bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4329: Enhancer mapping in triple-negative breast cancer as a tool for novel biomarker and oncogene discovery
Authors: Raisner Ryan , Bainer Russ , Gascoigne Karen
Published: August 2018

Breast cancer is the most commonly diagnosed cancer in women, affecting ~8% of women in the U.S. in their lifetime. Triple-negative breast cancer (TNBC) represents a heterogeneous class of aggressive cancers that comprise 15-20% of all breast cancers. TNBCs characteristically do not have significant levels of estrogen receptor (ER), progesterone receptor (PR), or overexpression of human epidermal growth factor 2 (HER-2). Consequently, there is a lack of proven drug therapies and biomarkers for TNBC. Here we have used ChIP-SEQ combined with RNA-SEQ to profile TNBC cell lines for their super-enhancer patterns. These noncoding, trans-acting elements control gene expression and play an essential role in the establishment and maintenance of cell states. It has been suggested that a wide range of cancers arise in part due to enhancer dysregulation, and key oncogenes genes coming under control of super-enhancers. This can occur through translocations, amplifications, or creation of de novo transcription factor binding sites. We hypothesize that mapping tumor-specific super-enhancer patterns in TNBC will identify novel tumor-specific gene-regulatory networks, and dysregulated genes that contribute uniquely to the development of tumors. We have conducted a CRISPR-mediated drop-out screen on a number of TNBC cell lines for genes that are controlled by cancer-specific super-enhancers with the hope of identifying novel oncogenic drivers.

Citation Format: Ryan Raisner, Russ Bainer, Karen Gascoigne. Enhancer mapping in triple-negative breast cancer as a tool for novel biomarker and oncogene discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4329.
Abstract 4355: Identification and functional characterization of glioma structural variants
Authors: Johnson Kevin C. , Barthel Floris P. , Tang Ming , Amin Samirkumar , Wang Qianghu , Sulman Erik P. , Rai Kunal , Verhaak Roel G.W
Published: August 2018

Adult diffuse gliomas are a diverse class of brain tumors that ultimately result in fatal malignant progression. The highly variable disease progression intervals and poor treatment response observed in glioma have been explained, in part, by the extent of heterogeneity within and across gliomas. Somatic structural variants such as deletions, duplications, insertions, inversions, translocations, and extrachromosomal DNA contribute to glioma heterogeneity by generating genomic instability, a hallmark of cancer genomes. While comprehensive approaches such as whole genome sequencing have begun to catalog the glioma structural variant landscape, the molecular mechanisms by which they contribute to tumor progression remains poorly understood. Here, we identified genomic rearrangements in the whole genomes of 147 gliomas and glioma cell lines. Among the whole-genome sequencing samples were 62 glioblastomas (TCGA), 52 low-grade gliomas (TCGA), and our own set of 33 patient-derived glioma sphere-forming cells. On average, glioblastomas demonstrated a greater frequency of high-confidence structural variants (162 per tumor) than low-grade gliomas (130 per tumor, P=0.02) with two glioblastomas displaying evidence of chromothripsis. Across the World Heath Organization's molecular classifications, the IDH-mutant 1p/19q co-deleted tumors demonstrated the lowest structural variant burden when compared with both IDH-wildtype and IDH-mutant non-co-deleted tumors. Structural variant frequencies were found to be similar between patient tumors and an independent set of patient-derived cell lines. Across all samples, a majority of the structural variant breakpoints were found in intronic (42%) and intergenic regions (55%) suggesting that rearrangements predominantly impact distal regulatory regions. To investigate the functional consequences of structural variants in these regions we integrated these samples with available RNA-sequencing and epigenetic data to characterize deregulated transcriptional circuits. Analyses examining the association between genomic rearrangements and chromatin states to determine potential mechanisms of oncogene activation in select tumor and cell line samples are now underway. Together, our study demonstrates the importance of integrating structural variant calls from whole genome sequencing with expression and epigenetic data to define functional genomic rearrangements.

Citation Format: Kevin C. Johnson, Floris P. Barthel, Ming Tang, Samirkumar Amin, Qianghu Wang, Erik P. Sulman, Kunal Rai, Roel G.W Verhaak. Identification and functional characterization of glioma structural variants [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4355.
Abstract 4374: Non-canonical activation of β-catenin by PRL-3 phosphatase in acute myeloid leukemia
Authors: Chong Phyllis SY , Zhou Jianbiao , Chooi Jing Yuan , Chng Wee Joo , Gunaratne Jayantha , Zeng Qi
Published: August 2018

Aberrant activation of Wnt/β-catenin signaling pathway is essential for the development of AML; however, the mechanistic basis for the dysregulation is unclear. PRL-3 is an oncogenic phosphatase implicated in the development of LSCs. Here, we identified Leo1 as a direct and specific substrate of PRL-3. Serine-dephosphorylated form of Leo1 binds directly to β-catenin, promoting the nuclear accumulation of β-catenin and transactivation of TCF/LEF downstream target genes such as cyclin D1 and c-myc. Importantly, overexpression of PRL-3 in AML cells displayed enhanced sensitivity towards β-catenin inhibition in vitro and in vivo, suggesting that these cells are addicted to β-catenin signaling. Altogether, our study revealed a novel regulatory role of PRL-3 in the sustenance of aberrant β-catenin signaling in AML. PRL-3 may serve as a biomarker to select for the subset of AML patients subset who are likely to benefit from treatment with β-catenin inhibitors. Our study presents a new avenue of cancer inhibition driven by PRL-3 overexpression or β-catenin hyperactivation.

