bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5228: mTORC2 mediates SDF-1α/CXCL12-induced angiogenesis
Authors: Ziegler Mary E. , Hatch Michaela M.S. , Hughes Christopher C.W.
Published: August 2015

Angiogenesis occurs when new blood vessels sprout from the existing vasculature and mature into an organized and functional circulatory system. Physiological angiogenesis is stringently regulated and occurs transiently. Numerous disease states, including chronic inflammation and cancer, induce pathological angiogenesis, which disrupts the stable vascular network by altering both positive and negative angiogenic regulators. The chemokine stromal-cell derived factor-1 (SDF-1α, also called CXCL12) and its receptor CXCR4 promote endothelial cell (EC) migration and tube formation. PI3K is a key downstream regulator of CXCR4-mediated chemotaxis and mammalian target of rapamycin (mTOR) is at the center of PI3K-mediated signal transduction. mTOR exists in two complexes: mTOR complex 1 (mTORC1) and 2 (mTORC2). Receptor induced mTORC1 signal transduction has been widely studied. In contrast, the signaling upstream of mTORC2 remains elusive. We hypothesized that the SDF-1 α/CXCR4/mTOR signaling axis contributes to the molecular mechanism of tumor angiogenesis. This study illustrates that SDF-1α activates a distinct molecular signaling cascade in EC that involves CXCR4, G protein, PI3K and mTORC2, but not mTORC1. CXCR4 inhibition blocks sprouting in a 3D in vitro angiogenesis model, and specific inhibition of each of the mTOR complexes reveals that sprouting angiogenesis requires mTORC2 signal transduction. In a mouse model, tumor angiogenesis is significantly reduced only when mTORC2 is targeted. An analysis of targets downstream of mTORC2 indicates that 6-phosphofructo-2-kinase (PFKFB3), which is a key regulator of glycolytic flux and sprouting angiogenesis, is reduced in vivo when mTORC2 is targeted and tumor angiogenesis is inhibited. This study provides evidence that mTORC2 is an important regulator of angiogenesis that is downstream of GPCR signaling and upstream of metabolic regulation. In addition, these data present a potential link between mTORC2, metabolism and angiogenesis.

Citation Format: Mary E. Ziegler, Michaela M.S. Hatch, Christopher C.W. Hughes. mTORC2 mediates SDF-1α/CXCL12-induced angiogenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5228. doi:10.1158/1538-7445.AM2015-5228
Abstract 5229: Disruption of the acetylcholine signaling pathway suppresses the growth and angiogenesis of human lung cancers
Authors: Dasgupta Piyali , Brown Kathleen C. , Lau Jamie K. , Dom Aaron M. , Thornhill Brent A. , Crabtree Clayton M. , Witte Theodore R. , Hardman W E. , Stover Cody A. , Carpenter A B. , Chen Yi C.
Published: August 2015

Cigarette smoking bears a strong association with the development of lung cancer. Nicotine is the addictive component of cigarettes. Several convergent studies show that nicotine facilitates the growth and angiogenesis of human lung cancers. The biological activity of nicotine is mediated by nicotinic acetylcholine receptors (nAChRs). The endogenous ligand of nAChRs is acetylcholine (ACh). Data from our laboratory and other research groups show that lung cancers express all of the genes for synthesis, transport and degradation of ACh. These include nAChRs, choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), choline transporter (ChT1) and acetylcholinesterase (AChE). Nicotine upregulates the ACh-signaling loop in human lung cancer cells. Therefore, we conjectured that disruption of ACh-signaling pathway should suppress the growth of human cancers. We show that alpha7-nAChR antagonists robustly suppress angiogenesis in human lung and retinal microvascular endothelial cells. The anti-angiogenic activity of alpha7-nAChR antagonists was also observed in chicken chorioallantoic membrane (CAM) and nude mouse models. Similarly, vesamicol, a small molecule antagonist of VAChT, decreases nicotine-induced tumor growth in human NSCLCs. Our studies suggest that the acetylcholine signaling pathway may be have potential applications in the therapy of human lung cancers. Our results are also relevant to lung cancer patients who are exposed to nicotine via secondhand smoke, nicotine patches, gums or electronic cigarettes.

Citation Format: Piyali Dasgupta, Kathleen C. Brown, Jamie K. Lau, Aaron M. Dom, Brent A. Thornhill, Clayton M. Crabtree, Theodore R. Witte, W E. Hardman, Cody A. Stover, A B. Carpenter, Yi C. Chen. Disruption of the acetylcholine signaling pathway suppresses the growth and angiogenesis of human lung cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5229. doi:10.1158/1538-7445.AM2015-5229
Abstract 525: PHD3-mediated prolyl hydroxylation of non-muscle actin impairs polymerization and cell motility
Authors: Luo Weibo , Semenza Gregg L.
Published: August 2015

Actin filaments play an essential role in cell movement and many post-translational modifications regulate actin filament assembly. Here we report that prolyl hydroxylase 3 (PHD3) interacts with non-muscle actin in human cells and catalyzes hydroxylation of actin at proline residues 307 and 322. Blocking PHD3 catalytic activity, by either a pharmacological inhibitor or short hairpin RNA knockdown of PHD3 expression, decreases actin prolyl hydroxylation. Knockdown of PHD3 significantly increases filamentous F-actin assembly, which is reversed by PHD3 overexpression. PHD3 knockdown significantly increases cell velocity and migration distance. Inhibition of PHD3 prolyl hydroxylase activity by dimethyloxalylglycine also increases actin polymerization and cell migration. These data reveal a novel role for PHD3 as a negative regulator of cell motility through post-translational modification of non-muscle actins.

