bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1742: Cancer cell-selective transcriptome analysis reveals new colorectal cancer molecular subtypes with improved biological resolution and superior predictive and prognostic performance
Authors: Isella Claudio , Bellomo Sara E. , Brundu Francesco , Galimi Francesco , Ficarra Elisa , Marchionni Luigi , Trusolino Livio , Bertotti Andrea , Medico Enzo
Published: July 2017

Molecular classification of colorectal cancer (CRC) based on gene expression profiling of tumor samples is known to be heavily affected by transcripts of stromal origin. As a consequence, current CRC transcriptional subtypes reflect an admixture of cancer cell-intrinsic traits and tumor microenvironment features. Whether selective analysis of the cancer cell transcriptome could improve CRC subtyping, remains an open issue. In patient-derived xenografts (PDXs), human transcripts only originate from cancer cells, because stromal transcripts are of mouse origin. We therefore assessed cancer-cell intrinsic transcriptional features of CRC by generating human-specific expression profiles of 515 PDXs from 244 CRC patients, and performing unsupervised class discovery. We identified five “CRC intrinsic subtypes” (CRIS A-E) only partially overlapping with the current ones, and robustly enriched for distinct molecular, functional and phenotypic traits: (i) CRIS-A: mucinous, glycolytic, CIMP, and enriched for microsatellite instability or mutations in KRAS; (ii) CRIS-B: marked TGF-β pathway activity, epithelial-mesenchymal transition and poor prognosis; (iii) CRIS-C: MSS, elevated EGFR signaling and sensitivity to EGFR-targeted treatments; (iv) CRIS-D: MSS, WNT activation, and IGF2 overexpression and amplification; (v) CRIS-E: MSS, Paneth cell-like phenotype and higher frequency of TP53 mutation. CRIS subtypes successfully categorized independent sets of primary and metastatic CRCs and cell lines, for a total of over 3000 samples profiled by microarrays and RNAseq. The new subtypes displayed unprecedented predictive and prognostic performances, indipendent from known markers including stromal signatures, whose integration with CRIS further enhanced prognostic significance.

Citation Format: Claudio Isella, Sara E. Bellomo, Francesco Brundu, Francesco Galimi, Elisa Ficarra, Luigi Marchionni, Livio Trusolino, Andrea Bertotti, Enzo Medico. Cancer cell-selective transcriptome analysis reveals new colorectal cancer molecular subtypes with improved biological resolution and superior predictive and prognostic performance [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 1742. doi:10.1158/1538-7445.AM2017-1742
Abstract 1749: Stability of copy-number profiles defines two molecular subtypes during urothelial carcinoma’s evolution
Authors: Faltas Bishoy M. , Prandi Davide , Tagawa Scott T. , Nanus David , Molina Ana M. , Beltran Himisha , Demichelis Francesca , Rubin Mark A.
Published: July 2017

Background: Somatic copy-number alterations (SCNAs) are distinct molecular events occurring in muscle-invasive urothelial carcinoma (UC). Defining the biologic role and the timing of SCNAs in UC’s evolution is critical for understanding disease biology and for precision therapy.

Methods: To examine whether distinct SCNAs define specific subtypes of UC and characterize the evolutionary dynamics of SCNA acquisition, we conducted whole-exome sequencing (WES) of a discovery cohort of 44 advanced UC tumors and matching germline samples, including 13 pairs of matched primary and metastatic tumors prospectively collected before and after chemotherapy. We queried WES data from 285 UCs from The Cancer Genome Atlas (TCGA) as a validation cohort. We performed a novel in-depth allele-specific copy-number analysis in 2503 cancer genes using the CLONET computational framework, which accounts for tumor ploidy and cellularity to infer the clonal hierarchy of SCNAs.

Results: Analysis of SCNAs from tumor pairs within each patient revealed punctuated evolution of SCNAs occurring early in UC’s development followed by minor changes (clonal stasis) throughout the tumor’s lifetime. Two distinct clusters of UCs with strikingly different SCNA profiles in the discovery cohort emerged. Cluster A was defined by diploid copy number background and focal deletions in the 9p21 region (CDKN2A, CDKN2B and MTAP). Cluster B was defined by genome-wide duplications and several enriched amplifications including 1q21.1 (SETDB1 and MLLT11), (P = 0.0002) and 6p22.3 (E2F3), (P = 0.001). TP53 mutations (P = 0.0001) were enriched in the cluster B, consistent with the role of functional p53 as a “guardian of the genome” preventing chromosomal instability. SCNAs clusters A and B were confirmed in the TCGA validation cohort. Cluster A was enriched with tumors belonging to TCGA bladder cancer cluster III (“basal/squamous-like”) (P = 0.02).

Conclusions: Using novel allele-specific SCNAs analysis, we define two distinct clusters of UC presenting a framework for understanding this aspect of UC’s biology. In contrast to somatic mutations, SCNAs are clonally static during each tumor’s evolution. This data has important implications for precision medicine for UC.

