bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4527: Cellular stress response 1 down-regulates the expression of epidermal growth factor receptor and platelet-derived growth factor receptor through inactivation of splicing factor 3A3
Authors: Luo Jian-Hua , Zuo Ze-Hua , Yu Yan P. 
Published: July 2016

Abstract
Cellular stress response 1 (CSR1) is a tumor suppressor gene that plays an important role in regulating cell death. In this report, we showed that the N-terminus of CSR1 interacts with splicing factor 3A, subunit 3 (SF3A3). The SF3A3 binding motif was identified in the region of amino acids 62-91 of CSR1 through cell-free binding analyses. The interaction between CSR1 and SF3A3 led to migration of SF3A3 from nucleus to cytoplasm. The cytoplasmic redistribution of SF3A3 significantly reduced the splicing efficiency of epidermal growth factor receptor and platelet-derived growth factor receptor. Induction of CSR1 or down-regulation of SF3A3 also significantly reduced the splicing activity of oxytocin reporter gene both in vivo and in vitro. Mutant CSR1 that lacks the SF3A3 binding motif contained no RNA splicing regulatory activity, while the peptide corresponding to the SF3A3 binding motif in CSR1 interfered with the wild type CSR1 mediated inhibition of RNA splicing. Interaction of CSR1 and SF3A3 is essential for CSR1 mediated cell death. To our knowledge, this is the first report demonstrating that RNA splicing is negatively regulated by redistribution of a splicing factor.
Citation Format: Jian-Hua Luo, Ze-Hua Zuo, Yan P. Yu. Cellular stress response 1 down-regulates the expression of epidermal growth factor receptor and platelet-derived growth factor receptor through inactivation of splicing factor 3A3. [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 4527.
Abstract 4538: Heterochromatin protein 1 alpha modulates the invasive potential of malignant cells
Authors: Cui Xiaoyan , Stimpson Lance , Hale Tracy , Contreras Alejandro 
Published: July 2016

Abstract
Altered chromatin patterning is observed in neoplastic cells, with loss of heterochromatin associated with aggressive malignancies. Heterochromatin is the tightly packed form of chromatin characterized by limited transcription and is identified by the localization of Heterochromatin Protein 1 alpha (HP1 alpha) and Heterochromatin Protein 1 beta (HP1 beta). HP1 alpha and HP1 beta help to maintain chromatin organization during the cell cycle and regulate gene expression. We have previously shown that HP1 alpha and HP1 beta are both downregulated in papillary thyroid carcinomas and that both proteins are lost to a greater degree in 3 out of 4 metastatic lesions of papillary thyroid carcinomas. In addition, others have shown a loss of HP1 alpha is associated with increased invasive potential and metastatic lesions in a range of human tumors.
By modulating the level of HP1 alpha in breast cancer cell lines we demonstrate a causal role for HP1 alpha in regulating invasive potential. To identify the molecular pathways through which HP1 alpha regulates this phenotype, RNA-seq was used to measure changes in both miRNA and mRNA expression after knock-down of HP1 alpha in the poorly invasive breast cancer cell line, MCF7. Reduction of HP1 alpha levels increased their invasive potential by 44% and this corresponded with differential expression of genes that promote an epithelial to mesenchymal transition (EMT). In addition, a tissue microarray containing 56 invasive breast carcinomas was immunohistochemically stained for HP1 alpha and HP1 beta. A majority of the breast carcinomas showed decreased expression of HP1 alpha when compared to HP1 beta (32/56 tumors). Taken together, these data suggest that loss of HP1 alpha results in a phenotype that is an intermediate of the EMT, and is supported by their altered cytoskeleton, cell-cell and cell-matrix interactions. HP1 alpha loss may confer a more aggressive, invasive potential in breast carcinomas.
By exploring these HP1 alpha −δϵπϵνδϵντ pathways, we seek to further elucidate the regulatory signals that allow a malignant epithelial cell to undergo EMT and begin to invade surrounding tissue.
Citation Format: Xiaoyan Cui, Lance Stimpson, Tracy Hale, Alejandro Contreras. Heterochromatin protein 1 alpha modulates the invasive potential of malignant 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 4538.
Abstract 4583: Potential role of neuropilin-2 in the regulation of c-MET-induced PD-L1 expression in renal cancer cells
Authors: Balan Murugabaskar , Pal Soumitro 
Published: July 2016

