL-60 cells and ara-C-resistant variant HL-60/ara-C cells were used. Growth inhibition effects were evaluated by using the XTT assay. The cell cycle distribution and the induction of apoptosis were determined by flowcytometric analysis. Autophosphorylation of aurora B was assessed by Western blotting. The XTT assay determined that the 50%-growth inhibitory concentrations of ara-C were 100 - 300 nM for HL-60 cells and 4,000 - 5,000 nM for HL-60/ara-C cells, respectively. When HL-60 cells were treated with barasertib-hQPA, the active compound of barasertib, the cells exhibited an increase in the percentage of > 4N at 48 h with the subsequent induction of sub-G1 population. Autophosphorylation of aurora B was inhibited by barasertib-hQPA simultaneously. When the cells were treated with ara-C, the accumulation at G2-M phase and the subsequent increase in sub-G1 phase were observed. When the cells were treated with barasertib-hQPA and ara-C in combination, the treatment induced the greater-than-additive induction of sub-G1 population. However, the augmentation was brought about only when the cells were treated with barasertib prior to ara-C or both simultaneously. Barasertib-hQPA similarly altered the cell cycle, inhibited autophosphorylation of auroa B, and induced apoptosis in HL-60/ara-C cells. Low concentrations of ara-C failed to modify cell cycle distribution without the induction of apoptosis in HL-60/ara-C cells. Nevertheless, the sequential combination between barasertib-hQPA and a moderate concentration of ara-C augmented the sub-G1 population. In conclusion, the combination of barasertib with ara-C provided greater cytotoxicity than barasertib alone in both ara-C-sensitive and ara-C-resistant AML cell lines in vitro. The sequential administration of barasertib with ara-C may be promising against ara-C-refractory AML.

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 2818. doi:1538-7445.AM2012-2818
Abstract 2821: The PKC-iota inhibitor ICA-1 overcomes chemoresistance and induces cell death in glioblastoma multiforme
Authors: McCray Andrea N. , Acevedo-Duncan Mildred
Published: August 2012

Glioblastoma multiforme is a very aggressive brain cancer that is refractory to most chemotherapeutics. The standard of care for glioblastoma patients is the administration of temozolomide following surgery. However, temozolomide provides an approximately 20% enhanced survival rate. Therefore, it is imperative to develop other novel chemotherapeutics to better enhance the survival rate and induce tumor regression in patients. A potential candidate for a pre-clinical glioblastoma study is the novel chemotherapeutic, ICA-1. ICA-1 is a PKC-iota inhibitor which specifically inhibits PKC-iota and not its homologue, PKC-zeta. Results demonstrated that ICA-1 inhibited cell proliferation rates in a range of T98G glioblastoma concentrations in vitro. Also, results showed that low density T98G cultures which have a high proliferation status and high S-phase promotion concomitantly demonstrated resistance to ICA-1 treatment. However, high density T98G cultures which have a lower proliferation status and low S-phase promotion are concurrently chemosensitive toward ICA-1. At 48h post ICA-1 treatment, the majority of cells in the high density cultures were in G0/G1 with a rise of cells in this phase of the cell cycle shown by day 5 post-treatment. Conversely, between 48h and day 5, 30-44% of cells from the low density cultures were in S phase irrespective of ICA-1 therapy. Furthermore, by day 5 post-treatment, ICA-1 induced significant cell death in T98G cells only at higher ranges (i.e., 20-40 microM of ICA-1). Interestingly, 40 microM ICA-1 caused a significant cell death rate of 45% when 7,500 cells were seeded into a 24-well plate on Day 0 followed by ICA-1 exposure on the next day. Forty microM ICA-1 induced 15% cell death when 3,750 cells were seeded. There was a stepwise increase in the amount of ICA-1 required to induce cell death as the cell concentration increased (i.e., high density T98G cultures required elevated levels of ICA-1). Therefore, the data suggested that the G0/G1 phase glioblastoma cells (i.e., the higher cell concentrations) were more sensitive to 40 microM ICA-1 therapy. Whereas, the S phase glioblastoma cells were less sensitive to the ICA-1 therapy. Future animal models may show that the more aggressive the tumor becomes, the greater the potential for the effectiveness of ICA-1 (i.e., greater chemosensitivity).

