bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1994: Smurf2 mediates ubiquitination and degradation of YY1 to suppress B-cell proliferation and lymphomagenesis.
Authors: Ramkumar Charusheila , Cui Hang , Kong Yahui , Jones Stephen , Gerstein Rachel , Zhang Hong
Published: August 2014

Current treatment of diffuse large B-cell lymphoma (DLBCL), the most common type of non-Hodgkin's lymphoma, has improved patient survival significantly. However, 40-50% of DLBCL patients still die from this disease. There is a critical need to better understand the specific molecular pathways that are perturbed in DLBCL for the development of new and effective therapeutic approaches. We show that mice deficient in the E3 ubiquitin ligase Smurf2 spontaneously develop B-cell lymphomas that resemble human DLBCL with molecular features of germinal center B cells. We discover that Smurf2 mediates ubiquitination and degradation of YY1, a key germinal center transcription factor. Importantly, Smurf2 deficiency enhances YY1-mediated transactivation of c-Myc and B-cell proliferation. Furthermore, the expression of Smurf2 is significantly decreased in primary human DLBCL samples compared to normal B cells, and low levels of Smurf2 expression correlate with poor survival prognosis in DLBCL patients. The Smurf2-YY1-c-Myc regulatory axis represents a novel pathway perturbed in DLBCL that suppresses B-cell proliferation and lymphomagenesis, suggesting Smurf2 as a new therapeutic paradigm for DLBCL.

Citation Format: Charusheila Ramkumar, Hang Cui, Yahui Kong, Stephen Jones, Rachel Gerstein, Hong Zhang. Smurf2 mediates ubiquitination and degradation of YY1 to suppress B-cell proliferation and lymphomagenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1994. doi:10.1158/1538-7445.AM2013-1994

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 1995: GKN1-miR-185-DNMT1 axis suppresses gastric carcinogenesis through regulation of epigenetic alteration and cell cycle.
Authors: Yoon Jung Hwan , Choi Won Suk , Park Won Sang , Kim Olga
Published: August 2014

Gastrokine 1 (GKN1) functions to protect the gastric antral mucosa and promotes healing by facilitating restitution and proliferation after injury. GKN1 is down-regulated in Helicobacter pylori-infected gastric epithelial cells and that loss of GKN1 expression is tightly associated with gastric carcinogenesis, but underlying mechanisms as tumor suppressor are largely unknown. In the present study, we demonstrated that restoration of GKN1 protein suppressed gastric cancer cell growth by inducing endogenous miR-185 that directly targets epigenetic effectors, DNMT1 and EZH2 in gastric cancer cells. Notably, GKN1 expression was inversely correlated with DNMT1 and EZH2 expression in a subset of gastric cancer tissues and various gastric cancer cell lines. In addition, ectopic expression of GKN1 suppressed histone deacetylase 1 and thereby induced cell cycle arrest via regulating cell cycle proteins in gastric cancer cells. Interestingly, it was found that regulatory domains of the GKN1, pGKN1D13N, pGKN1▵68-199 and pGKN1▵1-67, 165-199 recapitulated GKN1 functions, and GKN1 exerted synergistic anti-cancer effect with 5-FU on tumor cell growth implying that the amino-terminal regulatory motif and brichos domain of GKN1 are sufficient for its tumor suppressor activities and thereby suggesting therapeutic intervention of gastric cancer. Collectively, our results demonstrated that loss of GKN1 functions occur and that cause aberrant expression of DMNT1 and EZH2 by suppression of endogenous miR-185 contributing malignant gastric epithelial cell proliferation and transformation in gastric carcinogenesis.

Citation Format: Jung Hwan Yoon, Won Suk Choi, Won Sang Park, Olga Kim. GKN1-miR-185-DNMT1 axis suppresses gastric carcinogenesis through regulation of epigenetic alteration and cell cycle. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1995. doi:10.1158/1538-7445.AM2013-1995
Abstract 1999: A targeted exome sequencing platform for routine clinical molecular profiling of advanced thoracic malignancies relevant to targeted therapy.
Authors: Lau Christopher C. , Killian Keith , Zhu Yuelin J. , Wang Yonghong , Pineda Marbin , Thomas Anish , Wang Yisong , Morrow Betsy , Xi Liqiang , Raffeld Mark , Giaccone Giuseppe , Meltzer Paul S.
Published: August 2014

Increasing number of oncogenic mutations important to the clinical management of advanced thoracic malignancies is being identified. To translate this into routine clinical testing environment, we developed and validated a targeted exome sequencing method using next generation sequencing (NGS) technology that is designed to detect both single nucleotide variants and short insertions or deletions (indels) by employing a custom designed target selection system. In each individual assay, 197 cancer related genes, including 12 clinically relevant genes (AKT1, AKT2, BRAF, EGFR, ERBB2, HRAS, KIT, KRAS, MEK1, NRAS, PIK3CA, and PTEN) are simultaneously sequenced from 100-500ng of total DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue. To date, we have performed this assay on over 250 FFPE tissues from Non-Small-Cell Lung Cancers (NSCLC), Small-Cell Lung Cancers (SCLC), and thymic malignancies. Mutations in all 12 clinically relevant genes including EGFR L858R, KRAS codon 12 missense mutations as well as EGFR exon 19 deletions, EGFR exon 20 insertions, and ERBB2 exon 20 insertions have been identified and validated with alternate technology in approximately 30% of all samples tested. Compared with conventional capillary sequencing, which typically requires in excess of 25% mutant DNA, this assay can detect mutations with 5% - 10% mutant allele frequency. This is a robust, reliable and cost effective assay that not only is suitable for prospective molecular profiling of clinically relevant targets, but also provides a powerful tool for retrospective analysis of existing FFPE tissues from clinical trials.

