bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B17: Establishment, characterization and evaluation of a panel of patient-derived colorectal tumor models.
Authors: Wick Michael J. , Nieves Francis E. , Thangasamy Amalraj , Tolcher Anthony W. , Patnaik Amita , Drengler Ronald L. , Smith Lon S. , Garner Allison M. , Mangold Gina L. , Papadopoulos Kyriakos P.
Published: June 2012

Background: Patient-derived tumor models passaged only a few times in vivo retain physical and molecular characteristics of human cancer and may prove essential in identifying disease biomarkers and drug targets in later stage development. Currently we have collected tumor tissue from chemo-naïve and pretreated patients and established and characterized a panel of low passage colorectal tumor models.

Methods: For each model, tissue was implanted into immune-deficient mice and once established, each model was confirmed by histologic analysis and linked with donor patient treatment and outcome data. Model characterization including mutation profiling and drug sensitivity studies were performed and results compared with clinical patient information; each model was evaluated with the EGFR inhibitor cetuximab and two standard clinical therapies FOLFOX and irinotecan and compared with patient's drug sensitivity before and after tissue sample collection. Single agent tumor growth inhibition was evaluated and study endpoints included mean control tumor volumes of approximately 1 cm3 or up to sixty days following treatment initiation.

Results: Eighteen low passage colorectal models have been established and characterized. KRAS mutations were identified in 44% of models and activating mutations identified in some models include: PI3KCA (6%), TP53 (33%) and BRAF (6%). In vivo response to FOLFOX and irinotecan correlated to ≥65% of donor patient outcome to these treatments. Cetuximab sensitivity did not fully correlate with Ras mutation status as 4/6 wildtype and 4/8 Ras demonstrated cetuximab sensitivity in these studies.

Conclusion: We have generated a panel of low passage colorectal tumor models with differential mutation status and drug sensitivity profiles. Expansion of this panel of patient-derived tumors is planned and should further enhance its utility in identifying agents potentially useful for treatment of colorectal cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B17.
Abstract B192: Pharmacokinetic characterization of anti-ETBR antibody drug conjugate in preclinical species.
Authors: Zhang Crystal , Roth Leslie , Cook Ryan , Tsai Siao Ping , Qiu Julia , Nazzal Denise , Asundi Jyoti , Lin Kedan
Published: June 2012

Purpose. Anti-ETBR-MC-vc-PAB-MMAE (anti-ETBR-vc-E) is an antibody-drug conjugate (ADC) targeting the Endothelin B receptor. It comprises the humanized IgG1 anti-ETBR monoclonal antibody and a potent anti-mitotic agent, monomethyl auristatin E (MMAE), linked through MC-VC-PAB linker. Anti-ETBR antibody and its conjugate cross-react with mouse, rat, cynomolgus monkey and human, which provides an opportunity to compare and evaluate the impact of normal tissue expression on ADC disposition in preclinical species.

Methods. Anti-ETBR-vc-E was administered intravenously in mice (0.5 and 5 mg/kg), rats (0.5 and 5 mg/kg), and cynomolgus monkeys (0.3 and 1 mg/kg). The samples were assayed for total antibody and conjugated antibody concentrations in mice and rats while total antibody and antibody-conjugated MMAE concentrations were determined in monkeys. Concentration-time data were used to estimate the pharmacokinetic parameters.

Results. The pharmacokinetic behavior of the ADC was characterized by monitoring and comparing total antibody, conjugated antibody, and antibody-conjugated MMAE disposition. The clearances for all three analytes were dose-independent after intravenous administration in mice, rats, or cynomolgus monkeys over the dose range studied. Conjugated antibody and antibody-conjugated MMAE clearances were approximately 2-fold higher than total antibody clearance. Clearance of total antibody in rat was approximately 2-fold higher than in mouse and monkey, with values of 19.4, 7.91, and 8.99 mL/day/kg, respectively. Half-life ranged from 8 to 10 days and volume of distribution ranged from 37 to 40 mL/kg.

Conclusions. The pharmacokinetics of anti-ETBR-vc-E total antibody was dose proportional in rodents and monkey suggesting that the presence of cross-reactive antigen in the preclinical species had no impact on clearance. All three species showed a relatively higher deconjugation clearance compared to total antibody clearance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B192.
Abstract B200: Selective induction of CXCL8 signaling maintains viability in PTEN-depleted prostate cancer cells.
Authors: Maxwell Pamela J. , Coulter Jonathan , McKechnie Melanie , Kennedy Richard , Salto-Tellez Manuel , Albanese Chris , Waugh David J.
Published: June 2012

Background: PTEN loss is associated with early prostate cancer progression. We sought to characterize whether PTEN loss regulates pro-inflammatory chemokine signaling and its functional significance to PTEN-depleted prostate cancer cells.

Methods: Chemokine/chemokine receptor expression was assessed in vitro in established cell lines, exhibiting different levels of endogenous PTEN expression. Down-regulation of endogenous PTEN expression in DU145 and 22Rv1 cells was effected using transient siRNA or stable shRNA interventions. Chemokine expression was further evaluated by immunohistochemistry in prostate tissue from wild-type and PTEN+/− mice.

