bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4119: Tyrosine phosphorylation of MACC1 is essential and druggable for colorectal cancer metastasis restriction
Authors: Kobelt Dennis , Dittmar Gunnar , Fleuter Claudia , Smith Janice , Dahlmann Mathias , Migotti Rebekka , Schlag Peter M. , Stein Ulrike S.
Published: August 2015

We identified the previously undescribed gene Metastasis Associated in Colon Cancer 1 (MACC1). MACC1 is a metastasis inducer and prognostic biomarker for colorectal cancer (CRC). MACC1 has meanwhile been confirmed as decisive driver for tumorigenesis and metastasis for a broad variety of solid cancers. Here we aim to identify the impact of defined tyrosine phosphorylations on the function of the metastasis inducer MACC1.

In silico identified MACC1 tyrosine phosphorylation (pY) sites were ranked and most promising positions were site-directed mutated in wildtype (wt) MACC1 constructs. Human CRC cells were transduced with these constructs. Tyrosine phosphorylation was quantified by selected reaction monitoring (SRM)-mass spectrometry. Effects of pY-MACC1 mutants on cell migration, proliferation, dissemination and colony formation were assessed in cell culture as well as on liver metastasis formation in human CRC-xenografted mice. To identify MACC1-phosphorylating kinases the MACC1 interactome was identified using mass spectrometry. Most promising binding partners were validated by immunoprecipitation. Impact of inhibitors targeting kinases phosphorylating MACC1 was assessed on MACC1-induced tumor growth and liver metastasis in human CRC-xenografted mice by in vivo imaging.

We report that tyrosine phosphorylation of MACC1 is hierarchical and essential for motility and proliferation in cell culture, as well as for tumor growth and metastasis in mice. We identified kinases for MACC1 phosphorylation. Targeting these kinases using inhibitors employed in clinical trials restricts MACC1-induced tumor growth and metastasis in mice.

MACC1 tyrosine phosphorylation is crucial for metastasis and is druggable by small molecule inhibitors. This fundamental finding opens new therapeutic options for inhibition of MACC1-induced cancer metastasis.

Citation Format: Dennis Kobelt, Gunnar Dittmar, Claudia Fleuter, Janice Smith, Mathias Dahlmann, Rebekka Migotti, Peter M. Schlag, Ulrike S. Stein. Tyrosine phosphorylation of MACC1 is essential and druggable for colorectal cancer metastasis restriction. [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 4119. doi:10.1158/1538-7445.AM2015-4119
Abstract 4122: C-Met inhibition sensitivity in vitro: Autocrine vs. paracrine activation of the c-Met pathway
Authors: Hughes Veronica , Siemann Dietmar W.
Published: August 2015

Tumor cells frequently harbor abnormalities in signaling pathways, leading to increased migration, invasion, survival, angiogenesis, and proliferation. C-Met is one such commonly aberrant pathway. C-Met is a receptor tyrosine kinase critical for embryogenesis and liver repair, and protein levels are often elevated in a large variety of tumors. C-Met is activated by the endogenous ligand Hepatocyte Growth Factor (HGF). HGF is produced by mesenchymal cells and stimulates the c-Met protein, leading to a variety of downstream signaling pathways that result in increased migration, proliferation, survival, and angiogenesis.

While many tumor cells express the c-Met receptor, a number of tumor types, including glioblastoma and osteosarcoma, have been observed to co-express both HGF and c-Met, and activate the pathway in an autocrine manner. The purpose of the current study was to determine whether tumor cells utilizing autocrine c-Met signaling would more sensitive to c-Met inhibition than those relying on the paracrine pathway. Experimental procedures include ELISA, western, migration, invasion, and clonogenic cell survival. Cell lines investigated include: two glioblastoma cell lines (U87 and U118), two osteosarcoma cell lines (OS156 and OS521), two fibrosarcoma cell lines (KHT and RIF), a breast (MDA-MB-231) and a prostate cancer cell line (PC-3). The small molecule c-Met inhibitor BMS-777607 and an HGF-neutralizing antibody were used to compare the effects interrupting the c-Met axis in these tumor cell lines.

Data obtained using ELISA of conditioned media show that the glioblastoma (U87 and U118) and fibrosarcoma (KHT) cells secrete HGF, while the breast and prostate cells (MDA-MB-231; PC-3) do not. Furthermore western blot analysis showed higher basal levels of phospho-c-Met among the HGF-secreting cell lines in comparison to the non-HGF secreting cell lines, indicating that the KHT, U87, and U118 models activate c-Met in an autocrine manner, while the MDA-MB-231 and PC-3 lines activate c-Met in a paracrine manner. Importantly preliminary assessments indicate the autocrine glioblastoma and fibrosarcoma cell lines to be more sensitive to small molecule c-Met inhibition than the paracrine breast and prostate cancer cell lines. Investigations of additional cancer models are ongoing but our findings to date support the notion that cancer cells that autocrine activate the c-Met pathway may more susceptible to c-Met inhibition than those utilizing primarily paracrine activation of this pathway.