Citation Format: Christopher C. Lau, Keith Killian, Yuelin J. Zhu, Yonghong Wang, Marbin Pineda, Anish Thomas, Yisong Wang, Betsy Morrow, Liqiang Xi, Mark Raffeld, Giuseppe Giaccone, Paul S. Meltzer. A targeted exome sequencing platform for routine clinical molecular profiling of advanced thoracic malignancies relevant to targeted therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1999. doi:10.1158/1538-7445.AM2013-1999
Abstract 200: EGCG inhibits pancreatic cancer stem cell characteristics in human primary tumors, and carcinogenesis in KrasG12D transgenic mice.
Authors: Marsh Luke , Tang Su-Ni , Nall Dara , Jackman Chris , Shankar Sharmila , Srivastava Rakesh K.
Published: August 2014

EGCG, a component of green tea, exerts antiproliferative and proapoptotic actions on a number of different cancer cell lines through diverse mechanisms. However, the mechanisms by which EGCG inhibits cell proliferation and induces apoptosis are poorly understood. The objectives of this study were to examine the molecular mechanisms by which EGCG inhibits stem cell characteristics of pancreatic cancer stem cells (CSCs) derived from human primary tumors and carcinogenesis in KrasG12D transgenic mice. Human pancreatic CSCs (CD133+CD44+CD24+ESA+) are highly tumorigenic and form subcutaneous tumors in NOD/SCID IL2R gamma mice. Human pancreatic CSCs expressing high levels of CD133, CD24, CD44, ESA, and aldehyde dehydrogenase also express significantly more Nanog, Oct-4, Notch1, MDR1 and ABCG2 than normal pancreatic tissues and primary pancreatic cancer cells. Similarly, CSCs from KrasG12D mice express significantly high levels of pluripotency maintaining factors than pancreatic tissues from Pdx-Cre mice. EGCG inhibits the growth (size and weight) and development (PanIN lesions) of pancreatic cancer in KrasG12D mice by suppressing the activation of Kras, ERK, AKT and FoxO. EGCG inhibits the self-renewal capacity of pancreatic CSCs derived from human primary tumors and KrasG12D mice. EGCG inhibits pluripotency maintaining factors (Nanog, Sox-2, c-Myc and Oct-4) and drug resistance gene ABCG2 in CSCs. Inhibition of Nanog by shRNA enhances the inhibitory effects of EGCG on self-renewal capacity of CSCs. Finally, EGCG inhibits CSC's migration and invasion and markers of epithelial-mesenchymal transition (Zeb-1, Slug and Snail). These data suggest that EGCG can inhibit pancreatic cancer development in human and KrasG12D transgenic mice by inhibiting stem cell characteristics. In conclusion, EGCG can be used for the management of pancreatic cancer.

Citation Format: Luke Marsh, Su-Ni Tang, Dara Nall, Chris Jackman, Sharmila Shankar, Rakesh K. Srivastava. EGCG inhibits pancreatic cancer stem cell characteristics in human primary tumors, and carcinogenesis in KrasG12D transgenic mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 200. doi:10.1158/1538-7445.AM2013-200
Abstract 2000: Impact of delay to cryopreservation on RNA integrity and genome-wide expression profiles in resected tumor samples.
Authors: Le Calvez-Kelm Florence , Caboux Elodie , Paciencia Maria , Durand Geoffroy , Robinot Nivonirina , Wozniak Magdalena , Galateau-Salle Francoise , Byrnes Graham , Hainaut Pierre
Published: August 2014

Background: The quality of tissue samples and extracted mRNA is a major source of variability in tumor transcriptome analysis using genome-wide expression microarrays. During and immediately after surgical tumor resection, tissues are exposed to metabolic, biochemical and physical stresses characterized as “warm ischemia”. Current practice advocates cryopreservation of biosamples within 30 minutes of resection, but this recommendation has not been systematically validated by measurements of mRNA decay over time.

Methods: Using Illumina HumanHT-12 v3 Expression BeadChips, providing a genome-wide coverage of over 24,000 genes, we have analysed gene expression variation in samples of 3 hepatocellular carcinomas (HCC) and 3 lung carcinomas (LC) cryopreserved at times up to 2 hours after resection.

Results: RNA Integrity Numbers (RIN) revealed no significant deterioration of mRNA up to 2 hours after resection. Genome-wide transcriptome analysis detected non-significant gene expression variations of -2.4%/hr (95% CI: -5.5%/hr to 0.6%/hr; p=0.12). In LC, no consistent gene expression pattern was detected in relation with warm ischemia. In HCC, a signature of 6 up-regulated genes (CYP2E1, IGLL1, CABYR, CLDN2, NQO1, SCL13A5) and 6 down-regulated (MT1G, MT1H, MT1E, MT1F, HABP2, SPINK1) was identified (FDR <0.05).

Conclusions: Overall, our observations support current recommendation of time to cryopreservation of up to 30 minutes and emphasize the need for identifying tissue-specific genes deregulated following resection to avoid misinterpreting expression changes induced by warm ischemia as pathologically significant changes.

