bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1111: Preclinical evaluation of CP868,596, a novel PDGFRα Inhibitor for treatment of glioblastoma
Authors: Yang Xiao-Li , Mashimo Tomoyuki , Su Yang , Vemireddy Vamsidhara , Guntipalli Prathima , Ramachandran Abhijit , Chaudhary Preeti , Mickey Bruce , Hatanpaa Kimmo , Maher Elizabeth , Bachoo Robert M.
Published: June 2012

Background: Recent large scale genomic studies have shown that ∼13% of glioblastoma (GBM) have a copy number gain of the gene encoding for platelet-derived growth factor receptor alpha (PDGFRα). Animal studies have shown that PDGFRα signaling can drive tumor growth. Clinical studies, however, have failed to show efficacy when patients with recurrent GBM were treated with non-specific PDGFR inhibitors (Imatinib, Sunitinib). Drawing firm conclusions from such studies is limited by lack of patient stratification by PDGFRα expression and lack of biological data demonstrating effective target inhibition. CP-868,596 is a benzimidazole which is orally bioavailable, and has IC50s of 0.9 nM and 1.8 nM for PDGFRα and PDGFRb, respectively. Phase I trials of CP-868,596 have shown a favorable safety profile and serum concentrations up to 2000 nM. We are pursuing a systematic in vitro and in vivo preclinical evaluation to assess potential clinical efficacy of CP-868,596 for the treatment of glioma.

Methods: To evaluate IC50 for CP868,596, we have genetically engineered conditional Ink4a/Arf-/- mouse astrocytes to stably co-express both the human PDGFRα and its cognate ligand, PDGF-AA. Expression levels of PDGFRα and PDGF-AA levels were adjusted so they are comparable to those we have found in GBM tumors.

Results and Discussion: Immunoblot analysis shows that PDGFRα phosphorylation and its downstream signaling pathway (pAKT, phospho-S6 ribosomal protein, and p-4EBP1) activated either by autocrine and/or exogenous PDGF-AA ligand (1um) is completely blocked by CP868,596 (concentrations 0.1-1um). INK4a/Arf-/-, PDGFRα/PDGF-AA astrocytes, when implanted into the NOD-SCID mouse brain or subcutaneous space (flank), form orthotopic /heterotopic tumors, respectively. Using these glioma models, intratumoral CP868,596 levels and the ability of the drug to block PDGFRα phosphorylation is being evaluated (dose range 0.1-5 ug/kg/hr IV). While multiple signal transduction pathways are implicated in pathogenesis of GBM, CP868,596 may only be effective in those GBM where PDGFR is the dominant ‘driver’ of tumorigenesis. To test this hypothesis we have established a panel of primary GBM orthotopic mouse tumor lines which overexpress PDGFRα/PDGF-AA with and without EGFR and/or cMet gene overexpression and will evaluate response to treatment with CP868,596. In addition, a Phase II treatment trial in adult glioma patients is being initiated. Data from the in vitro and in vivo studies will be presented.

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 1111. doi:10.1158/1538-7445.AM2011-1111
Abstract 1120: Role and relevance of TrkB mutations and expression in non-small cell lung cancer
Authors: Harada Taishi , Wang Yisong , Yatabe Yasushi , Takeshita Masafumi , Koga Takaomi , Yano Tokujiro , Giaccone Giuseppe
Published: June 2012

Purpose: TrkB oncogene has been involved in poor cancer outcome. TrkB mutations have been reported in non-small cell lung cancer. In this study, we aimed at characterizing the role of 3 potentially sensitizing mutations previously reported in TrkB in lung cancer.

Experimental design: We characterized three activation loop mutants of TrkB (M713I, R715G and R734C) in terms of pathway activation/phosphorylation, migration, anchorage independent growth and sensitivity to a Trk inhibitor, using NIH3T3 cells and Baf3 cells. We also sequenced the tyrosine kinase domain of TrkB in a large number of lung cancer samples and cell lines.

Results: None of the mutants were constitutively active in NIH3T3 transformation and migration assays. M713I and R734C mutants showed low levels of autophosphorylation in comparison with wild-type TrkB. Although R715G showed similar level of autophosphorylation to wild-type TrkB upon BDNF stimulation, the mutant was not as competent as wild-type TrkB in supporting IL-3 independent growth of Baf3 cells. In addition, the Trk inhibitor inhibited wild-type TrkB induced cell migration and cell growth, whereas the mutants were relatively resistant to the Trk inhibitor compared to wild-type TrkB. We could not confirm the presence of non-synonymous mutation in 78 lung cancer samples and 29 cell lines.

Conclusions: Wild-type TrkB but not its activation loop mutations enhances cell migration and transformation. Our study suggests that TrkB mutations should not be used for selection of patients with lung cancer treated with Trk inhibitors. High expression of wild-type TrkB might be beneficial for studies of Trk inhibitors.

