bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2328: Targeting self-renewal in human colorectal cancer by inhibiting SUMOylation
Authors: Du Li , Chen Yuan 
Published: August 2015

Abstract
Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer death in the US. It is well recognized that cancer stem cells (CSCs) are responsible for treatment resistance, tumor metastasis and relapse, which cause treatment failure. SUMOylation is known to be important for pluripotency and is dysregulated in cancers to drive tumor growth and metastasis. Therefore, we investigate the role of SUMOylation in colorectal cancer CSC maintenance and self-renewal.
In this study, we established that aldehyde dehydrogenase 1 (ALDH1) activity is a valid marker of colorectal CSCs, because ALDH+ cells in HT29 displayed CSC properties including self-renewal, clonal formation and tumor initiation in NSG xenograft mouse model, while ALDH- cells did not. Profiling ALDH+ and ALDH- cells showed that SUMO-activating enzyme (SAE) is highly enriched in ALDH+ cells along with enhanced global SUMOylation. Overexpression of the catalytic subunit of SAE, SAE2, increased the population of ALDH+ cells while knockdown of SAE2 decreased the population of ALDH+ cells. This result suggests that increased SAE level promotes stemness in colorectal cells. To characterize CSC maintenance and self-renewal quantitatively, we performed limited dilution assays in vitro with sphere initiation and in vivo using mouse xenograft models. In in vitro assays, we observed 4-fold reduction in CSC self-renewal frequency in SAE2 knockdown cells compared to control cells in the colorectal cancer cell line HT29. In four colorectal cancer patient-derived primary culture cells, the frequency was 2∼6 fold lower in SAE2 knockdown groups than control. In the in vivo experiment, SAE2 knockdown group showed 12-fold reduction in self-renewal frequency of HT29 cells. These data demonstrate that silencing of SAE2 causes a significant decrease in stemness of colorectal cancer cells, both in HT29 cell line and primary human tumors. Mechanistic analysis regarding how SUMOylation regulate colorectal cancer CSC is underway and will be discussed.
In conclusion, our study indicates that SUMOylation, in particular the SAE, is an important regulator of colorectal CSC maintenance and self-renewal. Therefore, the data suggests that targeting SAE is a potential strategy to inhibit colorectal CSC.
Citation Format: Li Du, Yuan Chen. Targeting self-renewal in human colorectal cancer by inhibiting SUMOylation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2328. doi:10.1158/1538-7445.AM2015-2328
Abstract 236: Autocrine regulation of stress-induced cytotoxic Alu RNA expression in TNBC cells
Authors: Singhal Ashutosh , Mishra Smita , Chaudhuri Gautum 
Published: August 2015

Abstract
Breast tumor cells are often subject to various forms of proteotoxic stress in their microenvironment mainly presented by the stromal cells. We found that the highly aggressive breast cancer cells of the triple negative subtype (TNBC) are significantly more tolerant to environmental stress than the non-aggressive breast cancer cells. Major objective of the research presented here is to understand the mechanism of induction of cytotoxic Alu RNA in the stressed breast cancer cells and how the TNBC cells pacify this non-coding RNA-mediated cytotoxicity. We present evidence that stress-induced activation of HSF1 in the breast cancer cells stimulate the RNA polymerase III-mediated transcription of Alu RNA genes in these cells resulting in induction of severe cytotoxicity and apoptosis of these cells. Highly aggressive stress-tolerant TNBC cells secrete the matrix metalloprotease MMP1 which activates the G-protein coupled receptor PAR1 on their cell surface. Activation of PAR1 through the Galpha-q/PIPLC/PIP3 pathway raises the cytosolic concentration of Ca2+ thereby activating the Ca2+-dependent protease mu-calpain. Mu-calpain then proteolytically degrades the RNA polymerase III transcription factor TFIIIC110 at the PES sequence. As TFIIIC110 is required for the transcription of Alu RNA genes, its degradation ameliorates stress-induced elevation of Alu RNA and thus its cytotoxicity. We propose that inhibition of MMP1, PAR1 or mu-calpain in the TNBC cells will prevent this pacification mechanism promoting stress-induced demise of these cells. This research is supported in part by NIH/NCI grant 1R21CA181920-01 to GC.
Citation Format: Ashutosh Singhal, Smita Mishra, Gautum Chaudhuri. Autocrine regulation of stress-induced cytotoxic Alu RNA expression in TNBC cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 236. doi:10.1158/1538-7445.AM2015-236
Abstract 2436: Understanding the molecular mechanism of targeted kinase inhibitor resistance mediated by the FGFR1 gatekeeper mutation
Authors: Sohl Christal D. , Ryan Molly , Luo BeiBei , Frey Kathleen , Anderson Karen S. 
Published: August 2015