Citation Format: Phyllis SY Chong, Jianbiao Zhou, Jing Yuan Chooi, Wee Joo Chng, Jayantha Gunaratne, Qi Zeng. Non-canonical activation of β-catenin by PRL-3 phosphatase in acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4374.
Abstract 4375: High hydrostatic pressure modified potato patatin induces apoptosis like cell death in human colorectal adenocarcinoma (HT-29) cell line
Authors: Elahi Rizwan , MU Tai Hua
Published: August 2018

The current study assessed the anticancer activity of HHP-induced potato patatin on human colorectal adenocarcinoma (HT 29) cell line in vitro. Cell proliferation, apoptosis, necrosis and autophagy were investigated. HHP treatment inhibited HT-29 cell line proliferation in a dose a dependent manner. IC50 values showed antiproliferative activity (59.1%) at 4 mg mL-1 for HHP-induced patatin at 450 MPa. Flow cytometric analysis indicated that HHP-induced patatin at 450 MPa was the potent inducer of in vitro apoptotic cell death and showed significant (p<0.05) accumulation in S-phase followed by patatin pressurized at 550 MPa. Surface charge of patatin decreased with the increase in pressurization up to 350 MPa level, while at 450 MPa zeta potential value increased to (-13 mV) and (-11 mV) respectively. Overall, results indicated that 450 MPa patatin is a strong inhibitor of HT-29 and a potent inducer of apoptotic cell death. Thus, HHP treatment is an effective method for structural modification of patatin which ultimately enhance the anticancer potential against colorectal cancer cells.

Citation Format: Rizwan Elahi, Tai Hua MU. High hydrostatic pressure modified potato patatin induces apoptosis like cell death in human colorectal adenocarcinoma (HT-29) cell line [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4375.
Abstract 4385: p53 activation induces a targetable dependence on FLIPL
Authors: McIntyre Alexander , Lees Andrea , Falcone Fiammetta , Gregg Gemma , Tamas Sessler , Quinn Gerard , Crawford Nyree , McArt Darragh , Dunne Phillip , Lawler Mark , Daniel Longley B. , McDade Simon S.
Published: August 2018

Background

The tumor suppressive functions of the p53 transcription factor are inactivated via mutations or suppressed through non-mutational mechanisms in almost all cancer cells. A better understanding of the mechanisms through which p53 differentially regulates cell cycle arrest and cell death is important to maximize benefits from wild-type p53-dependent therapeutic strategies

Methods

A panel of matched p53 wild-type and deficient colorectal cancer cell line models were studied, using Nutlin-3A and Oxaliplatin as direct and indirect p53 activating agents respectively. A number of molecular (Western blot, RT-PCR), phenotypic (cell death) and genomic analyses were used to investigate the importance of p53 and its downstream transcriptional programs.

Results

Here, we report that activation of pro-apoptotic p53 targets in colorectal cancer cells imposes a critical targetable dependence on the long splice form of the caspase-8 regulator FLIP (FLIPL) for survival. p53 binds the promoter of the FLIP gene (CFLAR) and upregulates FLIPL expression in response to the p53 agonist Nutlin-3A in a manner dependent on HDAC1/2/3 activity. As such, preventing FLIPL upregulation with the clinically relevant HDAC1/2/3-selective inhibitor Entinostat promotes apoptosis induction in response to Nutlin-3A (or p53-activating chemotherapy), which otherwise predominantly induces growth arrest despite upregulating a range of pro-apoptotic target genes. Cell death in response to Nutlin-3A in FLIPL-depleted cells is primarily mediated via caspase-8. However, in the absence of caspase-8, apoptosis is delayed, but not prevented and is mediated via caspase-10. Of note, the cell death induced in both caspase-8-proficient and -deficient cells is mediated via TRAIL-R2 in a ligand-independent manner.

Conclusion

In summary, this work has uncovered novel, clinically-relevant biology, in which p53-mediated upregulation of FLIPL primes cells for TRAIL-R2-mediated apoptosis and identifies FLIPL as a key target for overcoming resistance to p53-stabilising agents in p53 wild-type cancers. Moreover, we show the potential of combining Nutlin-3A (or other p53 activating chemotherapies) with the clinically relevant Class I HDAC inhibitor Entinostat for the treatment of p53 wild-type CRC, and identify FLIPL as a critical p53-induced signaling node, the inhibition of which is necessary to promote Nutlin-3A-induced apoptosis.

