bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 505: Somatic and inherited riboSnitches in TPT1 and LCP1 mRNA secondary structures
Authors: Lackey Lela L. , Coria Aaztli , Tolson Chanin , McArthur Evonne , Laederach Alain
Published: July 2017

RiboSnitches are single nucleotide variants that change the secondary structures of RNA. These structural changes can have a regulatory or functional impact on the RNA. Many inherited single nucleotide variants function as riboSNitches. We wanted to investigate the potential of somatic mutations to act as riboSNitches. We determined the secondary structure of two cancer-associated mRNAs, TPT1 and LCP1, using the chemical probing SHAPE-Map technique. Both of these mRNAs are highly structured and have similar folds in vivo and in vitro. We analyzed the structural impact of all the synonymous somatic mutations identified in the COSMIC cancer sequencing database for both TPT1 and LCP1 mRNAs. In TPT1 we also tested several inherited variants. We found that both somatic and inherited variants can be riboSNitches, at approximately the same ratio. Our results are in accord with previous work indicating that ~15% of SNVs are capable of acting as riboSNitches. Although the impact of non-coding and synonymous somatic mutations are difficult to measure, it is becoming clear that these mutations can contribute to cancer progression and phenotype. The majority of our identified riboSNitches are detrimental according to FATHMM-MKL functional impact prediction. Our experiments indicate that a substantial fraction of somatic mutations can cause a measurable change to RNA structure, potentially changing the regulatory or functional behavior of that mRNA.

Citation Format: Lela L. Lackey, Aaztli Coria, Chanin Tolson, Evonne McArthur, Alain Laederach. Somatic and inherited riboSnitches in TPT1 and LCP1 mRNA secondary structures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 505. doi:10.1158/1538-7445.AM2017-505
Abstract 506: The role of Nek2 in hepatocellular carcinoma
Authors: Vincent Chan Shing Ho
Published: July 2017

Cancer is a disease of aging. Among different types of cancer, liver cancer is one of the most prevalent cancers over the world and particularly affects people in some East Asia countries such as Korea, Japan and China. The NIMA-related kinase 2 (Nek2), which regulates centrosome cohesion, is a potential player in carcinogenesis. Our evidence showed Nek2 mRNA and protein levels are overexpressed in liver cancer cells and promotes HCC cell growth. Since Nek2 is pertinent to centrosome, we speculated that it might take part in centrosome regulation. To study the effect of Nek2 in chromosomal instability, centrosome splitting and cell cycle, a stable isoform Nek2A overexpression inducible system was generated in different Hepatocellular Carcinoma cell lines for investigations through immunofluorescent staining and cell-cytometry. For the study of centrosome, we observed that higher proportion of cells with centrosome splitting occurred in the Nek2A overexpressing cells in both HepG2 and SMMC-7721 inducible cell lines. Moreover, cell cycle analysis showed an increased content of DNA when Nek2A is overexpressed, suggesting that Nek2A induces more aneuploidy cells. To conclude, overexpression of Nek2 exacerbates chromosomal instability. Dysregulation of centrosome may be the key for understanding of regulatory mechanism of chromosomal instability by Nek2.

Citation Format: Chan Shing Ho Vincent. The role of Nek2 in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 506. doi:10.1158/1538-7445.AM2017-506
Abstract 5061: TET inhibits prostate cancer tumor growth, progression and metastasis in TRAMP mice
Authors: Koul Hari K. , Shanmugam Prakash Srinivasan Timiri , Jaiswal Praveen K. , Koul Sweaty
Published: July 2017

Introduction: Prostate cancer (PCa) is the 2nd most common malignancy in USA. Novel agents for treatment of advanced PCa are warranted. Transgenic adenocarcinoma of the mouse prostate (TRAMP) is an autochthonous mouse model exhibits both histological and morphological features that mimic human prostate carcinogenesis. Herein, for the first time, we evaluated the in vivo effects of TET, a derivative of Tetrandrine in TRAMP model.

Methods: Beginning 12 weeks of age, male TRAMP mice were administrated with TET (30 mgm/kg body weight, orally, alternative days) in PBS or PBS alone (Control) till 30 weeks of age. Body weight (B) of animals was recorded weekly. At various time points animals were euthanized, genitourinary tract (G) were weighed. Prostate tissue was subjected to immunohistochemical analyses for SV40-TAg, epithelial-mesenchymal transition (EMT), proliferation, neuroendocrine differentiation (NED) and apoptosis. Multiple organs were examined for drug toxicity and lungs were analyzed for metastasis.

Results: TRAMP mice exhibit to high-grade prostatic intraepithelial neoplasia (PIN) by 12 weeks and progresses to poorly differentiated adeno-carcinoma by 30 weeks with distant metastasis to lungs. TET feeding did not show any considerable difference body weight loss profiles during the entire treatment regimen. At the time of necropsy, there was no evidence of edema, abnormal organ size or appearance in non-target organs. TET gavage group showed (p<0.005) lower G/B ratio compared to the PBS treated group. These findings clearly indicate that TET dosing is non-toxic and restricts the abnormal growth of the prostate in TRAMP mice. TET repress the EMT as well as NED transition and inhibits cell proliferation (p<0.005) by Ki-67 staining. Oral administration of TET inhibits PCa growth and progression by increases (p<0.005) apoptosis in tumor tissues. Further, TET inhibited metastasis as there was significant (p<0.005) decrease in metastasis to lungs in TET treated animals.