Results: Loss of PTEN induced transcription-mediated increases in expression of CXCL8 and its receptors, CXCR1 and CXCR1 in DU145 and 22Rv1 cells. Stress-induced expression of CXCL8, CXCR1 and CXCR2 was greater in magnitude and duration in PTEN-null PC3 and LNCaP cells, in contrast to the dampened response observed in PTEN-expressing cells. PTEN loss had no effect on basal or stress-induced expression of CCL2, CXCL12 or their receptors CCR2 or CXCR4 in prostate cancer cells. The efficacy of CXCL8 signaling upon HIF-1 and NF-B transcription was also greater in magnitude and duration in PTEN-null prostate cancer cells or following siRNA-mediated PTEN knockdown. Increased expression of the orthologous murine chemokine KC was elevated in atypical cytological features of PTEN+/− prostate tissue relative to normal epithelium in PTENWT glands. Attenuation of CXCL8 signaling using siRNA oligonucleotides or shRNA vectors in cell-based models of partial or complete PTEN-loss significantly decreased cell viability. Furthermore, attenuation of CXCL8 signaling modulates the response of PTEN-depleted prostate cancer cells to clinically-relevant doses of ionizing radiation.

Conclusion: PTEN loss promotes a selective up-regulation of CXCL8 signaling and increases the efficacy of CXCL8 signaling in prostate cancer cells. Functionally, this selective induction of CXCL8 signaling acts to maintain cell viability as an essential adaptation to the genetic instability arising from PTEN loss.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B200.
Abstract B205: Therapeutically targeting redundant, growth factor-induced prosurvival signaling with MM-141, a novel bispecific antibody targeting IGF-1R and ErbB3.
Authors: Lugovskoy Alexey , Johnson Bryan , Baum Jason , Adams Sharlene , Tang Jian , Kohli Neeraj , Rennard Rachel , Xu Lihui , Jiao Yang , Nilesen Ulrik , Fitzgerald Jonathan
Published: June 2012

Monoclonal antibodies have significantly advanced our ability to treat cancer, but most patients do not have durable responses to therapy. We find that the majority of tumor cell lines are responsive to activation by two or more growth factors. In particular cell lines grown in culture and in mice appear to frequently rely on Insulin-like growth factor 1 (IGF-1) and Heregulin (HRG) signaling to redundantly support their proliferation. Using a Network Biology approach, we have designed, constructed and optimized a novel bispecific antibody, MM-141, for simultaneous targeting and inhibition of ErbB3 and IGF-1R. MM-141 blocks IGF-1, IGF-2, and heregulin-induced AKT signaling, inhibits growth of multiple cancer cell lines, and is active in xenograft models of human pancreatic cancer (BxPC-3) and human prostate cancer (DU145). MM-141 does not bind the insulin receptor, thus strongly reducing the risk of metabolic side effects. MM-141 has favorable CMC and pharmacokinetic profiles and is being advanced into preclinical development. Taken together, these results suggest that MM-141 has the potential to be an effective therapeutic for treatment of patients with solid tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B205.
Abstract B211: Augmentation of Fas (CD95) signaling pathway sensitizes non-small cell lung cancer (NSCLC) cells.
Authors: Chiu Huan-Chih , Huang Chin-Ting , Chang Teng-Yuan , Hsu John T.-A.
Published: June 2012

Epidermal growth factor receptor (EGFR) is a proven therapeutic target to treat a subset of NSCLC harboring activating mutations within the EGFR gene. However, many NSCLC patients are not sensitive to EGFR kinase inhibitors, suggesting that other factors may play a role in determining survival of NSCLC cells. Signal transducers and activators of transcription 3 (Stat3) functions as a transcription factor to mediate cell survival and differentiation and the dysregulation of Stat3 has been described in numbers of cancers. Our previous report showed that suppression of Stat3 activity by a pharmacological approach, WP1066, sensitized NSCLC cells. Along with Stat3 inhibition, we also found that WP1066 treatment up-regulated the expression of Fas, a death receptor, regulating numbers of physiological and pathological process of cell death. Although Fas-mediated apoptosis pathway has been studied mostly in the immune system, the identification of Fas mutations in non-lymphoid malignancies, such as NSCLC, suggests its implication in the pathogenesis of non-lymphoid malignancies as well. Results from this study showed that levels of Fas were increased in cells with down-regulated Stat3 by small interfering RNA (siRNA), suggesting that Stat3 may play an inhibitory role to regulate the expression of Fas. To examine whether the Fas pathway is responsible for the WP1066-mediated cytotoxicity, Fas apoptosis signaling was induced by anti-Fas antibody and Fas ligand. Our results revealed that NSCLC cells showed different degrees of sensitivity to anti-Fas antibody but resistance to Fas ligand. However, augmentation of Fas expression by WP1066 remarkably increased the sensitivity of NSCLC cells to both anti-Fas antibody and Fas ligand. Taken together, our findings suggest that regulation of the Fas system may be a potential strategy to treat NSCLC and the combined use of a Fas inducer, such as WP1066, may further strengthen its efficacy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B211.
Abstract B244: The small molecule focal adhesion kinase inhibitor Y15 decreases human glioblastoma cell viability, clonogenicity, and tumor growth.
Authors: Golubovskaya Vita M. , Grace Huang , Ho Baotran , Yemma Michael , Morrison Carl , Song Liu , Hu Qiang , Cance William
Published: June 2012

Introduction: Glioblastomas are the third most frequent cause of cancer-associated deaths due to the cancer cell rapid growth and high invasion and novel therapeutic approaches are needed for this disease. Focal adhesion Kinase (FAK) is known to be highly expressed and activated in glioblastoma and plays significant role in tumorigenesis.

