bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3733: Heregulin as a novel resistant factor for cetuximab
Authors: Yonesaka Kimio , Okamoto Isamu , Satoh Taroh , Takeda Kohji , Takada Minoru , Nishio Kazuto , Fukuoka Masahiro , Janne Pasi A. , Nakagawa Kazuhiko 
Published: February 2011

Abstract
Background
Epidermal growth factor receptor (EGFR) is a therapeutic target in colorectal cancer (CRC). Patients with CRC with wild type KRAS have significant tumor regressions with cetuximab. However cancers ultimately acquire resistance. The mechanisms of these are still unknown. We investigated mechanisms of acquired resistance to cetuximab.
Methods
The cetuximab-resistance cell line, A431ER, was established from cetuximab-sensitive parent A431 by exposing cetuximab. In vitro sensitivity was analyzed using MTS assay. Expression of ErbBs and heregulin (HRG) was analyzed with RTK array, immunoblotting (IB) and ELISA. Plasma samples were studied using ELISA among 44 pts with CRC, treated with cetuximab.
Result
A431 was so sensitive to cetuximab that the growth inhibition following 10μg/ml cetuximab (GI10) was about 50% in MTS. In contrast, A431ER was completely resistance (GI10 &lt;10%). The RTK array showed that A431ER but not A431 had markedly phosphorylated ErbB2 and 3. Although ErbB2 and 3 were highly phosphorylated in A431ER, total protein level of those was equivalent to A431 in IB. Finally heregulin, a ligand for ErbB3, was detected significantly higher in A431 than A431ER using IB and also ELISA in culture mediums (355 vs 1025pg/ml). HRG inhibition with siRNA could restore the sensitivity to cetuximab in A431ER. And exogenous HRG induced A431 parent cell line resistant to cetuximab. The exogenous HRG also phosphorylated both Erb2 and 3 in A431, which means hetero-dimerization of those. So we did MTS assay with cetuximab and pertuzumab, which inhibited hetero-dimerization between ErbB2 and 3. Cetuximab alone or pertuzumab alone minimally effected in A431ER (GI10 was about 10%). But the combination of two drugs abundantly effected (GI10 was about 60%). About clinical samples, pts with progressive disease (PD, n=23) following cetuximab had higher expression of HRG in plasma than pts with non-PD (n=15) (median 1188 vs 4854pg/ml, p=0.0008). And low HRG group (&lt;2000pg/ml, n=22) had longer progression free survival (HR 0.2371 (95%CI 0.095-0.593), p=0.0021) and overall survival (HR 0.2274 (0.075-0.693), p=0.0092) than high HRG group (&gt;2000pg/ml, n=22). Finally, post- treatment samples had significantly higher HRG than pre-treatment in 6 pts, who acquired resistance after 5 months treatment (mean 904 vs 1890pg/ml, p=0.0161).
Conclusion
Our findings suggest that HRG could lead both de novo and acquired resistance to cetuximab. HRG-ErbB3-ErbB2 complex is a warranted target for overcoming resistance to cetuximab.
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 3733.
Abstract 374: VEGFR2/KDR polymorphisms and gene copy gain with outcome in non-small cell lung cancer
Authors: Yang Fei , Tang Ximing , Corvalan Alejandro , Behrens Carmen , Lin Heather , Raso Maria Gabriela , Lee J. Jack , Minna John D. , Wistuba Ignacio Ivan 
Published: February 2011

