tbuckley/cabot-search huggingface dataset:
Abstract 5662: MEK inhibitors potentiate tumor immune surveillance by enhancing cancer cell response of IFNγ
Authors: Mengyu Xie, Hong Zheng, Amer Beg
Journal: Cancer Research (2017)

Abstract FDA approved mitogen-activated protein kinase (MAPK) kinase (MEK) targeting inhibitors such as trametinib have recently been reported to enhance anti-tumor immunity in multiple preclinical models. It is hypothesized that the combination of such MEK inhibitors with immune checkpoint blockade will have synergistic effects and cause further tumor regression. Immune checkpoint inhibitors such as anti-PD-1 overcome immunosuppressive signaling in the activated T cells, yielding higher levels of Interferon-gamma (IFNγ) release. IFNγ plays a key role in a wide range of immune responses by direct activation of JAK-STAT1 pathway through the binding of IFNγ receptor. JAK-STAT1 regulates transcription of downstream effector genes that are involved in tumor immune surveillance. Many studies have shown that in cancer cells, transcription of T cell chemokines CXCL9,10,11, as well as PD-L1 and MHC-I are induced upon stimulation with IFNγ. While there are some recent studies indicating MEK inhibitors enhance T cell activity and function, here we report for the first time that targeted inhibition of MEK increases tumor cells response to IFNγ and results in significant upregulation of target genes including T cell chemokines, MHC-I, as well as PD-L1. We treated a panel of 20 human lung cancer cell lines with MEK inhibitor U0126 followed by IFNγ stimulation, and showed that the expression of CXCL10 is significantly increased as compared to IFNγ stimulation alone. Furthermore, we found that instead of MEK inhibition, knock down of KRAS in the KRAS mutant cell lines such as A549 and H2122 results in more dramatic CXCL10 upregulation upon IFNγ stimulation. This indicates the potential of increasing tumor T cell infiltration upon MEK targeted therapy. Next, to elucidate the underlying molecular mechanism, we analyzed JAK-STAT1 pathway in mouse lung cancer cell lines LKR, 344, and colon cancer cell line CT26, in which trametinib mediated synergistic expression of CXCL9,10, 11 and MHC-I, PD-L1 were observed. The phosphorylation as well as total protein of JAK2, STAT1 are increased in cells that are pre-treated with trametinib, as compared to IFNγ stimulation alone. Treatment of JAK inhibitor Ruxolitinib as well as knockout of IFNγR1 in LKR cells completely abolishes CXCL10 expression. Importantly, trametinib enhanced response to PD-1 blockade in the lung tumor models. In conclusion, our study demonstrates that targeting MEK signaling in cancer cells increases the response of IFNγ through JAK-STAT1 pathway, which may potentially enhance immune surveillance and response to immune checkpoint blockade. Citation Format: Mengyu Xie, Hong Zheng, Amer Beg. MEK inhibitors potentiate tumor immune surveillance by enhancing cancer cell response of IFNγ [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 5662. doi:10.1158/1538-7445.AM2017-5662
Abstract 4282: Germline <i>TP53</i> p.R337H mutations and Li-Fraumeni syndrome: A new variant form of the disease
Authors: Claire Freycon, Kelvin César De Andrade, Amina Yacouba, Maria Nirvana Formiga, Camila Bittar, Karina Miranda Santiago, Sharon Savage, Patricia Ashton-Prolla, Pierre Hainaut, Maria Isabel Achatz
Journal: Cancer Research (2017)

