bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2596: Identification and characteration of IKBKE kinase inhibitor selectively inhibits tumor growth in cancer cells
Authors: Guo Jianping , Kim Donghwa , Cheng Jin Q.
Published: June 2012

The serine/threonine kinase IKBKE is frequently altered in human cancer. Ectopic expression of IKBKE induces malignant transformation, cell migration, invasion and chemoresistance. Thus, IKBKE is an attractive target for anti-cancer drug discovery. By screening a small molecule compound library, we identified an IKBKE inhibitor, MCCK1. It inhibits IKBKE kinase as well as downstream targets of IKBKE including phosphorylation such as Iκ-Bα, P65 and IRF3. MCCK1 is highly selective for IKBKE and does not inhibit the activation of IKKβ, STAT3, Erk-1/2, p38 or JNK. The inhibition of IKBKE by MCCK1 results in induction of cell growth arrest and apoptosis selectively in human cancer cells that harbor aberrant expression IKBKE. Further, MCCK1 inhibits tumor growth in nude mice of human cancer cells in which IKBKE is elevated but not of those cancer cells in which it is not. These data indicate that MCCK1 is an IKBKE inhibitor with anti-tumor activity in vitro and in vivo and could be a potential anti-cancer agent for patients whose tumors express elevated IKBKE.

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 2596. doi:10.1158/1538-7445.AM2011-2596
Abstract 26: Gene expression profiling of oral cancer cells chronic exposed to areca nut extract
Authors: Li Yi-Chen , Cheng Ann-Joy
Published: June 2012

Oral cancer is the 6th most frequent cancer in Taiwan. The habit of areca nut chewing is the main etiological factor of oral cancer. To shed light on molecular basis of areca nut associated oral carcinogenesis, we established two oral cell sublines chronically treated with areca nut extract (ANE) at IC70 dose for 2 months. Affymatrix microarray was used in transcriptome profiling between parental and ANE sublines of oral cancer cells. Algorithmic analysis was applied to analyze the network regulatory pathways. RT-PCR was used to validate the genes altered expressions in ANE-sublines. Total of 35 genes was differentially expressed in both sublines. Several functional pathways were apparently altered, with lipid metabolism (P=1.95×10−10), oxidative phosphorylation (P=1.02×10−6), and cell adhesion (P=9.66×10−6) most significant. Seven genes were confirmed over 2-fold of changes, including HMGCS1, KRT-17 up-regulation and SMC4, CENPF, ID-1, IL1-alpha and Ches1 down-regulation. Further study revealed Ches1 was down regulation upon arecoline treatment. Consistently, this gene was reduced expression in 52% of oral cancer tissues, which was significantly correlated with areca nut chewing habit of patients (p = 0.04). Thus, these results provide information regarding the molecular mechanisms of areca nut-induced oral carcinogenesis.

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 26. doi:10.1158/1538-7445.AM2011-26
Abstract 2627: Antitumor effect in human lung cancer by a combination treatment of novel histone deacetylase inhibitors: SL142 or SL325 and retinoic acids
Authors: Fukazawa Takuya , Han Shaoteng , Yamatsuji Tomoki , Mastuoka Junji , Miyachi Hiroyuki , Morita Ichiro , Takaoka Munenori , Maeda Yutaka , Naomoto Yoshio
Published: June 2012

Histone deacetylase (HDAC) inhibitors arrest cancer cell growth and cause apoptosis with low toxicity thereby constituting a promising treatment for cancer. In this study, we investigated the anti-tumor activity in lung cancer cells of the novel cyclic amide-bearing hydroxamic acid based HDAC inhibitors SL142 and SL325. In A549 and H441 lung cancer cells both SL142 and SL325 induced more cell growth inhibition and cell death than the hydroxamic acid-based HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). Moreover, the combination treatment using retinoid drugs ATRA or 9-cis RA along with SL142 or SL325 significantly induced more apoptosis and suppressed colony formation than the single use of either. The expression of the retinoic acid receptors RAR α, RAR β, RXR α and RXR β were unchanged with the treatment. However a luciferase reporter construct (pGL4. RARE 7x) containing seven tandem repeats of the retinoic acid responsible element (RARE) generated significant transcriptional activity after the combination treatment of retinoic acids and SL142 or SL325 in H441 lung cancer cells. Moreover, apoptosis-promoting Bax expression and caspase-3 activity was increased after the combination treatment. These results suggest that the combination treatment of SL142 or SL325 with retinoic acids exerts significant anti-tumor activity and is a promising therapeutic candidate to treat human 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 2627. doi:10.1158/1538-7445.AM2011-2627
Abstract 2629: Sustained immediate-early gene induction is linked to histone deacetylase inhibitor-induced apoptosis in multiple tumour types
Authors: Chueh Anderly C. , Togel Lars , Mariadason John M.
Published: June 2012

Introduction: Histone deacetylase inhibitors (HDACi) are a novel class of cancer therapeutics, currently approved for the treatment of cutaneous T-cell lymphoma (CTCL) and undergoing clinical trials for other haematological and solid tumours. Through screening of a panel of 30 colorectal cancer cell (CRC) lines, we previously established that HDACi-induced apoptosis is linked to a specific transcriptional response consisting of induction of multiple immediate-early (IE) and stress response genes. The purpose of this study was to investigate whether the findings made in colorectal cancer cells are applicable to other tumor types and to further elucidate the mechanism of apoptosis induction involving IE genes.

