bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 922: Macrophage migration inhibitory factor (MIF) and miR-301b interactively enhance disease aggressiveness by targeting NR3C2 (nuclear receptor subfamily group c member 2) in human pancreatic cancer
Authors: Yang Shouhui , He Peijun , Wang Jian , Schetter Aaron , Tang Wei , Funamizu Naotake , Gaedcke Jochen , Ghadimi Michael , Gaida Matthias , Ried Thomas , Hannah Nader , Alexander H. Richard , Hussain S. Perwez
Published: August 2015

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal malignancy. Aberrant macrophage migration inhibitory factor (MIF) expression is associated with disease aggressiveness and increased MIF in PDAC predicts poor patient survival. Here we show that MIF-induced disease aggressiveness and poor survival in PDAC involves the inhibition of the nuclear receptor subfamily group c member 2 (NR3C2). Tumors with aberrant high levels of MIF (MIF-high) showed an increased expression of mir-301b and a decrease in NR3C2 expression as compared to the tumors with a lower level of MIF (MIF-low) in PDAC cases and a negative correlation existed between MIF and NR3C2 expressions in these tumors. Furthermore, patients with an increase in mir-301b or decrease in NR3C2 expression had a significantly shorter survival than other patients. MIF overexpression and knockdown confirmed that MIF up-regulates miR-301b, which then binds to the 3′UTR of NR3C2 and markedly decreases its expression. Moreover, MIF-overexpressing orthotopic tumor xenografts showed an increase in mir-301b and a decrease in NR3C2 expressions. MIF-induced regulation of mir-301b and NR3C2 functionally involved the PI3Kinase/Akt pathway. Examination of the tumor suppressor mechanism of NR3C2 revealed that it inhibits proliferation, colony formation, migration and invasion, and enhances sensitivity to chemotherapeutic drug gemcitabine in pancreatic cancer cells. Furthermore, NR3C2 knock down enhanced epithelial-to-mesenchymal transition. These data identify a novel MIF-induced signaling pathway targeting NR3C2, leading to increased disease aggressiveness and poor outcome in PDAC. We identified a MIF-driven signaling pathway that inhibits a previously undescribed tumor suppressor of PDAC, NR3C2, involving miR-301b. The inhibition of NR3C2 enhanced disease aggressiveness and predicted to poor survival, as shown by our survival analysis. Therapies that target the MIF-miR-301b-NR3C2 axis may improve disease outcome in pancreatic cancer.

Citation Format: Shouhui Yang, Peijun He, Jian Wang, Aaron Schetter, Wei Tang, Naotake Funamizu, Jochen Gaedcke, Michael Ghadimi, Matthias Gaida, Thomas Ried, Nader Hannah, H. Richard Alexander, S. Perwez Hussain. Macrophage migration inhibitory factor (MIF) and miR-301b interactively enhance disease aggressiveness by targeting NR3C2 (nuclear receptor subfamily group c member 2) in human pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 922. doi:10.1158/1538-7445.AM2015-922
Abstract 923: Nitric oxide signaling pathway as a pathogenic driver in pancreatic cancer
Authors: Wang Jian , He Peijun , Gaida Matthias M. , Yang Shouhui , Schetter Aaron , Gaedcke Jochen , Ghadimi Michael , Ried Thomas , Yfantis Harris G. , Lee Dong H. , Weiss Jonathan M. , Hanna Nadar , Alexander H. Richard , Hussain S. Perwez
Published: August 2015

Pancreatic Ductal Adenocarcinoma (PDAC) is among the most malignant cancers, with 5-year survival of 6%. Chronic inflammation is associated with increased risk of PDAC. Nitric oxide (NO) is an important mediator of inflammatory responses and plays a role in tumorigenesis. The principal source of an increased and sustained level of NO is inducible nitric oxide synthase (NOS2). In this study, we’ve tested the hypothesis that NO enhances tumor progression in pancreatic cancer. We found that higher NOS2 expression in tumors was associated with poor survival in resected PDAC patients (p = 0.011). We then investigated the role of NO by deleting NOS2 gene in a genetically engineered mouse model of pancreatic cancer (KPC mice) with pancreas-specific activation of mutant KRAS and P53, which faithfully recapitulates the development and progression of human pancreatic cancer. NOS2-deficient KPC mice showed longer survival compared to the KPC littermates with wildtype NOS2 (p<0.01). Compared to tumors from KPC mice, KPC/NOS2−/− tumors were less vascularized (p<0.001) and with less macrophage recruitment (p<0.005), indicated by decreased expression of CD31 and F4/80 respectively. NOS2 deficiency led to attenuated proliferation and invasion, and enhanced apoptosis indicated by high level of cleaved caspase-3 (p = 0.02). Consistent with the less malignant phenotype, NOS2 deficiency reduced nuclear pERK accumulation (P = 0.034) and the subsequent phosphorylation of FOXO3 (p = 0.026). Further investigation showed a positive correlation between NOS2 expression and pFOXO level in human PDAC specimen (p = 0.005). In addition, NOS2 deficiency reduced the expression of a well known oncogenic microRNA, miR21 (p = 0.001). In summary, NOS2 gene expression in tumors is a candidate prognostic marker in resected pancreatic cancer patients, and NOS2/NO signaling may contribute to the pancreatic tumor progression by inactivating FOXO3 in KPC mice. In this ongoing study, we are further investigating the mechanistic role of NO in disease progression.