Citation Format: Veronica Hughes, Dietmar W. Siemann. C-Met inhibition sensitivity in vitro: Autocrine vs. paracrine activation of the c-Met pathway. [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 4122. doi:10.1158/1538-7445.AM2015-4122
Abstract 4125: SSA, a novel sulindac derivative, inhibits breast cancer cell invasion and migration
Authors: Yi Bin , Feng Xingling , Ma Ruixia , Zhang Xiaoguo , Chang Hong , Zhao Hongyou , Liang Ziping , Chen Xi , Hu Xiuhua , Piazza Gary , Xi Yaguang
Published: August 2015

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as sulindac, have been reported for striking chemopreventive activity in various types of human cancer, including breast cancer. However, few studies have reported that sulindac is able to prevent tumor metastasis. In this study, we aim to study anti-metastatic activity of sulindac in breast cancer and explore the mechanistic basis responsible for this activity, which we hypothesize may involve a cyclooxygenase (COX) independent mechanism. Numerous studies have reported that the anticancer properties of sulindac might involve, at least partially, a non-COX mediated mechanism, which provides an insight into development of safer and more efficacious new derivatives. We have previously described a chemical derivative of sulindac, referred to as sulindac sulfide amide (SSA), which lacks inhibitory effect on COX-1 or -2, yet shows greater potency to inhibit tumor cell growth compared with sulindac sulfide (SS). Our results showed that SSA treatment at a sub-cytotoxic concentration (4μM) for 36 h significantly inhibits both migration and invasion of highly aggressive MDA-MB-231, BT-20 and SK-BR-3 breast tumor cells. When treating non-invasive breast MCF-7 cells with TGF-β1 to induce their motility, we found that SSA could significantly counteract the induced motility of these cells. These results indicate that SSA can suppress breast tumor cell invasion by modulation of TGF-β1 signaling. We further studied Smad-2/3 that are important downstream components in the TGF-β1 signaling pathway and found that SSA could inhibit Smad-2/3 phosphorylation and reduce their translocation to the nucleus. In addition, Smad-2/3 knockdown could mimic the anti-invasive effect of SSA in MDA-MB-231 cells, regardless of the presence of TGF-β1. In summary, we demonstrate that the non-COX inhibitory derivative, SSA can suppress breast cancer cell invasion and migration. These observations suggest that inhibition of TGF-β1/Smad signaling is responsible for the inhibitory effect of SSA on breast tumor cell invasion and migration.

Citation Format: Bin Yi, Xingling Feng, Ruixia Ma, Xiaoguo Zhang, Hong Chang, Hongyou Zhao, Ziping Liang, Xi Chen, Xiuhua Hu, Gary Piazza, Yaguang Xi. SSA, a novel sulindac derivative, inhibits breast cancer cell invasion and migration. [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 4125. doi:10.1158/1538-7445.AM2015-4125
Abstract 4127: Bolus high-dose neoadjuvant sunitinib treatment overcomes potential for rebound growth during pre-surgical treatment breaks
Authors: Mastri Michalis , Tracz Amanda , Shen Li , Pili Roberto , Ebos John M.L.
Published: August 2015

Preclinical and clinical studies have suggested that stopping antiangiogenic therapy may lead to rapid revascularization and rebound tumor growth in certain instances. However, the implications for these findings remain unclear. It is possible that treatment rebounds may impact disease progression following neoadjuvant therapy, where drugs are administered for short periods and then halted prior to surgical removal of a primary tumor. Indeed, recent retrospective clinical studies have suggested that neoadjuvant antiangiogenic treatment discontinuation increases vascular proliferation and, in turn, might increase post-surgical disease progression and metastasis. However, this hypothesis has not been studied experimentally in clinically relevant mouse models of metastatic disease.

We examined the effect of treatment discontinuation in the neoadjuvant setting using approved vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) such as sunitinib. Our studies utilized models of spontaneous metastatic breast, melanoma, and kidney cancer following surgical removal of orthotopically grown primary tumors. Neoadjuvant sunitinib treatment periods were 14 days in duration (60 mg/kg) with treatment breaks of 0, 3, 7, and 11 days compared. Pre-surgical molecular and cellular biomarkers were investigated as potential surrogates for post-surgical metastatic disease progression. These included tumor and vascular cell Ki67 and CD31 expression, as well as circulating tumor cells (CTCs) and myeloid derived suppressor cells (MDSCs).

Our results show that VEGF RTKI neoadjuvant treatment benefits observed pre-surgically (such as reduction in primary tumor growth) did not consistently correlate with post-surgical survival and reduced metastatic recurrence. The addition of treatment breaks prior to surgery had positive or negative impact on post-surgical survival depending on the tumor model used. Interestingly, high-dose bolus (3 day) neoadjuvant sunitinib (120 mg/kg) treatment consistently improved post-surgical benefits when compared to sustained treatments, despite gaps in therapy. Finally, our results show that tumoral CD31+/Ki67+ cells, CTCs, and MDSCs may serve as surrogate markers of metastatic potential and predict the impact of treatment cessation on disease recurrence.

