bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3223: Metabolomic study reveals smokers’ characteristic profile.
Authors: Hsu Ping-Ching , Zhou Bin , Ressom Habtom W. , Cheema Amrita , Loffredo Christopher A. , Pickworth Wallace , Shields Peter G.
Published: August 2014

Given recent FDA legislation to mandate cigarette performance standards and evaluate health claims for modified tobacco products, and separately the fact that most persons with lung cancer are former smokers, biomarkers of lung cancer risk are needed. Yet, today there are only a few biomarkers of exposure and none that are validated for lung cancer risk. This study identified putative biomarkers of exposure and harm through metabolomics, a powerful method to identify numerous metabolites and profiles. It utilized a previously conducted epidemiological study of well-characterized smokers. Using UPLC-QTOF-MS, we analyzed global metabolomic profiles of 160 smokers’ plasma totaling 613 repeated samples, and evaluated whether gender, race, number of cigarettes per day, nicotine metabolism, and type of cigarette is associated with smokers’ global metabolome. These subjects completed an extensive interview and smoked two cigarettes in a smoking laboratory. Blood and CO measurements were collected before and after each cigarette. Using subset analysis for the effect of gender on smokers’ metabolome, we were able to identify putative metabolites that are mostly steroid hormones or cholesterol derivatives, signifying the importance of sex-specific differences in metabolism. There was also significant discrimination in the metabolome of heavy and light smokers, of African-American and Caucasian smokers, and of menthol and non-menthol cigarette smokers. We also performed a paired analysis on menthol versus non-menthol smokers matched by race, gender, metabolizer status, and smoking status. Our result showed not only a significant discrimination between metabolomes of these two cigarette types, but also discriminated a cigarette brand with the lowest nicotine yield from the one with the highest yield. Putative metabolites were identified including several related to carcinogenesis and the inhibition of actin cytoskeleton activation. Further validation is needed to identify and characterize those metabolites.

In summary, we have shown that the potential biomarkers identified in this study are strongly related to other well established lung cancer risk factors including gender, race, and tobacco exposure variables, and therefore may be useful in cohort studies of persons at high risk for lung cancer.

Citation Format: Ping-Ching Hsu, Bin Zhou, Habtom W. Ressom, Amrita Cheema, Christopher A. Loffredo, Wallace Pickworth, Peter G. Shields. Metabolomic study reveals smokers’ characteristic profile. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3223. doi:10.1158/1538-7445.AM2013-3223
Abstract 323: High grade serous ovarian cancer cells spontaneously self-organize in vitro into multicellular irregular aggregates and highly organized spheroids.
Authors: Goyeneche Alicia A.
Published: August 2014

Ovarian cancer (OvCa) has the worst prognosis among gynecologic cancers because it is typically detected at an advanced stage. Accumulation of fluid inside the peritoneal cavity, and multicellular clusters featured within ascites are common manifestations of the disease. Patients undergo aggressive cytoreductive surgery followed by platinum-taxane therapy; yet in most cases, patients will relapse and die due to tumor progression. OvCa recurs as it presents, with growths within the peritoneal cavity, accumulation of ascites, but with a chemotherapy-resistant phenotype. Thus, understanding the dynamics of peritoneal metastases is of clear significance. This work provides evidences that OvCa cells derived from serous, treatment-resistant relapsed disease spontaneously develop multicellular anchorage-independent OvCa aggregates in vitro. The human serous ovarian adenocarcinoma PEO6 cells, while growing as adherent monolayer, spontaneously self-assemble into multicellular foci that float away off the adherent component of the culture. The floating phenotype is comprised of irregular cellular clusters and more organized spheroids with blastocyst-like morphology. Within each multicellular structure cells gather differently as evidenced by the distribution pattern of the cell junction adhesion molecule E-cadherin. Both types of non-adherent multicellular aggregates have live cells with no morphological features of apoptosis indicating their resistance to anoikis. Anchorage independent OvCa spheroids have the capacity to recreate the entire culture phenotype when placed in a new dish; the spheroids adhere upon transference and develop foci that grow upright irregular aggregates and more organized spheroids, ultimately leading to the generation of new non-adherent components. The floating PEO6 structures include clusters of cells expressing the cancer initiating antigen CD133 supporting their plasticity to perpetuate the anchorage-independent component of the culture. In summary, this study led to the characterization of an in vitro model of recurrent, treatment-resistant serous OvCa cells with intrinsic ability to gather in two types of clusters that survive in an anchorage-independent manner-a hallmark of transformation and critical factor in metastasis. The spontaneous in vitro development of OvCa multicellular irregular aggregates and spheroids at recurrence may represent a preclinical model to study the biology of selection and adaptation of disease malignancy and ways to interrupt its progression.

