bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A195: A population pharmacokinetic (PPK) model of bosutinib (BOS).
Authors: Hsyu Poe-Hirr , Mould Diane , Abbas Richat , Pearce Stuart , Amantea Michael
Published: June 2012

BOS is an orally active, dual Src/Abl kinase inhibitor. BOS has demonstrated efficacy and acceptable safety in patients (pts) with Philadelphia chromosome-positive (Ph+) leukemia. A PPK model was developed for BOS using pooled clinical data from a phase 1 trial of pts with advanced solid tumors given BOS 50 to 600 mg/d with food; a phase 1/2 trial of pts with tyrosine kinase inhibitor-resistant/intolerant Ph+ leukemia given BOS 400 to 600 mg/d with food; and a phase 3 trial of pts with newly diagnosed Ph+ chronic phase chronic myeloid leukemia given BOS 500 mg/d with food. 870 pts contributed to the PK analysis (typically 6–9 PK samples/pt). Pts were aged 18 to 91 y and weighed 35 to 221 kg. The final BOS PPK model was a 2-compartment model with first-order absorption and an absorption lag. PPK parameters were estimated with acceptable precision (see Table). The volume of the peripheral compartment was large with a slow turnover, and time to peak concentration was 5 to 6 h. The estimated alpha half-life was 19 h, with 68% and 32% of area under the curve (AUC) attributable to the alpha and beta half-lives, respectively. Residual unexplained variability was 30% at doses ≤100 mg and 32% at doses >100 mg. Dose-dependency in relative bioavailability (F) was seen, mostly at lower doses. PPK showed high inter-individual variability (IIV), consistent with high variability in BOS absorption. The lower F inferred for low doses could be accounted for by saturable active transport of bosutinib into the gut lumen, which shows more variability than absorption by passive diffusion. Baseline demographics and lab results could not account for the high IIV, and adjusting the BOS dose for body size was not beneficial. Model simulations showed that median AUC and peak concentration (Cmax) at steady-state were 4,322 ng/mL•h and 215 ng/mL, respectively, for BOS 500 mg/d. Within individuals, differences between peak and trough concentrations were relatively small, with a population fluctuation ratio (Cmax/Cmin) of 152%. BOS approached steady-state after 4 days, but concentrations were predicted to rise slowly during maintenance, characteristic of a drug with a large peripheral distribution volume. The model-based accumulation index was 2.45, which is in agreement with the 2- to 3-fold increase inferred from noncompartmental analysis. In conclusion, the PPK model of BOS showed acceptable descriptive and predictive performance, suitable for deriving individual exposure metrics for subsequent pharmacodynamic analyzes.

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 A195.
Abstract A236: Human liposarcoma growth inhibition by novel CDK4/6 inhibitor LEE011.
Authors: Zhang Yixiang , Sicinska Ewa , Moss Samuel , Czaplinski Jeffrey T. , Wang Yuchuan , Brain Christopher , Demetri George D. , Kim Sunkyu , Kung Andrew L. , Wagner Andrew J.
Published: June 2012

Background: Well-differentiated and de-differentiated liposarcomas (WD/DDLPS) are characterized by high-level chromosomal amplification of 12q13–15, a region including the cyclin-dependent kinase 4 (CDK4) oncogene. In this study, we explored the effects of LEE011, a novel selective inhibitor of CDK4/CDK6 on human liposarcoma cell lines and primary tumor xenografts.

Materials and Methods: We examined the expression of cell cycle regulatory proteins in human liposarcoma cell lines and human normal preadipocytes/adipocytes. CDK4 small interfering RNA (siRNA) or LEE011 was applied to liposarcoma cell lines and the biological consequences were determined by phospho-RB immunoblot, cell cycle assay and cell enumeration. In addition, liposarcoma cells were transfected with RB siRNA to determine the specificity of the effects of LEE011. Nude mice implanted with human liposarcoma cell lines or primary tumors were treated with LEE011 or vehicle by oral gavage. After 3 daily doses, in vivo BrdU incorporation assay, immunostains for phospho-RB, and 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan were performed. Tumor size and animal weight were serially measured during 3 weeks of dosing.

Results: CDK4 and p-Rb are highly expressed in human liposarcoma cell lines in comparison with normal preadipocytes/adipocytes. Both CDK4 siRNA and LEE011 inhibited RB phosphorylation at the CDK4/6-specific sites Ser780 and Ser807/811 in a dose-dependent manner and dramatically inhibited liposarcoma cell growth. Cell cycle analysis demonstrated arrest at G0/G1. siRNA-mediated knockdown of RB1 rescued the inhibitory effects of LEE011, suggesting that LEE011 inhibited proliferation as expected through the RB pathway. Oral administration of LEE011 to mice bearing human liposarcoma xenografts reduced tumor 18F-FDG uptakes by approximately 50% and dramatically decreased biomarkers including RB phosphorylation and BrdU incorporation in vivo. Continued LEE011 treatment inhibited growth of established cell line xenografts as well as primary human liposarcoma tumor xenografts without detrimental effects on mouse weight.

