bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-236: Patient derived xenografts as high-fidelity genomic models for advanced breast cancer.
Authors: Li Shunqiang , Shen Dong , Li Ding , Yu Tao , Luo Jingqin , Hoog Jeremy , McMichael Joshua , Miller Chris , Larson Dave , Bose Ron , Fulton Bob , Wilson Rick , Perou Charles , Mardis Elaine , Ellis Matthew
Published: August 2014

A limitation of recent genome studies is that they have almost exclusively focused on early stage untreated samples. Consequently the genomic landscape of advanced and treatment-resistant disease is poorly documented, even though Stage 4 patients stand to benefit most from new therapeutic approaches. To address this issue we developed a panel of patient-derived xenografts (PDX) from Stage 3 and 4 patients with treatment-resistant disease to create a platform for detailed molecular and pharmacological investigation. Recently we reported a whole genome sequencing study of a single example of a breast cancer primary, brain metastasis and PDX “trio” demonstrating that the PDX model efficiently captured almost all of the genome-wide variants observed in the tumor and was enriched for mutations present in the metastatic sample (Ding, Ellis et al., Nature 2010). We now extend these findings by conducting massively parallel sequencing of 13 additional PDX models from a diverse set of locally- advanced or Stage 4 breast cancers, all of whom subsequently died from their disease. Structural variants (deletions, inversions and translocations) were remarkably stable and although new single nucleotide variants were observed post-engraftment, most were either non-coding or not expressed and only one had established functionality (K-RAS). PDX models are therefore high-fidelity genomic models for the biological and pharmacological study of complex, often tumor-unique somatic events responsible for lethal drug-resistant advanced breast cancer.

Citation Format: Shunqiang Li, Dong Shen, Ding Li, Tao Yu, Jingqin Luo, Jeremy Hoog, Joshua McMichael, Chris Miller, Dave Larson, Ron Bose, Bob Fulton, Rick Wilson, Charles Perou, Elaine Mardis, Matthew Ellis. Patient derived xenografts as high-fidelity genomic models for advanced 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 LB-236. doi:10.1158/1538-7445.AM2013-LB-236
Abstract LB-237: Human and microbial transcriptomics from lean and obese individuals with colorectal cancer: A comparison of Total and Poly A RNA sequencing from clinical samples.
Authors: Grice Desma M. , Bauer Denis C. , Duesing Konsta , Li Dongmei , Greenfield Paul , Nielsen Sarah , Draganic Brian , Smith Steve , Pockney Peter , Scott Rodney , Hannan Garry N.
Published: August 2014

Australia and New Zealand have the highest worldwide CRC incidence with CRC being the 2nd most commonly diagnosed cancer and the 3rd most common cause of cancer death among both men and women. CRC is a complex disease arising from the impact of environmental factors, including diet and lifestyle choices on different genetic backgrounds. Obesity and type 2 diabetes are significant risk factors for CRC, the levels of which are increasing in Australia. As a consequence CRC is projected to increase, being the most common Australian cancer by 2025. While the association of obesity with CRC has been reported by a number of studies, the mechanism\s that contribute to CRC development in the context of obesity are unknown. Understanding these mechanisms and potential genetic susceptibility is crucial for developing effective intervention and screening strategies. Recent evidence suggests that gut microbial communities are altered in obese individuals, resulting in a change in the predominant species and overall loss of community diversity but it is unknown if these changes impact CRC development or progression. We have established a comprehensive tissue, blood and microbial collection from 150 lean and obese colorectal cancer patients in the Hunter Region, Australia and commenced an integrative pilot next generation sequencing project to begin to unravel the link between obesity and CRC. Twelve individuals (6 lean and 6 obese) were selected for complementary next-generation sequencing; generating matched sequencing data sets (Total RNA-seq, Poly A RNA-seq, microbial RNA-seq and exome-seq) from normal colon, colon tumor, adipose and digesta samples samples. For this purpose, we have developed a method for simultaneously isolating human and microbial RNA from gut lumen of sufficient quality and quantity from limited material. Results presented will evaluate the differences in host and microbial transciptomics in normal colon and tumor tissue of lean and obese individuals with CRC and methodological comparisons between Total RNA-seq and Poly A RNA-seq will be reported.

Citation Format: Desma M. Grice, Denis C. Bauer, Konsta Duesing, Dongmei Li, Paul Greenfield, Sarah Nielsen, Brian Draganic, Steve Smith, Peter Pockney, Rodney Scott, Garry N. Hannan. Human and microbial transcriptomics from lean and obese individuals with colorectal cancer: A comparison of Total and Poly A RNA sequencing from clinical 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 LB-237. doi:10.1158/1538-7445.AM2013-LB-237
Abstract LB-248: BRAFV600E remodels the melanocyte transcriptome and induces BANCR to regulate melanoma cell migration.
Authors: Flockhart Ross J. , Webster Dan E. , Qu Kun , Mascarenhas Nicholas , Kovalski Joanna , Kretz Markus , Paul Khavari A.
Published: August 2014