Citation Format: Alicia A. Goyeneche. High grade serous ovarian cancer cells spontaneously self-organize in vitro into multicellular irregular aggregates and highly organized spheroids. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 323. doi:10.1158/1538-7445.AM2013-323
Abstract 3252: A novel small molecule, LY5, selectively inhibits STAT3 phosphorylation and activities and exhibits potent growth suppressive activity in cancer cells.
Authors: Xiao Hui , Yu Wenying , Olson Veronica R. , Li Chenglong , Houghton Peter , Lin Jiayuh
Published: August 2014

In response to cytokines and growth factors, Signal Transducers and Activators of Transcription 3 (STAT3) signaling is activated which plays a critical role in oncogenesis, proliferation, survival, and invasion of various human cancers and cancer cell lines. Numerous evidences have demonstrated that inhibition of STAT3 signaling pathway results in decreased growth and apoptosis in human cancer cells. This makes STAT3 an excellent molecular target for cancer therapy. In this study, we investigated a novel non-peptide, cell-permeable, small molecule, named as LY5, which selectively targets STAT3. LY5 inhibited constitutive STAT3 activation in various human pediatric sarcoma and medulloblastoma cell lines expressing elevated levels of STAT3 phosphorylation. LY5 also blocked STAT3 phosphorylation induced by Interleukin-6, IGF-1, and OSM in SJSA human osteosarcoma cells, but did not inhibit STAT1, STAT2, STAT4, and STAT6 phosphorylation stimulated by interferon (IFN)-γ,IFN-α, and IL-4, respectively. Furthermore, LY5 suppressed the induction of STAT3 nuclear localization by IL-6, which could prevent STAT3 function as a transcription factor, but not STAT1 nuclear localization induced by IFN-γ. In addition, LY5 induced apoptosis in sarcoma and medulloblastoma cells as indicated by the increases of cleaved caspase-3, but LY5 did not induce apoptosis in normal primary human cells. The inhibition of STAT3 signaling by LY5 was further confirmed by down-regulating the expression of the downstream targets of STAT3, including cyclin D1, Bcl-XL, and survivin. Taken together, these findings indicated LY5 selectively inhibited constitutive STAT3 activation and suggested that LY5 is a promising therapeutic candidate for pediatric sarcoma and medulloblastoma through inhibiting STAT3 signaling.

Citation Format: Hui Xiao, Wenying Yu, Veronica R. Olson, Chenglong Li, Peter Houghton, Jiayuh Lin. A novel small molecule, LY5, selectively inhibits STAT3 phosphorylation and activities and exhibits potent growth suppressive activity in cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3252. doi:10.1158/1538-7445.AM2013-3252
Abstract 327: Establishment of patient primary ovarian cancer xenograft models for test of anticancer agents.
Authors: Liu Changnian , Xu Chunping , Li Wenwei , Zhou Wen , Liu Yong , Zhou Rui , Zhang Ning
Published: August 2014

BACKGROUND Human xenograft tumor models established by transplantation of human tumor cell lines into immunodifficient mice have been routinely used for preclinical test of anticancer agents. But tumor cell lines have a relatively low transplantability, which resulted in a limited number of tumor models available for selection of right tumor modes for test of targeted therapeutics. Recently, we have developed a large number of patient primary ovarian tumor xenograft models by transplanting human fresh ovarian tumor tissues into nude mice, which have been employed for preclinical test of clinically used drugs and novel anticancer agents for their chemosensitivity screening. METHODS The fresh ovarian tumor samples were collected from local hospitals. The tumor fragments of 2-3 mm were subcutaneously implanted in the flanks of nude mice by trocar needle. Sixteen tumor fragments were grafted into four mice from one patient tumor tissue (passage 0). The clinically used drugs included cisplatin, carboplatin, paclitaxel, and docetaxel. The histology and gene sequence of the established primary tumor models were analyzed and compared with patients’ original tumors. RESULTS A total of 77 patients’ ovarian tumor samples were implanted into nude mice; and 38 primary tumor models have been established with a tumor taking rates of 49% for the first passage. The tumor taking rates were higher in the later passages ranged from approximately 85-100%. The therapeutic efficacy of the test anticancer drugs was consistent with their clinical findings. The patients’ primary ovarian tumor xenografts from all 5 passages retained a similarity in architecture, histopathological morphology, and genomic mutation status to their patients’ original tumors. CONCLUSIONS The patient primary tumor model system can provide a larger number of models for selection of right models for preclinical testing novel agents based on their anticancer mechanism. The primary tumor models retain a similarity in histology and genomic mutation status to their patients’ original tumors. They may predict more relevant clinical response rate and higher correlation with clinical findings than use of traditional xenograft models established from long-term cultured cancer cell lines. Especially, they have advantages for test of target-oriented therapeutics in new drugs development programs.

Citation Format: Changnian Liu, Chunping Xu, Wenwei Li, Wen Zhou, Yong Liu, Rui Zhou, Ning Zhang. Establishment of patient primary ovarian cancer xenograft models for test of anticancer agents. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 327. doi:10.1158/1538-7445.AM2013-327
Abstract 328: A p53 activating mutation accelerates the progression of high-grade serous ovarian cancer arising from the fallopian tube.
Authors: Kim Jaeyeon , Coffey Donna M. , Ma Lang , Matzuk Martin M.
Published: August 2014

