bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A44: Inhibition of EGFR phosphorylation in a panel of human breast cancer cells correlates with synergistic interactions between gefitinib and 5'-DFUR, the bioactive metabolite of Xeloda®
Authors: Tihyaty Maria Ait , Rachid Zakaria , Jean-Claude Bertrand , Mihalcioiu Catalin
Published: June 2012

The introduction of Xeloda® (capecitabine) in the clinical management of breast cancer has significantly improved survival in patients with mammary carcinoma. It is administered orally and first is metabolized in the liver by carboxylesterases to generate 5'-deoxy- 5-flurocytidine ribose (5'-DFCR), which is subsequently converted to 5'-deoxy-5-fluorouridine ribose (5'-DFUR) by cytidine deaminase. While the latter conversion takes place in tumour and normal tissues, the conversion of 5'-DFUR to the cytotoxic compound 5-FU, occurs principally in the tumour. This reaction is catalyzed by thymidine phosphorylase (TP), which is overexpressed in cancer cells. It has been observed that tumours expressing high levels of TP are the most responsive to capecitabine treatment. Therefore, it was hypothesized that conditions leading to an increase of TP expression could potentiate the action of capecitabine. Our recent studies in a panel of human breast cancer cell lines showed an increase in TP levels upon exposure to gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR). Here, we report on the factors influencing the potency of gefitinib in combination with 5'-DFUR, the bioactive metabolite of capecitabine.

The results showed that: 1) 5'-DFUR activity linearly correlated with TP basal level (R2= 0.808), 2) importantly, the strength of the synergistic interaction between gefitinib and 5'-DFUR, as measured by the combination index at IC50 concentrations (CI50) increased with TP fold changes after gefitinib treatment (R2=0.6449), 3) inversely, it decreased with increasing thymidylate synthase (TS) fold changes after gefitinib treatment (R2=0.6229), 4) moreover, the strength of the synergy correlated with an increase in the proportion of cells arrested in the S and G2M phases of cell cycle (R2=0.6355), 5) changes in TP levels correlated with the magnitude of inhibition of EGFR phosphorylation by gefitinib (R2=0.63) but not with its IC50 values for growth inhibition in the cell panel (R2=0.03611), 6) likewise, DNA damage induced by 5'-DFUR alone or in combination with gefitinib did not correlate with IC50 values for growth inhibition. The results in toto suggest that the observed synergistic interactions between gefitinib and 5'-DFUR may be imputed to molecular events associated with inhibition EGFR phosphorylation and modulation of TP/TS expression in the cells.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A44.
Abstract A47: Possible effect of repetitive magnetic stimulation of the spinal cord on the limb angiogenesis in healthy rats and its clinical implication for the treatment of lymphedema
Authors: Min Yusun , Beom Jaewon , Oh Byung-Mo , Suh Kwan-Sik
Published: June 2012

Objective: To investigate the effect of repetitive magnetic stimulation of the spinal cord on limb angiogenesis in healthy rats and explore its implication for the treatment of lymphedema.

Methods: Twelve adult male Sprague-Dawley rats were divided into four groups as follows: sham repetitive magnetic stimulation (rMS) followed by tissue harvest 5 minutes later (group 1, n=2), 1 Hz rMS and tissue harvest 5 minutes later (group 2, n=3), 20Hz rMS and tissue harvest 5 minutes later (group 3, n=3), 20Hz rMS and tissue harvest 30 minutes later (group 4, n=4). Animals were treated with 20-minute rMS with 120% of the motor threshold on their left side of upper lumbar spinal cord. Expression of angiogenic factors, that is, Akt, phospho-Akt, endothelial nitric oxide synthase (eNOS), phospho-eNOS were measured by Western blot. Bilateral hindlimb muscles (quadriceps and gastrocnemius) were harvested.

Results: Expression of eNOS in quadriceps muscle was markedly increased in group 3 and 4 (6.4 and 7.7-fold each compared with group 1, p=0.04). Also, expression of eNOS in gastrocnemius muscle was increased in group 2 and 3 than in group 1 (p=0.02). Expression of Akt in gastrocnemius muscle tends to increase in rMS- treated groups than in sham rMS group (p>0.05). Expression of phospho-Akt and phospho-eNOS were not comparable between four groups (p>0.05).

Conclusion: Repetitive magnetic stimulation of the spinal cord may exert an angiogenic effect closely linked to lymphangiogenesis. It has clinical implication for the possible therapy of lymphedema caused by breast, cervical or endometrial cancer operation. Future studies with the specific lymphatic endothelial cell markers are required to confirm the effect of repetitive magnetic stimulation on lymphangiogenesis.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A47.
Abstract A48: Demethylating agent 5-Aza-2-deoxycytidine enhances susceptibility of breast cancer cells to anticancer agents
Authors: Mirza Sameer , Sharma Gayatri , Luthra Kalpana , Ralhan Ranju
Published: June 2012

DNA methylation plays an important role in regulation of gene expression and is increasingly being recognized as a determinant of chemosensitivity of human cancers. With the aim of improving the chemotherapeutic efficacy of breast carcinoma, the effect of DNA methyltransferase inhibitor, 5-Aza-2-deoxycytidine (5-aza-CdR), on the chemosensitivity of anticancer drugs was investigated. The cytotoxicity of paclitaxel (PTX), adriamycin (ADR) and 5-fluorouracil (5-FU) was analyzed against human breast cancer cell lines, MDA MB 231 and MCF 7 cell lines using the MTT assay, and the synergy of 5-aza-CdR and these agents was determined by Drewinko's fraction method. The effects of each single agent or the combined treatment on cell cycle arrest were analyzed by flow cytometric analysis. We also investigated the effect of each single agent or the combined treatment of anticancer drugs with 5-aza-CdR on the methylation status of the selected genes by Methylation Specific PCR.

