bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B49: Prox1 Transcription factor promotes colorectal cancer growth by expanding the Lgr5-positive stem cell pool.
Authors: Wiener Zoltan , Högström Jenny , Hyvönen Ville , Holopainen Tanja , Band Arja , Kallio Pauliina , Dufva Olli , Haglund Caj , Kruuna Olli , Ben-Neriah Yinon
Published: August 2014

The Wnt pathway that is central in the development of colorectal cancer (CRC) plays a critical role also in the maintenance of the normal gut. Inhibition of this pathway could thus lead to serious side-effects in CRC patients. We have previously shown that the Prox1 transcription factor is expressed only in a few cells of normal intestinal crypts, yet it contributes to CRC progression via an unknown mechanism. In this study, we show that Prox1 deletion in the WT intestinal epithelium has no obvious phenotypic consequence and that Prox1 regulates the number of Lgr5+ CRC stem cells via establishing a proper niche for them. Upon Apc deletion, Prox1 expression is rapidly induced in both the Lgr5+ CRC stem cells and Lgr5- non-stem. Prox1 deletion in 3D organoid cultures derived from mouse intestinal adenomas or human CRC cells leads to a decrease in lumen formation and crypt-like "outpocketings” that are enriched in Lgr5+ CRC stem cells. This results in a decreased number of Lgr5+ stem cells and a shift from the CRC stem cell-like phenotype to a progenitor-like phenotype, which consequently leads to decreased tumor cell growth. Interestingly, we show that silencing of the Prox1-suppressed Wnt-target Annexin A1 (Anxa1) mimics the effects of Prox1, including the establishment of a niche for Lgr5+ CRC stem cells. Anxa1 silencing in human and mouse CRC organoids results in an enhanced formation of outpocketings, an elevated number of Lgr5+ CRC stem cells and increased tumor growth in xenotransplantation assays. We propose a model where the deletion of the Apc gene induces both Anxa1 and Prox1 expression in the intestinal epithelium. Prox1 silencing elevates the expression of Anxa1, which inhibits the formation of crypt-like outpocketings and the Lgr5+ CRC stem cell niche, consequently leading to reduced tumor growth. Based on this study Prox1 is the first molecule which regulates the number of CRC stem cells without affecting the homeostasis of the adult WT intestine and it provides an attractive therapeutic target for drug development in CRC.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B49.

Citation Format: Zoltan Wiener, Jenny Högström, Ville Hyvönen, Tanja Holopainen, Arja Band, Pauliina Kallio, Olli Dufva, Caj Haglund, Olli Kruuna, Yinon Ben-Neriah. Prox1 Transcription factor promotes colorectal cancer growth by expanding the Lgr5-positive stem cell pool. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B49.
Abstract C111: In vitro characterization of TAS-121, a novel, highly potent, and mutant-specific EGFR-TKI.
Authors: Ito Kimihiro , Miyadera Kazutaka , Aoyagi Yoshimi , Kato Masanori , Yonekura Kazuhiko , Iwasawa Yoshikazu , Utsugi Teruhiro
Published: August 2014

Background: The active mutation of epidermal growth factor receptor (EGFR), L858R or deletion in exon19, are present in patients with NSCLC and responsive to EGFR tyrosine kinase inhibitors such as gefitinib and erlotinib. Over time, most tumors develop resistance to these EGFR inhibitors by the acquiring of drug-resistant mutations including gatekeeper T790M mutation (more than 50% cases). Severe skin rash and diarrhea caused by wild-type EGFR (wtEGFR) inhibition limit EGFR TKI treatment. Therefore targeting mutant EGFR (mtEGFR) but not wtEGFR represents an attractive therapeutic strategy.

In this report, we identify a small molecule EGFR inhibitor, TAS-121, that targets mtEGFR but not wtEGFR and its biological characterization in vitro.

Methods: In vitro enzyme inhibition activity of TAS-121 for EGFR and its mutants was determined by using purified EGFRs and peptide substrates. Cellular phosphorylation of EGFR was assayed by immunoblot analysis. For growth inhibition assay, cells were treated with TAS-121 for 3 days, and living cells were determined by using CellTiter GloTM which measures cellular ATP. Apoptosis assay was conducted by using Caspase-GloTM and Cell Counting Kit.

Results: TAS-121 was found to be a more potent mutant selective EGFR-TKI based on bioavailability characteristics compared to our proto-type compound, TAS-2913.

TAS-121 inhibits kinase activity of EGFR mutants harboring T790M in a sub-nano molar range and much more potently than that of wtEGFR. TAS-121 inhibits auto-phosphorylation of EGFR and intercellular signaling pathways in NCI-H1975 (EGFR T790M / L858R) and HCC827 (EGFR del E746-A750). In a cell proliferation assay, TAS-121 also suppresses growth of NCI-H1975 and HCC827 more potently than that of a normal cell which grows in an EGF-dependent manner. Therefore, the wtEGFR / mtEGFR inhibition ratio of TAS-121 appears to be higher than those of other EGFR TKIs. Furthermore, TAS-121 induces apoptosis in NCI-H1975 but erlotinib could not.

Conclusion: These results suggest that TAS-121, a potent mutant-selective EGFR inhibitor, may represent a new therapeutic strategy in the treatment of NSCLC resistant to currently available EGFR/TKIs. Further pre-clinical evaluations and development are ongoing.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C111.