Conclusion: Human achievable dose of TET treatment to TRAMP mice bearing prostate tumor, exhibited no-observed-adverse-effect-level in toxicology evaluations and also significantly inhibited tumor growth, progression, local invasion and distant metastasis involving suppression of tumor, and thus could have potential against human PCa.

Citation Format: Hari K. Koul, Prakash Srinivasan Timiri Shanmugam, Praveen K. Jaiswal, Sweaty Koul. TET inhibits prostate cancer tumor growth, progression and metastasis in TRAMP mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5061. doi:10.1158/1538-7445.AM2017-5061
Abstract 5065: Harnessing epigenetic reprogramming by histone deacetylase inhibitor MS275 for pancreatic cancer therapy
Authors: Liang Gaoyang , Yu Ruth , Liddle Christopher , Truitt Morgan , Antal Corina , Atkins Annette , Banayo Ester , Downes Michael , Evans Ronald
Published: July 2017

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 85% of pancreatic cancer and is one of the most lethal malignancies with limited therapeutic options. Chromatin-modulating small molecules, or epigenetic drugs, have the ability to reprogram cell fate and alter disease phenotypes. The potential of these drugs for PDAC therapy remains to be fully investigated. Screening a panel of epigenetic drugs identified MS275 (MS, also called entinostat), a histone deacetylase inhibitor, as capable of suppressing PDAC cell proliferation and inhibiting stromal fibrosis. Genome-wide expression analysis revealed that MS extensively reprograms the transcriptomes of tumor cells and cancer-associated fibroblasts (CAFs). In tumor cells, MS downregulates genes important for cell cycle progression inducing cytostasis. In CAFs, MS specifically represses the profibrotic transcription program responsive to TGF-beta, effectively inhibiting the fibrotic response. Consistent with this, MS blocks the activation of pancreatic stellate cells, the primary source for CAFs in PDAC, to repress the fibroblast-like phenotypes in these cells. Using an orthotopic transplantation model, we confirmed that MS treatment reduces tumor cell proliferation and decreases intratumoral fibrotic content. Importantly, we showed that MS substantially enhances chemocytotoxicity, synergizing with gemcitabine to reduce tumor burden in PDAC mouse models. Our study establishes a novel therapeutic strategy for PDAC based on epigenetic reprogramming induced by HDAC inhibition.

Citation Format: Gaoyang Liang, Ruth Yu, Christopher Liddle, Morgan Truitt, Corina Antal, Annette Atkins, Ester Banayo, Michael Downes, Ronald Evans. Harnessing epigenetic reprogramming by histone deacetylase inhibitor MS275 for pancreatic cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5065. doi:10.1158/1538-7445.AM2017-5065
Abstract 5074: Therapeutic targeting of bromodomain and extra-terminal proteins degradation in triple-negative breast cancer
Authors: Bai Longchuan , Zhou Bing , Yang Chao-Yie , Ji Jiao , McEachern Donna , Przybranowski Sally , Wang Shaomeng
Published: July 2017

Triple negative breast cancer represents the most clinically challenging subtypes of breast cancer for which targeted therapeutics are still lacking. BET proteins have emerged as new therapeutic targets for human cancer and other diseases.We have developed a highly potent BET degrader, BETd-246, with an exceptional selectivity based upon a new class of BET inhibitor, BETi-211, and investigated its therapeutic potential and mechanisms of action in TNBC. BETd-246 induces degradation of BET proteins at low nanomolar concentrations within 1 hour, leading to potent anti-proliferative activity and strong apoptosis induction in the majority of TNBC cell lines, and is much more effective than the BETi-211 treatment. RNA-seq analysis reveals that degradation of BET proteins by BETd-246 elicits distinct transcriptional response than BET BD inhibition in TNBC cell lines. Transcriptomic analysis also shows a number of proliferation and survival-related genes were differentially regulated by BETd-246 and BETi-211 which were confirmed by quantitative RT-PCR. Mechanistically, down-regulation of MCL1 by BETd-246 plays a key role in the robust apoptosis induction in TNBC cell lines. In in vivo models, BETd-246 effectively degrades BET proteins and suppresses MCL1 expression in xenograft tumor tissues and exhibits a strong antitumor activity at well-tolerated dose-schedules in mice. Our data strongly suggest that targeting BET protein degradation is an exciting therapeutic strategy for TNBC.