The tumor suppressor p53 is the most frequently mutated gene in high-grade serous ovarian cancer, the deadliest subtype responsible for 70% of all ovarian cancer deaths. Yet the precise role of p53 mutation in ovarian cancer remains unknown. To address this, we have incorporated a p53 activating mutation, p53R172H, into conditional Dicer-Pten double-knockout (DKO) mice, which develop metastatic high-grade serous carcinomas originating in the fallopian tube, to generate triple-mutant (TKO) mice (p53 LSL-R172H/+ Dicer flox/flox Pten flox/flox Amhr2 cre/+). Like DKO mice, these TKO mice develop high-grade serous carcinomas aggressively metastasizing throughout the abdominal cavity, inducing ascites and causing death. These TKO mice, however, die significantly earlier than DKO mice (average survival: 7.3 (n=31) for the TKO mice vs. 9.4 (n=24) months for the DKO mice; p<0.0001). Despite the overall similar extent of tumor burden and metastasis, TKO tumors appear to spread faster than DKO tumors. In TKO mice, tumor cells originating in the fallopian tube acutely penetrate the ovary, as marked by fallopian tube-specific epithelial markers, cytokeratin 14 and 17. In contrast, the ovary of DKO mice remains intact, largely free of metastasis during tumor progression. Moreover, unlike DKO ovaries, which alone fail to develop any tumors, TKO ovaries are able to initiate and develop metastatic ovarian tumors even after the fallopian tubes are removed, suggesting a tumor-initiating role of p53 mutation in the ovary. Collectively, these results thus reveal the critical role of p53 mutation in initiation and progression of ovarian cancer (Grant support: Ovarian Cancer Research Fund (OCRF); F32 National Research Service Award (NRSA)).

Citation Format: Jaeyeon Kim, Donna M. Coffey, Lang Ma, Martin M. Matzuk. A p53 activating mutation accelerates the progression of high-grade serous ovarian cancer arising from the fallopian tube. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 328. doi:10.1158/1538-7445.AM2013-328
Abstract 3293: Co-administration of lapatinib increases exposure to docetaxel but not doxorubicin in the small intestine of mice.
Authors: Hudachek Susan F. , Gustafson Daniel
Published: August 2014

Combination therapy is increasingly utilized for the treatment of metastatic breast cancer. However, co-administration of drugs, particularly agents that are substrates for or inhibitors of p-glycoprotein, can result in increased tissue toxicity. Unfortunately, determining levels of chemotherapeutics in human tissues is challenging and plasma drug concentrations are not always indicative of tissue toxicokinetics or toxicodynamics, especially when tissue penetration is altered.

The aim of the work presented herein was to determine if concomitant administration of compounds currently being combined in clinical trials for metastatic breast cancer treatment alters plasma and tissue pharmacokinetics in mice if both agents are p-glycoprotein substrates and/or inhibitors. Accordingly, we investigated the pharmacokinetic interactions of the classic cytotoxics and p-glycoprotein substrates docetaxel and doxorubicin when given concurrently with the targeted agent and p-glycoprotein inhibitor lapatinib.

Our time course plasma and tissue distribution studies showed that co-administration of lapatinib with doxorubicin did not appreciably alter the pharmacokinetics of this anthracycline in the plasma or six tissues evaluated in mice, presumably because, at doses relevant to human exposure, lapatinib inhibition of p-glycoprotein did not significantly alter doxorubicin transport out of these tissue compartments. However, combining lapatinib with docetaxel dramatically increased intestinal exposure to this chemotherapeutic, which has clinical implications for enhancing gastrointestinal toxicity. The significant lapatinib-docetaxel interaction is likely CYP3A4-mediated and thus, our study suggests that caution should be taken when this combination is administered, particularly to patients with compromised CYP3A activity, and recipients should be closely monitored for enhanced toxicity, particularly for adverse effects on the intestine.

Citation Format: Susan F. Hudachek, Daniel Gustafson. Co-administration of lapatinib increases exposure to docetaxel but not doxorubicin in the small intestine of mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3293. doi:10.1158/1538-7445.AM2013-3293
Abstract 3322: GW4716 selectively targets multiple p53 mutant cancer models.
Authors: Heckler Mary , Albanese Christopher , Riggins Rebecca
Published: August 2014

The TP53 gene is the most commonly mutated gene in all cancers, with over 50% of human cancers harboring an inactivating mutation. Most frequently when p53 is mutated, the mutation occurs as a single nucleotide substitution within the DNA-binding domain. The selective advantage for retaining mutant p53 varies between cancer cells. Mutant p53 can have both gain-of-function and loss-of-function properties. Given the high frequency of p53 mutations in human cancers, understanding mutant p53 function and identifying novel therapies is a clinically relevant and important area of research.

We have identified a novel pharmacological approach that selectively targets p53 mutant cancer cells across multiple cancer models using the acyl hydrazone GW4716. We have found cancer cells harboring a mutation in p53, treated with GW4716 for 24h, exhibit significantly greater cell death measured by DNA fragmentation (subG1) than p53 wild-type cells in both breast cancer and glioblastoma models. In contrast, GW4716 has little/no effect on normal (non-transformed) cells Furthermore, the mode of cell death induced by GW4716 differs between p53 wild-type and mutant cells. p53 mutants undergo a G2/M arrest, exhibit characteristics of mitotic catastrophe and ultimately apoptose in response to GW4716. MAPK signaling proteins (p38 and MK2) involved in G2/M checkpoint control, progression through mitosis, and cell death are induced by GW4716 treatment in p53 mutant cells. In contrast, p53 wild-type cells exhibit an induction of cell cycle regulatory proteins (p53 and p21) and the p53-specific autophagy marker DRAM, with a concomitant inhibition of p62 (SQSTM1).

This leads us to hypothesize that the cytotoxic effects of GW4716 treatment occur in a p53-dependent manner, and the mode of cell death caused by GW4716 differs depending on p53 status. We hypothesize the loss of functional p53 leads to aberrant mitosis and ultimately apoptosis. We also hypothesize that p53 wild-type cells, which are less sensitive to GW4716, undergo autophagy. With the increasing emphasis on personalized medicine, these data suggest a clinically relevant role for GW4716 in the treatment of multiple p53 mutant cancers.

