bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract DDT01-01: PT2385: First-in-class HIF-2α antagonist for the treatment of renal cell carcinoma
Authors: Wallace Eli M. , Cao Zhaodan , Cheng Tzuling , Czerwinski Robert , Dixon Darryl D. , Du Xinlin , Goggin Barry , Grina Jonas , Halfmann Megan , Han Guangzhou , Huang Heli , Josey John A. , Maddie Melissa A. , Olive Sarah , Rizzi James , Schlachter Stephen T. , Tan Hui-Ling , Wang Bin , Wang Keshi , Wehn Paul M. , Xie Shanhai , Xu Rui , Yang Hanbiao
Published: August 2015

Hypoxia-inducible factors (HIFs), including HIF-1α and HIF-2α, are transcription factors that mediate cellular response to changes of oxygen supply. These proteins become stabilized under hypoxia and subsequently activate the expression of genes to facilitate cell survival and proliferation. HIF proteins are activated in many types of cancers due to the tumor hypoxic microenvironment and have been implicated in cancer initiation, progression and metastasis. The oncogenic role of HIF-2α is pertinent in clear cell renal carcinoma (ccRCC). In the majority of ccRCC tumors, the von Hippel-Lindau protein (VHL) that targets HIF-2α for degradation is inactivated, leading to the accumulation of HIF-2α and the activation of genes that drive kidney cancer tumorigenesis. We have identified small molecules that bind to the PAS-B domain of HIF-2α protein and block it's dimerization with ARNT (aryl hydrocarbon receptor nuclear translocator, HIF-1β), a prerequisite for its transcriptional activities. Specifically, we describe PT2385, a selective, orally active HIF-2α antagonist with potent anti-cancer activity in mouse models of ccRCC. PT2385 is currently under evaluation in Phase I clinical trials for the treatment of ccRCC.

Citation Format: Eli M. Wallace, Zhaodan Cao, Tzuling Cheng, Robert Czerwinski, Darryl D. Dixon, Xinlin Du, Barry Goggin, Jonas Grina, Megan Halfmann, Guangzhou Han, Heli Huang, John A. Josey, Melissa A. Maddie, Sarah Olive, James Rizzi, Stephen T. Schlachter, Hui-Ling Tan, Bin Wang, Keshi Wang, Paul M. Wehn, Shanhai Xie, Rui Xu, Hanbiao Yang. PT2385: First-in-class HIF-2α antagonist for the treatment of renal cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr DDT01-01. doi:10.1158/1538-7445.AM2015-DDT01-01
Abstract LB-033: FAK promotes the Wnt/β-catenin pathway and intestinal tumorigenesis by phosphorylating GSK3ββ
Authors: Gao Chenxi , Chen Guangming , Kuan Shih-Fan , Zhang Dennis H. , Hu Jing
Published: August 2015

Aberrant activation of Wnt/β-catenin signaling plays an unequivocal role in colorectal cancer (CRC), but identification of effective Wnt inhibitors for use in cancer remains a tremendous challenge. New insights into the regulation of this pathway could reveal new therapeutic point of intervention, therefore are greatly needed. Glycogen synthase kinase 3β(GSK3β) is a major component of the Wnt/β-catenin pathway, how GSK3β is regulated in Wnt signaling and tumorigenesis remains largely unknown. This study investigated the function and regulation of GSK3β phosphorylation in Wnt/β-catenin signaling and Wnt-driven intestinal tumorigenesis. The function of GSK3β phosphorylation at tyrosine 216 (Y216) in Wnt/-catenin signaling and CRC cells was analyzed by a series of biochemistry experiments and anchorage independent growth assays. Phosphorylation of GSK3βY216 by focal adhesion kinas (FAK) was studied in in vitro reconstitution system and in cells. The role of FAK-mediated phosphorylation of GSK3βY216 was tested by examining adenoma formation and associated molecular changes in control and FAK inhibitor-treated APCmin/+ mice. Immunohistochemistry was used to evaluate the expression levels of FAK, p-GSK3βY216 and β-catenin in CRC patients. Our results showed that GSK3βY216 phosphorylation was required for the activation of the Wnt/β-catenin pathway. Pharmacological inhibition of FAK suppressed adenoma formation in APCmin/+ mice accompanied by reduced intestinal levels of p-GSK3βY216 and β-catenin. FAK, p-GSK3βY216 and β-catenin were elevated and positively correlated in human CRC tissues. Together, our findings indicate that FAK/GSK3βY216 axis is critical for the activation of Wnt/β-catenin signaling in APC-driven intestinal tumorigenesis, thus providing a compelling mechanistic justification for clinical exploration of FAK inhibitors in colorectal cancer patients carrying APC mutations.

Citation Format: Chenxi Gao, Guangming Chen, Shih-Fan Kuan, Dennis H. Zhang, Jing Hu. FAK promotes the Wnt/β-catenin pathway and intestinal tumorigenesis by phosphorylating GSK3ββ. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-033. doi:10.1158/1538-7445.AM2015-LB-033
Abstract LB-082: FLJ25439, a novel cytokinesis-associated protein, induces tetraploidization and maintains chromosomal stability via enhancing expression of endoplasmic reticulum stress chaperones
Authors: Ouyang Pin
Published: August 2015

Purpose of the study: Identify and characterize a novel D box-containing protein, FLJ25439 for tetraploid induction and maintenance of genomic stability.

