bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 375: Fluorescence-guided surgery leads to improved resection of primary pancreatic cancer and prolonged survival
Authors: Raimo Cristina A. Metildi , Kaushal Sharmeela , Hardamon Chanae R. , Snyder Cynthia S. , Hoffman Robert M. , Bouvet Michael
Published: August 2012

The aim of this study was to determine if fluorescence-guided surgery (FGS) could improve surgical outcomes, reduce recurrence rates and improve overall survival in orthotopic mouse models of human pancreatic cancer. Orthotopic mouse models of human pancreatic cancer were established using the BxPC-3 RFP-expressing pancreatic cancer cell line in nude mice. Two weeks after implantation, the mice were randomized to undergo bright light surgery (BLS) or fluorescence-guided surgery (FGS). Pre- and postoperative images were obtained with the Olympus OV-100 Small Animal Imaging System to assess completeness of surgical resection. Whole body imaging of the mice was performed weekly in the postoperative period to assess for recurrence and follow tumor progression. Additionally, half of the mice were randomly selected to undergo 4 weeks of postoperative gemcitabine treatment. At six weeks postoperatively, or when premorbid, the mice were sacrificed and primary pancreatic tumor burden was measured using ImageJ v1.440. A more complete resection of pancreatic cancer was achieved using FGS compared to BLS: 98.9% vs 77.1%, p=0.005. Sixty-three percent of the mice undergoing BLS had evidence of gross residual disease, whereas 20% of mice undergoing FGS received a complete resection and an additional 75% of the mice were left with minimal residual disease (p=0.0001). At six weeks, the primary pancreatic tumor burden was significantly less with FGS compared to BLS: 19.341 ± 5.26 mm2 vs. 6.194 ± 3.61 mm2, p=0.048. In a pilot survival study, FGS alone was associated with a decreased risk of tumor recurrence (HR=0.093, 95% CI 0.013-0.645), and mean overall survival was lengthened from 18.5 weeks to 28.2 weeks. The addition of adjuvant gemcitabine (GEM) to FGS further lengthened mean overall survival to 42.75 weeks (p=0.019). Three of the four mice in the FGS with adjuvant gemcitabine group were alive at 12 months postoperatively and all of the mice (n=4) were free of tumor at time of sacrifice. In this study, we achieved improved surgical outcomes in primary pancreatic cancer under fluorescence-guidance. FGS afforded a more complete resection of primary tumor and improved disease-free survival and overall survival. The combination of FGS and GEM lengthened disease-free survival and improved overall survival. This novel approach has potential to improve outcomes in the surgical treatment of pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 375. doi:1538-7445.AM2012-375
Abstract 3754: Characterization of NMS-P285, a new highly selective and potent BRAF inhibitor
Authors: Pulici Maurizio , Amboldi Nadia , Pastori Wilma , Marchionni Chiara , Traquandi Gabriella , Cribioli Sabrina , Lupi Rosita , Modugno Michele , Casale Elena , Scolaro Alessandra , Felder Eduard , Donati Daniele , Isacchi Antonella , Pesenti Enrico , Galvani Arturo , Ciomei Marina
Published: August 2012

Aberrant activation of the MAPK-mediated pathway components, RAF-MEK-ERK, is frequently found in human cancers and clearly contributes to oncogenesis. In particular, one of the three isoforms of RAF, BRAF, presents activating somatic mutations in 60% of melanomas, 50% of thyroid cancers, 10% of colon and 20% ovarian carcinomas. The most common BRAF mutation, substitution of glutamic acid for valine at position 600 within the activation segment of the kinase domain, accounts for 90% of mutated BRAF cases, and results in elevated kinase activity with consequent enhanced promotion of cell survival and proliferation. BRAF selective inhibitors as vemurafenib and dabrafenib have recently shown excellent results in patients with advanced melanoma expressing BRAF V600E mutant form. Here we describe the in vitro and in vivo properties of a novel potent and selective BRAF inhibitor belonging to the arylthiazole class of compounds. This, NMS-P285, is a potent inhibitor of both wild-type and mutated BRAF, with no cross-reactivity in a panel of 61 kinases. This compound occupies the ATP-binding pocket of the activated form of the enzyme (DFG motif in), partly filling the kinase back pocket, (i.e. type I ½ inhibitors). NMS-P285 has an antiproliferative activity in the low nanomolar range only against cell lines bearing BRAF V600E or V600D mutations. Its mechanism of action is confirmed: a strong inhibition of MAPK pathway was observed in BRAF mutated cells whereas in non-BRAF mutated cells MEK activation was not observed. NMS-P285 possesses a favourable in vitro ADME profile and a very good preliminary PK in mouse. When orally administered to mice with BRAF mutated human xenograft tumors, NMS-P285 resulted more potent than both vemurafenib and dabrafenib demonstrating high antitumor activity with strong and persistent tumor regression observed in all mice. Mechanism of action was demonstrated also ex vivo in A375 bearing mice: MAPK pathway resulted to be completely inhibited up to 6 hours after a single treatment at 30 mg/kg. In conclusion, NMS-P285 is a candidate suitable for preclinical development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3754. doi:1538-7445.AM2012-3754
Abstract 3761: Efficacy of the ATP-competitive mTOR inhibitor AZD8055 in PTEN-wild type cancer cells
Authors: Dai Yao , Siemann Dietmar W.
Published: August 2012

