bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A40: Epigenomic profiling identifies NCRNAs as novel tumor suppressors in developmental tumors
Authors: Herrero-Martin David , Court Franck , Rello-Varona Santiago , Sainz-Jaspeado Miguel , Buj Raquel , Moran Sebastian , Garcia-Monclus Silvia , Huertas-Martinez Juan , Mora Jaume , Peinado Miquel Angel , Alonso Javier , Alava Enrique de , Monk Dave , Esteller Manel , Tirado Oscar M.
Published: May 2016

Pediatric sarcomas represent a diverse group of rare bone and soft tissue malignancies. Although the molecular mechanisms that propel the development of these cancers are not well understood, identification of tumor-specific translocations in many sarcomas has provided significant insight into their tumorigenesis. Besides of acting as a direct modulator of transcription, fusion proteins appear to exert its oncogenic functions by epigenetic modifications on the transcriptome. Aberrant DNA methylations are thought to be closely related to the development of cancer. Therefore, the identification of specific DNA methylation markers would be helpful for understanding the pathogenetic mechanism as well as for developing new therapeutic strategies. By using the Illumina Infinium HumanMethylation450, we analyze the methylome of Ewing Sarcoma (ES) and Rhabdomyosarcoma (RMS) tumors and cell lines as developmental tumors in comparison to a significant number of normal tissues and cells as a reference. Our results uncover one miRNA with tumor suppressive activities in both tumor entities. Molecular mechanisms associated to these activities are further explored.

Citation Format: David Herrero-Martin, Franck Court, Santiago Rello-Varona, Miguel Sainz-Jaspeado, Raquel Buj, Sebastian Moran, Silvia Garcia-Monclus, Juan Huertas-Martinez, Jaume Mora, Miquel Angel Peinado, Javier Alonso, Enrique de Alava, Dave Monk, Manel Esteller, Oscar M. Tirado. Epigenomic profiling identifies NCRNAs as novel tumor suppressors in developmental tumors. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr A40.
Abstract B28: PTENpg1 antisense RNA mediates PTEN suppression in vemurafenib resistance and predicts clinical outcome in melanoma patients
Authors: Vidarsdottir Linda , Azimi Alireza , Serviss Jason , Ingvar Christian , Jönsson Göran , Olsson Håkan , Stolt Marianne Frostvik , Hansson Johan , Brage Suzanne Egyházi , Grandér Dan , Johnsson Per
Published: May 2016

Approximately 50% of cutaneous melanomas carry activating mutations in the serine/threonine protein kinase BRAF. Vemurafenib is a highly potent inhibitor of BRAFV600E and prolongs survival in ~80% of melanoma patients carrying the mutation. Unfortunately, almost all patients develop resistance within 6-8 months of starting treatment. The molecular mechanism explaining this scenario is largely unclear, but loss of PTEN expression, has been suggested.

In this study we reveal a role for the PTEN pseudogene encoded antisense RNA (PTENpg1 asRNA) in epigenetic suppression of PTEN in melanoma cell lines resistant to vemurafenib. Resistant cell lines showed increased PTENpg1 asRNA expression while PTEN expression was suppressed. ChIP analysis showed enrichment of the histone modification enzyme EZH2 and subsequent enrichment of H3K27me3 at the PTEN promoter in the resistant cell line. Total cellular levels of EZH2, DNMT3a and H3k27me3 were, however, unaffected thus indicating specific recruitment of these factors to the PTEN promoter in the resistant cells by a mechanism that is dictated by the increased expression of PTENpg1 asRNA. In addition, we show that PTEN is reactivated by the depletion of EZH2 and DNMT3a and that this reactivation of PTEN re-sensitizes the cells to vemurafenib treatment.

Finally, we show that PTENpg1 asRNA could be a promising prognostic marker of clinical outcome of melanoma patients. PTENpg1 asRNA expression levels were measured in samples from patients that had not received any oncological treatment and were classified with stage III melanomas. We found that high PTENpg1 asRNA expression correlates with short-term survival in melanoma patients.

In conclusions, the PTENpg1 asRNA appears to be an important player in vemurafenib resistance and could be an attractive therapeutic target. In addition, PTENpg1 asRNA is potentially a promising prognostic marker for clinical outcome for melanoma patients.

Citation Format: Linda Vidarsdottir, Alireza Azimi, Jason Serviss, Christian Ingvar, Göran Jönsson, Håkan Olsson, Marianne Frostvik Stolt, Johan Hansson, Suzanne Egyházi Brage, Dan Grandér, Per Johnsson. PTENpg1 antisense RNA mediates PTEN suppression in vemurafenib resistance and predicts clinical outcome in melanoma patients. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr B28.
Abstract B35: Differences in extracellular vesicle nucleic acid content show promise as prostate cancer biomarkers
Authors: Jankowski Helen , Goldie Belinda , Brzozowski Joshua , Bond Danielle , Scarlett Christopher , Skelding Kathryn , Weidenhofer Judith
Published: May 2016