Pertinent experimental procedures: Immunofluorescent microscopy and flow cytometry for cell cycle determination. Proteomics and bioinformatics approaches for protein category profiling.

Summary of the data: Investigation of the mechanisms leading to aneuploidy and polyploidy is critical to cancer research. Previous studies have provided strong evidence of the importance of tetraploidization as an early step in tumorigenesis. In cancer cells, tetraploid cells may contribute to abnormal mitotic progression, which may be associated with cytokinesis failure. Tetraploidy leads to genomic instability due to centrosome and chromosome over-replication. Until now, the mechanism by which cells maintain tetraploid status has been unknown. Here, we identified a novel D box-containing protein, FLJ25439, which displays a dynamic expression profile during mitosis/cytokinesis with the midbody as the most prominent associated structure. To understand the function of FLJ25439, we established stable cell lines overexpressing FLJ25439. FLJ25439-overexpression cells grew slower and displayed a tetraploid DNA content in comparison with diploid parental cells. They also showed aberrant mitosis and dysregulated expression of p53, pRb and p21, suggesting a defect in cell cycle progression. To explore the molecular mechanisms responsible for FLJ25439-induced tetraploidization, we conducted a comparative analysis of the global protein expression patterns of wild type and overexpressors using proteomics and bioinformatics approaches. Protein category profiling indicated that FLJ25439 is involved in pathways related to anti-apoptosis, protein folding, the cell cycle, and cytoskeleton regulation. Specifically, genotoxic-stress- and ER stress-related chaperone proteins greatly contributed to the FLJ25439 overexpression phenotypes.

Conclusion: The results of this study pave the way to our further understanding of the role of FLJ25439, a novel cytokinesis-related protein in protecting cells from environmental stress and tetraploid formation.

Note: This abstract was not presented at the meeting.

Citation Format: Pin Ouyang. FLJ25439, a novel cytokinesis-associated protein, induces tetraploidization and maintains chromosomal stability via enhancing expression of endoplasmic reticulum stress chaperones. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-082. doi:10.1158/1538-7445.AM2015-LB-082
Abstract LB-087: A facilitative role for caspase 3 in promoting genetic instability and carcinogenesis
Authors: LIU XINJIAN , Li Fang , Li Chuan-yuan
Published: August 2015

Apoptosis and apoptotic caspases are generally considered tumor-suppressive since there are involved in the elimination of unwanted or damaged cells. However, the relationship between caspases and carcinogenesis has not been thoroughly examined. In this study, we sought to determine the role of caspase 3 in chemical- and radiation-induced genetic instability and carcinogenesis. By use of a non-invasive caspase 3 reporter, we found that that a significant fraction of mammalian cells treated with ionizing radiation could survive, despite caspase 3 activation. Moreover, this sublethal activation of caspase 3 promoted persistent DNA damage, chromosome aberrations and oncogenic transformation. In addition, chemically-induced skin carcinogenesis was significantly reduced in mice genetically deficient in caspase 3. We provided strong evidence that activated caspase 3 can indeed promote oncogenic transformation in human cells and in mice by inducing persistent genetic instability. Since a wide array of environmental and endogenous stressors can trigger caspase 3 activation, our findings suggest that rather than acting as a broad inhibitor of carcinogenesis, caspase 3 activation may contribute to genome instability and play a pivotal role in tumor formation following damage.

Citation Format: XINJIAN LIU, Fang Li, Chuan-yuan Li. A facilitative role for caspase 3 in promoting genetic instability and carcinogenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-087. doi:10.1158/1538-7445.AM2015-LB-087
Abstract LB-088: Ptch1 heterozygosity predisposes mice to developing IR-induced BCCs
Authors: Wang Grace Y. , Libove Eileen , Tucker Danielle , Epstein Ervin
Published: August 2015

Basal cells nevus syndrome (BCNS, Gorlin syndrome) patients carry heterozygous germline mutations in PATCHED1 (PTCH1) gene, which encodes a receptor of hedgehog (HH) ligands and represses HH signaling in the absence of ligands. Mutated PTCH1 leads to aberrant activation of the HH signaling pathway, which is the pivotal driver underlying BCC carcinogenesis in both sporadic and BCNS BCCs. BCNS (PTCH1+/-) individuals are very susceptible to developing more BCCs at an earlier age but the mechanism for this genetic predisposition to BCCs remains elusive. In this study, we assessed how heterozygosity of the murine Ptch1 gene contributes to IR-induced BCC carcinogenesis.

Specifically, we treated Ptch1fl/+ K14CreER2 mice with tamoxifen either at age 4 weeks (group A) or at 9 weeks (group B) to delete one copy of Ptch1 in K14-expressing keratinocytes. We irradiated both groups of mice with IR at mouse age 8 weeks so that at the time of IR, keratinocytes in group A mice, like those in BCNS patients, were Ptch1+/-, and mice in group B remained Ptch1+/+ but subsequent to recovery from acute damage all mice had Ptch1+/- keratinocytes. We found that mice in both groups developed similar amounts of microscopic BCCs at age either 7- or 9-months. However, only mice of group A (3 out of 13 mice) developed visible BCCs; none of the mice of group B (n = 30) developed visible BCCs by age 18-months, the longest time point monitored based on our studies of Ptch1+/- mice. The difference is statistically significant (p = 0.03). Histologically, these visible BCCs closely resemble human BCCs. This finding indicates (i) that heterozygosity of the Ptch1 gene limited to keratinocytes (without gene deletion in stromal cells) is sufficient to produce susceptibility to IR-induced visible BCC development and (ii) surprisingly that heterozygosity of the Ptch1 gene during acute mutagenic damage dramatically increases eventual conversion of microscopic to visible BCCs, probably by affecting acute repair of this damage. To gain further insights into this possible mechanism, we are culturing keratinocytes from these mice and performing cell cycle and apoptosis analysis upon IR treatment in vitro.

