tbuckley/cabot-search huggingface dataset:
Abstract 2400: Identification of histone modifying enzymes associated with tamoxifen resistance in MCF7 breast cancer cells
Authors: Min-Ho Lee, Mi-Ock Lee
Journal: Cancer Research (2017)

Abstract Tamoxifen is widely used to treat estrogen receptor-alpha positive breast cancer. However, resistance to tamoxifen often prevent the success of endocrine therapy. Epigenetic change in tumors are associated with cancer development and progression. Although altered histone modification has been implicated in tumorigenesis, their role in endocrine resistance was little known. To identified tamoxifen-resistance associated histone methylation modifying enzyme, we examined the global histone H3 methylation patterns in tamoxifen-resistance MCF7 breast cancer cells. Our results show that, the levels of methylated histone H3 lysine 4 (H3K4) and histone H3 lysine 9 (H3K9) was upregulated in tamoxifen resistance MCF7 breast cancer cells. Next, we analysis expression levels of H3K4 and H3K9 methylation modifying enzyme in tamoxifen resistance breast cancer cells. qRT-PCR results show that H3K4 methyltransferases (KMT2A and KMT2C) is upregulated in tamoxifen resistance breast cancer cells. Moreover, we observed that si-RNA mediated knockdown of KMT2C was more susceptible to tamoxifen-induced growth inhibition. Finally, Analyses of publicly available patient data sets indicated that KMT2A and KMT2C levels are higher in patients after endocrine therapy failure (recurrence), compared to those of responders (non-recurrence). Our study indicates that elevated levels of KMT2A and KMT2C in the tamoxifen-resistance breast cancers may contributed tamoxifen resistance. Citation Format: Min-Ho Lee, Mi-Ock Lee. Identification of histone modifying enzymes associated with tamoxifen resistance in MCF7 breast 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 2400. doi:10.1158/1538-7445.AM2017-2400
Abstract 5486: Oxidative stress and selective protein carbonylation in human breast cancer tissue
Authors: Baikuntha P. Aryal, Ashutosh Rao
Journal: Cancer Research (2017)

Abstract Protein carbonylation is an irreversible modification to the side chain of amino acid residues induced by severe oxidative stress. Reactive oxygen species (ROS) are constantly produced under normal as well as stress-induced conditions, and play a role in both cancer progression and cancer suppression. Tumor tissue are known to have higher ROS levels compared to surrounding healthy tissue but ROS-induced specific protein carbonylation and its unique role in cancer progression/suppression are poorly understood. In this study we compared the relative total and specific protein carbonylation in flash frozen human breast cancer and matched adjacent normal tissue using ELISA, two-color western blot, mass spectrometry, and immunoprecipitation approaches. To understand antioxidant capacity in tumor tissue, we analyzed superoxide dismutase (SOD) for its antioxidant activity and protein level. Our results indicate that tumor tissue has greater total protein carbonylation, lower SOD activity, lower SOD protein levels, and elevated levels of autophagy compared to matched adjacent healthy tissue. We also identified three specific proteins that showed higher level of carbonylation selectively in tumor tissue compared to adjacent normal tissue. Our findings were further confirmed using the immortalized MDA-MB-231 breast cancer cell line and MCF-12A noncancerous normal human epithelial breast cell. Identification of selectively carbonylated proteins in cancer tissue, and understanding their specific role in cancer progression may promote the development of targeted therapeutic approaches to mitigate or enhance oxidative damage of such proteins selectively in tumor tissue. Citation Format: Baikuntha P. Aryal, Ashutosh Rao. Oxidative stress and selective protein carbonylation in human breast cancer tissue [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 5486. doi:10.1158/1538-7445.AM2017-5486
Abstract 4078: Tumors with class 3 BRAF mutants are sensitive to the inhibition of activated RAS
Authors: Zhan Yao, Rona Yaeger, Vanessa S. Rodrik-Outmezguine, Anthony Tao, Neilawattie M. Torres, Matthew T. Chang, Matthias Drosten, Huiyong Zhao, Fabiola Cecchi, Todd Hembrough, Judith Michels, Hervé Baumert, Linde Miles, Naomi M. Campbell, Elisa de Stanchina, David B. Solit, Mariano Barbacid, Barry S. Taylor, Neal Rosen
Journal: Cancer Research (2017)