In MDA MB 231 cells a synergistic antiproliferative effect was observed with a combination of 10 µM 5-aza-CdR and these 3 anticancer drugs, while in MCF 7 cells, a semiadditive effect was observed. Treatment with 5-aza-CdR and anticancer drug resulted in partial demethylation of a panel of genes including RAR 2, Slit2, GSTP1 and MGMT.

Based on these findings, we propose that 5-aza-CdR enhances the chemosensitivity of anticancer drugs in breast cancer cells and may be a promising approach for increasing the chemotherapeutic potential of these anticancer agents for more effective management of breast carcinomas.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A48.
Abstract A49: Induction of cell-cycle arrest and apoptosis in MCF7 cancer cells by Newcastle disease virus is associated with upregulation of p21cip and p27kip
Authors: Roslan Nurhidayah , Stanbridge Eric J. , Yusoff Khatijah , Shafee Norazizah
Published: June 2012

Newcastle disease virus (NDV), a member of Paramyxoviridae family, is known for its selective oncogenic effects in cancer cells. NDV infections in cancer cells resulted in cell death through apoptosis. The actual mechanism of this induction has not been thoroughly investigated. Therefore, the objective of the present study is to investigate the effects of infection of a local velogenic strain of NDV, designated as AF2240, on the cell cycle regulation of MCF7 breast cancer cells. Infection was done at a multiplicity of infection of 1, and cell lysates were collected at 3, 6, 9, and 12 hours postinfection. Protein samples were subjected to SDS-PAGE and immunoblotting with antibodies for CDK, CDK inhibitors, and the cyclin family of cell cycle regulatory proteins. Results showed that proteins involved in cell cycle arrest, especially p21cip and p27kip, were significantly increased by 6 hours postinfection. These results suggest that NDV infection leads to initial cell cycle arrest, which is a first step towards cell death through apoptosis, in part via induction of the CDK inhibitors p21cip and p27kip. Findings from this study will provide further understanding of the mechanism of oncolysis by NDV.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A49.
Abstract A5: Lenalidomide inhibits hypoxia-induced HIF-1α production and prevents the invasive phenotype in epithelial solid tumor cells
Authors: Lu Ling , Schafer Peter H. , Bartlett J. Blake
Published: June 2012

Background: In hematological malignancies lenalidomide (len) exerts tumoricidal and immunomodulatory effects and may also influence the tumor cell microenvironment by blocking the proangiogenic and proinvasive effects of growth factors and/or hypoxia. In solid tumor models len is antimetastatic but lacks overt tumoricidal activity. These observations led us to explore the effect of len on hypoxic solid tumor cells, in particular the expression of HIF-α and its upstream regulators p53 and HDM-2.

Methods: Eighteen solid tumor cell lines were tested for the effect of len on the response to hypoxia (1 % O2, 5% CO2, 94% N2; Invivo2 400 hypoxic workstation). Cell lysates from three cell lines (HCT-15, MDA-MB-231 and SKOV-2) were assessed for HIF-1α, p53 and HDM-2 proteins by immunoblot. We also performed immunoprecipitation studies to explore the effect of len on the interaction of these proteins. The effect of len on HIF-1α was assessed in p53 siRNA transfected HCT-15 cells and on HIF-1 α mRNA in transfected Luc-HIF NIH 3T3 cells. Len effects on hypoxia-induced trans-well invasion of three cell lines were also assessed.

Results: Len (1 µM) significantly inhibited hypoxia-induced HIF-1 a protein levels dose-dependently in the majority of tumor cell lines tested; breast (by 68%, MDA-MB-231; 65%, MCF-7), colorectal (76%, HCT-116; 65%, HCT-15; 82% HT-29), ovarian (71%, OVCAR-3; 66%, SKOV-3), renal (83%, 786-O; 57%, HEK293), prostate (54%, DU- 145) and pancreatic (45%, MiaPaca-3)(all p<0.05). Len had no effect on HIF-1 α in SW480 (colorectal), Panc-1, BxPC3 (pancreatic), SW579 (thyroid), NCI-H446 (SCLC) or Caki-1 (Renal) cell lines or on HCT-15 cells transfected with p53 siRNA. In addition to inhibition of HIF-1 α protein len also inhibited hypoxia-induced HIF-1α mRNA expression (p< 0.01). Len enhanced p53 levels in hypoxic HCT-15 cells (by 2-fold; p<0.05), SKOV-3 cells (by 4-fold; p<0.01) and MDA-MB-231 cells (by almost 2-fold; p<0.05) but had little apparent effect on the interaction of these proteins. Len totally inhibited the 2-fold hypoxic induction of HDM-2 levels in HCT-15 (p<0.05) and SKOV-3 (p<0.01) cells but had no effect on HDM-2 in p53 mutant MDA-MB-231 cells. Tumor cell invasiveness was enhanced in response to hypoxia by ~3- fold in all three lines and was blocked by 50-80% by len treatment (all p < 0.05).

