Cancer Chemistry最新文献

{"title":"Abstract 4538: Global and phosphoproteomic analysis of AML cell line response to phosphatase inhibitor treatment","authors":"P. Piehowski, J. Mcdermott, J. Hansen, S. Savage, C. Tognon, A. Agarwal, J. Tyner, B. Druker, K. Rodland","doi":"10.1158/1538-7445.SABCS18-4538","DOIUrl":"https://doi.org/10.1158/1538-7445.SABCS18-4538","url":null,"abstract":"","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85142457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 3642: Combination nanotherapy using the PARP inhibitor talazoparib and cyclin dependent kinase inhibitor dinaciclib","authors":"P. Baldwin, Adrienne M. Orriols, S. Sridhar","doi":"10.1158/1538-7445.AM2019-3642","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-3642","url":null,"abstract":"Introduction: PARP inhibitors exploit defects in DNA repair pathways to selectively target cancerous cells. As such, Talazoparib (TLZ), a potent PARP inhibitor, offers a way to target the biology of a number of cancers with DNA repair defects until these tumors develop resistance. PARP inhibitors must be used in combination with other inhibitors or chemotherapeutics to reverse resistance and sensitize non-responsive tumors. Dinaciclib, a potent cyclin dependent kinase (CDK) inhibitor, has been shown to sensitize both BRCA wild-type tumors and PARP inhibitor resistant tumors to PARP inhibition through disruption of homologous recombination. In clinical trials, Talazoparib and Dinaciclib have both demonstrated hematologic toxicities, suggesting a combination of these drugs would result in compounded toxicity, leading to dose reduction and an ineffective combination. Nanoparticle delivery systems offer a means to modify the toxicity profiles of these drugs and enhance the therapeutic window, therefore allowing for effective combination treatment. Methods: Separate nanoformulations of Talazoparib (NanoTLZ) and Dinaciclib (NanoDCB) were optimized, and pharmacokinetics and pharmacodynamics assessed. Nanoformulations were tested alone and in combination in vitro to ensure NanoDCB could sensitize a model with no known DNA repair defects to NanoTLZ. The combination of the two nanoformulations was then assessed for efficacy and toxicity in orthotopic MDA-MB-231 xenografts. Results: Robust formulations of NanoTLZ and NanoDCB were developed. Each nanoformulation extended the half-life of the drug it encapsulates. A constant low dose of Dinaciclib sensitized MDA-MB-231 cells to Talazoparib, significantly lowering the IC50 value. As a single agent NanoDCB was more effective in vitro than free Dinaciclib. In vivo, the combination of the two nanoformulations was more effective than either single nanoformulation or the combination of the two free drugs. Assessments of hematologic toxicities are underway, but thus far, there were no signs of gross toxicity in the combination therapy group. Conclusions: The combination of NanoDCB and NanoTLZ has provided an effective method for sensitizing tumors to PARP inhibition that are otherwise nonresponsive to this therapy. The development of two separate nanoformulations has allowed for tailored dosing. These long-circulating nanoformulations have proven more effective than the free drugs in stabilizing tumor growth and were well tolerated. This work was supported by ARMY/W81XWH-16-1-0731. Citation Format: Paige Baldwin, Adrienne Orriols, Srinivas Sridhar. Combination nanotherapy using the PARP inhibitor talazoparib and cyclin dependent kinase inhibitor dinaciclib [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 3642.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80328599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 2757: Discovery and characterization of covalent Pin1 inhibitors targeted to an active site cysteine","authors":"Benika J. Pinch, Zainab M. Doctor, Christopher M Browne, H. Seo, Behnam Nabet, S. Kozono, Xiaolan Lian, D. Zaidman, Dina Daitchman, N. London, L. Gong, Theresa D. Manz, Yujin Chun, L. Tan, J. Marto, S. Buratowski, S. Dhe-Paganon, Xiao Zhen Zhou, K. Lu, N. Gray","doi":"10.1158/1538-7445.AM2019-2757","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-2757","url":null,"abstract":"Proline-directed phosphorylation at serine or threonine residues (pSer/Thr-Pro) regulates