bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2502: Bioengineered-induced cancer-like stem cells: characterization and applications
Authors: Cho Sungpil , Park Hongsuk , Jarboe Elke A. , Peterson C Matthew , Bae You Han , Janat-Amsbury Margit Matthew 
Published: July 2016

Abstract
Cancer stem cells (CSCs) are a small subset of tumor cells capable of self-renewal, tumor initiation, and growth. Isolation, expansion, and differentiation of CSCs in the proper stem niches remain a topic of great debate. To address some of the challenges, we developed bioengineered-induced cancer like stem cells (iCLSCs) through in vitro oncogenic reprograming of C57BL/6 mouse embryonic stem cells (mESCs). We constructed retroviral plasmids through integration of well-defined oncogenic elements such as SV40LTg and HrasV12 into a mouse stem virus long terminal repeat (MSCV-LTR) plasmid fused with either a GFP or RFP gene. We successfully acquired these bioengineered-iCLSCs through retroviral introduction alongside with FACS sorting of positively infected mESCs. We then cultured the bioengineered-iCLSCs on mouse embryonic fibroblast (mEF) feeder cells. Bioengineered-iCLSCs expressed the introduced oncogenic genes and showed enhanced proliferation similar to cancer cells. In addition, we ascertained the unhampered stem properties of the bioengineered-iCLSCs by examining the maintenance of alkaline phosphatase activity as well as the expression of mouse stem cell marker SSEA-1. Furthermore, the orthotopic inoculation of these bioengineered-iCLSCs into either the mammalian fat pad or the ovarian bursa of female C57BL/6 mice lead to the formation of teratomas in supportive niches. Interestingly, the teratomas formed in the ovarian bursa exhibited malignant and immature features, whereas the iCLSCs introduced to the mammary fat pad were not able to generate teratomas with similar features. These observations call for additional research to identify the dependency on a supportive niche and their role in metastasis based on a tumor-favorable microenvironment. Our study helped to establish the use of in vitro oncogenic reprograming to generate bioengineered-iCLSCs and suggests the potential application for the initiation of organ-specific, malignant tumor formation in an orthotopic small animal cancer model.
Citation Format: Sungpil Cho, Hongsuk Park, Elke A. Jarboe, C Matthew Peterson, You Han Bae, Margit Matthew Janat-Amsbury. Bioengineered-induced cancer-like stem cells: characterization and applications. [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 2502.
Abstract 2503: NQO1's role in maintaining the cancer stem cell phenotype in NSCLC
Authors: Madajewski Brian , Bey Erik A. 
Published: July 2016

Abstract
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a phase II detoxifying enzyme responsible for quinone reduction, where it scavenges quinone induced reactive oxygen species. In recent studies, NQO1 has been investigated as a possible drug target due to its overexpression in a number of solid tumors. To this end, treatment with the quinone-analog drug, β-lapachone (ARQ-761), has progressed to Phase II clinical trials. In an effort to better understand the necessity of NQO1 in the overall lifecycle of cancer, our earlier work demonstrated that NQO1 played a vital role in a number of tumorigenic processes including anoikis resistance, and most interestingly alteration of aldehyde dehydrogenase (ALDH) activity. Given that ALDH is a widely reported cancer stem cell marker, and loss of NQO1 leads to a decrease in ALDH activity, we have begun to investigate the effect of NQO1 expression on the non-small cell lung cancer (NSCLC) stem cell population. Here, we present data that demonstrates NQO1 is vital to tumorsphere formation as demonstrated by decreased spheroid formation following NQO1 knocked down with shRNA. We also show that NQO1 appears to be necessary for cancer stem cell renewal as illustrated by decreased serial tumorsphere formation. In addition to these aforementioned data, in extreme limited dilution assays we demonstrate a reduced cancer stem cell frequency in NQO1 knockdown cells as compared to controls. Interestingly, in NQO1 knockdown populations, those cells that do form spheres show a remarkable re-expression of NQO1 as well as a rescue of ALDH activity, further supporting NQO1's role in tumorsphere formation and stem cell maintenance. Future work on this project will involve use of the CRISPR-Cas9 system to generate NQO1 knockout cell lines, drug resistance studies, cancer stem cell marker validation, and in vivo limited dilution assays to definitively demonstrate NQO1's necessity in maintaining the NSCLC stem cell population.