Aberrations of protein-coding genes are a focus of cancer genomics; however, the impact of oncogenes on expression of the ~50% of transcripts without protein-coding potential, including long noncoding RNAs (lncRNAs), has been largely uncharacterized. Activating mutations in the BRAF oncogene are present in >70% of melanomas, 90% of which produce active mutant BRAF(V600E) protein. To define the impacts of oncogenic BRAF on the melanocyte transcriptome, massively parallel cDNA sequencing (RNA-seq) was performed on genetically matched normal human melanocytes with and without BRAF(V600E) expression. To enhance potential disease relevance by verifying expression of altered genes in BRAF-driven cancer tissue, parallel RNA-seq was also undertaken of two BRAF(V600E)-mutant human melanomas. BRAF(V600E) regulated expression of 1027 protein-coding transcripts and 39 annotated lncRNAs, as well as 70 unannotated, potentially novel, intergenic transcripts. These transcripts display both tissue-specific and multi-tissue expression profiles and harbor distinctive regulatory chromatin marks and transcription factor binding sites indicative of active transcription. Coding potential analysis of the 70 unannotated transcripts suggested that most may represent newly identified lncRNAs. BRAF-regulated lncRNA 1 (BANCR) was identified as a recurrently overexpressed, previously unannotated 693-bp transcript on chromosome 9 with a potential functional role in melanoma cell migration. BANCR knockdown reduced melanoma cell migration, and this could be rescued by the chemokine CXCL11. Combining RNA-seq of oncogene-expressing normal cells with RNA-seq of their corresponding human cancers may represent a useful approach to discover new oncogene-regulated RNA transcripts of potential clinical relevance in cancer.

Citation Format: Ross J. Flockhart, Dan E. Webster, Kun Qu, Nicholas Mascarenhas, Joanna Kovalski, Markus Kretz, Khavari A. Paul. BRAFV600E remodels the melanocyte transcriptome and induces BANCR to regulate melanoma cell migration. [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 LB-248. doi:10.1158/1538-7445.AM2013-LB-248
Abstract LB-250: Development of a miR34-based cancer therapy.
Authors: Daige Chris , Wiggins Jason , Priddy Leslie , Kelnar Kevin , Zhao Jane , Bader Andreas , Brown David
Published: August 2014

miR-34 is a tumor suppressor miRNA that functions within the p53 pathway and regulates the expression of more than twenty oncogenes, including MET, MYC, WNT, and MYB. We have created a mimic of miR-34 called miR-Rx34 that induces cell cycle arrest, senescence, and apoptosis in cancer cells. Transient transfection of miR-Rx34 significantly reduces the proliferation of cancer cells derived from patients with liver, lung, breast, colon, and pancreatic cancers as well as melanoma, lymphoma, and multiple myeloma. miR-Rx34 has been encapsulated in an anionic liposome to produce a particle called MRX34 that has a diameter of ~120 nm. Intravenous injections of MRX34 causes dose-dependent increases in miR-34 levels in liver tumor, lung tumor, liver, lung, spleen, and other highly vascularized tissues in mice without inducing an immune response. Systemic delivery of MRX34 causes complete tumor regression in two orthotopic models of liver cancer. The exceptional potency of MRX34 likely results from its capacity to stimulate the p53 pathway and down-regulate genes in the wnt/B-catenin, MET, MAPK, and VegF pathways in liver tumors. The no adverse effects level observed for MRX34 in IND-enabling toxicology studies in monkeys and rats are 10-100-fold higher than the doses that produce complete tumor regression in mice, suggesting that the drug candidate will have a broad therapeutic window in cancer patients. Clinical studies with MRX34 that are expected to begin in early 2013 will provide the first measure of the therapeutic potential of a tumor suppressor miRNA.

Citation Format: Chris Daige, Jason Wiggins, Leslie Priddy, Kevin Kelnar, Jane Zhao, Andreas Bader, David Brown. Development of a miR34-based cancer 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 LB-250. doi:10.1158/1538-7445.AM2013-LB-250
Abstract LB-259: Arid1a loss in collaboration with PI3K pathway activation leads to ovarian tumorigenesis in mouse.
Authors: Guan Bin , Wang Tian-Li , Shih Ie-Ming
Published: August 2014

ARID1A encoding BAF250a is a recently identified tumor suppressor involved in chromatin remodeling. Inactivating somatic mutations occur in a wide variety of human cancers including ovarian carcinoma. Interestingly, ARID1A mutations significantly co-occur with either PIK3CA or PTEN mutations in human neoplastic tissues, suggesting a molecular collaboration of ARID1A and PI3K/PTEN pathways in tumor development. We tested this possibility in Arid1a knockout mice (n=10) and Arid1a/Pten double knockout mice (n= 12), in which Arid1a and Pten can be conditionally deleted in the mouse ovarian surface epithelium (OSE) by intra-ovarian bursal injection of Ad-Cre virus. Arid1a knockout mice did not develop discernable histopathological changes 12 months after Ad-Cre administration in OSE, a finding similar to Pten knockout mice as reported previously. In contrast, Arid1a/Pten double knockout mice developed ovarian tumors in 40% mice 6 months after Ad-Cre virus injection. The tumors effaced ovarian tissues, disseminated intraperitoneally and developed ascites. None of the tumors expressed detectable ARID1A and Pten immunoreactivity, while fibroblastic cells and OSE cells from control ovaries are positive for both markers. Although all the tumors appear poorly differentiated, 80% tumors were positive for cytokeratin 8, suggestive of an epithelial origin. The remaining 60% mice without grossly visible tumors showed hyperplasia of OSE in Ad-Cre treated ovaries but not in non-injected controls. The hyperplasia of OSE developed as early as 2 months after Ad-Cre administration. In summary, our results demonstrate that mutation of Arid1a requires a second hit to initiate tumorigenesis. Collaboration between Arid1a inactivation and PI3K/Pten pathway aberration is sufficient to induce OSE hyperplasia and to develop poorly differentiated carcinomas.