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 1120. doi:10.1158/1538-7445.AM2011-1120
Abstract 1126: The L858R mutation of the EGFR gene might be associated with smoking in non-small cell lung cancer
Authors: Buyru Nur , Baykara Onur , Tansarikaya Merve , Ulutin Turgut
Published: June 2012

Lung cancer, which involves malignant proliferation of the epithelial lining of the lower respiratory tract is the most common cause of cancer death in men and is second only to breast cancer in women. Smoking is considered to be one of the principal causes of lung cancer. However, as only a subgroup of smokers ever develop the disease, it has been suggested that genetic susceptibility may contribute to the risk. Recent studies have shown that some non-small cell lung cancer (NSCLC) patients harbor gain-of-function mutations in the epidermal growth factor receptor gene (EGFR). Phosphorylated EGFR triggers the activation of intracellular signal transduction pathways such as RAS-MAPK, PI3K-Akt and STAT. On the other hand, point mutations in codons 12, 13 or 61 of the K-Ras gene inactivate the GTPase activity of the K-Ras resulting in continuous stimulation of autonomous growth and contribute to neoplastic development.

The aim of this study was to investigate the presence and relationship of EGFR and K-Ras mutations with smoking history in a series of 50 primary NSCLC tumors.

DNA was isolated by digestion of tissue samples using a DNA isolation kit. EGFR and K-ras mutations were investigated by Real Time-PCR assay. To confirm the mutations exons 18-21 of the EGFR gene and the whole K-ras gene were also analyzed by cycle sequencing in the samples found positive by the real-time PCR assay.

In four patients (8%) EGFR mutations were detected. Two of these mutations were L858R and the remaining two were deletion mutations spanning codons from 746 to 750. The L858R mutation was significantly associated with smoking status (p=0.003). K-ras codon 12 and 61 mutations were also observed in 4 patients. However, no association was observed between K-ras mutations and tumor staging, sex, histology and smoking status of the patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1126. doi:10.1158/1538-7445.AM2011-1126
Abstract 1145: Circulating plasma MiR-141 is a novel biomarker for metastatic colon cancer and predicts poor prognosis
Authors: Chen Kexin , Cheng Hanyin , Zhang Lina , Cogdell David E. , Zheng Hong , Schetter Aaron J. , Nykter Matti , Harris Curtis C. , Hamilton Stanley R. , Zhang Wei
Published: June 2012

Background: Colorectal cancer (CRC) remains one of the major cancer types and cancer related death worldwide. Sensitive, non-invasive biomarkers that can facilitate disease detection, staging and prediction of therapeutic outcome are highly desirable to improve survival rate and help to determine optimized treatment for CRC. The small non-coding RNAs, microRNAs (miRNAs), have recently identified as critical regulators for various diseases including cancer and may represent a novel class of cancer biomarkers. The purpose of this study was to identify and validate circulating microRNAs in human plasma for use as such biomarkers.

Methodology/Principle Findings: By using quantitative reverse transcription-polymerase chain reaction, we found that circulating miR-141 was significantly associated with stage IV CRC in a cohort of 102 plasma samples. Receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of candidate plasma microRNA markers. We observed that combination of miR-141 and carcinoembryonic antigen (CEA), a widely used marker for CRC, further improved the accuracy of detection. These findings were validated in a cohort of 156 plasma samples collected at Tianjin, China. Furthermore, our analysis showed that high levels of plasma miR-141 predicted poor survival in both cohorts and that miR-141 was an independent prognostic factor for advanced CRC.

Conclusions/Significance: We propose that plasma miR-141 is a novel biomarker that complements CEA in detecting CRC with distant metastasis and that high levels of miR-141 in plasma were associated with poor 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 1145. doi:10.1158/1538-7445.AM2011-1145
Abstract 1151: microRNAs affect therapeutic sensitivity of human gliobastoma to temozolomide
Authors: Quintavalle Cristina , Garofalo Michela , Romano Giulia , Iaboni Margherita , Donnarumma Elvira , Nuovo Gerard , Croce Carlo M. , Condorelli Gerolama
Published: June 2012

Glioma is among the most deadly type of cancer. In spite of the enormous improvements made the prognosis of malignant glioma has remained poor over the last decade. Many glial-derived tumors seem to be particularly resistant to apoptosis following DNA damage. MicroRNAs (miRNA) represent a novel class of small RNAs that might play a fundamental role in tumorigenesis, cell proliferation, migration and apoptosis. Temozolomide is an alkylating agent used in glioma patients that alkylates/methylates DNA. The alkylation damages the DNA and triggers the death of tumor cells. O6-methylguanine DNA methyltransferase (MGMT) is a DNA repair enzyme which removes DNA adducts. MGMT activity is frequently lost in glioblastoma in the presence of CpG island hypermethylation in the promoter region. The methylation status of the MGMT promoter is considered to be indicative of a good outcome in patients with malignant gliomas. However, in some studies the correlation between MGMT promoter methylation and MGMT expression levels are contradictory. Other possible mechanisms of MGMT modulation should exist. Therefore, we investigated the role of miRs on the regulation of MGMT expression levels.

We analyzed temozolomide sensitivity of human glioma cell lines, T98G and U87MG. T98G resulted resistant to temozolomide, whereas U87MG cells were sensitive. Through a microarray analysis we provided evidences that miR-221/222 are differentially expressed in U87MG compared to T98G cells. Bioinformatics analysis through RNA Hybrid indicated a possible match between MGMT 3’UTR and miR-221/222. Luciferase assay confirmed that miR-221/222 are capable to bind the 3’UTR of MGMT and to impair its mRNA translation. Western blot and RT-PCR analysis upon synthetic pre-miR-221/222 transfection of T98G cells indicated that MGMT levels were significantly decreased. At the contrar, the transfection of U87MG cells with anti-miR-221/222 induced an increase of MGMT levels. Therefore this data indicate that MGMT is a new target of miRs -221/222. The analysis of cell death with MTT, Annexin V and colony assay upon temozolomide treatment in cells whose miR-221/222 levels were modulated, demonstrated an important role of those miRs in temozolomide sensitivity.

