bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B90: Nonviral delivery of apoptin for the treatment of brain tumor in a newly established brain tumor xenograft.
Authors: An Songhie , Choi Sunghyun , Nam Kihoon , Park Jong-Sang
Published: June 2012

We established a brain tumor xenograft to examine the application of gene therapy utilizing a tumor selectively killing gene together with a nonviral gene delivery carrier to treat brain tumor. To do so, we recombined the therapeutic gene apoptin with the JDK vector and delivered it into human brain tumor cells (U87MG) using PAM-RG4 as the gene delivery carrier. Studies in vitro showed that the PAM-R G4/Apoptin polyplex exhibited particularly high transfection activity of over 40% based on fluorescence-activated cell sorting (FACS) analysis and lower cytotoxicity than other control agents. Also, TUNEL assay and DAPI staining verified that tumor cells had undergone apoptosis, which was induced by the apoptin gene. Caspase-3 activity was about two times higher in the therapeutic group. For in vivo studies, the PAM-R G4/Apoptin polyplex was injected into the tumor, which was induced by injecting U87MG cells into the left flank of nude mice and letting them grow to a certain size. The size of the tumor exponentially grew with time in the control groups whereas the treated group did not exhibit any tumor growth. H&E staining and EGFR immunohistochemistry confirmed the existence of the tumor in the control groups and showed that there was no tumor in the treated group. Furthermore, no specific edema, irritation or other kind of harm to the skin could be observed when the polyplex was injected. After reverse-transcript PCR analysis, to verify the expression of apoptin in vivo, TUNEL assay and DAPI staining were, again, utilized to confirm the event of apoptosis in the therapeutic group. These findings indicate that the PAM-RG4/Apoptin polyplex is a very strong candidate for brain tumor therapeutics, due to the synergistic effect of the carrier's high transfection efficiency in neuron cells and the gene's selective apoptosis-inducing activity in tumor 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 B90.
Abstract B98: AUY922, a novel HSP90 inhibitor: Final results of a phase I dose escalation study in Japanese patients with advanced solid malignancies.
Authors: Onozawa Yusuke , Doi Toshihiko , Yamazaki Kentaro , Watanabe Junichiro , Fuse Nozomu , Yoshino Takayuki , Akimov Mikhail , Robson Matthew , Boku Narikazu , Ohtsu Atsushi
Published: June 2012

Background: AUY922 is a novel, highly potent, non-geldanamycin HSP90 inhibitor, which causes the degradation of multiple oncogenic cellular proteins, and has been suggested to have potential clinical activity in an earlier global Phase I study and ongoing global Phase II studies.

Methods: Single agent AUY922 was administered as a 1 hour weekly IV infusion to Japanese patients (pts) with advanced solid malignancies, This Phase I study was an open-label dose escalation study. Dose escalation was guided by a Bayesian logistic regression model with overdose control. Endpoints included safety, tolerability, preliminary activity, pharmacokinetics and pharmacodynamics.

Results: 31 pts received AUY922 at doses of 8, 16, 22, 28, 40, 54 and 70 mg/m2. Pt characteristics include: median age 60 yrs, 48.4% male, 51.6 % female and WHO performance status 0 (67.7 %) or 1 (32.3 %). Median duration of exposure was 7.3 weeks (range; 0.1, 55.0). The most frequently reported adverse events possibly related to AUY922 were diarrhea-20 pts, (64.5%), night blindness-13 pts, (41.9%), nausea-7 pts (22.6%), fatigue-6 pts (19.4%), rash-6 pts, (19.4%), decreased appetite-5 pts, (16.1%) and vomiting-5 pts (16.1%). Visual symptoms (grade 1–2 and mostly reversible) including night blindness and blurred vision were reported at doses of 22 mg/m2 and higher. A single patient at the 54 mg/m2 dose experienced a dose limiting toxicity of grade 3 fatigue and anorexia. Considering the safety data from a preceding global Phase I study and the potential increase of visual toxicity risk, 70 mg/m2 was declared as the recommended Phase II dose (RPTD) consistent with the RPTD found in the global Phase I study. Stable disease (SD) for at least 8 weeks was reported in 10 pts and 1 rectal carcinoid pt reported a confirmed partial response (PR). Blood concentration of AUY922 reached the peak at the end of infusion and declined slowly with a flat terminal phase.

Conclusions: Weekly IV infusion of single agent AUY922 was well tolerated at the RPTD of 70 mg/m2, confirming the tolerability of the RPTD found in a preceding global Phase I study. Clinical activity was observed in 1 patient in this study, further supporting efficacy of AUY922, as observed in ongoing global clinical studies, and pharmacokinetic parameters were comparable to those observed in non-Japanese patients in the aforementioned global Phase I study.

