bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3450: Growth-inhibitory effect of neurotrophin-3-secreting adipose tissue-derived mesenchymal stem cells on the D283-MED human medulloblastoma cell line
Authors: Kim Young-Hoon , Kim Chae-Yong , Cho Byung-Kyu , Wang Kyu-Chang , Kim Seung-Ki , Phi Ji Hoon , Cho Seung Hee , Lee Soo Jung , Choi Seung Ah , Kim Jin Wook , Park Chul-Kee
Published: June 2012

Medulloblastoma (MBL), the most common malignant pediatric brain tumor, is incurable in about one-third of patients and can lead to long-term disabilities despite current multimodal treatments. We evaluate the in vitro, growth-inhibitory effect of neurotrophin-3 (NT-3)-secreting stem cells on an MBL cell line and propose that this cell therapy may have therapeutic effects for MBL. NT-3-secreting stem cells were produced by nucleofecting pIRES2.EGFP-NT3 into human adipose tissue-derived mesenchymal stem cells (hAT-MSCs). Double-layered co-culture experiments with the NT-3-secreting hAT-MSCs and D283-MED MBL cells were performed, and NT-3-induced apoptosis was studied by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) test. The growth-inhibitory effects of these stem cells on human MBL in vitro were confirmed by 3-(4, 5-dimethylathiazol-2-yl)-2, 5-dephenyl-tetrazolium bromide (MTT) assay. We confirmed by western blotting that D283-MED cells express tyrosine kinase C, a specific receptor for NT-3, and we showed by fluorescence microscopy and RT-PCR that transfected hAT-MSCs express NT-3. The double-layered co-culture of D283-MED with NT-3-secreting hAT-MSCs induced a concentration-dependent increase in apoptosis in the tumor cell line. Consequently, the high concentrations of NT-3-secreting hAT-MSCs significantly (P < 0.001) increased the death of D283-MED cells in vitro. The present studies demonstrate the potential of NT-3-secreting hAT-MSCs as an effective therapeutic cell therapy for human MBL in vitro, but in vivo experiments and clinical studies will be required in the future.

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 3450. doi:10.1158/1538-7445.AM2011-3450
Abstract 3459: Expression of oncogene-induced senescence markers in pilocytic astrocytomaIs associated with younger age and longer survival
Authors: Lim Kah Suan , Bar Eli E. , Raabe Eric H. , Jain Deepali , Eberhart Charles G.
Published: June 2012

Pilocytic astrocytomas are the most common pediatric brain tumor. They are low grade neoplasms, and in some cases can spontaneously stop growing or regress. The recent discovery of constitutive BRAF activation in the majority of pilocytic astrocytomas, due either to gene duplication/fusion or point mutation, suggests a possible molecular basis for this relatively benign pathobiology. Oncogenic BRAF-induced senescence has previously been identified in benign melanocytic nevi and colonic polyps, but whether it also occurs in pilocytic astrocytomas is not clear. To investigate this, we examined the senescence marker acidic beta-galactosidase in low passage pilocytic astrocytoma cultures established from freshly resected tumors. Two of these cultures, tested at passages 2 to 3, were derived from tumors that contained KIAA1549:BRAF fusions, and both expressed the senescence marker in over half of the cells. Another culture tested at passage 3 was also strongly positive for acidic beta-galactosidase, but the genetic status of its parent tumor is not known. A final culture came from a pilocytic astrocytoma lacking the KIAA1549:BRAF fusion, or an activating V600E BRAF point mutation, and was negative for the senescence marker, but was tested at passage 10. To help confirm these effects in vivo, we immunostained a tissue microarray containing 78 pilocytic astrocytoma for p16 and p53, both of which have been implicated in oncogene-induced senescence in other tumor types. The majority of pilocytic astrocytoma expressed p16, but the 13% of tumors lacking this senescence marker were associated with significantly shorter overall survival (p = 0.0002). Patients whose pilocytic astrocytomas lacked p16 were also older (mean age 25 years) as compared to those with intermediate (mean age 12 years) or high expressing tumors (mean age 7 years). Immunohistochemical analysis of p53 revealed much weaker staining, and only 18 tumors were positive, but expression correlated positively with that of p16 (Spearman r = 0.45, p = 0.0001). Our data suggest that the low-grade phenotype of pilocytic astrocytomas may be due to oncogene-induced senescence driven by KIAA1549:BRAF fusions or BRAF V600E point mutations, and that expression of senescence markers in vivo is associated with younger age at presentation and better clinical outcomes.

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 3459. doi:10.1158/1538-7445.AM2011-3459
Abstract 3465: shRNA against uPA and uPAR enhances secretion of sVEGFr1 in tumor endothelial and glioblastoma cells independent of GMCSF
Authors: Raghu Hari , Gondi Christopher S. , Nalla Arun Kumar , Rao Jasti S.
Published: June 2012

