bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-144: GPR56 internalizes and degrades TG2 in melanoma
Authors: Yang Liquan , Friedland Scott , Corson Nancy , Xu Lei
Published: May 2015

Excessive accumulation of extracellular matrix (ECM) is a hallmark of tumor microenvironment and plays active roles during tumor progression. How this process is regulated and whether it is reversible for cancer treatment are outstanding questions. Our earlier study showed that an adhesion G protein-coupled receptor (GPCR), GPR56, inhibits melanoma growth and metastasis and binds to tissue transglutaminase (TG2), a major cross-linking enzyme in ECM. To understand the function of TG2 in GPR56-mediated melanoma inhibition, we generated immunodeficient Tg2-/- mice and performed xenograft transplantation studies in these mice. Our results revealed an antagonistic relationship between GPR56 and TG2 during melanoma growth: whereas TG2 promotes melanoma growth, GPR56 antagonizes this effect via receptor-mediated internalization and degradation. Furthermore, the down-regulation of TG2 by GPR56 is associated with a reduction in the levels of fibronectin and focal adhesion kinase (FAK), suggesting that the fibronectin-mediated cell adhesion is compromised upon GPR56 expression in melanoma. Taken together, our findings provide genetic evidence for the function of TG2 in GPR56-mediated melanoma inhibition. The uncovered antagonistic relationship between GPR56 and TG2 proposes a mechanism by which ECM accumulation/crosslinking may be reversed, and thus might be exploited for cancer control and treatment.

Citation Format: Liquan Yang, Scott Friedland, Nancy Corson, Lei Xu. GPR56 internalizes and degrades TG2 in melanoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-144. doi:10.1158/1538-7445.AM2014-LB-144
Abstract LB-15: Enhancement of radiotherapeutic efficacy by cisplatin-incorporated bionanocapsule without nephrotoxicity
Authors: Shin Seol Hwa , Park Seok Soon , Jeong Joohee , Choi Jinhyang , Park Jaesook , Lee Jae Hee , Park Hye Ji , Song Si Yeol , Jeong Seong-Yun , Kuroda Shun'ich , Choi Eun Kyung
Published: May 2015

Radiotherapy is one of the most effective tools in the clinical treatment for many types of solid tumors, but the therapeutic efficacy is often limited because of resistance to ionizing radiation. Although cisplatin (CDDP) is widely used as a radiosensitizer to improve therapeutic outcomes, its side effect such as acute nephrotoxicity limits application. To overcome the hurdle of CDDP, it is extremely necessary to apply a delivery system that can enhance the radiotherapeutic efficacy and reduce CDDP-induced side effects. Bionanocapsule (BNC) consisting of hepatitis B virus surface antigen (HBsAg) L protein is approximately 50-nm hollow particles displaying a human hepatocyte-recognizing molecule (pre-S1 peptide). BNC-liposome complex has been developed suitable to deliver drugs and genes to human hepatocytes specifically in vivo. Utilizing the character of BNC targeting hepatocytes and its property to carry anti-cancer agents, we designed a BNC complex incorporating liposomal CDDP (BNC-LP-CDDP) for hepatocellular carcinoma (HCC). HCC is the fifth most common cancer and the third most common cause of cancer related death worldwide. Although surgical resection is the optimal treatment approach, only a small proportion of patients are qualified for surgery and there is a high rate of tumor recurrence. BNC-LP-CDDP has been produced to destroy HCC without nephrotoxicity, and we aimed in this study to confirm the effect enhancing the radiotherapeutic efficacy in vitro and in vivo. The in vitro HCC-specific cytotoxicity of BNC-LP-CDDP was confirmed by comparison between human HCC Hep3B and human NSCLC A549 cells. The result of clonogenic assay to evaluate chemoradiotherapeutic efficacy of BNC-LP-CDDP demonstrated that survival fraction of hep3B showed radiosensitivity efficacy by BNC-LP-CDDP with IR. In vivo, treatment with BNC-LP-CDDP (2 mg/kg) and IR (3 Gy) delayed tumor growth accompanying increased apoptotic cell death more than that of other groups. Furthermore, BNC-LP-CDDP displayed decreased nephrotoxicity of CDDP.

Collectively, our results demonstrate that BNC-LP-CDDP in combination with ionizing radiation enhanced radiotherapeutic efficacy by human liver-pinpoint delivery and eliminated CDDP-induced nephrotoxicity.

Citation Format: Seol Hwa Shin, Seok Soon Park, Joohee Jeong, Jinhyang Choi, Jaesook Park, Jae Hee Lee, Hye Ji Park, Si Yeol Song, Seong-Yun Jeong, Shun'ich Kuroda, Eun Kyung Choi. Enhancement of radiotherapeutic efficacy by cisplatin-incorporated bionanocapsule without nephrotoxicity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-15. doi:10.1158/1538-7445.AM2014-LB-15
Abstract LB-151: A novel TGFβ 1/2 specific antibody suppresses 4T1 tumor growth by enhancing NK cell recruitment and function
Authors: Li Ou , Khan Shireen , Mendoza Nerissa , Vanegas Sandra , Tran Cat , Mirza Amer
Published: May 2015

