tbuckley/cabot-search huggingface dataset:
Abstract 3202: Pharmacologic modulation of Sigma1 induces autophagic degradation of programmed death-ligand 1 in cancer cells
Authors: Christina M. Maher, Jeffrey D. Thomas, Charles G. Longen, Derick A. Haas, Halley M. Oyer, Jane Y. Tong, Felix J. Kim
Journal: Cancer Research (2017)

Abstract Emerging evidence suggests that Sigma1 (also known as sigma1 receptor) is a unique ligand-operated integral membrane chaperone or scaffolding protein that contributes to cellular protein homeostasis. Previously, we found that treatment of various cancer cell lines with some prototypic small molecule modulators of Sigma1 can engage endoplasmic reticulum (ER) associated protein homeostasis pathways including the unfolded protein response and autophagy. Programmed death-ligand 1 (PD-L1) is a type 1 integral membrane glycoprotein that is processed and transported through the ER and secretory pathway of tumor cells. PD-L1 expressed at the surface of tumor cells can act as a T-cell inhibitory checkpoint molecule that inactivates tumor infiltrating immune cells that express PD-1, its cognate receptor. Here, we show that Sigma1 physically associates with PD-L1. In triple negative breast and androgen-independent prostate cancer cells, PD-L1 protein levels are suppressed by both RNAi mediated knockdown of Sigma1 and pharmacological modulation of Sigma1. We observe decreased cell surface and intracellular levels of PD-L1 by flow cytometry and biochemical subcellular fractionation respectively, which corresponds with a dose-responsive decrease in functional PD-L1/PD-1 interaction in a co-culture of cancer cells and T-cells. Inhibitors of autophagy block this suppression of PD-L1 protein levels, suggesting PD-L1 is degraded away by autophagy after Sigma1 modulation. Through confocal microscopy, we show that Sigma1 modulation results in colocalization of PD-L1 and GFP-LC3, a marker of autophagosomes. From these conclusions, we hypothesize that autophagic degradation of nascent PD-L1 after Sigma1 modulation plays a key role in preventing the transport of functional PD-L1 to the plasma membrane. Together, these data demonstrate that Sigma1 modulators have the potential to act as novel therapeutic agents in PD-1/PD-L1 blockade strategies. Citation Format: Christina M. Maher, Jeffrey D. Thomas, Charles G. Longen, Derick A. Haas, Halley M. Oyer, Jane Y. Tong, Felix J. Kim. Pharmacologic modulation of Sigma1 induces autophagic degradation of programmed death-ligand 1 in 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 3202. doi:10.1158/1538-7445.AM2017-3202
18F-FDG Uptake in Parsonage-Turner Syndrome
Authors: Gary Sem Wye Yoong, Arvind Kumar Sinha, Lih Kin Khor, Yazeed Nasser Bin Dous, James Thomas Patrick Decourcy Hallinan
Journal: Clinical Nuclear Medicine (2017)

A 55-year-old man with large B-cell lymphoma developed atraumatic left shoulder pain. 18F-FDG PET/CT revealed new left supraspinatus and infraspinatus muscle uptake while the initial disease resolved. Given the discrepancy between initial disease treatment response and new left shoulder findings, an MRI scan was performed. This demonstrated diffuse supraspinatus and infraspinatus muscle edema and enhancement with no focal lesion. Muscle biopsy was negative for lymphoma, but features of muscle denervation were seen. Overall, clinical and imaging findings were compatible with Parsonage-Turner syndrome (acute brachial neuritis), an uncommon condition that presented as a false-positive finding on PET/CT.
Bevacizumab for advanced cervical cancer: final overall survival and adverse event analysis of a randomised, controlled, open-label, phase 3 trial (Gynecologic Oncology Group 240)
Authors: Krishnansu S Tewari, Michael W Sill, Richard T Penson, Helen Huang, Lois M Ramondetta, Lisa M Landrum, Ana Oaknin, Thomas J Reid, Mario M Leitao, Helen E Michael, Philip J DiSaia, Larry J Copeland, William T Creasman, Frederick B Stehman, Mark F Brady, Robert A Burger, J Tate Thigpen, Michael J Birrer, Steven E Waggoner, David H Moore, Katherine Y Look, Wui-Jin Koh, Bradley J Monk
Journal: The Lancet (2017)
Abstract 3933: Characterization of oncogenic activity of interferon-induced protein with tetratricopeptide repeats 1 and 3 in human oral squamous cell carcinoma progression
Authors: Vijaya Kumar Pidugu, Ai-Hsin Yen, Ying-Chen Chen, Mei-Maan Wu, Chung-Ji Liu, Te-Chang Lee
Journal: Cancer Research (2017)