Experimental procedures: In this report we tested FAK autophosphorylation inhibitor, Y15 (called also Inhibitor 14) or 1,2,4,5-Benzenetetraamine tetrahydrochloride) that specifically decreased Y397-FAK autophosphorylation in DBTRG and U87 glioblastoma cells. To test Y15 we used the following in vitro assays: viability, clonogenicity, detachment, apoptosis, invasion, immunostaining, Western blotting and microarray analysis of gene expression; and in vivo assay: xenograft tumor growth model.

Results: Y15 significantly decreased viability and clonogenicity of DBTRG and U87 cells in a dose-dependent manner. Y15 inhibitor increased detachment, apoptosis and inhibited cell invasion in a dose-dependent manner. In addition, Y15 decreased autophosphorylation of FAK in a dose-dependent manner and changed cell morphology by causing cell rounding in DBTRG and U87 cells. Moreover, we tested the effect of Y15 on gene expression by Illumina Human HT12v4 microarray assay and among 34, 694 genes affected by Y15 there we 8087 and 6555 genes either up- or down-regulated in DBTRG and U87 cells, respectively (p<0.05). Moreover, Y15-treated DBTRG and U87 cells changed expression of 237 common genes more than 1.5 fold, p<0.05 that play role in survival signaling, cell growth and motility. In addition, combination of temozolomide with Y15 significantly decreased viability and clonogenicity in both cell lines. In addition, Y15 inhibitor delivered orally significantly decreased DBTRG xenograft tumor growth. The tumors from Y15-treated mice expressed decreased Y397-FAK autophosphorylation, activated PARP and caspase-3.

Conclusion: Inhibition of FAK autophosphorylation with the oral small molecule inhibitor Y15 can be an effective therapy approach to block glioblastoma tumor growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B244.
Abstract B39: Action of EC8042 in triple-negative breast cancer.
Authors: Pandiella Atanasio , Montero Juan Carlos , Cuenca-Lopez Lolin , Re-Louhau Florencia , Moris Francisco , Ocana Alberto
Published: June 2012

Breast cancer represents one of the most common tumoral pathologies in women. Although continuous advances in its treatment have improved its outcome, in the metastatic setting the disease still represents an important medical problem. For this reason, the incorporation of novel therapies is required. Immunohistochemical characterization of breast cancers led to their division into three main subtypes: hormone receptor positive, HER2 positive, or triple negative breast cancers. Triple negative breast cancers (TNBC) are characterized by the absence of hormonal and HER2 receptors, and represents around 15% of all breast tumors. TNBC are aggressive from the clinical perspective, and their therapy is mainly based on classical chemotherapeutic agents, with limited success in the metastatic setting. Here we have explored the action of a novel drug, named EC8042, in TNBC. The drug, which is a mithramycin derivative, decreased MTT uptake of several TNBC cell lines. The IC50 values obtained were in the nM range, indicating that the drug had a potent effect on these cell lines. Mechanistically, the drug caused accumulation of cells in the S phase of the cell cycle at doses of 100 and 500 nM in the cell lines HBL100 and MDA-MB231. Biochemically, EC8042 caused an increase in cyclin E, cyclin A, cyclin D3, cyclin B, and p27, and decreased cyclin D1 and Rb phosphorylation at serine 780. These data are consistent with an action of EC8042 on the cell cycle. Moreover, the increase in wee1 and pY15-CDK1 are in line with an effect of the drug blocking cell cycle progression through the S phase. Cell cycle analyses using propidium iodide staining also revealed an increase in the subG0 proportion of cells, especially in HBL100, suggestive of a potential indiction of cell death by EC8042. Annexin V staining indicated that treatment of HBL100 with 500 nM of EC8042 provoked apoptosis, which was also revealed by PARP processing. The treatment reduced the amounts of MCL1, BCLXL, and XIAP, but did not affect BCL2 levels. Together, our results indicate that EC8042 has a strong antitumoral action on TNBC cells, which is caused by increased apoptosis and a decrease in cell cycle progression, and opens the possibility for further development of this drug in TNBC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B39.
Abstract B40: The melphalan prodrug melphalan-flufenamide shows cytotoxic effect in bladder cancer cell lines and triggers JNK and caspase-3 mediated apoptotic signaling.
Authors: Juntti Therese , Zakharchenko Olena , Haag Petra , Zong Dali , Laitinen Sara , Larsson Rolf , Spira Jack , Lewensohn Rolf , Viktorsson Kristina , Ullen Anders
Published: June 2012

Background: Bladder cancer is the 4th most common cancer associated death in men in the western world. Cisplatin-based polychemotherapy (1st line) and vinflunine (2nd line) are the only chemotherapy regimens which show survival benefit in patients with metastatic disease. Hence, there is a major need to identify new effective treatment alternatives for patients with this disease. We have developed a prodrug of melphalan, Melphalan-flufenamide (Mel-flufen) which show enhanced cytotoxic efficacy compared to melphalan in several tumour types. Treatment with Mel-flufen gives 10–20 fold higher intracellular drug levels compared to the same dose of melphalan. Mel-flufen is currently undergoing Phase I/II clinical trials. Here we studied if this drug might be a useful in bladder cancer by analyzing its effects in a panel of bladder cancer cell lines.