The uPA/uPAR system is known to play a critical role in angiogenesis of glioblastomas. Previously, using protein array antibody analysis, we demonstrated that shRNA against uPA and uPAR (pU2) inhibits angiogenesis in vitro and in vivo by regulating a number of pro-angiogenic, angiostatic and anti-angiogenic molecules. GMCSF, a pleiotropic cytokine that stimulates proliferation, differentiation, and survival of various hematopoietic cells, was significantly inhibited in U87MG and 4910 cells co-cultured with endothelial cells and transfected with pU2. In this study, we evaluated the effect of shRNA against uPA and uPAR on GMCSF, sVEGFr1, GMCSF receptors and GMCSF-induced signaling and its significance on angiogenesis in glioblastoma and endothelial cells. ELISA revealed that simultaneous knockdown of uPA and uPAR in U87MG, 4910 and HMEC cells decreased secretion of GMCSF but enhanced the secretion of sVEGFr1, a known scavenger of VEGF-A. The results of the western blot analysis were consistent with our ELISA results. In endothelial cells treated with shRNA against GMCSF, recombinant uPA (ruPA) resulted in activation of GMCSFR-α and GMCSFR-β at very early time points. Moreover, endothelial tube formation was inhibited with the addition of rsVEGFr1, and antibody to rsVEGFr1 blocked GMCSF-induced tube formation in endothelial cells. The addition of ruPA to endothelial and glioblastoma cells activated phosphorylation of JAK2 and STAT3. p27, an effector of the GMCSF signaling pathway, was downregulated in puPA-, puPAR- and pU2-transfected U87MG and 4910 cells. To determine the significance of these events in vivo, nude mice were checked for levels of GMCSF and sVEGFr1 before and after tumor formation and also after treatment with puPA, puPAR and pU2. Results showed increased levels of sVEGFr1 but decreased levels of GMCSF in shRNA treated mice in comparison to controls. Taken together, these results suggest that knockdown of uPA/uPAR in tandem induces sVEGFr1, which plays a vital role in inhibition of angiogenesis, and its secretion is independent of GMCSF in endothelial cells.

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 3465. doi:10.1158/1538-7445.AM2011-3465
Abstract 348: Analysis of somatic hypermutations in IGHV genes from Hairy Cell Leukemia Immunoglobulin Heavy Chain rearrangements
Authors: Arons Evgeny , Suntum Tara , Roth Laura , Sapolsky Jeffrey , Kreitman Robert J.
Published: June 2012

The B-cell receptors of malignant B-cells each contain a monoclonal immunoglobulin sequence which may be relevant for both prognosis and cell of origin. The character of somatic hypermutations (SHM) has been studied to predict whether antigen contacted the B-cell prior to its malignant transformation, or at least whether the SHMs observed are ‘canonical’, or consistent with those expected from mutation machinery used for antigen-driven SHM. Hairy cell leukemia B-cell receptors have previously been evaluated for gene usage and homology to germline sequence, but detection of canonical SHMs was not previously possible because of the limited number of HCL rearrangements. To compare HCL with CLL and normal B-cells, somatic hypermutation (SHM) features in hairy cell leukemia (HCL) were examined in a series of 130 immunoglobulin heavy chain gene (IgH) rearrangements, including 102 from 100 classic (HCLc) and 28 from 26 variant (HCLv) patients. The frequency of unmutated rearrangements in HCLc was much lower than that in HCLv (18% vs 54%, p=0.0003) or historically in CLL (18% vs 46%, p=9×10-9), but HCLv and CLL were similar (p=0.45). As previously reported for CLL, evidence of canonical SHM was observed in HCLc rearrangements including 1) a higher ratio of replacement to silent mutations (R/S ratio) in the complementarity determining regions (CDRs) than framework regions (FRs) (2.83 vs 1.40, p < 0.0001), 2) higher than random transition to transversion ratio (1.48 vs 0.5, p=7 × 10-39), and 3) higher than random percentage of mutations located in RGYW hot spots (13.88% vs 3.31%, p=1.5×10-44). HCLv met these 3 criteria of canonical SHM to a lesser extent (p=0.067, p=8×10-6 and p=0.0001, respectively). In comparing HCLv with HCLc directly, HCLv showed 1) a trend for lower R/S ratios in the CDRs (p=0.07), 2) lower transition to transversion ratio (p=0.045), and 3) lower percent of mutations in RGYW hot spots (p=0.03). In comparing HCLv and HCLc with respect to specific immunoglobulin variable heavy chain (IGHV) families, it was noted that 1) R/S ratio trended lower for HCLv IGHV4 CDRs compared to HCLc IGHV4 CDRs (p=0.064) and 2) transition to transversion ratio was lower for HCLv IGHV3 compared to HCLc IGHV3 (p=0.0013). Thus HCLc rearrangements exhibited canonical SHM similarly to CLL and normal B-cells, and significantly more than HCLv rearrangements, suggesting that malignant cells from HCLc patients may have recognized antigen prior malignant transformation, and that in some HCLv patients the malignant cells may originate by a different pathway.

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 348. doi:10.1158/1538-7445.AM2011-348
Abstract 3485: Insulin-like growth factor binding protein-4 (IGFBP-4) differentially inhibits growth factor induced angiogenesis in vivo
Authors: Contois Liangru W. , Caron Jennifer M. , Tweedie Eric , Liebes Leonard , Friesel Robert , Vary Calvin , Brooks Peter C.
Published: June 2012

Angiogenesis contributes to the development and progression of malignant tumors. An expanding body of evidence also suggests that the response of both vascular and tumor cells to growth factor stimulation depends in part on cellular communication with the extracellular matrix (ECM), and studies have documented important roles for the integrin family of ECM receptors in modulating growth factor signaling. Therefore, uncovering molecular mechanisms by which integrin-mediated cellular communication with the ECM modulate the specificity of growth factor signaling during pathological angiogenesis may provide unique insight into malignant tumor progression.