Prostate cancer has one of the highest incidence rates of all cancers worldwide. Although 5-year survival rates are high, this is generally attributed to most prostate cancers either exhibiting a slow progression towards metastasis or being indolent. However current treatments for localized disease have devastating effects on quality of life and the biomarkers that are currently available are not accurate enough. This has resulted in many men with indolent disease being unnecessarily treated. Therefore, it is essential to identify new prognostic biomarkers that are accurate, sensitive and able to be tested for in non-invasive ways. Extracellular vesicles (EVs) have gained interest as a promising avenue for cancer biomarkers in recent years. EVs are small spherical shaped vesicles, which are secreted from their tissue of origin and contain high amounts of noncoding RNAs. EVs, from a panel of 20 prostate cell lines from normal, primary cancer or metastatic sites, were investigated by Affymetrix Human Transcriptome arrays (HTA 2.0). This enabled the identification of nucleic acids that contribute to the development of metastasis through comparison with EV and cellular function. EVs were collected from cell culture media devoid of supplements after 48 hours, by ultraconcentration. RNA was extracted with Trizol and evaluated using total RNA Agilent 2100 bioanalyzer chips. RNA was converted to labeled cDNA and hybridized to HTA 2.0 cassettes. Data was normalized using expression console and analyzed using transcriptome analysis console. Bioanalyzer results illustrated a unique RNA profile for each of the 20 cell lines. Preliminary analysis of nucleic acid content showed that the amount of mRNA, miRNA, snRNA, snoRNA, tRNA, and lncRNA packaged into EVs varies between cell lines further highlighting the differences observed with bioanalyzer profiles. Further several transcripts had significantly different abundance levels that discriminated between EVs released from cells of normal prostate, prostate cancer and metastatic origin, showing potential as biomarkers. Further analysis is ongoing to identify what mechanisms contribute to the differential packaging of nucleic acid into EVs in prostate cells and specific nucleic acid changes that could be used as novel biomarkers.

Citation Format: Helen Jankowski, Belinda Goldie, Joshua Brzozowski, Danielle Bond, Christopher Scarlett, Kathryn Skelding, Judith Weidenhofer. Differences in extracellular vesicle nucleic acid content show promise as prostate cancer biomarkers. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr B35.
Abstract B40: A two-microRNA signature in urinary exosomes for diagnosis of prostate cancer
Authors: Mouritzen Peter , Fredsøe Jacob Christian , Blondal Thorarinn , Rasmussen Anne Karin , Borre Michael , Haldrup Christa , Andreasen Ditte , Tolstrup Niels , Ørntoft Torben Falck , Sørensen Karina Dalsgaard
Published: May 2016

Antibody based detection of circulating prostate specific antigen (PSA) remains an important test in the diagnosis of prostate cancer. Unfortunately the test identifies a high number of false positives which require further testing to confirm the presence of cancer including several biopsies taken from the prostate itself. Whereas the performance of biopsies on individuals is associated with discomfort and risk of serious side effects, the invasive test also represents an expense to health care systems. Given the high number of false positives, the PSA test is therefore the direct cause of unnecessary suffering of healthy individuals and costs to health systems.

To investigate the possibilities for developing a non-invasive and more specific test, we have developed different technologies enabling the detection of prostate cancer microRNA biomarkers in exosomes derived from urine from non-prostate massaged men. The first of these technologies is a highly sensitive LNA™-based qPCR platform for microRNA detection, which enables profiling in biofluids where microRNA levels are extremely low. At this point we have already applied this platform on thousands of biofluid samples including serum/plasma and urine to establish normal reference ranges for circulating microRNAs as well as to identify biomarkers of disease. The second technology is a simple exosome precipitation system which only requires low speed centrifugation to harvest urine exosomes.

We have combined our developed technologies and applied this on cell-free urine from two different cohorts of approximately 220 patients each, to identify a number of differentially regulated microRNAs in urine from prostate cancer bearing individuals. Prostate cancer specific signatures have been obtained by different combinations of these differentially regulated microRNAs. The smallest signature is composed of two microRNAs which allows constructing receiver operating characteristic curves with areas under the curve well above 0.8.

Citation Format: Peter Mouritzen, Jacob Christian Fredsøe, Thorarinn Blondal, Anne Karin Rasmussen, Michael Borre, Christa Haldrup, Ditte Andreasen, Niels Tolstrup, Torben Falck Ørntoft, Karina Dalsgaard Sørensen. A two-microRNA signature in urinary exosomes for diagnosis of prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr B40.
Abstract IA11: Dependency of prostate cancer on HNRNPL and its associated RNAs
Authors: Fei Teng , Chen Yiwen , Brown Myles , Liu X. Shirley
Published: May 2016

RNA binding proteins (RBPs) play critical roles in RNA metabolism and underlie multiple cellular functions. However, how RBPs act in cancer remains obscure. Using an RBP-focused RNAi screen and a genome-wide CRISPR/Cas9 knockout screen, we identified HNRNPL as an RBP required for prostate cancer growth. To understand the HNRNPL function mechanistically, we profiled the HNRNPL-bound RNA landscape by RIP-seq and linked these RBP-RNA interactions to multiple RNA regulatory processes. HNRNPL directly regulates the alternative splicing of a set of associated RNAs, including those encoding the androgen receptor (AR), the key lineage-specific prostate cancer oncogene. Interestingly, HNRNPL also regulates circular RNA formation. Moreover, we identified LARP, a novel HNRNPL-associated long noncoding RNA (lncRNA), as a cofactor of HNRNPL's gene regulatory function. Collectively, our data reveal HNRNPL and its RNA partners as novel players in prostate cancer growth, suggesting the potential to target RBPs or RBP-RNA interactions therapeutically.