Abstract Approximately two hundred mutant BRAF alleles have been identified in human tumors. Physiologic activation of RAF isoforms requires RAS-dependent induction of their dimerization. Activating BRAF mutants cause ERK dependent feedback inhibition of RAS.GTP and are RAS independent. As we have shown previously, they signal either as active monomers or RAS-independent constitutively active dimers. Here, we characterized a third class of BRAF mutants—those that have impaired kinase activity or are kinase dead. These class 3 BRAF mutants are sensitive to ERK-mediated feedback and they function in a RAS-dependent manner. In tumors, they bind more tightly to active RAS, thus enhancing their heterodimerization with CRAF. This is associated with the amplification of RAS-RAF-MEK-ERK signaling. Since these mutants are sensitive to ERK-dependent feedback inhibition of RAS, their enhancement of ERK signaling in tumors requires concurrent dysregulation of RAS activation. Thus, melanomas with Class 3 mutations usually harbor coexistent RAS mutation or NF1 mutants/deletion, whereas receptor tyrosine kinase signaling is activated in lung and colorectal cancers with these mutants. Our model suggests that these tumors will be sensitive to the inhibition of RAS activation. Currently, no direct inhibitors of RAS activation are available. However, in support of this idea, inhibitors of activated RTK signaling in carcinomas with Class 3 BRAF mutants and wild type RAS is sufficient to markedly inhibit ERK signaling and their growth in in vivo murine models and in patients. We have thus defined a third subset of BRAF mutants, which is RAS-dependent. Tumors harboring such mutants are sensitive to tyrosine kinase inhibitors in tumors expressing wild type RAS and NF1. Citation Format: Zhan Yao, Rona Yaeger, Vanessa S. Rodrik-Outmezguine, Anthony Tao, Neilawattie M. Torres, Matthew T. Chang, Matthias Drosten, Huiyong Zhao, Fabiola Cecchi, Todd Hembrough, Judith Michels, Hervé Baumert, Linde Miles, Naomi M. Campbell, Elisa de Stanchina, David B. Solit, Mariano Barbacid, Barry S. Taylor, Neal Rosen. Tumors with class 3 BRAF mutants are sensitive to the inhibition of activated RAS [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 4078. doi:10.1158/1538-7445.AM2017-4078
Abstract 1830: Targeted inhibition of EGFR and glutaminase induces metabolic crisis in EGFR mutant lung cancer
Authors: Milica Momcilovic, Sean T. Bailey, Jason T. Lee, Daniel Braas, Thomas G. Graeber, Melissa Works, Francesco Parlati, Susan Demo, Tonya C. Walser, Steven M. Dubinett, Saman Sadeghi, Heather Christofk, David B. Shackelford
Journal: Cancer Research (2017)

Abstract Cancer cells exhibit increased use of nutrients including glucose and glutamine to support the bioenergetic and biosynthetic demands of proliferation. We tested CB-839, a small molecule inhibitor of glutaminase that impairs glutamine utilization, in combination with erlotinib on EGFR mutant non- small cell lung cancer (NSCLC) as a therapeutic strategy to simultaneously impair cancer glucose and glutamine utilization and thereby suppress tumor growth. Here we show that CB-839 synergizes with erlotinib to drive energetic stress and activate the AMPK pathway in EGFR (del19) lung tumors. Tumor cells undergo metabolic crisis and cell death resulting in rapid tumor regression in vivo in mouse NSCLC xenografts. Consistently, positron emission tomography (PET) imaging with 18F- fluoro-2-deoxyglucose (18F-FDG) and 11C-Glutamine (11C-Gln) of xenografts indicated reduced glucose and glutamine uptake in tumors following CB-839 + erlotinib treatment. Therefore, PET imaging with 18F-FDG and 11C-Gln can be used to non-invasively monitor tumor metabolic and therapeutic response to CB-839 and erlotinib combination therapy. Note: This abstract was not presented at the meeting. Citation Format: Milica Momcilovic, Sean T. Bailey, Jason T. Lee, Daniel Braas, Thomas G. Graeber, Melissa Works, Francesco Parlati, Susan Demo, Tonya C. Walser, Steven M. Dubinett, Saman Sadeghi, Heather Christofk, David B. Shackelford. Targeted inhibition of EGFR and glutaminase induces metabolic crisis in EGFR mutant lung 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 1830. doi:10.1158/1538-7445.AM2017-1830
Abstract 5268: Nexrutine and palmatine mediated effects on the STAT3/EP4/IL-6 axis in pancreatic cancer
Authors: Amanda R. Munoz, Roble G. Bedolla, Paul Rivas, Divya Chakravarthy, Robert L. Reddick, Martha A. Hanes, Glenn A. Halff, Rita Ghosh, Addanki P. Kumar
Journal: Cancer Research (2017)

