tbuckley/cabot-search huggingface dataset:
Abstract 3415: <i>RNF43</i> somatic mutations in endometrioid ovarian cancers occur in the setting of synchronous endometrioid endometrial cancers
Authors: Defne L. Levine, Fanny Dao, Narciso Olvera, Katherine LaVigne, David B. Solit, Petar Jelinic
Journal: Cancer Research (2017)

Abstract Introduction: Somatic frameshift mutations in RNF43 have previously been filtered out in cancer genome sequencing projects given that they occur in homopolymer tracts and resemble polymerase slippage errors. Two RNF43 hotspot mutations have been identified and validated in endometrioid endometrial cancer (EEC) and appear to negatively regulate Wnt signaling. These frameshift mutations occur at codons R117 and G659. Due to shared clinical and morphologic features of EEC and endometrioid ovarian cancer (EmOC), we determined the frequency of RNF43 somatic mutations in EmOC. Methods: We reviewed the clinical and pathologic features of EmOC samples diagnosed from 2006 to 2015, retrieved from laboratory databases and institutional archives. DNA was extracted from formalin-fixed, paraffin-embedded tumor samples using standard protocols. Sanger and next-generation sequencing (NGS) were used to screen for hotspot mutations at codons R117 and G659 with custom designed primers. NGS at each hotspot was covered with a minimum sequencing depth of 400X. Results: Forty-seven EmOC patients with available tumor specimens were identified and included in the analysis. The median age at diagnosis was 55 years old (range 34-84). The majority of patients had FIGO stage I or stage II disease (n=38, 81%). Thirteen (28%) patients had synchronous endometrial endometrioid or mixed histology tumors. Two (4.3%) RNF43 somatic mutations at codon G659 were identified in both Sanger and NGS from the EmOC tumor specimens. No mutations at codon R117 were identified. The allele fractions of the G659 mutations were 4.3% and 2.8% seen in 33 and 18 reads with a coverage of 775X and 646X, respectively. A review of pathology reports indicated that both mutated samples had synchronous EECs. These two mutated samples represent 15.4% of cases diagnosed with synchronous EmOC and EEC in this cohort. Conclusions: RNF43 somatic mutations are uncommon in EmOCs and associated with synchronous EECs. Recent massively parallel sequencing data suggests that EmOCs in the setting of synchronous EECs are clonally related and disseminated cells are related to nearby anatomic structures. Our data supports that RNF43 somatic mutations in EmOC are clonally expanded from EECs likely through trans-tubal migration. Citation Format: Defne L. Levine, Fanny Dao, Narciso Olvera, Katherine LaVigne, David B. Solit, Petar Jelinic. RNF43 somatic mutations in endometrioid ovarian cancers occur in the setting of synchronous endometrioid endometrial cancers [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 3415. doi:10.1158/1538-7445.AM2017-3415
Normal and Malignant Cells Exhibit Differential Responses to Calcium Electroporation
Authors: Stine K. Frandsen, Mie B. Krüger, Uma M. Mangalanathan, Trine Tramm, Faisal Mahmood, Ivana Novak, Julie Gehl
Journal: Cancer Research (2017)

Calcium electroporation may offer a simple general tool for anticancer therapy. Transient permeabilization of cancer cell membranes created by applying short, high-voltage pulses in tumors enables high calcium influxes that trigger cell death. In this study, we compared the relative sensitivity of different human tumor models and normal tissues to calcium electroporation. Plasma membrane Ca2+-ATPase (PMCA) protein expression was confirmed in vitro in all cancer cell lines and normal primary dermal fibroblasts studied. In all tumor types tested in vivo, calcium electroporation effectively induced necrosis, with a range of sensitivities observed (36%-88%) 2 days after treatment. Necrosis was induced using calcium concentrations of 100-500 mmol/L and injection volumes 20%-80% of tumor volume. Notably, only limited effects were seen in normal tissue. Calcium content increased >7-fold in tumor and skin tissue after calcium electroporation but decreased in skin tissue 4 hours after treatment to levels comparable with untreated controls, whereas calcium content endured at high levels in tumor tissue. Mechanistic experiments in vitro indicated that calcium influx was similar in fibroblasts and cancer cells. However, we observed decreased PMCA expression in cancer cells compared with fibroblasts, offering a potential explanation for the different calcium content in tumor cells versus normal tissues. Overall, our results suggest that calcium electroporation can elicit a rapid and selective necrosis of solid tumors, with limited deleterious effects on surrounding normal tissues. Cancer Res; 77(16); 4389-401. ©2017 AACR.
Abstract 5111: Norcantharidin impairs tumor growth <i>in vivo</i> and inhibits stemness of triple-negative breast cancer cells
Authors: Damian E. Berardi, Guido Cicuttin, Maria A. Taruselli, Stefano M. Cirigliano, Elisa D. Bal de Kier Joffé, Alejandro J. Urtreger, Laura B. Todaro
Journal: Cancer Research (2017)