Abstract
Background. The VEGF receptor 2 (VEGFR2) is the predominant mediator of VEGF-stimulated endothelial cell function. Recently, VEGFR2/KDR copy number gain and mutation, and VEGF copy number gain, have been described in lung adenocarcinoma tumor specimens. To better characterize the molecular changes of these two genes in non-small cell lung carcinoma (NSCLC), we investigated their abnormalities in NSCLC tumor tissue specimens and correlated with patients clinico-pathological characteristics.
Methods. We extracted DNA from microdissected tissue obtained from 200 surgically resected NSCLCs. KDR single nucleotide polymorphism (SNP) 889G/A (rs2305948), SNP 1416A/T (rs1870377) and SNP −37A/G (rs2219471) were genotyped by PCR-based sequencing. KDR and VEGF copy number were examined by quantitative (q)-PCR. Protein expressions of VEGF and VEGFR2, and CD34 for microvascular density (MVD) analysis were studied by immunohistochemistry. SNP genotypes, genes copy number and protein expression were correlated with NSCLC clinico-pathological features, including overall survival (OS) and recurrence-free survival (RFS).
Results. KDR 1416 AT/TT genotypes had significantly improved OS (HR = 0.56, 95% CI 0.33 to 0.96, P = 0.035) compared with KDR 1416 AA in all NSCLC patients in the multivariate analysis with adjustment of histology and tumor stage. In lung adenocarcinomas, KDR 1416 AT/TT genotypes and KDR −37AG/GG were associated with a favorable OS (HR = 0.43, 95% CI 0.20 to 0.92, P = 0.029; HR = 0.47, 95% CI 0.23 to 0.96, P = 0.039, respectively). Strikingly, KDR −37 AG/GG genotypes predicted a superior OS compared with KDR −37 AA genotype in the NSCLC patients treated with adjuvant therapy (HR = 2.45, 95% CI 1.06 to 5.66, P = 0.036). No genotype in KDR SNPs was associated with RFS in NSCLC patients. Gene copy gain of KDR and VEGF were detected respectively in 34/91 (37.4%) and 2/91 (2.2%) NSCLC tumors. Gene copy gain of KDR was associated with a poor overall survival in NSCLC patients (HR= 2.96, 95% CI 1.41 to 6.24, P = 0.004). Furthermore, tumors with gene copy gain of KDR showed significantly higher cytoplasmic (P = 0.013) and membrane (P = 0.009) VEGFR2 protein expression, lower cytoplasmic VEGF expression (P = 0.044), and higher MVD (P = 0.018) and larger vessel areas (P = 0.033) compared with tumors lacking KDR gene copy gain.
Conclusion. Our findings suggest an association between KDR SNP genotypes and survival in NSCLC patients receiving adjuvant therapy. KDR copy number gain was frequently identified in NSCLC and was associated with worse survival in NSCLC patients. (Supported by grant US DoD W81XWH-07-1-0306).
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 374.
Abstract 3741: Adjuvant active specific immunotherapy improves survival of patients with micro-satellite stable colorectal tumors, but not with micro-satellite instable tumors
Authors: de Weger Vincent A. , Euler Zelda , van Tinteren Harm , Bril Herman , Meijer Gerrit A. , Hooijberg Erik 
Published: February 2011

Abstract
Purpose: It has been documented that Active Specific Immunotherapy (ASI), given as adjuvant treatment, improves survival of patients with stage II and III colorectal cancer (CRC). Here we report on the effects of ASI on Micro-Satellite Stable (MSS) versus Micro-Satellite Instable (MSI) tumors.
Materials and Methods: From 196 patients with stage II or stage III CRC who previously participated in the ASI trial published previously (Vermorken et al. Lancet), we collected frozen tumor samples and/or paraffin embedded tumor material. From this material DNA was extracted and microsatellite stability status was assessed. Microsatellite status was associated with clinical outcome in both the placebo and ASI treatment groups using Kaplan Meier analysis.
Results: From 196 patients participating in the trial we retrieved good quality archival tumor DNA for further analysis of microsatellite stability (MS). We subsequently identified 162 (83%) MSS tumors and 34 MSI (17%) tumors. Irrespective of MS status a significant survival benefit for patients receiving ASI treatment (P=0.012) was observed, confirming previous results. New to this is that irrespective of treatment, patients with MSI tumors showed significantly less recurrences than patients with MSS tumors (P = 0.03). Taking both MS status and treatment into account we found no significant difference in survival between ASI treated versus placebo receiving patients with MSI tumors. In contrast, patients with MSS tumors benefited from ASI treatment showing a significantly improved recurrence free survival (P=&lt;0,05).
Conclusion: It can be concluded that only patients with MSS tumors will benefit from adjuvant ASI since only they showed significant improved recurrence free survival on ASI therapy. For the MSI group there is most likely no benefit of ASI therapy.
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 3741.
Abstract 3753: Quantitation of EGFR and phosphoEGFR in FFPE tissue
Authors: Hembrough Todd , Krizman David , Heidbrink-Thompson Jenny , Thyparambil Sheeno , Burrows Jon , Darfler Marlene , Taylor Paul , Tong Jiefie , Shi Warren , Tsao Ming , Moran Michael 
Published: February 2011

Abstract
The epidermal growth factor receptor (EGFR) is a drug target for both small molecule and antibody therapeutic approaches for several cancers; however, current methods of selecting patients that will most likely respond to anti-EGR therapy are not effective. Better methods for patient stratification are needed. To this end we have developed an approach which can determine both absolute EGFR levels and the phosphorylation status of EGFR directly in formalin-fixed paraffin-embedded (FFPE) patient tissue. This approach is based on the Liquid Tissue®-SRM technology platform, a combination of tissue microdissection, Liquid Tissue® processing which turns dissected tissue to a complete solubilized tryptic digest, and mass spectrometry-based selected reaction monitoring (SRM). This approach was used to measure the EGFR protein and its phosphorylation status in formalin fixed tissue culture cells, xenograft tumors, and patient tumor tissue. For assay development, 3 distinct tryptic peptides were assessed for absolute protein quantitation and multiple peptides where specific residues are known to become phosphorylated (pT693 and pY1197) were assessed for assaying the phosphorylation status of the EGFR protein. We demonstrate the ability to detect and quantify the EGFR protein and to monitor its phosphorylation status directly in patient tumor tissue. This approach offers a dynamic range and quantification which is superior to traditional IHC methods, and that could be used to identify and stratify patients most likely to benefit from anti-EGFR therapies.
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 3753.
Abstract 3764: Promoter methylation in exfoliated breast cells isolated from breast milk of women who have had a breast biopsy
Authors: Browne Eva P. , Punska Elizabeth C. , Anderton Douglas L. , Arcaro Kathleen F. 
Published: February 2011