Abstract With a 5 year survival of less than 8%, the poor prognosis of pancreatic cancer (PanCA) underlines the importance of improving therapies for effective management of this disease. In previous studies, we identified the tumor cell growth inhibitory activities for Nexrutine® (Nx, a bark extract from Phellodendron amurense) and palmatine (PMT) which is a constituent of Nx. These studies revealed an important role for downregulation of KRAS downstream effectors including GLI, STAT3 and NF-κB in mediating growth inhibitory effects. Remarkably, both Nx and PMT exerted synergistic growth inhibitory effects in combination with the conventional chemotherapeutic agent, Gemcitabine (GEM). Despite such promising in vitro observations, the in vivo efficacy of Nx or PMT had not been established. In this investigation, we evaluated the ability of Nx and PMT to (i) prevent the development of pancreatic tumors; and (ii) inhibit the growth of patient derived pancreatic cancer tissue in short term ex vivo cultures. Studies were also conducted to investigate the underlying molecular mechanism using cell culture models. Our results show that both Nx and PMT are well tolerated in vivo as evidenced by a lack of significant changes in the body weights of athymic mice implanted with Capan-2 cells. Interestingly, both Nx and PMT showed a significant decrease in the circulating levels of inflammatory molecules including IL-6 and CXCL1. In this first proof-of-concept study, PMT treated animals demonstrated a trend towards decreased pancreatic tumor weight with associated histopathogical changes. Remarkably, both Nx and PMT inhibited the growth of patient derived pancreatic cancer cells. Mechanistic investigations identified downregulation of STAT3, TrkA, Src, and RPS6 activities as potential contributors to Nx or PMT-induced synergistic growth inhibitory effects with GEM. Further investigation of STAT3 signaling revealed the involvement of the prostaglandin receptor, EP4, in a potential feedback loop with STAT3 and in asserting STAT3-mediated inhibition of autophagy. Taken together these data support potential utility for Nx and/or PMT in the management of PanCA and suggest that these agents use multiple mechanisms to affect growth of pancreatic tumors. Supported by NCCIH (R01 AT007448; APK) and VA-MERIT Award (I01 BX 000766; APK). Citation Format: Amanda R. Munoz, Roble G. Bedolla, Paul Rivas, Divya Chakravarthy, Robert L. Reddick, Martha A. Hanes, Glenn A. Halff, Rita Ghosh, Addanki P. Kumar. Nexrutine and palmatine mediated effects on the STAT3/EP4/IL-6 axis in pancreatic 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 5268. doi:10.1158/1538-7445.AM2017-5268
Exploratory analysis of the association of depth of response and survival in patients with metastatic non-small-cell lung cancer treated with a targeted therapy or immunotherapy
Authors: C.E. McCoach, G.M. Blumenthal, L. Zhang, A. Myers, S. Tang, R. Sridhara, P. Keegan, R. Pazdur, R.C. Doebele, D. Kazandjian
Journal: Annals of Oncology (2017)

Response Evaluation Criteria in Solid Tumors (RECIST) permits rapid evaluation of new therapeutic strategies in cancer. However, RECIST does not capture the heterogeneity of response in highly active therapies. Depth of tumor response may provide a more granular view of response. We explored the association between, depth of response (DepOR), with overall survival (OS) and progression-free survival (PFS) for patients with NSCLC being treated with an ALK inhibitor (ALKi) or an anti-PD-1 antibody (Ab).
Abstract 2654: Resveratrol and piceatannol synergistically induce PDL1 expression
Authors: Justin P. Lucas, Joseph M. Wu, TzeChen Hsieh, Zbigniew Darzynkiewicz, Halina Dorota Halicka-Ambroziak
Journal: Cancer Research (2017)