numerous cellular processes, including the cell cycle, transcription, and differentiation. Deregulation of such signaling networks is a hallmark of transformation and oncogenesis. Pin1, a peptidyl-prolyl isomerase, regulates the function and stability of phosphoproteins by catalyzing the cis/trans isomerization of pSer/Thr-Pro motifs. Pin1 is frequently overexpressed in human cancers, including pancreatic ductal adenocarcinoma (PDAC), and Pin1 is required for activated Ras to induce tumorigenesis. While mutations in KRAS are observed in 90-95% of human PDAC cases, it has historically proven very challenging to develop small molecules that inhibit mutant Ras function. Consequently, drug discovery efforts have turned to targets required for Ras-mediated transformation, such as Pin1. However, existing Pin1 inhibitors lack the potency, selectivity, and/or cell permeability to serve as informative cellular probes. We report a highly potent, cell-permeable Pin1 inhibitor that covalently targets Cys113, a conserved cysteine residue in the Pin1 active site. Through iterative rounds of synthesis and characterization, we developed inhibitor 1b. With a Ki of 15 nM as measured in biochemical binding and isomerase inhibition assays, 1bis currently the most potent Pin1 inhibitor available. Furthermore, in a chemoproteomic study using Covalent Inhibitor Target Site Identification (CITe-Id) to quantify the dose-dependent covalent labeling of 1b to individual cysteines across the proteome, Pin1 Cys113 was the only identified target, highlighting the pronounced selectivity of 1b for Pin1. We show that treatment with 1b diminishes viability of human PDAC cell lines, which can be fully rescued in corresponding Pin1 knockout cells generated using CRISPR/Cas9, showing that this phenotype is on-target. In parallel to inhibitor development, we used CRISPR/Cas9 GFP-dropout screens to further validate the dependence of these cell lines on Pin1. Genetic disruption of Pin1 led to antiproliferative effects, confirming the results of 1b treatment. We also employed the degradation tag (dTAG) approach to assess the effects of rapid and selective targeted Pin1 degradation through generation of FKBP12F36V-Pin1, Pin1-/-human PDAC cell lines. Treatment with a small molecule FKBP12F36V-degrader led to rapid ubiquitination and degradation of FKBP12F36V-Pin1, enabling comparisons of targeted inhibition and Pin1 degradation. Through the development of a selective Pin1 inhibitor coupled with genetic approaches and the chemical-genetic dTAG strategy, we demonstrate that Pin1 inhibition represents a tractable strategy in PDAC. Citation Format: Benika Pinch, Zainab Doctor, Christopher M. Browne, Hyuk-Soo Seo, Behnam Nabet, Shingo Kozono, Xiaolan Lian, Daniel Zaidman, Dina Daitchman, Nir London, Lu Gong, Theresa Manz, Yujin Chun, Li Tan, Jarrod Marto, Stephen Buratowski, Sirano Dhe-Paganon, Xiao Zhou, ","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90043274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 4455: Discovery of AMG 510, a first-in-human covalent inhibitor of KRASG12Cfor the treatment of solid tumors","authors":"B. Lanman, J. Chen, Longbin Liu, Patricia Lopez, Alexander J. Pickrell, Anthony B. Reed, Hui-Ling Wang, Pragathi Achanta, J. Canon, D. Erlanson, R. Fucini, Jeong Joon Won, C. Mohr, A. Y. Saiki, V. Cee, J. Lipford, K. Rex, Laurie P. Volak","doi":"10.1158/1538-7445.AM2019-4455","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-4455","url":null,"abstract":"The RAS gene family encodes the small GTPase proteins NRAS, HRAS, and KRAS, which play an essential role in cellular growth and proliferation. KRAS is one of the most frequently mutated oncogenes in human cancer, with KRAS p.G12D, p.G12V, and p.G12C constituting the major mutational subtypes across lung, colon, and pancreatic cancers. Despite more than three decades of research, indirect approaches targeting KRAS mutant cancers have largely failed to show clinical benefit, and direct approaches have been stymied by the apparently ‘undruggable’ nature of KRAS. Cysteine-12 of KRASG12C has recently emerged as a unique vulnerability in KRAS-mutant cancers, and a small number of cysteine-reactive inhibitory tool molecules have been disclosed. We here report independent efforts to identify