bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract CN06-02: Regulation of AR variants by BET bromodomains in prostate cancer
Authors: Dehm Scott M.
Published: May 2016

Expression of androgen receptor (AR) variants (AR-Vs) lacking the AR ligand binding domain (LBD) in prostate cancer tissues or circulating tumor cells is associated with poor clinical outcomes. AR-Vs function as constitutively active transcription factors and represent a resistance mechanism whereby the growth of prostate cancer cells can remain AR-dependent, yet uncoupled from endocrine regulation. Tumors that have developed this mechanism of resistance are unlikely to respond to successive generations of endocrine therapies. The absence of a LBD presents a formidable challenge for direct inhibition of AR-Vs because alternative sites on the AR protein appropriate for specific and high-affinity drug targeting are not evident. An indirect approach may be through inhibition of AR-V expression and/or transcriptional activation mechanisms. To this end, we have found that treatment of prostate cancer cell lines with the bromodomain and extraterminal (BET) inhibitor JQ1 resulted in inhibition of AR and AR-V chromatin binding and impaired AR and AR-V driven prostate cancer cell growth in vitro and in vivo. These anti-AR activities were associated with JQ1-mediated reduction in binding of the BET family member BRD2 to a region near the AR transcription start-site featuring broad enrichment of histone H3 acetylated at lysine 27. Consistent with these chromatin effects at the AR locus, JQ1 treatment down-regulated AR and AR-V transcript and protein expression. Overall, these findings highlight regulation of AR and AR-V expression by BRD2, and provide pre-clinical rationale for BET inhibition as a strategy for overcoming resistance mediated by constitutively active AR-Vs in prostate cancer.

Citation Format: Scott M. Dehm. Regulation of AR variants by BET bromodomains in prostate cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr CN06-02.
Abstract CN08-01: Role of mutations in epigenetic regulators in pathogenesis of myeloid malignancies
Authors: Levine Ross L. , Shih Alan , Guryanova Olga , Maydan Cem , Melnick Ari
Published: May 2016

Clinical, cytogenetic, and gene-based studies have been used to inform biology and improve prognostication for patients with acute myeloid leukemia (AML), myelodysplasia (MDS), and myeloroliferative neoplasms (MPN). Most recently, a series of candidate gene and whole genome studies have identified recurrent somatic mutations in AML patients including TET2, ASXL1, DNMT3A, and cohesin complex mutations. Moreover, these mutations can be used to improve risk stratification in AML independent of established clinical parameters. Integrating mutational data with dose-intensity revealed that high-dose daunorubicin improved survival in patients with DNMT3A/NPM1 mutations or MLL translocations relative to treatment with standard dose daunorubicin, but not in patients wild-type for these alterations. These data provide important clinical implications of genetic alterations in AML by delineating mutation combination genotypes that predict outcome in AML and improve AML risk stratification. Of biologic importance, the TET family of proteins have been shown to place a hydroxyl mark on methylated DNA and lead to DNA demethylation. We and others have found that TET2/IDH mutations leads to loss of DNA hydroxymethylation and a hypermethylation phenotype in leukemia patients. In addition, in vitro and in vivo studies show that TET2 loss or neomorphic IDH1/2 mutations leads to impaired hematopoietic differentiation, increased stem cell self-renewal, and myeloid transformation in vivo. We have also investigated the role of mutant DNMT3A in AML pathogenesis,a and shown these mutations cooperate with other disease alleles to induce leukemic transformation and to confer chemoresistance due to impaired DNA damage sensing. We will present novel data showing how these mutations coopt the epigenetic state of hematopoietic stem/progenitor cells in order to contribute to transformation and that these mutations have biologic and prognostic relevance.

Citation Format: Ross L. Levine, Alan Shih, Olga Guryanova, Cem Maydan, Ari Melnick. Role of mutations in epigenetic regulators in pathogenesis of myeloid malignancies. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr CN08-01.
Abstract ED01-01: Immunity against cancer: How to be enhanced?
Authors: Vries Jolanda De , Gerritsen Winald , Figdor Carl G.
Published: May 2016

Prevention of infectious diseases through immunization is one of the greatest achievements of modern medicine. Nonetheless, considerable challenges remain for improving the efficacy of vaccines currently employed to treat devastating diseases such as cancer. Dendritic cells (DC) are considered professional antigen-presenting cells of the immune system highly effective in initiating primary immune responses. Following infection or inflammation they undergo a complex process of maturation, and migrate to lymph nodes (LN) where they present antigens to T cells. Their decisive role in inducing immunity formed the rationale for DC immunotherapy: DC loaded with tumor antigens are injected into cancer patients to stimulate T cells to eradicate tumours. A major advantage of immunotherapy when compared to radio-, chemo- and targeted therapy is its low toxicity. To date, dendritic cell (DC)-based immunotherapy is explored worldwide in clinical vaccination trials with cancer patients. Although during the past 15 years the concept of DC vaccination has been clearly proven and found safe, the number of patients that have long-term benefit is still limited. Therefore the development of bioassays that predict clinical outcome are essential to optimize cellular anticancer immunotherapy. We have developed a robust and simple skin test to evaluate the capacity of tumor-specific T cells to migrate, recognize their targets, and exert effector functions. This bioassay detects skin infiltrating T lymphocytes (SKILs) with an elevated antineoplastic potential and hence identifies patients responding to immunotherapy once started. The identification of a biomarker already available before start of treatment would facilitate decision-making regarding (prophylactic) immunotherapy. We recently identified that the ratio between peri/intratumoral T cells in the primary tumor, is an excellent predictor of survival after DC-based immunotherapy in metastatic melanoma patients.

