bluuebunny/crossref_metadata_2025 huggingface dataset:
CXCL12 (SDF1α)-CXCR4/CXCR7 Pathway Inhibition: An Emerging Sensitizer for Anticancer Therapies?
Authors: Duda Dan G. , Kozin Sergey V. , Kirkpatrick Nathaniel D. , Xu Lei , Fukumura Dai , Jain Rakesh K.
Published: February 2011

Addition of multiple molecularly targeted agents to the existing armamentarium of chemotherapeutics and radiotherapies represents a significant advance in the management of several advanced cancers. In certain tumor types with no efficacious therapy options, these agents have become the first line of therapy, for example, sorafenib in advanced hepatocellular carcinoma or bevacizumab in recurrent glioblastoma. Unfortunately, in many cases, the survival benefits are modest, lasting only weeks to a few months. Moreover, they may not show benefit in patients with localized disease (i.e., in the adjuvant setting). Recent studies have provided increasing evidence that activation of the chemokine CXCL12 (SDF1α) pathway is a potential mechanism of tumor resistance to both conventional therapies and biological agents via multiple complementary actions: (i) by directly promoting cancer cell survival, invasion, and the cancer stem and/or tumor-initiating cell phenotype; (ii) by recruiting “distal stroma” (i.e., myeloid bone marrow–derived cells) to indirectly facilitate tumor recurrence and metastasis; and (iii) by promoting angiogenesis directly or in a paracrine manner. Here, we discuss recent preclinical and clinical data that support the potential use of anti-CXCL12 agents (e.g., AMD3100, NOX-A12, or CCX2066) as sensitizers to currently available therapies by targeting the CXCL12/CXCR4 and CXCL12/CXCR7 pathways. Clin Cancer Res; 17(8); 2074–80. ©2011 AACR.
The Association of MicroRNA Expression with Prognosis and Progression in Early-Stage, Non–Small Cell Lung Adenocarcinoma: A Retrospective Analysis of Three Cohorts
Authors: Saito Motonobu , Schetter Aaron J. , Mollerup Steen , Kohno Takashi , Skaug Vidar , Bowman Elise D. , Mathé Ewy A. , Takenoshita Seiichi , Yokota Jun , Haugen Aage , Harris Curtis C.
Published: February 2011

Purpose: There is increasing evidence that altered microRNA expression is associated with tumor progression and survival in cancer patients. We tested if the expression of specific microRNAs was associated with prognosis and disease progression in early-stage lung adenocarcinoma.

Experimental Design: The expression of miR-21, miR-17, and miR-155 was measured by quantitative RT-PCR in tissues from 317 non–small cell lung cancer (NSCLC) patients that originated from Maryland, Norway, and Japan. Kaplan-Meier and Cox regression analysis evaluated associations of microRNA expression with cancer-specific mortality and disease-free survival.

Results: Elevated miR-21 (HR 2.06, 1.13–3.75), miR-17 (HR 2.00, 1.10–3.61), and miR-155 (HR 2.37, 1.27–4.42) was associated with worse cancer-specific mortality in the Maryland cohort. These were evaluated in two additional cohorts and only miR-21 was associated with worse cancer-specific mortality in the Norwegian cohort (HR 2.78, 1.22–6.31) and worse relapse-free survival in the Japanese cohort (HR 2.82, 1.57–5.07). More advanced stage tumors expressed significantly higher levels of miR-21 compared with TNM stage I tumors. TNM stage I patients were evaluated separately and high levels of miR-21 was associated with worse cancer-specific mortality (HR 2.16, 1.11–4.21) and relapse-free survival (3.40, 1.57–7.36) independent of other clinical factors.

Conclusions: This is the first study to report that increased miR-21 expression is associated with disease progression and survival in stage I lung cancer. This suggests that expression of miR-21 may contribute to lung carcinogenesis and serve as a therapeutic target or early-stage prognostic biomarker for lung adenocarcinoma. Clin Cancer Res; 17(7); 1875–82. ©2011 AACR.
Abstract 10: Characterization of ovarian CSC using ALDH and CD133 identifies a cancer stem cell hierarchy
Authors: Silva Ines A. , Yang Kun , Mclean Karen , Minosyan Tamara , Spalinger Greg , Ginestier Christophe , Reynolds Kevin , Kueck Angie , Johnston Carolyn , Liu Rebecca , Wicha Max S. , Buckanovich Ronald J.
Published: February 2011