Citation Format: Brian Madajewski, Erik A. Bey. NQO1's role in maintaining the cancer stem cell phenotype in NSCLC. [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 2503.
Abstract 2511: Association of ALDH1A1 with cisplatin resistance via modulation of NEK-2 in ovarian cancer stem-like cells
Authors: Uddin Md. Hafiz , Song Yong Sang 
Published: July 2016

Abstract
Cisplatin (CDDP) resistance is the foremost obstacle in the treatment of ovarian cancer patients. According to the cancer stem cell hypothesis, the recurrence and chemoresistance are presumed to be linked to cancer stem/progenitor cells. Here, we investigated the cancer stem cell like phenotypes and mechanism of chemoresistance in CDDP resistant ovarian cancer cells.
A well-established CDDP sensitive ovarian cancer cell line A2780 and its resistant clone A2780 Cp were used and we also developed a supra resistant clone (SKOV3 Cp) from a naturally CDDP resistant cell line SKOV3 by six shocks treatment. Sensitiveness to CDDP was evaluated by MTT assay and self renewal efficiency by sphere formation, noble agar and clonogenic assays. A few cancer hallmarks and stem-cell markers were characterized using flow cytometry. Molecular analysis was performed using quantitative PCR and western blotting. For the silencing of selected genes small interfering RNA (siRNA) based approaches was utilized.
Both CDDP resistant A2780 Cp and supra resistant SKOV3 Cp cell lines showed significantly (P &lt; 0.05) higher self-renewal ability in sphere formation, noble agar and clonogenic assays than their parental counterparts. They also showed significant resistance to apoptosis and sub-G1 arrest upon CDDP treatment. Stem cell marker ALDH1 positivity rates were higher both in A2780 Cp and SKOV3 Cp cell lines, quantified by ALDEFLUORTM assay kit using flow cytometry. Hoechst 33342 dye effluxing side populations were increased about five folds in A2780 Cp cells and two folds in SKOV3 Cp cells compared to A2780 and SKOV3 cells respectively. Among major stemness related genes (OCT4, SOX2, NANOG, NESTIN, BMI1, KLF4 and ALDH1A1) quantitative PCR analysis showed significantly higher expression of ALDH1A1 and KLF4 genes in both resistant and supra resistant cells than their parental clones. Of two genes, silencing ALDH1A1 in A2780 and A2780 Cp cells using siRNA greatly reduced the stem cell population as detected by ALDEFLUORTM assay and sensitized cells to CDDP. Moreover, silencing of ALDH1A1 reduce the level of its downstream target NEK-2. We also observed the downregulation of ABC transporters (ABCB1, ABCG2 and ABCC1) by silencing either ALDH1A1 or NEK-2 gene.
Taken together, present study showed for the first time that stemness gene ALDH1A1 can be involved in CDDP resistance via the upregulation of NEK-2 in ovarian or solid cancer.
Citation Format: Md. Hafiz Uddin, Yong Sang Song. Association of ALDH1A1 with cisplatin resistance via modulation of NEK-2 in ovarian cancer stem-like 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 2511.
Abstract 2515: Pharmacological WNT-inhibition acts synergistically with chemo- and radiotherapy by overcoming treatment-resistance in glioma stem cells
Authors: Suwala Abigail K. , Kahlert Ulf D. , Maciaczyk Jaroslaw 
Published: July 2016

Abstract
Objective: Glioma Stem Cells (GSCs) are considered to be responsible for Glioblastoma's (GBM’s) dismal prognosis. WNT signaling is one of the major players in GSCs that promotes their radio- and chemoresistance. In this study we tested whether LGK974, an inhibitor of both canonical and non-canonical WNT signaling, might sensitize GBM cells to chemotherapeutics and irradiation and determined possible mechanisms causing treatment-resistance in GBM.
