bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 121: Analysis and comparison of somatic copy number alterations in gastric cardia adenocarcinoma and gastric non-cardia adenocarcinoma
Authors: Liu Manjiao , Liu Zhen , Bai Jian , Cai Hong , Ke Yang , Zeng Changqing
Published: July 2016

Gastric adenocarcinoma is one of the most common cancer type worldwide. Anatomically it may raise from the cardia or non-cardia part of the stomach and previous studies have shown differential susceptibilities loci and prognosis between gastric cardia adenocarcinoma (GCA) and gastric non-cardia adenocarcinoma (GNCA). To better understand the genomic alterations that drive gastric adenocarcinoma and to investigate the differences of genetic aberration between GCA and GNCA, we analyzed somatic copy-number aberrations in 205 gastric adenocarcinomas resected samples, including 114 GCAs and 91 GNCAs using Illumina Human OmniZhongHua BeadChips. We identified 49 significantly recurrent focal alterations in gastric adenocarcinoma. In addition to those previously reported in stomach cancer, several novel focal changes were also observed, including gain of 11p11.2, 6q23.3, 12p11.1, 5p15.33 and loss of 8p11.22, 9p22.2, 18q22.1, 15q21.2, 17q23.3. A few known or potential oncogenes such as TERT, MYB, and IRS2, were included in the focal amplified regions that were not reported in gastric cancer before. Also, a few potential tumor suppressors were seen in these focal loss regions, including DOK6, BRIP1 and NDST4. Especially, HDC, a gene involved in gastric acid secretory, was harbored in the newly identified focal loss region, 15q21.2. Three focal changes, loss of 20p12.1 (containing MACROD2), 6q26 (containing PARK2), and gain of 11p11.2 (containing CRY2), were identified to correlate to the post-surgery overall survival, which may deserve to be further investigated as the potential prognosis markers. Comparison of somatic copy number alternation patterns revealed that in chromosome arm level, 16p and 5q had distinct copy number status between GCA and GNCA samples. The frequencies of three novel focal changes were significantly different between GCA and GNCA. Furthermore, KRAS amplification, a well characterized gastric adenocarcinoma prognosis marker was associated with worse clinical outcome in GNCA, but not in GCA.

Taken together, these results provided novel candidate oncogenes or tumor suppressors for gastric adenocarcinoma and different features in structural alterations between GCA and GNCA, which potentially inform novel opportunities for targeted therapeutic interventions.

Citation Format: Manjiao Liu, Zhen Liu, Jian Bai, Hong Cai, Yang Ke, Changqing Zeng. Analysis and comparison of somatic copy number alterations in gastric cardia adenocarcinoma and gastric non-cardia adenocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 121.
Abstract 1224: Insights into the mechanism of action of NVP-HDM201, a differentiated and versatile Next-Generation small-molecule inhibitor of Mdm2, under evaluation in phase I clinical trials
Authors: Ferretti Stéphane , Rebmann Ramona , Berger Marjorie , Santacroce Francesca , Albrecht Geneviève , Pollehn Kerstin , Sterker Dario , Wartmann Markus , Hueber Andreas , Wiesmann Marion , Jensen Michael R. , Hofmann Francesco , Sellers William R. , Holzer Philipp , Jeay Sébastien
Published: July 2016

Activation of p53 by blocking p53-Mdm2 interaction using small-molecule inhibitors is being pursued as a promising cancer therapeutic strategy in p53 wild-type tumors. Here, we report the identification of NVP-HDM201, a novel, highly potent and selective inhibitor of the p53-Mdm2 interaction, with optimized drug-like properties allowing a versatile use with regard to route of administration, dose and scheduling. We determined the pharmacokinetics, pharmacodynamics and efficacy relationship of NVP-HDM201 with various dosing schedules in xenograft bearing mouse and rat models. NVP-HDM201 administered either daily at a low dose or once at a high dose revealed a differentiated engagement of the p53 molecular response. In contrast to the daily low dose treatment regimen, the single high dose NVP-HDM201 regimen resulted in a rapid and dramatic induction of p53-dependent PUMA expression and apoptosis. This was consistent with the finding that a single high dose NVP-HDM201 treatment, administered orally or intravenously, resulted in a robust and sustained tumor regression. Overall, both daily and once every 3 weeks dosing regimen showed comparable long term efficacy in preclinical studies. The ongoing clinical trial is currently designed to compare both dosing regimens with regard to efficacy and tolerability.

Citation Format: Stéphane Ferretti, Ramona Rebmann, Marjorie Berger, Francesca Santacroce, Geneviève Albrecht, Kerstin Pollehn, Dario Sterker, Markus Wartmann, Andreas Hueber, Marion Wiesmann, Michael R. Jensen, Francesco Hofmann, William R. Sellers, Philipp Holzer, Sébastien Jeay. Insights into the mechanism of action of NVP-HDM201, a differentiated and versatile Next-Generation small-molecule inhibitor of Mdm2, under evaluation in phase I clinical trials. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1224.
Abstract 1226: Highly specific ATR inhibitors as a therapeutic approach for a broad spectrum of cancers
Authors: Butler Laura R. , Ragland Ryan L. , Breslin Hank J. , Gill Tina , George Erin , Simpkins Fiona , Brown Eric J. , Gilad Oren
Published: July 2016

Ataxia Telangiectasia and Rad3-related (ATR) and Checkpoint kinase 1 (CHK1) stabilize stalled replication forks and prevent their collapse into DNA double strand breaks (DSBs). Inhibition of ATR in cells experiencing oncogenic stress or harboring other cancer-associated defects synergistically increases the formation of DSBs and causes synthetic lethality. Thus specific targeting of ATR represents an emerging strategy to treat a broad spectrum of cancers, most notably those that currently lack effective treatments.