Conclusions: These results suggest that len inhibits the proinvasive hypoxic response in multiple, diverse tumor lines and may exert antimetastatic effects within the hypoxic solid tumor microenvironment.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A5.
Abstract A50: Targeting 3-phosphoinositide-dependent kinase-1 and mammalian target of rapamycin synergistically inhibits cell proliferation of breast cancer cells
Authors: Walls Marlena , Baxi Sangita M. , Murphy Sean , Johnson Teddy W. , Tod Smeal , Yin Min-Jean
Published: June 2012

Aberration of receptor tyrosine kinases (RTKs), PTEN (phosphatase and tensin homolog deleted on chromosome 10), and PIK3CA (encodes the p110 subunit of phosphatidylinositol 3-kinase [PI3K]) frequently contribute to tumor progression through their ability to regulate the intracellular level of phosphatidylinositol-3,4,5- triphosphate (PIP3). PIP3 subsequently recruits 3-phosphoinositide- dependent kinase-1 (PDK-1), a serine/threonine kinase, to the plasma membrane and initiates PDK-1 kinase activity to phosphorylate AKT within the activation loop of the catalytic domain at the residue threonine-308 (T308). The mammalian target of rapamycin (mTOR) plays a critical role in the PI3K/AKT pathway. The mTOR kinase is present as two protein complexes, TORC1 and TORC2. The TORC1 complex is activated by PI3K/AKT and phosphorylates p70S6K and 4E-BP1 to modulate protein translation whereas the TORC2 complex phosphorylates AKT in the regulatory domain at residue serine 473 (S473). Phosphorylation of AKT at both T308 and S473 fully activates AKT function through downstream signaling to mediate cell proliferation, survival, migration, angiogenesis and other pathways which are critical for tumor progression. We have developed a potent and selective PDK1 inhibitor (PF-05177624) that is sufficient to inhibit the phosphorylation of AKT atT308 and block cell proliferation of cancer cells in vitro. In this study, we combined this PDK1 inhibitor (PF-05177624) and a selective mTOR kinase inhibitor (WYE-354) to perform the combination studies in breast cancer cell lines. Our data demonstrate that targeting both PDK1 and mTOR simultaneously produces a synergistic inhibitory effect in AKT phosphorylation. Moreover, this results in a synergistic inhibition of cell proliferation in breast cancer cells. Our data suggest that a combination strategy of targeting both PDK-1 and mTOR may have potential improved clinical efficacy in the development of cancer drugs for breast cancer patients.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A50.
Abstract A53: Lovastatin inhibits EGFR dimerization and AKT activation in squamous cell carcinoma cells: Potential regulation through targeting rho proteins
Authors: Zhao Tong T. , Dimitroulakos Jim
Published: June 2012

We recently demonstrated the ability of lovastatin to inhibit the function of the epidermal growth factor receptor (EGFR) and its downstream signaling of the PI3K/AKT pathway. Combining lovastatin with gefitinib, a potent EGFR inhibitor, induced synergistic cytotoxicity in various tumor-derived cell lines. In this study, lovastatin treatment inhibits ligand-induced EGFR dimerization in squamous cell carcinoma (SCC) cells and its activation of AKT and its downstream targets 4EBP1 and S6K1. This inhibition was associated with global protein translational inhibition demonstrated by a decrease in RNA-associated polysome fractions. The effects of lovastatin on EGFR function were reversed by the addition of the geranylgeranyl pyrophosphate that acts as a protein membrane anchor. Lovastatin treatment induced actin cytoskeletal disorganization and the expression of the geranylgeranylated rho family proteins that regulate the actin cytoskeleton, including rhoA. Lovastatin-induced rhoA was inactive as EGF stimulation failed to activate rhoA and inhibition of the rho-associated kinase, a target and mediator of rhoA function, with Y-27632 also showed inhibitory effects on EGFR dimerization. The ability of lovastatin to inhibit EGFR dimerization is a novel exploitable mechanism regulating this therapeutically relevant target. To assess the potential of this approach, we evaluated the effect of statin use in patients enrolled in the BR21 erlotinib phase III study in non-small cell carcinoma (NSCLC) patients. In the erlotinib arm of this trial, although not statistically significant due to the limited number of patients on statins, in general, patients that were on statins performed better than patients without statins.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A53.
Abstract A6: Cancer-associated fibroblasts (CAF) expressing CD44 high increased the aggressiveness of cancer cells
Authors: Shim Seon-Hui , Hah J. Hun , Sung Myung-Whun
Published: June 2012

Cancer-associated fibroblast (CAF) is considered of one of the most important factors influencing tumor microenvironment. CD44 is known to a marker of head and neck cancer stem cell and is a glycoprotein involved in cell-cell interactions, cell adhesion and migration. Tissues from several head and neck cancer patients were gathered and fibroblasts from tumor tissues and normal tissues away from cancer were isolated. We found CAF overexpressed CD44 when compared to normal part of fibroblast, thus investigated the role of CAF which is overexpressing CD44. Cancer cells which are co-cultured with CAF migrated better than normal fibroblast when wound assay were performed. To test whether this motility of cancer is related to CD44 on CAF, CAF was inhibited by neutralizing antibody of CD44. After treatment with neutralizing antibody, the motility of cancer cells reduced. To confirm that CAF influences tumor cell migration, mixture of CAF and cancer cells were laid on an upper well, then these cells would travel 3D environment which is made by our own idea. Cancer cells which get ability to migrate and can form colonies can survive on the bottom well. When treated neutralizing antibody, cells could neither migrate nor make colonies well than antibody-free mixture. In conclusion, CAF influenced cancer cell migration through the CD44. If CD44 on CAF was blocked, the movement and aggressiveness of cancer cells weakened.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A6.
Abstract A8: Cdk5 modulates ErbB2/3 phosphorylation and prostate cancer cell growth
Authors: Hsu Fu-Ning , Lin Ho
Published: June 2012