Citation Format: Jian Wang, Peijun He, Matthias M. Gaida, Shouhui Yang, Aaron Schetter, Jochen Gaedcke, Michael Ghadimi, Thomas Ried, Harris G. Yfantis, Dong H. Lee, Jonathan M. Weiss, Nadar Hanna, H. Richard Alexander, S. Perwez Hussain. Nitric oxide signaling pathway as a pathogenic driver in pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 923. doi:10.1158/1538-7445.AM2015-923
Abstract 93: Universal homogenous bioluminescent assay that monitor the activity various classes of methyltransferases in vitro
Authors: Hsiao Kevin , Goueli Said
Published: August 2015

Post transcriptional modifications of proteins and nucleic acids are well-recognized to play major role in influencing cell fate towards cellular proliferation, differentiation, and cell death. Such modifications that include

phosphorylation, acetylation, methylation, etc. have been validated as drug targets resulting in the development of several drugs. Recent biochemical and biological data suggest that the enzymatic activities of several of these enzymes have pathogenic roles in cancer, inflammation, and neurodegenerative diseases. Thus, pharmacological modulation of these enzymes by small molecules will be beneficial in developing novel therapeutics for multiple unmet medical needs. Of these, methyltransferases are known to alter the epigenome by altering the methylation status of nucleic acids or proteins resulting in changes in cellular functions. Towards this goal of

searching for activators/inhibitors of these enzymes for the development of next generation of drugs, screening assays for these modulators are urgently needed. To address these unmet needs, we have developed a novel assay that monitors the activities of these enzymes and their modulation by small molecules. The assay is bioluminescent based, HTS formatted and highly sensitive. The assay is universal since it is based on monitoring the formation of the universal product S-adenosylhomocysteine (SAH), i.e., capable of detecting changes in activity of a broad range of methyltransferases such as DNA, protein, RNA, and small molecules methyltransferases. In addition, the assay has been validated for all classes of protein methyltransferases (Lysine and Arginine), and with different types of substrates (small peptides, large proteins, or even nucleosomes). This enables determining the specificity of these enzymes and their substrate requirements. The assay has high signal to background and low C.V. The assay is robust (Z’ value > 0.7) and has been validated using various plate densities such as 96-, 384, and 1536-well plates. A strong feature of this assay is its utility with broad range of substrates with no limitations on the use of high concentrations of substrates or the composition of the substrates (short vs. long peptides), thus enabling the generation of kinetic data and determining the mechanism of action of various modulators of methyltransferases of interest.

Citation Format: Kevin Hsiao, Said Goueli. Universal homogenous bioluminescent assay that monitor the activity various classes of methyltransferases in vitro. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 93. doi:10.1158/1538-7445.AM2015-93
Abstract 940: Identification of Palbociclib response signature across indications
Authors: Zheng Xianxian , Ozeck Mark , Zhu Zhou , Ching Keith , Shields David , Hardwick James , Rejto Paul , VanArsdale Todd
Published: August 2015

Cellular proliferation is dependent on an orderly movement through the various phases of cell cycle. Progression through the G1 phase in particular requires phosphorylation of the retinoblastoma (Rb) protein which in turn releases E2F transcription factors resulting in transcriptional activation of response gene necessary for progression into S-phase. The cyclin D-CDK4/6 signaling pathway represent a critical regulatory pathway controlling transition from G1 into S-phase and greater than 90% of human tumors have mutations in this pathway. Palbociclib is a potent, selective, and orally bioavailable inhibitor of Cdk4/6. In human tumor xenograft models, Palbociclib has significant antitumor activities. The clinical activities of Palbociclib have also be demonstrated in the phase II PALOMA-1 trial for dramatic efficacy of postmenopausal patients with locally advanced or newly diagnosed estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer in combination with letrozole. To better understand the molecular mechanisms of Palbociclib response, we have identified a common set of gene signatures for ER+ BC as well as melanoma models. The physiological role of these genes regulated by Palbociclib is associated with DNA replication and repair, cell cycle, signal transduction, and Mitosis. Many of these genes have been previously identified as E2F signatures. In this study, we are aiming to expand this analysis to include two additional indications including Head and Neck squamous cell carcinoma (HNSCC) as well as squamous cell lung carcinoma (Sq lung) using Illumina RNASeq technology platform. Results from these studies will be presented and core Palbo-response signature will be discussed. In addition, we will also present the pharmacological effects of Letrozole on the gene expression changes for these core signatures in ER+ BC models.

Citation Format: Xianxian Zheng, Mark Ozeck, Zhou Zhu, Keith Ching, David Shields, James Hardwick, Paul Rejto, Todd VanArsdale. Identification of Palbociclib response signature across indications. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 940. doi:10.1158/1538-7445.AM2015-940
Abstract 948: A novel antibody-drug conjugate that induces long-term tumor regression and anticancer stem cell activity
Authors: Harper Jay W. , Lloyd Chris , Mao Shenlan , Lin Xin , Dimasi Nazzareno , Howard Phil , O'Connor Ellen , Farkas David , Barton Christopher , Smith Jeff , Zhong Helen , Chen Tracy , Hinrichs Mary Jane , Rebelatto Marlon , Yu Xiang-Qing , Spitz Susan , Pierce Andrew , Lai Dominic , Elaine Hurt , van Vlerken-Ysla Lilian , Sanjoo Jalla , Miller Katy , McCullough Karen , Kannan Priya , Thompson Simon , Mahadevia Parthiv , Martin Chris , Hollingsworth Robert , Kamal Adeela
Published: August 2015