Citation Format: Teng Fei, Yiwen Chen, Myles Brown, X. Shirley Liu. Dependency of prostate cancer on HNRNPL and its associated RNAs. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr IA11.
Abstract IA27: Advances in oligonucleotide chemistry for the treatment of neurodegenerative disorders and brain tumors
Authors: Khvorova Anastasia
Published: May 2016

RNA interference has revolutionized human functional genomics and therapeutics, but its impact on the development of new therapies for cancer has been surprisingly limited, due mainly to the lack of simple and efficient methods to deliver oligonucleotides to tumors, especially those located in the brain.

Our research shows that many cell types, including tumor, glial and neuronal, rapidly internalize fully stabilized, hydrophobically modified siRNAs (hsiRNAs) added directly to the culture medium and that hsiRNAs induce potent and long-lasting silencing in vitro. A single injection of unformulated hsiRNA (cholesterol-conjugated) into mouse brain silences locally with great potency and longevity in primary tumor, glial and neuronal cells. Limited distribution from the site of administration interferes with addressing metastasis, thus limiting the clinical utility to treatment of primary tumors only.

Using fully chemically modified siRNA scaffolds, we systematically screened a wide range of bioactive conjugates and demonstrated that the chemical nature of the conjugation modality has a major impact on brain tissue retention, distribution and selectivity of cellular uptake. We have identified several novel chemical classes of conjugates that demonstrate markedly improved brain distribution and robust in vivo efficacy, with some showing selective tumor, glia or neuronal uptake. Direct conjugation of a fully chemically modified siRNA to docosahexaenoic acid (DHA), the most abundant poly-unsaturated fatty acid in the brain, results in improved tissue retention with wide distribution and robust efficacy in the striatum and cortex after a single injection. Most importantly, DHA-hsiRNA conjugates do not induce neural cell death or measurable innate immune activation following the administration of concentrations 20-fold over the efficacious dose. Interestingly, variants of DHA-based conjugates support preferential delivery to glia cells, establishing a new approach toward targeted development of RNAi-based therapeutics for glioblastomas and other glia-associated cancers.

Citation Format: Anastasia Khvorova. Advances in oligonucleotide chemistry for the treatment of neurodegenerative disorders and brain tumors. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr IA27.
Abstract A12: Microenvironmental Interleukin-6 induced activation of STAT3 signaling in medulloblastoma: Implications for molecular pathology and therapy
Authors: Yan Shuang , Chatterjee Sampurna , Vardam Trupti , Kitahara Shuji , Hato Tai , Roberge Sylvie , Askoxylakis Vasileios , Duquette Mark , Fukumura Dai , Xu Lei , Jain Rakesh
Published: May 2016

Aberrant activation of Janus kinase (JAK) / signal transducer and activator of transcription (STAT) 3 pathway has been implicated in tumor initiation, progression and metastasis which make it a potential therapeutic target in human malignancies. In vitro STAT3 inhibition exhibited anti-tumor effect in medulloblastoma (MB) cell lines; however, little has been reported about the mechanisms of STAT3 activation in medulloblastoma (MB). We found that STAT3 was constitutively activated in both medulloblastoma patient samples and 3 mice models that were clinically classified as SHH subgroup, Group 3 and Group 4 in pediatric MB patients. By using PCR arrays we investigated the early expression profile of local cytokines in host cerebellum during MB pathogenesis and found increased IL17B, IL6 and TNFα in the microenvironment of MB mice models. In vitro cytokine stimulation assay indicated that IL6 was the major activator of STAT3 in D283 MB cells. Confocal immunofluorescence staining of different cell components in the cerebellum in D283 xenografts showed that the endothelial cells and Purkinje cells were the two major sources of IL6 secretion. Our data provides molecular and cellular clue for the activation of STAT3 signaling during MB tumorigenesis and might help to develop more effective therapeutic targets for STAT3 blockade in MB.

Citation Format: Shuang Yan, Sampurna Chatterjee, Trupti Vardam, Shuji Kitahara, Tai Hato, Sylvie Roberge, Vasileios Askoxylakis, Mark Duquette, Dai Fukumura, Lei Xu, Rakesh Jain. Microenvironmental Interleukin-6 induced activation of STAT3 signaling in medulloblastoma: Implications for molecular pathology and therapy. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr A12.
Abstract A32: Urine as a potential liquid biopsy for detecting tumor DNA in Wilms tumor patient: Detection of somatic mutations in urine opens perspectives of monitoring chemotherapy response in WT patients
Authors: Miguez Ana C. K. , Ramalho Rodrigo F. , Ferreira Elisa N. , Barros Bruna D. F. , Paula Claudia A. A. de , Valieris Renan , Mota Louise D. C. , Souza Jorge E. , Cunha Isabela W. , Costa Cecília L. , Souza Sandro J. de , Carraro Dirce M.
Published: May 2016

Detection of tumor DNA in urine has been shown as viable method of diagnosis not only for urinary tract (e.g., kidney and bladder) cancers but also for other types, e.g. prostate. Applications of such method, resemble those which use plasma DNA and include cancer detection, monitoring of tumor growth or recurrence and response to chemotherapy or radiation therapy. As far as we know, there is a lack of studies applying urine DNA detection in Wilms tumor (WT), an embryonary kidney cancer type.