Prostate cancer is an age-related carcinoma and the most commonly diagnosed malignancy in men. We have previously demonstrated a pivotal role for cyclin-dependent kinase (Cdk) 5 activity in modulating the proliferation on thyroid cancer cells. Cdk5 was originally defined as a trophic player in neurons and has been reported to phosphorylate ErbB2/3 and mediate ErbB2/3 activity. ErbB2/3 receptors are mentioned to be important to cancer cell survival. In recent decade, Cdk5 becomes a new target of interests in cancer research. Furthermore, Cdk5 activity is indicated to control cell motility and metastasis of prostate cancer. Initially, our immunohistochemical analysis on prostatic specimen revealed that five out of eight (62.5%) patients expressed relatively higher Cdk5 proteins in clinical tumor tissues than individual normal ones. Next, a Cdk inhibitor roscovitine (Rv, also named Seliciclib or CYC202, a clinical trial drug on non-small cell lung cancer and leukemia) was utilized to inhibit Cdk5 activity in prostate cancer cell line LNCaP. Rv treatment resulted in significant growth inhibition and morphology change of LNCaP cells. The results of in vitro kinase assay also exhibited that the activity of Cdk5 but not Cdk1 was obviously diminished by Rv. Then the association and co-localization between Cdk5 and ErbB2/3 in LNCaP cells were identified and this interaction could be interfered by Rv treatment. In addition, the serine phosphorylation of ErbB2/3 was reduced by inhibition of Cdk5 activity. Moreover, Rv further decreased the phosphorylation of Akt, Erk and STAT3 which were downstream signals of ErbB2/3 in the presence of heregulin (HRG, ligand of ErbB3) treatment. Finally, Rv dramatically blocked the HRG-stimulated growth of LNCaP cells. According to these results, we found that Cdk5 might regulate survival pathways through ErbB2/3 phosphorylation. Therefore, we suggest that Cdk5 may be a potential therapeutic target in prostate or other cancers.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A8.
Abstract A9: The HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) inhibits vascular endothelial growth factor C-induced lymphangiogenesis
Authors: Cheng Hsuen-Tsen , Hung Wen-Chun
Published: June 2012

The lymphatic system plays an important role in tissue fluid homeostasis, immune surveillance, and fat absorption and also is involved in various pathological situations. Recent studies showed that lymphangiogenesis is not only important for physiological regulations but also associated with the metastatic spread of cancer. The histone deacetylase (HDAC) inhibitor SAHA has been reported to inhibit tumor cell proliferation, induce apoptosis and reduce angiogenesis in different cancer types. In this study, prox1-overexpressing endothelial cell line EA.hy926-Prox1 with the characteristics of lymphatic endothelial is used to evaluate the anti-lymphangiogenic and anti-cancer activity of SAHA. SAHA at low concentrations inhibits growth of EA.hy926-Prox1 endothelial cells via induction of G2/M arrest. Multiple G2/M cell cycle regulators are changed by SAHA. At high concentrations, SAHA causes significant cell death. SAHA at non-cytotoxic concentrations prevents vascular endothelial growth factor C (VEGF-C)-stimulated sprouting and capillary-like structure of EA.hy926-Prox1 cells. In addition, we find that SAHA treatment can inhibit the expression and secretion of VEGF-C in breast cancer cells. Our results provide evidence that SAHA can inhibit lymphagiogenic through (A) regulating the proliferation, apoptosis, sprouting and tube formation in lypmphatic endothelial cells and (B) reducing the expression and secretion of VEGF-C in cancer cells. Thus, SAHA may function as a therapeutic agent for the treatment or prevention of tumor-induced lymphangiogensis.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A9.
Abstract B10: Genetic profiling reveals cross-contamination and misidentification of six adenoid cystic carcinoma cell lines
Authors: Phuchareon Janyaporn , Otha Yoshihito , Woo Jonathan M. , Eisele David W. , Tetsu Osamu
Published: June 2012

Cell lines established from human tissues are extensively used to study human diseases and other conditions. Lines derived from malignant neoplasms are particularly useful tools for investigating mechanisms of tumor initiation and development. These cells are often used as preclinical models for the disease, as sources for biomarker or drug target identification, and as vessels to screen for efficacy hits and for early toxicity indicators. Because of the increasing importance of cultured cells in cancer research and other biomedical studies, cross-contamination of cell lines is becoming a more frequently encountered problem. It has been reported that approximately 20% of cell lines are incorrectly designated. Here we report that all six salivary gland adenoid cystic carcinoma (ACC) cell lines had been contaminated with other cells. We performed DNA fingerprint analysis on six ACC cell lines using short tandem repeat (STR) examinations. ACC2, ACC3, and ACCM were determined to be cervical cancer cells (HeLa cells), whereas the ACCS cell line was composed of T24 urinary bladder cancer cells. These observations suggest that future studies using ACC cell lines should include cell line authentication to avoid the use of contaminated or nonhuman cells.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B10.
Abstract B11: An empirical evaluation of array normalization for Agilent microRNA expression arrays
Authors: Qin Li-Xuan , Satagopan Jaya , Singer Samuel
Published: June 2012