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 B98.
Abstract C101: The effect of folate-related SNPs on therapeutic responses to neoadjuvant chemotherapy in breast cancer molecular subtypes.
Authors: Babyshkina Nataliya
Published: June 2012

Background: Breast cancer is a heterogeneous disease, comprising several molecular subtypes with diverse biological behavior, clinical presentations and responses to therapy. Given the important role that folate plays in the availability of methyl groups and in the synthesis and repair of DNA, we examined the relationship between single nucleotide polymorphisms in folate-related genes MTHFR (677C>T, 1298A>C), MTR (2756A>G), MTRR (66G>A), DHFR del19, MTHFD1 (1958G>A), TS (28-bp repeat, 1494del6), RFC1 (80G>A), DNMT3b (149C>T) with therapeutic response to neoadjuvant chemotherapy of breast cancer patients according to molecular subtypes.

Material and methods: This study included 300 patients with histologically diagnosed primary breast cancer who were treated between 1998 and 2008 at the Tomsk Cancer Research Institute. Subgroups were classified on the basis of ER, PR, and HER2 immunohistochemical evaluation. PCR-RFLP analysis was used to determine the MTHFR 677C>T, MTHFR 1298A>C, MTR 2756A>G, MTRR 66G>A, MTHFD1 1958G>A and DNMT3b 149C>T polymorphisms. Genotyping for the DHFR del19, TS 28-bp repeat and TS 1494del6 were based on polymerase chain reaction.

Results: A trend was detected towards accumulation of the MTHFD1(AA) and RFC1(GG) genotypes in triple negative (TN) cases compared with the luminal A group (P = 0.06 and P = 0.07 respectively). In addition, we observed that the DHFR(del19/del19) and MTRR(GA) genotypes tended to show an association with HER2+ subtype (P = 0.06 and P = 0.09 respectively). We found that the TN women carrying MTRR(GG) genotype had a worse clinical response to neoadjuvant chemotherapy compared to luminal A cases but this difference did not reach statistical significance (P = 0.06). Luminal A subtype group with MTHFD1(AA) genotype showed an association with better response to neoadjuvant chemotherapy in comparison TN patients (P=0.03).

Conclusion: Our study indicates that the analysis of folate-related gene polymorphisms may help to identify patient subgroups at high risk for the progression of breast cancer. MTHFD1 (1958G>A) may be considered as a molecular marker associated with more aggressive tumor behavior such as TN 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 C101.
Abstract C12: Identification of predictive and pharmacodynamic biomarkers for an FGFR inhibitor.
Authors: Sharp Michael , Sadis Seth , Rhodes Dan , Thompson Neal , Otte Marcus , Alvarez John , King Peter , Winkler Hans , Platero Suso
Published: June 2012

Fibroblast growth factor receptors (FGFRs) are widely expressed in multiple organ systems and are involved in growth and angiogenesis. Mutations, translocations and amplifications in FGFR genes have been observed in several types of cancer. The purpose of this study was to identify biomarkers that may predict sensitivity and may change upon FGFR inhibition.

240 tumor cell lines from different types of cancer were treated with a small molecule FGFR inhibitor and IC50 values were calculated. Mutations, amplifications, deletions, gene expression analysis, and network analysis were used to find biomarkers that were sensitive or resistant to the inhibitor. Xenografts were used to identify pharmacodynamics biomarkers. Tumors from cancer patients were analyzed for FGFR gene amplifications using Fluorescent in situ hybridization.

FGFR1 mRNA overexpression and FGFR2 amplification were identified as sensitive biomarkers while Kras mutation was associated with resistance. Multiple sensitive cell lines (n = 2–4) were found in cells derived from breast, lung, gastric, kidney, lymphoma, sarcoma, melanoma, and endometrial cancer. No sensitive cell lines were found in colorectal, pancreatic, leukemia, myeloma, or ovarian cancer. In human breast cancer cell lines, amplifications were found for FGFR1 (23%), FGFR2 (11%), and FGFR4 (16%). Of the 26 breast cancer cell lines analyzed for FGFR1 amplification, 5 had moderate amplification (4–10 copies) and 1 was highly amplified (>10 copies). In non-small cell lung cancer cell lines, amplifications were found for FGFR1 (37%) and FGFR2 (20%). In xenografts, pS6 and pMAPK levels changed upon compound treatment. FGFR1 and FGFR2 amplifications were also found in prostate (15% and 15%, respectively) tumors from patients.

This study identified biomarkers for an FGFR small molecule inhibitor. These results may provide a rationale for patient selection and patient dosing when using a FGFR inhibitor.

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 C12.
Abstract C130: Inhibition of NF-κB activity promotes radiosensitivity of breast cancer cells in three-dimensional culture via a β1-integrin-mediated pathway.
Authors: Ahmed Kazi M. , Zhang Hui , Park Catherine C.
Published: June 2012