Conclusions: LEE011 decreases cell cycle progression, hypermetabolism, and proliferation of human liposarcomas in an RB-dependent manner, consistent with inhibition of CDK4. Clinical trials of LEE011 in patients with liposarcoma are warranted.

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 A236.
Abstract A39: Measurement of CUDC-101 target inhibition in circulating tumor cells using a fluorescent-based quantitative assay.
Authors: Davis Darren
Published: June 2012

Introduction: The occurrence of receptor signaling redundancy in multiple cancer pathways has led to the growing development of more potent, multi-kinase inhibitors that have the capability to block a broad array of tumor-related activation pathways. CUDC-101, is a clinical stage, network targeted agent designed to simultaneously inhibit EGFR, HER2 and HDAC in tumor cells. The ability to monitor the various activities of CUDC-101 in readily assessable clinical samples is critical for drug development processes including: (i) providing evidence of a pharmacodynamic effect in early clinical studies and (ii) facilitating the patient stratification strategy in advanced clinical studies.

Objective: To identify optimal biomarkers of CUDC-101 inhibition for pharmacodynamics monitoring by developing an assay to measure total and phosphoylated EGFR and HER2 proteins, and aceylated histone H3 (inhibition of HDAC leads to hyperacetylation of histones) in circulating tumor cells (CTCs).

Methods: CTCs were enriched from head and neck, or breast cancer patient blood samples treated ex vivo with CUDC-101 using CellSeach® Profile Kit. In parallel, two head and neck cancer cell lines, SCC-9 and SCC-15, were treated with vehicle or CUDC-101. The expression of pathway-specific proteins (total and phosphorylated) was quantified by laser scanning cytometry.

Results: Significant reduction in pEGFR (3 out of 5 patients) or pHER2 (2 out of 5 patients) was observed in enriched CTCs from CUDC-101 ex vivo treated blood compared with vehicle ex vivo treated blood samples. Among the patients that had reduced pEGFR and/or pHER2, a corresponding significant increase was also observed in acetylated histone H3. This data is consistent to parallel ex vivo treatment cell line studies which demonstrated that treatment of SCC-9 and SCC-15 cell lines with CUDC-101 at 10 uM led to a 21–33% reduction in pEGFR, a 22–40% reduction in pHER2 and conversely, a 51–177% increase in acetylated histone H3.

Conclusion: CUDC-101 was shown to successfully inhibit EGFR, HER2 and HDAC in ex vivo treated cancer patient blood CTCs. These assays are currently being applied in an ongoing phase I study of CUDC-101 in head and neck 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 A39.
Abstract A51: Quantitative assessment of VEGF combined with known clinical variables predicts outcome in patients with diffuse large B-cell lymphoma (DLBCL): Implications for guiding future treatment selection.
Authors: Donovan Michael J. , Puig Pere , Erill Nadina , Colomer Anna , Colomo Lluis , Campo Elias
Published: June 2012

Introduction: The pathogenesis of DLBCL is both complex and heterogeneous, and pathogenetic mechanisms remain largely unknown. A clinical index known as the international prognostic index (IPI) remains the ‘gold-standard’ for predicting response to therapy and overall survival; however, more recently, several groups have reported the utility of gene expression arrays to sub-classify patients and predict outcome. We sought to interrogate a series of biomarkers with multiplex quantitative immunofluorescence (QIF) to construct novel clinical algorithms which predict treatment response and overall survival (OS) post-treatment in a series of patients with DLBCL.

Methods: Clinical data including outcome and tissue microarray (TMA) cores for 149 patients were evaluated with QIF for association with response to standard chemotherapy and rituximab. Multiplex QIF with CRI Nuance imaging software for MUM1, Ki67, CD20, CD34, BCL2, BCL6, CD68, VEGF, HLA-DR, and NfKB. Kaplan-Meier survival function curves, hazard ratio and concordance index (CoI) were used to associate marker expression with OS and response to therapy.

Results: The cohort demographics for the 149 patients include a median age of 61 years; 43% female, 57% male and an IPI breakdown: Stage1 (30%), II (23%), III (25%) and IV (22%). Both low IPI and female gender were reliable predictors of good overall survival (p<0.001, respectively). 67 of 149 patients had complete clinical and QIF data for subsequent analysis. Increasing tumoral-CD68 positive cells were associated with a poor objective response to treatment (complete/partial vs. none; p=0.019). For OS, increasing levels of VEGF, on a continuous scale, were predictive of poor OS (VEGF: HR 1.23, 95%CI [.98–1.54], p=0.010, CoI 0.34 and when a cut-point of 0.18 is applied, the significance of VEGF improves, p=0.005. By contrast only the BCL6 cut-point (>3.84, p=0.003) was found to be significant in predicting poor OS. An expanded patient cohort will be needed to confirm both results, especially the BCL6 expression profiles. Optimal multivariate model to predict OS consisted of: Age, IPI index and VEGF levels (CoI 0.78, p=0.001), compared to a model with just age and IPI (CoI 0.72, p=0.02).

Conclusion: CD68, VEGF and BCL6 appear to be useful markers for understanding patterns of response and outcome for patients with DLBCL, post-treatment. A combined age, IPI and VEGF clinical algorithm may guide future treatment options for selected individuals.

