bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A50: Analysis of molecular mechanisms underlying colon cancer development by 3D culture system
Authors: Sakurai Atsuro , Imajo Masamichi , Matsuda Michiyuki
Published: August 2014

Intestinal stem cells produce all types of intestinal epithelial cells including absorptive enterocytes and secretory cells to maintain the homeostasis of intestinal tract. Activity of various signaling pathways not only in the epithelial cells but also in the stromal cells must be coordinately regulated to maintain the intact structure. Among them, Wnt pathway is regarded as one of the most critical pathways for stem cell homeostasis and colon cancer development, in which Wnt signaling is often activated due to mutations in tumor suppressor gene APC. However, it is still unclear how the activation of Wnt pathway causes colon cancer development.

To investigate the mechanisms underlying the colon cancer development, we utilized in vitro crypt culture, which recapitulates three-dimensional epithelial structure comprising of all types of intestinal epithelial cells. To reveal key molecules in colon cancer development upon Wnt activation, we performed microarray analysis of crypts cultured in the presence or absence of Wnt3a or GSK-3β inhibitor, both of which are activators of Wnt pathway. Consequently, we identified fifty genes as the Wnt-activated genes. We knocked down these genes by lentivirus-mediated RNA interference in cultured normal and adenomatous crypts to examine the contribution to the cell growth and crypt formation. This approach will help us to understand the signaling network that regulates the homeostasis of stem cells and the development of colon cancer.

Citation Format: Atsuro Sakurai, Masamichi Imajo, Michiyuki Matsuda. Analysis of molecular mechanisms underlying colon cancer development by 3D culture system. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A50.
Abstract A53: Genetic analysis of semaphorin 5A and plexin-B3 in human glioma
Authors: Jahan Fathima Rifkhana Shah , Lee Alan Yiu Wah
Published: August 2014

Semaphorins are a family of axon guidance molecules, which signal through their co-receptors neuropilins and plexins to subserve various functions in the nervous system, the immune system and during organogenesis. Contrary to their role in development, accumulating evidence suggests the pro- and anti-tumorigenic functions of semaphorins and plexins in different cancer types. Similar to other semaphorins, semaphorin 5A (Sema5A) has recently been implicated in various cancers, though its functions remain ambiguous. Our former study revealed the suppressive effect of Sema5A in glioma cell migration and invasion. Analysis of human glioma specimens revealed a marked down-regulation of Sema5A protein expression in high grade glioblastomas, which are highly infiltrative. Here, we provide evidence that forced expression of Sema5A inhbits glioma cell proliferation by disrupting the cell cycle. Taken together, these findings suggest a tumor suppressor function of Sema5A in glioma. Interestingly, real-time quantitative PCR analysis revealed no significant difference in Sema5A mRNA levels across different grades of glioma. Analysis of Sema5A gene in human glioma specimens detected no mutations but the presence of various alternatively spliced variants that could potentially lead to premature truncation of Sema5A protein. Notably, the predominant Sema5A splice variant is expressed at almost equal level as the wild-type counterpart in the glioma specimens analysed. Ectopic expression of this truncated isoform in fact results in an unstable protein that is targeted for proteasomal degradation. These findings reinforce our hypothesis that reduced Sema5A protein levels in glioblastomas could compromise its suppressive effects in glioma progression.

Citation Format: Fathima Rifkhana Shah Jahan, Alan Yiu Wah Lee. Genetic analysis of semaphorin 5A and plexin-B3 in human glioma. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A53.
Abstract A58: Epigenetic silencing of neurotensin receptor type 1 (NTSR1) in colorectal tumor
Authors: Suzuki Hiromu , Yamamoto Eiichiro , Maruyama Reo , Yamano Hiro-o , Nojima Masanori , Tsuyada Akihiro , Niinuma Takeshi , Sato Akiko , Masahiro Kai
Published: August 2014

Purpose: Aberrant DNA methylation plays important roles in the development of colorectal cancer (CRC), but its involvement in the flat-type colorectal tumors is poorly understood. In the current study, we aimed to understand the molecular basis of laterally spreading tumors (LSTs) which extend laterally and circumferentially rather than vertically along the colonic wall. Methods: Methylation was examined using Methylated CpG island amplification-microarray (MCAM) and bisulfite-pyrosequencing in colorectal tumors (n=214). Expression of NTSR1 was tested using TaqMan RT-PCR. Colony formation, MTT, Matrigel invasion assays and cDNA microarray were performed to analyze the functional of NTSR1. Results: MCAM analysis in LSTs identified a number of frequently methylated genes including neurotensin receptor type 1 (NTSR1), a known oncogene in CRC. LSTs showed elevated NTSR1 methylation levels than other types of colorectal tumors (p < 0.001). Ectopic expression of NTSR1 promoted colon cancer cell growth and invasiveness. Conversely, siRNA-induced knockdown of NTSR1 in CRC cells suppressed proliferation and invasiveness. Conclusions: Our results suggest that methylation of NTSR1 is associated with invasive behavior and lateral growth of colorectal tumors. Methylation of NTSR1 may be a useful marker to predict the growth pattern of colorectal tumors.

