bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2756: A high-resolution G-quadruplex structure involved in cmyc oncogene regulation
Authors: Dickerhoff Jonathan , Chen Luying , Wu Guanhui , Onel Buket , Lin Clement , Yang Danzhou 
Published: August 2019

Abstract
Gene expression needs strict regulation in human cells to prevent tumorigenesis. Among other control mechanisms, guanine-rich sequences which are clustered in promoter regions of oncogenes can form four stranded nucleic acid structures, called G-quadruplexes (G4), and regulate their transcription. The cmyc protein is the most important cellular regulator for proliferation and is often overexpressed in cancer cells. The DNA G-quadruplex formed in the cmyc promoter is a transcriptional silencer element and stabilization of this G4 by small molecules suppresses cmyc transcription, making it a promising target for cancer therapy. High-resolution structures of the highly diverse G4s provide the opportunity to understand their molecular interactions with transcription factors and to design small molecules that specifically bind a particular G4 conformer. Characteristically, multiple G4s can be formed in gene promoter regions because their G-rich sequence generally contains more than the minimum of four G-stretches. While all reported cmyc G4s share the same core with parallel oriented strands, their overall shape is individualized by distinct combinations of varying flanking and loop motifs. In this study, we present a new high-resolution NMR structure of a G4 found to form in the cmyc promoter region. The determined cmyc G4 has a 1:6:1 loop-size arrangement and its conformation is largely defined by its long central loop of 6 nt. We show that this G4 structure is the preferred target of nucleolin protein in comparison to other G4s formed in the cmyc promoter, demonstrating how the polymorphism of a G-rich sequence can modulate the interaction with transcription factors and other regulators. Our NMR structure shows that, despite the length of the 6-nt loop motif and the associated increased flexibility, the folding converges well due to a base pairing between the central loop and the 5’-flanking. Thus, the long loop is pulled towards the 5’-end while analogous loop-flanking interactions are prevented at the opposite 3’-site. In conclusion, the presented new addition to the ensemble of possible cmyc promoter G4 conformations extends the folding landscape for this promoter region, in particular due to the long central loop. This may shed light on how proteins such as nucleolin can target specific G4 and shift the equilibrium of folding to fine-tune gene expression. Finally, this new structure is another promising target for cancer drug development.
Citation Format: Jonathan Dickerhoff, Luying Chen, Guanhui Wu, Buket Onel, Clement Lin, Danzhou Yang. A high-resolution G-quadruplex structure involved in cmyc oncogene regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2756.
Abstract 2928: New insight into signaling contexts for the administration of the imipridone ONC201 to prostate cancer cells
Authors: Amoroso Francesca , Pickard Adam , Glass Kimberly , Tarapore Rohinton , Allen Josh , Mills Ian G. 
Published: August 2019

Abstract
Prostate cancer is the most common non-cutaneous cancer in men and a notable cause of cancer mortality. In the majority of the cases localised disease radical treatment consists of surgery or radiotherapy. Upon progression androgen deprivation therapy can extend survival however metastatic disease is incurable. The prostate is a specialized accessory gland with a high secretory capacity. As prostate cancer develops and treatment resistance emerges, the unfolded protein response (UPR) is an important adaptive biology which co-amplifies with key cancer drivers1. The UPR can be cytoprotective but when acutely activated can lead to cell death. In this study we sought to enhance the acute activation of the UPR using radiation and ONC201, previously reported to be a UPR activator2. We found that treating prostate cancer cells with ONC201 induced increases in the expression of components in all arms of the UPR - ATF4, ATF6 and IRE1-XBP1 - at protein and transcript levels at a 24-hour time point and this was followed at 72 hours by cell death. This delay in the induction of cell death provided a time window for the short-term administration of ONC201 to prime an enhanced cytotoxic response to radiation. Pre-treatment with ONC201 for 24 hours followed by withdrawal and subsequent irradiation led to enhanced cytotoxicity assessed by cell viability and clonogenic assays. In order to decipher the impact of ONC201 and radiation we undertook RNA-seq under a range of treatment conditions. We noted a durable suppression of transcripts encoding cell cycle regulatory genes when ONC201 pre-treatment was used to enhance radiation response and this translated into cell cycle arrest and induction of both necrotic and apoptotic cell death as assessed by flow cytometry. Pathway analysis of the RNA-seq suggests alternative targets that could replicate this priming effect to enhance radiation response.
1.Storm, M. et al., Oncotarget 7(33): 54051-54066 (2016).
2.Allen, J. et al., Oncotarget (2016). doi:10.18632/oncotarget.11814.
Citation Format: Francesca Amoroso, Adam Pickard, Kimberly Glass, Rohinton Tarapore, Josh Allen, Ian G. Mills. New insight into signaling contexts for the administration of the imipridone ONC201 to prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2928.
Abstract 2933: Application of a mouse model humanized for the major pathways of drug disposition in anticancer drug development and use
Authors: Henderson Colin J. , Scheer Nico , Kapelyukh Yury , McLaren Aileen , MacLeod Kenneth , Rode Anja , Lin De , Wolf C Roland 
Published: August 2019

