bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C105: DNA damage response deficiency (DDRD) in breast cancer is associated with a STING-dependent innate immune response
Authors: Parkes Eileen E. , Walker Steven M. , McCabe Nuala , Taggart Laura E. , Hill Laura , McCloskey Karen D. , Buckley Niamh E. , Salto-Tellez Manuel , Mullan Paul B. , Harkin D. P. , Kennedy Richard D.
Published: May 2016

Background

In breast cancer the presence of an immune infiltration has been recognised as a prognostic factor, however the mechanisms underpinning this response are not clearly defined. Previously we identified a gene expression signature that defines a DNA damage response defective (DDRD) molecular subgroup in breast cancer, that is enriched for BRCA1 and 2 mutations, and has a good outcome following DNA-damaging chemotherapy. Importantly, this DDRD subgroup is associated with up-regulation of type I Interferon-related genes. We therefore investigated the mechanism activating this immune response in the context of abnormal DNA repair.

Results

IHC analysis demonstrated that both intra-tumoral and stromal CD8+ and CD4+ T cell infiltration were associated with DDRD positive breast tumors. The CXCL10 and CCL5 cytokines were shown to be significantly up-regulated in DDRD positive breast tumours and in tissue culture models for the DDRD molecular subgroup. Furthermore, conditioned media from DDRD positive cell lines stimulated inward migration of peripheral blood mononuclear cells, when compared to media from DDRD negative cells, indicating the presence of active cytokines. We identified constitutive activation of the innate immune pathway STING/TBK1/IRF3 specifically in DDRD positive cells when compared to DDRD negative cells and found that binding of the DNA sensor cGAS to cytosolic Histone H3 was required for this immune response. Treatment of HeLa cells with DNA damaging chemotherapies but not taxanes resulted in STING-dependent expression of CXCL10 and CCL5 cytokines.

Conclusion

We have identified that the STING/TBK1/IRF3 immune pathway is activated by endogenous DNA damage in DDRD breast cancers and may explain lymphocytic infiltration observed in this subtype of breast tumours. These data suggest that the DDRD signature can identify an innate immune response to DNA damage in breast cancer, which may have therapeutic applications for immune targeted therapies.

Citation Format: Eileen E. Parkes, Steven M. Walker, Nuala McCabe, Laura E. Taggart, Laura Hill, Karen D. McCloskey, Niamh E. Buckley, Manuel Salto-Tellez, Paul B. Mullan, D. P. Harkin, Richard D. Kennedy. DNA damage response deficiency (DDRD) in breast cancer is associated with a STING-dependent innate immune response. [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 C105.
Abstract C112: Cabozantinib eradicates advanced murine prostate cancer by activating anti-tumor innate immunity
Authors: Patnaik Akash , Swanson Kenneth , Signoretti Sabina , Ye Huihui , Csizmadia Eva , Novak Jesse , Gehring Marina , Helenius Katja , Pyzer Athalia , Montaser Laleh , Wang Lily , Elemento Olivier , Levantini Elena , Clohessy John , Asara John , Kelly Kathleen , Pandolfi Pier Paolo , Rosenblatt Jacalyn , Avigan David , Balk Steven , Cantley Lewis
Published: May 2016

Several kinase inhibitors targeting aberrant signaling pathways in tumor cells have been deployed in cancer therapy. However, their impact on the tumor immune microenvironment remains poorly understood. The tyrosine kinase inhibitor cabozantinib showed striking responses in early phase clinical trials, particularly in cancer patients with bone metastases. Here we show that cabozantinib rapidly eradicates invasive, poorly-differentiated PTEN/p53 deficient murine prostate cancer. This was associated with increased neutrophil chemotactic factor expression, including CXCL12 and HMGB1 production by tumor cells, and robust infiltration of neutrophils into the tumor. Critically, cabozantinib-induced tumor clearance in mice was abolished by antibody-mediated granulocyte depletion or HMGB1 neutralization or blockade of neutrophil chemotaxis with the CXCR4 inhibitor, plerixafor. Collectively, these results demonstrate that cabozantinib triggers neutrophil-mediated anti-tumor innate immune response that results in tumor clearance.

(Manuscript submitted to Science)

Citation Format: Akash Patnaik, Kenneth Swanson, Sabina Signoretti, Huihui Ye, Eva Csizmadia, Jesse Novak, Marina Gehring, Katja Helenius, Athalia Pyzer, Laleh Montaser, Lily Wang, Olivier Elemento, Elena Levantini, John Clohessy, John Asara, Kathleen Kelly, Pier Paolo Pandolfi, Jacalyn Rosenblatt, David Avigan, Steven Balk, Lewis Cantley. Cabozantinib eradicates advanced murine prostate cancer by activating anti-tumor innate immunity. [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 C112.
Abstract C116: Concomitant blockade of glucose uptake and paracrine HGF signaling uncovers the metabolic vulnerability of KRAS-mutant colorectal tumors
Authors: Mira Alessia , Michieli Paolo
Published: May 2016