Citation Format: Bishoy M. Faltas, Davide Prandi, Scott T. Tagawa, David Nanus, Ana M. Molina, Himisha Beltran, Francesca Demichelis, Mark A. Rubin. Stability of copy-number profiles defines two molecular subtypes during urothelial carcinoma’s evolution [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 1749. doi:10.1158/1538-7445.AM2017-1749
Abstract 1767: Analysis of biomarkers and anthracycline benefit for hormone receptor-negative breast cancer: results from a randomized phase 2 neoadjuvant study (KBOG 1101 Study)
Authors: Ishikawa Takashi , Narui Kazutaka , Oba Mari S. , Yamada Akimitsu , Kida Kumiko , Tanabe Mikiko , Ichikawa Yasushi
Published: July 2017

AIM: We compared 6 cycles of docetaxel and cyclophosphamide (TC6) with 3 cycles of 5-fluorouracil and epirubicin and cyclophosphamide followed by 3 cycles of docetaxel (FEC-D) as neoadjuvant chemotherapy for patients with hormone receptor (HR)-negative breast cancer (BC) to identify biomarkers requiring anthracycline treatment.

Methods: In total, 103 patients with operable HR-negative BC were administered TC6 or FEC-D. Triple-negative BC was subdivided by CK5/6 and EGFR into basal- and non-basal BCs. The primary endpoint was pathological complete response (pCR). Secondary endpoints were safety, breast-conserving surgery ratio, disease-free survival, overall survival, and predictive factors (Ki-67, P-53, ALDH1 and TOP2A by IHC and TOP2A by FISH) for each regimen.

Results: Of the 103 patients, 97 completed the study. Overall pCR was higher for patients treated with FEC-D (36%) than for those treated with TC6 (25.5%) (P=0.265). FEC-D was significantly superior to TC6 in basal BC (42.9% vs 13.6%; P=0.033), while no differences in HER2 and non-basal BCs. Aldehyde dehydrogenase 1 (ALDH1) positivity was inversely associated with pCR for both regimens, significantly for FEC-D (FEC-D: p=0.047, TC6: p=0.085). Patients who achieved pCR tended to have longer DFS (P = 0.287) and OS (P = 0.069). Patients with basal and non-basal BC treated with FEC-D had significantly better DFS (P = 0.016) and OS (P = 0.034) than those with TC6.

Conclusion: We found TC6 was less effective than FEC-D for HR-negative BC because it was not sufficient to treat basal-BC. This suggests that DNA damaging agents like anthracyclines are required for treating basal-BC. Additionally, ALDH1 could be a marker for resistance to conventional chemotherapy.

Citation Format: Takashi Ishikawa, Kazutaka Narui, Mari S. Oba, Akimitsu Yamada, Kumiko Kida, Mikiko Tanabe, Yasushi Ichikawa. Analysis of biomarkers and anthracycline benefit for hormone receptor-negative breast cancer: results from a randomized phase 2 neoadjuvant study (KBOG 1101 Study) [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 1767. doi:10.1158/1538-7445.AM2017-1767
Abstract 177: Thymidine quinoxaline conjugates as a novel selective and effective photosensitizer for anticancer photodynamic therapy
Authors: Zhou Qibing , Wang Zhiwei , Yang Rong , Qian Ting , Zhang Dejun
Published: July 2017

Thymidine quinoxaline conjugates are a new class anticancer agent that exhibits selective anticancer activity by targeting the abnormally high level of thymidine kinase of the thymidine salvage pathway in cancer cells. In addition, the conjugated quinoxaline moiety could also act as a photosensitizer to generate reactive oxygen species that would significantly enhance the anticancer activity. Therefore, a variety of structural derivatives were synthesized and investigated for the potential of combined anticancer activity. We found that the thymidine moiety was critical for the accumulation of compounds in cancer cells and thus their activity. On the other hand, the substitutions and additional conjugation of quinoxaline moiety had significant impact on the effectiveness to generate reactive oxygen species for enhanced potency. Among all the compounds studied, dT-QP exhibited a potent activity against liver cancer cells with IC50 at 20 nM under photo-irradiation at 400 nm wavelength for 20 min. This potent activity of dT-QP was 12 times more effective than that of the clinically used photosensitizer protoporphyrin IX (IC50 at 250 nM) under the same condition and 5 times more potent than anticancer drug doxorubicin (IC50 at 100 nM). In addition, thymidine quinoxaline conjugates were found to form aggregates with an average size of 200 nm. Further optimization of the aggregating condition led to a highly stable suspension of 90 nm size nanoparticles containing a tumor-specific peptide that could be used for in vivo study. Therefore, thymidine quinoxaline analogs could be a selective anticancer agent and effective photosensitizer for potential photodynamic therapy.

Citation Format: Qibing Zhou, Zhiwei Wang, Rong Yang, Ting Qian, Dejun Zhang. Thymidine quinoxaline conjugates as a novel selective and effective photosensitizer for anticancer photodynamic therapy [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 177. doi:10.1158/1538-7445.AM2017-177
Abstract 1790: Evaluation of UCK2 protein expression as a potential predictive biomarker of RX-3117
Authors: Lee Young Bok B. , Kim Deog J. , George Christina , Ahn Chang-ho , Frank Julie , Mazhari Reza , Dauffenbach Lisa M. , Olsen Eric P.
Published: July 2017

Background: A novel, orally bioavailable nucleoside analogue, RX-3117, is a prodrug activated intracellularly by Uridine Cytidine Kinase 2 (UCK2) that is thought to be expressed predominantly in tumor tissue. RX-3117 is currently being evaluated in a Phase Ib/IIa multi-center, open-label clinical study in patients with advanced pancreatic and bladder cancer. In this study, we aimed to determine the relation between UCK2 tissue protein expression and the efficacy of RX-3117 in mice xenograft models and also UCK2 protein expression in a panel of human cancer tissues relative to normal tissue.