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 A51.
Abstract A52: PTEN/PTENP1 transcripts expression and alterations in a large panel of human tumor xenograft in nude mice: Implication for resistance to targeted therapies involving EGFR/PI3K/PTEN pathways.
Authors: Vuaroqueaux Vincent , Ackermann Andreas , Krumbach Rebekka , Tillmann Hanns-Christian , Foucault Frederic , Schuler Julia , Metz Thomas , Fiebig Heinz-Herbert
Published: June 2012

Background: PTEN alterations are major determinants of resistance to several new targeted therapies involving EGFR/PI3K/PTEN pathways. Recent findings also suggested implication of its associated PTENP1 pseudogene. PTEN can be altered at the gene or transcriptional level. PTEN expression is often higher in stroma than in tumor cells complicating readouts of assayed tumor samples. Taking advantage of the stroma of xenografted human tumors in nude mice being produced by the host, we characterized specific PTEN/PTENP1 tumor cell transcript expression levels and mutational status in a large panel of tumor models.

Materials and Methods: A total of 192 patient-derived xenografts of 23 different histotypes were investigated. Human and murine PTEN, PTENP1 mRNA levels as well as PTEN gene copy numbers were quantified by quantitative polymerase chain reaction using species specific assays; PTEN transcript was analyzed by sequencing. Results were analyzed by tumor type and compared to sensitivity to cetuximab.

Results: PTEN transcript alterations were observed in 32 of the 192 tumor xenografts (17%) and were shown to be due to loss of PTEN gene for 9, to loss of transcript expression for 4 and to frameshift or substitution-missense mutations for 14 and 7 samples, respectively. PTEN expression levels and alteration frequency were both associated with specific histotypes. Melanoma and breast cancer showed most PTEN alterations (6/11 and 6/16 respectively). PTENP1 pseudogene was shown to be well expressed in only 61% of tumor xenografts, whereby expression levels depended on the tumor type. No or low PTENP1 expression was found in tumor models having a PTEN alterations. Finally, in a tumor panel consisting of colon, non-small cell lung, gastric and head and neck cancer we found that none of the PTEN altered tumors analyzed were sensitive to cetuximab in vivo.

Conclusion: This study confirmed the multiplicity of PTEN alterations occurring in cancer. PTEN expression levels and alterations were associated with PTENP1 expression levels and depended on tumor types. PTEN alterations were shown to be associated with tumor resistance to cetuximab and their impact on other targeted therapies involving EGFR/PI3K/PTEN pathways should be evaluated.

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 A52.
Abstract A85: Mutant P53 as a potential target of chemopreventive isothiocyanates.
Authors: Wang Xiantao , DiPasqua Anthony , Mi Lixin , Greenspan Emily , Tomita York , Chung Fung-Lung
Published: June 2012

Studies in animals and humans support isothiocyanates (ITCs) as a promising class of cancer chemopreventive agents. It is believed that apoptosis induction and cell cycle arrest are important mechanisms underlying their chemopreventive effects. While several signaling pathways have been shown to be associated with their activities, little is known about the molecular targets of ITCs until recent years. Evidence obtained in this study supports a role of mutant p53 as a potential target of ITCs. We showed ITCs can selectively deplete mutant p53, but not the wild type, in various human cancer cells in a structure-dependent manner, as phenethyl ITC (PEITC) and benyl ITC (BITC) are potent mutant p53 depletors, whereas sulforaphane (SFN) is not. The SAR studies showed 2,2-diphenyl ITC, a synthetic compound, is the most potent mutant p53 depletor. We found the potencies of depletion coincide with their mutant p53 binding affinities, providing circumstantial evidence for a mechanism involving its direct binding by ITCs. The depletion of mutant p53 in cells by ITCs appears to involve protein aggregation. Nine pairs of isogenic cells with mutant p53 and shRNA knockdown were generated. Overall, cells with mutant p53 appear to grow faster than the corresponding cells with mutant p53 knockdown, consistent with its role in gain-of-function. However, no significant difference was noted in PEITC-induced apoptosis between the cell pairs examined so far, suggesting targets other than mutant p53 in these cancer cells may also be involved. DNA array studies using PEITC-treated SW480 colon cancer cells provide potential new lead targets. Furthermore, the role of mutant p53 depletion in preventing lung carcinogenesis by ITCs is also examined in mutant p53 transgenic animal 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 A85.
Abstract A9: Chronology of arterial hypertension and microalbuminuria associated with inhibiting treatments of vascular endothelium growth factor receptor in patients with cancer.
Authors: Pradera Jose Fuentes , Salvador Javier , Grilo Antonio , Rodriguez Maria , Lopez Amelia , Bernabe Reyes , Fernandez Eva , Gallego Inmaculada , Morales David
Published: June 2012