Abstract Triple-negative breast cancer (TNBC) is characterized by an abundance of treatment-resistant cancer stem cells (CSC). The absence of a molecular target, coupled with its highly aggressiveness, leads to the lack of an effective therapy for TNBC. Norcantharidin (NCTD) is a synthetic demethylated small-molecule analog of the naturally occurring cantharidin isolated from blister beetles (Mylabris phalerata Pall). Unlike the conventional chemotherapeutics, NCTD toxicity is higher to cancer cells than normal ones, making this small molecule promising for cancer treatment. The aims of this work were: A) To study the effect of NCTD on 4T1 cell line proliferation in vitro. B) To analyze the effect of NCTD on 4T1 derived CSC on self-renewal and clonogenic capacity. C) To evaluate the effect of NCTD on 4T1 tumor growth in vivo. We employed the well-known 4T1 triple-negative breast cancer cell model, which presents a huge proportion of CSC. We observed that NCTD treatment during 96 h significantly reduced 4T1 cell proliferation in vitro. In addition, the IC50 value of NCTD was 27.35 ± 2.83 μM. Related to CSC, NCTD pre-treatment for 96 h impaired CSC self-renewal (Number of secondary mammospheres: Control: 276±39; NCTD: 163±18; p≤0.05) as well as the clonogenic capacity (Number of colonies: Control: 359±38; NCTD: 122±11; p≤0.05). By q-PCR, we observed that NCTD treatment for 48 h significantly induced an increase of Gli-1 and Smooth in CSC, keys member of Sonic Hedgehog pathway. Finally, we performed an in vivo assay, where 4T1 cells were orthotopically inoculated on mammary gland of BALB/c mice, and NCTD was i.p. inoculated twice a week (5mg/kg). We observed that NCTD treatment significantly reduced tumor growth in vivo. Our data suggest that NCTD treatment reduces tumor growth both in vitro and in vivo, possibly through the direct effect on CSC self-renewal and clonogenic capacity, by modulating Sonic Hedgehog pathway. Citation Format: Damian E. Berardi, Guido Cicuttin, Maria A. Taruselli, Stefano M. Cirigliano, Elisa D. Bal de Kier Joffé, Alejandro J. Urtreger, Laura B. Todaro. Norcantharidin impairs tumor growth in vivo and inhibits stemness of triple-negative 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 5111. doi:10.1158/1538-7445.AM2017-5111
Abstract 2485: Development and validation of Predi-HRD liquid biopsy test for PARP inhibitor clinical trials
Authors: Zhixin Zhao, Toni Wiegers, Tak Cheung, Pan Du, Shidong Jia
Journal: Cancer Research (2017)

Abstract Response to DNA-damaging agents, such as platinum and recently emerged PARP inhibitors, is associated with homologous recombination deficiency (HRD) pathway. In fact, as reported by multiple clinical trials, patients with advanced breast, prostate, and ovarian cancers who have harmful mutations in BRCA1 and BRCA2 have demonstrated a great benefit from treatment of PARP inhibitors including olaparib, niraparib, and talazoparib. Current companion diagnostic assays that mainly examine germline defects from blood or somatic alterations from tumor tissues have shown several practical challenges: germline test does not capture somatic alterations of a tumor, initial biopsies from a tumor may not reflect the current status of the tumor’s genetic profile over time, and tissue biopsy may be of insufficient quantity or unavailable/unobtainable for downstream molecular profiling. Here we introduce the Predi-HRD blood test, a non-invasive, next-generation sequencing (NGS)-based multiplex assay that enables real-time monitoring of temporal change of tumor heterogeneity and highly sensitive detection of defects in HR genes including BRCA1, BRCA2, ATM, CHEK2, among others. Technical validation was performed to evaluate assay sensitivity, specificity and accuracy using reference samples with known genetic profiling and further validated on a variety of orthogonal platforms such as digital PCR, allele-specific PCR and Sanger sequencing. Mutation prevalence of HR genes was examined in clinical plasma samples from patients with advanced ovarian cancer after systemic chemotherapy. The successful development of Predi-HRD liquid biopsy test offers an efficient solution to stratify and monitor cancer patients who may benefit from HRD-targeted therapeutics such as PARP inhibitors. Citation Format: Zhixin Zhao, Toni Wiegers, Tak Cheung, Pan Du, Shidong Jia. Development and validation of Predi-HRD liquid biopsy test for PARP inhibitor clinical trials [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 2485. doi:10.1158/1538-7445.AM2017-2485
Abstract 4093: t-Darpp stimulates protein kinase A activity by interacting with its RI regulatory subunit
Authors: Dirk Theile, Shuhui Geng, Erin Denny, Jamil Momand, Susan E. Kane
Journal: Cancer Research (2017)