Abstract
Human fibroblast growth factor receptors (FGFRs) can serve as drivers of oncogenesis and are a target of several inhibitors in clinical trials. Unfortunately, resistance severely hampers the long-term success of tyrosine kinase inhibitors (TKIs), with mutations at the gatekeeper residue often serving as an early means of resistance to cancer therapy, resulting in tumor progression. Here we show the first crystal structures of the FGFR1 gatekeeper mutation, V561M FGFR1, and use kinetic and structural methods to explore the mechanisms of the catalytic activation we observe for this mutation. We show that while the FGFR1 gatekeeper mutation confers resistance to two inhibitors currently in clinical trials, the extent of change in efficacy differ, indicating two unique resistance profiles. We show that some affinity for one inhibitor is maintained by the V561M mutation due to a flexible linker that allows multiple binding conformations. This is the first example showing the same inhibitor binding in unique ways to the WT and gatekeeper mutant forms of FGFR, highlighting some regions of drug design flexibility both within the binding pocket and in the linker of the inhibitor. Identifying this flexibility in the context of the structural features of an active conformation of V561M FGFR1, the form most kinase inhibitors target, will provide critical insights for designing future inhibitors effective against the FGFR gatekeeper mutations.
Citation Format: Christal D. Sohl, Molly Ryan, BeiBei Luo, Kathleen Frey, Karen S. Anderson. Understanding the molecular mechanism of targeted kinase inhibitor resistance mediated by the FGFR1 gatekeeper mutation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2436. doi:10.1158/1538-7445.AM2015-2436
Abstract 2455: Differences in dynamic modulation of CoQ10 redox status and intracellular localization between non-disease and cancer cell lines
Authors: Krumova Katerina , Garg Sumit , Dhavala Sirisha , Vishnudas Vivek K. , Kiebish Michael A. , Sarangarajan Rangaprasad , Narain Niven R. 
Published: August 2015

Abstract
Although it is well recognized that Coenzyme Q10 (CoQ10) is present in all cellular membrane structures, its effects on cellular functions other than mitochondrial regulation is poorly understood. The present study was aimed at gleaning insights into effect on CoQ10 on sub-cellular metabolism, regulation of the redox status, as well as gene regulation. A series of fluorescent probes were developed with the ability to report on the consequence of specific biological events in which CoQ10 was involved. The probes constituted fluorescently labeled CoQ10 analogues designed to track the distribution, biochemical and redox behaviour of CoQ10 in a non-invasive manner providing real time information in live cells. Compartmentalization of fluorescent labeled CoQ10 probe incorporated within BPM 31510 liposomal formulation was characterized in human derived primary non-disease and cancer cell lines. Cellular distribution of the fluorescent CoQ10 varied depending upon cell type. The fluorescent CoQ10 probes were designed and utility to provide a time resolved assessment on the redox state of CoQ10 in whole cells and organelles as a measure of the cell's overall and intracellular location specific metabolic micro-environments. The ratio of reduced and oxidized form of fluorescent CoQ10 was also examined in relation to ROS production in cancer cells. The overall results describes the presence of a constant redox flux influencing the redox state of CoQ10 within cancer and normal cells with significant variation depending on cell type and disease status.
Citation Format: Katerina Krumova, Sumit Garg, Sirisha Dhavala, Vivek K. Vishnudas, Michael A. Kiebish, Rangaprasad Sarangarajan, Niven R. Narain. Differences in dynamic modulation of CoQ10 redox status and intracellular localization between non-disease and cancer cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2455. doi:10.1158/1538-7445.AM2015-2455
Abstract 2478: A mAb with in vivo therapeutic activity against spontaneous breast tumors in FVB-neuN mice recognizes SLP-2
Authors: Wang Li-Xin , Berk Michael , Plautz Gregory E. 
Published: August 2015