Citation Format: Kimihiro Ito, Kazutaka Miyadera, Yoshimi Aoyagi, Masanori Kato, Kazuhiko Yonekura, Yoshikazu Iwasawa, Teruhiro Utsugi. In vitro characterization of TAS-121, a novel, highly potent, and mutant-specific EGFR-TKI. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C111.
Abstract C132: Targeting heat shock factor 1 improves the antitumor efficiency of hyperthermia.
Authors: Scherz-Shouval Ruth , Bagley Alexander F. , Whitesell Luke , Bhatia Sangeeta N. , Lindquist Susan
Published: August 2014

The heat-shock response is a powerful transcriptional program which acts genome-wide, not only to restore normal protein folding through the induction of heat shock proteins (HSP), but to re-shape global cellular pathways controlling survival, growth and metabolism. In mammals, this response is regulated primarily by the Heat Shock Factor 1 (HSF1) transcription factor. We have previously shown that HSF1 plays a fundamental role in tumorigenesis, by promoting the survival and malignance of tumor cells, both in tissue culture and in mouse models of cancer [1]. HSF1 exerts its role by activating a unique transcriptional program in the cancer cells [2]. Indeed, increased HSF1 levels, as well as activation of its transcriptional signature, are associated with reduced survival in breast, lung and colon cancer patients [3].

Cancer cells are exquisitely dependent on HSF1 for survival. Exposure to additional stress, such as heat, further increases their dependency on HSF1. Recently we described how translation is linked to HSF1 activation using a derivative of the natural compound rocaglamide [4]. We found that this drug-like inhibitor of translation-initiation inhibits HSF1 and leads to tumor regression in hematopoietic malignancies. Here we combine this compound, or genetic inhibition of HSF1 expression, with focal heat therapy delivered via gold nano rods. We find that inhibiting HSF1 in solid tumors increases the efficiency of hyperthermia as an anticancer treatment.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C132.

Citation Format: Ruth Scherz-Shouval, Alexander F. Bagley, Luke Whitesell, Sangeeta N. Bhatia, Susan Lindquist. Targeting heat shock factor 1 improves the antitumor efficiency of hyperthermia. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C132.
Abstract C138: Loss of NF1 in melanoma cell lines is associated with active Ras and dependence on MEK even in the absence of BRAF or NRAS mutation.
Authors: Nissan Moriah H. , Pratilas Christine , Jones Alexis , Won Helen , Kong Li , Yao Zhan , Merghoub Taha , Ribas Antoni , Chapman Paul , Yaeger Rona , Taylor Barry , Shultz Nikolaus , Berger Michael F. , Rosen Neal , Solit David B.
Published: August 2014

Though two-thirds of cutaneous melanomas harbor activating mutations in the BRAF and NRAS genes, the alterations that drive tumor progression in the roughly 30% of melanoma tumors wild-type for BRAF and NRAS remain largely uncharacterized. The selective RAF inhibitors vemurafenib and dabrafenib inhibit MAPK pathway activity only in BRAF mutant cells, thus their clinical utility is restricted to patients with BRAF mutant tumors. MEK inhibitors, which have broader antitumor activity and have shown promising activity in NRAS mutant melanoma, may be effective in a broader range of MAPK pathway-dependent tumors. We performed a functional and genomic analysis of melanoma cell lines wild-type for BRAF and NRAS to determine whether occult mutations in RAS signaling were present. Elevated RAS-GTP was common in BRAF/NRAS wild-type melanoma cell lines, a subset of which exhibited total loss of NF1 protein expression. The proliferation of NF1-null melanoma cells was dependent upon MEK, though the cellular potency of several allosteric MEK inhibitors that are currently in clinical testing (PD0325901, AZD6244, MEK162 and trametinib) varied widely in NF1-null melanoma cells. The greatest antitumor activity was noted with trametinib, a MEK inhibitor that also blocks RAF mediated phosphorylation of MEK. Notably, alterations in NF1 also co-occurred with RAS and BRAF mutations in both cell lines and human melanomas. In the setting of BRAF co-mutation, loss of NF1 abrogated upstream negative feedback on RAS activation resulting in constitutive expression of RAS-GTP and resistance to RAF but not MEK inhibition. In summary, NF1 loss is a common event in cutaneous melanoma that is associated with RAS activation, MEK dependence and RAF inhibitor resistance.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C138.

Citation Format: Moriah H. Nissan, Christine Pratilas, Alexis Jones, Helen Won, Li Kong, Zhan Yao, Taha Merghoub, Antoni Ribas, Paul Chapman, Rona Yaeger, Barry Taylor, Nikolaus Shultz, Michael F. Berger, Neal Rosen, David B. Solit. Loss of NF1 in melanoma cell lines is associated with active Ras and dependence on MEK even in the absence of BRAF or NRAS mutation. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C138.
Abstract C149: The PKC inhibitor Sotrastaurin selectively inhibits the growth of GNAQ mutant uveal melanoma.
Authors: Barrett Rosemary , Guo Ribo , Yuan Jing , Cooke Vesselina , Vattay Anthony , Korn Joshua , Liang Guiqing , Li Xin , Thiruvamoor Ramu , Wylie Andrew , Bric Anka , Keen Nicholas , Sellers William
Published: August 2014

GNAQ mutations are early and frequent events in the pathology of Uveal Melanoma. These mutations hyper-activate PLCb-PKC-ERK1/2 signaling resulting in PKC dependence. Targeting GNAQ mutant Uveal Melanoma Cells with the PKC inhibitor AEB071 (Sotrastaurin) leads to pathway modulation and growth inhibition. The Myristoylated Alanine-rich C-kinase Substrate (MARCKS) is directly phosphorylated by PKC and can be used as a readout for PKC activation.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C149.