Radioresistance markedly impairs the efficacy of tumor radiotherapy and involves prosurvival signal transduction pathways that prevent radiation-induced cell death. Nuclear factor-κB (NF-κB), a stress-sensitive heterodimeric transcription factor in the regulation of the stress-responsive genes, has been shown to initiate prosurvival signaling in response to ionizing radiation (IR). The cooperative function of NF-κB with other key stress elements in radioresistance has not been clearly defined. We have previously reported that induction of β1-integrin is associated with the enhanced cell survival of breast cancer cells after exposure to clinically relevant doses of IR. Because a typical NF-κB binding site was identified in human β1-integrin promoter region, β1-integrin-mediated resistance to radiation may be regulated by NF-κB. The aim of the present study was to reveal a connection between NF-κB and β1-integrin pathways in radioprotection of malignant T4-2 mammary epithelial cells in 3D lrECM (three-dimensional laminin-rich extracellular matrix). We show that the elevated NF-κB activity was correlated with enhanced clonogenic survival with an increase in total and phosphorylated (Thr 788/789) β1-integrins. Inhibition of NF-κB activation significantly reduced clonogenic survival with the inhibition of β1-integrin, suggesting that NF-κB-mediated induction of β1-integrin is associated with an increased radiation resistance. Treatment of malignant human breast cell colonies, T4-2 with NF-κB activation inhibitor at Day 4 in 3D lrECM before exposure to IR (4-Gy X-ray) resulted in a reduction of the size of colonies. The surviving colonies were associated with a decrease in proliferation and increase in apoptosis, indicating a decrease of resistance to IR. Using an ELISA-based DNA binding assay, we next determined that the binding of NF-κB to its target sequence on β1-integrin promoter region was significantly increased by IR. These data suggest that IR-induced increase in β1-integrin protein expression is mediated by NF-κB activation and subsequent binding of NF-κB to the β1-integrin promoter. Taken together, our results provide the first evidence that NF-κB-mediated β1-integrin expression is responsible for tumor radioresistance. The NF-κB/β1-integrin pathway could provide new insight into the development of new therapeutic modalities to re-sensitize radioresistant tumor 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 C130.
Abstract C14: Tissue expression profile of novel tumor biomarkers identified by monoclonal antibodies.
Authors: Arlen Philip M. , Saric Olga , Arlen Myron , Bristol Andrew
Published: June 2012

Background: Monoclonal antibodies (mAbs) were raised against human colon tumor tissue extracts. Antibodies that specifically recognized tumor tissues, but did not cross-react with normal tissues, were selected for further characterization and development as diagnostic reagents and therapeutic candidates. Three mAbs that react with variant forms of MUC5AC, CEACAM molecules, and A33 were identified. The immunohistochemical staining profiles of these antibodies (NEO-101, NEO-201, and NEO-301) will be discussed.

Methods: The three antibodies (NEO-101, NEO-201, and NEO-301) were each biotin-labeled, and used to stain a variety of tumor and normal human tissue types, typically at 10 ug/mL. Binding of the primary antibody was detected using streptavidin-HRP conjugate. Slides were reviewed and scored by light microscopy.

Results: The NEO-101 antibody recognizes a variant form of MUC5AC expressed by colorectal (79%) and pancreatic (48%) cancer tissues. NEO-101 did not significantly cross-react with normal colon or pancreas tissues. Staining appeared to be cytoplasmic, membrane-associated, and elaborated into the lumenal spaces of positively stained tissues. The NEO-201 antibody recognizes variant forms of both CEACAM-5 and CEACAM-6. NEO-201 reacts with a wider variety of tumor tissue types including colorectal (98%), pancreatic (80%), lung (71%), stomach (100%), esophagus (61%), breast (31%), and ovarian (31%). Cross-reactivity to normal tissues was weak and sporadic. The NEO-301 antibody recognizes a variant form of A33, that is expressed by colorectal (46%), pancreatic (52%), lung (65%), and breast (45%) tumor tissues. NEO-301 also does not cross-react significantly with normal tissues. Antibodies NEO-201 and NEO-301 stained both cytoplasm and membranes of tissues examined.

Conclusions: NEO-101, NEO-201, and NEO-301 antibodies react specifically with tumor tissues without significant cross-reactivity to normal tissues, an attractive characteristic for developing effective therapeutic and diagnostic products for oncology indications. We suggest that the antigens they react with are novel variants of commonly known wild type proteins that can be used as biomarker since they do not cross-react with healthy tissues. Interestingly, although these 3 antibodies were generated from extracts of pooled human colon tumor tissues, the variant antigens they cross-react with are not restricted to expression by colon tumor tissues, supporting the idea that variant protein expression may be a general property of tumor cells compared to normal 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 C14.
Abstract C142: The development of a miRNA-based therapeutic candidate for hepatocellular carcinoma.
Authors: Daige Chris , Priddy Leslie , Kelnar Kevin , Zhao Jane , Dysart Sarah , Bader Andreas , Brown David
Published: June 2012