Antibody-drug conjugates (ADCs) selectively deliver cytotoxic agents to tumors and provide the potential for increased clinical benefit to cancer patients. We have developed an ADC consisting of an antibody against a target expressed on the surface of tumor cells that is site-specifically conjugated with a pyrrolobenzodiazepine (PBD) dimer payload (PBD-ADC). The tumor-associated antigen is overexpressed in many carcinomas, on both bulk tumor cells and cancer stem cells (CSCs), while normal tissue expression is limited, thus making it an ideal ADC target. The PBD payload was selected due to its picomolar potency and because, unlike tubulin inhibitors, it could be cytotoxic to CSCs as well as bulk tumor cells. The PBD-ADC is significantly efficacious in target-positive in vivo tumor models of gastric, breast and lung carcinomas, inducing long-term tumor regressions and demonstrates greater potency compared to ADCs conjugated with either tubulysin or auristatin payloads, both tubulin inhibitors. Additionally, the PBD-ADC significantly reduced the CSC population of tumors in vivo, unlike ADCs bearing tubulin inhibitor payloads. The PBD-ADC appears to be efficacious against tumors that have acquired resistance to a tubulysin-based ADC, however possible mechanisms of resistance to this PBD-ADC are being investigated. Collectively, this novel ADC represents a promising therapy that may deliver durable clinical responses in indications with unmet medical need.

Citation Format: Jay W. Harper, Chris Lloyd, Shenlan Mao, Xin Lin, Nazzareno Dimasi, Phil Howard, Ellen O'Connor, David Farkas, Christopher Barton, Jeff Smith, Helen Zhong, Tracy Chen, Mary Jane Hinrichs, Marlon Rebelatto, Xiang-Qing Yu, Susan Spitz, Andrew Pierce, Dominic Lai, Hurt Elaine, Lilian van Vlerken-Ysla, Jalla Sanjoo, Katy Miller, Karen McCullough, Priya Kannan, Simon Thompson, Parthiv Mahadevia, Chris Martin, Robert Hollingsworth, Adeela Kamal. A novel antibody-drug conjugate that induces long-term tumor regression and anticancer stem cell activity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 948. doi:10.1158/1538-7445.AM2015-948
Abstract 969: B-Raf activation loop phosphorylation is crucial for efficient MAPK signalling in vivo
Authors: Koehler Martin , Roering Michael , Braun Sandra , Brummer Tilman
Published: August 2015

Raf proteins are evolutionary conserved protein serine/threonine kinases and represent the MAPKKKs of the ERK-pathway. This pathway plays a crucial role in embryogenesis and is deregulated in multiple diseases. B-Raf represents the most potent MEK kinase of the Raf family and mutations in B-Raf or its upstream activators (e.g. Ras) are well-described in malignancies. So far, targeting the kinase function directly is flawed by paradoxical ERK activation in presence of oncogenic Ras. Therefore, a better understanding of its activation and finding an alternative targeting strategy is crucial. Phosphorylation of the T599VKS602-motif within the B-Raf activation loop is essential for full in vitro kinase activity stimulated by oncogenic Ras and is mimicked by oncogenic mutations such as V600E. To validate the importance of activation loop phosphorylation in vivo, we established a novel conditional BrafAVKA knock-in mouse that, upon Cre-mediated recombination, expresses the B-RafAVKA protein in which T599 and S602 are replaced by alanine residues.

Strikingly and in strong contrast to Braf knock-out mice, homozygous BrafAVKA mice are viable and show no early developmental defects suggesting that kinase impairment but not loss of the protein can be tolerated during embryogenesis. Additionally, these findings suggest that the B-RafAVKA mutant protein does not provoke a paradoxical ERK activation like the kinase dead B-RafD594A. However, neurological abnormalities such as ataxia or aberrant locomotion occur in older animals. This phenotype correlates with decreased MEK/ERK phosphorylation in total brain lysates. Also, signalling capacity of the ERK MAPK module, immediate early gene induction and proliferation are impaired in B-RafAVKA expressing MEFs.

Our findings support the concept that T599VKS602-motif phosphorylation is necessary for full B-Raf kinase activity in vivo. Therefore, blocking activation loop phosphorylation could be used to suppress aberrant ERK-pathway activity, e.g. by oncogenic Ras or RTKs, and circumventing paradoxical ERK activation in vivo.

Citation Format: Martin Koehler, Michael Roering, Sandra Braun, Tilman Brummer. B-Raf activation loop phosphorylation is crucial for efficient MAPK signalling in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 969. doi:10.1158/1538-7445.AM2015-969
Abstract 979: Dynamic epigenetic regulation of glioblastoma tumorigenicity through LSD1 modulation of MYC expression
Authors: Li Jie , Kozono David , Nitta Masayuki , Sampetrean Oltea , Gonda David , Kushwaha Deepa S. , Merzon Dmitry , Ramakrishnan Valya , Zhu Shan , Zhu Kaya , Matsui Hiroko , Harismendy Olivier , Hua Wei , Mao Ying , Kwon Chang-Hyuk , Saya Hideyuki , Carter Bob S. , Pizzo Donald P. , VandenBerg Scott R. , Chen Clark C.
Published: August 2015

Glioblastoma is the most common form of primary brain cancer and remains one of the deadliest of human cancers with near-uniform fatality. Increasing evidence suggests that the lethality of glioblastoma is driven by small subpopulations of cells with self-renew ability and tumorigenicity, termed as tumor initiating cells. The mechanism how the tumor initiating cells maintain and gain tumorigenicity in glioblastoma still remains unclear.