Citation Format: Rosemary Barrett, Ribo Guo, Jing Yuan, Vesselina Cooke, Anthony Vattay, Joshua Korn, Guiqing Liang, Xin Li, Ramu Thiruvamoor, Andrew Wylie, Anka Bric, Nicholas Keen, William Sellers. The PKC inhibitor Sotrastaurin selectively inhibits the growth of GNAQ mutant uveal melanoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C149.
Abstract C150: Depletion of cellular NAD using the NAMPT inhibitor GNE-617 leads to oncosis blister cell death.
Authors: O'Brien Thomas , Del Nagro Christopher , Xiao Yang , Oeh Jason , Rangell Linda , Reichelt Mike , Liang Xiaorong , Liederer Bianca M. , Dragovich Peter S. , Sampath Deepak
Published: August 2014

Nicotinamide adenine dinucleotide (NAD) is a critical cellular metabolite and the key enzyme in the NAD salvage pathway is nicotinamide phosphoribosyl transferase (NAMPT). Here we describe GNE-617, a novel orally bioavailable NAMPT inhibitor, and show that this compound promotes rapid depletion of NAD both in cells and in xenograft tumor models. Moreover, GNE-617 rapidly induced tumor regressions in colorectal (HCT-116), fibrosarcoma (HT-1080), prostate (PC3) and pancreatic (MiaPaca2) xenograft models. Despite increasing interest in exploiting cancer cell metabolism as a therapeutic strategy, there is still a poor understanding of cell death mechanisms following disruption of key metabolic processes. Here we show that depletion of NAD in cells induces a series of cellular events that leads to oncosis-Blister Cell Death (oncosis-BCD). In all cell lines examined, NAD was depleted >95% within 25-39 hours, which was rapidly followed by a loss of ATP (>95% depleted by 41-76 hours). Depletion of NAD correlates with loss of cell motility and a reduction in mitotic index, which may be explained by reduced activity of NAD-dependent protein deacetylases. In support of this, we find that α-tubulin-K40 is hyper-acetylation, a modification that is known to reduce tubulin dynamics and cell motility. Additionally, there is no evidence of histone H3-K9 deacetylation, which normally occurs as cells enter mitosis. Using a combination of approaches including live cell imaging and electron microscopy we found that cell lines with a more rapid depletion of ATP display signs of necrosis and oncosis-BCD, while cell lines with a slower depletion of ATP show signs of autophagy, apoptosis, necrosis and oncosis-BCD. In all cases however, oncosis-BCD is the predominant form of cell death and is characterized by plasma membrane swelling to form large organelle-free blisters. Finally, we conclude that cell death is due to loss of plasma membrane ion-homeostasis associated with ATP depletion. In conclusion, our data shows that there is an ordered progression of events that occurs in cancer cells following NAD depletion and reveals that oncosis-BCD is the predominant form of cell death in response to NAD depletion.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C150.

Citation Format: Thomas O'Brien, Christopher Del Nagro, Yang Xiao, Jason Oeh, Linda Rangell, Mike Reichelt, Xiaorong Liang, Bianca M. Liederer, Peter S. Dragovich, Deepak Sampath. Depletion of cellular NAD using the NAMPT inhibitor GNE-617 leads to oncosis blister cell death. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C150.
Abstract C185: CIP2A is a novel therapeutic target for an erlotinib derivative in EGFR wild-type NSCLC cells.
Authors: Chao Ting-Ting , Wang Cheng Yi , Chang Fang-Yu , Chen Yen-Lin , Shiau Chung-Wai , Chen Kuen-Feng
Published: August 2014

Rationale: Cancerous inhibitor of protein phosphatase 2A (CIP2A), a proto-oncogene inhibiting proteolytic degradation of c-MYC, is overexpressed in various types of human cancers, including lung cancer.

Objective: To determine if erlotinib and its derivative can inhibits EGFR mutation-negative NSCLC via CIP2A inactivation.

Methods: EGFR mutation-negative NSCLC cell lines (H358, H460, and H322) were treated with erlotinib or TD-19, an erlotinib derivative that closely resembled erlotinib structurally but devoid of tyrosine-kinase inhibitory activity. Apoptosis and signal transduction were analyzed. In vivo efficacy was determined in nude mice with H460 xenografts.