Introduction: Array normalization is an essential component of array data preprocessing, which removes array effects resulting from the experimental process. Methods for array normalization have been developed in the context of mRNA expression arrays, such as median normalization and quantile normalization. These methods assume few or symmetric differential expression of markers on the array. These assumptions are likely to be appropriate for mRNA expression arrays that consist of tens of thousands of markers with only a small fraction of these generally associated with the disease under study. In contrast, microRNA expression arrays consist of a few hundred markers and a reasonable fraction of them are anticipated to have disease-relevance; further, the numbers of over- and underexpressed microRNAs are not likely to be the same in studies involving tumors. Consequently, the performance of the existing normalization methods need to be reevaluated when applied to microRNA arrays of tumors.

Methods: In this study, we empirically examined sources of variations in microRNA array data using a set of Agilent microRNA arrays in liposarcoma (n=56) and evaluated methods for normalization using Solexa sequence data on a subset of these tumors (n=29) as the gold standard in the following three aspects: (1) correlation of the target-sequence-specific data on each array; (2) selection of significant microRNAs; (3) estimated direction of change for the significant microRNAs.

Results: We found that there is minimum variation between replicate probes for the same target sequence and moderate variation between multiple target sequences for the same microRNA. There is moderately high correlation between Agilent data and Solexa data on the same tumors, with the Pearson correlation coefficient ranging from 0.517 to 0.794. Quantile normalization has slightly improved the correlation with Solexa data, as well as the detection of differentially expressed microRNAs both in terms of statistical significance and the direction of change.

Conclusions: The number of replicate probes for each target sequence ranges from 4 to 16, which is unnecessarily high and can be reduced. Target sequences for the same microRNA need to be analyzed separately. Quantile normalization improves the accuracy of the analysis. Further investigations with other disease types are needed to validate this finding.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B11.
Abstract B13: OncoPredictor: An integrative genomics platform to systematically predict responsive tumor populations from in vitro drug response data
Authors: Rhodes Daniel R. , Daubresse Gary , Wyngaard Peter , Tomilo Mark , Williams Paul , O'Day Christine , Ovechkina Yulia , Warrior Usha , Sadis Seth
Published: June 2012

A key challenge in drug development is identifying clinically relevant genomic biomarkers from preclinical data. Here, we developed OncoPredictor, a cellular screening and bioinformatics platform to (1) evaluate multiple types of genomic biomarkers for association with in vitro drug response and (2) analyze identified biomarkers in clinical tumor populations, thereby suggesting potential drug development strategies. We examined data for 18 targeted, anticancer agents tested across more than 200 cancer cell lines for which detailed genomic data were collected. To support association analysis of drug response and genomic biomarkers, a cell line biomarker catalog was constructed including gene and pathway mutations, copy number aberrations and gene expression changes, in addition to tumor-derived gene expression molecular subtypes. Similarly, to support the rapid translation of in vitro biomarkers to clinical tumor populations, a tumor biomarker catalog was developed, characterizing the frequency of biomarkers across the Oncomine database, which includes more than 40,000 genomic profiles from tumor specimens. Notably, our analysis uncovered several known and novel drug- biomarker-tumor population associations providing a series of cancer treatment hypotheses. For example, within Ras/Raf mutant cell lines, overexpression of a novel biomarker associated with sensitivity to CI-1040, a MEK inhibitor, and identified a sub-population of Ras/Raf mutant colorectal cancer and melanoma that may be more likely to benefit from MEK inhibitors. Similarly, we showed that a growth factor activation network associated with a dramatic response to sunitinib and identified a fraction of glioblastoma and particular types of sarcoma with activation, suggesting that these indications may benefit from a tumor intrinsic response to sunitinib. Finally, for everolimus, an mTOR inhibitor, we found that a gene expression-based molecular subtype of breast cancer were particularly sensitive and demonstrated that the while subtype-positive breast cancers have a good prognosis, 10% of breast cancers that metastasize are subtype-positive, suggesting a defined clinical population that could benefit from mTOR inhibitors. In summary, our platform provides a comprehensive and clinically relevant framework to discover and apply genomic biomarkers of drug response.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B13.
Abstract B15: Genetic variation in DNA repair pathway genes and melanoma risk
Authors: Zhang Mingfeng , Qureshi Abrar , Guo Qun , Han Jiali
Published: June 2012