Citation Format: Michalis Mastri, Amanda Tracz, Li Shen, Roberto Pili, John M.L. Ebos. Bolus high-dose neoadjuvant sunitinib treatment overcomes potential for rebound growth during pre-surgical treatment breaks. [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 4127. doi:10.1158/1538-7445.AM2015-4127
Abstract 4138: Integrating SNPs, epigenetics and transcriptomics to better understand the inherited predisposition to breast cancer metastasis
Authors: Shukla Anjali , Bai Ling , Yang Howard , Doran Anthony , Hu Ying , Geiger Thomas , Lee Maxwell , Keane Thomas , Hunter Kent W.
Published: August 2015

Breast cancer is the most frequent cancer and the second leading cause of cancer mortality in women. The vast majority of breast cancer mortality is due to metastatic disease since the primary tumor can be relatively easily surgically resected. More comprehensive understanding of biology of metastasis is therefore clearly warranted to unveil novel metastasis-associated molecules and cellular processes that might be targeted for clinical intervention. Previously we demonstrated that like cancer incidence, metastatic progression has a significant inherited component. Using mouse complex trait mapping strategies we have been isolating metastasis susceptibility genes from backcross analysis. However, studies suggest that many of these QTL peaks are the result of the contribution of multiple genes, suggesting that causal genes are not being identified. To increase our ability to detect causal genes we have implemented a new integrated strategy. Whole genome sequencing of appropriate high or low metastatic mouse strains is performed to identify variants, which are then filtered for those within DNAse hypersensitive sites (DHS), based on the hypothesis that most inherited phenotypes are due to expression differences rather than missense variants. The genes associated with polymorphic DHS are then screened through mouse and human tumor expression databases to identify those genes associated with development of metastatic disease. This strategy was able to identify genes previously associated with metastatic breast cancer in both mouse and humans and new genes have also been validated. The results further suggest that inherited variation in cellular mediated immune response may be an important contributor to metastatic disease.

Citation Format: Anjali Shukla, Ling Bai, Howard Yang, Anthony Doran, Ying Hu, Thomas Geiger, Maxwell Lee, Thomas Keane, Kent W. Hunter. Integrating SNPs, epigenetics and transcriptomics to better understand the inherited predisposition to breast cancer metastasis. [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 4138. doi:10.1158/1538-7445.AM2015-4138
Abstract 4143: Discrete clones cooperate to promote tumor progression through a non-cell-autonomous mechanism in intestinal cancers
Authors: Leystra Alyssa A. , Wisinger Amanda M. , Zahm Christopher D. , Matkowskyj Kristina A. , Sievers Chelsie K. , Schwartz Alex , Albrecht Dawn M. , Clipson Linda , Deming Dustin A. , Newton Michael A. , Halberg Richard B.
Published: August 2015

Background: The process of tumor evolution has often been described as a single initiated cell propagating a tumor with subclones of that cell acquiring distinct molecular changes and competing for dominance within the tumor. However, colon tumors are now known to often be derived from multiple initiated progenitor cells. Distinct initiated clones might cooperate or alternatively compete during tumorigenesis, progression, and therapy.

Methods: Mice carrying the Min allele of Apc and expressing an oncogenic form of PI3K in a subset of colonic epithelial cells develop multiple adenomas and adenocarcinomas in the colon. We utilized cell lineage tracing to follow the progeny of individual progenitor cells through tumor establishment, progression, and treatment with GDC 0941, a PI3K inhibitor.

Results: Nearly half (44%; 30/68) of the tumors were derived from at least two progenitor clones, one of which expressed the oncogenic form of PI3K and one of which did not. The presence of both types of clones correlated to an increased frequency of either clone becoming invasive (p = 0.0002). Additionally, the presence of both clones appeared to protect susceptible clones from targeted therapy.

Conclusions: Taken together, these data indicate that genetically distinct tumor progenitors can establish a single lesion, and moreover cooperation amongst diverse clonal populations provides a fitness advantage during tumor progression and therapy.

Citation Format: Alyssa A. Leystra, Amanda M. Wisinger, Christopher D. Zahm, Kristina A. Matkowskyj, Chelsie K. Sievers, Alex Schwartz, Dawn M. Albrecht, Linda Clipson, Dustin A. Deming, Michael A. Newton, Richard B. Halberg. Discrete clones cooperate to promote tumor progression through a non-cell-autonomous mechanism in intestinal 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 4143. doi:10.1158/1538-7445.AM2015-4143
Abstract 4153: Investigating the role of Fn14 in EGFRvIII-driven glioblastoma
Authors: Roos Alison , Mayo Zachary , Pineda Michael , Winkles Jeffery A. , Berens Michael E. , Tran Nhan L.
Published: August 2015

Glioblastoma Multiforme (GBM) is the most common malignant brain tumor in adults. Most GBM patients succumb to the disease less than one-year post diagnosis due to the highly invasive nature of the tumor, which prevents complete surgical resection and gives rise to tumor recurrence. The invasive phenotype also confers radio-and chemoresistant properties to the tumor cells; therefore, there is a need to develop new therapeutics that target drivers of GBM invasion. Amplification of EGFR is observed in over 50% of GBM tumors, of which half concurrently overexpress the variant EGFRvIII, and expression of both receptors confers a worse prognosis. EGFR and EGFRvIII cooperate to promote tumor progression and invasion, in part, through activation of the JAK/STAT-signaling pathway. Here we report that GBM cells expressing EGFRvIII show increased expression of a previously established mediator of glioma cell invasion and survival, fibroblast growth factor-inducible 14 (Fn14), at the mRNA and protein level. Treatment with a STAT3, STAT5, or JAK inhibitor decreased Fn14 mRNA and protein expression. Finally, knockdown of Fn14 levels in the EGFRvIII-expressing glioma cells decreased both cell survival after temozolomide (TMZ) treatment and cell invasion, which suggests that Fn14, in part, mediates the oncogenic phenotypes conferred by EGFRvIII signaling. Since EGFR inhibitors display limited therapeutic efficacy in GBM patients, we hypothesize that Fn14-targeted therapies could potentially limit invasiveness and chemoresistance in these tumor subtypes.