Although the PI3K/Akt/mTOR pathway is frequently hyperactivated in human cancers due to the loss of function of the PTEN tumor suppressor, a proportion of cancer cells still carries wild type PTEN and thus the PI3K/Akt/mTOR pathway in these cells may remain unaltered. While it has been widely accepted that these cancer cells are less susceptible to the allosteric mTOR inhibitor rapamycin, it is unclear whether this is also the case for an ATP-competitive mTOR inhibitor. To address this question we evaluated the effects of the mTOR kinase inhibitor AZD8055 in a panel of wild type PTEN expressing cancer cells (6 cell lines of 4 tumor types). The phosphorylated Akt (S473) level was undetectable in most of these cells, suggesting the regular mTOR complex 1 (mTORC1) pathway and low mTOR complex 2 (mTORC2) activity. Cell proliferation was determined by WST-1 (MTT) assay and clonogenic survival was tested by colony formation assay. AZD8055 suppressed cell proliferation at the nanomolar level in a dose dependent manner, with IC50 values in a range of 6∼35 nM for different cell types. In contrast, rapamycin exhibited limited anti-proliferative effect, with less than 50% of inhibition observed even with higher doses in most cell lines. Similarly, clonogenic capacity was impaired by AZD8055 to a greater extent than was the case for rapamycin. To detect the mTOR pathway alterations by drug treatment, two cell lines with different expression levels of mTORC1 downstream pathways were selected: murine mammary tumor 4T1 cells (low phosphorylated S6 and high phosphorylated 4E-BP1) and human breast cancer MDA-MB-231 cells (normal phosphorylated S6 and moderate phosphorylated 4E-BP1). While the phospho-S6K (T389) and phospho-S6 (S235/236) pathway was potently inhibited by both agents, AZD8055 displayed more striking inhibition of the hierarchical 4E-BP1 phosphorylation (T37/46, T70 and S65) than rapamycin in both cells. In addition, both rapamycin and AZD8055 slightly increased Akt phosphorylation (T308 or S473), suggesting that the activation of the feedback loop controlled by S6K was functional. However, the PI3K inhibitor wortmannin did not sensitize cells to either agent, implying such feedback-dependent activation is dispensable for attenuating the drug response. Taken together, these findings indicate that AZD8055 significantly inhibits growth and survival of cancer cells that have wild type PTEN and normal PI3K/Akt/mTOR signaling, an observation mainly associated with the comprehensive activation of 4E-BP1. These data provide in vitro evidence in support of broadening the application of ATP-competitive mTOR inhibitors in cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3761. doi:1538-7445.AM2012-3761
Abstract 3766: Effects of a high-fat meal on the pharmacokinetics of orally administered GSK2118436 in patients with BRAF mutation-positive tumors
Authors: Grossmann Kenneth F. , Infante Jeffrey R. , LoRusso Patricia M. , Sharma Sunil , Blackman Samuel C. , Carson Stanley W. , Krachey Elizabeth C. , Nebot Noelia , Ouellet Daniele , Gordon Michael S.
Published: August 2012

GSK2118436 is a potent and selective small-molecule inhibitor of BRAF kinase activity that is currently being developed for the treatment of BRAF mutation-positive tumors. This study evaluated the effect of a high-fat meal on the pharmacokinetics (PK) of a single 150 mg oral dose of GSK2118436 administered to patients with BRAF-mutant solid tumors. This was an open-label, randomized, two-period crossover study. In a cohort of 14 patients, GSK2118436 was administered under fasted state or with a high-fat meal, with a 1-week washout between periods. Blood samples were collected up to 96 hours post-dose to characterize the PK of GSK2118436 and its circulating metabolites. PK parameters were calculated by non-compartmental methods (WinNonlin 5.2). Geometric mean ratios (fed/fasted) for the point estimate and 90% CIs were calculated for Cmax and AUC0-α, and median difference (90% CI) was calculated for tmax using the Hodges-Lehmann non-parametric method. The absence of a food effect can be concluded if the 90% CIs are contained between 0.8 and 1.25 for Cmax and AUC0-α. Following administration of a high-fat meal, median Cmax concentrations were delayed by 3.7 h (90% CI: 2.4-5.0) compared with the fasted state. A high-fat meal decreased the exposure to GSK2118436, with geometric mean ratios (90% CI) for Cmax and AUC0-α of 0.49 (0.35-0.69) and 0.69 (0.57-0.85), respectively. Metabolite exposures were decreased to a similar extent. Based on the data generated in this study, it appears that there is a food effect for GSK2118436, as the 90% CI are not contained within the acceptable boundaries of 0.8 and 1.25. In clinical studies GSK2118436 has been administered on an empty stomach, and results from this study are consistent with these recommendations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3766. doi:1538-7445.AM2012-3766
Abstract 377: Organic Anion Transporting Polypeptides (OATPs): A potential new molecular target for imaging/therapy of hormone dependent breast cancers
Authors: Banerjee Nilasha , Allen Christine , Bendayan Reina
Published: August 2012