cysteine-reactive molecules capable of selectively inhibiting KRASG12C. Through iterative screening and structural biology efforts, we identified a novel Cys12-reactive inhibitor scaffold that derived its potency from occupancy of a previously unknown cryptic pocket induced by side-chain motion of the His95 residue of KRAS. Employing a scaffold-hopping approach, we leveraged knowledge of this cryptic pocket to design a series of N-aryl quinazolin-2(1H)-one-based inhibitors that demonstrated significantly enhanced potency relative to prior tool compounds. Extensive optimization of these leads led to the identification of a highly potent, selective, and well-tolerated inhibitor of KRASG12C, which was nominated for clinical development as AMG 510. In preclinical tumor models, AMG 510 rapidly and irreversibly binds to KRASG12C, providing durable suppression of the mitogen-activated protein kinase (MAPK) signaling pathway. Dosed orally (once daily) as a single agent, AMG 510 is capable of inducing tumor regression in mouse models of KRASG12C cancer. AMG 510 is, to the best of our knowledge, the first direct KRASG12C therapeutic to reach human clinical testing and is currently in a Phase I clinical trial evaluating safety, tolerability, PK, and efficacy in subjects with solid tumors bearing the KRAS p.G12C mutation (NCT03600883). Citation Format: Brian A. Lanman, Jian Jeffrey Chen, Longbin Liu, Patricia Lopez, Alexander J. Pickrell, Anthony B. Reed, Hui-Ling Wang, Pragathi Achanta, Jude Canon, Daniel A. Erlanson, Raymond V. Fucini, Joon Won Jeong, Christopher Mohr, Anne Y. Saiki, Victor J. Cee, J. Russell Lipford, Karen Rex, Laurie P. Volak. Discovery of AMG 510, a first-in-human covalent inhibitor of KRASG12C for the treatment of solid tumors [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 4455.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90195430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 4529: Mapping the protein interactome of mitochondrial intermembrane space proteases identifies a novel function for HTRA2","authors":"Aaron Botham, É. Coyaud, Sanjit Nirmalanandhan, M. Gronda, R. Hurren, N. Maclean, Jonathan St. Germain, S. Mirali, E. Laurent, B. Raught, A. Schimmer","doi":"10.1158/1538-7445.SABCS18-4529","DOIUrl":"https://doi.org/10.1158/1538-7445.SABCS18-4529","url":null,"abstract":"Mitochondria possess unique proteases that localize to specific sub-compartments of the organelle. However, the functions of these proteases are largely ill-defined. Here, we used proximity-dependent biotinylation (BioID) to map the interactomes of seven proteases located in the intermembrane space of the mitochondria. The mitochondrial intermembrane space proteases HTRA2, OMA1, YME1L1, LACTB, IMMP1L, IMMP2L and PARL were cloned in-frame with the abortive E. coli biotin ligase BirA*, and expressed in 293 T-REx cells. Cell culture media was spiked with biotin for 24 hrs, the cells lysed, and biotinylated proteins were isolated and identified by mass spectrometry. In total, we identified 342 different proteins as high confidence interactors of the seven mitochondrial proteases. Of these, 272 are assigned a GO mitochondrial annotation, and 230 proteins interacted with only 1 or 2 proteases in our dataset. Validation efforts were focused on high temperature requirement peptidase A 2 (HTRA2). HTRA2 is a serine protease that is released into the cytoplasm during apoptosis where it binds Inhibitor of Apoptosis Proteins (IAPs). However, little is known about the function of HTRA2 in the mitochondria. HTRA2 interacted with 60 mitochondrial, 11 nuclear and 4 cytoplasmic proteins, including its known interactor XIAP, and consistent with its known localization to these cellular compartments. HTRA2 interacted with 8 out of 13 components of the MIB complex, a multiprotein assembly that is essential for proper mitochondrial cristae formation. Knockdown of HTRA2 with shRNA in 293T-REx cells disrupted cristae formation and this phenotype was rescued by expression of an shRNA-resistant HTRA2 cDNA. Compared to normal hematopoietic cells, HTRA2 mRNA expression levels are increased in a subgroup of primary AML cells. HTRA2 knockdown in OCI-AML2 leukemia cells led to a similar disruption of mitochondrial cristae. Knockdown of HTRA2 