bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2798: Enhanced HIF1α inhibition through dual inhibition of CDK and HSP90
Authors: Zhao Shuai , Dicker David T. , El-Deiry Wafik S. 
Published: July 2016

Abstract
A prevalent characteristic of solid tumors is the presence of hypoxic areas. Intratumoral hypoxia plays a well-known role in chemotherapy and radiotherapy resistance and is associated with poor prognosis as well as enhanced metastasis. Hypoxia-inducible factor 1α (HIF1α) is a major mediator of the cellular response to hypoxia, which promotes malignant proliferation and progression in cancers. HIF-1α expression is increased in a variety of tumors but this is not restricted to hypoxic regions. Understanding and targeting the mechanism of cancer-related HIF1α stabilization may help to improve current cancer treatments. We have previously shown that cyclin-dependent kinase 1 (CDK1) stabilizes HIF1α through direct phosphorylation of its Ser668 residue in a Von Hippel-Lindau (VHL)-independent manner both under hypoxia and at G2/M under normoxia (Warfel et al., Cell Cycle, 2013). Another previously acknowledged VHL-independent HIF1α stabilizer is the heat shock protein 90 (HSP90) that has been correlated with adverse prognosis and used as a therapeutic target in cancer. We investigated potential crosstalk between CDK1-mediated and HSP90-mediated HIF1α stabilization and the potential for therapeutic targeting. We found that under hypoxia, the interaction between HSP90 and HIF1α proteins is impaired by CDK1 inhibition in HCT116 colon cancer cells. Moreover, the level of HIF1α protein is increased by heat shock (40°C) treatment (as compared to 37°C), which can be reversed by the treatment with the HSP90 inhibitor, geldanamycin. Interestingly, administration of the CDK1 inhibitor, Ro-3306, is also able to decrease heat shock-induced HIF1α. Our results suggest that CDK1 activity may contribute to HSP90-mediated HIF1α stabilization. On the other hand, HIF1α level is decreased by HSP90 inhibition under hypoxia, which can be further reduced by the combination of HSP90 inhibition and CDK1 inhibition or knockdown. The joint inhibitory effect of CDK1 and HSP90 is observed in other cancer cell lines. In addition, we evaluated the combinational treatment of CDK4/HSP90 inhibition and found it robustly suppresses HIF1α expression in glioblastoma cell lines (i.e. T98G and SNB19). Ongoing studies are examining the biological function of CDK/HSP90 dual inhibition on cancer cell invasiveness as well as effects on cell viability. Our findings provide a rationale for targeting HIF1α through a novel combination of CDK and HSP90 inhibitors, a therapeutic strategy with clinical implications.
Citation Format: Shuai Zhao, David T. Dicker, Wafik S. El-Deiry. Enhanced HIF1α inhibition through dual inhibition of CDK and HSP90. [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 2798.
Abstract 2800: Target RNA sequencing analysis of hypoxia induced expression of stem cell genes in primary cultures of prostate cancer cells
Authors: Yin Hong , Greer Adam H. , Mills Glenn 
Published: July 2016