Abstract Interferon-induced protein with tetratricopeptide repeats (IFITs) family has multiple tetratricopeptide repeats with helix-turn-helix structural motifs that mediate a variety of protein-protein interactions. There are four IFIT genes that have been identified namely, ISG56/IFIT1, ISG54/IFIT2, ISG60/IFIT3, and ISG58/IFIT5. IFIT proteins have been documented to involve in a variety of cellular functions, such as cell proliferation, migration, virus-induced translation initiation, replication and double-stranded RNA signaling. Our previous study has demonstrated that IFIT2 inhibits oral squamous cell carcinoma (OSCC) metastasis. However, little is known about IFIT1 and IFIT3 in the progression of OSCC. In the present study, we are investigating the functional role of IFIT1 and IFIT3 genes in OSCC tumor progression. Immunohistochemical analysis of 147 patients derived tumor specimens with OSCC revealed a strong correlation between IFIT1 and IFIT3 proteins (p&amp;lt;0.001). Clinicoplathological characteristics correlation of IFIT1 and IFIT3 expression levels were positively associated with regional lymph node invasion and nerve invasion. IFIT1 was also associated with venous invasion. Ectopic expression of IFIT1 and IFIT3 proteins in Ca9-22 and SAS cells inducing PKC, EGFR, and AKT activation, resulting in OSCC cells resistance to cisplatin but highly susceptible to tyrosine kinase inhibitor gefitinib, whereas IFIT1 and IFIT3 knockdown SCC25 cells have shown opposite effect. Interestingly, IFIT1 and IFIT3 expression is associated with enhanced cell invasion activity and altered expression of epithelial-mesenchymal transition markers. These data suggested that IFIT1 and IFIT3 may serve as potential biomarkers for the OSCC treatment. The study on how IFIT1 and IFIT3 cause PKC, EGFR, and AKT activation and resistance to DNA damaging agents is ongoing. Our further investigations may explain the molecular signaling mechanism of IFIT1 and IFIT3 in OSCC tumor progression. Citation Format: Vijaya Kumar Pidugu, Ai-Hsin Yen, Ying-Chen Chen, Mei-Maan Wu, Chung-Ji Liu, Te-Chang Lee. Characterization of oncogenic activity of interferon-induced protein with tetratricopeptide repeats 1 and 3 in human oral squamous cell carcinoma progression [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 3933. doi:10.1158/1538-7445.AM2017-3933
Abstract 4981: Extracellular spacer and co-stimulatory domains define target sensitivity and persistence of CAR T cells for the treatment of PSCA+ bone metastatic prostate cancer
Authors: Kelly Kennewick, Dileshni Tilakawardane, Ethan Gerdts, John Murad, Anthony Park, Brook Jeang, Yukiko Yamaguchi, Stephen J. Forman, Saul Priceman
Journal: Cancer Research (2017)