Citation Format: Alexander McIntyre, Andrea Lees, Fiammetta Falcone, Gemma Gregg, Sessler Tamas, Gerard Quinn, Nyree Crawford, Darragh McArt, Phillip Dunne, Mark Lawler, Longley B. Daniel, Simon S. McDade. p53 activation induces a targetable dependence on FLIPL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4385.
Abstract 4386: Regulation of FIP200 by Her2 and its role in Her2-driven mammary tumors
Authors: Hao Mingang , Guan Jun-Lin
Published: August 2018

Autophagy has been shown to play both tumor promoting and suppressive roles in various cancers, although the underlying mechanisms are not well understood. Compared to other subtypes of breast cancer (BCa), Her2+ BCa displays a lower autophagy gene signature, suggesting a potentially tumor suppressive function of autophagy in this subtype of BCa. FIP200 is a component of the ULK1/ATG13/FIP200/Atg101 complex essential for autophagy induction in mammalian cells, and our previous studies showed that Fip200 deletion suppressed BCa in MMTV-PyMT mouse model. Indeed, analysis of TCGA database showed that higher FIP200 expression correlated with decreased survival of BCa patients including all subtypes. In contrast, in Her2+ BCa population specifically, higher expression of FIP200 correlated with better patient survival, suggesting a differential function of FIP200. To uncover the role of FIP200 and autophagy in Her2+ BCa, we studied Fip200 in MMTV-Neu mouse tumor cells that model Her2+ BCa. We found that inhibiting autophagy by deletion of Fip200 or Atg13 using Crispr-Cas9 led to increased migration and partial EMT for MMTV-Neu cells. Further, deletion of Fip200 or Atg13 as well as autophagy inhibition by Spautin1 significantly enhanced β-catenin/LEF1/TCF reporter activity, which may promote cell migration and EMT. These changes in Fip200-null tumor cells could be rescued by re-expression of ectopic FIP200, excluding any potential off-target effects of gene knockout. We also found that Her2 knockdown or lapatinib treatment of MMTV-Neu cells increased Fip200 expression and autophagy. Together, these results raised the interesting

possibility that Her2 may promote tumor development and/or progression at least in part by reducing FIP200 expression to inhibit autophagy, which might play a tumor suppressive role in Her2-driven BCa.

Citation Format: Mingang Hao, Jun-Lin Guan. Regulation of FIP200 by Her2 and its role in Her2-driven mammary tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4386.
Abstract 4389: HEXIM1 is a negative regulator of H. pylori-induced BIRC3 enhancer RNA
Authors: Sheppard Donald R.
Published: August 2018

The bacterium Helicobacter pylori inhabits the human stomach and is responsible for a number of pathologies, including being strongly associated with the development of gastric adenocarcinoma. H. pylori inhibits apoptosis in gastric cells, but the mechanism is poorly understood. We investigated how H. pylori inhibits apoptosis using cultured G27-strain H. pylori to stimulate cancer cell lines, and apoptosis was induced with Raptinal. We found that H. pylori induces the transcription of the apoptosis-inhibiting protein cIAP2, and this induction is sufficient to inhibit apoptosis in stimulated cells. We found an enhancer region upstream of the gene that codes for cIAP2 (BIRC3). H. pylori induces expression of RNA from this enhancer, and RNAi treatment targeting this eRNA inhibited induction of the BIRC3 mRNA. Chromatin immunoprecipitation revealed that positive transcription elongation factor b (P-TEFb) is recruited to the enhancer following H. pylori stimulation, and RNA polymerase II is activated. We found that the negative regulator of transcription HEXIM1 inhibits P-TEFb recruitment and eRNA production. HEXIM1 also inhibits BIRC3 mRNA transcription, cIAP2 protein induction and H. pylori's anti-apoptotic effect. Together, these findings indicate that H. pylori inhibits apoptosis induction in cultured cells, and this inhibition is mediated by the induction of BIRC3/cIAP2. H. pylori stimulates the production of RNA from the enhancer region of BIRC3, which is required for the induction of the gene, and the eRNA production is regulated by HEXIM1 and P-TEFb.

Citation Format: Donald R. Sheppard. HEXIM1 is a negative regulator of H. pylori-induced BIRC3 enhancer RNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4389.
Abstract 4390: Developing methods for investigating cold atmospheric plasma effects on cervical cancer
Authors: Sova Nicole J. , Zhu Yonry , Mitchell Quinn O. , Lanier Ariel L. , Burnette David , Burdick Monica M.
Published: August 2018

Cold atmospheric plasma (CAP) has been suggested for use as a novel cancer therapeutic due to its reported ability to induce cell-specific death. Cervical cancer is the fourth most common cancer in women. Its prevalence and accessibility for topical treatment make cervical cancer an ideal target for CAP treatments. Despite its potential impact, effects of CAP in biological systems are not well understood. To better understand the viability of CAP as a therapy, this project investigated in vitro cellular responses induced by CAP treatment within cancerous cervical cells (SiHa) and non-cancerous cervical (Ect1/E6E7 and End1/E6E7) and vaginal cells (VK2/E6E7).

Plasma is a state of ionized gas, produced using a controlled electric field or extreme heat. CAP, however, is a subset of plasma that is produced near 1 atm and 40oC. This allows for CAP treatment of biological systems without heating-induced effects. A dielectric barrier discharge plasma pen was developed for this study. Plasma modeling was conducted in order to predict the reactive species present in the system. CAP treatments were performed on cells for 30 seconds using a helium carrier gas at a flowrate of 1 L/min and a DC power supply with input settings of 10kV, 1µs, and 0.1A.