Citation Format: Jolanda De Vries, Winald Gerritsen, Carl G. Figdor. Immunity against cancer: How to be enhanced?. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr ED01-01.
Abstract ED02-01: National-scale cancer sequencing and treatment response data integration in The Netherlands
Authors: Cuppen Edwin
Published: May 2016

Next-generation DNA sequencing has boosted the promises of personalising cancer treatment. It has now become possible to routinely sequence the complete genome of a tumor from a patient. However, a main challenge remains how to optimally use such information for guiding therapy choice. Furthermore, it becomes clear that mutational profiling increasingly provides insight in the molecular processes driving tumorigenesis, but knowledge on prediciting the outcome of specific targeted treatments, both approved therapies and novel drugs that start becoming available for patients, remains difficult. While patient stratification based on a limited number of genetic measurements is steadily increasing, retrospective systematic analyses of genetic information and treatment outcome are still warranted to improve stratification as significant numbers of selected patients for specific treatments are non-responsive, yet may experience severe treatment side effects. In addition, ineffective treatment contributes significantly to the increasing economical burden of novel cancer treatment drugs on our national health care costs.

In 2010, we established the Center for Personalized Cancer Treatment (CPCT), a collaboration between all academic medical centers in the Netherlands and an increasing number of teaching hospitals, to address this challenge and work towards implementation of DNA-guided therapy choice into routine care in the Netherlands. In all associated hospitals, we have implemented trials to collect biopsies from tumor metastases before patients start treatment with specific targeted drugs. We aim for the discovery of predictive biomarkers or treatment resistance pathways. Within our nation-wide trials, we systematicly collect and integrate tumor sequencing data (whole exome and whole genome sequencing) plus clinical and treatment response data. In addition, we feed back therapy guidance information to the treating physician in case a patient does not respond to the current treatment. In this setup, both current and future patients may benefit from comprehensive DNA analyses. I will present the choices we made towards achieving our goals and discuss the operational and IT challenges in these processes.

Citation Format: Edwin Cuppen. National-scale cancer sequencing and treatment response data integration in The Netherlands. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr ED02-01.
Abstract KN01: Updates on engineered T cells as cancer therapies
Authors: June Carl H.
Published: May 2016

The field of adoptive cell transfer (ACT) is currently comprised of chimeric antigen receptor (CAR T) and TCR engineered T cells and has emerged from principles of basic immunology to paradigm-shifting clinical immunotherapy. ACT of T cells engineered to express artificial receptors that target cells of choice is an exciting new approach for cancer, and it holds equal promise for chronic infection and autoimmunity. Using principles of synthetic biology, advances in immunology, and genetic engineering have made it possible to generate human T cells that display desired specificities and enhanced functionalities. Clinical trials in patients with advanced B cell leukemias and lymphomas treated with CD19-specific CAR T cells have induced durable remissions in adults and children. The prospects for the widespread availability of engineered T cells have changed dramatically given the recent entry of the pharmaceutical industry to this arena. In this presentation, I will discuss some of the challenges and opportunities that face the field of ACT.

References:

1. Maude S, Frey N, Shaw P, Aplenc R, Barrett D, Bunin N, Chew A, Gonzalez V, Zheng Z, Lacey S, Mahnke Y, Melenhorst J, Rheingold S, Shen A, Teachey D, Levine B, June C, Porter D, and Grupp SA. Chimeric Antigen Receptor T Cells for Sustained Remissions in Leukemia. N Engl J Med. 2014;371(16):1507-17.

2. Lee DW, Gardner R, Porter DL, Louis CU, Ahmed N, Jensen M, Grupp SA, and Mackall CL. How I treat: current concepts in the diagnosis and management of cytokine release syndrome. Blood. 2014;124(2):188-95.

3. Rapoport AP, Stadtmauer EA, Binder-Scholl GK, Goloubeva O, Vogl DT, Lacey SF, Badros AZ, Garfall A, Weiss B, Finklestein J, Kulikovskaya I, Sinha SK, Kronsberg S, Gupta M, Bond S, Melchiori L, Brewer JE, Bennett AD, Gerry AB, Pumphrey NJ, Williams D, Tayton-Martin HK, Ribeiro L, Holdich T, Yanovich S, Hardy N, Yared J, Kerr N, Philip S, Westphal S, Siegel DL, Levine BL, Jakobsen BK, Kalos M, and June CH. NY-ESO-1-specific TCR-engineered T cells mediate sustained antigen-specific antitumor effects in myeloma. Nature Medicine. 2015;21(8):914-21.