Methods: The UCK2 protein expression in tumor tissues was analyzed by immunoblotting using clone 22-1 rabbit monoclonal antibody. The validated procedure for the immunohistochemistry (IHC) of UCK2 with clone 22-1 was performed in a panel of human formalin-fixed paraffin-embedded (FFPE) cancer and normal tissues.

Results: The immunoblotting protein level of UCK2 normalized to β-actin and corresponding tumor growth inhibition (oral RX-3117 dose of 500mg/kg, TIWK) were 57 and 67% in MiaPaCa2, 30 and -5% in BxPC3, 199 and 92% in Colo-205, 21 and 90% in Caki-1, 2 and 39% in A549, and 146 and 79% in H460, respectively. This data indicates an anti-tumor efficacy trend in a UCK2-dependent manner. The IHC of UCK2 showed that positive staining of UCK2 in cancer tissues was observed in 20/20 bladder cancer tissues (100% frequency), 19/20 CRC tissues (95% frequency), 18/20 NSCLC tissues (90% frequency), and 19/20 pancreatic cancer tissues (95% frequency). Average H-Scores of UCK2 in cancer tissues vs. normal tissues were 104 vs. 9 in lung, 97 vs. 20 in bladder, 67 vs. 41 in pancreas and 39 vs. 21 in colon, respectively.

Conclusions: The current data showed a correlation trend between UCK2 protein expression level and degree of antitumor activity of RX-3117 in xenograft models. It also supports a higher UCK2 protein expression level in human cancer tissues compared to their normal tissues. This suggests that RX-3117 activity may be specific to tumor tissue, and quantification of UCK2 expression in human cancer tissues may be useful as a predictive biomarker to select patients for their sensitivity to RX-3117 in future clinical studies.

Citation Format: Young Bok B. Lee, Deog J. Kim, Christina George, Chang-ho Ahn, Julie Frank, Reza Mazhari, Lisa M. Dauffenbach, Eric P. Olsen. Evaluation of UCK2 protein expression as a potential predictive biomarker of RX-3117 [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 1790. doi:10.1158/1538-7445.AM2017-1790
Abstract 1800: Noninvasive approach to assess metastatic lesion of advanced colorectal cancer by denoised deep target sequencing
Authors: Kang Jun-Kyu , Kim Hwang-Phill , Cheon Seul-Ki , Park Ye-Lim , Lim Yoojoo , Han Sae-Won , Kim Tae-You
Published: July 2017

The cell-free DNA (cfDNA) represents a minimally invasive and alternative source of tumor DNA for molecular profiling. Despite next-generation sequencing (NGS) technique is qualified for genotyping cancer using cfDNA as a noninvasive method, it has caused problems as sequencing error and reproducibility. cfDNA in plasma and gDNA of Peripheral Blood Mononuclear Cells (PBMC) were isolated from each 54 advanced colorectal cancer patients. 39 available tumor tissues were isolated from same patients. Deep target-sequencing was performed with paired-end library enriched exons of 10 genes which are recurrently mutated in colorectal cancer. To reduce sequencing error, we devised ‘Denoising’ and calculated concordance of somatic variants between cfDNA and tumor tissue sequencing data. In addition, correlation of concordance data was analyzed with the clinical information. As a result, we selectively could detect clinically important somatic alteration among low/high variant allele frequency (0.31%~79.42%). For somatic alteration of 10 genes, sensitivity, specificity and accuracy were increased from 84.5%, 74.6% and 76.9% to 87.6%, 92.0% and 91.1% respectively after ‘Denoising’. On the other hand, patients with high cfDNA concentration(>50ng/ml) had higher somatic mutant fragments and larger metastatic lesion in liver than patients who have low cfDNA concentration. Our study showed that denoised deep target-sequencing is a suitable method for cfDNA genotyping and provides insights into strategies for monitoring metastatic lesion of advanced colorectal cancer.

