bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3332: Targeting cancer stem cells in ovarian cancer
Authors: Kakar Sham S. , Ratajczak Mariusz Z.
Published: July 2016

Ovarian cancer is a disease commonly complicated by the presence of ascites in the abdominal cavity which represents a major clinical problem. Currently, the treatment for ovarian cancer entails cytoreductive surgery followed by chemotherapy, mainly cisplatin or carboplatin combined with paclitaxel. Although this regimen is initially effective in a high percentage of cases, unfortunately within few months of initial treatment, tumor relapse occurs because of platinum-resistance. This is attributed mainly due to the presence of cancer stem cells (CSCs) present in ascites which are chemo-resistant and responsible for recurrence of cancer. In our preliminary studies, we show for the first time that withaferin A (WFA), a bioactive compound isolated from the plant Withania somnifera targets putative CSCs. Treatment of nude mice bearing orthotopic ovarian tumors with WFA resulted in a 70% to 80% reduction in tumor growth, complete inhibition of metastasis, and a significant elimination of the cells expressing CSCs markers - CD44, CD24, CD34, CD117, ALDH1 and Oct4 and down regulation of Notch1 and its downstream signaling genes (Hes1 and Hey1) reported to play crucial role for self-renewal and maintenance of CSCs. In addition, WFA also resulted in a significant inhibition of securin expression an “oncogene” important in ovarian tumorigenesis. In contrast, treatment of mice with CIS alone had the opposite effects, causing an increase in cells expressing CSC markers and Notch1 signaling pathway. However, combining of WFA with CIS showed enhanced effects on suppression of securin as well as elimination of CSCs. This may explain the development of platinum-resistance and recurrence of cancer in patients treated with first line chemotherapy. Based on this information, we hypothesize that a combination of WFA with CIS should target ovarian cancer cells as well as cancer stem cells by reducing securin and CSCs thereby reducing CIS resistance and recurrence of ovarian cancer. In our study, we used cells from ascites from patients with recurrent ovarian cancer and determine the effect of WFA alone and in combination with CIS on tumorigenic functions of ascites cells and CSCs from ascites in vitro and in vivo, and defined the molecular mechanisms associated with self-renewal, maintenance and recurrence of cancer in relation to expression of securin. Because the two agents act synergistically, this combination may minimize side effects as well as induction of cisplatin resistance and recurrence of cancer. In addition, this study will justify the initiation of phase I/phase II clinical trials to assess potential toxicity and efficacy of WFA/CIS combination in advanced/recurrent ovarian cancer patients.

Citation Format: Sham S. Kakar, Mariusz Z. Ratajczak. Targeting cancer stem cells in ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3332.
Abstract 3375: Activation of the acid sphingomyelinase pathway as a potential mechanism of chemotherapy-induced normal tissue vasculature damage
Authors: Mizrachi Aviram
Published: July 2016

Background: Several classes of chemotherapy confer substantial risk for late-term vascular morbidity. We aimed to investigate the mechanisms of chemotherapy-induced vascular toxicity in normal tissues.

Methods: The effect of Doxorubicin and Cisplatin has been studied in-vitro using bovine aortic endothelial cells (BAEC) as a model of normal tissue vascular endothelium. Specifically, we investigated activation of the acid sphingomyelinase (ASMase) pathway, which may lead to endothelial dysfunction (vasoconstriction) and apoptosis following incubation with different concentrations of Doxorubicin and Cisplatin. ASMase activity was measured using radioenzymatic assay with [N-methyl-14C] sphingomyelin. Cellular Reactive Oxygen Species (ROS) production was assessed using the 2’,7’-dichlorofluorescin diacetate (DCFDA) detection assay kit (Abcam®). Endothelial apoptosis was quantified using the 3,5-bis-benzamide assay (Sigma-Aldrich®). For the in-vivo studies, mouse femoral arterial blood flow was measured in real-time during and after Doxorubicin (8 mg/kg intravenously) or Cisplatin (8 mg/kg) administration. Visualization of ovarian and femoral microvasculature was obtained by fluorescence optical imaging system, equipped with a confocal fiber microscope (Cell-viZio).

Results: Incubation of BAEC with Doxorubicin (0.25 μM or 0.50 μM) resulted in increased ASMase activity, production of ROS and induction of apoptosis in a dose-dependent fashion. Cisplatin (25 μM or 50 μM) generated significantly reduced effects in BAEC yet apoptosis and ROS were notable. In-vivo endoscopic fibered confocal microscopy following chemotherapy administration revealed a differential pattern between the two agents. While post Doxorubicin injection, there was a marked reduction in fluorescent signal in small vessels (<15 μM) indicating vessel constriction and disintegration of vessel's wall in larger vessels, Cisplatin treatment resulted in very minor vascular changes.

Conclusions: These findings suggest that chemotherapy-induced vascular damage in normal tissues may represent different modes of toxicity in vivo and in vitro, while is mediated via activation of the ASMase pathway in response to Doxorubicin and to a lesser extent in response to Cisplatin.