4. Garfall AL, Maus MV, Hwang WT, Lacey SF, Mahnke YD, Melenhorst JJ, Zheng Z, Vogl DT, Cohen AD, Weiss BM, Dengel K, Kerr ND, Bagg A, Levine BL, June CH, and Stadtmauer EA. Chimeric Antigen Receptor T Cells against CD19 for Multiple Myeloma. N Engl J Med. 2015;373(11):1040-7.

Citation Format: Carl H. June. Updates on engineered T cells as cancer therapies. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr KN01.
Abstract LB-A11: Expression of steroid sulfatase induces the integrin signaling pathway in HeLa cells
Authors: Ye Dong-Jin , Kwon Yeo-Jung , Shin Sangyun , Hong Mihye , Baek Hyoungseok , Ahn Seung-Ki , Shin Dongwon , Chun Young-Jin
Published: May 2016

Steroid sulfatase (STS) is responsible for the hydrolysis of aryl and alkyl steroid sulfates. STS has a pivotal role in regulating the level of estrogen and androgen responsible for growth of hormone-dependent tumors, such as breast or prostate cancer. However, the molecular function for tumor growth of STS is still not clear. To elucidate possible role of STS on cancer cell proliferation, we investigated whether STS is able to regulate integrin signaling pathway. In this study, we observed that overexpression of STS in HeLa cells induces the expression of integrin β1 and fibronectin, a ligand of integrin α5β1 at protein and mRNA levels. Dehydroepiandrosterone (DHEA), one of the main metabolite of STS, also induces mRNA and protein level of integrin β1 and fibronectin. We found that STS expression and DHEA enhance phosphorylation of focal adhesion kinase (FAK) at tyrosine 925 residue. Moreover, phosphorylation of ERK at threonine 202 and tyrosine 204 residues was also induced, indicating that STS may activate Ras/Raf/MEK signaling pathway. In conclusion, these results suggest that STS expression and DHEA may enhance Ras/Raf/MEK signaling through upregulation of integrin β1 and activation of FAK.

Citation Format: Dong-Jin Ye, Yeo-Jung Kwon, Sangyun Shin, Mihye Hong, Hyoungseok Baek, Seung-Ki Ahn, Dongwon Shin, Young-Jin Chun. Expression of steroid sulfatase induces the integrin signaling pathway in HeLa cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A11.
Abstract LB-A12: New target for cancer metabolism : Steroid Sulfatase
Authors: shin sangyun , Kwon Yeo-Jung , Ye Dong-Jin , Baek Hyoung-Seok , Chun Young-Jin
Published: May 2016

Steroid sulfatase (STS) expression has been considered to play a pivotal role in estrogen-dependent cancers. STS is known as a target enzyme for suppressing estrogen-mediated carcinogenesis. STS is able to convert estrogen sulfate to estrone form, like dehydroepiandrosterone sulfate (DHEA-S) to its' active form dehydroepiandrosterone (DHEA). Aerobic glycolysis is a hallmark of cancer metabolism. Lactic acid production was also increased by STS and DHEA.STS and its' major product DEHA reduced Oxygen consumption rate. STX064, a STS specific inhibitor inhibited DHEA formation and lactic acid production, recovered mitochondria resperation in HeLa cells. Hypoxia inducing factor 1 subunit HIF1α is recognized as an important regulator of aerobic glycolysis. To elucidate whether STS is able to regulate cancer metabolism, the effects on aerobic glycolysis were determined. STS overexpression significantly converted DHEA-S to DHEA. STS and the major product DHEA enhanced HIF1α protein, mRNA, promoter activity in HeLa cells. Glycolytic enzymes such as hexokinase 2 (HK-2) and glucose transporter (GLUT) were increased by STS overexpression and DHEA treatment in protein and mRNA levels. When cells were treated with HIF1α siRNA, all glycolytic enzymes induced by STS and DHEA were down-regulated. STS also regulated pyruvate kinase M (PKM)splicing. STS up-regulated PKM2 level and inhibited PKM1 level through transcription factor c-Myc. Phosphorylation of PKM2 was also induced by STS. In conclusion, STS and the major product DHEA may regulate aerobic glycolysis via HIF1α induction and c-Myc related PKM2 alternative splicing.

Citation Format: sangyun shin, Yeo-Jung Kwon, Dong-Jin Ye, Hyoung-Seok Baek, Young-Jin Chun. New target for cancer metabolism : Steroid Sulfatase. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A12.
Abstract LB-A13: Cellular characterization of the selective inhibition of UBA5 by organometallic, adenosine-based inhibitors
Authors: da Silva Sara R. , Geletu Mulu , Javed Fiza , Paiva Stacey-Lynn , Lewis Andrew M. , Li Honglin , Gunning Patrick T.
Published: May 2016