Citation Format: Jun-Kyu Kang, Hwang-Phill Kim, Seul-Ki Cheon, Ye-Lim Park, Yoojoo Lim, Sae-Won Han, Tae-You Kim. Noninvasive approach to assess metastatic lesion of advanced colorectal cancer by denoised deep target sequencing [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 1800. doi:10.1158/1538-7445.AM2017-1800
Abstract 1824: Endothelial mTORC2 deficiency inhibits tumor angiogenesis, tumor progression and metastasis in non-small cell lung cancer (NSCLC)
Authors: Wang Shan
Published: July 2017

Vascular endothelial cells (ECs) are specialized components of the tumor microenvironment that orchestrates tumor growth and invasion. They form tumor-associated blood vessels (angiogenic) that supply nutrients and oxygen, remove waste products, and also provide an entry site for tumorigenic cells to spread to secondary sites in various organs. One of the major signaling events in tumor vessels is PI3K/PDK-AKT-mTOR activation. mTOR is a serine/threonine kinase that functions in two distinct complexes, mTORC1 and mTORC2,which regulate a diverse array of cellular processes including cell growth, survival and metabolism. Although mTORC1, and to lesser extent, mTORC2, has been broadly studied in cancers and diseases, little is known regarding the relative contributions of mTORC1 versus mTORC2 in tumor endothelium. Using mouse model of endothelium-specific Rictor (a mTORC2 specific cofactor) gene targeting, we discovered that endothelial Rictor deletion decreased tumor neovascularization, suppressed tumor growth, and prevented metastasis in vivo. Direct co-culture of endothelial cells and NSCLC tumor cells in vitro showed that knockdown of endothelial Rictor inhibited tumor cell proliferation while Raptor (a mTORC1 specific cofactor) depletion had a modest effect. However, loss of endothelial Rictor or Raptor both markedly decreased tumor cell extravasation in response to endothelial cells, and also inhibited tumor spheroid formation in a direct co-culture system. Furthermore, a screen of phospho-kinase arrays revealed that Raptor or Rictor depletion in endothelial cells decreased various phosphor-RTKs in tumor cells that were co-cultured with ECs, including members of the Eph receptor family, Insulin receptor family and FGF receptor family. Additionally, endothelial Rictor knockdown suppressed phosphorylation levels of nerve growth factor receptors TrkB and TrkC in tumor cells. Collectively, these data suggest that endothelial mTORC1 and mTORC2 play critical roles in regulating tumor progression through distinct signaling pathways.

Note: This abstract was not presented at the meeting.

Citation Format: Shan Wang. Endothelial mTORC2 deficiency inhibits tumor angiogenesis, tumor progression and metastasis in non-small cell lung cancer (NSCLC) [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 1824. doi:10.1158/1538-7445.AM2017-1824
Abstract 1827: Using Drosophila to study the role of metabolic enzyme mutations in glioblastoma and leukemia
Authors: Fabiano Julia , Chiaramida Gabriela , Magner Mira , O'Connor Meghan , Stallone Joseph , DiDuca Nicholas , Neville Kathryn , Tartarini Richard , Tipping Marla
Published: July 2017

Metabolic reprogramming is a common hallmark shared by nearly all proliferating cancer cells, and thus has emerged as an exciting new direction in cancer research. Many signaling pathways have been implicated in mechanisms leading to the shift of metabolic programs in tumors, but more recently a small number of metabolic enzymes have also been identified in this process. Genes encoding the metabolic enzymes Isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) were found to be mutated in up to 70% of low-grade and medium grade gliomas, and in 15-20% of adult acute leukemia samples. These findings were the first to link the IDH gene to tumorigenesis. IDH1 and IDH2 function to irreversibly catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG). We are studying how mutations in IDH affect the metabolism and cellular processes of the cell. To this end, we have expressed IDH-R132H in Drosophila glial cells and hemoctyes to learn more about the impact of neomorphic activity of IDH in gliobastoma and chronic myeloid leukemia. We have verified that these cells now produce 2-HG, as is known in human tumors harboring IDH mutations. We have observed different cellular responses to IDH mutations in glia versus hemoctyes and have begun to investigate why this may be. Ultimately, the goal of our research is to elucidate the mechanism(s) that cause IDH to contribute to oncogenic activity in specific tissues, and use this knowledge to design tailored therapeutics.

Citation Format: Julia Fabiano, Gabriela Chiaramida, Mira Magner, Meghan O'Connor, Joseph Stallone, Nicholas DiDuca, Kathryn Neville, Richard Tartarini, Marla Tipping. Using Drosophila to study the role of metabolic enzyme mutations in glioblastoma and leukemia [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 1827. doi:10.1158/1538-7445.AM2017-1827
Abstract 1830: Targeted inhibition of EGFR and glutaminase induces metabolic crisis in EGFR mutant lung cancer
Authors: Momcilovic Milica , Bailey Sean T. , Lee Jason T. , Braas Daniel , Graeber Thomas G. , Works Melissa , Parlati Francesco , Demo Susan , Walser Tonya C. , Dubinett Steven M. , Sadeghi Saman , Christofk Heather , Shackelford David B.
Published: July 2017

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 1841: Characterization of neuronal alterations in a new mouse model of low grade glioma
Authors: Torres Daniela , Mela Angeliki , Sharma Sohani Das , Hornstein Nicholas , Sims Peter , Canoll Peter
Published: July 2017