Citation Format: Alison Roos, Zachary Mayo, Michael Pineda, Jeffery A. Winkles, Michael E. Berens, Nhan L. Tran. Investigating the role of Fn14 in EGFRvIII-driven glioblastoma. [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 4153. doi:10.1158/1538-7445.AM2015-4153
Abstract 4158: Novel PAK4-mediated regulation of endothelial CXCL1/CXCR2 signaling and angiogenesis in glioblastoma
Authors: Kesanakurti Divya , Xu Jihong , Canella Alessandro , Nagarajan Prabhakaran , Kaur Balveen , Puduvalli Vinay K.
Published: August 2015

Increased endothelial cell proliferation and aberrant neovascularization are pathological hallmarks of glioblastoma that correlate with clinical outcome. Recent studies have also implicated ionizing radiation (IR)-induced angiogenesis as a potential cause for tumor recurrence and metastases in several malignancies. Its impact in gliomas has not been characterized. Factors that drive endothelial proliferation, angiogenesis and interaction of endothelial cells with tumor cells in the context of radiotherapy are potentially novel targets for glioma therapy. Our previous studies demonstrated high levels of expression of p21-activated kinase 4 (PAK4) in gliomas; analyses of tumor cell medium (CM) prepared from shRNA-mediated PAK4-knockdown cells using an angiogenesis antibody array showed a significant decrease in key angiogenic factors including CXCL1. Treatment of human brain microvascular endothelial cells (HBMECs) with CM from PAK4-knockdown cells (PAK4-kd CM) significantly inhibited proliferation, migration and microtubule formation compared with CM from control and scrambled vector-expressing glioma cells. PAK4-kd CM treatment also suppressed CXCR2 activation and decreased the expression levels of p-STAT3, VEGF, MMP-2 and cyclinD1 in HBMECs. Additionally, treatment with CM from ionizing radiation (IR, 8 Gy)-treated cells resulted in elevated CXCL1, MMP-2 and VEGF levels in HBMECs, and induced high levels of endothelial capillary network formation on matrigel, indicating an IR-induced angiogenesis in these cells. Conversely, PAK4-kd inhibited IR-induced angiogenesis and decreased p-STAT3, VEGF and MMP-2 levels in IR-treated HBMECS. Further, in vivo experiments with orthotopic intracranial tumors in nude mice showed growth suppression in PAK4-knockdown tumors compared to control tumors. Immunohistochemical analyses of brain tumor sections revealed a significant decrease in CXCL1, VEGF and MMP-2 in PAK4.sh tumors. In summary, our studies emphasize a novel regulation of angiogenic switch and endothelial CXCL1/CXCR2 signaling by PAK4 in tumor cells, thereby, suggests the role of PAK4 as a critical mediator of tumor-endothelial cell interactions in glioblastoma. Abrogation of key angiogenic signaling after IR treatment and inhibition of in vivo tumor growth by PAK4 suppression indicates its therapeutic potential in the treatment of glioma.

Citation Format: Divya Kesanakurti, Jihong Xu, Alessandro Canella, Prabhakaran Nagarajan, Balveen Kaur, Vinay K. Puduvalli. Novel PAK4-mediated regulation of endothelial CXCL1/CXCR2 signaling and angiogenesis in glioblastoma. [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 4158. doi:10.1158/1538-7445.AM2015-4158
Abstract 4162: Interleukin–6 stimulates defective angiogenesis
Authors: Gopinathan Ganga , Milagre Carla , Pearce Oliver M.T , Reynolds Louise , Hodivala-Dilke Kairbaan , Leinster Andrew , Zhong Haihong , Hollingsworth Robert E. , Thompson Richard , Whiteford James R. , Balkwill Frances
Published: August 2015

The aim of this study was to investigate the effects of IL-6 in normal and tumour angiogenesis. In previous studies we found that elevated levels of the inflammatory cytokine interleukin-6, IL-6, were linked with poor prognosis in ovarian cancer patients by influencing tumour growth, invasion, angiogenesis and chemo-resistance. A clinical trial conducted in parallel with pre-clinical studies showed an anti-IL-6 antibody to have some activity in ovarian cancer patients and in xenograft models, with systemic and local reduction in pro-inflammatory and angiogenic factors such as TNF, IL-8 and VEGF.

IL-6 directly induced vessel sprouting in the ex vivo aortic ring model, as well as stimulated endothelial cell proliferation and migration, with similar potency to VEGF. However, IL-6 itself did not induce VEGF in the endothelial cells tested. In contrast to VEGF, IL-6-stimulated aortic ring vessel sprouts had defective pericyte coverage. The mechanism of the IL-6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as Angiopoietin 2. When peritoneal ovarian cancer xenografts were treated with an anti-IL-6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies there was an association between levels of IL-6mRNA, Jagged1 and Angiopoeitin2. Our findings have implications for the use of cancer therapies that target VEGF or IL-6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease and stroke.