Cells that undergo higher protein turnover, such as pancreatic secretory cells and cancerous cells, have the propensity to undergo endoplasmic reticulum (ER) stress. If left uncorrected, ER stress can result in the initiation of apoptosis. To avoid these fates, cells have developed support systems to counteract the apoptotic effects of ER stress, such as conjugation of certain stress-associated proteins with the ubiquitin-fold modifier 1 (UFM1) ubiquitin-like protein. Our research has recently focused on the discovery and in vitro validation of the first selective inhibitor of the UFM1 pathway, 5C-Z, which selectively targets the UFM1 E1 enzyme (UBA5) over other related enzymes and a panel of over 90 human kinases. This novel strategy of inhibiting UBA5 and subsequent UFMylation would make cancer cells that are highly dependent on this system more susceptible to pharmacological disturbances in ER homeostasis, which could lead to the use of milder drug dosing strategies. Our current efforts are focused on studying the effects of 5C-Z on intracellular signalling, the cellular distribution of proteins in the UFM1 pathway, and phenotypic changes within a lung cancer cell lung line (Sk-Luci6). Treatment of lung cancer cells that exhibit high levels of UBA5 protein expression results in decreased cell proliferation (EC50 = 216.9 μM, 95% C.I. = 211.5 - 222.5 μM), yet does not induce cell death in other diseased (A549) or healthy (MRC9) lung cells (up to 200 μM). The decreased cellular proliferation upon 5C-Z treatment mirrors the effect of treatment with UBA5 siRNA. Using immunocytochemistry, it appears that treatment with 5C-Z also induces changes in both cellular morphology and the distribution of UBA5-like staining within the cell. Furthermore, there is an apparent decrease in UFM1-like co-localization with its E2 conjugating enzyme (UFC1) after prolonged incubation with 5C-Z, although further intracellular analysis is required to confirm this observation. Preliminary work also indicates that these cellular effects may also be selective against the UFM1 pathway compared to related ubiquitin-like labelling pathways. We are currently evaluating the effects of 5C-Z on ER stress signalling pathways connected to the UFM1 labelling system.

Citation Format: Sara R. da Silva, Mulu Geletu, Fiza Javed, Stacey-Lynn Paiva, Andrew M. Lewis, Honglin Li, Patrick T. Gunning. Cellular characterization of the selective inhibition of UBA5 by organometallic, adenosine-based inhibitors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A13.
Abstract LB-A14: Targeting BAG3-dependent paracrine loop reduces growth and metastatic spreading of Pancreatic adenocarcinoma
Authors: De Laurenzi Vincenzo , Rosati Alessandra , Sala Gianluca , Turco Maria Caterina
Published: May 2016

Incidence and death rate of Pancreatic Ductal Adenocarcinoma (PDAC) has increased in recent years, therefore the identification of novel targets for treatment is extremely important. Interactions between cancer and stromal cells are critically involved in tumor formation and development of metastasis. We have recently shown (manuscript in press) that PDAC cells secrete BAG3 that binds and activates macrophages trough a specific receptor (IFITM2), inducing their activation and the secretion of PDAC supporting factors.

Treatment with a murine monoclonal antibody (AC-2) targeting BAG3 reduced tumor growth and impaired metastasis formation in mouse models. Here we report further characterization of the in vivo activity of the antibody. Moreover, we have now successfully generated humanized variants of the AC-2 antibody and report the in vitro and in vivo activity of the humanized antibodies. Both appear to have the ability to inhibit macrophage activation in vitro and reduce tumor growth in PDAC models to an extent comparable to the murine parental antibody (AC-2).

In conclusion, we have identified a novel paracrine loop involved in PDAC growth and metastatic spreading and shown that its pharmacological blockage with an anti-BAG3 antibody has therapeutic potential for PDAC treatment.

Citation Format: Vincenzo De Laurenzi, Alessandra Rosati, Gianluca Sala, Maria Caterina Turco. Targeting BAG3-dependent paracrine loop reduces growth and metastatic spreading of Pancreatic adenocarcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A14.
Abstract LB-B04: Complex drug combinations can induce apoptotic killing in robust colorectal cancer cells
Authors: Horn Thomas , Ferretti Stéphane , Ebel Nicolas , Tam Angela , Ho Samuel , Harbinski Fred , Farsidjani Ali , Zubrowski Matthew , Halilovic Ensar , Morris Erick , Sellers William R. , Schlegel Robert , Wuerthner Jens , Garraway Levi A. , Jeay Sébastien , Greshock Joel , Caponigro Giordano , Lehár Joseph
Published: May 2016

Tumors are complex and robust biological systems that harbor the potential to proliferate against various drug treatments. Drug combinations provide a promising therapeutic strategy, but it is not clear which and how many drugs are required to overcome cancers.

Using image-based proliferation and apoptosis assays in colorectal cancer cells we systematically investigated complex treatments composed of two to six drugs targeting critical oncogenic pathways. Drug pairs targeting growth signaling resulted in synergies across a broad spectrum of genetic backgrounds, but often yielded cytostatic responses and failed to induce apoptosis. Enhanced, and sometimes genotype-specific cytotoxicity was seen after targeting additional mechanisms including apoptosis or cell cycle. Cells that resisted all tested drug pairs and drug triples were protected by a mechanism that prevented apoptosis. Targeted inhibition of this mechanism using combinations of up to four compounds induced cytotoxic responses in cells in vitro and in vivo.

Our results demonstrate that complex combinations of targeted drugs might be required to induce killing in cancers and show how the cells' genetic alterations and a molecular understanding of drug responses can guide their identification. The identification of resistance mechanisms that are pre-existing in subpopulations of tumor cells also opens the exciting avenue of sequenced treatments, with each drug or drug combination targeting and eradicating a specific cell population.