Citation Format: Grace Y. Wang, Eileen Libove, Danielle Tucker, Ervin Epstein. Ptch1 heterozygosity predisposes mice to developing IR-induced BCCs. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-088. doi:10.1158/1538-7445.AM2015-LB-088
Abstract LB-092: Programmed death-ligand 1 is overexpressed in bronchial preneoplastic lesions: can it be a risk indicator
Authors: Park Hee Sun , Park Bo Mi , Park Dong Il , Uk Chung Jae , Moon Jae Young , Soo Jung Sung , Lee Choong Sik , Kim Ju Ock , Kim Sun Young , Koo Jaseok Peter
Published: August 2015

Compared to the vigorous development of targeted drugs and some of them are already become one of the best treatment of choices in lung adenocarcinoma, squamous lung carcinoma has no definite targets and treatment outcome is not yet superior to lung adenocarcinoma. Demonstration of initial carcinogenesis is benefitial in two aspects: cancer prevention and development of its targets. Studying preneoplastic lesions of bronchus can answer those questions. Preneoplastic lesion, which is considered to have malignant potential, may develop into invasive cancer by escaping from host immune response. CD274 (programmed death-ligand 1, PD-L1) interacts with PD-1, is known to inhibit CD8+ cytotoxic T lymphocyte and induce apoptosis and, also to promote the differentiation of CD4+ T cells into regulatory T cells, so finally evade immune surveillance. We hypothesized that PD-L1 may work as an immune evader in preneoplastic lesion during its carcinogenesis. We performed white light and/or autofluorescence bronchoscopy in patients who have risk factor(s) of lung cancer or are suspected to have a lung cancer. Interestingly, PD-L1 was also overexpressed in preneoplastic lesions especially in severe dysplasia of the bronchus. This finding implies overexpression of PD-L1 can involve at early step of carcinogenesis. Further studies are needed to demonstrate the role of PD-L1 in preneoplastic bronchial lesion potential to develop invasive cancer.

Citation Format: Hee Sun Park, Bo Mi Park, Dong Il Park, Chung Jae Uk, Jae Young Moon, Jung Sung Soo, Choong Sik Lee, Ju Ock Kim, Sun Young Kim, Jaseok Peter Koo. Programmed death-ligand 1 is overexpressed in bronchial preneoplastic lesions: can it be a risk indicator. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-092. doi:10.1158/1538-7445.AM2015-LB-092
Abstract LB-094: Regorafenib and sildenafil interact to kill tumor cells
Authors: Tavallai Mehrad , Booth Laurence , Roberts Jane L. , Poklepovic Andrew , Dent Paul
Published: August 2015

The present studies were to determine whether the multi-kinase inhibitor sorafenib or its derivative regorafenib interacted with phosphodiesterase 5 (PDE5) inhibitors such as sildenafil (Viagra) to kill tumor cells. PDE5 and PDGFR (alpha and beta) were over-expressed in liver tumors compared to normal liver tissue. In multiple cell types in vitro sorafenib/regorafenib and PDE5 inhibitors interacted in a greater than additive fashion to cause tumor cell death. Knock down of PDE5 or of PDGFR (alpha and beta) recapitulated the effects of the individual drugs. The drug combination increased ROS/RNS levels that were causal in cell killing. RNS stimulated the activation of the death receptor CD95 as well as the formation of autophagosomes and autolysosomes. Inhibition of CD95 / FADD / caspase 8 signaling suppressed drug combination toxicity. Knock down of ULK-1, Beclin1 or ATG5 suppressed drug combination lethality. The drug combination inactivated ERK, AKT, p70 S6K and mTOR and activated JNK. The drug combination also reduced mTOR protein expression. Activation of ERK or AKT was modestly protective whereas re-expression of an activated mTOR protein or inhibition of JNK signaling almost abolished drug combination toxicity. Sildenafil and sorafenib / regorafenib interacted in vivo to suppress xenograft tumor growth using liver and colon cancer cells. PDE5 inhibitors and sorafenib / regorafenib are FDA approved agents, and our data is now being translated into the clinic for further determination as to whether this drug combination is a useful anti-tumor therapy for solid tumor patients.