Methods: At first we analyzed MGMT promoter methylation status of several GBM cell lines in order to define cells resistant to the standard chemotherapeutic drug Temozolomide (TMZ). For further investigations we chose two cell lines resistant or sensitive to TMZ, respectively. IC50 concentrations of TMZ and LGK974 as well as IC50 dose of γ-irradiation were tested via Titer Blue cell viability assay. Effectiveness of different concentration of each single therapy and its combination with LGK974 was determined to create a drug-response-curve due to the computerized simulation of synergism and antagonism in drug combination studies (Chou, 2006). A reporter assay for canonical WNT/β-catenin signaling was used to quantify the effect of TMZ and irradiation alone and in combination with LGK974 on the canonical and non-canonical WNT pathway. Western Blot and qPCR were applied to analyze the effects of combinatory therapy on protein and gene expression concerning WNT pathway activation.
Results: We observed a significant synergy of combined irradiation/TMZ with LGK974 in all cell lines. There was no difference in effectiveness between cell lines resistant or sensitive to TMZ. Interestingly, following TMZ treatment or irradiation cells showed slightly decreased canonical WNT pathway activity. Furthermore, non-canonical target genes and receptors were upregulated under chemo- and radiotherapy, suggesting a reciprocal activation of the non-canonical branch of WNT signaling pathway. This phenomenon might possibly be responsible for the development of resistance against standard chemo- and radiotherapy.
Conclusions: We propose that GSCs undergo a shift from canonical to non-canonical WNT signaling to become treatment-resistant under standard chemo- and radiotherapy. Treatment with LGK974 results in therapeutic synergy at least in part via suppressing the therapy-induced activation of non-canonical WNT signaling. Our results confirm the potential benefit of combining TMZ or irradiation with the WNT inhibitor LGK974 to overcome therapy-resistance in GBM.
Citation Format: Abigail K. Suwala, Ulf D. Kahlert, Jaroslaw Maciaczyk. Pharmacological WNT-inhibition acts synergistically with chemo- and radiotherapy by overcoming treatment-resistance in glioma stem 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 2515.
Abstract 2517: Ewing sarcoma associated long non-coding RNA determines neural cell fate of the tumors
Authors: Mitra Sheetal A. , Mitra Anirban P. , Buckley Jonathan D. , Triche Timothy J. 
Published: July 2016

Abstract
BACKGROUND: Ewing sarcoma is a highly invasive pediatric bone and soft tissue malignancy with a 20% 5-year survival rate for patients with metastatic disease. 85% of Ewing sarcomas express a chimeric oncogene, mainly EWS-FLI1, which drives the gene expression signature in these tumors. The exact cell of origin for these primitive small round cell tumors is unknown. These undifferentiated tumors express some neuroectodermal, mesenchymal, and epithelial markers. Recently published work suggests that these tumors may have risen either from neural crest or mesenchymal stem cells. These genomic and phenotypic features may be responsible for the aggressive nature of this disease and understanding the tumor biology may help better treatment options for this metastatic cancer.
RESULTS: Our study on expression analysis of primary Ewing tumors using Affymetrix's Human Exon arrays identified a highly expressed novel long intergenic non-coding RNA (lincRNA), FEZF1-AS1 in these tumors. Its DNA sequence has no homology in most vertebrates. RNA-mediated knockdown of the lincRNA in Ewing cell lines decreased expression of some of the neural lineage genes as well as genes associated with cell adhesion and migration. In vitro matrigel assays detected a decrease in cell invasion capability of the lincRNA-knockdown cells. In the in vivo studies, the lincRNA-overexpressed cells had better engraftment and tumor growth in the liver than the normal controls. On attempt to differentiate the lincRNA-knockdown Ewing cell lines, we noted that a decrease in the lincRNA expression led to a decrease in the expression of neuroectodermal markers after a week of differentiation when compared to the control cells. We further detected temporal expression of this lincRNA during neuronal differentiation from embryonic stem cells.