Citation Format: Hiromu Suzuki, Eiichiro Yamamoto, Reo Maruyama, Hiro-o Yamano, Masanori Nojima, Akihiro Tsuyada, Takeshi Niinuma, Akiko Sato, Kai Masahiro. Epigenetic silencing of neurotensin receptor type 1 (NTSR1) in colorectal tumor. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A58.
Abstract A59: Protein kinase CK2 regulates β-catenin association to E-cadherin and hence viability and invasion of colorectal cancer cells
Authors: Yefi Roger , Silva Eduardo , Cabello Pablo , Niechi Ignacio , Huerta Hernan , Armisen Ricardo , Fernandez Cristina , Tapia Julio C.
Published: August 2014

The key factor in the canonical Wnt pathway is β-catenin which also functions in cell-cell adhesion forming a complex with E-cadherin at the cell surface. Activation of the canonical Wnt pathway is linked to the release of β-catenin from the cell surface, its cytoplasmic stabilization and nuclear import, followed by increased transcriptional activity on genes normally linked to cancer progression, such as survivin and cyclin D1. We already described that caveolin-1 is a member of this complex (termed CEB for caveolin-1/E-cadherin/β-catenin) which inhibits β-catenin transcriptional activity thereby acting as a tumor suppressor. Conversely, protein kinase CK2 is abnormally elevated in a wide variety of cancers, promoting progression by regulating oncogene and tumor suppressor proteins, but also promoting an elevated β-catenin activity. We already demonstrated that cyclooxygenase-2 (COX-2) is a target of CK2 and its metabolite, prostaglandin E2 (PGE2), is key to up-regulate cell proliferation and apoptosis resistance. However, how CK2, PGE2, and caveolin-1 participate in the mechanism of CK2-mediated colorectal cancer progression is yet unknown. In this work, we hypothesize that CK2 promotes cancer progression by augmenting COX-2 expression and subsequently PGE2 production, which disrupts the putative CEB complex in an autocrine manner, leading to the release of β-catenin and increase of its nuclear activity. This was investigated by determining the presence of CEB complex in DLD-1 colon cancer cells (IP), as well as by evaluating the effect of either PGE2 or a CK2 inhibitor (TBB) on in vitro proliferation (MTS®), apoptosis (Caspase-Glo®) and invasiveness (wound-healing and matrigel assays) of these cancer cells. Our results suggest that the CK2-dependent autocrine production of PGE2 in DLD-1 colon cancer cells promotes the dissociation of caveolin-1 from the CEB complex at the cell surface, allowing β-catenin to be apparently phosphorylated (WB anti-P-antibodies) and released to the cytosol, which increments its nuclear import and transcriptional activity on cancer-related genes. Supported by ICGEB (CRP/CHI10-01) and FONDECYT (11070116, 1120132) grants to J.C.T.

Citation Format: Roger Yefi, Eduardo Silva, Pablo Cabello, Ignacio Niechi, Hernan Huerta, Ricardo Armisen, Cristina Fernandez, Julio C. Tapia. Protein kinase CK2 regulates β-catenin association to E-cadherin and hence viability and invasion of colorectal cancer cells. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A59.
Abstract A66: Insights into the pathogenesis of hyperparathyroidism-jaw tumor syndrome: Deciphering the role of Hrpt2 within bone development
Authors: Droscha Casey J. , Cassandra Diegel , Williams Bart O.
Published: August 2014

Hyper-parathyroidism-jaw tumor (HPT-JT) syndrome is an autosomal dominant disorder in which patients present with parathyroid adenoma or carcinoma, renal cysts, and fibro-osseous tumors of the maxilla or mandible. HPT-JT is caused by loss of heterozygosity or inactivating mutations within the hyperparathyroidism 2 (HRPT2) gene that encodes the tumor suppressor parafibromin. As a core member of the Polymerase Associated Factors (PAF) complex, parafibromin binds to nuclear β-catenin and is known to associate with RNA Polymerase II to facilitate transcriptional initiation and elongation. Recently, the ability of parafibromin to associate with β-catenin and drive Wnt target gene transcription was found to be dependent on dephosphorylation by protein tyrosine phosphatase 2 (Shp2). Additionally, Bruton's Tyrosine Kinase (BTK) has been identified as a negative regulator of Wnt target gene transcription through interaction with parafibromin. Together, these findings suggest that the phosphorylation status of parafibromin may define its role as a transcriptional repressor or activator.

Our objective is to determine how the phosphorylation status of parafibromin regulates Wnt target gene transcription. As Wnt is well known as a positive regulator of osteogenesis, which plays an important role during HPT-JT, it is also important to decipher the role parafibromin plays within osteoblast differentiation. Conditional deletion of Hrpt2 within mature osteoblasts using osteocalcin-driven Cre results in increased bone mineral density, cortical thickness, and overall stiffness of 3- and 6-month-old murine femurs. In addition, loss of Hrpt2 within mesenchymal progenitors using Dermo1-driven Cre results in embryonic lethality at approximately embryonic day 12.5. However, initial in vitro investigations assessing rates of mineralization and calcium deposition within Hrpt2-null osteoblasts show no significant changes as compared to wildtype controls. From these results, it is clear that parafibromin is essential for embryonic development and is a potential inhibitor of bone mass accrual, yet further investigation as to what genes are being occupied and regulated by parafibromin is needed. These findings will aid in the understanding of bone development and may provide insight into the pathogenesis of HPT-JT.