Mutations in KRAS and over-expression of MET, the hepatocyte growth factor (HGF) receptor, are both negative prognostic factors for colorectal cancer (CRC). We studied the KRAS-MET interplay using human isogenic CRC cells with defined KRAS status and human HGF knock-in SCID mice, thereby reproducing species-specific HGF-MET paracrine signaling. We show that KRAS-mutant CRC cells display an extraordinary high glycolytic rate that makes them ‘addicted’ to glycolysis. When glucose availability is scarce or upon drug-mediated impairment of glucose metabolism, KRAS-mutant cells rapidly undergo apoptosis, unless ‘salvaged’ by micro-environment-borne HGF, which permits their survival by enhancing glucose influx, sustaining glycolysis and activating autophagy, thus improving energetic efficiency and preventing a mitotic catastrophe. In an orthotopic model of metastatic CRC using human HGF knock-in SCID mice and human KRAS-mutant CRC cells, combined pharmacological blockade of glucose metabolism and of HGF/MET signaling resulted in synthetic lethality and achieved superior tumor inhibition and metastasis suppression compared to metabolism-active drugs or HGF/MET inhibitors alone. In the same system, paracrine HGF signaling also protected KRAS-mutant tumors against anti-angiogenic therapy, which caused more dramatic and less specific metabolic stress by depriving tumors of both nutrients and oxygen. However, in contrast to selective glucose metabolism impairment, anti-angiogenic therapy exacerbated tumor hypoxia, promoted HGF-dependent metastatic dissemination and gave rise to acquired resistance. These results indicate that selective impairment of glucose metabolism is a much safer and effective approach to target KRAS-mutant CRC metabolic vulnerability compared to angiogenesis inhibition. They also show that microenvironment-borne HGF is a major source of resistance to anti-tumor therapies that cause metabolic stress to cancer cells. Considering that angiogenesis inhibition is the only biological therapy currently available for KRAS-mutant tumors, the data generated by this study open new perspectives for the treatment of this highly aggressive cancer type.

Citation Format: Alessia Mira, Paolo Michieli. Concomitant blockade of glucose uptake and paracrine HGF signaling uncovers the metabolic vulnerability of KRAS-mutant colorectal tumors. [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 C116.
Abstract C154: Integrated genomics approach to identify driver alterations
Authors: Chandrani Pratik , Upadhyay Pawan , Iyer Prajish , Tanna Mayur , Shetty Madhur , Gorantala Raghuram Venkata , Oak Ninad , Singh Ankita , Chaubal Rohan , Ramteke Manoj , Gupta Sudeep , Dutt Amit
Published: May 2016

Several statistical tools have been developed to identify genes mutated at rates significantly higher than the background, indicative of positive selection, involving large sample cohort studies. However, studies involving relatively smaller sample sizes or single data-type genome wide analysis are inherently restricted due to their limited statistical power to identify low frequency genetic variation. We undertook integrated copy number, mutation and expression analyses of head and neck cancer cell lines assessing multiple levels of biological regulation in individual samples to enrich for driver events affected by two or more alterations. Besides identifying TP53, PTEN, HRAS and MET as major altered HNSCC hallmark genes, this analysis uncovered 34 novel candidate tumor suppressor and oncogenes altered by at least two types of alterations. Of these, we find a driver heterozygous truncating mutation in Nuclear receptor binding protein NRBP1, a pseudokinase, identical to that reported in other cancers and similar to activating mutant alleles in non-human model organisms. In addition to demonstrating the ability of integrated analyses to uncover biologically important genetic variation in relatively small datasets, we report for the first time, mutant NRBP1 is oncogenic when ectopically expressed in NIH 3T3 cells. We further show that knockdown of NRBP1 in oral carcinoma cell lines bearing such NRBP1 mutations inhibits transformation and survival. In over all, this approach could be of immense value for studies involving fewer or rare clinical specimen that are otherwise inherently restrictive due to the limited statistical power to detect alterations existing at lower frequency.

Citation Format: Pratik Chandrani, Pawan Upadhyay, Prajish Iyer, Mayur Tanna, Madhur Shetty, Raghuram Venkata Gorantala, Ninad Oak, Ankita Singh, Rohan Chaubal, Manoj Ramteke, Sudeep Gupta, Amit Dutt. Integrated genomics approach to identify driver alterations. [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 C154.
Abstract C160: An RNAi kinome screen identifies YES1 as a potential target for glioblastoma
Authors: Goel-Bhattacharya Surbhi , Sengupta Sejuti , Cochran Brent H.
Published: May 2016

Glioblastoma stem like cells (GSC) are known to have gene expression patterns and growth phenotypes more similar to the tumor of origin than do traditional glioma cell lines grown in serum. They also exhibit increased resistance to drugs and radiation and are likely to be responsible for tumor recurrence following therapy. As a result, it is important to identify therapeutic targets for these cells. Toward this end, we have conducted RNAi kinome screens in GSCs to identify genes that are required for their growth and survival. In addition, glioblastomas (GBM) often have significant regions of hypoxia and GSCs tend to be resistant to hypoxia. We have therefore conducted shRNA screens in both normoxic and hypoxic conditions and screened three independent patient derived GSC lines. Of 501 kinases screened, 8-11% were scored as hits with at least 2 shRNAs per kinase in each cell line, but only ∼2% were common hits for all the cell lines in both oxygen conditions. The majority of the hits were shared in both oxygen conditions, but about one sixth were specific to hypoxia in each of the cell lines. However, none of the hypoxia specific hits were common to all three cell lines. Several genes well known to have a role in GBM such as EGFR, CDK4 and KDR were scored as common hits. The non-receptor associated tyrosine kinase YES1 was scored as a novel hit common to all the three cell lines in both the oxygen conditions. YES1 is overexpressed in GBM and several other solid tumors. Depletion of YES1 expression by shRNA and CRISPR was found to be strongly growth inhibitory in GSCs suggesting that it could be a therapeutic target for GBM. Ongoing experiments include studying the mechanism of YES1 associated cell death.

