bluuebunny/crossref_metadata_2025 huggingface dataset:
Exercise and arterial adaptation in humans: uncoupling localized and systemic effects
Authors: Rowley Nicola J. , Dawson Ellen A. , Birk Gurpreet K. , Cable N. Timothy , George Keith , Whyte Greg , Thijssen Dick H. J. , Green Daniel J.
Published: February 2011

Previous studies have established effects of exercise training on arterial wall thickness, remodeling, and function in humans, but the extent to which these changes are locally or systemically mediated is unclear. We examined the brachial arteries of the dominant (D) and nondominant (ND) upper limbs of elite racquet sportsmen and compared them to those of matched healthy inactive controls. Carotid and superficial femoral artery responses were also assessed in both groups. High-resolution duplex ultrasound was used to examine resting diameter, wall thickness, peak diameter, and blood flow. We found larger resting arterial diameter in the preferred arm of the athletes (4.9 ± 0.5 mm) relative to their nonpreferred arm (4.3 ± 0.4 mm, P < 0.05) and both arms of control subjects (D: 4.1 ± 0.4 mm; ND: 4.0 ± 0.4, P < 0.05). Similar limb-specific differences were also evident in brachial artery dilator capacity (5.5 ± 0.5 vs. 4.8 ± 0.4, 4.8 ± 0.6, and 4.8 ± 0.6 mm, respectively; P < 0.05) following glyceryl trinitrate administration and peak blood flow (1,118 ± 326 vs. 732 ± 320, 737 ± 219, and 698 ± 174 ml/min, respectively; P < 0.05) following ischemic handgrip exercise. In contrast, athletes demonstrated consistently lower wall thickness in carotid (509 ± 55 μm), brachial (D: 239 ± 100 μm; ND: 234 ± 133 μm), and femoral (D: 479 ± 38 μm; ND: 479 ± 42 μm) arteries compared with control subjects (carotid: 618 ± 74 μm; brachial D: 516 ± 100 μm; ND: 539 ± 129 μm; femoral D: 634 ± 155 μm; ND: 589 ± 112 μm; all P < 0.05 vs. athletes), with no differences between the limbs of either group. These data suggest that localized effects of exercise are evident in the remodeling of arterial size, whereas arterial wall thickness appears to be affected by systemic factors.
A Feasibility Study of Bevacizumab plus Dose-Dense Doxorubicin–Cyclophosphamide (AC) Followed by Nanoparticle Albumin–Bound Paclitaxel in Early-Stage Breast Cancer
Authors: McArthur Heather L. , Rugo Hope , Nulsen Benjamin , Hawks Laura , Grothusen Jill , Melisko Michelle , Moasser Mark , Paulson Matthew , Traina Tiffany , Patil Sujata , Zhou Qin , Steingart Richard , Dang Chau , Morrow Monica , Cordeiro Peter , Fornier Monica , Park John , Seidman Andrew , Lake Diana , Gilewski Theresa , Theodoulou Maria , Modi Shanu , D'Andrea Gabriella , Sklarin Nancy , Robson Mark , Moynahan Mary Ellen , Sugarman Steven , Sealey Jane E. , Laragh John H. , Merali Carmen , Norton Larry , Hudis Clifford A. , Dickler Maura N.
Published: February 2011

Purpose: Bevacizumab confers benefits in metastatic breast cancer but may be more effective as adjuvant therapy. We evaluated the cardiac safety of bevacizumab plus dose-dense doxorubicin–cyclophosphamide (ddAC) → nanoparticle albumin–bound (nab)-paclitaxel in human epidermal growth factor receptor 2 normal early-stage breast cancer.

Experimental Design: Eighty patients with normal left ventricular ejection fraction (LVEF) were enrolled. Bevacizumab was administered for 1 year, concurrently with ddAC → nab-paclitaxel then as a single agent. LVEF was evaluated at months 0, 2, 6, 9, and 18. This regimen was considered safe if fewer than three cardiac events or fewer than two deaths from left ventricular dysfunction occurred. Correlative studies of cardiac troponin (cTn) and plasma renin activity (PRA) were conducted.

Results: The median age was 48 years (range, 27–75 years), and baseline LVEF was 68% (53%–82%). After 39 months' median follow-up (5–45 months): median LVEF was 68% (53%–80%) at 2 months (n = 78), 64% (51%–77%) at 6 months (n = 66), 63% (48%–77%) at 9 months (n = 61), and 66% (42%–76%) at 18 months (n = 54). One patient developed symptomatic LV dysfunction at month 15. Common toxicities necessitating treatment discontinuation were hypertension (HTN, 4%), wound-healing complications (4%), and asymptomatic LVEF declines (4%). Neither cTn nor PRA predicted congestive heart failure (CHF) or HTN, respectively.