Citation Format: Longchuan Bai, Bing Zhou, Chao-Yie Yang, Jiao Ji, Donna McEachern, Sally Przybranowski, Shaomeng Wang. Therapeutic targeting of bromodomain and extra-terminal proteins degradation in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5074. doi:10.1158/1538-7445.AM2017-5074
Abstract 5078: EZH2 methyltransferase regulates disseminating tumor cells in breast cancer metastasis
Authors: Yomtoubian Shira , Ryu Seongho , Lee Sharrell , Markowitz Geoff , Gao Dingcheng , Mittal Vivek
Published: July 2017

Triple negative breast cancer (TNBC, ER-, PR-, HER2-) exhibits the worst outcome due to higher rates of metastasis compared to non TNBC subtypes. Despite this clinical significance, there is a conspicuous lack of FDA approved molecularly targeted anti-metastatic therapies for TNBC. The enhancer of zeste homolog 2 (EZH2), a catalytic core subunit of the Polycomb repressive complex 2 (PRC2) with histone methyltransferase (HMT) activity is associated with the worst clinical outcome in breast cancer patients. Using a combination of genetic and pharmacological approaches, we show that EZH2 HMT blockade did not impact primary tumor growth, but significantly reduced distal metastases. Metastasis suppression was associated with a marked reduction of tumor-initiating cells (TICs) in primary tumor, circulating tumor cells (CTCs) in the blood and impaired lung colonization. Using a SOX2/OCT4 promoter reporter system, we identified EZH2-sensitive metastatic cells with GATA3 low luminal progenitor phenotypes in the primary tumor, and EZH2 HMT blockade restored GATA3 expression, promoted differentiation of luminal progenitors and impaired metastasis. These key preliminary findings have led to the hypothesis that EZH2 promotes metastasis, and that inhibition of EZH2 HMT may constitute a viable anti-metastatic approach. We will also discuss the potential of EZH2 inhibition in combination with chemotherapy as an effective strategy against TNBC metastasis.

Citation Format: Shira Yomtoubian, Seongho Ryu, Sharrell Lee, Geoff Markowitz, Dingcheng Gao, Vivek Mittal. EZH2 methyltransferase regulates disseminating tumor cells in breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5078. doi:10.1158/1538-7445.AM2017-5078
Abstract 5096: Targeted ablation of essential oncogenes in rhabdomyosarcoma with CRISPR/Cas9 gene therapy
Authors: Phelps Michael , Yang Heechang , Chen Eleanor
Published: July 2017

Targeted therapy seeks to exploit unique vulnerabilities in cancer cells not present in normal tissue. The development of effective therapies targeting essential tumor proteins has had significant challenges particularly for tumor oncogenes many of which have proven “undruggable”. Targeting these critical tumor oncogenes has been one of the foremost challenges in cancer research. Current sequencing technology facilitates rapid identification of novel cancer mutations yet there are no effective therapeutic strategies aimed at targeting essential cancer genes at the genome level. To overcome the challenges associated with targeting “undruggable” cancer proteins, we have employed high efficiency CRISPR/Cas9 genome editing technology to destroy cancer cells by directly targeting the genomic DNA of essential cancer genes. We used pediatric rhabdomyosarcoma to demonstrate the potential of CRISPR/Cas9 gene therapy in solid tumor preclinical xenograft mouse models. Rhabdomyosarcoma is an aggressive pediatric sarcoma characterized by myogenic differentiation arrest. The two major subtypes of rhabdomyosarcoma (RMS), embryonal (ERMS) and alveolar (ARMS) are defined largely by either activation of the RAS pathway (ERMS) or the presence of a fusion oncogene between PAX3 and FOXO1 (ARMS). CRISPR/Cas9 was first used to target critical exons in the activated RAS or PAX3/FOXO1 oncogenes unique to each RMS subtype, using inducible or viral CRISPR delivery systems. Targeting these essential genes resulted in significant regression of tumor xenografts due to a combination of cell death and differentiation. By precisely targeting the activating mutations in the RAS oncogene or the fusion site in the PAX3/FOXO1 fusion gene we further demonstrate that tumor-specific CRISPR/Cas9-mediated gene therapy can also be achieved. This strategy disrupts the essential cancer oncogenes with minimal impact to normal cells that do not harbor the unique cancer mutations. Our results highlight the utility of exploiting essential cancer genetic mutations for personalized therapy. This novel approach to cancer therapy provides a potential alternative strategy for targeting “undruggable” oncogenes while establishing a foundation for further development of CRISPR/Cas9 gene therapy for cancer treatment

Citation Format: Michael Phelps, Heechang Yang, Eleanor Chen. Targeted ablation of essential oncogenes in rhabdomyosarcoma with CRISPR/Cas9 gene therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5096. doi:10.1158/1538-7445.AM2017-5096
Abstract 5108: Potent small molecule compounds that selectively inhibit proliferation of ABC-DLBCL cell lines
Authors: Satyam Leena Khare , Chikkanna Dinesh , Khairnar Vinayak , Pothuganti Manoj , Panigrahi Sunil , Lakshminarasimhan Anirudha , Rao Narasimha , Balasubramanian Wesley , Patil Sandeep , Gopinath Sreevalsam , Upendra Gunta , Nagaraj Jwala , Aithal Kiran , Ahuja Vijay , Giri Sanjeev , Pandit Chetan , Ramachandra Murali
Published: July 2017

Diffuse large B cell lymphoma (DLBCL), which accounts for 25% of all lymphomas cases, has been classified into molecular subtypes including germinal center B cell like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal B cell lymphoma (PMBL). Among these subtypes, patients with ABC-DLBCLs have the worst prognosis because of the high chemo-resistance, and require effective therapies.

Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 (MALT1) protease activity is linked to the pathogenesis of ABC-DLBCL. Therefore, a focused library of covalent compounds selected based on molecular docking on the reported crystal structure was screened for selective sensitivity to ABC-DLBCL, but not GCB-DLBCL cell lines. Optimization of initial hits resulted in the identification of lead compounds with an anti-proliferative EC50 of <100 nM selectively in ABC-DLBCL cell lines. Consistent with the previously reported role of MALT1 inhibitors, lead compounds also showed anti-proliferative activity in selected melanoma and NSCLC cell lines. The anti-proliferative activity of the lead compounds correlated well with the inhibition IL-6, a downstream marker of MALT1 signaling, in ABC-DLBCL cell line such as OCI-LY3. The lead compounds exhibited excellent drug-like properties including solubility, metabolic stability, lack of CYP inhibition, permeability and desired dose-dependent oral exposure in pharmacokinetic studies. In a repeated dose MTD study, the lead compounds showed good tolerability with an exposure multiple of >10 over cellular EC50 for up to 8 hours. The lead compounds showed dose-dependent tumor growth inhibition in a xenograft model upon oral dosing.

In summary, we have identified novel and potent MALT1 inhibitors capable of selectively inhibiting proliferation of DLBCL cell lines with optimized drug-like properties including oral bioavailability. The data presented here strongly support further development of these compounds for DLBCL and other indications.

Citation Format: Leena Khare Satyam, Dinesh Chikkanna, Vinayak Khairnar, Manoj Pothuganti, Sunil Panigrahi, Anirudha Lakshminarasimhan, Narasimha Rao, Wesley Balasubramanian, Sandeep Patil, Sreevalsam Gopinath, Gunta Upendra, Jwala Nagaraj, Kiran Aithal, Vijay Ahuja, Sanjeev Giri, Chetan Pandit, Murali Ramachandra. Potent small molecule compounds that selectively inhibit proliferation of ABC-DLBCL cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5108. doi:10.1158/1538-7445.AM2017-5108
Abstract 5113: Usnic acid, lichen secondary metabolite, inhibits glioblastoma progression through the reduction of epithelial-mesenchymal transition and glioma stemness factors
Authors: Lee Kyung-Hwa , Oh Se-Jeong , Jung Shin , Kim Kyung-Keun , Lee Jae-Hyuk , Moon Kyung-Sub
Published: July 2017

Background: Usnic acid (UA), an active compound mainly found in lichens, has shown some anti-tumoral activities for lung and breast cancers. The therapeutic role of UA in glioblastoma (GM) have not yet been determined, nor has the definitive relationships of UA with EMT and cancer stem cells.

Methods: We tested the anti-tumoral activities of UA against glioblastoma (GM) progression and further investigated the mechanistic link with epithelial-mesenchymal transition (EMT) and cancer stemness factors. The targeting and anti-tumor effect of UA was also checked in orthotopic mouse glioma model.

Results: In vitro assay, we found that UA increased apoptotic cell death and inhibited the invasion/migration of GM cells. Sphere and colony forming abilities were also decreased in treated GM cells. UA decreased the expression of the EMT markers (N-cadherin, ZEB1, ZEB2, SNAIL and SLUG) and the cancer stemness markers (CD133, ALDH1 and CD44). In orthotopic mouse glioma models, UA localized in GBM and significantly decreased tumor growth and progression to lead longer survival.

Conclusion: Taken together, these findings showed that UA prevent GBM invasiveness and progression, through the down-regulation of EMT and cancer stemness markers.

Citation Format: Kyung-Hwa Lee, Se-Jeong Oh, Shin Jung, Kyung-Keun Kim, Jae-Hyuk Lee, Kyung-Sub Moon. Usnic acid, lichen secondary metabolite, inhibits glioblastoma progression through the reduction of epithelial-mesenchymal transition and glioma stemness factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5113. doi:10.1158/1538-7445.AM2017-5113
Abstract 5114: Design, synthesis, and biological evaluation of tricyclic thieno[2,3- d]pyrimidines as microtubule targeting antitumor agents
Authors: Islam Farhana , Gangjee Aleem , Zhang Xin , Zhou Xilin , Mooberry Susan L.
Published: July 2017

Microtubules are dynamic structures that, together with actin microfilaments and intermediate filaments, constitute the cellular cytoskeleton. Besides their well-known roles in cell division, their functions involve maintenance of cell shape and morphology, cellular motility, and trafficking of organelles and vesicles. Recently, we reported a compound AG 370 as a microtubule targeting agent, that circumvented the Pgp and βIII-tubulin mediated drug resistance mechanisms that limit the efficacy of paclitaxel, docetaxel, and the vinca alkaloids. Molecular modeling and docking studies of the parent compound (AG 370) in the colchicine binding site (PDB: 402B) suggest that the C-5 and C-6 of parent compound are oriented towards the hydrophobic pockets with the side chain of Ala316, Val315, Leu255 and Met259. However, this binding pocket in tubulin is relatively large. To further explore the hydrophobic pocket, an additional cyclohexene ring was introduced at C-5 and C-6 of AG370. In the molecular modeling study, the resulting tricyclic scaffold showed hydrophobic interactions with the amino acids of the colchicine binding site. The 2-Me substituent of the tricyclic scaffold was replaced with a 2-H and a 2-NH2 group and 4-position of the scaffold was replaced with appropriate anilines. The 2-amino- N4-methoxyphenyl moiety (AG61) was found to be the most potent analog in the tricyclic series in both antiproliferative assay in human melanoma cancer cell line (MDA-MB-435 cell line, IC50 = 9.0 ± 0.2 nM) and in microtubule depolymerization assay in A-10 cells (EC50= 19 nM). Thus, we identified tricyclic thieno[2,3-d]pyrimidines as a novel structural scaffold with potent antiproliferative activity as well as microtubule depolymerizing activity. These analogs are selected for preclinical development.