Results: We screened a panel of 40 tumor cell lines including that of CTCL, multiple myeloma, NSCLC, melanoma, breast and prostate cancer, for HDACi (sodium butyrate and Vorinostat) sensitivity by PI/FACS analysis and identified highly sensitive and resistant cell lines. Consistent with the findings made in CRCs, quantitative RT-PCR analysis revealed that the expression of six representative IE genes (Fos, Jun, Atf3, Egr1, Egr3, Gadd45b) were preferentially induced by HDACi treatment in the 5 most sensitive cell lines compared to the 5 most refractory tumor cell lines. To study kinetics of IE gene induction, we performed time-course experiments on cancer cell lines treated with various stimuli, including EGF, phorbol ester PMA, and HDACi. While EGF and PMA induce IE gene expression in a rapid and transient manner, HDACi-induction of IE gene expression is sustained over 24 hours, suggesting that the prolonged expression of these genes may be responsible for apoptosis induction. By transient transfection of siRNA into tumour cell lines, we demonstrated that the down-regulation of the IE genes Jun and Atf3 partially blocks HDACi-induced apoptosis.

Conclusions: We demonstrated that HDACi-induced apoptosis is linked to sustained transcriptional induction of multiple IE genes in a variety of cancer cells. Furthermore, we demonstrated that IE genes of the AP-1 transcription factor family Jun and Atf3 are directly involved in the apoptosis response induced upon HDACi 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 2629. doi:10.1158/1538-7445.AM2011-2629
Abstract 2662: Radiosensitizing potential of the PI3K inhibitor, BKM-120 and the HSP 90 inhibitor, HSP990, is dependent on PTEN status of glioblastoma cells
Authors: Wachsberger Phyllis Rachelle , Lawrence Richard Y. , Feo Nick , Liu Yi , Andersen Barbara , Dicker Adam P.
Published: June 2012

Introduction: Radiation therapy plays an essential role in the treatment of Glioblastoma Multiforme (GBM), the most common primary adult brain tumor. GBMs frequently contain mutations in the tumor suppressor gene, PTEN, a down regulator of the pro-survival phosphatidylinositide-3-kinase (PI3K) pathway. PTEN loss causes overactivation of the pathway inducing radioresistance. Heat-shock protein (HSP) 90 is overexpressed in GBM; it is a chaperone for many oncogenic proteins and plays a key role in assisting tumor cell survival, proliferation, invasion, metastasis and tumor angiogenesis. The purpose of this study was to investigate the radiosensitizing potential of an HSP 90 inhibitor, (HSP990) and a PI3K inhibitor, (BKM-120) in U87 GBM cells expressing PTEN or null for PTEN.

Methods: Two isogenic U87 cell lines, stably transfected with wildtype PTEN (U87 wtPTEN) or lacking PTEN (U87PTEN null) were used. Radiosensitivity was determined by clonogenic and apoptotic assays (Annexin V kit). DNA damage and repair was assessed by quantifying gamma Histone 2AX (γH2AX) foci. Immunoblots were performed to assess pAkt levels. HSP990 and BKM -120 were provided by Novartis Pharmaceuticals.

Results: Neither HSP990 or BKM -120, alone or in combination, potentiated radiation-induced DNA damage in either cell line, as assessed by γH2AX foci. Radiation alone (6 Gy) activated AKT phosphorylation, with maximum activity occurring one hour post-radiation in both cell lines. Radiation-induced Akt phosphorylation was strongly inhibited by BKM -120 alone or in combination with HSP990 but not by HSP990 alone in both cell lines. In clonogenic assays, both drugs (alone or in combination), sensitized PTEN positive and PTEN null cells to radiation. Whereas the two drugs had similar efficacy in PTEN null cells, HSP990 was a better radiosensitizer than BKM -120 in U87 wtPTEN cells. Apoptosis assays revealed very little cell death 1 hr or 24 hr following drug and RT treatments. After 5 days, the percentage of apoptotic/necrotic cells increased >30% over control following treatment with BKM -120 alone or in combination with HSP 990 in PTEN null cells. In contrast, PTEN positive cells were more resistant to cell death following BKM -120.

Conclusions: The results suggest that PI3K inhibition with BKM -120 will enhance radiotherapy for GBM lacking PTEN activity. HSP 90 inhibition by HSP990 may be of benefit in enhancing radiotherapy for GBM expressing functional PTEN. Thus, it appears that the optimal choice of radiosensitizer depends upon PTEN status.