Citation Format: Mary Heckler, Christopher Albanese, Rebecca Riggins. GW4716 selectively targets multiple p53 mutant cancer models. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3322. doi:10.1158/1538-7445.AM2013-3322

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 3335: Ouabain, a cardiac glycoside, inhibits the Fanconi Anemia-BRCA pathway activated by DNA crosslinking agents.
Authors: Hwang Mihwa , Jun Dong Wha , Kim Hyun Jung , Hwang Soo Kyung , Lee Chang-Hun , Kim Sunshin
Published: August 2014

Most cancer therapies, including conventional chemotherapy and radiotherapy, are based on DNA damage-induced tumor cell death. In tumor cells, cellular DNA repair machinery can decrease anticancer drug efficacy and induce drug resistance. The DNA repair pathway has been an emerging target for development of anticancer drugs. DNA intercrosslinking, one of the most severe forms of DNA damage which are caused by anticancer drugs, such as cisplatin and mitomycin C (MMC), could activate the Fanconi anemia (FA)-BRCA DNA repair pathway. Inhibition of the FA-BRCA pathway can enhance the cytotoxic effects of anticancer drugs which induce DNA crosslinking and can reduce anticancer drug resistance. To find FA-BRCA pathway inhibitory small molecules, we established a cell-based high-content screening method for detecting the FA-BRCA pathway by measuring ubiquitinated FANCD2 foci on DNA lesions after immunofluorescence staining and then we applied our method to chemical screening. Using commercial LOPAC1280 chemical library screening, ouabain was identified as a competent FA-BRCA pathway inhibitory molecule. Ouabain, a member of the cardiac glycoside family and an endogenous mammalian hormone, binds to and inhibits the plasma membrane protein Na+/K+-ATPase and has been used for the treatment of heart disease for many years. We observed that ouabain, as well as its cardiac glycoside family members―digitoxin and digoxin―reduced monoubiquitination of FANCD2, inhibited ubiquitinated FANCD2 foci formation on DNA lesions and abrogated cell cycle arrest induced by MMC treatment. These inhibitory activities of the FA-BRCA pathway were independent of the cellular Ca++ ion increase or the drug uptake-inhibition effect which is known to be a function of ouabain. Furthermore, we found that ouabain potentiated cytotoxic effects of MMC in tumor cells. Taken together, we identified an additional role of ouabain as a FA-BRCA pathway inhibitor which has chemosensitization activity. The results of this study suggest that ouabain may serve as a chemosensitizer to anticancer drugs which induce DNA crosslinking.

Citation Format: Mihwa Hwang, Dong Wha Jun, Hyun Jung Kim, Soo Kyung Hwang, Chang-Hun Lee, Sunshin Kim. Ouabain, a cardiac glycoside, inhibits the Fanconi Anemia-BRCA pathway activated by DNA crosslinking agents. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3335. doi:10.1158/1538-7445.AM2013-3335
Abstract 3339: HSP90 inhibitor 17-allylamino-geldanamycin enhances sensitivity to double-strand DNA break-inducing agents (platinum and PARP inhibitors) in epithelial ovarian cancer.
Authors: Battelli Chiara , Morse Alexander , Hu Hai , Levantini Elena , Wulf Gerburg , Konstantinopoulos Panagiotis A.
Published: August 2014

Double-strand DNA break (DSB)-inducing agents such as platinum analogues and poly (ADP-ribose) polymerase inhibitors (PARPis) exhibit significant antitumor activity in epithelial ovarian cancer (EOC). Approximately 50% of patients with EOC harbor genetic or epigenetic alterations of the homologous recombination (HR) DNA repair pathway and are highly responsive to these agents. However, resistance to DSB-inducing agents develops in the majority of patients and represents a major limitation for successful treatment of EOC. We recently defined a gene expression profile of “BRCAness” that correlates with responsiveness to double-strand DNA break-inducing agents (platinum and PARPis) in EOC. We applied this profile to the Connectivity Map to identify candidate compounds that might be able to enhance sensitivity to these agents. This analysis showed that the top-performing compound was the heat shock protein 90 (HSP90) inhibitor 17-allylamino-geldanamycin (17-AAG) with very high connectivity scores (>0.8) across several cell lines and concentrations (permutation p value < 0.00001). We then evaluated the ability of 17-AAG to enhance sensitivity to double-strand DNA break-inducing agents in a panel of ovarian cancer cell lines. Exposure to increasing concentrations of 17-AAG (0.02-0.1uM) was associated with increased sensitivity of 36M2 and OVCAR5 cells to carboplatin in a dose response manner. Similarly, exposure to increasing concentrations of 17-AAG (0.02-0.1uM) was associated with increased sensitivity of 36M2 and OVCAR5 cells to PARPi olaparib in a dose response manner. Exposure of these cell lines to combination of 17-AAG with carboplatin induced increased phosphorylation of H2AX (gamma H2AX) - a surrogate of DNA double-strand breaks - compared to carboplatin alone, as assessed by Western blotting. In conclusion, the HSP90 inhibitor 17-AAG enhances sensitivity of ovarian cancer cell lines to carboplatin and olaparib. The mechanism of this previously unknown, off-target effect, seems to be due to increasing DNA double strand breaks.

