bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 344: Oxygen sensors are poor prognosticators for survival in NSCLC
Authors: Andersen Sigve , Donnem Tom , Al-Shibli Khalid , Al-Saad Samer , Stenvold Helge , Busund Lill-Tove , Bremnes Roy
Published: June 2012

Background: Most solid tumors are at least partly hypoxic. To survive hypoxia, cancer cells must adapt by hypoxic gene activation. Hypoxia-inducible factors (HIFs) have been recognized as key regulators of this transcriptional control. However, oxygen tension is sensed by three HIF prolyl hydroxylases (PHD1, PHD2 and PHD3) and one asparaginyl hydroxylase, FIH (Foctor inhibiting HIF). This study evaluates the prognostic impact of these four oxygen sensors in the biggest killer in cancer, Non-Small Cell Lung Cancer (NSCLC).

Methods: 335 unselected stage I-IIIA NSCLC-patients were included. Duplicate 0.6 mm diameter cores from both the viable neoplastic cell compartment (tumor) and stroma were collected in tissue microarrays (TMAs). Immunohistochemistry (IHC) was used to semiquantitatively evaluate the expression.

Results: There was only scorable expression in the tumor compartment. In univariate analyses high expression of all the oxygen sensors in tumor were significantly associated with a poor prognosis (PHD1, P = 0.023; PHD2, P = 0.013; PHD3, P = 0.018; FIH, P = 0.033). There were only weak correlations between these markers (strongest between PHD2 and FIH; r = 0.18, P = 0.001). In the multivariate analysis, entering all the significant clinicopathological variables and the oxygen sensors, we found only high expression of PHD2 (HR 2.03; CI 95% 1.20-3.42; P = 0.008) and PHD1 (HR 1.45; CI 95% 1.01-2.10; P = 0.047) of the molecular variables to be independent poor prognosticators.

Conclusions: Oxygen sensors were only scorable in tumor. High expression of all the oxygen sensors was associated with a poor prognosis. High expression of PHD1 and PHD2 were also significantly and independently associated with a dismal prognosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 344. doi:10.1158/1538-7445.AM2011-344
Abstract 3440: YWHAZ promotes slug transcription activity and lung cancer metastasis
Authors: Chen Ching-Hsien , Chen Hsuan-Yu , Lin Sheng-Yi , Tsai Meng-Feng , Yu Sung-Liang , Chen Jeremy
Published: June 2012

Metastasis is a major cause leading to mortality for lung cancer patients and gene copy variation is one common mechanism contributing to human malignancies. To identify the novel metastasis-related genes, an approach combined array comparative genomic hybridization and expression microarray was applied in a lung cancer invasion cell model. YWHAZ was identified as a potential candidate, which plays an important role in a wide variety of cellular processes. Nevertheless, its role and underlying mechanism in lung cancer metastasis remain unclear. In this study, we found that YWHAZ promotes cell proliferation, anchorage-independent growth, invasion and migration in vitro, as well as tumorigenesis and metastasis in vivo. It not only increases cell protrusions and branchings but also induces epithelial-mesenchymal transition. Furthermore, YWHAZ associates with β-catenin and enhances slug expression which is regulated by the β-catenin/TCF signaling pathway in lung cancer cells. Our findings demonstrate that YWHAZ plays a critical role in promoting invasion and metastasis of human lung adenocarcinoma cells, which might provide new insight into the future treatment of lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3440. doi:10.1158/1538-7445.AM2011-3440
Abstract 3445: The role of p38/MAPK14 in cerebellar granule neuron precursor proliferation and medulloblastoma
Authors: Guldal Cemile G. , Mainwaring Lori A. , Kenney Anna M.
Published: June 2012

Development of the cerbellum occurs primarily postnatally and is marked by a rapid proliferation of cerebellar granule neuron precursors (CGNPs). This proliferation requires the activity of the mitogen Sonic Hedgehog (Shh). CGNPs are proposed to be the cells of origin for some classes of medulloblastoma (MB), the most common solid pediatric tumor, making their proliferation an attractive target for cancer therapy. Since MAP kinases play important roles in many aspects of development, proliferation, and cancer, we investigated if any of the three major classes of MAP kinases were involved in Shh-driven CGNP proliferation. We have previously shown that p42/p44 ERK MAP kinases are not involved in Shh signaling in CGNP proliferation. We have also shown that JNK/SAP kinases are not involved in Shh-driven proliferation. However, p38/MAPK14 is induced and activated in proliferating CGNPs compared to CGNPs that exit the cell cycle and differentiate in the absence of Shh. Other known pathway components upstream and downstream of MAPK14, such as ASK1, MKK3 and ATF-2, are also activated in the presence of Shh. Antioxidants such as lipoic acid and n-acetyl-cysteine that relieve oxidative stress reduced Shh-induced activation of MAPK14 and caused a marked decrease in CGNP proliferation measured by Ki67 and BrdU staining. Knocking down p38 in CGNPs also causes a marked decrease in Shh-dependent proliferation and an increase in apoptosis, which indicates a role for MAPK14 in CGNP survival. We are currently investigating the mechanism of Shh regulation of p38 MAPK pathway, which will lead to a better understanding of CGNP proliferation, cerebellar development, and MB progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3445. doi:10.1158/1538-7445.AM2011-3445
Abstract 3452: Molecular genetic analysis of the WTX gene in medulloblastoma
Authors: Wenzl Eve-Kristin , Regehly Maren , Guse Katrin , Röhn Gabriele , Goldbrunner Roland , Hernáiz-Driever Pablo , Thomale Ulrich Wilhelm , Schüller Ulrich , Heppner Frank , Koch Arend
Published: June 2012