Tumor suppressor miRNAs function by regulating multiple cancer-related genes and pathways. The tumor suppressor miRNAs miR-34, let-7, miR-16, miR-26, and miR-145 have proven to be effective in inhibiting tumor growth in mouse models of cancer. Based upon the availability of systemic delivery technologies that provide significant accumulation of siRNAs in liver tumors, we chose to identify tumor suppressor miRNAs that might be used as therapies for hepatocellular carcinoma (HCC). Cell culture studies with mimics of eight tumor suppressor miRNAs revealed five with the capacity to significantly inhibit the proliferation of multiple HCC cell lines. The five miRNA mimics were complexed with several lipid formulations and injected into NOD/SCID mice with orthotopically grown Hep3B liver cancer xenografts. All five miRNAs significantly inhibited the growth of the liver tumors compared to animals treated with formulated negative control miRNAs. Intriguingly, mimics of three of the tumor suppressor miRNAs eliminated detectable tumors. Preliminary studies indicate that the formulated miRNAs are neither toxic nor immunostimulatory. The formulated miRNAs are currently being evaluated for therapeutic activity in mouse models of other cancers and a development program has been initiated in anticipation of creating candidates for 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 C142.
Abstract C148: SC144: The first orally active small molecule gp130 inhibitor for the treatment of ovarian cancer.
Authors: Xu Shili , Grande Fedora , Garofalo Antonio , Neamati Nouri
Published: June 2012

Ovarian cancer is one of the leading causes of cancer-related death in women in the United States. The gp130/Stat3 signaling axis plays an important role in carcinogenesis and drug resistance in a wide variety of human cancers, including ovarian cancer. As a downstream effector of gp130, Stat3 is constitutively activated and plays a critical role in ovarian cancer progression. In this study, we showed that a novel selective small molecule gp130 inhibitor, SC144, suppressed ovarian cancer progression both in vitro and in vivo. SC144 treatment in vitro induced gp130 phosphorylation and deglycosylation, resulting in the downregulation of surface-bound gp130 and the abrogation of gp130-associated Stat3 activation. In addition, SC144 selectively inhibited the downstream signaling activation induced by gp130 substrates, including IL-6 and LIF, whereas SC144 did not exhibit detectable effects on the downstream signaling activation induced by non-gp130 substrates, including IFN-γ, SDF-1α, and PDGF. Protein expression regulated by the gp130/Stat3 axis in OVCAR-8 cells was also down-regulated after SC144 treatment, including Bcl-2, Bcl-XL, survivin, cyclin D1, MMP-7, gp130 and Ape1/Rel-1. In vivo, SC144 significantly inhibited tumor growth in a mouse xenograft model of human ovarian cancer via i.p. or p.o. administration. After SC144 treatment for two months, gp130, Bcl-2, Bcl-XL, MMP-7 and Ape1/Ref-1 protein levels were substantially decreased in the tumor site in the treatment group compared with the control group. Our results further suggest gp130 is a novel drug target for ovarian cancer therapy, and the development of small molecule inhibitors of gp130 can help interrogate this unique signaling pathway in human diseases.

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 C148.
Abstract C158: Shoc2 gene induces chemotherapy sensitivity in acute lymphoblastic leukemia cell line.
Authors: Silveira Vanessa , Andrade Augusto , Cruzeiro Gustavo , Queiroz Rosane , Tone Luiz Gonzaga , Scrideli Carlos Alberto
Published: June 2012

Introduction: Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in childhood and represents a heterogeneous disease regarding its biology and prognosis. Major improvements have been made in the ALL treatment, which achieved successful rates of approximately 80% of long-terms survival. Despite the significant percentage of success, the remaining 20% still presents treatment failure and the molecular mechanisms involved in the resistance process remains unclear. The SHOC2 gene encodes a leucine-rich-repeats (LRR) protein which acts as a positive modulator of the RAS-MAPK signaling cascade. Its gene expression profile was previously related to daunorubicin sensibility in children with ALL, suggesting the correlation of SHOC2 with good prognostic factors. Thus, the present study was undertaken to better understand the possible mechanisms which involve SHOC2 gene to the chemotherapy response process.

Methods: Jurkat, ALL T-type cells, were cultured in standard RPMI medium supplemented with 10% of fetal calf serum (FCS) and transfected with siRNA using lipossomal transfection reagent to silence the gene SHOC2. Mock transfections were also performed. The silencing confirmation was done by real time quantitative PCR and Western blotting. Responsiveness of leukemia cells to vincristine, methotrexate and L-asparaginase was determined by the 4-day XTT in vitro drug resistance assay. The concentrations of L-asparaginase, methotrexate and vincristine were 2–12 IU/mL ASP, 0.25–2.0uM/mL MTX and 4.0–14.0 ng/mL VCR. SHOC2 effect on apoptosis was analyzed by Annexin V staining by flow cytometer. The t-test was conducted to determine statistical significance between two groups in triplicate of two independent experiments. The significance level was set at p ≤ 0.05.

Results: When treated with vincristine and methotrexate, the survival rates of Jurkat cell lines were significantly lower in non-transfected cells than in transfected group (p<0.05). The cytotoxic effects of the chemotherapeutic agent I-asparaginase, however, were not significantly modified by SHOC2 silencing. The apoptosis's induction after 72 hours of chemotherapy agent vincristine treatment did not show significant differences between transfected and non-transfected cells.