Citation Format: Florence Le Calvez-Kelm, Elodie Caboux, Maria Paciencia, Geoffroy Durand, Nivonirina Robinot, Magdalena Wozniak, Francoise Galateau-Salle, Graham Byrnes, Pierre Hainaut. Impact of delay to cryopreservation on RNA integrity and genome-wide expression profiles in resected tumor samples. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2000. doi:10.1158/1538-7445.AM2013-2000
Abstract 2004: International Cancer Genome Consortium (ICGC).
Authors: Hudson Thomas J. , Jennings Jennifer L.
Published: August 2014

The International Cancer Genome Consortium (ICGC) was established to bring together researchers from around the globe to comprehensively analyze the genomic, transcriptomic, and epigenomic changes in 50 different tumour types or subtypes that are of clinical and societal importance across the globe (International network of cancer genome projects. Nature 464, 993-998 (15 April 2010)).

As of October 2012, the ICGC has received commitments from researchers and funding organizations in Asia, Australia, Europe and North America for 47 project teams in 15 jurisdictions to study more than 21,000 tumour genomes. Over 23,000 tumours that meet ICGC requirements for consent have been obtained and over 20,000 samples have been approved by research pathologists as meeting ICGC standards. Raw datasets exist for > 10,000 tumours, including > 1,700 whole genome sequences, > 5,130 exomes, > 9,700 copy number alterations, > 4,900 transcriptomes (RNASeq) and over 6,600 methylomes. Processed data is available via the Data Coordination Centre (http://dcc.icgc.org) based at the Ontario Institute for Cancer Research and is updated bimonthly. The latest data release (Version 10) in October 2012 includes datasets from 33 ICGC members and five additional groups. In total, ICGC data release 10 comprises data from 7,022 cancer genomes.

In the next five years, ICGC will deliver on its initial and new objectives, including 1) sequencing a cumulative number of >25,000 tumour genomes from 50 or more tumour types, 2) improving data quality of ICGC datasets; 3) developing a scalable software infrastructure to support data management and cancer genome research; 4) streamlining data access mechanisms to accelerate usage and downstream discoveries without compromising the need to protect patient confidentiality; 5) coordinating cross-tumour analyses; 6) and training basic and clinician scientists to use ICGC datasets and tools. More information can be found on www.icgc.org

Citation Format: Thomas J. Hudson, Jennifer L. Jennings. International Cancer Genome Consortium (ICGC). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2004. doi:10.1158/1538-7445.AM2013-2004
Abstract 2013: Comprehensive genetic characterization of apocrine lesions of the breast.
Authors: Costa Jose L. , Justino Ana , Gomes Madalena , Alvarenga Cesar Augusto , Gerhard Renê , Vranic Semir , Gatalica Zoran , Machado Jose Carlos , Schmitt Fernando
Published: August 2014

Apocrine differentiation occurs in a variety of breast lesions, both benign and malignant. The molecular classification of breast cancer defined an apocrine molecular subtype of breast cancer. In general, apocrine carcinomas do not present clinical behavior distinct from the observed in ductal carcinomas of no special type. However, these carcinomas are frequently triple negative (ER-/PgR-/HER2-) with no targeted therapy and poor prognosis. Still they are unique in the aspect of the expression of a different nuclear receptor - androgen receptor (AR).

In this study we thought to perform a comprehensive genetic/molecular characterization of this type of lesions. For that, a series of 44 apocrine lesions were studied. These comprised 9 apocrine metaplasia, 8 apocrine adenosis, 13 apocrine in situ carcinoma and 18 apocrine invasive carcinoma. Importantly four samples contained different lesions in different stages in close proximity. Immunohistochemistry was performed to evaluate the ER, PgR, HER2 and AR status of these lesions. Genomic DNA was microdissected from FFPE slides and used both to identify chromosomal copy number aberrations using aCGH and to monitor 739 mutations from 46 oncogenes and tumor suppressor genes using the Ion PGM system.

The aCGH study allowed the identification of recurrent chromosomal aberrations. These were rare in benign apocrine lesions, mostly comprised of small gains and deletions, and dramatically increased in malignant lesions up to complete loss and gain of full chromosome arms. Also the analysis of the different lesions within the same sample indicates a putative existence of an apocrine tumor progression. Moreover the profiling of mutational status of the different tumor suppressor/oncogene allowed the identification of mutations that may provide new avenues for the development of new targetable therapeutically options and also corroborated the putative apocrine tumor progression.

The study of apocrine lesions in different differentiation stages allowed a deeper insight on the molecular complexity of these lesions. Although further studies are required to independently validate this work, this study identifies recurrent genomic alteration that may open targeted treatment opportunities that may be used independently or in combination with anti-androgen drugs.

Citation Format: Jose L. Costa, Ana Justino, Madalena Gomes, Cesar Augusto Alvarenga, Renê Gerhard, Semir Vranic, Zoran Gatalica, Jose Carlos Machado, Fernando Schmitt. Comprehensive genetic characterization of apocrine lesions of the breast. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2013. doi:10.1158/1538-7445.AM2013-2013
Abstract 2014: Gene expression profiling identifies characteristic oncogenetic pathways in age-related Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disorders.
Authors: Kato Harumi , Yamamoto Kazuhito , Karube Kennosuke , Takizawa Jun , Tsuzuki Shinobu , Yatabe Yasushi , Kanda Teru , Katayama Miyuki , Ozawa Yukiyasu , Ishitsuka Kenji , Okamoto Masataka , Kinoshita Tomohiro , Oshima Koichi , Nakamura Shigeo , Morishima Yasuo , Seto Masao
Published: August 2014