Here we show evidences of detection for two somatic variants in the urine DNA of one WT patient. By using NGS exome sequencing of tumor tissue and leukocytes samples of the same patient we were able to find new somatic variants: a frame-shift indel in TNRC18 and a misssense SNV in INTS1 gene. Target sequencing applied to the DNA from the patient's urine revealed the presence of these two somatic variants. More interestingly, both variants could not be found in the urine DNA of this patient after treatment (chemotherapy and nephrectomy). Additionally, these genes are poorly characterized in WT contributing for the comprehension of the cellular processes that are operating in tumorigenesis of WT. Altogether, our findings contribute with the mutational repertoire of WT and reveals the potential of using urine DNA sequencing as a noninvasive cancer screening approach.

Citation Format: Ana C. K. Miguez, Rodrigo F. Ramalho, Elisa N. Ferreira, Bruna D. F. Barros, Claudia A. A. de Paula, Renan Valieris, Louise D. C. Mota, Jorge E. Souza, Isabela W. Cunha, Cecília L. Costa, Sandro J. de Souza, Dirce M. Carraro. Urine as a potential liquid biopsy for detecting tumor DNA in Wilms tumor patient: Detection of somatic mutations in urine opens perspectives of monitoring chemotherapy response in WT patients. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr A32.
Abstract B05: Improved therapy for neuroblastoma using small molecule inhibitors in combination with chemotherapy
Authors: Chaturvedi Nagendra K. , Timothy McGuire R. , Coulter Don W. , Shukla Ashima , McIntyre Erin M. , Sharp J. Graham , Joshi Shantaram S.
Published: May 2016

Neuroblastoma is the most common pediatric malignancy with poor response to current therapy. The NF-kB/mTOR, hedgehog and PLK1 pathways/molecules are aberrantly expressed and activated in high-risk neuroblastoma, thereby targeting these pathways/molecules is an attractive therapeutic strategy. Therefore, we investigated the efficacy and associated molecular mechanism(s) of NF-kB/mTOR dual inhibitor 13-197, hedgehog inhibitor Vismodegib and PLK1 inhibitor BI2536 alone or in combination with Topotecan against high-risk neuroblastoma in vitro and in vivo. Using three neuroblastoma cell lines, the in vitro efficacy of the inhibitors as single agents or in combination with Topotecan on cell growth and apoptosis along with associated molecular mechanism(s) were investigated. In addition, the combined efficacy of Vismodegib and Topotecan was determined in vivo using a xenograft mouse model. Results showed that 13-197, BI2536 and Vismodegib significantly decreased neuroblastoma cell growth and induced apoptosis by targeting associated pathways and molecules in vitro. The 13-197 and BI2536 as single agents showed similar efficacies and were most potent in inhibiting cell growth and survival of neuroblastoma cells. In combination with Topotecan, BI2536 or Vismodegib further significantly decreased neuroblastoma cell growth/survival and neurospheres formation. Corresponding changes in the expression of targeted molecules following therapy were observed. Together, in vitro data demonstrated that hedgehog pathway inhibitor Vismodegib was most efficacious in potentiating Topotecan-induced antineuroblastoma effects. Therefore, as a next logical step, we tested the combined efficacy of Vismodegib and Topotecan against neuroblastoma in vivo using NOD-SCID Gamma deleted (NSG) mice. Our in vivo results showed that Vismodegib combined with Topotecan significantly (p<0.001) reduced tumor growth and increased survival of xenograft mice compared to single agent activity. This combination not only significantly reduced tumor growth and increased survival of the mice but also significantly enhanced antineuroblastoma efficacy by targeting hedgehog pathway components in neuroblastoma in vivo. Thus our studies lay a foundation for taking this therapeutic strategy to clinical setting to determine their efficacies in high-risk neuroblastoma patients.

Citation Format: Nagendra K. Chaturvedi, McGuire R. Timothy, Don W. Coulter, Ashima Shukla, Erin M. McIntyre, J. Graham Sharp, Shantaram S. Joshi. Improved therapy for neuroblastoma using small molecule inhibitors in combination with chemotherapy. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B05.
Abstract B16: NR5A2 as a potential therapeutic target for hepatoblastoma
Authors: Jin Jingling , Patel Roma , Jin Nan Ge , Shi Yan , Sun Wenjing , Yang Jianhua , Nuchtern Jed G. , Vasudevan Sanjeev A.
Published: May 2016