Abstract t-Darpp is the truncated form of the dopamine- and cAMP-regulated phosphoprotein of 32 kDa (Darpp-32) and has been demonstrated to confer resistance to trastuzumab, a Her2-targeted anticancer agent, via sustained signaling through the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt pathway. t-Darpp over-expression results in enhanced activity of protein kinase A (PKA), but the mechanism of t-Darpp-mediated PKA activation is poorly understood. In the PKA holoenzyme, when the catalytic subunits are bound to regulatory subunits RI or RII, kinase activity is inhibited. We investigated PKA activity and holoenzyme composition in cell lines that over-express t-Darpp (SK.tDrp) or a T75A phosphorylation mutant (SK.tDrp.T75A), as well as an empty vector control cell line (SK.empty). We also evaluated protein-protein interactions between t-Darpp and PKA catalytic (PKAc) or regulatory subunits RI and RII in those cell lines. Whereas SK.tDrp cells had elevated PKA activity, SK.tDrp.T75A cells did not. In agreement with the effects on activity, a proximity ligation assay showed that SK.tDrp cells, but not SK.tDrp.T75A cells, had diminished association of RI with PKAc. Moreover, t-Darpp was seen to bind directly to RI in co-immunoprecipitation studies. Cells that express both Darpp-32 and t-Darpp had PKA activity levels and RI-PKAc association that were similar to control SK.empty cells. This is consistent with our published findings that Darpp-32 reverses t-Darpp’s effects on trastuzumab resistance and CREB DNA binding activity (downstream of PKA). Taken together, our data suggest that T75 phosphorylation is crucial for t-Darpp-mediated PKA activation and this activation appears to occur through direct binding to RI and release of RI from PKAc. The t-Darpp-RI interaction could be a druggable target to reduce PKA activity in drug-resistant cancer. Citation Format: Dirk Theile, Shuhui Geng, Erin Denny, Jamil Momand, Susan E. Kane. t-Darpp stimulates protein kinase A activity by interacting with its RI regulatory subunit [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 4093. doi:10.1158/1538-7445.AM2017-4093
Abstract 1498: Melatonin inhibits mitochondrial transcription factor A expression in glioblastoma U87MG cell culture inducing an anti-tumorigenic effect
Authors: Daiane G. Franco, Isabele F. Moretti, Suely K. Marie
Journal: Cancer Research (2017)

Abstract Melatonin, the major hormone of pineal gland, has been described to induce intrinsic apoptosis in tumor cell, while it is inhibited in non-tumor cell. In tumor cell, melatonin stimulates intracellular production of reactive oxygen species (ROS) by a mechanism not completely understood. Here we propose that melatonin inhibits the expression of the mitochondrial transcription factor A (TFAM) in culture of glioblastoma (GBM) cell lineage, leading to an increase of the production of ROS. TFAM is an important mitochondrial protein that maintains the mitochondrial DNA (mtDNA) integrity and consequently the oxidative phosphorylation. Human U87MG GBM cell lineage was treated with melatonin (1 mM) for 72 h to evaluate the expression of TFAM and the mtDNA copy number through Real Time PCR. Proliferation, apoptosis, cell cycle and ROS production were also evaluated by cytometry (Muse - Millipore Corporation) and the results were normalized to control (vehicle: ethanol 0.3 %). Melatonin reduced the expression of TFAM in 17.5 % compared to the control group, but had no effect on the mtDNA copy number. Moreover, the incubation of U87MG with melatonin induced a reduction in cell proliferation in 14.24 % ± 4.3 compared to control, with an arrest of cell cycle in G0/G1 phase, which increased from 67.4 ± 3.71 % to 72.78 ± 3.18 % in the group treated with melatonin compared to the control. Production of ROS presented an increase of 7.1 %, with no significant effect on apoptosis. These results suggest that TFAM maybe a target for the melatonin function for an anti-tumorigenic effect through an increase of ROS production, inducing a delay in the cell cycle and a reduction of cell proliferation. The melatonin effect onTFAM maybe a novel signaling pathway that could be explored for the control of GBM progression. Citation Format: Daiane G. Franco, Isabele F. Moretti, Suely K. Marie. Melatonin inhibits mitochondrial transcription factor A expression in glioblastoma U87MG cell culture inducing an anti-tumorigenic effect [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 1498. doi:10.1158/1538-7445.AM2017-1498
Targeting intracellular drugs to macrophages using esterase-sensitive motif (ESM) technology: Application to anti-cancer
Authors: Alan Drummond, Alan Davidson, Lindsay Bawden, Deborah Brotherton, Vanessa Clark, Stephen Davies, Francesca Day, Valerie Legris, David Moffat, Jo Owen, Graham Wells, Lindsey Needham
Journal: Cancer Research (2008)