Abstract
Neuropilin-1 and -2 (NRP1 and NRP2) are the transmembrane glycoproteins that act as co-receptors for class III semaphorins and several members of the vascular endothelial growth factor (VEGF) family. In conjunction with VEGF receptors and plexins, NRPs and semaphorins modulate various biological responses. Recent studies suggest that NRPs are up-regulated in many types of cancer cells, and may play a major role in tumor growth. In addition to semaphorins and VEGF, NRP1 and NRP2 can also bind to hepatocyte growth factor (HGF), which is the ligand for the tyrosine kinase receptor c-MET. c-MET is highly over-expressed in renal cancer cells; however, the impact of NRPs on c-MET-mediated tumorigenic pathways have not been studied. Recently, we have reported that HGF-/c-MET-induced signaling increases the expression of immunosuppressive and negative-co-stimulatory molecule programmed death-1 ligand (PD-L1) on renal cell carcinoma (RCC) cells, and it protects tumor cells from immune-mediated killing. In this study, we investigated whether NRPs and its ligands can modulate the expression of HGF-/c-MET-induced PD-L1. We have observed that NRP2, and to a lesser extent NRP1, is over-expressed in human RCC cell lines (786-O, ACHN and Caki-1) compared with normal renal epithelial cells at both mRNA and protein level. siRNA-mediated silencing of NRP1 and NRP2 promoted apoptosis of renal cancer cells, suggesting possible role(s) of NRPs in tumor growth. The knock-down of NRP2 down-regulated the cell surface expression of PD-L1 possibly through the reduced interaction of growth-promoting ligands (like, HGF) with NRP2. Interestingly, SEMA3F, a class III semaphorin ligand for both NRP1 and NRP2, has been reported to have anti-tumorigenic effects. We observed that SEMA3F was significantly down-regulated in RCC cells compared with normal renal epithelial cells; and when we added SEMA3F to the cultures of renal cancer cells, it down-regulated both basal and HGF-/c-MET-induced PD-L1 expression. Together, our findings suggest that NRPs (primarily NRP2) can play a critical role in regulating HGF-/c-MET-induced PD-L1 expression in renal cancer cells to mediate immune escape of tumor cells. Therefore targeting NRP2 and/or its activation through SEMA3F/synthetic ligands may restrict c-MET-PD-L1-induced tumor promoting pathways in renal cancer cells.
Citation Format: Murugabaskar Balan, Soumitro Pal. Potential role of neuropilin-2 in the regulation of c-MET-induced PD-L1 expression in renal 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 4583.
Abstract 4587: Dynactin dysregulation-induced increase in EGFR on basal-like breast cancer cells
Authors: Chaudhuri Gautam , Misra Smita 
Published: July 2016