Diffusely infiltrating gliomas are the most common type of primary brain tumor seen in adults. Patients with low grade glioma (LGG) can survive for many years, but often suffer from seizures and cognitive impairment, and these symptoms are associated with an unfavorable prognosis. Glioma cells diffusely infiltrate cortical tissue, where tumor cells aggregate around neuronal cell bodies, a growth pattern referred to as perineuronal satellitosis, however the effects of tumor cells on neurons has not been well defined. To address this important issue we generated a mouse model that recapitulates the genetic and histological features of diffusely infiltrating LGG. In our model tumor growth is driven by PDGFA overexpression and p53 deletion in a RiboTag-Camk2a-Cre transgenic mouse. The RiboTag system allows for the isolation and sequencing of ribosome-bound transcripts from Camk2a neurons to obtain a measure of transcription and translation. Our analysis in non-tumor bearing brains identified neuron-specific genes that are highly regulated at the level of translation. mTOR signaling regulates cell growth, proliferation, and translation in response to diverse stimuli. To characterize mTOR signaling in our model we used immunohistochemical staining of pS6 as a marker of mTOR activity and found that neurons within the glioma infiltrated cortex have lower levels of pS6 staining compared to neurons in the surrounding cortex. To further assess these results we are using the RiboTag system to identify alterations in neuronal transcription and translation that occur in our model during glioma formation and in response to mTOR targeted treatments. These studies will provide new insights into the neuronal alterations contributing to seizures and cognitive impairment in glioma and enable the identification of potential molecular targets for novel therapies to treat the devastating consequences of cortical dysfunctions associated with glioma.

Citation Format: Daniela Torres, Angeliki Mela, Sohani Das Sharma, Nicholas Hornstein, Peter Sims, Peter Canoll. Characterization of neuronal alterations in a new mouse model of low grade glioma [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 1841. doi:10.1158/1538-7445.AM2017-1841
Abstract 1867: Near infrared fluorescent imaging of brain tumor with IR780 dye incorporated phospholipid nanoparticles
Authors: Li Shihong , Johnson Jennifer , Peck Anderson , Xie Qian
Published: July 2017

Background: Near-IR fluorescence (NIRF) imaging is becoming a promising approach in preclinical tumor detection and clinical image-guided oncological surgery. While heptamethine cyanine dye IR780 has excellent tumor targeting and imaging potential, its hydrophobic properties limit its clinical use. In this study, we developed nanoparticle formulations to facilitate the use of IR780 for fluorescent imaging of malignant brain tumor.

Methods: Self-assembled IR780-liposomes and IR780-phospholipid micelles were prepared and their NIRF properties were characterized. The intracellular accumulation of IR780-nanoparticles in glioma cells were determined using confocal microscopy. The in vivo brain tumor targeting and NIRF imaging capacity of IR780-nanoparticles were evaluated using U87MG glioma ectopic and orthotopic xenograft models and a spontaneous glioma mouse model driven by RAS/RTK activation.

Results: The loading of IR780 into liposomes or phospholipid micelles was efficient. The particle diameter of IR780-liposomes and IR780-phospholipid micelles were 95 nm and 26 nm, respectively. While stock solutions of each preparation were maintained at ready-to-use condition, the IR780-phospholipid micelles were more stable. In tissue culture cells, IR780-nanoparticles prepared by either method accumulated in mitochondria, however, in animals the IR780-phospholipid micelles showed enhanced intra-tumoral accumulation in U87MG ectopic tumors. Moreover, IR780-phospholipid micelles also showed preferred intracranial tumor accumulation and potent NIRF signal intensity in glioma orthotopic models at a real-time, non-invasive manner.

Conclusion: The IR780-phospholipid micelles demonstrated tumor-specific NIRF imaging capacity in glioma preclinical mouse models, providing great potential for clinical imaging and image-guided surgery of brain tumors.

Citation Format: Shihong Li, Jennifer Johnson, Anderson Peck, Qian Xie. Near infrared fluorescent imaging of brain tumor with IR780 dye incorporated phospholipid nanoparticles [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 1867. doi:10.1158/1538-7445.AM2017-1867
Abstract 1868: Molecular imaging of human esophageal cancer for early detection
Authors: Ma Xibo , Meng Hui , Tian Jie
Published: July 2017

Esophageal cancer was the sixth common cancer for incidence and ranks fourth for death rate in China, and squamous cell carcinoma is the main histological type. It is usually in an advanced stage at the time of diagnosis, resulting in an overall 5-year survival rate of <15%. Early detection can lead to an improvement in patient outcomes but is limited by nonspecific contrast mechanisms. As all we know, antibody and peptides establish a biological basis for image contrast, which could achieve sufficient target-to-background ratio for in vivo detection. In this paper, an EGFR antibody (Cetuximab) conjugated with an NIR dye (NIRDye800) was used for early detection of esophageal cancer. We demonstrated our technology could identify esophageal cancer in small size (<1 mm) and high-grade dysplasia from low-grade dysplasia. And 4.2-fold greater fluorescence intensity for esophageal cancer compared with surrounding normal esophageal tissues. No toxicity was observed in our experiments. The result indicated that this targeted, antibody-based imaging agents have great potential in early detection of esophageal cancer and other epidermal cancer.