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 2821. doi:1538-7445.AM2012-2821
Abstract 2832: Fibroblast growth factors in head and neck cancer: Genetic alterations and therapeutic targeting with ponatinib
Authors: Rieke Damian T. , Zuo Zhixiang , Endhardt Katharina , Keck Michaela , Khattri Arun , Mahmutoglu Derya , Leung Kelley , Dinali Mohamed El , Braegelmann Johannes , Seiwert Tanguy Y.
Published: August 2012

Background: FGF signaling plays an important role in cancer. Little is known about its involvement in head and neck squamous cell carcinoma (HNSCC). FGFR1 focal amplification and high expression (Freier, Schwaenen et al.), expression of FG-BP (Li et al.) and FGF2 autocrine signalling loops (Marshall et al.) have been described in connection with HNSSC. We therefore examined copy number alterations for several FGFR and FGF-related Genes in 159 patient tissues and cell lines as well as expression levels in 116 patient tissues and 40 cell lines. Based upon our findings we tried a combined FGFR-inhibiton with ponatinib in 5 head and neck cancer-cell lines alone and in combination with gefitinib. Methods: Copy Number Data analysis for 144 patient tissues and cell lines (Nanostring) as well as for 20 cell lines (aCGH) of which 5 were covered by both techniques and showed comparable results. Expression data analysis for 116 tissues and 40 cell lines (Agilent). Viability for 5 cell lines treated with gefitinib and ponatinib alone and in combination. Immunoblotting was performed to deterimed PI3K-AKT and MAPK signaling. Results: Frequent copy number increase could be detected for FGF19 in tissues and cell lines. FGFR1 copy number increase could be seen in only 1 tissue sample, but appeared to be deleted in several samples. High relative expression could be detected for FGFBP1 in tissues and cell lines. Viability testing showed high efficacy in 5/5 cell lines tested for ponatinib but was not solely mediated by AKT or MAPK signaling. Combined treatment with ponatinib and gefitinib was more effective than treatment with either agent alone and synergy was present. Conclusions: FGF signaling is important in Head and Neck Cancer. FGF19 amplification is frequent. We were unable to replicate FGFR1 amplification with only one tissue showing FGFR1 copy number increase. High expression levels could be shown for FGFBP1, providing an alternative hypothesis for explaining the efficacy of FGF2 inhibition as previously shown (Marshall et. al.). Ponatinib is effective as a single agent on HNSSC cell line models and shows synergistic effect in combination with gefitinib. It is promising to evaluate FGF pathway inhibition (e.g. with ponatinib) in its ability to overcome EGFR-inhibitor resistance.

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 2832. doi:1538-7445.AM2012-2832
Abstract 2858: Mirk/dyrk1B kinase inhibition increases ROS and apoptosis in ovarian cancer cells, but has little effect on normal diploid cells
Authors: Hu Jing , Friedman Eileen A.
Published: August 2012

Quiescent cancer cells in vivo, including stem cell populations, are relatively insensitive to most chemotherapeutic drugs and radiation. Tumor cells in culture can be placed in G0 by serum or nutrient deprivation, and then can be targeted by a small molecule Mirk kinase inhibitor. Mirk/dyrk1B levels are elevated up to 10-fold in quiescent tumor cells where Mirk blocks cell cycling and increases viability by decreasing reactive oxygen species (ROS). In prior studies Mirk was detected in 75% of ovarian cancers, and was amplified in a subset. In contrast, Mirk expression was quite low in most normal cell types and Mirk knockout or depletion had no detectable effects on normal cells. Response to a Mirk kinase inhibitor was compared between two strains of normal diploid fibroblasts, early passage cultures of normal human ovarian epithelial cells, and a series of ovarian cancer cell lines where Mirk had been shown to be an active kinase. Serum-starved normal diploid cells entered a G0 quiescent state and had minimal response to the Mirk inhibitor, but serum-starved cancer cells were kept in cycle by the Mirk inhibitor, which reduced E2F4 sequestration by p130/Rb2 by 2-3fold. Mirk inhibitor treated cancer cultures had several-fold more sub-G0/G1 apoptotic cells and about 30-fold higher levels of the apoptotic proteins cleaved PARP and cleaved caspase 3 compared with normal diploid cells. The Mirk inhibitor increased total ROS levels and superoxide levels only in the cancer cells, in a rapid time-course of 2-3 days. Cancer cell loss after Mirk kinase inhibitor treatment was due at least in part to ROS, since the ROS scavenger N-acetyl cysteine reduced the amount of cleaved PARP and the extent of cancer cell loss. The Mirk inhibitor decreased the EC50 of cisplatin up to 9-fold in ovarian cancer cells. Thus ovarian cancer cells, which exhibit elevated Mirk expression/amplification and active Mirk kinase, were shown to be more susceptible to the Mirk kinase inhibitor than normal diploid 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 2858. doi:1538-7445.AM2012-2858
Abstract 2861: Inhibition of mTOR and AKT as a potential strategy for the treatment of basal-like breast cancer
Authors: Ma Cynthia X. , Guo Zhanfang , Xu Siguang , Li Shunqiang , Ellis Matthew
Published: August 2012