Atrin Pharmaceuticals has synthesized a novel series of small molecules that inhibit ATR at low nanomolar concentrations in cultured cells. These compounds have the highest known potency for inhibiting ATR and maintain >800-fold lower cellular activity towards other kinases of the same family (ATM, DNA-PKcs and mTOR), which are substantially off-targeted by previously reported ATR inhibitors. Atrin's lead compound (ATRN-119), as a single agent, selectively kills cancer cells subjected to oncogenic stress, alternative lengthening of telomeres (ALT) or loss of double strand break (DSB) homologous recombination repair mechanism (BRCA1 or BRCA2 deficiency). Furthermore, ATRN-119 cytotoxicity is synergistically enhanced when combined with conventional chemotherapeutics, such as etoposide, cisplatin and olaparib. Therefore, this inhibitor can be used in combination with other therapeutics to potentiate its anti-tumor activity.

In vivo studies of RAS oncogene driven HCT116 p53-null flank tumors in mice demonstrate the ability of our lead compound to slow tumor progression, with minimal toxicity to tissues under normal proliferative control, including the bone marrow and intestine. Additionally, mice engrafted with BRCA2-mutant patient-derived ovarian tumors show a significant reduction in progression after 5 weeks treatment (100 mg/kg BID) of ATRN-119, and display no toxicity or significant weight loss. Thus, ATRN-119 is highly efficacious in suppressing tumor growth in multiple murine models, including suppression of patient-derived BRCA2-mutant ovarian cancer, suggesting that the clinical application of the ATRN series will provide a new and effective treatment for human malignancies with fewer side effects than conventional chemotherapies.

Citation Format: Laura R. Butler, Ryan L. Ragland, Hank J. Breslin, Tina Gill, Erin George, Fiona Simpkins, Eric J. Brown, Oren Gilad. Highly specific ATR inhibitors as a therapeutic approach for a broad spectrum of cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1226.
Abstract 1228: Indolo-pyrido-isoquinolin based alkaloid inhibits epithelial-mesenchymal transition and stemness via activation of p53-miR34a axis
Authors: Nagalingam Arumugam , Avtanski Dimiter. B , Tomaszewski Joesph , Prabhakar Risbood , Difillippantonio Michael , Mears Brian , Saxena Neeraj , Malhotra Sanjay , Malhotra Sanjay , Sharma Dipali
Published: July 2016

The tumor suppressor p53 plays a critical role in suppressing cancer growth and progression and is the most frequently mutated and functionally inactivated gene in all human malignancies. Owing to its widespread alteration/inactivation in cancer, p53 is an attractive target for the development of new targeted therapies. We synthesized several indolo-pyrido-isoquinolin based alkaloids to restore/activate p53 function and examined their therapeutic efficacy using NCI-60 screening. Here, we provide molecular evidence that one of these compounds, 11-Methoxy-2,3,4,13-tetrahydro-1H-indolo[2’,3’:3,4]pyrido[1,2-b]isoquinolin-6-ylium-bromide (termed P18 or NSC-768219) inhibits growth and clonogenic potential of cancer cells. P18 treatment results in downregulation of mesenchymal markers and concurrent upregulation of epithelial markers as well as inhibition of migration and invasion. Experimental epithelial-mesenchymal-transition (EMT) induced by exposure to TGFβ/TNFα is also completely reversed by P18. Importantly, P18 also inhibits mammosphere-formation along with a reduction in the expression of stemness factors, Oct4, Nanog and Sox2. We show that P18 induces expression, phosphorylation and accumulation of p53 in cancer cells. P18-mediated induction of p53 leads to increased nuclear localization and elevated expression of p53 target genes. Using isogenic cancer cells differing only in p53 status, we show that the alteration of mesenchymal and epithelial genes, inhibition of migration and invasion of cancer cells mediated by P18 is p53-dependent. Furthermore, P18 increases miR-34a expression in p53-dependent manner and inhibition of mammosphere-formation by P18 is further enhanced by miR-34a mimic. Collectively, these data provide evidence that p53-miR-34a activation by P18 may represent a promising therapeutic strategy for the inhibition of growth and progression of cancer.