Recent studies in ovarian cancer suggest that the protein CD133 may be a marker of cancer stem cells (CSC). CSC studies in several solid tumors have identified Aldehyde dehyrogenase (ALDH) enzymatic activity as a CSC marker, however ALDH has not been studied in ovarian cancer. We sought to determine if ALDH alone or in combination with CD133 could better define CSC in ovarian cancer. We analyzed the expression of these markers in 13 consecutive primary human ovarian tumor specimens and 8 cell lines. 70% of primary ovarian tumors analyzed had CD133+ cells detectable in low number in, and many tumor cell lines lacked CD133 expression. In contrast, 100% of the primary human ovarian tumor specimens and ovarian cancer cell lines demonstrated ALDH activity. ALDH+ cells isolated from 6 ovarian cancer cell lines preferentially grew larger tumors at a faster rate compared to ALDH− cells. In some cases ALDH− cells were incapable of generating tumors, suggesting ALDH is a good marker of ovarian CSC in cell lines. Importantly, as few as 1000 ALDH+ cells directly isolated from human ovarian tumors were capable of generating tumors in immune deficient mice. ALDH− cells did not form tumors in mice. Interestingly, when ALDH was used in combination with CD133 to analyze ovarian cancer cell lines we observed greater growth in the ALDH+CD133+ cells compared to ALDH+CD133− cells suggesting a potential hierarchy of the stem cells. Consistent with this, as few as 11 ALDH+CD133+ cells freshly isolated from human tumors were capable of forming tumors in mice. Consistent with a stem cell hierarchy, tumors formed from ALDH+CD133+ cells demonstrated a poorly differentiated histology, whereas tumors formed from ALDH+ cells alone demonstrated a more differentiated histology. Finally analysis of tumors generated from ALDH+ and ALDH+CD133+ tumors demonstrated a significant increase in microvascular density compared to ALDH− tumors. qRT-PCR analysis demonstrated that ALDH+ cells compared to ALDH− cells preferentially express numerous angiogenic factors. Taken together our studies: (1) indicate ALDH as a marker of ovarian CSC, (2) suggest a hierarchy of ovarian cancer stem cell differentiation state, and (3) demonstrates that ovarian CSC are highly angiogenic to recruit vasculature to create a stem cell niche.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 10.
Abstract 1006: Tumor associated mesenchymal stem cells protect ovarian cancer cells from hyperthermia through stromal cell derived factor-1 (SDF-1) secretion
Authors: Lis Raphael , Mirshahi Pejman , Fares Fadoua , Touboul Cyril , Taha Rowaida , Mirshahi Massoud , Rafii Arash
Published: February 2011

Background: Hyperthermia therapy is a medical procedure where local body tissues are exposed to high temperatures ranging from 40oC to 43oC with the aim of killing microscopic tumor residue, being more susceptible to heat than normal cells. When combined with hyperthermia during cytoreductive surgeries, intraperitoneal chemotherapy was clinically proved to be more effective. While hyperthermia's cytotoxicity was tested on cancer cells, its effect on interactions between cancer cells and tumor stroma cells was minimally scrutinized. In this study, we investigate the effect of tumor associated mesenchymal stem cells, on inducing resistance of ovarian cancer cells (OCC) to hyperthermia.

Methods: OCC viability was challenges by heat shock at 42 degrees, in simple or co-culture systems. Cell viability was determined using Calcein Violet AM by Fluorescence Activated Cell Sorting, FACS. The same experiment was replicated using a transwell system. Using the trogocytosis assay we measured the interaction between the different cell types. Multiparameter flow cytometry was used to study the relation between intercellular interaction and thermoresistance. Finally using inhibitors and blocking antibodies we were able to analyse the role of SDF1 pathway in thermoresistance.

Results: At 42oC, an increase in viability of OCC, co-cultured with ‘MSC, was detected in comparison to cells cultured alone. The same result was attained using the transwell experiment. Antibody and siRNA for CXCR4 reversed the heat resistant effect of MSC cells on OCC. More interestingly we were able to demonstrate an increased expression of CXCR4 in cancer cells co-cultured with the MSC, and increased thermoresistance in the subset of cancer cells with more interaction (as measured by oncologic trogocytosis).

Conclusions: This study proved that contact and non contact-based cell to cell interactions between MSC cells and OCC help ovarian cancer cells resist hyperthermia. Within these interactions, MSC-secreted SDF-1 could be the major inducer of heat resistance. Combining monoclonal antibody against CXCR4 with hyperthermic intraperitoneal chemotherapy could eliminate the protective effect of tumor associated mesenchymal stem cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1006.
Abstract 1014: Semaphorin 4D involves in the regulation of cell motility through its receptor Plexin B1 in pancreatic cancer
Authors: Shingo Kato , Kubota Kensuke , Shimamura Takeshi , Kobayashi Noritoshi , Watanabe Seitaro , Nagashima Yoji , Nakajima Atsushi
Published: February 2011

Introduction: Semaphorins are a large family of either membrane-bound or secreted proteins that provide axonal guidance in neuronal tissues and regulate cell motility in many types of cells. Recent articles reported that Semaphorin 4D (Sema 4D) enhanced in vitro motility and invasiveness through its receptor Plexin B1 and Met, and increased in vivo metastasis potential in breast cancer. However, these expression and function in pancreatic cancer is not known.

Purpose: In the present study, we investigated the clinicopathological significance of Sema 4D and Plexin B1 expression in surgically resected pancreatic ductal adenocarcinoma sections and the regulation of cell motility through the Sema 4D - Plexin B1 signaling pathway.