Purpose: Angiogenesis plays a major role in cancer. Drugs blocking the growth factor receptor in the vascular endothelium constitute a fundamental treatment in several cancers. Hypertension (HBP) and proteinuria associated with these treatments is frequent and presents in an oscillating and irregular way and is generally controlled by scarcely reliable means. Methods: We started a prospective study with the determination of microalbuminuria (MAL) in 24 hours orine samples and the execution of pre- and post-treatment 24 h-ambulatory blood pressure monitoring (ABPM) and selfmeasured of BP every 12 hours at home, during 60 days, in patients with cancer under treatment with either bevacizumab or sunitinib with a view to identifying the variations in MAL, ABPM and the onset of HBP at an early stage. For ABPM, a validated recording device was used; a recording was made prior to the start of the anti-angiogenic treatment and 20 days (at least) after the first dose. An OMRON M6 tensiometer validated by the European HBP Society was used, with the ambulatory BP figures being collected at home as per standards. MAL was measured in 24h orine samples in mg/L and mg/gr creatinine. The primary goal is to find differences of at least 16 mmHg in the mean BP between the two ABPM readings. Results: N=21. Eighteen patients received bevacizumab and three sunitinib. Mean age 57.0 years (26–79). Three patients was known to be hypertensive. Differences of 4.9 and 3.9 mmHg were found between the mean systolic and diastolic BPs before and after treatment (p<0.05). Conclusions: Our data revealed a statically significant increase of blood pressure in patients treated with antiangiongenics as determined by ABMP. The data point to a greater increase in nocturnal BP suggesting a non-dipper pattern. The self measured records shown an early onset HBP. Microalbuminuria trends to increase in this patients. All data will be shown at the meeting.

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 A9.
Abstract B105: Ganetespib, a unique resorcinolic Hsp90 inhibitor, exhibits potent antitumor activity and a superior safety profile in preclinical models.
Authors: Ying Weiwen , Proia David A. , Zhou Dan , Inoue Takayo , Tatsuta Noriaki , Sang Jim , Ye Shuxia , Acquaviva Jaime , Ogawa Luisa Shin , Wada Yumiko , Chimmanamada Dinesh , Zhang Shijie , Koya Keizo
Published: June 2012

Targeted inhibition of the molecular chaperone heat shock protein 90 (Hsp90) results in the simultaneous blockade of multiple oncogenic signaling pathways and has thus emerged as an attractive strategy for the development of novel cancer therapeutics. Ganetespib (STA-9090) is a unique resorcinolic inhibitor of Hsp90 currently in clinical trials for a number of human cancers. Here we describe the key interaction of ganetespib with a number of amino acid residues in the ATP binding pocket of Hsp90 which results in high affinity binding. Ganetespib exhibits potent in vitro cytotoxicity in a range of solid and hematological tumor cell lines. By using a novel isotope-labeling scheme and LC-MS/MS detection technique, we have determined that Hsp90 occupancy by ganetespib in cancer cells is relatively fast under saturating conditions, reaching equilibrium within 5 minutes of ganetespib exposure. In vivo, ganetespib demonstrated strong single-agent activity in solid and hematological xenograft models, as evidenced by significant tumor growth inhibition and/or regression. Of note, evaluation of the microregional activity of ganetespib in tumor xenografts showed that ganetespib efficiently distributed throughout tumor tissue, including hypoxic regions >150 m from the microvasculature, to inhibit proliferation and induce apoptosis. Most importantly, ganetespib showed no evidence of cardiac or liver toxicity and exhibited minimal potential risk for CNS or ocular toxicities. Taken together, this preclinical activity profile suggests that ganetespib may have broad application for a variety of human malignancies and mechanistic and safety advantages over other first- and second-generation Hsp90 inhibitors.

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 B105.
Abstract B127: Establishment and characterization of in vitro co-culture assays comprising tumor and fibroblast cells that more closely model the cell/stroma interactions of human tumors.
Authors: Eberlein Cath , Ross Sarah , Rooney Claire , Farren Matthew , Weir Hazel , Barry Simon
Published: June 2012

Human solid tumours are comprised of epithelial cells interacting with a surrounding stroma or microenvironment. The stroma consists of several cell types including immune cells, endothelial cells and fibroblasts as well as macromolecules constituting the extracellular matrix. It has become clear from both pre-clinical and clinical studies that the tumour stroma plays a critical role in tumour progression and response to therapeutics. TGF-b is one of a number of pivotal regulators of the tumour microenvironment. Among its roles, TGF-b drives the cross-talk between tumour cells and fibroblasts resulting in a cancer associated fibroblast phenotype. This activated CAF state is linked to increased progression and survival of tumour cells and response of tumours to therapeutics.

Modeling this cross-talk is challenging however we have developed in vitro assays using tumour cells from a range of tissue types, for example NSCLC, breast, pancreatic and prostate, co-cultured with normal human fibroblasts and assessed cell/cell and cell/extracellular matrix interactions using a range of end-points including -smooth muscle actin and fibronectin. We have further characterized the assays, for NSCLC cell lines, using pharmacologically active agents to modulate canonical and non-canonical TGF-beta signaling pathways and assessed the effects on tumour cell growth, fibroblast activation and secretion of key growth factors, cytokines and proteases. We have also used RNA expression profiling of a selection of genes to investigate signaling pathways activated in tumour and fibroblast co-cultures compared to when the cells are grown as monocultures.

