bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4877: Discovery of paralog-specific SUMO1 and SUMO2 functions using human cancer knockout cells
Authors: Bouchard Danielle , Yang Wei-Chih , Matunis Michael J. 
Published: September 2020

Abstract
Small ubiquitin-related modifiers (SUMOs) are ∼100-amino acid polypeptides that function as posttranslational protein modifications and thereby regulate many essential cellular processes, many of which are relevant to cancer. Vertebrates express five SUMO paralogs (SUMO1-5), of which, SUMO1 and SUMO2 are the most widely studied. Biochemical and in vivo studies suggest that SUMO1 and SUMO2 have non-redundant functions, however, the full range of their distinct activities are not fully understood. Understanding these unqiue functions and their molecular bases could lead to more precise therapeutic interventions that target the SUMO pathway. To help define SUMO paralog-specific functions, we used CRISPR-Cas9 to knockout (KO) individual SUMO genes in osteosarcoma U2OS cells. We observed that SUMO2 KO cells were unique in exhibiting a change in cell morphology, changing from epithelial-like to fibroblast-like, thus revealing a potential role for SUMO2 in affecting cell shape. To test the hypothesis that the observed change in morphology is driven in part by changes in gene expression, we sequenced the transcriptome of the parental and SUMO KO cell lines. In alignment with the observed change in SUMO2 KO cell shape, differentially expressed genes (DEGs) involved in the extracellular matrix, basement membrane and epithelial to mesenchymal transition were uniquely enriched in SUMO2 KO cells. Further consistent with SUMO1 and SUMO2 having unique effects on transcription, we found a significantly greater number of unique DEGs in SUMO2 KO cells as compared to SUMO1 KO cells. Furthermore, an overwhelming number of DEGs were down-regulated in the SUMO1 KO cells, suggesting a specific role for SUMO1 in activating, or maintaining, gene expression. In contrast, DEGs in SUMO2 KOs were equally up and down regulated. Collectively, our findings demonstrate that SUMO1 and SUMO2 have unique biological roles and we look forward to better characterizing these paralog-specific functions in future studies.
Citation Format: Danielle Bouchard, Wei-Chih Yang, Michael J. Matunis. Discovery of paralog-specific SUMO1 and SUMO2 functions using human cancer knockout cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4877.
Abstract 4884: To Investigate the mechanism and function of nucleobindin-2 in human hepatoma cells
Authors: Hung Jui-Hsiang , Tsao Hsiu-Ping , Li Ren-Hao , Li Chih-Han , Chang Hut-Min 
Published: September 2020

Abstract
Hepatocellular carcinoma is a common malignancy affecting approximately one million people worldwide annually. Recent studies have shown that appetite-associated nucleobindin-2 (NUCB-2) is over-expressed in clinical tumor samples such as gastric cancer, prostate cancer, renal cell carcinoma, endometrial carcinoma cells, colon cancer and breast cancer. The survival rate of high-level expression of NUCB-2 in cancer patients was lower than cancer patients with low-level expression of NUCB-2. In addition, overexpression of NUCB-2 was observed in liver cancer by using bioinformatics analysis. The liver cancer patients with NUCB-2 overexpression are associated with poor prognosis. However, the effect of NUCB-2 overexpression on tumor cells is still unclear. In this project, we evaluated the novel role and mechanisms of NUCB-2 overexpression in hepatoma cells. Our results indicated NUCB-2 mRNA expression level was induced by ER stress as determined with RT-PCR and real-time PCR, and induction of NUCB-2 protein level was significantly increased by ER stress. Increased ER stress by pre-S2Δ protein was significantly enhanced NUCB-2 expression. We also observed that the overexpression of NUCB-2 was corrected with ER stress in human hepatocellular carcinoma tumor samples. Consequently, this mechanistic research may provide a molecular basis to develop a biomarker and novel cancer chemotherapeutic agent for high level expression of NUCB-2 in cancer patients.
keywords:Endoplasmic reticulum stress, Nucleobindin-2, real-time PCR, RT-PCR, HBV large surface mutant protein pre-S2Δ, Hepatocellular carcinoma, Huh-7, HepG2, MCF-7, Tunicamycin, Brefeldin A.
Citation Format: Jui-Hsiang Hung, Hsiu-Ping Tsao, Ren-Hao Li, Chih-Han Li, Hut-Min Chang. To Investigate the mechanism and function of nucleobindin-2 in human hepatoma cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4884.
Abstract 4891: Hepatitis B virus remodels host protein interaction networks to generate distinct cellular dependencies
Authors: Gordan John D. , Pitea Adriana , Eckhardt Manon , Jang Gwendolyn , Turnham Rigney E. , Choi Alex L M. , Von Dollen John , Lim Huat C. , Thayer Elizabeth F. , Kelley R. Katie , Swaney Danielle L. , Zhang Wei , Theis Fabian J. , Ideker Trey , Krogan Nevan J. 
Published: September 2020