Citation Format: Chiara Battelli, Alexander Morse, Hai Hu, Elena Levantini, Gerburg Wulf, Panagiotis A. Konstantinopoulos. HSP90 inhibitor 17-allylamino-geldanamycin enhances sensitivity to double-strand DNA break-inducing agents (platinum and PARP inhibitors) in epithelial ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3339. doi:10.1158/1538-7445.AM2013-3339
Abstract 3373: Clinical trial simulation for the individualization of docetaxel dosing.
Authors: Perez-Ruixo Carlos , Valenzuela Belen , González-Sales Mario , Calvo Emiliano
Published: August 2014

Background and objective: To evaluate if docetaxel severe neutropenia can be reduced by pharmacokinetic (PK) and absolute neutrophils counts (ANC) guided dose individualization.

Methods: The incidence of Grade 4 neutropenia following docetaxel 75 mg/m2 every 3 weeks (Arm A) or docetaxel individualized dose (Arm B) was predicted on the basis of the model proposed by Bruno [1] and Quartino [2]. Optimal sampling times for PK and ANC assessments after an initial test dose were determined. The individual model parameters estimated using the maximum a posteriori estimation in NONMEM 7 were used to determine the individualized docetaxel dose, defined as the maximum dose that yields a probability of neutropenia Grade 4 lower than 30%.

Results: An initial dose of 50 mg/m2 at least 2 weeks earlier, plasma concentrations collected at 1, 3 and 7 h after the start of the infusion, and ANC measurements determine at 0, 7, 14, and 21 days were adequate to determine the individualized dose, without any carry-over effect. The neutropenia Grade 4 incidence was 55% and 45% in arms A and B, respectively. A sample size of 154 patients per arm was need to have a 82% power of detecting the effect of dose individualization. The average docetaxel individualized dose was 55 mg/m2.

Conclusions: Docetaxel PKPD guided dose individualization is potentially useful in controlling the PKPD variability and decreasing the incidence of neutropenia Grade 4.

1.Bruno R, Vivier N, Vergniol JC, De Phillips SL, Montay G, Sheiner LB.A population pharmacokinetic model for docetaxel (Taxotere): model building and validation. J Pharmacokinet Biopharm. 1996; 24: 153-172.

2.Quartino AL, Friberg LE, Karlsson MO. A simultaneous analysis of the time-course of leukocytes and neutrophils following docetaxel administration using a semi-mechanistic myelosuppression model. Invest New Drugs. 2012; 30: 833-845.

Citation Format: Carlos Perez-Ruixo, Belen Valenzuela, Mario González-Sales, Emiliano Calvo. Clinical trial simulation for the individualization of docetaxel dosing. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3373. doi:10.1158/1538-7445.AM2013-3373
Abstract 3384: Depletion of NEDD9 destabilizes Aurora A kinase and augments efficacy of inhibitors.
Authors: Ice Ryan J. , McLaughlin Sarah , Culp Mark , Eddy Erik , Livengood Ryan , Pugacheva Elena
Published: August 2014

Aurora A Kinase (AURKA) is overexpressed in 96% of human cancers and is considered an independent marker of poor prognosis. While the majority of tumors have elevated levels of

AURKA protein, only few have AURKA gene amplification; therefore, posttranscriptional mechanism regulating AURKA protein levels are significant. In this study, we show that the known activator and binding partner of AURKA, NEDD9, is directly involved in AURKA stability. Analysis of comprehensive breast cancer tissue microarray revealed a tight correlation between expression of both proteins and significantly increased prognostic value. A decrease in AURKA proteins, concomitant with increased ubiquitination and proteasome-dependent degradation, occurs due to depletion or knockout of NEDD9 proteins. Re-expression of wild type (WT) NEDD9 was sufficient to rescue the observed phenomenon. Binding of NEDD9 to AURKA is critical for AURKA stabilization. Mutation of S296E was sufficient to disrupt the binding and reduce the level of AURKA protein. Mechanistically, NEDD9 stabilizes AURKA by limiting the binding of cdh1-substrate recognition subunit of APC/C Ubiquitin Ligase to AURKA. Moreover, depletion of NEDD9 in tumor cells increased their sensitivity to AURKA inhibitors. Combinational therapy using NEDD9 shRNAs and AURKA inhibitors had a profound inhibitory effect on tumor initiation and later, metastasis in lungs of human tumor xenografts. Our findings provide evidence for successful application of AURKA inhibitors for treatment of solid tumors, which often overexpress NEDD9.

Citation Format: Ryan J. Ice, Sarah McLaughlin, Mark Culp, Erik Eddy, Ryan Livengood, Elena Pugacheva. Depletion of NEDD9 destabilizes Aurora A kinase and augments efficacy of inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3384. doi:10.1158/1538-7445.AM2013-3384
Abstract 3398: Overexpression of ATP-binding cassette transporter ABCG2 as a potential mechanism of acquired resistance to vemurafenib in BRAF(V600E) mutant cancer cells.
Authors: Wu Chung-Pu , Sim Hong-May , Huang Yang-Hui , Liu Yen-Chen , Hsiao Sung-Han , Cheng Hsing-Wen , Li Yan-Qing , Ambudkar Suresh , Hsu Sheng-Chieh
Published: August 2014