Citation Format: Casey J. Droscha, Diegel Cassandra, Bart O. Williams. Insights into the pathogenesis of hyperparathyroidism-jaw tumor syndrome: Deciphering the role of Hrpt2 within bone development. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A66.
Abstract A67: Methylation of ESR1 and 14-3-3 sigma promoter in serum as possible biomarkers for screening and diagnosis for breast cancer
Authors: Martinez-Galan Joaquina , Torres-Torres Blanca , Delgado Juan Ramón
Published: August 2014

Background: To investigate the association between gene hypermethylation and the major clinico-pathological features of breast cancer, including diagnosis and treatment response.

Material and Methods: 107 women with breast cancer and 108 control subjects were recruited. Real Time QMS-PCR SYBR green (methylation-specific PCR) was used to analyze the utility of circulating DNA with CpG island hypermethylation of APC, RAR-β, E-Cadherin, ESR1 and 14-3-3 sigma; gene promoter regions as breast cancer biomarkers. Sera were collected in 107 operable breast cancer patients (pts) previously surgery and in 60 of those pts after treatment. Respect controls, 34 had benign breast disease and 74 with no evidence of breast disease.

Results: We found significant differences between breast cancer patients and healthy controls in relative serum levels of methylated gene promoters ESR1 (p = 0.0112) and 14-3-3sigma (p=0.0047). We observed that hypermethylation of these combined two genes differentiated between breast cancer patients and healthy controls (p <0.0001) with a sensitivity of 81% (95% CI: 72–88%) and specificity of 88% (95% CI: 78–94 %). Presence of methylated ESR1 in serum of breast cancer patients was associated with ER-negative phenotype (p = 0.0179); and presence of methylated 14-3-3-sigma was associated with T3-4 stage (OMS) (p< 0.05) and nodal positive status (p< 0.05). We observed lower methylated ERS1 or 14-3-3-sigma values after surgery, respect pretreatment levels, but without an overall statistically significant difference. With a median follow up of 6 years, we found that patients with a significant decrease of sera methylated levels of both genes after surgery had better time to progression an overall survival respect patients without this observation.

Conclusions: this panel of genes detected in ductal lavage and blood specimens could be useful as markers for early detection of breast carcinoma. These findings cast some doubts on the utility for early cancer diagnosis of highly sensitive techniques to identify hypermethylation of specific gene promoters in DNA extracted from serum. Although numerous issues remain to be resolved, the quantitative measurement of circulating methylated DNA is a promising tool for cancer risk assessment.

Note: This abstract was not presented at the conference.

Citation Format: Joaquina Martinez-Galan, Blanca Torres-Torres, Juan Ramón Delgado. Methylation of ESR1 and 14-3-3 sigma promoter in serum as possible biomarkers for screening and diagnosis for breast cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr A67.
Abstract B05: Urothelial carcinoma exosomes contain Del1/EDIL-3 and facilitate bladder cancer progression
Authors: Beckham Carla , Silvers Christopher , Olsen Jayme , Yin Peng-nien , Wu Chia-Hao , Ting Huei-ju , Hagen Fred , Scosyrev Emelian , Messing Edward
Published: August 2014

Small membrane-bound vesicles called exosomes are proving to be critical mediators of tumor progression. Here we show, for the first time, that exosomes isolated from the urine of patients with high-grade bladder cancer facilitate tumor progression and contain the matrix-associated glycoprotein EGF-like repeats and discoidin I-like domains (EDIL-3 aka Del1). EDIL-3 is a well-known tumor-associated angiogenic factor and increased expression of EDIL-3 has been shown in numerous tumors to correlate with poor prognosis. We demonstrate, that exosome-derived EDIL-3 is important for angiogenesis as well as urothelial and endothelial cell migration. Importantly, we show that recombinant (r)EDIL-3 is sufficient to promote migration of human urothelial carcinoma 5637 cells and blockade of either the epidermal growth factor receptor (EGFR) and/or the EGFR signal transduction propagating integrin beta 1 abrogated this effect. These data suggest a novel mechanism by which EDIL-3 may be involved in signal transduction pathways in cancer.