Citation Format: Ganga Gopinathan, Carla Milagre, Oliver M.T Pearce, Louise Reynolds, Kairbaan Hodivala-Dilke, Andrew Leinster, Haihong Zhong, Robert E. Hollingsworth, Richard Thompson, James R. Whiteford, Frances Balkwill. Interleukin–6 stimulates defective 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 4162. doi:10.1158/1538-7445.AM2015-4162
Abstract 4163: Targetting VPAC1 for intestinal cancer prevention
Authors: Liu Shaohua , Zeng Yunjie , Ouyang Nengtai
Published: August 2015

Vasoactive intestinal peptide (VIP) is a neurotransmitter that primarily functions as a vasodilator. VIP plays its role through binding to its receptors known as VIP/pituitary adenylate cyclase-activating peptide receptors (VPACs). In this study, we examined the expression of VPAC1 in human colon cancer tissues, analyzed the relationship between VPAC1 expression and cancer malignancy, and explored the possible mechanisms using immunohistochemistry and immunofluorescence double staining. The results showed that: 1) poorly-differentiated colon cancers have significantly higher VPAC1 expression than well-differentiated colon cancers do (p<0.01); 2) phospho-EGFR overexpression/activation in the cytoplasm of cancer cells is related to VPAC1 overexpression; 3) blood vessels surrounding colon cancer have significantly more VPAC1-positive than normal colon mucosa does; 4) Tumor-Associated Macrophages (TAMs) of colon cancer have a higher level of VPAC1 expression than macrophages in normal colon mucosa do. These data suggest that VPAC1 overexpression is associated with poorer differentiation of colon cancer, which is likely caused by subsequent EGFR activation in cancer cells. In addition, VPAC1 overexpression in both blood vessels and macrophages in tumors may also play an important role in the development of aggressive cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Shaohua Liu, Yunjie Zeng, Nengtai Ouyang. Targetting VPAC1 for intestinal cancer prevention. [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 4163. doi:10.1158/1538-7445.AM2015-4163
Abstract 4167: Snai2(Slug) regulates tumor angiogenesis through the induction of EndoMT
Authors: Wu Nan , Welch-Reardon Katrina , Hughes Christopher
Published: August 2015

Anti-angiogenic therapy remains an attractive option in the treatment of cancer since it has the potential to both control growth of the primary tumor and limit metastasis. However, many current anti-angiogenic cancer drugs fail to deliver long-term efficacy, likely due to adaptation of the tumor to utilize alternative angiogenic pathways. The high level of cross talk between pro-angiogenic pathways makes targeting the downstream effectors a potentially more beneficial strategy.

We have recently demonstrated that the transcription factor Slug (Snai2), a master regulator of epithelial-to-mesenchymal transition (EMT), is expressed in angiogenic endothelial cells (EC) and can augment sprouting angiogenesis in vitro, likely by inducing a partial endothelial-to-mesenchymal transition (EndoMT). Slug is induced by many pro-angiogenic pathways (e.g. TGFβ, Notch, VEGF) and can directly regulate several key steps in angiogenesis, such as migration and proliferation, making it an attractive anti-angiogenic drug target.

In this study we used Slug knockout mice, which are viable but runted, to test the hypothesis that Slug regulates pathological angiogenesis in vivo by inducing an EndoMT. Using a Matrigel plug assay we found that angiogenesis was reduced in Slug knockout mice compared to littermate controls. Initial analysis suggests this is the result of impaired vascular recruitment. In addition, a syngeneic subcutaneous tumor model showed that the growth of wild type tumor cells is reduced by over 50% in Slug knockout mice compared to controls. In an in vitro angiogenesis assay Slug overexpression induces hypersprouting and an increased number of disconnected cells, suggesting the complete loss of cell-cell junctions, consistent with a full EndoMT. RNA-seq comparing Slug overexpressing EC to wild type EC revealed targets that are implicated in both autocrine and paracrine regulation of tumor angiogenesis. In conclusion, these data suggest that EC expression of Slug regulates tumor angiogenesis, and that the level of slug expression may set the threshold between a partial and a full EndoMT.

Citation Format: Nan Wu, Katrina Welch-Reardon, Christopher Hughes. Snai2(Slug) regulates tumor angiogenesis through the induction of EndoMT. [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 4167. doi:10.1158/1538-7445.AM2015-4167
Abstract 4168: Robo1 promotes angiogenesis through CDC42/Rho GTPases signaling pathway in hepatocellular carcinoma
Authors: Sun Hui-Chuan , Ao Jian-Yang , Chai Zong-Tao , Zhang Yuan-Yuan
Published: August 2015

Angiogenesis is essential for cancer growth and metastasis. Since present anti-angiogenesis strategies could not fulfill the expected clinical efficacy in hepatocellular carcinoma (HCC), novel key regulatory molecules involving this process are still under investigation. It has been reported that the axon guidance receptor gene Robo1 is involved in tumor angiogenesis. Here, we report the function of Robo1 in human umbilical vein endothelial cells (HUVEC) as well as the hepatocellular carcinoma endothelial cells. High Robo1 expression in the tumor vessels associated with a poor survival in patients. Over-expression of Robo1 in HUVEC cell lines results in increased proliferation, migration and tube formation in HUVECs. These changes could be reversed by knockdown of Robo1. Moreover, we show that Robo1 expression promoted CDC42 and Rho expression in HUVEC. We demonstrated that Robo1/CDC42/Rho signaling axis in HUVECs, which is important for function of HUVECs. Taken together, our results showed that Robo1 promoted angiogenesis in hepatocellular carcinoma and provide new target for anti-angiogenesis therapy in HCC

Note: This abstract was not presented at the meeting.