Conclusions: Bevacizumab with ddAC → nab-paclitaxel had a low rate of cardiac events; cTn and PRA levels are not predictive of CHF or HTN, respectively. The efficacy of bevacizumab as adjuvant treatment will be established in several ongoing phase III trials. Clin Cancer Res; 17(10); 3398–407. ©2011 AACR.
Abstract 1000: Rad6B induced β-catenin stabilization requires intact Wnt signaling
Authors: Gerard Brigitte , Tait Larry , Shah Seema , Nangia-Makker Pratima , Shekhar Malathy PV
Published: February 2011

Aberrant activation of Wnt signaling results from stabilization and transcriptional activation of β-catenin and is often associated with carcinogenesis. Clinical evidence suggests that β-catenin accumulation occurs in breast cancer although activating mutations are rare. We have previously shown that Rad6B positively regulates β-catenin stability and transcriptional activity in breast cancer cells by inducing stable polyubiquitin modifications. Here we show that Rad6B physically interacts with β-catenin within the β-catenin amino acid segment containing the first armadillo repeat, which is also a binding site for casein kinase 1 (CK1). β-catenin phosphorylation by GSK3β and subsequent ubiquitination and proteasomal degradation is dependent upon CK1-mediated initiating phosphorylation of β-catenin at Ser45. In vitro kinase assays showed that Rad6B inhibits Ser45 phosphorylation by CK1, and Ser45 phosphorylated β-catenin is decreased in Rad6B overexpressing breast cancer cells. In vitro and in vivo mapping, and site-directed mutation analysis identified K394 of β-catenin as the predominant site for ubiquitination by Rad6B. MCF-7 breast cancer cells engineered to express myc-tagged K394R-β-catenin showed decreased steady-state levels and β-catenin transcriptional activity as compared to cells expressing wild type β-catenin. We also determined whether Rad6B-mediated β-catenin stabilization occurs independently of the canonical Wnt signaling pathway. MDA-MB-231 breast cancer cells overexpressing endogenous Rad6B were isolated on the basis of Rad6B promoter activity, and the consequences of Wnt disruption on β-catenin levels, transcriptional activity and Rad6B expression were determined by expressing a dominant negative mutant of Wnt coreceptor, LRP6. Disruption of Wnt signaling inhibited Rad6B expression and β-catenin accumulation. Both Wnt signaling disruption and Rad6B silencing separately enhanced localization of β-catenin on the cell membranes and decreased intracellular β-catenin accumulation. In summary, our data suggest that the Rad6B overexpression frequently observed in breast carcinomas contribute to β-catenin stabilization and transcriptional activation by inhibiting the CK1-mediated initiating phosphorylation and by ubiquitinating K394. However, the Rad6B induced β-catenin stabilization requires intact Wnt signaling. Supported by DOD W81XWH07-1-0562.

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 1000.
Abstract 1004: Investigating the role of Cdc42 in the developing mouse mammary gland
Authors: Bray Kristi M. , Vargo-Gogola Tracy
Published: February 2011

Rho GTPases coordinate and transmit extracellular signals to control downstream effectors. The Rho GTPase cell division cycle 42 (Cdc42) is overexpressed and hyperactivated in human breast cancers. Cdc42 regulates cell polarity, mitosis, adhesion, migration, and stem cell function. These same cellular processes also function in normal mammary gland development. Exactly which functions of Cdc42 are crucial for normal mammary gland (MG) development and its precise role in mammary tumor formation and progression remain unknown. We hypothesize that Cdc42 plays critical and pleiotropic roles in normal MG development and tumorigenesis through regulation of the signal transduction pathways that are involved in cell cycle progression, cell polarity determination, cell motility, and cell adhesion. To investigate the molecular mechanisms by which Cdc42 regulates MG development, we studied the effects of Cdc42 deletion on morphogenesis of primary mammary epithelial cells (MECs). Adeno-cre viral transduction was used to introduce cre recombinase into Cdc42fl/fl primary MECs, and effects on morphogenesis were assessed using a three-dimensional mammary morphogenesis assay. Transduction efficiency ranged from 50-80% and ∼70% percent knockdown of Cdc42 expression was achieved. Control Adeno-GFP transduced MECs developed into polarized mammary acini whereas morphogenesis was markedly perturbed in the Cdc42 deficient MECs. Cdc42 knockout MECs formed small (30 µm in diameter compared to 45 µm in the control structures, p < .001, n = 28), disorganized structures lacking polarity and lumens (99% vs. 8% in the controls, n > 30). Markers of normal development including polarity markers, pERM and α6; adhesion, ZO-1; and downstream signaling, pkc-ζ, displayed aberrant expression patterns in the knockout structures. Interestingly, Cdc42 deficient structures contained invasive cells, which were rarely seen in control acini (41% vs 7%, n=80), suggesting that loss of Cdc42 induces aberrant migration. Cdk4 levels were also reduced in Cdc42 deficient cells and cell cycle analysis by flow cytometry demonstrated an increase in the percentage of cells in G1, suggesting that loss of Cdc42 inhibits MEC proliferation by blocking the transition from G1 to S phase. In addition, analysis of an S phase marker, phospho-histone H3, was performed at an early time point (3 days) in morphogenesis. Only 35% of the transduced knockout structures expressed phospho-histone H3, compared to 100% in the controls (n>20). These studies demonstrate a vital role for Cdc42 in the processes of growth, adherence, and polarity establishment during mammary gland development.