Cell vitality assays demonstrated induced cell death following exposure to CAP treatment in both cancerous and noncancerous cervical cells as indicated by flow cytometric analysis and florescence microscopy. CAP treatment induced cell death in 76 ± 8% of treated cancerous, SiHa, cells. In comparison, noncancerous cell lines Ect1/E6E7, End1/E6E7, and VK2/E6E7 underwent 49 ± 8%, 42 ± 13%, and 51 ± 7% cell death, respectively. Flow cytometry characterization and wound healing assays indicate that CAP treatment does not significantly affect the expression of investigated cell surface adhesion molecules or cell migration. Cells were treated with helium carrier gas as the negative control and hydrogen peroxide as an induced death control.

Altered levels and locations of uptake of FITC and quantum dots following CAP treatment suggest modification of cell membranes as compared to carrier gas treatment controls. Adjustments in membrane permeability may be a mechanism through which CAP treatment increases exposure to apoptotic triggers.

In conclusion, comprehensive understanding of CAP effects on cancerous and non-cancerous cells could lead to the development of effective CAP-based therapies for cervical cancer.

Citation Format: Nicole J. Sova, Yonry Zhu, Quinn O. Mitchell, Ariel L. Lanier, David Burnette, Monica M. Burdick. Developing methods for investigating cold atmospheric plasma effects on cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4390.
Abstract 4394: Novel edible medicinal plant induced cytotoxic and apoptotic effects on ovarian cancer cells
Authors: Mbemi Ariane T.
Published: August 2018

Ovarian cancer (OC) is the leading cause of death in gynecologic cancer and the fifth most common form of cancer diagnosed among women. Caucasians have a higher incidence and mortality rate compared to African-Americans. The low survival rate of ovarian cancer among patients is caused by the fact that ovary organs are located inside the pelvic region in the female reproductive system; many cases are diagnosed in advanced stage, when cancer has already metastasized beyond the ovaries. Consequently, there is an urgent need to prevent ovarian cancer at the early stage and provide effective treatment. Herbal medicine with lesser or no side effect is currently considered as an alternative cancer treatment because it possesses many bioactive compounds essential to destroy cancer cells. A preliminary study in our laboratory demonstrates that extracts of Vernonia species have antitumor activities against cancer cells. Therefore, our overall goal in this study was to test the therapeutic mechanisms of a Vernonia species (an edible medical plant) in the treatment of ovarian cancer. To reach our goal, we tested the cytototic and apoptotic effects of the Vernonia species on OVCAR-3 cells. Data generated from the trypan blue test and MTT assay demonstrated that extracts of Vernonia species exhibited significant growth-inhibitory effects on OVCAR-3 cells. Oxidative stress biomarkers showed slight decrease in the production of malondialdehyde (MDA) levels and an increase in catalase activity and glutathione peroxidase in treated cells compared to the control group. Further experiments, including cell morphology and apoptosis analysis, showed that VA caused growth-inhibitory effects on OVCAR-3 cells through cell cycle arrest at the Go/G1 checkpoint and activation of caspase-3 activity leading to apoptosis. Collectively, findings from this study provide convincing scientific evidence that the Vernonia species tested here may represent a potential anticancer candidate against ovarian cancer.

This research work was supported by a grant from the National Institutes of Health (Grant No. NIMHD-G12MD007581).

Citation Format: Ariane T. Mbemi. Novel edible medicinal plant induced cytotoxic and apoptotic effects on ovarian cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4394.
Abstract 4395: KP-1339 (IT-139) induces the hallmarks of immunogenic cell death in a colon cancer 3D model in vitro
Authors: Wernitznig Debora , Favero Giorgia Del , Kiakos Konstantinos , Harrer Nathalie , Machat Herwig , Marko Doris , Jakupec Michael , Sommergruber Wolfgang , Keppler Bernhard K.
Published: August 2018

Chemotherapeutic drugs exert their activity by directly killing tumor cells through a variety of cellular targets eventually leading to apoptosis. Apoptosis is regarded as non-inflammatory and non-immunogenic, however, recent data confirm that the induction of damage-associated molecular patterns by dying cancer cells treated with certain chemotherapeutic agents, such as oxaliplatin, lead to their recognition by the immune system, and result in dendritic cell maturation and immune responses, a mechanism described as Immunogenic Cell Death (ICD). The main hallmarks of ICD are: Calreticulin (CRT) exposure on the cell membrane and release of high mobility group box-1 (HMGB-1) and ATP from dying cells. We have recently shown that the mode of action of KP-1339, a clinically investigated ruthenium-based metal complex, involves the enhancement of endoplasmic reticulum stress (ERS) and the induction of apoptosis-like events. We next investigated the ability of KP-1339 to trigger ICD. There is currently no reliable method to study ICD in vitro, and therefore we aimed at a more suitable model that better mimics the tumor microenvironment in comparison to 2D monolayer cultures. For this reason, ICD was assessed in human colorectal cancer HCT-116 3D multicellular spheroids in vitro. We demonstrate that spheroids treated with KP-1339 activate the PERK/Phospho-eIF-2alpha pathway of the ERS, a prerequisite for CRT exposure on the cell membrane. HMGB1 protein levels decrease considerably during a 72 hours drug treatment, as shown by Immunoblotting, suggesting the depletion of the protein. Additionally, treated spheroids released significantly more ATP than untreated controls. Immunofluorescence of cryosections of KP-1339 treated spheroids stained for CRT and HMGB1 confirmed the above observations and, clearly showed the translocation of CRT to the cell membrane.