Conclusions: this data suggests that the SHOC2 gene could play an important role in leukemic cell's sensibility to chemotherapy agents by modifying the cell proliferation and the apoptosis' processes. Thus, this gene could be considered as a target for developing new therapeutic interventions for ALL 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 C158.
Abstract C185: Register trial of sorafenib (S) for patients (pts) with metastatic uveal melanoma (metUvMel).
Authors: Scheulen Max E. , Nokay Bahar , Richly Heike , Hoffmann Andreas C. , Kalkmann Janine , Stattaus Joerg , Bornfeld Norbert , Schuler Martin , Hense Joerg
Published: June 2012

Background: There is no effective systemic therapy for patients (pts) with metastatic uveal melanoma (metUvMel). Due to the paucity of clinical trials pts are frequently offered individual treatment options. We have analyzed the outcome of pts treated for metUvMel with the oral multikinase inhibitor sorafenib (S) in an IEC-approved register trial of the West German Cancer Center, a national reference center for uveal melanomas.

Methods: Pts with metUvMel were treated with S [at a dose of 400 mg bid in the first group (G1) and of 200 mg bid in the second group (G2)]. Overall survival (OS) and time to symptomatic progression (TTPsymp) were studied as primary outcome parameters. Secondary outcomes included time to radiologic progression (TTPrad) according to CT and safety. In addition, digital contrast-enhanced NMR (DCE-NMR) and contrast-enhanced ultrasound (CEUS) of liver metastases were performed in selected pts.

Results: A total of 62 pts (median age 63 yrs, range 35–83 yrs; 31 female [50%], 31 male [50%], ECOG 0 44 pts [71%], ECOG 1 15 pts [26%], ECOG 2 2 pts [3%]) were included in the analysis on an intent to treat basis (ITT). Fortysix pts had no prior systemic treatment (74%). Metastatic sites included liver in 60 pts (97%) in addition to other organs in 20 pts (32%). Only two pts (3%) had exclusively extrahepatic metastases. Following 4 CTC-Grade 4 toxicities [hand-foot-syndrome (HFS) and/or diarrhea] in the first 31 pts (G1) (13%), the starting dose of S was reduced to 200 mg twice daily in the subsequent 31 pts (G2) effectively preventing further severe side effects. Median OS was 10.8 mths (CI 6.1–15.1 mths) in G1 and 14.0 mths (CI 6.4-nd mths) in G2, median TTPrad was 5.0 mths (CI 3.1–8.9 mths) in G1 and 4,5 mths (CI 1.5–6.0 mths) in G2 and TTPsymp was 4.1 mths (CI 3.1–5.2 mths) in G1 and 7.1 mths (CI 3.2–10.6 mths) in G2 (Wilcoxon 0.043), respectively.

Conclusions: S at a dose of 200 mg bid is safe in pts with metUvMel predominantly metastatic to the liver and seems to be effective with a median OS of more than 10 mths. Treatment results are encouraging in an orphan malignant disease without established palliative systemic treatment options. A multicenter randomized discontinuation trial with S in pts with metUvMel will be performed.

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 C185.
Abstract C186: In vitro profiling and compare analysis of the novel HDAC6-selective inhibitor ST80 in 42 human tumor cell lines.
Authors: Kelter Gerhard , Metz Thomas , Diana Stolfa , Jung Manfred , Fiebig Heinz-Herbert
Published: June 2012

Inhibitors of histone deacetylases (HDAC) have been shown to be potent anti-proliferative agents mediated in part by induction of histone acetylation, resulting in growth arrest, cell differentiation and apoptosis. ST80, a novel HDAC inhibitor of the hydroxamate class was investigated for anti-tumor activity towards a panel of human tumor cell lines. At Oncotest a cellular profiling screen was developed in which new compounds are being tested in a standard cell line panel consisting of 42 cell lines from all major solid tumor types. The read-out of the assay is propidium iodide-based fluorescence, which is a measure of viable cell number. For the purpose of mechanism of action (MOA) analysis, the IC50 pattern of the new compounds is compared with the corresponding patterns of 118 agents with a known MOA. Additionally, Compare Analysis can indicate off-target effects of compounds for which targets have previously only been confirmed biochemically. Simultaneously, particularly sensitive and resistant cell lines are identified, helpful for the selection of cell lines and tumor xenografts for follow-up studies like the ex vivo tumor colony assay or in vivo studies using human tumor xenografts growing in nude mice.

Concentration-dependent antitumor activity was detected for ST80 towards all cell lines tested with a mean IC50 value of 26.8 μM. Compare Analysis revealed the highest correlations towards HDAC inhibitors M344 (spearman's rho=0.84) and SBHA (rho=0.80) of the hydroxamate class, followed by apicidin (cyclic peptide, rho=0.60) and SAHA (hdroxamate, rho=0.57). Only the 5th ranked compound in Compare Analysis (daunorubicin, rho=0.53) was not an HDAC inhibitor, underscoring ST80's highly specific activity towards HDAC. The relative HDAC inhibiting potential was compared against immunoprecipitated FLAG-tagged HDAC1 and 6. ST80 demonstrated a 31-fold higher catalytic inhibition of purified HDAC6 activity (IC50= 0.9 μM) relative to HDAC1 activity (IC50= 29 μM). HDAC6 selectivity of ST80 was confirmed by acetylation of alpha-tubulin, an HDAC6 specific substrate, relative to acetylation of lysine 12 on histone H4 by immunoblotting whole cell lysate from SKBR3 cells treated for 24 h with 50 μM of ST80.