Citation Format: Thomas Horn, Stéphane Ferretti, Nicolas Ebel, Angela Tam, Samuel Ho, Fred Harbinski, Ali Farsidjani, Matthew Zubrowski, Ensar Halilovic, Erick Morris, William R. Sellers, Robert Schlegel, Jens Wuerthner, Levi A. Garraway, Sébastien Jeay, Joel Greshock, Giordano Caponigro, Joseph Lehár. Complex drug combinations can induce apoptotic killing in robust colorectal cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-B04.
Abstract LB-B06: Functionally defined therapeutic targets in diffuse intrinsic pontine glioma
Authors: Grasso Catherine S.
Published: May 2016

Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood cancer that has a limited response to treatment (median survival after diagnosis is only 9 months). Historically, DIPG research has been limited by a dearth of tumor tissue available for study and a lack of experimental model systems. Recently, both cell cultures derived from patients with DIPG and orthotopic xenograft models have been established. We performed a chemical screen in 16 patient-derived DIPG cultures using 83 drugs, selected by pediatric neurooncologists as either promising small-molecule compounds or traditional chemotherapeutic agents. Of these 83 drugs, 14 showed activities against three or more DIPG cultures. Notable ‘misses’ that highlight the resistance of this tumor to traditional chemotherapies included temozolomide, carboplatin, and vincristine, while DIPG cell cultures were reported to have substantial sensitivity to histone deacetylase inhibitors, consistent with the highly recurrent H3K27M driving mutations in ∼80% of DIPG. Panobinostat was one of the most effective drugs screened, with 12/16 DIPG cultures showing sensitivity to this drug. Compared to vorinostat, another HDAC inhibitor, panobinostat exhibited substantially greater potency against DIPG cells. Treatment of DIPG cultures with panobinostat yielded a time and dose-dependent decrease in viability (RNA-mediated knockdown of HDAC1 and HDAC2 confirmed the mechanism of action). Treatment of DIPG cultures with panobinostat also increased H3 acetylation and H3K27 trimethylation, and led to a partial rescue of the H3K27M induced global hypotrimethylation phenotype. Increased K27 trimethylation was an unexpected effect of the drug, but it is consistent with recent findings that acetylated H3K27 can ‘detoxify’ K27M-induced inhibition of PCR2. RNA-seq performed on panobinostat- or vehicle-treated DIPG cells revealed sweeping changes in gene expression, including normalization of the K27M gene expression signature and decrease of the oncogenic MYC target gene-expression signature. In addition, the multi-histone deacetylase inhibitor panobinostat demonstrated efficacy in DIPG orthotopic xenograft models administered using convection enhanced delivery. Combination testing of panobinostat and the histone demethylase inhibitor GSK-J4, recently shown to decrease viability of mutant DIPG cells, revealed that the two had synergistic effects. Together, these data suggest a promising FDA-approved therapeutic strategy for DIPG that could be rapidly translated for use in the clinic, further indicating that epigenetic modifying therapies are emerging as the most promising class of agents for the treatment of DIPG.

Citation Format: Catherine S. Grasso. Functionally defined therapeutic targets in diffuse intrinsic pontine glioma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-B06.
Abstract LB-B12: Using MiXeno Mouse Models as Robust Tool to Evaluate T Cell Dependent Immunotherapies
Authors: Zhang Juan , Qiao Meng , Shi Qian
Published: May 2016

Backgrounds: Fighting cancer by taking advantage of a patient's own immune system is showing considerable success in oncology research. Using therapeutic antibodies against tumor-associated antigens or modulating the host immune system, has been shown to prolong survival of patients with certain solid tumors or leukemia, particularly when combined with conventional treatments. Recent fast-track designations and regulatory approvals (including the first FDA approvals of anti-PD-1 agents in advanced melanoma) have signified the coming of age of cancer immunotherapy as a treatment paradigm, creating both potential patient benefits and commercial success for the pharmaceutical industry. A lack of experimental immunotherapy models is a major obstacle toward answering these questions and developing better treatments, and there is a high unmet need for new preclinical models to help drive forward immune therapy research and to recapitulate clinical treatments.

Results: Crown Bioscience has created transient human immunity in mice (MiXeno) for testing human immunotherapeutics, particularly T cell engaged immunotherapies by mixing human peripheral blood mononucleated cells (PBMC) with xenograft models. Our data showed that anti-human PD-1 or PD-L1 antibodies demonstrated significant anti-tumor activities in several Mixeno models, including A375 melanoma model and KARPAS-299 lymphoma model. The emergence of the efficacy coincided with the T cell reconstitution in mouse blood. T cells are also recruited to the tumor microenvironment. The number of T cells in the tumor microenvironment varies significant and is largely dependent on tumor cells itself.

Conclusion: The MiXeno model provides an alternative to the full stem cell reconstitution approach, and may allow T cell engaged immunotherapies (monotherapies or combinational therapies) to be evaluated in xenograft models.