Hepatoblastoma (HB) is the most common malignant liver tumor in very young children. Because of multidrug resistance and severe side effects of anti-HB drugs during HB chemotherapy, it is urgent and important to develop new effective therapeutic agents with less toxicity for the treatment of pediatric patients with liver cancer. Nuclear Receptor Subfamily 5 Group A Member 2 (NR5A2; LRH-1) has been linked to various types of malignancies, and it is an emerging therapeutic target for many cancers. However the role of NR5A2 in liver cancer remains elusive. In this study, we found that both mRNA and protein expression levels of NR5A2 were significantly higher in HepG2 and HuH6 human HB cell lines and mouse orthotopic HB liver than the normal liver cell and normal liver tissue. Lentiviral-Mediated Short Hairpin RNA (shRNA) knockdown of NR5A2 inhibited HepG2 and HuH6 cell proliferation and colony formation compared with control cells. Furthermore, we found that silencing of NR5A2 induced downregulation of cell cycle gene CCND1 and the regulator gene c-myc. Similar to the effects of shRNA, we found the NR5A2 antagonist treatment also inhibited the proliferation of human HB cell lines (HepG2, HuH6 and HepT1 cells), reduced colony formation and CCND1 and c-Myc expression. Finally, flow cytometry results showed that the NR5A2 antagonist treatment induced a decreased percentage of cells in S phase which resulted in a significant decrease in the rate of cell proliferation and tumorigenicity, and induced an increased number of cells in the G2/M phase, leading to HB cell cycle arrest at G2/M phase. Collectively, our results suggest that NR5A2 play an important role in HB cancer cell proliferation. Interference of NR5A2 by shRNA or the NR5A2 antagonist inhibits HB cell proliferation and colony formation by inhibiting the cell cycle process through downregulation of CCND1 and c-Myc expression. By targeting NR5A2 signaling pathway, NR5A2 antagonist has promising therapeutic potential in the treatment of HB cancer.

Note: This abstract was not presented at the conference.

Citation Format: Jingling Jin, Roma Patel, Nan Ge Jin, Yan Shi, Wenjing Sun, Jianhua Yang, Jed G. Nuchtern, Sanjeev A. Vasudevan. NR5A2 as a potential therapeutic target for hepatoblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B16.
Abstract B24: Targeting promoter regions of oncogenic drivers in pediatric AML cells using G-quadruplex Interacting Drugs (GQIDs)
Authors: Patel Apurvi , Montoya Justin J. , Turnidge Megan , Sabir Marya , Wai Daniel H. , Lee David W. , Gokhale Vijay , Aleem Eiman , Hurley Laurence J. , Arceci Robert J. , Azorsa David O.
Published: May 2016

Cancer is primarily a disease characterized by aberrant gene expression that is manifested by the overexpression of key genes that support tumor development and maintenance. In many instances, oncogenic drivers are frequently ‘undruggable’ because of structural challenges, the inability to effectively inhibit high concentrations of overexpressed proteins, and the development of drug resistance mutations. An alternative therapeutic approach is to directly inhibit gene transcription by targeting unique secondary DNA structures, called G-quadruplexes, that are associated with subsets of promoters. Our laboratory investigated the activity of a class of compounds termed G-quadruplex Interacting Drugs (GQIDs) that are able to shut down the expression of specific genes used by tumor cells for growth and survival. We tested the activity of two GQIDs GQC-05 and GSA-1103 on cell growth of a panel of eight pediatric and eight adult AML cell lines. Drug dose response analysis showed IC50 values ranging from approximately 10 nM to 1 µM for GQC-05 and from 40 nM to 2 µM for GSA-1103. The AML cell lines had different sensitivities to each GQID indicating a different mechanism of action for each compound. Three AML cell lines that were highly resistant to cytarabine were among the more sensitive to GQC-05. Four cell lines sensitive to GQC-05 had high expression of either c-myc and/or bcl-2, both of which are potential targets of these two GQIDs. Furthermore, treatment of cells with the GQC-05 decreased expression of c-myc and bcl-2. These studies will help define a novel approach of repressing key drivers of leukemia by targeting selective promoter structures. Validation of such an approach for AML will have important implications for testing this therapeutic approach to other childhood cancers in order to improve the length and quality of survival.

Citation Format: Apurvi Patel, Justin J. Montoya, Megan Turnidge, Marya Sabir, Daniel H. Wai, David W. Lee, Vijay Gokhale, Eiman Aleem, Laurence J. Hurley, Robert J. Arceci, David O. Azorsa. Targeting promoter regions of oncogenic drivers in pediatric AML cells using G-quadruplex Interacting Drugs (GQIDs). [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B24.
Abstract B37: Detection of sarcoma circulating tumor cells using a size based microfiltration device
Authors: Hayashi Masanori , Zhu Peixuan , Albert Catherine M. , Steppan Diana , McCarty Gregory , Jackson Kyle W. , Tang Cha-Mei , Loeb David M.
Published: May 2016