In conclusion, by using Oncotest's Compare Analysis inhibition of HDAC by ST80 was clearly confirmed. Selective catalytic activity towards HDAC6 was demonstrated biochemically.

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 C186.
Abstract C187: Posttreatment with PI3-kinase inhibitor enhances the chemotherapeutic effect of cisplatin nanoparticles in breast cancer.
Authors: Pandey Ambarish , Roy Bhaskar , Sarangi Sasmit , Sengupta Poulomi , Kopparam Jawahar , Basu Sudipta , Sengupta Shiladitya
Published: June 2012

Nanoformulations of chemotherapeutic drugs are increasingly being studied for their potential to improve efficacy and safety. However, limited studies have been done on sequential dosing of nanochemotherapeutics and signal transduction inhibitors. In this study, pre-treatment and post-treatment dosing of PI-3 kinase inhibitor PI828 was used with cisplatin nanoparticles in murine breast cancer model. In vitro cell proliferation assay showed an enhanced cytotoxic capacity of cisplatin nanoparticle when used in combination with PI828. Moreover, post-treatment with the signal transduction inhibitors was found to be significantly more effective than pre-treatment. Western blot analysis showed a time dependent upregulation of phospho- AKT expression after administration of cisplatin nanoparticles, which was efficiently suppressed by PI828 in the post-treatment schedule. The upregulation of piAKT dependent signalling was mediated by both an EGFR dependent downstream activation of PI3 kinase pathway and an increased nuclear transcription of Akt gene. Post treatment with EGFR inhibitor (Erlotinib) showed similar enhancement in cytotoxicity of cisplatin nanoparticle.

In a 4T1 syngenic murine cancer in-vivo model, post-treatment with PI828 and Erlotinib following cisplatin nanoparticles treatment significantly suppressed tumor growth as compared to the pre-treatment or nanoparticles alone. These results indicate that sequence of administration of signal transduction inhibitors can impact the outcome of treatment with cisplatin nanotherapeutics.

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 C187.
Abstract C210: Microregional distribution and activity of camptothecins in tumor xenografts.
Authors: Kyle Alastair H. , Baker Jennifer H.E. , Gandolfo Maria-Jose , Minchinton Andrew I.
Published: June 2012

Background: The tumor microenvironment plays an important role in determining the activity of many anticancer drugs and one critically important factor that has recently garnered considerable interest is the micro-regional distribution of anticancer drugs within tumors. One of the key issues being whether chemotherapy drugs reach all the cells within a tumor at concentrations high and long enough to exert a therapeutic effect. Irinotecan and topotecan are two camptothecin analogues with differing pharmacological and physicochemical properties, both exhibit clinical activity though are not curative. In this study the micro-regional distribution of the two analogues was compared to their pattern of activity with tumor cryosections.

Methods: Using whole tissue section mapping and multiplexed immunostaining techniques irinotecan and topotecan fluorescence was detected in relation to tumor vasculature in cryosections from HCT116 xenografts 1, 2, 4, 8 & 24 hours following their administration. The tissue sections were subsequently stained to map drug activity via apoptosis and proliferation status at early (1–24 hours) and late (1–14 days) times after treatment.

Results: Topotecan exhibited a faster and more uniform tissue distribution than irinotecan but experienced significant wash-out within the first 2 hours following treatment. Irinotecan exhibited a larger concentration gradient in relation to tumor blood vessels but appeared to benefit from a longer retention within the tissue, with significant exposure occurring out to 8–24 hours following treatment. Interestingly, irinotecan did not appear to permeate equally from all vessels within the tumors. Some areas of the tumors received much higher exposure than others. At 50 mg/kg irinotecan and 10 mg/kg topotecan, both agents were able to exert a uniform block of cycling tumor cells within 4 hours of treatment but by 24 hours tumor proliferation status had returned to near normal levels indicating neither drug was retained long enough to exert activity on cells that were out of cycle at time of treatment.

Conclusions: Development of new camptothecin analogues might benefit from design strategies to increase tumor retention and uniformity in tissue distribution. While both irinotecan and topotecan were able to exert a significant and uniform cell cycle block within 4 hours of treatment in the HCT116 xenografts, due to their short retention proliferation was seen to recover by 24 hours. Irinotecan appeared to distribute less uniformly within the 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 C210.
Abstract C217: Aneuploidy induction by the microtubule-stabilizing agent peloruside A involves the cell cycle checkpoint proteins MAD2 and p55CDC.
Authors: Chan Ariane , Miller John H.
Published: June 2012