The purpose of this research is to explore the potential of Organic Anion Transporting Polypeptides (OATPs), a family of membrane-associated uptake transporters, as a novel molecular target for imaging and treatment of breast cancers. It has been reported that some of the OATP isoforms (e.g. OATP1A2, OATP2B1) are over expressed (up to ten times) in breast cancer tissues as compared to surrounding normal tissues. Furthermore, estrone-3-sulpahte (E3S), a predominant source for tumour estrogen in post-menopausal patients with hormone dependent breast cancers has been characterized to be a substrate for many of the OATP isoforms. This suggests that the two- three times higher E3S concentration reported in malignant tissues, as compared to the surrounding normal tissues, could be due to higher expression and/or increased functional activity of OATPs in breast tumour tissues. By characterizing the differential expression and function of OATPs in breast epithelial cells and breast cancer cells, their potential as novel molecular targets can be established. In this study, the gene and protein expression of seven OATPs (i.e. OATP1A2, OATP1B1, OATP1B3, OATP1C1, OATP2B1, OATP3A1 and OATP4A1) that are known to recognize E3S as a substrate, were compared in normal breast epithelial cells (MCF10A), hormone dependent breast cancer cells (MCF7) and hormone independent breast cancer cells (MDA/LCC6-435, MDA-MB-231 and MDA-MB-468) by real time qPCR and immunoblotting. OATP mediated E3S uptake was also characterized by transport experiments. Six of the seven OATPs (except SLCO1C1) were found to be expressed in breast cancer cells at the transcript level. Expression of SLCO1A2, 1B1, 1B3, 2B1 and 3A1 was exclusive, similar or significantly higher (p<0.001) in cancer cell lines compared to the normal breast epithelial cells (MCF10A). At the protein level, expression of all the OATP isoforms was observed to be either exclusive or higher in the cancer cell lines as compared to the MCF10A cells. Specificity of OATP mediated E3S uptake was observed only in the cancer cells with significantly higher total uptake in the MCF7 cells. Estimation of the transport kinetics (Km and Vmax) of E3S uptake by the breast cancer cell lines, demonstrated E3S transport efficiency to be 10 times greater in the hormone dependent breast cancer cells than in the hormone independent cells. Taken together, these data suggest that i) OATPs can be a potential molecular target for hormone dependent breast cancers in post menopausal patients and ii) E3S can be used a ligand for actively targeting hormone dependent breast cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 377. doi:1538-7445.AM2012-377
Abstract 3779: Novel oral gallium compounds as modulators of cancer-related accelerated bone loss
Authors: Warrell Raymond P. , Thottathil John K.
Published: August 2012

Accelerated bone loss is associated with a number of metabolic and neoplastic conditions. Estrogen-receptor modulation, bisphosphonates (BP), and RANKL-inhibitors (RLI) are useful for metabolic bone disease. Parenteral BPs and RLIs are also associated with skeletal morbidity, including osteonecrosis. No oral agent has yet proved suitable for treatment or prevention of adverse skeletal-related events (SREs) in cancer patients (pts) with bone metastases. Our prior work showed that low-dose gallium (G) nitrate administered by subcutaneous injection (SC) reduced markers of accelerated bone resorption in pts with bone metastases from various tumor types, as well as advanced Paget's disease. Moreover, extended therapy for 6-12 mos (0.5 mg/kg SC 2 wks on/2 wks off) produced substantial increases in total body calcium (measured by neutron activation analysis) in pts with myeloma receiving chemotherapy. However, inorganic G-compounds also exhibit low oral availability. Therefore, we synthesized a series of organic G-containing compounds to test their suitability as facilitators of long-term G administration. This work isolated several lead compounds that were then evaluated in animal studies. Methods: Isolated compounds were administered by oral gavage to dogs (Calvert Laboratories, Inc.), which then underwent serial blood sampling over 24 hrs. The objective was to achieve target plasma concentrations at specific times that had proved effective in acutely normalizing elevated blood calcium in human subjects with cancer-related hypercalcemia. Results: Various amino acid-like complexes yielded unpredictable results. Proline and carnosine showed only modest oral availability, compared with mandalate and histidine complexes that were superior. Among other organic bidentate G compounds, G4544(a) achieved a peak target, but time-to-peak (TTP) concentrations was delayed. G-4544(b), the same complex but with reduced nitrate content, improved TTP concentrations, but a follow-on study in human subjects failed to reproduce observations in dog (Proc. AACR 2010). To date, the complexes G4546 and G4547 yielded the best results, promptly achieving peak stable concentrations consistent with target objectives. Conclusion: The organic G compound, G4546, will be advanced into human clinical trials to determine its suitability for extended treatment of oncology patients who may develop accelerated bone loss.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3779. doi:1538-7445.AM2012-3779
Abstract 3787: Pharmacokinetics and pharmacodynamics of AV-203, a humanized anti-ERBB3 antibody
Authors: Meetze Kristan , Tyler Steven M. , Fleet Christina , Vincent Sylvie , Gifford James , Gyuris Jeno
Published: August 2012