Citation Format: Carla Beckham, Christopher Silvers, Jayme Olsen, Peng-nien Yin, Chia-Hao Wu, Huei-ju Ting, Fred Hagen, Emelian Scosyrev, Edward Messing. Urothelial carcinoma exosomes contain Del1/EDIL-3 and facilitate bladder cancer progression. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B05.
Abstract B11: The early autophagy inhibitor verteporfin moderately enhances the antitumor activity of gemcitabine in a pancreatic ductal adenocarcinoma model
Authors: Donohue Elizabeth , Thomas Anitha , Maurer Norbert , Manisali Irina , Zeisser-Labouebe Magali , Zisman Natalia , Anderson Hilary J. , Webb Murray , Bally Marcel , Roberge Michel
Published: August 2014

Autophagy, a cellular self-eating process that is activated by several cancer drugs and appears to function as a protective mechanism, is a promising therapeutic target. Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to chemotherapy, and has been described as requiring elevated autophagy for growth. To date, all preclinical reports and clinical trials investigating pharmacological inhibition of autophagy have used chloroquine or hydroxychloroquine, which block autophagy at a late stage. Verteporfin is a newly discovered autophagy inhibitor that blocks autophagy at an early stage by inhibiting autophagosome formation. Here, we report that PDAC cell lines show variable sensitivity to verteporfin in vitro and that verteporfin inhibits autophagy stimulated by gemcitabine, the current standard treatment for PDAC. Pharmacokinetic and efficacy studies in a BxPC-3 xenograft mouse model demonstrate that verteporfin accumulated in tumors at autophagy-inhibiting levels but did not reduce tumor volume or increase survival as a single agent. However, in combination with gemcitabine, verteporfin moderately reduced tumor growth and enhanced survival compared to gemcitabine alone. Our results do not agree with the premise that autophagy inhibition is effective against PDAC as a single-modality treatment, but they support autophagy inhibition as an approach to sensitize PDAC to gemcitabine.

Citation Format: Elizabeth Donohue, Anitha Thomas, Norbert Maurer, Irina Manisali, Magali Zeisser-Labouebe, Natalia Zisman, Hilary J. Anderson, Murray Webb, Marcel Bally, and Michel Roberge. The early autophagy inhibitor verteporfin moderately enhances the antitumor activity of gemcitabine in a pancreatic ductal adenocarcinoma model. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B11.
Abstract B13: Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention
Authors: Fischer Jared M. , Shibata Darryl , Liskay R Michael
Published: August 2014

Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitated the sporadic inactivation of Apc via frameshift reversion of Cre in single, isolated cells. Our system enables tracking the fates of Apc-deficient intestinal stem cells. Our results suggest that consistent with Apc being a “gatekeeper”, loss of Apc early in life during intestinal growth leads to adenomas or increased crypt fission, manifested by fields of mutant but otherwise normal-appearing crypts. By contrast, later-occurring in life Apc loss has minimal consequences with mutant crypts being less prone to either increased crypt fission or adenoma formation. Using the stem cell specific Lgr5-CreER mouse, in which Apc loss is induced at defined ages and in varying numbers of crypts, we find that Apc-deficient field size again correlates with progression to adenoma. To evaluate this early stage prior to adenoma formation as a therapeutic target, we examined the chemopreventive effects of sulindac on Apc-deficient crypt field formation. We found that sulindac reduces adenomas and inhibits the morphologically occult spread of Apc-deficient crypts. Taken together these results suggest that: 1) A field of Apc-deficient crypts is an important intermediate between loss of Apc and adenoma formation, 2) Earlier Apc loss promotes increased crypt fission and subsequent field formation, and 3) Normal-appearing Apc-deficient crypts are potential unappreciated targets for cancer screening and chemoprevention.

Citation Format: Jared M. Fischer, Darryl Shibata, R Michael Liskay. Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B13.
Abstract B18: Targeting rapamycin-induced autophagy in cancer
Authors: Alayev Anya , Snyder Rose B. , Holz Marina K.
Published: August 2014

Mechanistic target of rapamycin complex 1 (mTORC1) is an important regulator of cell cycle progression and proliferation, and is a target of the inhibitor rapamycin. The 40S ribosomal S6 Kinase 1 (S6K1) is one of the best characterized downstream targets of mTORC1. The mTORC1/S6K1 pathway is hyperactivated in many types of cancer, contributing to cancer pathogenesis and progression.

Autophagy is a cellular mechanism conserved in all eukaryotes, whose role is to maintain homeostasis of the cell under stress-induced conditions by recycling intracellular components. In cancer, autophagy may serve to protect cancer cells from cell death and may contribute to acquired drug resistance. The mTORC1/S6K1 signaling pathway is an important regulator of autophagy. One of the concerns that arise with the use of mTORC1 inhibitors, such as rapamycin analogs (or rapalogs), is that rapalogs promote autophagy and cause cell senescence, which protects cancer cells from undergoing apoptosis.

Recent evidence suggests that a possible mechanism by which mTORC1 regulates autophagy may involve the tumor suppressor programmed cell death protein 4 (PDCD4), which is a downstream target of S6K1. Inhibition of mTORC1/S6K1 signaling causes upregulation of PDCD4 expression, which correlates with increased autophagy induction. We observed that suppressing PDCD4 expression in combination with rapamycin reduces autophagy and causes cancer cells to undergo cell death via apoptosis. Our results indicate that such strategy prevents rapamycin-induced upregulation of autophagy, while maintaining inhibition of mTORC1/S6K1 signaling, and promotes progression to apoptosis.