Age-related EBV-associated B-cell lymphoproliferative disorder (AR-EBVLPD) is newly classified as a subtype of diffuse large cell lymphoma (DLBCL) according to the WHO classification. AR-EBVLPD cases have poor prognosis compared to that of EBV-negative DLBCL patients. Until now, its molecular pathogenesis remains largely unknown. We investigated gene expression profiling to identify molecular genetic characterization of AR-EBVLPD. Total RNA was extracted from fresh-frozen tumor samples of five AR-EBVLPD and eight EBV-negative DLBCL cases. Expression profiling was studied using the Agilent 44K human oligonucleotide microarray. Genes highly expressed in AR-EBVLPD included inflammatory and immune-related genes. Gene set enrichment analysis and gene ontology analysis showed that gene sets of the JAK-STAT and NF-kB pathways were enriched in AR-EBVLPD cases. In vitro analysis showed that high activation of JAK-STAT and NF-kB pathways was induced by EBV infection into DLBCL cell lines. The immunoprecipitation assay confirmed that the NF-kB pathway was activated in EBV-infected cell lines compared to EBV-naïve cell lines. The protein expression level of phosphorylated STAT3 increased in an EBV-infected cell line according to western blot analysis. A total of 61 patients (25 AR-EBVLPD and 36 EBV-negative DLBCL) were analyzed immunohistochemically for pSTAT3. Protein expression of phospho-STAT3 was frequently observed in lymphoma cells of AR-EBVLPD clinical samples using immunohistochemistry [AR-EBVLPD: (80.0%, n=20/25) vs. EBV-negative DLBCL: (38.9%, n=22/36), p=0.001]. These results suggested that STAT3 and NF-kB activation was characteristic of AR-EBVLPD, which may reflect the nature of EBV-positive tumor cells. Targeting these pathways as therapies might improve clinical outcomes of AR-EBVLPD.

Citation Format: Harumi Kato, Kazuhito Yamamoto, Kennosuke Karube, Jun Takizawa, Shinobu Tsuzuki, Yasushi Yatabe, Teru Kanda, Miyuki Katayama, Yukiyasu Ozawa, Kenji Ishitsuka, Masataka Okamoto, Tomohiro Kinoshita, Koichi Oshima, Shigeo Nakamura, Yasuo Morishima, Masao Seto. Gene expression profiling identifies characteristic oncogenetic pathways in age-related Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disorders. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2014. doi:10.1158/1538-7445.AM2013-2014
Abstract 2015: BRCA1 expression and genomic aberrations in triple negative breast tumors.
Authors: Tapia Teresa , Aravena Andrés , Alvarez Carolina , Cornejo Valeria , Fernandez Wanda , Camus Mauricio , Maass Alejandro , Carvallo Pilar
Published: August 2014

Among breast cancer tumors, a group named as triple-negative breast cancer (TNBC) which do not express hormone receptors and HER2 (ER-, PR-, HER2-) do not have specific therapy. Therefore, knowing the genes involved in this type of tumor is highly relevant for treatment. Intense research in these tumors has been performed in order to identify new targets. We studied 48 TNBC tumors from Chilean patients by different approaches. In these tumors, we determined the expression, by immunohistochemistry, the different cytokeratins (CK5, CK14, and CK8/18) and EGFR. In addition, we analyzed BRCA1 expression and localization by immunohistochemistry. Using array-CGH, we characterized the genomic aberrations, in order to identify common alterations between tumors. A 62.5% (30/48) of the tumors were classified as basal-like. Expression and localization of BRCA1 analysis revealed that a 22.9% (11/48) of tumors presented normal expression of nuclear BRCA1, a 29.2% (14/48) has low or absent nuclear expression and a 47.9% (23/48) has altered BRCA1 localization, in addition to low expression in some cases. This suggests that the loss of expression of BRCA1 or its altered localization may be relevant for tumor progression. Analysis of genomic alterations by array-CGH revealed regions of gain (4p16.3-p16.2, 7p22.3-p22.2, 11p15.5, 19p13.3) and deleted regions (1q21.1, 6p11.2; 11q22.3) shared by more than 30% of these tumors. By grouping these tumors we identified three main groups, one of which correlates with the low expression / miss-localization of BRCA1. An analysis of the genes contained in these regions can determine the signaling pathways relevant to the progression of breast cancer. In this regard, by clustering, we identified a group of TNBC tumors (17/48) with amplification of AKT1, which may be relevant as a therapeutic target. FONDECYT 1080595, CONICYT 24091058.

Citation Format: Teresa Tapia, Andrés Aravena, Carolina Alvarez, Valeria Cornejo, Wanda Fernandez, Mauricio Camus, Alejandro Maass, Pilar Carvallo. BRCA1 expression and genomic aberrations in triple negative breast tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2015. doi:10.1158/1538-7445.AM2013-2015
Abstract 202: Tocopherols inhibit the dietary carcinogen PhIP-induced prostate carcinogenesis in a CYP1A-humanized mouse model.
Authors: Li Guangxun , Wang Hong , Liu Anna B. , Chen Jayson X. , Lee Mao-Jung , Yang Chung S.
Published: August 2014