Results: Erlotinib showed differential effects on apoptosis in 3 human NSCLC cell lines. Erlotinib induced significant apoptosis in H358 cell line; however, H460 and H322 cell lines showed resistance to erlotinib-induced apoptosis at all tested doses. Down-regulation of CIP2A, a cellular inhibitor of protein phosphatase 2A (PP2A), mediated the apoptotic effect of erlotinib in H358 cell line. Erlotinib inhibited CIP2A in a dose- and time-dependent manner in sensitive NSCLC cells whereas no alterations in CIP2A were found in resistant cells. Overexpression of CIP2A upregulated phospho-Akt and protected H358 cells from erlotinib-induced apoptosis. In addition, silencing CIP2A by siRNA restored the effects of erlotinib in H460 cells. Moreover, adding okadaic acid, a PP2A inhibitor, abolished the effects of erlotinib on apoptosis in H358 cells. TD-19 had better effects than erlotinib on growth inhibition and apoptosis in erlotinib-resistant H460 and H322 cell lines through CIP2A-PP2A-Akt pathway. Overexpression of CIP2A upregulated phospho-Akt and protected H460 cells from TD-19-induced apoptosis. Moreover, adding okadaic acid, a PP2A inhibitor, abolished the effects of TD-19 on apoptosis in H460 cells. Furthermore, in vivo xenograft data showed that TD-19 inhibited the growth of H460 tumor but erlotinib had no effect on H460 tumor. TD-19 downregulated CIP2A and upregulated PP2A activity in H460 tumors, but erlotinib did not.

Conclusions: Inhibition of CIP2A determines the effects of erlotinib and its derivative on apoptosis in EGFR mutation-negative NSCLC. CIP2A may be useful as a therapeutic target for erlotinib and its derivative in EGFR mutation-negative NSCLC treatment.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C185.

Citation Format: Ting-Ting Chao, Cheng Yi Wang, Fang-Yu Chang, Yen-Lin Chen, Chung-Wai Shiau, Kuen-Feng Chen. CIP2A is a novel therapeutic target for an erlotinib derivative in EGFR wild-type NSCLC cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C185.
Abstract C21: Molecular mechanism of Mangiferin induced cytotoxicity in cervical carcinoma cells.
Authors: Komal Komal , Singh Mayank , Sharma Alpana , Deshwal Vishal
Published: August 2014

Background: Cervical cancer is the leading cause of mortality in women amongst all cancers. Mangiferin is a plant natural polyphenol of C-glycosylxanthone structure and various pharmacological activities. It can be found in many plant species, among which the mango tree (Mangifera indica) is one of the primary sources. Several studies indicated also its ability to inhibit carcinogenesis and cancer cells growth by apoptosis induction in vitro and in vivo.

Methods: HPV-positive cervical cancer cell lines HeLa, CaSki and SiHa were cultured in DMEM/RPMI media respectively, supplemented with 10% FBS in a humidified atmosphere of 5% CO2 at 37°C. They were treated with 5 and 10μg/ml Mangiferin for 24 hrs. Apoptosis was measured by flow cytometery and TUNEL assay. Expression of various proteins levels were assessed by western blotting while caspase -3 and -9 activation was measured by fluorimetry.

Results: Mangiferin induced dose dependent cytotoxicity in both HPV 16 and HPV 18 positive cell line. Mangiferin repressed activation of NFkB Transcription factor. The observed apoptosis was caspase dependent. Caspase dependent apoptosis was mediated through mitochondrial intrinsic pathway involving release of cytochrome c with increase in level of proapoptotic Bax and decrease in levels of Antiapoptotic Bcl XL. Mangiferin also repressed activation of NFkB Transcription factor and its nuclear translocation. Mangiferin also repressed the level of E6 oncoproteins.

Conclusion: The present study establishes the potency of Mangiferin as a potential chemotherapeutic agent in female cancers as it targets cervical cancer cells by repression of NFkB transcription factor and inducing dose dependent cytotoxicity.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C21.

Citation Format: Komal Komal, Mayank Singh, Alpana Sharma, Vishal Deshwal. Molecular mechanism of Mangiferin induced cytotoxicity in cervical carcinoma cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C21.
Abstract C223: Network-based approach aids in the discovery of context-specific druggable targets for treatment of glioblastoma.
Authors: Dhruv Harshil D. , Kim Seungchan , Kiefer Jeff , Emig-Agius Dorothea , Finlay Darren , Jung Sungwon , Vuori Kristiina , Berens Michael
Published: August 2014

Systematic discovery of actionable cancer targets could fill an unmet need for improved approaches to manage Glioblastoma Multiforme (GBM). Critical barriers to the discovery of druggable targets in cancer include: 1) molecular heterogeneity of the disease across patients, 2) implementation of a systematic approach to utilize existing knowledge and molecular data for target discovery, and 3) the lack of a relevant, rapid and systematic pipeline to enable empirical testing of hypotheses. We describe a network-based method to stratify GBM clinical samples into molecularly homogeneous subsets based on gene expression, gene copy number, and miRNAs, which we term “molecular contexts," or mCs. Within these mCs, a knowledge-based topological analysis of pathway elements was used to uncover discrete mC-specific targets. An empiric chemical screen probed the target space across different mCs, mC-4 and mC-14, which were molecularly orthogonal to each other. Specimens in mC-4 were enriched with samples previously classified as Mesenchymal-type GBM, while mC-14 was enriched with Proneural-subtype GBM. The chemical screen was carried out using short-term in vitro cultures derived from patient-derived GBM xenografts, which mapped to mC4 and mC14 based on gene expression. We employed a network-based topological approach to discern targets and pathways as candidate druggable vulnerabilities. The chemical validation screen was carried out with an assembled chemical biology fingerprint (CBF) library comprised of 650 small molecules targeting multiple cancer-associated pathways and processes. Matching specific chemical hits to their respective targets allowed for validation of specific gene hits from the topological analysis. Of particular interest were two molecular context specific lethal compounds in the screen, tamoxifen citrate and arsenic trioxide, specific to the mC4 and mC14, respectively. PKC, among the targets of Tamoxifen citrate, was a predicted node of vulnerability for mC-4 GBM, while PML gene, a target of Arsenic Trioxide, was a predicted target for mC-14. In summary, our results suggest that context analysis coupled with knowledge-based enrichment and topological analysis identifies specific GBM contexts with novel unique drugable targets. Supported by NIH U01 CA168397.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C223.