Citation Format: Hui-Chuan Sun, Jian-Yang Ao, Zong-Tao Chai, Yuan-Yuan Zhang. Robo1 promotes angiogenesis through CDC42/Rho GTPases signaling pathway in hepatocellular 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 4168. doi:10.1158/1538-7445.AM2015-4168
Abstract 4172: Differential angiogenesis-related cytokines release in tumor interstitial fluid and plasma in ER-positive and triple-negative breast cancers overexpressing VEGF
Authors: Dore-Savard Louis , Lee Esak , Popel Aleksander S. , Bhujwalla Zaver M.
Published: August 2015

Interstitial fluid (IF) is a key component of the tumor microenvironment (TME) that has been largely overshadowed by proteomic and genomic analysis of the cancer cell and stromal compartments of the TME. Early studies of tumor IF by Gullino and colleagues showed elevated protein and lactic acid levels and the absence of glucose. Modern analytical methods allow for comprehensive characterization of IF proteins to better understand the TME. We modified Gullino's model and created a collection chamber adapted to collect IF from mouse tumors. We used ER-positive MCF-7 and triple negative MDA-MB-231 breast cancer cells in SCID mice. Additionally, we created VEGF-overexpressing cells from each cell line to evaluate the effect of VEGF overexpression on angiogenic cytokines in tumor IF. The chamber was implanted with small tumor pieces in the subcutaneous space until the tumor encompassed the chamber (4 to 12 weeks depending on cell types). The tumor was then removed and the tumor IF (approximate volume 40μl) and blood plasma were collected. IF and plasma samples were analyzed using a multiple cytokine immunoassay (Proteome Profiler Human Angiogenesis Kit, R & D Systems Inc., Minneapolis MN). Among the 55 human angiogenesis-related cytokines tested, only 4 were detected in MCF-7 tumors IF, and 24 were detected in MDA-MB-231 IF sample. As anticipated, high VEGF levels were detected in MCF-7 overexpressing cells. Additionally, we observed a tendency to an elevated level of TIMP metallopeptidase inhibitor 1 (TIMP-1). All 4 cytokines detected in MCF-7 IF were also detected in MDA-MB-231 IF. VEGF overexpression had minimal effect on the tested cytokines. However, decreased levels of angiogenin and endostatin were observed. In plasma of tumor-bearing mice, 5 cytokines were detected. For instance, Serpin E1 (PAI-1) and TIMP-1 were detected in the plasma of both MCF-7 and MDA-MB-231, at lower levels than in IF. However, urokinase plasminogen activator was present only in mice with triple negative MDA-MB-231 tumors. We anticipate that a better understanding of the TME, via the characterization of the IF, will help identify new targets for diagnosis and therapy of cancer. We intend to examine correlations between the present data and human databanks to confirm the relevance of our model systems.

Citation Format: Louis Dore-Savard, Esak Lee, Aleksander S. Popel, Zaver M. Bhujwalla. Differential angiogenesis-related cytokines release in tumor interstitial fluid and plasma in ER-positive and triple-negative breast cancers overexpressing VEGF. [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 4172. doi:10.1158/1538-7445.AM2015-4172
Abstract 4174: Molecular changes in the EGFR pathway and RAS/RAF genes identify subtypes of metastatic and nonmetastatic colorectal cancer associated with different outcomes
Authors: Bahnassy Abeer A. , Salem Salem E. , Hussein Nehal , Yousif Hend F. , Marwa  , Al-Desouky Iman , Zekri Abdel-Rahman N.
Published: August 2015

Background: Categorization of colon cancers into distinct subtypes using a combination of pathway-based biomarkers and RAS/RAF mutations provides better insight into the variability in patient outcomes. We assessed the incidence, prognostic and predictive values of KRAS/BRAF mutations and some EGFR pathway genes in metastatic and non- metastatic CRC (mCRC and nmCRC) patients from Egypt.

Methods: 396 CRC patients (240 metastatic& 156 non metastatic) were assessed for KRAS/BRAF mutations by conventional PCR and immunohistochemistry (IHC). EGFR, PI3K, MEK and ERK expressions were assessed by quantitative real time PCR (qPCR) and IHC. Results were correlated to standard prognostic factors, response to treatment overall and disease free survival (OS&DFS).