Medulloblastomas (MBs) represent the most frequent malignant brain tumors of childhood. Previous genetic studies in MBs have identified mutations in genes coding for beta-catenin, AXIN1 and Conductin (AXIN2), which cause activation of the Wnt signaling pathway in about 20% of this malignant tumors. The Wnt signaling pathway is negatively controlled by the Wilms tumor suppressor gene WTX, a component of this signaling complex.

To investigate whether alterations in WTX may also be involved in the pathogenesis of sporadic MBs, we performed a mutational screening of the WTX gene in 76 MB biopsy samples and 5 MB cell lines using single-strand conformation polymorphism and sequencing analysis. Two rare WTX single nucleotide polymorphisms (SNPs) c.135C>T in exon 2 of two different MBs (Ser > Ser; TCC >TCT), both of them are not yet known, where identified.

To investigate if the tumor suppressor WTX is regulated in MBs an mRNA expression analysis in 46 MBs and 5 MB cell lines revealed reduced expression of WTX mRNA compared to fetal cerebella tissues. Interestingly, when compared to adult cerebella tissue, WTX is up-regulated in fetal cerebella of different embryonic ages, which indicates a possible involvement of WTX during cerebella development. Moreover, wild-type WTX was found to be over-expressed in tumor cell lines in which the Wnt signaling pathway is activated by mutations in beta-catenin. Our findings indicate that the activation of the Wnt signaling pathway in MBs is not caused by alterations in WTX. However, the down-regulation of WTX could be a possible explanation for the Wnt activation in a subset of MBs. The up-regulation of WTX (related to adult controls) and in particular in Wnt-activated tumor cells suggests that WTX could be a potential target gene of the Wnt signaling pathway, which interacts in a negative feedback loop mechanism.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3452. doi:10.1158/1538-7445.AM2011-3452
Abstract 3463: Treatment of young children with localized medulloblastoma by chemotherapy alone: Final results of the prospective multicenter trial HIT 2000 confirming the prognostic impact of histology
Authors: von Bueren Andre O. , von Hoff Katja , Pietsch Torsten , Gerber Nicolas , Warmuth-Metz Monika , Deinlein Frank , Zwiener Isabella , Faldum Andreas , Fleischhack Gudrun , Benesch Martin , Krauss Juergen , Kuehl Joachim , Kortmann Rolf D. , Rutkowski Stefan
Published: June 2012

Background: This study was designed to confirm the previously observed favorable survival rates and prognostic factors in young children with non-metastatic medulloblastoma (MB) treated by postoperative chemotherapy alone.

Methods: Patients diagnosed between January 2001 and December 2005 and younger than 4 years received three cycles of postoperative systemic multiagent chemotherapy and intraventricular methotrexate. In case of complete remission, treatment was terminated after two additional cycles of chemotherapy. Otherwise secondary surgery, radiotherapy and consolidation chemotherapy were recommended.

Results: The 5-year event-free survival (EFS) and overall survival (OS) (±SE) rates of 45 patients were 57 ± 8% and 80 ± 6% (median follow-up: 4.5 years, median age: 2.5 years). Nineteen patients with desmoplastic / nodular MB variants had better EFS and OS (5-year rates: 90 ± 7% and 100 ± 0%) compared to 23 patients with classic MB (30 ± 11% and 68 ± 10%; p< 0.001 for EFS, p=0.008 for OS). Five-year EFS and OS rates of 3 children with anaplastic MB were 33 ± 27%. Desmoplastic / nodular histology was an independent prognostic factor for EFS. Twenty-nine of 30 (97%) patients without postoperative residual tumor remained in continuous complete remission.

Conclusions: Our results confirm histology of MB variants as a strong prognostic factor in this age-group. Sustained tumor control and favorable survival rates can be achieved by this chemotherapy regimen in young children with desmoplastic / nodular MB variants. For children with non-desmoplastic / non-nodular MB variants, where predominantly local relapses lead to less favorable survival rates, local radiotherapy has been introduced after chemotherapy since 2006.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3463. doi:10.1158/1538-7445.AM2011-3463
Abstract 3472: Endothelial FAK is required for tumor angiogenesis
Authors: Tavora Bernardo , Hodivala-dilke Kairbaan
Published: June 2012

Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that plays a fundamental role in integrin and growth factor mediated signalling and is an important player in cell migration and proliferation, processes vital for angiogenesis. However, the role of FAK in adult pathological angiogenesis is unknown. We have generated endothelial-specific tamoxifen-inducible FAK knockout mice by crossing FAK-floxed (FAKfl/fl) mice with the Pdgfb-iCreER mice. Tamoxifen-treatment of Pdgfb-iCreER;FAKfl/fl mice results in FAK deletion in adult endothelial cells (EC) without any adverse effects. Importantly however, endothelial FAK-deletion in adult mice inhibited tumour growth and reduced tumour angiogenesis. Furthermore, in in vivo angiogenic assays FAK-deletion impairs vascular endothelial growth factor (VEGF) induced neovascularisation. In addition, in vitro deletion of FAK in ECs resulted in reduced VEGF-stimulated AKT phosphorylation, and correlating reduced cellular proliferation and increased cell death.