Citation Format: Farhana Islam, Aleem Gangjee, Xin Zhang, Xilin Zhou, Susan L. Mooberry. Design, synthesis, and biological evaluation of tricyclic thieno[2,3- d]pyrimidines as microtubule targeting antitumor agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5114. doi:10.1158/1538-7445.AM2017-5114
Abstract 5125: Muscadine grape extract inhibits breast cancer brain metastatic cells by multiple mechanisms
Authors: Chen Wenhong , Gallagher Patricia , Tallant Ann , Metheny-Barlow Linda J.
Published: July 2017

Tumor metastasis to the brain is a common complication of cancer, affecting 500,000 patients each year. Due to poor penetration of most chemotherapeutics into the brain, brain metastasis may occur even while systemic disease in under control. Despite aggressive treatments including radiation therapy, survival at 12 months following diagnosis is only 20%, underscoring the need for better means to prevent and/or treat brain metastases.

Natural products have historically been a very successful source of new drugs. We are investigating the anti-cancer potential of a proprietary muscadine grape extract (MGE; from Piedmont Research & Development Corp.) on breast cancer cell lines that are metastatic to the brain. In a colony formation assay, MGE (10 μg/mL) decreased clonogenic survival of 4T1.luc2.Br5 cells by 50% (n=3, p<0.0001). The Eo771.luc.Br5 cells were more sensitive to MGE, showing 33% inhibition at 5 μg/mL (n=3, p<0.001) and 91% inhibition at 7.5 μg/mL (n=3, p<0.0001). We also assessed response to the combined treatment of MGE and ionizing radiation (IR). While MGE did not sensitize cells to IR, combined administration of MGE and IR resulted in decreased clonogenic survival compared to either modality alone for both cell lines (n=3-4 experiments, p<0.01), suggesting an additive effect.

Mechanistically, acute exposure (24 h) to 10 μg/mL MGE induced apoptosis in 4T1.luc2.Br5 cells as evidenced by PARP cleavage and detection of activated cleaved caspase 3. Further, ERK1/2 activation was decreased 68% at this time point (n=3, p<0.05). In contrast, although Eo771.luc.Br5 cells are more sensitive to clonogenic inhibition, no PARP cleavage, caspase 3 cleavage, or ERK1/2 inhibition was observed. Analysis of cyclin D1, a major regulator of cell cycle progression, identified >80% decrease following MGE treatment (24 h, 10 μg/mL) in both cell lines. Together these data suggest that MGE inhibits breast cancer brain metastatic cell proliferation by multiple mechanisms, including inhibition of clonogenic growth through induction of apoptosis and/or decreased cell cycle progression, suggesting that MGE may have utility in the treatment of breast cancer brain metastasis.

Citation Format: Wenhong Chen, Patricia Gallagher, Ann Tallant, Linda J. Metheny-Barlow. Muscadine grape extract inhibits breast cancer brain metastatic cells by multiple mechanisms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5125. doi:10.1158/1538-7445.AM2017-5125
Abstract 5129: Cell-penetrating doxorubicin released from Elastin-like polypeptide kills doxorubicin-resistant cancer cells
Authors: Ryu Jung Su , Raucher Drazen
Published: July 2017

A drug-releasing system facilitated by external stimuli could be used to deliver cytotoxic chemotherapy agents to tumor sites selectively and safely. Among many suggested strategies, elastin-like polypeptide (ELP) exploits its characteristic of phase transitioning in response to changes in ambient temperature. This unique property permits selective targeting of the polymer to hyperthermic tumors by aggregating as it transitions. ELP therefore can be used as a thermosensitive vector for the delivery of chemotherapy agents and therapeutic peptides, resulting in a rise in drug concentration exclusively in tumors. This novel strategy introduces unprecedented options for treating cancer, with fewer concerns about indiscriminate side effects from the chemotherapy.

In this study, the ELP-drug conjugate was further modified with incorporation of an enzyme-specific cleavable linker in order to trigger drug release within tumors. The suggested system is composed of ELP, a matrix metalloproteinase (MMP) substrate, a cell penetrating peptide (CPP), and 6-maleimidocaproyl amide derivative of doxorubicin (Dox). Rationale for this design is that this construct may be initially targeted to the tumor site by local application of mild heat. When the construct reaches tumor site, it is cleaved by MMP, releasing CPP conjugated Dox, which is able to more efficiently infiltrate tumor tissues and penetrate cancer cell membranes. This strategy shows up to 4-fold increase in cell penetration up to four times and results more cell death in breast cancer cells than the ELP-doxorubicin complex. Even in doxorubicin-resistant cancer cells (NCI/ADR and MES/ADR), ELP-released, cell-penetrating doxorubicin demonstrated better membrane penetration (two fold), leading to at least twice killing of the resistant cancer cells than ELP-Dox and free Dox.