We will describe the development of methods to establish and quantify the different end-points explored in tumour and fibroblast co-culture assays and show data using inhibitors to validate these methods with NSCLC cell lines. We will show data from further comparison of monocultures and co-cultures by analysis of RNA and protein in cell lysates and conditioned media samples.

The development of more complex in vitro assays with more than a single cell type allows greater insight into the various tumour-stromal interactions that take place in tumours in vivo. This allows early understanding and testing of agents which may provide therapeutic benefit in limiting tumour-stromal interactions and signalling in 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 B127.
Abstract B138: Harnessing the glycolytic switch for therapy in a novel mouse model of anaplastic thyroid carcinoma.
Authors: Gabriela Valeria , Arciuch Antico , Russo Marika , Cristofano Antonio Di
Published: June 2012

Most cancer cells exhibit a peculiar metabolic behavior, producing energy by aerobic glycolysis instead of oxidative phosphorylation (Warburg effect). Several oncogenes directly drive this switch modulating the levels and activity of, among others, Hexokinase II, Lactate Dehydrogenase A, Pyruvate Kinase M2, and Pyruvate Dehydrogenase Kinase 1.

Anaplastic thyroid carcinoma (ATC) is the most aggressive form of thyroid cancer, and often derives from pre-existing well-differentiated tumors. Despite a relatively low prevalence, it accounts for a disproportionate number of thyroid cancer-related deaths, due to its resistance to any therapeutic approach. We have engineered the first mouse model of ATC by combining in the mouse thyroid follicular cells two molecular hallmarks of human ATC: activation of PI3K (via Pten deletion) and inactivation of p53. By 9 months of age, over 75% of the compound mutant mice develop aggressive, undifferentiated thyroid tumors that evolve from pre-existing follicular hyperplasia and carcinoma. Expression of the Foxe1, Pax8, and Nkx2–1 transcription factors, as well as of the thyroid-specific genes Duox2, Tpo, Tg, Tshr, and Slc5a5 (Nis) is reduced to almost undetectable levels in the anaplastic tumors, resembling the significant deregulation found in human ATC. Strikingly, the undifferentiated areas of all the tumors analyzed lose the expression of the epithelial marker E-cadherin, acquire the expression of the mesenchymal marker Vimentin, and display high levels of phosphorylated Smad2, strongly suggesting that elevated Tgf-β signaling contributes to the establishment and maintenance of EMT (epithelial-mesenchymal transition). Furthermore, similar to the human tumors, [Pten, p53]thyr−/− cells and tumors undergo the glycolytic switch known as Warburg effect. They display an up-regulation in the expression of Hexokinase II, Pyruvate Kinase M2, and Hypoxia-inducible factor 1α, and an increase in the amount of lactate levels. ATCs show an increase in glucose uptake by positron emission tomography (PET) and established cell lines derived from these tumors exhibit a high sensitivity to the therapeutic use of glycolytic inhibitors such as 3-bromopyruvate and 2-deoxyglucose, which synergize with standard chemotherapy.

Taken together, this model represents a novel, powerful tool to understand the biology of human thyroid anaplastic carcinomas, and provide a compelling rationale for targeting glycolysis to increase chemotherapy response in ATC patients. The elucidation of this process will lead to innovative targeted approaches to selectively disrupt tumor progression, while preserving normal metabolism in non mutated cells.

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 B138.
Abstract B143: PKM2 metabolic activator slows lung cancer xenograft growth.
Authors: Parnell K. Mark , Foulks Jason M. , Clifford Adrianne , Bullough Jeremy , Luo Bai , Vollmer David , Liu Jihua , McCarthy Virgil , Shaffer Matthew , Senina Anna , Liu Xiao-Hui , Pearce Scott , Xu Yong , Saunders Michael , Ho Kan , McCullar Michael V. , Kanner Steven B.
Published: June 2012

Tumor cells primarily utilize aerobic glycolysis, rather than oxidative phosphorylation, to metabolize glucose (the Warburg effect). The M2 splice form of pyruvate kinase (PKM2), the enzyme catalyzing the rate-limiting final step of glycolysis, is highly upregulated in tumors. Unlike the M1 splice form (PKM1), a constitutively active tetramer found predominantly in non-cancerous tissues, PKM2 is an inactive dimer under normal physiological conditions. Tetramerization of PKM2 requires binding of the allosteric activator fructose-1,6-bisphosphate (FBP), an upstream glycolytic intermediate, resulting in a fully active enzyme. Inactivation of PKM2 by cancer cells may allow glycolytic intermediates to be diverted into other biosynthetic pathways necessary for biomass production. The finding that PKM2 rather than PKM1 expression enhances tumorigenicity suggests that activators of PKM2 may have anti-tumor properties. We have identified and developed a series of small molecule PKM2 activators that exhibit low nM activation activity in biochemical and cell-based assays that measure pyruvate and ATP production. The extent of activation of these compounds is equal to or greater than that of FBP in biochemical assays. In addition, preliminary studies show that PKM2 activators inhibit the growth of lung cancer cell lines in vitro. The current lead compound was tested in established subcutaneously implanted A549 lung adenocarcinoma xenografts, where we observed a statistically significant 54% decrease in tumor growth, with no observable toxicity. These data suggest that this class of PKM2 activators is effective as tumor cell metabolic regulators with anti-tumor activity for lung cancer and potentially other malignancies.