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 2662. doi:10.1158/1538-7445.AM2011-2662
Abstract 2714: High HIV-1 DNA copy number defines a unique subset of AIDS-related lymphoma
Authors: Huysentruyt Leanne C. , Bracci Paige M. , McGrath Michael S.
Published: June 2012

Despite highly active antiretroviral therapy (HAART), the risk of developing non-Hodgkin lymphoma is ∼100X greater in the HIV-infected population compared to non-infected individuals and AIDS-related lymphoma (ARL) prevalence is expected to rise in the future. Preliminary reports have suggested that some ARLs contain HIV-infected macrophages that may contribute to ARL pathogenesis. A recent study evaluating HIV sequence evolution in the contest of metastatic ARL found lymphoma specific HIV compartmentalized within sites of lymphoma that was distinct from HIV present in non-lymphoma sites (Salemi et al, PLOSone Dec 3, 2009). These data suggested the existence of a lymphoma specific form of HIV evolving within individuals who develop ARL. The goal of this research was to determine the prevalence and quantity of HIV-1 DNA in 119 ARL biopsies from the entire span of the HIV epidemic (1982-2007) by utilizing whole genomic amplified (WGA) ARL DNA, provided by the AIDS and Cancer Specimen Resource (ACSR). The presence of HIV-1 DNA was determined by quantitative amplification of the HIV gag gene using single copy genes to define HIV copy numbers per genomic equivalent. Of the 119 ARL cases, 45% contained detectable levels of HIV-1 DNA (> 1 copy per 30,000 cells). The relationship between HIV DNA presence and tumor immunophenotype was determined using ARL data from the ACSR on the cases studied. The level of HIV per genomic equivalent in the 45% HIV DNA positive cases was as high as one/cell equivalent. There was a significant (p<0.01) decrease in the prevalence of HIV-1 DNA-positive ARL cases post-HAART (after 1996; 39%) as compared to pre-HAART (before 1996; 54%). Additionally, our data suggest that the overall amount of HIV-1 DNA present in ARLs was less in the post-HAART era when compared to the pre-HAART era. The HIV DNA positive cases fell into a positive outcome category (MUM1 negative and CD10 positive) based on lymphoma immunophenotype literature (p< 0.02). Thus, a subset of ARLs containing high levels of HIV DNA, falls into a better outcome category based on immunophenotype data and may represent a different lymphoma pathogenic process. The existence of lymphoma specific variants of HIV is currently under investigation.

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 2714. doi:10.1158/1538-7445.AM2011-2714
Abstract 2722: Transcription factor NF-kB in esophageal squamous cell carcinoma: Alterations in activity and expression during Human Papillomavirus infection
Authors: Hussain Showket , Singh Neha , Salam Irfana , Bhat Mohammad A. , Kakkar Nandita , Mir Mohammad M. , Siddiqi Mushtaq A. , Basir Seemi F. , Bharti Alok C. , Bharadwaj Mausumi , Das Bhudev C.
Published: June 2012

Background: Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related deaths in Jammu and Kashmir (J&K) region of India. A substantial proportion of esophageal carcinoma is associated with infection of high risk HPV type 16 and HPV18, the oncogenic expression of which is controlled by host cell transcription factor Nuclear factor kappa B (NF-kB). We therefore have investigated the role of DNA binding and expression pattern of NF-kB in esophageal cancer with or without HPV infection.

Methods: Seventy five histopathologically-confirmed esophageal cancer and an equal number of corresponding adjacent normal tissue biopsies from Kashmir were analyzed for HPV infection, DNA binding activity and expression of NF-kB family of proteins by PCR, gel shift assay and immunoblotting respectively.

Results: A high DNA binding activity and elevated expression of NF-kB proteins was observed in esophageal cancer tissue biopsies whereas, it was undetectable or reduced in all corresponding normal adjacent tissues but did not differ with respect to different grades of ESCC. In order to examine the composition of functional NF-kB complex both in HPV positive and negative esophageal tumors gel supershift assays were performed by adding specific antibodies to all 5 members of NF-kB family proteins (p50, p52, p65, RelB, and cRel). Supershift analysis revealed that p50 was a major binding partner and showed a preferential homodimerization in HPV negative esophageal tumors (61/75) and this participation was more evident in advanced grade of the disease (MDSCC+PDSCC; 46/61). On the other hand, HPV16 infected tumor tissues (n=14) showed hetrodimerization between p50 and cRel in more than 85% (12/14) of esophageal tumors. Interestingly, 2 cases with HPV infection p65 was also found to participate along with p50 and cRel in well-differentiated state of esophageal cancer. It is quite likely that the functional NF-kB complex formation in advanced grade of esophageal cancer comprises of p50/p50 homodimerization whereas in HPV infected esophageal tumors p50/cRel hetrodimerization occurs along with p65 in well differentiated state of the disease.

Conclusion: Differential NF-kB dimerization and expression of its specific proteins between HPV – positive and HPV – negative cases indicate that NF-kB may play an important role during HPV induced esophageal carcinogenesis.