Citation Format: Aviram Mizrachi. Activation of the acid sphingomyelinase pathway as a potential mechanism of chemotherapy-induced normal tissue vasculature damage. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3375.
Abstract 3378: Using multiplex immunoassays for profiling the circulating and tissue angiogenic biomarkers in mouse and human cancer
Authors: Lie Wen-Rong , Mistry Jehangir
Published: July 2016

Monitoring the expression levels of multiple pro- and anti-angiogenic factors in circulation and tumor microenvironment is crucial in examining the role of angiogenesis in cancer pathological processes or in identifying potential biomarkers for oncology drug development. The Luminex xMAP technology allows simultaneous detection of multiple proteins in a single sample and has been used widely in cancer biomarker discovery. Using the Luminex xMAP technology, we developed two Human Angiogenesis Panels (17-plex and 20-plex) and a Mouse Angiogenesis Panel (27-plex) for the simultaneous detection of multiple angiogenic biomarkers in less than 50 μL of human or mouse samples. We report here the protein biomarker profiles of these 37 human angiogenic factors in 1) serum samples, collected from breast cancer and colorectal cancer patients and normal donors, 2) tumor extracts, collected from breast tumor and colorectal tumor extracts and their matched adjacent normal tissue, 3) conditioned media in cultured tumor cells and stromal cells, and in addition, the protein biomarker profiles of 27 mouse angiogenic factors in the conditioned media of various mouse tumor cells and stromal cells. For example, of the 37 human angiogenesis serum protein markers tested, 16 biomarkers [angiopoietin-2 (ANGPT-2), EGF, endoglin, follistatin, G-CSF, HGF, PLGF, sAXL, PDGF-AB/BB, osteopontin (OPN), sHGFR/c-Met, suPAR, sTie-2, sHer2, soluble neuropilin-1 (sNRP-1), and tenascin-C] showed significant difference in expression levels between normal and breast cancer serum samples (p<0.05) and 13 biomarkers [ANGPT-2, EGF, PLGF, sAXL, sHer3, OPN, thrombospondin-2 (TSP-2), sHGFR/c-Met, suPAR, sTie-2, sNRP-1, sIL-6R, and tenascin-C] showed differential expression levels between normal and colorectal cancer serum samples (p<0.05). Altogether, the results of this study demonstrate the utility of these human and mouse angiogenesis multiplex panels as a useful tool in studying circulating and tissue protein biomarker profiles in cancer research.

Citation Format: Wen-Rong Lie, Jehangir Mistry. Using multiplex immunoassays for profiling the circulating and tissue angiogenic biomarkers in mouse and human cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3378.
Abstract 3380: Direct contact with perivascular tumor cells enhances integrin αvβ3 signaling and migration of endothelial cells
Authors: Burgett Monica , Lathia Justin , Roth Patrick , Nowacki Amy , Pugacheva Elena , Huang Ping , Vasanji Amit , Meizhang Li , Byzova Tatiana , Mikkelsen Tom , Bao Shideng , Rich Jeremy , Weller Michael , Gladson Candece
Published: July 2016

The secretion of soluble pro-angiogenic factors by tumor cells and stromal cells in the perivascular niche promotes the aggressive angiogenesis that is typical of glioblastoma (GBM), which requires endothelial cell (EC) migration. Here, we show that angiogenesis can also be promoted by a direct interaction between brain tumor cells, including tumor cells with cancer stem-like properties (CSCs), and ECs. The direct interaction between CSCs and ECs was mediated by binding of integrin αvβ3 expressed on ECs to the RGD-peptide in L1CAM expressed on CSCs. Using in vitro assays, we found that this interaction increased network formation and migration-associated signaling events in ECs, including activation of integrin αvβ3, FAK, bone marrow tyrosine kinase on chromosome X (BMX), p130CAS, ERK and JNK. Comparison of the effects of co-culturing CSCs with ECs versus the effects of conditioned media from CSCs co-cultured with ECs indicated that upstream and downstream effector activation was not attributed to a secreted factor(s). Activation of αvβ3 and BMX was required for migration stimulated by direct binding but not for migration stimulated by soluble factors. RGD-peptide treatment of mice with established intracerebral GBM xenografts significantly reduced the percentage of Sox2-positive tumor cells (consistent with CSCs) in close proximity to ECs, decreased integrin αvβ3 and BMX activation and p130CAS phosphorylation in the ECs, and reduced the vessel surface area. These results show that direct interactions between CSCs and ECs have potent effects on EC migration and reveal a previously unrecognized aspect of the regulation of angiogenesis in GBM that can impact therapeutic anti-angiogenic targeting.

Citation Format: Monica Burgett, Justin Lathia, Patrick Roth, Amy Nowacki, Elena Pugacheva, Ping Huang, Amit Vasanji, Li Meizhang, Tatiana Byzova, Tom Mikkelsen, Shideng Bao, Jeremy Rich, Michael Weller, Candece Gladson. Direct contact with perivascular tumor cells enhances integrin αvβ3 signaling and migration of endothelial cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3380.
Abstract 3383: Tumor vasculature normalization by recoupling nitric oxide synthase with a tetrahydrobiopterin precursor
Authors: Rabender Christopher , Bruno Ninu , Mikkelsen Ross B.
Published: July 2016