Citation Format: Bin Guan, Tian-Li Wang, Ie-Ming Shih. Arid1a loss in collaboration with PI3K pathway activation leads to ovarian tumorigenesis in mouse. [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 LB-259. doi:10.1158/1538-7445.AM2013-LB-259
Abstract LB-261: Mammary tumorigenesis in haploinsufficient Cripto-1 mice.
Authors: Rangel Maria Cristina , Raafat Ahmed , Castro Nadia P. , Klauzinska Malgorzata , Karasawa Hideaki , Baker Alyson , Callahan Robert , Salomon David S.
Published: August 2014

The embryonic gene Cripto-1 (Cr-1) is expressed at very low levels in normal adult tissues and detected at high levels in several human tumors. We have previously found that Cr-1 can facilitate the proteolytic intracellular processing of all four Notch receptors. Transgenic mice overexpressing the Notch4 intracellular domain (Int3) in the mammary gland under the control of the whey acidic protein (WAP) promoter rapidly develop mammary hyperplasias and undifferentiated mammary adenocarcinomas in aged nulliparous females and after multiple cycles of pregnancy. Eighty percent of WAP-Int3 females develop mammary tumors by the second pregnancy. To assess the contribution of Cr-1 in the hyperplasias and tumors that arise in transgenic WAP-Int3 mice, we developed a bi-transgenic mouse model lacking one allele of Cr-1, by crossing the knock-in Cr-1/LacZ mice (containing a promoter-less bacterial β-galactosidase gene which disrupts one of the Cr-1 alleles) to WAP-Int3 transgenic mice. We found a 90% reduction in the frequency of mammary hyperplasias in these Cr-1/LacZ/WAP-Int3 mice in comparison to WAP-Int3 mice. Additionally, in the absence of one allele of Cr-1, Int3-induced transformation of mouse mammary epithelial cells was delayed in vivo, and additional cycles of pregnancy were required to observe tumor growth. Notably, only 20% of the Int3/Cr-1 haploinsufficient mice developed mammary tumors by the second pregnancy, as compared to 80% of those mice that preserve two alleles of Cr-1. The few tumors derived from these mice also showed a significantly more differentiated histology in comparison to those tumors that arose from mice preserving both alleles of Cr-1. We are currently generating a mouse model which conditionally lacks the two alleles of Cr-1 in the mammary gland, what should better address our question regarding the functional significance of Cr-1 in the development of Int3-induced mammary tumorigenesis.

Citation Format: Maria Cristina Rangel, Ahmed Raafat, Nadia P. Castro, Malgorzata Klauzinska, Hideaki Karasawa, Alyson Baker, Robert Callahan, David S. Salomon. Mammary tumorigenesis in haploinsufficient Cripto-1 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 LB-261. doi:10.1158/1538-7445.AM2013-LB-261
Abstract LB-266: SIRT1 governs GnRH neuron migration and The Kallmann syndrome phenotype.
Authors: Wang Liping , Sante Gabriele Di , Wang Chenguang , Powell Michael J. , McBurney Michael W. , Pestell Richard G.
Published: August 2014

SIRT1 is a type III histone deacetylase, linked to diverse functions in a variety of physiological settings. SIRT1 is highly expressed in gonadogenesis and Sirt1−/− mice demonstrate infertility and die post-natally from a variety of abnormalities, including pancreas, lung, skeletal, and heart defects. Recent studies have shown reduced intratesticular testosterone levels in Sirt1−/− mice. The normal migration of GnRH neurons from the vomeronasal organ (VNO) to hypothalamus is required for their destined location where GnRH stimulates the anterior pituitary to secrete gonadotropins. A subset of genes has been found to be involved in this process. In the current studies, we investigated the function of the hypothalamic pituitary gonadal axis in Sirt1−/− mice. Herein, a GnRH stimulation test was conducted on Sirt1−/− mice or littermate controls. The addition of GnRH to Sirt1−/− mice resulted in an increase in testosterone, LH and FSH levels, to a level similar to physiological secretion in normal controls. Immunostaining of mouse E14.5 brain in sagittal sections demonstrated that most of the GnRH positive neurons migrated to the forebrain in Sirt1+/+ mice whereas in Sirt1−/- mice, all of GnRH neurons resided in the VNO region and are undetectable in the forebrain. Treatment of hypothalamic neuronal cell lines, GN11 cells or GT1-7 cells with either Sirtinol or Nicotinamide, reduced cell migration in wound-healing and Matrigel invasion assays, most dramatically in trans-well migration assays. Retroviral gene transduction of cells with an expression vector encoding SIRT1, enhanced wound closure and invasiveness while transduction with the SIRT1 H363Y mutant abrogated migration. Cortactin is an F-actin binding protein involved in cancer cell migration and neurite outgrowth. Immunoprecipitation of FLAG-tagged SIRT1 and subsequent Western blot analysis revealed the association of SIRT1 with cortactin. Inhibition of SIRT1 activity by trichostatin A (TSA) or Nicotinamide, increased cortactin acetylation in 3T3 Sirt1+/+ cells, while in 3T3 Sirt1−/− cells, Nicotinamide did not increase cortactin acetylation. Deacetylation of cortactin by SIRT1 may play a role in GnRH neuronal migration. These studies demonstrated the critical role of SIRT1 activity in GnRH neuron migration and invasion both in cultured cells and in vivo.

