bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3736: Schlafen 11 (SLFN11) blocks RNA synthesis upon replicative damage, a novel mechanism for killing cancer cells in response to DNA damaging agents
Authors: Murai Junko , Tang Sai-wen , Pommier Yves 
Published: July 2016

Abstract
The putative DNA/RNA helicase, SLFN11, is a recently discovered determinant of response to DNA damaging agents including topoisomerase inhibitors (camptothecin, irinotecan, topotecan, doxorubicin and etoposide) and cisplatin. SLFN11 is inactivated in approximately 40% of cancer cell lines (NCI-60 and CCLE). Until now, the molecular mechanisms of SLFN11 action in response to DNA damage have been unknown. Using isogenic SLFN11-knockout cells as well as SLFN11-overexpressing cells, we will show that SLFN11 irreversibly arrests cells in S-phase without cell cycle recovery under camptothecin treatment, whereas SLFN11-negative cells continue cell cycle progression. Notably, the action of SLFN11 is independent of ATR-mediated S-phase checkpoint. Co-immunostaining of 5-Ethynyl Uridine (EU) and gamma-H2AX revealed that SLFN11 blocks RNA synthesis upon replicative damage. Comprehensive analysis of cell cycle genes revealed that genes that drive S-phase progression are selectively turned-off in SLFN11-positive cells, whereas p53-dependent genes remain induced by camptothecin. Accordingly, critical proteins for S-phase progression such as cyclin A, cyclin B, CDK1 and CDK2 were suppressed in SLFN11-positive but not in SLFN11-negative cells, which causality links SLFN11-mediated S-phase arrest in camptothecin-treated cells with inactivation of cell cycle-driving pathways. This mechanism is supported by the fact that the CDK inhibitor roscovitine recapitulates the S-phase arrest even in SLFN11-deficient cells. Finally, by contrast to normal SLFN11, overexpression of SLFN11 helicase-dead mutant failed to block RNA synthesis and to kill camptothecin-treated cells, indicating that the helicase activity of SLFN11 is necessary for its RNA synthesis regulatory function. Our study reveals a novel cell cycle regulation mechanism by SLFN11 that links DNA damage and transcriptional responses in cancer cells with replicative DNA damage.
Citation Format: Junko Murai, Sai-wen Tang, Yves Pommier. Schlafen 11 (SLFN11) blocks RNA synthesis upon replicative damage, a novel mechanism for killing cancer cells in response to DNA damaging agents. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3736.
Abstract 3739: Efficacy of CD46-mediated Ad5/35 chimeric adenoviral gene therapy in colorectal cancers
Authors: Cho Young Seok , Do Hung Manh , Lee Sang-Jin , Hemmi Silvio , Joo Young-Eun , Jung Chaeyong 
Published: July 2016

Abstract
CD46 is a complement inhibitor membrane cofactor protein and also acts as a receptor for certain pathogenic microbes, including group B denovirus (Ad). Whereas many Ads infect cells through coxsackie-adenovirus receptor (CAR), CAR expression is downregulated in many cancers preventing effective therapeutics of Ad-based therapies. There have been increasing numbers of studies in cancer gene therapy by modification of Ad fiber knobs to utilize more ubiquitously expressed CD46. However, very limited information is available on expression status of CD46 in many cancers. Our tissue microarray data demonstrated that CD46 was generally overexpressed to cancers from prostate and colon. To seek the evidence whether colorectal cancers (CRC) are good target for Ad-mediated gene therapy, chimeric Ad5 vectors that are capable of targeting CD46 were employed. CD46-ovrexpressed cells showed significantly higher response not only to Ad5/35-GFP but to Ad5/35-TK/GCV suicide therapy. While CRC cells express variable levels of CD46, CD46 expression was positively correlated with Ad5/35-mediated GFP fluorescence and cell killing, demonstrating that HCT-116, DLD-1, and Caco-2 cells are highly responsive. Furthermore, injection of Ad5/35-TK/GCV caused significantlyhigher anti-cancer effects in nude mice bearing CD46-overexpressed cancer cells compared to mice with mock cells. Using 80 selected CRC, immunohistochemical studies showed that there is inverted correlation between CD46 expression and clinico-pathological parameters in terms of differentiation, invasion, metastasis, T stage, and survival, suggesting that adenoviral gene therapy may not be as effective to the patients with highly advanced colorectal cancers. Taken
altogether, our study demonstrated that CD46 is generally overexpressed in CRC in which group B-based adenoviral gene therapy seems to be suitable approach but careful consideration needs to be given to select cancer types and cancer status for effective cancer gene therapies.
