bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4804: Multitargeted kinase inhibition (AEE788) alleviates mTOR inhibitor drug resistance in triple-negative breast cancer
Authors: He Jichao , McLaughlin Ronan P. , Noord Vera van der , Westen Gerard van , Zhang Yinghui , Water Bob van de 
Published: August 2018

Abstract
Triple negative breast cancer (TNBC), although accounting for 15-20% of breast cancer, is disproportionally responsible for female cancer death. Despite therapeutic strategies being advanced, the clinical outcome of mTOR-targeted chemotherapy remains poor in the past decades. Recent data have evidenced the interdependence of kinase signaling networks and their involvement in treatment refractory TNBC settings. Thus, a combinatorial therapy targeting multiple components of signaling cascade is urgently needed. We assessed drug response phenotype across 20 TNBC cell lines by profiling the effect of a kinase inhibitor library consisting of &gt;350 different kinase inhibitors (KIs). A panel of TNBC cell lines clustered with resistance phenotype against rapalogues (rapamycin analogues). Rapamycin efficacy on TNBCs was detected by performing proliferation assays and calculating their IC50, respectively. Given the role of the mTOR pathway in translational control, the relationship between rapamycin responses (IC50) and translational factors expression in TNBC cell lines was studied by Pearson analysis. Notably, translation initiation factor EIF2B2, EIF2S3, EIF3S8 and EIF1AX positively correlated with rapamycin response, whereas EIF4EBP2 and EIF2AK2 displayed negative correlation. Next, a rapamycin combination KI library screen was performed to identify kinase inhibitors synergizing with mTOR inhibition. AEE788, a multiple kinase targeting inhibitor, synergistically enhanced inhibitory effect of rapamycin on TNBC cell proliferation. Moreover, AEE788 dose-dependently synergized with mTOR targeted therapy in several TNBC cell lines. The combination treatment significantly decreased phosphorylation level of mTOR and 4EBP1 as well as ERK, indicating downregulation of PI3K/AKT and MAPK pathways. ChEMBL-based cheminformatics analysis indicated that, besides VEGFR and EGFR, a number of other kinases were predicted as the targets of AEE788, including RPS6K1, AKT2 and CDK7. Altogether, our data reveals the essential role of rapamycin-associated translation factors in TNBC, and provides insight in the resistance of TNBC to rapamycin analogues as well as potential therapeutic approaches to alleviate rapamycin resistance.
Citation Format: Jichao He, Ronan P. McLaughlin, Vera van der Noord, Gerard van Westen, Yinghui Zhang, Bob van de Water. Multitargeted kinase inhibition (AEE788) alleviates mTOR inhibitor drug resistance in triple-negative 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 4804.
Abstract 4817: EP-100 sensitizes BRCA wild-type ovarian cancer cells to PARP inhibitor
Authors: Ma Shaolin , Pradeep Sunila , Wu Sherry , Kim Mark Seungwook , Hu Wei , Mangala Selanere , Coleman Robert L. , Sood Anil K. 
Published: August 2018

Abstract
EP-100 is a synthetic lytic peptide specific for targeting LHRH receptors on cancer cells that is being clinically tested for treatment of ovarian cancer. In this study, we aimed to identify combination approaches with EP-100 in ovarian cancer models. We carried out a series of in vitro (MTT assay, immunoblot analysis, Q-PCR, reverse phase protein array (RPPA), comet assay and immunofluorescence staining) and in vivo (orthotopic mouse model) experiments in ovarian cancer models to determine the biological effects of EP-100 alone and in combination with standard of care drugs. We first examined the cytotoxic effects of EP-100 alone on 8 ovarian cancer cell lines with variable expression level of LHRH receptors and the IC50 values ranged from 0.5 to 2.0 µM. We then tested the effect of combining EP-100 with standard drugs (e.g., cisplatin, paclitaxel, doxorubicin, topotecan, and olaparib) on ovarian cancer cells. Of those drugs, we found that combination of EP-100 and olaparib was highly synergistic in drug sensitive and multi-drug resistant ovarian cancer cell lines (HeyA8, HeyA8-MDR, A2780, and A2780CP20). The combination indices (CI) were &lt; 0.9 at the ED50 level. Furthermore, the nuclear foci of γH2AX were significantly increased in combination group of EP100 and olaparib after 24 h incubation compared with control, EP-100 alone, or olaparib alone groups (p &lt; 0.0001, ANOVA). In addition, there was increased DNA accumulation in tails using comet assay after treating cells with EP-100 and olaparib for 24 h (p &lt; 0.001, ANOVA). RPPA results identified that PI3K/AKT pathway can be blocked significantly by the combination treatment. The study in HeyA8 xenograft mouse models showed that mice treated with EP-100 and olaparib had the lowest tumor weight (0.06 ± 0.05 g) compared with those treated with vehicle (1.19 ± 0.39 g, p &lt; 0.008), EP-100 alone (0.62 ± 0.28 g, p &lt; 0.008), and olaparib alone (0.50 ± 0.22 g, p &lt; 0.01). EP-100 has efficacy in preclinical models of ovarian cancer, especially in combination with olaparib. Our findings suggested that combining EP-100 with olaparib could be a promising therapeutic strategy for ovarian cancer.