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 1004.
Abstract 1015: Head and neck cancer expression of YAP65: A novel oncogene
Authors: Ge Lin , Ge Lin , Meng Wenxia , Zhou Hongmei , Bhowmick Neil
Published: February 2011

Yes-associated protein (YAP), a transcription coactivator associated with maintaining tissue size, is reported as an oncogene in many types of cancer including ovarian, liver, lung, colon and prostate. However, the role of YAP in head and neck carcinomas is not known. Our objective was to explore the role of YAP in head and neck carcinomas. We found YAP overexpressed in the epithelial and stromal compartments of head and neck carcinomas compared to benign tissues in 140 samples. Interestingly, the squamous cell carcinomas, had elevated YAP expression in the epithelial cytoplasm in 36% of the patients. However, we observed both cytoplasmic and prominently nuclear localization of YAP in the adenocarcinomas. The tumor microenvironment is widely accepted as a promoter of tumor progression, where carcinoma-associated fibroblasts (CAFs) constitute the majority of cells. In the stroma, YAP was found to be expressed in endothelial cells and some heterogenously within the CAF population. As reported for prostate cancer, we found the transforming growth factor-beta (TGF-ß) receptor type II expression to be lost in the head and neck cancer-associated stromal cells. Since YAP has never been reported to be associated with CAFs, we performed in vitro experiment to determine the relationship of YAP and TGF-ß signaling in primary stromal cells associated with benign and head and neck cancer cells. We found TGF-ß1 can promote YAP expression and nuclear localization in normal fibroblasts. The oral human CAFs have differential expression of YAP and α-smooth muscle actin (α-SMA). Although CAFs are commonly characterized by their expression of α-SMA, YAP-expressing CAFs expressed less α-SMA and α-SMA-expressing CAFs expressed less YAP in seven independent CAF lines developed. However, all of these heterougenous head and neck CAF lines had the loss of TGF-ß receptor type II expression and concomitant upregulation of Wnt5a. Interestingly, those CAFs expressing YAP had 2-fold greater Wnt5a expression. In conclusion YAP expression is differentially expressed in adeno- and squamous cell carcinomas of head and neck carcinomas, and is heterogenously expressed in the associated CAF. YAP may regulate Wnt5a as a paracrine factor, reported to promote the progression of oral carcinomas, in a TGF-ß dependent and independent manner.

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 1015.
Abstract 1018: Analyzing αvβ8 integrin functions in mouse and human glioma cells
Authors: Tchaicha Jeremy H. , McCarty Joseph H.
Published: February 2011

In this study we aim to determine the functional roles for αvβ8 integrin in glioblastoma multiforme (GBM)-induced angiogenesis. These studies originate from our analyses of αvβ8 integrin in developmental brain angiogenesis. αv and β8 knockout (KO) mice develop brain-specific vascular phenotypes that resemble vascular pathologies observed in GBM. Thus, we hypothesize that altered αvβ8 integrin expression and/or function in tumor cells leads to vascular pathologies like those in GBM. Indeed, a murine xenograft model of astrocytoma suggested a role for the integrin in glioma-induced angiogenesis. Primary mouse astrocytes were cultured from wild type (WT) and β8 KO neonates to be immortalized (HPV:E6/E7) and transformed (HRas:G12V). WT and β8 KO transformed astrocytes were intracranially injected into athymic mice. WT tumors displayed pathological features of grade III astrocytomas, whereas β8 KO tumors resembled grade IV GBMs. KO tumors contained widespread edema and hemorrhage as well as pathological angiogenesis, as assessed by quantitation of microvascular density. Interestingly, astrocyte transformation resulted in a significant reduction in αvβ8 integrin cell surface expression in WT cells. Additionally, WT mouse transformed astrocytes lost αvβ8 integrin expression after approximately eight passages in vitro. Exogenous expression of β8 integrin in β8 KO transformed astrocytes resolved the pathologies observed in KO tumors giving further credence to the idea that loss of αvβ8 integrin expression correlates with tumorigenic potential of oncogene-transformed astrocytes. To compliment our mouse model, several established human glioma cell lines were characterized for expression of αvβ8 integrin protein. Some of the cell lines displayed diminished expression of αvβ8 integrin, whereas others showed increased levels, as compared to non-malignant human astrocytes. Intracranial implantation of high and low β8 integrin-expressing human glioma cell lines resulted in tumors exhibiting similar phenotypes to those observed in the mouse model; low expressers were marked by vascular pathologies indicative of β8 KO mouse tumors. Upon overexpression of β8 integrin in a low β8 integrin-expressing human glioma cell line, angiogenic pathologies were largely resolved. Collectively, these data suggest an important functional role for αvβ8 interin in glioma angiogenesis.