TGFβ can play an important role in tumor progression. Whether expressed by the tumor, or the tumor microenvironment, it has a profound impact on not only the tumor itself but also the host immune system. There are three isoforms of TGFβ: TGFβ1, TGFβ2 and TGFβ3. The functions of TGFβ1 and 2 have been widely studied. However, little is known about how TGFβ3 affects both tumor growth and the host. Here we used a novel human antibody that neutralizes only TGFβ1 and 2, while leaving TGFβ3 activity untouched. By specifically blocking TGFβ1 and 2 functions, we were able to investigate the role of TGFβ3 in modulating the immune compartment, and its ability to combat tumor growth. We used the 4T1 murine breast carcinoma model, which secretes all three isoforms of TGFβ. Tumor-bearing mice were treated with 10mg/kg the novel anti-TGFβ1/2 antibody, which inhibited 25% of 4T1 tumor growth after 20 days. We evaluated the immune cells from tumors and found there was a significant increase (14%) in the NK cells that infiltrated the tumor site in the antibody-treated group. To explore the mechanism underlying this phenomenon, we evaluated the effect of tumor-secreted TGFβ isoforms on NK cells in vitro in a co-culture system. When 4T1 tumor cells were co-cultured with enriched NK cells, the TGFβ1/2 antibody elevated the levels of IFNγ, GzmB and perforin. However, the expression levels of NKG2D, CD69, Ly49A and C were unchanged. We also detected a significant upregulation of FasL on NK cells treated with the TGFβ1/2 antibody. Moreover, NK cells treated with the TGFβ1/2 antibody in the co-culture system showed improved killing activity towards Yac-1 cells, which was confirmed to be mediated by GzmB. In summary, a novel therapeutic antibody candidate that specifically neutralizes TGFβ1 and 2 inhibits 4T1 tumor growth by (i) changing the tumor microenvironment to attract NK cells to tumor sites; and (ii) by increasing NK cell function via upregulation of FasL and GzmB.

Citation Format: Ou Li, Shireen Khan, Nerissa Mendoza, Sandra Vanegas, Cat Tran, Amer Mirza. A novel TGFβ 1/2 specific antibody suppresses 4T1 tumor growth by enhancing NK cell recruitment and function. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-151. doi:10.1158/1538-7445.AM2014-LB-151
Abstract LB-155: Ovarian cancer-induced changes in the intestinal microbiota as potential biomarkers for early detection
Authors: Schmelz Eva M. , Roberts Paul C. , Ponder Monica A.
Published: May 2015

Early detection of cancer can drastically increase the survival rate of the patient. While tremendous efforts were devoted to developing early detection tools, especially cancers in the peritoneal cavity such as ovarian cancer are often detected late after the exfoliated cancer cells have spread throughout the peritoneal cavity and have formed metastases, leading to a high mortality. However, early detection can increase the 5-year survival rate of afflicted women from less than 30% to more than 80%, highlighting the importance of developing early detection tools. Ideally, these tools should be specific for ovarian cancer but include most histological sub-types, and be non-invasive. An attractive source of biomarkers lies within the complex gut microbiome- whose membership and functionality are tightly associated with the health of its host. Changes to the gut microbiota, a concept referred to as dysbiosis, are associated with disease in humans. Here we describe changes in the intestinal microbiota as a function of the presence of ovarian cancer metastases in the peritoneal cavity. We postulate that these might serve as useful markers for earlier detection of ovarian cancer or other peritoneal-associated cancers.

Citation Format: Eva M. Schmelz, Paul C. Roberts, Monica A. Ponder. Ovarian cancer-induced changes in the intestinal microbiota as potential biomarkers for early detection. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-155. doi:10.1158/1538-7445.AM2014-LB-155
Abstract LB-157: VISTA deficiency synergizes with a non-redundant immune checkpoint pathway and leads to enhanced immune activation
Authors: Wang Li , LeMercier Isabelle , Suriawinata Arief , Chen Wenna , Noelle Randolph J. , Li Jiannan
Published: May 2015

V-domain Ig suppressor of T cell activation (VISTA) is a novel negative checkpoint ligand that suppresses T-cell mediated immune responses. Previous studies using VISTA-neutralizing monoclonal antibody show that VISTA-blockade enhances T cell-activation in an inflammatory disease model EAE, as well as in murine tumor models. Current study describes a comprehensive characterization of VISTA knockout (KO) mice. We show that despite the apparent normal hematopoietic development in young ko mice, VISTA genetic deficiency leads to a pro-inflammatory phenotype in aged animals, as well as enhanced T-cell activation in response to acute antigen immunization. In addition, we show that VISTA deficiency significantly enhanced disease development in a spontaneous model of autoimmune disease, which is correlated with the spontaneous activation of auto-antigen specific CD4+ T cells. Lastly, when combined with the genetic deficiency of another checkpoint molecule, synergistic or additive immune activation was observed. The implication of such enhanced immunity in cancer development and treatment will be discussed.