in OCI-AML2 cells led to increased levels of the MIB subunit IMMT, but not two other MIB complex subunits, SAMM50 and CHCHD3. Finally, in cell-free assays, we demonstrate that recombinant HTRA2 can degrade recombinant IMMT, but not SAMM50 or CHCHD3.Thus, we have mapped the interactomes of the proteases of the mitochondrial intermembrane space. Through this effort, we discovered that HTRA2 regulates protein levels of the MIB complex subunit IMMT and that disruption of this process affects mitochondrial cristae formation. Citation Format: Aaron D. Botham, Etienne Coyaud, Sanjit Nirmalanandhan, Marcela Gronda, Rose Hurren, Neil Maclean, Jonathan St. Germain, Sara Mirali, Estelle Laurent, Brian Raught, Aaron Schimmer. Mapping the protein interactome of mitochondrial intermembrane space proteases identifies a novel function for HTRA2 [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 4529.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89679550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 989: The relationship between TP53 gene status and carboxylesterase 2 expression in human gastric cancer","authors":"Yoshinori Kohira, Hyeon-Cheol Lee, Momoko Ishimine, H. Orita, Toshiyuki Kobayashi, Koich Sato, T. Yokomizo, T. Fukunaga","doi":"10.1158/1538-7445.AM2019-989","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-989","url":null,"abstract":"Carboxylesterases are serine hydrolases that are involved in the metabolisms of various endogenous and exogenous compounds. They are also required for activation of many anti-cancer prodrugs. For example, irinotecan (CPT-11), an anti-cancer prodrug that has been approved for the treatment of many types of solid tumors including gastric cancer, is converted by the carboxylesterase CES2 to its active metabolite 7-ethyl-10-hydroxycamptothesin (SN-38), a very potent topoisomerase I inhibitor. Among carboxylesterase isozymes, CES2 is most highly expressed in the gastrointestinal tract. Thus, the expression of CES2 may play an important role in local (i.e., intratumoral) activation of anti-cancer prodrugs such as irinotecan in the gut. Recent studies with cultured cancer cell lines have shown that CES2 expression is regulated by the tumor suppressor protein p53. However, whether CES2 expression is affected by the presence of p53 mutation in clinical cancer samples still remains unclear. In this study, we focused on the regulatory mechanism of CES2 expression in gastric cancer. First, we examined the relationship between TP53 gene status and CES2 expression using gastric cancer cell lines. Several gastric cancer cell lines expressing wild-type p53 (AGS, NUGC4, MKN74, and HSC58) were treated with nutlin-3a, a drug that inhibits the interaction between p53 and the E3 ubiquitin ligase MDM2 and thereby directly activates p53 signaling without genotoxic side effects. The expression of p21, a downstream target of p53, was increased following nutlin-3a treatment in two p53 wild-type cell lines NUGC4 and HSC58. The expression of CES2 was also upregulated by nutlin-3a in three p53 wild-type cell lines AGS, NUGC4, and HSC58. As expected, the expression levels of p21 and CES2 were not largely affected by nutlin-3a in gastric cancer cell lines with TP53 mutations. These results indicate that CES2 expression is positively regulated by the p53 pathway in most gastric cancer cells. We also investigated the relationship between TP53 gene status and CES2 expression in human gastric cancer samples. Our results may provide useful information for predicting the efficacy of anti-cancer prodrugs that are activated by CES2 in gastric cancer. Note: This abstract was not presented at the meeting. Citation Format: Yoshinori Kohira, Hyeon-Cheol Lee, Momoko Ishimine, Hajime Orita, Toshiyuki Kobayashi, Koichi Sato, Takehiko Yokomizo, Tetsu Fukunaga. The relationship between TP53 gene status and carboxylesterase 2 expression in human gastric 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 989.