bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3116: Dysregulated cholesterol synthesis is a therapeutic vulnerability in glioblastoma
Authors: Kambach Diane M. , Halim Alan S. , Cauer A. Gesine , Sun Qian , Tristan Carlos A. , Celiku Orieta , Kesarwala Aparna H. , Shankavaram Uma , Batchelor Eric , Stommel Jayne M. 
Published: July 2017

Abstract
A hallmark of cellular transformation is the evasion of contact-dependent inhibition of growth. To find new therapeutic targets for glioblastoma, we looked for pathways that are inhibited by high cell density in normal astrocytes but have lost this regulation in glioma cells. Here we report that at high cell density, normal astrocytes turn off cholesterol synthesis but glioma cells keep this pathway on. Correspondingly, cholesterol pathway upregulation is associated with poor prognosis in glioblastoma patients. Densely-plated glioma cells increase oxygen consumption to synthesize cholesterol, resulting in a decrease in reactive oxygen species, TCA cycle intermediates, and ATP, but without a compensating increase in aerobic glycolysis. This constitutive cholesterol synthesis is controlled by the cell cycle, as it can be turned off by cyclin dependent kinase inhibitors and it correlates with disabled cell cycle control though loss of p53 and RB. Finally, glioma cells, but not astrocytes, are sensitive to cholesterol synthesis inhibition downstream of the mevalonate pathway, suggesting that specifically targeting cholesterol synthesis might be an effective treatment for glioblastoma.
Citation Format: Diane M. Kambach, Alan S. Halim, A. Gesine Cauer, Qian Sun, Carlos A. Tristan, Orieta Celiku, Aparna H. Kesarwala, Uma Shankavaram, Eric Batchelor, Jayne M. Stommel. Dysregulated cholesterol synthesis is a therapeutic vulnerability in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3116. doi:10.1158/1538-7445.AM2017-3116
Abstract 3124: Expression and therapeutic implications of cyclin dependent kinase 4 (CDK4) in osteosarcoma
Authors: Zhou Yubing , Hornicke Francis , Duan Zhenfeng 
Published: July 2017

Abstract
Overexpression and/or hyperactivation of cyclin-dependent kinase 4 (CDK4) has been found in many types of human cancers, and a CDK4 specific inhibitor, palbociclib, has been recently approved by the FDA for the treatment of breast cancer. However, the expression and the therapeutic potential of CDK4 in osteosarcoma remain unclear. In the present study, CDK4 was found to be highly expressed in human osteosarcoma tissues and cell lines as compared with normal human osteoblasts. Elevated CDK4 expression correlated with metastasis potential and poor prognosis in osteosarcoma patients as determined by immunohistochemical analysis in a human osteosarcoma tissue microarray (TMA). CDK4 inhibition by either palbociclib or specific small interference RNA (siRNA) exhibited dose-dependent inhibition of osteosarcoma cell proliferation and growth, accompanied by suppression of the CDK4/6-cyclinD-Rb signaling pathway. Flow cytometry analysis showed that CDK4 knockdown arrested osteosarcoma cells in the G1 phase of the cell cycle and induced cell apoptosis. Furthermore, inhibition of CDK4 significantly decreased osteosarcoma cell migration in vitro determined by the wound healing assay. These data highlight that CDK4 may be a potential promising therapeutic target in the treatment of human osteosarcoma.
Citation Format: Yubing Zhou, Francis Hornicke, Zhenfeng Duan. Expression and therapeutic implications of cyclin dependent kinase 4 (CDK4) in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3124. doi:10.1158/1538-7445.AM2017-3124
Abstract 3133: NF-κB-dependent inflammatory responses offset sorafenib cytotoxicity in hepatocellular carcinoma via TIFA
Authors: Wei Tong-You Wade , Wu Pei-Yu , Wu Ting-Jung , Tsai Ming-Daw 
Published: July 2017