All these data indicate that miR-221/222 might represent a new strategy for regulation of MGMT expression levels and thus temozolomide sensitivity and an improvement in chemotherapy strategy for glioblastoma patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1151. doi:10.1158/1538-7445.AM2011-1151
Abstract 1174: Genetic variations in microRNA biogenesis pathway genes as susceptibility loci for lung cancer risk
Authors: Ye Yuanqing , Spitz Margaret R. , Yang Hushan , Wu Xifeng
Published: June 2012

Many studies have demonstrated that genetic susceptibility played an important role in lung cancer etiology. It has been estimated that microRNAs (miRNAs) may regulate the expression of one third of all human genes and are related to carcinogenesis through their function as oncogenes or tumor suppressors. To test the hypothesis that common sequence variants in microRNA pathways may affect individuals’ lung cancer susceptibility, we assessed the association of 75 haplotype tagging and potential functional single nucleotide polymorphisms (SNPs) in 8 miRNA biogenesis pathway genes with lung cancer risk in a case control study of 1135 lung cancer cases and 803 healthy controls among Caucasians. Overall, SNP rs2302905 from RNASEN exhibited the strongest association and remained significant after adjusting for multiple comparisons using q value at 10% level. Individuals carrying the variant allele of rs2302905 showed a 1.40-fold increased risk of lung cancer (95% CI = 1.11- 1.77; P = 0.0042). Interestingly, similar to rs2302905, two additional SNPs (rs10805564 and rs639174) from RNASEN also showed increased risk of lung cancer (OR = 1.29, 95% CI = 1.04- 1.60; and OR = 1.24, 95% CI = 1.00- 1.53). Two SNPs (rs197412 and rs85276) from DDX20 had significantly reduced lung cancer risk (OR = 0.80, 95% CI = 0.65- 1.00; and OR = 0.78, 95% CI = 0.61- 1.00). Stratified analyses by age, gender, and smoking status identified several additional SNPs that were associated with lung cancer risks in sub-populations. We also counted the number of unfavorable genotypes in each individual to assess the cumulative effect of the top 5 SNPs on lung cancer risk and found a significant gene-dosage effect (P for trend = 0.00028). Compared to the individuals with ≤ 3 unfavorable genotypes in the low risk group, carriers of 4 and 5 unfavorable genotypes had increased risk of lung cancer (OR = 1.30, 95% CI = 0.96 to 1.77; and OR = 2.09, 95% CI = 1.47 to 2.98, respectively). In conclusion, genetic variants in miRNA biogenesis pathway genes may affect the risk of lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1174. doi:10.1158/1538-7445.AM2011-1174
Abstract 1183: miR-199a-3p targets CD44 and reduces proliferation of CD44 positive hepatocellular carcinoma cell lines
Authors: Henry Jon C. , Park Jong-Kook , Jiang Jinmai , Kim Ji Hye , Roberts Lewis R. , Nagorney David M. , Banerjee Soma , Schmittgen Thomas D.
Published: June 2012

Previous work by us and others reported decreased expression of miR-199a-3p in hepatocellular carcinoma (HCC) tissues compared to adjacent benign tissue. We report here a significant reduction of miR-199a-3p expression in 7 HCC cell lines (Huh7, HepG2, SNU182, PLC/PRF/5, Hep3B, SNU423 and SNU449) compared to primary hepatocytes. To determine if miR-199a-3p has a tumor suppressive role, miR-199a-3p mimetic was transfected into the 7 HCC cell lines. miR-199a-3p mimetic reduced cell proliferation by approximately 60% compared to control oligonucleotide in only two cell lines (SNU449 and SNU423); the proliferation of the other 5 treated cell lines was similar to control oligonucleotide. A miR-199a-3p mimetic formulated with chemical modifications to enhance stability while preserving processing reduced cell proliferation in SNU449 and SNU423 to the same extent as the commercially available miR-199a-3p mimetic. Furthermore, only the duplex miR-199a-3p mimetic, and not the guide strand alone, was effective at reducing cell viability. Since a CD44 variant was essential for c-Met signaling (Orian-Rousseau, et al., Genes Dev. 2002) and c-Met is a known miR-199a-3p target, we hypothesized that miR-199a-3p may also target CD44. Indeed, miRNA target algorithms predict miR-199a-3p to be a putative target of CD44. Immunoblotting confirmed that only the HCC lines that were sensitive to the effects of miR-199a-3p mimetic (SNU449 and SNU423) were CD44+. Direct targeting of CD44 by miR-199a-3p was confirmed using luciferase reporter assays and immunoblotting. Transfection of miR-199a-3p into SNU449 cells reduced in vitro invasion and sensitized the cells to doxorubicin; both effects were enhanced when hyaluronic acid was added to the cell cultures. An inverse correlation between the expression of miR-199a-3p and CD44 protein was noted in primary HCC tissue specimens. The anti-proliferative and anti-invasive properties of miR-199a-3p mimetic on CD44+ HCC may be a useful targeted therapy for CD44+ HCC.