Abstract
Hypoxia plays important regulatory roles in expanding the tumor stem cell population. In prostate cancer, hypoxia is a feature of poor prognosis. The association of prostate cancer stem cells with hypoxia has been investigated. The altered stem cell gene expression in prostate cancer cells under the hypoxic condition has been documented. The majority of the investigations were performed with established prostate cancer cell lines. However, little is known about the expression of stem cell genes in primary cultures of prostate cancer. In this study, we examined the hypoxia-regulated expression of stem cell genes with primary cultures of human prostate cancer. Cells were isolated from three patient's prostate cancer samples. Isolated cells were cultured in prostate epithelium culture medium CnT-52. After 48 hours of exposure to 1% oxygen, RNA was extracted and quantified. The library was prepared with Illumina's TruSeq Targeted RNA Expression Stem Cell Panel. The sequencing was performed on Miseq platform with MiSeq Reagent Kits v2 (300cycles). FastQ files were generated by Miseq Reporter and analyzed further by Truseg Target RNA v1.0(Illumina), Cufflinks Assembly &DE(Illumina), and Biomedical Genomics Workstation(Qiagen).The results showed that of the 100 tested stem cell genes, seven genes were significantly upregulated(FDR p-value&lt;0.05). They are BMP1, BMP2, FZD7, JUND, NOTCH1, NOTCH3, and PPARD. Three genes, PSEN2, SDAD1, and SOX2, were significantly down-regulated. To validate sequencing results, we examined NOTCH1 and NOTCH3 expression with RT-PCR. Compared to cells under normoxic condition, hypoxia induced expression of NOTCH1 increased by 3.7, 3.9 and 3.1 fold, respectively among three hypoxic cultures, while the expression of NOTCH3 increased by 8.1, 5.9, and 7.5 fold, respectively. However, the investigation of hypoxia affected expression of stem cell genes in LNCaP, an established prostate cell line, showed that the significant decreased expression of BMP1, FZD7, PPARD, and NOTCH3 was seen under hypoxic condition(FDR p-value &lt;0.05). RT-PCR analysis showed that expression of NOTCH3 in hypoxic LNCaP, PC3, and DU145 cells was decreased by 7.7, 6.1, and 1.2 fold, respectively. The expression profile of stem cell genes in response to hypoxia was different between primary cultures of prostate cancer cells and established prostate cancer cell lines. The activation of BMP-NOTCH signaling could be one character of stemness of prostate cancer in response to hypoxia.
Citation Format: Hong Yin, Adam H. Greer, Glenn Mills. Target RNA sequencing analysis of hypoxia induced expression of stem cell genes in primary cultures of prostate cancer cells. [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 2800.
Abstract 2801: Arginylation as a novel regulator of prostate cancer progression
Authors: Birnbaum Michael , Kumar Akhilesh , Zhang Fangliang 
Published: July 2016

Abstract
Post-translational arginylation, mediated by Arginyltransferase (Ate1), is an important protein modification involved in stress response yet remains poorly studied. Our lab recently reported that a loss of Ate1 is sufficient to induce tumorigenesis and loss of contact inhibition in fibroblasts. However, the role of Ate1 in cancer initiation and progression is not clear. This study examines the effects of Ate1 loss in prostate cancer models of tumorigenesis and progression. We first show that Ate1 is required for normal cellular responses to several types of stress present in cancer. Preliminary data in fibroblasts shows that Ate1 is essential for cell death following oxidative stress, hypoxia, UV and gamma radiation, and apoptosis-inducing drugs. These results inspired further tests to examine if cancer progression may be directly stimulated by a loss of Ate1 through increased cell survival and invasiveness. To study the effects of lost Ate1, we characterize established prostate cancer cell lines with Ate1 stably knocked down. In PC-3 prostate cancer cells, a reduction of Ate1 corresponded with increased invasiveness in the Boyden Chamber invasion assay, and reduced H2O2-induced cell death. In LnCaP prostate cancer cells, reduced Ate1 induced significantly higher anchorage-independent growth during a soft-agar growth assay. In conclusion, our data suggests that the loss of Ate1 in prostate cancer serves to stimulate cancer progression, and that Ate1 protein expression levels may predict malignancy.
Citation Format: Michael Birnbaum, Akhilesh Kumar, Fangliang Zhang. Arginylation as a novel regulator of prostate cancer progression. [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 2801.
Abstract 2807: Coordinated upregulation of peroxiredoxins in breast cancer
Authors: Muhlbauer Jillian , Phelan Shelley A. 
Published: July 2016

Abstract
Peroxiredoxins (Prdxs) are a group of thiol-specific antioxidant proteins that are involved in many cellular processes, including growth, proliferation, differentiation, and the stress response. The family includes six proteins in humans, which show differences in substrate specificity, tissue expression, and cellar localization and distribution. Cancer cells commonly exhibit aberrantly regulated expression of antioxidants, which can support cancer cell survival in the face of elevated levels of reactive oxygen species. Breast cancers exhibit significantly elevated Prdx levels of Prdx. We previously reported overexpression of many Prdx proteins in the MCF-7 breast cancer line, and further demonstrated their importance in cell survival and doxorubicin-resistance in this line. To further investigate the misregulation of these proteins in human breast cancer, we compared Prdx levels between breast tumor and adjacent normal breast tissue from 20 breast cancer patients. We showed that most patients exhibited elevated levels of several Prdx proteins in the tumor tissue. We have gone on to analyze the promoters of these genes in an effort to identify potential mechanisms of coordinate regulation, as well as downstream targets that may mediate their role in cell survival. Together, we feel that this family of proteins may be useful biomarkers, and also targets, in breast cancer biology.
Citation Format: Jillian Muhlbauer, Shelley A. Phelan. Coordinated upregulation of peroxiredoxins in breast cancer. [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 2807.
Abstract 2812: Targeting reactive oxygen species in human cancer cell growth and metastasis in nude mouse
Authors: Inufusa Haruhiko 
Published: July 2016