Citation Format: Li Wang, Isabelle LeMercier, Arief Suriawinata, Wenna Chen, Randolph J. Noelle, Jiannan Li. VISTA deficiency synergizes with a non-redundant immune checkpoint pathway and leads to enhanced immune activation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-157. doi:10.1158/1538-7445.AM2014-LB-157
Abstract LB-16: Discovery of novel SGK1 inhibitors by a fragment-based approach: Generating patentable, chemically tractable and ligand efficient leads
Authors: Alton Gordon , Wade Warren , Lingardo Laura , Batova Ayse , Smart Tom , Buhr Chris , Zapf James W. , Pallai Peter
Published: May 2015

Triple negative (ER, PR and HER2/neu negative) breast cancer (TNBC) can have an unfavorable prognosis compared to other breast cancers. TNBC is more difficult to treat since most targeted breast cancer therapies are directed at one of the three receptors. Aggressive combinatorial therapies are usually required and the cytotoxic agents used in these regimens frequently loose effectiveness with time. Serum and glucocorticoid-regulated kinase 1 (SGK1) (a serine/threonine protein kinase), promotes the growth and invasiveness of breast cancer cells. SGK1 is a key protein regulated by the glucocorticoid receptor (GR). In TNBC tumors, high expression/activity in the GR/SGK axis correlates with shorter survival times and resistance to chemotherapy. The small numbers of SGK1 inhibitors reported in the literature have resulted from screening against other kinases (such as CHK1/azaindoles) and thus are not selective and lack patentable chemical diversity. We describe the identification of novel SGK1 inhibitors using a fragment-based library screening approach. The BioBlocks Leap-To-Lead platform contains a library of novel fragment-like compounds that span a range of polarities and sizes without compromising on flexibility. For example, this 275 compound library has an average molecule weight of 160 Da; AlogP, 1.1; hydrogen bond donors, 1.1; hydrogen bond acceptors, 2.2, and rotatable bonds, 0.7 yet still contains 114 unique rings. The library was screened against fully activated human SGK1 in an ADP-Glo assay using physiologically relevant peptide substrate and an optimal ATP concentration to also identify non-classical kinase inhibitor mode binders. The fragment library was screened at 2 mM and hits were profiled in IC50 dose response. From these, several novel chemical matter hit compounds were selected that had ligand efficiency values greater than 0.3 and spanned IC50 values from 75 µM to 2000 µM.

In summary, a fragment-based screening approach was used to identify several novel scaffolds that represent both classical and non-classical kinase inhibitor binding modes as hit-to-lead starting points for the optimization of novel, potent and selective SGK1 inhibitors.

Citation Format: Gordon Alton, Warren Wade, Laura Lingardo, Ayse Batova, Tom Smart, Chris Buhr, James W. Zapf, Peter Pallai. Discovery of novel SGK1 inhibitors by a fragment-based approach: Generating patentable, chemically tractable and ligand efficient leads. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-16. doi:10.1158/1538-7445.AM2014-LB-16
Abstract LB-164: Towards operative in vivo fluorescence imaging of c-Met proto-oncogene for personalization of therapy in ovarian cancer
Authors: Liu Shujuan , Zheng Yong , Volpi Davide , El-Kasti Muna , Klotz Daniel , Tullis Iain , Henricks Andrea , Campo Leticia , Myers Kevin , Laios Alex , Thomas Peter , Ng Tony , Dhar Sunanda , Becker Christian , Vojnovic Borivoj , Ahmed Ahmed A.
Published: May 2015

The recent recognition of the scale of the problem of tumour heterogeneity has made it clear that standard biomarker testing of a single macroscopic disease sites is unlikely to be sufficient. A focus on examining global biomarker expression or activity is needed for appropriate selection of targeted therapies. A particular attention to microscopic residual chemotherapy-residual disease (MRCD) would ensure appropriate targeting of chemotherapy resistance. However, the techniques for global assessment of biomarkers in patients with MRCD have not established.

Using an in-house developed fluorescent imaging device we show that it is possible to identify global c-Met expression in submillimeter peritoneal metastases that were freshly excised from a human high-grade serous ovarian cancer. We evaluated a modified Cy5-tagged peptide (GE137) that selectively binds to the c-Met tyrosine kinase and demonstrated the feasibility of detecting submillimeter ovarian cancer cell peritoneal metastases in vivo following intravenous injection of this peptide. GE137 specifically accumulated in cells that express c-Met via clathrin-mediated endocytosis and emitted a fluorescent signal that lasted for at least 8 hours in tumour xenografts in vivo with a sustained high signal to noise ratio. Thus, intraoperative optical imaging could provide a new paradigm for selecting cancer patients with MRCD for appropriate targeted therapies following initial chemotherapy.

Citation Format: Shujuan Liu, Yong Zheng, Davide Volpi, Muna El-Kasti, Daniel Klotz, Iain Tullis, Andrea Henricks, Leticia Campo, Kevin Myers, Alex Laios, Peter Thomas, Tony Ng, Sunanda Dhar, Christian Becker, Borivoj Vojnovic, Ahmed A. Ahmed. Towards operative in vivo fluorescence imaging of c-Met proto-oncogene for personalization of therapy in ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-164. doi:10.1158/1538-7445.AM2014-LB-164
Abstract LB-168: Perivascular, CXCR4-expressing macrophages in tumors promote relapse following chemotherapy
Authors: Lewis Claire E.
Published: May 2015