Citation Format: Young Seok Cho, Hung Manh Do, Sang-Jin Lee, Silvio Hemmi, Young-Eun Joo, Chaeyong Jung. Efficacy of CD46-mediated Ad5/35 chimeric adenoviral gene therapy in colorectal cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3739.
Abstract 3745: Tumor fibroblast targeting via uPAR retargeted measles virus: In vitro and in vivo effects
Authors: Jing Yuqi , Zaias Julia , Merchan Jaime 
Published: July 2016

Abstract
Tumor stromal cell components, in particular cancer associated fibroblasts, play an important role in cancer progression. Few studies have focused on stromal fibroblast targeting by oncolytic viruses. The urokinase receptor (uPAR) is a clinically and biologically validated target, which is overexpressed in tumor and stromal cells compared to non-cancer tissues. MV-h-uPA and MV-m-uPA are fully retargeted oncolytic measles viruses directed against human and murine uPAR, respectively, which have shown in vitro and in vivo safety and antitumor effects. Species specific retargeted viral vectors allow to dissect the specific effects of the viruses on murine vs. human tissues in xenograft models. Our aim is to characterize the in vitro and in vivo effects of stromal targeting by oncolytic measles virus via uPAR, with a focus on tumor fibroblasts. In vitro, MV-h-uPA and MV-m-uPA preferentially infected and induced cytotoxicity in human cancer associated fibroblasts (CAF 19, CAF 23) as well as murine fibroblasts (3T3), compared to non-tumorigenic fibroblasts. Murine-murine and human-human fibroblast to cancer cell viral transfer via heterofusion was observed after fibroblast infection by species specific MV-uPA, in breast, colon and renal cancer models, while no viral transfer was observed between cells of different species. In vivo, systemic administration of the murine uPA retargeted virus (MV-m-uPA) significantly decreased tumor progression and prolonged survival in a human breast cancer xenograft model (MDA-MD231), where the host stroma expresses murine uPAR (target of MV-m-uPA). Tumor studies revealed induction of apoptosis (TUNEL assay), while no significant effects on cancer cell proliferation was observed. Dual staining for measles virus nucleocapsid proteins and fibroblasts markers demonstrated viral infection of fibroblasts in treated tumors. Gene expression studies using murine as well as human specific arrays were performed to characterize the effects of stromal targeting by the murine retargeted virus on murine stroma as well as the indirect effects on human cancer cells in vivo.
In conclusion, for the first time our results show feasibility and antitumor effects of stromal fibroblast targeting by oncolytic measles virus via uPAR and demonstrate that stromal fibroblasts are viable targets for oncolytic virotherapy. Studies characterizing other stromal cell components and evaluation of the molecular changes in the tumor stroma as result of viral infection are underway.
Citation Format: Yuqi Jing, Julia Zaias, Jaime Merchan. Tumor fibroblast targeting via uPAR retargeted measles virus: In vitro and in vivo effects. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3745.