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 1183. doi:10.1158/1538-7445.AM2011-1183
Abstract 1198: Connexin 43 is an estrogen receptor β1 regulated gene in breast cancer
Authors: Badiani Ketan , McLachlan Elizabeth , Ung Kanyarat , Ung Charles , Murphy Leigh C.
Published: June 2012

Connexins are a family of transmembrane proteins that allow direct cell to cell communication. Normal human mammary epithelium expresses both connexin 43 (Cx43) and connexin 26 (Cx26) and when overexpressed, these connexins have been shown to act as tumor suppressors in human breast cancer. We have previously characterized two human breast cancer cells lines that inducibly overexpress estrogen receptor β1 (ERβ1) and we utilize these cells to examine the regulation of Cx43 by ERβ1 in human breast cancer. We observe that in both MCF7 and MDA-MB-231 cells that inducibly overexpress ERβ1, upon estradiol (E2) stimulation, there is a 4-fold or greater increase in Cx43 protein, regardless of whether cells are grown in two-dimensional (2D) or organotypic three-dimensional (3D) cell culture. Cx43 mRNA increases 2-fold upon ERβ1 induction and E2 stimulation of MDA-MB-231 cells with no co-incident change in Cx26 mRNA. Cx43 protein significantly increases upon treatment of cells with selective ERβ agonists, like DPN or genistein, but not with the ERα agonist PPT. Treatment of cells with ICI 182780 inhibits the E2 stimulated increase in Cx43 protein, while, the E2 stimulated increase was still seen in the presence of the anti-progestin RU486. Moreover, we observe a morphological shift in the appearance of MDA-MB-231 cells that overexpress ERβ1 when grown in 3D culture to that of a more differentiated-like organoid. Further work will involve an analysis of the interaction between ERβ1 and the Cx43 promoter. Taken together, the data suggests that Cx43 is an ERβ1 regulated gene. This research is funded by grants from CBCRA (Canadian Breast Cancer Research Alliance), CIHR (Canadian Institutes for Health Research), and CCMF (CancerCare Manitoba Foundation). EM is the recipient of a post-doctoral research fellowship from the Canadian Cancer Society Research Institute – Terry Fox Foundation.

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 1198. doi:10.1158/1538-7445.AM2011-1198
Abstract 120: Over-expression of microRNA-221 causes neoplastic cell transformation through induction of the epithelial-mesenchymal transition in non-tumorigenic liver cells
Authors: Tryndyak Volodymyr P. , Beland Frederick A. , Pogribny Igor P.
Published: June 2012

MicroRNAs (miRNAs) are negative regulators of gene expression with immense significance in cancer progression. In cancer cells, aberrant expression of miRNAs has been associated with every aspect of tumor biology, including tumor progression, invasiveness, metastasis, and acquisition of resistance of malignant cells to chemotherapeutic agents. MicroRNA miR-221 is frequently up-regulated in several major human cancers, including liver cancer. More importantly, up-regulated miR-221 is capable of enhancing liver carcinogenesis; it is not clear, however, if over-expression of any given miRNA, including miR-221, is sufficient to initiate neoplastic cell transformation. The goal of our study was to determine the tumorigenic potential of the miR-221 on normal non-transformed liver cells. Non-tumorigenic TRL-1215 rat liver cells were transfected with 20 nM of either scrambled RNA oligonucleotide (control) or pre-miR-221. At 72 hours post-transfection, adherent cells were harvested, re-seeded, and transfection was repeated, a process that was repeated for 10 months. After 1, 2, 4, and 10 months, control and miR-221-transfected cells were collected for subsequent analyses. Ectopic transfection of miR-221 for 1, 2, and 4 months resulted in significant down-regulation of the experimentally confirmed targets of the miR-221, including p27, Ddit4, and Esr1 genes and a number of newly predicted target genes. Previous reports have linked the oncogenic properties of miR-221 in liver carcinogenesis to down-regulation of critical cancer-related genes p27, Ddit4, and Esr1; however, despite a profound and early inhibition of these target genes, we did not find any evidence of neoplastic cell transformation until 10 months of pre-miRNA-221 transfection. At that time, we detected substantial morphological changes in the miR-221-transfected cells and the accumulation of neoplastic phenotypic features (i.e., soft agar colony formation and increase in cell invasiveness). These changes were accompanied by a significant decrease in the levels of plasma membrane E-cadherin. Array-based RT-PCR analysis demonstrated changes in the expression of a number of extracellular matrix and adhesion genes, including more than a 50 fold up-regulation of the mesenchymal cell marker N-cadherin (Cdh2) gene. In conclusion, our results demonstrate that the up-regulation of miR-221 not only enhances liver tumorigenesis, but also initiates the neoplastic cell transformation of the normal liver 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 120. doi:10.1158/1538-7445.AM2011-120
Abstract 1201: Role of the chemokine CXCL12 in the estrogen response of breast cancer cells
Authors: Hawsawi Nahed M.
Published: June 2012

The purpose of this study was to investigate the extent to which CXCL12 mediates the effects of estrogen in estrogen-responsive breast cancer cells. Expression microarray studies have identified CXCL12 as a gene regulated consistently by estrogen in estrogen-responsive breast cancer cells in our own and other laboratories and it has been reported that CXCL12 mediates the proliferative effects of estrogen. CXCL12 activates two seven transmembrane G protein-coupled receptors, CXCR4 and CXCR7, that transducer signals via heterotrimeric G-proteins. CXCR4 has long been accepted, whereas CXCR7 was identified more recently as a potential CXCL12 receptor.