Citation Format: Mehrad Tavallai, Laurence Booth, Jane L. Roberts, Andrew Poklepovic, Paul Dent. Regorafenib and sildenafil interact to kill tumor cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-094. doi:10.1158/1538-7445.AM2015-LB-094
Abstract LB-095: Distribution and clearance of single-walled carbon nanotubes in mouse tissues: in situ detection, imaging and analysis
Authors: Barlas Afsar , Xu Ke , Romin Yevgeniy , Alidori Simone , Yarilin Dmitry , Fan Ning , Turkekul Mesruh , Fujisawa Sho , Scheinberg David A. , McDevitt Michael R. , Manova-Todorova Katia
Published: August 2015

Single-walled carbon nanotubes (SWCNT) are the subject of expanding research in the fields of targeted drug delivery and biosensors for disease treatment and monitoring. Functionalization of the SWCNT has proven to enhance the efficiency of distribution in the organism. The goal of this project was to establish and standardize methods of detection and characterization of the local tissue distribution of functionalized SWCNT in mouse models. We investigated the distribution and clearance of SWCNT in several tissues at various times after injection, up to one month. We also try to standardize methods of tracking SWCNT in both live and fixed tissues and image analysis protocols to quantify the distribution of the SWCNT in tissues. Another aim is to evaluate local immune response to SWCNT. We have analyzed liver, kidney, spleen, lung, brain, ovary, colon and small intestine from mice sacrificed 24 hours, 3 days, 7 days and 30 days following the injection of SWCNT. Our evaluation revealed that some organs, like kidney and small intestine, retain SWCNTs for at least a month. Slow rates of SWCNT removal from these organs do not appear to affect the overall health of the animals. We have made multiple attempts to image anesthetized live animals and detect SWCNTs in situ, however, the fluorescent signal emitted from SWCNT is too low to be reliably detected. The tissues must be fixed and signals amplified through immunodetection. Detection of immune markers, especially in immunologically active tissues such as spleen is a challenge for histological experiments, but is extremely important and such experiments is underway. Our findings of SWCNT persistence in certain organs 30 days post-injection is surprising and should be studied further. This observation opens further questions about the effect of long-term presence of SWCNT in some tissues and shows that careful investigation into the advantages and disadvantages of SWCNT retention is necessary.

Citation Format: Afsar Barlas, Ke Xu, Yevgeniy Romin, Simone Alidori, Dmitry Yarilin, Ning Fan, Mesruh Turkekul, Sho Fujisawa, David A. Scheinberg, Michael R. McDevitt, Katia Manova-Todorova. Distribution and clearance of single-walled carbon nanotubes in mouse tissues: in situ detection, imaging and analysis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-095. doi:10.1158/1538-7445.AM2015-LB-095
Abstract LB-097: Targeted degradation of the androgen receptor in prostate cancer
Authors: Jin Meizhong , Winkler James D. , Coleman Kevin , Crew Andrew P. , Rossi AnnMarie K. , Willard Ryan R. , Dong Hanqing , Siu Kam , Wang Jing , Gordon Deborah A. , Chen Xin , Ferraro Caterina , Crews Craig M. , Neklesa Taavi K.
Published: August 2015

Progression of prostate cancer in patients treated with anti-androgen therapy usually involves several mechanisms of enhanced Androgen Receptor (AR) signaling, including increased intratumoral androgen synthesis, increased AR expression and AR mutations. We have developed a protein degradation technology called PROTACs (PROteolysis TArgeting Chimera), which uses bi-functional molecules that simultaneously bind a target of choice and an E3 ligase. PROTACs, via induced proximity, cause ubiquitination and degradation of the targeted, pathological protein. As opposed to traditional target inhibition, which is a competitive process, degradation is a progressive process. As such, it is less susceptible to increases in endogenous ligand, target expression, or mutations in the target. Thus this technology seems ideal for addressing the mechanisms of AR resistance in patients with prostate cancer.

AR PROTACs were shown to degrade AR in LNCaP and VCaP cells, with low nM to pM potency, and had a >85% reduction in AR concentration (Dmax). Degradation was rapid, with 50% of AR lost within 15 minutes and maximal degradation observed by 4 hours. The degradation process in cells was specific, as the PROTAC activity can be competed with excess E3 ligand and PROTACs with an inactive epimer for E3 ligase binding did not degrade AR. AR PROTACs induced rapid apoptosis and cell death in VCaP cells. In LNCap and VCaP cell systems, AR PROTACs were anti-proliferative under conditions in which enzalutamide was inactive, such as increasing concentrations of the AR agonist R1881 and cells containing the ARF876L mutation. AR PROTACs typically exhibited good pharmacokinetic properties, with t1/2 values of several hours and bioavailability of >50% after ip or sc injection. In mice, AR PROTACs demonstrate in vivo activity, including reduction of AR protein levels, prostate involution and tumor growth inhibition.

In summary, PROTACs designed to degrade AR are potent, specific, active in vitro and in vivo, and have cellular efficacy superior to enzalutamide. Targeted degradation of AR may provide a novel mechanism for providing efficacious therapy for patients with prostate cancer for whom current therapies have failed.

Citation Format: Meizhong Jin, James D. Winkler, Kevin Coleman, Andrew P. Crew, AnnMarie K. Rossi, Ryan R. Willard, Hanqing Dong, Kam Siu, Jing Wang, Deborah A. Gordon, Xin Chen, Caterina Ferraro, Craig M. Crews, Taavi K. Neklesa. Targeted degradation of the androgen receptor in prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-097. doi:10.1158/1538-7445.AM2015-LB-097
Abstract LB-129: Identifying tumor subpopulations and the functional consequences of intratumor heterogeneity using single-cell profiling of breast cancer patient-derived xenografts
Authors: Savage Paul , Saleh Sadiq M. , Iacucci Ernesto , Revil Timothe , Wang Yu-Chang , Bertos Nicholas , Monast Anie , Zhao Hong , Souleimanova Margarita , Szulwach Keith , Batchu Chandana , Omeroglu Atilla , Park Morag , Ragoussis Ioannis
Published: August 2015