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 1018.
Abstract 1020: Combined effects of BCL-2 pathway gene variants on the risk of endometrial cancer: results from Shanghai Endometrial Cancer Study
Authors: Dorjgochoo Tsogzolmaa , Long Jirong , Xiang Yong-Bing , Cai Qiuyn , Cai Hui , Cheng Jiarong , Zheng Wei , Shu Xiao-ou
Published: February 2011

The BCL-2 pathway genes may play important roles in regulation of apoptosis. It has been suggested that overexpression of the antiapoptotic Bcl2 gene variants associated with the risk of endometrial cancer. Proapoptotic BAX, BAK, BAD are believed to diffuse in cell carcinogenesis. We hypothesized that single-nucleic polymorphisms (SNPs) in the Bcl-2 pathway genes including Bcl2, BAX, BAD and BAK1 may be associated with endometrial cancer risk. Included in this study were 1,028 endometrial cancer cases and 1,003 controls from the Shanghai Endometrial Cancer Study. A total of 77 tagging SNPs were genotyped for these genes using the Affymetrix MegAllele Targeted Genotyping system. A logistic regression was used to estimate the association between SNPs and the cancer risk. Genetic risk score (GRS) was calculated using a simple count method that included the SNPs that showed significant associations and are not in LD with each other (r2 <0.8). Significant associations with cancer risk were found for SNP rs477895 in the BAD gene and 7 SNPs in the Bcl2 gene, including rs7243091, rs7230177, rs7231901, rs17759659, rs4941195, rs2279115 and rs1944423. Women carrying the minor homozygous and heterozygous genotypes of SNPs including rs7243091, rs17759659, rs4941195, rs2279115 and rs1944423 have an increased risk of endometrial cancer (age adjusted odds ratio [OR] range, 1.2-2.1; P trend <0.05 for all), compared with women carrying the major homozygous genotypes. For SNPs rs7230177 and rs7231901, a decreased risk was observed among individuals carrying minor homozygous genotype and heterozygous compared with the major genotype (P trend <0.01). Haplotype analyses of the Bcl2 gene showed two haplotypes, GTCGCTG and ACAAATG were associated with a significant increase in risk of endometrial cancer (P value <0.05). The risk of endometrial cancer tended to increase with higher GRS (based on 5 SNPs of the Bcl2) (multivariate OR=1.96, 95% CI: 1.44-2.65 for ≥5 vs. ≤1 GRS, P trend <0.01). This increased risk was stronger among postmenopausal or obese (BMI ≥27.5) women than among premenopausal or non-obese women (P trend <0.05 for both). These findings suggest that BCL-2 pathway genes, particularly Bcl2 genetic variations are significantly associated with an increased risk of endometrial cancer among Chinese women. A GRS which combines information from several variants of Bcl2 gene might have a potential to identify the women at a high risk of endometrial 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 1020.
Abstract 1023: Cytoplasmic domain of interferon-gamma receptor beta chain (IFNγR2) has an antiapoptotic activity as a Bax inhibitor
Authors: Gomez Jose , Sun Weiyong , Gama Vivian , Hajkova Dagmar , Yoshida Tomoyuki , Wu Zhengrong , Pink John , Jackson Mark , Miyagi Masaru , Matsuyama Shigemi
Published: February 2011

Bax is a pro-apoptotic protein mediating intrinsic cell death signal. New Bax inhibitor was searched by using yeast-based functional screening, and Interferon Gamma Receptor Beta chain (IFNγR2) was cloned as a Bax suppressor. IFNγR2 is a receptor protein, which is a part of the IFNγ receptor complex with IFNγR1, involved in the Jak/STAT signaling pathway. Upon IFNγ binding a conformational change in the receptor complex occurs, followed by activation of Jak kinases, and STAT1. We found that the C-terminus region of IFNγR2 amino acids 296-337 (IFNγR2296-337) contains the novel Bax inhibiting domain. This portion does not contain the Jak2 binding domain, therefore IFNγR2 anti-apoptotic function is independent of the well characterized JAK/STAT signaling. IFNγR2296-337 rescued human cells from apoptosis induced by overexpression of Bax, but not Bak. Overexpression of IFNγR2 (wild type and IFNγR2296-337) rescued cells from apoptosis induced by Etoposide and Staurosporine that are known to activate Bax-mediated cell death. Interestingly, IFNγR2 inhibited apoptosis induced by the BH3 only protein Bim-EL, suggesting that IFNγR2 inhibits Bax activation by BH3 protein. The binding of Bax and the C-terminus of IFNγR2 was confirmed by co-immunoprecipitation using cell lysate and binding experiments using purified recombinant proteins. Interestingly, recombinant Bcl-2 protein competed with IFNγR2 to bind Bax in cell lysates, suggesting that IFNγR2 and Bcl-2 share a similar mechanism to bind Bax. We found that the C-terminal fragment (cytoplasmic domain) of IFNγR2 is expressed in the cytosol of transformed, and in some human prostate cancer cell lines (PC3, and DAMI cells). Our preliminary study suggests that the cytoplasmic IFNγR2 C-terminal fragment is produced by proteolytic cleavage of IFNγR2 at the plasma membrane. The cytoplasmic IFNγR2 fragment may have a certain role to confer cancer cells resistant to apoptotic stress. The discovery of anti-Bax activity of the cytoplasmic domain of INFγR2 may shed new light on the mechanism of how cell survival is controlled by IFNγ and Bax.