Abstract
A vast number of targeted anticancer drugs are being developed in the pharmaceutical industry whose efficacy will only become fully realized through their combination with other established or novel anti-tumor agents. This is particularly the case because combination chemotherapy is a major approach being taken to overcome the rapid onset of drug resistance which current dosing regimens can cause. This has raised the conundrum of which of the large number of possible drug combinations, which may involve combinations of more than two drugs, have the greatest chance of success. It is not possible to test all the possible combinations by clinical trial alone so more informative preclinical models are badly needed. Nearly all targeted anti-tumor agents are substrates for the cytochrome P450-dependent monooxygenase system. The testing of novel drug regimens in mice is severely compromised by the major species differences in this enzyme system both in catalytic function, in the pattern of metabolite formation and the regulation by transcription factors such as CAR and PXR. In order to circumvent this problem we have created a mouse model where thirty four murine P450’s have been deleted from the mouse genome and substituted for the major enzymes involved in drug disposition in man ie CYP1A1, CYP1A2, CYP2C9, CYP2D6, CYP3A4 and CYP3A7. The mice have also been humanized for the transcription factors CAR and PXR. CYP3A4 and CYP2D6 are expressed off the human promoters. We report the validation the utility of this model by studying the in vivo metabolism and disposition of model drugs and the metabolism and disposition of the EGFR inhibitor, osimertinib and the BRAF inhibitor, dabrafenib. We show that the use of this model allows accurate prediction of clinically observed drug exposures, in the generation of human metabolites and drug/drug interactions. This model has therefore great potential for the development of combination therapies involving complex drug regimens and in the design of clinical trials targeted at overcoming drug resistance.
Citation Format: Colin J. Henderson, Nico Scheer, Yury Kapelyukh, Aileen McLaren, Kenneth MacLeod, Anja Rode, De Lin, C Roland Wolf. Application of a mouse model humanized for the major pathways of drug disposition in anticancer drug development and use [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2933.
Abstract 2941: Combination of hemiasterlin derivative (R)(S)(S)-BF65 and PI3K/mTOR dual inhibitor NVP-BEZ235 as a new strategy to inhibit ovarian cancer growth and metastasis
Authors: Su Po-Chia , Huang Tzu-En , Hsu Lih-Ching 
Published: August 2019

Abstract
Metastasis is a big issue to cancer therapy and is the major cause of therapeutic failure and cancer death. Therefore, inhibiting cancer metastasis is a key challenge in cancer treatment. Ovarian cancer is the most deadly cancer among women and combination treatment strategy is usually used to fight against this disease not only to reduce the toxicity and side effects, but also to enhance the anticancer effect.
(R)(S)(S)-BF65 is a hemiasterlin derivative and potent anti-tubulin agent with IC50 values in the low nanomolar range against various cancer cells. Previous studies indicated that (R)(S)(S)-BF65 in combination with an allosteric Akt inhibitor MK-2206 synergistically inhibited the growth of SKOV3 human ovarian cancer cells. Using the MTT assay, we demonstrated that (R)(S)(S)-BF65 could also enhanced the growth inhibitory effect of NVP-BEZ235, a PI3K/mTOR dual inhibitor in SKOV3 cells. The IC50 was 11.6 μM for NVP-BEZ235 and 20.6 nM for (R)(S)(S)-BF65 after 48 h-treatment. With a molar ratio of 1:1000 or 1:500, the combination of (R)(S)(S)-BF65 and NVP-BEZ235 displayed an additive to mild synergistic cytotoxic effect with CI50 values of 0.96 and 0.91, respectively.
Interestingly, the combination of (R)(S)(S)-BF65 and NVP-BEZ235, at concentrations much lower than those required for growth inhibition, significantly inhibited cell migration and invasion as demonstrated by wound healing migration, transwell migration and invasion assays. The combinatorial effect was much more effective than single treatments.
Epithelial-mesenchymal transition (EMT) plays an important role in cancer metastasis. It has been reported that activation of the PI3K/Akt pathway leads to phosphorylation and inactivation of GSK3β, which may in turn induce EMT. Western blot analysis of EMT markers revealed that NVP-BEZ235 downregulated mesenchymal markers β-catenin and Slug, and upregulated the epithelial marker, E-cadherin. (R)(S)(S)-BF65 also downregulated mesenchymal markers β-catenin and Snail, but had no effect on E-cadherin. The combination of both led to downregulation of more mesenchymal markers including β-catenin, Slug, Snail and ZEB1, and upregulation of E-cadherin, which may at least in part explain why the combination was more effective than single treatments to suppress cell migration and invasion.
Taken together, the combination of (R)(S)(S)-BF65 and NVP-BEZ235 may be a promising strategy to inhibit ovarian cancer growth and metastasis.
Citation Format: Po-Chia Su, Tzu-En Huang, Lih-Ching Hsu. Combination of hemiasterlin derivative (R)(S)(S)-BF65 and PI3K/mTOR dual inhibitor NVP-BEZ235 as a new strategy to inhibit ovarian cancer growth and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2941.
Abstract 2955: Development of non-apoptotic, caspase-independent cell death inducers against cancer cells
Authors: Pasternak Mariah A. , Hussein Noor , Chandrabose Karthikeyan , Erhardt Paul W. , Tiwari Amit K. 
Published: August 2019