Here we provide evidence that disruption of αvβ3-dependent interaction with the ECM enhance expression of Insulin-like growth factor binding protein-4 (IGFBP-4), a well-known regulator of IGF-1 signaling. Interestingly, IGFBP-4 significantly (P<0.05) inhibited IGF-1 and bFGF-induced angiogenesis by greater than 50%. In contrast, IGFBP-4 alone failed to inhibit VEGF-induced angiogenesis in chick CAM. Levels of phosphorylated p38 MAP kinase were elevated in chick CAM tissues treated with VEGF as compared to those in tissues stimulated with either IGF-1 or bFGF. Surprisingly, while the p38 MAP kinase inhibitor SB 202190 alone had little effect on VEGF-induced angiogenesis, a combination of IGFBP-4 and the p38 MAP kinase inhibitor significantly (P<0.05) inhibited VEGF-induced angiogenesis. These novel findings are consistent with a role for elevated levels of activated p38 MAP kinase in modulating the anti-angiogenic activity of IGFBP-4 in vivo. Taken together, our experimental findings provide additional molecular insight into how integrin-mediated interactions with the local ECM microenvironment may modulate the responses of cells to distinct growth factor signaling pathways during 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 3485. doi:10.1158/1538-7445.AM2011-3485
Abstract 3486: CXCR1 and CXCR2 silencing alters endothelial cell proliferation, migration and capillary tube formation
Authors: Singh Seema , Varney Michelle L. , Singh Rakesh K.
Published: June 2012

CXCR1 and CXCR2 are receptors for CXCL-8 and are differentially expressed on endothelial cells, however, their functional significance in angiogenesis remains unclear. In this study, we determined the functional role of these receptors in modulating endothelial cells phenotype by knocking-down the expression of CXCR1 and/or CXCR2 in human microvascular endothelial cells (HMEC-1) using short-hairpin RNA (shRNA). Cell proliferation, migration, invasion and capillary tube formation were carried out in in vitro. Our data demonstrate that knock-down of CXCR1 and/or CXCR2 expression, inhibited endothelial cell proliferation, survival, migration, invasion and capillary tube formation in vitro. Additionally, we examined the mechanism of CXCL-8-dependent CXCR1 and/or CXCR2 mediated phenotypic changes by evaluating ERK phosphorlyation and cytoskeletal rearrangements. We observed inhibition of ERK phosphorylation and cytoskeltal rearrangement in HMEC-1-shCXCR1, HMEC-1-shCXCR2 and HMEC-1-shCXCR1/2 cells. The number of apoptotic cells acquiesced with decreased survival-associated gene expression. Together, these data demonstrate that CXCR1 and CXCR2 expression play a critical role in regulating multiple biological activities in human microvascular endothelial cells.

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 3486. doi:10.1158/1538-7445.AM2011-3486
Abstract 3491: Chromosome 14q loss leads to haploinssuficiency of HIF-1a and poor outcomes in metastatic clear cell renal cell carcinoma
Authors: Monzon Federico A. , Alvarez Karla , Peterson Leif , Tannir Nizar , Jonasch Eric
Published: June 2012

Purpose – One of the current key dilemmas in the management of metastatic renal cell carcinoma (mRCC) is the manifestation of innate or acquired resistance to anti-angiogenic therapy. Currently there are no biomarkers of therapeutic efficacy for antiangiogenic agents in clear cell renal cell carcinoma (ccRCC). Loss of chromosomal arm 14q has been previously associated with poor outcomes in surgically treated patients. We evaluated the association between 14q loss and therapeutic resistance in metastatic ccRCC (mRCC) and explored the role of candidate effector genes on this chromosome.

Experimental Design – DNA from archival FFPE tumor specimens from 56 mRCC patients treated with sorafenib or bevacizumab was analyzed with Affymetrix 250K Nsp SNP microarrays. We identified the presence of genomic imbalances focusing on the presence of 14q loss. We then evaluated candidate genes in chromosome 14 by qPCR and immunohistochemistry (IHC) in the bevacizumab treated cohort.

Results – 14q loss showed a significant association with worse response (SDPD vs. CRPR) in bevacizumab cohort (Fisher's exact test, p=0.0473), and with shorter progression free survival (PFS) in the sorafenib cohort (p=0.0318). HIF1A mRNA expression was significantly reduced in specimens with loss of 14q and was associated with PFS in the bevacizumab treated cohort (p=0.045). HIF-1alpha protein expression was also reduced in samples with 14q loss.

Conclusions – Our studies demonstrate an association between a specific chromosomal alteration (14q loss) and clinical outcome in patients with advanced renal cell carcinoma treated with antiangiogenic agents. Loss of 14q was also associated to changes in the expression of HIF1A. Low HIF1A expression was strongly correlated with shorter PFS. We hypothesize that loss of 14q could lead to an imbalance in HIF-1α/HIF-2α activity, leading to increased HIF-2α, which has been shown to improve tumor cell viability by upregulating various pro-survival pathways.

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 3491. doi:10.1158/1538-7445.AM2011-3491
Abstract 3517: Epigenetic interactive regulation and synergistic action of Trichostatin A, 5-aza-2′-deoxycytidine and Cisplatin in ovarian cancer
Authors: Meng Fanliang , Sun Guigin , Zhong Mei , Yu Yanhong , Brewer Molly A.
Published: June 2012

Objective: To investigate the relationship between histone modification, DNA methylation and DNA damage repair response that occur in platinum resistant ovarian cancer cell lines treated with epigenetic modifiers in combination with low dose chemotherapy to develop new approaches for chemotherapy resistant ovarian cancer.