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 1023.
Abstract 1029: BB a novel Bim isoform upregulated in acute lymphoblastic leukemia after glucocorticoid monotherapy confers a novel apoptosis regulation mechanism
Authors: Trockenbacher Alexander , Mansha Muhammad , Ploner Christian , Kofler Reinhard
Published: February 2011

Glucocorticoids (GCs) are fundamental components of most chemotherapies employed against lymphoid malignancies because they cause apoptosis and cell cycle arrest. In this study we investigate the possible role of a novel splice variant of human BCL2L11/Bim, termed BB, for GC-induced apoptosis. First evidence for BB was obtained by Affymetrix-based whole genome comparative expression profiling, where a corresponding probe set was found to be induced in 8 of the 13 ALL children and 1 adult during systemic GC monotherapy (Schmidt et al., 2006). The postulated BB mRNA consists of the 5’ portion of Bim (up to and including the BH3-containing exon 8) and the 3’ portion of Bam, a cDNA originally discovered in a multiple myeloma cDNA library (Claudio et al., 2002). Thus, it encodes a putative protein consisting of the N-terminal region of Bim (including its BH3 domain) and 40 C-terminal amino acids derived from Bam and not present in any known Bim transcript. BB and Bim proteins have similar molecular masses and could not be distinguished by conventional Western technology when probed by α-Bim antibody as most α-Bim antibodies recognize the N-terminal region which is common to both isoforms. RT-PCR data and protein analyses carried out by using α-Bam antibody (that recognizes the Bam specific C-terminal region) on GC-treated CEM-C7H2 cells supported the existence of the postulated BB mRNA and protein. Subcellular localization analysis of BB suggested that BB may be directed to mitochondria, ascribed probably to its BH3-domain interaction with other BCL2 proteins and not by its unique C-terminus which in contrast to the Bim C-terminus doesn't localize to mitochondria. The functional analyses with conditional overexpression in ALL in vitro model revealed that overexpressed BB is a killer protein with potency similar to that of Bim and thus may contribute to the anti-leukemic effects of GCs and perhaps other apoptotic responses.

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 1029.
Abstract 1034: Combination therapy with gossypol reveals synergism against gemcitabine resistance in cancer cells with high Bcl-2 expression
Authors: Wong Foong Ying , Liem Natalia , Wang Lingzhi , Xie Chen , Yong Wei Peng
Published: February 2011

Gemcitabine is an anticancer agent used in breast, non-small cell lung, pancreatic and ovarian cancer. However, many cancers have been showed to be resistant to gemcitabine. Recent studies have demonstrated that gemcitabine resistance can be overcome when combined with gossypol. Gossypol is an inhibitor of Bcl-2 that induces apoptosis in various cancer cell lines. The aim of our study was to determine whether gossypol can overcome gemcitabine resistance via its interaction with the Bcl-2 protein. IC50 of gossypol and gemcitabine, as well as baseline expression of Bcl-2 were determined in 10 cell lines derived from nasopharyngeal (n=4), breast (n=3) and gastric (n=3)cancers. High Bcl-2 baseline expression that was observed in 3/10 cell lines, had higher IC50 to gemcitabine. Upregulation of Bcl-2 levels were also observed after treatment in cell lines that high Bcl-2 baseline expression. These findings suggest an interaction between Bcl-2 protein and gemcitabine resistance. Furthermore, in 7/10 cell lines that were sensitive to gemcitabine, five showed low Bcl-2 expression, suggesting that Bcl-2 levels plays a role in gemcitabine response in cancer. To determine whether gossypol can overcome gemcitabine resistance, combination treatments were carried out either by adding the drugs simultaneously or sequentially to the cell lines. Dual drug treatment was found to be synergistic to cell lines that have both high Bcl-2 level and were resistant to single agent, gemcitabine. Intrestingly cell lines that were sensitive to both drugs, and had high Bcl-2 level were also synergistic when treated with the combined drugs. In contrast, cell lines that were sensitive to both drugs and had low Bcl-2 level were antagonistic to combined drug treatments. The (-) enatiomer of gossypol (AT101) has been reported to be more potent than gossypol in inhibiting cell growth and inducing apoptosis in cancer cells. This suggests that AT101 is a more effective drug than gossypol in overcoming gemcitabine resistance. Cell lines treated with AT101 had lower IC50 compared to those treated with gossypol. Two cell lines (HK1 and AGS) that were intermediate responders to gossypol demonstrated higher sensitivity when treated with AT101, suggesting that AT101 is a more effective drug than gossypol. Futhermore, in vitro durg response studies comparing the 2 drugs in 35 gastric cell lines reveals an overall hypersensitive to AT101 compared to gossypol. Current studies are underway to investigate combination treatment of AT101 with gemcitabine, as well as its interactions with the Bcl-2 family proteins.

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 1034.
Abstract 1036: ARC synergizes with ABT-737 to induce apoptosis in human cancer cells
Authors: Bhat Uppoor , Pandit Bulbul , Gartel Andrei L.
Published: February 2011