Human breast tumors have been shown to exhibit extensive inter- and intra-tumor heterogeneity. While recent advances in genomic technologies have allowed us to deconvolute this heterogeneity, few studies have addressed the functional consequences of diversity within tumor populations. Here, we identified an index case for which we have derived a patient-derived xenograft (PDX) as a renewable tissue source to identify subpopulations and perform functional assays. On pathology, the tumor was an invasive ductal carcinoma which was hormone receptor-negative, HER2-positive (IHC 2+, FISH average HER2/CEP17 2.4), though the FISH signal was noted to be heterogeneous. On gene expression profiling of bulk samples, the primary tumor and PDX were classified as basal-like. We performed single cell RNA and exome sequencing of the PDX to identify population structure. Using a single sample predictor of breast cancer subtype, we have identified single basal-like, HER2-enriched and normal-like cells co-existing within the PDX tumor. Genes differentially expressed between these subpopulations are involved in proliferation and differentiation. Functional studies distinguishing these subpopulations are ongoing. Microfluidic whole genome amplification followed by whole exome capture of 81 single cells showed high and homogeneous target enrichment with >75% of reads mapping uniquely on target. Variant calling using GATK and Samtools revealed founder mutations in key genes as BRCA1 and TP53, as well as subclonal mutations that are being investigated further. Loss of heterozygocity was observed in 16 TCGA cancer driver genes and novel mutations in 7 cancer driver genes. These findings may be important in understanding the functional consequences of intra-tumor heterogeneity with respect to clinically important phenotypes such as invasion, metastasis and drug-resistance.

Citation Format: Paul Savage, Sadiq M. Saleh, Ernesto Iacucci, Timothe Revil, Yu-Chang Wang, Nicholas Bertos, Anie Monast, Hong Zhao, Margarita Souleimanova, Keith Szulwach, Chandana Batchu, Atilla Omeroglu, Morag Park, Ioannis Ragoussis. Identifying tumor subpopulations and the functional consequences of intratumor heterogeneity using single-cell profiling of breast cancer patient-derived xenografts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-129. doi:10.1158/1538-7445.AM2015-LB-129
Abstract LB-138: Use of cerebral organoids to model pediatric gliomas with H3.3K27M and H3.3G34R
Authors: Ismail Amin
Published: August 2015

Glioblastoma (GBM) is the most devastating brain cancer with dismal prognosis both in adults and children and accounts for 16% of primary brain tumors. Despite aggressive therapeutic approaches, the majority of patients die within one year after diagnosis. Giving the limitation of current GBM mouse models, which do not reflect the biological properties of human tumors, in particular, tumor heterogeneity and pathogenesis, there is a growing need for new models. Current in vitro 3D models involve the use of hydrogel scaffolds and cell lines, which do not represent a viable developmental context where the tumor mass interacts with and invades the surrounding brain tissues. Starting with pluripotent human embryonic stem cells we reproduced a 3D tissue structure (so-called cerebral organoid) representing a developing human brain in vitro. We engineered these mini-brains to express oncogenic hits responsible for the derivation of tumors in pediatric GBM patients. Pediatric GBM is driven by a combination of epigenetic and genetic hits including the expression of a mutant histone H3 variant H3F3A (mutated at K27M or G34R) or a gain of function mutant isocitrate dehydrogenase IDH1R132H in combination with the loss of the histone remodeling factor ATRX and/or p53 tumor suppressor. We used a combination of these oncogenic hits to create a model of tumor engineering representing the first 3D human tissue model of GBM. This model combines the accurate multi-lineage differentiation and physiology of human brain with the easiness of manipulation of in vitro systems.

H&E staining of the modified organoids shows remarkable dysplasia reminiscent of human primary glioma. Different genetic hits result in different type of dysplasia with IDH1R132H showing distinct morphology, suggestive of a broad range of applicability to model oncogenic-dependence in pediatric GBM.

Cerebral organoids may also be used as a model to study tumor invasion starting with glioma stem-like cells (GSCs, which are believed to be the tumor-initiating cells in GBM). Indeed 923 GSCs (which are not invasive in mice brain) quickly and spontaneously (within few days) invade a co-cultured cerebral organoid.

This study is the first to engineer a human CNS tumor in vitro. The model carries a tremendous potential to uncover the pathogenesis and initiation of brain cancer in pediatric settings.

Citation Format: Amin Ismail. Use of cerebral organoids to model pediatric gliomas with H3.3K27M and H3.3G34R. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-138. doi:10.1158/1538-7445.AM2015-LB-138
Abstract LB-145: Pten deletion in SOX9+ cells synergizes with hepatic injury to drive tumor development in mouse liver
Authors: Zeng Ni , Kassa Anketse , Kopp Janel , He Lina , Sander Maike , Stiles Bangyan
Published: August 2015

Liver cancer is an extremely deadly disease ranked as the third most common cancer and the second leading cause of male cancer-related death worldwide. Among primary liver cancers, hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the two most frequent subtypes, accounting for 85-95% of the total liver cancer cases, and both types of liver cancer have been found to originate from the expansion and differentiation of tumor initiating cells (TICs). Thus, it is critically important to understand mechanisms that regulate liver TICs activation. By utilizing a Pten(loxp/loxp); Albumin-Cre+ mouse liver cancer model (L-PKO), our previous studies have confirmed the activation of TICs during liver tumorigenesis. We also found that SOX9 was expressed in both HCC and CC, suggesting that SOX9 might serve as a liver TICs marker. We thus used the Pten(loxp/loxp); SOX9-CreER+ mouse model (TIC-PKO) to study the role of PTEN in TICs during liver tumorigenesis. Liver tumor development was observed in TIC-PKO mice at the age of 12 months old, and immunohistochemical analysis revealed that the tumors were heterogeneous, indicating TICs were involved in the tumorigenesis process. In addition, treatment of DDC, which is a liver toxin and thus causes hepatocyte death, dramatically increased the incidence and led to the early onset of liver tumorigenesis in the mutant but not the control mice, suggesting that liver injury served as an essential microenvironmental niche in promoting liver tumor development. Together, our observations suggested that the PTEN signaling is critical for TICs regulation and Pten deletion synergizes with liver injury to drive both TICs activation and liver tumorigenesis.