The relapse of cancer after frontline therapies like chemotherapy is a major clinical problem as tumors often grow back at the site of surgical removal and/or as metastases. Tumor-associated macrophages (TAMs) are a major cellular component of both primary and metastatic tumors, and promote such key processes in tumor progression as angiogenesis, immunosuppression, invasion, and metastasis. Gene expression profiling and immunostaining studies have identified both classically (M1) and alternatively (M2) activated TAMs in human and mouse tumors. Heavily M2-skewed TAMs - those expressing the angiopoietin receptor, TIE2 - have been shown to be important for angiogenesis and immunosuppression in mouse tumors. Moreover, high levels of TAMs expressing another M2 marker, CD163, correlate with poor prognosis in various forms of human cancer. TAMs have been shown recently to reduce the sensitivity of mouse mammary tumors to cytotoxic agents like paclitaxel (PTX) and doxorubicin. Here, we report on our use of various mouse tumor models to investigate the role of TAMs in tumor relapse after chemotherapy. Our studies show that a distinct subset of M2-skewed, CXCR4hi VEGF+ TAMs cluster around blood vessels after administration of various cytotoxic agents. This correlated with increased tumor CXCL12 levels - and the selective depletion of this perivascular TAM subset, using the CXCR4 antagonist, AMD3100 (Plerixafor), revealed an important role for these cells in driving revascularisation and regrowth in post-chemotherapy tumors. Additionally, adoptive transfer of this TAM subset into tumor-bearing mice after chemotherapy accelerated tumor regrowth. No such effect was seen with non-M2 skewed TAMs isolated from the same tumors. These studies suggest that combining chemotherapy with inhibitors of the CXCL12-CXCR4 axis could delay tumor relapse in cancer patients.

Citation Format: Claire E. Lewis. Perivascular, CXCR4-expressing macrophages in tumors promote relapse following chemotherapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-168. doi:10.1158/1538-7445.AM2014-LB-168
Abstract LB-17: Oral delivery of taurocholic acid-linked heparin-docetaxel conjugates for tumor and its angiogenesis therapy
Authors: Khatun Zehedina , Nurunnabi MD , Huh Kang Moo , Lee Yong-kyu
Published: May 2015

Oral delivery is the preferred route to deliver therapeutics via nanoparticles due to ease of administration and patient acceptance. Here, we report on the findings of the absorption pathway of taurocholic acid (TCA)-linked heparin and docetaxel (DTX) conjugate, which we refer to as HDTA. The ternary biomolecular conjugates formed self-assembly nanoparticles where docetaxel was located inside the core and taurocholic acid was located on the surface of the nanoparticles. The oral absorption profile demonstrated that the concentration of the conjugates in plasma is about 6 fold higher than heparin alone. An anti-tumor study in MDA-MB231 and KB tumor bearing mice showed significant tumor growth inhibition activity by the ternary biomolecular conjugates. We studied the oral absorption of HDTA using a Caco-2 cell transport system and an animal model. We have also used other absorption enhancers, such as ethylene glycol tetraacetic acid (EGTA), or inhibitors, such as sodium azide, to compare the relative permeability of HDTA conjugates. In vivo comparative studies were conducted using free TCA as a pre-administration and exhibited the maximum absorption site of the organ after oral administration of HDTA conjugates. HDTA was found to be absorbed mainly in the ileum and Caco-2 cell monolayer through passive diffusion and bile acid transporters. High fluorescence intensity of HDTA in mice came from the ileum, and it was eliminated from the body through colon. This novel formulation could be further investigated by clinical trials to find the prospect of oral anti-cancer drug delivery through anti-angiogenic treatment strategies.

Citation Format: Zehedina Khatun, MD Nurunnabi, Kang Moo Huh, Yong-kyu Lee. Oral delivery of taurocholic acid-linked heparin-docetaxel conjugates for tumor and its angiogenesis therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-17. doi:10.1158/1538-7445.AM2014-LB-17
Abstract LB-178: In vivo validation of candidate radiosensitizers that target ionizing radiation induced foci
Authors: Efimova Elena V. , Mauceri Helena J. , Labay Edwardine , Sutton Harold , Haraf Ashly , Kron Stehen J. , Weichselbaum Ralph
Published: May 2015

Even after several decades of use, radiation therapy (RT) remains an important tool in the treatment of different types of cancers. Discovery of novel non-toxic radiosensitizers that halt tumor growth and/or restore senescence checkpoint growth arrest are highly desirable. Our work, along with other studies, has revealed that disrupting the repair of DNA double strand breaks (DSBs) can sensitize cancer cells to genotoxic stress. In our prior work we used GFP-53BP1 expressed in the MCF-7 breast cancer cell line as a sensor to screen small molecules that affect radiation-induced foci (IRIF) persistence. The screening of libraries of approved and investigational drugs identified several “hits”, a surprising number of which were compounds without known connections to the DNA damage response or to chromatin alteration. Significantly, several compounds that promote IRIF persistence also restore the senescence checkpoint in irradiated cancer cells. To validate the candidate radiosensitizers we demonstrated that selected hits induced IRIF persistence and senescence in a variety of different cell lines, including HNSCC, and pancreatic and melanoma cells. Based on in vitro analysis, we identified the most promising compounds/”hits” for testing in tumor growth studies. Combining selected “hits” with radiation treatment (RT) induced IRIF persistence and increased senescence induction in MCF7-GFP-53BP1 xenografts growing in nude mice. We report that drug “hits” combined with RT induced senescence and suppressed tumor regrowth in highly radioresistant B16-SIY melanoma tumors growing in syngeneic C57BL/6 mice. Our data suggest that the use of nontoxic radiation sensitizers which enhance the effects of DNA damage and overcome intrinsic tumor radioresistance may be employed to enhance the therapeutic ratio of radiotherapy.