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89418054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 13: Structure elucidation, metabolism, and drug interaction potential of ACP-5862, an active, major, circulating metabolite of acalabrutinib","authors":"T. Podoll, Paul G. Pearson, Jerry B. Evarts, Timothy G Ingallinera, Hao Sun, S. Byard, A. Fretland, J. Greg Slatter","doi":"10.1158/1538-7445.AM2019-13","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-13","url":null,"abstract":"Acalabrutinib (Calquence®) is a potent, selective, orally administered, covalent inhibitor of Bruton tyrosine kinase (BTK) that received accelerated approval for relapsed/refractory mantle cell lymphoma from the US FDA in October 2017. Profiling of acalabrutinib metabolites in human plasma revealed a late-eluting, +16 Da metabolite circulating at concentrations higher than parent drug. Metabolite regiochemistry could not be determined by mass spectrometry. In vitro metabolism and preparative HPLC was used to generate a pure sample of the metabolite for structural characterization by NMR. Confirmatory chemical synthesis revealed a pyrrolidine ring-opened ketone. The structure of the metabolite, designated ACP-5862, and a smaller -2 Da peak, identified as dehydropyrrolidine, M25, inferred a common carbinolamide intermediate in their genesis. Both metabolites retained the butynamide electrophile responsible for the inactivation of BTK. In vitro studies on the inhibition of BTK and related Tec and Src kinases revealed that ACP-5862 was active against BTK with similar selectivity and potency to acalabrutinib (Kaptein et al, 2019) This work then investigated the in vitro metabolism and drug transport features of acalabrutinib, and the metabolite ACP-5862, to establish the potential for clinical drug-drug interactions (DDI) via CYPs, UGTs and drug transporters. CYP reaction phenotyping indicated CYP3A4 was responsible for both the formation and further metabolism of ACP-5862. Km and Vmax values for the formation of ACP-5862 using rCYP3A4 were 2.78 μM and 4.13 pmol/pmol CYP/min, respectively. The in vitro intrinsic clearance of ACP-5862 was 23.6 μL/min/mg. Acalabrutinib weakly inhibited CYP2C8, CYP2C9 and CYP3A4 in vitro, and ACP-5862 weakly inhibited CYP2C9 and CYP2C19, with no inhibition of CYP1A2, CYP2B6, or CYP2D6. Similarly, UGT1A1, UGT2B7, and aldehyde oxidase were not inhibited. Neither parent or ACP-5862 strongly induced CYP1A2, CYP2B6, or CYP3A4 mRNA. Acalabrutinib and ACP-5862 were substrates of MDR1 and BCRP in vitro, but were not substrates of OATP1B1 or OATP1B3. Acalabrutinib was not a substrate of OAT1, OAT3, and OCT2. Based on static PK model calculations, acalabrutinib may cause a modest increase in exposure to coadministered BCRP substrates by inhibition of intestinal BCRP, but with no inhibition of BCRP at the systemic level. The PK of substrates of MDR1, MATE1, MATE2-K, OATP1B1, OATP1B3, OAT1, OAT3, and OCT2 are not likely to be altered by acalabrutinib or ACP-5862. These data were combined with clinical DDI data (Izumi et al, 2017) to simulate DDI in the presence of CYP3A inhibitors and inducers. PBPK models confirmed that acalabrutinib and ACP-5862 were not likely to perpetrate CYP2C8 or CYP3A4 mediated drug interactions (Zhou et al., 2019). Overall, acalabrutinib and major metabolite, ACP-5862 have a favorable drug interaction profile. Citation Format: Terry Podoll, Paul G. Pearson, Jerry Evarts, Tim Ingallinera, Hao Sun, Stephen By","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89974660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 6: Computationally assisted target screening of STING agonist for immunologic therapy","authors":"Grace Binder, Christine S. Gambino, A. Kharitonova, Rainer Metcalf, K. Daniel, W. Guida","doi":"10.1158/1538-7445.AM2019-6","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-6","url":null,"abstract":"Stimulator of interferon genes (STING) is a receptor protein involved in the propagation of innate immune sensing of cytosolic DNA through the production of IFN-β. Mechanistic studies have shown IFN-β production within the tumor microenvironment can result in activation of tumor antigen-specific CD8+ T-cell immunity that can lead to tumor regression [1, 2]. STING activation by STING agonists should result in innate T-cell mediated anti-tumor immunity in the tumor microenvironment and have significant potential as a cancer therapeutic. Conversely, inhibition of STING would lead to a decreased production of IFN-β which could have implications in the treatment of autoimmune disease