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 2722. doi:10.1158/1538-7445.AM2011-2722
Abstract 2768: Single molecule approach detects significant mutation heterogeneity at the androgen receptor locus in prostate tumors
Authors: Makridakis Nick , Mukhopadhyay Sudurika , Chen Desheng
Published: June 2012

Studying the impact of genomic instability in cancer has been traditionally performed with PCR-based techniques. PCR-based methods may underestimate the total number of somatic mutations present in heterogeneous tumor genomes. Using standard PCR based methods we identified many missense somatic mutations of the DNA repair polymerase genes pol beta, pol eta and pol kappa in 30 prostate tumors. However, using a single molecule random cloning/sequencing method we uncovered a very high frequency of somatic alterations in prostate tumors: 0.52 somatic alterations per Kb of genomic DNA sequence (which corresponds to 1.8 million alterations per tumor cell genome). We then examined the somatic alteration frequency present in exon 2 of the androgen receptor (AR) gene, an established “driver” gene in prostate tumor progression. Exon 2 of the AR gene includes part of the DNA binding domain of this trancription factor. We report a similarly high somatic alteration frequency (including 50 missense AR mutations) and extreme AR mutation heterogeneity in prostate cancer patients with Gleason scores 5-9. Each somatic mutation was present in 1-5% of the tumor clones. Thus most of these “driver” mutations are not detectable by direct sequencing of a PCR product. All four cysteine residues that comprise the first Zinc-finger (Zf1) of the AR DNA-binding domain (the only zinc finger present in exon 2) had missense mutations in these patients (including recurrent mutations). In fact, we found missense or stop codon mutations of almost all Zf1 residues in these tumors. Some of these mutations have been shown to confer higher oncogenic transformation potential and hormone promiscuity to the androgen receptor. These data provide a molecular basis for the understanding of both a) the impact of genomic instability and b) anti-androgen drug resistance during prostate cancer 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 2768. doi:10.1158/1538-7445.AM2011-2768
Abstract 2797: Breast cancer methylomes establish an epigenomic foundation for metastasis
Authors: Chan Timothy A. , Fang Fang , Turcan Sevin , Rimner Andreas
Published: June 2012

Cancer-specific alterations in DNA methylation are hallmarks of human malignancies. The nature of the breast cancer epigenome and its effects on metastatic behavior remain obscure. To address this issue, we used genome-wide analysis to characterize the methylomes of breast cancers with diverse metastatic behavior. Here, we describe the identification of novel groups of breast tumors characterized by the presence or absence of coordinate hypermethylation at a large number of genes, demonstrating the existence of a breast-CpG island methylator phenotype (B-CIMP). B-CIMP imparts a distinct epigenomic profile and is a strong determinant of metastatic potential. Specifically, the presence of B-CIMP in tumors is associated with low metastatic risk and survival, and the absence of B-CIMP is associated with high metastatic risk and death. B-CIMP loci are highly enriched for genes comprising the metastasis transcriptome. Importantly, methylation at B-CIMP genes accounts for much of the transcriptomal diversity between breast cancers of varying prognosis, indicating a fundamental epigenomic contribution to metastasis. Comparison of the loci affected by B-CIMP with those affected by the hypermethylator phenotype in glioma and colon cancer reveals the presence of a CIMP signature shared by multiple human malignancies. These data provide a unifying epigenomic framework linking breast cancers with varying outcome and transcriptomic changes underlying metastasis. Our findings have significant implications for the understanding of breast cancer oncogenesis and for the development of new diagnostic and therapeutic modalities for this common malignancy.

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 2797. doi:10.1158/1538-7445.AM2011-2797
Abstract 2825: Characterization of a novel small molecule antagonist of 6-phosphofructo-2-kinase that suppresses glucose metabolism and tumor growth
Authors: Clem Brian , Tapolsky Gilles H. , O'Neal Julie , Chand Pooran , Clem Amy , Trent John , Telang Sucheta , Chesney Jason
Published: June 2012

Over-expression of HIF-1α, activation of Ras and loss of p53 tumor suppressor function are associated with the development of human cancers and each of these genetic alterations converge on glycolysis by activating the 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (PFKFB). The PFKFB enzymes interconvert fructose-6-phosphate (F6P) and fructose-2,6-bisphosphate (F2,6BP) and F2,6BP is an allosteric activator of 6-phosphofructo-1-kinase (PFK-1), a rate-limiting enzyme and control point in the glycolytic pathway. There are four PFKFB family members which are encoded by separate genes (PFKFB1-4) and characterized by distinct kinase:bisphosphatase ratios. The PFKFB3 family member is of particular interest since it has been found to be activated in human cancer cell lines and tumors, to be increased by hypoxic exposure via HIF-1α and by oncogenic Ras, and to be required for tumorigenic growth.

We recently discovered a competitive antagonist of PFKFB3 (3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one [3PO]) that reduces the glucose uptake, F2,6BP, lactate secretion, steady-state concentration of ATP, and growth of multiple transformed cell lines. Using a rationale design based approach, we have synthesized derivatives of 3PO and identified a compound (PFK-015) that: (i) more potently inhibits recombinant PFKFB3 (IC50:110 nM); (ii) inhibits PFKFB3 activity in cancer cells (IC50: 20 nM); (iii) is not a Pgp substrate as determined by transport and cell permeability assays in Caco-2 and MDCK-MDR1 (Papp A-B / B-A results 1.8 / 4 and 5 / 5 10−6 cm/s); (iv) inhibits cancer cell proliferation in a panel of 17 cancer cell lines; and (v) suppresses glucose uptake in cancer cells. Rodent PK studies following IV dosing at 5 mg/kg resulted in a profile with a satisfactory half-life (5.1 hours), exposure (AUCinf 1804 ng.h/ml), tissue distribution (Vd 20.5 L/kg) and reasonable clearance (46.2 mL/min/kg). Also, pre-clinical efficacy studies of C57Bl/6 mice bearing Lewis Lung Carcinoma (LLC) xenografts demonstrated ∼80% tumor growth inhibition relative to vehicle control. Finally, micro-PET studies performed on mice bearing LLC tumors showed a significant inhibition of tumor 2-[18F]-fluoro-2-deoxy-glucose uptake. These studies demonstrate that PFK-015 is an effective inhibitor of PFKFB3, possesses compelling in vitro properties, has satisfactory PK properties in rodents, and suppresses tumor glucose metabolism and growth in an aggressive mouse model of non-small cell lung cancer. These results support further development of PFK-015 as a novel anti-cancer agent.