CONCLUSIONS: Our study identified a unique lincRNA in Ewing sarcoma that may be partly responsible for inducing expression of the neural lineage genes in these tumors as its reduced expression impaired differentiation in the Ewing cell lines. Its prometastatic behavior helps the aggressive nature of these tumors. Its expression during neural differentiation along with its involvement in cell migration suggests that FEZF1-AS1 may be responsible for imparting neural stem cell like-characteristics to Ewing sarcoma.
Citation Format: Sheetal A. Mitra, Anirban P. Mitra, Jonathan D. Buckley, Timothy J. Triche. Ewing sarcoma associated long non-coding RNA determines neural cell fate of the tumors. [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 2517.
Abstract 2518: Crosstalk between stem and non-stem cells in glioblastoma promotes radioresistance in a CD109-dependent manner
Authors: Minata Mutsuko , Nakano Ichiro , Kim Sunghak , PavliuKov Marat , Wang Jia , Komarova Svetlana , Wang Jun 
Published: July 2016

Abstract
Glioblastoma (GBM) is a lethal brain tumor that contains cancer stem cells that are bestowed with tumor initiating and treatment resistant properties. Patient-derived glioma stem-like cells (GSCs) that resemble the clinically relevant MES subtype harbor more aggressive and therapy resistant properties. Here we report that exposure of GSCs to ionizing radiation (IR) provokes inter-cellular signals from therapy-induced senescent non-stem cancer cells to stimulate compensatory growth in cancer stem cells resulting in persistent transcriptomic and phenotypic shift toward a more MES subtype. This IR-induced gain of MES features in GSCs is accompanied by conversion of CD133+ stem cell populations to CD133- /CD109+ cells. In both de novo and IR-induced MES GSCs, CD109+, but not CD109- populations are highly tumorigenic and multipotent in vivo. Inhibition of CD109 attenuates clonogenicity and radioresistance in MES GSCs GBM. Clinically, CD109 expression is significantly associated with the MES GBMs and poorer prognosis of GBM patients. Taken together, our data imply that radiation of GSCs induces direct transformation of cancer stem cells to the MES subtype accompanied by a loss of the widely adopted stem cell marker CD133 and a gain of a novel, tumor propagating, and clinically relevant MES stem cell marker, CD109.
Citation Format: Mutsuko Minata, Ichiro Nakano, Sunghak Kim, Marat PavliuKov, Jia Wang, Svetlana Komarova, Jun Wang. Crosstalk between stem and non-stem cells in glioblastoma promotes radioresistance in a CD109-dependent manner. [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 2518.
Abstract 2523: Transcriptional profiling of glioblastoma stem-like cells reveals enrichment of ion channels with functional implications for malignancy
Authors: Pollak Julia , Rai Karan G. , Paddison Patrick J. , Rostomily Robert C. , Ramirez Jan-Marino 
Published: July 2016

Abstract
Glioblastoma Multiforme (GBM) is the most prevalent and aggressive form of cancer in the adult central nervous system. Ion channels are increasingly being linked to cancer progression through the regulation of cell proliferation and migration. However, the role of ion channels in GBM tumor formation and progression is not well understood. Glioblastoma stem-like cells (GSCs) are a source of tumor formation and recurrence, suggesting that ion channel expression may be perturbed in this population. Here, we used RNA-sequencing to assess the expression patterns of ion channels and transporters and identify uniquely enriched ion channels in GSCs. Twenty-two patient-derived GSC samples were expression profiled along with human neural stem cell (NSC) and astrocyte control cell populations. Differential expression analysis revealed a set of ion channels highly enriched in GSCs compared with controls. Real-time PCR analysis confirmed the increased expression of ion channels of interest across selected GSC lines compared to NSCs. The expression pattern of ion channel candidates was also more likely to be associated with distinct GBM molecular subtypes. Next, an integrative approach was taken to further identify ion channels unique to GSCs; the abovementioned findings were compared to results from transcriptome analyses of GBM bulk tumor cells (The Cancer Genome Atlas) and region-specific GBM cells (Ivy Glioblastoma Atlas Project). Ion channels that were identified in these analyses were associated with altered clinical outcomes. The functional implications of these expression changes were further assessed with targeted drug screening of GSCs and NSCs. Pharmacological antagonists of GSC-enriched ion channels suppressed stem cell viability. These antagonists similarly hindered BrdU incorporation of dividing GSCs, suggesting that these channels play a role in stem cell proliferative capacity. Finally, calcium imaging was used to test the real-time functional responses of GSCs to channel blockers, and these outcomes will be discussed. Collectively, these findings suggest the presence of ion channels that uniquely identify GSCs from other neural cell types and influence GSC proliferation, a hallmark of GBM tumor recurrence.