Melanoma is the most serious type of skin cancer with a high potential for metastasis and very low survival rates. The discovery of constitutive activation of the BRAF kinase caused by activating BRAF(V600E) kinase mutation in most melanoma patients led to the discovery of the first potent BRAF(V600E) signaling inhibitor, vemurafenib. Vemurafenib was effective in treating advanced melanoma patients and was proposed for the treatment of other BRAF(V600E) mutant cancers as well. Unfortunately, the success of vemurafenib was hampered by the rapid development of acquired resistance in different types of BRAF(V600E) mutant cancer cells. It becomes important to identify and evaluate all of the potential mechanisms of cellular resistance to vemurafenib. In this study, we characterized the interactions of vemurafenib with three major ATP-binding cassette (ABC) transporters, ABCB1, ABCC1 and ABCG2. We found that vemurafenib stimulated the ATPase activity and potently inhibited drug efflux mediated by ABCB1 and ABCG2. Vemurafenib also restored drug sensitivity in ABCG2-overexpressing cells. Moreover, we revealed that in the presence of functional ABCG2, BRAF kinase inhibition by vemurafenib is reduced in BRAF(V600E) mutant A375 cells. Taken together, our findings indicate that ABCG2 confers resistance to vemurafenib in A375 cells, suggesting involvement of this transporter in acquired resistance to vemurafenib. Thus, combination chemotherapy targeting multiple pathways could be an effective therapeutic strategy to overcome acquired resistance to vemurafenib for cancers harboring the BRAF(V600E) mutation.

Citation Format: Chung-Pu Wu, Hong-May Sim, Yang-Hui Huang, Yen-Chen Liu, Sung-Han Hsiao, Hsing-Wen Cheng, Yan-Qing Li, Suresh Ambudkar, Sheng-Chieh Hsu. Overexpression of ATP-binding cassette transporter ABCG2 as a potential mechanism of acquired resistance to vemurafenib in BRAF(V600E) mutant cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3398. doi:10.1158/1538-7445.AM2013-3398
Abstract 3402: Relief of feedback inhibition of HER3 transcription by RAF and MEK inhibitors attenuates their antitumor effects in BRAF mutant thyroid carcinomas.
Authors: Montero-Conde Cristina , Ruiz-Llorente Sergio , Dominguez Jose M. , Knauf Jeffrey A. , Viale Agnes , Sherman Eric J. , Ryder Mabel , Ghossein Ronald A. , Rosen Neal , Fagin James A.
Published: August 2014

The RAF inhibitor vemurafenib (PLX4032) increases survival in patients with BRAF-mutant metastatic melanoma, but has limited efficacy in patients with colorectal cancers. A trial with vemurafenib for thyroid cancer patients is now in progress.

We compared the response of thyroid and melanoma cell lines harboring BRAFV600E to vemurafenib and found that the majority of thyroid cancer cells were refractory to the inhibitor (IC50 > 1.5 μM). In addition, thyroid cancer cell lines showed a rebound in pERK beginning 6h post-treatment and a transient activation of pAKT. Expression profiling and pRTK array screens of PLX4032-treated cells showed higher expression and activation of HER family receptors, particularly HER2 and HER3. Phosphorylation of HER3 represented the most consistent PLX4032-dependent RTK activated across thyroid cancer cell lines (5/6 lines tested) and was not detectable in any of the melanoma or colorectal cancer cells we investigated. HER3 phosphorylation was also induced by the allosteric MEK inhibitor PD0325901 in thyroid cancers of TPO-Cre/LSL-BrafV600E mice. We identified HER2 as the main HER3 heterodimerization partner, which was activated via a neuregulin-dependent autocrine loop, which was specific to the thyroid cancer lineage, as it was not observed in either melanoma or colorectal BRAF-mutant lines. HER3 transcription was induced by MAPK inhibition, via dissociation of the CTBP1/2 transcriptional repressors from the HER3 gene promoter. Finally, the HER2/HER3 kinase inhibitor lapatinib sensitized BRAF-mutant thyroid cancer cells to growth inhibition by RAF or MEK inhibitors in vitro and in vivo, providing rationale for combination therapies in this disease. Hence, the early response of BRAF-mutant cancers to selective MAPK pathway inhibitors is marked by the relaxation of oncoprotein-driven negative feedback events, which differ between tumors of various lineages, and which predict a requirement for distinct therapeutic strategies.

Citation Format: Cristina Montero-Conde, Sergio Ruiz-Llorente, Jose M. Dominguez, Jeffrey A. Knauf, Agnes Viale, Eric J. Sherman, Mabel Ryder, Ronald A. Ghossein, Neal Rosen, James A. Fagin. Relief of feedback inhibition of HER3 transcription by RAF and MEK inhibitors attenuates their antitumor effects in BRAF mutant thyroid carcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3402. doi:10.1158/1538-7445.AM2013-3402
Abstract 3408: The anticancer mechanisms of ciclopirox olamine.
Authors: Shen Tao , Zhou Hongyu , Huang Shile
Published: August 2014

Ciclopirox olamine (CPX), a synthetic fungicide clinically used to treat mycoses of the skin and nails, has been demonstrated as a novel anticancer agent. However, the underlying anticancer mechanisms are not well understood. Here we show that CPX suppressed cell proliferation, induced cell death (apoptosis and autophagy), and inhibited cell motility in breast cancer (MDA-MB-231) and rhabdomyosarcoma (Rh30) cells. We observed that CPX induced inhibitory phosphorylation of CDK2 and inhibited cyclin D1 expression, resulting in dephosphorylation of Rb in the tumor cells, which was correlated to cell cycle arrest at G1 phase. Furthermore, we found that CPX caused DNA damage and activated ATR-Chk1 axis, increasing phosphorylation and degradation of Cdc25A, a critical protein involved in the regulation of cell cycle progression and apoptosis. CPX also activated JNK cascade, associated with apoptosis. Moreover, CPX downregulated cellular protein expression of small GTPases (RhoA, Cdc42 and Rac1) and induced inhibitory phosphorylation of FAK, related to cell migration. In addition, we found that CPX inhibited the signaling of mTOR, a central controller of cell proliferation, survival (apoptosis and autophagy) and motility. The results suggest that CPX exerts its anticancer activity by targeting multiple signaling molecules.