Here, we used sphere formation and tumor propagating potential to measure the tumorigenicity in established cell line and primary glioblastoma cells. The results indicated that glioblastoma tumorigenicity appears largely deterministic, though spontaneous gain and loss of this property occur at low frequency. Mechanically, this dynamic transition in tumorigenicity was governed by MYC level which was modulated epigenetically by the lysine-specific demethylase 1 (LSD1). Elevated MYC expression, in turn, regulates OLIG2, SOX2 and POU3F2, a core set of transcription factors required for reprogramming glioblastoma cells into stem-like states. Our model suggests epigenetic regulation of key transcription factors facilitates transitions between tumorigenic states and provides a framework for glioblastoma therapeutic development.

Importantly, the effect of LSD1 on tumorigenity is “Janus”-like; partial depletion of LSD1 caused increased MYC expression and a pro-tumorigenic state. In contrast, complete suppression of LSD1 induced cell death. As such, therapeutic strategies targeting LSD1 and other targets manifesting similar “Janus” effect should be designed to prevent unintended induction of tumorigenesis during treatment.

Citation Format: Jie Li, David Kozono, Masayuki Nitta, Oltea Sampetrean, David Gonda, Deepa S. Kushwaha, Dmitry Merzon, Valya Ramakrishnan, Shan Zhu, Kaya Zhu, Hiroko Matsui, Olivier Harismendy, Wei Hua, Ying Mao, Chang-Hyuk Kwon, Hideyuki Saya, Bob S. Carter, Donald P. Pizzo, Scott R. VandenBerg, Clark C. Chen. Dynamic epigenetic regulation of glioblastoma tumorigenicity through LSD1 modulation of MYC expression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 979. doi:10.1158/1538-7445.AM2015-979
Abstract 986: Role of Gpr43 in intestinal inflammation and carcinogenesis
Authors: Sivaprakasam Sathish , Gurav Ashish , Vadivel Ganapathy , Singh Nagendra
Published: August 2015

Consumption of dietary fiber is positively correlated with lower incidence of inflammation and carcinogenesis in intestine. In colon dietary fibers are fermented by gut microbiota into short chain fatty acids (SCFA, acetate, propionate and butyrate). Several studies demonstrate that SCFA play a key role in protection of intestine from inflammation and carcinogenesis. However, detail molecular mechanisms underlying the biological effects of SCFA on intestine health are not fully understood. Gpr43 is cell surface receptor for SCFA and recent evidences suggest that it regulates colonic inflammation in a context dependent manner. Intestinal inflammation is one of the risk factor for development of cancer in gut. Based on these findings, role of Gpr43 in regulation of colon carcinogenesis was evaluated. Colitis associated colon cancer in wild type (WT) and Gpr43-/- mice was induced by single intraperitoneal injection of azoxymethane (AOM) and repeated cycles of dextran sulfate sodium (DSS) in drinking water. Gpr43-/- mice showed drastically reduced survival, severe weight loss and increased diarrhea and rectal bleeding than WT mice. At the end of treatment, colons of Gpr43-/- mice exhibited increased number of polyps than that of WT mice. Reciprocal bone marrow chimera experiments revealed that Gpr43 expression in non-hematopoietic cells play a major role in suppression of colonic inflammation and carcinogenesis. The data presented here suggest a model in which Gpr43 plays a critical role in facilitating positive effects of dietary fiber and gut microbiota on intestinal health.

Citation Format: Sathish Sivaprakasam, Ashish Gurav, Ganapathy Vadivel, Nagendra Singh. Role of Gpr43 in intestinal inflammation and carcinogenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 986. doi:10.1158/1538-7445.AM2015-986
Abstract 990: Saxifragifolin D induces autophagy via activating IRE1α/ JNK pathway in breast cancer cells
Authors: Bai Liang-Liang , Shi Jun-Min , Chen Min-Feng , Zhang Dong-Mei , Wang Ying , Ye Wen-Cai
Published: August 2015

Background and Objective: Saxifragifolin D (SD) was isolated from Androsace umbellata by our group. It has been reported to inhibit some types of cancer cells, such as Hep3B, HepG2, SK-OV-3, A549, HCT-115 and multidrug resistante cell line HepG2/ADM. However, the growth inhibitory effect of SD on breast cancer cells and the mechanisms is still unclear. In this study, we explored the underlying molecular mechanisms of SD-induced autophagy in breast cancer cells.

Methods and Results: The autophagosomes, double membrane vacuolar structures, were observed in SD-treated MCF-7 and MDA-MB-231 cells by transmission electronic microscopy. And the autophagic vacuoles labeled by MDC were also increased in a time-dependent manner significantly. Besides, the autophagic ratio, quantified by using Cyto-ID® detection kit, was enhanced in a dose-dependent manner in these two cells. What's more, the marker of autophagy, LC3, was activated in MCF-7 and MDA-MB-231 cells treated with SD showed by western blot assay, further confirmed autophagy induced by SD. We also found that IRE1α which associated with endoplasmic reticulum (ER) stress was activated, and the JNK and Bcl-2 were phosphorylated in SD-treated MCF-7 and MDA-MB-231 cells by western blot assay. Accordingly, the up-regulation of Beclin1, Vps34, Atg5 and Atg16L were also detected in these two cells. Furthermore, suppression of autophagy by pretreating with Beclin1 siRNA or bafilomycin A1 decreased apoptosis and cell death, and resulted in decreases in expression of LC3- II and cleaved PARP. It's worth noting that inhibition of ER stress by IRE1α siRNA or TUDCA suppress autophagy and apoptosis, and the down-expression of LC3- II and cleaved PARP were measured.

Conclusion: SD induces autophagy associated with IRE1α/ JNK pathway in breast cancer cells and these findings will provide molecular bases for molecular mechanistic studies of SD-treated breast cancer cells.

Key words: Saxifragifolin D, autophagy, breast cancer.