Citation Format: Ni Zeng, Anketse Kassa, Janel Kopp, Lina He, Maike Sander, Bangyan Stiles. Pten deletion in SOX9+ cells synergizes with hepatic injury to drive tumor development in mouse liver. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-145. doi:10.1158/1538-7445.AM2015-LB-145
Abstract LB-155: Epigenetic profiling of chemotherapy sensitivity
Authors: Gurard-Levin Zachary A. , Pancaldi Vera , Wilson Laurence OW , Marangoni Elisabetta , Roman-Roman Sergio , Valencia Alfonso , Cottu Paul , Almouzni Genevieve
Published: August 2015

Many anti-cancer drugs act by directly binding or modifying DNA, or through indirect binding during processes that rely on the chromatin architecture. Mis-regulation of the expression of epigenetic factors may perturb chromatin organization and contribute to drug resistance mechanisms. Here, we aim to investigate the power of chromatin regulators and epigenetic factors as predictive markers for the efficacy of single chemotherapy drugs.

We exploit transcriptome data from breast cancer cell lines and a validation set comprised of breast cancer patient derived xenograft (PDX) models that are either sensitive or resistant to individual chemotherapy agents, to correlate mRNA expression of chromatin regulators to drug efficacy. We then use Random Forests, a non-parametric machine learning method, to model the cell lines’ response to different compounds. The model is then used to predict the patients’ response to each drug, identifying which genes contribute the most to the prediction. We then compare our predictive gene signature to commercially available prognostic kits.

Random Forest analysis revealed a 28-gene signature (termed EPOCH28) containing several histone chaperones, histone variants, histone modifying enzymes, among other chromatin regulators, which is highly predictive of drug efficacy. Indeed, our model accurately predicts 11 of 14 resistant PDX models and 15 out of 17 sensitive PDX models (∼ 84%), with an average confidence level of over 73%. Importantly, we find that the EPOCH28 gene signature is specific, and is thus not a general prognostic signature for patients who will benefit from any chemotherapy. In line with this, the EPOCH28 outperforms the breast cancer prognostic gene signatures of Mammaprint and Oncotype DX, suggesting that while these commercial tests may help guide clinical decisions, it will be critical to consider additional factors that can help identify which drug will be most beneficial to an individual patient.

The integration of chromatin regulators as clinical biomarkers, in particular in the context of predictive markers for the response to a single drug, will help guide clinical decisions and treatment options for breast cancer. Importantly, our approach is general and thus can be applied to other chemotherapy drugs, including those in clinical trials to develop companion diagnostics, and for other cancer types.

Citation Format: Zachary A. Gurard-Levin, Vera Pancaldi, Laurence OW Wilson, Elisabetta Marangoni, Sergio Roman-Roman, Alfonso Valencia, Paul Cottu, Genevieve Almouzni. Epigenetic profiling of chemotherapy sensitivity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-155. doi:10.1158/1538-7445.AM2015-LB-155
Abstract LB-177: Novel approaches for improving interpretation and predictive models of comparative genomic hybridization data
Authors: Rotroff Daniel , Breen Matthew , Motsinger-Reif Alison
Published: August 2015

As costs of genome wide analyses decline and become more accessible, their use in both human and animal cancer studies are generating increasing information regarding underlying cancer etiology. Comparative genomic hybridization (CGH) is providing valuable information relating copy number aberrations (CNAs) to cancer mechanisms and clinical outcomes. However, challenges exist to interpreting and fully utilizing these data. First, without matched tumor and healthy tissue samples from individuals, distinguishing naturally occurring copy number variations (CNVs) from CNAs is difficult. Second, the large search space of genome wide analyses makes finding combinations of CNAs with improved predictive potential compared to single CNAs challenging. Here we provide novel methods to address these challenges associated with CGH data. Many new resources (e.g. The Cancer Genome Atlas (TCGA)), are making large volumes of genomic data publically accessible. However, most datasets do not have matched normal and tumor tissue samples between subjects. We tested matched normal and tissue samples from 30 patients with colorectal, lung, and pancreatic cancer and compared CNVs and CNAs to findings in larger, non-matched samples in TCGA. Even with limited matched samples, this approach allows for the differentiation of CNVs from CNAs discovered in analyses of non-matched samples.

In some cases, combinations of CNAs can provide improved predictive capability compared to any single CNA. However, it is computationally intractable to exhaustively test combinations of CNAs in a genome-wide study. To address this limitation, we use a novel approach for CNA feature reduction that minimizes the variance within CNA segments across subjects, and Random Forest Ensemble Classification. This approach provides CNA combinations with balanced accuracies of 83.5% and 94.9% for distinguishing 52 cases of canine ALL/AML and 71 cases of B-CLL/T-CLL, respectively. These two approaches address frequent limitations in the interpretation CGH data. Better distinguishing CNVs and interrogating CNA combinations, can provide additional information about the role of CNAs in disease mechanisms and improve treatment decisions.