Abstract
Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Advanced HCC has proven particularly difficult to treat because of a scarcity of clear genetic drivers of cancer progression; thus, there are currently no predictive markers that guide HCC therapy. HCC arises in the context of co-morbid hepatitis due to hepatitis B virus (HBV), hepatitis C (HCV) or fatty liver disease. We hypothesize that protein-protein interactions (PPIs) between viral proteins and HCC genes may contribute to tumor initiation and maintenance. In order to characterize these PPIs, we performed affinity purification - mass spectrometry (APMS), defining 145 HBV/host PPIs including known and novel interacting partners. We next used a network propagation algorithm to identify host genes and protein complexes that were preferentially mutated in the absence of HBV infection. HBV is a small DNA virus, with 4 genes of which only one has enzymatic activity, raising a question as to how HBV interaction modifies host behavior. Using AP-MS of host proteins, we found that the HBV X protein (HBx) remodels multiple host protein complexes through direct interaction. These physical effects on complex components result in distinct biochemical behavior from the CRL4 E3 ubiquitin ligase complex as well as the phosphatase PP2A, as determined through global phosphoproteomics and ubiquitin analysis. We show that this remodeling driven by HBx substantially changes cellular protein turnover and downstream signaling dynamics. We followed this up with assessments of cellular viability and proliferation in response to pharmacological inhibition or CRISPRi-based knockdown of HBx effectors. Our data support a model where HBV proteins alter the components and behavior of key regulatory protein complexes in the cell, altering tumor behavior and raising the possibility of precision therapeutics for HCC.
Citation Format: John D. Gordan, Adriana Pitea, Manon Eckhardt, Gwendolyn Jang, Rigney E. Turnham, Alex L M. Choi, John Von Dollen, Huat C. Lim, Elizabeth F. Thayer, R. Katie Kelley, Danielle L. Swaney, Wei Zhang, Fabian J. Theis, Trey Ideker, Nevan J. Krogan. Hepatitis B virus remodels host protein interaction networks to generate distinct cellular dependencies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4891.
Abstract 4915: Nerve growth factor (NGF) facilitates LOX expression and promotes tumor metastasis by inhibiting miR-149-5p in human chondrosarcoma cells
Authors: Louis Anoop Thadevoos , Lin Chih-Yang , Tang Chih-Hsin 
Published: September 2020