Abstract
[Purposes of the study] Reactive oxygen species (ROS) are associated with clinical condition, and closely involved in cancer growth and metastasis. Twendee X is a composition consisting of Vitamin C, Glutamine, Cystine, Riboflavin, Succinic acid, Fumaric acid, Coenzyme Q10, and Niacin. Twendee X strongly reduces oxygen radicals or ROS in vitro and in vivo (World Intellectual Property Organization WO/2013/072441 COMPOSITION FOR PROTECTION AGAINST CELL-DAMAGING EFFECTS). Effects of Twendee X on human colon cancer cell lines growth and metastasis in nude mouse was examined.
[Experimental procedures] Human colon cancer cell line RPMI4788 human gastric cancer cell line MKN45 was used in this study. Ten nude mice (BALB/C nu-nu, 4wks, Male) per each group of experiments were used, and repeated twice. Two cell lines were inoculated in subcutaneous of nude mouse, and tumor growth monitored for days. Lung metastasis was counted weeks after injection RPMI4788 cells into the tale vein of nude mouse. Twendee X was added to the free drink water around 37mg/kg/day by calculation. Serum of tumor bearing nude mouse was sampled just before sacrifice. Free Calpe Diem (Diacron International, Italy) was used to measure ROS related marker d-ROMs test (detect hydrogen peroxide). Natural Killer cell (NK) activity also measured in tumor bearing nude mouse.
[Data] Tumor growth of RPMI4788 and MKN45 was reduced 25% and 40% respectively by Twendee X administration. Metastatic nodule of RPMI4788 was reduced to 1/7 by Twendee X administration. Increase value of d-ROMs test reduced to 60% compare to the control by Twendee X administration. NK activity of RPMI4788 tumor bearing nude mouse was reduced to 28% compare to the normal mouse, and increased to 56% by Twendee X administration.
[Conclusion] Twendee X has significant effects of reducing tumor growth and inhibition metastasis. Hydrogen peroxide level (d-ROMs test) of tumor bearing nude mouse in serum was significantly reduced. ROS effects on immune cell activity, and Twendee X recovered suppressed NK activity. Thus, Twendee X effects on ROS inhibition and suppressed RPMI 4788 tumor growth and metastasis to the lung of nude mouse. Metastatic nodules receiving larger blood flow compare to the tumor in the back of mouse, thus means anti-tumor immune cells in blood may easier attack cancer cells.
Citation Format: Haruhiko Inufusa. Targeting reactive oxygen species in human cancer cell growth and metastasis in nude mouse. [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 2812.
Abstract 2814: Comparative DNA damage and transcriptomic effects of engineered nanoparticles in human lung cells in vitro
Authors: Nelson Garret B. , Thai Sheau-Fung Y. , Jones Carlton P. , Barbee Audrey , Killius Micaela , Ross Jeffrey A. 
Published: July 2016

Abstract
A series of six titanium dioxide and two cerium oxide engineered nanomaterials were assessed for their ability to induce cytotoxicity, reactive oxygen species (ROS), various types of DNA damage, and transcriptional changes in human respiratory BEAS-2B cells exposed in vitro at several concentrations for 72 hours. Only limited cytotoxicity was observed at concentrations up to 300 μg/ml for all of the nanomaterials. Small increases in 8-oxo-deoxyguanosine were induced by some of the nanomaterials, but did not achieve statistical significance. No increases in ethenoadenosine or ethenocytidine were detected by ELISA assays for any of the tested nanomaterials. Several of the nanomaterials exhibited concentration related increases in levels of apurinic/apyrimidinic sites, endogenous DNA adducts measured by 32P-postlabeling, lipid peroxidation, and ROS. Consistent with these findings, several of the nanomaterials also affected expression of genes involved in p53, ATM, and mismatch repair pathways. Integrin signaling pathways were also altered by a majority of the nanomaterials tested. There was general agreement between activity in DNA damage assays and extent of pathway transcriptional alteration. One out of the cerium oxide nanomaterials tested did not induce a high enough incidence of differentially expressed genes relative to controls to allow analysis at the pathway level, and also elicited the lowest response in multiple DNA damage assays. Taken together, these data are consistent with the contribution of DNA damage induced by reactive oxygen species as mediators of potentially adverse biological effects following exposure to engineered titanium and cerium oxide nanomaterials, and suggests the utility of short term in vitro tests to predict relative potencies of these particles.
This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.
Citation Format: Garret B. Nelson, Sheau-Fung Y. Thai, Carlton P. Jones, Audrey Barbee, Micaela Killius, Jeffrey A. Ross. Comparative DNA damage and transcriptomic effects of engineered nanoparticles in human lung cells in vitro. [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 2814.
Abstract 2823: Identification of highly selective inhibitors of cyclin-dependent kinase 12
Authors: Choidas Axel , Schultz-Fademrecht Carsten , Degeenhardt Carsten , Habenberger Peter , Koch Uwe , Eickhoff Jan E. , Greifenberg Ann Kathrin , Nussbaumer Peter , Geyer Matthias , Klebl Bert M. 
Published: July 2016