Citation Format: Juan Zhang, Meng Qiao, Qian Shi. Using MiXeno Mouse Models as Robust Tool to Evaluate T Cell Dependent Immunotherapies. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-B12.
Abstract LB-C10: Identification of Therapeutic Targets for Chemotherapy-Resistant Colon Cancer Stem Cells
Authors: Francipane Maria Giovanna , Bulanin Denis , Lagasse Eric
Published: May 2016

Current first-line chemotherapy generally consists of cytotoxic agents. While these agents may initially control disease by effectively debulking tumors, the tumors invariably recur due to the ability of cancer stem cells (CSCs) to survive and repopulate the tumor mass.

To identify potential molecular targets in 5-fluorouracil (5-FU) refractory CSCs, we developed 5-FU resistant cell lines over a period of a year.

Here we show that 5-FU maintains colon CSCs in an undifferentiated state in vitro. While untreated control cells passaged in parallel progressively acquired a differentiated morphology comprising crypt-villus structures, cells treated with an IC50 dose or escalating doses of 5-FU organized in round colonies with defined edges. Cells from these chemoresistant colonies exhibited a high nucleus-to-cytoplasm ratio and prominent nucleoli, features of pluripotent stem cells. Chemoresistant cells showed a reduced proliferation rate with respect to their counterparts. While immunofluorescent analysis revealed chemoresistant cells expressed a panel of pluripotency markers, flow cytometric analysis indicated a change in CD antigens associated with tumorigenicity and pluripotency in chemoresistant cells as compared to untreated cells. These results suggest colon CSCs, while under the selective pressure of chemotherapy in vitro, are likely to display an adaptive plasticity resembling fate reprogramming.

Three-dimensional growth in Matrigel revealed untreated cells were able to arrange themselves in a ring around a well-defined central lumen. Conversely, chemoresistant cell-derived organoids had poorly defined or no central lumens. While untreated cells generated fast-growing, well-differentiated tumors, resistant cells generated slow-growing, moderately differentiated tumors in vivo.

Finally, a large number of genes were screened in cell/tissue from both groups using Real-Time PCR arrays. Through this analysis, we identified molecular targets that might assist in the development of therapeutic strategies which will counteract the mechanisms of chemoresistance.

Citation Format: Maria Giovanna Francipane, Denis Bulanin, Eric Lagasse. Identification of Therapeutic Targets for Chemotherapy-Resistant Colon Cancer Stem Cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-C10.
Abstract PL02-02: Progress in lung cancer treatment with immunotherapy
Authors: Garon Edward B.
Published: May 2016

As recently as a few years ago, non-small cell lung cancer (NSCLC) was not considered particularly amenable to therapeutic approaches that manipulated immune responses. The rapid transition to inhibition of the programmed cell death 1 (PD-1) immune checkpoint in routine management of NSCLC patients has been remarkable. Although the duration of response to this class of drugs is impressive, particularly in light of comparator therapies, the restriction of responses to a minority of those treated limits the benefit to select patients. During the development of inhibitors of the PD-1 immune checkpoint in NSCLC, biospecimens including tissue and blood have been collected to evaluate predictors of response to this class of agents. Despite extensive evaluation though, controversy exists. The role of various factors in identifying patients likely to respond to inhibition of the PD-1 immune checkpoint is an area of intensive investigation. The relative importance of factors 1) intrinsic to the tumor such as staining for biomarkers including the PD-1 ligand PD-L1 and tumor mutational load, 2) factors seen in the infiltrating immune cells, including the presence and types of immune cell and staining for PD-L1, and 3) factors specific to the patient and the process of carcinogenesis (such as prior smoking history) are being defined.

Citation Format: Edward B. Garon. Progress in lung cancer treatment with immunotherapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PL02-02.
Abstract PL03-01: Targeting K-RAS driven cancer
Authors: Barbacid Mariano
Published: May 2016

K-RAS oncogenes have been implicated in about one fifth of all human cancers including lung adenocarcinoma and pancreatic ductal adenocarcinoma, two tumor types with some of the worse prognosis. In order to identify effective therapeutic strategies to treat these tumors, we have developed genetically engineered mouse (GEM) models that closely recapitulate their natural history. We are using these mice to validate targets of potential therapeutic value with the ultimate goal to translate these findings to the clinic. In previous studies, we have crossed these GEM models with mice that carried either germ line or lox-Cre conditional knock out loci encoding each of the downstream kinases of the Raf/Mek/Erk pathway as well as the cell cycle interphase Cdks to interrogate their role in the development of K-Ras driven lung adenocarcinomas. These studies have led us to validate the c-Raf and Cdk4 kinases as essential targets for these tumors (Puyol et al., Cancer Cell 2010; Blasco et al., Cancer Cell 2011). Following a similar strategy, we have demonstrated that the EGF Receptor and c-Raf were also absolutely essential for the development of pancreatic ductal adenocarcinomas (Navas et al., Cancer Cell 2012). Importantly, systemic ablation of either c-Raf or Cdk4 has no significant effect on normal homeostasis. Now, we have decided to interrogate the role of these targets in advanced tumors. To this end, we have generated new GEM models in which expression of the resident K-Ras oncogene, as well as ablation of the p53 tumor suppressor is mediated by the frt-FLp(o) targeting system, a strategy that allows temporal separation of tumor development from target ablation. In addition, we have generated lox-Cre based conditional knock-in strains that upon recombination direct the expression of kinase dead isoforms instead of inducing protein ablation. We feel that these strains should serve as better models to mimic drug intervention in the clinic. Finally, we are now combining ablation (or inactivation) of these targets in order to identify combinations that may eventually eradicate advanced tumors. We hope that these studies will serve to guide the design of future clinical trails to treat patients carrying K-RAS mutant tumors.