Abstract
Chondrosarcomas are malignant bone tumors that commonly produce cartilaginous chondroid matrix and are associated with metastases in the lung, especially in patients with high-grade chondrosarcoma. Neurotrophins such as nerve growth factor (NGF) are recognized as being drivers of neurogenesis during development and regeneration, and their expression in human tumors can stimulate cancer cell growth. Importantly, the infiltration of nerves in the tumor microenvironment actively stimulates cancer cell mitogenesis, invasiveness and metastasis. Until now, it has been unclear as to the potential involvement of NGF in human chondrosarcoma metastasis. This study reports that NGF induces migration and invasion of chondrosarcoma cell lines JJ012 and SW1353 and significantly increasing LOX expression. Significant dose-dependent increases were observed in levels of LOX mRNA and protein expression in both cell lines. In immunohistochemistry analyses, levels of NGF and LOX expression in human chondrosarcoma cartilage correlated with tumor stage and were substantially higher than NGF and LOX expression in normal cartilage. NGF-induced stimulation of metastasis and increases in LOX expression were prevented by pretreatment of the cell lines with PI3K, Akt and mTOR inhibitors, or transfection with small interfering RNAs (siRNAs). Further analysis revealed that NGF induced PI3K/Akt/mTOR signaling and dose-dependently downregulated mature microRNA-149-5p (miR-149-5p), which targets the 3' untranslated region (3'-UTR) of LOX. Furthermore, JJ012 cells overexpressing NGF induced LOX expression and increased cell migration and invasion. In summary, NGF stimulates LOX expression and promotes chondrosarcoma cell migration and invasion by inhibiting miR-149-5p via the PI3K/Akt/mTOR signaling pathway.
Citation Format: Anoop Thadevoos Louis, Chih-Yang Lin, Chih-Hsin Tang. Nerve growth factor (NGF) facilitates LOX expression and promotes tumor metastasis by inhibiting miR-149-5p in human chondrosarcoma cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4915.
Abstract 4922: NEUROD1 is highly expressed in extensive small cell lung cancer by promoting migration
Authors: Ikematsu Yuki , Tanaka Kentaro , Ando Nobuhisa , Ijichi Kayo , Yoneshima Yasuto , Inoue Hiroyuki , Toyokawa Goji , Tagawa Tetsuzo , Nakanishi Yoichi , Okamoto Isamu 
Published: September 2020

Abstract
Introduction:Small cell lung cancer (SCLC) exhibits high-grade neuroendocrine features and recent genomic analyses revealed that aberrant expression of bacic helix loop helix transcription factors such as neurogenic differentiation 1 (NEUROD1) as well as achaete-scute homolog 1(ASCL1) have also been observed in SCLC. NEUROD1 plays important role for the development, maturation in several nerve system and formation of distal lung of neuroendocrine morphology. Previous report showed that mRNA expression as well as target genes of NEUROD1 are largely distinct from those of ASCL1 in human SCLC cell lines, however, protein level and expression patterns of these transcription factors in SCLC clinical tumor samples as well as its relation to clinicopathological characteristics have not been fully elucidated.
Method: We retrospectively analyzed specimens from 95 SCLC patients between June 1988 and December 2017, and immunohistochemical (IHC) staining of NEUROD1 as well as ASCL1 was performed. Furthermore, we examined the effect of gain or loss of NEUROD1 function on proliferation and migration by transfection in SCLC cell lines.
Result:Dual high staining score of ASCL1 and NEUROD1 was present in SCLC samples (32/95: 34%) and IHC score of NEUROD1 was higher in extensive disease (ED) samples than those in limited disease (LD) samples (median score 160 vs 80 ; P = 0.0389).Overall survival did not significantly differ between SCLC patients with high or low score of NEUROD1 or ASCL1. Next, our vitro data showed that upregulation of NEUROD1 in SCLC cell lines promoted transwell migration whereas downregulation of NEUROD1 reduced cell migration.
Conclusion: Our results from clinical and in vitro experimental data collectively indicate that NEUROD1 expression increases in extensive SCLC by promoting migration and metastasis of SCLC cells.
Citation Format: Yuki Ikematsu, Kentaro Tanaka, Nobuhisa Ando, Kayo Ijichi, Yasuto Yoneshima, Hiroyuki Inoue, Goji Toyokawa, Tetsuzo Tagawa, Yoichi Nakanishi, Isamu Okamoto. NEUROD1 is highly expressed in extensive small cell lung cancer by promoting migration [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4922.
Abstract 4932: mTORC1 regulates FAK phosphorylation
Authors: Li Lin , Luo Yan , Liu Lei , Huang Shile 
Published: September 2020