Citation Format: Surbhi Goel- Bhattacharya, Sejuti Sengupta, Brent H. Cochran. An RNAi kinome screen identifies YES1 as a potential target for glioblastoma. [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 C160.
Abstract C161: CRISPR/Cas9 genome-wide gRNA library screening platform
Authors: Tedesco Donato , Diehl Paul , Makhanov Mikhail , Baron Sylvain , Suchkov Dmitry , Chenchik Alex
Published: May 2016

CRISPR/Cas9 gene knock-out technology can be used as a powerful tool for large-scale functional genomic analysis in mammalian cells. With the goal to establish a cost-effective functional genomics platform for the discovery of therapeutic targets, we developed a highly functional high throughput lentiviral gRNA/CRISPR screening platform, enabling scientists to perform pooled format genome-wide CRISPR/Cas9 genetic screens. Three 55K gRNA libraries were designed to cover the whole protein-encoding human genome with a redundancy of 8 gRNAs per gene. As supporting tools, we developed protocols, reagents, and software tools for hit validation and target prioritization.

Here we show the results of parallel genetic screens in a pair of isogenic CML cell lines (CML-R and CML-P), where the performance of CRISPR/Cas9 and RNAi screening platforms was compared for each cell line.

Citation Format: Donato Tedesco, Paul Diehl, Mikhail Makhanov, Sylvain Baron, Dmitry Suchkov, Alex Chenchik. CRISPR/Cas9 genome-wide gRNA library screening platform. [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 C161.
Abstract C41: A phase 1 study of OMN54 in patients with advanced malignancies
Authors: Renouf Daniel , Kollmannsberger Christian , Chi Kim , Chia Stephen , Tinker Anna , Mitchell Teresa , Lam Stephen , Joshi Teresa , Kwok David , Ostrem John , Sutcliffe Simon , Gelmon Karen A.
Published: May 2016

Purpose: With the increasing interest in natural products as therapeutics, we performed a Phase I open label study of OMN54 in patients with advanced malignancies to determine toxicity, maximum tolerated dose (MTD), dose limiting toxicities (DLT), and pharmacokinetics (PK). OMN54 is a multitargeted agent prepared from three Chinese botanical sources: Ganoderma lucidum, Salvia miltiorrhiza, and Scutellaria barbata, each with long histories of use as single agents.

Methods: Eligible patients (pts) were ≥ 18 years with advanced solid tumor malignancies, able to swallow oral capsules, ECOG performance status ≤ 2, measurable disease as defined by RECIST 1.0, and adequate organ function.

Results: 22 pts were enrolled in 6 dose levels, 2 at daily and 4 with twice daily dosing ranging from 1 to 5 gm orally per day; all evaluable for toxicity and 20 for response. Most common cancers included colorectal (13 pts), non small cell lung (3 pts), and ovarian (2 pts). 5 pts patients completed Cycle 1, 9 pts Cycle 2, 3 pts Cycle 3 and 1 pt each completed Cycles 4, 5, and 8. 2 pt had < 1 cycle. Only 7 AEs in 5 pts were reported as possibly related to study drug; 6 were gastrointestinal disorders, 1 a skin disorder. One GR 2 AE of vomiting was probably related to study drug. All other AEs were Grade 1. There were no treatment-related SAEs or DLTs. A recommended phase II dose (RP2D) is 2.5 g orally twice daily. PK data revealed evidence of detectable plasma total OMN54 in cohorts 1 to 6 with all 4 parent drug chemical markers with plasma half-lives of 1- 2 hours and no evidence of accumulation. Preliminary evidence of biological activity was seen with stable disease for 8 months in 1 pt and 4 pts with dose responsive reductions in TGF-β, EGF & Rantes, biomarkers of immune suppression. Significant TGF-β decreases were seen for 4 pts at doses of 2gm daily to 2.5 gm bid including an ovarian, colorectal, fallopian tube and esophageal cancer.

Conclusion: OMN54 was well tolerated with no DLTs observed. Further studies at RP2D of 2.5 g bid orally should be done to assess activity.