Citation Format: Jung Su Ryu, Drazen Raucher. Cell-penetrating doxorubicin released from Elastin-like polypeptide kills doxorubicin-resistant cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5129. doi:10.1158/1538-7445.AM2017-5129
Abstract 5141: Optimizing peptide-drug conjugate delivery as an alternative to antibody-drug conjugates for solid tumors
Authors: Sottero Theo L. , Girard Emily J. , Myers Carrie H. , Olson James M.
Published: July 2017

Antibody-drug conjugates (ADCs) have been FDA approved for targeted delivery of chemotherapy to a small subset of cancers. However, there are significant limitations in their clinical utility in the majority of cancers: despite hundreds of clinical trials, there are only two FDA approved drugs currently on the market. ADCs are further limited by their poor penetration into solid tumors and an inability to cross the blood-brain-barrier (BBB). Our lab has over a decade of experience with peptide-dye conjugates such as chlorotoxin-Cy5.5, which demonstrates tumor-specific accumulation in a wide range of cancers including solid tumors and tumors protected by the BBB. However, chlorotoxin-Cy5.5 accumulates in mouse liver – a potential liability if a chlorotoxin-drug conjugate exhibited similar biodistribution. Tumor Paint/BLZ-100 is a derivative of this molecule optimized for tumor accumulation that is currently in clinical trials to aid in cancer surgery. We sought to expand upon the utility of Tumor Paint and optimize a novel peptide that is capable of delivering both imaging agents and chemotherapeutics specifically to tumor cells in vitro and in vivo.

We have identified a novel Optide (OPtimized knottin pepTIDE) able to accumulate in a range of cancers (lymphoma, sarcoma, colon cancer, and pediatric medulloblastoma). To test whether an Optide could be created with a greater tumor specificity, we looked to both natural homologs as well as specific charged residue modifications. We have identified two next-generation Optides with enhanced uptake in mouse models of sarcoma. We have used these peptides to deliver a microtubule inhibitor to sarcoma and lymphoma in vitro and in vivo. Using in vitro flow cytometry, we have also identified multiple FDA approved drugs that upregulate or downregulate uptake of our family of peptide drug-conjugates. In understanding the pathways regulating the uptake of these peptides, we hope to both be able to identify tumors best suited for treatment with peptide-drug conjugates (PDCs) based on our Optide scaffold.

Citation Format: Theo L. Sottero, Emily J. Girard, Carrie H. Myers, James M. Olson. Optimizing peptide-drug conjugate delivery as an alternative to antibody-drug conjugates for solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5141. doi:10.1158/1538-7445.AM2017-5141
Abstract 5143: Fusogenic targeted liposomes: novel nanotherapy for specific treatment of prostate cancer
Authors: Mriouah Jihane , Nesbitt Rae Lynn , Richter Susan , Wuest Melinda , Pink Desmond , Sosnowski Deborah , Duncan Roy , Wuest Frank , Zijlstra Andries , Lewis John
Published: July 2017

Metastatic or castrate-resistant prostate cancer is the second-leading cause of cancer mortality in males. In the past 3 years, chemotherapies have extended survival, but efficacy is limited by dose-limiting toxicities due to suboptimal biodistribution. Here, we have addressed the lack of specificity and accumulation in Castrate Resistant Prostate Cancer (CRPC) by developing a unique nano-carrier for drug delivery: molecular targeted fusogenic liposomes. Previously, we have developed a platform whereby lipid nanoparticles are formulated with fusion associated small transmembrane (FAST) protein p14. The p14 protein catalyzes mixing of the nanoparticle lipids with target plasma membrane to deliver the cargo directly into the cytoplasm. In this study, we have engineered the p14 protein to incorporate the prostate cancer targeting ligand bombesin, which binds specifically to the Gastrin-releasing Peptide (GRPR) that is overexpressed in prostate cancer. We hypothesized that this novel targeted fusogenic liposome formulation would significantly improve the biodistribution and efficacy of chemotherapy. A clinical liposomal doxorubicin formulation (DOXIL) was modified to incorporate targeted fusogenic p14 protein, and the efficacy and biodistribution of these new formulations was evaluated using in vitro and in vivo models of CRPC. In PC3 cells, compared to conventional liposomes, intracellular levels of doxorubicin are increased by 15 and 25 times when p14 or p14-bombesin liposomes are used. Additionally, the IC50 is reduced from 85mM to 2mM. In mice bearing PC3 tumors treated with targeted fusogenic liposomal doxorubicin, we observed improved tumor growth inhibition by 57% (vs control) and 1.5 fold increased accumulation in tumors within 24h after administration. These proof of concept experiments indicate that molecular targeted fusogenic nanomedicines can improve both the intracellular delivery and tumor accumulation of chemotherapy, improving outcomes in this preclinical model. This highlights the potential for improved outcomes in patients with CRPC through the enhancement of approved drugs.

Note: This abstract was not presented at the meeting.