Citation Format: Xibo Ma, Hui Meng, Jie Tian. Molecular imaging of human esophageal cancer for early detection [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 1868. doi:10.1158/1538-7445.AM2017-1868
Abstract 1877: Coordination of Rac1 and Cdc42 by centrosomal microtubules in focal adhesion dynamics and directed cell migration
Authors: Kuo Jean-Cheng
Published: July 2017

Cancer metastasis causes the increase of mortality in most cancer patients, and abnormal cell migration contributes to this disease progression. To control cell migration, the dynamical control of a protein complex within focal adhesions has to be regulated appropriately. It is known that focal adhesions can be regulated dynamically by microtubules. To examine the effects of centrosomal microtubules and non-centrosomal microtubules in regulating focal adhesion dynamics and directed cell migration, we first generated centrosome-deficient cells. We find that centrosomal microtubules and non-centrosomal microtubules control focal adhesion dynamics through modulating focal adhesion composition, which dynamically control the activity of small GTPases Rac1 and Cdc42. Deficiency of centrosomal microtubules significantly disrupts the balance of Rac1 and Cdc42, thereby inhibiting directed cell migration. This study reveals the effects of centrosome in focal adhesions, and indicates an important role for Rac1 and Cdc42 activation that controls actin polymerization, cell polarization and directed cell migration.

Citation Format: Jean-Cheng Kuo. Coordination of Rac1 and Cdc42 by centrosomal microtubules in focal adhesion dynamics and directed cell migration [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 1877. doi:10.1158/1538-7445.AM2017-1877
Abstract 1879: Transcriptional regulation of KAI1 by p73 in colorectal cancer metastasis
Authors: Bae Woo Kyun , Yoo Kyung Hyun , Kang Keunsoo , Hennighausen Lothar , Chung Ik-Joo
Published: July 2017

Background: p73 is a member of the p53 family transcription factors and known tumor suppressor. However, its transcriptional activity is complex owing to its multiple isoforms, and limited information is available regarding the transcriptional and functional regulation of the p73 gene in colorectal cancer. In this study, we examined the role of p73 in colorectal cancer.

Methods: We established a TAp73 overexpressing cell line using the Tet-on inducible expression system and analyzed global RNA expression by RNA-sequencing (RNA-seq). We studied the effects of TAp73 expression on the migration, invasiveness, and EMT of colon cancer cells. We conducted experiments in animals with liver metastasis of colorectal cancer. To investigate the roles of p73 in colon cancer, we examined the samples from patients, who had undergone surgical resection for colorectal cancer between 2009 and 2013. mRNA expression of TAp73 and KAI1 was analyzed in 108 colorectal cancer specimen and adjacent non-cancerous tissues by real-time RT-PCR.

Results: RNA-seq showed the association between TAp73 and KAI1 expression. Migration and invasiveness of colon cancer cells were reduced by TAp73 expression, but induced by KAI1 knockdown. TAp73 regulates KAI1 expression in colon cancer cell lines. TAp73-induced decrease in invasiveness and epithelial-mesenchymal transition (EMT) was abrogated by KAI1 knockdown in TAp73 overexpressing cells. Migration ability of TAp73 overexpressing cells was recovered by KAI1 knockdown. Hepatic metastases were significantly reduced in mice injected with TAp73 overexpressing cells and increased in those injected with TAp73 overexpressing cells with KAI1 knockdown. mRNA expression of TAp73 and KAI1 was higher in colorectal cancer tissues than in adjacent non-cancerous tissues. Significant correlation between TAp73 and KAI1 mRNA expression was detected in early stage primary colorectal cancer, but not in the advanced stage.

Conclusions: This study suggests that p73 (TAp73) acts as a tumor suppressor in the progression of colorectal cancer and regulates the expression of KAI1, which is a key target of p73 in colorectal cancer liver metastases.

Note: This abstract was not presented at the meeting.

Citation Format: Woo Kyun Bae, Kyung Hyun Yoo, Keunsoo Kang, Lothar Hennighausen, Ik-Joo Chung. Transcriptional regulation of KAI1 by p73 in colorectal cancer metastasis [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 1879. doi:10.1158/1538-7445.AM2017-1879
Abstract 1886: mGluR1 drives invasion of proneural subtype of glioblastoma cells
Authors: Gladwin Alena , Peng Sen , Kiefer Jeff , Kim Seugchan , Berens Michael , Dhruv Harshil D.
Published: July 2017

A major cause for the therapeutic failure and subsequent morbidity and mortality of glioblastoma (GBM) is the aggressive invasion of malignant cells into the surrounding normal brain that effectively renders complete surgical resection impossible and virtually assures recurrent tumor growth. Multi-omic profiling of GBM led to their molecular sub-classification into two distinct molecular subtypes: proneural (PN) and mesenchymal (MES). However, very little is known about shared or distinct invasion processes of cells in these genomically different subtypes. Using Microarray gene expression profiles of microdissected paired stationary core and invasive rim samples from 19 patients, we demonstrated that invasive gene signature of MES subtypes differs from PN. Specifically, using three orthogonal but intersecting bioinformatic approaches, i.e. gene set variation analysis, causal network analysis, and iRegulon analysis; we discovered that genes differentially expressed between PN core and rim could, to a meaningful degree, be accounted for based on their annotation as “regulated by the transcription factor REST”. REST functions as a repressor of gene expression. Of the genes repressed by REST, mGluR1 (Metabotropic Glutamate Receptor 1) was significantly overexpressed at the rim of PN glioma cells as compared to the core. Finally, we also investigated the role of mGluR1 in glutamate induced glioma cell migration; our results show that glutamate stimulates migration of proneural-like glioma cells (A172) as compare to non-proneural-like glioma cell (T98G). mGluR1 activation by glutamate has shown to induce activation of Pyk2 and Src in astrocytes; knockout of mGluR1 is not embryonic lethal. In summary, our data demonstrate that glutamate-induced glioma cell migration of PN subtype of GBM is dependent on mGluR1 and thus raises the prospect that therapeutic targeting of mGluR1 may be a novel approach to controlling the invasion of this deadly disease.