Citation Format: Elena V. Efimova, Helena J. Mauceri, Edwardine Labay, Harold Sutton, Ashly Haraf, Stehen J. Kron, Ralph Weichselbaum. In vivo validation of candidate radiosensitizers that target ionizing radiation induced foci. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-178. doi:10.1158/1538-7445.AM2014-LB-178
Abstract LB-180: Prognostic analysis of invasive circulating tumor cells (iCTCs) to monitor epithelial ovarian cancer
Authors: Chen Wen-Tien , Dong Huan , Zhao Qiang , Yang Jie , ZHANG QIAO , Zucker Stanley , Pearl Michael L.
Published: May 2015

Purpose:

Cancer antigen 125 (CA125) is recognized as the leading biomarker in monitoring Epithelial Ovarian Cancer (EOC). More recently, invasive circulating tumor cells (iCTCs) have been introduced as a biomarker for metastatic potential. The goal of this research is to compare this biomarker with CA125 to determine the response to surgery and chemotherapy.

Experimental Design:

We compared clinical parameters with serial assays for iCTCs and CA125 in 129 fresh blood and 169 serum samples, respectively, from 31 patients who were receiving surgery and chemotherapy. iCTCs were capable of ingesting matrices (Cell Adhesion Matrix CAM+) and identified using positive tumor markers, Epi (EPCAM and CA125 or seprase and CD44), and negative selection markers, which exclude Epi-positive hematopoietic lineage (HL) cells, and enumerated by flow cytometry. iCTCs and CA125 levels were measured at time point less than 3-days apart.

Results:

A significant correlation was identified between changes in iCTC counts and CA125 levels (r=0.67, P<0.001) in the 83 samples collected prior to and after surgery and therapy. CA125 levels, but not iCTCs, were significantly reduced after surgery. During therapy, a significantly stronger concordance with clinical status was noted for decreasing values (specificity, 93.8% CA128; 90.6% iCTCs) compared with increasing values (sensitivity, 61.3% CA125; 83.9% iCTCs). Notably, increases in iCTCs, not CA125, were associated with increased risks for progressive disease (P<0.001). In the 8 patients who had >4 serial samples during therapy, changes in iCTC counts provided earlier measure of therapy response than CA125.

Conclusion:

This analysis showed that iCTC assay compared favorably with CA125 to monitor the response of chemotherapy in EOC patients, whereas changes of CA125 correlated better with reduced tumor burden after surgery.

Citation Format: Wen-Tien Chen, Huan Dong, Qiang Zhao, Jie Yang, QIAO ZHANG, Stanley Zucker, Michael L. Pearl. Prognostic analysis of invasive circulating tumor cells (iCTCs) to monitor epithelial ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-180. doi:10.1158/1538-7445.AM2014-LB-180
Abstract LB-181: The impact of Ras/MAPK/S6K signaling pathway on prediction of clinical outcome in metastatic Her-2 positive breast cancer patients treated with trastuzumab
Authors: Svoboda Marek , Khoylou Marta , Grell Peter , Navratil Jiri , Fabian Pavel , Juracek Jaroslav , Palacova Marketa , Vyzula Rostislav , Hajduch Marian
Published: May 2015

Background: The overexpression of Her-2 (c-erbB2/Neu) in breast cancer is associated with poor prognosis, tumor recurrence and shortened survival. The administration of the trastuzumab significantly improves patients prognosis. However, in spite of these successful results, trastuzumab is effective only in 30-50% of cases. PI3K/Akt and Ras/MAPK signaling pathways are activated through Her-2 receptor and other growth factors’ receptors and both play important role in tumor behavior.

Methods: The study included 76 women with verified Her-2+ metastatic breast cancer (MBC) who were treated with trastuzumab based palliative chemotherapy. Immunohistochemistry was performed on formalin fixed, paraffin embedded tissue sections with antibodies against S6K, p-S6K-Ser235/236, MAPK, p-MAPK-Thr202/Tyr204, GSK3β, p-GSK3β-Ser9, mTOR, p-mTOR-Ser2448. The cytoplasmatic and nuclear fractions of the staining were assessed separately.

Results: Patients whose tumors showed cytoplasmic (c) and nuclear (n) expression of p- GSK3β-Ser9 exhibited worse PFS compared to tumors with negative p-GSK3β-Ser9 (PFS 5,1 vs 9,1 months; P=0,006). Similar results were also found in p-S6K kinase activity, with the difference that it was possible to observe the dependence on the p-S6K kinase compartmentalization. Patients whose tumors showed p-S6K-Ser235/236 expression accompanied with only cytoplasmatic (c) or nuclear and cytoplasmatic (n+c) staining exhibited worse PFS compared to tumors with negative p-S6K-Ser235/236 expression (negat) (c vs negat: 6,3 vs 16,1 months, P=0,006; n+c vs negat: 7,8 vs 16,1 months, P=0,025).

Of the remaining kinases, we showed no effect of their expression on treatment outcome.

Conclusions: This study confirms that prediction of the response or resistance to trastuzumab treatment depends on the S6K and GSK3β kinase activity. Patients, whose tumors had high level of p-S6K or p-GSK3β, had poorer benefit from trastuzumab based therapy. These patients are candidates for targeted blockade of PI3K/Akt and/or RAS/MAPK signaling pathways. Supported by the Internal Grant Agency of Ministry of Health, Czech Republic, No.NT/14599 and Biomedreg CZ.1.05/2.1.00/01.0030.