Citation Format: Weibo Luo, Gregg L. Semenza. PHD3-mediated prolyl hydroxylation of non-muscle actin impairs polymerization and cell motility. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 525. doi:10.1158/1538-7445.AM2015-525
Abstract 5253: LTβ receptor and NIK signaling activates the alternative NF-kB pathway in head and neck squamous cell carcinoma
Authors: Das Rita , Cheng Tsu-Fang , coupar Jamie , Saleh Anthony , Yang Xingping , Zhang jialing , Cornelius shaleeka , Van Waes Carter , Chen zhong
Published: August 2015

Head and neck squamous cell carcinomas (HNSCC) are highly inflammatory and preferentially metastasize to lymph nodes. NF-κB, a key target and regulator of inflammatory and cancer genes is constitutively activated in HNSCC, but the upstream regulation, especially for activation of alternative pathway involving LTβ/LTβR is not clear. We hypothesized that LTβ/LTβR mediated alternative NF-kB pathway signaling is an important mechanism for activation of downstream target genes, and promotion of malignant and metastatic phenotypes in HNSCC. In this study, we have found that LTβ and LTβR are overexpressed in subsets of HNSCC (UM-SCC) tissues and cell lines. In UM-SCC cell lines, LTβ mainly activated the alternative NF-kB pathway, enhancing nuclear translocation of RELB and NF-κB2/p52, in contrast to TNFα induced activation of classical NF-κB pathway. Knockdown of LTβR by Si RNA decreased LTβR mRNA by quantitative RT-PCR and protein expression by Western blots. Knockdown of LTβR decreased its target kinase NIK, and downstream NF-κB subunits RELB and NF-κB2/p52 protein expression. Knockdown of NIK protein decreased RELB and p52 protein expression, while LTβ treatment stabilized NIK, RELB and NF-κB2/p52 expression. LTB mediated NF-κB activity was examined by transient luciferase reporter assay or using stably transfected NF-κB reporter cell line through beta lactamase Fret Blazer activity. Knockdown of LTBR and NIK functionally decreased NF-κB reporter activity, while treatment of LTB partially restored the NF-κB reporter activity. Our data have shown that constitutive and LTβ induce activation of NIK and downstream NF-κB alternate pathway proteins, RELB and NF-kB2/p52 in HNSCC. LTβ and NIK activation of the alternative NF-κB pathway may contribute to the malignant phenotype and metastasis of HNSCC.

Citation Format: Rita Das, Tsu-Fang Cheng, Jamie coupar, Anthony Saleh, Xingping Yang, jialing Zhang, shaleeka Cornelius, Carter Van Waes, zhong Chen. LTβ receptor and NIK signaling activates the alternative NF-kB pathway in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5253. doi:10.1158/1538-7445.AM2015-5253
Abstract 5260: Mitochondrial DNA phylogenetic analysis for local recurrences and second primary tumors from patients with oral cavity squamous cell carcinoma
Authors: Lai Chih-Hsiung
Published: August 2015

Local recurrences (LRs) and second primary tumors (SPTs) are commonly observed in patients with oral squamous cell carcinoma (OSCC). A lower survival rate has been demonstrated in patients with LRs with respect to patients with SPTs. Therefore, the criteria for differentiating LRs and SPTs are indispensable for determining appropriate treatment. Currently, criteria based on histology, the distance and relapse time between new lesions and index primary tumor are generally used in clinical classification. In the genomic era, molecular classification based on the clonal relationship between the first and the second lesions may be more reliable than traditional clinical classification. The aim of the present study tried to establish a feasible molecular classification based on mitochondrial DNA (mtDNA) phylogenetic analysis. The study population consisted of 44 OSCC patients with multiple lesions for a total of 47 (19 LRs and 28 SPTs) paired lesions. The mtDNA analysis was performed by direct sequencing. The phylogenetic and molecular evolutionary analyses were conducted by using MEGA software version 6 and three common phylogenetic evolutionary methods (Maximun Likelihood (ML), Neighbor-Joining (NJ) and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) method) were applied. Preliminary analysis indicated that the prevalence of clonality for LRs and SPTs was 26.3% and 3.6%, respectively. A discrepancy between the clinical classification and mtDNA analysis was found in 15 paired tumors (31.9%) in which 14 paired lesions were classified as LRs based on clinical criteria, while mtDNA analysis suggested that they were nonclonal-related SPTs. Survival analysis indicated that there was no difference between patients with LRs and patients with SPTs based on clinical classification. On the other hand, patients with clonal second lesions had poorer overall survival than patients with nonclonal second lesions based on mtDNA analysis. In conclusion, our preliminary findings suggested that molecular clonality analysis could improve the accuracy in differentiating LRs from SPTs.