such as lupus erythematosus. MD equilibrated crystal structures for human HAQ, REF, and WT alleles were clustered to find optimal conformations for diverse chemical library screening. Novel consensus docking protocols utilizing rigid receptor, induced fit, and quantum polarized ligand docking were applied for quantifying and refining proposed binding mechanisms of STING isoforms. Models for STING agonists and antagonists were developed. From directed virtual screening, a novel low-molecular-weight organic molecule (GF3-002) that is not based on a cyclic dinucleotide was found as a potential STING activator and is currently under investigation. GF3-002 and analogs were synthesized and structures were confirmed with LCMS and proton NMR. Both the HAQ and WT alleles, representing 78.3% of the human population were tested against compounds and controls. 2,3-cGAMP and DMSO were used as positive and negative controls, respectively. Microscale thermophoresis and SPR confirmed binding of GF3-002 to WT STING CTD with a kD of 3.2 ± 1.7 μM. IFN-dependent luciferase expression was measured by luminescence in THP-1 monocytic leukemia cells and found an EC50 of 29 ± 1.6 μM, compared to the native ligand 2,3-cGAMP EC50 of 42 ± 4.1 μM. Finally, qPCR was used quantify production of IFN-β via treatment of dendritic cells with GF3-002. 1. Sali, Characterization of a Novel Human-Specific STING Agonist that Elicits Antiviral Activity Against Emerging Alphaviruses. 2017. 2. Corrales, L., et al., Direct activation of STING in the tumor microenvironment leads to potent and systemic tumor regression and immunity. Cell reports, 2015. 11(7): p. 1018-1030. Citation Format: Grace A. Binder, Christine S. Gambino, Anna Kharitonova, Rainer S. Metcalf, Kenyon G. Daniel, Wayne C. Guida. Computationally assisted target screening of STING agonist for immunologic therapy [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 6.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79140783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 1856: Targeting human telomeres by binding of epiberberine to telomeric G-quadruplex","authors":"Clement Lin, Guanhui Wu, Kai-Bo Wang, B. Onel, S. Sakai, Danzhou Yang","doi":"10.1158/1538-7445.AM2019-1856","DOIUrl":"https://doi.org/10.1158/1538-7445.AM2019-1856","url":null,"abstract":"Human telomeres play critical roles in cancer, aging, and genetic stability. Human telomeric DNA consists of tandem repeats of the sequence d(TTAGGG) and can form G-quadruplexes. G-quadruplexes are non-canonical DNA secondary structures formed in G-rich sequences, built upon the H-bonded G-tetrads and stabilized by monovalent cations such as K+ or Na+. Telomerase is a reverse transcriptase activated in 80-85% of human cancers. Small molecules that stabilize the telomeric G-quadruplex have been demonstrated to inhibit telomerase and disrupt telomere capping and maintenance, resulting in cancer cell apoptosis. Thus, the human telomeric G-quadruplex is considered an attractive target for anticancer drug development. G-quadruplexes formed in human telomeres are structurally polymorphic. The hybrid-2 G-quadruplex is the major form in the wild-type human telomeric DNA in the physiologically relevant K+ solution. Protoberberines are medicinal natural products with anticancer and anti-inflammatory activities. We show for the first time that a small molecule (epiberberine) specifically binds and induces the physiologically relevant hybrid-2 human telomeric G-quadruplex and converts other telomeric G-quadruplexes to the hybrid-2 structure, the first such small molecule reported. We determined the molecular structure of the 1:1 complex of epiberberine and hybrid-2 human telomeric G-quadruplex in K+ solution by NMR, which elucidates the molecular basis for this specific recognition. Epiberberine binding induces extensive rearrangement of the previously disordered 5′ flanking and loop segments to form an unprecedented four-layer binding pocket specific to the hybrid-2 human telomeric G-quadruplex. Epiberberine recruits the flanking (-1) adenine to form a “quasi-triad” intercalated between the external G-tetrad and a T:T:A triad, capped by a T:T base-pair. The crucial hydrogen-bonded pair is observed between epiberberine and the flanking (-1) adenine in