Reduced DNA repair capacity has been proposed as a predisposing factor for melanoma. We comprehensively evaluated 1465 genetic variants across 60 DNA repair-related pathway genes in relation to melanoma risk in a nested case-control study of 218 melanoma cases and 218 matched controls within the Nurses’ Health Study (NHS). We then genotyped the two variants with the smallest P value in two replication sets: 184 melanoma cases and 184 matched controls in the Health Professionals Follow-Up Study (HPFS); and 183 melanoma cases and 183 matched controls in the NHS. The SNP rs3219125 in the PARP1 gene was significantly associated with melanoma risk in the discovery set (odds ratio (OR) 3.14; 95% confidence interval (CI) 1.70-5.80) and in the HPFS replication set (OR, 1.92; 95%CI, 1.05-3.54), but not in the NHS replication set (OR, 1.07; 95%CI, 0.58-1.97), while in the joint analysis, the OR was 1.89 (95%CI, 1.34-2.68) for this polymorphism. Given that DNA repair protects against UV-induced melanoma, the sun-exposed body sites are more prone to insufficiency in DNA repair capacity. Thus, we further conducted subgroup analysis of this SNP by body sites and found that the increased risk of this variation was more pronounced among patients with lesions in head/neck (OR, 3.19; 95% CI, 1.77-5.73 for head/neck, and OR, 1.54; 95% CI, 1.03-2.30 for other sites, P value for heterogeneity test = 0.036), which further suggested the involvement of this locus in the etiology of melanoma via its influence on DNA repair capacity. In addition, there were significantly fewer head/neck melanoma cases in the NHS replication set (20.4% in the discovery set, 28.1 % in the HPFS replication set, and 9.5% in the NHS replication set, P < 0.001), which may explain the failure of the replication in the NHS replication set. In conclusion, our findings implicate the PARP1 variant in the etiology of melanoma cancer, especially for sites with high sun exposure. Further work is needed to replicate these results and clarify the mechanism by functional studies.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B15.
Abstract B16: Indigeneously synthesized inorganic coordination complex act as apoptotic agent in cancerous cells
Authors: Banerjee Payel , Majumder Paramita , Mazumder Santasree
Published: June 2012

Objective: Metal complexes play an important role in chemotherapy. Arguably the most prominent metal complex in medicine is the anticancer agent cisplatin (cis-diamineplatinum (II) dichloride). Cisplatin and other chemotherapeutic metal complexes also have certain reported side effects and their cost is very high for a country like India. In the present study we aim to evaluate the effect of novel inorganic coordination complexes in comparison to cisplatin in the treatment of cancer of different origin such as lung, cervix, and ovary.

Method: The decrease in cell viability was determined by MTT assay followed by wound healing and DNA hypoploidy assay Apoptosis has been studied by Annexin V-FITC/PI dual staining flow cytometric assay. Following this: (1) chromosomal condensation by DAPI staining, (2) determination of ROS generation by DCFDA staining, and (3) measurement of altered mitochondrial membrane potential with JC1 dyes was performed. Changes in Bcl 2/Bax ratio and release of Cytochrome-C protein by Western blot technique confirm apoptosis.

Results: Our results establish that both cisplatin and the novel inorganic complex can inhibit the proliferation of A549, Hela, and PA 1 cells. The novel inorganic coordination complex in the study shows the IC 50 at 75 µM,150 µM, and 250 µM in Hela, A 549 and PA 1 respectively with respect to cisplatin which shows the IC 50 at 50 µM, 100 µM and 300 µM in Hela, PA 1, and A 549 respectively. After treatment with cisplatin and inorganic cooedination complex, Bax/Bcl-2 ratio was strongly up regulated in Hela cells and moderately elevated in A 549 and PA 1 cells. We demonstrate that a combination of anti proliferative measures such as delay in cell cycle progression, induction of apoptosis and generation of ROS act together to mediate the effects of cisplatin and the novel inorganic complex on cancer cells.

Conclusion: The present study showed that Hela is more sensitive than A 549 and PA1 to cisplatin and the novel inorganic complex. Although the novel inorganic complex is found to be more effective anticancer agent than cisplatin in case of A 549 when compared with the other two cell lines, Hela and PA1. These results have pointed out that cisplatin and the novel inorganic complex might exert chemopreventive effect through ROS generation and induction of apoptogenic signals via mitochondrial death cascade in human lung, cervical and ovarian carcinoma cells. The novel inorganic coordination complex is more effective anticancer agent in lung carcinoma cells when compared to cervical and ovarian cancer cells.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B16.
Abstract B17: PDL192, a humanized antibody to TweakR exhibits potent antitumor activity in pancreatic cancer models
Authors: Hylander Bonnie L. , Choi Donghee , Sho Mien , Chao Debra T. , Starling Gary C. , Culp Patricia A. , Repasky Elizabeth A.
Published: June 2012

Approximately 42,000 new cases of pancreatic cancer were diagnosed in the United States in 2009, and the 5-year survival rate for this disease is exceedingly low (approximately 5%). Given the lack of therapeutic success with current standards of care, new therapies are clearly needed to treat this disease. We have generated PDL192, a humanized IgG1 antibody to TweakR (Fn14, TNFRSF12A, CD266), a cell surface protein and member of the TNF receptor superfamily. PDL192 has been shown to exhibit antitumor activity in xenograft models on a range of solid tumor types via both direct tumor cell growth inhibition and by antibody-dependent cellular cytotoxicity. In this study, we explored the activity of PDL192 in pancreatic cancer models. Approximately 60% of primary pancreatic cancers express TweakR protein at high levels, as determined by immunohistochemistry. PDL192 exhibited potent anti-tumor activity in two cell line xenograft models, Panc1 and MiaPaCa2. PDL192 also exhibited significant anti-tumor activity against 3 of 6 primary tumor xenograft models derived from pancreatic patients. PDL192 was also tested in combination with gemcitabine, the most common treatment for pancreatic cancer patients. In the Panc1 and MiaPaCa2 xenograft models, the combination of PDL192 and gemcitabine exhibited more potent activity than either agent alone. In three of five primary tumor xenograft models tested, combining PDL192 and gemcitabine also resulted in greater anti-tumor activity than either agent alone. In one of the primary tumor models, where neither PDL192 nor gemcitabine alone exhibited significant anti-tumor activity, the combination completely inhibited tumor growth. The activity of PDL192 in multiple pancreatic xenograft models using both cell lines and primary tumors is supportive of the use of PDL192 for the treatment of pancreatic cancer. PDL192 is currently being evaluated in a phase1 safety study in patients with solid tumors.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B17.
Abstract B2: Alterations of p53, PTEN, and EGFR genes in glioblastoma multiforme
Authors: Bankovic Jasna , Milinkovic Vedrana , Rakic Miodrag , Jokovic Milos , Andjelkovic Tijana , Podolski-Renic Ana , Tanic Nikola , Ruzdijic Sabera
Published: June 2012