Abstract
Since most cancer therapeutics currently exert their effects using apoptotic pathways to which cancer cells can become resistant, it is important to develop new drug molecules that work through non-apoptotic pathways. A novel, non-apoptotic cell death mechanism called “methuophagy,” which combines features of both autophagy and methuosis, is being examined using structure-activity relationship (SAR) studies of synthesized compounds. Methuosis is a non-apoptotic cell death that includes macropinocytosis and the fusing of smaller vesicles into larger vesicles that is seen along with cell death. BAPT compounds that induce methuophagy have been synthesized, and minor changes on a primary scaffold are being used to determine the SAR for the series. The series retains the 4-pyridinyl moiety that induced methuosis with the compound MOMIPP. Screening experiments with HCT-116 colorectal cancer cells (CRC), BT-20 triple-negative breast cancer cells (TNBC), and U-251 glioblastoma cancer cells (GBM) have shown that compounds having a rigid, completely aromatic structure with three aromatic centers induce methuophagy more potently than compounds with a “hydrazone-like” moiety or a non-aromatic linker. The cell death caused by methuophagy can be seen as early as 6 hours, with small vacuoles that coalesce together to form larger vacuoles. From these screening experiments, it has been concluded that the completely aromatic compounds are the most promising candidates for methuophagy drug development and will be used in experiments to determine protein targets and in vivo to further determine efficacy.
Citation Format: Mariah A. Pasternak, Noor Hussein, Karthikeyan Chandrabose, Paul W. Erhardt, Amit K. Tiwari. Development of non-apoptotic, caspase-independent cell death inducers against cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2955.
Abstract 2958: Evaluating the therapeutic effects of methylene blue against prostate cancer
Authors: Shanthi Priyadarshini Thiruvalluvan , Foes Abigail , Munirathinam Gnanasekar 
Published: August 2019

Abstract
Prostate cancer (PCa) is the second most commonly occurring cancer among men and the fourth most commonly occurring cancer overall. According to American Cancer Society, in the year 2018, it was estimated that there will be 164,690 new cases and 29,430 deaths from PCa. The treatment options currently available for PCa are found to be ineffective with varied side effects and complications associated with the development of resistance among patients. Therefore, there is an unmet need to find a safe and potent agent to treat PCa. In our study, we focused on studying the anticancer potential of Methylene Blue (MB) which belongs to the class of phenothiazinium salt. MB has been widely used to treat the condition of methemoglobinemia, emerging studies have shown that it has been effectively used as a photosensitizer in the treatment of cancer by means of photodynamic therapy (PDT). Our initial analysis showed that MB effectively reduced the viability of androgen-dependent (LNCaP) and androgen-independent (PC3 and DU145) PCa cells. Further experimental evaluations showed that MB inhibited the colony forming ability of PCa cells in-vitro suggesting its tumor suppressive potential. In addition, our studies showed that MB treatment disrupted the migration potential of PCa cells in a wound healing assay indicating the anti-metastatic function of MB. Moreover, confocal and FACS analysis using Annexin V FITC and propidium iodide staining revealed that MB effectively targeted the PCa cell lines by inducing apoptotic cell death. To delineate the underlying anticancer mechanism of MB, apoptosis protein array was performed employing LNCaP cells, and the results of which showed that key apoptotic molecules such as Bax, TRAIL
R2/D5, and phospho p53 (Serine 15, Serine 46, Serine 392) were robustly upregulated in LNCaP cells following MB treatment. In conclusion, our findings suggest that MB induces apoptosis in PCa cells and thus could serve as a potential anticancer agent for treating both hormone-dependent and -independent PCa.
Citation Format: Priyadarshini Thiruvalluvan Shanthi, Abigail Foes, Gnanasekar Munirathinam. Evaluating the therapeutic effects of methylene blue against prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2958.
Abstract 2960: NCX4040, a nitric oxide (NO) donating form of aspirin as a potential treatment for prostate cancer
Authors: CHINNAPAKA SOMAIAH , Munirathinam Gnanasekar 
Published: August 2019

Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to be beneficial in preventing various types of cancers including prostate cancer (PCa). Of all the NSAIDs in use, Aspirin appears to be one of the promising anticancer agents for PCa management. However, experimental and epidemiological studies indicated that larger doses of Aspirin and long term supplementation is required to achieve anticancer effect with accompanied side effects. Therefore, our study focused on evaluating Aspirin derivative, namely NCX4040 which is a NO releasing form of Aspirin as a potent alternative for PCa treatment while minimizing the side effects. In the present study, we assessed the anticancer effects of NCX4040 on PC-3, a bone metastatic PCa cell line employing various in-vitro cellular assays. In our preliminary studies, we compared the effects of NCX4040 with that of Aspirin and NO releasing compound DETA/NO on PC-3 cells using MTT as read out. These results showed that NCX4040 is highly potent in inhibiting the viability of PC-3 cells when compared to Aspirin or DETA/NO treatments. Hence, further studies were focused on characterizing the anticancer properties as well as the underlying anticancer mechanism of NCX4040. Of note, our results showed that NCX4040 robustly inhibited the colony forming ability of PC-3 cells in-vitro implicating its antitumorigenic potential. In addition to inhibiting colony formation of PC-3 cells, NCX4040 also suppressed the Transwell matrigel invasion of PC-3 cells suggesting the antimetastatic effects of NCX4040. The observed antimetastatic effect of NCX4040 in PC-3 PCa cells appears to be via targeting actin cytoskeleton as confirmed by confocal microscopic analysis using phalloidin stain. Following these findings, we performed cell cycle analysis to determine whether NCX4040 enforces cell cycle arrest in PC-3 cells. These results showed that NCX4040 induced robust G0 cell cycle arrest in a dose dependent manner. Moreover, flow cytometry analysis using Annexin V and PI staining revealed that NCX4040 induced potent apoptotic cell death in PC-3 cells. To delineate the underlying anticancer mechanism of NCX4040, PC-3 cells treated with NCX4040 was subjected to apoptotic protein array analysis. Results of this study inferred that NCX4040 down regulated the expression of key anti-apoptotic proteins such as Survivin, XIAP and IAPs. In conclusion, our study suggests that NCX4040 is a promising alternative agent for PCa treatment.
Citation Format: SOMAIAH CHINNAPAKA, Gnanasekar Munirathinam. NCX4040, a nitric oxide (NO) donating form of aspirin as a potential treatment for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2960.
Abstract 3219: In vivo efficacy and safety evaluation of anti-human PD-1 and CD40 mAbs using double humanized PD-1/CD40 mouse model
Authors: Guo Yanan 
Published: August 2019

Abstract
In recent years, monoclonal antibodies have been successfully used in clinical trials to block or activate key mediators of immune checkpoint pathways, including CTLA4, PD-1, PD-L1, CD40 and others. Combination therapy can promote antigen release and T cell priming, T cell activation and homing, which helps to overcome tumor immune-evasive mechanisms and maximize efficacy, ultimately benefitting most patients. However, along the IO drug development process, in vivo efficacy models have always been a rate-limiting step, especially to test combination therapy using two IO antibodies.
The transmembrane protein receptor CD40 is a member of the tumor necrosis factor (TNF) receptor super family and is involved in co-stimulation of immune cells. CD40 is expressed by antigen-presenting cells (APCs) including dendritic cells (DCs), B-cells, macrophages, and monocytes. It has the ability to "wake" DCs to prime effective cytotoxic T-cell responses. Thus, effective anti-CD40 antibodies provide an ideal therapy alternative in combination with other IO antibodies.
To evaluate the in vivo efficacy and safety (immune-related adverse events) of CD40 and PD-1 combination antibodies, we developed a double humanized B-hPD-1/hCD40 mouse model. In this model, mouse PD-1 gene exon 2, and CD40 gene exons 2-7 were replaced with their human counterparts. Murine colon cancer MC38 cells were subcutaneously implanted into homozygous B-hPD-1/hCD40 mice. We compared the effect among single hPD-1 antibody Keytruda, single hCD40 antibody Selicrelumab and combination of the two.
Combination treatment of Selicrelumab and Keytruda show higher inhibitory effects than single antibody treatments. The blood chemistry assays showed that the CD40 antibody had no toxicity effects compared with the control group. Based on these findings, we conclude that the B-hPD-1/hCD40 double-humanized mouse model is a powerful tool for in vivo efficacy and safety evaluation of hPD-1 and hCD40 antibodies for combination therapy.
Citation Format: Yanan Guo. In vivo efficacy and safety evaluation of anti-human PD-1 and CD40 mAbs using double humanized PD-1/CD40 mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3219.