Abstract
The mammalian target of rapamycin (mTOR) functions as two complexes, mTORC1 and mTORC2, regulating cell growth, proliferation, survival, and motility. Previous studies have shown that mTORC2 controls cytoskeleton and cell motility. Recently, we have demonstrated that both mTORC1 and mTORC2 participate in the regulation of cell motility. Further studies have shown that rapamycin suppresses IGF-I induced cell motility by inhibiting S6K1-mediated phosphorylation of focal adhesion kinase (FAK), protein phosphatase 2A (PP2A)-mediated phosphorylation of Erk1/2, as well as expression and activities of the small GTPases (RhoA, Cdc42 and Rac1). As FAK plays a pivotal role in the regulation of cell motility, this study was set to determine how mTORC1 regulates the phosphorylation of FAK. By co-immunoprecipitation (co-IP) and immunoblotting (IB), we failed to detect a physical interaction between FAK and S6K1, suggesting that S6K1 may regulate the phosphorylation of FAK indirectly. Besides, knockdown of protein phosphatase 2A (PP2A) enhanced the phosphorylation of FAK and conferred resistance to rapamycin inhibition of IGF-I-stimulated phosphorylation of FAK. However, the co-IP/IB results revealed no direct interaction between FAK and PP2A either. Of interest, knockdown of protein phosphatase 5 (PP5) suppressed IGF-I stimulated cell motility, while knockdown of ATG13 increased IGF-I stimulated cell motility, suggesting that PP5 positively regulates cell motility, whereas ATG13 negatively regulates cell motility. It is well known that PP5 is an anti-apoptotic phosphatase, negatively regulating the ASK1-JNK cascade, and mTORC1 regulates autophagy through the ULK1/2-ATG13-FIP200 complex. Further research will determine how mTORC1 regulates cell motility in part by regulating the phosphorylation of FAK via S6K1, PP2A, PP5 and ATG13. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA.)
Citation Format: Lin Li, Yan Luo, Lei Liu, Shile Huang. mTORC1 regulates FAK phosphorylation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4932.
Abstract 4935: T-DM1-resistant cells gain high invasive activity via EGFR and integrin cooperated pathways
Authors: Endo Yukinori , Olson Zachary , Wu Wen Jin 
Published: September 2020

Abstract
Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate developed to treat trastuzumab-resistant cancer. Despite initial favorable outcomes, most patients eventually cease to respond by developing acquired resistance to T-DM1. Currently, there is no targeted therapy to treat T-DM1-resistant cancer. To explore novel therapeutic targets to overcome T-DM1 resistance, we generated T-DM1-resistant cells using trastuzumab-resistant JIMT1 cells. We found that the loss of human epidermal growth factor receptor 2 (HER2) confers T-DM1 resistance, which in turn activates a compensatory mechanism that increases epidermal growth factor receptor (EGFR) expression. Upregulation of EGFR increases the protein levels of α5β1 integrin, resulting in enhanced motility and invasion of T-DM1-resistant cells. However, silencing β1 integrin expression by siRNA or β1 integrin blockage induced by an inhibitory antibody, MAB 13, significantly increases invasion of T-DM1-resistant cells. The discovery of functional cooperation between EGFR and integrin in regulating cell growth and invasion provides an opportunity to develop novel therapeutic strategy by dual-targeting EGFR and specific integrin to overcome T-DM1 resistance. We now try to identify downstream molecules involved in the increased invasion using next generation sequencing (NGS) technology in β1 integrin-deficient T-DM1 resistant cells.
Citation Format: Yukinori Endo, Zachary Olson, Wen Jin Wu. T-DM1-resistant cells gain high invasive activity via EGFR and integrin cooperated pathways [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4935.
Abstract 4949: Essential role of arachidonic acid metabolism in prostate cancer stem cell survival
Authors: Monga Jitender , Carney Brendan , Patil Sejal , Ghosh Jagadananda 
Published: September 2020