Citation Format: Alena Gladwin, Sen Peng, Jeff Kiefer, Seugchan Kim, Michael Berens, Harshil D. Dhruv. mGluR1 drives invasion of proneural subtype of glioblastoma 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 1886. doi:10.1158/1538-7445.AM2017-1886
Abstract 1916: Peptidylarginine deiminase IV (PADI4) is a novel tumor suppressor that may contribute to regulation of breast cancer stem cell dynamics
Authors: Moshkovich Nellie
Published: July 2017

Breast cancer is a global problem that accounts for almost a fourth of all cancers in women. Despite the many therapeutic strategies currently in use, treated patients often suffer from cancer relapse and metastasis due to the presence of a subpopulation of tumorigenic cells capable of self-renewal and termed cancer stem cells (CSCs). To address the properties of this critical sub-population, we utilized our recently-developed lentiviral CSC reporter carrying an Oct4/Sox2 response element coupled to a green fluorescent protein (SORE6-GFP) to detect and isolate the CSC population in a low-grade ER+ human breast cancer model, MCF10Ca1h, by FACS. Whole transcriptome sequencing analysis (RNA-seq) on the sorted cells identified Peptidylarginine deiminase IV (PADI4) as differentially expressed between CSCs and non-CSCs. PADI4 was recently shown to regulate citrullination of histone H1, displacing it from chromatin and resulting in global chromatin decondensation and pluripotency induction in embryonic stem cells (Christophorou, et al., 2014, Nature 507:104). Thus, we hypothesized that PADI4 may also regulate the stemness phenotype in breast cancer CSCs, likely through effects on chromatin structure. We showed that PADI4 protein expression is higher in luminal breast cancer cell lines than other subtypes, and we did shRNA knockdown (KD) of PADI4 in the luminal MCF10Ca1h model. PADI4 KD increased tumorosphere formation and clonogenicity indicating increased CSC population/activity. Additionally, MCF10Ca1h cells treated with a PADI4 selective inhibitor showed an increase in CSCs as assessed using the SORE6-GFP stem cell reporter. In vivo limiting dilution studies demonstrate that PADI4 KD increased tumor incidence at low cell inoculum, reflecting a statistically significant 2-4 fold increase in CSCs upon PADI4 KD. Our findings suggest that PADI4 may function as a tumor suppressor in luminal breast cancer. In support of this conclusion, deep deletions of PADI4 locus are found in 1% of human breast cancers in the TCGA datasets. Analysis of the effect of PADI4 KD on chromatin organization in the CSC and non-CSC compartments is ongoing.

Citation Format: Nellie Moshkovich. Peptidylarginine deiminase IV (PADI4) is a novel tumor suppressor that may contribute to regulation of breast cancer stem cell dynamics [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 1916. doi:10.1158/1538-7445.AM2017-1916
Abstract 1922: S-SHIP promoter expression identifies a putative cancer stem cell population in C3(1)/Tag murine mammary tumors
Authors: Tian Lu , Lagadec Chann , Adriaenssens Eric , Bouchaert Emmanuel , Roy Hélène Bauderlique-Le , LeBourhis Xuefen , Bourette Roland P.
Published: July 2017

Breast cancer is the most common cancer in women worldwide. The isolation and characterization of breast cancer stem cells (CSC) are crucial for understanding cancer biology and revealing potential therapeutic targets. One of the major issues in the study of CSC is the lack of reliable markers. A transgenic mouse model (Tg 11.5kb–GFP) was generated using the 11.5kb s-SHIP (stem-SH2-containing 5’-Inositol Phosphatase) promoter that specifically expressed enhanced green fluorescent protein (GFP) in embryonic and various tissue stem cells. In the mammary gland, previous experiments showed that GFP labels puberty cap cells and pregnancy basal alveolar bud cells, and it has been demonstrated that these mammary GFP+ cells are activated tissue stem cells. In order to determine if s-SHIP promoter expression could also mark mammary cancer stem cells, we generated a bi-transgenic mouse model by crossing Tg 11.5kb-GFP mice with Tg C3(1)/Tag mice. Tg C3(1)/Tag mice express SV40 T antigen under the regulatory control of the rat prostatic steroid binding protein C3(1) gene. In female mice, the transgene is expressed primarily in the mammary gland. Mice develop mammary hyperplasia by 3 months of age with subsequent development of mammary adenocarcinoma by 6 months of age.