Basal-like breast cancer is an aggressive disease, for which effective targeted therapies are lacking. The frequent loss of phosphatase and tensin homolog (PTEN) and aberrant activation of phosphatidylinositol 3-kinase (PI3K)-AKT-mTOR pathway in basal-like breast cancer make it an attractive therapeutic strategy to target AKT and mTOR. To evaluate the effect of PTEN loss on tumor cell sensitivity to mTOR inhibition, we performed PTEN knockdown experiment in vitro using a basal-like breast cancer cell line WU-BC3, which was derived from a patient with triple negative breast cancer. A more dramatic reduction in cell proliferation was observed in WU-BC3 siPTEN compared to that in WU-BC3 siControl following 7 days of treatment with the mTOR inhibitor MK-8669 (p<0.001). We then tested MK-8669 and MK-2206 (an allosteric, selective pan-AKT inhibitor), either alone or in combination, in 2 Human Tumor in Mouse (HIM) models of basal-like breast cancer, WU-BC4 and WU-BC5, that are deficient in PTEN expression in vivo. In both models, MK-8669 alone significantly inhibited tumor growth (p<0.001). However, the combination of MK-8669 and MK-2206 was more effective than either MK-8669 (p<0.05) or MK-2206 (p<0.01) alone. Biomarker studies indicated that the combination therapy resulted in a more dramatic inhibition of tumor cell proliferation (as assessed by Ki67) and angiogenesis (as assessed by CD31 staining) than single agents alone in both models. In addition, treatment with MK-2206 abolished the MK-8669-induced AKT activation in vivo, suggesting the inhibition of the feedback loop between mTOR and AKT being a potential underlying mechanism for the enhanced anti-tumor effect observed with the combination therapy. Our results provide a preclinical rationale for future clinical investigation of this combination in basal-like 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 2861. doi:1538-7445.AM2012-2861
Abstract 2887: Nanoconstructs for the efficient delivery of siRNA molecules against Aquaporin-1 for anti-angiogenic therapies
Authors: Stigliano Cinzia , Ananta Jeyarama , Acharya Swetadrinadha , Mackeyev Yuri , Wilson Lon , Nicchia Grazia Paola , Svelto Maria , Decuzzi Paolo
Published: August 2012

Aquaporins (AQPs) are water-specific, membrane-channel proteins expressed in diverse tissues. In particular, AQP1 has been reported to be specifically and strongly expressed in most tumor microvascular endothelial cells. Angiogenesis and tumor progression have been dramatically impaired, in AQP1-null mice [Saadoun et al. Nature 434:2005]. These findings support the notion that AQP1 could be considered as a specific target for the treatment of various neoplasias. The AQP1 proteins can be specifically blocked by using small interference RNA molecules (siRNAs). However, despite the considerable potential of RNA interference for the treatment of cancer, the proper systemic delivery of exogenous siRNA molecules is still a challenge. The most significant obstacle is ensuring specific and effective delivery of siRNAs to the cytoplasm of the target cell, limiting toxic effects and serum degradation by RNAses. The use of nanoparticles, as intravascular delivery vehicles, has potential in supporting the efficient, effective and safe systemic delivery of siRNAs. Herein, multiple nanotechnological platforms (nanoconstructs) are used to deliver siRNAs against AQP1. The performance of the different nanoconstructs is assessed in vitro using HeLa cells, transfected to express AQP1 molecules. Three nanoconstructs are studied: fullerenes (C60), poly(lactic-co-glycolic acid) (PLGA) nanospheres and hydrogel-template nanoparticles. Positively charged fullerenes are sub-nanometer spheres (diameter ∼ 0.71 nm) that complex with the negatively charged siRNA molecules forming a stable compound under physiological conditions (pH = 7.4). Differently, the PLGA nanospheres and hydrogel-template nanoparticles are loaded with siRNA molecules during their synthesis process. The silencing performance of the three different nanoconstructs is assessed in vitro at multiple time points, over a period of 6 days post incubation. The loading efficiency, the release rate, the cell-entry mechanisms and potential cytotoxic response are analyzed. The performance of the nanoconstructs is compared with traditional delivery systems based on the use of transfection agents (oligofectamine). AQP1 is here used as a model system, and the optimized nanoconstructs could be utilized also for other siRNA therapeutics.