Abstract The interaction of programmed cell death-1 (PD-1) and its ligand programed cell death-1 ligand (PD-L1) is a major focus of recent immune oncology therapy efforts. The expression of PD-1 on T lymphocytes and its subsequent interaction with PD-L1, either from antigen presenting or tumor cells, will result in apoptosis-dependent inactivation of the T lymphocytes. This interaction plays an integral role in tumor immunology, specifically augmenting immune evasion. Relatively little is known about the regulation of PD-L1 in either the tumor or normal environment. We investigated the ability of natural dietary compounds to induce PD-L1 expression on normal epithelial cells and various cancer cell lines. These molecules have been evolutionary selected to control inflammation and cancer cell transformation and progression, understanding their mechanism of action could be important to understanding how this system works. Using flow cytometry and immunohistochemistry, we focused our studies on resveratrol and its metabolite piceatannol, key phytochemicals extracted from grapes, after an initial screen of various natural products. Experimental data showed that both compounds can individually up-regulate the expression of PD-L1 on tumor cell lines and normal epithelial cells, by an IFN-γ-independent mechanism. PD-L1 induction by both of these compounds was higher in tumor than in normal epithelium, suggesting greater significance in tumor regulation than inflammation. Additionally, the combination of resveratrol and piceatannol acted synergistically, leading to a significantly greater induction of PD-L1 expression across multiple tumor indications. Understanding whether resveratrol and piceatannol use a common signaling pathway to induce PD-L1 expression in tumor cells, was critical to understand the synergistic induction observed. Studies utilizing specific inhibition of IKK phosphorylation were accompanied by a significant reduction in the ability to induce PD-L1 expression on tumor cells, either as single agents or in combination. These results are consistent with the hypothesis that induction of PD-L1 by resveratrol or piceatannol, or their combination involves molecular determinants down-stream of NF-kB signaling. Citation Format: Justin P. Lucas, Joseph M. Wu, TzeChen Hsieh, Zbigniew Darzynkiewicz, Halina Dorota Halicka-Ambroziak. Resveratrol and piceatannol synergistically induce PDL1 expression [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 2654. doi:10.1158/1538-7445.AM2017-2654
Abstract 2648: CD47 antibody-induced engulfment of human T-cell leukemia cells by bone marrow-derived macrophages
Authors: Gillian Lovell, Clare Szybut, Kalpana Patel, Hinnah Campwala, Nicola Bevan, Dan Appledorn, Tim James Dale, Derek John Trezise
Journal: Cancer Research (2017)

Abstract CD47 is a trans-membrane “don’t-eat-me” signaling protein that enables tumor cells to evade clearance by neighboring phagocytes. Blocking CD47 allows phagocytes to identify and clear tumor cells and is a promising new approach for cancer immunotherapy. In this study, we characterized anti-CD47 antibody-mediated engulfment of living tumor cells (CCRF-CEM) by mouse bone-marrow derived macrophages (BMDMs) or immortalized mouse macrophages (J774A.1). Phagocytosis was quantified using a pH-sensitive cell-labeling fluorescent probe, pHrodo, and automated kinetic live-cell analysis (IncuCyte). CCRF-CEM cells were first labeled using pHrodo (250ng ml-1 for 1h), washed and then treated with antibody for 1 h. Target cells were then added to BMDMs or J774A.1 that had been seeded overnight on 96-well plates. Phase- and fluorescence images were captured and quantified every 15min. Anti-CD47 antibody (B6H12.2, 0.04-5μg ml-1), but not IgG-control, produced time- and concentration-dependent engulfment of CCRF-CEMs by BMDMs (30’-4h), as evidenced by an increase in intracellular fluorescence as the label accumulates in the acidic phagosome. After 4h the red fluorescence area was increased by 25-fold (1975 ± 391 μm2 vs 80 ± 41 μm2). From close inspection of the time-lapse images cellular engulfment could be clearly observed, coincident with the appearance of the fluorescent signal. Similar observations were made with J774A.1 as the effector cell. Interestingly, the rate and degree of engulfment appeared effector cell-dependent. The mechanism of engulfment was not via induction of target cell apoptosis since anti-CD47 did not induce PS externalization (Annexin V) or activate caspase 3/7. Anti-CD47 had no direct effect on CCRF-CEM proliferation for the first 4 h but upon longer exposures (&amp;gt;8 h) cell growth was attenuated. Our experimental findings substantiate the known pro-phagocytic effects of anti-CD47 antibodies, and provide a model system and method for quantitative functional analysis and mechanistic insight of CD47 modulators as cancer therapeutics. Citation Format: Gillian Lovell, Clare Szybut, Kalpana Patel, Hinnah Campwala, Nicola Bevan, Dan Appledorn, Tim James Dale, Derek John Trezise. CD47 antibody-induced engulfment of human T-cell leukemia cells by bone marrow-derived macrophages [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 2648. doi:10.1158/1538-7445.AM2017-2648
Abstract 2882: The miR-200b-ZEB1 circuit regulates diverse stemness of human hepatocellular carcinoma
Authors: Sen-Yung Hsieh, Su-Chun Tsai
Journal: Cancer Research (2017)