Citation Format: Chih-Hsiung Lai. Mitochondrial DNA phylogenetic analysis for local recurrences and second primary tumors from patients with oral cavity squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5260. doi:10.1158/1538-7445.AM2015-5260
Abstract 5262: Specific mtDNA variants and colorectal adenopolyps
Authors: Wallace LaShanale M. , Mehrabi Sharifeh , Yao Xuebiao , Aikhionbare Felix O.
Published: August 2015

The clinical frequency of colorectal cancer occurrence increase in adenomas with a predominant villous histopathology: tubular (5%), tubulovillous (22%) and villous (40%). Adenoma may develop throughout the gastrointerestinal tract with coarse lobulations formed by branching tubular glands whose lumens open on the surface which are rare in most patient gastrointerestinal tract areas other than the colorectum. The adenoma-carcinoma sequence is clinically associated in patients with polyposis and ulcerative colitis since their predilection for developing carcinoma in adenomatous epithelium is greatly increased. This study focused on COX, ATPase, rRNA, Cytb and ND genes of the mitochondrial genome that have been associated as modifying risks of cancer. Using PCR-based sequence and High resolution restriction endonuclease, we investigated the potential role of mtDNA alterations in colorectal adenopolyps (Tubular, Tubulovillous, and Villous) and carcinoma. Fifty-eight primary tissues of colorectal adenopolyps, carcinoma and their matched normal controls were used in this study. Twenty-two variants were observed and most of these variants were germline and homoplasmic transitions. Unreported germline variants Cytb-A14782T (90%) and MT-ATPase 8 A9169C (75%) were associated with tubular adenomas. Also, MT-ATPase 6- variant T8994A (85%) was associated with tubulovillous adenomas. Moreover, in the highly conservative region of rRNA, variant T1738C was found in colorectal carcinoma only. Results suggest that some specific mtDNA variants may exert their effects on colorectal adenopolyps to gain a proliferative advantage in patients bearing CRC.

Citation Format: LaShanale M. Wallace, Sharifeh Mehrabi, Xuebiao Yao, Felix O. Aikhionbare. Specific mtDNA variants and colorectal adenopolyps. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5262. doi:10.1158/1538-7445.AM2015-5262
Abstract 5270: IDH mutation status and role of WHO grade and mitotic index in overall survival in grade II-III diffuse gliomas
Authors: Olar Adriana , Wani Khalida , Diefes Kristin , Heathcock Lindsey , van Thuijl Hinke , Gilbert Mark , Armstrong Terri , Sulman Erik , Cahill Daniel , Reijneveld Jaap , Ylstra Bauke , Wesseling Pieter , Aldape Kenneth
Published: August 2015

Diffuse gliomas are up till now graded based upon morphology. Recent findings indicate that isocitrate dehydrogenase (IDH) mutation status defines biologically distinct groups of tumors. The role of tumor grade and mitotic index in patient outcome has not been evaluated following stratification by IDH mutation status. To address this, we interrogated 558 WHO grade II-III diffuse gliomas for IDH1/2 mutations and investigated the prognostic impact of WHO grade within IDH-mutant and wild-type tumor subsets independently. The prognostic impact of grade was modest in IDH-mutant [hazard ratio (HR) = 1.21, 95% confidence interval (CI) = 0.91-1.61] compared to IDH-wild type tumors (HR = 1.74, 95% CI = 0.95-3.16). Using a dichotomized mitotic index cut-off of 4/1000 tumor cells, we found that while mitotic index was significantly associated with outcome in IDH-wild type tumors (log-rank p<0.01, HR = 4.41, 95% CI = 2.55-7.63), it was not associated with outcome in IDH-mutant tumors (log-rank p = 0.471, HR = 1.10, 95% CI = 0.80-1.51), and could demonstrate a statistical interaction (p<0.01) between IDH mutation and mitotic index. Patient age, an established prognostic factor in diffuse glioma, was associated with outcome only in the IDH-wild type subset, and consistent with prior data, 1p/19q co-deletion conferred improved outcome in the IDH-mutant cohort. These findings suggest that stratification of grade II-III gliomas into subsets defined by the presence or absence of IDH mutation leads to subgroups with distinct prognostic characteristics. Further evaluation of grading criteria and prognostic markers is warranted within IDH-mutant versus IDH-wild type diffuse grade II-II gliomas as independent entities.

Citation Format: Adriana Olar, Khalida Wani, Kristin Diefes, Lindsey Heathcock, Hinke van Thuijl, Mark Gilbert, Terri Armstrong, Erik Sulman, Daniel Cahill, Jaap Reijneveld, Bauke Ylstra, Pieter Wesseling, Kenneth Aldape. IDH mutation status and role of WHO grade and mitotic index in overall survival in grade II-III diffuse gliomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5270. doi:10.1158/1538-7445.AM2015-5270
Abstract 5289: The role of the immune system in lymph node positive ER+ breast cancer
Authors: Cockburn Jessica G. , Gillgrass Amy , Bane Anita
Published: August 2015