Citation Format: Daniel Renouf, Christian Kollmannsberger, Kim Chi, Stephen Chia, Anna Tinker, Teresa Mitchell, Stephen Lam, Teresa Joshi, David Kwok, John Ostrem, Simon Sutcliffe, Karen A. Gelmon. A phase 1 study of OMN54 in patients with advanced 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 C41.
Abstract C67: Mitochondrial dysfunction confers therapy resistance in Hep3B hepatocellular carcinoma cell line
Authors: Han YuSeon , Je Gal MyeongEun , Yi EuiYeun , Kim YungJin
Published: May 2016

Mitochondria dysfunctional cells are useful models in studies for mitochondrial diseases, apoptosis, cancer and aging, but their functional aspects have not been fully understood. Mitochondrial dysfunction (MD) is found in many type of cancer such as colorectal, liver, pancreatic, breast, prostate, ovarian cancer etc. MD has also been known to be associated with cancer malignancy, especially apoptosis resistance (therapy resistance). Using mitochondrial-depleted P0 derived from Hep3B, we have tested the effects of mitochondrial dysfunction on the chemical and radiation resistance. When compared to parental cells, Hep3B/P0 cells were much less sensitive to doxorubicin and sorafenib and irradiation. Hep3B/P0 cells also showed increased efflux, decreased target molecules, rapid repair and DNA protection. These results suggest that mitochondrial dysfunction confers therapy resistance on the cancer cells, which could be a novel therapeutic target for cancer therapy.

Citation Format: YuSeon Han, MyeongEun Je Gal, EuiYeun Yi, YungJin Kim. Mitochondrial dysfunction confers therapy resistance in Hep3B hepatocellular carcinoma cell line. [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 C67.
Abstract CN08-04: Targeting super-enhancer driven transcriptional dependencies in cancer
Authors: George Rani E.
Published: May 2016

Super-enhancers are acquired by cancer cells through gene amplification, translocation or transcription factor overexpression and facilitate high-level expression of genes including MYC, whose protein products are critical for the control of cell identity, growth and proliferation, and which are especially sensitive to perturbation. We demonstrate that the genomically amplified MYCN oncogene, by promoting the development of super-enhancers, leads to upregulation of the active transcriptional program of neuroblastoma cells. Using THZ1, a novel covalent inhibitor of cyclin-dependent kinase 7 (CDK7), a widely expressed regulator of transcription and cell cycle progression, we demonstrate selective targeting of MYCN-amplified neuroblastoma cells, leading to global repression of MYCN-dependent transcriptional amplification. This response translated to significant tumor regression in a mouse model of high-risk neuroblastoma, without toxicity to normal cells. The selectivity of THZ1 for MYCN-amplified cells was associated with preferential downregulation of super-enhancer-associated genes, including MYCN and other known lineage-specifying genes in neuroblastoma. These results indicate that CDK7 inhibition, by selectively targeting the mechanisms that promote transcriptional amplification in tumor cells, may be useful therapy for cancers that are driven by oncogenic transcription factors such as MYC.

Citation Format: Rani E. George. Targeting super-enhancer driven transcriptional dependencies in 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 CN08-04.
Abstract LB-A02: trans,trans-Conjugated linoleic acid induces apoptosis by enhancing gap junctional intercellular communication inhuman breast cancer MCF-7 cells
Authors: Ha Yeong Lae , Rakib Abdur , Kim Jeong O.
Published: May 2016

t,t-Conjugated linoleic acid (CLA) isomers reported to exert antitumor effects by inducing apoptosis. However, the precise mechanism underlying remains unclear. Restoration of reduced gap junctional intercellular communication (GJIC) in cancer cells inhibits cell growth by apoptosis. We hypothesized, t,t-CLA might cause apoptosis with enhanced GJIC in MCF-7 cells. Growth inhibitory effects of t9,t11-and t10,t12-CLA were investigated with reference to t10,c12-CLA,which is equally effective with c9,t11-CLA. Results demonstrated, t,t-CLA inhibited cell growth with cell shrinkage, nuclear condensation, increased cell population in sub-G1 phase in cell cycle and elevated caspase-3 which indicate apoptosis. It enhanced GJIC with increased connexin43 (Cx43) at the mRNA and protein levels with higher efficacy as compared to t10,c12-CLA but t9,t11-CLA is superior to t10,t12-CLA. Findings suggest, the growth inhibitory effect of t,t-CLA isomers might be associated with the up-regulation of Cx43, which enhances GJIC in MCF-7 cells. t,t-CLAs inhibited nuclear factor- κB (NF-κB) translocation and increased reactive oxygen species (ROS) generation which might trigger up-regulation of Cx43 and restore GJIC.

Keywords: t,t-CLA, Apoptosis,Cx43, GJIC, ROS.

Citation Format: Yeong Lae Ha, Abdur Rakib, Jeong O. Kim. trans,trans-Conjugated linoleic acid induces apoptosis by enhancing gap junctional intercellular communication inhuman breast cancer MCF-7 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-A02.
Abstract LB-A19: Ceramide-Rubusoside, an Ultrasmall Nanomicells Effectively Restores p53 Expression in the Missense Mutant Cancer Cells
Authors: Liu Yong-Yu , Liu Zhijun , Khiste Sachin K. , Hosain Salman B.
Published: May 2016