Furthermore, using a combination of genetic ablation and inhibition of FAK we are studying a new role of endothelial FAK in the regulation of the vascular barrier function with implications on the metastatic process.

Our data suggest that FAK is required for adult pathological angiogenesis and suggests a possible role of endothelial FAK in the regulation of the vascular barrier function.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3472. doi:10.1158/1538-7445.AM2011-3472
Abstract 3473: Endothelin axis autocrine loop is positively regulated by the interplay between ET-1 and hypoxia-inducible factor-1α in melanoma cells
Authors: Spinella Francesca , Caprara Valentina , Cianfrocca Roberta , Rosanò Laura , DiCastro Valeriana , Natali Pier Giorgio , Bagnato Anna
Published: June 2012

Phenotypic and genotypic analyses of cutaneous melanoma have identified the endothelin B receptor (ETBR) as tumor progression marker, thus representing a potential therapeutic target. We previously demonstrated that ETBR activation by endothelin (ET)-1, promotes melanoma progression and lymphatic vessel growth through a hypoxia-inducible factor (HIF)-1α-mediated mechanism and cooperates with hypoxia to increase this effect. In this study we show that in melanoma cells ETs increase ET-1 and ETBR mRNA and protein expression and their promoter activity that were completely blocked by the selective ETBR antagonist, BQ788, supporting the presence of a positive ET-1-autocrine loop. Moreover when melanoma cells were exposed to hypoxia the induction of both ETBR and ET-1 was markedly enhanced demonstrating that hypoxia potentiates the ET-1-autocrine loop by reinforcing the expression of ETBR and the secretion of ET-1 that, in turn, increases simultaneously ET-1/ETBR expression. Silencing HIF-1α or HIF-2α significantly reduced the promoter activity and the expression of ET-1 and ETBR in response to hypoxia or ETs. Chromatin immunoprecipitation assay showed increased HIF-1α and HIF-2α binding to ET-1 and ETBR promoter in response to hypoxia or ET-1 stimulation. Interestingly, ETs through ETBR enhance both vascular endothelial growth factor (VEGF)-A and VEGF-C mRNA and protein expression and promoter activity. At functional level silencing of HIF-1α and HIF-2α inhibited the ET-1 and hypoxia-induced VEGF-A and VEGF-C expression, providing that hypoxia and ET-1 axis share the same transcriptional machinery through which may control angiogenic and lymphangiogenic response. Moreover, in melanoma xenografts, ETBR antagonist suppressed tumor growth, neovascularization-related effectors, indicating that targeting ETBR related signalling cascade may represent a novel treatment of melanoma by impairing the positive feedback loop between ET axis and hypoxic melanoma microenvironment. Supported by AIRC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3473. doi:10.1158/1538-7445.AM2011-3473
Abstract 3479: Claudin-14: A novel regulator of angiogenesis
Authors: Baker Marianne , Robinson Stephen D. , Hodivala-Dilke Kairbaan , Ben-Yosef Tamar
Published: June 2012

Angiogenesis, the formation of new blood vessels from pre-existing ones, is vital for tumor growth and spread. A better understanding of angiogenic processes, particularly cell-cell adhesion, is required for the development of effective anti-angiogenic drugs.

Claudin-14 (Cldn14) is a component of Tight Junctions (TJ) and its function in angiogenesis is not yet known. Other TJ molecules such as JAMs are known to be involved in angiogenesis; for example, we have identified a novel dosage-dependent role for JAM-B in the regulation of angiogenesis in the context of trisomy of human chromosome 21 (Hsa21) genes (Reynolds et al. Nature 2010); Cldn14 is also present on Hsa21. Therefore we hypothesise that Cldn14 may also play a role in the regulation of angiogenesis.

Here we show that depletion of Cldn14 enhances VEGF-stimulated angiogenesis in the ex vivo aortic ring assay and increases primary mouse lung endothelial cell proliferation via changes in downstream signalling. Viable Cldn14 knockout mice exhibit normal vasculature in unchallenged organs, suggesting that the effect may be specific to pathological states. These data reveal novel regulatory roles for Cldn14 and future work will characterise further the functions of Cldn14 in angiogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3479. doi:10.1158/1538-7445.AM2011-3479
Abstract 3487: Molecular basis for induction of IL-8 expression by thymidine phosphorylase
Authors: Akiyama Shin-ichi
Published: June 2012

Thymidine phosphorylase (TP) is identical to platelet-derived endothelial cell growth factor (PD-ECGF) and has an angiogenic activity. 2-Deoxy-D-ribose, one of the degradation products of thymidine, is a down stream mediator of the TP function.