Citation Format: Harshil D. Dhruv, Seungchan Kim, Jeff Kiefer, Dorothea Emig-Agius, Darren Finlay, Sungwon Jung, Kristiina Vuori, Michael Berens. Network-based approach aids in the discovery of context-specific druggable targets for treatment of glioblastoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C223.
Abstract C230: A platform for discovery of novel stem cell modulators and subsequent development of therapeutic targets.
Authors: Ainsworth Shaun , Hoyle Sarah , Bonavita Aude-Marine , Kemp Laura , Read Jo , Murdoch Alan , Woolford Lorna , Miele Gino , Booth Cath
Published: August 2014

In recent years, there has been a significant and growing interest in specific pathways the human body utilizes in response to damage and their exploitation to induce cell proliferation, differentiation and apoptosis. Epistem's Novel Therapies division has created a discovery platform to allow identification of novel soluble regulators for development of therapeutic targets in oncology, regenerative medicine, and gastrointestinal diseases. Target discovery and identification starts with a known stem cell model and the creation of a disease system in vivo to identify potential stem cell markers. A damage response model of the gastrointestinal tract for stem cell proliferation and apoptosis post-irradiation describes the different phases of the cell recovery process. Post-irradiation, the stem cells, which are located at the base of the intestinal crypt, undergo apoptosis, followed by a rapid phase of regeneration, resulting in an ‘overshoot’ in crypt cell numbers, with homeostasis finally achieved by a ‘shut off’ phase with a decrease in proliferation to basal levels. Using high resolution gene expression profiling of dissected crypts (upper and lower), from small intestine and colon, isolated at various key time points post irradiation, we have identified many candidate novel stem cell regulators involved in damage response. Recombinant proteins have been produced; purified; and characterized, then tested using our proprietary in vitro model assays, looking for efficacy in cell proliferation, apoptosis and differentiation. Proteins that demonstrated robust and reproducible activities were then further evaluated using our industry standard in vivo intestinal stem cell function assays. Pharmocodynamic gene expression profiling was then applied to establish mechanism of action (MOA) linkages between in vitro and in vivo data. Having identified novel protein therapeutics, we are currently focused on pharmacotherapeutics that can modulate the identified pathways.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C230.

Citation Format: Shaun Ainsworth, Sarah Hoyle, Aude-Marine Bonavita, Laura Kemp, Jo Read, Alan Murdoch, Lorna Woolford, Gino Miele, Cath Booth. A platform for discovery of novel stem cell modulators and subsequent development of therapeutic targets. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C230.
Abstract C26: Development and validation of a scoring system using insulin-like growth factor to assess hepatic reserve in hepatocellular carcinoma.
Authors: Kaseb Ahmed O. , Xiao Lianchun , Naguib Rania , El-Shikh Wafaa , Hassan Manal , Hassabo Hesham , Lee Jeong-Hoon , Yoon Jung-Hwan , Lee Hyo-Suk , Chae Young Kwang , Abbruzzese James L. , Morris Jeffrey
Published: August 2014

Background: The Child-Turcotte-Pugh (CTP) score inaccurately predicts survival in patients with chronic liver disease, including hepatocellular carcinoma (HCC), yet remains the standard tool for assessing hepatic reserve and guiding therapeutic decisions. CTP scoring relies on objective laboratory values for albumin, bilirubin, and prothrombin time and subjective clinical grading of hepatic encephalopathy and ascites. Since liver production of insulin-like growth factor 1 (IGF-1) is significantly reduced in patients with cirrhosis, we hypothesized that IGF-1 could be a valid surrogate for hepatic reserve to replace the subjective parameters in CTP score.

Methods: We prospectively enrolled patients and collected data and retrospectively tested plasma IGF-1 levels in four independent cohorts: two HCC cohorts from the United States, n=310 (training set) and n=99 (validation set 1); one HCC cohort from Korea, n=188 (validation set 2); and one cirrhosis cohort from Egypt, n=71 (validation set 3). Recursive partitioning identified within the training set three optimal IGF-1 ranges that correlated with survival: >50 ng/mL = 1 point; 26-50 ng/mL = 2 points; and <26 ng/mL = 3 points. We modified the CTP score by replacing ascites and encephalopathy grading with IGF-1 value, subjected both the resulting IGF score and the CTP score to log-rank analysis, and quantified the prognostic values with C-statistics to compare the scores’ performance in all cohorts.

Results: The IGF score was significantly more accurate in predicting survival and improved the stratification of all CTP classes in the training and validation cohorts.

Conclusion: The new IGF score is simple and blood-based, and validated well on multiple independent HCC cohorts. It could identify a subpopulation of patients who may benefit from active therapy because of their preserved hepatic reserve, as distinct from patients for whom therapy can be deferred or avoided.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C26.