Citation Format: Anya Alayev, Rose B. Snyder, Marina K. Holz. Targeting rapamycin-induced autophagy in cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B18.
Abstract B65: Immune cell priming and potentiation of anti-tumor effects by Imprime PGG®
Authors: Yokoyama Yumi , Nelson Mariana I. , Ottoson Nadine C. , Kirstein Mark N. , Walsh Richard , Michel Kyle S. , Danielson Michael E. , Antonysamy Mary A.
Published: August 2014

Biothera is developing Imprime PGG® (Imprime PGG) for cancer that is synergistic with multiple anti-tumor monoclonal antibodies, demonstrating the potential to improve patient outcomes in a wide range of cancer indications. Although, the antitumor potential of Imprime PGG has now been well documented in several preclinical models, its immunomodulatory potential has not been fully elucidated. Here, we studied the in vivo effects of Imprime PGG, a pharmaceutical grade soluble yeast-derived β-1,3/1,6 glucan, on immune cell binding and function, using both tumor bearing and non-tumor bearing mice. Immunodeficient nude mice, with or without tumor (i.e. MiaPaCa-2 human pancreatic tumor), were administered a single dose of Imprime PGG (i.v.) and 3 days later, immune cells in peripheral blood, spleen, and/or tumor were isolated and evaluated for Imprime PGG binding and function. Using flow cytometric methods, Imprime PGG was found to bind B cells, macrophages, and neutrophils in whole blood and in addition, bound to NK cells in spleen. Notably, in mice bearing tumor, Imprime PGG administration lead to a relatively high percentage of Imprime PGG-bound macrophages and neutrophils in the tumor microenvironment. Furthermore, for the first time, we were able to demonstrate that Imprime PGG administered in vivo had the ability to “prime” immune cells and enhance their antitumor function. Administration of Imprime PGG increased the cytotoxic ability of immune cells, such as macrophages and NK cells, and lead to higher antibody mediated cytotoxicity and increased sensitivity to non-specific stimuli. Likewise, immune cells primed in vivo with Imprime PGG demonstrated increased cytokine responses (such as KC; a mouse isoform of human IL-8, IL-6, G-CSF, and MIP-1α and preliminary cytokine data on tumor infiltrating effector cells support an antitumor profile. Collectively, these results indicate that Imprime PGG when administered in vivo “primes” immune effector cells for enhanced antitumor activity. These observations further validate the potential benefit of combining this unique immunomodulatory drug with antitumor monoclonal antibodies as a positive treatment strategy in cancer.

Citation Format: Yumi Yokoyama, Mariana I. Nelson, Nadine C. Ottoson, Mark N. Kirstein, Richard Walsh, Kyle S. Michel, Michael E. Danielson, Mary A. Antonysamy. Immune cell priming and potentiation of anti-tumor effects by Imprime PGG®. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B65.
Abstract C02: Transient metabolic complex, the purinosome, for metabolic adaptation in cancer cells
Authors: An Songon , Kyoung Minjoung
Published: August 2014

Sequential metabolic enzymes have long been hypothesized to form transient multienzyme complexes to regulate metabolic pathways in cells. Human de novo purine biosynthetic complex, the “purinosome,” stands as first examples of this cellular phenomenon. The purinosome formation indeed increased desired metabolic flux in cells. The purinosome assembly/disassembly was also dynamically regulated by multiple cellular factors; including microtubule networks, protein kinase CK2, and Gi-protein coupled receptors. However, we barely understand the structural organization of the purinosome. We will discuss our recent progress providing unprecedented insights into the mechanism of purinosome assembly/disassembly upon environmental changes. Taken together with our knowledge of purinosome regulatory systems, we propose that the purinosome dynamics could be part of metabolic alterations and adaptations of cancer cells. Given that purine biosynthesis has been a validated target for anticancer chemotherapy, this new level of understanding purine biosynthesis will open new opportunities of therapeutic intervention in human cancers.

Citation Format: Songon An, Minjoung Kyoung. Transient metabolic complex, the purinosome, for metabolic adaptation in cancer cells. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C02.
Abstract C33: Integrated analysis of sequence variations and copy number in TCGA colon adenocarcinoma data
Authors: O'Hara Andrea , Keshavan Raja , Culot Louis , Shams Soheil
Published: August 2014

The Cancer Genome Atlas (TCGA) data is available via the TCGA portal and includes copy number data and whole exome sequencing data. Nexus Copy Number 7 was used to evaluate level-1 approved SNP array data from the colon adenocarcinoma (COAD) data set. All samples were subjected to match-paired analysis to evaluate somatic copy number variation. Samples were subjected to extensive pre-processing, including systematic G/C wave correction, ploidy correction, gender correction and quality control. Corresponding level-3 somatic mutation data was used for an integrated analysis of copy number and sequence variation with the COAD data set. Comprehensive copy number analysis identified frequent (>35%) copy number gains of chr7, chr8q, chr13 and chr20, and losses of chr8p, chr17p, and chr18. GISTIC analysis further identified statistically significant focal changes which included loss of FHIT on chr3. Genes KRAS and BRAF were among the most frequently mutated genes. Integrated analysis identified several regions of copy number change that significantly co-occurred with BRAF mutation. Copy number profiles varied significantly between hypermutable and non-hypermutable samples. Potential chromothriptic events were also observed within the COAD dataset. An approach that can integrate structural and sequence variation among samples will be presented.