Material and Methods: The bladder cancer cell lines J82, RT4, 5637 and TCC-SUP were profiled for Mel-flufen and melphalan sensitivity using MTT and FMCA cell viability assay. Mel-flufen signaling was measured as caspase-3 and Bak/Bax activation in flow cytometry and PARP cleavage, JNK phosphorylation, p53 and p21WAF1/Cip1 induction on western blot respectively.

Results: Mel-flufen caused a dose and time dependent inhibition of cell growth in all the four bladder cancer cell lines studied. Comparison with the parental drug revealed an enhanced cytotoxic effect of Mel-flufen at equimolar doses. Molecular profiling of the apoptotic response showed that Mel-flufen induced activation of the Bcl-2 proteins Bak and Bax followed by caspase-3 activation and induction of apoptotic morphology. Albeit Mel-flufen induced activation of p53, the cytotoxic effect was not dependent on p53 as it was also observed in p53-mutant bladder cancer cell lines. A prominent activation of JNK1/2 was observed in response to Melflufen. Importantly, this JNK activation preceded induction of Melflufen-induced apoptotic signaling and was critical for the induced cytotoxicity in these bladder cancer cell lines.

Conclusion: Our data demonstrate that the melphalan prodrug Mel-flufen significantly inhibits bladder cancer cell growth in vitro. Importantly, we show that Mel-flufen is more efficient in inhibiting bladder cancer growth than the parental drug melphalan and causes a more pronounced apoptotic signaling. Taken together these data suggests that Mel-flufen may be a good candidate for bladder cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B40.
Abstract B5: Tumor-cell-induced angiopoietin-2 secretion from endothelial cells results in destabilization of the endothelial/smooth muscle cell interaction of blood vessels.
Authors: Molnar Nikolett , Siemann Dietmar W.
Published: June 2012

The angiopoietin-Tie2 axis is considered to be a key contributor in tumor associated angiogenesis. Angiopoietin-2 (Ang-2) is an endothelial cell secreted protein that is upregulated by angiogenic stimuli that leads to vessel destabilization by facilitating the disruption of cell-cell contacts between endothelial and periendothelial cells (ie. smooth muscle cells) in the vasculature. Ang-2 is stored in Weibel-Palade bodies and quickly secreted by stimuli such as hypoxia and inflammation; conditions commonly found in solid tumors. In the present study, the effect of renal cell carcinoma tumor cells (Caki-1, Caki-2) on endothelial cell secretion of Ang-2 and the ability to destabilize endothelial-smooth muscle cell co-culture spheroids was evaluated. As anticipated, enzyme-linked immunosorbent assay (ELISA) showed only minimal Ang-2 secretion from Caki tumor cells; 0.02 ng/ml (Caki-1) and 0.005 ng/ml (Caki-2). However, stimulation of endothelial cells with Caki conditioned media showed high levels of Ang-2 secretion from endothelial cells; 1.9 ng/ml (Caki-1) and 3.6 ng/ml (Caki-2), a 95-fold and 720-fold increase respectively. Furthermore, a greater increase in the level of Ang-2 secretion was observed when endothelial cells were stimulated with Caki cells maintained under hypoxic conditions; 3.5 ng/ml (Caki-1) and 5.5 ng/ml (Caki-2), a 1.8-fold and 1.5-fold increase, respectively, compared to cells maintained under normoxic conditions. When media collected from Caki-1 and Caki-2 cells were added to endothelial-smooth muscle cell co-culture spheroids, endothelial cells were rapidly lost from the smooth muscle cell core. Consistent with the levels of Ang-2 secretion, media collected from Caki-2 cells had a greater effect on endothelial cell dissociation from the co-culture spheres than did media from Caki-1 cell culture. This endothelial cell loss was further enhanced when co-culture spheres were exposed to media derived from tumor cell cultures maintained under hypoxic conditions. Using an in vitro endothelial-smooth muscle cell co-culture sphere model we demonstrate that tumor cells can modulate endothelial cell Ang-2 secretion and thereby destabilizing the endothelial cell/smooth muscle cell association of blood vessels. These results support a rationale for targeting Ang-2 as a novel anti-angiogenic strategy in cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B5.
Abstract B58: Phase I study of the IGF-1R antibody ganitumab (AMG 479) in combination with everolimus in patients with advanced solid tumors.
Authors: Vlahovic Gordana , Meadows Kellen , Arrowood Christy , Meadows Jennifer , Morse Michael , Uronis Hope , Riedel Richard , Crawford Jeffrey , Zafar S. Yousuf , Hurwitz Herbert
Published: June 2012

Background: Preclinical data suggests the combination of IGF-1R inhibitor Ganitumab and mTOR inhibitor everolimus may increase anti-tumor activity compared to each agent alone. Therefore we evaluated the maximum tolerated doses/recommended phase II dose for the doublet combination, Ganitumab (G) plus Everolimus (E) followed by an expanded cohort to better understand the safety and tolerability profile.