Previously, we reported that the nucleoside analog/transcriptional inhibitor ARC was able to induce p53-independent apoptosis in multiple cancer cell lines of different origin. This occurred at least in part by the suppression of Mcl-1 expression, which a short-lived, pro-survival member of the Bcl-2 family. Interestingly, pan-caspase inibitor Z-VAD-FMK protected leukemia cells from ARC-induced mitochondrial damage and apoptosis, and Mcl-1 mRNA and protein from down-regulation by ARC. At the same time treatment of human cancer cells with the pan-Bcl-2 inhibitor ABT-737 alone led to up-regulation of Mcl-1 protein expression. Combination of sub-apoptotic concentrations of ABT-737 and ARC suppressed Mcl-1 expression, induced mitochondrial injury and potent apoptosis in wide variety of human cancer cell lines. In prostate cancer cells co-treatment with ARC and ABT-737 resulted in synergistic induction of cell death with combination index 0.7-0.8. These data suggest that ABT-737/ARC combination that simultaneously targets Bcl-2 and Mcl-1 may be efficient against human 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 1036.
Abstract 1038: Defining the mechanism by which melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24)-induced autophagy switches to apoptosis in prostate cancer cells
Authors: Bhutia Sujit K. , Dash Rupesh , Azab Belal , Das Swadesh , Su Zhao-zhong , Lee Seok-Geun , Grant Steven , Dent Paul , Curiel David T. , Sarkar Devanand , Fisher Paul B.
Published: February 2011

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), a unique member of the IL-10 gene family, displays a broad range of antitumor properties including cancer-specific induction of apoptosis, inhibition of tumor angiogenesis, and modulation of an anti-tumor immune response. Apoptosis induction by mda-7/IL-24, when delivered by an adenovirus (Ad. mda-7), involves an endoplasmic reticulum (ER) stress response and generation of ceramides. Additionally, Ad. mda-7 promotes autophagy in certain cancer cell types. In the present study, we document that Ad-mda-7-induced ER stress and ceramide generation result in induction of autophagy in prostate cancer cells, without affecting normal human prostate epithelial cells, via the canonical autophagic pathway, involving Beclin-1, atg5 and hVps34. Autophagy is evident until 24 h post Ad. mda-7-infection and then switches to apoptosis at 48 h. Inhibition of autophagy by 3-methyladenosine (3-MA) significantly increases Ad. mda-7-induced apoptosis suggesting that autophagy might first be initiated as a cytoprotective mechanism in prostate cancer cells. Inhibition of apoptosis by overexpression of anti-apoptotic proteins Bcl-2 or Bcl-xL increases autophagy upon Ad. mda-7 infection. During the apoptotic phase, MDA-7/IL-24 protein physically interacts with Beclin-1 and this interaction might inhibit Beclin-1 function culminating in apoptosis. Conversely, Ad. mda-7 infection leads to calpain-mediated cleavage of ATG5 protein that might also facilitate a biochemical switch from autophagy to apoptosis. Our present studies reveal novel aspects of interplay between autophagy and apoptosis that underlie the cytotoxic action of mda-7/IL-24 in prostate cancer cells. These new insights into mda-7/IL-24 action provide interesting leads for developing innovative combinatorial approaches for prostate cancer therapy.

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 1038.
Abstract 104: Breast cancer stem cell extinction models: Implications for HER2 targeted therapy
Authors: Riley Lindsay A. , Zhou Hua , Lange Kenneth , Sinsheimer Janet S. , Sehl Mary E.
Published: February 2011

Treatment with trastuzumab therapy has been shown to dramatically improve survival and reduce recurrence of breast cancer in patients with overexpression of HER-2/neu. A subpopulation of cells in human breast tumors has been identified with characteristics of cancer stem cells. These breast cancer stem cells (BC SCs) have been recently shown to have increased expression of HER-2/neu, suggesting that BC SCs might have a chance of being eradicated with therapy targeting HER-2. We propose a mathematical model to examine the feasibility of eradicating breast cancer stem cells with HER-2 targeted therapy. Using a linear birth-death process model, we can predict the likelihood that BC SCs have become extinct after a year of trastuzumab therapy. We examine the effects of varying degrees of HER-2/neu overexpression and susceptibility of BC SCs to trastuzumab therapy by changing the death rates under targeted therapy (see Table). We also quantify the average time to extinction of BC SCs and the average number of BC SCs remaining after a year of therapy. We conclude that trastuzumab may be effective in eradicating BC SCs in the adjuvant therapy setting, even in patients in whom the bulk of the tumor population does not overexpress HER-2/neu.BC SC population size and extinction likelihood for varying death rates.Death rate (per week)Mean extinction time (SD) (weeks)Probability of extinction in 1 year (52 weeks)0.3433 (4.1)0.9990.3038 (4.6)0.9900.2841 (5.0)0.9720.2644 (5.4)0.9220.2448 (5.9)0.7950.2253 (6.5)0.5250.2059 (7.3)0.1640.2066 (8.2)0.0060.1676 (9.4)<0.0001

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 104.
Abstract 1042: Diminished caspase 8 and c-Myc protein expression in human fibroblasts provides insight into normal cell resistance to TRAIL-mediated apoptosis
Authors: Crowder Roslyn N. , Dicker David T. , El-Deiry Wafik S.
Published: February 2011