Estrogen receptor (ER) positive breast cancer (BC) accounts for 70% of BC diagnoses and is associated with a good outcome when treated with conventional therapies, including tamoxifen. However, there remains a sub-population of patients who undergo relapse within 10 years of diagnosis and do not respond well to standard therapies. While lymph node (LN) status is an important indicator of poor prognosis, additional information is needed to more accurately predict patients who will or will not relapse. Previous genomic studies from our lab have shown that immune response is an important feature of LN+ BCs that do not relapse. In addition, other studies have also examined the role of the immune system in ER+ BC, but due to varying study designs, it is unclear how immune response pertains to ER+ BC relapse. The goal of this project is to characterize immune response in ER+ BC by measuring levels of immune markers using immunohistochemistry (IHC) and RNA expression levels and comparing those to tumour characteristics. We have developed a cohort of retrospective ER+ BC patients with tumour samples available through the Hamilton Health Science tumour bank. Patients were selected for eligibility based on ER status, early stage disease, and having long term clinical follow-up. Clinical charts for each patient were reviewed and pathological, treatment, and outcome data were abstracted. Tumour blocks were obtained and sections stained for haematoxylin and eosin were marked for tumour boarders then used to construct Tissue microarrays (TMA) for IHC assays and RNA is to be extracted from each tumour block. 318 patient samples have been obtained that meet eligibility requirements. Among those, 163 are LN- and 110 are LN+, and the remainder have unknown LN status. Primary endpoint for this study is the development of distant metastasis. Roughly 10% of LN- patients developed distant metastasis within 10 years and roughly 20% of LN+ patients developed distant metastasis. In total, 14% of patients came to endpoint during the study period. TMAs were stained for pathological markers, including ER, PR, HER2, and Ki67 as well as immune markers such as CD8 and CD20. RNA expression levels for each of these were also determined and both were compared with clinical outcome. Here we present a retrospective cohort of ER+ BC patients with 10 years of clinical follow-up data that can be used for IHC and RNA analysis. Further, we have examined the association between immune response and prognosis in lymph node positive ER+ BC patients.

Citation Format: Jessica G. Cockburn, Amy Gillgrass, Anita Bane. The role of the immune system in lymph node positive ER+ breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5289. doi:10.1158/1538-7445.AM2015-5289
Abstract 529: Phosphorylation of Thr165 within the activation loop of Nek3 kinase is necessary for its pro-migratory function in breast cancer cells
Authors: Harrington Katherine M. , Clevenger Charles V.
Published: August 2015

The polypeptide hormone prolactin (PRL) is increasingly recognized as contributing to the development and progression of human breast cancer. Activation of the prolactin receptor (PRLr) by PRL contributes to the growth, survival and motility of human breast cancer cells. The PRL/PRLr complex activates multiple signaling pathways, including the serine/threonine kinase, Nek3 (NIMA-related kinase 3). PRL acts as a chemoattractant for breast cancer cells, accompanied by reorganization of the cytoskeleton. However, the molecular mechanisms by which PRLr signaling contributes to the invasive breast cancer cellular phenotype is not fully understood. Nek3 [NIMA (never in mitosis gene a)-related kinase 3] is a member of the serine/threonine (S/T) Nek protein kinases. Data from our laboratory suggests that Nek3 may contribute to breast cancer pathogenesis through regulation of cell migration/invasion, apoptosis, and cytoskeletal reorganization. Therefore, targeting Nek3 in breast cancer cells represents a novel therapeutic approach to potentially improve the treatment of breast cancer. We previously demonstrated that PRL/PRLr-signaling activates Nek3, however the molecular mechanisms of Nek3 kinase activation remain to be elucidated. Therefore, to better understand the mechanism of PRL-dependent regulation of Nek3 kinase activity, we focused on determining whether Nek3 activity is regulated by phosphorylation and to identify the potential sites(s) of autophosphorylation. Through site-directed mutagenesis of Nek3 residues in the activation segment, we identified threonine residue 165 (Thr165), as a major site that regulates the catalytic activity of Nek3. In addition to being autophosphorylated in vitro, Nek3 Thr165 was also phosphorylated in response to the PRL-MEK-ERK1/2 signaling pathway in PRL-stimulated breast cancer cells. We show here that phosphorylation at Thr165 Nek3 plays an important regulatory role in cell migration and adhesion, steps that are critical in the invasive process leading to tumor metastasis. In order to test this, we expressed wild-type Nek3 and a nonphosphorylatable Nek3 mutant (T165V) in the breast cancer cell lines T47D and MCF7. We found that expression of T165V Nek3 resulted in a significant decrease in cell adhesion to the basement membrane matrix, Matrigel, while additionally inhibiting cell motility in a wound healing assay. Ongoing studies are further examining the role of Nek3 in regulating focal adhesion dynamics and cytoskeletal remodeling.

Citation Format: Katherine M. Harrington, Charles V. Clevenger. Phosphorylation of Thr165 within the activation loop of Nek3 kinase is necessary for its pro-migratory function in breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 529. doi:10.1158/1538-7445.AM2015-529
Abstract 5292: Determination of the receptor for advanced glycation end-products in breast cancer patients previous chemotherapy
Authors: Guadarrama-Orozco Jorge A. , Ruiz-García Erika B. , Maldonado-Martinez Hector A. , Barron-Rodríguez Lilia P. , Mainero-Ratchelous Fernando , Astudillo-delaVega Horacio
Published: August 2015

The receptor for advanced glycation end-products (RAGE) is a newly recognized factor regulating cancer cell invasion and metastasis. RAGE has recently been recognized as a cancer-associated protein responsible for cancer progression and metastasis in gastrointestinal and epithelial cancers. The aim was to examine the role of RAGE in breast cancer previous to chemotherapy treatment.

Methods: A retrospective study in surgical specimens obtained from 68 consecutive patients who underwent surgery for stage II-III breast cancer at the Oncology Hospital at National Medical Center SXXI, between 2008 and 2009. RAGE expression was examined by immunohistochemistry (IHQ) and PCR in 68 patients with stage II or III breast cancer previous chemotherapy treatment. RAGE expression was compared with clinicopathological parameters including clinical stage, invasive depth, nodal metastasis, disease recurrence and disease-free survival. The positive expression rate of RAGE was defined as 50% or more of stain in IHQ.