Citation Format: Ahmed O. Kaseb, Lianchun Xiao, Rania Naguib, Wafaa El-Shikh, Manal Hassan, Hesham Hassabo, Jeong-Hoon Lee, Jung-Hwan Yoon, Hyo-Suk Lee, Young Kwang Chae, James L. Abbruzzese, Jeffrey Morris. Development and validation of a scoring system using insulin-like growth factor to assess hepatic reserve in hepatocellular carcinoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C26.
Abstract C263: mTOR inhibition specifically sensitizes colorectal cancers with KRAS or BRAF mutations to BCL-2/BCL-XL inhibition by suppressing MCL-1.
Authors: Coffee Erin M. , Faber Anthony C. , Costa Carlotta , Dastur Anahita , Ebi Hiromichi , Hata Aaron N. , Yeo Alan T. , J Elena , Song Youngchul , Tam Ah Ting , Boisvert Jessica L. , Milano Randy J. , Roper Jatin , Kodack David P. , Jain Rakesh K. , Corcoran Ryan B. , Rivera Miguel N. , Ramaswamy Sridhar , Hung Kenneth E. , Benes Cyril H. , Engelman Jeffrey A.
Published: August 2014

Colorectal cancers (CRCs) harboring KRAS or BRAF mutations are refractory to current targeted therapies. Using data from a high-throughput drug screen, we have developed a novel therapeutic strategy that combines targeting of the apoptotic machinery using the BCL-2 family inhibitor ABT-263 (navitoclax) in combination with a TORC1/2 inhibitor, AZD8055. This combination leads to efficient apoptosis specifically in KRAS mutant (MT) and BRAF MT but not wild-type (WT) CRC cells. This specific susceptibility results from TORC1/2 inhibition leading to suppression of MCL-1 expression in mutant, but not wild-type CRCs, leading to abrogation of BIM/MCL-1 complexes. This combination strategy leads to tumor regressions in both KRAS MT colorectal cancer xenograft and genetically-engineered mouse models of CRC, but not in the corresponding KRAS WT CRC models. These data suggest that the combination of BCL-2/XL inhibitors with TORC1/2 inhibitors constitutes a promising targeted therapy strategy to treat these recalcitrant cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C263.

Citation Format: Erin M. Coffee, Anthony C. Faber, Carlotta Costa, Anahita Dastur, Hiromichi Ebi, Aaron N. Hata, Alan T. Yeo, Elena J, Youngchul Song, Ah Ting Tam, Jessica L. Boisvert, Randy J. Milano, Jatin Roper, David P. Kodack, Rakesh K. Jain, Ryan B. Corcoran, Miguel N. Rivera, Sridhar Ramaswamy, Kenneth E. Hung, Cyril H. Benes, Jeffrey A. Engelman. mTOR inhibition specifically sensitizes colorectal cancers with KRAS or BRAF mutations to BCL-2/BCL-XL inhibition by suppressing MCL-1. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C263.
Abstract C277: INCB018424 induces apoptotic cell death through the suppression of pJAK1 in human colon cancer cells.
Authors: Choi Eun Kyoung , Ha Seung Hee , An Ho Jung , Kim Jin-Sun , Hong Seung-Woo , Moon Jai-Hee , Shin Jae-Sik , Kim Kyu-Pyo , Hong Yong Sang , Lee Jae-Lyun , Choi Eun Kyung , Lee Jung Shin , Jin Dong-Hoon , Kim Tae Won
Published: August 2014

Janus kinase (JAK) is one of the main upstream activators of signal transducers and activators of transcription (STAT) that are constitutively activated in various malignancies and are associated with cell growth, survival, and carcinogenesis. Here, we investigated to role of JAKs in colorectal cancer in order to develop effective therapeutic targets for INCB018424, which is the first JAK1/2 inhibitor to be approved by FDA. After examining the basal expression levels of phospho-JAK1 and phospho-JAK2, we measured the effects of INCB018424 on the phosphorylation of JAK1/2 using western blot analysis. Cell viability was determined using the trypan blue exclusion assay. The cell death mechanism was identified by the activation of caspase 3 using western blot and annexin V staining. The basal levels of phospho-JAK1 and phospho-JAK2 were cancer cell type dependent. Colorectal cancer cell lines that phosphorylate both JAK1 and JAK2 include DLD-1 and RKO. INCB018424 inactivates both JAK1 and JAK2 in DLD-1 cells but inactivates only JAK1 in RKO cells. Cell death was proportional to the inactivation of JAK1 but not JAK2. INCB018424 causes caspase-dependent cell death, which is prevented by treatment with z-VAD. The inhibition of JAK1 phosphorylation seemed sufficient to allow INCB018424-mediated apoptosis. JAK1 is a key molecule that is involved in colon cancer cell survival and the inhibition of JAK1 by INCB01424 results in caspase-dependent apoptosis in colorectal cancer cells. The use of selective JAK1 inhibitors could be an attractive therapy against colorectal cancer, but further clinical investigations are needed to test this possibility.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C277.

Citation Format: Eun Kyoung Choi, Seung Hee Ha, Ho Jung An, Jin-Sun Kim, Seung-Woo Hong, Jai-Hee Moon, Jae-Sik Shin, Kyu-Pyo Kim, Yong Sang Hong, Jae-Lyun Lee, Eun Kyung Choi, Jung Shin Lee, Dong-Hoon Jin, Tae Won Kim. INCB018424 induces apoptotic cell death through the suppression of pJAK1 in human colon cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C277.
Abstract C33: Prognostic value of C-myc overexpression in patients with resectable pancreatic cancer.
Authors: Lim Seungtaek , Choi Hye Jin , Lee Jae-hoon , Lee Soohyeon
Published: August 2014

Purpose: Pancreatic cancer is one of the leading causes of cancer-related mortality and it is well known for extremely aggressive tumor growth rate, high incidence of metastasis and high metabolic rate. The aim of this study is to determine the value of metabolic gene expression as prognostic markers in patients with resectable pancreatic cancer. We also investigate the possible association among clinical parameters, 18F-2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) and metabolic markers.