Abstract
BCSC (breast cancer stem cells) derived from FVB-neuN mice bearing primary breast tumors were used to vaccinate mice and vaccine-draining lymph node T cells were adoptively transferred to mice with advanced primary tumors. Treated mice experienced tumor regression and importantly a concomitant serologic response was induced to an antigen that is expressed by BCSC even in Neu-antigen loss tumor cells. We generated a specific mAb (mAb2) reactive against a membrane antigen on BCSC tumorsphere cultures derived from NeuN spontaneous breast tumors but not the counterpart adherent cultures. In vivo administration of mAb2 inhibited progression of macroscopic primary tumors in Her-2/neu transgenic mice. We further observed that the molecule bound by mAb2 is expressed on proliferating but not growth-arrested C2D1-tumorspheres and this antigen is re-expressed when cells are digested into single cell suspension and re-fed with fresh medium. Similar results are observed with 4T1-tumorsphere cells, an additional breast cancer cell line arising initially in BALB/c mice. Interestingly, the target of mAb2 is also down-regulated following irradiation-induced growth arrest of tumor cells. To identify the antigen recognized by mAb2, cultured C2D1-tumorsphere or 4T1-tumorspheres were cells were lysed and the supernatant was immunoprecipitated with mAb2. The proteins captured by mAb2 were separated by 10% SDS-PAGE and visualized by silver staining. The bands of interest were excised then subjected to liquid chromatography-mass spectrometric (LC-MS/MS) analysis. A ∼40 KDa protein was detected in all five experiments from either C2D1-tumorsphere or 4T1-tumorsphere cells. Stomatin-like protein 2 (SLP-2) a 38.5 KDa protein was consistently identified whereas 14 other proteins were sporadically found. Western blots of mAb2 immunoprecipitates from C2D1 or 4T1-tumorsphere lysates were probed with two distinct commercial antibodies against SLP-2 and we confirmed its presence. To validate SLP-2 as the target, an expression vector was transfected into NIH 3T3 cells and FACS analysis demonstrated 19% positive cells versus 3.6% for un-transfected 3T3 cells. SLP-2 overexpression is associated with tumor metastasis and poor prognosis in several types of human tumors. Our results indicate that the antigen recognized by this auto-antibody might have immunodiagnostic or immunotherapeutic potential.
Citation Format: Li-Xin Wang, Michael Berk, Gregory E. Plautz. A mAb with in vivo therapeutic activity against spontaneous breast tumors in FVB-neuN mice recognizes SLP-2. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2478. doi:10.1158/1538-7445.AM2015-2478
Abstract 2509: Human anti-MUC1 antibodies elicited by a prophylactic cancer vaccine for mAb and CAR-modified T cell immunotherapies
Authors: Lohmueller Jason J. , Sato Shuji , Cheung Wan Cheung , Chu Isabel , Popova Lana , Manning Christopher A. , Crosby Katherine , Grange Christopher , Ham James D. , Polakiewicz Roberto D. , Finn Olivera J. 
Published: August 2015