Citation Format: Liang-Liang Bai, Jun-Min Shi, Min-Feng Chen, Dong-Mei Zhang, Ying Wang, Wen-Cai Ye. Saxifragifolin D induces autophagy via activating IRE1α/ JNK pathway in breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 990. doi:10.1158/1538-7445.AM2015-990
Abstract 993: The relationship between autophagy, senescence, and DNA repair
Authors: Alotaibi Moureq R. , Povirk Lawrence , Gewirtz Daivd
Published: August 2015

Radiotherapy is used along with other modalities such as surgery, chemotherapy, and immunotherapy to either shrink tumors before surgery or kill surviving tumor cells post surgery. Although radiation (and chemotherapy) induce different modes of cell death, recurrence of cancer may occur. It has been shown that DNA damage can induce cells to undergo both autophagy and senescence where both responses can function either as a pro-survival mechanism or in promoting loss of self-renewal capacity in the tumor cell. The relationship between autophagy, senescence, and the DNA repair system has not been well-characterized. The primary aims of this work were to understand whether autophagy and senescence might be permissive for DNA repair, thereby allowing the tumor cells to overcome the persistent DNA damage and recover using HCT116 WT and HCT116 Ligase IV (-/-) human colon carcinoma cells. Irradiation caused HCT116 Ligase IV (-/-) cells to lose their capacity to proliferate followed by delayed cell death, whereas HCT116 WT cells showed proliferative recovery 72 hours post-treatment, consistent with deficiencies in DNA repair in the Ligase IV (-/-) cells. Irradiation of both cell lines resulted in enlargement in cell size and accumulation of acidic vacuoles, indicative of the induction of autophagy. Inhibition of autophagy by Bafilomycin and Choroquine resulted in radio-sensitization in HCT116 WT cells but not in HCT116 Ligase IV (-/-) cells, indicating that radiation-induced autophagy in HCT116 WT cells is likely to be cytoprotective. Both repair competent HCT116 colon carcinoma cells and Ligase IV deficient cells demonstrated significant increases in senescent populations upon irradiation based on β-galactosidase staining and enlargement of treated cells. The PARP inhibitor, Olaparib, enhanced the efficacy of radiation through interference with DNA repair and the promotion of both autophagy and senescence but not apoptosis. Taken together, it appears that both autophagy and senescence may facilitate DNA repair during exposure to genotoxic stress, and that autophagy and senescence are closely linked responses in irradiated tumor cells.

Citation Format: Moureq R. Alotaibi, Lawrence Povirk, Daivd Gewirtz. The relationship between autophagy, senescence, and DNA repair. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 993. doi:10.1158/1538-7445.AM2015-993
Abstract 996: Retinoic acids activate autophagy in breast cancer cells through the FOXO3A-RARA pathway and blocking autophagy enhances retinoic acid-mediated cell death
Authors: Schlaefli Anna M. , Garattini Enrico , Tschan Mario P.
Published: August 2015

A series of pre-clinical studies showed promising anti-cancer effects of retinoic acids (RA) in breast cancer models. However, clinical studies were mostly disappointing possibly also due to the trial design and emerging resistances. One way to confer resistance to a given treatment is activation of protective autophagy. Autophagy is a cellular recycling mechanism that is characterized by the formation of double-membraned autophagosomes. Autophagosomes engulf bulk cytoplasm or selected contents thereof and transfer them to lysosomes for degradation. Activation of autophagy upon anti-cancer treatment may allow prolonged survival of the tumor cells. We therefore asked if autophagy is activated by all-trans retinoic acid (ATRA), a pan-retinoic acid receptor (RAR) agonist, in mammary tumor cells and if autophagy might protect the cells from the pro-apoptotic effects of ATRA. We found that ATRA induces autophagic flux in ATRA-sensitive SKBR3 but not in -resistant MD-MBA- 453 human breast cancer cells as seen by increased LC3B-II protein abundance and turnover of long-lived proteins. Moreover, using RA receptor alpha (RARA), RARB and RARG agonists as well as RARA knockdown breast cancer cells we demonstrated that activation of autophagy by RA depends on RARA expression. RA-treatment also caused induction of the transcription factor FOXO3A, a known transcriptional target of RARA. Since the expression of several autophagy genes namely the ATG8 family members, Beclin-1 and PI3KC3 are controlled by FOXO3A, we tested if FOXO3A might link ATRA-mediated signaling to autophagy activation. Indeed, depleting FOXO3A in SKBR3 cells resulted in significantly decreased autophagic activity and autophagy gene expression upon RA treatment. Importantly, blocking autophagy by knocking down the key autophagy genes ATG5 or ATG7 in breast cancer cells resulted in significantly increased apoptosis under ATRA treatment. Of note, inhibition of autophagy also attenuated cyto-differentiation similarly to the phenotype seen in RARA knockdown breast cancer cells. In summary, our data demonstrate for the first time that retinoic acids induce autophagy in breast cancer cells via the FOXO3A-RARA axis. Furthermore, inhibition of autophagy results in enhanced ATRA-mediated apoptosis representing a potential new treatment strategy for a selected group of breast cancer patients.