Abstract
Sorafenib is the promising first-line drug to treat advanced hepatocellular carcinoma (HCC), with the acquired resistance within 6 months in most treated patients. The epithelial-mesenchymal transition (EMT)-driven cancer metastasis contributes to sorafenib resistance via multiple signaling pathways, but the underlying molecular mechanism remains elusive. Recent studies showed that inflammatory cytokines TNF-α functionally initiates EMT through NF-κB mediated Snail activation in HCC, and that TRAF-interacting protein TIFA sustains the positive feedback loop between TNF-α and NF-κB that enhances chemoresistance in AML. Here we investigated the functional link between TIFA-regulated NF-κB inflammatory signaling and sorafenib resistance as a potential therapeutic target in the treatment of HCC. We showed that severe hepatitis induced in HCC mice promoted intrahepatic metastasis concurrently with NF-κB-driven EMT via Snail, and that HCC patients with hepatitis displayed poorer responses to sorafenib and unfavorable clinical outcome. In support, inflammatory TNF-α stimulation promoted levels of TIFA, NF-κB signaling factors, and EMT axis independent of sorafenib treatment, while silencing of TIFA or RelA perturbed sorafenib-dependent cytokine secretion in HCC cells. In addition, silencing of TIFA or RelA suppressed pro-survival factors Bcl-2 and Bcl-XL, and promoted pro-apoptotic factor BAX in response to sorafenib treatment in vitro. Consequently, HCC cells regained sorafenib chemosensitivity upon silencing of TIFA or RelA through promoted apoptosis. To further explore the therapeutic relevance, shRNAs were delivered using the liver-tropic adeno-associated virus serotype 8 in mice with orthotopic HCC xenografts, and results showed that targeting TIFA or RelA specifically enhanced sorafenib chemotoxicity resulting in more prominent tumor regression. Our results collectively showed that TIFA and NF-κB support inflammatory responses to offset sorafenib cytotoxicity, and that their targeting are therapeutically effective concomitant with sorafenib treatment in HCC.
Citation Format: Tong-You Wade Wei, Pei-Yu Wu, Ting-Jung Wu, Ming-Daw Tsai. NF-κB-dependent inflammatory responses offset sorafenib cytotoxicity in hepatocellular carcinoma via TIFA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3133. doi:10.1158/1538-7445.AM2017-3133
Abstract 3157: Osimertinib (AZD9291) is effective against NSCLC cells harboring EGFR exon 20 insertion mutations
Authors: Lee Yusoo , Kim Tae Min , Kim Dong-Wan , Ahn Yong-Oon , Kim Soyeon , Keam Bhumsuk , Kim Miso , Heo Dae Seog 
Published: July 2017

Abstract
Background: Although EGFR exon 20 insertion mutation is the third most common among EGFR-mutant NSCLC, this mutant clones are resistant to the first-generation EGFR TKIs. In addition, the efficacy of the second or third-generation EGFR TKIs is unknown in NSCLC with EGFR exon 20 insertion mutation.
Methods: Various EGFR exon 20 insertion mutations were introduced into Ba/F3 cells as follows: A763_Y764insFQEA in C-helix; and V769_D770insASV, D770_N771insNPG, D770_N771insSVD, P772_H773insPR, H773_V774insNPH, H773_V774insH, and H773_V774insAH in loop following C-helix. The patient-derived SNU-3173 cell line was developed in a patient with EGFRH773_V774insAH mutation. Ba/F3 cells transfected with EGFR exon 20 insertion mutations and SNU-3173 were exposed to the EGFR TKIs (the 1st-generation gefitinib and erlotinib; the 2nd-generation dacomitinib and afatinib; and the 3rd-generation rociletinib, olmutinib, nazartinib, and osimertinib) and cell viability assays were performed. In addition, immunoblotting was performed to evaluate the downstream signals of EGFR pathway.
Results: Cell viability assay showed that EGFR exon 20 insertion mutants are resistant to the 1st-generation EGFR TKIs, except for EGFRA763_Y764insFQEA-mutant Ba/F3 cells. IC50 values of the 2nd-generation EGFR TKIs are five to hundred-folds lower than the 1st-generation EGFR TKIs. The 2nd-generation EGFR TKIs were effective against EGFR exon 20 inserted Ba/F3 cells and down-regulated EGFR downstream signals. The 3rd-generation EGFR mutation-selective inhibitors showed a moderate efficacy except osimertinib that was effective and down-regulated EGFR downstream signals. In addition, SNU-3173 cells were moderately toxic to afatinib (IC50 46.2±5.2nM) as well as osimertinib (IC50 403.2±3.0nM).
IC50 values of EGFR exon 20 insertion mutation Ba/F3 cellsIC50 (nM)FQEAASVSVDNPGPRHAHNPHGefitinib32.7525.7752.71597.01363.02581.02259.01701.0Erlotinib22.3486.9338.3765.7798.21523.01438.0562.1Dacomitinib0.00243.55.715.0205.0608.4556.312.3Afatinib0.0082.344.911.494.7297.7204.425.4Rociletinib219.7367.191.5131.21093.93710.05085.4498.7Olmutinib76.082.195.664.5332.6952.41406.6337.1Osimertinib3.68.18.9128.2247.2128.2880.338.2Nazartinib28.322.336.657.6747.8872.11606.8118.0
Conclusions: Overall, osimertinib showed effectiveness against NSCLC cells with EGFR exon 20 insertion mutations. Our results warrant a clinical trial of osimertinib in NSCLC patients with EGFR exon 20 insertion mutations.
Citation Format: Yusoo Lee, Tae Min Kim, Dong-Wan Kim, Yong-Oon Ahn, Soyeon Kim, Bhumsuk Keam, Miso Kim, Dae Seog Heo. Osimertinib (AZD9291) is effective against NSCLC cells harboring EGFR exon 20 insertion mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3157. doi:10.1158/1538-7445.AM2017-3157
Abstract 3162: HRAS G12V predicts for innate resistance to PI3Kα inhibition in head and neck squamous cell cancer
Authors: Ruicci Kara M. , Sun Ren , Black Morgan , Pinto Nicole , Yoo John , Fung Kevin , Macneil Danielle , Aillies Lauire , Mymryk Joseph S. , Boutros Paul C. , Barrett John W. , Nichols Anthony C. 
Published: July 2017