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 B143.
Abstract B156: An epithelial to mesenchymal transition (EMT) gene expression signature predicts resistance to PI3K/Akt pathway inhibitors in non-small cell lung cancer.
Authors: Byers Lauren Averett , Wang Jing , Diao Lixia , Girard Luc , Peyton Michael , Coombes Kevin R. , Weinstein John N. , Gandi Varsha , Krett Nancy , Rosen Steven T. , Minna John D. , Heymach John V.
Published: June 2012

Background: Epithelial/mesenchymal transition (EMT) is associated with loss of cell adhesion molecules such as E-cadherin and increased invasion, migration, and proliferation in epithelial cancers. In non-small cell lung cancer (NSCLC), EMT is associated with greater resistance to EGFR inhibitors. However, its potential to predict response to other targeted drugs or chemotherapy has not been well characterized. Using a previously-derived EMT gene signature, we tested the association between EMT and drug response in a panel of >50 NSCLC cell lines.

Materials/Methods: NSCLC cell lines were classified as epithelial or mesenchymal by a previously described 76-gene EMT gene expression signature. IC50s for more than 30 drugs or drug combinations were determined by MTS assay. Differences in IC50 between epithelial and mesenchymal lines were assessed by t-test (p-values ≤ 0.05 were considered significant).

Results: As expected, EGFR mutated cell lines were classified by the EMT signature as epithelial and were highly sensitive to EGFR inhibition by erlotinib. Among wild-type EGFR cell lines, those that had undergone EMT were significantly more resistance to erlotinib (p=0.029). NSCLC cell lines with mesenchymal signatures were also more resistant to drugs targeting the PI3K/Akt pathway such as GDC0941 (p=0.037) and 8-amino-adenosine (p=0.009). A trend towards greater resistance was also seen in mesenchymal cells treated with the Akt inhibitor MK2206 (p=0.12). There was no association between EMT and response to cytotoxic chemotherapies, including cisplatin, carboplatin, gemcitabine, pemetrexed, docetaxel, paclitaxel, and platinum-doublets (p-values ≥0.2).

Conclusion: EMT is associated with greater resistance to PI3K/Akt pathway inhibitors and may be a useful predictive marker for patients treated with these drugs. The EMT signature is being investigated prospectively in patients treated with an Akt inhibitor in an ongoing clinical trial. Supported in part by the NIH Lung Cancer SPORE grant P50 CA70907.

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 B156.
Abstract B166: Defining the mechanism of action and enzymatic selectivity of psammaplin A against its epigenetic targets.
Authors: Fuchter Matthew J. , Baud Matthias G. J. , Leiser Thomas , Samlal Sharon , Wong Ai Ching , Wood Robert J. , Gunaratnam Mekala , Hughes Siobhan M. , Buluwela Lakjaya , Turlais Fabrice , Neidle Stephen , Meyer-Almes Franz-Josef
Published: June 2012

Naturally isolated products continue to play a significant role in anticancer drug discovery. In line with our interest in small molecule compounds which effect epigenetic gene regulation, we are interested in the structural and biological properties of the natural product Psammaplin A. While it has been implicated as an inhibitor of numerous targets such as mycothiol-S-conjugate amidase, topoisomerase II and aminopeptidase N, studies by Crews and co-workers showed it to be an extremely potent inhibitor of both histone deacetylase (HDAC) and DNA methyltransferase (DNMT) enzymes. Our goal was to establish structure-activity relationships around psammaplin A, probing the molecular features responsible for the chemical biology of this natural product. We developed a number of versatile synthetic routes towards small compound libraries based on the psammaplin core [1]. We subsequently assessed the activity of these compounds against a selection of histone deacetylases, DNMT1, and in cell based assays. Analysis of the data revealed psammaplin A to be a natural prodrug; the central disulphide being reduced to a free thiol. Indeed, we showed the corresponding thiol not only to be a potent inhibitor of HDAC1 (IC50 0.001 μM), but to have remarkable selectivity against HDAC6 (IC50 0.360 μM), HDAC7 (IC50 17.4 μM) and HDAC8 (IC50 1.34 μM) in cell-free assays. Cell-based (MCF7) studies confirmed the HDAC targeting potential of psammaplin A and confirmed the selectivity observed in vitro. Curiously, our psammaplin A derivatives demonstrated no activity against DNMT1 in cell-free assays. Taken together with other reports, this data suggests psammaplin A may not be an inhibitor of DNMT1 as previously reported. In conclusion, we have explored the epigenetic activity of psammaplin A and have found it to have significant potency and selectivity against HDACs, whereas we find no evidence for DNMT1 activity.

Reference:

1. “New synthetic strategies towards Psammaplin A, access to natural product analogues” Baud, M. G. J.; Leiser, T.; Meyer-Almes, F.-J.; Fuchter, M. J. Org. Biomol. Chem. 2011, 9, 659–662.