Citation Format: Anna M. Schlaefli, Enrico Garattini, Mario P. Tschan. Retinoic acids activate autophagy in breast cancer cells through the FOXO3A-RARA pathway and blocking autophagy enhances retinoic acid-mediated cell death. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 996. doi:10.1158/1538-7445.AM2015-996
Abstract CT113: A phase III, multicenter, randomized study evaluating the efficacy and safety and efficacy of erythrocyte encapsulated l-asparaginase (Ery001) versus native l-asparaginase (L-asp) in combination with COOPRALL regimen in patients with first relapse of acut
Authors: Bertrand Yves , Baruchel Andre , Thomas Xavier , Blin Nicolas , Tavernier Emmanuelle , Perel Yves , Vey Norbert , Gandemer Virginie , ElHariry Iman , Godfrin Yann
Published: August 2015

Asparaginases are a cornerstone in the treatment of ALL, but their utility is limited by toxicities including hypersensitivity. ERY001 improves pharmacokinetics and tolerability, while maintaining circulating asparaginase (ASPA) activity due to the protective barrier of the erythrocyte membrane.

This phase III study enrolled pts with primary relapsed/refractory Ph- ALL. The co-primary endpoints were the duration of ASPA activity equal or greater than 100IU/L and the incidence of ASPA hypersensitivity during induction. Patients, aged 1-55 years, without prior ASPA hypersensitivity were randomized to ERY001 (150 IU/kg) or L-ASP(10.000IU/m2) in combination with COOPRALL. The patients with prior ASPA hypersensitivity received ERY001.

ERY001 significantly reduced the incidence of ASPA hypersensitivity (0% vs 43%; p100IU/l significantly longer than L-ASP (20.5±5.2 vs 9.2±7.5 days; p<0.001). CR and clotting parameters were also significantly improved in the ERY001 arm. Other adverse events were generally similar in. One-year OS was 77% in the ERY001 arm vs 68% in L-ASP arm. ASPA activity was not reduced in hypersensitive patients.

These highly encouraging results show that ERY001 is a suitable option for patients with relapsed ALL maintaining ASPA efficacy with improved tolerability.

Citation Format: Yves Bertrand, Andre Baruchel, Xavier Thomas, Nicolas Blin, Emmanuelle Tavernier, Yves Perel, Norbert Vey, Virginie Gandemer, Iman ElHariry, Yann Godfrin. A phase III, multicenter, randomized study evaluating the efficacy and safety and efficacy of erythrocyte encapsulated l-asparaginase (Ery001) versus native l-asparaginase (L-asp) in combination with COOPRALL regimen in patients with first relapse of acut [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT113. doi:10.1158/1538-7445.AM2015-CT113
Abstract CT126: Phase II study of CEPSP chemotherapy for newly diagnosed stage IV extranodal natural killer (NK)/T-cell lymphoma, nasal type
Authors: Zheng Jun , Zhao Yajun , Xue Hui , Bai Xiufeng , Wang Ke , Zhang Mengqi , Du Chanyuan , He Shuyang , Wang Xiaoming , He Sanhu , Sun Moyi , Li Gang
Published: August 2015

Purpose: Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKL) is rare, it takes longer to make a definite diagnosis when compared with other head and neck malignancy, and its standard therapy has not been well established. To explore a more effective treatment for newly diagnosed stage IV ENKL, we conducted a phase II study of the Cisplatin + Etoposide + Pingyangmycin + Semustine + Prednisone (CEPSP) regimen.

Patients and Methods: We retrospectively reviewed the medical records of 21 patients diagnosed with ENKL who were enrolled to our hospital between January 1993 and June 2013. Patients with newly diagnosed stage IV and a performance status of 0 to 2 were eligible. Two cycles of CEPSP chemotherapy via temporal shallow artery intubation were administered as the protocol treatment with little adjustment in individual. The primary endpoints were overall response rate (ORR) and complete remission rate after the protocol treatment. The secondary endpoints were 3-year overall survival, 3-year progression-free survival, and toxicity.

Results: A total of 21 eligible patients were enrolled. The median age was 41 years (range, 20 to 69 years), and the male vs female ratio was 13:8. The disease status was newly diagnosed stage IV in 21 patients. The eligibility was revised to include lymphocyte counts of 500/μL or more because the first patient died from myelosuppression. No treatment-related deaths were observed after the revision. The ORR and complete remission rate after two cycles of CEPSP chemotherapy were 86% (92% CI, 61% to 85%) and 63%, respectively. In the 21 patients who completed the protocol treatment, 7 underwent blood component transfusion. The 2-year overall survival rate was 68% (93% CI, 41% to 65%). Grade 4 neutropenia was observed in 89% of the patients. The most common nonhematologic complication was gastrointestinal reaction (58%).

Conclusion: CEPSP chemotherapy via temporal shallow artery intubation is an effective treatment for newly diagnosed stage IV ENKL. During the period of treatment, myelosuppression and gastrointestinal reaction should be treated carefully.

Citation Format: Jun Zheng, Yajun Zhao, Hui Xue, Xiufeng Bai, Ke Wang, Mengqi Zhang, Chanyuan Du, Shuyang He, Xiaoming Wang, Sanhu He, Moyi Sun, Gang Li. Phase II study of CEPSP chemotherapy for newly diagnosed stage IV extranodal natural killer (NK)/T-cell lymphoma, nasal type. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT126. doi:10.1158/1538-7445.AM2015-CT126
Abstract CT304: Phase Ib trial of trastuzumab emtansine (TE) in combination with lapatinib (L) plus nab-paclitaxel (A) in metastatic HER2-neu overexpressed breast cancer patients: STELA trial results
Authors: Patel Tejal , Mejia Jaime , Rodriguez Angel , Chang Jenny
Published: August 2015

Background: Multiple large randomized clinical trials have demonstrated that dual HER2 targeted therapies are synergistic and result in improved efficacy. We conducted a phase Ib trial of trastuzumab-emtansine (TE) and lapatinib (L), together with Nab paclitaxel (A) in patients with HER2 over-expressed stage IV breast cancer.