5612  Tumor-associated macrophages (TAMs) are now thought to have the potential to facilitate, rather than restrict, the development of human cancer. The availability of agents that reliably alter the function of TAMs would allow a thorough investigation of their role in cancer and potentially provide a novel therapeutic approach. ESM technology uses the carboxylesterase, hCE-1, which is only found in monocyte/macrophages, to drive the selective delivery of many classes of drugs. The technology involves the use of specifically designed amino acid ester motifs that are selectively hydrolysed intracellularly by hCE-1 to charged amino acid derivatives which accumulate only in monocytes and macrophages. These motifs can be incorporated into a range of agents and a series of drug types have been synthesised targeting enzymes such as histone deacetylase, p38 MAP kinase, PI-3 kinase, dihydrofolate reductase and IκB-2. Qualitatively similar data, in terms of macrophage-targeting, are found irrespective of the parent molecule. In many cases, the amino acid ester derivative is significantly less effective (
Abstract 4026: Bioluminescent metabolite assays enable easy measurement of changes in tumor biology
Authors: Michael Valley, Mary Sobol, Donna Leippe, Jolanta Vidugiriene
Journal: Cancer Research (2017)

Abstract Tumor cells rely on metabolic reprogramming to meet their increased demands for energy and biomass. Such reprogramming is exemplified by increased rates of glucose uptake, greater utilization of glycolysis, and a reliance on glutaminolysis. Cancer cells also have a strong dependence on lipids and cholesterol and thus feature enhanced rates of biosynthesis and uptake of these molecules as well. We have developed a suite of bioluminescent assays that can monitor metabolites in all of these important pathways. These assays share a core technology that couples the production of NAD(P)H to the generation of light through a variety of metabolite specific dehydrogenases. Changes in glycolysis and glutaminolysis can be followed by measuring glucose, lactate, glutamate, and/or glutamine through their respective dehydrogenases (and glutaminase). Glucose uptake is typically monitored through the accumulation and phosphorylation of 2-deoxyglucose to produce 2-deoxyglucose-6-phosphate, and this can be measured by employing glucose-6-phosphate dehydrogenase. These bioluminescent assays are homogeneous and can be multiplexed with viability, cytotoxicity, and protein quantitation assays. Metabolites can be measured extracellularly (i.e. from media) or intracellularly and the assays can be performed in 96- or 384-well plates. These assays are simple and sensitive and can provide a greater understanding of how various treatments affect the metabolic state of a tumor cell. Citation Format: Michael Valley, Mary Sobol, Donna Leippe, Jolanta Vidugiriene. Bioluminescent metabolite assays enable easy measurement of changes in tumor biology [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 4026. doi:10.1158/1538-7445.AM2017-4026
Abstract 1400: Using tumor spheroids to evaluate the efficacy of EZH2 inhibitors in clear cell renal cell carcinoma (ccRCC)
Authors: Darmood Wei, Youfeng Yang, Christopher J. Ricketts, Carole Sourbier, Laura S. Schmidt, William M. Linehan
Journal: Cancer Research (2017)