The abnormal, irregular nature of tumor vasculature has been well documented. The aberrant nature of the vasculature results in uneven, heterogeneous blood flow and leaky, hemorrhagic blood vessels. Due to the unusual nature of tumor vessels, areas of hypoxia tend to develop that contribute to radioresistance and inefficiency of therapeutic drug delivery. Our current studies examine the role of nitric oxide synthase (NOS) in tumor vasculature. NOS has been demonstrated to be “uncoupled” in tumor cells due to reduced levels of tetrahydrobiopterin (BH4), a necessary cofactor, resulting in peroxynitrite (ONOO-) formation in lieu of nitric oxide (NO). NO signaling is critical for vascular function and thus uncoupling of eNOS in the endothelial cells may partly explain the poor vasculature structure found within solid tumors. Having previously demonstrated that NOS can be “recoupled” and NO production restored through treatment of tumor cells with Sepiapterin (SP), a BH4 precursor, we examined whether SP could normalize tumor vasculature, promoting radiosensitivity and improving drug uptake. Multispectral optoacoustic tomography analysis of both flank tumor xenografts and a spontaneous breast tumor model (MMTV) demonstrate that SP given orally significantly enhances the percent of oxyhemoglobin in the tumor. Immunohistochemical analysis of tumors treated with SP showed a significant reduction in CD31 staining and a significant increase in smooth muscle actin (SMA), both hallmarks of vascular normalization. Ex vivo analysis of tumors revealed that the enhanced tumor oxygenation resulted in over a two-fold increase in radiation induced cell killing. These preliminary data demonstrate great potential for SP as an adjuvant in the treatment of cancer, especially when we take into consideration that SP has been demonstrated to be cytotoxic to both breast and colon tumors. Future studies will examine drug uptake in tumors as well as the mechanism behind the vascular normalization.

Citation Format: Christopher Rabender, Ninu Bruno, Ross B. Mikkelsen. Tumor vasculature normalization by recoupling nitric oxide synthase with a tetrahydrobiopterin precursor. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3383.
Abstract 339: Identification of novel covalent inhibitors of K-Ras G12C that are efficacious in a xenograft model of NSCLC
Authors: Satyam Leena Khare , Chikkanna Dinesh , G Aswani K. , Khairnar Vinayak V. , Reddy Sreekanth , Durgaprasad Vakkapatla , Radhakrishna Kowju , Panigrahi Sunil K. , Ramanathan Anuradha , Mahasweta Kumari , Lakshminarasimhan Anirudha , K Narasimha R. , R Vinutha , Gopinath Sreevalsam , Kumar Suryakant , Shah Mubarak H. , Ramachandra Raghuveer , B Kiran A. , Pandit Chetan , Ramachandra Murali
Published: July 2016

KRAS is the frequently mutated isoform in RAS driven cancers. The G12C mutation is more predominantly associated with various tumor types over other changes in K-Ras. Although direct targeting of RAS is very challenging, it is possible to selectively target G12C mutant K-Ras using a covalent approach. Mutant specific covalent inhibitors with high selectivity against wild type K-Ras and other GTPases are expected to lead to efficacy with a very high degree of tolerability. Here, we report identification of lead compounds from two distinct chemical series that selectively target K-Ras G12C. Molecular modeling based on the reported crystal structures aided in the identification of these compounds. Covalent binding of the lead compounds to K-Ras G12C was demonstrated by MALDI-TOF. Lead compounds were potent in selectively inhibiting proliferation of cell lines with K-Ras G12C mutation but not with wild type K-Ras. The anti-proliferative activity of the lead compounds correlated well with their potency in a cellular mechanistic assay. Lead compounds from both series exhibited excellent drug-like properties including solubility, metabolic stability, permeability lack of CYP inhibition and desired exposure in pharmacokinetic studies. In a xenograft model of NSCLC, the lead compound demonstrated dose-dependent tumor growth inhibition with excellent tolerability upon oral dosing. In summary, we have identified a novel, potent and selective K-Ras G12C inhibitor with optimized drug-like properties including oral bioavailability and efficacy in a NSCLC derived xenograft model. Toxicity evaluation is ongoing towards progressing the lead compound to the clinic.

Citation Format: Leena Khare Satyam, Dinesh Chikkanna, Aswani K. G, Vinayak V. Khairnar, Sreekanth Reddy, Vakkapatla Durgaprasad, Kowju Radhakrishna, Sunil K. Panigrahi, Anuradha Ramanathan, Kumari Mahasweta, Anirudha Lakshminarasimhan, Narasimha R. K, Vinutha R, Sreevalsam Gopinath, Suryakant Kumar, Mubarak H. Shah, Raghuveer Ramachandra, Kiran A. B, Chetan Pandit, Murali Ramachandra. Identification of novel covalent inhibitors of K-Ras G12C that are efficacious in a xenograft model of NSCLC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 339.
Abstract 3396: Purinergic regulation of tumor-mediated angiogenesis: A role for exosomal NM23
Authors: Nordmeier Senny , Duan Suzann , Buxton. Iain L.O.
Published: July 2016