Citation Format: Marek Svoboda, Marta Khoylou, Peter Grell, Jiri Navratil, Pavel Fabian, Jaroslav Juracek, Marketa Palacova, Rostislav Vyzula, Marian Hajduch. The impact of Ras/MAPK/S6K signaling pathway on prediction of clinical outcome in metastatic Her-2 positive breast cancer patients treated with trastuzumab. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-181. doi:10.1158/1538-7445.AM2014-LB-181
Abstract LB-188: Co-evolution of primary and metastatic colorectal cancer
Authors: Yeatman Timothy J. , Teer Jamie , Grenawalt Danielle , Kim Richard , Schell Michael J.
Published: May 2015

Introduction: Metastasis is thought to be a clonal event whereby a single cell initiates the development of a new tumor that reproduces the primary tumor at a distant site. We hypothesized that primary tumors and their derivative metastases might be genetically identical. To test this hypothesis, we used deep nextgen sequencing to assess the molecular composition of primary:metastatic tumor pairs. Methods: Nearly 20,000 tumors were molecularly profiled as part of a large personalized medicine initiative. Of these, 468 colorectal tumor samples were further assessed by targeted exome sequencing of 1321 individual genes. 16 patients produced genomic profiles paired primary:metastatic specimens; 2 patients produced paired metastases. Non-synonymous, deleterious, single nucleotide variants were identified as potential driver or passenger mutations using the BWA/GATK pipeline.

Results: An average of 33.3 mutations/tumor was concordant (shared), with common drivers identified (APC, KRAS, TP53). An average of 2.3 mutations/tumor was discordant (unshared) in the paired primary and metastatic sites. Thus, the overall concordance rate for mutations was 93.5%; however, nearly all (17/18 (94.4%)) paired tumors showed at least one mutational discordance: TTN, the largest gene (5 discordant pairs); ADAMTS20, APC, MACF1, RASA1, TP53, and WNT2 (2 discordant pairs); SMAD2, SMAD3, SMAD4, FBXW7, and ∼66 others (1 discordant pair).

Conclusions: Primary and metastatic tumors displayed little variance overall supporting clonality; however, in ∼50% of cases, co-evolution produced incremental, potential driver mutations in both. These results suggest analysis of the primary lesion alone may be insufficient to precisely tailor therapy.

Citation Format: Timothy J. Yeatman, Jamie Teer, Danielle Grenawalt, Richard Kim, Michael J. Schell. Co-evolution of primary and metastatic colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-188. doi:10.1158/1538-7445.AM2014-LB-188
Abstract LB-189: GRK3 is essential for metastatic cells and promotes prostate cancer progression
Authors: Ai Nanping , Hulsurkar Mohit , Akslen Lars , Watnick Randolph , Harlow Ed , Li Wenliang
Published: May 2015

Metastasis is responsible for over 90% of cancer deaths. However, biochemical and molecular mechanisms that regulate tumor progression to metastatic phenotype are still poorly understood, especially the control of survival and proliferation of metastatic cells. Kinases play key roles in regulation of many cellular processes. Here we employed an unbiased RNAi in vitro screen against human kinases and a focused cDNA in vivo screen to identify kinases that have novel roles in metastasis. Beta adrenergic receptor kinase 2 (BARK2, ADRBK2, GRK3) was one of the kinases we discovered to have a novel role in cancer progression through this work. It was essential for survival and proliferation of metastatic cells in vitro and in vivo. Moreover, it was also sufficient to promote primary prostate tumor growth and metastasis upon exogenous expression in poorly metastatic cells in mouse xenograft models. Mechanistically, we found that GRK3 functions at least in part through regulating several angiogenic factors and stimulating angiogenesis. Furthermore, GRK3 was found to be overexpressed in human prostate cancers, especially in metastasis. Taken together, these data suggest that GRK3 plays an important role in prostate cancer progression and metastasis.

Citation Format: Nanping Ai, Mohit Hulsurkar, Lars Akslen, Randolph Watnick, Ed Harlow, Wenliang Li. GRK3 is essential for metastatic cells and promotes prostate cancer progression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-189. doi:10.1158/1538-7445.AM2014-LB-189
Abstract LB-190: Soluble E-Cadherin promotes cell invasion but not proliferation in prostate cancer
Authors: Fang Xiaolan , Balaji K. C. , NickKholgh Bita , Gyabaah Kenneth
Published: May 2015

Metastasis is responsible for the majority of prostate cancer-related deaths. Despite progress in early detection and management, there remains no effective, long-term cure for metastatic prostate cancer, partially due to the unclear molecular mechanism of cancer cell invasion and metastasis. Clinical reports discovered that soluble E-cadherin (sE-Cad, the cleaved ectodomain of human E-Cadherin protein) was elevated in body fluids and serum of patients with a variety of cancers, and its serum levels have been shown to correlate positively with metastatic cancers and disease invasiveness. However, little is known about the role of sE-Cad in metastasis, or the molecular mechanism of its abnormal accumulation in cancerous microenvironment. Our lab generated C4-2 prostate cancer cell lines which would secret synthetic sE-Cad by Doxycycline induction. We found that increased sE-Cad in the conditioned medium promotes cell invasion, but not cell proliferation. We analyzed the protein subcellular localizations in different cell compartments (membrane, cytoskeleton, nucleus and cytoplasm) and observed increased binding of synthetic sE-Cad to membrane E-Cadherin, indicating that sE-Cad could promote cell motility by interacting with membrane proteins and possibly disrupting the cell-cell adhesion. This work is supported by Wake Forest University institutional funds to KC Balaji and by NIH grant CA079448 to X Fang.