Abstract
Aggressive triple-negative basal-like breast cancer (BLBC) cells are often characterized with overabundance of the epidermal growth factor receptor (EGFR). Major objective of our research is to explore the possibility that dysregulation of the function of the dynactin complex as a mechanism of over-abundance of EGFR on BLBC cell surface. Our notion is that molecular defects in the dynactin-mediated retrograde EGFR recycling pathway in the BLBC cells causes the accumulation of this receptor on their cell surface making them hyper-responsive to EGF signaling. Our comparative transcriptome analysis between BLBC cells with higher levels of EGFR and the non-BLBC cells with lower levels of EGFR revealed that the expression of dynactin complex subunits 1, 2, 3, 4 and 6 (DCTN1, 2, 3, 4, 6), are significantly reduced in the EGFR-high aggressive BLBC cells. In addition, EGFR-high BLBC cells also have lower levels of two other dynactin-associated proteins, CLIP1 and LRRK1. Interestingly, elevation of surface EGFR levels in BLBC cells are associated with higher levels of the long non-coding RNA PVT1. Six miRNAs are generated from the precursor of PVT1 RNA during cis-splicing. They are miR-1204, miR-1205, miR-1206, miR-1207-3p, miR-1207-5p and miR-1208. We found that relative levels of these miRNAs are significantly higher in EGFR-high BLBC cells and tissues in comparison to the non-aggressive EGFR-low BLBC cells. Bioinformatics analysis followed by experimental validation revealed that miR-1207-5p inhibits DCTN1, DCTN3 and ACTR1A; DCTN2 is inhibited by miR-1205 and miR-1208. MiR-1208 also inhibits DCTN6 and CLIP1 whereas LRRK1 and CAPZA1 are inhibited by miR-1207-3p and miR-1206, respectively. Moreover beta-spectrin (SPTB), a protein associated with dynactin complex, is also inhibited by miR-1205 and miR-1207-3p. Treatment of the cells with the antagomirs of the miRNAs increased the levels of their respective target proteins with concomitant decrease in the surface level of EGFR. Our data suggest that BLBC cells maintain a robust level of EGFR on the cell surface by repressing the retrograde transport of EGFR through the repression of the proteins in the dynactin complex and thus sustain their higher growth rates. This research is supported in part by DOD-CDMRP IDEA Expansion Grant# BC103645 and NIH/NCI grant 1R21CA181920-01 to GC.
Citation Format: Gautam Chaudhuri, Smita Misra. Dynactin dysregulation-induced increase in EGFR on basal-like breast 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 4587.
Abstract 4589: Perturbation of epidermal growth factor (EGF) receptor internalization by novel aspirin analogues in SW480 cells
Authors: Bashir Asma’U I.J. , Jones Sarah , Perry Christopher J. , Safrany Stephen T. , Nicholl Iain D. 
Published: July 2016

Abstract
BACKGROUND
Colorectal cancer (CRC) is a global phenomenon with over 135 million new cases and over 600,000 deaths worldwide annually. The EGFR regulates normal growth and differentiation of cells, however its dysregulation is the cause of a wide range of cancers, including CRC. Activation of the EGFR requires phosphorylation at specific sites, which then leads to the recruitment of proteins and ultimately its internalization.
The use of low-dose aspirin as a preventative agent is a controversial topic, particularly as the mechanism of action is hotly disputed. We have previously determined that novel aspirin analogues dramatically reduce EGFR phosphorylation in SW480 CRC cells; these cells express neither COX-1 nor COX-2, the perceived target for aspirin-like compounds. We have seen these aspirin analogues to also perturb the internalization of this receptor.
METHODS
SW 480 CRC cells were cultured in Leibovitz's L-15 medium on glass slides and starved for 48 hours. The cells were then treated with 0.5 mM aspirin analogues (ortho-aspirin, meta-aspirin, para-aspirin, ortho-thioaspirin, meta-thioaspirin and para-thioaspirin) for 30 minutes and then treated with EGF-tagged with AlexaFluor 555 for an hour. The reaction was the quenched with cold PBS, fixed and mounted on microscope slides with VectaShield + DAPI. Confocal microscopy was used to study the effect of these aspirin analogues on EGFR internalization.
RESULTS
EGF increased phosphorylation at all sites tested. We have peviously shown that these effects were prevented by preincubation with thioaspirins more potently than with aspirin and its positional isomers. These novel thioaspirins are also more potent in inhibiting proliferation of SW480 CRC cells. We now show these analogues prevent the internalization of EGFR. Instead they permit the formation of clusters. Aspirin and its analogues can perturb EGFR internalization and signalling in SW 480 cells.
CONCLUSION
The EGFR signalling pathway is a target for aspirin and aspirin analogues. The inhibition of receptor phosphorylation is accompanied by the loss of receptor internalization.
Citation Format: Asma’U I.J. Bashir, Sarah Jones, Christopher J. Perry, Stephen T. Safrany, Iain D. Nicholl. Perturbation of epidermal growth factor (EGF) receptor internalization by novel aspirin analogues in SW480 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 4589.
Abstract 459: The use of circulating SAA and CXCL4 to predict outcome of osteosarcoma at diagnosis
Authors: Flores Ricardo J. 
Published: July 2016