Exogenous nucleoside diphosphate kinase (eNDPK or NM23) has been shown to promote endothelial cell proliferation and migration and tumor-mediated angiogenesis. This is facilitated by its transphosphorylase activity, in which a gamma terminal phosphate group from a triphosphate nucleoside is transferred to a diphosphate nucleoside, resulting in elevated ATP levels. ATP can active purinergic receptors (P2Y1) on adjacent endothelial cells to promote angiogenesis. We previously reported that eNDPK was detected in conditioned media of breast cancer cells and in the serum of breast cancer patients (Yokdang, et al., 2011; Yokdang, et al., 2015). This suggests that eNDPK may have a role in tumorigenesis, but the mechanism by which eNDPK is released into the extracellular environment remains unknown. It is known that all cell types secrete small vesicles called exosomes, 30-100 nm wide vesicles of endocytic origin. We hypothesize that exosomal eNDPK secreted by breast cancer cells targets and promotes endothelial cell tubulogenesis and direct inhibition of eNDPK and P2Y1 activity attenuates angiogenesis. Exosomes were purified from human breast cancer cells, MDA-MB-231 (231) and non-tumorigenic human mammary epithelial cells (HME1) using ExoQuick TC. Transmission electron microscopy, mass spectrometry, and flow cytometry were performed to characterize the exosomes. Purified exosomes labeled with GFP-tagged tetraspanin (CD63) were introduced to human umbilical vein endothelial cells (HUVEC) to detect and measure tubulogenesis formation. We show that 231 secreted exosomes contain eNDPK and HUVEC cells treated with NDPK in the presence of ADP and GTP form tubules. In addition, fluorescently-labeled exosomes are associated with HUVEC tubules. The role of exosomal NDPK released by cancer cells in promoting angiogenesis and tumorigenesis may be used as a potential biomarker and target for treatment in breast cancer management. For future investigations of exosomal eNDPK, this study suggests that breast cancer exosomes promote endothelial tubulogenesis in a P2Y receptor-dependent manner.

Citation Format: Senny Nordmeier, Suzann Duan, Iain L.O. Buxton. Purinergic regulation of tumor-mediated angiogenesis: A role for exosomal NM23. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3396.
Abstract 3399: CTGF promotes tumor angiogenesis process in osteosarcoma through induction of angiopoietin-2
Authors: Cheng Yu-che , Tsai Hsiao-Chi , Tan Tzu-Wei , Tang Chih-Hsin
Published: July 2016

Osteosarcoma is the most common primary malignant bone tumor. Angiogenesis is essential for the tumor growth. Angiopoietin-2 (Angpt2) plays a critical role in angiogenesis and tumor progression. Connective tissue growth factor (CTGF), a secreted protein that binds to integrins, modulates the angiogenesis of certain human cancer cells. However, the effect of CTGF on Angpt2 expression in human osteosarcoma cells is mostly unknown. In this study, we found that overexpression of CTGF in osteosarcoma promoted angiogenesis in vitro and in vivo by tube formation assay, and Matrigel plug assay. Knockdown of CTGF obviously reduced expression of Angpt2 and angiogenesis. Recently, microRNAs (miRNAs) have been demonstrated that functions as oncogenes or angiogenesis regulators in human cancer. Here, we also found that overexpression of CTGF significantly decreased miR-543 in osteosarcoma cells. Transfection of miR-543 mimic reduced Angpt2 expression and angiogenesis. Taken together, CTGF promotes angiogenesis via up-regulation of Angpt2 by decreasing miR-543 in human osteosarcoma. These findings certify that CTGF functions as a tumor enhancer gene, suggesting that CTGF may be a potential therapeutic target for osteosarcoma patients.

Citation Format: Yu-che Cheng, Hsiao-Chi Tsai, Tzu-Wei Tan, Chih-Hsin Tang. CTGF promotes tumor angiogenesis process in osteosarcoma through induction of angiopoietin-2. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3399.
Abstract 34: Monocarboxylate transporters as potential therapeutic targets in human ovarian cancer
Authors: Boyers Amy , Stratford Ian
Published: July 2016

Introduction- Cancer cells have the ability to favour glycolysis for the production of lactate even in the presence of sufficient levels of oxygen. This is known as the ‘warburg effect’ or ‘aerobic glycolysis’. As a consequence of this glycolytic switch, there is an accumulation of lactate within cells. Therefore, cells must remove this excess lactate in order to prevent cell death via intracellular acidosis. In order to do this cells use Monocarboxylate Transporters (MCTs), which are responsible for the transport of lactate in and out of cells. MCT1 and MCT4 have been found to be over expressed in many types of human cancers, including ovarian cancer.

Aims- The aim of this study was to assess how changing the expression levels of MCT1 and MCT4 effects the growth and response to therapy of four Human Ovarian cancer cell lines (Skov3, Caov3, OV90 and Ovcar3).

Methods- Cell lines were stably transfected to either over express MCT1 (Skov3, Caov3, and OV90 cells), MCT4 (OV90 cells) or to contain doxycycline inducible silencing of MCT4 (Skov3, Caov3 and Ovcar3 cells). The effect of changing the expression levels of MCT1 and MCT4 on the function of these cell lines was assessed. Assays to look at changes in cell proliferation, lactate accumulation and release, and the cytotoxicity of Paclitaxel and Carboplatin were determined in both normoxia (21% O2) and hypoxia (0.1/1% O2).

Results- Over expressing MCT1 in the three human ovarian cell lines had no effect on cell growth or lactate release in normoxia or hypoxia. Also when MCT1 was over expressed in Skov3 and Caov3 cells there were no changes in their sensitivity to Carboplatin or Paclitaxel. However, when MCT1 was over expressed in OV90 cells, they became slightly more resistant to Paclitaxel. Over expressing MCT4 in OV90 cells also had no effect on cell growth in normoxia, but significantly more lactate was released by these cells. Secondly, when these cells were grown in hypoxia they survived for a greater period of time than wild type cells. This correlated with a much higher amount of lactate being released by these cells. Finally, these cells were more resistant to Paclitaxel than both the MCT1 over expressing cell lines and their wild type counterparts.