Citation Format: Daniel Rotroff, Matthew Breen, Alison Motsinger-Reif. Novel approaches for improving interpretation and predictive models of comparative genomic hybridization data. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-177. doi:10.1158/1538-7445.AM2015-LB-177
Abstract LB-182: Improved survival among lung cancer patients taking antidepressants
Authors: Zingone Adriana , Brown Derek , Bowman Elise , Vidal Oscar , Neal Joel , Sage Julien , Ryan Brid M.
Published: August 2015

In recent years, the anti-cancer properties of several commonly used drugs have been explored, with drugs such as aspirin and beta-blockers associated with improved cancer outcomes. Emerging evidence suggests that the antidepressant family of drugs may target key pathways in cancer cells, raising the possibility that such drugs could be re-purposed for cancer treatment. Here, using the NCI-MD lung cancer study, we assessed antidepressant use in 1,098 lung cancer patients. Strikingly, antidepressant use was associated with a significant extension of lung cancer-specific survival (HR = 0.78, 95% C.I. = 0.63 - 0.97, P = 0.027) (model adjusted for age, gender, race, smoking status, pack-years of smoking, tumor stage and histology). When assessing distinct classes of antidepressants, we observed that NDRIs (norepinephrine and dopamine reuptake inhibitors) and TCAs (tricyclic antidepressants) were specifically associated with extended survival: TCA HR = 0.40, 95% C.I. = 0.18 - 0.91, P = 0.028 and NDRI HR = 0.61, 95% C.I. = 0.39 - 0.95, P = 0.027). In contrast, SRIs (serotonin reuptake inhibitors) were linked with worse survival (HR 1.94 95% C.I. 1.10 - 2.42, P = 0.023). Importantly, the extended survival time associated with antidepressants was not associated with the typical indications for these drugs, suggestive of a direct effect on lung cancer cells. In addition, as we assessed lung cancer-specific survival we conducted a competing risks analysis, the results of which showed that both NDRIs and TCAs were associated with lung cancer survival (fully adjusted model NDRI, HR: 0.63, 95% C.I. 0.40 - 1.00, P = 0.05) (fully adjusted model TCA, HR: 0.36, 95% C.I. 0.17 - 0.76, P = 0.007). We provide strong evidence that lung cancer patients taking antidepressants, particularly NDRIs and TCAs, have a significantly prolonged survival. Considering the manageable and largely tolerable side effects of antidepressants, and the low cost of these drugs, these results indicate that repositioning antidepressants as adjunct therapeutics with chemotherapy may have a rapid and significant translational impact for lung cancer patients.

Citation Format: Adriana Zingone, Derek Brown, Elise Bowman, Oscar Vidal, Joel Neal, Julien Sage, Brid M. Ryan. Improved survival among lung cancer patients taking antidepressants. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-182. doi:10.1158/1538-7445.AM2015-LB-182
Abstract LB-205: Myeloid cells are required to establish an immune-suppressive regulatory network in pancreatic cancer by activating the PD-1/PD-L1 checkpoint
Authors: ZHANG YAQING , MATHEW ESHA , MENDEZ FLOR , FLANNAGAN KEVIN , SIMEONE DIANE , PASCA DI MAGLIANO MARINA
Published: August 2015

Background: Pancreatic cancer is characterized by the accumulation of a fibro-inflammatory stroma. Myeloid cells are a predominant population within the stroma. Different myeloid cell subsets have been correlated with tumor promotion and unmasking of anti-tumor immunity.

Objective: The goal of this study was to determine the effect of myeloid cell depletion on the onset and progression of pancreatic cancer, and to understand the relationship between myeloid cells and T cell infiltration and activity within the pancreatic cancer microenvironment.

Methods: Primary mouse pancreatic cancer cells were transplanted in CD11b-DTR mice. CD11b+ cells (most myeloid cell populations) were depleted by Diphtheria Toxin treatment; either at the time of tumor implantation or after tumors had formed.

Results Depletion of myeloid cells delayed tumor initiation. In pre-established tumors, myeloid cell depletion resulted in arrest of growth or tumor regression. We observed that tumor regression was dependent myeloid cell-mediated blockade of CD8+ T cell anti-tumor activity. We investigated the mechanism of this inhibition. We found that myeloid cells regulate expression of the immune checkpoint ligand Programmed death-ligand 1 (PD-L1) in the tumor cells in an EGFR/MAPK dependent manner.

Conclusions: Our results show that myeloid cells regulate a complex network of signals that ensure immune suppression within the pancreatic cancer microenvironment. Moreover, we show that depletion of the myeloid cell population is sufficient to restore anti-tumor immunity mediated by CD8+ T cells, a finding with implications for the design of immune therapies for pancreatic cancer.