Abstract The founder germline TP53 mutation, p.R337H, was detected in South and Southern Brazil in families with Li-Fraumeni Syndrome (LFS). The aim of this study was to estimate the burden and patterns of cancer in p.R337H carriers and other germline TP53 mutations. We analyzed data on 539 individuals from the LFS/LFL database from A.C. Camargo Cancer Center in São Paulo, Brazil and compared to International Agency for Research on Cancer (IARC) germline TP53 mutations database (R17). A total of 144 p.R337H carriers have developed 147 cancers (16.7% multiple primaries). The most frequent malignancies were soft tissue sarcoma (STS; 25.9%), breast cancer (24.5%) and adrenocortical carcinoma (ACC; 17.7%). Compared to IARC database, p.R337H carriers had a higher risk of ACC and STS, a lower risk of brain tumors and osteosarcomas (P&amp;lt;0.01). Patients with p.R337H were at risk for developing thyroid and kidney cancers. The median age at diagnosis was 43 years in p.R337H carriers, 30 in other mutations carriers and 65 in the general population. The overall penetrance was similar in both groups until age 12 years. Penetrance was lower in p.R337H carriers (27% at 30 years, 55% at 60 years). The lifetime penetrance was significantly higher in females (79%) than in males (48%). p.R337H-associated disease resembles LFS until age 12, and then diverges, with differences in men and women and a predisposition to cancers that are not part of the LFS spectrum. These observations suggest that p.R337H could predispose to a variant form of LFS. Citation Format: Claire Freycon, Kelvin César De Andrade, Amina Yacouba, Maria Nirvana Formiga, Camila Bittar, Karina Miranda Santiago, Sharon Savage, Patricia Ashton-Prolla, Pierre Hainaut, Maria Isabel Achatz. Germline TP53 p.R337H mutations and Li-Fraumeni syndrome: A new variant form of the disease [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 4282. doi:10.1158/1538-7445.AM2017-4282
Abstract 2117: TRAIL-induced apoptosis in TRAIL-resistant breast carcinoma
Authors: Jasmine M. Manouchehri, Michael Kalafatis
Journal: Cancer Research (2017)

Abstract Recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL), the optimized form of the endogenous death ligand TRAIL, shows therapeutic potential for cancer due to its ability to induce apoptosis in cancer cells independent of p53, while exhibiting minimal toxicity to normal cells. Despite this, a majority of breast cancers display resistance to rhTRAIL treatment due to up-regulation of pro-apoptotic proteins, down-regulation of anti-apoptotic proteins, and/or up-regulation of death receptors (DR) 4 and 5. To overcome rhTRAIL resistance, natural compounds have been investigated as sensitizing agents. This study considered the application of the naturally occurring flavonol Quercetin (Q). Q has been shown to have the ability to up-regulate DR5 and down-regulate anti-apoptotic proteins in cancer cells, and thereby, making Q a favorable choice to be employed as a sensitizing agent. The intention of this study was to ascertain the capacity of Q to sensitize rhTRAIL-resistant triple negative breast cancer BT-20 cells and hormone-dependent breast cancer MCF-7 cells to rhTRAIL-induced apoptosis and elucidate the underlying mechanism for Q’s sensitization. Q demonstrated the ability to intensify rhTRAIL’s pro-apoptotic effects in the breast cancer BT-20 and MCF-7 cell lines as detected through Annexin V/PI assays followed by FACS analysis. In comparison to single agent treatments, the cotreatment of Q and rhTRAIL enhanced the induction of the extrinsic pathway of apoptosis as marked by PARP cleavage (a hallmark of apoptosis), activation of caspase 8, and activation of the executioner caspases 3 and 7. The mechanism for Q’s augmentation in breast cancer was determined to be through the down-regulation of c-FLIPL (caspase 8 inhibitor) in a dose-dependent manner. Furthermore, Q promoted the ubiquitination of c-FLIPL facilitating the proteasome-mediated degradation of c-FLIPL in breast cancer. An additional mechanism for Q’s sensitization was displayed in breast cancer BT-20 cells. Q up-regulated DR5 membrane and protein expression in breast cancer BT-20 cells in a dose-dependent manner. RT-PCR analysis revealed that Q’s influence on DR5 expression occurred at the transcriptional level in those breast cancer cells. Thus, these data suggest that the cotreatment of Q and rhTRAIL possesses the therapeutic potential to be an effective anti-breast carcinoma regimen. Citation Format: Jasmine M. Manouchehri, Michael Kalafatis. TRAIL-induced apoptosis in TRAIL-resistant breast 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 2117. doi:10.1158/1538-7445.AM2017-2117