Results: In all 68 samples no RAGE membrane expression was found significantly. Just one specimen was 50% positive in tumor IHQ and no clinicopathological correlation was found. In PCR the results were more significant. Our findings shows suggestive no evidence for the presence of RAGE in membrane, but possibly RAGE gene expression could had relationship in the progression of breast cancer in stages II and III.

Citation Format: Jorge A. Guadarrama-Orozco, Erika B. Ruiz-García, Hector A. Maldonado-Martinez, Lilia P. Barron-Rodríguez, Fernando Mainero-Ratchelous, Horacio Astudillo-delaVega. Determination of the receptor for advanced glycation end-products in breast cancer patients previous chemotherapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5292. doi:10.1158/1538-7445.AM2015-5292
Abstract 5295: Latent class longitudinal modeling of CTCs in ER+ metastatic breast cancer patients
Authors: Hyslop Terry , Li Xuechan , Duan Rui , Giuliano Mario , Giordano Antonio , Orloff Marlana , Rui Hallgeir , Reuben James M. , Cristofanilli Massimo
Published: August 2015

The baseline and longitudinal monitoring of circulating tumor cells (CTCs) demonstrated strong prognostic and predictive value in patients with metastatic breast cancer (MBC) irrespective of tumor subtype but particularly in ER+ disease. Utilizing a cohort of ER+ MBC patients, with longitudinal assessments of CTCs, we applied a novel statistical model to identify subgroups of CTC patterns that inform patient prognosis.

This is a retrospective analysis of 516 patients with MBC who had CTCs serially enumerated as part of their disease evaluation and monitoring. Two-hundred and six patients with ER+ disease and at least 3 CTC measures were identified and constitute the cohort for this analysis. Peripheral blood samples (7.5 ml) collected within 30 days before starting any systemic treatment were drawn into CellSave tubes and processed within 72 hours of collection. The standardized US Food and Drug Administration-cleared CellSearch System was used to isolate and count CTCs. Two-stage models, consisting of patterns of trajectories of CTCs in stage 1, defined via a latent class zero-inflated Poisson model, followed by a probability weighted Cox model of survival outcomes were employed. Both overall survival (OS) and progression free survival (PFS) were considered separately. Model selection was based on Akaike Information Criteria (AIC).

Three classes of CTC trajectories are identified (always low = L, 70.3%, controlled moderate = M, 20.9%, high uncontrolled = H, 8.7%) with significant differential OS (AHR M vs L 5.32, p<0.001, H vs L 10.41, p<0.001, H vs M 1.96, p = 0.039) and PFS (AHR M vs L 2.05, p<0.001, H vs L 4.24, p<0.001, H vs M 2.06, p = 0.015) in multivariable modeling adjusting for bone metastases (Y vs. N), number of metastatic sites, and Her2 status.

In summary, longitudinal monitoring of CTCs in patients with ER+ MBC can provide additional prognostic stratification and predictive value compared to standard baseline assessment and could potentially assist in better therapy selection and specific efficacy monitoring.

Citation Format: Terry Hyslop, Xuechan Li, Rui Duan, Mario Giuliano, Antonio Giordano, Marlana Orloff, Hallgeir Rui, James M. Reuben, Massimo Cristofanilli. Latent class longitudinal modeling of CTCs in ER+ metastatic breast cancer patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5295. doi:10.1158/1538-7445.AM2015-5295
Abstract 5306: Microparticles as novel prognostic markers in multiple myeloma
Authors: Rajeev Krishnan Sabna , Bebawy Mary , Brown Ross Duncan , Luk Frederick , Kwan Yiulam
Published: August 2015

Introduction: Multiple Myeloma (MM) is an incurable hematological malignancy affecting plasma cells marked by highly heterogeneous survival rates and confinement of the disease to bone marrow (BM). Relapse is a significant impediment in the clinical setting and the development of multidrug resistance (MDR) to therapy is the main cause of relapse. Currently, risk stratification to MM sub-groups and categorization of complete response to therapy are established on molecular and cytogenetic markers using bone marrow biopsies. We are exploring the clinical significance of plasma cell derived microparticles as a novel prognostic indicator in MM. Materials and Methods: We have analysed 79 de-identified MM patients and 24 normal subjects. Platelet free plasma was centrifuged and plasma cell derived MPs were identified and quantified by flow cytometry using Annexin V450, CD138 APC, anti-P-glycoprotein (P-gp)-FITC (17F9) in BD TruCount tubes. Platelet derived MPs were excluded from the analysis using CD41a-PE. All patient samples were compared to age-matched healthy volunteers. Western blot analysis was conducted on MP lysates probing for the presence of Lung-Resistance related Protein (LRP) and P-glycoprotein (P-gp). Morphology and the size of MP fraction from MM patients were investigated using scanning electron micrographs Results: The number of systemic MPs and CD138+MPs were found to be significantly higher in MM patient samples compared to the healthy volunteers. MDR markers (LRP & P-gp) were expressed on systemic MPs from relapsing MM patients. MPs from patients were spherical in shape and had smooth surface consistent with those isolated from the MM cell line OPM2.

Conclusions: There are elevated numbers of systemic MPs in all the 79 MM subjects (across all disease stages) compared to the healthy volunteers. The expressions of CD138 on MPs in the MM patients offer a sensitive assessment of disease progression and therapeutic outcome. Systemic MPs from MM patients carry a ‘snapshot’ of the less accessible bone marrow compartment and may provide a novel systemic ‘biosignature’ of MM progression and therapeutic outcome in the clinical setting. The MDR markers on systemic MPs may support dosage regimen and therapeutic decisions in MM clinical setting.