Materials and Methods: We retrospectively reviewed the medical records of 49 pancreatic cancer patients who underwent curative resection. Using formalin fixed paraffin embedded tissues of primary tumors, immunohistochemistry (IHC) was done for GLUT1, hexokinase (HK), p53, IDH, pmTOR, PKM2, CMYC, and AMPK. Kaplan meier analysis and Cox-regression was used for univariate and multivariate analysis to examine the prognostic impact of each marker on survival. Also, Fisher's exact test was performed to examine correlation between metabolic makers and FDG uptake.

Results: Median overall survival (OS) of all patients was 27.3 months (95% CI, 15.9 - 38.6). In univariate analysis, longer overall survival was seen in patients with c-myc overexpression, higher FDG uptake, and poorly differentiated histology. Multivariate analysis revealed that c-myc overexpression was an independent poor prognostic factor after adjustment of higher FDG uptake and tumor differentiation. No association was found between clinical parameters, FGD uptake, and metabolic markers. However, higher FDG uptake was correlated with low AMPK expression (P=0.017).

Conclusions: Our study demonstrated that the c-myc overexpression identified by IHC is an independent prognostic factor in pancreatic cancer patients who underwent curative resection. Future studies are required to explore the underlying mechanism how c-myc overexpression contributes to the progression of pancreatic cancer in consideration with cancer metabolism.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C33.

Citation Format: Seungtaek Lim, Hye Jin Choi, Jae-hoon Lee, Soohyeon Lee. Prognostic value of C-myc overexpression in patients with resectable pancreatic cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C33.
Abstract C47: Inference of tumor evolution during chemotherapy by computational modeling and single cell analysis of diversity.
Authors: Almendro Vanessa , Cheng Yu-Kang , Gönen Mithat , Itzkovitz Shalev , Marusyk Andriy , Ametller Elisabet , Gonzalez-Farre Xavier , Muñoz Montse , Russnes Hege , Helland Åslaug , Rye Inga , Borresen-Dale Anne Lise , Maruyama Reo , van Oudenaarden Alexander , Dowsett Mitchell , Jones Robin L. , Reis-Filho Jorge , Gascon Pere , Michor Franziska , Polyak Kornelia
Published: August 2014

Cancer therapy exerts a strong selection that shapes tumor evolution, yet our knowledge of how tumors change during treatment is limited. Here we report the analysis of single-cell heterogeneity of genetic and phenotypic features and their spatial distribution in breast tumors pre and post neoadjuvant therapy. We found that broad intratumor genetic diversity is tumor subtype specific but does not change significantly during treatment. However, we observed significant alterations in the spatial distribution of cells after chemotherapy whereas adjacent tumor cells were more likely to be genetically divergent yet phenotypically similar. We then developed a stochastic computational model to infer tumor growth patterns and evolutionary dynamics from these topologic features. Lastly, we found that lower pretreatment genetic diversity is associated with a better response, emphasizing the clinical utility of our study. Our results highlight the importance of an integrated analysis of genotype and phenotype of single cells in intact tissue to predict how tumors evolve.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C47.

Citation Format: Vanessa Almendro, Yu-Kang Cheng, Mithat Gönen, Shalev Itzkovitz, Andriy Marusyk, Elisabet Ametller, Xavier Gonzalez-Farre, Montse Muñoz, Hege Russnes, Åslaug Helland, Inga Rye, Anne Lise Borresen-Dale, Reo Maruyama, Alexander van Oudenaarden, Mitchell Dowsett, Robin L. Jones, Jorge Reis-Filho, Pere Gascon, Franziska Michor, Kornelia Polyak. Inference of tumor evolution during chemotherapy by computational modeling and single cell analysis of diversity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C47.
Abstract C54: Aryl-N-(1H-imidazol-2-yl)-acetamides: Nonpeptidic binders of Bir3 cIAP protein.
Authors: Palermo Mark G. , Beckwith Rohan , Straub Christopher S. , Herlihy Kara , Shen Yiping , Zhang Xiaolu , Clapham Matthew , Hurley Brian
Published: August 2014

Inhibitor of Apoptosis Proteins (IAP) negatively regulate cell death through a caspase-3 and caspase-7 activation. IAP inhibitors (IAPi) were derived from the peptide sequence Alanine-Valine-Proline (AVP) based on Smac-protein binding to the BIR-3 domain of IAP protein. These peptidic compounds are low molecular weight and mimic Smac when binding to the BIR3 domain of XIAP, CIAP1, and CIAP2. However, peptides generally suffer from poor permeability that can potentially influence the amount of drugability largely due to the amide backbone and an alternate chemotype was sought. In an effort to find a replacement for AVP scaffolds, an FBS by NMR identified indole-carboxylic acid 1 as a hit in competitive binding studies. The indole scaffold was further refined through FEPOP, virtual screening, and SAR leading to the benzimidazole scaffold which upon further docking studies resulted in 2-aminobenzimidazole 2. In silico tools were utilized to propose a synthetic pharmacophore which resulted in a phenyl-hetero-imidazole tricyclic series peptidomimetic with only one amide moiety.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C54.