Methods: Key inclusion criteria are stage IV HER2 positive breast cancer, LVEF ≥ 45%, and Peripheral neuropathy < grade 2. Primary phase Ib objective was to evaluate the maximum tolerated dose (MTD) of TE with L and A using a standard 3+3 dose de-escalation design for up to 9 patients. Safety, tumor response and pharmacokinetics (PK) were also assessed. Dose limiting toxicities (DLTs) were defined as ≥ grade 3 non hematological toxicity attributed to the study drugs.

Results: Nine patients, median age 47 (range 44-64) years were enrolled. All patients are currently off the study. The DLTs were grade 3 diarrhea (n = 1) and grade 3 elevated transaminase (n = 1). Grade 3-4 hematological toxicities included neutropenia (N = 6) and thrombocytopenia (N = 1). Other AEs included grade 1-2 mucositis (n = 2), diarrhea (N = 2), and liver function tests abnormality (N = 5). The 24 hour trough levels of each of the drug were within the range of the values reported in the literature. The MTD of TE, L and A was reached at: TE 3.0 mg/kg, Lapatinib 750mg and Abraxane (A) 80 mg/m2. Eight patients, with a median of 1 prior metastatic therapy (range 0-5) were evaluable for response. Five patients, 62.5% derived clinical benefit, including 1 patient with complete response and 4 patients with partial response.

Conclusions: TE plus L and A therapy was well tolerated with antitumor activity observed. STELA Ib trial has been expanded to include twelve additional patients for safety and efficacy evaluation.

Citation Format: Tejal Patel, Jaime Mejia, Angel Rodriguez, Jenny Chang. Phase Ib trial of trastuzumab emtansine (TE) in combination with lapatinib (L) plus nab-paclitaxel (A) in metastatic HER2-neu overexpressed breast cancer patients: STELA trial results. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT304. doi:10.1158/1538-7445.AM2015-CT304
Abstract CT319: Determination of FGF-19, 21, and 23 protein levels in a phase I clinical trial of ARQ 087, an oral pan-FGFR inhibitor
Authors: Hall Terence , Kazakin Julia , Schwartz Brian , Savage Ronald
Published: August 2015

Background: Early biomarker development is vital in the current clinical landscape of targeted oncology therapies. Biomarkers that can be used to assess target engagement are increasingly being developed in parallel with novel agents. Fibroblast growth factors (FGFs) represent a potentially useful biomarker for use with pan-FGFR inhibitors such as ARQ 087. To evaluate this possibility, levels fibroblast growth factors 19, 21, and 23 were monitored using during the phase I trial of ARQ 087.

Study Design: Plasma was collected from 61 pts (dose range 25-425mg QOD or QD). FGF levels were quantified using commercially available ELISA kits for FGF-19 and 21 (R&D Systems, Minneapolis, MN), and FGF-23 (EMD-Millipore, Billerica, MA). The kits were validated at ArQule for use with human clinical samples. Experiments were designed based on the FDA guidance for bioanalytical method development, and conducted using standard curves and quality control samples prepared in plasma. Performance parameters included selectivity, specificity, precision, accuracy, stability, and effect of sample collection tube additives on measured protein levels.

Results: The kits were successfully validated for all three FGFs. Changes from baseline levels of all three FGFs were observed in patients. Full data tables and results from our evaluation, along with clinical and preclinical data will be presented.

Conclusions: Although there are previous reports of altered FGF-23 levels in patients treated with an FGFR inhibitor, FGF-19 and 21 represent novel biomarkers, which have not previously been reported in the literature. These biomarkers may assist in identifying ARQ 087 activity in patients, and contribute to defining an optimal clinical development strategy.

Citation Format: Terence Hall, Julia Kazakin, Brian Schwartz, Ronald Savage. Determination of FGF-19, 21, and 23 protein levels in a phase I clinical trial of ARQ 087, an oral pan-FGFR inhibitor. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT319. doi:10.1158/1538-7445.AM2015-CT319
Abstract LB-010: Hijacking the E3 ubiquitin ligase cereblon to create efficient BRD4 degraders
Authors: Lu Jing , Qian Yimin , Altieri Martha , Dong Hanqing , Wang Jing , Raina Kanak , Winkler Jim , Crew Andy , Coleman Kevin , Hines John , Crews Craig
Published: August 2015

BRD4, a member of the bromodomain and extraterminal domain (BET) family, has emerged as an attractive target in multiple pathological settings. For example, recent studies have demonstrated its importance in driving the proliferation of several cancers including NUT midline carcinoma, acute myelogenous leukemia (AML), multiple myeloma, Burkitt's Lymphoma (BL), and prostate cancer. Thus, BET bromodomain inhibitors have showed promising effects in certain preclinical settings, particularly in MYC-driven hematological malignancies, such as BL. Interestingly, we found that BRD4 inhibitors lead to a rapid and robust accumulation of BRD4 that, together with the reversible nature of binding to BRD4, may account for their moderate suppression of MYC expression and inhibition of cell proliferation. To circumvent these limitations, we designed a Proteolysis Targeting Chimera (PROTAC) compound, containing a BRD4 binding moiety and an E3 ubiquitin ligase cereblon ligand. By actively engaging the E3 ligase-proteasome degradation machinery, BRD4 PROTAC leads to fast and efficient degradation of BRD4. Consequently, it is more effective than small molecule BRD4 inhibitors in suppressing MYC levels and downstream signaling, which are associated with proliferation and survival of malignant cells. More importantly, we also demonstrated that BRD4 PROTAC is more effective in inhibiting BL cell proliferation and inducing apoptosis compared to BRD4 inhibitors. Our findings strongly demonstrate that a degrader of BRD4, in the form of a cereblon-based PROTAC, provides a better and more efficient strategy in targeting BRD4 than traditional small molecule inhibitors.