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 2887. doi:1538-7445.AM2012-2887
Abstract 3014: Expression of hypoxia-inducible factors (HIF-1alpha) mediates Matrix Metalloproteinases (MMP) in colorectal carcinomas progression
Authors: Ahmed Maqbool , Hussain Azhar R. , Bavi Prashant , Bu Rong , Al-Janadi Sahar M A , Al-Dayel Fouad , uddin Shahab , Al-Kuraya Khawla S.
Published: August 2012

Hypoxia-inducible factors (HIFs) are transcription factors that respond to changes in available oxygen in the cellular environment, specifically, to decreases in oxygen, or hypoxia. Most, if not all, oxygen-breathing species express the highly-conserved transcriptional complex HIF-1, which is a heterodimer, composed of an alpha and a beta subunit. HIF-1 transcription factor has been shown to promote pathogenesis of several malignancies. We have shown previously using a large cohort of CRC samples in a tissue micro array (TMA) format found that HIF-1α was expressed in the majority of CRC samples. HIF-1α over expression was found to be associated with MMP-2, and MMP-9. In the current study we investigated whether down regulation of HIF-1α by YC-1 a pharmacological inhibitor and gene silencing with specific HIF-1α siRNA leads to inhibition of cell proliferation and inhibition of apoptosis using a panel of CRC cell lines. Treatment of CRC cell lines with YC-1, inhibitor of HIF-1α resulted in inhibition of cell viability via induction of apoptosis. This apoptosis was initiated via loss of mitochondrial potential leading to the release of cytochrome c that resulted in sequential activation of caspases-9, and -3 and cleavage of PARP. Interestingly, pharmacological inhibition of HIF-1α also down-regulated expression of MMP-2, and MMP-9 in CRC cell lines. This data was further validated by siRNA knockdown strategy where expression of siRNA against HIF-1α also down-regulated the expression of HIF-1α, MMP-2 and MMP-9. Altogether, these data suggests that HIF-1α and its associated signaling pathway play a critical role in CRC tumorigenesis, therefore targeting of HIF-1α expression may be a viable therapeutic intervention for treatment of these cancers.

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 3014. doi:1538-7445.AM2012-3014
Abstract 3042: Glypican-1 (GPC1) promotes S-phase entry and DNA replication in human glioma cells
Authors: Qiao Dianhua , Meyer Kristy , Friedl Andreas
Published: August 2012

Glypican-1 (GPC1), the most ubiquitously expressed member of the glypican family of heparan sulfate proteoglycans (HSPGs), is highly expressed in the developing brain and gliomas. In gliomas, GPC1 is overexpressed in both tumor blood vessel endothelial cells (ECs) and the neoplastic cells. Prior work by us in ECs indicates that GPC1 is overall mitogenic and essential for cell cycle progression and proliferation, implying a role in glioma angiogenesis. The present study focused on the role of GPC1 in glioma cells to explore potential roles in tumorigenesis and growth. The expression of GPC1 in U87 cells, a human glioma cell line with a relatively low basal level of GPC1, was titrated by adenoviral transduction. BrdU pulse-labeling showed a robust induction of S-phase entry and DNA replication by expression of GPC1 in a dose-dependent manner. GPC1 overexpression ultimately led to DNA re-replication and aneuploidy as well as enlarged nuclei and cell rounding. Consistent with these cell cycle effects, ectopic expression of GPC1 significantly induced downregulation of pRb, p21Cip1 and p27Kip1 and upregulation of cyclin E, CDK2 and E2F transactivation activity. These cellular and molecular activities of GPC1 were independent of serum concentrations in the growth medium, suggesting that they do not require exogenous growth factors. This activity required intact GPC1 as neither unglycanated GPC1 core protein nor isolated GPC1 HS chains induced the cell cycle and molecular alterations seen after intact GPC1 was added. The more general relevance of our observation to other cell types and the HS-dependency of the GPC1 activity were confirmed by GPC1 transduction of wild-type and HS synthesis-defective CHO cells. Overexpression of GPC1 induced dramatic S-phase entry in wild-type but not in HS-deficient mutant CHO cells. In summary, this work reveals a potent S-phase promoting activity of GPC1 in glioma cells, which may lead to accelerated cell growth and/or increased genomic instability and, therefore, implies a role for GPC1 in glioma tumorigenesis and growth.

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 3042. doi:1538-7445.AM2012-3042