Citation Format: Julia Pollak, Karan G. Rai, Patrick J. Paddison, Robert C. Rostomily, Jan-Marino Ramirez. Transcriptional profiling of glioblastoma stem-like cells reveals enrichment of ion channels with functional implications for malignancy. [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 2523.
Abstract 2525: Sema3C promotes glioma stem cell survival and radioresistance
Authors: Man Jianghong , Shoemake Jocelyn , Wu Qiulian , Yu Jennifer 
Published: July 2016

Abstract
Introduction: Different cancer cell compartments often communicate through soluble factors to facilitate tumor growth. Glioma stem cells (GSCs) are a subset of tumor cells that resist standard therapy to contribute to disease progression. How GSCs employ a distinct secretory program to communicate with and nurture each other over the non-stem tumor cell (NSTC) population is not well defined.
Methods/Materials: GSCs were enriched from patient specimens and functionally validated. We used a candidate approach to screen for secreted factors that were preferentially used by GSCs but not NSTCs. Expression was assessed by Western blot, and confirmed by immunohistochemistry and immunofluorescence in vitro and in human and mouse GBM tissues. Ligand-receptor interactions were confirmed by co-immunoprecipitation. Rac activity was assessed by Rac-GTP pulldown. Co-culture epistasis experiments were performed using knockdown and recombinant protein approaches. Glioma stem cell marker analysis (CD133, Sox2, Olig2), cell viability (ATP-dependent assays), apoptosis (TUNEL, PI/AnnexinV, cleaved caspase 3/7), self-renewal (tumorsphere formation and limiting dilution assay) and invasion (transwell migration assay) were performed. GSCs were separated in PlexinD1 hi and lo populations by FACS. Radiation (3 Gy) was delivered by Cs-137 irradiator. GSCs were used to establish orthotopic xenograft models of glioblastoma and tumor growth and animal survival were assessed.
Results: We have found that GSCs preferentially secrete Sema3C and coordinately express PlexinA2/D1 receptors to activate Rac1/NF-κB signaling in an autocrine and paracrine loop to promote their own survival. Importantly, Sema3C is not expressed in neural progenitor cells (NPCs) or NSTCs. Disruption of Sema3C induced apoptosis of GSCs, but not NPCs or NSTCs, and suppressed tumor growth in orthotopic models of glioblastoma. Introduction of activated Rac1 rescued the Sema3C knockdown phenotype in vivo. Furthermore, GSCs that expressed high levels of Plexin receptors were more resistant to radiation, and Sema3C and Plexin receptors were upregulated after irradiation. Together, these data support that Sema3C signaling contributes to radiation resistance.
Conclusions: Our study supports targeting Sema3C to break this GSC-specific autocrine/paracrine loop to improve glioblastoma treatment, potentially with a high therapeutic index.
Citation Format: Jianghong Man, Jocelyn Shoemake, Qiulian Wu, Jennifer Yu. Sema3C promotes glioma stem cell survival and radioresistance. [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 2525.