Citation Format: Mark G. Palermo, Rohan Beckwith, Christopher S. Straub, Kara Herlihy, Yiping Shen, Xiaolu Zhang, Matthew Clapham, Brian Hurley. Aryl-N-(1H-imidazol-2-yl)-acetamides: Nonpeptidic binders of Bir3 cIAP protein. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C54.
Abstract C92: MET amplification and overexpression sustain resistance and drive drug dependency to the DN30Fab antibody in MET-addicted cells.
Authors: Martin Valentina , Corso Simona , Petronzelli Fiorella , De Santis Rita , Comoglio Paolo M. , Giordano Silvia
Published: August 2014

The establishment of the oncogenic role of the tyrosine kinase receptor for hepatocyte growth factor, encoded by the MET gene, led to the development of several specific inhibitors, many of which are currently in clinical trials. Clinical experience has shown that the main limit to the efficacy of targeted treatments is represented by resistance. Although the mechanisms underlying resistance to MET-specific Tyrosine Kinase Inhibitors (TKIs) have been already described, nothing is known, up to now, about the emergence of resistance to treatment with MET monoclonal antibodies (mAbs). To predict the mechanisms of acquired resistance, we generated resistant cells by treating a MET-addicted lung cancer cell line (EBC1) with increasing concentrations of the monovalent form of the DN30mAb (DN30Fab), previously developed as a therapeutic tool to block MET activation. The molecular analyses revealed that resistant cells underwent MET amplification and reached such a level of MET overexpression that DN30Fab was no longer able to efficiently downregulate MET and to abrogate its constitutive activation. However, resistant cells remained MET-addicted as they were still sensitive to MET TKIs. Interestingly, resistant cells acquired drug dependence, since removal of DN30Fab led them to death due to excess of signal. Finally, we also show that cells with acquired resistance to MET TKIs are still sensitive to treatment with DN30Fab and that the two drugs have a synergistic effect on tumor cells. Our findings might have important clinical meaning, since they indicate a combined therapy (mAb plus TKI) and a discontinuous treatment as possible strategies to bypass resistance to anti-MET antibodies.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C92.

Citation Format: Valentina Martin, Simona Corso, Fiorella Petronzelli, Rita De Santis, Paolo M. Comoglio, Silvia Giordano. MET amplification and overexpression sustain resistance and drive drug dependency to the DN30Fab antibody in MET-addicted cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C92.
Abstract CN05-04: Novel DNA repair targets for anticancer treatments.
Authors: Helleday Thomas
Published: August 2014

Mutations in DNA repair are sometimes found in cancer, such as mutations in mismatch repair or BRCA1 or BRCA2 genes. We previously demonstrated that PARP inhibitors can selectively kill BRCA2 defective tumours through synthetic lethality.

Here, I describe efforts into translating the synthetic lethal approach into treatment of cancer in the clinic and the challenges. The overall conclusion is that the synthetic lethal approach offers significant advantages, but no real cancer cures and suffer from similar resistance problems as many other targeted therapies.

I exemplify how DNA repair inhibitors to a novel DNA repair target, MTH1, can be used in a different context, to overload the high level of DNA damage that is present in cancer. The MTH1 protein sanitises oxidized dNTP pools, converting 8-oxo-dGTP to 8-oxo-dGMP, to prevent incorporation of damaged bases during DNA replication. Here we show that cancer cells are dependent on MTH1 activity for survival, due to the effects of MTH1 in preventing incorporation of oxidized dNTPs into DNA to avoid ATM and p53 mediated apoptosis. We validate MTH1 as an anticancer target in vivo and describe small molecules that potently and selectively inhibit MTH1. Protein co-crystal structures demonstrate that the compounds bind as inhibitors in the enzymatic pocket of MTH1. These first-in-class inhibitors of the Nudix hydrolase family cause increased incorporation of oxidized dNTPs in cells subject to high ROS levels, causing DNA damage and cytotoxicity to cancer cells. This study exemplifies a new general therapeutic approach by using enzyme inhibitors to increased overall DNA damage load in cancer. This strategy may offer a treatment for a broad spectrum of cancers, regardless of cancer genotype.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN05-04.

Citation Format: Thomas Helleday. Novel DNA repair targets for anticancer treatments. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr CN05-04.
Abstract CN08-02: Therapeutic biomarker discovery in cancer cells.
Authors: Garnett Mathew
Published: August 2014

There is compelling evidence that alterations in cancer genomes strongly influence clinical responses to anticancer therapies. Indeed, there are now several examples where genomic changes are used as molecular biomarkers to stratify patients most likely to benefit from a treatment (e.g. BRAF in melanoma). Despite these successes, the majority of cancer drugs have not been linked to specific molecular features that could be used to direct their clinical use to maximize patient benefit. We are using pharmacogenomic profiling in a panel of >1,000 cancer cell lines as a biomarker discovery platform by systematically linking pharmacological data with extensive genomic information. I will present results from our most current large-scale analysis of drug screening results as well highlight some the new approaches we have developed to harness clinical sequencing data to guide our analyses.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN08-02.

Citation Format: Mathew Garnett. Therapeutic biomarker discovery in cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr CN08-02.