Methods: Expression of CXCL12, CXCR4 and CXCR7 was measured in five estrogen-responsive and five estrogen-nonresponsive breast cancer cell lines by qRT-PCR and western transfer analysis. The effects of CXCL12 on proliferation of the cells were assessed by DNA quantification and on migration in a modified Boyden chamber assay. The ability of CXCL12 to activate the downstream signalling molecules, MAPK and Akt, was measured by western transfer analysis with a phospho-specific antibodies. The motogenic responses of different breast cancer cell lines to CXCL12 were measured in modified Boyden chamber and in vitro wounding assays. The relative importance of CXCR4 in the CXCL12 response was probed with a specific inhibitor of CXCR4 receptor.

Results: The expression of CXCL12, CXCR4 and CXCR7 varied greatly between the ten breast cancer cell lines analyzed. CXCL12 expression was highest in estrogen-responsive T-47D cells whereas CXCR4 and CXCR7 expression was highest in estrogen-nonresponsive MDA-MB-231 cells. CXCL12 was detected after secretion into medium conditioned by T-47D and MCF-7 breast cancer cells. CXCL12 did not stimulate the proliferation of MCF-7 or T-47D cells in the absence or presence of estrogen. CXCL12 did stimulate breast cancer cell migration in a concentration-dependent manner and cells that express high concentrations of the CXCL12 receptor were more responsive to CXCL12. CXCL12 stimulated Phosphorylation of both MAPK and Akt in estrogen-responsive and non-responsive breast cancer cells.

Conclusion: This study shows that CXCL12 does not mediate the proliferative effects of estrogen on breast cancer cells. CXCL12 does however stimulate the migration of both estrogen-responsive and estrogen non-responsive breast cancer cells. CXCL12 mediates it effects in breast cancer cells by activation on both the MAPK and Akt signal transduction 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 1201. doi:10.1158/1538-7445.AM2011-1201
Abstract 1203: Therapeutic opportunities for anti-Met antibody (MetMAb) in breast cancer
Authors: Mark Merchant , Zheng Zhong , Peng Jing , Li Jun , Mai Elaine , Young Judy , Darlene Dela Cruz , Liu Jinfeng , Yauch Robert , Zha Jiping , Filvaroff Ellen
Published: June 2012

The hepatocyte growth factor (HGF)/Met pathway drives cell proliferation, survival, migration and invasion, which are hallmarks of cancer. Animal models and microarray data suggest that elevated expression of Met is a poor prognostic factor in breast tumors. Our evaluation of primary breast tumors and cell lines has confirmed that expression of Met is found predominantly in the basal sub-type, which includes estrogen receptor (ER), progesterone receptor (PR) and HER2 triple negative (3N) tumors as well as some HER2+ basal tumors. In a panel of 3N basal breast tumors, 96% (25/26) of samples express Met by enzyme-linked immunosorbant assay (ELISA), with 42% (11/26) positive by immuno-histochemistry (IHC). All of the samples were positive for HGF as determined by ECLA, with 32% (8/25) of these primary tumors showing robust staining by IHC. To further explore the biological response of basal breast cancers to HGF, a panel of basal breast cancer cell lines were evaluated in cell proliferation, migration and invasion assays. While most lines tested showed a modest response to HGF in proliferation assays, the migratory and invasive response to HGF was more robust. Assessment of signaling pathways and gene signatures was also performed to better understand the nature of Met signaling leading to biological outcomes. HGF responsive lines were evaluated for growth in transgenic SCID mice expressing human HGF. MetMAb, a potent HGF-blocking Met monovalent monoclonal antibody, acts to inhibit HGF-driven effects in basal breast cancer cell lines in vitro and xenograft growth in vivo. Taken together, these data suggest that Met can drive invasive growth of basal breast tumors, and that treatment with MetMAb, alone or in combination with standard of care, may be therapeutically beneficial in these tumors.

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 1203. doi:10.1158/1538-7445.AM2011-1203
Abstract 1214: Single nucleotide polymorphism in HER family members increases susceptibility to human invasive cervical cancer
Authors: Ma Duanduan , Hovey Raymond , Zhang Zhengyan , Nguyen Loan , Borecki Ingrid , Rader Janet
Published: June 2012

Cervical cancer is the second-most common cancer among women worldwide (Parkin et al. 1999). Some studies address prognostic roles that different genes play after the development of cervical cancer. However, there is a lack of studies addressing polymorphisms in genes of normal tissues that influence susceptibility to cervical cancer prior to malignant transformation. Such studies could be pivotal in prevention and timely diagnosis. It is well-known that Human Papillomavirus (HPV) infection appears to be the primary causative factor for cervical cancer, but host factors must be crucial since only a fraction of HPV-infected women develop cervical cancer. HPV antigens are the ligands of HER family members, and the E5 protein may play a role in the early stage of HPV infection before transformation. Thus, we studied whether there are excessive parent-to-offspring transmissions of specific HER SNP variants in EGFR, ERBB2, ERBB3 and ERBB4, in cases of invasive cervical cancer (ICC) or cervical intraepithelial neoplasia grade 3 (CIN3). Based on single SNP TDT tests, we identified a significant association between ICC/CIN3 and rs11770506, which is located at intron1 of EGFR and in high linkage disequilibrium (LD) with multiple enhancers. Our study provides clues for the identification of vulnerable populations and will advance the development of early detection of ICC in appropriate populations.