Citation Format: Tao Shen, Hongyu Zhou, Shile Huang. The anticancer mechanisms of ciclopirox olamine. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3408. doi:10.1158/1538-7445.AM2013-3408
Abstract 3421: Differential potentiation of temozolomide and camptothecin by the PARP inhibitors olaparib and veliparib in relationship with their PARP-DNA trapping abilities, and lack of impact of PARP inhibitors on cisplatin activity.
Authors: Pommier Yves G. , Murai Junko
Published: August 2014

We recently showed that poly(ADP-ribose) polymerase (PARP) inhibitors act by a novel allosteric mechanism of action that involves the trapping of PARP-DNA complexes in addition to their previously established NAD-competitive catalytic inhibitory mechanism). We also demonstrated that PARP inhibitors differ in their ability to trap PARP-DNA complexes, with olaparib being more effective than veliparib in spite of their comparable potency as catalytic PARP inhibitors). Here, by using PARP knockout cells, olaparib and veliparib, we tested the role of PARP trapping in the potentiating effect of PARP inhibitors with the alkylating agent temozolomide and the topoisomerase I inhibitor, camptothecin. Using isogenic chicken DT40 cells, we show that PARP-dependent potentiation of temozolomide is markedly greater for olaparib than veliparib, and goes beyond knocking out PARP-1. On the other hand, in the case of camptothecin, knocking out PARP-1 has a greater effect than veliparib or olaparib. In human DU145 prostate cancer and SF295 glioblastoma cells, olaparib is markedly more potent than veliparib in potentiating the cytotoxicity of temozolomide whereas both olaparib and veliparib are almost comparable in the case of camptothecin. By measuring cellular PARP-DNA complexes), we find that in the case of temozolomide, olaparib is a least 10-fold more potent than veliparib at trapping PARP-DNA complexes. On the other hand, in the case of camptothecin, neither olaparib nor veliparib produced detectable trapping of PARP-DNA complexes. Finally, olaparib fails to sensitize DT40, DU145 or SF295 cells to cisplatin and does not induce detectable PARP-DNA complexes in cisplatin-treated cells. These results suggest that, in the case of temozolomide, olaparib trapping of PARP-DNA complexes is more toxic than inactivating PARP catalytic activity, which is not the case for topoisomerase I-induced DNA damage, where catalytic inactivation of PARP appears to be the sole enhancing mechanism.

Citation Format: Yves G. Pommier, Junko Murai. Differential potentiation of temozolomide and camptothecin by the PARP inhibitors olaparib and veliparib in relationship with their PARP-DNA trapping abilities, and lack of impact of PARP inhibitors on cisplatin activity. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3421. doi:10.1158/1538-7445.AM2013-3421
Abstract 344: Subpopulations of lung neuroendocrine cells mirror neuronal development.
Authors: Suau Florent , Linnoila Ilona , Naizhen Xu
Published: August 2014

Pulmonary neuroendocrine cells (PNECs) which comprise less than 1% of airway epithelium were recently shown to be the cell of origin for small cell lung cancer (SCLC). SCLC is the most aggressive form of human lung cancers and characterized by early dissemination or metastases and neuroendocrine features. We used immunohistochemistry (IHC) and animal models in order to delineate the cellular hierarchy of PNEC potentially leading to cancer.

PNECs were first identified in the early lung development (E12.5) as positive for the proneural basic helix-loop-helix transcription factor Achaete-scute homolog-1 (Ascl1) which is pivotal for PNEC differentiation and highly expressed in SCLC. Later in the development (E16.5) and in adulthood, PNECs coexpressed Ascl1 and calcitonin gene-related peptide (CGRP), a primary neuropeptide in mouse lung.

Interestingly, we showed that doublecortin (DCX), a marker of immature migrating neurons, is transiently expressed in PNECs during the early development. Later in the development (E16.5), we observed a subpopulation expressing the neural-specific β3-tubulin (TUBB3), a neuronal marker. We also observed that neural cell adhesion molecule (NCAM), a marker of SCLC, is transiently expressed in a low number of PNECs in the late embryonic period. In parallel, using the transgenic CC10-hASH1 mouse model, where Ascl1 is overexpressed in non-neuroendocrine airway epithelial cells, we determined that it is not sufficient to induce neuroendocrine differentiation or expression of DCX, TUBB3 and NCAM.

We conclude that Ascl1, DCX and TUBB3 are consecutively expressed in PNECs during development, similarly to the pattern observed during neuronal development. However, Ascl1 expression seems to be maintained even in the mature PNECs unlike in the mature neurons where it is turned off. On the other hand, NCAM expression in PNECs is transient and maybe reactivated during the instance of SCLC. To establish the relationships between the different PNEC populations and Ascl1 expression, we are currently evaluating Cre-dependent conditional Ascl1 deletion in mouse lung. Further work will be necessary to address the functional potential of the PNEC subpopulations in tumorigenesis.