Citation Format: Shaolin Ma, Sunila Pradeep, Sherry Wu, Mark Seungwook Kim, Wei Hu, Selanere Mangala, Robert L. Coleman, Anil K. Sood. EP-100 sensitizes BRCA wild-type ovarian cancer cells to PARP inhibitor [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 4817.
Abstract 482: Epstein-Barr virus-encoded miRNAs target ATM-mediated response in nasopharyngeal carcinoma
Authors: Lung Raymond W. , Hau Po-Man , Tong Joanna H. , Lam Ka-Hei , Chan Anthony W. , Yip Kevin Y. , Tsao George S. , Lo Kwok-Wai , To Ka-Fai 
Published: August 2018

Abstract
Nasopharyngeal carcinoma (NPC) is a highly invasive epithelial malignancy that is prevalence in southern China and Southeast Asia. It is well-known to be associated with latent Epstein-Barr virus (EBV) infection. By using small RNA sequencing, we previously established a comprehensive miRNA profile in a panel of NPC samples and revealed that the EBV-encoded miRNAs derived from BamHI-A rightward transcripts (miR-BARTs) are abundantly expressed. The important roles of miR-BARTs in cancer development have been reported extensively. In the present study, we identified multiple putative binding sites of miR-BART5-5p, BART7-3p, BART9-3p and BART14-3p on the 3'-UTR of a critical DNA double-strand break (DSB) repair gene, Ataxia-Telangiectasia-Mutant (ATM). Notably, the expression of these 4 miR-BARTs represented more than 10% of all EBV-encoded miRNAs in NPC cells while downregulation of ATM expression was observed in our local primary NPC samples in both qRT-PCR and immunohistochemical (IHC) staining analysis. In addition, the abilities of miR-BARTs to downregulate ATM expression were demonstrated in the transient transfection experiments. By manipulating the miR-BARTs expression in epithelial cell lines, we further revealed that these four viral miRNAs could inhibit both ionizing radiation (IR)-induced ATM kinase activity and BZLF1-induced viral lytic reactivation. In conclusion, our findings suggest that miR-BART5-5p, BART7-3p, BART9-3p and BART14-3p work co-operatively to modulate DNA damage response and to maintain viral latency, contributing to the NPC tumorigenesis. Acknowledgement: Theme-based Research Scheme (T12-401/13-R) and GRF (14104415 and 14138016), Research Grant Council, Hong Kong.
Citation Format: Raymond W. Lung, Po-Man Hau, Joanna H. Tong, Ka-Hei Lam, Anthony W. Chan, Kevin Y. Yip, George S. Tsao, Kwok-Wai Lo, Ka-Fai To. Epstein-Barr virus-encoded miRNAs target ATM-mediated response in nasopharyngeal carcinoma [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 482.