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 2825. doi:10.1158/1538-7445.AM2011-2825
Abstract 2827: Activity of the proprietary Hsp90 inhibitor IPI-493 in models of colorectal cancer correlates with RAS pathway activation
Authors: West Kip A. , Hafeez Nafeeza , Dougall John Mac , Normant Emmanuel , Palombella Vito , Fritz Christian
Published: June 2012

Heat shock protein 90 (Hsp90) plays a role in regulating the stability of key cancer-causing proteins through its role as a protein chaperone. Proteins chaperoned by Hsp90, known as client proteins, include cancer-causing forms of ALK, BCR-ABL, EGFR, FLT3, and HER2. Infinity is developing two drug candidates in its Hsp90 chaperone inhibitor program: IPI-504 (retaspimycin hydrochloride), an intravenously-administered small molecule, and IPI-493, which is administered orally. To investigate the activity of IPI-493 in colorectal cancer (CRC), we performed in vitro growth inhibition (GI) studies on a CRC cell line panel. IPI-493 demonstrated GI50s in the range of 10-100nM in cell lines harboring either kRAS or bRAF mutations. To explore the in vivo potency of IPI-493, several mutant bRAF, mutant kRAS, as well as a wild-type kRAS/bRAF xenograft models were developed. Administration of IPI-493 at 100 mg/kg three times weekly demonstrated dramatic effects in all of the mutant models tested, with tumor growth inhibition (TGI) values between 70 and 90% and regression in one mutant bRAF model. Importantly, when IPI-493 was evaluated in combination with irinotecan, the combination resulted in greater tumor regression than seen with either agent alone with complete regressions observed in 4 of 10 animals. Interestingly, in the wild-type kRAS/bRAF models, IPI-493 administration did not lead to tumor growth inhibition. These results suggest that activation of the MAPK pathway may predispose these cells to sensitivity to Hsp90 inhibition. To investigate the effect of IPI-493 on MAPK pathway activity, we performed pharmacodynamic analysis after a single dose of IPI-493 in multiple xenograft models differing in their RAF/RAS mutation status. In mutant bRAF models, pathway activity was high, and IPI-493 administration resulted in downregulation of the activity of both bRAF and MEK. In models containing no mutations in kRAS or bRAF, we detect low baseline levels of both p-bRAF and p-MEK and little effect of IPI-493 administration. When Ras pathway activity in all CRC xenografts was compared with IPI-493 efficacy, there was a clear correlation between pathway activation and tumor growth inhibition by IPI-493. Our finding that Ras pathway activation predisposes CRC cells to sensitivity to IPI-493 and our combination data with irinotecan provide a clear rationale for the evaluation of Hsp90 inhibitors in colorectal 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 2827. doi:10.1158/1538-7445.AM2011-2827
Abstract 2851: Metronomic doxorubicin blocks hypoxia inducible factor-mediated responses to hypoxia in sarcomas and augments the effects of anti-VEGF therapy
Authors: Kim Yeo-Jung , Zhang Alexia Y. , Karl Daniel , Eisenger Karin , Simon M. Celeste , Yoon Sam S.
Published: June 2012

Introduction: Levels of hypoxia and hypoxia inducible factors (HIFs) in human sarcomas correlate with tumor progression and metastasis. Prolonged anti-angiogenic therapy of sarcomas can inhibit tumor growth but may also increase hypoxia and HIF activation. The most commonly used chemotherapeutic drug for sarcomas, doxorubicin (dox), was recently found to block HIF binding to DNA at low metronomic doses.

Methods: 20 patients with soft tissue sarcomas were treated with anti-VEGF antibody (bevacizumab). The tumors, before and after treatment, were examined for changes in microvessel density using CD31 immunohistochemical staining and global gene expression using microarrays. Patients’ tumors were then treated with a combination of bevacizumab and radiation followed by surgical resection. Expression of specific HIF-target genes in the response to hypoxia and/or dox was examined in vitro in 4 sarcoma cell lines by q-RT-PCR. HT1080 human sarcoma xenografts and sarcomas in genetically engineered LSL-KrasG12D/+Trp53fl/fl mice were treated with anti-VEGF receptor antibody (DC101) and/or metronomic dox and analyzed for levels of hypoxia, HIFs, and HIF-target genes.