Citation Format: Jing Lu, Yimin Qian, Martha Altieri, Hanqing Dong, Jing Wang, Kanak Raina, Jim Winkler, Andy Crew, Kevin Coleman, John Hines, Craig Crews. Hijacking the E3 ubiquitin ligase cereblon to create efficient BRD4 degraders. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-010. doi:10.1158/1538-7445.AM2015-LB-010
Abstract LB-022: Aptamer-mediated inhibition of EGFRvIII mutant in glioblastoma cells
Authors: Camorani Simona , Crescenzi Elvira , Colecchia David , Carpentieri Andrea , Amoresano Angela , Chiariello Mario , Cerchia Laura
Published: August 2015

High-grade glioblastoma multiforme (GBM) is the most aggressive and common of gliomas in human populations, accounting for 55% of primary brain tumors. The prognosis of GBM is very poor and most patients die of tumor recurrence.

The epidermal growth factor receptor (EGFR) and the platelet-derived growth factor receptor β (PDGFRβ) are hallmarks in GBM since they influence multiple aspects of tumor biology including cell proliferation, migration, invasiveness and resistance to treatment. In approximately half of the tumors with amplified EGFR, the EGFRvIII truncated extracellular mutant is detected. EGFRvIII does not bind ligand, is highly oncogenic and appears to be relatively resistant to treatment with conventional anti-EGFR agents such as ligand blocking monoclonal antibodies or EGFR tyrosine kinase inhibitors (TKIs). Recently, it has been demonstrated that EGFRvIII-dependent cancers may escape targeted therapy by developing dependence on PDGFRβ signaling, thus providing a strong rationale for combination therapy aimed at blocking both EGFRvIII and PDGFRβ signaling.

We have generated two nuclease resistant 2′F-Py RNA aptamers, CL4 and Gint4.T, as high affinity ligands and inhibitors of human wild-type EGFR (EGFRwt) and PDGFRβ, respectively. Thanks to their unique characteristics (low size, good target affinity, no immunogenicity, high stability) aptamers represent a new class of molecules with a great potential to rival monoclonal antibodies in both therapy and diagnosis.

Herein, by different approaches we demonstrate that CL4 aptamer binds to the EGFRvIII mutant even though it lacks amino acids 6-273 in the extracellular domain. As a consequence of binding, the aptamer inhibits EGFRvIII activation by hampering receptor homodimerization and downstream STAT3 pathway, thus confirming the critical role of EGFRvIII dimerization for signaling. Further, we show that targeting EGFRvIII by CL4, as well as by erlotinib and gefitinib, causes upregulation of PDGFRβ as a compensatory response to support cancer cell survival. Importantly, CL4 and EGFRTKIs cooperate with the anti-PDGFRβ aptamer in inhibiting survival and proliferation of EGFRvIII-overexpressing glioblastoma cells.

Given the paucity of selective inhibitors for receptor tyrosine kinases, this study could have impact in the fields of targeted molecular cancer therapeutics and may result in progress against GBM.

Citation Format: Simona Camorani, Elvira Crescenzi, David Colecchia, Andrea Carpentieri, Angela Amoresano, Mario Chiariello, Laura Cerchia. Aptamer-mediated inhibition of EGFRvIII mutant in glioblastoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-022. doi:10.1158/1538-7445.AM2015-LB-022
Abstract LB-023: Caspase-9b directly interacts with cIAP1 to drive agonist-independent NF-κB activation and tumorigenesis in non-small cell lung cancer
Authors: Vu Ngoc T. , Park Margaret A. , Shultz Michael D. , Ladd Amy C. , Chalfant Charles E.
Published: August 2015

Caspase-9 has two isoforms with opposing functions, pro-apoptotic caspase-9a (C9a) and anti-apoptotic caspase-9b (C9b). C9b expression has been reported to augment the anchorage-dependent growth (AIG) and tumorigenic capacity of non-small cell lung cancer (NSCLC) cells. The mechanism of this biological observation was revealed in this study. Specifically, C9b was demonstrated to have a dual caspase-9a-independent function in regulating the survival/oncogenic nuclear factor κB (NF-κB) pathway. In particular, C9b was shown to activate the canonical arm and inhibit of the non-canonical arm of the NF-κB pathway by destabilizing NF-κB inhibitor alpha (IκB-α) and NF-κB-inducing kinase (NIK). Importantly, this new role for C9b contributes to the enhanced survival and AIG of NSCLC cells conferred by C9b expression. The link between C9b expression and NF-κB activation was also validated in human NSCLC tumors. Further mechanistic studies revealed a direct association of C9b with the cellular inhibitor of apoptosis 1 (cIAP1), a regulatory factor in both arms of the NF-κB network, via its IAP-binding motif (IBM). Through this interaction, C9b induces the E3 ligase activity of cIAP1, which regulates NF-κB activation, and promotes the viability, AIG and tumorigenicity of NSCLC cells. Hence, C9b/cIAP1 interaction is a new attractive molecular target for developing therapeutics to treat NSCLC.

Citation Format: Ngoc T. Vu, Margaret A. Park, Michael D. Shultz, Amy C. Ladd, Charles E. Chalfant. Caspase-9b directly interacts with cIAP1 to drive agonist-independent NF-κB activation and tumorigenesis in non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-023. doi:10.1158/1538-7445.AM2015-LB-023