Citation Format: Florent Suau, Ilona Linnoila, Xu Naizhen. Subpopulations of lung neuroendocrine cells mirror neuronal development. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 344. doi:10.1158/1538-7445.AM2013-344
Abstract 3442: Olaparib increases antitumor effects on epigenetically RAD51C-deficient human cancer cells.
Authors: Min Ahrum , Kim Seongyeong , Im Seock-Ah , Yoon Young-Kwang , Song Sang-Hyun , Nam Hyun-Jin , Hur Hyung-Seok , Lee Kyung-Hun , Han Sae-Won , Oh Do-Youn , Kim Tae-You , O'Connor Mark J. , Kim Woo-Ho , Bang Yung-Jue
Published: August 2014

Background: The poly (ADP-ribose) polymerase (PARP) inhibitor, olaparib, has been found to have a therapeutic potential for treating cancers that have an impaired DNA repair ability. RAD51C has been reported to play an essential role in DNA repair mediated by homologous recombination. In addition, RAD51C is a gene that affects human cancer susceptibility, similar to BRCA1 and BRCA2. RAD51C-defective cancers can therefore be potentially treated with olaparib because DNA damage induced by olaparib cannot be effectively repaired by HR since RAD51C deficiency interferes with RAD51-mediated HR.

Materials and Methods: We studied the growth inhibitory effects of olaparib on human cancer cell lines using clonogenic survival assays. Cell cycle analysis and molecular changed induced by olaparib were also performed. DNA methylation status in cancer cells and tumor tissue samples was also determined by using bisulfate sequencing.

Results: Olaparib is effective to RAD51C-defective cells. Olaparib leads to the accumulation of unrepaired DSBs due to dysfunctional RAD51 foci formation along with increased caspase 3-dependent cell death and G2/M arrest in RAD51C-defective cells. Moreover, the growth of RAD51C-deficient SNU601 tumor cells in a xenograft model decreased significantly following treatment with olaparib. Furthermore, RAD51C expression was significantly decreased in cancer and the lack of RAD51C was attributed to DNA methylation and histone modification. Our findings showed that the loss of RAD51C expression due to epigenetic silencing leads to olaparib sensitivity in cancer cells.

Conclusion: The loss of RAD51C expression was frequently associated with human cancers. We used a novel synthetic lethal approach using PARP inhibitors and observed that RAD51C was a participant in the DNA repair pathway. Our findings have potential clinical application for treating cancers with RAD51C deficiencies. Furthermore, we determined that RAD51C may serve as a novel biomarker for identifying olaparib-sensitive patients, thereby allowing physicians to select the most effective modalities for treating these individuals.

Citation Format: Ahrum Min, Seongyeong Kim, Seock-Ah Im, Young-Kwang Yoon, Sang-Hyun Song, Hyun-Jin Nam, Hyung-Seok Hur, Kyung-Hun Lee, Sae-Won Han, Do-Youn Oh, Tae-You Kim, Mark J. O`Connor, Woo-Ho Kim, Yung-Jue Bang. Olaparib increases antitumor effects on epigenetically RAD51C-deficient human cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3442. doi:10.1158/1538-7445.AM2013-3442
Abstract 3445: Specific inhibitors of nuclear export (SINE) for cancer therapy: from bench to bedside.
Authors: Azmi Asfar S. , Bao Bin , Kauffman Michael , Shacham Sharon , Mohammad Ramzi M.
Published: August 2014

Nuclear protein transport is an evolutionary conserved mechanism that controls aberrant cell proliferation through balanced nuclear expression of tumor suppressor proteins (TSPs). In cancers, overexpression of exportin protein chromosome region maintenance 1 (CRM-1) disrupts this balance leading to nuclear exclusion of TSPs leading to the low efficacy of traditional anti-cancer drugs. Our recent screening of pancreatic, colon, triple negative breast cancer (TNBC) and non-Hodgkin's lymphoma (NHL) patient samples showed over-expression of CRM-1. These important finding suggests that therapeutic targeting of CRM-1 leading to restoration of TSPs in the nucleus is an attractive strategy against cancer. Earlier attempts to develop CRM-1 inhibitor were not successful as exemplified by the failure of the Leptomycin B in a single clinical trial due to severe off-target toxicity. Since then the field has not witnessed any serious attempts to develop newer classes of CRM-1 inhibitors that could be used clinically. We have developed specific inhibitors of nuclear export (SINE) that are highly specific, orally active drugs with excellent pharmacokinetic parameters. We tested SINEs as targeted inhibitors of CRM-1, in a panel of pancreatic, colon, prostate, breast, NHL cell lines. SINE showed cancer selectivity (IC50s in low nano molar range in cancer cells and >20 micro Molar in normal lymphocytes, fibroblasts and NIH-3T3 cells). SINE induces global re-alignment of important tumor suppressors such as IKB, FOXO, p53, p73 and p27. SINEs were ineffective in killing cancer cells that were transduced with cys528 mut-CRM-1 proteins (a binding site for SINE) confirming the drugs selectivity. In in vivo studies, the clinical grade SINE induced significant tumor growth inhibition in subcutaneous and orthotopic solid and disseminated NHL xenografts. Our new class of SINEs has excellent pharmacokinetic parameters and has passed advanced toxicity profiling. Based on our strong preclinical data, SINE has entered clinical trials for both solid tumors and hematological malignancies.

Citation Format: Asfar S. Azmi, Bin Bao, Michael Kauffman, Sharon Shacham, Ramzi M. Mohammad. Specific inhibitors of nuclear export (SINE) for cancer therapy: from bench to bedside. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3445. doi:10.1158/1538-7445.AM2013-3445