Methods: For dose escalation, eligible patients had advanced solid tumors with adequate organ function and no increased risk for class-related toxicities. G was given intravenously, and E was orally administered; cycle length was 28 days. G was dosed at 12 mg/kg every 14 days; E was dosed at 5 mg daily in cohort one and 5 mg three times weekly in cohort −1. An intermediate dose of E at 5 mg five times weekly was added to better maximize dose intensity. Dose limiting toxicity (DLT) was assessed in cycle 1.

Results: Dose escalation is complete with 17 subjects evaluable for DLT toxicity and 16 evaluable for efficacy. Two out of 5 subjects experienced DLTs in cohort one due to dose holdings related to grade 3 hematologic toxicities: thrombocytopenia and neutropenia plus thrombocytopenia. No DLTs were observed out of 6 subjects in cohort −1; one DLT was observed out of 6 subjects in the intermediate cohort due to dose holding related to grade 2 intolerable skin rash and oral mucositis. Possible grade 3 treatment-related adverse events included neutropenia, thrombocytopenia, elevated AST/ALT, hypertriglyceridemia, vomiting and erythema multiforme minor. There were no grade ≥4 treatment-related toxicities. One non treatment- related death was due to disease progression. Two subjects had clinically significant skin rashes which resulted in protocol discontinuation. Twelve subjects have available efficacy data; 4 subjects have not yet been restaged. Two subjects with refractory NSCLC achieved a complete response. Six additional subjects had stable disease as best response.

Conclusion: The recommended phase II dose for this doublet combination is G at 12 mg/kg every two weeks and E at 5 mg five times weekly. At this dose, this novel regimen is well-tolerated with potential activity in NSCLC. Enrollment in the expanded cohort has started.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B58.
Abstract B67: Correlation of pharmacokinetics (PK), pharmacodynamics (PD) and in vivo antitumor activity of BMN 673 in preclinical models.
Authors: Feng Ying , Shen Yuqiao , Musson Don , Zhou Huiyu , Scholler Oriane , Post Leonard E.
Published: June 2012

Poly (ADP-ribose) polymerase (PARP) inhibitors are emerging as an exciting class of novel chemotherapeutic agents for the treatment of cancers with specific DNA-repair defects, such as homologous recombination (HR) deficiency as a result of mutations of the BRCA genes. We have developed a specific, orally active PARP-1 and -2 inhibitor, BMN 673, that is highly potent in blocking PARP-1 enzyme activity (IC50 = 0.57nM) and can selectively kill tumor cells harboring BRCA1 and BRCA2 mutations (ED50 = 0.3 nM for BRCA1−/− MX-1 cells). Inhibition of PARP enzyme activity is associated with decreased intracellular PARylated proteins (PAR), thus PAR is selected as pharmacodynamic (PD) marker to monitor PARP inhibitor activities in preclinical models. Here we describe the pharmacokinetics (PK) of BMN 673 in a mouse model during 14-day repeat oral daily administration and the antitumor efficacy of BMN 673 in MX-1 xenograft mouse model, suggesting BMN 673 is a highly potent anti-cancer agent in vivo. In addition, a rat PK/PD study was conducted with BMN 673 at 0.3, 0.1 and 0.03 mg/kg, both in single dose and in 5-day repeat daily dose. Various rat tissues including bone marrow, muscle, and peripheral blood mononuclear cells (PBMCs) were harvested after BMN 673 exposure to examine tissue PAR levels or PAR formation from PBMCs using a sensitive functional PD assay. Corresponding plasma samples were also collected to monitor BMN 673 drug level. The PK/PD results demonstrated that BMN 673 was effective at blocking PARP activity in vivo at the lowest dose tested (0.03 mg/kg), and the tissue PAR level (PARP inhibition) is correlated with BMN 673 dose and plasma exposure. BMN 673 is currently being evaluated in Phase I clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B67.
Abstract B76: In vitro screen to identify ALK mutations conferring crizotinib resistance.
Authors: Nicolas Jean-Paul , Dassencourt Laurent , Herve Francoise , Wolfrom Meredith , Lennon Amanda , Delarbre Laure , Hoffmann Dietmar , Leroy Vincent , Calvet Loreley , Garcia-Echeverria Carlos , Valtingojer Iris
Published: June 2012

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase belonging to the insulin receptor superfamily. Activating mutations in ALK are oncogenic and cause 10 to 15% of neuroblastoma cases. Similarly, activating ALK fusions have been detected in several cancers, including ALCL (NPM-ALK in 70% of patients) and NSCLC (EML4-ALK in 3–7% of patients). ALK inhibitors from different compound classes and kinase selectivity profiles are currently undergoing clinical development, among which crizotinib has recently received marketing approval from the US FDA. This non-selective ALK inhibitor has provided clinical benefit to lung cancer patients, but its sustained efficacy seems to be impaired by acquired drug resistance and several publications have already described ALK secondary mutations identified in patients who progressed while on crizotinib therapy. In this study, we have used the Ba/F3 system to identify EML4-ALK mutations able to confer resistance to crizotinib. To this end, we have generated a cDNA library containing random mutations in EML4-ALK using an E. Coli strain deficient in DNA repair pathways. The library was then subcloned in a retroviral vector and used to infect Ba/F3 cells. The cells were plated in 96 well microplates at an appropriate dilution and allowed to grow in the presence of 500 nM of crizotinib. The resistant cells were cultured and EML4-ALK was sequenced.