Citation Format: Liping Wang, Gabriele Di Sante, Chenguang Wang, Michael J. Powell, Michael W. McBurney, Richard G. Pestell. SIRT1 governs GnRH neuron migration and The Kallmann syndrome phenotype. [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 LB-266. doi:10.1158/1538-7445.AM2013-LB-266
Abstract LB-272: AXL induces epithelial to mesenchymal transition and regulates the function of breast cancer stem cells.
Authors: Asiedu Michael K. , Beauchamp-Perez Francis , Ingle James N. , Behrens Marshall D. , Radisky Derek C. , Knutson Keith
Published: August 2014

Despite significant progress in the treatment of breast cancer particularly through the use of targeted therapy, relapse and chemo-resistance remain a major hindrance in the fight to minimize the burden of the disease. Accumulating evidence suggest that breast cancer stem cells (BCSCs), which show resistance to chemotherapy and radiation, drive tumor initiation and disease recurrence. It is becoming increasingly clear that a rare subpopulation of cells known as cancer stem cells (CSC), able to be generated through epithelial to mesenchymal transition (EMT) and capable of tumor initiation and self-renewal, contributes to treatment resistance and metastases. This means that a more effective therapy should target both the chemoresistant CSCs and the proliferating epithelial cells that give rise to them in order to reverse EMT and attenuate their conversion to CSCs. Here, we demonstrate a novel function of AXL in acting upstream to induce EMT in normal and immortalized human mammary epithelial cells in an apparent positive feedback loop mechanism and regulate breast CSC (BCSC) self-renewal and chemoresistance. Downregulation of AXL expression using AXL inhibitor MP470 (amuvatinib) or shRNA reversed EMT in mesenchymal normal human mammary epithelial cells and murine BCSCs attenuating self-renewal and restored chemosensitivity of the BCSCs. AXL expression was also found to be associated with expression of stem cell genes, regulation of metastases genes, increased tumorigenicity, and was important for BCSC invasion and migration. Inactivation of AXL also led to downregulation of NFκB pathway and reduced tumor formation in vivo. Together, our data suggest that targeted therapy against AXL, in combination with systemic therapies, has the potential to improve response to anti-cancer therapies and to reduce breast cancer recurrence and metastases.

Citation Format: Michael K. Asiedu, Francis Beauchamp-Perez, James N. Ingle, Marshall D. Behrens, Derek C. Radisky, Keith Knutson. AXL induces epithelial to mesenchymal transition and regulates the function of breast cancer stem 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 LB-272. doi:10.1158/1538-7445.AM2013-LB-272
Abstract LB-276: CLCA2 interactor EVA1 maintains epithelial differentiation of HMEC.
Authors: Elble Randolph C. , Ramena Grace , Walia Vijay
Published: August 2014

CLCA2 is a p53-inducible transmembrane protein that is frequently downregulated in breast cancer. It is induced during MET in immortalized HMEC, and its knockdown causes EMT. To determine how CLCA2 promotes epithelial differentiation, we searched for interactors using membrane dihybrid screening. We discovered a strong interaction with the cell junctional protein EVA1 (Epithelial V-like Antigen 1), confirmed by co-immunoprecipitation and immunolocalization experiments. Like CLCA2, EVA1 is a type I transmembrane protein that is regulated by p53. It mediates homophilic cell-cell adhesion in diverse epithelial tissues. We found that EVA1 is frequently downregulated in breast tumors and breast cancer cell lines, especially those of mesenchymal phenotype. Like CLCA2, knockdown of EVA1 resulted in rapid EMT in immortalized HMEC and increased invasiveness. The interacting domains were delimited by deletion analysis, revealing that the CLCA2 transmembrane segment (TMS) alone was sufficient for the interaction with EVA1. Surprisingly, EVA1 bound to the TMS only in the context of full length CLCA2 precursor, but not in the context of the C-terminal cleavage product, suggesting that cleavage of CLCA2 causes a conformational shift and release of EVA1. The interaction was specific, as other transmembrane proteins did not interact with CLCA2 or EVA1. To determine whether CLCA2 regulates EVA1 localization to tight junctions or hemophilic ligation, we fused the CLCA2 or EVA1 TMS to a secreted heterologous protein to create competitive inhibitors. These results identify the CLCA2-EVA1 complex as pivotal in maintaining epithelial differentiation and explain the downregulation of both genes during tumor progression.