The inability to effectively treat hematogenous metastasis remains the largest challenge of sarcoma therapy. The ability to isolate, quantify, and study circulating tumor cells (CTC) in sarcomas has the potential to enhance our understanding of the biology of metastasis, altering the way we treat patients with high grade sarcomas. Using a size based filtration device, CellSieve™, we were able to successfully identify and quantify CTC in a metastatic xenograft model as well as in blood samples from patients with high grade sarcomas. In mice, we utilized our orthotopic implantation/amputation model of metastasis. Using a TdTomato-expressing Ewing sarcoma cell line and a cocktail of fluorescently labeled antibodies to vimentin and CD45, we were able to detect both CTC and circulating tumor clusters (CTCL) in mice with growing tumors and with metastatic disease, but not in mice immediately post-amputation. These experiments were augmented with samples collected from patients with high grade sarcomas. In 18 samples from 15 patients, we were able to identify both CTC and CTCL. Furthermore, we were also able to validate the presence of CTC by PCR amplification of sarcoma-associated chromosomal translocations. Future work will use this system to explore the biology of sarcoma metastasis by studying genetic, transcriptional, and epigenetic characteristics of CTC and CTCL and comparing these cells to those in the bulk primary tumor. We will also further explore the possibility that CTC and/or CTCL might serve as a biomarker of disease burden, response to treatment, or metastatic risk.

Citation Format: Masanori Hayashi, Peixuan Zhu, Catherine M. Albert, Diana Steppan, Gregory McCarty, Kyle W. Jackson, Cha-Mei Tang, David M. Loeb. Detection of sarcoma circulating tumor cells using a size based microfiltration device. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B37.
Abstract IA13: Mechanisms of chromatin regulation by the EWS-FLI1 fusion protein in Ewing sarcoma
Authors: Rivera Miguel N.
Published: May 2016

Our laboratory uses genomic approaches to identify and characterize abnormalities in gene regulation in cancer. Large scale sequencing studies have shown that transcriptional regulators, including transcription factors, chromatin modifiers and histones, are frequently altered in cancer and may thus contribute to transformation through widespread changes in gene expression programs. This is particularly evident in pediatric tumors, which have low numbers of recurrent genetic events and where alterations in a transcriptional regulator may be the sole genetic “driver”. In the case of Ewing sarcoma, the second most common pediatric bone cancer, translocations involving EWS and the ETS transcription factor FLI1 generate a fusion protein that has been shown to be essential for the growth and survival of tumor cells. We recently used genome-wide chromatin profiling to study the mechanisms of action of EWS-FLI1 and found that it utilizes two distinct patterns of chromatin remodeling to either activate or repress enhancers. At repeats of the GGAA ETS recognition motif, which are poorly conserved in evolution, EWS-FLI1 multimers induce chromatin opening and create active enhancers de novo. These repeat enhancers can loop to physically interact with target promoters, as demonstrated by chromosome conformation capture assays. In contrast, at conserved enhancers containing canonical ETS motifs, EWS-FLI1 displaces wild-type ETS transcription factors and leads to significant reductions in enhancer activity. These different chromatin remodeling mechanisms are associated with the repression of tumor suppressors and mesenchymal lineage genes and the activation of oncogenes and potential therapeutic targets. Our studies thus illustrate how chromatin profiling can reveal mechanisms of chromatin regulation that are critical in establishing an oncogenic regulatory program in cancer.

Citation Format: Miguel N. Rivera. Mechanisms of chromatin regulation by the EWS-FLI1 fusion protein in Ewing sarcoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr IA13.
Abstract CS1-3: Contemporary role of radiotherapy in axillary management
Authors: Jagsi R
Published: May 2016

Sentinel lymph node evaluation is an innovation that has radically transformed the surgical approach to the axilla in many patients with breast cancer. This revolution in surgical management has important implications for the optimal use of radiotherapy. The context of decision-making has changed dramatically with the recent maturation of studies that have demonstrated low rates of axillary failure in select patients with clinically negative axillae and 1-2 nodes positive on sentinel node biopsy, even without completion axillary dissection. Optimizing the radiotherapeutic management of the axilla in this modern context requires sophisticated understanding of the characteristics of patients who enrolled on trials such as ACOSOG Z0011 and IBSCG 23-01, including their risk factors and systemic management, as well as the radiation fields actually treated. Many patients treated on these trials received substantial incidental radiation to axillary levels I and II from tangential radiotherapy fields, and some even received directed nodal irradiation, but others did well with little or no radiation at all to the axilla. Understanding how to apply the results of these trials to guide current practice requires the radiation oncologist to integrate the insights of these studies with those from other recent studies evaluating the role of more comprehensive regional nodal radiotherapy that included the supraclavicular and internal mammary regions. Recognizing how the patient populations treated on the NCIC MA20 and EORTC 22922 trials may have differed from those on ACOSOG Z0011 and IBSCG 23-01 is necessary to help reconcile the findings of these studies and guide us in optimizing our patients' radiotherapeutic management decisions. In addition, the landmark AMAROS study, in which patients with clinically negative axillae were randomized to axillary dissection versus axillary radiation after a positive sentinel node biopsy, adds to a long history of clinical trials evaluating the question of optimal axillary management. These studies must be considered in detail in order to determine how best to individualize the use of radiation therapy to maximize disease control and minimize treatment-related morbidity. These issues will be the focus of this clinical science symposium lecture, which will provide a radiation oncologist's perspective on regional nodal management for patients diagnosed with invasive breast cancer, with a specific focus on the axilla.