TNF-related apoptosis-inducing ligand (TRAIL)-mediated cell death is currently being exploited in clinical trials for cancer therapy. However, the molecular basis of normal cell resistance to TRAIL-mediated apoptosis, and thus therapeutic index, remains largely unexplored. We found that normal HFF and WI38 fibroblasts expressed slightly lower levels of TRAIL receptor DR5 as compared to human lung and colon cancer cells. While normal and cancer cells showed comparable DcR2 expression, the WI38 and HFF expressed little DR4 and DcR1. Normal fibroblasts were examined for increased expression of proteins known to inhibit TRAIL-mediated cell death. Anti-apoptotic Bcl-xL and Mcl-1 expression in WI38 and HFF was comparable to expression found in cancer cells, while no XIAP expression was detected in the normal fibroblasts. c-Myc, a major determinant of TRAIL sensitivity in cancer cells, was found to be decreased in the normal fibroblasts and thus may be a contributing factor to their escape from TRAIL-induced cell death. NF-κB activation was assessed after 4 hours of TRAIL exposure, but minimal IκB degradation was observed in the normal fibroblasts, suggesting their resistance to TRAIL may not be mediated through induction of pro-survival factors by NFkB. Expression and activation of initiator caspases, required for complete TRAIL signaling, was investigated and although its levels were elevated, no caspase 10 activation was observed in normal WI38 and HFF cells after TRAIL treatment. Extremely low caspase 8 protein expression was detected in the normal human fibroblast lines, at levels barely detectable as compared to tumor cells that generally show robust caspase 8 expression. Reduced caspase 8 expression may be considered as another contributing factor to the resistance of normal cells to TRAIL. Expression and activation of effector caspase 3 was also examined. After TRAIL stimulation, expression of full length caspase 3 declined in normal and tumor cells. However, cleavage of caspase 3 substrate, PARP, was only seen in cancer cells. Our current studies are focused on further analysis of mediators of cell death signaling by TRAIL, whether treatment of normal fibroblasts with proteasome inhibitors, histone deacetylase inhibitors, and/or DNA methylation inhibitors might result in increased caspase 8 protein expression and susceptibility to TRAIL-mediated apoptosis. We are further investigating the effects of serum and growth factors to drive cell proliferation of normal cells on c-Myc expression and TRAIL sensitivity.

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 1042.
Abstract 1045: Enhancement of drug-induced apoptotic cell death in human hepatocellular carcinoma cells with knock-down of BNIP3
Authors: Yau Pak Lun , Tsang Tsun Yee , Co Ngai Na , Choi Siu Cheong , Yeung Chi Lam Au , Kwok Tim Tak
Published: February 2011

Although BNIP3 is known for its pro-apoptotic function by forming dimer to help the release of cytochrome c in apoptosis, its role in the cell death pathways was not yet well-defined. To investigate the role of BNIP3 in drug-induced apoptosis, stable transfectants were established from human hepatocarcinoma HepG2 cells transfected with pSilencer inserted with scramble oligos or BNIP3 siRNA. By MTT assay, knock-down of BNIP3 in HepG2 stable transfectant decreased cell survival towards vincristine, Taxol and doxorubicin. By DNA fragmentation assay and Annexin V binding assay, the level of drug-induced apoptosis in BNIP3i cells was elevated as compared with the control cells. Further analyses on caspases activation and mitochondrial cytochrome c release were done by Western blot analysis while the mitochondrial membrane depolarization was monitored by flow cytometry of JC-1 dye staining. By comparing with the control cells, the presence of vincristine or Taxol induced less cytochrome c release, mitochondrial membrane depolarization and activation of caspases-3, −8 and −9 in HepG2 BNIP3i cells. The results from present study indicated that BNIP3 might induce apoptosis by therapeutic drugs in HepG2 cells through a non-classical apoptotic pathway.

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 1045.
Abstract 1048: Homogenous, bioluminescent and HTS formatted assay for quantization of ADP production in kinase and ATPase reactions
Authors: Goueli Said , Hsiao Kevin , Zdanovoskaia Marina , Vidugiriene Jolanta , Zegzouti Hicham
Published: February 2011

Because of its versatility (all types of substrates), robustness (Z’>0.8), rapid performance, and its ease of use, the luminescence based Kinase GloTM assays platform have gained wide acceptance in many drug screening programs for protein kinase inhibitors. We have attempted to extend our strategy by now monitoring ADP product formation in the kinase reaction. The new assay we developed (ADP Glo) maintains all the positive features of Kinase GloTM such as universality, and applicability to all kinds of kinase substrates regardless of their nature with no prior modification (peptides, protein, polymer, lipids, and sugars) but In stead of measuring ATP depletion, it monitors ADP production. It detects ADP at early stages of enzyme reactions with very high signal to background (SB) ratio. It can be run at a wide range of ATP concentrations (low micromolar to millimolar), is sensitive to low ADP concentrations (0.1 pmol), and it can be carried out in high density plate formats. This assay is robust and homogenous, and does not require antibodies or custom synthesized substrates. It is ideal to search for optimal substrates in a collection of peptides, proteins, or lipids in a single assay format, and to screen for ATP competitive and Non competitive inhibitors. Because of the high dynamic range and more importantly, the high SB values even at low % ATP to ADP conversion, the assay allows the use of low amounts of enzyme during high-throughput screening. Evaluation of this assay in a screen of a large chemical library showed minimal false hits attesting to the quality of this system. The ADP-GloTM assay is applicable to all types of kinases, ATPases, multidrug resistant proteins such as MDR1-Pgp, helicases, topoisomerases, and heat shock proteins and as well as many other ADP producing enzyme reactions.