Conclusions- Changing the expression levels of MCT1 and MCT4 in Human Ovarian cancer cells have an effect on normal cell function. This suggests that MCTs could be potential therapeutic targets in ovarian cancer.

Citation Format: Amy Boyers, Ian Stratford. Monocarboxylate transporters as potential therapeutic targets in human ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 34.
Abstract 3400: An angiogenesis gene signature points to active TGF-beta/JAK signaling pathways in a subset of human pancreatic ductal adenocarcinoma cancer patients that are distinct from pathways in pancreatic neuroendocrine tumors
Authors: Craven Kelly E. , Gore Jesse , Wilson Julie L. , Korc Murray
Published: July 2016

Pancreatic Ductal Adenocarcinoma (PDAC), which comprises 85% of pancreatic cancers, is the 4th leading cause of cancer death in the United States with a 5-year survival of 7%. While human PDACs (hPDACs) are hypovascular, they also overexpress a number of angiogenic growth factors and receptors. Additionally, the use of anti-angiogenic agents in murine models of PDAC leads to reduced tumor volume, tumor spread, and microvessel density, and improved survival. Nonetheless, clinical trials using anti-angiogenic therapy have been overwhelmingly unsuccessful in hPDAC. On the other hand, pancreatic neuroendocrine tumors (PNETs) account for only 2% of pancreatic tumors, yet they are very vascular and classically angiogenic, respond to anti-angiogenic therapy, and confer a better prognosis than PDAC even in the metastatic setting.

By analyzing the recently expanded TCGA (The Cancer Genome Atlas) dataset, we report here that an angiogenesis gene signature is present in ∼35% of PDACs and is mostly distinct from an angiogenesis signature present in PNETs. Additionally, principal component analysis (PCA) of the entire or angiogenic PDAC and PNET transcriptomes from TCGA indicates that there are large differences in gene expression between these two tumor types. For example, PDACs exhibit a transcriptome that reflects active TGF-β signaling, and up-regulation of several pro-inflammatory genes, including members of JAK signaling pathways. Functionally, targeting the TGF-β type I receptor (TβRI) kinase with SB505124 and JAK1-2 with ruxolitinib blocks proliferative cross-talk between human pancreatic cancer cells and human endothelial cells. Tumors from the KRC (oncogenic Kras, deleted Rb1) PDAC mouse model show superior enrichment and differential expression of the angiogenic gene signature compared to tumors from the KPC (oncogenic Kras, mutated Trp53) PDAC mouse model. Moreover, treatment of KRC and KPC mice with ruxolitinib suppresses murine PDAC progression in KRC mice but not in KPC mice. These findings suggest that targeting both TGF-β and JAK signaling in the 35% of PDAC patients whose cancers exhibit an angiogenesis gene signature should be explored in the clinic and that this could lead to improved responses to anti-angiogenic therapy in PDAC.

Citation Format: Kelly E. Craven, Jesse Gore, Julie L. Wilson, Murray Korc. An angiogenesis gene signature points to active TGF-beta/JAK signaling pathways in a subset of human pancreatic ductal adenocarcinoma cancer patients that are distinct from pathways in pancreatic neuroendocrine tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3400.
Abstract 3402: Ephrin B2 and Dll-4 mediated co-dependence of tumor and endothelial progenitor cells in human hepatocellular carcinoma
Authors: Kore Rajshekhar A. , Upreti Meenakshi , Jamshidi-Parsian Azemat , Dings Rudd P.M. , Makhoul Issam , Griffin Robert J.
Published: July 2016

Hepatocellular carcinoma (HCC) is a highly vascularized tumor, which preferentially recruits new blood vessels from the hepatic artery to fuel its growth, through mechanisms not well understood. Here, we examined the intercellular cross-talk of HepG2 (human HCC) and endothelial progenitor cells (EPC) in transwell co-cultures to mimic initial tumor parenchyma and stroma interactions. We present evidence showing that, in culture, HepG2 cells secrete factors to induce an ‘activated’ EPC phenotype, namely, an increase in survival, growth, proliferation and migration rates. EPC cells showed a significant increase in growth (∼40%) and survival (∼80%) when co-cultured with HepG2 cells. Simultaneously, activated EPCs improved the viability of HepG2 cells. A major mediator of intercellular crosstalk are the secreted microvesicles called exosomes. Exosomes constitute a set of distinct nanovesicles (30-100 nm), endosomal in origin, constitutively secreted by many cells. They are involved in intercellular communication by transferring proteins and RNA from one cell to another. Intercellular crosstalk between these HepG2 cells and EPCs cells lead to qualitative and quantitative changes in the exosomal cargo secreted by the respective cells. The exosomal cargo constituting various proteins and genetic material have been demonstrated to be involved in processes which promote remodeling of extracellular matrix (ECM), biological adhesion and pathways modulating developmental processes and progression of inflammation, leading to cancer growth and development. In other work with glioma cell-derived exosomes has shown the presence of Ephrin A and B receptors which suggests a prominent role of secreted exosomes in stimulating and guiding tumor angiogenesis, a hallmark characteristic of glioblastoma multiforme (GBM). Additionally, our results with co-cultures of tumor and endothelial cells show that angiogenesis signaling in EPC appears to be induced by HepG2 cells via elevated endothelial Ephrin B2 and DLL-4 expression. Overall, our results demonstrate the co-dependence of HCC and EPC intercellular crosstalk, likely accomplished via secreted exosomes, in the initial stages of HCC establishment and stimulation of angiogenesis and development, thus a promising target for new clinical strategies.