Citation Format: Jagsi R. Contemporary role of radiotherapy in axillary management. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr CS1-3.
Abstract ES4-3: Regimens in HER2+ disease
Authors: Hurvitz SA
Published: May 2016

The discovery of the HER2 alteration and subsequent development of HER2-targeted therapy has substantially improved the natural history of HER2-positive metastatic breast cancer. In the past 17-years, four biologically targeted agents have been approved for the treatment of this disease subtype. These therapeutic advances have, in large part, been responsible for the significant improvement in median overall survival that can be expected now for a patient diagnosed with advanced HER2+ disease. While this progress has been remarkable, long-term durable remission is still rare, as the vast majority of patients will experience tumor progression with all available therapies. Thus the development of agents that prevent or circumvent mechanisms of resistance is still needed.

During this educational session, data relating to the use of trastuzumab, lapatinib, pertuzumab and trastuzumab emtansine will be explored in detail. Regimens involving chemotherapy, anti-hormonal treatment, and combinations of HER2-targeted agents will be evaluated. Specifically, questions surrounding optimal choice for first- and second-line therapy will be addressed by discussing the results of the CLEOPATRA, EMILIA and MARIANNE trials. The challenge of treating central nervous system metastases will be examined with a focus on promising agents under clinical investigation. In addition, differences in treatment response and disease outcome will be explored based on hormone receptor co-expression or activation of the PI3K pathway. As key evidence is discussed, the audience will be led through the decision-making process using case-based examples. Finally, innovative treatments undergoing clinical evaluation will be considered with a critical appraisal of preclinical and early clinical data.

It is expected that by the end of this session, audience members will possess an in-depth understanding of data relating to optimal treatment of HER2+ advanced disease and will be aware of promising avenues of research for continued areas of unmet need.

Citation Format: Hurvitz SA. Regimens in HER2+ disease. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES4-3.
Abstract ES8-2: Prognostic indicators in treatment of DCIS
Authors: Euhus DM
Published: May 2016

The goal of DCIS treatment is to avoid a future invasive breast cancer. Invasive breast cancer risk is heterogeneous across the population of DCIS patients. More than 40% of women with minimal, low grade DCIS will develop invasive breast cancer if left untreated and followed for more than 10 years. Risk of invasive recurrence is about 2% per year for DCIS treated by simple excision (lower for small low grade lesions and higher for larger high grade lesions). A reliable approach for risk-stratifying individual DCIS lesions could permit tailored approaches to therapy or avoidance of therapy all together in the lowest risk women. Screen-detected, grade 1 and 2 micropapillary DCIS in older women is likely the lowest risk lesion. Progression to invasive breast cancer is more likely related to focal myoepithelial cell dysfunction than molecular alterations in the bulk luminal cell populations. Nevertheless, p16, ER, COX2, HER-2/neu, and Ki67 staining patterns in the bulk luminal cell population have been linked to recurrence risk. A 12 gene recurrence score has been shown to predict the risk of recurrence for DCIS treated by excision without radiation. This assay was adapted from the 21-gene OncoTypeDx test and is weighted heavily towards proliferation markers. Accurate prediction of invasive recurrence risk will likely require detection of focal alterations in myopeithelial cells and the basement membrane.

Citation Format: Euhus DM. Prognostic indicators in treatment of DCIS. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES8-2.
Abstract MS1-2: Targeting CDK 4/6 in breast cancer
Authors: Finn R
Published: May 2016

For decades, cyclin-dependent kianses (CDKs) have been known to be critical regulators of cell cycle progression leading to the Nobel Prize in 2001 for their identification and characterization. Subsequently, alteration in these and associated proteins have been implicated in cancer. In breast cancer, they have been associated with various molecular subtypes, prognosis, and response to therapy. The concept of blocking CDKs has been around for some time but only recently have they seen clinical success. First generation CDK inhibitors did not demonstrate significant clinical activity and had unacceptable toxicity. In addition to having an appropriate compound, as with other molecular targeted agents, identification of a patient population most likely to benefit is critical to successful clinical development. Palbociclib (PD-0332991, Pfizer) is a first-in-class CDK 4/6 specific inhibitor. Pre-clinical studies identified that ER+ breast cancer models were most sensitive to growth inhibition with palbociclib and identified a synergistic interaction in inhibiting proliferation in combination with anti-estrogens (Finn et al 2009). These data served as a hypotheses for the Phase II Paloma-1/ TRIO 18 study of palbociclib +letrozole vs letrozole alone (Finn et al Lancet Oncolog 2015). Results of this study demonstrated a significant improvement in PFS with the combination and served as the basis for the expedited approval of palbociclib +letrozole as first line therapy for advanced post-menopausal ER+ breast cancer. Most common toxicities were neutropenia, leukopenia and fatigue. Subsequently, a consistent benefit was seen in combination with fulvestrant in more advanced settings (Turner et al NEJM 2015) with a similar toxicity profile. Currently there are several other CDK 4/6 inhibitors in development in breast cancer and other malignancies including abemaciclib (LY2835219, EliLilly) and ribociclib (LEE011, Novartis). In the presentation we will review the rationale for CDK 4/6 inhibition in breast cancer as well as clinical efficacy and toxicity data and the ongoing development of this new class of agent in breast cancer.