ERBB3 is widely expressed in human carcinomas, and its over expression is associated with poor prognosis in patients with various carcinomas, (i.e., breast, ovarian, prostate, colorectal, pancreatic, gastric, and head and neck cancers). The presence of ERBB3 correlates with local to distal metastasis in lung, gastric, and colorectal cancers as well as bone invasion in prostate cancer. Activation of ERBB3 is also implicated in the development of resistance to current cancer treatments. Due to its lack of kinase activity, the activation of the ERBB3 receptor is dependent on heterodimerization with active receptor tyrosine kinases (RTKs). The recruitment of ERBB3 into active, heterodimer complexes is mediated by its ligand Neuregulin-1 (NRG-1) or by amplified, over expressed RTKs in a ligand independent manner. Therefore, ERBB3 can crosstalk with most major receptors involved in cancer development and maintenance such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and c-MET. AV-203 is a potent, humanized anti-ERBB3 antibody that inhibits both ligand-dependent and independent activation of ERBB3 both in vitro and in vivo. Pharmacokinetics and pharmacodynamics of AV-203 were characterized in mice using the A549 non-small cell lung cancer xenograft model. AV-203 administered IV in mice exhibits acceptable pharmacokinetics supporting preclinical efficacy studies. AV-203 administered IV in A549 NSCLC xenograft tumor bearing mice had lower serum AUC than naïve mice, demonstrating that the presence of human ErbB3 may alter the PK parameters of AV-203. In evaluating pharmacodynamics in vivo, AV-203 was able to down regulate total ERBB3 and ERBB3 signaling in A549 tumors in a time-dependent manner. Inhibition of ERBB3 signaling correlated with significant dose-dependent tumor growth inhibition in the A549 xenograft model. Dose scheduling studies with the constant AV-203 dose of 2.5 mg/kg revealed that the most efficacious schedule is the more frequent dosing at Q3D. In comparing the total dose of 10 mg/kg per 14 day cycle, at varying dose per injection and frequency, AV-203 resulted in significant tumor growth inhibition at all dose schedules. These data conclude that the efficacy of AV-203 is driven by total drug exposure and that AV-203 is not dependent on Cmax for its antitumor activity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3787. doi:1538-7445.AM2012-3787
Abstract 3797: Hyperphosphorylation and desumoylation of RanGAP1·SUMO1
Authors: Oussenko Irina , Holland James F. , Reddy E. Premkumar , Ohnuma Takao
Published: August 2012

Previous work from our laboratory showed that tumor cells exposed to an anticancer mitotic inhibitor, regosertib (ON 01910.Na), resulted in G2/M arrest and hyperphosphorylation of RanGAP1·SUMO1 (HRGS). These findings suggest that regosertib may act either as an inhibitor of a RanGAP1·SUMO1 phosphatase or stimulant of a new kinase (Cancer Res 2011; 71; 4968-76). We further studied the relationship between dephosphorylation and deSUMOylation of HRGS. In the present study we used DU145 prostate cancer cell line. After exposure to one microM regosertib for 24 h, cells were collected and subjected, in equal portions, to lysis in different lysis buffers composed of basic lysis buffer and varied in supplemented inhibitors. Basic lysis buffer contained 10 mM Tris-HCl, pH 8.0; 150 mM NaCl; 1% Triton; 0.5% NP-40; 1 mM EGTA and 1 mM EDTA. Thus, prepared cell lysates were analyzed by Western blot for expression of phosphorylated and non-phosphorylated forms of RanGAP1, RanGAP1·SUMO1, PP1 and Cdc25C. Results: Roche protease inhibitor cocktail, PMSF (0.5 mM), NaF (1 mM) and Na3VO4 (1mM) as inhibitors added to the basic lysis buffer were unable to protect against loss of SUMO-group from RanGAP1·SUMO1 and, concomitantly, against de-phosphorylation of PP1 phosphatase at T-320. However, addition of N-ethylmaleimide (NEM, an inhibitor of deSUMOylation) as a single inhibitor supplement in the basic lysis buffer resulted in concentration-dependent (2.5 ∼ 40mM) inhibition of deSUMOylation of HRGS. Yet, even at lower NEM concentration RanGAP1, devoid of the SUMO-group, was still phosphorylated. This might be in correlation with our finding that even low concentration of NEM in the lysis buffer kept PP1 in phosphorylated state at T320 (which is inhibitory to PP1), preventing it from auto-dephosphorylation and re-activation. Also, neither regosertib (up to 100 microM) nor okadaic acid (OA, up to 1 microM), added to the basic lysis buffer as putative inhibitors, could prevent loss of SUMO group from HRGS and dephosphorylation of PP1 at T320. Regosertib in the lysis buffer did not prevent dephosphorylation of hyperphosphorylated Cdc25C (aka mitotic Cdc25C), while NEM and OA did (the latter implies that dephosphorylation was carried out by PP1 in the lysate). Conclusion: These data show that hyperphosphorylated RanGAP1·SUMO1 can be deSUMOylated, but remains phosphorylated. DeSUMOylation may be a prerequisite for RanGAP dephosphosphorylation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3797. doi:1538-7445.AM2012-3797
Abstract 3798: Cryptotanshinone inhibits lymphatic endothelial cell tube formation by suppressing VEGFR-3/ERK and small GTPase pathways
Authors: Luo Yan , Huang Shile
Published: August 2012