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 B166.
Abstract B182: Nuclear sequestration of ErbB4 receptor tyrosine kinase by PIAS3.
Authors: Korhonen Anna , Sundvall Maria , Vaparanta Katri , Anckar Julius , Halkilahti Kalle , Salah Zaidoun , Aqeilan Rami , Palvimo Jorma J. , Sistonen Lea , Elenius Klaus
Published: June 2012

Background: ErbB4 is a member of EGFR/ErbB family of receptor tyrosine kinases (RTK). ErbB4 is subjected to regulated intramembrane proteolysis (RIP), resulting in the release of a soluble ErbB4 intracellular domain (ICD) into the cytosol. ErbB4 ICD can translocate to the nucleus and function as a transcriptional coregulator. Although nuclear ErbB4 immunoreactivity is frequently observed in breast cancer sections and has been associated with poor clinical outcome compared to membranous or cytosolic ErbB4, little is known how the subcellular localization and functions of ErbB4 ICD are regulated.

Results: In search of regulatory mechanisms of ErbB4 ICD localization and function, we identified protein inhibitor of activated STAT3 (PIAS3) as a novel interaction partner of ErbB4 ICD. According to the small ubiquitin-related modifier (SUMO) E3 ligase function of PIAS3, we showed that ErbB4 ICD is post-translationally modified by SUMO-1, and that PIAS3 stimulates SUMOylation of ErbB4 ICD. Upon overexpression of PIAS3, ErbB4 ICD generated from the full-length receptor accumulated into the nucleus and colocalized with PIAS3 and SUMO-1 in promyelocytic leukemia (PML) nuclear bodies, nuclear domains involved in regulation of transcription. Accordingly, PIAS3 overexpression had repressive effects on the transcriptional coregulatory activity of ErbB4. Finally, knockdown of PIAS3 with siRNA decreased nuclear ErbB4, and partially rescued the inhibitory effect of ErbB4 ICD on differentiation of MDA-MB-468 breast cancer and HC11 mammary epithelial cells.

Conclusions: We demonstrate that PIAS3 regulates the nuclear sequestration and functions of ErbB4 RTK. Our findings indicate the importance of subcellular distribution of ErbB4 ICD in determining the outcome of ErbB4 signaling in normal and malignant breast cell lines.

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 B182.
Abstract B190: Pharmacokinetics of the AKT inhibitor CCT128930 from dried blood spots sampled from caudal bleeding compared with conventional cardiac puncture.
Authors: Raynaud Florence I. , Hayes Angela , Asad Yasmin J. , Johnson Louise , Henley Alan T. , Caldwell John J. , Collins Ian , Garrett Michelle D.
Published: June 2012

There has been much increase in the use of blood spots in recent years as a result of the ease of storage and transport of blood dried on cards compared with frozen plasma. In preclinical studies in oncology, mice are the model used for therapy experiments and blood spots allow full pharmacokinetic (PK) studies in 3–4 animals versus 21–27 for conventional plasma pharmacokinetics analysis, saving animals and decreasing compound usage. We here apply the blood spots technology to the early pharmacokinetic analysis of the AKT inhibitor CCT128930 dosed i.v. at 10mg/kg and bled from the tail vein.

The PK are very reproducible between individual mice and the blood levels are not affected by the type of anticoagulant used (heparin or EDTA) or by use of the FTA-DMPK card. CCT128930 shows a blood clearance of 0.092L/h (<liver blood flow) and volume of distribution of 140mL. However, the PK parameters evaluated in blood water by conventional methods (cardiac puncture) differ significantly to those from the blood spot experiments. The overall blood clearance is 1.6-fold higher following blood measurement in samples taken by cardiac puncture versus serial tail bleed. The 6h post-dosing concentrations of CCT128930 following caudal sampling are 10-fold higher than that measured after cardiac puncture although there is no difference in Cmax. These data suggest that the serial bleeding from the tail vein affects the PK parameters of this compound compared with conventional bleeding. We have used blood spots extensively in our drug discovery programs checking the 6h sample versus conventional cardiac bleed and this strategy has allowed us to save over 50% of animals in the last year in our preclinical PK evaluations.

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 B190.
Abstract B201: Identification of miRNA modulators to PARP inhibitor response.
Authors: Neijenhuis Sari , Bajrami Ilirjana , Campbell James , Lord Christopher J. , Ashworth Alan
Published: June 2012

Many pre-clinical and clinical studies have shown that inhibitors of the DNA repair protein PARP can have potentiating effects when combined with DNA damaging treatment modalities such as IR and temozolomide. Moreover, PARP inhibitors can be used as an efficient single agent in treatment of tumors carrying homologous recombination (HR) gene defects such as BRCA1 and BRCA2.

Genetic screens have previously been used to identify additional genetic deficiencies, which render tumor cells sensitive to PARP inhibitors. As yet, the contribution of microRNAs (miRNAs) to PARP inhibitor sensitivity has not been comprehensively studied. In this study our aim was to identify miRNA determinants of PARP inhibitor sensitivity and resistance, and in doing so potentially refine the eventual clinical use of these agents.