Citation Format: Finn R. Targeting CDK 4/6 in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr MS1-2.
Abstract OT1-03-02: Evaluation of the use of oral care to prevent oral mucositis in estrogen receptor positive metastatic breast cancer patients treated with everolimus: Phase III randomized control trial
Authors: Niikura N , Ohta Y , Hayashi N , Naito M , Kashiwabara K , Watanabe K , Yamashita T , Mukai H , Umeda M
Published: May 2016

Background:

In patients with estrogen receptor (ER)-positive advanced breast cancer, everolimus plus exemestane prolongs progression-free survival compared to exemestane monotherapy. However, as an adverse event from everolimus, oral mucositis (all grades) has been reported in 58% of all patients and 81% of Asian patients. Although no established prevention method is available, a previous study reported that professional oral care might prevent oral mucositis, and dentists have hypothesized that such care can reduce the occurrence of oral mucositis induced by everolimus. To evaluate this hypothesis, we compare the incidence of oral mucositis with and without professional oral care.

Method:

This is a randomized, multi-center, open-label, phase III study to evaluate the efficacy of professional oral care in preventing oral mucositis induced by everolimus in postmenopausal ER-positive metastatic breast cancer (MBC). Patients will be randomized into professional oral care and control groups (1:1 ratio). All patients will receive everolimus (10 mg daily) with exemestane (25 mg daily) and will continue everolimus until disease progression. Before the initiation of everolimus, instruction on a professional brushing method will be provided to both groups by specialists. In the professional oral care group, patients will receive teeth surface cleaning, scaling, and tongue cleaning before starting everolimus, and will continue to receive professional oral care weekly from oral surgeons throughout the 8 week treatment. In the control group, patients will brush their own teeth and gargle with 0.9% sodium chloride solution or water. The primary endpoint is the incidence of all grades of oral mucositis. The secondary endpoints are the incidence of over grade 2 and over 3 oral mucositis as determined by an oncologist and oral surgeons. The endpoints include onset and duration of oral mucositis. Major eligibility criteria include: 1) Postmenopausal women with ER positive MBC, and 2) No more than one prior chemotherapy treatment for MBC. Target accrual is 200 patients with a two-sided type I error rate of 5% and 80% power to detect 25% risk reduction. This study has just begun, and 5 of a planned 200 patients have been enrolled. (This study was registered with the UMIN 000016109).

Citation Format: Niikura N, Ohta Y, Hayashi N, Naito M, Kashiwabara K, Watanabe K, Yamashita T, Mukai H, Umeda M. Evaluation of the use of oral care to prevent oral mucositis in estrogen receptor positive metastatic breast cancer patients treated with everolimus: Phase III randomized control trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-02.
Abstract OT2-02-05: POSNOC: Positive sentinel node—Adjuvant therapy alone versus adjuvant therapy plus clearance or axillary radiotherapy: A randomised trial looking at axillary treatment in early breast cancer
Authors: Goyal A
Published: May 2016

Background

Women with early breast cancer that has spread to 1 or 2 sentinel nodes (SNs) undergo axillary node clearance (ANC) or axillary radiotherapy (ART). The publication of the Z11 trial challenged this practice. There are however concerns about this trial which may limit the interpretation and generalisability of its results. These issues include the proportion of patients with micrometastases, variability in radiotherapy and applicability in patients undergoing mastectomy. Therefore further randomized trials are needed to define the role of axillary treatment in patients with 1 or 2 SNs with macrometastases. The UK-ANZ POSNOC trial is asking this question and will provide a more solid evidence base to inform clinical practice.

Methods

Trial design: A pragmatic, randomized, multicenter, non-inferiority trial.

Interventions: All participants will receive systemic adjuvant therapy according to local guidelines and radiotherapy to breast or chest wall if indicated. Women in the intervention group will receive systemic adjuvant therapy alone, whereas those receiving standard care will receive adjuvant therapy plus ANC or ART.

Study population: Women with unifocal or multifocal invasive breast cancer(≤5 cm) undergoing breast conserving surgery or mastectomy, who have 1 or 2 nodes with macrometastases at SN biopsy. The sample size is 1900 women. All participants will be followed up for 5 years.

Primary outcome: axillary recurrence at 5 years.

Secondary outcomes: arm morbidity, quality of life, anxiety, loco-regional recurrence, distant metastasis; time to axillary recurrence, axillary recurrence-free survival, disease-free and overall survival, contralateral breast cancer, non-breast malignancy and economic evaluation.

Key differences from Z11

a) stringent radiotherapy quality assurance program, b) prospective pathology reporting, b) axillary ultrasound is mandatory, b) mastectomy patients are eligible, c) axillary treatment in the standard group may be ANC or ART.

Current enrollment

126 patients.

Further information

Web - www.posnoc.co.uk

Email - posnoc@nottingham.ac.uk

Citation Format: Goyal A. POSNOC: Positive sentinel node—Adjuvant therapy alone versus adjuvant therapy plus clearance or axillary radiotherapy: A randomised trial looking at axillary treatment in early breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-02-05.