Abstract Enhancer of zeste homolog 2 (EZH2) is a key component of the polycomb repressive complex 2 (PRC2). EZH2 is frequently overexpressed in a wide variety of human malignancies including non-Hodgkin lymphoma, gastric cancer, pancreatic cancer, and lung cancer. Thus it has potential to become a therapeutic target. Characterization of EZH2 as a therapeutic target in clear cell renal cell carcinoma (ccRCC) has not been fully explored. ccRCC have been defined by mutation of the von Hippel-Lindau (VHL) tumor suppressor gene in combination with chromosome 3p loss. Recent sequencing efforts have revealed that several chromatin remodeling genes encoded on chromosome 3p are often mutated, of which PBRM1 is the most frequent (41%). The PBRM1 gene codes for the BAF180 protein, a SWI/SNF chromatin remodeling complex subunit. Loss of BAF180 in ccRCC may disrupt the PBAF variant of the SWI/SNF complex. The SWI/SNF complex remodels the chromatin landscape by either sliding or evicting the nucleosomes from the chromatin. This chromatin remodeling modulates the accessibility to promoter regions by transcriptional machinery. It is through this mechanism that the SWI/SNF complex can regulate a range of cellular processes. It has been demonstrated that the SWI/SNF complex can act antagonistically to the PRC2 complex by evicting PRC2 complex from the promoters of tumor suppressors. Disruption of the SWI/SNF complex would impede the eviction of the PRC2 complex, similarly observed in SNF5-deficient malignant rhabdoid tumors. Therefore, we hypothesize that PBRM1 inactivation disrupts specific SWI/SNF complexes allowing EZH2 to bind and repress target tumor suppressor genes. Thus inhibition of EZH2 in ccRCC may present as a targeted therapeutic option in tumors with PBRM1 mutations. We have investigated EZH2 in ccRCC cell lines with PBRM1 mutations and observed that these cells lines have overexpression of EZH2 in comparison to RPTEC (renal cortex proximal tubule epithelium cell line). We examined the effects of two EZH2 inhibitors (GSK126 and EPZ6438) on ccRCC tumor spheroids. Our preliminary data suggests EZH2 inhibition results in reduced growth of PBRM1 mutant cell lines grown as tumor spheroids. Citation Format: Darmood Wei, Youfeng Yang, Christopher J. Ricketts, Carole Sourbier, Laura S. Schmidt, William M. Linehan. Using tumor spheroids to evaluate the efficacy of EZH2 inhibitors in clear cell renal cell carcinoma (ccRCC) [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 1400. doi:10.1158/1538-7445.AM2017-1400
Abstract 5494: Hypoxia via HIF1alpha can regulate Wnt signaling in human colon cancer cells
Authors: Yung Lyou, Amber Habowski, Stephanie Sprowl-Tanio, Kira Pate, George Chen, Marian L. Waterman
Journal: Cancer Research (2017)

Abstract Standard-of-care treatment for metastatic colorectal cancer combines chemotherapy with bevacizumab, an angiogenesis inhibitor that depletes nutrients and triggers hypoxia. Unfortunately, this strategy extends patient survival only a few months because tumors acquire adaptive resistance, enabling resumption of angiogenesis. Adaptive resistance arises from reprogrammed metabolism, but the regulatory networks that govern reprogramming are not defined. Our studies have shown that overactive Wnt signaling, which is the most common cause of colon cancer, programs cancer metabolism by promoting glycolysis and angiogenesis. Interestingly, metabolic genes targeted by Wnt are also regulated by the hypoxia transcription factor HIF1alpha suggesting there may be crosstalk between the two pathways. Several studies suggest that HIF1alpha can influence Wnt signaling, but the reported effects are variable ranging from positive to negative. We find that HIF1alpha and LEF/TCF/beta-catenin complexes co-regulate metabolic targets including LEF1 and TCF1 (TCF7) expression. Using luciferase reporters driven by LEF/TCF promoters, we observe significantly increased LEF1/TCF1 but not TCF3(TCF7L1)/TCF4(TCF7L2) promoter activity in hypoxic colon cancer cells. We identified putative hypoxia responsive elements (HREs) in the human LEF1 promoter and deletion of these HREs reduced responsiveness to hypoxia. Furthermore, when colon cancer cells were treated with inhibitors that either inactivate or reduce HIF1alpha protein, there was a significant decrease in Wnt reporter activity. These results suggest that hypoxia and the Wnt pathway crosstalk wherein hypoxia co-regulates metabolism genes and increases Wnt signaling capacity via LEF/TCF expression. Current studies are underway to investigate the mechanisms of crosstalk and joint regulation of metabolic gene programs during adaptive resistance. Citation Format: Yung Lyou, Amber Habowski, Stephanie Sprowl-Tanio, Kira Pate, George Chen, Marian L. Waterman. Hypoxia via HIF1alpha can regulate Wnt signaling in human colon 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 5494. doi:10.1158/1538-7445.AM2017-5494