Abstract
Introduction: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with an incidence of ~600 000 new cases per year and a 50% mortality rate for advanced disease. The mutational landscape of HNSCC has been recently elucidated, introducing the possibility for targeted therapeutic approaches. PIK3CA—which encodes the α-catalytic subunit of PI3K (PI3Kα)—is the most frequently altered actionable target in HNSCC, however it is not presently clear which patients benefit most from PI3Kα-inhibition. BYL719 is a leading PI3Kα inhibitor in clinical development for HNSCC. We previously examined the responses of a large panel of genetically-characterized HNSCC cell lines to BYL719 and identified activating HRAS G12V mutations as strong predictors for BYL719 resistance. Here we examine if this mutation is able to individually modulate BYL719 response through overexpression and knockdown studies.
Methods: To determine if HRAS G12V was able to modulate BYL719 sensitivity, we knocked down HRAS in HRAS G12V and HRAS wild-type (WT) cell lines using RNA interference, and then treated cells over 10-point dose ranges with BYL719. Sensitivity was determined by calculating IC50 (half-maximal inhibitory concentration) values at 72 hours using PrestoBlue®. Constructs expressing wildtype (WT) HRAS or HRAS G12V were transfected into BYL719-sensitive cells for overexpression studies and cells were selected using G418 Sulfate for 1 month. Proliferation and BYL719 sensitivity (IC50 values) were measured as described. Immunoblotting was used to examine activity of the PI3K-AKT axis with and without BYL719 (1μM) for 24 hours.
Results & Conclusions: HRAS knockdown sensitized HRAS G12V lines to BYL719 (lower IC50), but did not affect the response of WT HRAS cells. WT HRAS and HRAS G12V overexpression significantly increased cellular proliferation and promoted BYL719 resistance. In HRAS G12V cell lines, we observed high levels of active phosphorylated AKT (S473/T308), even in the presence of BYL719. Collectively these findings highlight the predictive role of HRAS G12V for innate BYL719 resistance and contribute to our understanding of which patients may respond best on BYL719 therapy.
Citation Format: Kara M. Ruicci, Ren Sun, Morgan Black, Nicole Pinto, John Yoo, Kevin Fung, Danielle Macneil, Lauire Aillies, Joseph S. Mymryk, Paul C. Boutros, John W. Barrett, Anthony C. Nichols. HRAS G12V predicts for innate resistance to PI3Kα inhibition in head and neck squamous cell cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3162. doi:10.1158/1538-7445.AM2017-3162
Abstract 3167: MIF-induced stat3 activation promotes resistance to MEK blockade in KRAS mutant colorectal cancer cells
Authors: Cheon Seul-Ki , Kim Hwang-Phill , Park Ye-Lim , Lee Si Hyun , Kang Jun-Kyu , Lim Yoojoo , Song Sang-Hyun , Han Sae-Won , Kim Tae-You 
Published: July 2017