Cryptotanshinone (CPT), a natural compound isolated from the plant Salvia miltiorrhiza Bunge, is a potential anticancer agent. However, the underlying mechanism is not well understood. Here we show that CPT inhibited the tube formation of mouse lymphatic endothelial cells (LECs) in a concentration- and time-dependent manner. This effect was in part associated with inhibition of VEGFR-3 expression, as overexpression of VEGFR-3 conferred resistance to CPT inhibitory effect on tube formation in LECs, whereas downregulation of VEGFR-3 mimicked the effect of CPT, blocking the tube formation. Further study revealed that CPT inhibited phosphorylation of the extracellular signal-related kinase 1/2 (ERK1/2), a downstream effector of VEGFR-3. Overexpression of VEGFR-3 attenuated CPT inhibition of ERK1/2 phosphorylation, whereas downregulation of VEGFR-3 inhibited ERK1/2 phosphorylation in LECs. Ectopic expression of constitutively active MKK1 resulted in activation of ERK1/2, and partially prevented CPT inhibition of LEC tube formation. In addition, we also found that CPT inhibited protein expression and activities of Cdc42 and Rac1, but not RhoA. Downregulation of Cdc42 or Rac1 inhibited LEC tube formation, mimicking the effect of CPT. However, expression of constitutively active Cdc42 and Rac1 concurrently, but not Cdc42 or Rac1 alone, rendered resistance to CPT inhibition of LEC tube formation. The results suggest that CPT inhibits LEC tube formation at least in part through inhibiting VEGFR-3-mediated ERK and the small GTPase signaling pathways.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3798. doi:1538-7445.AM2012-3798
Abstract 3799: Polyamine Transport System (PTS) activity and hijacking in cancer cells: New option in Head and Neck tumors treatment with the polyamine-containing drug candidate F14512
Authors: Meignan Samuel , Mouawad Francois , Dewitte Amelie , Bertheau Charlotte , Wattez Nicole , Gros Abigaelle , Lartigau Eric , Chevalier Dominique , Bailly Christian , Lansiaux Amelie
Published: August 2012

The Polyamine Transport System, although not clearly identified at the molecular level in eukaryotic organisms, was found over activated in many types of cancer cells, such as leukemia, prostate, melanoma and NSCLC. Polyamines are implicated in many biological functions, and the need for polyamines in tumor cells, conveyed by the PTS, is crucial. New therapeutic strategies consist to use this transport system to deliver a cytotoxic agent specifically into cancer cells. Head and neck cancer remains the 6th common cancer with a very poor survival rate indicating the crucial need for new targeted strategies. For this study, we used 4 Head and Neck (H & N) cancer cell lines representative of various localizations: CAL 33 and CAL 27 from base of the tongue, Fadu from the pharynx and SQ20B from the larynx. Here, using a polyamine-coupled fluorescent probe, we show that the PTS is active in all head and neck cancer cell lines regardless the tumor localization. In these models, flow cytometry demonstrated that the PTS incorporates quickly, massively and specifically the probe into cancer cells. Confocal microscopy observations revealed that the spermine probe accumulates into the cell nuclei, the site of action of F14512 which is a potent topoisomerase II inhibitor. Considering this property, we evaluated the potential of the F14512 (Pierre Fabre laboratories, France) in these H & N cancer cell lines. F14512 contains a PTS-recognized spermine side chain attached to an epipodophyllotoxin moiety targeting topoisomerase II. We found that F14512 presents a much higher cytotoxicity than etoposide in the 4 cell lines. Competition assays showed that this effect is dependent of the PTS activity and confirmed the targeted action of F14512 against cells with active PTS. The high efficiency of F14512 in the head and neck cancer cell lines is reported here for the first time and may be of interest for the future development of this novel drug candidate, currently in phase 1 clinical trial in leukemia. Studies are in progress, using fresh tumor biopsies from patients with head and neck cancer, to analyze the PTS status of the tumors using the specific spermine-containing fluorescent probe and to evaluate the activity of F14512.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3799. doi:1538-7445.AM2012-3799
Abstract 380: Optimization of novel therapeutic paradigms for ovarian cancer using molecular imaging
Authors: Wang Hanxiao , Galban Stefanie , Wu Rong , Bowman Brittany , Fletcha Athena , Witte Amanda , Chughtai Komal , Ross Brian , Cho Kathleen , Rehemtulla Alnawaz
Published: August 2012

Ovarian cancer is the fifth leading cause of cancer death among American woman. Platinum-based chemotherapy, such as cisplatin, represents the standard of care for ovarian cancer. However, toxicicity and acquired resistance to cisplatin have been proven challenging in the treatment of cancer patients. Here, we evaluate the efficacy of targeted inhibition of Akt in combination with cisplatin in an ovarian endometrioid adenocarcinoma (OEA) mouse model wherein Wnt and PI3K signaling pathways are disrupted thus recapitulating the human disease. In cell culture and mouse xenograft models, inhibition of Akt activity in combination with cisplatin is more potent at inducing apoptosis compared to either agent alone. To further explore this finding in living animals, we incorporate a bioluminescence apoptosis reporter into the existing OEA mouse model, to enable monitoring of apoptosis dynamically and non-invasively in real time. Our results demonstrate that Akt inhibitors augment the efficacy of cisplatin by inducing apoptosis more efficiently in our newly developed transgenic OEA model. Magnetic resonance (MR) imaging was also accomplished to determine tumor burden and normalize changes in bioluminescence. Our results show that inhibition of Akt sensitizes OEA to apoptosis in response to cisplatin thus resulting in reducing tumor burden.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 380. doi:1538-7445.AM2012-380
Abstract 3808: Tetrandrine blocks cell cycle progression and promotes growth arrest in prostate cancer cells by up-regulating CDK inhibitors (p21 and p27) and suppressing cyclin expression.
Authors: Koul Sweaty , Meacham Randall B. , Koul Hari K.
Published: August 2012