Materials and Methods: We selected two common epigenetic modifiers Trichostatin A (TSA), a histone deacetylase inhibitor and 5-aza-2′-deoxycytidine (decitabine), a demethylating agent which were evaluated alone and in combination with low dose Cisplatin for their tumorigencity in SCID mice and their spheroid formation in serum-free medium with two ovarian cancer cell lines SKOV3 and Hey. We also measured the effect of these drugs on tumor suppression pathways, AKT pathway, and expression of cadherins as well as histone modification.

Results: All combinations of TSA, decitabine and Cisplatin inhibited both tumorigenicity and spheroid formation in both cell lines with Hey exhibiting more resistance to treatment. E-cadherin expression was suppressed in SKOV3 cells while N-caderin expression was suppressed in Hey cells with both TSA and Cisplatin and decitabine and Cisplatin. In the Hey cell line, p53 expression was increased by sequential treatment with low dose decitabine and low dose cisplatin and by low dose TSA and low dose cisplatin. The profiling of histone code revealed distinctly different chromatin regulation between Hey cells and SKOV3 cells. The expression patterns and characteristics of cell adhesion, mutiple-drug transporter, apoptosis are distinctly different in these two ovarian cancer cell lines, which may be due to the different origins and stages of these cell lines.

Conclusions: The combinations of decitabine, TSA and Cisplatin suppressed the formation and growth of xenograft and tumor spheroid, altered the molecular mechanism of cell adhesion, chemosensitivity, and chromatin modification which may provide a new and promising treatment strategy for chemoresistant ovarian 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 3517. doi:10.1158/1538-7445.AM2011-3517
Abstract 3520: The use of vasodilators to enhance efficacy of hypoxia or acid activated prodrugs in pancreatic cancers
Authors: Cornnell Heather H. , Baker Amanda F. , Torres Tedman A. , Hashim Arig Ibrahim , Rejniak Katarzyna A. , Gatenby Robert A. , Gillies Robert J.
Published: June 2012

The vasculature of tumors is torturous and immature and in many cases lacks tone (the ability to self-regulate pressure). The administration of vasodilating agents induces a drop in systemic blood pressure which is not matched in the tumor, resulting in decreased intratumoral perfusion due to the “steal phenomenon”. This research uses this phenomenon to induce decreased tumor perfusion which results in increased tumor acidity and hypoxia. We hypothesize that this change in the tumor microenvironment can be used in combination with hypoxia- and acid-activated prodrugs (HAPs and AAPs) to enhance their efficacy, by increasing both the depth and distribution of hypoxia or acidosis within the tumor. Specifically, we have investigated the administration of hydralazine in several pancreatic xenograft tumors and used a needle microelectrode to measure decreases in pH as a result of decreased perfusion. We have also employed a computational math model to investigate the timing of the delivery of both hydralazine and HAPs to optimize the cell death.

Preliminary computational results suggest that multiple rounds of vasodilators may be given with a single round of HAPs, depending on several factors including duration of vasodilation effect and half-life of the HAP. The pH investigation showed a substantial pH drop in one tumor type (MiaPaca2), but no change in two others (HS766t and SU8686), suggesting that the ‘steal’ phenomenon is not universal. Preliminary data suggest that combination therapy in the ‘steal’-sensitive models will increase efficacy. We are continuing research with the combination therapy, employing the timing strategies suggested by the computational models. We are also investigating different imaging modalities to monitor the effects of the steal phenomenon, including Ultrasound (for perfusion) and MRI (for bulk tumor changes and monitoring pH).

In conclusion, the preliminary data supports the hypothesis that vasodilatation agents may be used to induce increases in acidosis and hypoxia within the microenvironment of some (but not all) tumors. These effects can be taken advantage of through combination with HAPs or AAPs to enhance antitumor effects. Further, computational math models can be employed to help determine the best timing for the combination therapies.

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 3520. doi:10.1158/1538-7445.AM2011-3520
Abstract 3522: Pre-treatment with FSH enhances the ability of EP-100 to target and destroy human pancreatic cancer cells
Authors: Solipuram Rajasree , Aggarwal Sita , Leuschner Carola , Alila Hector , Hansel William
Published: June 2012