Abstract Advancing chimeric antigen receptor (CAR)-engineered adoptive T cells for the treatment of solid cancers is a major focus in the field of immunotherapy, given impressive recent clinical responses in hematological malignancies. Prostate cancer should be amenable to CAR-based immunotherapy given that several tumor antigens, including prostate stem-cell antigen (PSCA), are widely over-expressed in metastatic disease. The selectivity of CARs for solid cancers is crucial, however, due to the absence of truly restricted tumor antigen expression and potential safety concerns with “on-target off-tumor” activity. Here, we show that optimized co-stimulatory signaling and extracellular spacer domains are essential in defining a CAR’s selectivity towards tumor cells that over-express the target antigen. The 4-1BB co-stimulatory domain in PSCA-CARs confers enhanced tumor selectivity with dampened yet dose-responsive cytokine production, reduced T cell exhaustion phenotype, and equivalent tumor killing ability compared to PSCA-CARs containing the CD28 co-stimulatory domain. CARs containing a short extracellular spacer demonstrate the most selective killing of high PSCA-expressing tumors but are unable to produce the inflammatory cytokines important for a complete anti-tumor response. We show that longer extracellular spacers in PSCA-CARs are necessary for both tumor killing and cytokine production. PSCA-CARs exhibit robust in vivo anti-tumor activity in subcutaneous and orthotopic bone-metastatic patient-derived prostate cancer xenograft models, and 4-1BB-containing CARs show superior persistence in controlling metastatic disease compared with CD28-containing CARs. Our study demonstrates the critical impact of CAR components in defining an optimized tumor-selective CAR T cell, and also highlights the importance of clinically relevant animal models in developing effective solid cancer CAR T cell therapies. Citation Format: Kelly Kennewick, Dileshni Tilakawardane, Ethan Gerdts, John Murad, Anthony Park, Brook Jeang, Yukiko Yamaguchi, Stephen J. Forman, Saul Priceman. Extracellular spacer and co-stimulatory domains define target sensitivity and persistence of CAR T cells for the treatment of PSCA+ bone metastatic prostate 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 4981. doi:10.1158/1538-7445.AM2017-4981
Abstract LB-068: From intracellular antibody fragments to small molecule inhibitors of mutant KRAS
Authors: Camilo E. Quevedo, Abimael Cruz, Hanna Tulmin, Carole J. Bataille, Tomoyuki Tanaka, Donna Petch, Angela J. Russell, Simon Phillips, Terence H. Rabbitts
Journal: Cancer Research (2017)

Abstract Our aim was to develop methods to employ intracellular antibody fragments as lead macromolecules for small compound selections. We have used this approach to identify small molecules binding to mutant RAS with potential to inhibit the RAS-effector interactions. Mutation in RAS family members is among the most frequent in human cancer and the mutant RAS proteins are tumour-specific proteins for therapy. We have previously selected an intracellular antibody single domain fragment that binds to mutant forms of KRAS and HRAS and used this antibody fragment to demonstrate that blocking RAS-effector interaction-dependent signal transduction prevents tumour initiation and overt tumour growth in mouse preclinical models. The antibody fragment binds to GTP-bound RAS with high pM affinity and we have used this property to isolate compounds from a fragment library using a competitive SPR method that places the compounds in the region of the binding site of the antibody fragment. Using a combination of X-ray crystallography and medicinal chemistry, we have obtained a family of compounds that bind adjacent to the KRAS switch I region with nM affinity and that inhibit the downstream phosphorylation of AKT and ERK that results from RAS signaling. The chemical evolution and interaction characteristics of the KRAS-binding compounds will be described and their biochemical and cell-based properties presented. We have validated our approach using an antibody fragment as a screening tool for the identification of small molecule inhibitors of the RAS-effector interaction. This approach has yielded small compound fragments that are currently being developed as potential RAS-effector inhibitors in our medicinal chemistry programme. Citation Format: Camilo E. Quevedo, Abimael Cruz, Hanna Tulmin, Carole J. Bataille, Tomoyuki Tanaka, Donna Petch, Angela J. Russell, Simon Phillips, Terence H. Rabbitts. From intracellular antibody fragments to small molecule inhibitors of mutant KRAS [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 LB-068. doi:10.1158/1538-7445.AM2017-LB-068
Abstract 886: An integrative platform for three-dimensional quantitative analysis of spatially heterogeneous metastasis landscapes
Authors: Ian H. Guldner, Lin Yang, Fang Liu, Danny Z. Chen, Siyuan Zhang
Journal: Cancer Research (2017)