Citation Format: Rajshekhar A. Kore, Meenakshi Upreti, Azemat Jamshidi-Parsian, Rudd P.M. Dings, Issam Makhoul, Robert J. Griffin. Ephrin B2 and Dll-4 mediated co-dependence of tumor and endothelial progenitor cells in human hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3402.
Abstract 3408: Oncogenic SOX2 signaling in bladder cancer
Authors: Wu Chia-Chang , Chiu Yu-Fan , Chou Yu-Ting , Wang Yuan-Hung
Published: July 2016

The intriguing phenomenon that cancer cells have biological features similar to stem cells suggests that cancer and stem cells may share the same regulatory signaling pathway. We found that SOX2, a master transcriptional factor controlling self-renewal of stem cells, was highly expressed in a subgroup of transitional cell carcinoma of bladder cancer, correlating with the advanced pathological grade. Moreover, SOX2 expression was associated with poor overall survival and recurrence-free survival outcomes in patients with bladder cancer. Knockdown of SOX2 in SOX2-high 5637 bladder cancer cells attenuated cell growth. Consistently, ectopic expression of SOX2 in SOX2-low T24 bladder cancer cells endowed cells with increased cell proliferation. Spheroid assay showed that SOX2 expression encouraged spheroid-forming ability of bladder cancer cells in low serum condition, demonstrating the involvement of SOX2 signaling in the maintenance of stemness in bladder cancer cells. Immunoblotting revealed that the expression of SOX2 induced phosphorylation of AKT in the serum-free condition, supporting that SOX2 regulates bladder cancer cell survival. Gene expression microarray analysis showed that SOX2 expression induced IGF2, which was further confirmed by Q-PCR analysis in bladder cancer cells. Chi-square test assay showed that IGF2 expression correlated with the advanced tumor stages in bladder cancer. Pharmacological inhibition of IGF2 signaling attenuated cell growth in SOX2-postive bladder cancer cells. Our findings support the notion that SOX2-IGF2 signaling axis confers aggressiveness in bladder cancer cells with potentials as biomarkers and therapeutic targets for bladder cancer intervention.

Citation Format: Chia-Chang Wu, Yu-Fan Chiu, Yu-Ting Chou, Yuan-Hung Wang. Oncogenic SOX2 signaling in bladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3408.
Abstract 3411: Role of mucin gene variations in microRNA binding sites in modulating colorectal cancer susceptibility and clinical outcomes
Authors: Bendova Petra , Vymetalkova Veronika , Pardini Barbara , Rosa Fabio , di Gaetano Cornelia , Vodickova Ludmila , Buchler Tomas , Naccarati Alessio , Vodicka Pavel
Published: July 2016

Mucins, high molecular weight glycoproteins predominantly expressed at the epithelial surface of tissues, provide protection for colon surface under normal physiological conditions. Mucinous colorectal carcinoma is generally defined as having greater than 50% of the tumor area with a mucinous differentiation by histologic examination.

MiRNAs have recently emerged as important regulators for altered mucin expression during malignant development. MiRNAs are short non-coding RNAs that regulate gene expression by binding to the 3’untranslated regions (3’UTR) of target mRNA thereby hampering protein translation or inducing mRNA destabilization. Aberrant miRNA expression and/or function are frequently observed in colorectal cancer (CRC). Polymorphisms in miRNA binding sites may affect miRNA binding to target genes, resulting in differential mRNA and protein expression and susceptibility to common diseases. We hypothesize that variations in mucin genes may modulate signaling response affecting cancer susceptibility, cancer survival and efficacy of chemotherapy.

Thirteen polymorphisms in nine mucin genes (MUC6, MUC7, MUC13, MUC14, MUC15, MUC17, MUC20, MUC21 and MUC24) were analyzed in DNA samples of 1111 cases and 1469 controls from the Czech Republic. Investigated variants were also studied in association with clinical outcome in all patients provided with detailed information on follow up.

Genetic variations in mucin genes were associated with clinical outcome. In particular, CRC patients carrying the CC genotype for rs886403 in MUC21 gene displayed a shorter survival and higher recurrence risk (HR 1.69; 95% CI 1.13-2.46; p = 0.01 and EFS: HR 1.99; 95% CI 1.38-2.84; p = 0.0002, resp.). The observed association was strikingly pronounced in colon cancer patients while individuals with rectal cancer and carrying variant CC genotype of rs4729655 in MUC17 displayed better overall survival (HR 0.27; 95% CI 0.14-0.54; p = 0.0002).

Expanding our knowledge on mucin involvement in CRC may help us better understand the etiopathogenesis of this disease and thereby contribute to the development of new treatment strategies. The present results identified plausible candidate SNPs potentially affecting miRNAs that target mucin genes in relation to CRC patients’ survival.