Citation Format: Andrea O'Hara, Raja Keshavan, Louis Culot, Soheil Shams. Integrated analysis of sequence variations and copy number in TCGA colon adenocarcinoma data. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C33.
Abstract C51: Interleukin-4 receptor α chain regulates the growth of primary and metastatic mammary tumors
Authors: Venmar Katherine T. , Hwang Daniel , Dozier Ashley , Carter Kathy , Gillani Sareena , Fingleton Barbara
Published: August 2014

This abstract is being presented as a short talk. A full abstract is printed in the Proffered Abstracts section (PR13) of the Conference Proceedings.

Citation Format: Katherine T. Venmar, Daniel Hwang, Ashley Dozier, Kathy Carter, Sareena Gillani, Barbara Fingleton. Interleukin-4 receptor α chain regulates the growth of primary and metastatic mammary tumors. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C51.
Abstract IA25: Metastasis pathways
Authors: Massagué Joan
Published: August 2014

The mechanisms that turn disseminated tumour cells (DTCs) into metastasis-initiating seeds are largely unknown. We recently identified molecular sensors and stromal factors that amplify cell survival and stem cell pathways in DTCs from breast, lung, and renal cancers. These mechanisms prime tumor cells for metastasis in animal models and are associated with relapse in patients. For example, SRC primes triple-negative (TN) breast cancer DTCs for a robust response of the PI3K-Akt pathway to CXCL12 and IGF1 in the bone marrow. The leukocyte-tethering receptor VCAM-1 primes TN DTCs for PI3K-Akt activation in the lungs. For stem cell fitness, the extracellular matrix protein tenascin-C (TNC) forms micrometastatic niches that amplify WNT and NOTCH signaling in TN breast cancer cells. A CXCL1-S100A8 paracrine loop protects DTCs from the stresses of metastasis and chemotherapy, suggesting a link for the clinically coupled phenomena of relapse and chemoresistance. Though encouraging, this progress has only accentuated an old puzzle: How do organ-specific metastatic traits emerge in primary tumors? We identified a role of the breast tumor stroma in selecting cancer cells in TN breast cancers that are primed for metastasis to bone. Cancer-associated fibroblasts (CAFs) in TN breast tumors skew heterogeneous cancer cell populations towards a predominance of clones that thrive on the CAF-derived factors CXCL12 and IGF1. Carcinoma clones selected in this manner are primed for metastasis in the CXCL12-rich microenvironment of the bone marrow. Coupled with processes of tumour self-seeding, whereby DTCs may recirculate, reseed and expand in their tumors of origin, the process of metastatic seed pre-selection may further sway the organotropic metastatic traits of tumors. We conclude that stromal signals resembling those of a distant organ select for cancer cells that are primed for metastasis in that organ, thus illuminating the evolution of metastatic traits in a primary tumour and its distant metastases.

In related studies we identified mediators of brain metastasis of lung adenocarcinoma and breast cancer.

Citation Format: Joan Massagué. Metastasis pathways. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr IA25.
Abstract IA29: Functional genomics, experimental models and cancer
Authors: Hahn William C.
Published: August 2014

Large scale characterization of cancer genomes has led to information regarding the identify, number, and types of alterations found in human tumors. However, the large number of mutations identified to date require complementary approaches to understand the function of these mutated genes and to elucidate pathways involved in cancer initiation and progression. Over the past several years, we have developed genome scale RNAi libraries and open reading frame expression libraries that permit a systematic evaluation of genes involved in cancer initiation and maintenance. We have used these tools to dissect known and novel pathways involved in malignant transformation. In particular, we have dissected the signaling pathways related to beta catenin and KRAS, two well-known cancer drivers that have proven difficult to target therapeutically. These approaches have identified new components of these pathways, which may provide a foundation for therapeutic strategies.

Citation Format: William C. Hahn. Functional genomics, experimental models and cancer. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr IA29.
Abstract IA32: Targeting cancer cell dependencies on developmental signal transduction pathways
Authors: Lum Lawrence
Published: August 2014

Developmentally important signal transduction pathways such as those controlled by the secreted Wnt and Hedgehog (Hh) ligands are frequently exploited in cancerous cells to promote unfettered growth. We describe functional and chemical genomics-based efforts to recover actionable mechanisms sustaining cancer-associated Wnt and Hh signaling. We discuss chemically tractable strategies for disrupting the fatty acylation of Wnt proteins and unanticipated vulnerabilities in Hh signaling to inhibitors of the Bcl-2 antiapoptotic proteins. Our findings extend the portfolio of druggable enzymes with anti-cancer relevance and reveal novel compensatory prosurvival mechanisms in cancerous cells that incorporate developmental pathway components.