Material & Methods: The mRNA expression level of Sema 4D and Plexin B1 were evaluated by Quantitative Real Time PCR from 12 surgical specimens and 10 normal pancreatic tissues. Expression of Sema 4D and Plexin B1 were also evaluated immunohistochemically from 90 patients. Using pancreatic cancer cell lines, the expression of endogenous Plexin B1 and Met protein was investigated by western blotting. And the phosphorylation of Met protein after stimulating by Sema4D was evaluated. As functional analysis, scratch assay and MTT assay were carried out.

Results: The mRNA expression level of Sema 4D and Plexin B1 were significantly high in cancer tissues compared to normal pancreas tissues. Immunostaining showed that Sema 4D strongly expressed in lymphocytes and macrophages, as previously reported. Ninety two percent (83 out of 90 cases) pancreatic cancer samples overexpressed Plexin B1 compared to normal pancreas tissues. Endogenous Plexin B1 and Met protein were detected in eight pancreatic cancer cell lines, with a variety of expression levels. Sema 4D stimulation activated Met protein, and significantly induced cell migration.

Discussion: Here we show that Sema 4D involves in the regulation of cell motility through its receptor Plexin B1. And the results of immunostaining suggest that Sema 4D could play a role in the interaction between tumor cells and tumor microenvironment in pancreatic cancer tissues. As many attempts are now ongoing to target the tumor stroma, these findings provide a new insight into molecular targeted therapies for pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1014.
Abstract 1021: Use of functional tumor cell line mitochondria to explore the mechanisms of BH3 peptides and ABT-737-induced mitochondrial membrane permeabilization
Authors: Buron Nelly , Porceddu Mathieu , Rustin Pierre , Jacotot Etienne , Borgne-Sanchez Annie
Published: February 2011

Current limitations of chemotherapy include toxicity on healthy tissues and multidrug resistance on malignant cells. A number of recent anti-cancer strategies are targeting the mitochondrial apoptotic machinery to induce tumor cell death. In this study, we set up protocols to isolate mitochondria from various origins with high purity, quality and functionality. We analyzed the effect of putative Bcl-2 inhibitors on both healthy and tumor isolated mitochondria. We measured mitochondrial membrane permeabilization (swelling), mitochondrial transmembrane potential (ΔΨm) and mitochondrial outer membrane permeabilization (MOMP) in both isolated healthy and tumoral cell mitochondria. Like t-Bid and some BH3 peptides, the molecule ABT-737 was found to present a tumor-specific mitochondrio-toxicity, while compounds like HA-14.1, YC-137, Chelerythrine, Gossypol, TW-37 or EM20-25 did not. We thus demonstrated that ABT-737 can induce a relatively large and targeted MOMP triggering the release of apoptotic proteins from tumoral cell mitochondria (Cytochrome c, Smac/Diablo and Omi/HtrA2 but not AIF) however without any mitochondrial swelling. Furthermore, ABT-737 addition to isolated tumoral cell mitochondria induced specific Bax/Bak channel formation by oligomerizing monomeric Bax and/or Bak already inserted in the mitochondrial membrane. We also provided evidence that tumoral cell mitochondria can be either resistant or sensitive to ABT-737-induced MOMP, depending on their origin and interactions between pro- and anti-apoptotic proteins. Finally, this method based on MOMP is an interesting screening tool, tailored for identifying Bcl-2 antagonists with selective toxicity profile against tumoral cell mitochondria but devoid of toxicity against healthy mitochondria.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1021.
Abstract 1025: Rac1 is a novel binding partner of the anti-apoptotic protein Bcl-2
Authors: Kang Jia , Velaithan Rathiga , Hirpara Jayshree L. , Loh Thomas , Brenner Catherine , Clement Marie-Veronique , Pervaiz Shazib
Published: February 2011

We have previously reported that Bcl-2 expression resulted in an increase in intracellular superoxide anion and that a dominant negative mutant of the small GTPase Rac1 sensitized Bcl-2 expressing cells to apoptosis. Here we report that silencing and functional inhibition of Rac1 blocks Bcl-2 mediated increases in intracellular and mitochondrial superoxide levels in tumor cells. We provide evidence that this effect is mediated via specific interaction between the two proteins using co-immunoprecipitation, confocal and electron microscopy, as well as GST-fusion proteins. Analysis of the sub-cellular localization of these proteins revealed increased association of Bcl-2 and mitochondrial Rac1 in Bcl-2 overexpressing cells. This interaction can be blocked in vitro and in vivo by BH3 mimetics such as HA14-I, BH3-I as well as synthetic Bcl-2 BH3 domain peptides. That this interaction is functionally relevant is supported by the ability of the Bcl-2 BH3 peptide to inhibit intracellular superoxide production as well as overcome drug resistance in Bcl-2 overexpressing cells. Lastly, using patient-derived primary tissues, we observed the interaction only in cancerous tissues with marked overexpression of Bcl-2 and not in peripheral blood leukocytes or samples from non-cancerous tissue. These data provide a novel facet in the biology of Bcl-2 with potential implications for targeted anti-cancer drug design.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1025.
Abstract 1032: Impact of HOXC9 recapitulation on cancer biology and clinical outcome in gastric cancer
Authors: Moon Sungmin , Hong Changsoo , Lee Sangrok , Zhao Xue-Feng , Lee Hyewon , Kim Semi , Han Sang-Uk , Chung Ik-Joo , Park Young-Kyu
Published: February 2011