Citation Format: Randolph C. Elble, Grace Ramena, Vijay Walia. CLCA2 interactor EVA1 maintains epithelial differentiation of HMEC. [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 LB-276. doi:10.1158/1538-7445.AM2013-LB-276
Abstract LB-282: Loss of PTP-PEST promotes tumor invasion, apoptosis resistance and activation of STAT3 in metastatic colon cancer.
Authors: Espejo Rosario , Jeng Yowjiun , Johnson Camille , Carmical Russ , Brasier Allan , Chao Celia , Sastry Sarita K.
Published: August 2014

The transcription factor STAT3 is hyperactivated by phosphorylation on Y705 in over 75% of metastatic colon cancers and is associated with EMT, cancer stem cells, survival and chemoresistance. However, the mechanisms of STAT3 inactivation are not well-defined. Here, we identified the protein tyrosine phosphatase, PTP-PEST, as a novel negative regulator of STAT3 in colon carcinoma cells. Using lentiviral-mediated shRNA silencing of PTP-PEST in HCT116 colon carcinoma cells, we show that PTP-PEST knockdown enhances activation of STAT3. Whereas STAT3 is activated by cell attachment to collagen in control cells expressing non-targeting shRNA, PTP-PEST knockdown leads to constitutive, anchorage-independent STAT3 activity. Silencing of PTP-PEST enhances anchorage-independent survival in soft agar, tumor sphere growth and matrigel invasion in vitro. Consistent with increased invasion and survival, PTP-PEST knockdown cells showed enhanced expression of STAT3 target genes, MMP2 and mcl-1. Significantly, PTP-PEST knockdown enhanced apoptosis resistance in three-dimensional matrigel cultures in response to the chemotherapy drug, 5-fluorouracil (5-FU). PTP-PEST knockdown cells treated with 5-FU in 3-D matrigel spheroid cultures showed increased cell viability, reduced caspase-3 activation and enhanced activation of STAT3 relative to non-targeting controls. Furthermore, in subcutaneous nude mouse xenografts, although overall tumor growth was not affected by PTP-PEST knockdown, immunohistochemistry showed reduced caspase-3 and elevated P-STAT3 levels in these tumors. Intrasplenic injection of PTP-PEST knockdown cells in athymic nude mice resulted in enhanced metastatic potential as assessed by quantitative PCR for human DNA content in mouse liver. Finally, reduced PTP-PEST expression correlates with metastasis in clinical specimens from colon cancer patients. Taken together, these findings suggest that down-regulation of PTP-PEST in colon cancer may promote metastasis through increased invasion and apoptosis resistance, mediated, in part, by enhanced activation of STAT3.

Citation Format: Rosario Espejo, Yowjiun Jeng, Camille Johnson, Russ Carmical, Allan Brasier, Celia Chao, Sarita K. Sastry. Loss of PTP-PEST promotes tumor invasion, apoptosis resistance and activation of STAT3 in metastatic colon 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 LB-282. doi:10.1158/1538-7445.AM2013-LB-282
Abstract LB-284: Bone marrow-derived progenitor cells develop into myeloid-derived suppressor cells at metastatic sites.
Authors: Giles Amber , Vicioso Yorleny , Persenaire Christianne , Kasai Miki , Highfill Steven , Mendoza Arnulfo , Kaplan Rosandra
Published: August 2014

The ability of tumor cells to metastasize to distant tissues is the most lethal aspect of cancer. Prior to detectable metastasis tumors elicit distant changes within the bone marrow and future sites of metastasis, including formation of the pre-metastatic niche. We have found that prior to detectable spontaneous metastasis, a primary tumor causes enhanced production and mobilization of progenitor cells from the bone marrow into the blood. We find in cancer patients that increased circulating progenitors are associated with metastatic disease progression. By utilizing bone marrow transplant models and a novel ex vivo lung culture, we demonstrate that bone marrow-derived progenitor cells accumulate at the primary tumor as well as metastatic lesions. As our cancer models approach detectable spontaneous metastases, we observe a loss of progenitor cells in pre-metastatic sites and an increase in myeloid-derived suppressor cells (MDSCs). We further traced adoptively transferred bone marrow-derived progenitors in tumor-bearing mice and demonstrate that these cells contribute to the MDSC population. Together, these data suggest that circulating progenitor cells provide a prognostic tool to predict metastatic dissemination. Furthermore, these cells likely contribute to metastatic progression by developing into MDSCs within the primary tumor and at metastatic sites.

Citation Format: Amber Giles, Yorleny Vicioso, Christianne Persenaire, Miki Kasai, Steven Highfill, Arnulfo Mendoza, Rosandra Kaplan. Bone marrow-derived progenitor cells develop into myeloid-derived suppressor cells at metastatic sites. [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 LB-284. doi:10.1158/1538-7445.AM2013-LB-284
Abstract LB-306: A novel RNA oligonucleotide improves liver function and inhibits liver carcinogenesis in vivo.
Authors: Reebye Vikash
Published: August 2014

Hepatocellular carcinoma (HCC) occurs predominantly in patients with liver cirrhosis. Therapies to simultaneously reduce tumour burden and improve liver function are limited. Here, we show an innovative RNA-based targeted approach to enhance endogenous albumin production whilst reducing liver tumour burden.

We designed short activating RNA (saRNA) oligonucleotides to enhance expression of the transcriptional regulator and activator of albumin gene expression, CCAAT/enhancer-binding protein-α (C/EBPα). Increased levels of both C/EBPα and albumin mRNA in addition to a 3-fold increase in albumin secretion and a 50% decrease in cell proliferation were observed in saRNA transfected hepatocellular carcinoma cells (HepG2).

Intravenous injection of C/EPBα-saRNA in a liver cirrhotic rat model with multifocal liver tumours caused a significant increase in circulating serum albumin levels, and reduction in circulating ALT and AST levels- suggesting an amelioration of liver function. Concomitantly a significant reduction in tumour burden and pre-neoplastic transformation placental glutathione S-transferase (GST-p) staining was observed.