Results: Bevacizumab alone reduced microvessel density in sarcomas by a median of 53% (p<0.05). Gene set enrichment analysis of microarrays found the Gene Ontology category “Response to hypoxia” (which includes HIF-1a, HIF-2a, and ARNT) was upregulated in sarcomas with a poor response to combination therapy (bevacizumab plus radiation). Dox at 1-10 uM blocked HIF induction of VEGF and CA-9 in all 4 sarcoma cell lines by 83.7-97.0% and 88.6-97.6%, respectively, while inhibition of other HIF-target genes including c-MET and FOXM1 was variable. HT1080 sarcoma xenografts and LSL-KrasG12D/+Trp53fl/fl sarcomas demonstrated increasing hypoxia with larger tumor size and with treatment with an anti-VEGFR-2 antibody (DC101). Increasing hypoxia corresponded to greater nuclear expression of HIF-1α and HIF-2α, and metronomic Dox lowered expression of HIF-depended genes by up to 92.3%. Combining VEGFR-2 antibody and metronomic Dox therapies had a synergistic effect in suppressing tumor growth.

Conclusion: Human sarcomas respond to increased hypoxia by expressing HIF-target genes which promote compensatory responses. This hypoxic response may be exacerbated by anti-VEGF therapies and promote resistance to such therapies. Low metronomic doses of dox can block activation of HIF-target genes and works synergistically with anti-VEGF therapies to inhibit tumor growth.

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 2851. doi:10.1158/1538-7445.AM2011-2851
Abstract 2871: JNK1-phosphorylation of Bcl-2 is essential for adenoviral-induced autophagic cell death in glioma cells
Authors: Klein Sarah R. , Piya Sujan , White Erin J. , Jiang Hong , Yung W.K.Alfred , Gomez-Manzano Candelaria , Fueyo Juan
Published: June 2012

Purpose: Delta-24-RGD is a highly selective and potent oncolytic adenovirus that is currently being tested in a clinical trial for patients with malignant gliomas. The mechanism of oncolysis for Delta-24-RGD is defined as autophagic cell death, yet the signal transduction and molecular interactions responsible remain uncharacterized. Methods: Utilizing JNK1- and JNK2-null mouse embryonic fibroblasts, we analyzed the involvement of JNK in Bcl-2 phosphorylation and degradation, and adenoviral-induced autophagy. Mutations at the phosphorylation sites of Bcl-2 were employed to determine which are necessary for release of Beclin 1, degradation of Bcl-2, and induction of autophagy by adenovirus. Results: In this report, we reveal that activation of c-Jun N-terminal kinase 1 (JNK1) is required to initiate and maintain autophagy induced by wild-type and Delta-24-RGD adenoviruses in the host cell. In addition, JNK1-dependent phosphorylation of Bcl-2 at serine 87 (but not serine 70) and subsequent inhibition of Bcl-2:Beclin 1 heterodimerization is necessary for autophagy to occur in infected cells. Upon phosphorylation and release from Beclin 1, Bcl-2 is degraded by the proteosome. Finally, the activation of JNK leads to its translocation to the nucleus and results in the transcription of autophagy-related (ATG) genes for the maintenance of autophagy, as yet undocumented in mammalian cells. Conclusion: Adenoviruses have thus evolved a highly complex mechanism of regulating autophagy which differs from the typical cellular stress response that may be exploited in the treatment of gliomas.

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 2871. doi:10.1158/1538-7445.AM2011-2871
Abstract 2884: Resveratrol, a red wine polyphenol, suppresses pancreatic cancer by inhibiting leukotriene A4 hydrolase
Authors: Cho Yeon-Yong , Oi Naomi , Jeong Chul-Ho , Nadas Janos , Pugliese Angelo , Bode Ann M. , Dong Zigang
Published: June 2012

Considerable attention has focused on the anticancer effects of red wine. Resveratrol (3,5,4’-trihydroxy-trans-stilbene) is a well-known polyphenolic compound found in red wine and recognized as a key substance for cancer chemoprevention. Leukotriene A4 hydrolase (LTA4H) is a bi-functional zinc enzyme that is regarded as a relevant target in certain types of human cancers. Our data indicate that knockdown of LTA4H decreased production of leukotriene B4 (LTB4), the enzymatic product of LTA4H, and suppressed anchorage-independent growth of MIA PaCa-2 pancreatic cancer cells. An in silico prediction using a shape-similarity approach suggested that LTA4H might be a potential target of resveratrol. Results showed that resveratrol directly bound to LTA4H in vitro and ex vivo and suppressed proliferation and anchorage-independent growth by inhibiting LTA4H activity in MIA PaCa-2 cells. Importantly, resveratrol exerted stronger inhibitory effects compared to bestatin, a well-known inhibitor of LTA4H activity. The inhibitory effects of resveratrol were reduced in MIA PaCa-2 cells transfected with sh-LTA4H compared with sh-mock transfected cells. Notably, in an in vivo xenograft mouse model, resveratrol suppressed MIA PaCa-2 tumor formation by inhibiting LTA4H activity. These findings suggest that LTA4H is a novel target for the preventive and/or therapeutic effects of resveratrol on pancreatic 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 2884. doi:10.1158/1538-7445.AM2011-2884
Abstract 2937: The LKB1-STRADα axis regulates vimentin to control cancer cell metastasis
Authors: Kline Erik , Hales Katherine , Marcus Adam I.
Published: June 2012