Mutation of tumor suppressor p53, which exhibits oncogenic gain-of-function (GOF) and promotes tumor progression, emerges as a therapeutic target for approximately 50% of all cancer cases. However, it is still unclear whether it is possible to restore GOF of p53 mutants without heterotetramer effect, as this often eliminates the efficacy of current approaches used to restore p53 function in p53 mutant cancers. Ceramide, an active sphingolipid metabolite, has pro-apoptotic effects on cancer cells but the hydrophobicity it has limits to develop ceramide as therapeutic agents. Here, we report that the ceramide-rubusoside (Cer-RUB), an ultrasmall nanomicelles enhances the bioavailability of C6-ceramide in vivo and restores wild-type p53 expression and its function in tumor suppression. We found that Cer-RUB nanomicelles enhanced the aqueous solubility of ceramide by 2,000-folds (2 mg/ml vs. <1.0 μg/ml), presented mono-disperse with an average particle sizes of 4 nm in cell culture medium, and elongated ceramide activity, due to a decrease in Cer-RUB glycosylation, compared to the C6-ceramide. More interestingly, Cer-RUB treatments (0.6 μM; 1 mg/kg) restored wild-type p53 expression documented in protein levels of phosphor-p53 and p53 responsive genes (p21, Bax) in cancer cell lines carrying R248G and R273H missense mutants and in heterozygous transgenic mice of 129S4-Trp53tm2.1Tyj. Cer-RUB significantly sensitized the resistance of these cells to anticancer drugs and eliminated cancer stem cells in cell culture and in tumor-bearing mice. This study indicates that Cer-RUB is a new approach to effectively target p53 mutant cancers.

Citation Format: Yong-Yu Liu, Zhijun Liu, Sachin K. Khiste, Salman B. Hosain. Ceramide-Rubusoside, an Ultrasmall Nanomicells Effectively Restores p53 Expression in the Missense Mutant 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-A19.
Abstract LB-A21: Single-agent activity and favorable pharmaceutical properties of orally bioavailable next-generation CDK4/6 inhibitor, ON 123300
Authors: Hoffman Benjamin , Reddy Ramana , Mallireddigari Muralidhar , Fox Daniel , Ren Chen , Maniar Manoj
Published: May 2016

Introduction: Recent proof-of-concept for targeting cyclin dependent kinases 4 and 6 (CDK4/6) culminated in the approval for breast cancer of the first-in-class CDK4/6 inhibitor, palbociclib (Ibrance®). Palbociclib and other potent but narrowly targeted CDK4/6 inhibitors are cytostatic rather than cytotoxic (Leonard et al, 2012), and require combination therapy for optimal activity. ON 123300 is a next-generation CDK4/6 inhibitor with improved single-agent cytotoxicity. This novel compound is a potent CDK4 and CDK6 inhibitor (IC50 = 3.9 nM and 9.8 nM, respectively) that is cytotoxic against breast and other cancer cell lines (Reddy et al, 2014). We present pre-IND profiling pharmacology, physicochemical and ADME studies to support ON 123300 as a clinical candidate and next-generation CDK4/6 inhibitor.

Methods and Results: Non-clinical studies were conducted in order to assess the drug-like properties of ON 123300 and its pharmaceutical salts. Physicochemical parameters were determined for the compound. ON 123300 was highly soluble below pH 4.0, with reduced solubility in more basic conditions. Predicted intestinal absorption, as measured by Caco-2 permeability, was 1.95×10-5 cm/s with a low efflux ratio. Based on these characteristics, the compound was advanced to lead profiling against 68 primary molecular targets. Radioligand binding studies revealed limited receptor inhibition (11/68 targets) with 10 μM of ON 123300. Human Ether-a-go-go (hERG) inhibition testing revealed no significant effect (IC50 > 25 μM). In vitro metabolism studies indicated metabolism through CYP3A4 and CYP2C8. Finally, in silico based modeling (Cloe® PK) integrating all key non-clinical parameters was carried out in order to estimate the potential for oral absorption in humans. Preliminary analysis suggests good oral bioavailability and the potential to establish an acceptable therapeutic window.

Conclusions: The well differentiated biochemical, anticancer and pharmaceutical properties of ON 123300 provide the basis for pre-clinical toxicology testing, leading to an investigational new drug (IND) filing and clinical exploration of this compound across tumor types that share targets accessed by this next-generation CDK inhibitor.

Citation Format: Benjamin Hoffman, Ramana Reddy, Muralidhar Mallireddigari, Daniel Fox, Chen Ren, Manoj Maniar. Single-agent activity and favorable pharmaceutical properties of orally bioavailable next-generation CDK4/6 inhibitor, ON 123300. [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-A21.
Abstract LB-B05: MM-151 overcomes acquired resistance to cetuximab and panitumumab in colorectal cancer cells harboring EGFR extracellular domain mutations
Authors: Arena Sabrina , Siravegna Giulia , Mussolin Benedetta , Kearns Jeffrey D. , Wolf Beni B. , Misale Sandra , Lazzari Luca , Bertotti Andrea , Trusolino Livio , Adjei Alex A. , Montagut Clara , Di Nicolantonio Federica , Nering Rachel , Bardelli Alberto
Published: May 2016

Cetuximab and panitumumab are monoclonal anti-EGFR antibodies (moAbs) currently used for the treatment of ‘RAS’ wild type colorectal cancers (CRC). Development of acquired resistance almost invariably limits the efficacy of these agents. At relapse, about 20% of tumors treated with cetuximab and panitumumab carry EGFR extracellular domain (ECD) mutations (S492R, R451C, S464L, G465R, G465E, K467T, I491M), which impair antibody binding. We postulated that mCRC patients who become resistant to cetuximab or panitumumab due to the emergence of EGFR ECD mutations may still benefit from further line of treatment with EGFR blockade. We observed that the EGFR ECD variants are effectively targeted by the oligoclonal anti-EGFR antibody MM-151. MM-151 inhibits EGFR signaling and cell growth in preclinical models, including patient-derived cells carrying mutant EGFR.