The HOX genes encode transcription factors and may be implicated in the growth and the progression of many types of tumors. There are growing lines of evidence that dysregulation of HOX gene expression plays important roles in cancer. The aim of this study is to determine the level of HOXC9 expression during gastric cancer progression and the impact of its alteration on cancer biology and clinical outcome. HOXC9 expression was evaluated in normal mucosa, malignant legions, gastric cancer tissues by RT-PCR, western blot and immunohistochemistry. We established AGS gastric cancer cell in which HOXC9 was knock-down by shRNA and conditionally knock-down the HOXC9 expression by tetracycline-regulated gene expression (Tet-Off) system. The effect of HOXC9 knock-down on cell proliferation and apoptosis in AGS gastric cancer line were analyzed by tetrazolium salt-based proliferation assay (WST assay) and FACScan. Knockdown of HOXC9 by specific shRNA (67.3%) increased apoptosis, compared to scambled (7.3%) after 48 hours treatment of doxycycline, and increased active form of cellular apoptosis-related enzyme capsae-9, caspase-3 and poly (ADP-ribose) polymerase, whereas decreased expression of Bcl-xL, a mitochondria dependent anti-apoptosis factor. There was a gain or substantial increase of HOXC9 protein expression according to gastric cancer progression. Kaplan-Meier survival curves showed that HOXC9 overexpression is correlated with inferior disease-specific survival (P<0.001). multivariate Cox repression analysis revealed HOXC9 expression was an independent poor prognostic factor (Hazard ratio, 1.74; 95% CI, 1.01 to 2.99; P=0.047). We then demonstrated that HOXC9 directly regulated Bcl-xL transcription by binding to a HOXC9-responsive element in the Bcl-xL promoter by reporter gene assay, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA). In conclusion, these results suggest that HOXC9 overexpressed in advanced gastric cancer setting and its expression should be useful as a prognostic marker in gastric cancer patients. HOXC9 dependent Bcl-xL overexpresion may be an important mechanism by which HOXC9 protects gastric cancer cells from apoptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1032.
Abstract 1035: Bcl2 is regulated by PKC and Akt and is associated with resistance to cisplatin in endometrial cancer cells.
Authors: Rouette Alexandre , Girouard Julie , Leblanc Valérie , Parent Sophie , Asselin Éric
Published: February 2011

Endometrial carcinomas often show resistance to cisplatin. Bcl2 has been shown to be associated with cisplatin resistance in different types of cancers. However, there is no information concerning its possible involvement in chemoresistance and its regulation in endometrial carcinomas. We have tested the ability of cisplatin to induce apoptosis in KLE, a resistant endometrial carcinoma cell line, and examined the putative role for Bcl2 in regulating drug sensitivity. We have investigated the impact of cisplatin treatment on Bcl2 family members and Xiap, an inhibitor of caspase activity. Cisplatin treatment upregulated Bcl2 protein expression in a time-dependant manner in KLE cells, but had no significant impact on the levels of Bax, Bcl-xL and Xiap proteins. As demonstrated by RT-PCR, Bcl2 mRNA was not upregulated in response to cisplatin, suggesting that cisplatin act on Bcl2 expression through a post-translational mechanism. In KLE cells, Bcl2 inhibition by HA14-1 led to increased apoptosis induced by cisplatin. It has been shown that Akt, MAPK and PKC pathways are involved in the regulation of Bcl2 under various conditions and in different cell types. Therefore, KLE cells were treated with inhibitors of MAPK (PD98059) and PKC (CalphostinC) prior to cisplatin treatment. Inhibition of PKC prevented cisplatin-dependant upregulation of Bcl2 protein, while MAPK inhibition had no impact. We previously showed that KLE cell line express high levels of phosphorylated Akt (pAkt) isoforms. Then, KLE cells stably expressing shRNA for all three Akt isoforms were established. Treatment of these cells with cisplatin prevented the increase of Bcl2 expression and led to increased apoptosis by cisplatin. These data suggest a role for Bcl2 in cisplatin resistance in endometrial carcinoma cells. Also, they indicate that PKC and Akt are involved in regulation of Bcl2 expression in this experimental model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1035.
Abstract 1037: Lysophosphatidic acid upregulates Bcl-2 production and secretion in ovarian cancer cells
Authors: Anderson Nicole S. , Rojiani Mumtaz , Kruk Patricia A.
Published: February 2011