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 1214. doi:10.1158/1538-7445.AM2011-1214
Abstract 1228: Resistance to discodermolide, a microtubule stabilizing agent and senescence inducer, is 4E-BP1 dependent
Authors: Chao Suzan K. , Lin Juan , Brouwer-Visser Jurriaan , McDaid Hayley M. , Horwitz Susan B.
Published: June 2012

Discodermolide is a microtubule stabilizing agent that induces accelerated cell senescence. A discodermolide-resistant cell line, AD32, was generated from the human lung cancer cell line A549. We hypothesize that the major resistance mechanism in these cells is escape from accelerated senescence. AD32 cells have decreased levels of 4E-BP1 mRNA and protein, relative to the parental discodermolide-sensitive A549 cells. Lentiviral-mediated re-expression of wild type 4E-BP1 in AD32 cells increased the proliferation rate and reverted resistance to discodermolide via restoration of discodermolide-induced accelerated senescence. Consistent with this, cell growth and response to discodermolide was confirmed in vivo using tumor xenograft models. Furthermore, re-introduction of a non-phosphorylatable mutant (Thr 37/46 Ala) of 4E-BP1 was able to partially restore sensitivity and enhance proliferation in AD32 cells, suggesting that these effects are independent of phosphorylation by mTORC1. Microarray profiling of AD32 resistant cells versus sensitive A549 cells, and subsequent unbiased gene ontology analysis, identified molecular pathways and functional groupings of differentially expressed mRNAs implicated in overcoming discodermolide-induced senescence. The most-statistically significant classes of differentially expressed genes included p53 signaling, G2/M checkpoint regulation and genes involved in the role of BRCA1 in the DNA damage response. Consistent with this, p53 protein expression was up-regulated and had increased nuclear localization in AD32 cells relative to parental A549 cells. Furthermore, the stability of p53 was enhanced in AD32 cells. Our studies propose a role for 4E-BP1 as a regulator of discodermolide-induced accelerated senescence.

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 1228. doi:10.1158/1538-7445.AM2011-1228
Abstract 1257: Tyrosine phosphorylation of mitochondrial pyruvate dehydrogenase kinase 1 is important for cancer metabolism
Authors: Chung Tae-Wook , Hitosugi Taro , Fan Jun , Wang Xu , Gu Ting-Lei , Roesel Johannes L. , Boggon Titus , Chen Zhuo (Georgia) , Khuri Fadlo R. , Kang Sumin , Chen Jing
Published: June 2012

Many tumor cells rely on aerobic glycolysis for their continued proliferation and survival, which is in part due to actively inhibited mitochondrial function. Myc and HIF-1 are believed to promote such inhibition by upregulating gene expression of pyruvate dehydrogenase kinase 1 (PDHK1), which phosphorylates and inactivates mitochondrial pyruvate dehydrogenase complex (PDC). However, how oncogenic signals activate PDHK1 to regulate cancer cell metabolism remains unclear. Here we report that oncogenic FGFR1 activates mitochondrial PDHK1 by tyrosine phosphorylation. FGFR1 directly phosphorylates PDHK1 at Y136, Y243 and Y244. Mutational, structural and biochemical studies revealed that phosphorylation at both Y243 and Y244, but not Y136 is required to promote ATP binding to PDHK1, which consequently facilitates PDHK1 binding to PDC scaffold to access substrate PDHA1. In contrast, Y136 phosphorylation may only function to enhance binding between PDHK1 and PDC. We also found that PDHK1 is commonly tyrosine phosphorylated by diverse oncogenic tyrosine kinases in different human cancers. Moreover, we generated cancer cells with stable knockdown of endogenous human PDHK1 and “rescue” expression of phosphorylation-deficient, catalytic hypomorph mouse PDHK1 mutants including Y134F and Y239/240F (mouse PDHK1 numberings correspond to human PDHK1 Y136F and Y243/244F, respectively). These “rescue” cancer cells demonstrated decreased cell proliferation under hypoxia, increased oxidative phosphorylation with decreased lactate production, and reduced tumor growth in xenograft nude mice.

Our findings suggest that tyrosine phosphorylation activates PDHK1 to inhibit mitochondrial function, providing a metabolic advantage for tumor growth. This represents a common, short-term molecular mechanism underlying the active inhibition of mitochondrial function in tumor cells, in addition to the chronic changes that are believed to be regulated by Myc and HIF-1. Moreover, inhibition of PDHK1 attenuates tumor growth, suggesting that PDHK1 may serve as a therapeutic target in 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 1257. doi:10.1158/1538-7445.AM2011-1257
Abstract 1265: Survival under glucose and serum deprivation is increased by DN-mutant p53 R175H in human melanoma: A possible gain of oncogenic function
Authors: Chavez-Perez Valery , Strasberg-Rieber Mary , Rieber Manuel
Published: June 2012