Abstract 5123: Targeted thieno[2,3-d]pyrimidines with fluorinated phenyl side chains as antitumor agents
Authors: Nian Tong, Aleem Gangjee, Adrianne Wallace Povrik, Carrie O’Connor, Aamod Aamod Dekhneb, Zhanjun Hou, Larry H. Matherly
Journal: Cancer Research (2017)

Abstract The reduced folate carrier (RFC) is ubiquitously expressed in tissues and tumors and is the major tissue transporter for folate cofactors. Folate receptor (FR) α and β, as well as the proton-coupled folate transporter (PCFT), exhibit narrower patterns of tissue expression and are likely to serve more specialized physiologic roles. FRs are expressed in a subset of cancer cells (e.g., ovarian and non-small cell lung cancer for FRα, acute myelogenous leukemia for FRβ), whereas PCFT is expressed in a wide range of human solid tumors but not leukemias. Earlier generations of glycinamide ribonucleotide formyltransferase (GARFTase) and de novo purine nucleotide biosynthesis (e.g., Lometrexol) have shown promise as antitumor drugs. However, these compounds are excellent substrates for RFC and thus are non-selective for tumors, leading to dose-limiting toxicities. We previously reported a novel class of 6-substituted thieno[2,3-d] pyrimidines with a phenyl side chain and 3- and 4-carbon bridge lengths (AGF17 and AGF23, respectively) which selectively targeted FRs but not RFC or PCFT. To increase antitumor efficacy, we synthesized fluorinated analogs of AGF17 and AGF23, designated as AGF309 and AGF304, respectively. AGF309 and AGF304 potently inhibited proliferation of Chinese hamster ovary (CHO) cell lines engineered to individually express human FRα (IC50s of 1.08 and 2.27 nM, respectively) or FRβ (IC50s 0.48 and 1.14 nM, respectively). AGF304 and AGF309 showed nominal activity toward RFC- and PCFT-expressing CHO cells. Both AGF309 and AGF304 were also potently inhibitory toward FRα-expressing human KB human tumor cells (IC50s of 7.19 and 5.27nM, respectively). By analogy with previous iterations of 6-substituted thieno [2,3-d] pyrimidine compounds, growth inhibitory activity by AGF309 and AGF304 likely involves inhibition of de novo purine biosynthesis at GARFTase and potentially a secondary intracellular target. Collectively, our in vitro findings of the potent and selective antitumor activity and FR selectivity suggest that further preclinical evaluation of AGF309 and AGF304 as potential antitumor agents is warranted. Citation Format: Nian Tong, Aleem Gangjee, Adrianne Wallace Povrik, Carrie O’Connor, Aamod Aamod Dekhneb, Zhanjun Hou, Larry H. Matherly. Targeted thieno[2,3-d]pyrimidines with fluorinated phenyl side chains as antitumor agents [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 5123. doi:10.1158/1538-7445.AM2017-5123
Abstract 2201: Downregulation of NF-<i>k</i>B by nanoconjugates to overcome drug resistance in ovarian tumors
Authors: Ajit P. Zambre, Sarjukumar Panchal, Alyssa Worland, Sarah Chapman, Matthew Leevy, Anandhi Upendran, Raghuraman Kannan
Journal: Cancer Research (2017)

Abstract Ovarian cancer is the fifth leading cause of cancer deaths in women. Globally, around 140k women die from ovarian cancer per year. Recurrence can lead to development of resistance to first line agents such as platinum analogs, taxanes, and doxorubicin. Several studies have shown that decrease of NF-κB expression will inhibit P-glycoprotein maturation and thereby overcome drug resistance. In this context, it is well known that Disulfiram (DSF), a FDA approved drug for anti-alcoholism, have been identified as moderate inhibitor of NF-κB activity. It is also shown that DSF possess mild anti-cancer effects via increased permeability of the outer membrane of mitochondria resulting in leakage of proteins, such as cytochrome C, generation of ROS that simulates