Abstract 483: BRCA1 protein expression is downregulated by miR-185, miR-93 and miR-107 in breast cancer tumors
Authors: Zavala Valentina A. , Gajardo Patricia , Faundez Paola , Alvarez Carolina , Carvallo Pilar 
Published: August 2018

Abstract
BRCA1 is a tumor-suppressor gene whose mutations confer a high risk to breast cancer. Fifty percent of hereditary breast cancer tumors without germline mutation have impaired BRCA1 expression, as well as 30% of sporadic cases. Somatic events that silence BRCA1 expression have been described in breast cancer tumors, such as promoter hypermethylation and BRCA1 gene deletion; however, these mechanisms do not completely explain the loss of BRCA1 expression in breast tumors. Our aim is to identify miRNAs differentially expressed in tumors with negative or moderate BRCA1 protein, which could regulate BRCA1 expression. Total RNA from 50 fresh-frozen breast cancer tumors was isolated and miRNA profiling was performed using miRNA microarrays. Sixteen miRNAs were found exclusively upregulated in BRCA1-negative, and ten in BRCA1-moderate tumors. Among them, in silico analyses predicted eleven miRNAs that could regulate BRCA1 expression. The effect of five of these microRNAs was assessed using a luciferase reporter assay in HEK293T cells, where the complete BRCA1 3'UTR, or a segment of its coding region, was cloned within the 3' end of the Luciferase gene. Cells were co-transfected with each of the selected microRNAs. MiR-185, miR-93 and miR-107 significantly downregulated luciferase activity by binding to the 3'UTR. Also, we transfected these microRNAs into a nontumorigenic breast cell line (MCF10A), where miR-93 diminished endogenous BRCA1 expression in 48%, miR-185 in 39% and miR-107 in 38%, in relation to non-transfected cells. These results strongly support that these microRNAs are potential regulators of BRCA1 expression in breast cancer tumors.
FONDECYT1120200, CONICYT21120269.
Citation Format: Valentina A. Zavala, Patricia Gajardo, Paola Faundez, Carolina Alvarez, Pilar Carvallo. BRCA1 protein expression is downregulated by miR-185, miR-93 and miR-107 in breast cancer 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 483.
Abstract 4838: R loop-driven genome instability by G-quadruplex binders in BRCA2-silenced human cancer cells
Authors: Magis Alessio De , Manzo Stefano Giustino , Russo Marco , Sordet Olivier , Morigi Rita , Capranico Giovanni 
Published: August 2018

Abstract
G-quadruplexes (G4s) and R-loops are non-B DNA structures that can regulate basic processes such as transcription and replication. Unscheduled formation of R-loops is regarded as highly deleterious to cells, as R loops can induce replicative stress and DNA damage leading to genome instability. G4s are formed by four guanine residues held together by Hoogsteen hydrogen bonds and stabilized by monovalent cations. R loops are triple-stranded structures that contain an RNA-DNA hybrid duplex and a displaced single-stranded DNA. We have recently shown that Topoisomerase I (Top1) can affect genome-wide levels of R loops in human cancer cells consistently with the knowledge that DNA superhelical tension is a main driving force allowing non-B DNA structure formation. As G4 ligands were suggested to synergize with Top1 inhibitors, we asked the question of whether G4 ligands can affect R loops. We have thus investigated by immunofluorescence microscopy the effects of two different G4 binders, Pyridostatin (PDS) and FG (compound 1 in Amato et al J Med Chem 2016), on R-loops in human cancer cells. These G4 binders can increase both G4s and R loops while an inactive derivative of FG cannot induce them. Interestingly, the induction of G4s and R loops well correlate to each other in time and intensity with PDS being more effective than FG. After 24 hours, G4 binders induce a cell cycle arrest at the G2/M phase associated to double-stranded DNA cleavage as detected by γH2AX and 53BP1 foci formation and to activation of checkpoint response as shown by ATM phosphorylation. Interestingly, overexpression of RNaseH1 reduces both R loops and γH2AX foci induced by G4 binders showing that the ligands induce DNA cleavage via an R loop-mediated mechanism. Then, we silenced the BRCA2 gene by RNAi in U2OS cells and the results show that BRCA2 depletion increased γH2AX foci induced by PDS while overexpression of RNaseH1 rescue DNA cleavage induction. We also determined genomic R loop maps by DRIP-seq, and bioinformatic analyses of the specific location of G4-stabilized R loops provided information consistent with a model in which a G4 opposite to a DNA:RNA hybrid can stabilize R loops. Our study establishes for the first time that G4 binders stabilize either G4s and R loops in human cancer cells, and that they induce genome instability with a mechanism dependent on R loop formation. Partially supported by AIRC, Milan.
Citation Format: Alessio De Magis, Stefano Giustino Manzo, Marco Russo, Olivier Sordet, Rita Morigi, Giovanni Capranico. R loop-driven genome instability by G-quadruplex binders in BRCA2-silenced human 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 4838.