γ-TmT, a tocopherol mixture that is rich in γ-tocopherol (γ-T), containing 56.8% γ-T, 24.3% δ-T, 13.0% α-T and 1.5% β-T, has been shown to inhibit colon, lung, mammary and prostate tumorigenesis in our previous studies, whereas α-T was ineffective. The present work investigated the inhibition of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced prostate carcinogenesis in CYP1A-humanized (hCYP1A) mice by γ-TmT. Male hCYP1A mice, maintained on the AIN93M diet or the same diet supplemented with 0.3% γ-TmT, were treated with a dose of PhIP (200 mg/kg, i.g.). At week 40 after PhIP treatment, all mice developed high-grade prostate intraepithelial neoplasia (hgPIN) in the dorso-lateral glands. The hgPIN was associated with elevated levels of 8-oxo-deoxyguanosine (8-oxo-dG), DNMT1, COX-2 and p-AKT, as well as with loss of expression of the tumor suppressor PTEN, E-cadherin, GSTP1 and Nrf2 in the dorso-lateral glands. In the γ-TmT group, the number of glands with hgPIN (per 100 glands) was significantly lower than the control group (14.6 ± 4.87 vs. 34.81 ± 3.87, p < 0.01). The γ-TmT treatment also prevented the elevation of 8-oxo-dG, COX-2 and p-AKT and the loss of PTEN and Nrf2. The γ-TmT treatment significantly increased the plasma levels of γ-T and δ-T (to 1.7 and 0.8 μM, respectively) as well as their side-chain degradation metabolites, carboxyethyl hydroxychromans and carboxymethylbutyl hydroxychromans (to 2.6-4.0 μM, higher than their parent tocopherols). In a short-term experiment, PhIP-treatment elevated levels of 8-oxo-dG, γH2AX and DNMT1, and caused gene expression changes in several p53-associated genes, including p53bp1, p21WAF1/CIP1, cyclin D1, Bax, Igf1 and cyclinG1 at 1 and/or 3 days after PhIP treatment. Dietary γ-TmT treatment partially prevented the elevation of 8-oxo-dG, γH2AX and DNMT1. This action may contribute to the prostate cancer preventive effect of tocopherols. The presently observed inhibitory activities of γ-TmT against prostate carcinogenesis are hypothesized to be due to the decrease of oxidative stress and inhibition of AKT phosphorylation by γ- and δ-tocopherols, and this hypothesis remains to be tested further (supported by NIH grants CA159361 & CA133021).

Citation Format: Guangxun Li, Hong Wang, Anna B. Liu, Jayson X. Chen, Mao-Jung Lee, Chung S. Yang. Tocopherols inhibit the dietary carcinogen PhIP-induced prostate carcinogenesis in a CYP1A-humanized mouse model. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 202. doi:10.1158/1538-7445.AM2013-202
Abstract 2028: Co-targeting histone deacetylases and oncogenic BRAF synergistically kills human melanoma cell by caspase-independent cell death.
Authors: Guo Su Tang , Lai Fritz , Jiang Chen Chen , Wang Chun Yan , Farrelly Margaret , Tseng Hsin-Yi , Chi Meng Na , Jin Lei , Hersey Peter , Zhang Xu Dong
Published: August 2014

Inherent and acquired resistance of melanomas carrying active mutations in BRAF to mutant BRAF inhibitors (BRAFi) remains a major obstacle for curative treatment of the disease. Since both BRAFi and histone deacetylase inhibitors (HDACi) kill sensitive melanoma cells by activating the BH3-only protein Bim, we examined whether they cooperate in killing of BRAF(V600E) melanoma cells. We show here that co-treatment with the HDACi SAHA and the BRAFi PLX4720 synergistically kills BRAF(V600E) melanoma cells in vitro, and that the combination of SAHA and the clinically available BRAFi vemurafenib cooperatively inhibits melanoma growth in vivo. Although SAHA plus PLX4720 activated the caspase cascade, the latter did not appear to be indispensable for induction of cell death. Likewise, PLX4720 alone kills sensitive melanoma cells in a caspase-independent manner. Similar to caspases, Bim seemed dispensable for synergistic killing by SAHA and PLX4720. The mechanism by which co-treatment with HDACi and BRAFi kills BRAFV600E melanoma cells remains to be elucidated, but we have found that this is not mediated by receptor-interacting protein 1 (RIP1), which is essential for induction of programmed necrosis. Regardless, our results suggest that combinations of HDACi and BRAFi may have therapeutic advantages, in that the conventional caspase-dependent, mitochondrial-mediated apoptotic machinery is often suppressed in melanoma cells.

Citation Format: Su Tang Guo, Fritz Lai, Chen Chen Jiang, Chun Yan Wang, Margaret Farrelly, Hsin-Yi Tseng, Meng Na Chi, Lei Jin, Peter Hersey, Xu Dong Zhang. Co-targeting histone deacetylases and oncogenic BRAF synergistically kills human melanoma cell by caspase-independent cell death. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2028. doi:10.1158/1538-7445.AM2013-2028
Abstract 2038: Unraveling the mechanism of action: drugs that activate the tumor suppressor 2A .
Authors: Dun Matthew D. , Smith Amanda M. , Kahl Richard G. S. , Smith Nathan D. , Khanna Anchit , Don Anthony S. , Toop Hanish F. , Morris Jonathan C. , Verrills Nicole M.
Published: August 2014