Introduction: Prostate cancer (PCa) is the second leading cause of cancer deaths in men. De-regulated cell cycle progression is one of the hallmarks of cancer cells. While many agents are available to inhibit growth and proliferation of normal cells, we do not have efficient agents that inhibit growth and proliferation of tumor cells, and no agents are able to achieve growth arrest and inhibition of cell cycle progression in castrate resistant prostate cancer. In this study we evaluated effects of Tetrandrine (Tet: a bis-benzylisoquinoline alkaloid isolated from the root of Stephania tetrandra) that has been shown to have diverse biological properties, on cell growth, proliferation and cell cycle progression in prostate cancer cells. Methods: Prostate cancer cells, LNCaP cells (androgen dependent), LNCaP C-4 and C4-B (castrate resistant lineages derived from LNCaP cells) cells were obtained from ATTCC. Cells were maintained in select media and grown in 5% CO2 in a humidified incubator maintained at 37C. Where indicated Tet (1-20 uM) was added to the growth media for various time points as indicated. Cell growth and proliferation was monitored by MTT assay and cell cycle distribution was measured by FACS assay following labeling of the cells with Propedium Iodide. Western Blotting was used to monitor changes in the levels of various cell cycle related proteins. Results: Tet treatment inhibited cell growth and proliferation in all three cell lines tested. The effects of Tet on cell growth and proliferation were dose dependent with complete growth inhibition at 20 uM. Tet treatment resulted in a significant increase in cyclin dependent kinase inhibitory (CDKi) protein p21 (WAF1, Cip1) and p27 (Kip1) and with p21 increase being most prominent. Moreover, p21 was associated with Cyclin D kinases as monitored by IP assays. Gene expression analysis revealed that Tet decreased mRNA levels of cyclins. FACS analysis revealed that Tet treatment resulted in cell cycle arrest in G1/G0 phase of cell cycle. Finally TET inhibited growth of LNCaP-derived tumors in nude mice. These in vivo effects of TET were also associated with a dramatic increase in p21. Conclusions: Tet inhibits growth and proliferation of prostate cancer cells by effectively blocking cell cycle progression, in part by mediating increase in p21 (WAF1, Cip1) and p27 (Kip1) proteins and suppressing cyclin expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3808. doi:1538-7445.AM2012-3808
Abstract 381: Non-invasive histology for early detection of cutaneous melanoma and pigmented lesions in vivo
Authors: Degan Simone , Wilson Jesse W. , Mitropoulos Tanya E. , Zhang Jennifer Y. , Selim Maria A. , Warren Warren S.
Published: August 2012

Rationale The diagnosis of melanoma is based on clinical identification followed by histopathologic confirmation. Surgical excision remains the mainstay for a suspicious lesion that will be evaluated for the morphological and cytological signatures of melanomas. However, in some patients such as those with atypical mole syndrome, multiple biopsies of each lesion can be burdensome. We have previously reported that imaging the distribution of eumelanin and pheomelanin can be used to detect melanomas from benign lesions (Matthews TE et al. Sci Transl Med Feb 23;3(71)). In this pre-clinical study we extend our investigation in vivo using nonlinear pump-probe microscopy. We assess cellular morphology and detect the expression of eumelanin and pheomelanin, the two forms of melanin found in skin as markers of melanoma progression. Methods Two melanoma cells lines (A2058; SK-MEL-28) were incubated in human skin dermis. Grafts were xenotransplanted onto SCID mice (n=13, A2058; n=6, SK-MEL-28; n=2 control) and imaged every 8-10-days for cancer progression and morphological changes. Pump-probe microscopy was performed concurrently with two other established laser scanning microscopy methods, multiphoton autofluorescence (MPAF) and reflectance confocal scanning laser microscopy (RCSLM). After 4-8 weeks the subjects were euthanized and the tumor excised for histological examination. Hematoxylin and eosin staining was performed to confirm the presence of the tumor and to correlate with the morphological findings after laser image acquisition. Results The in vivo pump-probe images of the cancer subjects showed an irregular distribution of the pigment, lacking the organized structure typical of skin. Pump-probe images of both melanoma cell lines indicated pigmentation that was either primarily eumelanin or a mixture of eumelanin and pheomelanin with marked spatial heterogeneity. Pigmentation was observed in the two control mice but localized on the basal cells with a well-organized cellular architecture. At the end of the cancer subjects’ life the histological examination showed atypical melanocytes mainly present as single cells in the dermal area. Hyperplasia was also present in the dermal compartment and in the dermal-epidermal junction of the skin. Conclusions The present work may open new avenues for the non-invasive detection of cellular and pigment lesions to prevent melanoma development and invasiveness. Such method can play a role in the diagnosis of melanoma in those patients with multiple lesions or in the areas of the body where the lesion is very exposed such as the face or neck and in ocular region.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 381. doi:1538-7445.AM2012-381
Abstract 3810: Ciclopirox olamine downregulates Cdc25A expression in tumor cells
Authors: Shen Tao , Zhou Hongyu , Huang Shile
Published: August 2012