Work supported by IGA MZ: NT 15-26535A

Citation Format: Petra Bendova, Veronika Vymetalkova, Barbara Pardini, Fabio Rosa, Cornelia di Gaetano, Ludmila Vodickova, Tomas Buchler, Alessio Naccarati, Pavel Vodicka. Role of mucin gene variations in microRNA binding sites in modulating colorectal cancer susceptibility and clinical outcomes. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3411.
Abstract 3423: Overweight and obesity predict better overall survival rates in cancer patients with distant metastases
Authors: Tsang Ngan M.
Published: July 2016

Background: Recent studies conducted in patients with chronic diseases have reported an inverse association between body mass index (BMI) and mortality. However, the question as to whether BMI may predict prognosis in patients with metastatic cancer remains open. We therefore designed the current retrospective study to investigate the potential association between BMI and overall survival (OS) in patients with distant metastases (DM) and a favorable performance status.

Methods: Between 2000 and 2012, a total of 4,010 cancer patients with DM who required radiotherapy (RT) and had their BMI measured at the initiation of RT were identified. The relation between BMI and OS was examined by univariate and multivariable analysis.

Results: The median OS time was 3.23 months (range: 0.1−122.17) for underweight patients, 6.08 months (range: 0.03−149.46) for normal-weight patients, 7.99 months (range: 0.07−158.01) for overweight patients, and 12.49 months (range, 0.2−164.1) for obese patients (log-rank: P < 0.001). Compared with normal-weight patients, both obese (HR = 0.676; 95% P < 0.001) and overweight individuals (HR = 0.84; P < 0.001) had a reduced risk of all-cause mortality in multivariable analysis. Conversely, underweight patients had a significantly higher risk of death from all causes (HR = 1.41; P < 0.001).

Conclusions: Overweight and obesity are independent predictors of better OS in metastatic patients with a good performance status. Increased BMI may play a role to identify metastatic patients with superior survival outcome and exhibit a potential to encourage aggressive management in those patients even with metastases.

Citation Format: Ngan M. Tsang. Overweight and obesity predict better overall survival rates in cancer patients with distant metastases. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3423.
Abstract 3445: C-reactive protein and lung cancer risk: a Mendelian randomization analysis
Authors: Panagiotou Orestis A. , Caporaso Neil E. , Landi Maria T. , Chatterjee Nilanjan ,   NCI Lung Cancer GWAS Group
Published: July 2016

Background: Elevated levels of C-reactive protein (CRP) are associated with increased risk of lung cancer in observational studies. We investigated the causal relation between CRP and lung cancer using previously discovered single-nucleotide polymorphisms (SNPs) associated with CRP levels as genetic instruments.

Methods: We analyzed four lung cancer case-control studies (EAGE, PLCO, ATBC, CPSII) with available GWAS data (total 5,713 cases and 5,736 controls). We identified 21 SNPs associated with CRP levels at P<10-7 in genome-wide association studies (GWAS) and constructed a weighted polygenic score (PGS) multiplying the number of CRP-increasing alleles in each locus by the GWAS-reported effect of the respective allele on CRP levels; this is the largest number of CRP SNPs used in a Mendelian randomization for lung cancer to date. We first examined whether the PGS is associated with smoking phenotypes (smoking status, cigarettes per day, pack-years, smoking duration). Subsequently, we used this PGS as an instrumental variable and estimated the odds ratio (OR) and 95% confidence interval (CI) of lung cancer per standard deviation change in the PGS using logistic regression and adjusting for age, gender, and smoking. We conducted subgroup analyses for different types of lung cancer histologies. Analyses were performed separately for each study and study-specific results were combined through random-effect meta-analysis.

Results: The PGS was not significantly associated with the number of cigarettes smoked per day (P = 0.621), pack-years (P = 0.829), smoking status (0.739), or smoking duration (P = 0.743). Overall, there was no association between PGS and lung cancer risk in EAGLE (OR = 1.02, 95% CI 0.77-1.36; P = 0.876), PLCO (OR = 0.94, 95% CI 0.68-1.31; P = 0.722), ATBC (OR = 0.80, 95% CI 0.59-1.07; P = 0.132), or CPSII (OR = 0.61, 95% CI 0.37-1.02; P = 0.059) as well as after meta-analysis (OR = 0.88, 95% CI 0.73-1.05; P = 0.149; I2 = 17.3%]. Meta-analysis results were similar for adenocarcinoma (OR = 0.94, 95% CI 0.74-1.20; P = 0.630; I2 = 9.3%), squamous cell carcinoma (OR = 1.03, 95% CI 0.79-1.34; P = .844; I2 = 0%), small-cell lung cancer (OR = 0.97, 95% CI 0.62-1.50; P = 0.882; I2 = 34.9%), and other non-small cell lung cancer (OR = 0.93 (0.53-1.65), P = 0.815, I2 = 59.2%).

Conclusions: Genetically elevated CRP levels are not associated with the risk lung cancer. Hence, our results provide no evidence of causality between CRP and lung cancer.