We investigated the molecular basis for the induction of an angiogenic factor, interleukin-8 (IL-8) by TP. First we confirmed that the enzymatic activity of TP is needed for the induction of IL-8 by TP in KB cells, and 2-deoxy-D-ribose increased the expression level of IL-8. ROS generated by TP augmented the expression of heme oxygenase-1 (HO-1) and increased the expression of IL-8. Two inhibitors of NADPH oxidase, apocynin and diphenyleneiodonium, suppressed the expression of HO-1 and IL-8 in TP-overexpressing KB/TP cells. Knock down of the component of NADPH oxidase, Nox2 or p22phox, also suppressed the enhanced expression of IL-8 in KB/TP cells. ROS generated by TP activated NFκB, which subsequently enhanced the promoter activity of IL-8. Our findings suggest that NADPH oxidase is involved in the ROS generation by TP, and the ROS caused the activation of NF-κB, which subsequently enhanced the expression of IL-8.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3487. doi:10.1158/1538-7445.AM2011-3487
Abstract 3488: PGE2 promotes angiogenesis by activating PKA catalytic subunit gamma
Authors: Zhang Yushan , Daaka Yehia
Published: June 2012

The Cyclooxygenase-2 product PGE2 is suggested to be involved in angiogenesis, but its exact role and the underlying mechanisms remain unclear. In the present study, we show that PGE2 dose-dependently promotes the in vitro tube formation of human microvascular endothelial cells (HMVEC). PGE2 also increases vessel density in chicken chorioallantoic membrane, and vessel outgrowth of mouse aortic rings. All cognate PGE2 receptors, namely EP1, EP2, EP3 and EP4 can be detected in the HMVECs at both the gene and protein levels. Using EP-specific ligand agonists and antagonists our data demonstrate the EP4-dependent tube formation. Concordantly, knockdown of EP4, but not EP1, EP2 or EP3 with siRNA attenuates the PGE2-induced tube formation. Treatment with PGE2 increases cAMP accumulation and PKA activation, and knockdown of EP4 attenuates the PKA activation, suggesting a principally EP4-to-PKA signal. Remarkably, the treatment with selective PKA inhibitors H89 or PKI attenuates the PGE2-mediated tube formation. There are three PKA catalytic subunits and the knockdown of catalytic subunit gamma (PKACg) prevents the PGE2-regulated tube formation. To begin to identify the PKA substrate(s) involved in tube formation, a panel of SMARTpool siRNAs targeting 16 PKA substrates was tested. Results show that heat shock protein B6, endothelial nitric oxide synthase and small GTPase Rap1A exert pro-tube formation effects, whereas small GTPase RhoA and GSK3b may be involved in anti-tube formation. Our data suggest that PGE2 promotes angiogenesis through a EP4-cAMP-PKACgamma pathway. Targeting EP4 and PKACgamma may serve as an efficient strategy to control initiation and progression of diseases affected by angiogenesis, such as cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3488. doi:10.1158/1538-7445.AM2011-3488
Abstract 35: Genome-wide molecular profiling of peri-tumoral neocortex revealed genes possibly responsible for tumor-induced epilepsy
Authors: Li Xiaojin , Xu Jun , Fan Xuemo , Niesen Charles E. , Wang Charles
Published: June 2012

Epilepsy is a common cause of morbidity affecting approximately one third of patients with primary brain tumors. The molecular mechanism underlying the tumor induced epileptogenesis is poorly understood. Since the alteration in the peritumoral microenvironments is believed to play a significant role in inducing the epileptic state, we hypothesize that the change in gene expression of neighboring astrocytes and neurons may contribute to the increased neuronal excitability. To identify the genes possibly responsible for tumor induced epilepsy, a genome-wide gene expression profiling was conducted using Affymetrix HG U133 plus 2.0 arrays and RNAs derived from 1-5 year old formalin-fixed paraffin embedded (FFPE) peritumoral cortex from 5-paired (seizure vs. non-seizure) low grade brain tumor patients. RNAs were extracted from 3-5 microdisections of FFPE tissue blocks using Qiagen RNeasy FFPE kit and cDNA were synthesized and amplified using NuGen's WT-Ovation FFPE RNA amplification system and FL-Ovation cDNA biotin module. Our results showed that although FFPE derived RNAs were significant fragmented with a peak of 100-200 bases, gene detection rate was found to be significant high (up to 49.8%) with excellent 3’/5’ ratios (GAPDH, 1-3.4). The rate of gene detection is depending on the archive time of tissue blocks (correlation coefficient = -0.71, P< 0.05). We identified 345 differentially expressed genes (DEGs, 2-fold plus P < 0.05). Principal Component Analysis (PCA) based on both global genes and 345 DEGs showed that epilepsy samples were clustered together tightly (except one sample) and were clearly separated from the non-epilepsy samples. Gene Ontology (GO) analysis on 345 DEGs revealed several important functional groups of genes including signal transduction (20.6%), metal ion binding (18.2%), cation binding (17.9%), receptor activity (10.8%) and receptor binding (4.0%). Other significant DEGs include transcription factors, glutamate receptors and intercellular matrix proteins. Pathway analysis showed these 345 DEGs were mainly involved in focal adhesion (12 genes), ECM-receptor interaction (11 genes) and cell communication (9 genes) pathways. In conclusion, our study showed that (1) archival FFPE brain tissue is an excellent resource for genomic studying; and (2) the altered gene expression in the peri-tumoral neurons implicate multiple cellular pathways in the induction of the epileptic state. Identification of genes responsible for brain tumor-induced epilepsy may lead to novel and better management of epilepsy in brain tumor patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 35. doi:10.1158/1538-7445.AM2011-35
Abstract 3500: Histone deacetylator (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA) sensitizes squamous carcinoma cells of lung to pemetrexed
Authors: Kim Soyeon , Kim Tae Min , Lee Se-Hoon , Kim Dong-Wan , Heo Dae Seog
Published: June 2012

Objectives: The multitargeted antifolate pemetrexed is approved as a first-line or second-line treatment of nonsquamous nonsmall cell lung cancer. The expression of the thymidylate synthase (TS) gene may mediate resistance to pemetrexed. In this study, we investigated whether the pemetrexed in combination with SAHA enhances the cytotoxicity of squamous carcinoma cells of lung.