Abstract Metastatic microenvironments are spatially and compositionally heterogeneous. This seemingly stochastic heterogeneity provides researchers great challenges in elucidating factors that determine metastatic outgrowth. Herein, we develop and implement an integrative platform that will enable researchers to obtain novel insights from intricate metastatic landscapes. Our two-segment platform begins with whole tissue clearing, staining, and imaging to globally delineate metastatic landscape heterogeneity with spatial and molecular resolution. The second segment of our platform applies our custom-developed SMART 3D (Spatial filtering-based background removal and Multi-chAnnel forest classifiers-based 3D ReconsTruction), a multi-faceted image analysis pipeline, permitting quantitative interrogation of functional implications of heterogeneous metastatic landscape constituents, from subcellular features to multicellular structures, within our large three-dimensional (3D) image datasets. Coupling whole tissue imaging of brain metastasis animal models with SMART 3D, we demonstrate the capability of our integrative pipeline to reveal and quantify volumetric and spatial aspects of brain metastasis landscapes, including diverse tumor morphology, heterogeneous proliferative indices, metastasis-associated astrogliosis, and vasculature spatial distribution. Collectively, our study demonstrates the utility of our novel integrative platform to reveal and quantify the global spatial and volumetric characteristics of the 3D metastatic landscape with unparalleled accuracy, opening new opportunities for unbiased investigation of novel biological phenomena in situ. Citation Format: Ian H. Guldner, Lin Yang, Fang Liu, Danny Z. Chen, Siyuan Zhang. An integrative platform for three-dimensional quantitative analysis of spatially heterogeneous metastasis landscapes [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 886. doi:10.1158/1538-7445.AM2017-886
Abstract 592: Distinct cellular mechanisms mediate anti-CTLA-4 and anti-PD-1 checkpoint blockade
Authors: Spencer C. Wei, Jacob H. Levine, Dana Pe'er, James P. Allison
Journal: Cancer Research (2017)

Abstract Checkpoint blockade is able to achieve durable responses in a subset of patients, however the biological variables that distinguish responders from non-responders are not well understood. Furthermore, we lack a satisfying comprehension of the underlying mechanisms of anti-CTLA-4 and anti-PD-1 induced tumor rejection. Given that PD-1 and CTLA-4 attenuate T cell activity through distinct mechanisms that are separated spatially and temporally, we hypothesized that responses to anti-CTLA-4 and anti-PD-1 are driven by distinct mechanisms. To address this hypothesis we utilized mass cytometry to comprehensively profile the effect of checkpoint blockade on tumor immune infiltrates in murine tumor models. This approach allows for the interrogation of greater than 40 analytes at single cell resolution. We demonstrate that high dimensional mass cytometry analysis enables unsupervised identification of biologically relevant tumor infiltrating immune populations with high sensitivity and specificity. Using this approach we analyzed immune infiltrates of MC38 and B16BL6 murine tumors in mice treated with anti-CTLA-4, anti-PD-1, or control antibodies. In both tumor models we identify 15 distinct T cell populations with 0.5% or greater frequency. The T cell populations identified in MC38 and B16BL6 tumors were highly congruent. Notably, some but not all of these T cell populations were responsive to checkpoint blockade. A subset of tumor infiltrating CD8 T cell populations expanded following both anti-CTLA-4 and anti-PD-1. Conversely, a subset of regulatory T cell populations contracted following both anti-CTLA-4 and anti-PD-1. Interestingly, we observed expansion of a Th1-like CD4 effector T cell population only in response to anti-CTLA-4 treatment. Thus, we find that anti-PD-1 predominantly engages subsets of tumor infiltrating CD8 T cells whereas anti-CTLA-4 engages both the CD4 and CD8 effector compartments. Our findings indicate that anti-CTLA-4 and anti-PD-1 utilize distinct cellular mechanisms to induce tumor rejection. These findings highlight the importance of expanding our mechanistic understanding of immunotherapeutic approaches for the rational design of combinatorial therapeutic approaches. Furthermore, these results demonstrate that mass cytometry analysis can be utilized to identify biologically relevant tumor infiltrating T cell populations. We acknowledge the MDACC core facility NCI Support Grant P30CA16672. Citation Format: Spencer C. Wei, Jacob H. Levine, Dana Pe'er, James P. Allison. Distinct cellular mechanisms mediate anti-CTLA-4 and anti-PD-1 checkpoint blockade [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 592. doi:10.1158/1538-7445.AM2017-592
Abstract 3300: Inhibition of autophagy by 3-MA enhances the effect of ursolic acid-induced apoptosis in hepatoma SK-Hep-1 cells
Authors: Chuang Wan-Ling, Lin Ping-Yi, Chen Yao-Li
Journal: Cancer Research (2017)