The tumor suppressor 2A (PP2A) is a multi-enzyme complex that targets a variety of oncogenic signaling cascades such as Raf, MEK and AKT. Numerous reports have now emerged indicating that the inhibition of PP2A leads to the development of tumors including breast, gastric and lung and a range of hematological malignancies such as chronic and acute myeloid leukemia (CML and AML, respectively). We and others have shown that inhibition of PP2A is crucial for the oncogenic effects of leukemia associated receptor tyrosine kinases such as BCR/Abl, c-KIT and FLT3. Importantly when PP2A is reactivated using pharmacological agents (FTY720 and AAL(S)), growth and survival of these cells is inhibited. This approach targets molecules downstream of these oncogenic kinases and thus PP2A reactivation is designed to avoid resistance associated with kinase inhibitor therapy. As the mechanism of action of these PP2A activators is unknown, it is essential that we now determine the molecular targets of these compounds to generate more effective drugs. Using a chemical proteomics approach incorporating click chemistry linking the drugs to beads, unbiased pull down assays were performed in myeloid leukaemia cells and protein isolates were identified by mass spectrometry. Using this approach we have identified a novel cellular target, which is known to be overexpressed in a range of cancers, including leukemias. We have also shown that this protein associates with PP2A complexes in these cells, and thus may act as an endogenous inhibitor of PP2A activity. We have also performed phospho-proteomics and co-immunoprecipitation studies to identify protein changes in myeloid leukemia cells in response to PP2A activators. In addition to identifying known PP2A targets, such as Akt and ERK, we have also identified a number of novel protein changes, including altered expression of the SET oncoprotein. SET is a known inhibitor of PP2A, suggesting that FTY720 may act via inhibition of SET. Other PP2A regulatory proteins such as CIP2A, PME-1 and PP2A-B56alpha are also affected by FTY720/AAL(S) treatment. Our research findings are thus providing the vital clues necessary for determining the mechanism of action of clinically relevant PP2A activators, thereby moving us towards the provision of novel anti-cancer treatment regimes.

Citation Format: Matthew D. Dun, Amanda M. Smith, Richard G. S. Kahl, Nathan D. Smith, Anchit Khanna, Anthony S. Don, Hanish F. Toop, Jonathan C. Morris, Nicole M. Verrills. Unraveling the mechanism of action: drugs that activate the tumor suppressor 2A . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2038. doi:10.1158/1538-7445.AM2013-2038
Abstract 204: Breast cancer stem and non-stem-like cells express varying levels of selectin ligand activities.
Authors: Shirure Venktesh S. , Xiong Chengkai , Benencia Fabian , Burdick Monica M.
Published: August 2014

Cancer stem cells are a subset of tumor cells proposed to possess traits enabling metastatic invasion. Independently, selectins and their ligands are believed to play major roles in mediating the adhesion of circulating tumor cells to vascular endothelium during hematogenous metastasis. We thus hypothesized that the expression level of selectin ligands on breast cancer cells is related to breast cancer stem cell (BSC) or non-BSC phenotypes. Five breast carcinoma cell lines analyzed by flow cytometry were categorized as BSCs by the surface expression profile CD44+/CD24-/low, or non-BSCs marked by alternative expression of these proteins. All cell lines positively expressed E-, P-, and L-selectin ligand activity by flow cytometric analysis as well as under physiological flow conditions. Consistent with their E-selectin ligand activities, all cell lines expressed putative glycans for E-selectin binding, including sLeX, sLeA, and/or VIM-2 glycans, found by flow cytometric analysis. Yet the level of selectin ligand activity and glycan expression in BSCs was conspicuously lower than in non-BSCs. The abundant production of selectin-reactive glycans in non-BSCs was associated with α-(1,3)- and α-(1,4)-fucosyltransferases, as indicated by qRT-PCR analysis. Importantly, BSCs as well as non-BSCs expressed molecules, such as CD44, that are capable of carrying carbohydrates necessary for E-selectin ligand function. Furthermore, BSCs were mesenchymal-like and non-BSCs were epithelial-like cells, as found by immunostaining of breast cancer cells for E-cadherin and N-cadherin in fluorescence microscopy. Significantly, treatment of a non-BSC cell line with TGF-β induced epithelial-to-mesenchymal transition (EMT) marked by changes in cell morphology, increases in expression levels of N-cadherin, and increases in E-cadherin suppressor genes. These EMT cells showed reduced levels of E-selectin ligand activity under physiological flow conditions, indicating loss of selectin ligand activity upon acquisition of mesenchymal properties. In summary, the selectin ligand activity of BSCs is lower than that of non-BSCs, and the level of selectin ligand activity of breast cancer cells is potentially controlled by BSC and EMT states.

Citation Format: Venktesh S. Shirure, Chengkai Xiong, Fabian Benencia, Monica M. Burdick. Breast cancer stem and non-stem-like cells express varying levels of selectin ligand activities. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 204. doi:10.1158/1538-7445.AM2013-204
Abstract 2041: Inhibition of autophagy in melanoma: using cell lines to model chloroquine sensitivity.
Authors: White Kirsten A. , Torres Salina M. , Gurule Natalia J. , Berwick Marianne , Hu Chien-An A.
Published: August 2014

Metastatic melanoma offers an ongoing clinical challenge. According to the American Cancer Society, the 5-year survival rate in 2012 for stage IV melanoma is only about 15% even with therapies. To improve outcomes, it is important to investigate new pathways involved in the regulation of metastasis as possible targets for prevention or treatment, such as autophagy. Autophagy (self-eating pathway) destroys a cell's damaged proteins and organelles through lysosomal degradation and has been shown to play roles in a wide variety of normal physiological processes including energy metabolism, nutrient or stress responses, growth regulation, and aging. The role of dysregulated autophagy in melanoma has not been well characterized. Preliminary research found cutaneous malignant melanoma cells display high levels of autophagy suggesting that this cellular process may provide an active metabolic state for invasive and metastatic melanoma. Chloroquine (CLQ), a classic antimalarial agent, is a potent inhibitor of autophagy and has been used safely in human patients for decades. This study is designed to dissect the role of autophagy in melanoma using melanoma cell lines (e.g. SK-Mel 19, 103, and 147), and primary melanocytes as controls to determine whether these cell types respond to CLQ as measured by cell viability . Similar to pancreatic and prostate cancer cell lines, our preliminary results indicate that metastatic melanoma cells require autophagy for growth and show high sensitivity to CLQ at doses as low as 20uM which resulted in greater than 60% decreases in cell viability. These findings suggest that metastatic melanoma cell lines rely on lysosomal degradation to a greater extent than what has been reported for other cell types. In addition, both N-ras mutation and androgen deprivation mitigate the effects of CLQ on melanoma cells. Ongoing experiments will confirm the expression of autophagy related genes, as well as imaging to determine the rate of autophagy in these cell lines. Finally, we will introduce stripped hormonal factors including vitamin D and estrogen, to evaluate whether this addition will progressively restore the original chloroquine sensitive phenotype. Findings from this work have the potential to be immediately translatable to patients as CLQ is already approved for therapeutic use in other human diseases.