Glioblastomas are the most frequent and the most aggressive human brain tumors. Glioblastoma multiforme is one of the most intensively investigated human malignancy but the molecular mechanisms associated with the evolution of this type of tumor are still poorly understood. The aim of this study was to investigate alterations in EGFR oncogene and PTEN and p53 tumor supressor genes in 35 glioma specimen and to evaluate their role in glioma pathogenesis. DNA from tumor and blood of 35 patients with glioma was isolated and used to perform analysis of p53 mutational status using single-strand conformational polymorphism analysis (PCR- SSCP) and sequencing, evaluate loss of heterozigosity (LOH) in p53 and PTEN by fragment analysis, and to asseess EGFR gene amplification by differential PCR. Obtained results were further correlated with clinicopathological parameters. Loss of heterozygosity of PTEN was the most frequent alteration present in 62.86% of samples, followed by EGFR amplification detected in 40% of cases, while p53 gene was mutated in 28.57% of cases and inactivated by LOH in 20% of cases. All three genes were altered in 11.43% of samples, while 45.71 % of samples had only one of these three genes aberrant. We also identified 5 novel mutations in p53 that were not associated with brain tumors before. Correlation analysis indicated that p53 alterations were significantly associated with younger age (<50) and lower tumor grade in contrast to PTEN and EGFR. Concomitant PTEN inactivation and EGFR amplification appeared significantly more frequent in higher grade tumors. This suggests that p53 alteration could be an early event in tumor development, while PTEN inactivation and EGFR amplification may lead to tumor progression and therefore indicate a subgroup of patients with more aggressive disease. Further investigations, that are underway, including analysis of other genes involved in glioma pathogenesis, will enable us to gain more detailed insight into the glioma pathogenesis.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B2.
Abstract B21: CD1 d-expressing breast cancer cells promote iNKT-mediated antitumor immunity in a mouse model of breast cancer bone metastasis
Authors: Hix Laura M. , Shi Yihui H. , Stein Paul L. , Wang Chyung-Ru , Zhang Ming
Published: June 2012

Overcoming tumor tolerance and immune suppression remains a formidable obstacle to the development of immunotherapeutics that harness the immune system to eradicate breast cancer. We have developed a syngeneic mouse model to study mechanisms of tumor tolerance and immune suppression during breast cancer bone metastasis. Comparative analysis of low metastatic vs. highly bone metastatic tumor cells isolated from mice revealed several important genetic alterations related to immune control of tumor progression. Of these, a significant downregulation of cd1d1 was observed in the highly bone metastatic tumor cells. The cd1d1 gene in mice encodes the MHC class I-like molecule CD1d, which presents glycolipid antigens to a specialized subset of T cells that bridge the innate and adaptive immune response to cancer, known as invariant natural killer T (iNKT) cells. Activated iNKT cells mediate antitumor immunity in cell culture and in mouse models in vivo. Clinically, iNKT levels are significantly reduced in solid tumors, and this reduction is correlated with a poor prognosis in many types of cancers, including breast cancer. It is well known that the majority of advanced breast cancer patients present with bone metastases, and NKT cells have been shown to comprise a significant portion of the T cells found in healthy bone marrow. We hypothesize that downregulation of CD1d by breast cancer cells enables evasion of iNKT immune surveillance and inhibition of iNKT-mediated antitumor immunity, and may be an important prerequisite for the ability of breast cancer cells to colonize bone. In this study, we demonstrate in a mouse model of breast cancer bone metastasis that tumor cells expressing CD1d can induce direct iNKT-mediated cytolysis in a CD1d-dependent manner in vitro, and demonstrate increased CD1d-dependent iNKT-mediated antitumor immunity in vivo. Using transgenic knockout (KO) models, we show that the ability of CD1d-expressing tumor cells to metastasize to bone is dependent on the presence of CD1 d-restricted NKT cells. The results of this study further support research into therapeutic strategies that boost iNKT-mediated antitumor immunity for the treatment of advanced metastatic breast cancer. In addition, we propose the use of our novel mouse model of breast cancer bone metastasis as an ideal system for conducting further studies into mechanisms of immune regulation of breast cancer.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B21.
Abstract B22: Oncogenic MCT-1 upregulates EGFR expression through YY1 transcription factor that cooperatively prevents apoptosis
Authors: Lin Tai-Du
Published: June 2012