Lysophosphatidic acid (LPA) is elevated in the plasma and ascites fluid of ovarian cancer (OC) patients and has been proposed as a diagnostic tool for OC. LPA is the simplest glycerophospholipid and has been shown to have an extensive range of biological activities. LPA is involved in wound healing and tissue regeneration, cell proliferation and survival, platelet aggregation, and tumor cell invasion. In addition, LPA elicits anti-apoptotic activity through upregulation of Bcl-2 in other systems. Bcl-2, the prototypical anti-apoptotic protein, is commonly overexpressed in OC. The purpose of this study was to determine whether LPA regulates Bcl-2 in OC. Using an in vitro cell culture model system, OC cells were treated ± LPA. We found that LPA increased Bcl-2 expression at the protein and message levels using western immunoblotting, ELISA and luciferase reporter assays. Interestingly, LPA also promoted Bcl-2 secretion by OC cells, which is a novel action of Bcl-2. Secreted Bcl-2 appears to modulate angiogenesis by affecting endothelial cell migration as well as tube formation in an in vitro angiogenesis assay using HUVECs. Given that both LPA and Bcl-2 are potential targets in ovarian cancer intervention, elucidating their inter- and regulatory relationships may be of clinical importance and warrants further investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1037.
Abstract 1051: Quantitative assay for simultaneous assessment of phosphorylation and cell migration
Authors: Olive Michael , Chen Huaxian
Published: February 2011

Introduction: Cell migration is a critical process in angiogenesis and inflammation as well as tumor progression and metastasis. The acquisition of the ability to migrate is dependent on the activation of key cell signaling pathways, two of which are modulated by AKT and ERK kinases. Screening assays that can simultaneously quantify cell migration and the activity of the underlying signaling kinases may facilitate more efficient identification of therapeutic compounds.

Methods: Oris™ Cell Migration Assay plates (Platypus Technologies, Madison, WI) were seeded with HT1080 cells. The Oris plates contain a stopper, which when removed following 24 h cell growth, creates a defined cell-free region on the plate. After removal of the stoppers, PI3 kinase and MEK inhibitors were added and cells allowed to migrate. After fixing and permeabilization, cell migration was measured by staining with primary mouse antibodies against total ERK2 and histone H3, application of a plate-specific mask that allowed detection of only migratory cells, and quantification by staining with IRDye 680-labeled goat anti-mouse antibodies. Phosphorylation was measured simultaneously by staining with rabbit antibodies against either phospho-AKT or phospho-ERK and detection with IRDye 800CW-labeled goat anti-rabbit antibodies. Fluorescence was detected by scanning with either an Aerius or Odyssey instrument.

Results: AKT and ERK phosphorylation were specifically inhibited by their respective drugs. The level of inhibition of phosphorylation correlated with decreased migration in a dose-dependent manner. The robustness of the assay was exemplified by its high signal to noise ratio.

Conclusions: Anti-cancer drugs developed by assessment phosphorylation state alone may identify hits that inhibit the target kinase, yet fail to retard functional outcomes such as migration and proliferation. We have designed a quantitative assay that allows for simultaneous assessment of a biochemical characteristic, namely phosphorylation state, and a functional parameter related to metastasis. This quantitative assay may facilitate a better understanding of the mechanisms underlying cell movement and metastasis, and may facilitate a more efficient means of developing anti-cancer drugs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1051.
Abstract 1055: Character of tumor assocated protien recognized by monoclonal antibody against yunnan gejiu lung cancer
Authors: Wang Qinqin
Published: February 2011

Character of tumor assocated protien recognized by monoclonal antibody against Yunnan Gejiu lung cancer: about protein N35

WANG Qinqin

The Clinical Reseach Center. The First Hospital of Kunming Medial College

Kunming, Yunnan, P.R. China 650032

ABSTRACT Objectives: To identify and characterize lung cancer associated protein N35 and attempt to learn the prospective possibility of the clinical application of the protein N35. Methods: Immunoprecipitation, immunoblotting, differential centrifigation and subcellular assay, immunohistochemistry, Nglycanase digestion, mitotic cell immunoflourescence and multiple methods of affinity chromatography have been used with the monoclonal antibody N-35 to detect the distribution of the protein N35 among the various cancer cell lines and normal human tissue, the relationship between the protein N35 and glycoprotein, the location of the subcellular structure and chromosomal domain of the protein N35,the most effective way of purification of tumor associated protein N35. Results: The protein N35 is a glycoprotein, distributes to the human lung cancer cell line GLC-82, human cervical cancer cell line Hela, human hepatic cancer cell line HepG-2 and human breast cancer cell line PMC with different relative molecular mass(Mr), but no expression of the protein ingredient in normal human fresh tissue; concentrates at the nuclei significantly, much more than at the mitochondrail and membrane, locates at the centriole of the chromosomal domain. Conclusions: The lung cancer associated protein N35 might be expressed only by the cancer cells and related with the proliferation of cancer cells as a role of tumor cell growth regulator.