Abstract Purpose The aim of this study is to investigate the autophagic effect of Ursolic Acid (UA) on hepatoma SK-Hep-1 cells. Methods The cytotoxicity of UA in hepatoma SK-Hep-1 cells was measured by MTT assay, the accumulation of acidic vesicular organelles was measured by FACS, the protein expression of LC3-II was detected by immunofluorescence staining, and the autophagic protein expression was evaluated by western blotting. Hepatoma SK-Hep-1 cells treated with a combination of autophagy inhibitor 3-Methyladenine (3-MA) and UA, then use Annexin V/PI Double Staining and western blotting to detect apoptosis and apoptotic protein levels. Statistical Analyses Data was expressed as the mean ± standard deviation and were compared using the Student’s t-test. A p value of &amp;lt;0.05 was considered to indicate statistical significance. All statistical analyses were performed using GraphPad Prism software, version 4.0 (GraphPad Software, Inc., La Jolla, CA, USA). Preliminary Results SK-Hep-1 cells treated with different concentrations of UA (0, 20, 40, and 60 μM). Regarding the results, the half-maximal inhibitory concentration (IC50) was 45.9 and 36.6 μM for 24 and 48 h, respectively. The FACS results showed that when increase the dose of UA could increase the percentages of autophagic populations. The anti-autophagic proteins such as Beclin, Atg-5, Atg-7, and LC3-II, in our results showed that UA decreased the protein expression of mTOR, PI3K, and p62 and PI3K/Akt/mTOR expression. Immunocytochemistry staining showed that SK-Hep-1 cells treated with UA increased the protein expression of LC3-II. The combination treatment of 3-MA and UA significantly increased the apoptotic cell death as monitored by increased protein expression of Caspase-3 and PAPR. Conclusions UA could induced autophagy in hepatoma SK-Hep-1 cells through inhibition of mTOR and PI3K signaling pathways. SK-Hep-1 cells treated with UA exhibited LC3-І/LC3-II conversion, increased protein expression levels of Beclin, Atg-7, and Atg-5 along with reduced protein expression levels of p62. UA-induced apoptosis was enhanced by the treatment of autophagy inhibitor 3-MA. Our findings may assist in the development of novel chemotherapeutic agents for the treatment of malignant types of liver cancer. Citation Format: Chuang Wan-Ling, Lin Ping-Yi, Chen Yao-Li. Inhibition of autophagy by 3-MA enhances the effect of ursolic acid-induced apoptosis in hepatoma SK-Hep-1 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 3300. doi:10.1158/1538-7445.AM2017-3300
Abstract 3125: Therapeutic implications of mTORC1 and mTORC2 inhibitors in genetically heterogeneous glioblastoma
Authors: Anubhav G. Amin, Arthur Wang, Alex Braun, Michael Tobias, Raj Murali, Meena Jhanwar-Uniyal
Journal: Cancer Research (2017)

Abstract Glioblastoma (GB) is the most common malignant primary brain tumor, which is characterized by marked intra-tumor genetic heterogeneity in receptor tyrosine kinases (RTK) genes. Aberrations in the RTK/PI3K/Akt pathways in GB leads to an abnormal signaling pathway of mechanistic target of Rapamycin (mTOR). mTOR exists in two distinct complexes, namely, mTORC1 and mTORC2, which are involved in regulation of cell survival, growth, and motility. In this investigation, we test the hypothesis that the genetic heterogeneity of GBM cells and its stem cells with respect to the expression of EGFR and/or PDGFRα may define the treatment efficacy of RTK inhibitors with or without PI3K/ mTOR inhibitors. We demonstrated that GB tumors over-expressed PDGFRα and EGFR at range of 80% and 30%, respectively, with varying degree of overlap. Combined treatment with the inhibitors of PDGFRα (AC 710) or EGFR (gefitinib), with or without inhibitors of mTORC1 (rapamycin) or mTORC1/2 (Torin1 and Torin 2), led to suppression of cell proliferation, cell cycle, cell migration and drug resistance in GB cells to varying degrees that correlated with EGFR or PDGFRα expression. Downstream signaling pathway substrates of mTORC 1 and 2, namely pS6k and pAkt, respectively, were suppressed by combined treatments of RTK and mTORC1/2 inhibitors. Furthermore, GB stem cell self-renewal and growth was also suppressed with combined treatments. The combination of AC710 plus mTORC1/2 inhibitor, Torin2, was the most effective. These findings underscore the usefulness of determining PDGFRα and EGFR status when considering viable PI3K/mTOR inhibitors for targeted treatment of GB. Citation Format: Anubhav G. Amin, Arthur Wang, Alex Braun, Michael Tobias, Raj Murali, Meena Jhanwar-Uniyal. Therapeutic implications of mTORC1 and mTORC2 inhibitors in genetically heterogeneous 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 3125. doi:10.1158/1538-7445.AM2017-3125