Citation Format: Lawrence Lum. Targeting cancer cell dependencies on developmental signal transduction pathways. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr IA32.
Abstract PR14: Lineage labeling elucidates the natural history of metastatic colonization
Authors: Aiello Nicole M. , Bajor David L. , Vonderheide Robert H. , Stanger Ben Z.
Published: August 2014

Compared to primary tumor formation and invasion, relatively little is known about later stages of the metastatic cascade, including the seeding and colonization of distal tissues. To visualize these late steps in metastasis, we have generated an autochthonous mouse model of pancreatic ductal adenocarcinoma in which all pancreatic epithelial cells are genetically labeled with yellow fluorescent protein (the KPCY model). This system allows for the detection of single seeded tumor cells in distant organs, as well as micrometastasis and larger lesions. We have assessed the size distribution of metastatic lesions in two frequently colonized organs, the liver and lung, and found that single cells and clusters consisting of less than ten cells represent the majority of lesions in both tissues; however these small lesions only progress to gross metastasis in the liver, not the lung. We have previously used the KPCY model to study the dynamic process of epithelial-mesenchymal transition (EMT) and its involvement in invasion and dissemination from the primary tumor. We have extended these studies to assess the role of EMT and the reverse phenomenon, mesenchymal-epithelial transition (MET), in seeding and colonization at metastatic sites. Our results suggest that while EMT is favored for entry into the circulation, there may be selection for epithelial tumor cells or MET at the metastatic site. Additionally this model allows us to investigate the parallel evolution of metastatic lesions, from single cells to macrometastasis, and the associated metastatic microenvironment.

Citation Format: Nicole M. Aiello, David L. Bajor, Robert H. Vonderheide, Ben Z. Stanger. Lineage labeling elucidates the natural history of metastatic colonization. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr PR14.
Abstract B40: Mitochondrial superoxide dismutase (Sod2) confers a survival advantage to ovarian cancer cells under stress conditions by enhancing mitochondrial respiratory reserve capacity
Authors: Dier Usawadee , Uusitalo Larissa , Giroux Corinne , Hempel Nadine
Published: August 2014

The formation of cellular spheroids is considered to be an important step in the metastatic progression of ovarian cancer. These clusters of tumor cells are characterized by an enhanced survival within the peritoneal cavity, the ability to attach at secondary metastatic sites within the cavity and associated with increased chemoresistance. High expression of mitochondrial superoxide dismutase (Sod2), which regulates mitochondrial redox balance, has been observed in metastatic ovarian cancer, specifically ovarian clear cell carcinomas (CCC), and in vitro, following spheroid formation. To assess the role of Sod2 in spheroid formation and ovarian cancer metastasis we utilized siRNA knock-down to decrease Sod2 expression in Ovcar3 and the CCC cell line ES-2. Surprisingly, under normal culture conditions, decreasing Sod2 levels had little effect on proliferation and spheroid formation. To elucidate the role of Sod2 on ovarian cancer mitochondrial function an extracellular flux metabolic analyzer (Seahorse Bioscience) was utilized to measure rates of cellular respiration. While the basal oxygen consumption rate remained unchanged, a decrease in Sod2 expression resulted in a concomitant decrease in respiratory reserve capacity. This reserve capacity is an important determinant of a cell's ability to increase metabolic rate under stress conditions. Given that ovarian cancer spheroids are exposed to the hypoxic environment of the peritoneal cavity, the role of Sod2 on ovarian cancer spheroid formation was assessed under low oxygen (1%) conditions. Hypoxia increased the clonogenicity and spheroid size of control cells, which was significantly abrogated following Sod2 knock-down. These data suggest that Sod2 confers a survival advantage to ovarian cancer spheroids under stress conditions by maintaining an adequate mitochondrial respiratory reserve. Manipulating mitochondrial function and redox balance by effectively targeting mitochondrial antioxidant enzymes may enhance chemosensitivity and allow for novel therapeutic strategies against ovarian cancer.

Citation Format: Usawadee Dier, Larissa Uusitalo, Corinne Giroux, Nadine Hempel. Mitochondrial superoxide dismutase (Sod2) confers a survival advantage to ovarian cancer cells under stress conditions by enhancing mitochondrial respiratory reserve capacity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B40.
Abstract B41: Investigating ARID3B regulation of ovarian cancer metastasis
Authors: Gellerman Katrina , Samyesudhas Serene , Joseph Stancy , Dahl Karen Cowden
Published: August 2014

Over 60% of ovarian cancer cases are detected with widespread metastases. In an effort to define the associated molecular mechanisms of metastasis in ovarian cancer, recent findings have implicated a novel DNA-binding protein, ARID3B, as a contributor to ovarian cancer growth and metastasis. We recently demonstrated that increased expression of ARID3B promotes metastatic growth of ovarian cancer cells in a xenograft mouse model. The purpose of this study is to identify target genes of ARID3B, with the goal of elucidating a mechanism for this metastatic support. ChIP-on-chip analysis comparing ovarian cancer cells in the presence and absence of exogenous overexpression of ARID3B revealed a multitude of potential gene targets. These targets have been functionally sorted into 21 distinct groups and among these groups, 21 genes were selected for further analysis. Validation of these targets via RT-PCR has identified c-Myc, a known regulator of metastasis, as a putative target of ARID3B. Our results reveal an increase in c-Myc mRNA levels in response to ARID3B, implicating c-Myc as putative direct target of ARID3B. We used chromatin immunoprecipitation to study the potential interaction of ARID3B with the c-Myc promoter. The specifics of the regulation of c-Myc are currently under investigation. In conjunction with gene regulation, metastasis-associated phenotypes were examined, as well. ARID3B overexpression increases extracellular matrix adhesion and vitronectin haptotaxis. Specifically, we investigated the contribution c-Myc to ARID3B induced adhesion and motility as a means for promoting metastatic progression. We accomplished this via adhesion and haptotaxis assays using ovarian cancer cells exogenously overexpressing ARID3B, followed by siRNA knockdown of c-Myc. Further study will serve to define how ARID3B regulation of c-Myc contributes to ovarian cancer progression. Should c-Myc prove to be a biologically relevant target, ARID3B regulation of c-Myc could represent an important mechanism for the associated advancement of ovarian cancer metastasis.