Abstract
MUC1 is a tumor-associated protein that is abnormally expressed on human adenocarcinomas. In our recent clinical trial, individuals at-risk for colonic adenocarcinoma received a prophylactic MUC1 cancer vaccine. Many individuals responded to the vaccine by producing high titers of anti-MUC1 IgG antibodies (Kimura, 2013). We isolated a panel of these antibodies and are seeking to develop them as antibody and chimeric antigen receptor (CAR) T cell cancer immunotherapies. To this end we used a novel method combining proteomics and next-gen DNA sequencing to identify and recombinantly produce 12 high-affinity anti-MUC1 antibodies from the sera of vaccinated individuals. By ELISA we determined that the antibodies bind with high-affinity to diverse epitopes within the MUC1 vaccine peptide. We also found that several of the antibodies can stain MUC1+ pancreas, colon, and breast cancer cell lines, but not a cell line expressing normal MUC1. We then determined that the antibodies could stain MUC1+ human pancreas and colon tumor samples, but not normal tissues. Having established tumor-specificity we have begun assessing the antibodies in a series of functional assays. In preliminary in vitro testing we determined that several of the antibodies can be internalized by MUC1+ cells making them potential candidates for toxin delivery as antibody drug conjugates (ADCs). Additionally, we found that two of the antibodies are capable of efficiently performing complement-dependent cytotoxicity (CDC) on MUC1+ cells. Finally, we have constructed CAR lentiviral expression constructs using the variable regions of several of the antibodies as targeting domains and are testing their ability to mediate MUC1-specific T cell activation, cytokine production, and target cell lysis. As the antibodies are human-derived, indication of efficacy in pre-clinical testing has the potential to directly enable clinical trials and hopefully approval of these reagents for therapy of cancer patients.
Citation Format: Jason J. Lohmueller, Shuji Sato, Wan Cheung Cheung, Isabel Chu, Lana Popova, Christopher A. Manning, Katherine Crosby, Christopher Grange, James D. Ham, Roberto D. Polakiewicz, Olivera J. Finn. Human anti-MUC1 antibodies elicited by a prophylactic cancer vaccine for mAb and CAR-modified T cell immunotherapies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2509. doi:10.1158/1538-7445.AM2015-2509
Abstract 2542: Lurbinectedin (PM01183) synergizes in vivo the antitumor activity of doxorubicin in SCLC tumor xenografts
Authors: Guillen Maria Jose , Cataluña Oscar , Palomares Mandy , Lopez Raquel , Nuñez Praxedes , Cuevas Carmen , Aviles Pablo M. 
Published: August 2015

Abstract
Background: Lurbinectedin (PM01183) is a synthetic tetrahydroisoquinoline alkaloid currently evaluated as single agent and in combination in phase I and II clinical trials for solid tumors and hematological malignancies. In living cells, PM01183-DNA adducts stall replication and transcription giving rise to double strand breaks, inducing accumulation of cells in the S-phase of the cell cycle and triggering apoptosis. Studies aimed at defining the in vivo synergism of PM01183 and doxorubicin in the treatment of Small Cell Lung Cancer (SCLC) xenografted tumors are presented here.
Material and Methods: Athymic nude mice were implanted with SCLC cells (NCI-H82 or NCI-H526). Mice bearing tumors (ca. 150 mm3) were allocated (N = 6-8/group) to experimental groups, namely: placebo; PM01183 at MTD (0.18 mg/kg), 0.75MTD, 0.5MTD and 0.25MTD; doxorubicin at their MTD (8.0 mg/kg), 0.75MTD, 0.5MTD and 0.25MTD; and, PM01183 combined with doxorubicin at (1+1), (0.75+0.75), (0.50+0.50) and (0.25+0.25) MTDs. All treatments were given intravenously once per week during the placebo-treated survival time. The antitumor effect induced by the treatments was analyzed using two-tailed Mann-Whitney U test. Also, the synergism was defined by the combination index (CI) determined by the CI-isobol method.
Results: In both experiments, the combination of PM01183 and doxorubicin resulted in stronger antitumor effect (P&lt;0.05) than that obtained with the more active single agent at the highest dose (MTD level). Analyses of the results by the CI-isobol method indicated that, after the treatment with PM01183 plus doxorubicin in the SCLC models resulted in an additive (at Fa = 0.97, CI = 1.05) or synergistic (at Fa = 0.97, CI = 0.66) effect.
Conclusion: An improved (additive or synergism) in vivo antitumor activity was recorded after the treatment with PM01183 plus doxorubicin of mice bearing SCLC xenografted tumors.
Citation Format: Maria Jose Guillen, Oscar Cataluña, Mandy Palomares, Raquel Lopez, Praxedes Nuñez, Carmen Cuevas, Pablo M. Aviles. Lurbinectedin (PM01183) synergizes in vivo the antitumor activity of doxorubicin in SCLC tumor xenografts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2542. doi:10.1158/1538-7445.AM2015-2542
Abstract 2565: Aryl hydrocarbon receptor agonist 5F 203 induces oxidative stress triggering DNA damage and cytoglobin up-regulation in human breast cancer cells
Authors: Rowland Leah K. , McLean Lancelot S. , Campbell Petreena , Watkins Cheri N. , Zylstra Dain , Amis Louisa H. , Senthil Maheswari , Brantley Eileen 
Published: August 2015