Using mRNA expression microarray, quantitative PCR, Western blot and methylation analysis of CpG islands in C/EPBα-saRNA transfected HepG2 cells, we found up-regulation of C/EBPα and albumin; and a negative regulation of IL6R, c-Myc and STAT3 phosphorylation.

We demonstrate for the first time that a novel injectable saRNA oligonucleotide successfully reduces tumour burden and simultaneously improves liver function in a clinically relevant liver cirrhosis/HCC model.

Citation Format: Vikash Reebye. A novel RNA oligonucleotide improves liver function and inhibits liver carcinogenesis in vivo. [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 LB-306. doi:10.1158/1538-7445.AM2013-LB-306

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract LB-313: Development of a novel anti-MYC therapeutic with efficacy against liver and kidney cancers.
Authors: Bellovin David I. , Yevtodiyenko Aleksey , Adam Stacey J. , Fernando Hanan , Arzeno Julia , Gabay Meital , Felsher Dean W.
Published: August 2014

One of the most attractive, yet elusive, targets for cancer therapy is the MYC oncogene. MYC is overexpressed in the majority of human cancers, and we and others have shown that suppression of this oncogene is sufficient to induce sustained tumor regression, a phenomenon known as oncogene addiction. However, no viable therapy has been developed as yet that targets this crucial regulator of the tumor phenotype. Here, we report the development of a novel antisense therapeutic that targets the MYC oncogene. This inhibitor can potently suppress MYC expression in primary tumors in vivo, as demonstrated by immunohistochemistry and real-time PCR. Importantly, we show that treatment with the anti-MYC drug significant reduces tumor onset and progression in transgenic mouse models of primary hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) cancer. We imaged tumor growth via MRI and utilized quantitative image analysis to demonstrate the inhibition of HCC and RCC progression, confirming our results on total tumor burden histologically after four weeks of drug treatment. Additionally, this antisense therapy against MYC can also attenuate the growth of human HCC cells in vivo, irrespective of the inducing oncogene. In contrast with other reported MYC inhibitors, our approach results in no discernible toxicity due to MYC suppression on any organs examined in the treated animals. Thus, we have established a novel therapy that directly inhibits the MYC oncogene, representing a potentially exciting advance in the field of targeted cancer therapeutics.

Citation Format: David I. Bellovin, Aleksey Yevtodiyenko, Stacey J. Adam, Hanan Fernando, Julia Arzeno, Meital Gabay, Dean W. Felsher. Development of a novel anti-MYC therapeutic with efficacy against liver and kidney cancers. [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 LB-313. doi:10.1158/1538-7445.AM2013-LB-313

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract LB-318: Reshaping the cancer proteome: therapeutic targeting of signaling and resistance in cancer by antisense manipulation of RNA processing.
Authors: Cartegni Luca , Spraggon lee
Published: August 2014

Activation of the receptor tyrosine kinase (RTK) signaling pathways represents a key aspect of tumorigenesis in a broad range of human cancers. Thus, targeting of pathogenic RTKs, mainly with small molecule inhibitors and antibodies, has become an attractive therapeutic approach for cancer therapy. However, resistance by multiple mechanisms, including mutational re-activation of RTK signaling, activation of alternative RTK pathways, EMT transition and others, inevitably occurs over time.

We recently identified a number of novel secreted soluble decoy RTKs isoforms (sdRTKs) generated by a U1-snRNP-dependent alternative intronic polyadenylation mechanism. We therefore developed a novel antisense-based method to effectively activate the expression of these sdRTKs, both in vitro and in vivo. This leads to the generation of endogenous dominant negative variants of RTKs, which can specifically affect the signaling of pathogenic RTKs and therefore provides a novel cancer therapy approach.

Employing specific antisense compounds designed to activate intronic polyA sites, we are able to induce natural truncated EGFR variants that encode its extracellular ligand-binding domain but lack the intracellular signaling domain. These compounds thus can inhibit EGFR signaling by a three fold-mechanism: 1) removal of FL receptor, 2) sequestration of ligands and 3) non-productive dimerization with residual receptors. They are therefore designed to affect signaling both of targeted cells and of bystanders.

Here we will show that, using this approach, we can target EGFR signaling both in vitro and in tumors. Importantly, with this method we can bypass the emergence of resistance typically seen with targeted drug treatments. Further development of this methodology will therefore provide the basis for an exciting novel approach to targeting and inhibiting oncogenic EGFR signaling and other pathways in a variety of cancers.

Citation Format: Luca Cartegni, lee Spraggon. Reshaping the cancer proteome: therapeutic targeting of signaling and resistance in cancer by antisense manipulation of RNA processing. [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 LB-318. doi:10.1158/1538-7445.AM2013-LB-318
Abstract LB-321: Combination dendritic cell and conventional chemoradiation therapy improves survival for rectal cancer in a murine model.
Authors: Kachare Swapnil D. , Cayer Jennifer M. , Carver F. Melinda , Englert Zachary P. , Verbanac Kathryn M. , Zervos Emmanuel E. , Vohra Nasreen A.
Published: August 2014