Methods: Squamous carcinoma cells of lung (NCI-H157, HCC-95 and HCC-1588) were exposed to 10-3M to 10-7M of pemetrexed with various HDAC inhibitors and their cytotoxicities were analyzed using the colorimetric assay. Cell cycle and apoptosis analyses were evaluated by flow cytometry. The mRNA and cellular protein levels were detected by RT-PCR and western blot assay.

Results: After NCI-H157 was exposed to SAHA, TS mRNA and protein expression levels were strongly suppressed by time and dose-dependent manner, respectively. Additionally, although pemetrexed activated phosphorylation of AMPK-α, secondary target (AICAR) of pemetrexed, co-treatment of pemetrexed and SAHA decreased phosphorylation of AMPK-α and mTOR pathway. NCI-H157, HCC-95, and HCC-1588 treated with sequential SAHA (24h) followed by SAHA plus pemetrexed (72h) represented more synergistic cytotoxicities than those treated with simultaneous 96h exposure combination (p<0.05). This sequential treatment was significantly associated with TS inhibition as well as apoptosis of squamous carcinoma cells. While pemetrexed increased expressions of p21, PARP, and cleaved caspase 3 and reduced expression of bcl-2, the combination of pemetrexed and SAHA additionally increased the pro-apoptotic molecules. Sequential treatment of SAHA followed by pemetrexed resulted in 10-fold and 1.6-fold higher sub-G1 portions than control and pemetrexed alone groups, respectively in NCI-H157 cell. In particular, the sequential administration produced more apoptotic index as compared to pemetrexed alone in NCI-H157 cell (27% vs 8%).

Conclusion: Our results demonstrate SAHA reduces TS expression and sequential treatment with pemetrexed has a synergistic cytotoxicity in squamous cell carcinoma of lung.

Sequential treatment of SAHA and pemetrexed might be a new strategy to overcome pemetrexed resistance in patients with squamous cell carcinoma of lung.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3500. doi:10.1158/1538-7445.AM2011-3500
Abstract 3515: Combined effects of leptomycin B and doxorubicin on lung cancer
Authors: Lu Chuanwen , Cobos Everardo , Gao Weimin
Published: June 2012

To develop novel molecularly targeted therapy has become an important focus of research efforts in lung cancer treatment. Our previous study has shown leptomycin B (LMB), by blocking chromosome maintenance region 1 (CRM1), significantly inhibits cell proliferation in lung cancer cells in a p53-dependent manner. These results suggest the potential use of LMB as a new therapeutic regimen for lung cancer treatment. On the other hand, doxorubicin (DOX) is one of the most effective anticancer agents, which induces p53 activation and nuclear accumulation. The objective of this study is to determine the combinative cytotoxic and molecular effects of LMB and DOX on lung adenocarcinoma cell line, A549. Cells were treated with DOX alone, pre-treatment of DOX/LMB and subsequent treatment of LMB/DOX, or DOX and LMB simultaneously. Cell viability was measured by the MTT assay. The inhibitory effects of DOX on A549 were dose and time-dependent (P<0.001). The 50% inhibitory concentrations (IC50s) of DOX at 24, 48, and 72 h were 60.0, 2.2, and 1.7 µM, respectively. The pre-treatment of 0.5 µM DOX for 24 h significantly improved the cytotoxic effects of LMB on A549 cells at 48 h (P<0.05). The resulting IC50 of LMB was decreased more than 2 fold after pre-treatment of DOX (4.4 nM) as compared to that of LMB alone (10.6 nM). However, the pre-treatment of LMB and the simultaneous treatment of DOX and LMB did not change the cytotoxic effects of either treatment of LMB or DOX. p21 and survivin are well-known p53 downstream genes that play important roles in cell cycle arrest and/or apoptosis. The protein expression levels of these two genes were further analyzed by western blots. Our results showed that the protein expression level of p21 was significantly increased while the protein expression level of survivin was significantly decreased in A549 cells treated with either pre-treatment of DOX and LMB or LMB alone in comparison with those of controls. Furthermore, these changes were more pronounced in pre-treatment of DOX and LMB group as compared to those of LMB alone group. Taken together, our data suggest that the combined therapy using an initial DOX treatment (through activating p53) and subsequent LMB treatment (through blocking the CRM1 function to accumulate activated p53 in the cellular nucleus), that lead to the activation of p53 downstream transcripted genes for cell cycle arrest and apoptosis, might be more effective as a new therapeutic strategy for lung cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3515. doi:10.1158/1538-7445.AM2011-3515
Abstract 3521: Alleviation of cancer chemotherapeutic agent-induced toxicity by the synthetic panaxytriol analogues of Panax Ginseng
Authors: Chou Ting-Chao , Dong Huajin , Zhang Xiuguo , Lei Xiaoguang , Danishefsky Samuel J.
Published: June 2012