Abstract Background &amp; aims: Hepatocellular carcinoma (HCC) can be derived from cancer stem cells (CSCs), which contribute to tumor initiation, metastasis, chemoresistance, and post-treatment recurrence. A great variety of HCC CSCs resulting in diverse clinical manifestations have been reported. We aimed to elucidate how CSC diversity is regulated. Methods: MicroRNAs deregulated in HCC were identified by using array-based microRNA profiling. Diversity of HCC CSCs was assayed by flow-cytometry, in vitro and in vivo assays for tumorigenicity. Results: MiR-200b downregulation occurred in early HCC and associated with shorter disease-free and overall survival. Ectopic expression of miR-200b or silencing of ZEB1 led to a decrease in CD13+ and CD24+ HCC CSCs and an increase in EpCAM+ HCC CSCs. MiR-200b directly suppressed BMI1 and ZEB1 expressions. ZEB1 transcriptionally upregulated CD13 and CD24 expression and downregulated EpCAM expression via directly targeting their promoters. Neither miR-200b nor ZEB1 had obvious effects on CD133 or CD90 expression. Silencing CD13 or CD24 expression suppressed tumorigenicity of HCC cells. Ectopic expression of CD24 reversed the suppression of tumorigenicity when these HCC cells had been ectopically expressing miR-200b. Clinically, miR-200b downregulation was coupled with ZEB1 upregulation in approximately two-thirds of HCC patients. ZEB1 expression was positively correlated with CD13 and CD24 expressions, while EpCAM expression was positively correlated with miR-200b expression in HCCs. Conclusions: The miR-200b-ZEB1 circuit is a master regulator of diverse stemness of HCC, which distincts HCCs into those containing CD13+/CD24+ CSCs from those containing EpCAM+ CSCs, and a thus potential target for anti-HCC therapy. Citation Format: Sen-Yung Hsieh, Su-Chun Tsai. The miR-200b-ZEB1 circuit regulates diverse stemness of human hepatocellular carcinoma [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 2882. doi:10.1158/1538-7445.AM2017-2882
Abstract 4473: SRRM4 drives treatment-induced neuroendocrine transdifferentiation of prostate adenocarcinoma under androgen receptor pathway inhibition
Authors: Yinan Li
Journal: Cancer Research (2017)

Abstract Treatment-induced neuroendocrine prostate cancer (t-NEPC) is an aggressive subtype of castration-resistant prostate cancer that typically does not respond to AR pathway inhibition (ARPI) and its diagnosis is increasing. To understand its development, we analyzed transcriptomes of prostate tumors to identify t-NEPC-specific RNA splicing. Interestingly, more than 66% of the splice events are predicted to be regulated by the RNA splicing factor, Serine/Arginine Repetitive Matrix 4 (SRRM4). We confirmed in vitro and in vivo that one SRRM4 target gene is the RE1-Silencer Factor (REST), a master regulator of neurogenesis. SRRM4 strongly stimulates adenocarcinoma cells to express t-NEPC biomarkers and this is exacerbated by ARPI. ARPI combined with gain of SRRM4 results in adenocarcinoma cells to assume multicellular spheroid morphology and establishes progressive NEPC xenografts. These SRRM4 actions are further enhanced by loss-of-function of TP53. We conclude that SRRM4 drives t-NEPC progression. This knowledge may guide the development of novel therapeutics aimed at t-NEPC. Citation Format: Yinan Li. SRRM4 drives treatment-induced neuroendocrine transdifferentiation of prostate adenocarcinoma under androgen receptor pathway inhibition [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 4473. doi:10.1158/1538-7445.AM2017-4473