Abstract 3753: Improved oncolytic virotherapy by increasing adenovirus spread
Authors: Wechman Stephen L. , Rao Xiao-Mei , McMasters Kelly Marc , Zhou Heshan Sam 
Published: July 2016

Abstract
Lung cancer is the leading cause of cancer-related death worldwide and kills more patients than the next four cancers combined (Colon, breast, prostate, and pancreas). Currently available lung cancer treatments have not been effective. Therefore the development of novel lung cancer therapeutics is of critical importance. One emerging treatment option is the use of E1b-deleted adenoviruses (Ads) which preferentially lyse cancer cells. Although E1b-deleted Ads have been applied in clinical trials, their efficacy remains low. We have developed a novel oncolytic vector, AdUV, via the bioselection of the cancer selective E1b-deleted Ad Adhz60. We have demonstrated that AdUV is much more potent against multiple cancer cell lines than the parental vector Adhz60 in vitro and suppressed tumor growth in vivo.
We compared AdUV treated cells to cells treated with the wildtype Ad5 and the E1b-deleted Adhz60. AdUV lysed A549 lung cancer cells more efficiently than Adhz60, but neither AdUV nor Adhz60 killed MRC5 and HBEC normal lung cells. Possible mechanisms of action were then investigated to determine how AdUV lysed A549 cells more effectively. AdUV virions were shown to release from infected A549 cells and induce autophagy more effectively than both Adhz60 and Ad5. Autophagy induction is known to support Ad replication and spread through cancer cell monolayers. The plaque assay was used to verify if AdUV could spread more effectively than Ad5 and Adhz60 because viruses which efficiently replicate and release from cells are known to form larger plaques. The average size of plaques formed by AdUV is 340% and 214% larger than those plaques formed by Adhz60 and Ad5, respectively. In vivo, AdUV was non-lethal to athymic nude mice and strongly suppressed A549-xenograft tumor growth, prolonging murine survival. These results indicate that AdUV is a more effective, safe oncolytic Ad vector. Our findings also demonstrate the utility of bioselection of the generation of more effective cancer therapeutic vectors.
Citation Format: Stephen L. Wechman, Xiao-Mei Rao, Kelly Marc McMasters, Heshan Sam Zhou. Improved oncolytic virotherapy by increasing adenovirus spread. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3753.
Abstract 3757: A novel class of chemicals that react with damaged DNA and specifically kill B-cell cancers
Authors: Wei Shanqiao , Watuthanthrige Madusha , Shalhout Sophia , Bhagwat Ashok S. 
Published: July 2016

Abstract
Majority of B-cell malignancies arise in germinal center, where the processes of somatic hypermuation (SHM) and class switch recombination (CSR) for antibody maturation are initiated by activation-induced demainase (AID). AID belongs to the AID/APOBEC family and deaminates cytosine in DNA creating uracil. We have previously shown that B-cell lymphoma cell lines and patient tumors express AID at high levels and contain high levels of uracils in their genome. These cells also contain uracil-DNA glycosylase that removes uracils generating high levels of abasic (AP) sites. AP sites exist in equilibrium with the open form of deoxyribose sugar that reacts with alkoxyamines forming a stable oxime. This principle was used to block the repair of excess AP sites in B cell cancers using an alkoxyamine, AA3. We found that AA3 effectively kills B-cell lymphoma cell lines which have high levels of endogenous AP sites. In contrast, AA3 is not toxic to normal human B cells and mouse splenocytes, as well as non-hematological cancers. To elucidate the molecular mechanism of selective cell killing by AA3, we compared the number of AP sites in B cell cancers and non-hematological cancers and confirmed that B cell cancer cells contained many more AP sites in their genome. Additionally, we found that AA3 was covalently linked to B cell cancer genome and AA3-DNA adducts caused cell death by blocking DNA replication and elevating DNA strand breaks. To determine which functionality of AA3 is responsible for its cytotoxicity and to discover better candidates for killing B cell cancers, we designed and synthesized a series of AA3 analogues. Using this approach, we have defined the functional groups required for AA3 toxicity. Overall, we have discovered that AA3 is selectively toxic to B cell cancers. This new family of chemicals could be developed further as novel and unique anti-cancer drugs.