the ROS-MAPK pathway leading to apoptosis, and inhibition of P-glycoprotein. As such DSF is not a strong therapeutic agent; however, in combination with copper it showed excellent therapeutic benefit. This effect is mainly attributed to metabolite diethyldithio-carbamate -a proteasome inhibitor that was produced upon complexation of DSF with copper. However, delivery of DSF-Cu complex was not successful in clinical setting. We hypothesized gold nanoparticles can serve as potential delivery vehicle to selectively transfer Cu-DSF to turmor without toxicity. Indeed, cellular studies in drug sensitive (OVCAR) and Adriamycin resistant p-glycoprotein expressing (NCI-ADR/RES) ovarian cancer cells indicated that the gold nanoconjugate exhibit significant cytotoxicity and the IC-50 values was decreased 2.5 fold times compared to the Cu-DSF complex. NF-κB expression was decreased by two folds compared to native Cu-DSF complex. Detailed cellular and mechanistic studies along with the evaluation of [Au(DSF-Cu)NP] in human multi-drug resistant (NCI-ADR/RES) mouse xenografts will be presented. Citation Format: Ajit P. Zambre, Sarjukumar Panchal, Alyssa Worland, Sarah Chapman, Matthew Leevy, Anandhi Upendran, Raghuraman Kannan. Downregulation of NF-kB by nanoconjugates to overcome drug resistance in ovarian tumors [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 2201. doi:10.1158/1538-7445.AM2017-2201
Abstract 69: Diminished T-Tubule Density in Newborn Human Ventricular Cells Is Associated with Heterogeneity of Calcium Transients
Authors: Talib Saafir, Brian Crawford, Ming Shen, Guoliang Ding, Paul M Kirshbom, Mary B Wagner
Journal: Circulation Research (2012)

For children with congenital heart disease (CHD), therapies developed for adults may have different effects on immature myocardium. Thus, it is critical to understand calcium handling in the young human ventricle. Methods: Human ventricular cells were isolated from tissue removed as part of the surgical repair for CHDs from two age groups: newborns (&lt;1 week old) and infants (2-12 months old). Developmental changes in t-tubules were examined in live cells with Di-8 ANEPPS which highlights the cell membrane. We measured the T-index (percent of cell interior occupied by t-tubules), averaged for at least 3 confocal z-sections per cell. Changes in calcium transients were measured by confocal line scans in cells loaded with Fluo-4 and field stimulated (37°C). Results: Newborn human myocytes have very few t-tubules whereas infant myocytes have a range of t-tubule densities. The T-index in newborn myocytes was significantly less than in infant myocytes (4.4±0.2%, n=8 cells, 3 newborns vs. 9.1±0.9%, n=55 cells, 7 infants). Furthermore, there was sizable heterogeneity in the T-index for each patient in the infant group, in which some cells had few t-tubules and others had many t-tubules. We calculated the coefficient of variation (CV=SD/mean*100) for each patient and compared CV values for newborns vs. infants. CV was significantly greater in infants compared to newborns (46.5±7.4%, n=7, vs. 9.4±1.9%, n=3, p&lt;0.02). In addition, calcium transients from newborn cells had a ‘U’ shaped wavefront with calcium first increasing at the outer edge of the cell then propagating toward the center. In contrast, infant cells had a homogenous calcium wavefront. The delay of peak calcium from the edge to center was significantly longer in newborns compared to infants (61.7±8.9 ms, n=8 cells, 3 newborns vs. 10.6±1.6 ms, n=6 cells, 4 infants, p&lt;0.001). Conclusions: There are heterogeneous calcium transients in newborn human myocytes that correspond to a lack of t-tubules. Furthermore, t-tubule development occurs in a heterogeneous manner throughout the first year of life with cells from the same patient exhibiting different degrees of t-tubule development. This is the first study to examine t-tubule development and calcium transients in the very young human ventricular myocardium.