Citation Format: Arumugam Nagalingam, Dimiter. B Avtanski, Joesph Tomaszewski, Risbood Prabhakar, Michael Difillippantonio, Brian Mears, Neeraj Saxena, Sanjay Malhotra, Sanjay Malhotra, Dipali Sharma. Indolo-pyrido-isoquinolin based alkaloid inhibits epithelial-mesenchymal transition and stemness via activation of p53-miR34a axis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1228.
Abstract 1234: Galeterone-induced degradation of the androgen receptor involves inhibition of deubiquitinating enzymes
Authors: Dransfield Daniel T. , Namdev Nivedita , Jacoby Douglas B. , Ferrante Karen
Published: July 2016

Galeterone is a highly selective oral small molecule drug candidate that disrupts androgen receptor (AR) signaling through degradation of the AR, is a potent CYP17 lyase inhibitor, and possesses AR antagonist activity. Galeterone-induced AR degradation was observed in models having either full-length AR or known constitutively active truncated forms of the AR receptor that lack the ligand binding domain (LBD), AR-V7 and AR567es, suggesting the LBD of the AR is not required for galeterone-dependent AR degradation. Further, galeterone-induced AR degradation activity is blocked by co-administration of the proteasome inhibitor MG132. Along these lines, galeterone-induced AR degradation can be blocked by selective knock-down of the E3 ligases, Mdm2 and CHIP. We utilized a series of biochemical and cell-based in vitro methodologies to further elucidate and characterize additional signaling molecules participating in the proteasomal-dependent mechanism of galeterone-induced AR degradation. We screened a panel of 22 deubiquitinating enzymes (DUBs) in vitro and demonstrated that galeterone selectively inhibited enzymatic activity of two of the DUBs, USP12 and USP46. Separately, we used surface plasmon resonance to demonstrate a dose-dependent direct binding of galeterone to each of USP12 and USP46, alone or when pre-complexed with UAF1. USP12 is a co-activator of the AR, and selective knock-down of this DUB has been shown to increase AR degradation. USP12/USP46 have also been linked to regulation of phosphatases (PHLPPs) through ubiquitination. PHLPPs dephosphorylate AKT, providing an important regulatory mechanism for controlling the PI3K/AKT pathway. It is known that galeterone induces an increase in pAKT and pMdm2, the latter being a substrate of activated AKT. This suggests that inhibition of USP12/USP46 may regulate pAKT levels through enhanced degradation of PHLPPs via increased ubiquitination. These data support a differentiating mechanism of galeterone from other AR targeting agents whereby inhibition of USP12/USP46 leads to enhanced AR degradation.

Citation Format: Daniel T. Dransfield, Nivedita Namdev, Douglas B. Jacoby, Karen Ferrante. Galeterone-induced degradation of the androgen receptor involves inhibition of deubiquitinating enzymes. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1234.
Abstract 1244: A novel microtubule-disrupting indole-based chalcone that induces caspase-independent cell death in glioblastoma and melanoma cells
Authors: Du Shengnan , Sarver Jeffrey G. , Trabbic Christopher J. , Erhardt Paul W. , Overmeyer Jean H. , Maltese William A.
Published: July 2016

Indolyl-pyridinyl-propenones (a subclass of synthetic indole-based chalcones) have been shown to induce a novel form of cell death termed ‘methuosis’ in glioblastoma and other tumor cell lines. This form of cell death is caspase-independent and involves massive vacuolization of macropinosome and endosome compartments. In the course of structure-activity relationship studies identifying a lead compound, 3-(5-methoxy-2-methyl-1H-indol-3-yl)-1-(4-pyridinyl)-2-propene-1-one (abbreviated 5-MOMIPP), we discovered that changing the methoxy substitution from the 5-position to the 6-position on the indole ring markedly alters the biological activity of the compound. 6-MOMIPP exhibits potent anti-proliferative and cytotoxic activity in glioblastoma, melanoma and other cancer cell lines at a concentration of 100 nM, nearly two orders of magnitude lower than the maximally effective concentration of 5-MOMIPP. Instead of inducing methuosis, 6-MOMIPP (at > 500 nM) immediately disrupts microtubules, as confirmed by immunofluorescence microscopy. By 24 h the majority of the cells are rounded and arrested in mitosis, and by 48 h cell viability is greatly reduced. The few remaining live cells contain multiple abnormal nuclei. Extensive cell death occurs before activation of caspases 3, 7 and 9 can be detected. Scintillation proximity assays show that 6-MOMIPP competes with 3H-colchicine, but not 3H-vinblastine, for binding to tubulin. Studies aimed at testing the toxicity of 6-MOMIPP in normal cells are in progress, but work with a closely related microtubule-active indole-based chalcone indicates that toxicity is substantially reduced in quiescent human fibroblasts and rat neuronal progenitor cells. Although drugs targeted to microtubules (e.g., Vinca alkaloids and taxanes) are widely used as anti-neoplastic agents, they have shown little efficacy in treating primary or metastatic brain tumors, partly due to limited penetrance of the blood-brain barrier (BBB). Preliminary pharmacokinetic studies in mice show that 6-MOMIPP injected IP can readily cross the BBB, attaining brain concentrations nearly equal to plasma concentrations within 30 min to 1 h. Therefore, these preliminary findings suggest that 6-MOMIPP merits further preclinical evaluation as a potential therapeutic agent for primary and metastatic brain tumors. Supported by NIH grant CA115495 and by the Helen and Harold McMaster Endowment.

Citation Format: Shengnan Du, Jeffrey G. Sarver, Christopher J. Trabbic, Paul W. Erhardt, Jean H. Overmeyer, William A. Maltese. A novel microtubule-disrupting indole-based chalcone that induces caspase-independent cell death in glioblastoma and melanoma cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1244.
Abstract 1269: Enhanced cytotoxicity in primary human metastatic melanoma cells via inhibition of the transient receptor potential melastatin-2 (TRPM2) channel
Authors: Koh David W. , Blake Steven D. , Powell Daniel P.
Published: July 2016

The transient receptor potential melastatin-2 (TRPM2) cation channel was previously identified as a potential target in various cancers, where its pharmacologic inhibition caused increased DNA damage and the selective eradication of cancer cells. In this study, we utilized several human primary metastatic melanoma cell lines, in which we analyzed TRPM2 and its isoforms, and evaluated the ability of TRPM2 inhibition to modulate cell death.