BACKGROUND.- To help counteract tumor development, the p53 tumor suppressor protein functions to preserve genomic stability, when inhibiting cell cycle progression or inducing senescence or apoptosis. However, cancer-associated dominant-negative (DN) p53 mutations can override the tumor suppressor functions of wt p53, through possible gain-of oncogenic functions including those increasing resistance to metabolic stress. OBJECTIVES.- Since hypoglycemia and growth factor shortage may intermittently occur in the microenvironment of poorly vascularized tumors, this report investigated whether metabolic restriction (glucose deprivation and low serum supplementation), unequally influence the survival of genetically-matched human C8161 melanoma harbouring wt or DN-R175H mutant p53.(Strasberg-Rieber, M. et al. Clin. Cancer Res.7(2001)1446). RESULTS.- Cell death by prolonged metabolic restriction increased oxidative stress, since it was counteracted by the anti-oxidant N-acetylcysteine. Melanoma cells harbouring the DN-mutant p53 R175H were more resistant to cell death induced by shorter metabolic restriction. DPI, a NADPH oxidase inhibitor of superoxide generation counteracted the greater resistance of glucose-deprived mutant p53 cells, by altering expression of mitochondrial Mn-SOD∼SOD2. Pyruvate preferentially protected from DPI treatment under metabolic restriction, restoring levels of MnSOD. CONCLUSIONS. our results suggests that tumor cell death in response to anti-glycolytic treatment, may be antagonized by DN-mutant p53R175H.

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 1265. doi:10.1158/1538-7445.AM2011-1265
Abstract 128: MicroRNA-23b acts as an oncogenic microRNA in renal cancer
Authors: Zaman Mohd Saif , Deng Guoren , Shahryari Varahram , Saini Sharanjot , Majid Shahana , Singh Kamaldeep , Sandhu Herman , Chang Inik , Tanaka Yuichiro , Dahiya Rajvir
Published: June 2012

The North American region has the highest rates of renal cancers in the entire world. MicroRNAs are small noncoding RNAs that play important roles in numerous cellular processes including development, proliferation, and apoptosis. miR-23b is part of a cluster of miRNAs which includes among others miR-24-1, miR-27b and miR-30a. Recent studies have demonstrated that miR-23b plays different roles in different organs of the body. This led us to speculate its role in urological cancers in general and renal cancer in particular. In the current study we observe the role of miR-23b in renal cancer. The expression of miR-23b was checked in 30 pairs of renal cancer and normal tissues. The samples included three different types of renal cancer tissues, clear cell, papillary and tubular. 55% of clear cell carcinoma and all tubular samples showed high expression of miR-23b as compared to the normal. Interestingly, papillary carcinoma showed a contrasting result in which miR-23b levels were found to be down regulated in almost 90% of the samples. The expression in renal cancer cell lines, A498, ACHN, Caki-1 and Caki-2 was found to be significantly higher as compared to the normal cell line HK-2. The chemo preventive agent Genistein (25µM for 96 hours) was able to reduce the expression of miR-23b in A498 cells by more than 50%. Inhibition of miR-23b expression by the anti-miR-23b antagonist in A498 cells resulted in a significant increase in apoptosis, as detected through flow cytometry analysis. In contrast over expression of mir-23b in A498 cells resulted in a decrease in apoptosis. No significant effect on cell cycle was observed in either over expressing or inhibiting miR-23b in A498 cells. Cell viability assays also did not show any major effect due to the inhibition of expression of miR-23b. Moreover, the expression of miR-23b was correlated with 5 year survival rate of patients. For patients with low levels of miR-23b, 85% of patients survived after 5 years of operation, whereas in case of high expression of miR-23b only 50% survived. Our data suggests that miR-23b acts as an oncogenic mi-RNA in renal 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 128. doi:10.1158/1538-7445.AM2011-128
Abstract 129: miR-345 is a novel tumor suppressor microRNA in pancreatic cancer
Authors: Srivastava Sanjeev K. , Singh Seema , Bhardwaj Arun , Grizzle William E. , Singh Ajay P.
Published: June 2012

Pancreatic cancer is a highly lethal malignancy due to late diagnosis, rapid progression and lack of effective therapies for treatment. In majority of cases, the disease is diagnosed at a stage when it is locally advanced or has already metastasized to distant organs. In that scenario, chemotherapy is considered as an option, but the effects are usually modest due to chemo-resistance. Hence, there is an urgent need to identify novel diagnostic/therapeutic targets for effective management of this malignancy. MicroRNAs (miRNAs) have received significant attention as a new class of non-coding-RNAs engaged in the regulation of gene expression. It is now evident that miRNAs exhibit differential expression in cancer and play important roles in the disease processes. According to recently published studies, a number of miRNAs are differentially expressed in pancreatic cancer, including miR-345, which is among the top aberrantly-expressed genes exhibiting significant downregulation. miR-345 has remained an understudied miRNA with no report on its functional role in pancreatic cancer. Here, we show that miR-345 is differentially-expressed in pancreatic cancer cell lines with relatively more downregulated expression in poorly-differentiated cancer cells. Ectopic overexpression of miR-345 in two poorly-differentiated pancreatic cancer cell lines, Panc1 and MiaPaCa, diminished their growth, clonogenicity, motility and invasion, and enhanced cell-cell interaction. miR-345-overexpressing cells had distinguishable morphological differences and an increased expression of epithelial (E-cadherin) and loss of mesenchymal markers (N-cadherin, vimentin, twist, slug and snail) as compared to the control cells. Furthermore, our data showed that miR-345-overexpressing pancreatic cancer cells were more sensitive to gemcitabine-cytotoxicity as compared to the control cells. Altogether, our findings demonstrate novel tumor suppressive roles of miR-345 in pancreatic cancer and indicate that miR-345 downregulation may be one of the mechanisms underlying the chemo-resistance of 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 129. doi:10.1158/1538-7445.AM2011-129
Abstract 1292: Pharmacokinetics of CPX-351: A nano-scale liposomal fixed molar ratio of cytarabine-daunorubicin (Cyt:Daun) in patients with advanced leukemia
Authors: Feldman Eric J. , Lancet Jeffrey E. , Kolitz Jonathan E. , Trang John M. , Mayer Lawrence D. , Swenson Chris E. , Chiarella Michael T. , Louie Arthur C.
Published: June 2012