In conclusion, we have established a 3D tumor spheroid model as an alternative to the 2D monolayer cultures to study ICD in vitro. This model more closely resembles the tumor microenvironment and recapitulates relevant aspects of the in vivo situation. We successfully employed this model to demonstrate that the clinically investigated compound KP-1339 triggers the main hallmarks of ICD, which suggests enhanced induction anti-tumor immunity in colorectal cancer.

Citation Format: Debora Wernitznig, Giorgia Del Favero, Konstantinos Kiakos, Nathalie Harrer, Herwig Machat, Doris Marko, Michael Jakupec, Wolfgang Sommergruber, Bernhard K. Keppler. KP-1339 (IT-139) induces the hallmarks of immunogenic cell death in a colon cancer 3D model in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4395.
Abstract 4396: Targeting survivin to overcome docetaxel resistance in prostate cancer
Authors: Peery Robert C.
Published: August 2018

Despite therapeutic advancements, castration-resistant prostate cancer (CRPC) remains the second most common cause of cancer-related mortality in men. Docetaxel is the first cytotoxic agent to show modest improvements in overall survival rate in patients with CRPC. Unfortunately, over half of these patients do not respond to treatment and ultimately all develop resistance. The mechanism mediating docetaxel resistance remains unknown. However, survivin, an inhibitor of apoptosis (IAP) family member, and known mediator of chemo-resistance has been previously associated with docetaxel resistance, as inhibition of survivin expression sensitized prostate cancer cells to docetaxel in vitro, and a small molecule inhibitor targeting survivin expression led to a significant regression in prostate cancer xenograft tumors when given in combination with docetaxel. However, how survivin may mediate docetaxel resistance in prostate cancer remains unknown. In this study, we tested the hypothesis that overexpression of nuclear survivin contributes to docetaxel resistance in prostate cancer cells. First, utilizing western blot to assess protein level and methylene blue assays to determine ability to proliferate under cytotoxic conditions, we found that survivin expression and docetaxel IC50 correlates strongly in five prostate cancer cell lines. Furthermore, using paired parental drug sensitive and stepwise selected docetaxel resistant cell lines, we determined that resistant cells overexpress survivin as compared to parental cells, and knockdown of survivin decreases resistance to docetaxel. Our studies suggest that survivin is likely implicated in CRPC and treatment with a direct survivin inhibitor may sensitize resistant cells to docetaxel. We are in the process of determining how this IAP may mechanistically mediate docetaxel resistance.

Citation Format: Robert C. Peery. Targeting survivin to overcome docetaxel resistance in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4396.
Abstract 4405: Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology
Authors: Yahyanejad Sanaz , Gunst Thijs de , Schultz Iman , Boer Harm den , Raimo Monica , Telford Bryony , Vos Rogier , Pinxteren Laurens van , Schaapveld Roel , Janicot Michel
Published: August 2018

MicroRNAs (miRNAs) are a family of small, non-coding RNAs and serve as small snippets of genetic material that regulate gene expression. As a result, miRNAs modulate a wide range of biological processes including; cell cycle control and apoptosis, cell signaling and differentiation, cell adhesion and motility. Thus, it is not surprising that their misregulation is linked to cancer initiation, treatment response, and metastasis. Due to the inherent ability of miRNAs to concurrently target multiple pathways, their therapeutic potential to be used as anti-cancer drugs is attractive. In this study, we are investigating the mode of action and development of a novel synthetic miRNA mimic (INT-1B3) as a therapeutic candidate for substitution and functional restoration of a depleted miRNA in variety of cancers. To identify miRNAs that control the survival of cancer cells, we performed a functional miRNA screening in which a wide range of relevant miRNAs were selected and miR-193a-3p was chosen as the potential candidate for further preclinical characterization. Compelling evidence demonstrate a tumor suppressor function for miR-193a-3p in many cancer types and link its reduced expression with cancer, metastasis and therapy resistance. Consistent with the described role for miR-193a-3p in literature, our cell-based assays conducted in various experimental tumor cell systems demonstrated efficient target engagement leading to reduced cell proliferation/survival, cell cycle arrest and induction of apoptosis, inhibition of cell motility as well as a potential immune-modulatory role (via adenosine-mediated tumor immune evasion). Furthermore, development of a novel lipid nanoparticle-based formulation as an efficient delivery system demonstrated a marked anti-tumor activity of INT-1B3 as single agent following systemic administration in tumor-bearing mice. Robust tumor growth inhibition in these experimental tumor models is correlated and consistent with efficient target engagement in tumor cells and relevant organs. We are currently investigating the in vitro and in vivo effect of INT-1B3 in variety of cancer types including hepatocellular carcinoma, melanoma and triple negative breast cancer. Our data thus far supports an anti-tumor role for INT-1B3 and encourages further preclinical and clinical investigation.