Multiple copies in T cell malignancy 1 (MCT-1) is an oncogene initially identified in a human lymphoid cell line. Constitutive expression of MCT-1 induces cell proliferation and activates survival pathways. We now demonstrate that MCT-1 upregulats epidermal growth factor receptor (EGFR) and Yin Yang 1 (YY1) proteins. EGFR modulates cell proliferation, differentiation, and survival. EGFR promoter function is modulated by YY1, a ubiquitously expressed, multifunctional zinc-finger transcription factor. By silencing of MCT-1, p53 is upregulated but EGFR and YY1 expressions are depressed. YY1 and EGFR levels are increased when the intrinsic p53 is abolished via shRNA interference, proving their counteraction relationship. Shedding YY1 levels in ectopic MCT-1 context, EGFR expression is repressed but p53 decline is attenuated. Intriguingly, upon NNK (tabacoo carcinogen) exposure advances ROS generation in ectopically expressed MCT-1 and EGFR conditions, but those cells still highly defy to apoptosis. Cooperative effect of MCT-1 and EGFR also more resist to apoptosis as counters with the oxidant in the gas phase of cigarette smoking, H2O2. Hence, MCT-1 inactivates p53 but stimulates YY1-mediated EGFR expression, subsequently prevents the oxidation-induced apoptosis. We prospect that the combination inactivation of MCT-1 and YY1 will undoubtedly develop new and improved targeted therapies for the cancers origin from EGFR deregulation.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B22.
Abstract B23: Dominant stablized ß-catenin induces adenomyosis formation and ablation of Mig-6 accelerates progress of adenomyosis formation
Authors: Shin Jung-Ho , Kim Tae Hoon , Large Michael J. , Cho Sung Nam , Oh Seo Jin , Lim Jeong Mook , Taketo Makoto M. , Broaddus Russell R. , Jeong Jae-Wook
Published: June 2012

Adenomyosis is a common gynecological disorder defined by the presence of endometrial glands and stroma within the myometrium. Despite its frequent occurrence, the precise etiology of adenomyosis is still unknown, although it has often been associated with endometrioid adenocarcinoma. β-catenin abnormalities are common in endometrioid type endometrial carcinomas. The expression of the dominant stabilized β-catenin in the murine uterus (PRcre/+ Ctnnb1f(ex3)/+) resulted in endometrial glandular hyperplasia. In addition to the glandular hyperplasia phenotype, uteri of PRcre/+ Ctnnb1f(ex3)/+ mice exhibited an abnormal myometrial structure and proceed to develop adenomyosis. Ablation of Mig-6 in the murine uterus (PRcre/+ Mig-6f/f) leads to the development of endometrial hyperplasia and estrogen-induced endometrial cancer. Concomitant stabilization of β -catenin and ablation of Mig-6 dramatically accelerated the development of adenomyosis and glandular hyperplasia compared to stablizing β-catenin alone. The adenomyosis phenotype of ovariectomized Pffre/+ Ctnnb1f<ex3)/+ and PRcre/+ Ctnnb1f(ex3)/+Mig-6f/f mice manifests in the presence of E2 and P4, but not, however, in the absence of ovarian hormones. Importantly, increased nuclear β-catenin expression and decreased MIG-6 expression was observed in women with adenomyosis, providing compelling support for and implicating an important role of β-catenin and MIG-6 in the etiology of adenomyosis in both humans and mice. We have demonstrated that abnormal activation of β-catenin induces adenomyosis formation and ablation of Mig-6 accelerates the progress of adenomyosis formation in the murine uterus. These mouse models are useful and allow us to investigate in detail the initiation and progression of adenomyosis because they mimic several features of human adenomyosis.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B23.
Abstract B25: Effects of co-injection of somatic cells on stem cell allograft success and differentiation
Authors: Park Jong-Heum , Oh Seo-Jin , Gong Seung-Pyo , Kim Bo-Yun , Ahn Ji-Yeon , Lim Jeong-Mook
Published: June 2012

Two consecutive experiments were conducted for understanding immunity, stemness, and tumorigenesis of the embryonic stem cells (ESCs) in their allograft. In the first series of experiment, we evaluated whether co-injection of the stem cells with somatic cells could evade the immune response. Donor B6CBAF1 mouse ESCs were subcutaneously co-injected either alone or with ovarian stromal cells, fetal fibroblasts, or adult fibroblasts isolated from the recipient B6D2F1 mouse strain. ESCs by themselves induced teratomas (14%). However, when somatic cells were injected together, ESC-mediated teratoma formation significantly increased (33-75%). Especially, the highest rate of the teratoma formation was observed in ESCs and fetal fibroblasts co-injected recipient B6D2F1 mice (75%). Next, we derived ESC-like, cancer stem cells from the teratomas with enzymatic digestion and their differentiation potential was subsequently evaluated. Except for one cell line, other all cell lines showed a similar morphology to that of original ESCs and retained alkaline phosphatase activity, ESC-specific gene expression (Oct-4, Nanog, Cripto, and Rex-1), and Oct-4 protein expression regardless of their increased abnormality in chromosome number. Relative quantification of lineage-specific gene (Nestin, SMA, Desmin, and Krt8) expression of teratoma-derived cell lines showed the significant changes between the ESCs and the teratoma-derived, ESC-like cells derived from the cell co-injection. Variations in the type of co-injected cells led to lineage-specific changes, changes in gene expression in isolated colony-forming cells, and alterations in stem-cell-like cells derived from allografted tissues. In conclusion, our results suggest that cell-to-cell interaction regulates cellular immunity for implanted cells, which further affects tumorigenesis and stemness [Supported by a grant (SC-5160) from Stem Cell Research Center of the 21st Century Frontier Research Program awarded by Jeong-Mook Lim]. Jong-Heum Park and Seo-Jin Oh contributed equally to this work.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):B25.