Citation Format: Katrina Gellerman, Serene Samyesudhas, Stancy Joseph, Karen Cowden Dahl. Investigating ARID3B regulation of ovarian cancer metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B41.
Abstract C74: Temozolomide-perillyl alcohol conjugate is cytotoxic for glioma cancer stem cells
Authors: Jhaveri Niyati , Agasse Fabienne , Hofman Florence M. , Chen Thomas C.
Published: August 2014

Glioblastoma multiforme (GBM), the most malignant glioma, is a highly invasive tumor which is usually fatal within 2 years. The chemotherapeutic agent of choice is temozolomide (TMZ); however glioma patients inevitably become resistant to TMZ and tumors recur. Tumor recurrence has been associated with highly invasive, chemoresistant cancer stem cells (CSC) which is resistant to TMZ. We have constructed a new chemical entity by conjugating TMZ to perillyl alcohol (POH) via a carbamate bond. This compound, TMZ-POH, contains POH, a naturally occurring monoterpene that reduces tumor cell migration and has anti-tumor properties against gliomas as well as other cancers. In the studies presented here we demonstrate that TMZ-POH is cytotoxic to CSCs without affecting normal stem cells. The mechanism of TMZ-POH induced cytotoxicity is mediated in part through the DNA damage response pathway and apoptosis. Furthermore, the TMZ-POH conjugate is 5 to 10 fold more effective in inducing cell death compared to TMZ, POH or the mixture of these agents. Our data show that TMZ-POH is a promising novel compound directed against cancer stem cells and therefore important for the treatment of drug resistant, recurrent gliomas.

Citation Format: Niyati Jhaveri, Fabienne Agasse, Florence M. Hofman, Thomas C. Chen. Temozolomide-perillyl alcohol conjugate is cytotoxic for glioma cancer stem cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C74.
Abstract C91: PyVmT luminal and EMT cell lines exhibit characteristic patterns of orthotopic and tail vein metastasis
Authors: Ellies Lesley G. , Kuo Christopher
Published: August 2014

Understanding pathways leading to metastasis remains a primary goal of breast cancer research. Epithelial to mesenchymal transition (EMT) is thought to be critical in this process as tumor cells migrate through the stroma and undergo deformation while passing endothelial cells to enter the circulation. To examine the role of EMT in tumor metastasis, we have developed a number of stable cell lines in polyomavirus middle T (PyVmT) mammary tumors congenic in the C57Bl/6 background. In this study we characterized the metastatic properties of a luminal cell line Py230 and an EMT cell line Py8119, both of which have cancer stem cell properties of self-renewal, differentiation and tumor initiation. Py230 cells form well-differentiated epithelial adenocarcinomas typical of the spontaneous PyVmT model when injected orthotopically. Injection of 1-10 cells at a single site can give rise to 1-2 metastases over a period of approximately 20 weeks, however the number of metastases can be increased and the duration of the experiment reduced, by injecting 106 cells at 4 sites and removing the tumors at 5-6 weeks when they reach 7-8 mm diameter. After an additional 4-5 weeks multiple lung metastases are visible. Multiple lung metastases can also be achieved by tail vein injection of 5 x 105 cells and inflammation plays a role in the growth at this site as a significant reduction in metastasis is observed in mice lacking the inducible nitric oxide synthase. No Py230 tumor metastases are found in other tissues such as liver, kidney or spleen either with orthotopic or tail vein injection. In contrast, Py8119 cells form highly invasive, poorly differentiated claudin low EMT tumors upon injection into the mammary fat pad. The tumors grow rapidly, but excision does not result in lung metastasis despite their highly invasive phenotype, indicating that EMT alone is not sufficient for metastasis from the mammary fat pad. However, when the cells are injected into the tail vein, metastases develop at multiple tissue sites including lung, liver, kidney and spleen. Py8119 cells upregulate markers of EMT including twist, sna1, sna2 and MMP2 in comparison to Py230 cells, but whether Py230 cells undergo transient EMT and MET during metastasis is currently unknown. Additional luminal or EMT cell lines exhibit similar patterns of metastasis to the Py230 and Py8119 cell lines respectively. Since the majority of human breast cancers are luminal and the less frequent claudin low tumors have a poor prognosis, both the Py230 and Py8119 cell lines should be a useful in dissecting pathways of metastasis relevant to human breast cancer.

Citation Format: Lesley G. Ellies, Christopher Kuo. PyVmT luminal and EMT cell lines exhibit characteristic patterns of orthotopic and tail vein metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C91.