Citation Format: Sanaz Yahyanejad, Thijs de Gunst, Iman Schultz, Harm den Boer, Monica Raimo, Bryony Telford, Rogier Vos, Laurens van Pinxteren, Roel Schaapveld, Michel Janicot. Pharmacologic profile of INT-1B3: A novel synthetic microRNA 193a-3p mimic for therapeutic intervention in oncology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4405.
Abstract 4419: FOXP3 mediated transcriptional regulation of microRNAs in breast cancer
Authors: Liu Wei , Gao Song , Li Xin , Hu Fengpin , Wang Lizhong
Published: August 2018

MicroRNAs (miRs) have potential as non-invasive biomarkers, but their relevance as biomarkers is limited by inconsistent results, and their regulatory mechanisms remain elusive. In the present study, our results show that the levels of miR-200c and 141 in tumor cells and in circulation differ for mice and for humans between cases with metastatic breast cancer, cases with localized breast cancer, and healthy female controls. The levels of miR-200c and 141 are low in primary tumor cells but are high in the circulation of patients with metastatic breast cancer. Further, we suggest the potential cell origin of circulating miR-200c and 141 and describe their transcriptional regulation in cultured cells and during tumor progression in animal models of spontaneous breast cancer. These results could provide useful insights in early prediction of tumor metastasis and influence treatment strategies for patients at high risk of developing metastatic breast cancer.

Citation Format: Wei Liu, Song Gao, Xin Li, Fengpin Hu, Lizhong Wang. FOXP3 mediated transcriptional regulation of microRNAs in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4419.
Abstract 4421: A novel long non-coding RNA competes with endogenous RNA and mediates prostate cancer progression
Authors: Shi Xiao-Lei , Xiao Yu-Tian , Liu Fei , Yang Yue , Nian Xin-Wen , Zhu Ya-Sheng , Ren Shancheng , Sun Yinghao
Published: August 2018

Prostate cancer (PCa) remains the leading cancer among men worldwide. There is a critical need for new biomarkers to predict PCa progression and emerging mechanisms of resistance. Long non-coding RNAs(lncRNAs) play pivotal roles in a plethora of cellular processes. Understanding the molecular mechanisms of lncRNAs implicated in the progression of PCa could have an important impact on cancer detection, diagnosis and prognosis.

We previously identified 17 lncRNAs that were found to be differentially expressed in oriental PCa patients. Here, We focused on one uncharacterized lncRNA, which is highly expressed in locally advanced or metastatic PCa, and named it lncAPP. Silencing of lncAPP in PCa inhibitied proliferation and tumour invasion both in vitro and in vivo, resulting in a less aggressive phenotype. In addition, we found that expression of lncAPP in PCa correlated with epithelial-to-mesenchymal-transition(EMT). Using miRDB and Target Scan prediction algorithm, we identified a list of putative lncAPP-binding miRNAs. Specifically, using RNA immunoprecipitation assay and luciferase reporter assay, we demonstrated that lncAPP functions as a molecular sponge for miR218 to facilitate expression of ZEB2 and CDH2.

In conclusion, we discovered a novel lncRNA which is highly expressed in PCa patients of poor prognosis. The expression of lncAPP is associated with tumor progression. We conclude that lncAPP is an intriguing therapeutic target in PCa.

Citation Format: Xiao-Lei Shi, Yu-Tian Xiao, Fei Liu, Yue Yang, Xin-Wen Nian, Ya-Sheng Zhu, Shancheng Ren, Yinghao Sun. A novel long non-coding RNA competes with endogenous RNA and mediates prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4421.
Abstract 4426: Automated miRNA purification from plasma, serum or exosomes
Authors: Mandrekar Michelle , English Jami , Horejsh Douglas , Moreland Chris , Karlen Herly , Urh Marjeta
Published: August 2018

Introduction: MicroRNAs (miRNAs) are endogenous small noncoding RNAs 18-24 nucleotides in size that play important roles involving gene regulation associated with cancer, disease control and gene silencing. Because of the impact on disease progression, miRNA research is rapidly shifting towards biomarker discovery. Many of the commercially available miRNA purification methods involve organic extraction during preprocessing. Here, we describe a novel chemistry that enables RNA purification including smaller RNA such as miRNA. This chemistry offers significant advantages with a simple automated workflow, no organic extraction and minimal preprocessing.

Method: In this study we show successful purification of small RNA, including miRNA, from 100uL to 500uL liquid samples utilizing a novel chemistry on the Maxwell® RSC instrument, which can process between 1 and 16 samples. Proteinase K and Lysis Buffer C are added to the liquid samples and incubated before being transferred to the Maxwell cartridge for miRNA isolation. Sample types tested include plasma, serum and isolated exosomes. The miRNA were evaluated using RT-qPCR including miR-16, miR-21, and let-7a.

Results: The eluates had high levels of small RNA including miRNA at levels comparable to manual competitor methods that require organic extraction. Quantitative PCR showed that the eluates had little or no detectable DNA contamination. Integration of the chemistry onto this automated platform reduced hands-on time while maintaining high quality needed for use in downstream RT-qPCR amplification assays.