Lung cancer remains the most lethal form of cancer, and non-small cell lung cancer (NSCLC) patients have a 5-year survival rate of only 15-25%. Metastasis is the major cause of death in nearly all cancer cases. Therefore, determining which genes are altered during cancer invasion and the functional consequences of their alteration will broaden our understanding of metastatic disease and unveil novel targets for anti-metastatic therapies. The pleiotropic tumor suppressor LKB1 is mutated in ∼30% of NSCLC cases and is the third most frequently mutated gene in lung adenocarcinoma. Originally recognized as a regulator of the energy stress pathway and cell cycle signaling, we and others have identified LKB1 and its activating co-factor STRADα as regulators of the lung cancer cell polarity program through the small Rho GTPase cdc42 and its downstream binding partner p21-activated kinase (PAK). We expand these studies and investigate the LKB1-STRADα pathway during the transition from cell polarity to cell motility. We show that when a cancer cell becomes motile, STRADα re-localizes to associate with vimentin intermediate filaments in a motility-dependent manner. Vimentin is specifically overexpressed in invasive human tumors, which also correlates with metastatic disease, poor prognosis, and reduced patient survival. To dissect the mechanistic basis of this observation, we tested the hypothesis that STRADα regulates vimentin function to oversee cancer cell motility. STRADα loss results in aberrant lamellipodia formation, uncoordinated movement, and vimentin bundling. Conversely, STRADα overexpression disassembles the vimentin network with no apparent effect on cell survival. A phospho-proteomic screen in isogenic NSCLC cell lines showed that out of 580 possible proteins the cdc42 GEF, VAV2, demonstrated the greatest loss in phosphorylation upon vimentin depletion. Western blot analysis confirmed that vimentin-depletion decreased phosphorylation of VAV2 at residue Y-142. Dual overexpression of LKB1 and STRADα enhances VAV2 phosphorylation in vimentin-positive cells but not in vimentin-depleted cells. These findings suggest a cell polarity-motility program whereby LKB1-STRADα initiates cell polarity through cdc42-PAK, then STRADα re-localizes to the vimentin cytoskeleton to oversee vimentin dynamics. LKB1-STRADα also regulates VAV2 phosphorylation through vimentin signaling. These results link the LKB1-STRADα tumor suppressor pathway to the lung cancer cell polarity and motility programs, and explain how defects in the LKB1-STRADα alter lung cancer invasion.

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 2937. doi:10.1158/1538-7445.AM2011-2937
Abstract 299: CDK1 and CDK2 activity is a strong predictor of renal cell cancer recurrence
Authors: Hongo Fumiya , Takaha Natsuki , Kimura Yasunori , Nakamura Terukazu , Mikami Kazuya , Nakayama Satoshi , Matsushima Tomoko , Ishihara Hideki , Sakai Toshiyuki , Miki Tsuneharu
Published: June 2012

Background: We established original methods enabling simultaneous analysis of protein expressions and kinase activities of the CDK (cyclin-dependent kinase) molecules in lysate of tumor tissue in a clinical setting (C2P technology, Ishihara et al: Biochim Biophys Acta. 1741; 226-233, 2005). The clinical utility of the technology was first evaluated in breast cancer, and combination analysis of CDK1 and CDK2 activity was shown to be a significant prognostic indicator for relapse (Kim et al: Ann Oncol. 19; 68-72, 2009). The objective of our study is to evaluate the efficacy of CDK1 and CDK2 activity as a prognostic marker in human renal cell carcinoma (RCC).Methods: Surgical specimens were obtained from 125 patients with RCC without metastasis. These patients were selected randomly for this study. Protein expression and kinase activity of CDKs and cyclins were analyzed using a newly developed assay system. The system to measure the CDK specific activity (SA) is named C2Ps (Sysmex, Kobe, Japan). We then examined the specific activities of CDK1 and CDK2 and calculated CDK2/CDK1 ratio in RCC. Also, risk score (RS) was examined as described in previous study (JGH van Nes et al: Br J Cancer. 100; 494-500, 2009). Cut off value was calculated by ROC analysis.Results: 125 cases were tested, though 34 cases were excluded of low sample quality (25 cases) and of assay failure (9 cases). 91 cases were analyzed. They included 68 male and 23 female patients, ranging in age from 19 to 83 years. At a median follow up of 36 months (1-109M), tumor with low CDK2/CDK1 ratio showed significantly better 5-year progression free survival (PFS) than those with high CDK2/CDK1 ratio (88.7% vs 54.7%, P=0.00141). Also, RS enabled the classification of RCCs into high-risk and low-risk groups, patients with tumors classified as low RS showed better PFS than patients with tumors with high RS (88.7% vs 54.7%, P=0.0141).Conclusion: CDK1 specific activity of tumors and the CDK2 specific activity are both associated with recurrence and prognosis. Analysis of cyclin-dependent kinase activity in the clinical setting could be a powerful approach for predicting cancer recurrence and prognosis in RCC after surgery and has potential for use as a routine laboratory test.