We have analyzed liquid biopsies of 11 CRC patients that developed resistance to previous treatment with cetuximab and were then enrolled in the first MM-151 phase I study. Longitudinal profiling of circulating cell-free tumor DNA (ctDNA) samples collected during MM-151 treatment revealed a decrease of EGFR ECD mutant levels that paralleled the response as measured by radiological methods.In conclusion, we provide mechanistic evidence for the efficacy and use of MM-151 as a therapeutic opportunity for patients whose tumors develop EGFR ECD mutations as the prevalent mechanism of acquired resistance to cetuximab or panitumumab treatment.

Citation Format: Sabrina Arena, Giulia Siravegna, Benedetta Mussolin, Jeffrey D. Kearns, Beni B. Wolf, Sandra Misale, Luca Lazzari, Andrea Bertotti, Livio Trusolino, Alex A. Adjei, Clara Montagut, Federica Di Nicolantonio, Rachel Nering, Alberto Bardelli. MM-151 overcomes acquired resistance to cetuximab and panitumumab in colorectal cancer cells harboring EGFR extracellular domain mutations. [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-B05.
Abstract LB-B21: BI-69A11 inhibits Epithelial to Mesenchymal Transition exploiting β-catenin pathway in colon carcinoma
Authors: Pal Ipsita , Mandal Mahitosh
Published: May 2016

EMT is a potential biological phenomena required for metastatic dissemination. Although targeting EMT for therapeutic implication has been gaining interest to the scientific community, only few molecules have succeeded to employ their anti-metastatic effect so far. BI-69A11 has been earlier proved for its anti-tumor activity in prostate and colon carcinoma. This study aims to elucidate the biological consequence of BI-69A11 on EMT in colon carcinoma in vitro and in vivo. Our findings showed that BI-69A11 increased epithelial signature marker E-cadherin and reciprocally decreased the mesenchymal markers snail, slug and vimentin. Moreover, cellular migration, invasion and adhesion were potentially hampered by BI-69A11 through β-catenin dependent pathway. The underlying molecular mechanism behind BI-69A11 induced inhibition of EMT includes suppression of nuclear transport of β-catenin, diminished phosphorylation of β-catenin accompanied with enhanced E-cadherin- β-catenin complex formation at the membrane. Moreover, BI-69A11 controlled the transcriptional activity and reversed nuclear translocation by decrease in the phosphorylation at ser552 and ser45/Thr41 residue. The growing interaction between E-cadherin and β-catenin complex also promoted the E-cadherin transcription leading to the reversal of EMT. BI-69A11 caused increasing accumulation of vinculin in the membrane that in turn strengthened the focal adhesion junction leading to the inhibition of metastasis. Overall, these evidences present a thoughtful insight towards underlying molecular mechanism of BI-69A11 induced reversal of EMT in colorecteal carcinoma in vitro and in vivo.

Citation Format: Ipsita Pal, Mahitosh Mandal. BI-69A11 inhibits Epithelial to Mesenchymal Transition exploiting β-catenin pathway in colon carcinoma. [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-B21.
Abstract LB-C01: Patient-derived tumor xenografts in humanized NSG-SGM3 mice: A new immuno-oncology platform
Authors: Yao Li-Chin , Cheng Mingshan , Wang Minan , Banchereau Jacques , Shultz Leonard , Palucka Karolina , Keck James G.
Published: May 2016

Humanized mice engrafted with tumors enable in vivo investigation of the interactions between the human immune system and human cancer. We have recently found that humanized NOD-scid IL2Rγnull (NSG) mice bearing patient-derived xenografts (PDX) allow efficacy studies of check-point inhibitors. Next generation NSG strains include triple transgenic NSG mice expressing human cytokines KITLG, CSF2, and IL-3 (NSG-SGM3). Here we provide a direct comparison of check-point inhibitors evaluation in NSG and NSG-SGM3 mice engrafted with CD34+ human hematopoietic progenitor cells (HPCs) from the same donor and implanted with PDX tumors. Corroborating earlier studies, reconstitution of human immune system in the blood was faster and more robust in NSG-SGM3 compared to NSG recipients throughout the course of the study (18 weeks). Human CD45+ cells reached 25% of total blood cells at week 4 in hu-NSG-SGM3 mice and at week 9 in hu-NSG mice. A majority of blood hCD45+ cells in hu-NSG-SGM3 at week 4 were CD33+ myeloid cells. Circulating hCD3+ T cells reached 10% at week 9 and included regulatory T cells (Tregs), consistent with earlier studies. Hu-NSG mice displayed comparable hCD3+ T cells in the blood only at 12-15 weeks and did not contain Tregs. PDX tumors were then engrafted into partially HLA-matched hu-NSG-SGM3 mice at 9 weeks post engraftment. Two PDX models previously shown to respond to anti-PD1 therapy in hu-NSG mice, BR1126 and LG1306, were used. Treatment with the anti-PD-1 receptor antibody pembrolizumab (Keytruda) significantly reduced tumor growth in both models. Thus, PDX-bearing hu-NSG-SGM3 mice might serve as a new and improved platform for preclinical immuno-oncology efficacy studies.