Summary: This novel chemistry and method enables purification of small RNA from a range of samples types and volumes. The purified RNA has little or no detectable DNA contamination. Phenol extraction is not required, improving safety and simplifying waste disposal. Also, the automation of this workflow decreases manual hands-on time, saving scientist time and reducing the risk of RNase contamination.

Citation Format: Michelle Mandrekar, Jami English, Douglas Horejsh, Chris Moreland, Herly Karlen, Marjeta Urh. Automated miRNA purification from plasma, serum or exosomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4426.
Abstract 4430: Genistein regulates non-coding RNA HOTAIR and epithelial-to-mesenchyme transition in renal cancer cells
Authors: Sumida Mitsuho I. , Tanaka Yuichiro , Dahiya Rajvir , Yamamura Soichiro
Published: August 2018

Renal cell carcinoma (RCC) is one of the most common malignancies. Despite the development of therapeutic regimens, the prognosis of patients with RCC is poorly understood. Genistein, a naturally occurring isoflavone, has been reported to have anti-cancer effects on a variety of cancer types. While several studies have shown that genistein inhibits kidney cancer progression in various in vitro and in vivo models, the basic molecular mechanisms of genistein action have not been investigated in kidney cancer. In malignancies, long non-coding RNAs (lncRNAs) are differentially expressed in various tissues and have important functions in cell proliferation, motility and apoptosis. HOX transcript antisense RNA (HOTAIR) is a lncRNA localized in the Homeobox C gene cluster on chromosome 12. HOTAIR is necessary to target the polycomb repressive complex 2 (PRC2) in trans to the HOXD locus and can interacts with (PRC2, which enhances H3K27 trimethylation and represses the expression of tumor suppressors. HOTAIR is highly expressed in various cancers and involved in their progression and metastasis. In our study, we investigated the molecular mechanisms of genistein action through a novel pathway that represses HOTAIR. We found that HOTAIR expression is higher in renal cancer cell lines compared to normal controls. Genistein treatment was found to significantly decrease HOTAIR expression in renal carcinoma cell lines (786-O and ACHN cells). Genistein treatment also reduced expression of epithelial-to-mesenchyme transition (EMT)-related proteins, causing reduced cell migration, invasion, and increased apoptosis. We performed RNA immunoprecipitation assays, and found that genistein inhibits HOTAIR binding to PRC2. One of the other EMT markers, a tight junction protein ZO-1, is upregulated by genistein. We further investigated whether genistein represses PRC2 recruitment to the ZO-1 promoter by inhibiting binding of HOTAIR to PRC2. In this study, we revealed detailed mechanism of antitumor action of genistein. These insights indicate that genistein is a potent therapeutic agent not only for renal cancer but also for a broad spectrum of cancers.

Citation Format: Mitsuho I. Sumida, Yuichiro Tanaka, Rajvir Dahiya, Soichiro Yamamura. Genistein regulates non-coding RNA HOTAIR and epithelial-to-mesenchyme transition in renal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4430.
Abstract 4433: Upregulation of BLU tumor suppressor gene by miR-34a
Authors: Ohno Shinichiro , Sambu Yoshihiro , Oikawa Keiki , Naito Yoshitaka , Harada Yuichirou , Kuroda Masahiko
Published: August 2018

miR-34a is down-regulated in several tumor tissues and well known as strong tumor suppresser miRNA. However, the mechanisms of tumor suppression by miR-34a remain unclear. To elucidate the mechanisms of tumor suppression by miR-34a, we performed microarray analysis of miR-34a transfected cells. Interestingly, we found that the number of up-regulated genes was larger than down-regulated genes by the transfection of miR-34a. The tumor suppresser BLU (ZMYND10) is strongly up-regulated by miR-34a that primarily expressed in the normal lung and down-regulated in non-small cell lung cancer (NSCLC). Therefore, we investigated the possibility that miR-34a inhibits lung cancer development through inducing BLU expression. It was recently reported that miRNA also regulate transcription in the nucleus through binding to the lncRNA from promoter locus. Because, the predicted two binding sites of miR-34a are located in the BLU promoter locus, we searched the lncRNA expressed from the BLU promoter locus. As a result, we identified the lncRNA from the BLU promoter and siRNA against the lncRNA also induced BLU expression. These results suggest that miR-34a induced tumor suppresser BLU through the binding to the promoter-associated lncRNA.

Citation Format: Shinichiro Ohno, Yoshihiro Sambu, Keiki Oikawa, Yoshitaka Naito, Yuichirou Harada, Masahiko Kuroda. Upregulation of BLU tumor suppressor gene by miR-34a [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4433.
Abstract 4449: Synthetic lethality between CSTF2 and CSTF2T in lung adenocarcinoma and melanoma cell lines
Authors: Popow Johannes , Wieshofer Corinna , Schlattl Andreas , Woehrle Simon , Neumüller Ralph , Petronczki Mark P. , Boettcher Jark , Koegl Manfred , Pearson Mark
Published: August 2018