Citation Format: Orestis A. Panagiotou, Neil E. Caporaso, Maria T. Landi, Nilanjan Chatterjee, NCI Lung Cancer GWAS Group. C-reactive protein and lung cancer risk: a Mendelian randomization analysis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3445.
Abstract 3461: Smoking cessation following a limited 5A intervention in a cohort of patients with head and neck cancer attending for treatment at a regional cancer program in Ontario, Canada
Authors: Conlon Michael S.C. , Saunders Deborah P.
Published: July 2016

A smoking cessation intervention at the time of cancer treatment is an important opportunity to improve patient quality of life, treatment outcome, and survival in people with cancer. This prospective observational study was designed to assess intention to quit, motivation to quit, smoking characteristics and interest in smoking cessation, and assessment of cessation following a standardized smoking cessation intervention. The intervention was a limited clinical 5A intervention offered by trained health professionals and occurred within a dental oncology clinic that offered regular follow-up and any needed pharmacotherapy through the course of cancer treatment. The cohort was composed of head and neck cancer patients who were self-reported ever-smokers at enrolment and who attended the Northeast Cancer Centre, a regional cancer centre in Northeastern Ontario, Canada, for cancer treatment. There were 377 cancer patients who participated in study, with 35.8% (n = 135/377) self-reporting as current smokers. Most current smokers had high nicotine dependence, with 82.2% (n = 111/135) reporting a time to first cigarette (TTFC) of 30 minutes or less; 84.4% (n = 114/135) were interested in quitting smoking. By 1 year post intervention 10 patients had died and 28 patients were lost to follow-up; of the remainder 29 smokers had cessated yielding a cessation rate of 29.9% (n = 29/97); or 23.2% (n = 29/125) conservatively assuming those lost to follow-up remained current smokers. Offering comprehensive smoking cessation during the course of cancer treatment yields long term smoking cessation benefits in a cohort of patients with smoking associated cancers.

Citation Format: Michael S.C. Conlon, Deborah P. Saunders. Smoking cessation following a limited 5A intervention in a cohort of patients with head and neck cancer attending for treatment at a regional cancer program in Ontario, Canada. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3461.
Abstract 347: Developing a novel immunotoxin that targets cells overexpressing ErbB2
Authors: Shen Luqun , Weigel Kelsey , Thomas Clayton , Drapalik Lauren , Schafer Zachary T. , Lee Shaun
Published: July 2016

Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain. The use of a membrane lysin as the toxin domain distinguishes our immunotoxins from numerous others in that internalization of the toxin is not required to induce cell death. One particular peptide candidate, NL1.1-PSA, demonstrated selective cytotoxicity towards ErbB2-overexpressing cell lines. We utilized a bioengineering strategy to show that recombinant NL1.1-PSA immunotoxin expression by Escherichia coli also conferred selective cytotoxicity towards ErbB2-overexpressing cells. Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics. While Herceptin treatment has been effective in patients with ErbB2 positive breast cancer, our novel immunotoxin may ultimately prove to be a novel and efficacious addition to the arsenal of approaches used to eliminate Herceptin-resistant breast cancer cells.

Citation Format: Luqun Shen, Kelsey Weigel, Clayton Thomas, Lauren Drapalik, Zachary T. Schafer, Shaun Lee. Developing a novel immunotoxin that targets cells overexpressing ErbB2. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 347.
Abstract 3476: Factors related to cervical cancer screening differences between regions around Bagamoyo, Tanzania
Authors: Rooney Brianna , Cummings Autumn , Soliman Amr , Kahesa Crispin
Published: July 2016

Background: With cervical cancer being among the most common cancers in East Africa among women, it is important to look at the factors related to referral differences in Tanzania, especially in rural areas where there is little to no access to cervical cancer screening clinics (CCS). Cervical cancer is related to HIV because a woman is 13.3 times more likely to develop cervical abnormalities if she is HIV positive. There are more HIV-positive women that attend CCS than HIV-negative women. This leads to more research to discover the variation in screening rates between HIV-positive and HIV-negative patients within the same village, as well as the variation in the screening rates between different villages.

Purpose: This study aims to determine the multi-level factors related to differences in cervical cancer screening frequencies between villages in Bagamoyo, Tanzania, and providers’ perception of barriers to screening at the Bagamoyo District Hospital (BDH). Factors identified that influence CCS attendance are HIV prevalence, distance to BDH, number of clinics, and female population.

Methods/Design: This mixed method design includes data obtained from the Tanzania Ministry of Health, the Bagamoyo District Medical Officer, and BDH medical records, as well as additional data from questionnaires conducted with health care providers, doctors or nurses, employed at BDH. The questionnaires included written informed consent. Data obtained from CCS medical records were used to estimate the frequency of women screened from 42 villages. ANOVA analysis was used to compare the percent of women screened from each village to the identified risk factors, HIV prevalence, distance, access to clinics, and population. Chi-square analysis was conducted in order to determine associations between type of health care provider and previously identified barriers to screening.

Discussion: This is the first study to examine providers’ perceived barriers to screening in relation to previously identified factors related to differences in cervical cancer screening rates. Further analysis of patient perceived barriers to screening should be conducted in order to better understand differences in screening rates.

Funding: Funding was received from the National Cancer Institute through the Cancer Epidemiology Education in Special Populations program.

Citation Format: Brianna Rooney, Autumn Cummings, Amr Soliman, Crispin Kahesa. Factors related to cervical cancer screening differences between regions around Bagamoyo, Tanzania. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3476.