Here we show the presence of a rare population of GFP+ cells in mammary tumors of female bi-transgenic mice by using immunohistochemical and flow cytometry analysis. The GFP+ mammary cancer cells are also CD24+/CD49f+/CD29+. As compared to GFP- cells, GFP+ cells exhibit both a higher tumor sphere-forming potential, and a higher tumorigenicity when transplanted into SCID and FVB recipient mice. Moreover, upon subsequent transplantation, the GFP+ cells generated heterogeneous tumors that displayed properties similar to the primary tumor. Currently, we are conducting transcriptomic analysis of these GFP+ and GFP- cells in order to reveal differentially expressed genes. Altogether, these results suggest that s-SHIP promoter expression may be a new marker of mammary CSC that enables their identification and isolation via a single consistent parameter. Furthermore, our bi-transgenic C3(1)/Tag x 11.5kb-GFP mice provide a novel model for study of mammary cancer stem cells and investigation of potential therapeutic targets for breast cancer.

Citation Format: Lu Tian, Chann Lagadec, Eric Adriaenssens, Emmanuel Bouchaert, Hélène Bauderlique-Le Roy, Xuefen LeBourhis, Roland P. Bourette. S-SHIP promoter expression identifies a putative cancer stem cell population in C3(1)/Tag murine mammary 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 1922. doi:10.1158/1538-7445.AM2017-1922
Abstract 1955: Targeting ribonucleotide reductase (RNR) in Ewing sarcoma
Authors: Goss Kelli , Koppenhafer Stacia , Harmoney Kathryn , Gordon David
Published: July 2017

Ewing sarcoma is a highly aggressive bone and soft tissue cancer that is caused by the EWS-FLI1 fusion protein. The EWS-FLI1 oncoprotein functions, in part, as an aberrant transcription factor and is required for tumor growth and survival. In order to identify downstream targets of EWS-FLI1, we used human embryonic stem cells that express inducible EWS-FLI1 to model the initiation and development of Ewing sarcoma in a genetically defined system. We then used this model system and a gene expression based approach to identify that Ewing sarcoma cells are uniquely vulnerable to inhibitors of ribonucleotide reductase (RNR), which impair DNA replication by blocking the synthesis of deoxyribonucleotides. Here we report that the treatment of Ewing sarcoma cells with gemcitabine, an irreversible inhibitor of the RRM1 subunit of RNR, results in impaired DNA replication, cell cycle arrest, and apoptosis in Ewing sarcoma cells. Additionally, we have found that the effect of gemcitabine on the viability of Ewing sarcoma cells is sustained even after removal of the drug from the cell culture medium. Moreover, ataxia telangiectasia and rad3-related protein (ATR) and checkpoint kinase 1 (CHK1) inhibitors increase the toxicity of gemcitabine in Ewing sarcoma cells by blocking the adaptive response to impaired DNA replication. Currently, ongoing work is focused on the in vivo testing of gemcitabine, alone and in combination with CHK1 and ATR inhibitors, as a novel therapeutic approach for the treatment of Ewing sarcoma.

Citation Format: Kelli Goss, Stacia Koppenhafer, Kathryn Harmoney, David Gordon. Targeting ribonucleotide reductase (RNR) in Ewing sarcoma [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 1955. doi:10.1158/1538-7445.AM2017-1955
Abstract 1959: MTA1 promotes tumor progression and bone metastasis in prostate cancer via positive regulation of MUC1 and CTSB
Authors: Kumar Avinash , Dhar Swati , Campanelli Gisella , Butt Nasir A. , Gomez Christian R. , Schallheim Jason M. , Levenson Anait S.
Published: July 2017

About 80% of the time that prostate cancer cells metastasize, they spread to the bones. Metastasis involves activation of invasive programs through genetic and epigenetic alterations, including changes in expression of chromatin remodeler proteins. We have previously identified metastasis-associated protein 1 (MTA1), a chromatin remodeler, as a component of vicious cycle of bone metastasis and confirmed significantly higher expression of MTA1 in bone metastatic samples from patients. In an attempt to dissect molecular mechanisms of MTA1 action, we performed integrative analysis of our bone metastasis signature data along with MTA1 ChIP-Seq data, which revealed mucin 1 (MUC1) and cathepsin B (CTSB) as strong potential candidates responsible for MTA1-driven invasiveness.Here, we show that loss of function studies with MTA1 in PC3M cells exhibit reduced expression for MUC1 and CTSB. We also demonstrate that depletion of MTA1 in PC3M aggressive prostate cancer cellsdoes not affect cell proliferation but leads to decrease in colony forming ability, invasive and migratory property of these cells. When PC3M cells silenced for MTA1 and tagged with luciferase are used to generate subcutaneous or intracardiac xenografts, it leads to reduced tumor progression or decreased metastasis to bone, respectively as evident by bioluminescent measurements and histology of tumors. Ongoing experiments aim to validate the role of MUC1 and CTSB in MTA1-driven invasiveness and metastasis in prostate cancer.

Citation Format: Avinash Kumar, Swati Dhar, Gisella Campanelli, Nasir A. Butt, Christian R. Gomez, Jason M. Schallheim, Anait S. Levenson. MTA1 promotes tumor progression and bone metastasis in prostate cancer via positive regulation of MUC1 and CTSB [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 1959. doi:10.1158/1538-7445.AM2017-1959