Abstract
Background: Osteosarcoma is the most common malignant bone tumor in children. The survival rate of osteosarcoma is 60-70%, which has remained stagnant for the past four decades. Identifying biomarkers that can better prognosticate osteosarcoma patients and guide therapies would improve survival of this disease.
Material and Methods: In this study, we used ELISA to evaluate the expression of two previously identified circulating biomarkers, namely Serum Amyloid A (SAA) and CXC Chemokine Ligand 4 (CXCL4), in a large cohort of serum samples (n = 233) obtained at from the Children's Oncology Group at initial diagnosis. The biomarkers’ expression was correlated with survival and evaluated for prognostic significance in the OS patients.
Results: Analysis showed that patients with high SAA and low CXCL4 levels had significantly poorer outcome (p = 0.014, HR = 1.68), which was independent of initial metastasis status. The 5-year overall survival rates for the “high-risk” and “low-risk” groups were 47% (95% CI; 36% - 62%) and 64% (95% CI; 57% - 72%), respectively. In addition, low tumor expression of CXCL4 correlated with poor survival (p = 0.017) in an osteosarcoma tissue microarray. In conclusion, this study reports a novel prognostic model consisting of high SAA and low CXCL4 levels in sera that prognosticates osteosarcoma patients at initial diagnosis. This model could serve as the basis for future biomarker-guided clinical trials by incorporating targeted therapy for the poor prognostic population.
Citation Format: Ricardo J. Flores. The use of circulating SAA and CXCL4 to predict outcome of osteosarcoma at diagnosis. [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 459.
Abstract 4600: Regulation of Wnt/β-catenin signaling by Wnt co-receptor LRP6 in colorectal cancer cells
Authors: Li Yonghe , Lu Wenyan , King Taj D. 
Published: July 2016

Abstract
Mutations of APC and CTNNB1 are two major factors for Wnt/β-catenin signaling over-activation in colorectal cancer, however recent studies indicate that the levels of Wnt/β-catenin signaling in colorectal cancer cells could be modulated on the cell surface. The low-density lipoprotein-related protein 6 (LRP6) is an essential Wnt co-receptor for the Wnt/β-catenin signaling pathway. Herein, we reported that LRP6 expression is up-regulated in colorectal cancer. Moreover, LRP6 silencing significantly reduced Wnt/β-catenin signaling in colorectal cancer HCT116 cells (harboring a CTNNB1 mutation) and DLD-1 cells (harboring an APC mutation) and inhibited cancer cell viability. In addition, treatment of HCT116 cells with Wnt3A resulted in LRP6 phosphorylation and activation of Wnt/β-catenin signaling, which was blocked by LRP6 antagonist Mesd. Finally, we found that salinomycin, a potent small molecule inhibitor of LRP6, suppressed LRP6 expression and phosphorylation, inhibited Wnt/β-catenin signaling in colorectal cancer HCT116 and DLD-1 cells, and repressed cancer cell viability and colony formation within the same concentration range. Together, these results indicate that LRP6 plays an important role in over-activation of Wnt/β-catenin signaling in colorectal cancer cells, and that LRP6 is a potential therapeutic target for colorectal cancer.
Citation Format: Yonghe Li, Wenyan Lu, Taj D. King. Regulation of Wnt/β-catenin signaling by Wnt co-receptor LRP6 in colorectal 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 4600.
Abstract 4626: In-vitro growth inhibitory effects of diosmetin on human prostate cancer cells
Authors: Pakradooni Rebecca , Patel Riddhi , Srivastava Janmejai K. , Shukla Sanjeev 
Published: July 2016