Citation Format: Jihane Mriouah, Rae Lynn Nesbitt, Susan Richter, Melinda Wuest, Desmond Pink, Deborah Sosnowski, Roy Duncan, Frank Wuest, Andries Zijlstra, John Lewis. Fusogenic targeted liposomes: novel nanotherapy for specific treatment of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5143. doi:10.1158/1538-7445.AM2017-5143
Abstract 5146: Increasing penetration of anticancer drugs through sortilin receptor-mediated cancer therapy: A new targeted and personalized Approach in the treatment of ovarian cancer
Authors: Demeule Michel , Curie Jean-Christophe , Larocque Alain , Charfi Cyndia , Béliveau Richard , Vezeau Claude , Annabi Borhane
Published: July 2017

The development of personalized therapies against ovarian cancer remains highly challenging in current modern oncology. One way to achieve greater selectivity and better anticancer drug delivery into cancer cells is to conjugate cytotoxic agents to specific peptide ligands that will selectively target receptors abundantly and/or exclusively expressed on these cells. Increased expression of Sortilin, a scavenging receptor, has been clinically observed in several human cancers including breast, prostate, colon, pancreas, skin, and pituitary. In particular, Sortilin has also been reported to be overexpressed in ovarian cancers as compared to non-malignant ovarian tissue. In light of this, we developed a peptide conjugation platform using a new Sortilin receptor-mediated vectorization strategy to increase cell targeting selectivity and cell delivery efficacy of anticancer agents. As a proof-of-concept, Doxorubicin was conjugated to peptide sequences, termed Katana peptides (KA). In vitro, significantly increased Sortilin mediated intracellular delivery of the Doxorubicin-Katana peptide conjugate (DoxKA) was observed in SKOV3 and ES-2 ovarian cancer cell line models, with conserved efficient Doxorubicin cytotoxic mechanism. Uptake of DoxKA in ES-2 ovarian cancer cells was reduced when Sortilin expression was specifically silenced by using siRNA or upon competition with the Sortilin ligands neurotensin and progranulin. In addition, DoxKA was found to bypass the P-glycoprotein (P-gp) efflux pump since, in contrast to Doxorubicin uptake in MDCK-MDR1 cells overexpressing the P-gp efflux pump, the uptake of DoxKA was unaffected by the P-gp inhibitor Cyclosporin A. In vivo, DoxKA was better tolerated and caused a more potent inhibition of human ovarian tumor xenografts growth than did Doxorubicin alone. These results provide strong evidence for the potential of this drug development platform in the generation of novel personalized therapeutics with specific targeting of SORT1-positive cancer cells.

Citation Format: Michel Demeule, Jean-Christophe Curie, Alain Larocque, Cyndia Charfi, Richard Béliveau, Claude Vezeau, Borhane Annabi. Increasing penetration of anticancer drugs through sortilin receptor-mediated cancer therapy: A new targeted and personalized Approach in the treatment of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5146. doi:10.1158/1538-7445.AM2017-5146
Abstract 5156: A synthesized RNA aptamer targeting and inhibiting non-small cell lung cancer
Authors: Wang Hanlu , Qin Meng , Ren Zhihua , Chen Irvin S.Y. , Jiang Yongping
Published: July 2017

A specific RNA aptamer (RA16) targeting non-small cell lung cancer (NCI-H460 cells) was previously reported by in vivo SELEX. The aptamer RA16 was identified specifically targeting and inhibiting human NCI-H460 cell proliferation in vitro, as well as xenograft tumor tissues in vivo. In this study, we synthesized RNA aptamer (syn-RA16) and make comparison studies with transcribed RNA aptamer (trans-RA16) in vitro in respect of the specific targeting and direct inhibitory activity towards NCI-H460 cells.To characterize the targeting specificity in vitro, biotin-labeled syn-RA16 and trans-RA16 were incubated with NCI-H460 cells, other tumor cell lines or normal control cells. Specific fluorescent binding was observed only for NCI-H460 cells, but not for HEK293T, Hela, and Jurkat cells or buffer control. Moreover, binding affinity of Kd values to the NCI-H460 cells for syn-RA16 and trans-RA16 were determined at 24.75±2.28 nM and 12.14±1.46 nM(n=3), respectively, by flow cytometry using streptavidin-PE labelling, indicating that the specific targeting binding affinity for syn-RA16 was highly retained, as trans-RA16. On the other hand, syn-RA16 aptamer, like trans-RA16 aptamer, was also capable of inhibiting non-small cell lung cancer cell (H460) proliferation in a dose-dependent manner. At 300 nM, syn-RA16 aptamer suppressed cell proliferation by 84.5%, comparing by 86.8% with trans-RA16. The IC50 for syn-RA16 was determined at 118.4±1.1 nM, while trans-RA16 was at 105.7±1.2 nM (n=4). Intestinally, both syn-RA16 and trans-RA16 exhibited no any inhibitory effect on HeLa and Jurkat cell lines even at concentration of 600 nM. In conclusion, a specific entire RA16 RNA aptamer was synthesized. The synthesized RA16, like transcribed RA16 aptamer, demonstrated the specific targeting ability and inhibitory activity to human NCI-H460 cells. The syn-RA16 could be potential to develop a diagnostic kit or treatment for NCI-H460 cell-related non-small cell lung cancer in the clinic.