Results: We detected KRAS mutations in 47.7% (27% in codon 12, 35.6% in codon 13 and 14.3% in 12/13), BRAF in 31.3% and EGFR in 54.6% of the cases. KRAS and EGFR were significantly higher in mCRC cases (p = 0.012& p = 0.045). Tumors were categorized into 4 genetically different groups: EGFR-/KRAS+, EGFR-/KRAS-, EGFR+/KRAS-, EGFR+/KRAS+ (30.3%,28.3%,24%, 17.4%). Significant correlations were found between EGFR, KRAS/BRAF mutations and PI3K-RNA in metastatic and non metastatic CRC (0.02&<0.001). In mCRC, correlations were found between 1) RAS mutations and all markers except EGFR (0.028&<0.001), 2) RAF and MEK/EGFR (0.045&<0.005), 3) PI3K and all genes (<0.001) except BRAF, 4) ERK and MEK (<0.001). In nmCRC, correlations were reported between 1) PI3K and EGFR (p<0.001), 2) RAS and MEK/ERK (p<0.001), 3) MEK and ERK (p<0.001), 4) EGFR and PI3K (p<0.001). DFS significantly correlated with K13RAS mutations, PI3K and positive family history (p<0.05). OS correlated with K13 RAS/BRAF mutation, PI3K and age (p<0.05).

Conclusions: KRAS/BRAF mutations and aberrations in EGFR pathway contribute differently to the development and progression of metastatic and non metastatic CRC cases in Egypt. These markers could be used for monitoring patients during treatment with conventional chemotherapy regimens and can provide candidates for targeted therapy.

Citation Format: Abeer A. Bahnassy, Salem E. Salem, Nehal Hussein,Hend F. Yousif, Marwa, Iman Al-Desouky, Abdel-Rahman N. Zekri. Molecular changes in the EGFR pathway and RAS/RAF genes identify subtypes of metastatic and nonmetastatic colorectal cancer associated with different outcomes. [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 4174. doi:10.1158/1538-7445.AM2015-4174
Abstract 4177: Simultaneous activation of C-X-C chemokine receptor 4 and cannabinoid receptor 2 results in decreased angiogenesis
Authors: Scarlett Kisha A. , Sandifer Brittney , Coke Christopher J. , Hinton Cimona V.
Published: August 2015

Tumor angiogenesis is a complex process modulated by numerous signaling molecules and pathways that influence cell migration, invasion, survival and tube formation. The expression of the G-protein-coupled receptor (GPCR) C-X-C Chemokine Receptor 4 (CXCR4) has been correlated with the increased angiogenic potential of cancer cells. The ligand-specific binding of CXCL12 to CXCR4 increases tumor angiogenesis by upregulating the expression of vascular endothelial growth factor (VEGF) at both mRNA and protein levels. Thus, modulating the CXCR4/CXCL12 signaling axis provides an attractive target for the inhibition of tumor angiogenesis and cancer progression. Recent studies have suggested that in addition to its palliative properties, cannabis may have anti-proliferative and anti-metastatic effects by acting through the GPCR, cannabinoid receptor 2 (CB2R). GPCR heterodimerization has emerged as a means by which new signaling entities can be created with respect to agonist binding. Preliminary co-immunoprecipitation data from our lab indicates that agonist-bound CXCR4 and agonist-bound CB2R interact at the cell membrane and that receptor interaction mitigates the effects of CXCL12-mediated CXCR4 signaling. Here we show that co-stimulation of prostate cancer cells with CXCR4 and CB2R-specific agonists results in decreased VEGF expression in vitro. Furthermore, treatment of human endothelial cells with conditioned medium collected from co-stimulated prostate cancer cells decreased endothelial cell migration in wound healing and invasion assays, and decreased endothelial cell tubulogenesis. Taken together, these results demonstrate that desensitization of CXCR4 signaling through association with CB2R is a novel anti-angiogenic strategy and reinforces the clinical relevance of cannabinoids in cancer treatment.

Note: This abstract was not presented at the meeting.

Citation Format: Kisha A. Scarlett, Brittney Sandifer, Christopher J. Coke, Cimona V. Hinton. Simultaneous activation of C-X-C chemokine receptor 4 and cannabinoid receptor 2 results in decreased 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 4177. doi:10.1158/1538-7445.AM2015-4177
Abstract 4178: L1CAM and integrin αvβ3 mediate direct cell contact between cancer stem cells and endothelial cells: Promotion of endothelial cell migration and survival
Authors: Burgett Monica E. , Lathia Justin D. , Roth Patrick , Nowacki Amy S. , Huang Ping , Vasanji Amit , Li Meizhang , Byzova Tatiana , Mikkelsen Tom , Bao Shideng , Rich Jeremy , Weller Michael , Gladson Candece L.
Published: August 2015

Sprouting angiogenesis requires endothelial cell (EC) migration. In glioblastoma (GBM), cancer stem cells (CSC) in the perivascular niche secrete factors that promote EC migration. Here, we identify a direct interaction between the CSCs and ECs that is mediated by RGD-peptide-dependent binding of L1CAM on CSCs with integrin αvβ3 on ECs. Using in vitro assays, we found that this interaction increased migration-associated signaling events in ECs, including activation of integrin

αvβ3, ERK, JNK and Akt, and VCAM-1 and E-selectin mRNA expression. Comparison of the effects of co-culturing CSCs with ECs versus the effects of conditioned media from CSCs co-cultured with ECs indicated that the effects of the direct interaction and soluble factors differed quantitatively and qualitatively. The direct interactions stimulated the migration of ECs and primed them to the migratory effects of soluble factors produced by the CSCs. The direct interaction also enhanced expression of pro-survival genes in CSCs and ECs. In GBM biopsies, Sox2-positive tumor cells were localized in close proximity to ECs and injection of β3-negative ECs or L1CAM-negative CSCs into brain slices in organotypic culture resulted in reduced interactions between ECs and CSCs.