Ciclopirox olamine (CPX), a synthetic fungicide clinically used to treat mycoses of the skin and nails, has been demonstrated as a novel anticancer agent. Recently we have identified that CPX inhibits tumor growth by inhibiting proliferation and inducing apoptosis of tumor cells. This study was set to investigate the underlying mechanisms. We found that CPX slowed down cell cycle progression and accumulated cells at G1 phase in a concentration-dependent manner in human rhabdomyosarcoma (Rh30) and breast carcinoma (MDA-MB-231) cells. Concurrently, CPX downregulated Cdc25A protein, a key cell cycle regulator that is frequently overexpressed in tumor cells. Further studies revealed that CPX did not alter the mRNA and protein synthesis level, but promoted the protein degradation of Cdc25A. In addition, we found that CPX caused DNA damage, activated ATR/ATM-Chk1 cascade, elevated phosphorylation of Cdc25A (S76) and inhibitory phosphorylation on both CDK2 (T14/Y15) and CDK6 (Y24), and reduced phosphorylation of retinoblastoma protein (Rb). Furthermore, CPX activated JNK pathway, which links to apoptosis, and is negatively regulated by Cdc25A. Moreover, CPX disrupted the interaction between ASK1 and Cdc25A. These results suggest that CPX may inhibit cell proliferation and induce cell apoptosis by targeting Cdc25A.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3810. doi:1538-7445.AM2012-3810
Abstract 3811: The receptors-independent anti-cancer effect of anandamide in head and neck squamous cell carcinoma cells
Authors: Park Seok-Woo , Sung Myung-Whun
Published: August 2012

It has been suggested that endocannabinoids, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), might be the promising anti-cancer agents in clinical fields of cancer treatment. In this study, we tried to check the anti-cancer effects of AEA and 2-AG in head and neck squamous cell carcinoma (HNSCC) cell lines. AEA inhibited effectively cell proliferation of three HNSCC cells (SNU-1041, 1066 and 1076) but 2-AG did not. Cannabinoid receptor-1 (CB1) was expressed only in SNU-1066 and expression of VR1 was observed in all tested cells (no CB2 was detected). Anti-cancer effect of AEA seemed to be mediated by their receptors-independent action since the antagonist of CB1 and VR1 (AM251, cay10448 and capsazepine) did not reverse AEA-inhibited cell proliferation. From references on cancer-cell killing effect of COX-2 metabolites of AEA in some types of cancer such as colon cancer, we checked the possibility of COX-2-mediated anti-cancer effect of AEA in HNSCC cells but COX-2 inhibition (by its inhibitors and siRNA) had no effect on it. Instead, we observed the increase of reactive oxygen species (ROS) and 8-isoprostane production by AEA and antioxidants (NAC and ebselen) reversed AEA-inhibited cell proliferation partially. In addition, AM404 and cay10412 (inhibitors of AEA transporter) reversed perfectly AEA-inhibited cell proliferation. These findings suggest that AEA might have anti-cancer effect by their receptors-independent action in intracellular localization of HNSCC cells (such as increase of ROS). The investigation on detailed mechanism of anti-cancer action of AEA in HNSCC cells is ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3811. doi:1538-7445.AM2012-3811
Abstract 3816: Comparative cellular effects of 4-phenyl-3-butenoic acid and suberoylanilide acid in tumorigenic and non-tumorigenic cells
Authors: Burns Timothy , Matesic Diane
Published: August 2012

4-phenyl-3-butenoic acid (PBA) is a small molecule anti-inflammatory agent which was previously shown to inhibit growth, increase gap junction intercellular communication, increase phosphorylation of p38 mitogen activated protein kinase (p38 MAPK), and decrease phosphorylation of c-Jun N-terminal Kinase (JNK) in tumorigenic cells at concentrations that do not similarly affect non-tumorigenic cells. Suberoylanilide acid (SAHA), which is also known as vorinostat, is a relatively new anticancer agent structurally similar to PBA. The purpose of this study was to compare the effects of these two agents on JNK and p38 activation in vitro, as well as on cell growth. p38 MAPK and JNK are stress-activated members of the MAPK family that play important roles in the control of cell proliferation in a wide variety of cell types. Altered expression or activation of these MAPKs has been observed in numerous tumorigenic cells and human cancers. Our studies utilized human lung carcinoma cells (H2009), transformed rat liver epithelial cells (WB-ras) as well as non-tumorigenic cells from the same line (WB-neo). Cells were grown to 60-70% confluence and were subjected to treatment with PBA (0.1 mg/ml), SAHA (500 nM) or vehicle for 48 hours. Whole cell lysates were extracted and individual proteins were separated by SDS-PAGE, followed by western blotting using phosphorylation site-specific antibodies to p38 and JNK proteins. For cell counting, cells were trypsinized and suspended followed by counting utilizing a Biorad TC-10TM cell counter. PBA and SAHA were shown to have similar effects on JNK and p38 MAPK phosphorylation in tumorigenic WB-ras and H2009 cell lines. These effects included an increase in p38 MAPK phosphorylation and a decrease in JNK phosphorylation. Both compounds were shown to significantly decrease cell growth under these conditions. In untransformed WB-neo cells significant differences in p38 MAPK phosphorylation were not seen with either treatment. However it was shown that a decrease in phosphorylation of JNK occurred following SAHA treatment, but not PBA treatment in the WB-neo cells. Overall these studies demonstrate that PBA has similar effects on JNK and p38 MAPK compared to SAHA in tumorigenic cells, while being less potent in the non-tumorigenic WB-neo cells. This earmarks PBA for further studies as a targeted anti-tumor therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3816. doi:1538-7445.AM2012-3816
Abstract 384: CD14+S100A9 high monocytic myeloid-derived suppressor cells and their clinical relevance in non-small cell lung cancer
Authors: Feng Po-Hao , Lee Kang-Yun , Chang Ya-Ling , Kuo Han-Pin
Published: August 2012