Genomic instability is a hallmark of cancer and can result in the deletion of genes with no apparent or as yet unknown relevance to tumor survival and proliferation. Although the deletion of such genes may be tolerated due to functional compensation it, however, entails a cancer cell specific vulnerability as the tumor cell relies on the function of compensating redundant genes. Recurrent deletions of cleavage stimulation factor subunit 2 Tau (CSTF2T) have been observed in several tumor samples (TCGA). During meiosis CSTF2, a paralogue of CSTF2T, which resides on the X-chromosome, is transcriptionally silenced and the zygote depends on the activity of CSTF2T. As a result, CSTF2T knockout mice exhibit male sterility which corroborates that CSTF2 and CSTF2T form a functionally redundant pair of genes with an essential function (Dass et al. 2007). With the aim to apply these findings to tumor biology, we therefore tested whether tumor cells with homozygous CSTF2T deletions depend on CSTF2 using CRISPR-based growth competition assays and confirmed this concept in lung adenocarcinoma and melanoma cell line models. Our data establish synthetic lethality between CSTF2 and CSTF2T and suggest inhibition of CSTF2 in CSTF2T deficient tumors as a new therapeutic concept.

Citation Format: Johannes Popow, Corinna Wieshofer, Andreas Schlattl, Simon Woehrle, Ralph Neumüller, Mark P. Petronczki, Jark Boettcher, Manfred Koegl, Mark Pearson. Synthetic lethality between CSTF2 and CSTF2T in lung adenocarcinoma and melanoma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4449.
Abstract 4462: RUNX1 global binding and gene regulation in mammary epithelial cells revealed novel Runx1 mediated cellular activities
Authors: Hong Deli , Fritz Andrew J. , Tye Coralee E. , Page Natalie A. , Boyd Joseph R. , Lian Jane B. , Stein Janet L. , Stein Gary S.
Published: August 2018

The transcription factor RUNX1 is one of the most frequently mutated genes in breast tumors. However, the role of RUNX1 in the mammary gland is understudied. Previously, our group established that RUNX1 has tumor suppressor activities in both normal mammary epithelial and breast cancer cells, including inhibition of epithelial to mesenchymal transition (EMT), migration, and invasion. To better understand the cellular consequences mediated by RUNX1 loss-of-function in mammary epithelial cells, we performed global gene expression profiling (RNA-seq) in Runx1-depleted MCF10A cells. Upon loss of RUNX1, the expression of 1806 genes was significantly altered (with 2-fold change cutoff). Pathway analysis on these differentially expressed genes revealed that RUNX1 is involved in many cellular activities, including lipid metabolism, cell growth and cell cycle control, which were not previously reported. Consistent with expression profiling results, flow cytometry analysis showed the mitotic population in RUNX1 depleted cells was significantly decreased, indicating RUNX1 is important for proper cell division. To investigate the mechanisms by which RUNX1 controls expression of those differentially expressed genes, RUNX1 genome-wide occupancy analysis (ChIP-seq) was performed in MCF10A cells. We found that although RUNX1 binding is enriched at transcription start sites (TSS), RUNX1 also binds to loci distal to TSSs and multiple other regulatory elements. Therefore, RUNX1 has the capability to utilize multiple mechanisms to control target gene expression. Our results highlight crucial roles for RUNX1 in controlling normal growth of mammary epithelial cells, consistent with its tumor suppressor activities. Loss of RUNX1 leads to improper gene regulation and cell cycle defects, which may contribute to tumor progression in breast cancer. These RUNX1-mediated mechanisms point to novel intervention strategies for early stage breast cancer.

Citation Format: Deli Hong, Andrew J. Fritz, Coralee E. Tye, Natalie A. Page, Joseph R. Boyd, Jane B. Lian, Janet L. Stein, Gary S. Stein. RUNX1 global binding and gene regulation in mammary epithelial cells revealed novel Runx1 mediated cellular activities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4462.
Abstract 4468: Repression of CD44 expression by p53 in a breast cancer progression model
Authors: Liu Fang , Liu Zhengxue , Wang Guannan , Roy-Kundu Tanima , Matsuura Isao
Published: August 2018

CD44 is an important molecule in breast cancer. Although CD44 lacks its own signaling domain, it can associate with and co-stimulate signaling by a number of growth factor receptors, such as Her2 and EGF receptor 1. Knockdown of CD44 significantly reduces mammary tumor-initiating frequency and tumor weight. Disruption of tumor cell surface CD44 function induces apoptosis in metastatic mammary carcinoma cells in vivo. Some studies showed that the breast cancer stem cells are enriched in the CD44highCD24low population. The tumor suppressor p53 is mutated or functionally inactivated in over 70% of cancer. In breast cancer, p53 is mutated in ~35% cases, and ~50% breast cancers contain MDM2 or MDMX overexpression. A previous study showed that p53 repressed the expression of CD44 and that this activity was essential for the tumor-suppressor function of p53. We find that p53 potently represses the expression of CD44 in normal human breast epithelial cells. Mutation of the p53 binding site on the CD44 promoter greatly reduces the ability of p53 to repress CD44 expression. We show that p53 repression of CD44 expression is progressively reduced in a breast cancer progression model. Our ongoing studies are elucidating the underlying mechanisms. Our findings will help for better understanding and treatment of breast cancer.

Citation Format: Fang Liu, Zhengxue Liu, Guannan Wang, Tanima Roy-Kundu, Isao Matsuura. Repression of CD44 expression by p53 in a breast cancer progression model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4468.