Overall, this screen identified mutations at 24 positions in the ALK kinase domain. Some of these mutations (L1152R, C1156Y, F1174L) correspond to the ones known to cause resistance in lung cancer patients treated with crizotinib. Ba/F3 cell lines stably expressing a selected number of the 24 mutations have been generated and used to evaluate the activity of in-house and reference ALK kinase modulators. This work has shown that several mutations known to activate ALK in neuroblastoma are also able to confer resistance to crizotinib.

The Ba/F3 cell lines expressing EML4-ALK mutants have been useful tools to characterize the activity profile of a range of ALK kinase inhibitors and several of our in-house compounds have been identified as active against the crizotinib-allele resistant mutants.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B76.
Abstract B87: Multiplexed, bioluminogenic probes for evaluating histone deacetylase inhibitor efficacy and safety.
Authors: Somberg Richard L. , Evans Nathan , Kirkland Thomas , Niles Andrew
Published: June 2012

Aberrant epigenetic modifications are known to contribute to hematological and solid cancer malignancies. Members of an important class of chromatin modifying enzymes, histone deacetylases (HDACs), have been found to be dysregulated in many tumor types. Their specific contribution to oncogenesis is unknown, but numerous studies have linked increased HDAC inhibition to transcriptional repression of gene expression, cell cycle checkpoint activation and other tumor suppression activities. Therefore, HDAC inhibitors (HDACi) are an emerging and important class of modulators for use as single agents or in combination with other anti-neoplastics. Many current HDACi have undesirable off-target toxicities, which may be related to inhibition of specific HDAC isozymes that are required for normal cellular function. In an effort to rapidly and efficiently understand the beneficial and detrimental effects of new HDACi within a cellular context, we have developed a set of selective and pan-active bioluminogenic assay probes for evaluating the effects of HDACi. When multiplexed with same well fluorescent viability and cytotoxicity assays, these probes provide a functional readout of HDACi on-target efficacy and off-target safety in primary or cancer cell models.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B87.
Abstract C10: Class III β -tubulin predicts pathological response to neoadjuvant docetaxel-based chemotherapy in breast cancer patients.
Authors: Moon Yongwha , Koo Ja Seung , Han Hyunju , Park Byeong-Woo , Kim Seung Il , Park Seho , Chung Hyun Cheol , Kim Joo-Hang , Sohn Joo Hyuk
Published: June 2012

Background: Class III β-tubulin has been suggested as a potential predictor of taxane response for several cancers including breast cancer, although controversies exist. We evaluated correlations between class III β-tubulin and docetaxel response in neoadjuvant setting of breast cancer, focusing on pathological response which is considered the most powerful predictor of outcome.

Materials and Methods: Fifty-five patients with primary breast cancer who had undergone neoadjuvant doxetaxel and adriamycin were included in this study. Class III β-tubulin was measured by immunohistochemistry in prechemotherapy paraffin-embedded tumor tissues. The cutoff value of ‘high’ and ‘low’ expression of class III β-tubulin was set at 50% of tumor cell staining. ‘Good pathological response’ was defined by pathological complete response (pCR) or microscopic residual disease (i.e., breast tumor ≤1cm and negative axillary node). The counterpart was designated as ‘poor pathological response’.

Results: Before chemotherapy, 14 patients were in clinical stage II and 41 were in clinical stage III. After the median 4 cycles of preoperative chemotherapy, clinical downstaging was observed in 40 patients whereas clinical staging did not change in the remaining patients. Eleven patients (20%) showed good pathological response (pCR, 6; microscopic residual disease, 5) and 44 (80%) showed poor pathological response. Thirty-six (65.5%) and 19 patients (34.5%) were categorized into low and high class III β-tubulin groups, respectively. Low class III β-tubulin was associated with low histologic grade (P=0.052). However, in multivariate logistic regression adjusted by known prognostic factors including histologic grade, low expression of class III β-tubulin (hazard ratio = 11.1; P = 0.049) and triple negative status (hazard ratio = 6.86; P = 0.022) were independent predictors of good pathological response. At the median follow-up of 40.8 months after surgery, recurrence occurred in 11 patients (5 in low class III β-tubulin group; 6 in high). Low expression of class III β-tubulin showed a favorable risk of relapse (P=0.152) which did not reach statistical significance probably due to short follow-up period.