The expression of luteinizing hormone releasing hormone (LHRH) receptors by pancreatic cancer cells has been clearly established. We observed that pancreatic cancer cell lines contain different numbers of LHRH receptors (BxPC3>MIAPaCa-2>PANC-1) using relative quantitation of RNA by real time PCR. In an in vitro study, we found that treatment of PANC-1 cells in culture with small amounts (10 or 30 ng/ml) of follicle stimulating hormone (FSH) caused a 3-fold increase in LHRH receptor gene expression. Therefore, we hypothesized that pre-treatment of nude mice bearing PANC-1 tumor xenografts with FSH will increase the number of LHRH receptors which will enhance the ability of the EP-100 (LHRH conjugated lytic peptide) to target and destroy PANC-1 pancreatic cancer cells. Our main objective was to determine in vitro and in vivo if FSH enhances the efficacy of EP-100 in targeting and destroying PANC-1 cells. PANC-1 cells (5000/well) were pretreated with FSH (10 and 30 ng/mL) for 24 h followed by EP-100 (4 and 6 µM) for 24 h in a medium containing 0.2% Dextran charcoal treated serum. MTT cell viability assay results showed that pre-treatment of PANC-1 cells with FSH significantly (P<0.001) enhanced the cytotoxicity of EP-100. PANC-1 tumor xenograft bearing Athymic Balb/C nude mice (n=11) were treated with EP-100 (0.2 and 0.02 mg/kg), iv, once a week for three weeks with or without FSH pre-treatment, sc, (3 mg/kg for three days prior to administering the conjugate). The treatment groups included were baseline (sacrificed at the beginning of treatment), vehicle, FSH alone, EP-100 (0.02 mg/kg) alone, EP-100 (0.02mg/kg) with FSH, EP-100 (0.2 mg/kg) alone, EP-100 (0.2 mg/kg) with FSH. FSH pre-treatment significantly enhanced the ability of EP-100 (0.02 mg/kg – P<0.05 and 0.2 mg/kg – P<0.001 compared to baseline) to regress the growth of PANC-1 tumor xenografts in vivo. Histopathological evaluation revealed an increase in tumor necrosis in FSH pre-treated mice.

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 3522. doi:10.1158/1538-7445.AM2011-3522
Abstract 3524: Structure-based molecular docking of DNA polymerase β as a novel target for chemotherapeutic intervention of colorectal cancer
Authors: Jaiswal Aruna S. , Banerjee Sanjeev , Aneja Ritu , Sarkar Fazlul H. , Ostrov David A. , Narayan Satya
Published: June 2012

Colorectal cancer is the third most common cancer and the second most common cause of cancer related deaths worldwide. In the year 2010, an estimated 102,900 new colorectal cases will be diagnosed and 51,370 deaths will occur in the United States only. Chemoprevention presents a major strategy for the medical management of colorectal cancer risk. Most drugs used for colorectal cancer therapy induce DNA alkylation damage, which are primarily repaired by the base excision repair (BER) pathway. Thus, blockade of BER pathway is an attractive option to inhibit the spread of colorectal cancer. Here we used structure-based molecular docking of DNA polymerase β (Pol-β) and identified a potent anti-Pol-β compound NSC-124854. Our aim was to examine whether NSC-124854 could enhance the therapeutic efficacy of DNA-alkylating agent, Temozolomide (TMZ), by blocking BER. First, we determined the specificity of NSC-124854 for Pol-β by using in vitro activities of APE1, Fen1, DNA ligase I, and Pol-β-directed single nucleotide (SN)- and long-patch (LP)-BER. Second, we determined the effect of NSC-124854 on the cytotoxicity of TMZ to mismatch repair (MMR)-deficient and MMR-proficient colon cancer cells by using in vitro clonogenic assays. Third, we used female homozygous SCID mice as a pre-clinical xenograft model to determine the effect of NSC-124854 on the in vivo tumor growth inhibition of MMR-deficient and MMR-proficient colonic tumors in mice. Our data showed that NSC-124854 elicit specificity to Pol-β and blocked Pol-β-directed SN- and LP-BER activities in vitro reconstituted system. Furthermore, NSC-124854 effectively induced the sensitivity of TMZ to MMR-deficient and MMR-proficient colon cancer cells both in vitro cell culture system and in vivo mouse model. Our findings suggest a potential novel strategy for the development of highly specific, and thus safer structure-based inhibitor(s) for the prevention of colonic tumor progression. This work has been supported by NCI/NIH grants (R01 CA-097031 and CA-100247) to SN.

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 3524. doi:10.1158/1538-7445.AM2011-3524
Abstract 3530: Chemicals that stimulate iron uptake: a novel approach to cancer treatment
Authors: Li Zhen
Published: June 2012

Cancer cells have increased levels of transferrin receptor and lower levels of ferritin, an iron deficient phenotype that has led to the use of iron chelators to further deplete cells of iron to limit growth. Chelators have not proven, however, to be successful anti-cancer agents. As cancer cells also have increased reactive oxygen species (ROS) we hypothesized that a contrarian approach of enhancing iron entry would allow for further increased generation of ROS causing oxidative damage and cell death. Molecules that accelerate iron uptake were identified using high through-put screening of a reporter system of K562 cells loaded with the divalent metal chelator calcein whose fluorescence is quenched with chelation of Fe2+. A small molecule library consisting of ∼11,000 compounds was screened and a class of compounds identified that stimulated iron-induced quenching of calcein fluorescence. The stimulation was verified by dose-dependent 55Fe uptake in various cancer cell lines. The lead compound LS081 exhibited an IC50 = 1.22 ± 0.48 μM and also increased the uptake of Fe from transferrin (Tf). LS081 decreased PC-3 cell growth in the presence of Fe2+ by 64 ± 8% compared to 14 ± 1% decrease with LS081 alone (mean decrease ± SEM, n = 3) with minimal effects on the immortalized, non-malignant prostate cell line 267B1 cells. LS081 plus Fe increased DNA strand breaks and induced cell cycle arrest at the G1 phase of PC-3 cells. In addition, LS081 markedly decreased HIF-1α and HIF-2α levels in the DU-145 prostate cancer and the MDA-MB-231 breast cancer cell lines. LS081 also stimulated ROS production by nearly 3-fold and decreased clonogenicity by greater than 50% in PC-3 cells. In summary, we have developed a high through-put screening technique that identified small molecules that stimulate iron uptake both from ferri-Tf and non-Tf bound iron. These molecules have properties that suggest that these iron facilitator compounds may serve as anti-cancer agents.