Peloruside A (PelA) is a novel secondary metabolite isolated from the New Zealand marine sponge Mycale hentscheli. It is a potent microtubule-stabilizer and binds to a distinct site on -tubulin compared to the widely used anti-cancer drug paclitaxel. PelA has clear potential benefits over paclitaxel, including increased solubility, reduced sensitivity to multiple drug resistance in cancer cell lines, and improved tolerability and efficacy in non-small cell lung cancer xenografts in mice. Previous chemical genetics studies have indicated that MAD2 (mitotic arrest deficiency-2), a spindle-assembly checkpoint (SAC) protein, could potentially be a secondary target of PelA. Premature dissociation of MAD2 from the SAC protein, p55CDC, has been implicated in the induction of aneuploidy in response to low concentrations of paclitaxel; thus, we sought to validate and investigate MAD2 as an additional target of PelA. Flow cytometric analysis of 1A9 (human ovarian carcinoma) cells confirmed that low concentrations of PelA (< 40 nM) induced chromosome mis-segregation in up to 15% of cells. Western blot analyses detected minimal changes in the abundance levels of MAD2, BUBR1 and p55CDC at both high (100 nM) and low (40 nM) PelA concentrations. However, differences in the association between MAD2 and BUBR1 with p55CDC were observed after cells were released from synchronization and assessed by co-immunoprecipitation. The mitotic arrest seen at 100 nM PelA was accompanied by a sustained formation of MAD2/p55CDC and BUBR1/p55CDC complexes; whereas, 40 nM PelA resulted in a similar dissociation profile of these complexes compared to controls. Given that PelA-induced aneuploidy coincides with G2-M progression, it is likely that dissociation of these complexes occurs despite aberrant microtubule-kinetochore attachments. Studies are currently underway to determine whether this increase in aneuploidy is due to the presence of erroneous attachments that are not detected by the SAC, such as merotelically oriented chromosomes. Aneuploidy is important because of its link to apoptosis and cancer cell death, and these experiments will help to elucidate some of the underlying signalling pathways. Additionally, these studies improve our understanding of the molecular actions of PelA during the cell cycle and highlight the importance of characterizing the concentration-dependent effects of drug interactions.

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 C217.
Abstract C218: Novel therapeutic potential in targeting micro tubules by naturally occurring anti cancer agent withaferin A in human cancers.
Authors: Ghosh Kamalini , Sengupta Sumita
Published: June 2012

Background: Chemical compounds from natural sources continue to serve as important pharmacological tools for the understanding of biological pathways and also provide chemical platform for new drug discovery. The utility of various anti-microtubule agents from natural origins are the best examples that continuously serve these two purposes. In this study, we have identified a novel tubulin-targeting activity of a natural product Withaferin-A. Though several groups have already shown that Withaferin-A is a potent anti-cancer agent, can kill variety of carcinomas by inducing apoptosis, but not much is known about its molecular targets inside the cell. This study is to evaluate the therapeutic efficacy of WA towards human cancer, in relation to its ability to directly targeting microtubule dynamics within cell.

Methods: The IC-50 value of WA was determined by MTT assay, apoptosis and cell cycle assay was performed by FACS analysis, wound healing assay was done to see cellular migration, immune fluorescent detection was done to check microtubular network of WA treated cells. Effect of WA on tubulin polymerization in cell free system was studied by light scattering assay, binding measurements of WA to tubulin was determined by flurometric assay and probable WA-tubulin interaction site was proposed by molecular modeling method.

Results: We have identified WA as a novel anti-microtubule agent that inhibits proliferation, migration and cellular progression by affecting mitosis in HeLa and MCF-7 cells. Brief incubation with nontoxic concentrations of WA induced significant depolymerization of interphase and mitotic spindle microtubules. It inhibits tubulin polymerization, induces conformational changes in tubulin by directly binding to purified tubulin. Both in silico and in-vitro studies indicated that WA preferably binds to a novel site on tubulin.

Conclusion: It is evident that WA suppresses microtubule dynamics by directly binding to tubulin which sheds light on mechanisms behind its anti-proliferative activity towards cancer 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 C218.
Abstract C24: Phase I trial of dasatinib and ixabepilone in patients with solid tumors.
Authors: Herbolsheimer Pia M. , Kapoor Rita , Smith Karen L. , Perry David , Verma Nitin , Veytsman Irina , Jelinek James , Swain Sandra M.
Published: June 2012

Background: Ixabepilone is an epothilone B analog that stabilizes tubulin, disrupts homeostasis and induces apoptosis. Dasatinib is a potent oral tyrosine kinase inhibitor (TKI), which inhibits multiple targets including SRC. Synergistic activity has been reported when combining dasatinib with chemotherapy agents. This phase I study was conducted to determine the dose-limiting toxicities (DLTs), maximum tolerated doses (MTDs), pharmacokinetics (PK) and preliminary antitumor activity for ixabepilone and dasatinib when used in combination.

Methods: Patients with metastatic or unresectable solid tumors who progressed on standard therapy received ixabepilone and dasatinib at escalating doses. An expansion cohort was formed after the MTD was reached. PK studies were performed.