The goal of neoadjuvant therapy in rectal cancer is to downstage or preferably eradicate the tumor prior to resection. Achieving complete pathologic response (CPR) using neoadjuvant chemoradiation is associated with improved overall and disease free survival. The aim of this study was to achieve improved complete pathologic response rates and survival by combining intra-tumoral injection of dendritic cells with conventional therapy. A syngeneic rectal cancer cell line (CT26) was subcutaneously injected into the thigh of immunocompetent Balb/c mice. Mice either received no treatment, conventional chemoradiation (CXRT) (5-fluorouracil + XRT) for 3 weeks, or CXRT plus tumor-lysate pulsed dendritic cells (CXRT/DC). Specific anti-CT26 cytotoxic T cell (CTL) activity was determined using standard chromium release assay. Flow cytometry for immune cell subsets was performed on cells isolated from spleens and tumors. Animals in the control group showed predictable uninhibited growth and all were euthanized due to tumor size. CXRT animals showed improved survival but none achieved complete response. Thirty three percent of the animals in CXRT/DC group exhibited CPR. Median survival for the control, CXRT, and CXRT/DC treated animals was 24, 46.5, 67 days, (p<0.0001). Splenocytes from CXRT/DC treated mice exhibited higher specific anti-CT26 CTL activity (28%) when compared to CXRT (17%), untreated control (11%) and naïve mice (<1%). Flow cytometry demonstrated an increase in regulatory T cells (Tregs), macrophages, granulocytic myeloid derived suppressor cells (MDSCs) and monocytic MDSCs in tumor bearing animals, (p<0.05). Dendritic cell activity stimulates anti-tumor CTL responses, but may also decrease MDSC and Treg mediated immunosuppression. Addition of dendritic cells to conventional chemoradiation therapy for rectal cancer increases complete pathologic response and thereby survival via immune modulation. Further analysis will allow subset comparisons between treatment groups.

Citation Format: Swapnil D. Kachare, Jennifer M. Cayer, F. Melinda Carver, Zachary P. Englert, Kathryn M. Verbanac, Emmanuel E. Zervos, Nasreen A. Vohra. Combination dendritic cell and conventional chemoradiation therapy improves survival for rectal cancer in a murine 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 LB-321. doi:10.1158/1538-7445.AM2013-LB-321
Abstract LB-325: Sphingosine-1-phosphate links chronic intestinal inflammation to development of colitis-associated cancer.
Authors: Nagahashi Masayuki , Liang Jie , Kim Eugene Y. , Harikumar Kuzhuvelil B. , Yamada Akimitsu , Huang Wei-Ching , Hait Nitai C. , Allegood Jeremy C. , Price Megan M. , Avni Dorit , Takabe Kazuaki , Kordula Tomasz , Milstien Sheldon , Spiegel Sarah
Published: August 2014

Inflammatory bowel disease is an important risk factor for colorectal cancer. The pro-inflammatory cytokines TNF-alpha and IL-6 and their downstream master transcription factors NF-kappaB and Stat3 are critical regulators of chronic inflammation and cancer. There is growing evidence that sphingosine-1-phosphage (S1P), a pleiotropic bioactive sphingolipid metabolite formed inside cells by two closely related sphingosine kinases, SphK1 and SphK2, is involved in inflammation and cancer. In this work, we have shown that S1P produced by upregulation of SphK1 links chronic intestinal inflammation to CAC and both are exacerbated by deletion of SphK2. S1P is essential for production of the multifunctional NF-kappaB-regulated cytokine IL-6, persistent activation of the transcription factor Stat3, and consequent upregulation of the S1P receptor, S1PR1. Adoptive transfer demonstrated that SphK2 deficiency in hematopoietic cells contributed to colitis severity, IL-6 production, and activation of Stat3 and NF-kappaB. The pro-drug FTY720 decreased SphK1 and S1PR1 and eliminated the NF-kappaB-IL-6-Stat3 amplification cascade and development of CAC even in SphK2-/- mice, suggesting that FTY720 may be useful in treating colon cancer in individuals with ulcerative colitis. Thus, the SphK1-S1P-S1PR1 axis is at the nexus between NF-kappaB and Stat3 and connects chronic inflammation and CAC.

This work was supported by NIH grants R37GM043880, R01CA61774 (to S.S.) and K12HD055881 and the Susan G. Komen for the Cure Research Foundation grant (to K.T.). M.N. is a Japan Society for the Promotion of Science Postdoctoral Fellow. E.Y.K. and J.C.A. were supported by NIH training grant T32HL094290.

Citation Format: Masayuki Nagahashi, Jie Liang, Eugene Y. Kim, Kuzhuvelil B. Harikumar, Akimitsu Yamada, Wei-Ching Huang, Nitai C. Hait, Jeremy C. Allegood, Megan M. Price, Dorit Avni, Kazuaki Takabe, Tomasz Kordula, Sheldon Milstien, Sarah Spiegel. Sphingosine-1-phosphate links chronic intestinal inflammation to development of colitis-associated 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 LB-325. doi:10.1158/1538-7445.AM2013-LB-325
Abstract LB-340: Mechanism of bevacizumab internalization and fate by brain endothelial cells .
Authors: Muller-Greven Gaelle M. , Carlin Cathleen , Gladson Candece L.
Published: August 2014