Therapeutic index (TI) of cancer therapeutic agent is the ratio of maximal tolerated dose (MTD) and the optimal therapeutic dose (OTD). “Reduction in toxicity” and/or “increasing efficacy” by augmentation or synergy will invariably lead to improved TI and patient's well-being during therapy. We found a series of polyacetylene small molecules that is promising just to do that. Through total synthesis, we designed the panaxytriol (PXT) analogs of panax ginseng C.A. Meyer, such as PXTA, PXTAI, PXTAEI and its isomers that are biologically more active than their parent natural ingredient, PXT. At sub-toxic doses, the PXT-compounds, as a single entity (e.g., not an extract, mixture or preparation), are found to process the following intriguing pharmacological properties that have potential applications in cancer chemotherapy or radiation therapy. They are: (i) Exhibited moderate anti-tumor effect in the absence of any toxicity, and slightly augment or synergize anti-tumor effect of taxol or epothilones, in xenograft tumor bearing nude mice; (ii) Significantly or markedly reduced cancer therapeutic agent-induced toxicity such as body-weight losses (e.g., by Taxol, iso-oxazole fludelone, iso-oxazole dehydelone, 5-FU, cyclophosphamide), lethality (e.g., high dose 5-FU) and neurotoxicity (e.g., peripheral neuropathy induced by Taxol); (iii) Showed moderate anti-inflammatory effect in foot-paw-carrangreenan assays in CD-1 mice; (iv) Improved the hematological parameters following high dose 5-FU; (v) The alleviation of body-weight loss also manifested by the oral administration; (vi) Reduced the radiation-induced body-weight loss in CD-1 mice; (vii) Reduced the lethality of radiation; and (viii) Induced the cancer preventive phase II enzyme, quinone reductase (NQ01). PXT-analogs also stimulated human PBMC proliferation in a biphasic and delayed manner in vitro and stimulated splenocyte proliferation of CD-1 mice in delayed manner, suggesting the immuno-enhancing effect. In conclusion, our results demonstrate that co-administration of PXT-based agent with a range of cancer chemotherapeutic agents or radiation therapy will decrease various therapy-associated toxicities and thus increase the therapeutic index. These findings indicate a promising improvement for the cancer chemotherapeutic or radiation therapeutic strategies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3521. doi:10.1158/1538-7445.AM2011-3521
Abstract 3536: Caulobacter crescentus as new intravesical treatment for bladder cancer
Authors: Gust Kilian M. , Lange Dirk , Nomellini John F. , Smit John , So Alan I.
Published: June 2012

Introduction and Objectives: The standard of care for high risk non-muscle invasive bladder cancer is the intravesical instillation of Bacillus Calmette-Guérin (BCG), an attenuated strain of the pathogen Mycobacterium bovis, associated with significant side effects often ending treatment prematurely. Using nonpathogenic bacterial strains with anti-tumor activity would thus be beneficial. Caulobacter crescentus is a gram-negative, non-pathogenic fresh water bacterium that does not replicate in a mammalian host and therefore qualifies for having a good bio-safety profile. Caulobacter crescentus has previously been shown to have anti-tumor activity in a model of mammary carcinoma. The aim of this study was to evaluate the anti-tumor activity of intravesical administered Caulobacter cresecentus in an immuno-competent animal model for bladder cancer.

Materials and Methods: In vitro, the mouse bladder tumor cell line MBT-2, derived from C3H/He mice, was treated with increasing concentrations of Caulobacter crescentus (C.cresc.). Microscopy and growth assays were performed. In vivo, the same cell line, previously lenti-viral transduced with a luciferase gene (MBT-2 luc), was instilled in the bladder of 6 week old, female C3H/He mice (3×106 cells/50ul). Bioluminescent imaging was performed to determine tumor burden on day 5 and mice were randomized to treatment groups. Intravesical treatments (109 C.cresc. in 50ul of H2O or H2O as control) were performed on days 6, 8, 11 and 15 and tumor growth was examined by bioluminescence after i.p. injection of luciferin. Mice were euthanized on day 20 and mouse bladders processed for histology and immuno-histochemistry.

Results: In vivo, intravesical treatment of MBT-2 luc tumor bearing C3H/He mice showed a significant inhibition of tumor growth compared to the control group, while no side-effects due to the intravesical C.cresc. application were observed.

Additionally performed in vitro experiments revealed that incubation of MBT-2 cells with C.cresc. resulted in a concentration dependent growth inhibition.