Citation Format: Shanqiao Wei, Madusha Watuthanthrige, Sophia Shalhout, Ashok S. Bhagwat. A novel class of chemicals that react with damaged DNA and specifically kill B-cell cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3757.
Abstract 3765: Induction of amineoxidases as a possible mechanism of action of tamoxifen metabolites
Authors: Thomas T. J. , Keinanen Tuomo A. , Hyvonen Mervi T. 
Published: July 2016

Abstract
To elucidate the mechanism of action of endoxifen in breast cancer, we determined its effects on estradiol-mediated growth of ERalpha-positive MCF-7 cells. Endoxifen is the active metabolite of tamoxifen; the most widely used selective estrogen receptor modulator for anti-estrogen therapy for women with estrogen receptor alpha-positive breast cancer. Clinical trials recognized that tamoxifen was a prodrug and got converted to active metabolites in the human body. Earlier studies recognized 4-hydroxytamoxifen (4HT) as the active metabolite of tamoxifen, although recent studies showed that the concentration of endoxifen was up to 10-fold higher than that of 4HT in patients treated with tamoxifen. These metabolites are formed by the action of cytochrome P450 2D6 (CYP2D6). We used quantitative PCR analysis to examine the effects of endoxifen on estrogenic stimulation of early response genes, c-myc, c-fos and Tff1. Since the natural polyamines, putrescine, spermidine and spermine, play important roles in estrogenic function, we also measured the activities of enzymes in the polyamine biosynthetic/metabolic pathway: ornithine decarboxylase (ODC), S-adenosyl-L-methionine decarboxylase (AdoMetDC), spermidine/spermine N1-acetyltransferase (SSAT), spermine oxidase (SMO), and acetylpolyamine oxidase (APAO). Polyamine levels were quantified by high performance liquid chromatography. Our results showed that estradiol increased the proliferation of MCF-7 cells by 2- to 3-fold and endoxifen suppressed the effects of estradiol on cell growth. The expression of c-myc, c-fos and Tff1 genes was significantly increased by estradiol, while the addition of endoxifen suppressed estradiol-mediated increase in gene expression. Estradiol increased the activity of ODC and AdoMetDC, whereas endoxifen suppressed the activity of these enzymes. Endoxifen had no effect on SSAT activity, whereas it significantly increased activities of amineoxidases, SMO and APAO. Estradiol increased putrescine and spermidine levels and endoxifen inhibited this increase. There was no significant effect on spermine levels. These data suggest that endoxifen exerts its growth inhibitory effects on MCF-7 cells by suppressing the expression of estradiol-stimulated oncogenes and polyamine biosynthetic pathway. The antiestrogenic effect of endoxifen is also manifested through the stimulation of polyamine oxidase enzymes, SMO and APAO. These results indicate for the first time that the upregulation of SMO and APAO is important in the mechanism of action of endoxifen in breast cancer cells.
Citation Format: T. J. Thomas, Tuomo A. Keinanen, Mervi T. Hyvonen. Induction of amineoxidases as a possible mechanism of action of tamoxifen metabolites. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3765.
Abstract 3766: Targeting promoter regions of c-Myc and Bcl-2 in AML cells using G-quadruplex interacting drugs
Authors: Turnidge Megan , Montoya Justin J. , Patel Apurvi , Lee David W. , Aleem Eiman , Wai Daniel H. , Hurley Laurence H. , Gokhale Vijay , Arceci Robert J. , Azorsa David O. 