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 299. doi:10.1158/1538-7445.AM2011-299
Abstract 3093: Gene regulation induced by constitutive expression of HIF-1α in transgenic mice
Authors: Ide Masaru , Sueoka-Aragane Naoko , Sato Akemi , Nakamura Tomomi , Yokoo Masako , Kimura Shinya , Tanimoto Keiji , Sueoka Eisaburo
Published: June 2012

Hypoxia-inducible factor-1α (HIF-1α) has a central role on regulation of various genes under hypoxic condition linked to regulation of angiogenesis, metabolism and tumor development. Expression of HIF-1α was reported in many cancers associated with tumor progression, invasion and metastasis. We reported that constitutive expression of HIF-1α in transgenic mice induced tumors in lymphoid, lung and breast tissues in last this meeting. The incidence of tumors in transgenic mice was up to 90% until 18 months after birth. To clarify the molecular mechanism of lymphomagenesis in the transgenic mice, lymphocyte subsets, gene expression and mitogenic responsiveness on lymphoid tissues were analyzed. Although population of T and B cell subset in spleen, maturation pattern of T cells in thymus, or cell growth rate after treatment with various mitogens were not changed by HIF-1α overexpression, the lymphocytes from transgernic mice showed longer survival than those from wild mice. The lymphocytes also showed resistance for genotoxic stimuli like topoisomerase inhibitors. We next compared gene expression profile on lymphocyte from transgenic mice and wild mice by cDNA microarray and RT-PCR. The expression of over a hundred of genes including HIF-1α itself was altered on T and B cells in transgenic mice. Among them the gene associated with cell survival and cell transformation-related genes were further analyzed by validation study. In this paper, we present the results concerning the role of HIF-1α in lymphoma occurrence, and will discuss the contribution of the transcription factor in human cancer development.

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 3093. doi:10.1158/1538-7445.AM2011-3093
Abstract 3109: Wnt2 secreted by tumor fibroblasts promotes tumor growth and cell motility in esophageal carcinoma
Authors: Guan Xin-Yuan , Fu Li , Zhang Chunyu , Dong Sui Sui , Li Yan , Chen Juan
Published: June 2012

Interaction between neoplastic and stromal cells plays an important role in the tumor progression. Recently, we found that Wnt2 was frequently overexpressed in fibroblasts isolated from tumor tissue (TFs) compared to fibroblasts from non-tumor tissue (NFs) in esophageal squamous cell carcinoma (ESCC). In the present study, we studied the effect of TF-secreted Wnt2 in ESCC development via the tumor-stroma interaction. Quantitative real-time PCR found that Wnt2 expression was about 4 folds higher in the TFs than the NFs. Interestingly, no visible protein expression of WNT2 was detected in all tested ESCC cancer cell lines and clinical ESCC samples. Immunohistochemistry study showed that WNT2(+) cells was were mainly detected in the boundary between stroma and tumor tissue or scattered within tumor tissue. Furthermore, Wnt2-positive ESCC (defined as 5 or more Wnt2(+) cells observed in 200× microscopy field) was detected in 22/51 cases, which was significantly associated with the lymph node metastases (P=0.001), advanced TNM stage (P=0.001) and disease-specific survival (P<0.0001). To further investigate the effect of secreted Wnt2 on ESCC cells, an in vitro Wnt2 secreting system was established using Chinese hamster ovary (CHO) cells and conditioned medium was collected for functional study. Functional assays demonstrated that secreted Wnt2 could promote cell growth and cell migration. Molecular study found that the cell growth promoting effect of Wnt2 was via activating Wnt/β-catenin signaling pathway and subsequently upregulating cyclin D1 and c-myc expression. Wnt2 could also induce epithelial-mesenchymal transition (EMT) and promote cell motility. In conclusion, our data demonstrate that TF-secreted Wnt2 can promote cell growth through activating the canonical Wnt/β-catenin signaling pathway and increase cell motility by inducing EMT in esophageal cancer cells. Further characterization of the effect of Wnt2 secreted by TF on cancer development and progression will reveal the molecular mechanisms of how TF provide cancer cells a suitable microenvironment and find new therapeutic targets 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 3109. doi:10.1158/1538-7445.AM2011-3109
Abstract 3112: Host MMP-2 impacts tumor survival in the metastatic bone microenvironment through a TGFβ dependent mechanism
Authors: Thiolloy Sophie , Edwards James , Fingleton Barbara , Rifkin Daniel , Schwartz Herbert S. , Mundy Gregory , Matrisian Lynn M. , Lynch Conor C.
Published: June 2012

Breast to bone metastases frequently induce a “vicious cycle” in which osteoclast mediated bone resorption and proteolysis results in the release of bone matrix sequestered factors that drive tumor growth. While osteoclasts express numerous proteinases, analysis of human breast to bone metastases unexpectedly revealed that bone forming osteoblasts were consistently positive for the proteinase, MMP-2. In immunocompetent murine models of the lytic tumor-bone microenvironment, we identified that, independent of osteoclast function, osteoblast derived MMP-2 promoted tumor survival by regulating the bioavailability of TGFβ, a factor critical for cell-cell communication in the bone. Collectively, these studies identify a novel interplay between the osteoblast and tumor compartments that is key for tumor survival in the bone microenvironment.

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 3112. doi:10.1158/1538-7445.AM2011-3112