Citation Format: Mariano Barbacid. Targeting K-RAS driven cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PL03-01.
Abstract PL05-01: ERCC1 alternative readouts
Authors: Kuo Mei-Shiue , Olaussen Ken A. , Soria Jean-Charles
Published: May 2016

Platinum-based compounds, including cisplatin and oxaliplatin, trigger cell death by distorting the helix structure and subsequently affecting DNA replication and transcription. The therapeutic efficacy of platinum-based chemotherapy varies among patients and only a portion of them have real benefits. Precision medicine searches for the optimal therapy for each patient. The proteins involved in DNA repair are thus potential biomarkers to select patients more prone to respond to platinum-based chemotherapy.

The ERCC1 (excision repair cross-complementation group 1) protein is essential in nucleotide excision repair (NER) and other repair pathways involved in the repair of platinum-induced DNA damages. ERCC1 with its partner XPF (xeroderma pigmentosum complementation group F) form a structure-specific endonuclease that is responsible for 5' incision during DNA repair. ERCC1 has been reported to be a prognostic and predictive biomarker for cisplatin treatments in various cancers. Many studies have shown that the ERCC1 status, including ERCC1 polymorphisms, ERCC1 RNA expression and ERCC1 protein expression, are associated with platinum-based therapy efficacy. However, this correlation between ERCC1 status and the clinical outcome has not always reached a consensus, probably due to inadequate methods to determine ERCC1 expression and unreliability of the current commercial ERCC1 antibodies.

Alternative splicing leads to several isoforms of ERCC1. We have reported that only ERCC1-202 mediates highly efficient removal of platinum-GG intrastrand adducts and should therefore be considered as the only functional isoform. Putative roles of the other isoforms remain unknown. The expression of ERCC1 is mostly determined by qRT-PCR or IHC. However, these two methods are not able to discriminate the functional ERCC1-202 isoform from other isoforms. We will present the design of a tailor-made antibody directed against the interacting complex ERCC1/XPF. This new ERCC1/XPF heterodimer-specific antibody permits the detection of the functional ERCC1-202 isoform when it is used in combination with other antibodies in proximity ligation assays (PLA). The applicability of this alternative read out for ERCC1 expression on clinical samples will be discussed.

Citation Format: Mei-Shiue Kuo, Ken A. Olaussen, Jean-Charles Soria. ERCC1 alternative readouts. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PL05-01.
Abstract PL08-04: High-throughput drug screens in cancer cell models to enable precision cancer medicine
Authors: Garnett Mathew
Published: May 2016

Alterations in cancer genomes strongly influence clinical responses to therapy and can be used as molecular biomarkers of response to targeted agents. However, the identification of biomarkers for effective patient stratification remains a considerable challenge for the development of effective therapies.

We are performing large-scale drug sensitivity screens using genetically characterised in vitro cellular models of human cancer. Cancer cells are profiled for differential sensitivity to clinical, pre-clinical and experimental anti-cancer compounds and drug response is linked with genomic features. We aim to identify the molecular features of cancer cells which impact on drug sensitivity and resistance, and investigate the molecular rationale for the observed sensitivity. This provides insights into mechanism of drug action, identifies opportunities for re-purposing existing drugs for new indications, and enables the identification of biomarkers to facilitate the development of targeted cancer therapies.

I will describe results from our recent analysis of how cancer-driving alterations identified from the analysis of 11,000 patient tumours correlate with response to 265 compounds profiled in a panel of 1,000 human cancer cell-lines. This comprehensive analysis provides an initial glimpse of the landscape of pharmacogenomic interactions operative in human cancer, and is a resource to identify novel therapeutic possibilities for selected cancer sub-populations.

Citation Format: Mathew Garnett. High-throughput drug screens in cancer cell models to enable precision cancer medicine. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PL08-04.
Abstract PR03: Novel ceritinib resistance mechanisms: new resistant mutation, fibroblast growth factor receptor 3 overexpression and cMET amplification-mediated ceritinib resistance
Authors: Katayama Ryohei , Sakashita Takuya , Yanagitani Noriko , Takeuchi Kengo , Nishio Makoto , Fujita Naoya
Published: May 2016

Anaplastic lymphoma kinase (ALK) rearrangement, which was first identified in non-small cell lung cancer (NSCLC) in 2007, is observed in 3%-5% of non-small-cell lung cancer (NSCLC) patients. For the treatment of ALK-rearranged non-small-cell lung cancer (NSCLC) patient, crizotinib, cMET/ALK/ROS1-TKI was tested and has shown remarkable tumor shrinkage in clinical trials for the treatment of advanced ALK-rearranged NSCLC patients. However, these tumors inevitably develop resistance to crizotinib due to various secondary mutations, ALK fusion gene amplification, or bypass pathway activation mediated by other receptor tyrosine kinases. To overcome crizotinib resistance, multiple ALK-TKIs have been developed. Ceritinib, a next-generation ALK-TKI, showed great efficacy in crizotinib-refractory, ALK-rearranged NSCLC patients in a clinical trial. However, the emergence of resistance to ALK-TKI is a major limitation for the effective therapy. Although various secondary mutations or bypass pathway activation-mediated resistance have been identified, large part of the resistance mechanism is still unknown.