Keywords: Lung cancer cells, Tumor associated protein, Glycoprotein, Centriole

Qinqin Wang

Prof of The Clinical Reseach Center. The First Hospital of Kunming Medial College

295 Xichang Rd. 650032

Kunming Yunnan, P.R. China

Tel:868714191985

Fax: 868715336015

Email: zys@public.km.yn.cn

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1055.
Abstract 1062: Numb, an intrinsic Notch inhibitor, possesses a tumor suppressor role through regulation of Plk1 localization during mitosis
Authors: Schmit Travis L. , Setaluri Vijayasaradhi , Spiegelman Vladimir S. , Ahmad Nihal
Published: February 2011

Numb, an intrinsic Notch inhibitor and cell fate determinant, has been shown to possess many functions in proper cell division. These include its role in endocytosis, a tumor suppressor role via regulation of p53 stability, and asymmetric self renewal during progenitor cell division. Studies have shown that a proper localization of fully functional Plk1 is required for mitotic entry, progression and exit. Plk1 has been shown to play a critical role in bi-polar spindle formation and maturation during mitosis. It has been shown that chemical inhibition as well as genetic knockdown of Plk1 results in cells forming a mono-polar spindle phenotype surrounded by DNA rather than a bi-polar arrangement on either side of the metaphase plate. This severe mitotic phenotype results in a G2/M cell cycle arrest and mitotic catastrophe. Also, milder inhibition of Plk1 has been shown to result in errors in bi-polar spindle formation including multi-polar phenotypes or incomplete microtubule attachment and division. Some of these less pronounced phenotypes may not prevent cell division and may contribute to cellular aneuploidy and cancer. In this study, employing melanoma cell lines A375 and HS294T, we demonstrated that Numb and Plk1 interact as shown by co-immunoprecipitation and immunofluorescent assays. In addition, we found that both Plk1 and Numb co-localize to the spindle poles in metaphase. Further, using lentiviral shRNA knockdown of Plk1 or Numb, we also found that loss of Plk1 or Numb dysregulates the localization of the other. Most striking was the pronounced mislocalization of Plk1 from the spindle poles. Although, the majority of metaphase cells were still bi-polar, there was a marked increase in mislocalized γ-tubulin in some instances. Additionally, in the cells with two defined spindle poles, γ-tubulin still appears to be less pronounced at strictly the spindle pole with an apparent indistinct staining surrounding the poles indicating that Numb may not be directly required for γ-tubulin localization to the spindles but the misregulated Plk1 localization slows or prevents spindle pole maturation and γ-tubulin recruitment. Conversely, the differing phenotypes of γ-tubulin localization may also be explained by a redundant role of Numb-like, though this is yet to be explored. Overall, these data suggested that Numb may possess tumor suppressor functions by regulating proper Plk1 localization and proper spindle pole maturation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1062.
Abstract 1068: Cooperation between BRCA1 and Aurora A kinase regulates in vitro crisis in epithelial cells derived from benign ovarian tumors
Authors: Marion Christine M. , Dubeau Louis , Yu Vanessa
Published: February 2011

Aneuploidy, as defined by a chromosome number that is not a multiple of the haploid number, is a hallmark of cancer. We used an in vitro cell culture model where explants of benign epithelial ovarian tumors (cystadenomas) were transfected with an expression vector for SV40 Large T Antigen, allowing bypass of senescence due, in part, to p53 and Rb inhibition by this antigen. We previously showed that such cells eventually reach a crisis event that is associated with a cell cycle arrest at the M phase and is independent of telomere attrition. Cells that recover from this event do not complete cytokinesis and become polyploid, which is a precursor to aneuploidy. Decreased BRCA1 expression facilitates abrogation of mitotic arrest, leading to increased rates of aneuploidy.

We hypothesized that Aurora A plays a role in regulating this ploidy-associated crisis event by acting as an upstream regulator of BRCA1 expression. Here we show that Aurora A kinase activity and expression is up-regulated in cells approaching crisis. Over-expression of Aurora A resulted in decreased levels of BRCA1, resulting in increased tetraploidy and aneuploidy, secondary to cells overcoming a ploidy-associated crisis. Levels of BRCA1 expression increased upon knockdown of Aurora A kinase using siRNA, further suggesting an inverse relationship between expression levels of these two proteins. Inhibition of Aurora A in cultured ovarian cystadenomas approaching crisis led to decreased cell proliferation and a concomitant decrease in tetraploidy. We tested the hypothesis that this was associated with an increase in crisis-related apoptosis by knocking down Aurora A kinase using siRNA technologies in cells approaching crisis, followed by western blotting using antibodies against PARP and cleaved CASPASE 7 fragment. The results indeed showed increased levels of these two protein fragments upon Aurora A knockdown, indicating activation of a caspase-regulated apoptotic pathway.