Abstract
Analysis of promoter methylation patterns in genes frequently downregulated in breast cancer may serve as an early indicator of breast cancer risk. To date, studies of methylation patterns in breast epithelial cells from asymptomatic women have been limited to cells obtained from fine nipple aspirate and ductal lavage. Analysis of promoter hypermethylation in exfoliated epithelial cells isolated from breast milk provides a non-invasive opportunity to assess breast cancer risk. Our preliminary data indicate that we can detect a cancer methylation phenotype in the milk of women at high risk. We propose that epithelial cells isolated from breast milk of lactating women scheduled to have a breast biopsy provide a resource for assessing early changes in DNA related to increased breast cancer risk.
Two hundred and fifty breast milk samples from women who are scheduled to have, or have had a breast biopsy will be collected. Of these women, we expect that roughly ten percent will be diagnosed with breast cancer. Breast milk will be collected from both the biopsied and contralateral breast of each participant. To date, 153 participants have donated breast milk, yielding 300 breast milk samples with an average size of 50 ml (±30 ml) per breast. After collection, the epithelial enriched and epithelial depleted cells from each breast were isolated. Subsequent DNA isolation of both the epithelial enriched and depleted fraction of cells yielded an average of 372 ng (range 12-5000 ng) of high quality DNA.
Using the DNA extracted from epithelial enriched and depleted fractions of cells isolated from breast milk, the promoter methylation level of 9 genes known to be methylated in breast cancer will be examined using pyrosequencing technology. We will assess the promoter methylation levels of: CDH1, DAP-K, ER-α, GSTP1, HIN1, P16, RAR-ß, RASSF1A, and SFRP1 in the epithelial enriched and depleted bisulfite treated DNA of each breast milk sample. Preliminary pyrosequencing assays conducted in our lab have shown that there is a difference in RASSF1A methylation levels between the epithelial enriched DNA from the cancerous breast compared to the epithelial depleted DNA from the non-cancerous breast of the same participant. Further methylation analysis may prove that breast milk can be used as non-invasive alternative to ductal lavage or fine needle aspirate, which may yield accurate breast cancer risk assessment.
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 3764.
Abstract 3779: Combination chemoprevention of hepatocellular carcinoma using acyclic retinoid
Authors: Shimizu Masahito , Moriwaki Hisataka 
Published: February 2011

Abstract
Background and aims: A malfunction of retinoid X receptor-α (RXRα) due to phosphorylation by the Ras/MAPK signaling pathway is associated with the development of hepatocellular carcinoma (HCC). Acyclic retinoid (ACR: the same material as NIK-333), which has been clinically shown to reduce the incidence of a post-therapeutic recurrence of HCC, can inhibit both the Ras activity and phosphorylation of the ERK and RXRα proteins. The effects of a combination of ACR plus other agents on the inhibition of cell growth in human HCC cells were herein examined to develop a more effective strategy for the prevention of HCC.
Methods and results: The combination of ACR plus vitamin K2, which inhibits the phosphorylation of the RXRα protein through the inhibition of Ras/MAPK activation, synergistically induced apoptosis and inhibited the growth of human HCC cells without affecting the growth of normal human hepatocytes. ACR and trastuzumab, the humanized anti-HER2 monoclonal antibody, also synergistically inhibited the activation of HER2, a member of receptor tyrosine kinase (RTK), and its downstream signaling pathways, thus subsequently inhibiting the phosphorylation of RXRα and the growth of HCC cells. ACR in combination with valproic acid, a histone deacetylase inhibitor, also synergistically inhibited the growth of human HCC cells and this was associated with the inhibition of phosphorylation of the RXRα and Akt proteins by valproic acid.
Conclusion: The combination of ACR plus a specific agent that targets RTK and its downstream signaling pathways, including the Ras/MAPK and PI3K/Akt pathways, may be able to inhibit the phosphorylation of RXRα and it may therefore be a promising strategy to prevent the development of HCC. ACR, which targets phosphorylated RXRα, may thus play a critical role in preventing the development of HCC when it is used either alone or in combination with other agents.
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 3779.
Abstract 3782: Benzyl isothiocyanate-induced apoptosis in human breast cancer cells is mediated by downregulation of X-linked inhibitor of apoptosis protein
Authors: Kim Su-Hyeong , Singh Shivendra V. 
Published: February 2011