Citation Format: Kirsten A. White, Salina M. Torres, Natalia J. Gurule, Marianne Berwick, Chien-An A. Hu. Inhibition of autophagy in melanoma: using cell lines to model chloroquine sensitivity. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2041. doi:10.1158/1538-7445.AM2013-2041
Abstract 2042: TOB1 promotes cell survival in estrogen-independent estrogen receptor-positive breast cancer.
Authors: Zhang Yong-Wei , Nasto Rochelle , Clarke Robert , Weiner Louis M.
Published: August 2014

Antiestrogens are the most widely administered endocrine agents for the treatment of estrogen receptor (ER)-expressing breast cancers, such as tamoxifen, fulvestrant and aromatase inhibitor. However, most initially responsive breast tumors acquire resistance and become estrogen-independent. To find potential therapeutic target(s) against drug resistance, we performed siRNA library screening studies to identify cell survival determinants in estrogen independent cell lines from 631 ER network related genes. LCC1 and LCC9 cells, derivatives of MCF-7, are estrogen-independent. LCC1 cells are sensitive to fulvestrant and tamoxifen. LCC9 cells are resistant to fulvestrant and cross-resistant to tamoxifen. A number of genes selectively support the survival of estrogen-independent tumor cells, including TOB1 (Transducer of ErbB2). TOB1 gene knockdown significantly inhibited (>50%) estrogen-independent cell growth in LCC1 and LCC9 cells, but had much less effect on the survival of MCF-7 cells (10%). These cell lines have similar levels of Tob1 protein. TOB1 knockdown did not cause apoptosis or autophagy. DNA replication was reduced and G1 to S phase transition was blocked by TOB1 knockdown in the estrogen-independent cell lines. Next, we studied cell-signaling pathways that regulate cell cycle transition. Cyclin D1 was upregulated and activated by TOB1 knockdown in estrogen-independent cells, but not in MCF-7 cells. Therefore, cyclin D1 might be involved in G1/S transition blockage induced by Tob1 inhibition. TOB1 knockdown also activated cell cycle checkpoint kinase 2 (Chk2) and induced DNA damage. Our data demonstrated that Tob1 promotes cell survival after ER+ breast cancer cells acquire estrogen-independence, which might be mediated by cyclin D1.

Citation Format: Yong-Wei Zhang, Rochelle Nasto, Robert Clarke, Louis M. Weiner. TOB1 promotes cell survival in estrogen-independent estrogen receptor-positive breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2042. doi:10.1158/1538-7445.AM2013-2042
Abstract 2044: Down-regulation of YAP sensitizes lung cancer cells to platinum and ionizing radiation.
Authors: Cheng Haiying , Zhang Zhenfeng , Rodriguez-Barrueco Ruth , Yu Jiyang , Silva Jose M. , Cheng Simon , Perez-Soler Roman , Halmos Balazs
Published: August 2014

Platinum compounds are the foundation of chemotherapy regimens for non-small cell lung cancer despite poor response rates and limited response duration. In order to identify novel target genes the modulation of which could influence drug sensitivity of lung cancer cells in response to cisplatin, we performed a high-throughput RNAi screen targeting the majority of genes in the human genome. We first transfected PC9 lung cancer cells with an shRNA library containing ∼60,000 individual shRNAs, then identified depleted versus enriched shRNAs following two weeks of cisplatin treatment versus vehicle in surviving cells. Standard quality control studies suggested good correlation among triplicates. After using strict selection criteria, we selected a narrow list of highly depleted genes- genes the activity of which is expected to be required for cell survival in the face of cisplatin therapy, including YAP (Yes associated protein). YAP shRNAs were depleted 80 fold in the cisplatin screen. YAP was initially identified as a protein interacting with the non-receptor tyrosine kinase c-Yes and is considered a nuclear effector of the Hippo pathway that promotes cell growth as a transcription co-activator. To validate this promising target identified in our screen, we first confirmed that an siRNA pool targeting YAP can efficiently knockdown YAP protein expression in multiple lung cancer cell lines, then next examined the effects of YAP knockdown on drug responses. YAP knockdown indeed quite prominently improved sensitivities not only to cisplatin, but also to ionizing radiation in several cell lines. Furthermore, YAP knockdown also induces prominent apoptosis as measured by induction of PARP cleavage concurrent with platinum therapy. Our findings indicate the YAP inhibition is potentially relevant to improve sensitivities to platinum-based chemotherapy and chemoradiation in lung cancer.