Abstract
Although MEK blockade has been highlighted as a promising anti-tumor drug, it has poor clinical efficacy in KRAS mutant colorectal cancer. Several feedback systems have been described in which inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single-MEK targeted therapies. In this study, we describe a feedback mechanism in which MEK inhibition leads to activation of macrophage migration inhibitory factor (MIF)-induced stat3 signaling pathway in KRAS mutant colorectal cancer (CRC) cells. We found that KRAS mutant CRC cells with refametinib, MEK inhibitor, induced MIF secretion and resulted in activation of Stat3. MIF knockdown by siRNA partially restored sensitivity to refametinib in KRAS mutant cells. In addition, combination with refametinib and 4IPP, a MIF inhibitor, effectively reduced the activity of stat3 and MAPK, more than single agent treatment. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against refametinib-resistant cells by downregulating MIF expression. These results reveal that MIF-induced stat3 activation evoked an intrinsic resistance to refametinib. Our results provide the basis for a rational combination strategy against KRAS mutant colorectal cancers, predicated on the understanding of cross-talk between the MEK and MIF pathways.
Citation Format: Seul-Ki Cheon, Hwang-Phill Kim, Ye-Lim Park, Si Hyun Lee, Jun-Kyu Kang, Yoojoo Lim, Sang-Hyun Song, Sae-Won Han, Tae-You Kim. MIF-induced stat3 activation promotes resistance to MEK blockade in KRAS mutant colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3167. doi:10.1158/1538-7445.AM2017-3167
Abstract 3171: Analysis of "drug addiction" mechanisms in the drug-resistant ROS1-rearranged cancer cells
Authors: Ogura Hayato , Adachi Jun , Tomonaga Takeshi , Fujita Naoya , Katayama Ryohei 
Published: July 2017

Abstract
ROS1-rearranged non-small-cell lung cancer (NSCLC) is observed in approximately 1% of lung cancer patients. Crizotinib, ALK/ROS1/cMET tyrosine kinase inhibitor (TKI), showed high effect against ROS1-rearranged NSCLC in the clinical trials and is approved in US and EU. However, the cancers inevitably relapse due to the acquired resistance such as ROS1-G2032R mutation. We previously reported that cabozantinib could overcome those secondary mutations mediated crizotinib-resistance. Based on this finding, we tried to establish cabozantinib-resistant ROS1 mutant cells by ENU mutagenesis screening. Surprisingly, we found out a few CD74-ROS1 mutant clones that only grew in the presence of low-dose cabozantinib. Namely, these mutant clones were “addicted” to cabozantinib. When the fluorescent labeled cabozantinib addicted ROS1 mutant cells were co-cultured with non-addicted CD74-ROS1-WT-BaF3 cell in the presence or absence of low-dose cabozantinib, the drug-addicted cells became dominant in the low-dose cabozantinib, and CD74-ROS1-WT cells became dominant in the absence of it. To analyze the molecular mechanism of “drug-addiction” in the addicted CD74-ROS1 mutant cells, we performed comprehensive analysis such as inhibitor screening, cDNA microarray, and phosphoproteome analysis. As the result, we observed that the expression and phosphorylation of CD74-ROS1 in the addicted cells were excessively upregulated within 24 hours after removal of cabozantinib or other ROS1 inhibitors, such as crizotinib or lorlatinib. We also observed that the apoptosis was induced in these cells upon ROS1 inhibitor removal, whereas ROS1 mediated growth signaling were simultaneously activated. Consistent with this, cDNA microarray analysis revealed that the expression of both cell survival and cell death related genes were changed by ROS1 inhibitor removal. Furthermore, we identified that several proteins were highly phosphorylated by excessive ROS1 activation originated from ROS1 inhibitor removal. These observations suggest that these drug-addicted cells were died by excessive oncogenic signaling, and the appropriate oncogene signaling by low-dose TKI made them survive and grow without inducing apoptosis. Thus, the excessive oncogene signaling has “double-edged sword” characteristics for cancer cell viability and those characteristics could be a new therapeutic target.
Citation Format: Hayato Ogura, Jun Adachi, Takeshi Tomonaga, Naoya Fujita, Ryohei Katayama. Analysis of "drug addiction" mechanisms in the drug-resistant ROS1-rearranged cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3171. doi:10.1158/1538-7445.AM2017-3171
Abstract 3175: Context-dependent role of ARF for response to chemotherapy in muscle invasive bladder cancer
Authors: Rong Lijie , Owczarek Tomasz , Kobayashi Takashi , Abate-Shen Cory 
Published: July 2017