Abstract
CDK12 and CDK13 belong to the cyclin-dependent kinase (CDK) family, which includes at least 20 different human CDKs and CDK-like enzymes. One subclass of CDKs (e.g. CDK7, CDK8, CDK9, CDK12 and CDK13) preferentially regulates transcription by phosphorylation of the C-terminal domain of RNA polymerase II (RNAPII), whereas another subgroup of CDKs plays a pivotal role in controlling cell cycle progression (e.g. CDK1, CDK2, CDK4, CDK6 and CDK7). Both groups - cell cycle as well as transcriptional CDKs - have been reported to be involved in cancer development and progression. Recent reports indicated CDK12 to be involved in DNA damage repair mechanisms and linked its mutation to high-grade serous ovarian carcinoma rendering CDK12 a promising target for drug development. However, the pivotal role of individual CDKs and their complex regulation requests for highly selective inhibitors to avoid unwanted adverse effects. Non-specific first-generation CDK-inhibitors cause toxicity in vivo issues. They showed little to no therapeutic window in clinical trials and thus shifted the focus to the optimization of selective small molecule CDK inhibitors.
To identify selective small molecular weight inhibitors of CDK12 and CDK13 we employed a rationale drug discovery approach based on a focused kinase library screen. Screening of slightly over 16.000 compounds identified several hit compound classes. Medicinal chemistry based optimization yielded nanomolar CDK12 inhibitors. The selectivity of these improved CDK12 inhibitors is excellent, when tested against 12 CDK family members. Such selective CDK12 inhibitors have also shown promising physicochemical properties, indicating lead- and drug-likeness. Although, potency on the target still needs to be improved, the frontrunners from our selective CDK12 inhibitor family have shown cellular inhibition of CDK12 substrate phosphorylation such as those of RNA polymerase II. Currently, potency of these CDK12 inhibitors is being improved by using structure-guided medicinal chemistry-based optimization. The resulting lead candidates will then be tested in in vivo cancer models.
Citation Format: Axel Choidas, Carsten Schultz-Fademrecht, Carsten Degeenhardt, Peter Habenberger, Uwe Koch, Jan E. Eickhoff, Ann Kathrin Greifenberg, Peter Nussbaumer, Matthias Geyer, Bert M. Klebl. Identification of highly selective inhibitors of cyclin-dependent kinase 12. [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 2823.
Abstract 2829: Preclinical analysis and characterization of abemaciclib using three-dimensional patient-derived colorectal cancer organoid cultures
Authors: Boehnke Karsten , Calsina Bruna , Amat Joaquín , Hermoso Ana , Torres Raquel , Reinhard Christoph , Velasco Juan A. , Iversen Philip W. , De Dios Alfonso , Buchanan Sean , Beckmann Richard P. , Schumacher Dirk , Regenbrecht Christian RA , Yaspo Marie-Laure , Lehrach Hans , Lallena María José 
Published: July 2016