As TRPM2 is known to exist as a plasma membrane cation channel in noncancerous cells, we investigated the localization of TRPM2 in melanoma cells. In three lines of primary human metastatic melanoma cells, TRPM2 was localized in the nucleus, as compared to an extra-nuclear localization in noncancerous primary epidermal keratinocyes. Because TRPM2 exists in several isoforms in cancer cells, we investigated the cellular localization of these isoforms. Subcellular fractionations demonstrated that only full-length TRPM2 was localized to the nucleus in primary human metastatic melanoma cells, whereas two smaller isoforms were localized exclusively in the cytoplasmic fraction.

Treatment with the TRPM2 inhibitor, clotrimazole, caused decreased proliferation in all three lines of primary human metastatic melanoma cells. Further, treatment with the DNA alkylating agent, temozolomide (TMZ), led to increased levels of cell death in melanoma cells pretreated with clotrimazole, but not in noncancerous primary epidermal keratinocyes after pretreatment. Similar increases in cell death were observed after RNAi silencing of TRPM2 followed by TMZ treatment.

Taken together, this study demonstrated that TRPM2 inhibition selectively increases cell death in primary human metastatic melanoma cells. Further, the data suggests that, similar to our previous results in breast adenocarcinoma cells, full-length TRPM2 appears to have a novel role in melanoma cell growth and survival. The results therefore suggest that TRPM2 is a potential target in melanoma, where its inhibition may cause the selective eradication of metastatic melanoma.

Citation Format: David W. Koh, Steven D. Blake, Daniel P. Powell. Enhanced cytotoxicity in primary human metastatic melanoma cells via inhibition of the transient receptor potential melastatin-2 (TRPM2) channel. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1269.
Abstract 1275: Suppression of platelet aggregation and tumor metastasis by anti-podoplanin mAbs recognizing a novel CLEC-2 binding domain
Authors: Sekiguchi Takaya , Takemoto Ai , Fujita Naoya
Published: July 2016

Tumor-induced platelet aggregation promotes tumor growth and hematogenous metastasis by secreting growth factors from platelets, by avoiding immune system and shear stress, and by stimulating the formation of tumor emboli in microvasculature. Thus, tumor-platelet interaction could be a promising target for cancer therapy. We previously identified a sialoglycoprotein podoplanin, also known as Aggrus, as a key factor in tumor-induced platelet aggregation enhancing tumor metastasis. Podoplanin is expressed in various cancers and reported to be a candidate for cancer stem cell marker. Podoplanin-induced platelet aggregation depends on binding to its platelet receptor CLEC-2. Here, we report the discovery of a novel platelet aggregation-stimulating domain PLAG4 in human podoplanin critical for the binding to CLEC-2. Mutant analyses indicated that PLAG4 exhibits a predominant CLEC-2 binding ability and platelet-aggregating function when compared to the previously reported PLAG3. Moreover, mutation of both PLAG3 and PLAG4 domains could almost completely attenuate its CLEC-2 binding ability and its platelet-aggregation activity. To validate the inhibitory effect against PLAG4 domain, we established anti-PLAG4-neutralizing monoclonal antibodies (mAbs), PG4D1 and PG4D2. Both mAbs recognized PLAG4 domain and exhibited a high affinity to podoplanin. We confirmed those neutralizing ability against PLAG4-CLEC-2 interaction and platelet aggregation. Remarkably, the administration of each mAbs significantly suppressed pulmonary metastasis of podoplanin expressing tumor.

Taken together, we suggest that PLAG4 is the novel CLEC-2 binding and platelet aggregation-stimulating domain on podoplanin and has a role in podoplanin-mediated metastasis formation. Blocking the podoplanin-CLEC-2 interaction targeting PLAG3 or PLAG4 would be a promising strategy for suppressing hematogenous metastasis.

Citation Format: Takaya Sekiguchi, Ai Takemoto, Naoya Fujita. Suppression of platelet aggregation and tumor metastasis by anti-podoplanin mAbs recognizing a novel CLEC-2 binding domain. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1275.
Abstract 1281: Prostaglandin D synthase is a potential novel therapeutic agent for the treatment of gastric carcinomas expressing PPARγ
Authors: Yashiro Masakazu , Fukuoka Tatsunari , Kinoshita Haruhito , Masuda Go , Kitayama Kishu , Miki Yuichiro , Morisaki Tamami , Hasegawa Tsuyoshi , Hirakawa Kosei
Published: July 2016

Background & Aims: The antitumor activity of prostaglandin (PG) D2 has been demonstrated against some types of cancer, including gastric cancer. However, exogenous PGD2 is not useful from a clinical point of view because it is rapidly metabolized in vivo. The aim of this study was to clarify the antitumor efficacy of an alternative, PGD2 synthase (PGDS), on gastric cancer cells. This is the first report showing that PG synthase is a promising agent for the treatment of gastric carcinomas that express peroxisome proliferator-activated receptor γ (PPARγ).