Published: July 2016

Abstract
Cancer is a disease that can be characterized by overexpression of key oncogenic drivers that support tumor development and maintenance. In many instances, these oncogenic drivers are ‘undruggable’ because of structural challenges, the inability to effectively inhibit high concentrations of overexpressed proteins, and the development of drug resistance mutations. An alternative therapeutic approach is to directly inhibit gene transcription by targeting unique secondary DNA structures, called G-quadruplexes, that are associated with subsets of promoters. We investigated the activity of a class of compounds termed G-quadruplex Interacting Drugs (GQIDs) that are able to shut down the expression of specific oncogenic drivers, such as c-Myc and Bcl-2, used by tumor cells for growth and survival. We tested the activity of two GQIDs, GQC-05 and GSA-1103, on cell growth of a panel of eight pediatric and eight adult acute myeloid leukemia (AML) cell lines. Drug dose response analysis showed IC50 values ranging from approximately 10 nM to 1 μM for GQC-05 and from 40 nM to 2 μM for GSA-1103. The AML cell lines had different sensitivities to each GQID indicating a different mechanism of action for each compound. Three AML cell lines that were highly resistant to cytarabine were among the more sensitive to GQC-05. Four cell lines sensitive to GQC-05 had high expression of either c-Myc and/or Bcl-2, both of which are potential targets of these two GQIDs. Furthermore, treatment of the highly sensitive line MV-4-11 with GQC-05 showed a 3-4 fold decrease in expression of c-Myc and Bcl-2 mRNA. Furthermore, GQC-05 treatment resulted in decreased levels of both c-Myc and Bcl-2 proteins. These studies will help define a novel approach of repressing key drivers of leukemia by targeting selective promoter structures.
Citation Format: Megan Turnidge, Justin J. Montoya, Apurvi Patel, David W. Lee, Eiman Aleem, Daniel H. Wai, Laurence H. Hurley, Vijay Gokhale, Robert J. Arceci, David O. Azorsa. Targeting promoter regions of c-Myc and Bcl-2 in AML cells using G-quadruplex interacting drugs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3766.
Abstract 3767: Highly effective inhibitory agent identified by high-throughput screening of genetically characterized anaplastic thyroid cancer cell lines
Authors: Pinto Nicole C. , Black Morgan , Ruicci Kara , Yoo John , MacNeil Danielle , Fung Kevin , Datti Alessandro , Prokopec Stephenie , Boutros Paul , Barrett John , Nichols Anthony 
Published: July 2016

Abstract
Introduction
While most types of thyroid cancer are treatable, anaplastic thyroid cancer (ATC) is the most lethal human malignancy. Current treatment strategies are largely ineffective with only 10% of patients surviving longer than one year. As such, new treatments are desperately needed to improve patient survival in this aggressive cancer.
Objective
Identify highly effective drugs using high-throughput screening methods with a large panel of kinase inhibitors that can be used in the treatment of ATC.
Methods
High-throughput screening (HTS) of 13 genetically characterized ATC cell lines was carried out over a 6-dose range using 320 kinase inhibitors. Dose-response curves were generated and drugs with high potency were identified. Drugs with the highest activity were selected for further evaluation including investigating mechanism of action and cell death, and assays for migration and invasion.
Results
Based on HTS studies, Lestaurtinib was identified as a highly effective agent with submicromolar mean inhibitory concentrations in all 13 ATC cell lines. Lestaurtinib was found to inhibit STAT5 phosphorylation, as well as cell line migration and invasion. The anti-proliferative effect of Lestaurtinib did not cause apoptosis, autophagy or cell senescence.
Conclusions
With the use of HTS, we have identified many (&gt;20) kinase inhibitors as highly effective agents in the control of ATC. The kinase inhibitor Lestaurtinib was effective at controlling ATC cell proliferation, invasion and migration. Future in vivo analysis of Lestaurtinib with patient-derived xenografts are planned to continue preclinical development of this drug with the ultimate goal of improving outcomes for patients suffering with ATC.
Citation Format: Nicole C. Pinto, Morgan Black, Kara Ruicci, John Yoo, Danielle MacNeil, Kevin Fung, Alessandro Datti, Stephenie Prokopec, Paul Boutros, John Barrett, Anthony Nichols. Highly effective inhibitory agent identified by high-throughput screening of genetically characterized anaplastic thyroid cancer cell lines. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3767.