Abstract
Proper patient-tailoring strategy and the validation of novel therapeutic targets remain enormous challenges during drug discovery processes. Patient-derived three-dimensional organoid cell culture models possess great potential to associate compound sensitivity and disease complexity in order to provide a key missing link between compound screening and clinical trials. Abemaciclib is a reversible, ATP competitive, selective inhibitor of the kinase activity of both CDK4 and CDK6 and is currently undergoing advanced clinical testing.
In this study, we established and characterized three-dimensional organoid cultures from primary colorectal cancer patients and validated their use as drug sensitivity models. We aimed to explore the antitumor activity of abemaciclib in colon cancer organoid cultures by assessing markers for cell viability, proliferation, cell cycle, senescence and apoptosis. Single cell suspension of patient-derived samples were precultured for four days to allow for complete morphogenesis of three-dimensional organoid structures. Subsequently, the cultures were treated for at least two population doubling times and analyzed by luminescent cell viability, immunohistochemistry and flow cytometry assays.
Our data suggest that abemaciclib treatment decreased the cell viability of patient-derived colorectal cancer organoid cultures characterized by G1 cell cycle arrest and reduced Ki-67-positive cells. Furthermore, treated cultures showed elevated levels of reactive oxygen species and increased markers for early and late apoptosis. In summary, complex organoid models have the potential to further evaluate the antitumor activity of abemaciclib in various tumor types by enabling mechanistic studies in a patient-specific preclinical setting.
Citation Format: Karsten Boehnke, Bruna Calsina, Joaquín Amat, Ana Hermoso, Raquel Torres, Christoph Reinhard, Juan A. Velasco, Philip W. Iversen, Alfonso De Dios, Sean Buchanan, Richard P. Beckmann, Dirk Schumacher, Christian RA Regenbrecht, Marie-Laure Yaspo, Hans Lehrach, María José Lallena. Preclinical analysis and characterization of abemaciclib using three-dimensional patient-derived colorectal cancer organoid cultures. [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 2829.
Abstract 2833: Genetic and pharmacologic inhibition of mTOR delays mortality due to thymc lymphoma formation in mice and is associated with decreases in cell cycle proteins
Authors: Zhang Shuling , Gary Joy M. , Simmons John K. , Xu Jinfei , Gamache Benjamin J. , Zhang Ke , Watson Nicholas , Kovalchuk Alexander L. , Michalowski Aleksandra M. , Chen Jin-Qiu , Herrmann Michelle A. , Thaiwong Tuddow , Kiupel Matti , Dubois Wendy , Testa Joseph R. , Mock Beverly A. 
Published: July 2016

Abstract
The AKT/mTOR pathway is frequently hyperactivated in T-cell acute lymphoblastic leukemia (T-ALL). To model inhibition of this pathway in lymphoma, mice with T-lymphocyte-specific, constitutively active AKT (Lck-MyrAkt2) were crossed to mice with genetically reduced mTOR expression (knock-down, KD). Mice with genetic reduction of mTOR had increased survival by 10 weeks relative to wild type mTOR mice, though both developed thymic pre-T-cell lymphoblastic leukemia/lymphoma (pre-T LBL). Similarly, when mTOR wild type Lck-MyrAkt2 mice were treated for 8 weeks with the rapamycin analog, everolimus, an inhibitor of the mTOR TORC1 complex, survival was also increased. Gene expression profiling of thymic lymphomas from the mice revealed that mTOR KD was associated with decreased expression of Cdk6, a critical proliferative control node in T-cell development and oncogenic transformation. Pharmacologic inhibition of mTOR in tumor cells also decreased CDK6. The combination of a mTOR inhibitor (rapamycin) and a CDK4/6 inhibitor (PD-0332991, Palbociclib) synergistically decreased the overall viability and signaling downstream of drug targets in mouse lymphoma cells and in human T-ALL/LBL cell lines. This combination was also evaluated in mice using a disseminated leukemia model. In vivo treatment with this combination not only reduced tumor size by inhibiting tumor cell proliferation and arresting tumor cell cycle, but also increased overall survival. We are currently validating upstream regulators of Cdk6 as well as downstream targets in the pre-T LBL tumors from the mTOR deficient mice.
Citation Format: Shuling Zhang, Joy M. Gary, John K. Simmons, Jinfei Xu, Benjamin J. Gamache, Ke Zhang, Nicholas Watson, Alexander L. Kovalchuk, Aleksandra M. Michalowski, Jin-Qiu Chen, Michelle A. Herrmann, Tuddow Thaiwong, Matti Kiupel, Wendy Dubois, Joseph R. Testa, Beverly A. Mock. Genetic and pharmacologic inhibition of mTOR delays mortality due to thymc lymphoma formation in mice and is associated with decreases in cell cycle proteins. [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 2833.