Methods: The effects of PGD2 and PGDS on the proliferation of gastric cancer were examined in vivo and in vitro for five human gastric cancer cell lines. The expression levels of PGD2 receptors and PPARγ were evaluated by RT-PCR. The effects of PGD2 and PGDS on the expression of c-myc and cyclin D1 were examined by Western blotting in the presence or absence of a PPARγ antagonist.

Results: PPARγ was expressed in gastric cancer cell lines, but PGD2 receptors were not. PGD2 and PGDS significantly decreased the proliferation of gastric cancer cells that highly expressed PPARγ. PGDS increased the PGD2 production of gastric cancer cells. A PPARγ antagonist significantly suppressed the growth-inhibitory effects of PGD2 and PGDS. Expression of c-myc and cyclin D1 was significantly decreased by PGD2; this inhibitory effect was suppressed by the PPARγ antagonist. Both PGD2 and PGDS significantly decreased subcutaneous tumor growth in vivo. Tumor volume after PGDS treatment was significantly less than after PGD2 treatment. PGD2 decreased the proliferation of gastric cancer cells through PPARγ signaling.

Conclusion: PGDS and PGD2 decreased the proliferation of gastric cancer via the PPARγ pathway. PGDS is a promising therapeutic agent for gastric cancer and PPARγ might be a predictive biomarker for PGDS treatment in gastric cancer.

Citation Format: Masakazu Yashiro, Tatsunari Fukuoka, Haruhito Kinoshita, Go Masuda, Kishu Kitayama, Yuichiro Miki, Tamami Morisaki, Tsuyoshi Hasegawa, Kosei Hirakawa. Prostaglandin D synthase is a potential novel therapeutic agent for the treatment of gastric carcinomas expressing PPARγ. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1281.
Abstract 1293: JQ1 sensitivity of patient-derived xenograft models of cholangiocarcinoma
Authors: Miller Aubrey L. , Garcia Patrick L. , Gamblin Tracy L. , Council Leona N. , Cui Xiangqin , Bradner James E. , Yang Eddy S. , Yoon Karina J.
Published: July 2016

Cholangiocarcinoma (CCA) is a lethal malignancy arising from cholangiocytes in any part of the biliary tree. The incidence of CCA has been on the rise worldwide, and the prognosis and clinical outcome have remained essentially unchanged for 30 years. The majority of patients are diagnosed at late stage, and surgery continues to be the only cure. Patients receive systemic chemotherapy with the first-line combination therapy comprising gemcitabine and cisplatin. Median survival for these patients is <12 months, emphasizing the need to improve current treatment. A step toward improving outcome is the pre-clinical evaluation of novel therapeutics. Recently the bromodomain and extra-terminal domain (BET) inhibitor JQ1 has been shown to suppress tumor growth in preclinical models of multiple tumor types. The therapeutic effect of JQ1 has been attributed, at least in part, to its ability to inhibit c-Myc expression. 95% of CCA tumors express c-Myc and its down-regulation has been shown to reduce the invasive potential of CCA cells, suggesting that c-Myc contributes to CCA phenotype. Our lab recently evaluated the efficacy of the BET inhibitor JQ1 in CCA patient-derived xenograft mouse models. JQ1 suppressed CCA tumor growth in 2 of the 3 models.

To determine gene products whose upregulation or downregulation is responsible for the differences in sensitivity to JQ1 among our CCA models, we generated expression profiles of tumors from vehicle control and JQ1 treated mice using NanoString technology (nCounter PanCancer Pathways panel). Our data demonstrate that JQ1 inhibited the expression of c-Myc to a greater extent in the sensitive models than in the insensitive model. Expression array data showed further that gene products involved in cell cycle and DNA repair pathways were also decreased by JQ1. Of particular interest were two transcriptional targets of c-Myc, Chk1 and BRCA2, each of which is involved in DNA damage response. Immunohistochemistry staining confirmed expression profile analyses. We conclude that the inhibition of cell cycle and DNA repair genes may contribute to the mechanism of action of JQ1 in CCA tumors.

Citation Format: Aubrey L. Miller, Patrick L. Garcia, Tracy L. Gamblin, Leona N. Council, Xiangqin Cui, James E. Bradner, Eddy S. Yang, Karina J. Yoon. JQ1 sensitivity of patient-derived xenograft models of cholangiocarcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1293.
Abstract 1318: Pancreatic cancer therapy using polyion micelles co-loaded with cyclopamine and paclitaxel
Authors: Zhao Jun , Wu Chunhui , Wen Xiaoxia , Li Junjie , Huang Qian , Ma Ying , Ullrich Stephen , Wang Huamin , Fleming Jason , Li Chun
Published: July 2016