Conclusions: These preliminary results support the safety and efficacy of Caulobacter crescentus as a novel intravesical treatment for bladder cancer. Further investigation is needed to reveal the exact mechanism of action and to distinguish, if a direct anti-tumor effect of C.cresc. or the host immune-response is the driving component of the anti-tumor effect.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3536. doi:10.1158/1538-7445.AM2011-3536
Abstract 3538: In vivo combination studies of PM01183 with alkylating, antimetabolites, DNA-topoisomerase inhibitors and tubulin binding agents
Authors: Guillén Ma José , Cataluña Oscar , Palomares Mandy , Lopez Raquel , Cuevas Carmen , Aviles Pablo M.
Published: June 2012

PM01183 is a new synthetic tetrahydroisoquinoline alkaloid that binds to selected DNA sequences and promotes apoptosis by inducing double-strand breaks at nanomolar concentrations. PM01183 displays significant antitumor activity in several murine models of human cancer. PM01183 is currently in phase I/II clinical development for cancer treatment. Nonclinical combination studies are increasingly relevant during the development of any anticancer compound. As such, PM01183 was assayed in combination (two-drugs) with representatives of alkylating agents (dacarbazine, temozolomide and cisplatin), antimetabolites (5-FU and gemcitabine), DNA-topoisomerase inhibitors (irinotecan and doxorubicin) and tubulin binding agents (paclitaxel and vinorelbine). Different models were used depending on the combination explored: STS (HT1080) for dacarbazine; glioma (U-87 MG) for temozolomide; gastric (HGC-27) for cisplatin and 5-FU; pancreas (SW1990) for gemcitabine; colon (HT-29) and NSCLC (H460) for irinotecan; and ovarian (A2780) for doxorubicin, paclitaxel and vinorelbine. Athymic nu/nu mice bearing tumors (ca. 150 mm3) were randomly allocated to 13 treatment groups: i) placebo; ii) PM01183 at 4 different dose levels, namely MTD (0.180 mg/kg), 0.75MTD, 0.5MTD and 0.25MTD; iii) Compound to be combined, at 4 different dose levels MTD, 0.75MTD, 0.5MTD and 0.25MTD; and, iv) PM01183 plus the combined compound, administered with the combination at (1+1), (0.75+0.75), (0.50+0.50) and (0.25+0.25) of MTD ratios. The antitumor activity was followed by T/C, (change in tumor volume for each treated -T- and placebo -C- groups during placebo-treated survival period). Then, the fraction affected (Fa) by the treatment was calculated (1-T/C) and, the combination index (CI) by the CI-isobol method determined. Synergism (CI ≤ 1 at Fa > 0.8) was recorded when PM01183 was combined with dacarbazine (HT1080), cisplatin (HGC-27), 5-fluororacil (HGC-27), gemcitabine (SW1990), irinotecan (H460), doxorubicin (A2780), paclitaxel (A2780) and vinorelbine (A2780).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3538. doi:10.1158/1538-7445.AM2011-3538
Abstract 3542: A novel Hedgehog pathway inhibitor in combination with chemotherapy in mesothelioma cell lines
Authors: Lui Natalie , Li Hui , Do Hanh , Sheng Qing , Jablons David , He Biao
Published: June 2012

We tested a novel Hedgehog pathway inhibitor in combination with chemotherapy to determine if there are synergistic effects in mesothelioma cell lines. The Hedgehog signaling pathway has been shown to be activated in many types of cancer. Our laboratory developed a novel Hedgehog pathway inhibitor that has promising characteristics. Several mesothelioma cell lines were treated with this new compound in combination with two standard chemotherapeutic agents, pemetrexed and cisplatin. The cells were seeded in 96-well plates on day 1 and then treated with a matrix of drug dosages on day 2. Cell viability was measured on day 5 using the CellTiter-Glo Luminescent Cell Viability Assay (Promega). The dose-effect relationship was plotted for each drug alone to determine the IC50, the inhibitory concentration at which cell viability was 50%. The IC50 of our Hedgehog inhibitor ranged from 1uM to 10uM for various cell lines. The dose-effect relationship in the combination studies was analyzed using Calcusyn (Biosoft). A combination index less than 0.9, indicating synergy, was found at several dose combinations in multiple cell lines. In summary, a novel Hedgehog pathway inhibitor in combination with chemotherapy showed synergy in multiple mesothelioma cell lines, showing high potential for this new compound to improve standard chemotherapeutic regimens and allow treatment at lower doses with fewer side effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3542. doi:10.1158/1538-7445.AM2011-3542
Abstract 3545: Autophagy inhibition as a therapeutic strategy in cancer
Authors: Chen Ning , Price Sandy , Karantza Vassiliki
Published: June 2012