Acknowledgements: This project has ethical approval from Sydney Local Health District Human Research Ethics Committee (CRGH)- EC00118 # HREC/11/CRGH/223 (CH62/6/2011/150).

We would like to thank all the volunteers whom have contributed to this study.

Citation Format: Sabna Rajeev Krishnan, Mary Bebawy, Ross Duncan Brown, Frederick Luk, Yiulam Kwan. Microparticles as novel prognostic markers in multiple myeloma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5306. doi:10.1158/1538-7445.AM2015-5306
Abstract 5309: The role of aquaporin-1 as the prognostic factor for triple negative breast cancer
Authors: Lim Young Ah , Kim Lee-Su
Published: August 2015

Aquaporins(AQPs) area a large family of integral membrane water transport cannel proteins that facilitate the transport of water through the cell membrane. And in the subgroup of AQPs, AQP1 are expressed in many epithelia and endothelia such as kidney and lung. Recent studies revealed that AQPs were associated with human malignancies, since they are likely to play a role in the promotion of tumor progression and invasion. In this study, we evaluated the correlation with AQP1expression and invasive breast cancer, especially triple negative breast cancer(TNBC) and we analyzed AQP1 expression and the clinicopathologic factor. The present study was based on 277 patients of primary breast carcinomas who underwent surgery and treatment, presenting between Jan. 2003 and Dec. 2008. The immunohistochemical expression of AQP1 was investigated and compared with clinicopathologic factors. AQP1 expression was demonstrated in 17 tumors(6.1%) for all patinets. In 50 patients who were diagnosed with TNBC, 12 patients(24%) showed AQP1 expression. In the result, AQP1 expression was associated with TNBC. For all patients, AQP1 expression was associated with poor prognostic factor. In TNBC patients, AQP1 expression was not associated with prognostic factor. In consideration of AQP1 expression for TNBC patients, our results suggested AQP1 expression is a new prognostic factor of TNBC which is aggressive subgroup of breast carcinoma.

Note: This abstract was not presented at the meeting.

Citation Format: Young Ah Lim, Lee-Su Kim. The role of aquaporin-1 as the prognostic factor for triple negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5309. doi:10.1158/1538-7445.AM2015-5309
Abstract 5317: Preclinical evaluation of IQS019, a novel BCR kinase inhibitor, in in vitro and in vivo models of non-Hodgkin lymphoma
Authors: Balsas Patricia , Roldan Jocabed , Jimenez Laura , Rodriguez Vanina , de la Bellacasa Raimon Puig , Teixido Jordi , Matas-Cespedes Alba , Moros Alexandra , Martinez Antonio , Campo Elias , Borrell Jose I , Perez-Galan Patricia , Colomer Dolors , Roue Gael
Published: August 2015

Constitutive activation of B-cell receptor (BCR) signaling is a hallmark of several B-cell non-Hodgkin lymphoma (B-NHL), including diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular lymphoma (FL) and chronic lymphocytic leukemia (CLL). Despite the promising clinical activity of the first BCR kinase inhibitors in some of these entities, the design of new compounds is warranted to improve the survival of B-NHL patients who are poorly responsive, and/or who eventually develop resistance to current BCR-targeting therapies. In this context, we recently described the synthesis of IQS019, a 4-aminopyrido[2,3-d]pyrimidine with improved inhibition pattern against the three BCR-related kinases Lyn, Syk and Btk, when compared to reference BCR kinase inhibitors. Here, by assessing the activity of IQS019 in a panel of 21 human cell lines and 17 primary samples representative of the main B-NHL subtypes, we show that doses of IQS019 in the micromolar range allowed to a rapid and dose-dependent de-phosphorylation of both constitutive and Ig-activated Syk, Lyn and Btk in CLL, MCL, FL and DLBCL cell lines and CLL primary cultures. IQS019 treatment impairs cell proliferation and CXCL12-dependent cell migration, and leads to the induction of caspase-dependent apoptosis. Of interest, in CLL primary cells, these effects were independently of IGVH mutational status. In xenotransplant mouse models of MCL and FL, daily dosing of 2 mg/kg IQS019 for two weeks demonstrated to be safe for the animals and allowed to a 50-60% reduction in tumor outgrowth and glucose uptake, together with a 52% decrease in cell infiltration into the spleen (p < 0.05). These effects were accompanied by a significant (p < 0.05) downregulation of p-Syk, p-Lyn and p-Btk, and consequent mitotic arrest and induction of apoptosis in human malignant B cells. Altogether, these results define the BCR kinase inhibitor IQS019 as a potential candidate in antitumor therapy against a variety of B-NHL subtypes with aberrant activation of BCR pathway.