Abstract
Muscle invasive bladder cancer (MIBC) is a significant cause of cancer death, in part because there are relatively few treatments and these have limited efficacy. Our studies show that expression of 14ARF (aka ARF), one of the major transcripts encoded by the CDKN2A tumor suppressor locus, is frequently up-regulated in MIBC, particularly in more aggressive disease subtypes. Our results further show that accumulation of ARF protein in the nucleolus is associated with poor outcome and reduced response to chemotherapy. Using both genetically-engineered mouse (GEM) models and human xenograft models of MIBC, we demonstrate that tumors expressing ARF display poor response to treatment with the platinum-based chemotherapy agent cisplatin. This is mediated in part by expression of the integrin-binding protein ITGB3BP (CENPR) and reflects ARF-dependent inhibition of protein translation, which is attenuated by drug treatment. Our findings reveal an unexpected context-dependent role for ARF in modulating drug response in bladder cancer through its ability to regulate protein translation.
Citation Format: Lijie Rong, Tomasz Owczarek, Takashi Kobayashi, Cory Abate-Shen. Context-dependent role of ARF for response to chemotherapy in muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3175. doi:10.1158/1538-7445.AM2017-3175
Abstract 3190: Using a genome-wide shRNA screen to investigate the mechanism of stroma-conferred gemcitabine resistance in pancreatic ductal adenocarcinoma
Authors: Mills Graham D. , Erard Nicolas , Richards Frances M. , Hannon Gregory J. , Jodrell Duncan I. 
Published: July 2017

Abstract
The purpose of this study is to identify mechanisms of resistance to gemcitabine in pancreatic ductal adenocarcinoma (PDAC) using an in vitro coculture system. The inherent resistance of PDAC to first line treatments such as gemcitabine has been attributed to the dense fibrotic stroma. Targeting stromal components, in particular cancer-associated fibroblasts (CAFs), the activated form of pancreatic stellate cells (PSCs), is a promising avenue for therapeutic intervention. We have demonstrated previously the induction of gemcitabine resistance when co-culturing KRAS G12D; p53 R172H; Pdx-cre (KPC) mouse PDAC-derived tumour cells with αSMA+ fibroblast-like cells from PDAC tumour (FLCs), in comparison to PDAC cells co-cultured with PSCs or in monoculture. This resistance-inducing effect is specific to cells of mesenchymal phenotype, is transient in nature and a product of cell-cell contact. To investigate the exact mechanism by which PDAC cells become resistant to gemcitabine in coculture, we undertook a genome-wide shRNA depletion viability screen, infecting KPC mouse PDAC cells with a pooled shERWOOD UltramiR shRNA library both in mono- and co-culture with FLCs, in the presence and absence of gemcitabine. Next-generation sequencing and differential expression analysis, using DESeq2, identified shRNAs depleted through 6 cycles of gemcitabine treatment in coculture, indicating they target genes driving the resistance effect. Pathway analysis of differential expression using MetaCore implicated DNA damage repair and protein modification pathways in the gemcitabine resistance effect. Depletion of p97, ATR, or Chk1 all sensitised PDAC cells to gemcitabine in coculture, corroborating findings with translational value in previous studies. Further evaluation is ongoing using validation shRNA dropout assays in combination with targeted literature reviews to collate a candidate list of targetable genes with translational value in preventing and combating chemotherapy resistance in patients with PDAC.
Citation Format: Graham D. Mills, Nicolas Erard, Frances M. Richards, Gregory J. Hannon, Duncan I. Jodrell. Using a genome-wide shRNA screen to investigate the mechanism of stroma-conferred gemcitabine resistance in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3190. doi:10.1158/1538-7445.AM2017-3190