the human telomeric sequences. This strong recognition determines the epiberberine’s ability to convert other human telomeric G-quadruplex structures to the hybrid-2 structure, regardless of the presence and types of monovalent cation in solution. The deep intercalation of epiberberine in this multi-layer binding pocket explains the significant fluorescence enhancement of epiberberine induced by human telomeric sequences in K+. Our study provides structural insights into rational design of small molecule drugs targeting the hybrid-2 G-quadruplex predominant in the human telomeres in physiologically relevant K+ solution. Furthermore, the human telomeric sequence is polymorphic in nature and various G-quadruplexes can exist in dynamic equilibrium, the discovery of epiberberine provides a potential means to study the specific protein interactions and biological functions of the hybrid-2 telomeric G-quadruplex. Citation Format: Clement Lin, Guanhui Wu, Kaibo Wang, Buket Onel, Saburo Sakai, Danzhou Yang. Targeting h","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81279486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract 3626: Develop novel nanoparticle formulations of disulfiram copper for cancer therapy","authors":"Wu Chen, Wen Yang, Landon F. Stewart, David T. Coombs, Jianzhong Shen, Pengyu Chen, Feng Li","doi":"10.1158/1538-7445.SABCS18-3626","DOIUrl":"https://doi.org/10.1158/1538-7445.SABCS18-3626","url":null,"abstract":"Despite remarkable progress in cancer treatment, drug resistance remains a significant issue for prostate cancer, breast cancer, and others. Disulfiram (DSF), an alcohol-aversion drug, has been repurposed for cancer treatment and overcome drug resistance. DSF and copper ions form a copper diethyldithiocarbamate (Cu-DSF) complex which has a potent anticancer activity. However, the poor aqueous solubility of Cu-DSF creates a significant formulation challenge, and there is no formulation available for clinical use. We developed a S tabilized M etal I on L igand Nanocompl e x ( SMILE ) technology to prepare Cu-DSF nanoparticle (NP) formulations where in situ formed DSF-Cu NPs were stabilized by an optimal amount of stabilizers ( e.g. poly(ethylene glycol)-poly(lactide)). The SMILE technology involves a novel formulation design and an innovative preparation process using a 3D-printed microfluidic device. After optimizing the protocol, we can prepare Cu-DSF NPs with size in the sub-100 nm range which are suitable for intravenous injection and can target solid tumors through enhanced permeability and retention (EPR) effects. Cu-DSF NPs prepared with SMILE method showed high drug loading efficiency (above 90%) and high drug concentration (at least 2 mg/mL). The drug concentration of Cu-DSF NPs developed in our study was much higher than those in micelle NP formulations prepared with the classical film-dispersion method. Since we used generally recognized as safe (GRAS) excipients approved by the US Food and Drug Administration (FDA) or other excipients with well-recognized safety profiles, the developed NP formulations will have less regulatory hurdle for FDA approval. Because of the novel preparation process and unique formulation design, the SMILE technology can produce Cu-DSF NPs on a large scale and thus paved the way for its mass production and commercialization. We also determined the anticancer effects of Cu-DSF NPs with multiple assays including MTT assay, colony-forming assay, calcein-AM/propidium iodide staining, and others. Cu-DSF NPs showed excellent anticancer activity against various prostate cancer and breast cancer cells as well as drug-resistant cancer cells. In summary, we developed a novel SMILE method to prepare Cu-DSF NP formulations which could address drug delivery and formulation challenges of DSF-based chemotherapy and facilitate the clinical translation. Citation Format: Wu Chen, Wen Yang, Landon F. Stewart, David T. Coombs, Jianzhong Shen, Pengyu Chen, Feng LI. Develop novel nanoparticle formulations of disulfiram copper for cancer therapy [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 3626.","PeriodicalId":9563,"journal":{"name":"Cancer Chemistry","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90290531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}