Citation Format: Li-Chin Yao, Mingshan Cheng, Minan Wang, Jacques Banchereau, Leonard Shultz, Karolina Palucka, James G. Keck. Patient-derived tumor xenografts in humanized NSG-SGM3 mice: A new immuno-oncology platform. [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-C01.
Abstract LB-C03: Lovastatin induced anti-proliferation through multi-pathways in human intrahepatic cholangiocarcinoma
Authors: Yang Yu-Chen , Lin Hung-Yun
Published: May 2016

Lovastatin induced anti-proliferation through multi-pathways in human intrahepatic cholangiocarcinoma.

Yu-Chen Yang1, Hung-Yun Lin1, Chun A Changou1,2,3, Chun-Han Chen1, Yun-Ru Liu4, Jinghan Wang5, Xiaoqing Jiang5, Yun Yen1*

1PhD Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.2Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan.3Core Facility, Taipei Medical University, Taipei, Taiwan. 4Office of Human Research, Taipei Medical University, Taipei, Taiwan and 5The First Department of Biliary Surgery, Eastern Hepatobiliary Surgical Hospital, Second Military Medical University, Shanghai, China.

Abstract

Human intrahepatic cholangiocarcinomas are one of the most difficult cancers to treat. Lovastatin, a 3-hydroxy-3-methylglutaryl-coenzyme-CoA (HMG-CoA) reductase inhibitor, exhibits anticancer properties. In this study, lovastatin inhibited cell proliferation, cell migration and cell adhesion. Results showed lovastatin inhibited the gene expressions of integrin β1 and integrin β3 but not integrin αv or integrin β5. Furthermore, gene expressions of transforming growth factor (TGF)-β1, cyclooxygenase (COX)-2 and intercellular adhesion molecule (ICAM)-1 were inhibited by lovastatin. Also, the cholesterol-depleting agent, methyl-beta-cyclodextrin (MβCD), reduced the expression of β3 integrin, but not that of the other genes in either cancer cell line. The lovastatin-induced inhibitory effects on expressions of TGFβ1, COX2, and ICAM-1 were positively controlled by the tumor suppressor, LKB1; however, the inhibition of integrin β3 by lovastatin was negatively affected by LKB1. The inhibitory effect of lovastatin on cell adhesion was associated with decreased expression of integrin β3 and the presentation of cell surface heterodimer integrin αvβ3. Furthermore, lovastatin strongly inhibited integrin αvβ3 downstream FAK activation, and the expression of β-catenin, vimentin, ZO-1, and β-actin. Therefore, in addition to the cholesterol-depleting effect, lovastatin modified the expressions of cell adhesion molecules leading to reduced tumor cell proliferation and migration. These advantageous effects of lovastatin may be mediated by blocking integrin β3 signaling suggesting a novel treatment option for cholangiocarcinomas.

Keywords: Bile duct cancer, HMG-CoA reductase inhibitor, Integrin, LKB1, TGF-β1

Citation Format: Yu-Chen Yang, Hung-Yun Lin. Lovastatin induced anti-proliferation through multi-pathways in human intrahepatic cholangiocarcinoma. [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-C03.
Abstract LB-C24: Resistance to ALK inhibition is associated with enhanced BRD4 dependence in ALK-mutated MYCN-amplified neuroblastoma
Authors: Debruyne David , Sharma Bandana , Gray Nathanael , George Rani
Published: May 2016

Despite substantial therapeutic advances, the long-term survival rate of patients with high-risk neuroblastoma (NB), a tumor of the peripheral sympathetic nervous system is still dismal. Activating mutations in the anaplastic lymphoma kinase (ALK) receptor tyrosine kinase represent promising therapeutic targets in this disease and have prompted clinical trials of ALK inhibitors. But as with all molecularly targeted therapies, resistance is inevitable and will limit the ultimate utility of this therapeutic strategy. To elucidate the mechanisms of resistance to ALK inhibitors, we have generated isogenic NB cells, expressing the tumorigenic ALKF1174L mutation and amplified MYCN, with acquired resistance to the ALK inhibitor TAE684, through continuous exposure of increasing concentrations of the compound over time. We found that resistance was associated with downregulation of ALK activity, thus ruling out secondary mutations as a mechanism of resistance, and interestingly the other major oncogenic driver in neuroblastoma, MYCN, was downregulated as well. A comparative genome-wide expression analysis revealed global transcriptional downregulation in the resistant cells, as compared with their parental sensitive counterparts, in accordance with the aforementioned MYCN downregulation, as MYCN is known to act as a transcriptional amplifier in MYCN-amplified NB cells. Additionally, these resistant cells exhibited a 10-fold increased sensitivity to the BRD4 inhibitor JQ1, compared to sensitive cells, and MYCN as well as global gene expression were rescued after treatment. These results strongly suggest that resistance to ALK inhibition in ALKF1174L MYCN-amplified NB cells leads to a MYCN-independent enhanced BRD4 dependence, therefore providing a rationale for the use of BET inhibitors to overcome such resistance. Studies are currently underway to characterize the unique epigenetic landscape driving the resistant cells' survival and therefore identify novel targets that could be taken advantage of in future therapeutic strategies.