RGD-peptide treatment of mice with established intracerebral GBM xenografts increased the mean distance of Sox2-positive tumor cells from ECs, decreased integrin αvβ3 activation and decreased vessel surface area. These data show that direct interactions between CSCs and ECs have potent effects on EC migration and angiogenesis in GBM and have implications for the design of angiogenesis-targeted therapies.

Citation Format: Monica E. Burgett, Justin D. Lathia, Patrick Roth, Amy S. Nowacki, Ping Huang, Amit Vasanji, Meizhang Li, Tatiana Byzova, Tom Mikkelsen, Shideng Bao, Jeremy Rich, Michael Weller, Candece L. Gladson. L1CAM and integrin αvβ3 mediate direct cell contact between cancer stem cells and endothelial cells: Promotion of endothelial cell migration and survival. [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 4178. doi:10.1158/1538-7445.AM2015-4178
Abstract 4187: Expression of ion channels in a cervical cancer mouse model
Authors: RAMIREZ ANA , VERA EUNICE , LAMBERT PAUL , GARIGLIO PATRICIO , CAMACHO JAVIER
Published: August 2015

Introduction. Because some ion channels have been suggested as early tumor markers and therapeutic targets, in the present study we examined the expression of ion channels in the cervical cancer transgenic mouse model K14E7 expressing the HPV16 E7 oncogene under the control of the human keratin 14 promoter.

Methods. We used the K14E7 transgenic mouse; some groups were treated with 17β-estradiol. Continuous release pellets delivering 0.05 mg of 17β-estradiol were implanted into 4-6 weeks old female mice during 90 days to obtain low grade cervical dysplasia or during 180 days to produce cervical cancer. The cervix was removed at the end of the treatment. Protein and mRNA expression of 4 ion channels (Cav3.1, Cav3.2, Kv10.1, KCa1.1) were analyzed by qRT-PCR and immunohistochemistry, respectively.

Results. We found increased expression of Cav3.1, Kv10.1 and KCa1.1 in mice with cervical dysplasia in comparison to control animals. This increase was even higher in animals with cervical cancer. In contrast, Cav3.2 expression decreased in animals with cervical dysplasia and increased in mice with cervical cancer. We also found overexpression of the KCa1.1 protein in the transformed zone of the cervical cancer group, but not in the control group.

Conclusions. The channel expression profile here studied might serve as a cervical cancer marker. This work was partially supported by Conacyt grant 141126 to JC.

Citation Format: ANA RAMIREZ, EUNICE VERA, PAUL LAMBERT, PATRICIO GARIGLIO, JAVIER CAMACHO. Expression of ion channels in a cervical cancer mouse model. [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 4187. doi:10.1158/1538-7445.AM2015-4187
Abstract 4189: Analgesic effect of quetiapine on the cancer induced bone pain animal model
Authors: Park Keon Uk , Heo Mi Hwa , Kim Jin Young , Hwang Ilseon , Ryoo Hun Mo
Published: August 2015

Background: Cancer induced bone pain is one of the most common pain in patients with advanced cancer. Because of treatment associated side effects, it has been reported that more than half of cancer patients have inadequate and undermanaged pain control. Therefore, new mechanism-based therapies need to be developed to reduce cancer pain. Quetiapine is a commonly used atypical antipsychotic drug that has superior therapeutic effects in patients with schizophrenia and other neurological disorders like depression. We reported that a study of anti-inflammatory effect of quetiapine on collagen induced arthritis mouse model. Now we focused on the potential analgesic effects of quetiapine on the cancer induced bone pain (CIBP) animal model and the mechanism of bone pain evaluated by various nociceptors expression.

Methods: Fifteen male C3H/HeN mice were randomly divided into five groups: Control, CIBP, CIBP + quetiapine treatment, CIBP + opioid treatment and CIBP + melatonin treatment. Treatments were started when mouse showed positive signs of bone tumor until the day 28, according to the protocol, daily for 12 days. Pain thresholds of CIBP mouse model were measured by aesthesiometer for each group. At the end of the treatment period, tissue of mouse tibia were removed and quantitative and qualitative evaluation of TRPV1, TRPV4, ASIC1, ASIC2, and ASIC3 expression were done.

Results: The data showed that mouse behavior about pain thresholds was marked improved in CIBP + quetiapine treatment group compared with CIBP group. The expression of TRPV1, TRPV4, ASIC1, ASIC2, and ASIC3 in CIBP + quetiapine treatment group was significantly lower than those in CIBP groups.

Conclusions: These results suggest analgesic effect of quetiapine on CIBP animal model and provide the possibility that TRPV and ASICs could be a potential target of cancer pain management.

Citation Format: Keon Uk Park, Mi Hwa Heo, Jin Young Kim, Ilseon Hwang, Hun Mo Ryoo. Analgesic effect of quetiapine on the cancer induced bone pain animal model. [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 4189. doi:10.1158/1538-7445.AM2015-4189