Sonic hedgehog (SHH) signaling pathway is an important regulator during the initiation and progression of pancreatic cancer, and sustained activation of this pathway contributes to excessive deposition of tumor stroma and maintenance of tumor-initiating cells. Cyclopamine, a potent inhibitor of the SHH pathway, has shown promising antitumor efficacy. However, cyclopamine is insoluble in water and is highly toxic, and cyclopamine monotherapy did not effectively inhibit tumor growth in a range of preclinical pancreatic cancer models. We hypothesized that polyion complex polymeric micelles that simultaneously deliver cyclopamine and paclitaxel (M-CPA/PTX) would display greater efficacy against pancreatic tumor than micelles loaded with cyclopamine alone (M-CPA) or paclitaxel alone (M-PTX). We tested this hypothesis in cell cultures and in an orthotopic human pancreatic cancer Miapaca-2 xenograft model and a genetically engineered mouse model of pancreatic ductal carcinoma (PDAC), the KPC model. Our results showed that M-CPA interrupted the SHH pathway by antagonizing the smoothened receptor, reduced expression of Gli-1 transcription factor, and inhibited proliferation of Miapaca-2 cells and stroma-producing human pancreatic stellate cells. In Miapaca-2 cells, M-CPA decreased the fraction of CD133+ cells (cancer stem cells) and decreased tumorsphere formation, whereas M-TXL increased the fraction of CD133+ cells and tumorsphere formation. M-CPA negated the stimulation of human pancreatic stellate cells by exogenous SHH ligands. In vivo, M-CPA/PTX reduced tumor cell proliferation, depleted tumor stroma, and increased tumor vasculature density, leading to effective inhibition of tumor growth in Miapaca-2 xenografts. In the KPC model, M-CPA/PTX significantly prolonged media survival of mice with PDAC compared to non-treatment control mice. In conclusion, M-CPA/PTX was an effective strategy to treat pancreatic cancer. (supported in part by the Viragh Family Foundation and the John S. Dunn Foundation)

Citation Format: Jun Zhao, Chunhui Wu, Xiaoxia Wen, Junjie Li, Qian Huang, Ying Ma, Stephen Ullrich, Huamin Wang, Jason Fleming, Chun Li. Pancreatic cancer therapy using polyion micelles co-loaded with cyclopamine and paclitaxel. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1318.
Abstract 1322: Folate receptor-targeted lipid coated albumin nanoparticles (F-LCAN) for therapeutic delivery of RX-0201 (Archexin®), an antisense oligonucleotide against Akt-1
Authors: Li Hong , Cheng Xinwei , Liu Yang , Lee Young Bok , Kim Deog Joong , Ahn Chang-ho , Lee Robert J.
Published: July 2016

Akt-1 is a protein kinase that contributes to cancer progression by promoting proliferation and inhibiting apoptosis of tumor cells. RX-0201 (Archexin®), a 20-mer phosphorothioate antisense oligonucleotide that inhibits the expression of Akt-1, is currently in a Phase IIa clinical trial for metastatic renal cancer. To further improve the efficacy of RX-0201, folate receptor-targeted lipid coated albumin nanoparticles containing RX-0201 (F-LCAN-RX-0201) were synthesized and evaluated for Akt-1 inhibition and antitumor activity. These nanoparticles are composed of DOTAP/soyPC/TPGS/folate-PEG-DSPE (25:70:4:1), a cationic human serum albumin-pentaethylenehexamine (HSA-PEHA) conjugate, and RX-0201. F-LCAN-RX-0201 had a particle size of 108.6±5.8 nm, zeta potential of 10.5±3.2 mV and 71.5% antisense loading efficiency. F-LCAN-RX-0201 in folate receptor-expressing KB cells inhibited cell growth at IC50 of 11.9 ± 4.0 μM while free RX-0201 did not show significant cytotoxicity at concentration up to 250 μM. Cellular uptake and Akt-1 inhibition of F-LCAN-RX-0201 was greater than the non-targeted LCAN-RX-0201 and was partially blocked by excess free folate. Pharmacokinetic studies showed that F-LCAN-RX-0201 had a longer half-life than that of free RX-0201 (30 ± 4 min vs 10 ± 2 min). In a KB xenograft tumor model, F-LCAN-RX-0201 exhibited higher tumor suppressive activity compared to the non-targeted LCAN-RX-0201 at 16 mg/kg (as a RX-0201 amount) without body weight changes. Moreover, the antitumor activity of F-LCAN-RX-0201 at a dose of 16mg/kg (as a RX-0201 amount) was similar to free RX-0201 at a dose of 90mg/kg. In conclusion, LCAN is a highly effective formulation for therapeutic delivery of antisense agents and F-LCAN-RX-0201 could be a potential therapeutic agent for tumors with increased folate-receptor expression.

Citation Format: Hong Li, Xinwei Cheng, Yang Liu, Young Bok Lee, Deog Joong Kim, Chang-ho Ahn, Robert J. Lee. Folate receptor-targeted lipid coated albumin nanoparticles (F-LCAN) for therapeutic delivery of RX-0201 (Archexin®), an antisense oligonucleotide against Akt-1. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1322.
Abstract 1333: Bigelovin inhibits colorectal cancer by suppressing the growth and inducing apoptosis both in vitro and in vivo
Authors: Li Ming-Yue , Yue Grace Gar-Lee , Tsui Stephen Kwok-Wing , Fung Kwok-Pui , Tan Ning-Hua , Lau Clara Bik-San
Published: July 2016