Citation Format: Xiaolan Fang, K. C. Balaji, Bita NickKholgh, Kenneth Gyabaah. Soluble E-Cadherin promotes cell invasion but not proliferation in prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-190. doi:10.1158/1538-7445.AM2014-LB-190
Abstract LB-193: Separable bilayer microfiltration device for viable label-free enrichment of circulating tumor cells
Authors: Zhou Ming-Da , Hao Sijie , Williams Anthony J. , Lv Bo , Zhu Jiyue , Cote Richard J. , Datar Ram H. , Tai Yu-Chong , Zheng Siyang
Published: May 2015

We designed a new separable bilayer (SB) microfiltration device for the viable enrichment of circulating tumor cells (CTCs) independent of antigen expression. Bilayer pore structures at the micro scale decrease cell damage to preserve viability, while maintaining throughput to allow rapid enrichment. The large pore size (40 um) of the upper layer facilitates the CTCs proliferation on chip. The separability enables the efficient release of the CTCs after successful on chip culture of captured CTCs.

We characterized the device performances including capture efficiency, enrichment against leukocytes, viability and proliferability. The SB device can enrich tumor cells with 80% capture efficiency, higher than 103 enrichment, and better than 70% viability from 1 mL whole blood samples on a 1 cm2 device. Multiple cell lines were shown to be able to proliferate after captured on SB device. Furthermore, using CTCs derived from an in vivo model system, cell cultures were established by releasing the captured CTCs from the chip. The cultured CTCs and their corresponding parental cell lines were injected into mice. Tumors were established with no discernable differences in volume and rate of growth, demonstrating similar tumorigenicity of viable CTCs recovered by the SB device. In a feasibility study, we successfully detected CTCs from 1 mL of clinical whole blood sample enriched via SB device.

Citation Format: Ming-Da Zhou, Sijie Hao, Anthony J. Williams, Bo Lv, Jiyue Zhu, Richard J. Cote, Ram H. Datar, Yu-Chong Tai, Siyang Zheng. Separable bilayer microfiltration device for viable label-free enrichment of circulating tumor cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-193. doi:10.1158/1538-7445.AM2014-LB-193
Abstract LB-203: Structural variants shuffle chromatin to activate GFI1 family oncogenes in medulloblastoma
Authors: Lee Catherine , Northcott Paul A. , Zichner Thomas , Lichter Peter , Korbel Jan O. , Pfister Stefan M. , Wechsler-Reya Robert J.
Published: May 2015

Medulloblastoma is a highly malignant pediatric brain tumor currently treated with a combination of surgery, radiation, and non-specific chemotherapy, posing a significant threat to the developing child. Genomics has illuminated the extensive intertumoral heterogeneity of medulloblastoma and identified four distinct molecular subgroups. Group 3 and Group 4 subgroup medulloblastomas account for the majority of pediatric cases, yet, oncogenic drivers for these subtypes remain poorly understood. Here we report a series of prevalent, highly disparate genomic structural rearrangements, restricted to Groups 3 and 4, resulting in specific and mutually exclusive activation of the growth factor independent 1 family proto- oncogenes, GFI1 & GFI1B. Diverse mechanisms of structural variation activate GFI1/GFI1B expression through relocation of their coding sequences to genomic regions of transcriptionally active chromatin. Moreover, Gfi1 and Gfi1b each cooperate with Myc, an important oncogene in Group 3 medulloblastomas, to drive tumor initiation in mice. These data reveal GFI1 and GFI1B as novel medulloblastoma oncogenes, warranting their prioritization for molecularly targeted therapy of a marked proportion of Group 3 and Group 4 patients.

Citation Format: Catherine Lee, Paul A. Northcott, Thomas Zichner, Peter Lichter, Jan O. Korbel, Stefan M. Pfister, Robert J. Wechsler-Reya. Structural variants shuffle chromatin to activate GFI1 family oncogenes in medulloblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-203. doi:10.1158/1538-7445.AM2014-LB-203
Abstract LB-204: Somatic mutations in DROSHA and DICER1 impair microRNA biogenesis in Wilms tumors
Authors: Rakheja Dinesh , Chen Kenneth S. , Liu Yangjian , Chang Tsung-Cheng , Shukla Abhay A. , Malter James , Mendell Joshua T. , Amatruda James F.
Published: May 2015