Abstract
Benzyl isothiocyanate (BITC) is a highly promising cancer chemopreventive constituent of edible cruciferous vegetables such as gardencress. We have shown previously that BITC treatment inhibits viability of MDA-MB-231 (an estrogen-independent cell line expressing mutant p53) and MCF-7 (an estrogen-responsive cell line with wild-type p53) by causing reactive oxygen species-mediated apoptosis. In addition, oral administration of BITC inhibits growth of MDA-MB-231 human breast cancer cells subcutaneously or orthotopically implanted in female athymic mice without causing weight loss or any other side effects. More recent studies from our laboratory have indicated that dietary feeding of BITC offers protection against mammary hyperplasia and carcinoma development in MMTV-neu transgenic mice. The present study extends these exciting observations and determines role of p53 and inhibitor of apoptosis (IAP) family proteins in regulation of BITC-induced apoptosis. Exposure of MCF-7 and MDA-MB-231 cells to apoptosis inducing concentrations of BITC (2.5 and 5.0 μM) resulted in up-regulation of p53 in MCF-7 cell line and down-regulation of X-linked inhibitor of apoptosis (XIAP) in both cell lines. The BITC-mediated down-regulation of XIAP was evident as early as 8 h post-treatment. BITC-treated cell also exhibited induction of survivin especially in the MCF-7 cell line. The level of cIAP2 protein was only modestly increased upon treatment of MCF-7 and MDA-MB-231 cells with BITC. The BITC-induced apoptosis was only marginally affected by knockdown of p53 protein level by RNA interference. On the otehr hand, forced expression of XIAP protein conferred significant protection against BITC-mediated cytoplasmic histone-associated apoptotic DNA fragmentation in both cell lines. The BITC-induced cytoplasmic histone-associated apoptotic DNA fragmentation was significantly increased by knockdown of survivin protein in the MCF-7 cell line but not in the MDA-MB-231. These results indicate that down-regulation of XIAP contributes to the BITC-induced apoptosis in breast cancer cells. In addition, induction of survivin confers resistance against BITC-mediated cell death at least in the MCF-7 cell line. This study was supported by the National Cancer Institute grant CA129347-03.
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 3782.
Abstract 3786: Activation of KLF4 by 3,3′-Diindolylmethane contributes to the cell differentiation and grow inhibition of pancreatic cancer cells
Authors: Wei Daoyan , Xie Keping 
Published: February 2011

Abstract
3,3′-Diindolylmethane (DIM), the major bioactive metabolite of the phytochemical indole-3-carbinol present in cruciferous vegetables, is a promising cancer preventative and anti-tumor agent for various tumor types, including pancreatic cancer. However the underlying molecular mechanisms by which DIM exerts its antitumor activity remain poorly understood. Our previous studies indicate that KLF4 has a tumor suppressive function in pancreatic cancer by up-regulation of p27 expression and induction of cell cycle arrest, which has also been suggested to be the mechanistic action of DIM in pancreatic cancer cells. However, whether KLF4 is involved in DIM's antitumor activity and if so, what are the underlying molecular mechanisms in pancreatic cancer have not been defined. In the present study, we found that DIM treatment dose dependently induced the expressions of KLF4 and its downstream target gene p27 and p21 in several, and cytokeratin 19 in Panc-28 and PANC-1 pancreatic cancer cells. Consistently, induction of KLF4 expression correlated with significant inhibition of cell cycle progression and cell growth as determined by Flow cytometry and MTT assay, while knockdown or conditional knockout of KLF4 expression significantly reduced the sensitivity of pancreatic cancer cells to DIM treatment determined by IC50 assay. These results indicate that KLF4 plays a critical role in mediating the antitumor activity of DIM in pancreatic cancer cells. To further investigate the molecular mechanism underlying DIM's induction of KLF4 expression, KLF4 promoter deletion mutation analysis identified a DIM responsible region (from nucleotide −780 to −346) in the KLF4 promoter, within which a candidate Egr-1 cis-acting element was found by computer-based motive analysis. Functionally, significant induction of Egr-1 protein expression was observed as early as 1 hr after DIM treatment in time-course experiments, which was prior to the induced expression of KLF4 in FG cells. Consistently, forced or knocking down Egr-1 expression increased or reduced the response of BxPC3 cells to DIM treatment, which was correlated with increased or decreased KLF4 expression. In addition, chromatin immunoprecipitation assay showed that Egr-1 protein physically interacted with and DIM treatment increased the binding of Egr-1 to the DIM responsive region of KLF4 promoter in FG cells in vivo. Collectively, our results suggest that Egr-1/KLF4 signaling pathways play an important role in DIM's antitumor activity in pancreatic cancer cells.
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 3786.