Colorectal cancer (CRC) is one of the most common cancers with high incidence and mortality worldwide. In 2014, CRC was the second commonest cancer and second leading cause of cancer deaths in Hong Kong. National Cancer Institute estimates that 132,700 people will be diagnosed with CRC and 49,700 people will die from the disease in 2015 worldwide. Despite effectiveness of the chemotherapeutics, severe side effects often affect patients’ normal life. Traditional Chinese medicines can be a good source of anti-tumor agent with better safety profile. Here, we reported a sesquiterpene lactone (bigelovin) isolated from Inula helianthus- aquatica, which was shown to induce anti-angiogenesis1 and apoptosis2 in vitro. Although previous studies reported its apoptotic effects on various cell lines, there were no detailed mechanistic or animal studies on its effect on colon cancer cells. To further explore its effect on CRC, we used both in vitro and in vivo assays. The effects of bigelovin in vitro were determined by Annexin V/PI double staining, cell cycle assay and western blotting. Bigelovin was shown to have better selectivity in colon cancer cells than primary normal colon cells. Besides, CRC cells treated with bigelovin resulted in decrease in cell proliferation and increase in apoptosis in both time- and dose-dependent manner. Western blot results also showed caspase activation and protein changes of key molecules (p-H2A.X-DNA damage marker, Cyclin B1-cell cycle, etc). Furthermore, bigelovin (20 mg/kg) significantly reduced the growth of CRC cells-driven tumors in vivo without severe side effects comparing to FOLFOX (containing folinic acid, 5-fluorouracil and oxaliplatin) treatment. Taken together, these results suggested that bigelovin can be a promising therapeutic candidate for colorectal cancer.

References:

1. Yue, G.G.L., et al. Anti-angiogenesis and immunomodulatory activities of an anti-tumor sesquiterpene bigelovin isolated from Inula helianthus-aquatica. Eur J Med Chem, 2013, 59: 243-52.

2. Zhang, H.H., et al. Bigelovin inhibits STAT3 signaling by inactivating JAK2 and induces apoptosis in human cancer cells. Acta Pharmacol Sin, 2015, 36(4): 507-16.

Citation Format: Ming-Yue Li, Grace Gar-Lee Yue, Stephen Kwok-Wing Tsui, Kwok-Pui Fung, Ning-Hua Tan, Clara Bik-San Lau. Bigelovin inhibits colorectal cancer by suppressing the growth and inducing apoptosis both in vitro and in vivo. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1333.
Abstract 1347: NTRK1/TRKA as a therapeutic target in castration resistant prostate cancer
Authors: Korkola James E. , Liu Moqing , Smith Rebecca , Liby Tiera , Gray Joe W.
Published: July 2016

Treatment options remain limited for men with castration resistant prostate cancer, with current chemotherapy offering mainly palliative benefits. Thus, there is an urgent need to identify new targets for therapeutic intervention in men who have progressed on anti-androgen therapy. We have compiled a panel of 20 prostate cancer cell lines that has been extensively characterized at the molecular level that enables us to perform high throughput drug and siRNA screens to identify novel therapeutic targets. We performed an siRNA screen targeting kinases using eight representative lines, both in the presence and absence of the anti-androgen MDV3100. Knockdown of NTRK1 (TRKA) significantly inhibited growth in 4/8 of the cell lines tested. To confirm this, we screened the entire panel of cell lines with the inhibitor CEP-701, which targets FLT3, JAK2, and TRK-A/B/C. CEP-701 showed GI50 values (dose required to inhibit growth by 50%) less than 400 nM in 8/20 cell lines. Since this drug had already been tested in clinical trials for prostate cancer and the trials were discontinued due to lack of PSA decline, we looked for other drugs that also inhibit TRKA. Both BIBF-1120 and GSK-1363089 are also known to inhibit TRKA, but neither have been tested in prostate cancer expressing TRKA. We tested GSK-136089 in a subset of 9 prostate cell lines, and found that 4/9 lines reached GI50 at 1 uM or less, including AR mutant or null lines such as 22rv1 and PC3 that are non-responsive to MDV3100. Additional tests with BIBF-1120 and GSK-1363089 are underway. These data suggest that NTRK1 may be a potential target for patients with castration resistant prostate cancer.

Citation Format: James E. Korkola, Moqing Liu, Rebecca Smith, Tiera Liby, Joe W. Gray. NTRK1/TRKA as a therapeutic target in castration resistant prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1347.
Abstract 1350: New NCI experimental therapeutics program (NExT) small molecule libraries for academic investigator hts projects
Authors: Misra Raj N. , Eckert Michael , Laggner Christian
Published: July 2016

The NCI Experimental Therapeutics Program (NExT) is making available two new smaller (3.5K) screening libraries suitable for academic investigator HTS drug discovery programs. The NExT program is a partnership between NCI's Division of Cancer Treatment and Diagnosis (DCTD) and the Center for Cancer Research (CCR). NExT consolidates NCI's anticancer drug discovery and development resources with the goal of maintaining a robust and balanced therapeutics pipeline. It encompasses tasks from new target validation through Phase III clinical trial evaluation. The Program is designed to streamline development and testing of promising new anticancer drugs and to expedite their delivery to the bedside. As part of the Program to support HTS drug discovery, NCI has previously offered academic oncology investigators access to our full 83K NExT Diversity Library in single-use, 384-well plate format. The set was designed to identify lead small molecules for drug discovery programs. We are now making available 2 smaller pre-plated subsets of this library, the NExT Diversity 3500 and NExT Diversity 3500 SAR, for when screening the full set is not appropriate. Each library contains 3,500 compounds: NExT Diversity 3500 is a diverse sampling across the entire 83K library while the NExT Diversity 3500 SAR is designed to facilitate rapid SAR follow-up by sampling only those compounds that have at least 5 close neighbors in the 83K library. The new libraries were designed by initially filtering the full NExT Diversity Library for undesirable compounds such as PAINS. Both atom-pair based 2D pharmacophore fingerprints and ECFP6 topological fingerprints from ChemAxon were then employed to generate the two non-overlapping subset libraries. The NExT screening libraries are provided as a resource to academic oncology investigators through the NExT Program (see NExT Resources: http://next.cancer.gov/). The design details and physiochemical characteristics of the two new sets, NExT Diversity 3500 and NExT 3500 SAR, and procedures and criteria for accessing this resource are presented along with several other screening sets available through the Developmental Therapeutics Program (DTP).