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 1048.
Abstract 1049: Akt1 and Akt2 are associated with poor outcome in glioblastoma multiforme
Authors: Joy Anna M. , Smirnov Ivan , Nakada Mitsutoshi , Feuerstein Burt G.
Published: February 2011

The Akt pathway is implicated in progression of astrocytic tumors. To refine the Akt pathway as a therapeutic target in glioblastoma multiforme (GBM) we determined activated Akt isoform(s) that mediate cellular behavior, and are associated with clinical parameters. Akt1 and Akt2 message is associated with worse clinical outcome while Akt3v1 message is associated with better clinical outcome. Silencing individual isoforms with shRNA gives different phenotypes. Bioinformatic analysis indicates that PI3K/Akt pathway components cluster with individual Akt isoforms and with tumor subtype suggesting that different arms of the PI3K/Akt pathway are associated with individual isoforms. Taken together, the data indicate that Akt3 function differs from Akt1 and 2 function, and support a role for Akt1 and 2 in the malignant behavior of glioma cells. Selective inhibition of Akt1 and/or 2, or their downstream effectors may be more effective and less toxic than general inhibition of Akt or PI3K. Supported by the Barrow Neurological Foundation (AJ and BGF).

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 1049.
Abstract 1050: CD109 expression promotes cell activity and enhances EGF signaling in human glioblastoma cells
Authors: Murakumo Yoshiki , Zhang Jing-min , Takahashi Masahide
Published: February 2011

CD109 is a glycosylphosphatidylinositol (GPI)-anchored cell surface protein whose expression is predominantly detected in squamous cell carcinomas of esophagus, lung, uterus and oral cavity. In the previous study, we found CD109 expression in cell lines derived from human glioblastomas by Northern blot analysis, however, the role of CD109 expression in glioblastoma cells is unclear. Here, we describe our study on significance of CD109 expression in biology of human glioblastoma cells. CD109-overexpressing glioblastoma cells exhibit upregulation of cell growth, motility and invasion ability compared with control cells. Evaluation of intracellular signaling status revealed that the CD109-overexpressing cells showed enhanced phosphorylation of ERK, AKT, and p38MAPK. After epidermal growth factor (EGF) stimulation, strong and sustained phosphorylation of these molecules and EGF receptor (EGFR) was observed in the CD109-overexpressing cells. In addition, we found an interaction between CD109 and EGFR and colocalization of these molecules without EGF stimulation. However, the interaction and colocalization were abolished after EGF stimulation, and EGFR internalization was not affected by CD109 overexpression. These findings suggest that CD109 facilitates EGF signaling via binding to EGFR and its expression is associated with the malignant behavior of glioblastoma 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 1050.
Abstract 1058: E-cadherin mutations contribute to gastric carcinogenesis by modulating multiple EGFR-dependent downstream signaling pathways
Authors: Heindl Stefan , Lang Christina , Böllner Claudia , Malinowsky Katharina , Becker Karl- Friedrich , Luber Birgit
Published: February 2011

Mutations in the gene encoding the cell adhesion molecule E-cadherin and overexpression of the epidermal growth factor receptor (EGFR) represent fundamental genetic alterations associated with diffuse-type gastric cancer. Mutations, e.g. in frame deletion of exon 8 (del 8), lead to loss of putative extracellular Ca2+-binding sites of E-cadherin, thereby impairing its functionality. Several studies have shown a bidirectional crosstalk between E-cadherin and EGFR. Functional wild-type (wt) E-cadherin inhibits ligand-induced EGFR activation, but mutations lead to a loss of its suppressive function, resulting in increased EGFR activation and recruitment of downstream signalling components. The phenotype of cells harboring such mutations is characterized by increased proliferation and elevated migratory and invasive potential.

Our project aims at studying the impact of somatic mutations of E-cadherin on EGFR-mediated signalling pathways, in order to identify signalling molecules of these pathways as molecular targets for selective therapies in gastric cancer.

Cell lines expressing wt or mutant E-cadherin (del 8) were EGF-stimulated and cellular lysates were analyzed by commercial proteome profiler antibody array (R&D Systems). The array allowed detection of the phosphorylation status of 48 signalling molecules and facilitated identification of differential activation. We found differential response to EGF stimulation of proteins involved in DNA damage and repair, such as p53 and CHK2, in both cell lines. As both proteins are tumorsuppressors, their dysfunction could contribute to tumor progression. Furthermore, Src-family kinases (SFKs) like Src, Yes, Fgr, Lck and Lyn exhibited different activation profiles in response to EGF-stimulation in both cell lines. As SFKs are key players in multiple cellular processes like cell growth, differentiation, cellular adhesion, migration and invasion, the impact of their differential activation on the cellular phenotype is subject of ongoing experiments. To determine the role of the identified targets in gastric carcinogenesis and the mechanisms of crosstalk between E-cadherin and EGFR a protein microarray platform was established, allowing analysis of multiple samples under the same experimental conditions. This approach will reveal new insights in EGFR-mediated signalling pathways contributing to gastric carcinogenesis and complete our data describing how tumor associated mutations of E-cadherin affect cellular signalling.

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 1058.