Abstract 2610: A database for evaluating methylation biomarkers in bladder cancer
Authors: Meaghan M. Kennedy, Garrett M. Dancik
Journal: Cancer Research (2017)

Abstract Bladder cancer is the fourth-most common cancer in men, one of the most expensive types of cancer to treat, and recurs frequently. While the genomic pathways associated with high-grade, muscle invasive (MI) tumors and low-grade, non-muscle invasive (NMI) tumors are well-established, recent studies have also found that MI and NMI tumors have unique methylation patterns, and that methylation may play a role in the development of early-stage bladder cancer. Interestingly, bladder cancer patients have frequent mutations in chromatin remodeling genes that alter known histone markers of DNA methylation. Since methylation marks are pharmacologically reversible, the identification of methylation biomarkers is a promising avenue for therapeutic treatment. Indeed, several candidate prognostic methylation biomarkers have been identified, but await prospective evaluation. The Bladder Cancer Biomarker Evaluation Tool (BC-BET) is a web-based resource for rapidly evaluating biomarkers in publicly available genomic datasets. Initially developed for gene expression biomarkers, BC-BET includes 1451 patients across 13 cohorts, and 40 bladder cancer cell lines, with gene expression profiles. In this work, we describe the addition of methylation data to BC-BET, so that candidate methylation biomarkers can be rapidly evaluated across multiple patient cohorts. BC-BET now contains methylation profiles from four patient cohorts (250 patients) and includes the available bladder cancer data from the Gene Expression Omnibus and The Cancer Genome Atlas. In "evaluation" mode, a user selects a gene of interest, and BC-BET evaluates whether the selected gene is differentially methylated between tumor vs. normal samples, NMI vs. MI tumors, and low- vs. high-grade tumors. Alternatively, the “biomarker discovery” mode allows a user to identify all differentially methylated genes at a desired false discovery rate (FDR). In both cases, graphical summaries of the results are displayed and statistical results can be downloaded to an Excel spreadsheet. The methylation module of BC-BET is implemented using shiny, a web application framework for R for developing interactive web pages. The addition of methylation data to BC-BET makes it a valuable resource for evaluating methylation biomarkers in bladder cancer. BC-BET is available from the following link: https://gdancik.github.io/bioinformatics/BCBET Citation Format: Meaghan M. Kennedy, Garrett M. Dancik. A database for evaluating methylation biomarkers in bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2610. doi:10.1158/1538-7445.AM2017-2610
Abstract 434: Characterizing the role of serine metabolism in pediatric sarcomas
Authors: Sameer Issaq, Ria Kidner, Jason Rohde, Matthew Boxer, Lee Helman
Journal: Cancer Research (2017)

Abstract Sarcomas represent a diverse group of malignancies with unique molecular and pathological characteristics. In order to improve sarcoma treatment, a better understanding of the alterations associated with specific sarcoma subtypes is critically important. Renewed interest in the altered metabolic properties of cancer cells has led to an exploration of targeting metabolic dependencies as a novel therapeutic strategy. Metabolism of the amino acid serine is frequently altered in cancer, supporting a number of critical biological processes, including protein, lipid, and nucleotide synthesis, and redox balance. The first, rate-limiting step in the serine synthesis pathway is catalyzed by the enzyme 3-phosphoglycerate dehydrogenase (PHGDH), which is overexpressed in several cancers. Previous work has shown that PHGDH loss or inhibition is selectively toxic to cancer cells with high PHGDH expression or increased flux through the serine synthesis pathway. In this study, we have characterized the dependency of pediatric sarcomas on serine metabolism by examining expression of PHGDH in Ewing sarcoma and rhabdomyosarcoma cell lines, and evaluating the effects of PHGDH inhibition and serine deprivation on cellular proliferation and bioenergetic properties. We show that PHGDH is highly expressed in pediatric sarcoma cell lines, and that PHGDH knockdown resulted in decreased proliferation, especially under conditions of serine limitation. Moreover, pharmacological inhibition of PHGDH resulted in a dose-dependent decrease in proliferation and mitochondrial bioenergetic function. Furthermore, individual sarcoma cell lines were differentially sensitive to serine deprivation, indicating that some sarcoma cells may depend on extracellular serine in addition to de novo serine synthesis. Our findings suggest that the dependency of pediatric sarcomas on serine metabolism should be further investigated in order to identify vulnerabilities that could be targeted for potential therapeutic benefit. Citation Format: Sameer Issaq, Ria Kidner, Jason Rohde, Matthew Boxer, Lee Helman. Characterizing the role of serine metabolism in pediatric sarcomas [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 434. doi:10.1158/1538-7445.AM2017-434