Abstract
Breakthroughs are needed in breast cancer therapy to improve clinical outcomes. Emerging evidence suggests that tumorigenesis stems, in part, from epigenetically silenced tumor suppressor genes (TSGs) and restoring TSGs may represent a viable strategy to treat breast cancer. We previously found that aryl hydrocarbon receptor (AhR) agonist 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) exhibits potent cytotoxicity, increases reactive oxygen species (ROS), induces DNA damage and up-regulates the expression of putative tumor suppressor gene cytoglobin in breast cancer cells. In the current study, we seek to delineate the mechanism by which 5F 203 induces DNA damage and cytoglobin expression in susceptible breast cancer cells. We found that 5F 203 activated p38 mitogen activated protein kinase (p38) and c-Jun-N terminal kinase (JNK) signaling in breast cancer cells. Pretreatment with antioxidant N-acetyl-L-cysteine or AhR inhibitor α-naphthoflavone diminished 5F 203-mediated p38 or JNK activation in a cell context-dependent fashion. Pretreatment with pharmacological inhibitors of p38 or JNK suppressed 5F 203-mediated increases in intracellular ROS to suggest the presence of a positive feedback loop. 5F 203 induced oxidative DNA damage in breast cancer cells but not breast epithelial MCF-10A cells unlike AhR agonist benzo[a]pyrene which induced oxidative DNA damage more indiscriminately. Pretreatment with p38 or JNK inhibitors suppressed 5F 203-induced single strand break formation and cytoglobin mRNA expression in breast cancer cells. Our data show 5F 203 confers anticancer activity in breast cancer cells in part by increasing ROS via a positive feedback loop to sustain p38 and JNK activation resulting in DNA damage and cytoglobin restoration.
Citation Format: Leah K. Rowland, Lancelot S. McLean, Petreena Campbell, Cheri N. Watkins, Dain Zylstra, Louisa H. Amis, Maheswari Senthil, Eileen Brantley. Aryl hydrocarbon receptor agonist 5F 203 induces oxidative stress triggering DNA damage and cytoglobin up-regulation in human breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2565. doi:10.1158/1538-7445.AM2015-2565
Abstract 2600: Targeting cancer stem cell through blocking the Erk pathway with Kazinol-E from Broussonetia kazinoki
Authors: Jung Yu-Chae , Han Seula , Hua Li , Zhao Hui-Yuan , Lee Cheol-Jung , Cho Yong-Yeon , Jeon Raok , Ryu Jae-Ha , Kim Woo-Young 
Published: August 2015

Abstract
Growing evidence suggests that a small population of cells, called cancer stem cells (CSCs) contribute to the heterogeneity, recurrence and resistance to chemotherapy in breast cancer. In this regard, CSC is considered to be a good target to cure breast cancers. The extracellular signal-regulated kinase (ERK) signaling pathway is one of the major determinants in the control of diverse cellular process including the maintenance of CSCs. Kazinol-E is an antioxidant flavan purified from the root bark of Broussonetia kazinoki (Moraceae, paper mulberry). In this study, we found the anti CSC effect of Kazinol-E through targeting ERK pathway. It decreased the population of a breast cancer cell (MCF-7) CSCs which are CD44+/CD24- or aldehyde dehydrogenase positive, at the concentration that does not influence the growth of general MCF-7 cells cultured with serum. It targeted and inhibited ERK kinase activities in vivo in both CSC and in regular cultured cells suggesting the CSCs depend more than the rest of cancer cells do on Erk signaling for the survival. In vitro kinase assay using purified Erk-1 and p90RSK2, as the substrate, and the molecular docking study suggest that the Kazinol-E suppress the Erk activity by direct binding to the ATP binding pocket of Erk-1. Interestingly, a Kazinol-C which is very similar with Kazinol-E in structure did not show the Erk-1 inhibition nor anti CSC activity. These results collectively suggest that Kazinol-E may be a specific anti CSC agent targeting Erk pathway.
Citation Format: Yu-Chae Jung, Seula Han, Li Hua, Hui-Yuan Zhao, Cheol-Jung Lee, Yong-Yeon Cho, Raok Jeon, Jae-Ha Ryu, Woo-Young Kim. Targeting cancer stem cell through blocking the Erk pathway with Kazinol-E from Broussonetia kazinoki. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2600. doi:10.1158/1538-7445.AM2015-2600