Antiangiogenic immunotherapy shows great promise for treatment of malignancies, including cancer. Bevacizumab is a humanized monoclonal antibody that inactivates vascular endothelial growth factor-A (VEGF-A), thereby inhibiting angiogenesis. It has received FDA approval for patients with recurrent glioblastoma (GBM); however, more than 30% of patients are non-responsive. The internalization and fate of bevacizumab in endothelial cells (ECs) may play a critical role in the response to therapy, i.e., bevacizumab may be degraded, recycled to the vessel lumen, or transcytosed to the sub-basal EC where tumor cell VEGF-A is found. We examined the internalization of bevacizumab by normal brain ECs in different conditions and found that internalization increased in a time-dependent manner (30 min - 24 hrs). Epidermal growth factor (EGF) stimulated internalization, suggesting bevacizumab enters the cells by an endocytic pathway that is induced by growth factors, such as macropinocytosis. Also, internalized bevacizumab was compartmentalized into vesicles that in part co-localized with the EGF receptor. Treatment with Amiloride (inhibitor of macropinocytosis) decreased the number of bevacizumab-containing vesicles per cell, suggesting macropinocytosis may be one mechanism of internalization. Treatment with Bafilomycin A1 (inhibitor of lysosomal acidification) caused accumulation of bevacizumab, suggesting one fate is lysosomal degradation. Ongoing experiments will determine the endocytic compartment(s) containing bevacizumab, its trafficking, and whether it is transcytosed across normal brain and tumor-associated ECs. Understanding the mechanism of internalization and trafficking of bevacizumab in brain ECs will positively impact the design and modification of monoclonal antibody therapy for GBM patients and for other cancers.

Citation Format: Gaelle M. Muller-Greven, Cathleen Carlin, Candece L. Gladson. Mechanism of bevacizumab internalization and fate by brain endothelial 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 LB-340. doi:10.1158/1538-7445.AM2013-LB-340
Abstract LB-342: Macrophage-secreted cytokines drive acinar-to-ductal metaplasia of the pancreas.
Authors: Liou Geou-yarh , Doeppler Heike , Storz Peter
Published: August 2014

In response to inflammation, pancreatic acinar cells can undergo acinar-to-ductal metaplasia (ADM), a reprogramming event that induces transdifferentiation to a duct-like phenotype and in the context of additional oncogenic stimulation, contributes to development of pancreatic cancer. The signalling mechanisms underlying pancreatitis-inducing ADM are largely undefined. Our results provide evidence that macrophages infiltrating the pancreas drive this transdifferentiation process. We identify the macrophage-secreted inflammatory cytokines RANTES and TNFα as mediators of such signaling. Both RANTES and TNFα induce ADM through activation of nuclear factor κ-B and its target genes involved in regulating survival, proliferation and degradation of extracellular matrix. In particular we identify matrix metalloproteinases (MMPs) as targets that drive ADM, and provide in vivo data suggesting that MMP inhibitors may be efficiently applied to block pancreatitis-induced ADM in therapy.

Citation Format: Geou-yarh Liou, Heike Doeppler, Peter Storz. Macrophage-secreted cytokines drive acinar-to-ductal metaplasia of the pancreas. [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 LB-342. doi:10.1158/1538-7445.AM2013-LB-342
Abstract LB-343: Host response to paclitaxel chemotherapy promotes metastasis via the secretion of VEGF-C by macrophages.
Authors: Gingis-Velitski Svetlana , Kaidar-Person Orit , Alishekevitz Dror , Bril Rotem , Fremder Ella , Shaked Yuval
Published: August 2014

Recent studies indicate that while chemotherapy can strongly restrict or reverse tumor growth, the response of the normal host tissue to the therapy can counteract tumor growth control by promoting the re-growth of residual tumor cells and the outgrowth of metastases. We sought for host factors promoting metastasis following paclitaxel (PTX) chemotherapy. The prolymphangiogenic growth factor, VEGF-C, was highly expressed in plasma of PTX-treated mice, and could induce migration, invasion, and tube formation of lymphatic vessels when compared to plasma from control mice. In both 4T1 breast and Lewis lung carcinomas we found an increased number of lymphatic vessels positioned at the center of the tumors from PTX-treated mice, in contrast to tumors from control mice, in which lymphatic vessels were positioned at the tumor periphery. Since VEGFR3 is the major receptor for VEGF-C-induced lymphangiogenesis, we evaluated the therapeutic effect of anti-VEGFR3 blocking antibody in combination with PTX. 4T1 bearing mice treated with PTX+anti-VEGFR3 exhibited a significant reduction in tumor re-growth and inhibition of metastasis which enhanced their overall survival, when compared to mice treated with PTX alone. However, no significant difference in survival of mice bearing 4T1 experimental metastasis in the lungs, was observed in any of the treatment groups, suggesting that VEGFR3 and VEGF-C promote tumor cell dissemination from treated tumors, but may not affect their seeding at metastatic sites. In addition, an abundant number of macrophages highly secreting VEGF-C were found to colonize 4T1 tumors from PTX-treated mice when compared to tumors from untreated mice. Similarly, breast carcinomas from cancer patients after neoadjuvant chemotherapy exhibited high expression of VEGF-C when compared to their pre-treated biopsies. Overall, our results suggest an additional role for macrophages in the tumor microenvironment, which in response to chemotherapy promote tumor re-growth and metastasis spread, a process which can be blocked by the disruption of VEGF-C/VEGF-R3 pathway.

Citation Format: Svetlana Gingis-Velitski, Orit Kaidar-Person, Dror Alishekevitz, Rotem Bril, Ella Fremder, Yuval Shaked. Host response to paclitaxel chemotherapy promotes metastasis via the secretion of VEGF-C by macrophages. [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 LB-343. doi:10.1158/1538-7445.AM2013-LB-343