Autophagy is an evolutionarily conserved process involving degradation of cellular components in lysosomes to maintain protein and organelle quality control, and temporarily sustain cell viability in response to stressful stimuli. Several studies have demonstrated the dual role of autophagy in tumorigenesis as both a tumor suppressor and a protector of cancer cell survival under stress. It is well recognized that anticancer therapies, such as chemotherapy and irradiation (RT), induce autophagy as a pro-survival response, likely resulting in therapeutic resistance. Therefore, concurrent autophagy inhibition as a chemo- and RT-sensitizer has generated great interest in cancer therapy. We generated Beclin1+/+ and Beclin1+/- immortalized mouse mammary epithelial cells (iMMECs) stably expressing the apoptosis inhibitor BCL-2 and the autophagy marker EGFP-LC3 to investigate how acute autophagy inhibition and chronic autophagy deregulation impact tumor sensitivity to anticancer drugs commonly used against breast cancer. We also used human cancer cell lines, including MCF-7, PANC-1, MIA PaCa-2 and HCT-116 cells, to explore whether pharmacologic autophagy inhibition or genetic knockdown of autophagy regulators exhibits a synergistic anticancer effect with newer antineoplastic drugs, such as mTOR inhibitors (CCI-779 and RAD001) and novel antimicrotubule agents (ixabepilone). Treatment efficacy was evaluated by clonogenic survival and cytotoxicity assays in 2D- and 3D-epithelial cell culture in vitro and by tumor responsiveness assays in mice in vivo. Autophagy inhibition sensitized Beclin1+/+ apoptosis-defective iMMECs to doxorubicin, but not to paclitaxel, and had an even greater impact on autophagy-deficient cells. Moreover, autophagy inhibition via choloroquine or Beclin1 knockdown enhanced the treatment efficacy of mTOR inhibitors on MCF-7, PANC-1, MIA PaCa-2 and HCT116 cells in vitro and in xenograft tumors in nude mice in vivo. These studies provide insight into how autophagy functional status in tumors impacts treatment responsiveness and into how to best incorporate pharmacologic autophagy modulation in the decision tree for cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3545. doi:10.1158/1538-7445.AM2011-3545
Abstract 3546: Cucurbitacin B as a direct mTOR inhibitor synergizes with methotrexate for treatment of human osteosarcoma
Authors: Lee Dhong Hyun Tony , Thoennissen Nils , Goff Catherine , Iwanski Gabriela , Doan Ngan , Said Jonathan , Koeffler H. Phillip
Published: June 2012

The mammalian target of rapamycin (mTOR) pathway is one of the most important oncogenic pathways in cancer, and the upregulation of the mTOR pathway is frequently observed in human osteosarcoma (OS). In this study, we demonstrated for the first time that cucurbitacin B, a plant-derived tetracyclic triterpenoid, is a direct mTOR inhibitor in OS using drug affinity responsive target stability (DARTS) analysis. Binding of cucurbitacin B to mTOR resulted in the inhibition of mTOR phosphorylation in MG-63 and SAOS-2 human OS cells in vitro, which was further confirmed by the inhibition of ribosomal S6 protein kinase (S6K) and eukaryotic translation initiation factor 4E binding protein 1 (4EBP1). This finding led us to hypothesize the possible use of cucurbitacin B as a single agent as well as in combination with methotrexate (MTX) for OS treatment. Cucurbitacin B in combination with MTX synergistically inhibited OS cell growth in vitro such that combination index (CI) < 0.9. Murine xenografts treated with either low-dose cucurbitacin B (LD-CuB, 0.5 mg/kg body weight) or low-dose MTX (LD-MTX, 150 mg/kg) alone failed to decrease tumor size. However, combined therapy at identical concentrations inhibited tumor growth by 62% vs LD-CuB and 81% vs LD-MTX (p<0.001). The effect persisted even at a two-thirds decrease (50 mg/kg) in the MTX dose. In conclusion, cucurbitacin B is a direct inhibitor of mTOR, and the combined use of cucurbitacin B with MTX showed promising antiproliferative activity against human OS. The use of this combination should be explored further in clinical studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3546. doi:10.1158/1538-7445.AM2011-3546
Abstract 3550: Curcumin suppresses growth of human mesothelioma cells in vitro and in vivo, in part, by stimulating apoptosis
Authors: Wang Ying , Rishi Arun K. , Wu Wenjuan , Polin Lisa , Sharma Sunita , Levi Edi , Albelda Steven , Pass Harvey I. , Wali Anil
Published: June 2012

Malignant Pleural Mesothelioma (MPM) is an aggressive, asbestos-related malignancy of the thoracic pleura. Although platinum-based agents are the first line of therapy, there is an urgent need for second-line therapies to treat the drug-resistant MPM. Cell cycle as well as apoptosis regulatory pathways are frequently altered in MPM and thus remain attractive targets for therapeutic intervention strategies. Curcumin, the major component in the spice turmeric, alone or in combination with other chemotherapeutics has been under investigation for a number of cancers. Here we investigated the biological and molecular responses of MPM cells to Curcumin treatments and the mechanisms involved. Flow-cytometric analyses coupled with western immunoblotting and gene-array analyses were conducted to determine mechanisms of Curcumin-dependent growth suppression of human (H2373, H2452, H2461, and H226) and murine (AB12) MPM cells. Curcumin inhibited MPM cell growth in a dose and time dependent manner while pretreatment of MPM cells with Curcumin enhanced Cisplatin efficacy. Curcumin activated stress-activated p38 kinase, caspases 9 and 3, caused elevated levels of proapoptotic proteins Bax, stimulated PARP cleavage, and apoptosis. In addition, Curcumin treatments stimulated expression of novel transducers of cell growth suppression such as CARP-1, XAF1, and SULF1 proteins. Oral administration of Curcumin inhibited growth of murine MPM cell-derived tumors in vivo in part by stimulating apoptosis. Thus, Curcumin targets cell cycle and promotes apoptosis to suppress MPM growth in vitro and in vivo. Our studies provide a proof-of-principle rationale for further in-depth analysis of MPM growth suppression mechanisms and their future exploitation in development of effective therapeutic treatment options against resistant MPM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3550. doi:10.1158/1538-7445.AM2011-3550