Abstract
Characterization of effective chemo-preventive agents for treatment of prostate cancer is an utmost priority. Diosmetin (5, 7-Trihydroxy-4′-methoxyflavone), a natural flavonoid present in citrus plant, has anti-mutagenic and anti-allergic properties. However, the anticancer properties of diosmetin have not been explored in prostate cancer. Present study demonstrates, cell growth inhibition and induction of apoptosis in human prostate carcinoma LNCaP (androgen-responsive) and PC-3 (androgen-refractory) cells by diosmetin, however, no significant growth inhibition observed in normal prostate epithelial cells (RWPE1). Cell growth is a fundamental biological process, where mTOR (mammalian target of rapamycin) pathway has its role, regulates cell growth by coordinating energy and nutrient signals with growth factor. mTOR protein kinase have two different complexes; complex-I contains major component raptor; a target of rapamycin and complex II; insensitive to rapamycin, has major component rictor. Rictor is important as it phosphorylates Ser-473 of Akt/PKB, which is essential for full Akt/PKB activation. We observed diosmetin treated prostate cancer cells was able to inhibit growth factor (IGF-1) and cytokine (IL-6) induced rictor expression. Furthermore, diosmetin (20μM) treatment to prostate cancer cells prevented rictor nuclear localization and subsequently inhibited phospho-Akt (Ser-473), which subsequently resulted in increased FOXO3a nuclear presence. Downstream pathway p70S6 kinase, which has a critical role in cell cycle, growth and survival, was also inhibited after diosmetin treatment. These effects were associated with a marked decrease in the protein expression of cyclin D1 and their activating partner, cyclin-dependent kinase (cdk) 2 and 4 with concomitant upregulation of KIP1/p27 and INK4a/p16. Additionally diosmetin treatment to these cells modulated cell survival machinery by down regulating key molecules viz., c-Myc, Survivin and XIAP (X-Linked Inhibitor of Apoptosis). Diosmetin treatment also resulted in alteration in Bax/Bcl2 ratio in favor of apoptosis, which was associated with an increase in cleaved caspase-3. Taken together, our studies demonstrate that diosmetin-mediated growth inhibition and induction of apoptosis in both LNCaP and PC-3 cells were due to deregulated levels of rictor and Akt signaling cascade and modulation of cell-cycle machinery. We are documenting these evidences for the first time that diosmetin acts against potential molecular targets to alter cellular events to elicit anticancer effects in prostate cancer cells.
Citation Format: Rebecca Pakradooni, Riddhi Patel, Janmejai K. Srivastava, Sanjeev Shukla. In-vitro growth inhibitory effects of diosmetin on human 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 4626.
Abstract 463: Immunohistochemical study of TROP-2 protein expression in thyroid lesions
Authors: Liao Zhiming 
Published: July 2016

Abstract
Introduction
Tumor-associated calcium signal transducer 2 (TROP-2) is a transmembrane glycoprotein overexpressed in various types of epithelial carcinomas from lung, breast, stomach, ovary, cervix, colon and pancreas. A recent immunohistochemical (IHC) study indicated that TROP-2 is also overexpressed in thyroid papillary carcinoma, but the sensitivity is only 82% in formalin-fixed and paraffin-embedded thyroid (FFPE) tissues when a polyclonal anti-TROP-2 antibody was used. A high quality of TROP-2 antibody for IHC applications is needed to improve the sensitivity of the detection of thyroid papillary carcinoma in FFPE tissues.
Methodology
A rabbit monoclonal antibody (clone SP295) against human TROP-2 protein was developed. Western blot was performed using SK-BR-3 cell lysates to verify the specificity of the TROP-2 antibody. An IHC study of TROP-2 was performed on normal tissue and tumor arrays from the thyroid and other organs. TROP-2 staining intensity was semi-quantitatively scored using a 0-3 scale. The sensitivity and specificity of the TROP-2 IHC assay for detecting papillary carcinoma were determined using 65 cases of thyroid papillary carcinoma, 29 cases of follicular carcinoma, and 31 cases of other thyroid conditions (normal, adenoma, Grave's disease, thyroiditis, Goiter, medullary carcinoma, clear cell carcinoma, squamous cell carcinoma, and undifferentiated carcinoma).
Results
A single band at 33 kDa was detected by SP295 on a western blot. In normal tissues, TROP-2 is detectable by IHC mostly in squamous epithelia of many normal organs (skin, pharynx, esophagus, and cervix) and cuboidal and columnar epithelium (breast, kidney, liver, uterus, pancreas, prostate and transitional epithelium of the bladder). In thyroid lesions, the TROP-2 positive rate is 100% (65/65) in papillary adenocarcinoma and it is negative in all other thyroid conditions (normal, adenoma, Grave's disease, thyroiditis, Goiter, medullary carcinoma, clear cell carcinoma, squamous cell carcinoma, and undifferentiated carcinoma). The sensitivity and specificity of TROP-2 IHC for detecting papillary carcinoma were both 100% in this study.
Conclusions
Rabbit monoclonal TROP-2 antibody (clone SP295) is highly sensitive and specific for detecting TROP-2 in FFPE tissues and it can be used to identify thyroid papillary carcinoma.
Citation Format: Zhiming Liao. Immunohistochemical study of TROP-2 protein expression in thyroid lesions. [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 463.