Citation Format: Haiying Cheng, Zhenfeng Zhang, Ruth Rodriguez-Barrueco, Jiyang Yu, Jose M. Silva, Simon Cheng, Roman Perez-Soler, Balazs Halmos. Down-regulation of YAP sensitizes lung cancer cells to platinum and ionizing radiation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2044. doi:10.1158/1538-7445.AM2013-2044
Abstract 2052: WNT/beta-catenin signaling inhibitors improve the anti-proliferative effect of sorafenib against hepatocellular carcinoma (HCC) cells.
Authors: Lin Hsiao-Hui , Feng Wen-Chi , Lu Li-Chun , Shao Yu-Yun , Cheng Ann-Lii , Hsu Chih-Hung
Published: August 2014

[Background] Sorafenib, a multikinase inhibitor targeting Raf kinase and vascular endothelial growth factor receptor, is currently the only indicated therapy for patients with advanced hepatocellular carcinoma (HCC). The aberrant activation of WNT/β-catenin signaling pathway, which is associated with the carcinogenetic process of HCC, has been shown to mediate the resistance to various types of anti-cancer therapy. We hypothesized that inhibition of WNT/β-catenin signaling pathway might improve the anti-tumor effect of sorafenib in HCC.

[Materials and Methods] Huh7, HepG2, PLC5, and Hep3B HCC cells were treated with sorafenib with or without inhibitors of WNT/β-catenin pathway, and evaluated for viability in vitro. WNT/β-catenin signaling inhibitors included ICG-001 which down-regulates β-catenin/TCF signaling by specifically binding to cyclic AMP response element-binding protein, and XAV939 which targets tankyrases and facilitates degradation of β-catenin.

[Results] Sorafenib induced an anti-proliferative effect in HCC cells, with IC50s of 3.5±0.3 μM, 3.7±0.4 μM, 7.7±0.8 μM and 14±0.3 μM for HepG2, Huh7, PLC5, and Hep3B cells, respectively. Upon treated with 10 μM sorafenib for 24 hours, the total cellular amounts of β-catenin were significantly decreased in HepG2 and Huh7 cells, moderately decreased in PLC5 cells, and unchanged in Hep3B cells. In all HCC cells, XAV939 or ICG-001 enhanced the anti-proliferative effect of sorafenib dose-dependently. The median effect analysis showed a synergistic anti-proliferative effect for the combination of ICG-001 plus sorafenib in all HCC cells.

[Conclusion] Inhibitors of WNT/β- catenin signaling pathway in combination with sorafenib resulted in an improved anti-tumor effect against HCC in vitro. (The study was supported by the grant NSC 100-2325-B-002-043 from National Science Council of Taiwan)

Citation Format: Hsiao-Hui Lin, Wen-Chi Feng, Li-Chun Lu, Yu-Yun Shao, Ann-Lii Cheng, Chih-Hung Hsu. WNT/beta-catenin signaling inhibitors improve the anti-proliferative effect of sorafenib against hepatocellular carcinoma (HCC) cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2052. doi:10.1158/1538-7445.AM2013-2052
Abstract 2060: Metronomic chemotherapy (MCT): comparison of the efficacy of two combinations of drugs for the treatment of murine mammary adenocarcinomas.
Authors: Rico María J. , Mainetti Leandro E. , Perroud Herman A. , Rozados Viviana R. , Scharovsky O. Graciela
Published: August 2014

Metronomic chemotherapy (MCT) refers to the chronic, equally spaced, delivery of low doses of different chemotherapeutic drugs, without extended interruptions. We have developed two combined MCT schemes for the treatment of mammary tumors: A) cyclophosphamide (Cy) 30 mg/kg/day p.o. + celecoxib (Cel) 30 mg/kg p.o. 5 times/week, and B) Cy 20 mg/kg/day p.o. + doxorubicin (Dox) 0.5 mg/kg, 3 times/week i.p. They were tested in two experimental models of mammary adenocarcinomas: I) M-406 and II) M-234p syngeneic with inbred CBi and BALB/c mice, respectively. Our present aim was to compare efficacy and toxicity of MCT combined A and B treatments in both tumor-models. There were analyzed antitumor and antimetastatic effects, survival and toxicity. The % of reduction of tumor volume of animals in the treated group with respect to control group without treatment [median (range): AI: 77.9 (50.9-89.9), AII: 84.4 (30-99.4), BI: 95.6 (57-99.6), BII: 75.5 (62.5-96.8)] didn't differ between treatments or between tumor-models (non parametric ANOVA). The % of reduction of lung metastatic burden [AI: 99.8 (97.1-99.2) AII: 99.7 (98.7-100), BI: 90.6 (35.9-96.6), BII: 90 (48.4-99.3)] was significantly different among all the groups (P<0.01); Dunn's post-test showed differences in AII vs BII (P<0.05). The analysis of survival showed higher values in treated groups, being the % of survival increase with respect to controls [AI: 56.5 (4.3-56.5) AII: 77.6 (5.3-84.2), BI: 110.9 (60-308.2), BII: 36.1 (12.4-113)] did not reach statistical significance (P=0.054). The treatments toxicity, evaluated by evolution of body weight and total leucocytes count, was similar in both tumor-models and treatments. The antitumor therapeutic efficacy was comparable in both MCT schemes and so was the toxicity generated by them. The combination Cy + Cel was superior than Cy + Dox related to antimetastatic power, suggesting its potential use at the adjuvant setting. That observation, together with the advantage that represents the oral administration of the Cy + Cel drug combination, thus leading to a better quality of life for tumor bearers, points at its election for the treatment of mammary tumors with metronomic chemotherapy.

Citation Format: María J. Rico, Leandro E. Mainetti, Herman A. Perroud, Viviana R. Rozados, O. Graciela Scharovsky. Metronomic chemotherapy (MCT): comparison of the efficacy of two combinations of drugs for the treatment of murine mammary adenocarcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2060. doi:10.1158/1538-7445.AM2013-2060