In this study, we explored ceritinib-resistant mechanisms using ceritinib-resistant, echinoderm microtubule-associated protein-like 4-ALK-positive H3122 cells and ceritinib-resistant patient-derived cells. Genetic alteration was examined by sequencing of cancer related genes. Protein expression related to ceritinib was examined by receptor-tyrosine kinase (RTK) array, immunoblotting and IHC. To overcome the identified resistance, single or combination treatment of the kinase inhibitors was testes in vitro and in vivo.

We identified three novel ceritinib resistance mechanisms: a resistance mutation (L1198F), fibroblast growth factor receptor 3 (FGFR3) activation, and cMET gene amplification. L1198F-mutated ALK was the most sensitive to crizotinib. Molecular dynamic structure simulation successfully predicted the affinity of ceritinib or crizotinib to wild type and L1198F-mutated ALK. The patient-derived cMET-amplified ceritinib-resistant cells were sensitive to crizotinib, and the FGFR3-upregulated, ceritinib-resistant H3122 cells were re-sensitized to ALK-TKIs by FGFR inhibitor co-treatment.

Our study revealed multiple ceritinib resistance mechanisms and suggest that some of the ceritinib resistance can be overcome by crizotinib.

Citation Format: Ryohei Katayama, Takuya Sakashita, Noriko Yanagitani, Kengo Takeuchi, Makoto Nishio, Naoya Fujita. Novel ceritinib resistance mechanisms: new resistant mutation, fibroblast growth factor receptor 3 overexpression and cMET amplification-mediated ceritinib resistance. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PR03.
Abstract PR07: AZD9291 activity in patients with leptomeningeal disease from non-small cell lung cancer: a Phase I study
Authors: Lee Dae Ho , Kim Dong-Wan , Ahn Myung-Ju , Cho Byoung Chul , Lee Jong Seok , Ye Xin , Yang Pamela , Jiang Haiyi , Yang James Chih-Hsin
Published: May 2016

This abstract has been withheld from publication due to its inclusion in the AACR-NCI-EORTC Molecular Targets Conference 2015 Official Press Program. It will be posted online at the time of its presentation in a press conference or in a session.

Citation Format: Dae Ho Lee, Dong-Wan Kim, Myung-Ju Ahn, Byoung Chul Cho, Jong Seok Lee, Xin Ye, Pamela Yang, Haiyi Jiang, James Chih-Hsin Yang. AZD9291 activity in patients with leptomeningeal disease from non-small cell lung cancer: a Phase I study. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PR07.
Abstract A11: Identification of the premalignant cell of origin in human glioblastoma multiforme
Authors: Mitra Siddhartha S. , Gholamin Sharareh , Sinha Rahul , Morganti Rachel M. , Weissman Irving , Cheshier Samuel H.
Published: May 2016

One of the major difficulties in identifying the cell of origin for glioblastoma is the complex cellular composition of this disease. It is now hypothesized that the different subtypes of high-grade glioma may have different cell of origin and in mouse models it has been shown that the cell of origin resides within the progenitor populations. To identify the human cell of origin we delineated the stages of CNS stem cell differentiation in fetal and adult human brain. After a functional high throughput screen, we identified a panel of four antibodies (i.e CD15, Notch1, EGFR, and CD90) that in various combinations can separate long-term self-renewing multi-potent neural stem cells (NSCs) from multi-potent progenitors with limited self-renewal capacity (NPC) from non-neoplastic human fetal and adult Brain (sub-ventricular zone). FACS sorted cells were analyzed for single cell lineage multi-potentiality, lineage bias and self-renewal to trace and characterize their lineage relationships. In surgical human glioblastoma samples, however we observed in-vivo tumor initiating and in-vitro tumorsphere-forming frequency was predominant in the progenitor cells and not in the neural stem cells. Interestingly we did observe a small frequency of NSC cells forming distinct lesions in the brain, which on further analysis showed the presence of both the NSC and NPC, whereas the tumor initiating enriched population did not show the presence of the NSC but only tumor initiating NPCs. Taken together our data suggests the presence of “normal” or pre-malignant stem cells in glioblastoma, RNAseq and targeted sequencing of known mutations identified the genomic events which can distinguish these pre-malignant neural stem cells from the tumor initiating cancer stem cells. These pre-malignant cells could comprise a cellular reservoir that may need to be targeted to prevent tumor relapse.

Citation Format: Siddhartha S. Mitra, Sharareh Gholamin, Rahul Sinha, Rachel M. Morganti, Irving Weissman, Samuel H. Cheshier. Identification of the premalignant cell of origin in human glioblastoma multiforme. [abstract]. In: Proceedings of the AACR Special Conference: Advances in Brain Cancer Research; May 27-30, 2015; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2015;75(23 Suppl):Abstract nr A11.