Citation Format: David Debruyne, Bandana Sharma, Nathanael Gray, Rani George. Resistance to ALK inhibition is associated with enhanced BRD4 dependence in ALK-mutated MYCN-amplified neuroblastoma. [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-C24.
Abstract PL03-05: Drugging RAS into oblivion
Authors: Verdine Gregory L.
Published: May 2016

The two major oncogenic drivers of human cancer, RAS and MYC, have thus far proven recalcitrant toward therapeutic targeting by any small-molecule agent. WarpDrive Bio has pioneered a potentially transformational solution toward drugging such recalcitrant oncogenic drivers using multiple independently acting agents. The company's proprietary new targeting technology, the Small Molecule-Assisted Receptor Targeting modality (SMART modalityTM), has enabled WarpDrive Bio to make significant progress toward the development of multiple agents that independently target RAS in the GTP and GDP states, respectively, and that are either selective for particular mutations or engage the effector surface and are expected to function as pan-RAS antagonists. Our strategy of targeting RAS using multiple agents, each of which engages the protein in a unique way, is ultimately intended to increase the durability of patient responses to anti-RAS therapy by decreasing the probability of mutational escape. Progress toward our ultimate goal of drugging RAS-driven cancers into oblivion via RAS-directed polypharmacy will be reviewed in this talk.

Citation Format: Gregory L. Verdine. Drugging RAS into oblivion. [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 PL03-05.
Abstract PL05-04: PARP trapping versus PARP catalytic inhibition and coupling with TDP1
Authors: Pommier Yves G. , Murai Junko
Published: May 2016

The five clinical PARP inhibitors (veliparib, olaparib, niraparib, rucaparib and talazoparib) are potent submicromolar competitive NAD+ inhibitors for PARP1 and PARP2, thereby blocking PARylation reactions [i.e. formation of poly(ADPribose) polymers]. In addition, PARP trapping, which determines the anticancer activity of PARP inhibitor as single agents, is drug-specific, and PARP inhibitors can be ranked according to their PARP trapping potency: talazoparib >> niraparib ≈ olaparib ≈ rucaparib > veliparib. We will review evidence that PARP trapping is the primary cytotoxic mechanism of PARP inhibitors as single agents and that cancer-specific DNA repair alterations as well as SLFN11 expression determine the cytotoxicity of trapped PARP-DNA complexes in cancers beyond BRCA inactivation. Used in combination in cellular models, PARP inhibitors are highly synergistic with alkylating agent (temozolomide or methyl methanesulfonate) and topoisomerase I (Top1) inhibitors (camptothecin and its clinical derivatives (topotecan and irinotecan) and the non-camptothecin indenoisoquinoline Top1 inhibitors in clinical development (LMP400, LMP776 and LMP744). Both alkylating agents and Top1 inhibitors induce DNA single-strand breaks sensed by PARP. Yet, the molecular mechanisms of synergy are different. For alkylating agents (temozolomide and MMS), both PARP trapping and PARylation inhibition account for the synergy, whereas for Top1 inhibitors, there is no involvement of PARP trapping and it is PARylation inhibition that deters the coupling of PARP with the repair enzyme, tyrosyl-DNA phosphodiesterase, TDP1. We will review the molecular pharmacology differences between PARP inhibitors as single agents and the rationale for choosing among different PARP inhibitors in combination with alkylating agents or Top1 inhibitors based on trapping vs. catalytic inhibition.

Citation Format: Yves G. Pommier, Junko Murai. PARP trapping versus PARP catalytic inhibition and coupling with TDP1. [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 PL05-04.
Abstract PR04: Comprehensive analyses of tumor immunity with implications to cancer immunotherapies
Authors: Li Bo
Published: May 2016

Recent breakthrough in checkpoint blockade drugs achieved remarkable success in treating late stage tumors, although a substantial fraction of patients failed to respond. Despite growing efforts, the clinical and molecular prognostic predictors of immunotherapy response remain elusive. We developed a novel computational method to deconvolute six tumor-infiltrating immune cells from the molecular profiles of over 10,000 samples across 23 cancer types, and validated the estimates using simulations, orthogonal estimates, and pathology. Correlating the computationally-inferred immune infiltrates with patient clinical features, viral infection status, and cancer genetic alterations, we discovered associations not only extensively supported by previous studies, but also novel ones such as B cell infiltration with better outcome in glioblastoma. Analysis of cancer/testis antigen expression and CD8 T-cell abundance suggested that MAGEA3 is potentially effective in melanoma but not in NSCLC, and implicated CALR3 and SPAG5 as alternative cancer vaccine targets. We also observed PD-1 and CTLA4 expression to be associated with CD8 T-cell abundance in most cancers, supporting combined use of checkpoint blockade drugs. Finally, we found that melanomas expressing high levels of CTLA4 showed two distinct levels of CD8 T-cell infiltration, which may influence clinical responses to anti-CTLA4 agents. Taken together, our systematic analyses of tumor immunity have the potential to inform effective cancer vaccines and checkpoint blockade therapies.

Citation Format: Bo Li. Comprehensive analyses of tumor immunity with implications to cancer 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 PR04.