Citation Format: Hanlu Wang, Meng Qin, Zhihua Ren, Irvin S.Y. Chen, Yongping Jiang. A synthesized RNA aptamer targeting and inhibiting non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5156. doi:10.1158/1538-7445.AM2017-5156
Abstract 5157: Preparation of curcumin analog nanoparticles and determination of their anticancer activity in prostate cancer
Authors: Juan-Rivera Maylein C. , Sánchez-Vázquez Maria M. , Maldonado Gamalier , Ruíz Geovanny , Vázquez Noralejandra , Vélez Christian , Zayas Beatriz , Cabrera Carlos , Martínez-Ferrer Magaly , Sanabria-Ríos David
Published: July 2017

Prostate cancer is the most frequently diagnosed cancer and the second cause of cancer-related deaths in American men. Bioavailability of therapeutic agents is important for the treatment effectiveness. Previous studies have shown that the development of nanoparticles (NPs) drug delivery vehicles offers an opportunity for targeted drug delivery to tumor cells. Natural compounds such as curcumin have shown decreased bioavailability and stability when used as anticancer agents. Therefore, the purpose of this study is to synthesize the curcumin analog m-nitrochalcone (3bNchalc) encapsulated into poly (lactic-co-glycolic acid) (PLGA) NPs and determine the anticancer activity against prostate cancer cell lines. In our approach, 3bNChalc were encapsulated into PLGA NPs in the presence of PVA using the single emulsion-solvent evaporation method. 3bNChalc loading, encapsulation efficiency, and drug release was determined by spectrophotometric techniques. Physico-chemical properties such as zeta potential, particle size, polydispersity index (PDI), and morphology was measured using a combination of Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). Cell viability and proliferation of PC3 and 22RV1 prostate cancer cell lines treated with 3bNchalc NPs and control were assessed using the MTS assay. 3bNchalc PLGA NPs were found to have a particle size of 250 nm and smooth spherical shape. In addition, zeta potential and mobility values revealed that 3bNChalc PLGA NPs are negatively charged and they tend to repel each other avoiding the tendency to flocculate. Moreover, 22RV1 cells treated with 3bNchalc PLGA NPs showed decreased in viability and proliferation when compared to control. We demonstrated that 3bNChalc was successfully encapsulated into PLGA NPs. In addition, our results showed that 3bNchalc PLGA NPs decreased the viability of 22RV1 prostate cancer cells when compared to control, suggesting that PLGA improves the delivery of 3bNChalc inside the cell. Results of our study will impact broadly the field by developing more effective and less toxic PLGA NPs based therapies.

Citation Format: Maylein C. Juan-Rivera, Maria M. Sánchez-Vázquez, Gamalier Maldonado, Geovanny Ruíz, Noralejandra Vázquez, Christian Vélez, Beatriz Zayas, Carlos Cabrera, Magaly Martínez-Ferrer, David Sanabria-Ríos. Preparation of curcumin analog nanoparticles and determination of their anticancer activity in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5157. doi:10.1158/1538-7445.AM2017-5157
Abstract 5164: A pyrrole-Imidazole polyamide conjugate targeting KRAS oncogenic mutations is a promising approach against KRAS mutated colorectal and pancreatic cancers
Authors: Nagase Hiroki , Takatori Atsushi , Watanabe Takayoshi , Koshikawa Nobuko , Lin Jason
Published: July 2017

Although a tremendous amount of studies has been made to directly target oncogenic drivers, such as RAS and MYC, no drug is clinically available because of difficulties to develop RAS- or Myc-targeted anti-cancer therapeutics due to the smooth 3D surface topology. One of major limitations of targeting the RAS pathway may be intrinsic or acquired resistance as seen in the other molecular target therapy. A new approach that directly target driver genes may provide a more direct route to help address unmet medical needs for refractory cancer conquest. We therefore synthesized the Pyrrole-Imidazole polyamide conjugate, KR12, specifically alkylated KRAS codon 12 mutant DNA (G12D or G12V). KR12 reduced expression of the mutated oncogenic-protein by RNA transcription inhibition and induced cancer cell death at low dose (1 to 50 nM). We also applied a novel enrichment-based sequencing and computational pipeline, which first identifies a PIP’s genomic binding sites through next-generation sequencing followed by gene expression microarray studies. The computational analysis suggested non-KRAS binding overall had little contribution to changes at the phenotypic level in colorectal cancer cell lines. We also the anti-cancer event is not only for colorectal but also pancreatic ductal adenocarcinoma (PDAC). Significant tumor reduction was observed in a mouse model of spontaneous PDAC (LSL-KrasG12D/+,Ptf1aCre/+,Tgfbr2flox/flox). In animal studies we also observed KR12 intakes and retentions in tumor but not any other organs 24 hours after I.V. administration. We will summarize the sequence-dependent alkylating approach using antibiotic mimics of alkylating PI-polyamide conjugates, may open a new strategy targeting the driver oncogene mutated DNA sequence. This approach should be used for medicine against variety of unfavorable KRAS mutated cancers.

Note: This abstract was not presented at the meeting.

Citation Format: Hiroki Nagase, Atsushi Takatori, Takayoshi Watanabe, Nobuko Koshikawa, Jason Lin. A pyrrole-Imidazole polyamide conjugate targeting KRAS oncogenic mutations is a promising approach against KRAS mutated colorectal and pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5164. doi:10.1158/1538-7445.AM2017-5164