Abstract
Background: Cancer stem cells (CSC) are rare group of neoplastic cells with features that include, self-renewal, pluripotency and tumorigenicity, and are thought to be responsible for tumor recurrence and metastasis. Thus, a lot of excitement surrounds the idea of going right to the root of the tumor and target the stem cells to eradicate cancer permanently. A hierarchically organized CSC model in prostate cancer is evident with CD44 (+), CD133 (+) subpopulations isolated from human prostate tumors. While most therapies are directed to the fast-growing tumor mass made of differentiated cells, they cannot target the relatively slow-dividing and resistant cancer stem cells, which may underlie as a mechanism of why the cancer is not permanently eradicated with standard chemotherapy. Thus, an important challenge is to find measures to eliminate the CSCs, which by definition, will stop tumor growth and prevent recurrence. However, knowledge about molecular features critical for prostate cancer stem cells (PCSC) is meager. Thus, we wanted to examine the role of arachidonate 5-lipoxygenase (ALOX5) which plays critical role in the survival of cancer (but not of normal) cells, in the biology of PCSC.
Methods: Using an established, clinically-relevant in vitro model of human PCSCs which express both pluripotency markers (Nanog, c-Myc, Sox2) and tumor-progenitor markers (CD44, CD133, ALDH1), we interrogated the role of a fatty acid metabolic pathway in stem cell vulnerability. Especially, our goal was to characterize the effects of targeting ALOX5 to see whether it could be a new target to eliminate PCSCs.
Results: Inhibition of ALOX5 by shRNA or MK591 dramatically decreased the protein levels of Nanog and c-Myc, suggesting a role for ALOX5 in prostate cancer stemness. Moreover, ALOX5 inhibition was found to selectively kill PCSCs (but not normal stem cells) by inducing apoptosis via inhibition of survivin, cyclin D1 and CDK4, and activation of c-Jun N-terminal Kinase and caspase 3, suggesting an essential role of ALOX5 in the survival of PCSC. Interestingly, non-cancer parenchyma body cells, including normal stem cells, do not express ALOX5 (presumably because of promoter hypermethylation) and are not affected by ALOX5 inhibitors.
Conclusion: Our findings indicate that ALOX5 plays a causal role in maintaining prostate cancer stemness by regulating Nanog and c-Myc oncogenes, and suggest that an effective, long-lasting therapy of prostate cancer may be possible by targeting ALOX5 to kill and eliminate PCSCs to block prostate tumor growth and prevent recurrence.
Citation Format: Jitender Monga, Brendan Carney, Sejal Patil, Jagadananda Ghosh. Essential role of arachidonic acid metabolism in prostate cancer stem cell survival [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4949.
Abstract 4956: PrPc depletion in glioblastoma patient derived xenograft cells by CRISPR/Cas9
Authors: Escobar Maria Isabel Melo , Coelho Barbara Paranhos , Prado Mariana Brandão , Iglesia Rebeca , Lopes Marilene Hohmuth 
Published: September 2020

Abstract
Glioblastoma (GBM), the most common primary malignant brain tumor, exhibits a highly proliferative cell subpopulation called Glioblastoma stem-like cells (GSCs), presumed to contribute to the aggressive behavior of GBM. Our group has shown that the Prion Protein (PrPC), a cell surface glycoprotein and regulator of several stem cell functions, is enriched in GSCs and co-expresses with conventional GSCs markers. PrPC has been proposed as a scaffold protein, able to govern the assembly of multi-component complexes in the cell membrane. Integrin α6 (ITGA6), a cell surface laminin receptor, is enriched in GSCs as well, and exhibits relevant effects on GSCs biology, related to self-renewal and migration. To investigate a potential association between PrPC and ITGA6, we will perform loss-of-function experiments in GSCs via siRNA and CRISPR/Cas9 to characterize these cell surface molecules expression and their effect on GSCs proliferation, migration and invasion. Preliminary results show that depletion of PrPC perturbates ITGA6 labeling on plasma membrane of GSC. Thus far, cells from patient-derived xenografts (GBM33-PDX2) were transfected a construct for PrPC knockout by CRISPR/Cas9 via Nucleofector Technology. We found around 60% GFP-positive cells via flow cytometry for the CRISPR pool and we are currently isolating clones to confirm PrPC expression. Remarkably, the colonies exhibited distinct morphologies such as neural-like, epithelial-like and stem cell-like, indicating the heterogenous nature of this tumor. Western blotting assays will be performed to assess PrPC and ITGA6 expression in both commercial cell line U87 and GBM33-PDX2. The characterization of PrPC-ITGA6 association might provide insight into GSCs behavior and new anti-GBM therapeutic strategies.
Citation Format: Maria Isabel Melo Escobar, Barbara Paranhos Coelho, Mariana Brandão Prado, Rebeca Iglesia, Marilene Hohmuth Lopes. PrPc depletion in glioblastoma patient derived xenograft cells by CRISPR/Cas9 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4956.