Citation Format: Patricia Balsas, Jocabed Roldan, Laura Jimenez, Vanina Rodriguez, Raimon Puig de la Bellacasa, Jordi Teixido, Alba Matas-Cespedes, Alexandra Moros, Antonio Martinez, Elias Campo, Jose I Borrell, Patricia Perez-Galan, Dolors Colomer, Gael Roue. Preclinical evaluation of IQS019, a novel BCR kinase inhibitor, in in vitro and in vivo models of non-Hodgkin lymphoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5317. doi:10.1158/1538-7445.AM2015-5317
Abstract 5324: Selective Inhibition of HDAC6 regulates preferential cytotoxicity in cancer cells by modulating p53 and Hsp90 stability
Authors: Kwon So Hee
Published: August 2015

A HDAC6-selective inhibitor is a promising new therapeutic agent for cancer treatment, but its precise mechanisms of actions are not well understood. In particular, the relevance of p53 for HDAC6 inhibitor-induced effects has not been fully elucidated. Here, we show that a γ-lactam based HDAC inhibitor A452 selectively inhibits HDAC6 catalytic activity in vivo and in vitro. A452 causes cell death as well as growth inhibition of transformed cells not observed in normal cells. A452 exhibits differential cytotoxicity for wild-type (wt) and mutant p53 (mutp53) human colorectal cancer cells. Interestingly, A452 shows different mechanisms of action of modulating p53 in cancer cells. A452 increases wtp53 by destabilizing MDM2 and MDMX. In contrast, A452 causes mutp53 destabilization by inhibiting complex formation between Hsp90 and hyperstable mutp53, which is a hallmark of p53 mutation and cancer cell-specific. A452 also chemosensitizes cancer cells differing in p53 status for chemotherapy due to its ability to degrade mutp53 and stabilize wtp53. Intriguingly, acetylation of Hsp90 by A452 results in its degradation as well as inactivation of its chaperone activity. Furthermore, A452 effectively suppresses cell migration and invasion. These results demonstrate that A452 is a specific HDAC6 inhibitor and requires for p53 and Hsp90 for inducing anticancer action. Therefore, these results suggest that therapeutic targeting of HDAC6 may represent a new way to treat cancers expressing mutant forms of p53.

Citation Format: So Hee Kwon. Selective Inhibition of HDAC6 regulates preferential cytotoxicity in cancer cells by modulating p53 and Hsp90 stability. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5324. doi:10.1158/1538-7445.AM2015-5324
Abstract 5325: A c-Kit targeting antibody-drug conjugate is efficiently metabolized and activated inside cancer cell lines and xenograft tumors
Authors: Hong Erica , Qiu Qifeng , Wu Rui , Wilhelm Alan , Whiteman Kathleen , Pinkas Jan , Erickson Hans , Abrams Tinya , Schleyer Siew
Published: August 2015

We have developed an antibody-drug conjugate (ADC) targeting the c-Kit receptor tyrosine kinase, which is selectively expressed on the cell surface of various tumors including gastrointestinal tumors (GIST), small cell lung cancer (SCLC) and acute myelogenous leukemia (AML). The ADC consists of a humanized c-Kit-binding monoclonal antibody (c-Kit-Ab) covalently attached to a maytansinoid tubulin inhibitor, DM1, via a non-cleavable linker, SMCC. Like other ADCs, the c-Kit ADC is a pro-drug that is activated upon metabolism inside cells. Its target-mediated internalization and lysosomal degradation generates active maytansinoid metabolites that bind and inhibit microtubule dynamics. To understand the activation of the ADC, we studied the kinetics and efficiency of its metabolism in cancer cells and xenograft tumor models. Using radiolabeled ADC and c-Kit-Ab, we followed the formation of metabolites in SCLC and AML cells and in SCLC tumors, as well as in engineered cell lines that express various mutant forms of c-Kit.

We found that the ADC and c-Kit-Ab are efficiently metabolized in c-Kit-positive cancer cells irrespective of the mutational status or the activation state of c-Kit. The degradation half-life of c-Kit-Ab is 3-fold lower than that observed for T-DM1 and SGN35, indicating a faster rate of activation. Moreover, cell surface repopulation with c-Kit is highly efficient after ADC-mediated internalization, allowing multiple rounds of ADC recruitment and activation. Interestingly, cell surface repopulation of c-Kit is more rapid for cells with a c-Kit mutation than those with wild-type c-Kit, leading to generation of greater levels of active metabolites in cells with mutant c-Kit. This may lead to better targeting of the c-Kit-mutated cancer cells over normal cells with wild-type c-Kit, which may improve the safety of the c-Kit ADC.

Consistent with the in vitro findings, the ADC was found to undergo efficient metabolism in tumors in vivo. While tumor localization of the ADC over a non-targeting conjugate is similar to that observed with T-DM1 and SAR3419, its tumor-specific formation of active metabolites is 3-fold greater. Thus, the c-Kit-targeting ADC is particularly efficient at achieving high levels of active metabolites inside c-Kit-positive tumor cells, consistent with its robust efficacy in mouse xenograft models.

Citation Format: Erica Hong, Qifeng Qiu, Rui Wu, Alan Wilhelm, Kathleen Whiteman, Jan Pinkas, Hans Erickson, Tinya Abrams, Siew Schleyer. A c-Kit targeting antibody-drug conjugate is efficiently metabolized and activated inside cancer cell lines and xenograft tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5325. doi:10.1158/1538-7445.AM2015-5325
Abstract 5334: Oncolytic Newcastle disease virus: armed but not dangerous
Authors: Carroll Danielle K. , Harper James , Burke Shannon , Travers Jon , Franks Ruth , Navarro Christel , Cheng Xing , Wilkinson Robert W. , Jin Hong
Published: August 2015

Oncolytic viruses are live, replication-competent viruses that infect and/or replicate selectively in tumour cells leading to the destruction of the infected cell. Cell lysis occurs as a natural consequence of the viral life cycle and released virions can infect and kill neighbouring tumour cells leading to an amplified therapeutic effect. Oncolysis has the added benefit of releasing multiple tumour antigens that may further induce an immune-mediated therapeutic response.