Background: CPX-351 is a liposomal formulation that co-encapsulates Cyt and Daun enabling delivery of both drugs at a synergistic 5:1 molar ratio. A Phase I study in advanced AML patients demonstrated substantial efficacy with complete remissions (CRs) and acceptable safety. The MTD was 101 units/m2. One unit of CPX-351 contains 1 mg Cyt and 0.44mg of Daun. Here we examine the PK of CPX-351 as a function of dose, inter-patient variability and patient characteristics in order to identify potential PD relationships. Methods: 35 male and female patients with advanced hematologic malignancies were included in the PK portion of this Phase I trial and received 24, 32, 43, 57, 76, 101, or 134 units/m2 of CPX-351 by IV infusion over 90 minutes on Days 1, 3, and 5. Validated LC/MS/MS assays were used for determination of total plasma Cyt and Daun. PK parameters [Cmax, AUC, t1/2, Vss, CL, Cmax/Dose, AUC/Dose] were determined on Days 1 and 5. Results: Mean Cyt and Daun PK parameters are presented in the table below. No significant differences were observed in t1/2, Vss, CL, Cmax/Dose, or AUC/Dose among dose groups on either study day, although some drug accumulation was observed from day 1 to day 5. Cyt and Daun PK parameters were not correlated with patient gender, age or race. Incidence of non-hematologic toxicity increased with dose and systemic exposure. CRs were observed in patients receiving doses of 32-134 units/m2 of CPX-351. The responses at 101 units/m2 and above appear to be more durable. The Cyt:Daun molar ratio remained near 5:1 for up to 48 hours on both study days for all dose levels. Conclusions: Cyt and Daun delivered in CPX-351 exhibited linear single dose and multiple dose PK and low inter-patient variability in plasma concentrations within dose groups. CPX-351 provides predictable, extended systemic exposure of elevated Cyt:Daun concentrations near a 5:1 molar ratio. The 100 unit/m2 dose is undergoing testing in Phase II studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1292. doi:10.1158/1538-7445.AM2011-1292
Abstract 1302: Delayed elimination of SN-38 and prolonged neutropenia in cancer patients with severe renal failure requiring dialysis who receive irinotecan
Authors: Fujita Ken-Ichi , Sunakawa Yu , Miwa Keisuke , Akiyama Yuko , Sugiyama Minako , Kawara Kaori , Ishida Hiroo , Yamashita Keishi , Mizuno Keiko , Saji Shigehira , Ichikawa Wataru , Yamamoto Wataru , Nagashima Fumio , Miya Toshimichi , Narabayashi Masaru , Ando Yuichi , Hirose Takashi , Sasaki Yasutsuna
Published: June 2012

Purpose: We prospectively examined the effects of severe renal failure on the pharmacokinetics and toxicity of irinotecan.

Experimental Design: The pharmacokinetics of irinotecan, SN-38 and SN-38 glucuronide (SN-38G), and irinotecan-induced toxicity in 3 cancer patients with severe renal failure (creatinine clearance [Ccr] ≤20 mL/min) who were undergoing dialysis and received 100 mg/m2 irinotecan as monotherapy were compared with those in 5 cancer patients with normal renal function (Ccr ≥60 mL/min). To ensure that the subjects had similar genetic backgrounds of UDP-glucuronosyltransferase (UGT) 1A1, patients with UGT1A1*1/*1, *1/*6, or *1/*28 were enrolled.

Results: The estimated terminal elimination rate constant of SN-38 in patients undergoing dialysis was about one tenth that in patients with normal renal function (P=0.025). Consequently, the estimated t1/2 of SN-38 in patients with severe renal failure was roughly 10 times longer than that in patients without renal failure (P=0.025). About 50% of SN-38 was dialyzed with a 2.1-m2 dialysis membrane, whereas 27% was dialyzed with a 1.5-m2 membrane. All patients with severe renal failure experienced neutropenia (grade 2, 3 or 4 at nadir). In two of them experienced grade 2 or 3 neutropenia, the second irinotecan infusion was delayed 10 or 20 days by the prolonged neutropenia.

Conclusions: Our results showed that the elimination of SN-38 was significantly delayed in patients with severe renal failure as compared with patients with normal renal function. We demonstrated SN-38 was partly dialyzed. The prolonged neutropenia was seen in patients with severe renal failure.

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 1302. doi:10.1158/1538-7445.AM2011-1302