Conclusions: Low expression of class III β-tubulin by immunohistochemistry predicts good pathological response to neoadjuvant docetaxel in breast cancer, suggesting implications for improving chance to define docetaxel-beneficial group in this setting.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C10.
Abstract C108: An expanded imaging cohort of pazopanib in children and adolescents with relapsed or refractory soft tissue sarcoma (ADVL0815): A Children's Oncology Group phase I consortium trial.
Authors: Glade-Bender Julia , Khrichenko Dmitry , Voss Stephan , Lee Alice , Ingle Ashish Mark , Ahern Charlotte H. , Weigel Brenda , Blaney Susan , Roberts Timothy
Published: June 2012

Background: Pazopanib (NCT00929903) is an orally available small molecule inhibitor of VEGFR 1–3, PDGFR α/β, and c-kit, which has been shown to prolong progression free survival in adults with soft tissue sarcoma (STS). Following a standard phase I dose escalation trial to determine the pediatric maximum tolerated dose (MTD), an expanded cohort of children and adolescents with relapsed and refractory STS and at least one lesion amenable to dynamic contrast enhanced MRI (DCE-MRI) was studied to explore changes in tumor blood volume and vascular permeability following initiation of pazopanib, and to correlate these changes with clinical outcome.

Methods: Oral pazopanib was administered at 450mg/m2 once daily in 28 day cycles, for up to 24 cycles. DCE-MRI scans were obtained at baseline and within 15 × 2 days after initiation of pazopanib. DCE-MRI data sets were analyzed using a two compartment kinetic model yielding estimates of fractional blood volume and the permeability transfer constant (Ki).

Results: 10 subjects were enrolled [5 male; median age 17 yrs (range, 8–23)], of whom 8 had paired DCE-MRI scans of sufficient quality to be evaluable. Subjects received a median of 4 cycles (range 1–7; 3 remain on study receiving courses 6, 7 and 8). One subject had a dose limiting toxicity of Gr3 back and extremity pain with Gr3 sensory neuropathy. Other non-dose limiting toxicities occurring in >10% of subjects (n=10) during the first cycle included mild myelosuppression, sinus bradycardia, fatigue, diarrhea, nausea, vomiting, anorexia, dehydration, dizziness, headache, liver transaminase elevation and hyperglycemia. All subjects with evaluable DCE-MRI (n=8) experienced a decrease in tumor blood volume following initiation of pazopanib, with a mean pre-treatment level of 16% (range 1–29%) versus 7% (0–15%) post-treatment (p<0.01). Similarly all subjects had a decrease in Ki with mean pretreatment values of 7.74 (range 2.31–20.38) ml/100g/min, decreasing post-treatment to 4.28 (range 0.19–12.60) ml/100g/min (p<0.01). Although limited by the small sample size, there is a suggestion that patients with best response of stable disease appear to have lower tumor blood volume at baseline than those with progressive disease.

Conclusions: DCE-MRI changes in tumor blood volume and Ki in pediatric and adolescent patients with soft tissue sarcoma are supportive of physiological activity and the antiangiogenic mechanism of pazopanib.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C108.
Abstract C109: Association of TP53 gene polymorphism with response to platinum-based doublet chemotherapy in non-small cell lung cancer patients.
Authors: Shiraishi Kouya , Kunitoh Hideo , Tanai Chiharu , Goto Yasushi , Yamamoto Seiichiro , Nokihara Hiroshi , Yamamoto Noboru , Sekine Ikuo , Ohe Yuishiro , Tamura Tomohide , Yokota Jun , Kohno Takashi
Published: June 2012

Here we show that TP53 SNP is involved in chemotherapeutic responses in non-small cell lung cancer (NSCLC) patients. To identify polymorphisms in DNA repair genes that affect responses to platinum-based doublet chemotherapy, 640 NSCLC patients, who received platinum-based doublet chemotherapy and whose responses were evaluated by the Response Evaluation Criteria in Solid Tumors, were subjected to an association study between the response and genotypes for 30 SNPs in 27 DNA repair genes. Candidate SNPs were selected by screening of a discovery set of 201 cases and their associations were validated in an independent set of 439. Homozygotes for the TP53–72Pro allele of the TP53-Arg72Pro SNPs showed a better response rate (54.3%) than those for the TP53–72Arg allele (29.1%), and TP53–72Pro allele homozygotes had significantly longer progression-free and overall survivals than TP53–72Arg allele homozygotes. Minor allele carriers for a SNP, Lys940Arg, in the PARP1 (poly ADP-ribose polymerase 1) gene showed a better response rate to the regimen using paclitaxel (45.8%) than to the regimen using gemcitabine (10.5%). These results indicate that polymorphisms in the TP53 and PARP1 genes are involved in inter-individual differences in the response to platinum-based doublet chemotherapy in NSCLC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C109.
Abstract C112: Debrisoquine as a model substrate of the organic cation transporter OCT1.
Authors: Saadatmand Ali R. , Brockmoller Jurgen , Tzvetkov Mladen V.
Published: June 2012

Organic cation transporters are involved in the cellular uptake of chemotherapeutic drugs like cisplatin, oxaliplatin and imatinib. We have also shown that genetic polymorphisms in the liver-specific organic cation transporter OCT1 may affect pharmacokinetics and efficacy of supportive care drugs like the antiemetics ondansetron and tropisetron or the opioid tramadol. Here we tested whether debrisoquine, a model drug used to phenotype CYP2D6 activity, is a substrate of the liver-specific organic cation transporter OCT1 and whether genetic polymorphisms in OCT1 affect debrisoquine cellular uptake.