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 3530. doi:10.1158/1538-7445.AM2011-3530
Abstract 3532: Antitumor activity of SR16388 on multiple myeloma targets factors needed for adaptation to bone marrow microenvironment
Authors: Chao Wan-Ru , Dinh Dominic H. , Shi Yihui , Hou Carol , Sato Barbara , Alt Carsten , Collins Nathan , Sambucetti Lidia
Published: June 2012

Multiple myeloma (MM) is a B-cell malignancy that is characterized by accumulation of clonal plasma cells in the bone marrow. The bone marrow microenvironment plays a critical role in MM cell pathogenesis and progression. In the bone marrow milieu, MM cells adhere to the bone marrow stromal cells and trigger the secretion of growth factors such as vascular endothelial growth factor (VEGF). VEGF in turn upregulates the secretion of interleukin-6 (IL-6), the major cytokine that mediates MM cell growth and survival in part through the activation of Janus kinase (Jak)/signal transducers and activators of transcription 3 (STAT3). VEGF also stimulates the proliferation of endothelial and stromal cells and induces angiogenesis via its receptors. Thus, targeting both myeloma cells and bone marrow microenvironment is a valid approach for the development of therapeutic agents for MM. At SRI International, we have developed an antiestrogen, SR16388, that binds to ER-α, ER-β and ERR-α with potent antitumor and antiangiogenic properties. We have previously reported that SR16388 inhibited MM cell proliferation in vitro and MM tumors in vivo. In the current study, we are presenting data to show that the inhibitory effect of SR16388 on MM cell proliferation was achieved by inducing apoptosis, and arresting cells at the G2 phase. Furthermore, at nanomolar concentrations SR16388 inhibited IL-6-induced cell proliferation and blocked the activation of STAT3 induced by IL-6 in RPMI-8226 human MM cells. In human endothelial cells, SR16388 inhibited VEGF-induced cell proliferation and VEGF-induced phosphorylation of STAT3. In a RPIM-8226 tumor xenograft model, the microvessel density in the tumor tissue was markedly reduced by treatment with SR16388. We are currently investigating the effect of SR16388 in combination with known therapeutic agents on the growth of MM tumors in vivo.

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 3532. doi:10.1158/1538-7445.AM2011-3532
Abstract 3541: Combination of the ruthenium compound KP1339 with the tyrosine kinase inhibitor sorafenib: A promising approach for the treatment of human hepatoma
Authors: Heffeter Petra , Atil Bihter , Kryeziu Kushtrim , Jungwirth Ute , Gal Elisabeth , Keppler Bernhard K. , Berger Walter
Published: June 2012

Aim of this study was to test the in vitro and in vivo activity of KP1339, a promising ruthenium-based anti-cancer compound, in combination with the tyrosine kinase inhibitor sorafenib against human hepatoma cells. As a first approach, the drugs were tested together against a hepatoma cell line panel (n=7) by MTT assay. Combination of KP1339 with sorafenib induced additive to synergistic effects in all cell lines tested. Especially at higher sorafenib concentrations (10 µM) strong synergism with CI values between 0.1 and 0.5 were observed. Notably, synergistic activity with KP1339 was found in sorafenib-resistant as well as sorafenib-responsive cell lines. Recently, we have presented that KP1339 treatment induced phosphorylation of P38, JNK and erk and led to cell cycle arrest in G2/M Phase. Consequently, the effects of sorafenib on KP1339-induced P38 phosphorylation were investigated. Western blot analyses revealed that sorafenib strongly reduced phosphorylation of P38 and erk after KP1339 treatment. Moreover, addition of sorafenib reduced KP1339-induced G2/M arrest. Finally, the activity of the KP1339/sorafenib combination was evaluated in xenograft experiments (Hep3B cells). KP1339 monotreatment led to a 2.4-fold increase in life span (mean survival 80 days vs. 33 days in control) and thus was superior to sorafenib monotherapy, which induced a 1.9-fold survival increase (60 days). Combination of KP1339 with sorafenib increased the mean survival by 3.9-fold to 96 days. Together, our data indicate that the combination of KP1339 with Sorafenib is very promising in vitro and in vivo especially against human hepatoma cells.

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 3541. doi:10.1158/1538-7445.AM2011-3541
Abstract 356: Reconstruction of nuclear receptor network reveals that NR2E3 is a novel upstream regulator of ESR1 in breast cancer
Authors: Park Yun-Yong , Kim Kyoungjyun , Kim Sang-Bae , Hennessy Bryan , Kim Soo Mi , Park Eun Sung , Lim Jae Yun , Li Jane , Lu Yiling , Gonzalez-Angulo Ana , Mills Gordon , Safe Stephen , Lee Ju-Seog
Published: June 2012