Citation Format: Raj N. Misra, Michael Eckert, Christian Laggner. New NCI experimental therapeutics program (NExT) small molecule libraries for academic investigator hts projects. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1350.
Abstract 1361: Progress in light activatable prodrug for the combinational treatment of PDT and site-specific chemotherapy: paclitaxel prodrugs
Authors: Thapa Pritam , Li Mengjie , Bio Moses , Rajaputra Pallavi , Sun Yajing , Woo Sukyung , You Youngjae
Published: July 2016

We developed the photoactivatable prodrug of Paclitaxel (PTX) for the combinational treatment of chemo and photodynamic therapy (PDT). PTX causes dose-limiting side effects as other anticancer drugs when administered systemically. On the other hand, PDT suffers from incomplete ablation and subsequent reoccurrence in part due to the short half-life and poor diffusion rate of singlet oxygen. We prepared a conjugate of PTX with phthalocyanine via a singlet oxygen cleavable linker, as a unique prodrug of PTX, to overcome the problems of PDT and systemic chemotherapy. The PTX prodrug was evaluated for tubulin polymerization, the release rate of PTX from prodrug upon illumination at 690 nm, stability in complete media, and the combination effect in killing ovarian cancer cells in vitro (SKOV-3). The PTX prodrug did not enhance the tubulin polymerization unlike PTX. While it was stable in the media under dark, it rapidly released PTX upon illumination with far-red light: > 90% release in 30 min. The prodrug showed much lower dark toxicity compared to PTX. When illuminated with 690 nm at 5.6 mW/cm2, the prodrug showed very potent phototoxicity: IC50 = 3.9 nM, through the combinational effect of PDT and PTX. In conclusion, we found that the PTX prodrug have desired properties as light-activatable prodrug expressing the combinational effect of PDT and local PTX chemotherapy. Animal study is underway to evaluate the antitumor effect of the PTX prodrug.

Citation Format: Pritam Thapa, Mengjie Li, Moses Bio, Pallavi Rajaputra, Yajing Sun, Sukyung Woo, Youngjae You. Progress in light activatable prodrug for the combinational treatment of PDT and site-specific chemotherapy: paclitaxel prodrugs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1361.
Abstract 1362: Novel proton coupled folate transporter (PCFT) and reduced folate carrier (RFC) pharmacophore models for development of transporter-selective antifolates
Authors: Raghavan Sudhir , Gangjee Aleem , Matherly Larry H.
Published: July 2016

RFC is a ubiquitously expressed folate transporter that is present in normal tissues and tumors. RFC is utilized by reduced folates and by all the clinically used classical antifolates. In contrast, PCFT shows more limited expression in normal tissues and is highly effective in folate transport under low pH conditions associated with hypoxic solid tumors. Antifolates that are selectively transported by PCFT over RFC offer significant promise for development of targeted therapies of tumors (over)expressing PCFT. We previously reported 6-substituted pyrrolo[2,3-d]pyrimidines and thieno[2,3-d]pyrimidines as part of a continued effort to elucidate the SAR for substrate binding and cellular uptake for RFC, PCFT as well as folate receptors (FRs). While the X-ray crystal structure of FRs bound to antifolates has been resolved, the absence of X-ray crystal structures of PCFT and RFC has hindered structure-based medicinal chemistry efforts for development of antifolates selectively transported by PCFT. To address this, pharmacophore models were developed for the first time using Discovery Studio for PCFT and RFC using a series of thirty six 6-substituted bicyclic pyrrolo[2,3-d]pyrimidines and/or thieno[2,3-d]pyrimidines that included highly potent and selective compounds such as AGF94 (PCFT = 0.3 nM; RFC = 101 nM) previously reported by us. Compounds used for model development displayed a 3-log range inhibition of cancer cells overexpressing PCFT or RFC. The best models display a 4-point pharmacophore with excellent regression values (r2 PCFT = 0.96; RFC = 0.92). The models were internally validated by leave-one-out analysis (q2 PCFT = 0.752; RFC = 0.59) and externally validated using a test set of 6-substituted bicyclic analogs not used in model development. Comparison of the pharmacophore models indicates different conformational and structural requirements for compounds for binding to PCFT or RFC. We have used these models to explain the potent PCFT inhibitory activity and selectivity of compounds such as AGF94. These models are being used in the development of selectively transported targeted antifolates that would result in decreased toxicity compared to standard antifolates such as methotrexate (MTX) or pemetrexed (PMX) which utilize all three folate transport systems.

Citation Format: Sudhir Raghavan, Aleem Gangjee, Larry H. Matherly. Novel proton coupled folate transporter (PCFT) and reduced folate carrier (RFC) pharmacophore models for development of transporter-selective antifolates. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1362.