Our findings suggest a novel role for Aurora A's influence on BRCA1 expression levels in cells approaching ploidy dependent crisis. This may, in part, explain the increased rate of near polyploidy associated with high grade ovarian carcinomas and may provide insights into the mechanism underlying aneuploidy development in epithelial cancers in general.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1068.
Abstract 1071: DeltaEF1 promotes breast cancer cell proliferation through down-regulating p21 expression
Authors: Hu Fen , Wang Chuan , Zhu Tianhui , Yang Shuang
Published: February 2011

Background: Deregulation of the cell cycle and abnormal cell proliferation are involved in breast carcinogenesis. Recent evidence suggests that deltaEF1, a zinc finger-homeodomain transcription factor, is a potential regulatory factor at the crossroad between proliferation and differentiation. However, how deltaEF1 mediates its proliferative effects in tumorigenesis has not been recognized yet.

Materials and Methods: Quantitative RT-PCR and immunoblotting were used to determine the expressions of deltaEF1, p21, p27, CDK2, CDK4, and CDK6 at the mRNA and the protein levels, respectively, in MCF-7, MDA-MB-231, T47D, and ZR-75-1 breast cancer cells, as well as in 22 breast cancer specimens. Cell proliferation and BrdU incorporation assays as well as flow cytometry were used to determine cell proliferation of MDA-MB-231 cells with deltaEF1-overexpression or deltaEF1 siRNA knockdown. Luciferase assay was used to determine deltaEF1-driven transcriptional activities of the wild-type and mutant human p21 promoters. Quantitative CHIP assay was used to detect the direct association of deltaEF1 with the wild-type human p21 proximal promoter.

Results: We found that ectopic expression of deltaEF1 in MDA-MB-231 cells significantly promoted cell proliferation as indicated by an increase of cells in S phase of the cell cycle. As anticipated, deltaEF1 knockdown by RNA interference decreased the cells in S phase, suggesting a role of deltaEF1 in the G1-S transition of breast cancer cells. Importantly, we also demonstrated that deltaEF1 down-regulated p21 with up-regulation of CDK2 and CDK4. Furthermore, our studies revealed that deltaEF1 inhibited p21 transcription after recruited to the E2-box element on the p21 promoter. Depletion of endogenous deltaEF1 was sufficient to trigger p21 expression in MDA-MB-231 cells, resulting in the cell cycle arrest. In addition, an inverse correlation of deltaEF1 and p21 expression was detected in both breast cancer cell lines and clinical tumor specimens, further supporting the role of p21 down-regulation in the stimulatory effect of deltaEF1 on cell proliferation.

Conclusions: We conclude that deltaEF1 plays a critical role in promoting cell proliferation in breast cancer. Given that higher expression level of deltaEF1 is associated with more progressive phenotype of breast cancer, our collective data suggest that deltaEF1 is a key regulatory factor at the crossroad between proliferation and differentiation, thus underscoring tumor progression and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1071.
Abstract 1079: Targeted disruption of Nemo-like kinase inhibits tumor cell growth by simultaneous suppression of cyclin D1 and CDK2 in human hepatocellular carcinoma
Authors: Jung Kwang Hwa , Kim eong Kyu , Noh Ji Hein , Eun Jung Woo , Bae Hyun JIn , Xie Hong Jian , Park Wong Sang , Lee Jung Young , Nam Suk Woo
Published: February 2011

The wnt/β-catenin signaling pathway regulates various aspects of development and plays important role in human carcinogenesis. Nemo-like kinase (NLK), which is mediator of wnt/β-catenin signaling pathway, phosphorylates T-cell factor/lymphoid enhancer factor (TCF/LEF) factor and inhibits interaction of β-catenin/TCF complex. Although, NLK is known to be a tumor suppressor in wnt/β-catenin signaling pathway of colon cancer, the other events occurring downstream of NLK pathways in other types of cancer remain unclear. In the present study, we identified that expression of NLK was significantly up-regulated in the HCCs compared to corresponding normal tissues in five selected tissue samples. Immunhistochemical analysis showed significant over-expression of NLK in the HCCs. Targeted-disruption of NLK suppressed cell growth and arrested cell-cycle transition. Suppression of NLK elicited anti-mitogenic properties of the Hep3B cells by simultaneous inhibition of cyclinD1 and CDK2. The results of this study suggest that NLK is aberrantly regulated in HCC, which might contribute to the mitogenic potential of tumor cells during the initiation and progression of hepatocellular carcinoma; this process appears to involve the induction of CDK2 and cyclin D1 and might provide a novel target for therapeutic intervention in patients with liver cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1079.
Abstract 1080: Molecular and cellular pharmacology of BI 811283, a potent inhibitor of Aurora B kinase
Authors: Tontsch-Grunt Ulrike , Gürtler Ulrich , Zahn Stephan K. , Boehmelt Guido , Jarvis Marc , Adolf Guenther R. , Solca Flavio
Published: February 2011

Background. The serine/threonine kinase Aurora B is involved in the regulation of several mitotic processes, including chromosome condensation, congression and segregation as well as cytokinesis. These essential functions of Aurora B and its overexpression in many cancer types render this protein kinase an attractive target for anticancer drug development.