ESR1 is one of the most important oncogenes and therapeutic targets in breast cancer. By applying systems-level re-analysis of publicly available gene expression data, we uncovered potential regulator of ESR1. We demonstrated that orphan nuclear receptor NR2E3 regulates ESR1 via direct binding to the ESR1 promoter with concomitant recruitment of PIAS3 to promoter in breast cancer cells, and is essential for physiological cellular activity of ESR1 in estrogen receptor (ER)-positive breast cancer cells. Moreover, expression of NR2E3 was significantly associated with recurrence-free survival and favorable response to tamoxifen treatment in women with ER-positive breast cancer. Our results provide mechanistic insight into how ESR1 is regulated by NR2E3 and clinical relevance of NR2E3 in breast 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 356. doi:10.1158/1538-7445.AM2011-356
Abstract 3591: Discovery of SB1317: A novel small molecule macrocycle with a unique kinase inhibitory spectrum in phase 1 clinical trials for hematological malignancies
Authors: William Anthony , Blanchard Stephanie , Lee Angeline , Poulsen Anders , Sun Eric , Teo Ee Ling , Nagaraj Harish , Goh Kay Lin , Ong Wai Chung , Goh Kee Chuan , Pasha Mohammed K. , Jayaraman Ramesh , Wood Jeanette M. , Ethirajulu Kantharaj , Dymock Brian W.
Published: June 2012

Introduction: During our quest to find novel kinase inhibitor motifs for our protein kinase research projects we discovered a novel series of macrocyclic structures which possess unique but tunable kinase inhibitory profiles. Here we present the chemical structure of SB1317 and the SAR studies leading to the discovery of this novel CDK/FLT3/JAK2 inhibitor, currently in clinical trials for hematological malignancies.

Methods/Results: The unusual structure of SB1317 is characterized by a biaryl connection to the hinge-binding 2-anilinopyrimidine and an allylic tertiary amine – homo allylic ether linker forming an 18-membered macrocyclic ring. Combination of the biaryl motif and unsaturation in the linker confers limited conformational freedom and may explain the specific biological activity observed with this series. Following extensive SAR studies a single preferred compound, SB1317, emerged with potent CDK (IC50 against CDKs 1, 2 and 9 = 9, 5 and 3 nM, respectively), FLT3 (IC50 = 19nM) and JAK2 (IC50 = 19nM) potency. SB1317 has low molecular weight and good physicochemical properties conferring good oral exposure and prompting its further evaluation in vitro and in in vivo cancer models. Following promising efficacy data in these studies, SB1317 was nominated as the preferred candidate for progression to the clinic. SB1317 was synthesized via a ring-closing metathesis (RCM) strategy where the macrocycle was formed from coupling the two halves of the molecule to provide a diene which was then closed by RCM using either Grubbs or Zhan catalysts. Crucially the RCM reaction requires acidic conditions to neutralize the basic centre to allow the metathesis to proceed.

Conclusions: SB1317 is a low molecular weight compact macrocyclic structure with a unique spectrum of kinase activity suggesting it may have particular utility in the treatment of hematological malignancies and potential for solid tumor therapy as well. SB1317 is currently being developed in the clinic by Tragara Pharmaceuticals (San Diego, CA) under the name TG02.

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 3591. doi:10.1158/1538-7445.AM2011-3591
Abstract 3593: Generation of a potent and selective inhibitor of ALK, CH5424802, showing superior oral bioavailability, PK profile and in vivo efficacy
Authors: Oikawa Nobuhiro , Kinoshita Kazutomo , Asoh Kohsuke , Furuichi Noriyuki , Itoh Toshiya , Kawada Hatsuo , Hara Sosuke , Miyagi Takuho , Ohwada Jun , Taniguchi Saori , Hattori Kazuo , Tsukuda Takuo , Takanashi Kenji , Sakamoto Hiroshi , Tsukaguchi Toshiyuki , Ishii Nobuya , Aoki Yuko , Shimma Nobuo
Published: June 2012

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase that is constitutively activated in some cancers, due to gene alterations such as chromosomal translocation, amplification, or point mutation. It has been recognized as an attractive solid tumor target since the discovery in 2007 of the fusion gene, comprised of portions of the echinoderm microtubule-associated protein-like 4 (EML4) gene and the ALK gene, which is detected in ca. 6.7% of non-small-cell lung cancer (NSCLC) patients. We have identified a lead compound as an ALK inhibitor through kinase panel screening of in-house kinase-oriented library. The lead compound had a unique scaffold but showed a rather broad kinase inhibition profile. Therefore, we examined structure-activity relationship from the viewpoint of the kinase selectivity as well as ALK inhibition potency. Finally, we identified CH5424802 as a clinical candidate having high selectivity over other kinases including c-Met, c-Kit and KDR. CH5424802 has a preferable PK profile and good oral bioavailability in rats and monkeys. CH5424802 showed preferential antitumor activity against cancers with gene alterations of ALK, such as non-small cell lung cancer (NSCLC) cells expressing EML4-ALK fusion both in vitro and in vivo. CH5424802 is currently being investigated in Phase I/II clinical trials for patients with ALK-positive NSCLC.

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 3593. doi:10.1158/1538-7445.AM2011-3593
Abstract 3599: Aurora kinase inhibitors as a novel targeted drug therapy for bladder cancer
Authors: Zhou Ning , Singh Kamini , Almasan Alexandru , Hansel Donna
Published: June 2012

Introduction: Conventional chemotherapy for invasive bladder cancer has limited efficacy and is generally associated with poor patient prognoses. This study aims to evaluate the potential of targeting the aurora kinases, a family of mitotic regulators, with pharmacologic inhibitors as a novel treatment for bladder cancer.