Abstract 4845: Preclinical evaluation of HWH340, a novel PARP inhibitor
Authors: Sun Wenjie , Yue Yang , Chen Hailiang , Tu Ronghua , Shen Jie , Li Gang , Ma Guoqiang , Zhang Zhixiang , Ding Charles Z. , Chen Shuhui 
Published: August 2018

Abstract
Objective: Poly-ADP-ribose polymerase (PARP) participates in DNA repair, replication and transcription, and is important to maintaining genome stability and integrity. PARP inhibitors have proven to be efficacious in the clinic to treat BRCA-deficient cancers. PARP inhibitors may also be used as sensitizing agent in combination with other antitumor agents. The purpose of this study is to investigate in preclinical models the antitumor activity of HWH340, a novel potent and selective PARP inhibitor currently undergoing clinical investigation.
Method: HWH340 was evaluated for its PARP1/2 enzymatic activity in corresponding enzyme assays and its cellular PARylation inhibitory activity in HCC1937 cells. The anti-proliferative activity and the synergistic effect in combination with temozolamide (TMZ) were evaluated in vitro in a BRCA-deficient cell line MDA-MB-436 and BRCA proficient cell line MDA-MB-231. Antitumor activity was evaluated by daily oral administration of in xenograft tumor models. Synergistic effect in combination with TMZ was also determined. The animal models used were PARP highly expressed patient-derived xenograft (PDX) model of small cell lung cancer (SCLC) LU-01-0547 and BRCA1/2-deficient CDX models of breast cancer MDA-MB-436 and pancreatic cancer CAPAN-1.
Result: HWH340 displayed potent PARP1/2 enzymatic inhibitory activity with IC50 1.14 nM and 1.72 nM respectively. It also potently inhibited cellular PARylation in HCC1937 cell with IC50 2.77 nM. In BRCA proficient cell line MDA-MB-231, HWH340 showed no synergistic effect when combined with TMZ and a weak anti-proliferative activity with IC50 5.83 uM and 4.86 uM. In contrast, it displayed potent anti-proliferative activity and a synergistic effect in combination with TMZ with IC50 of 71 nM and 7 nM in the BRCA1/2-deficient MDA-MB-436 cells, respectively. HWH340 showed excellent in vivo antitumor efficacy in PARP overexpressed SCLC LU-01-0547 PDX model (TGI=81.69%@50mpk, QD). In BRCA-deficient breast cancer MDA-MB-436 CDX model, HWH340 showed potent antitumor efficacy as single agent (TGI=122% @12.5mpk, QD). In BRCA-deficient pancreatic cancer CAPAN-1 CDX model, it showed potent antitumor efficacy in combination with TMZ (TGI=79.61% @25mpk+ TMZ 30mpk, QD).
Conclusion: HWH340 is a potent PARP inhibitor. Its antitumor activity in the preclinical tumor models together with its excellent pharmaceutical properties provide confidence that HWH340 may have high potential in the clinic for treatment of BRCA deficient solid cancers.
Citation Format: Wenjie Sun, Yang Yue, Hailiang Chen, Ronghua Tu, Jie Shen, Gang Li, Guoqiang Ma, Zhixiang Zhang, Charles Z. Ding, Shuhui Chen. Preclinical evaluation of HWH340, a novel PARP inhibitor [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 4845.
Abstract 4854: Targeting ribonucleotide reductase M2 using didox causes inhibition of estrogen receptor-negative, inflammatory breast cancer cell proliferation and tumor emboli formation in culture
Authors: Patel Pranalee , Mirman Ben , Zhan Renzhi , Devi Gayathri R. 