Wilms tumor is the most common pediatric kidney cancer and the fourth most common childhood cancer overall. It is treated with a combination of surgery, chemotherapy, and radiation, and, while most children are cured, survival remains poor in those with advanced-stage disease. Known driver mutations (in WT1, WTX, and CTNNB1) account for only one-third of Wilms tumor cases. To better define the genomic landscape of Wilms tumor, we performed whole-exome sequencing of 44 Wilms tumors. We also sequenced matched germline DNA by whole-exome sequencing (15 cases) or targeted Sanger sequencing of candidate mutations (29 cases) to identify somatic mutations. Through this approach, we identified recurrent somatic mutations in MYCN, DROSHA, and DICER1 which were mutually exclusive with known Wilms tumor mutations in WT1 and CTNNB1. The ribonucleases DROSHA and DICER1 perform two key steps in the biogenesis of microRNAs (miRNAs), which are ∼22-nt non-coding RNAs that regulate the stability and translation of target mRNAs. DROSHA and DICER1 mutations occurred at or near conserved metal-binding residues in their ribonuclease (RNase) IIIB domains. In vitro processing assays modeling these mutations showed that they partially or completely disrupt the ribonuclease activity of DROSHA and DICER1. In addition, next-generation sequencing of small RNAs in these tumors revealed that the DICER1 mutations preferentially impaired processing of miRNAs derived from the 5′ arm of pre-miRNA hairpins, including the let-7 tumor suppressor miRNA family. Although DROSHA-mutant tumors did not exhibit skewed expression of 5′ vs. 3′-derived miRNAs, expression of let-7 and other putative tumor suppressor miRNAs was reduced in these tumors as well. While germline and somatic mutations in DICER1 have been reported in some cancers, this is the first report of recurrent DROSHA mutations in any human tumor type. Moreover, these results suggest that impairment of miRNA processing by somatic mutation of DROSHA and DICER1 defines a novel subclass of Wilms tumor.

Citation Format: Dinesh Rakheja, Kenneth S. Chen, Yangjian Liu, Tsung-Cheng Chang, Abhay A. Shukla, James Malter, Joshua T. Mendell, James F. Amatruda. Somatic mutations in DROSHA and DICER1 impair microRNA biogenesis in Wilms tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-204. doi:10.1158/1538-7445.AM2014-LB-204
Abstract LB-216: Integrated analysis of differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer
Authors: Sos Martin L. , Levin Rebecca , Gordan John , Oses-Prieto Juan , Webber James , Salt Megan , Hann Byron , Burlingame Alma , Mccormick Frank , Bandyopadhyay Sourav , Shokat Kevan
Published: May 2015

Despite the development of potent RAF-MAPK pathway inhibitors, only a fraction of BRAF-mutant patients responds to the treatment with these drugs. Here, we applied a combined chemo-genomics and chemo-proteomics approach to gain insights into the dynamics of primary resistance signaling and to define novel cancer vulnerabilities in these tumors. These analyses uncovered differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer cells. Using forward- and reverse-genetics we identify the assembly of RAS/RAF/MEK complexes as a critical force to override RAF-MAPK pathway inhibitor efficacy. Mapping of global phosphorylation dynamics using orthogonal mass-spectrometry based methods revealed multi-layered MAPK pathway feedback-loop release that feeds into MAPK-pathway hyperactivation. The phosphoprotein nuclear interacting partner of ALK (NIPA) identified in the phosphoproteome screen is critical for maintenance of the primary resistance phenotype. Overall, our data provide a kinome- and phosphoproteome-wide view of the adaptive process of primary resistance to MAPK inhibitors in BRAF-mutant tumors and reveals translatable strategies toward improvement of the efficacy of individualized therapies in these patients.

Citation Format: Martin L. Sos, Rebecca Levin, John Gordan, Juan Oses-Prieto, James Webber, Megan Salt, Byron Hann, Alma Burlingame, Frank Mccormick, Sourav Bandyopadhyay, Kevan Shokat. Integrated analysis of differential pathway resiliency in response to MAPK inhibition in BRAF-mutant cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-216. doi:10.1158/1538-7445.AM2014-LB-216
Abstract LB-219: Synthetic lethal screening reveals FGFR as one of combinatorial targets to overcome resistance to Met-targeted therapy
Authors: Kim Bogyou
Published: May 2015

Met is a receptor tyrosine kinase that promotes cancer progression. In addition, Met has been implicated in resistance of tumors to various targeted therapies such as EGFR inhibitors in lung cancers, and has been prioritized as a key molecular target for cancer therapy. However, the underlying mechanism of resistance to Met targeting drugs is poorly understood. Here, we describe screening of 1310 genes to search for key regulators related to drug resistance to an anti-Met therapeutic antibody (SAIT301) by employing a siRNA-based synthetic lethal screening method. We found that knockdown of 69 genes in Met-amplified MKN45 cells sensitized the anti-tumor activity of SAIT301. Pathway analysis of these 69 genes implicated FGFR as a key regulator for anti-proliferative effects of Met targeting drugs. Inhibition of FGFR3 increased target cell apoptosis through the suppression of Bcl-xL expression, followed by reduced cancer cell growth in the presence of Met targeting drugs. Treatment of cells with the FGFR inhibitors substantially restored the efficacy of SAIT301 in SAIT301-resistant cells and enhanced the efficacy in SAIT301-sensitive cells. In addition to FGFR3, integrin β3 is another potential target for combination treatment with SAIT301. Suppression of integrin β3 decreased AKT phosphorylation in SAIT301-resistant cells and restores SAIT301 responsiveness in HCC1954 cells, which are resistant to SAIT301. Gene expression analysis from using CCLE DB shows cancer cells with high levels of FGFR and integrin β3 are resistant to crizotinib treatment, suggesting FGFR and integrin β3 could be used as predictive markers for Met targeted therapy and provide a potential therapeutic option to overcome acquired and innate resistance for the Met targeting drugs.

Citation Format: Bogyou Kim. Synthetic lethal screening reveals FGFR as one of combinatorial targets to overcome resistance to Met-targeted therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-219. doi:10.1158/1538-7445.AM2014-LB-219