We measured the inhibition of OCT1 by debrisoquine and OCT1-mediated uptake of debrisoquine using HEK293 cells genetically engineered to overexpress wild type or loss-of-function OCT1 isoforms. We overexpressed OCT1 isoforms carrying the common loss-of-function amino acids substitutions in Caucasians Arg61Cys, Cys88Arg, Gly401Ser, Gly465Arg or deletion of Met420. Debrisoquine inhibited the uptake of the model OCT1 substrate MPP+ with IC50 below 10 μM. Debrisoquine uptake was significantly increased both in time and in concentration dependent manner in cells overexpressing wild-type OCT1 (KM of 5.9 ×1.5 μM and vMAX of 41.9 ×4.5 pmol/min/mg protein). OCT1-mediated uptake of debrisoquine was reduced or missing in cells expressing the common loss-of-function isoforms. The deletion of Met420 and the substitutions of Arg61Cys and Gly401Ser reduced vMAX by 48, 63 and 91%, respectively, but did not affect the Km of the OCT1-mediated debrisoquine uptake. The OCT1 isoforms carrying Cys88Arg or Gly465Arg substitutions completely lacked OCT1-mediated debrisoquine uptake.

In conclusion, debrisoquine is a substrate of OCT1 and common loss-of-function OCT1 polymorphisms affect debrisoquine uptake. Debrisoquine has a potential to be used as phenotyping marker for OCT1 activity. Moreover, known in vivo variations in debrisoquine pharmacokinetic and their relation to development of lung and bladder cancer may be related to variation not only in CYP2D6, but also in OCT1 activity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C112.
Abstract C143: Combining siRNAs targeting thymidylate synthase and thymidine kinase 1 or 2 sensitizes human tumor cells to 5FUdR and pemetrexed.
Authors: Cresce Christine Di , Figueredo Rene , Ferguson Peter J. , Vincent Mark D. , Koropatnick James
Published: June 2012

Thymidylate synthase (TS) is the only de novo source of thymidylate (dTMP) for DNA synthesis and repair. Drugs targeting TS protein are a mainstay in cancer treatment, but off-target effects and toxicity limit their use. Cytosolic thymidine kinase (TK1) and mitochondrial thymidine kinase (TK2) contribute to an alternative dTMP-producing pathway, by salvaging thymidine from the tumor milieu, and may modulate resistance to TS-targeting drugs. Combined downregulation of these enzymes is an attractive strategy to enhance cancer therapy. We have previously shown that antisense targeting TS enhanced tumor cell sensitivity to TS-targeting drugs in vitro and in vivo. As both TS and TKs contribute to increased cellular dTMP, we hypothesized that TKs mediate resistance to the capacity of TS siRNA to sensitize tumor cells to TS-targeting anticancer drugs. We assessed the effects of targeting TK1 or TK2 with siRNA alone and in combination with siRNA targeting TS and/or TS-protein targeting drugs on tumor cell proliferation. Downregulation of TK with siRNA enhanced the capacity of TS siRNA to sensitize tumor cells to traditional TS protein-targeting drugs (5FUdR and pemetrexed). The sensitization was greater than that observed in response to any siRNA used alone, and was specific to drugs targeting TS. Upregulation of TK1 in response to combined 5FUdR and TS siRNA suggests that TK knockdown may be therapeutically useful in combination with these agents. TKs may be useful targets for cancer therapy when combined with molecules targeting TS mRNA and TS protein.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C143.
Abstract C146: In human lung carcinoma cells that contain estrogen receptor-α(ER), thyroid hormone-induced proliferation initiated at an integrin requires ER.
Authors: Meng Ran , Tang Heng Yuan , Mousa Shaker A. , Luidens Mary K. , Davis Faith B. , Davis Paul J. , Lin Hung Yun , Hercbergs Aleck A.
Published: June 2012

We examined the molecular basis of thyroid hormone-induced proliferation of two estrogen receptor-α (ER)-expressing human lung cancer cell lines, non-small cell carcinoma NCI-H522 and small cell carcinoma NCI-H510A. At a physiologic total L-thyroxine (T4) concentration (10[−7] M) and supraphysiologic 3,5,3'-triiodo-L-thyronine (T3) levels, thyroid hormone significantly increased proliferating cell nuclear antigen (PCNA) content of both cell lines. Neutralizing antibody to integrin αvβ3 and integrin-binding Arg-Gly-Asp (RGD) peptide inhibited cell proliferation stimulated by thyroid hormone. Tetraiodothyroacetic acid (tetrac) blocks binding of T4 and T3 to the hormone receptor on αvβ3 and inhibited thyroid hormone-induced cancer cell proliferation. Thus, the thyroid hormone effect is initiated nongenomically at the cell surface thyroid hormone receptor we have described on integrin αvβ3. The thyroid hormone isoforms also caused serine phosphorylation of ER in NCI-H522 and NCI-H510A cells. The ER antagonist, ICI 182,780 (fulvestrant) inhibited stimulation by T4 and T3 of ER phosphorylation, of PCNA accumulation and of radiolabeled thymidine incorporation by the cells. These results are consistent with existence of crosstalk between the plasma membrane receptor for iodothyronines and ER in these lung cancer cells. We conclude that endogenous T4 is a growth factor for ER-containing lung cancer cells and this hormonal action is subject to inhibition by tetrac and by fulvestrant.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C146.