Published: August 2018

Abstract
Ribonucleotide reductase (RR) catalyzes the conversion of ribonucleotides to deoxyribonucleotides during the rate-limiting step of DNA synthesis. Given its significant role in cell cycle regulation, RR and its catalytic subunits are significant molecular targets for inhibiting tumor cell growth and proliferation. Didox (3,4-dihydroxybenzohydroxamic acid) is a known inhibitor of the catalytic RR subunit of RRM2 and overall DNA synthesis. Previous meta-analyses have revealed that RRM2 is highly expressed in estrogen receptor-negative (ER-) breast cancer tumors. As ER negativity is frequent in inflammatory breast cancer (IBC), a distinct and the most aggressive breast cancer subtype, we proposed to evaluate efficacy of didox in IBC cell models. ER- inflammatory breast cancer (IBC) cell lines SUM149 (ER-, PR-, EGFR-activated), lapatinib-resistant SUM149 (rSUM149), and non-IBC BT474M1 metastatic subline of BT474 (ER+, PR+, HER2+) were compared for the cytotoxic and cytostatic effects of didox using cell viability (trypan blue exclusion) and proliferation (MTT) assays. Protein profiling was performed to evaluate changes in molecular expression of key proteins involved in cellular signaling pathways for apoptosis and proliferation. Only ER- cell lines exhibited decreased dose-dependent decrease in viability following didox treatment. In addition, didox inhibited tumor emboli formation in a novel ex vivo tumor emboli in culture assay that mimics the clinicopathologic hallmark of IBC disease in patients. Moreover, didox decreased proliferation in lapatinib-resistant rSUM149, suggesting that the drug may help circumvent lapatinib resistance. Studies are ongoing to evaluate the mechanism of didox in overcoming lapatinib resistance and evaluation in an in vivo IBC invasion model. IBC is rare but accounts for 10% of breast cancer deaths, and despite multimodal therapy the 5-yr survival is only 25-55%. Further, there is a need to identify new therapies that can inhibit IBC tumor emboli formation and migration. Didox has demonstrated minimal toxicity in human phase I/II cancer clinical trials and therefore is an attractive strategy for inflammatory breast cancer therapy.
Support in part from the Development funds (GRD) of the Duke Cancer Institute as part of the P30 Cancer Center Support Grant NIH CA014236 and Department of Defense Breakthrough Level 2 W81XWH-17-1-0297 (GRD).
Citation Format: Pranalee Patel, Ben Mirman, Renzhi Zhan, Gayathri R. Devi. Targeting ribonucleotide reductase M2 using didox causes inhibition of estrogen receptor-negative, inflammatory breast cancer cell proliferation and tumor emboli formation in culture [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 4854.
Abstract 4867: Treating hepatocellular carcinoma metastasis and overcoming chemoresistance through inhibiting the MDM2 oncogene
Authors: Wang Wei , Hu Bo , Qin Jiang-Jiang , Cheng Jianwen , Li Xin , Hu Ming , Buolamwini John , Yang Xin-Rong , Fan Jia , Zhang Ruiwen 
Published: August 2018

Abstract
Hepatocellular carcinoma (HCC) poses a major health problem worldwide and novel, effective therapeutic approaches are urgently needed. The MDM2 oncogene is amplified and overexpressed in HCC and associated with its initiation, progression, metastasis, and chemoresistence. MDM2 has been demonstrated to be as a promising therapeutic target for the treatment of HCC. However, most of the current MDM2 inhibitors have been designed to block the binding between MDM2 and p53, and have limited efficacy against tumors with mutant or deficient p53. We recently performed a high-throughput virtual and cell-based screening, yielding a novel MDM2 inhibitor, termed SP141. The present study was designed to evaluate the anti-HCC activity of SP141, its potential to chemosensitize HCC cells to other anticancer agents, and to determine the underlying mechanism(s) of action of SP141 in various in vitro and in vivo models with different backgrounds of p53 (wildtype, mutant or null). Our results demonstrated that SP141 inhibited cell growth and prevented cell migration and invasion, independent of p53. Mechanistically, SP141 directly bound to the MDM2 protein and promoted MDM2 degradation. The inhibition of MDM2 by SP141 also increased the sensitivity of HCC cells to sorafenib. In addition, in orthotopic and patient-derived xenograft (PDX) models, SP141 inhibited MDM2 expression and suppressed tumor growth and metastasis, without any host toxicity. Furthermore, mechanistic study demonstrated that the inhibition of MDM2 by SP141 was essential for its anti-HCC activities. In conclusion, MDM2 inhibition by SP141 resulted in the inhibition of HCC tumor growth and metastasis and sensitization of HCC cells to chemotherapy, regardless of their p53 status. These results provide support for the further development of SP141 as a lead candidate for the treatment of HCC. (Supported by NIH R01 CA186662 and R01CA214019 and ACS RSG-15-009-01-CDD.)
Citation Format: Wei Wang, Bo Hu, Jiang-Jiang Qin, Jianwen Cheng, Xin Li, Ming Hu, John Buolamwini, Xin-Rong Yang, Jia Fan, Ruiwen Zhang. Treating hepatocellular carcinoma metastasis and overcoming chemoresistance through inhibiting the MDM2 oncogene [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 4867.