The human genome encodes over 1000 well annotated miRNAs. We used a high throughput method of miRNA mimetic screening to identify novel modulators of PARP inhibitor response. The assay involved transfecting cells with a library of approximately 900 miRNA mimics in a 384-well plate format. 48 hours after transfection half of the cells were treated with PARP inhibitor Olaparib and the other half with the drug vehicle. We identified several miRNA mimetics that modulate the response to Olaprib. Hits were validated by long-term survival assays as well as by analyses of DNA damage foci.

We used several strategies to determine the target genes of our hits. We performed westerns, qRT-PCR, luciferase reporter assays and immunoprecipitation assays and demonstrated several miRNAs involved in regulating the HR repair pathway.

Genes that modulate the response to PARP inhibitors are often implicitly involved in controlling DNA repair by HR and thus frequently found to be mutated in cancers. Our future work will focus upon whether the miRNAs identified in our screen drive HR dysfunction in human tumors and could be used as biomarkers to direct the use of 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 B201.
Abstract B212: Inhibition of Gli transcriptional factors sensitizes multiple carcinoma cell lines to erlotinib treatment.
Authors: Li Hui , Do Hanh , Sheng Qing , Cheng Tiffany , Liu Natalie , Xu Fengfeng , Jablons David , He Biao
Published: June 2012

The aberrant activation of Hedgehog/Gli transcriptional factor has been implicated with a broad spectrum of lethal tumors. Targeted inhibition at cell membrane level of the Hh pathway, i.e. Smo and Hh inhibitors, has shown promising anti-tumor activity in both preclinical and clinical trials. A growing body of evidence has revealed additional mechanisms of Gli activation which are independent of Hh/SMO regulation and are stimulated by the crosstalk between components downstream of Hh/Smo and several other oncogenic signaling pathways, such as the Epidermal Growth Factor Receptor (EGFR) pathways. We hypothesized that the simultaneous inhibition of the EGFR pathway and Gli function could abrogate the interaction and result in synergistic anti-tumor effects. In order to test this hypothesis, we have undertaken studies in multiple lung cancer and mesothelioma cell lines. Effects of combination treatments with EGFR tyrosine kinase inhibitor erlotinib and an Hh pathway inhibitor were examined by using MTS assay. In our studies, the application of the Hh pathway inhibitor sensitized lung cancer cells to erlotinib treatment with a higher than 10 fold decrease of IC50. We also used the CalcuSyn software to calculate Combination Index (CI), in order to evaluate the effects of combination treatments (CI<1 indicates Synergism, CI=1 indicates Additive effects, and CI>1 indicates Antagonisim). In many lung and mesothelioma cell lines, the dual treatment of the Hh inhibitor and erlotinib showed synergistic effects with a Combination Index (CI) lower than 0.7. To elucidate the mechanism of the crosstalk between the two pathways, we have examined the activities of EGFR and Hh pathways upon single and dual treatments. Based on our studies, we speculate that dual inhibition of Hh/Gli and EGFR pathways may become a promising targeted therapy for lung cancers and mesothelioma.

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 B212.
Abstract B216: A soil-to-seeds anticancer strategy: Targeting stroma to kill cancer cells.
Authors: Ni Yicheng
Published: June 2012

Rationale: We propose a dual targeting anticancer theragnostic strategy called OncoCidia, with which we intend to destroy and radioactively contaminate tumor stroma (soil) in order to eradicate all cancer cells (seeds) using vascular disrupting agents (VDAs) followed by radiolabeled necrosis-avid compounds (NACs), both of which are small molecular, naturally or synthetically derivable, systemically injectable, and of unique and complementary targetabilities.

Methods: Combretastatin A4 phosphate (CA4P) and Hypericin, as a representative of VDAs and NACs respectively, were tested among liver and subcutaneous tumor models (Ø > 0.8 cm) in rats, mice and rabbits (n > 100). We first injected CA4P intravenously at a dose of 10 mg/kg to cause tumor necrosis that became the next target. Hypericin was labeled with iodine-131 to form 131I-Hypericin (131I-Hyp), which was then iv injected at 300 MBq/kg 24h after administration of CA4P. 131I-Hyp accumulated in necrotic tumor, killing adjacent residual cancer cells by cross-fire irradiation and preventing tumor re-growth. We studied OncoCidia by comparing vehicle-control, single-targeting (either CA4P or 131I-Hyp) and dual-targeting (CA4P plus 131I-Hyp) groups using in vivo MRI and scintiscans, and ex vivo gamma-counting, autoradiography and histology.

Results: Eight days after only one dosage of each drug, typically the tumor size in vehicle-controls doubled that in single-targeting groups (p < 0.001), and was 5-times that in dual-targeting group (p < 0.0001), without treatment-related animal death. Tumors in OncoCidia groups appeared as hot-spots on scintiscans even weeks after treatment, corresponding to > 3.34% ID/g of 131I-Hyp and a target-to-liver ratio > 20. Significantly prolonged survival and reduced lung metastases occurred in tumor-bearing mice and rabbits respectively. Such encouraging results with histomorphological proofs were independent of animal species and tumor types.

Conclusion: Our preclinical experiments suggest that OncoCidia may present a simple, workable, affordable and general solution for treatment, detection and therapeutic monitoring of diverse solid malignant tumors, and deserve further exploitation.

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 B216.