Materials and Methods: RNA microarray and reverse-transcriptase polymerase chain reaction (RT-PCR) were utilized to evaluate expression of genes associated with the mitotic spindle checkpoint, including aurora kinases A and B, in clinical tissue samples of urothelial carcinomas of the bladder and normal urothelium. Human urothelial carcinoma cell lines UM-UC-3 and T24 were treated with the nonspecific aurora kinase inhibitor ZM447439 and the aurora kinase A inhibitor MLN8237, either alone or in combination with gemcitabine or paclitaxel. Effects of drug treatments were evaluated by flow cytometry with propidium iodide staining, immunofluorescence microscopy, MTS proliferation assay, and TUNEL labeling.

Results: RNA microarray analysis comparing human tissue specimens of urothelial carcinomas of the bladder (N=10) to normal urothelium (N=8) identified overexpression of 13 gene transcripts related to the mitotic spindle checkpoint, including aurora kinases A and B, in the cancer specimens. Upregulation of these genes was validated by RT-PCR on a separate set of clinical samples (N=4 for each group). Next, the impact of aurora kinase inhibitors on bladder cancer cell lines was assessed. ZM447439 and MLN8237 treatment of UM-UC-3 and T24 cell lines at concentrations of 10 nM to 1 uM induced G2/M cell cycle arrest and aneuploidy in a dose dependent manner. Immunofluorescence microscopy showed abnormal mitotic figures with multipolar spindle apparatuses in treated cells. Both cell lines also exhibited cell death by positive TUNEL staining 48 hours after treatment with either inhibitor. Simultaneous treatment of T24 cells with MLN8237 and paclitaxel and subsequent MTS proliferation assay revealed an antagonistic interaction between paclitaxel and MLN8237, whereas simultaneous treatment with MLN8237 and gemcitabine resulted in an additive effect.

Conclusion: Several mitotic spindle checkpoint proteins, including the aurora kinases, are overexpressed in bladder cancer. Our data indicate that aurora kinase inhibitors have significant potential as a novel therapy for bladder cancer, as they induce abnormal mitosis, cell cycle arrest, and eventual death of bladder cancer cells in vitro.

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 3599. doi:10.1158/1538-7445.AM2011-3599
Abstract 360: Effect of adrenogenic androgens on androgen receptor activity in prostate cancer microenvironment
Authors: Mizokami Atsushi , Kumaki Misako , Shima Takashi , Izumi Kouji , Kadono Yoshifumi , Konaka Hiroyuki , Namiki Mikio
Published: June 2012

One of the mechanisms by which advanced prostate cancer (PCa) usually relapses after androgen deprivation therapy (ADT) is the adaptation to residual androgens in PCa tissue. The origin of residual androgenic in PCa tissue is regarded as adrenogenic DHEA. Previously, we reported that prostate cancer-derived stromal cells (PCaSC) coordinately synthesize DHT from adrenal DHEA with LNCaP cells and that accelerated AR activity in LNCaP cells induced by DHEA. However, DHEA of high concentration was needed to accelerate androgen receptor (AR) activity. Therefore, We investigated whether adrenogenic other androgens of the physiological concentration in castrated PCa patient (androstenedione and androstenediol) could activate AR of LNCaP cells in the presence of PCaSC. Androstenedione of the physiological concentration as well as DHEA of the high concentration activated AR in the presence of PCaSC. Now we are investigating the relationship between degree of AR activity induced by adrenal androgens in the presence of PCaSC and 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 360. doi:10.1158/1538-7445.AM2011-360
Abstract 3606: CH5126766 is a novel allosteric inhibitor of MEK that prevents its phosphorylation by RAF
Authors: Ishii Nobuya , Harada Naoki , Sakamoto Hiroshi , Matsuda Yutaka , Tomii Yasushi , Tachibana-Kondo Yukako , Miura Takaaki , Ohara Kazuhiro , Iikura Hitoshi , Aoki Toshihiro , Shimma Nobuo , Arisawa Mikio , Joseph Eric , Poulikakos Poulikos , Sowa Yoshihiro , Rosen Neal , Aoki Yuko , Sakai Toshiyuki
Published: June 2012

Tumors with mutant BRAF or RAS are often dependent on the ERK signaling pathway. MEK and RAF inhibitors have significant antitumor activity in patients with BRAF mutant melanoma, but, thus far, MEK inhibitors have little activity in patients whose tumors contain mutant RAS. The effectiveness of the drugs seems to require near complete inhibition of ERK signaling. MEK inhibition has been shown to lead to relief of feedback inhibition of RAF and induction of MEK phosphorylation. It is possible that this induction attenuates inhibition of the pathway and reduces clinical activity.

We have now isolated and characterized an allosteric inhibitor of MEK, CH5126766, with novel properties that prevent its induction of MEK phosphorylation. CH5126766 causes MEK to bind to RAF tightly and in a conformation in which it cannot be phosphorylated. MEK in this complex has low kinase activity and may act as a dominant negative inhibitor when bound to RAF. Compared to the MEK inhibitor PD0325901, CH5126766 inhibits ERK signaling output in cells more potently and has greater antitumor activity in the KRAS mutant colorectal cancer HCT116 grown as a murine xenograft. MEK inhibitors such as CH5126766 will inhibit feedback induction of MEK phosphorylation and this may allow more complete pathway inhibition and result in greater antitumor activity.

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 3606. doi:10.1158/1538-7445.AM2011-3606