Introduction: Myeloid-derived suppressor cells (MDSCs) are heterogeneous family of myeloid cells suppressing T cell immunity in tumor bearing hosts. We recently described an increased population of granulocyte-like CD11b+/CD14-/CD15+ MDSC in non-small cell lung cancer (NSCLC) patients. The role of CD11b+/CD14+ MDSC, being characterized as an inflammatory-type monocyte in mice, has not been well studied in human cancer. Methods: CD11b+/CD14- and CD11b+/CD14+ cells, determined and phenotyped by FACS analysis, in the peripheral blood mononuclear cells (PBMCs) of treatment-naïve advanced NSCLC patients were correlated to clinical data. T cells activation in response to CD3/CD28 co-stimulation was determined by CFSE staining and ELISA analysis of IFN-γ. Cytokines and growth factors in the cultured supernatants were analyzed by ELISA. Results: NSCLC patients had significant higher ratio of CD11b+/CD14+ and CD11b+/CD14- cells than normal subjects. CD11b+/CD14+, but not CD11b+/CD11b- cells, correlated with poor performance and poor response to chemotherapy. Suppression of CD8+ and CD4+ T cells in NSCLC PBMCs was reversed by depleting either CD11b+ cells or CD14+ cells, an effect not seen in normal PBMCs. Both isolated CD11b+/CD14- and CD11b+/CD14+ cells suppressed CD8+ T cells proliferation and IFN-γ production in CD11b-depleted PBMC with equal ability. Enrichment of HLA-DR-/low cells decreased the suppressive ability of the CD14+ cells. CD11b+/CD14+ cells were monocyte-like expressing CD33+, CD15-/low, IL-4Rα+ and S100A9high and produced iNOS/arginase. The ratio of S100A9high cells positively correlated with the suppressive ability of the CD14+ cells and was associated with poor response to chemotherapy. CD11b+/CD14+ cell suppression of T cell proliferation was revered by the iNOS inhibitor aminoguanidine hydrochloride, the arginase inhibitor nor-NOHA, the STAT3 inhibitor AG490 and the blocking antibodies for IL-13, IL-4Rα+ and IL-10. CD11b+/CD14+ MDSCs secreted significant higher amounts of TNF-α, IL-8, IL-10, IL-13 and HGF than normal CD11b+/CD14+ cells. Conclusion: The CD11b+/CD14+ inflammatory monocyte in NSCLC patients is a distinct subset of MDSC with important clinical relevance, probably through secreting inflammatory cytokines and growth factors. These cells expressed IL-4Rα and high levels of S100A9. Among CD11b+/CD14+ monocytic MDSC, the expression of S100A9 protein seemd to be related to the immunosuppression activity and clinical response to chemotherapy. The role of S100A9 protein deserves further investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 384. doi:1538-7445.AM2012-384
Abstract 3978: Mechanism of orlistat hydrolysis by fatty acid synthase thioesterase
Authors: Fako Valerie E. , Liu Jingyuan , Zhang Jian-Ting
Published: August 2012

Fatty acid synthase (FASN), a seven domain enzyme, is the sole protein capable of de novo synthesis of free fatty acids, most commonly 16-carbon palmitate. The fatty acid synthesis cycle begins with the condensation of acetyl-CoA and malonyl-CoA, and continues with the elongation of the fatty acid chain, which is tethered to an acyl carrier protein domain (ACP), via a repeating cycle. At the end of elongation, the thioesterase (TE) domain of FASN, a member of the serine hydrolase family with an Asp-His-Ser catalytic triad, cleaves the bond between palmitate and ACP, and releases free palmitate. FASN has been found to be over-expressed in a wide variety of human cancers, and this over-expression is correlated to a higher metastatic potential and poorer prognosis in cancer patients. FASN over-expression is also associated with increased resistance toward cancer chemotherapeutics. Orlistat, an FDA approved drug for obesity treatment that prevents uptake of dietary fats by inhibiting pancreatic lipases in the gastrointestinal tract, is a compound found to act as a reversible inhibitor of FASN TE. A previous study using the co-crystal structure of the TE domain with orlistat found that orlistat was covalently bound to the active site Ser within the TE domain, indicating that inhibition of FASN by orlistat halts the fatty acid synthesis cycle by blocking the release of free palmitate from the ACP. A hydrolyzed form of orlistat was also observed in the active site of TE, demonstrating that orlistat is not a stable inhibitor of FASN. In this study, we examined the mechanism of orlistat hydrolysis within the TE domain of FASN using molecular dynamics simulations. We found that the hexanoyl tail of orlistat is capable of shifting while covalently bound to the active site Ser, and that this shift is accompanied by the destabilization of a hydrogen bond that exists between a hydroxyl moiety of orlistat and the active site His. Once this hydrogen bond is destabilized, a catalytic water molecule can enter the active site of TE with the proper orientation for catalysis of the covalent bond between orlistat and Ser. These findings suggest that the hexanoyl tail of orlistat plays an important role in its hydrolysis and may guide the future design of new inhibitors that target the TE domain of FASN with greater endurance for potential use in the treatment of cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3978. doi:1538-7445.AM2012-3978