Citation Format: YAQING ZHANG, ESHA MATHEW, FLOR MENDEZ, KEVIN FLANNAGAN, DIANE SIMEONE, MARINA PASCA DI MAGLIANO. Myeloid cells are required to establish an immune-suppressive regulatory network in pancreatic cancer by activating the PD-1/PD-L1 checkpoint. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-205. doi:10.1158/1538-7445.AM2015-LB-205
Abstract LB-210: Telomerase activation by genomic rearrangements in high-risk neuroblastoma
Authors: Peifer Martin , Roels Frederik , Hertwig Falk , Menon Roopika , Kraemer Andrea , Buettner Reinhard , Perner Sven , Schramm Alexander , Schulte Johannes H. , Westermann Frank , Thomas Roman K. , Fischer Matthias
Published: August 2015

Neuroblastoma is a malignant pediatric tumor of the sympathetic nervous system. While roughly half of these tumors regress spontaneously or are cured by limited therapy, high-risk neuroblastomas have an unfavorable clinical course, despite intensive multimodal treatment. The genetic basis of the various clinical subtypes of the disease has remained largely elusive. To gain a better understanding of the genetic events that may drive neuroblastoma tumorigenesis, we here performed whole-genome sequencing of 42 primary neuroblastomas (high-risk, n = 25; low-risk, n = 17). We identified genomic rearrangements affecting chromosome 5p15.22 in a 50 kb region centromeric of the human telomerase reverse transcriptase gene (TERT) in 8 tumors. The rearrangements occurred only in high-risk neuroblastomas (8/25, 32%) in mutually exclusive fashion with MYCN amplifications and ATRX mutations, which are known genetic events in this tumor type. In an Independent validation cohort of 14 high-risk neuroblastomas, we detected rearrangements of the TERT locus in 4 additional samples. The structure of the rearrangements varied greatly, including balanced translocations, low-level copy number gains, focal amplifications and chromothripsis. Independent of the copy number at this region, all alterations consistently induced massive transcriptional up-regulation of TERT and of three additional genes located in close proximity to the chromosomal breakpoint. By contrast, MYCN-amplified tumors showed only up-regulation of TERT itself, suggesting that both MYCN amplification and TERT rearrangements converge on TERT activation. Supporting a functional role of TERT, both MYCN-amplified neuroblastoma cell lines and cell lines bearing TERT rearrangements exhibited elevated TERT expression and enzymatic telomerase activity in comparison to cell lines without these aberrations. Our findings show that remodeling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma, and places telomerase activation in the center of transformation in a large fraction of these tumors. More broadly, our findings provide a mechanistic basis for molecular diagnosis and therapy of this deadly pediatric tumor entity.

Citation Format: Martin Peifer, Frederik Roels, Falk Hertwig, Roopika Menon, Andrea Kraemer, Reinhard Buettner, Sven Perner, Alexander Schramm, Johannes H. Schulte, Frank Westermann, Roman K. Thomas, Matthias Fischer. Telomerase activation by genomic rearrangements in high-risk neuroblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-210. doi:10.1158/1538-7445.AM2015-LB-210
Abstract LB-219: Interleukin-8 promotes generation of M2 macrophages and arginase-producing granulocytes: Prognostic significance of interleukin-8 and infiltration of immune cells positive for CD163 and CD66b in tumor tissues in patients with oral squamous cell carcinoma
Authors: Okamoto Masato , Fujita Yohei , Goda Hiroyuki , Nakashiro Koh-ichi , Hamakawa Hiroyuki
Published: August 2015

Biomarkers are essential for improving the effectiveness of treatments for patients with cancer. The immunological status in a tumor microenvironment is closely associated with the prognosis of cancer patients. Here we investigated whether serum interleukin (IL)-8 reflects the tumor microenvironment and has prognostic value in 50 patients with resectable oral squamous cell carcinoma (OSCC). We found that the relapse-free survival (RFS) was significantly longer in the Stage I/II OSCC patients with low serum IL-8 levels compared to those with high levels (p = 0.001). The tumor expression of IL-8, the infiltration of CD163-positive cells, and of CD66b-positive cells in the tumor tissues were correlated with the serum IL-8 level (p = 0.033, p = 0.038 and p = 0.044, respectively), and they were associated with poor clinical outcome (p = 0.007, p = 0.002 and p = 0.001 respectively, in DFS) in all patients. A multivariate analysis revealed that N status, tumor IL-8 expression, CD163 and CD66b infiltration significantly affected the DFS of the patients. A further analysis suggested that the combination of N status with serum IL-8, tumor IL-8, CD163 and CD66b infiltration in the tumor tissues may be a new criterion for discriminating between OSCC patients at high and low risk for tumor relapse. Finally, the in vitro experiments clearly demonstrated that IL-8 enhanced the generation of CD163-positive M2 macrophages from peripheral blood monocytes, and that the cells produced IL-10 which suppress anti-tumor immunity. Furthermore, IL-8 increased the generation of arginase-producing, CD66b-overexpressing cells from peripheral blood polymorphonuclear cells. These findings indicate that IL-8 may be involved in poor clinical outcomes via the generation of CD163-positive M2 macrophages and CD66b-overexpressing, arginase-producing granulocytes, and that these factors may have prognostic value as well as may be new targets for treatment in patients with resectable OSCC.

Citation Format: Masato Okamoto, Yohei Fujita, Hiroyuki Goda, Koh-ichi Nakashiro, Hiroyuki Hamakawa. Interleukin-8 promotes generation of M2 macrophages and arginase-producing granulocytes: Prognostic significance of interleukin-8 and infiltration of immune cells positive for CD163 and CD66b in tumor tissues in patients with oral squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-219. doi:10.1158/1538-7445.AM2015-LB-219