Methods. BI 811283 was profiled in enzymatic kinase assays as well as in proliferation assays on various human cancer cell lines. Cell cycle status was assessed by DNA content analysis (Cellomics ArrayScan, FACScalibur). Histone H3 phosphorylation was determined by immunofluorescence (Cellomics ArrayScan). Apoptosis was detected by Western blotting for cleaved PARP and microscopic enumeration of DAPI-stained cells showing nuclear fragmentation. Senescent cells were identified by staining for SA-ß-Gal activity.

Results. BI 811283 inhibited human Aurora B kinase activity with an IC50 value of 9 nM, Aurora A and C kinases with 70 nM and 17 nM, respectively. In a panel of 46 additional kinases representative of the human kinome, BI 811283 at 1000 nM inhibited 7/46 kinases by more than 50%. EC50 values for inhibition of proliferation of >20 human cancer cell lines were in the range of 2 to 14 nM. In the non-small cell lung cancer cell line NCI-H460, treatment with BI 811283 resulted in a rapid (<1 h) inhibition of histone H3 phosphorylation. Within 48 h of treatment, the fraction of polyploid cells increased from <5% to >80%, paralleled by a marked increase in cell volume. An increase of cleaved poly (ADP-ribose) polymerase and a concomitant increase in the fraction of cells with nuclear fragmentation from <1% to 7% was observed after 72 h and 96 h of treatment. Within 96 h, the fraction of senescent cells markedly increased from <3% to 25% of the population.

Conclusions. BI 811283 is a potent and selective Aurora kinase inhibitor that inhibits proliferation of cancer cells independent of tissue origin or oncogenome status. Treated cells exhibit a polyploid phenotype characteristic for Aurora B inhibition and show hallmarks of senescence as well as a slow onset of apoptosis in a small fraction of cells. In vivo activity of BI 811283 has been demonstrated in multiple cancer xenograft models in nude mice (see accompanying poster). Phase I clinical trials are ongoing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1080.
Abstract 1086: The role of HEF1 protein in stabilization and activation of AurA kinase in metastatic breast cancer
Authors: Pugacheva Elena N. , McLaughlin Sarah , Hindman Bridget , Golemis Erica A.
Published: February 2011

AurA kinase expression is linked to human disease since the extent of AurA up-regulation was significantly associated with advanced tumor stage and the occurrence of metastasis. AurA inhibitors have recently entered phase II clinical trials for cancer treatment, but application of these inhibitors for treatment of advanced human cancers has demonstrated limited efficacy. The reasons why potent in vitro inhibitors of AurA are inefficient under these conditions are unknown. In our current study, we define the mechanisms by which AurA is upregulated in breast tumor cells and what impact HEF1 expression has on AurA-associated occurrence of metastasis. Our hypothesis is that over-expression of HEF1 protein in breast cancer cells will protect AurA from proteolytic degradation, resulting in activation of AurA kinase. Here we demonstrate that direct binding of HEF1 stabilizes AurA by blocking the cdh1 binding site and limiting AurA ubiquitination. HEF1 binding decreases the efficacy of AurA inhibitors in cell culture. Deletion of HEF1 by gene knockout and depletion by siRNA in cell lines cause dramatic decreases in AurA protein level and kinase activity - indicating HEF1 is the major AurA regulator in vivo. We further show that deletion of HEF1 reduces tumor cell proliferation and invasion in mouse mammary tumor models. These data provide insights into the potential development of small molecule inhibitors that could be used therapeutically to target the HEF1/AurA pathway and thereby inhibit tumor formation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1086.
Abstract 1092: Alterations of the retinoblastoma gene in stage III breast cancers
Authors: Berge Elisabet O. , Knappskog Stian , Geisler Stephanie , Staalesen Vidar , Puntervoll Pål , Pacal Marek , Børresen-Dale Anne-Lise , Lillehaug Johan R. , Lønning Per E.
Published: February 2011

We report the novel finding of point mutations affecting the RB1 gene in breast cancer tissue. Analyzing 73 locally advanced (stage III) breast cancers, we identified two somatic and one germline single nucleotide changes, each leading to amino acid substitution; Leu607Ile, Arg698Trp, and Arg621Cys, respectively. In addition, MLPA analysis revealed two large multiexon deletions (exons 13 to 27 and exons 21 to 23) with the exons 21-23 deletion occurring in the tumor also harboring Leu607Ile. All three RB1 point mutations encoded stable nuclear proteins with impaired ability to induce apoptosis compared to wild-type pRb in vitro. Interestingly, Leu607Ile and Arg621Cys are both located within the spacer region of the protein. Mutations in this part of the RB1 gene have previously been identified in retinoblastoma-prone families. Multiple sequence alignment across species indicates this area to be evolutionary conserved. Notably, three out of four tumors harboring RB1 mutations displayed primary resistance to treatment with either mitomycin or doxorubicin while only 14 out of 64 tumors without mutations were resistant (p = 0.046). Although rare, our findings suggest RB1 mutations to be of biological importance in breast cancer.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1092.