Newcastle Disease Virus (NDV) is an avian paramyxovirus, which has proven safety and demonstrated efficacy against a variety of preclinical cancer models and in PhI clinical studies as an oncolytic agent, oncolysate or whole cell vaccine. Using reverse genetics, we have generated a recombinant strain of NDV that overcomes environmental and regulatory concerns uncoupling oncolytic potency and avian pathogenicity. Furthermore we have enhanced the immune modulatory properties of

NDV by engineering the virus to express granulocyte/macrophage colony-stimulating factor (GM-CSF). We have evaluated the biological characteristics of recNDVGM-CSF in vivo and in vitro. RecNDVGM-CSF

selectively replicates in and kills a wide variety of human and mouse tumour cell lines. Additionally NDV infection of cancer cells results in the increased production and secretion of pro-inflammatory cytokines and chemokines which are able to recruit mediators of both the innate and adaptive immune responses. NDV is a potent activator of the type I interferon response and is also able to directly activate many immune cell types. In vivo, using a range of syngeneic and xenograft models we have demonstrated that NDV treatment has profound anti-tumour activity. In a

HT1080 fibrosarcoma xenograft model a single administration (intra-tumoural or systemic) was able to cure 80% of tumour bearing mice. In syngeneic mouse tumour models, NDV treatment causes profound changes in the immune suppressive microenvironment and can result in long-lasting anti-tumour immune responses.

The inherent properties of NDV (self-propagation, tumour-selective replication, and immunostimulatory properties) coupled with the ability to genetically engineer NDV to express therapeutic transgenes may provide a multi-modal attack on the tumour, delivering greater benefit to patients.

Citation Format: Danielle K. Carroll, James Harper, Shannon Burke, Jon Travers, Ruth Franks, Christel Navarro, Xing Cheng, Robert W. Wilkinson, Hong Jin. Oncolytic Newcastle disease virus: armed but not dangerous. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5334. doi:10.1158/1538-7445.AM2015-5334
Abstract 5348: The extracellular domain of thrombomodulin induces erythroid differentiation and hampers proliferation of human leukemia cells in vitro and in vivo
Authors: Ikezoe Takayuki , Yang Jing , Nishioka Chie , Honda Goichi , Yokoyama Akihito
Published: August 2015

Thrombomodulin (TM) is a glycosylated type I transmembrane molecule with multiple domains that include an NH2-terminal lectin-like region, six tandem epidermal growth factor (EGF)-like structures, an O-glycosylation site-rich domain, a transmembrane domain, and a cytoplasmic tail domain. TM is ubiquitously expressed on endothelial cells and acts as an anticoagulant via generation of activated protein C. Recombinant human soluble thrombomodulin (rTM) comprises the active, extracellular domain of TM, and inactivates coagulation. Use of rTM for the treatment of disseminated intravascular coagulation was approved in Japan in 2008. We previous showed that exposure of acute promyelocytic leukemia or acute myelomonocytic leukemia cells to rTM induced myeloid differentiation and growth arrest in vitro (Exp Hemat. 2012, Leuk Res. 2012). The present study found that exposure of K562 and KU812 cell lines that were derived from chronic myeloid leukemia cells to rTM increased expression of cell surface glycophorin CD235a in association with upregulation of GATA1 mRNA, indicating a differentiation of leukemia cells toward erythroid lineage. Interestingly, treatment of K562 bearing immunodeficient mice with rTM significantly decreased number of K562 cells infiltrating in liver and prolonged their survival compared to mice who received control diluent. These observations shed light on a novel function of TM in hematopoietic cells.

Note: This abstract was not presented at the meeting.

Citation Format: Takayuki Ikezoe, Jing Yang, Chie Nishioka, Goichi Honda, Akihito Yokoyama. The extracellular domain of thrombomodulin induces erythroid differentiation and hampers proliferation of human leukemia cells in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5348. doi:10.1158/1538-7445.AM2015-5348
Abstract 5352: Mesenchymal stem cell as delivery carrier for prodrug gene therapy against colorectal cancer cell
Authors: Salehi Nasrin , Peng Ching-An
Published: August 2015

Gene-directed enzyme prodrug therapy (GDEPT) is an approach that delivers a suicidal gene to cancer cells for the expression of prodrug-activating enzyme which converts prodrug into cytotoxic drug. One of the major impediments of GDEPT is to have the therapeutic gene specifically target on cancer cells prior to the administration of prodrug. Among various gene delivery methods, mesenchymal stem cells (MSCs) have emerged as potential carriers for gene delivery. They exhibit remarkable tumor-tropic and low immunogenic capacities. In this study, MSCs was engineered to express thymidine phosphorylase (TP) which has the capability of converting the prodrug doxifluridine into toxic 5-fluorouracil. TP expression in the MSCs post-transfection of TP cDNA was confirmed by immunoblotting analysis and its activity was determined by spectrophotometric assay. Our results showed the anticancer effectiveness of human HT29 colorectal adenocarcinoma cells co-cultured with TP-expressing MSCs was enhanced with the addition of various dosages of doxifluridine.

Citation Format: Nasrin Salehi, Ching-An Peng. Mesenchymal stem cell as delivery carrier for prodrug gene therapy against colorectal cancer cell. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5352. doi:10.1158/1538-7445.AM2015-5352