Results: Nineteen patients were enrolled. No DLTs were seen at dose level (DL) 1 (ixabepilone 30 mg/m2 IV Q 3 weeks, dasatinib 100 mg PO QD). At DL 2 (ixabepilone 40 mg/m2 IV Q 3 weeks, dasatinib 100 mg PO QD), the second patient had 3 DLTs (grade 3 diarrhea, grade 4 neutropenia and grade 3 febrile neutropenia), thus DL 2 was expanded to include 6 patients. No additional DLTs were seen at DL 2. At DL 3 (ixabepilone 40 mg/m2 IV Q 3 weeks, dasatinib 150 mg PO QD), the first patient developed grade 3 diarrhea during cycle 2 and the second patient had a DLT (grade 3 diarrhea) and grade 3 mucositis during cycle 2. Accrual to DL 3 was halted due to these toxicities and MTDs were designated to be ixabepilone 40 mg/m2 IV every 3 weeks and dasatinib 100 mg PO daily (DL 2). Additional 8 patients were then enrolled to DL 2. Three of these patients experienced DLTs (grade 4 neutropenia, grade 3 hyperkalemia and grade 3 fatigue). The best responses included one (5%) partial response (PR) in a lung cancer patient. Twelve (63%) patients had stable disease (SD) for at least 2 cycles. Altogether 13 (68%) patients came off study due to toxicities.

Conclusion: The combination of ixabepilone and dasatinib showed modest clinical activity with doses 40 mg/m2 IV every 3 weeks and100 mg PO QD, respectively. Treatment related toxicities were seen frequently.

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 C24.
Abstract C4: Specific targeting of spontaneous medulloblastoma tumors in mice by IRDye 800CW chlorotoxin.
Authors: Kovar Joy L. , Curtis Evan , Othman Shadi F. , Simpson Melanie A. , Olive D. Michael
Published: June 2012

Studies of primary brain tumors such as medulloblastoma are hampered by the nature of the cancer and the location of these tumors. Improving our ability to detect and assess intracranial tumor growth would significantly advance diagnosis and inform recommendations by clinicians for subsequent therapy and treatment. Use of molecular imaging with targeted near infrared optical imaging agents has been successfully implemented in the visualization, characterization and measurement of biological processes including cancer. Our studies seek to define the use of IRDye 800CW chlorotoxin (CLTX) as a targeted imaging agent for brain tumors in a spontaneous mouse model of medulloblastoma, ND2:SmoA1. Early detection of tumors was accomplished by MRI followed by IRDye 800CW CLTX administration. Blood-brain-barrier integrity was examined by Evan's Blue testing prior to sacrifice. Additional information was obtained with brain imaging and tissue section analysis of H&E staining to confirm colocalization of tumor and fluorescent probe signal. Results show IRDye 800CW CLTX successfully targeted tumor tissue with minimal Evan's Blue staining, indicating retention of blood-brain-barrier integrity.

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 C4.
Abstract C40: Understanding the mechanism of action of novel iron chelators on drug-resistant neoplastic cells.
Authors: Yamagishi Tetsuo , Jansson Patric J. , Sharp Danae , Richardson Des R.
Published: June 2012

Introduction: Deprivation of cellular iron (Fe) may represent a novel and effective anti-cancer strategy1. Our laboratory has developed iron chelators with marked and selective anti-tumor activity against a variety of tumor types in vitro and in vivo. One of our leading compounds, Dp44mT, demonstrated potent anti-tumor activity against drug-resistant cell lines1,2 over-expressing P-gp and MRP1. Moreover, these compounds possess high activity at releasing cellular 59Fe3.

Aims: To further understand the mechanism of chelator-mediated cellular 59Fe release we investigated:The difference in iron efflux between drug-resistant MCF7-VP (MRP1 hyper-expressing) cells and their wild-type counterparts (MCF7);Whether chelator-mediated Fe release was MRP1 and/or GSH-dependent and;If chelator-mediated cellular Fe release was temperature-dependent.

Results: These studies demonstrated that MRP1 over-expressing MCF7-VP cells showed reduced chelator-mediated59Fe release compared to MCF-7 cells (P<0.001). However, this was not due to functional MRP1 and was not GSH-dependent, as neither MRP1 inhibition (using MK571) nor GSH-depletion (using BSO) had any effect on chelator-mediated 59Fe efflux. We found 59Fe efflux was shown to be temperature-dependent, as chelator-mediated 59Fe efflux was reduced at 4°C compared to 37°C. This suggested chelator-mediated Fe release by chelators was an energy dependent process.

Interestingly, MCF7-VP cells showed higher 59Fe uptake from 59Fe-transferrin than wild-type cells. This was due to marked transferrin receptor-1 expression in MCF7-VP compared to MCF7 cells. Additionally, the only known Fe efflux pump, ferroportin1, was down-regulated in MCF7-VP cells. This latter observation was intriguing as chelator-mediated Fe efflux was depressed in this cell type. These studies indicate that chelator-mediated 59Fe release is temperature-dependent and MRP-independent. Further studies will examine the role of MRP1 in Fe uptake and metabolism.

References:

1. Whitnall, M., Howard, J., Ponka, P., and Richardson, D. R., Proc Natl Acad Sci U S A 103 (40), 14901 (2006).

2. Richardson, D. R. and Milnes, K., Blood 89 (8), 3025 (1997).

3. Richardson, D. R., Biochim Biophys Acta 1320 (1), 45 (1997).

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 C40.