bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1158: Multiple molecular targeting effects by miR-7 in EGFR tyrosine kinase inhibitor-resistant lung cancer xenograft models
Authors: Rai Kammei , Takigawa Nagio , Ito Sachio , Kiura Katsuyuki , Yasuda Tateji , Shimizu Kenji , Tanimoto Mitsune 
Published: June 2012

Abstract
Background and Purpose: Since T790M secondary mutation in exon 20 restores the affinity of ATP to the ATP binding site of mutated EGFR, the oncogene addiction by EGFR pathway is presumed to sustain in the EGFR tyrosine kinase inhibitor (TKI)-resistant cells harboring T790M. MicroRNA-7 (miR-7) was reported to regulate signaling pathway by targeting EGFR, IRS-1 and RAF1. We previously showed that miR-7 had potential tumor suppressor effect by binding 3′-untranslated region of EGFR mRNA in vitro as predicted in silico, which could be observed in xenograft model using gefitinib-resistant lung cancer cell line (RPC-9) carrying a secondary mutation T790M from EGFR mutated (delE746-A750 in exon 19) PC-9 cell line (#4041, Annual AACR meeting, 2010). We explored the efficacy and further mechanisms in other lung cancer cell lines and xenograft models.
Material and Methods: H3255 harboring L858R and H1975 carrying both L858R mutation in exon 21 and T790M mutation in exon 20 were used as EGFR addicted cell lines, while A549 was used as the cell line driven by not EGFR but KRAS. Each anti-proliferation effect was evaluated at 60 hours after transfection of miR-7 by the cell count assay. As EGFR-TKI resistant xenograft models, we selected H1975. Two million cells were injected s.c. into the backs of the athymic mice. After confirming the tumor formation of 7 mm in the diameter, we injected 3μg of control siRNA expressing plasmid and miR-7 expressing plasmid weekly into the each tumor by using optimized cationic liposome. Protein expression was determined by Western blotting.
Results: Significant growth inhibition by miR-7 was observed in the H3255 cells (p = 0.006) and H1975 cells (p = 0.004), while inhibition in A549 cells was likely to be moderate (p =0.07). Total EGFR was decreased and phosphorylation of AKT was suppressed in all cell lines by the treatment, moreover, total IRS-1 and total RAF-1 were also suppressed. Marked anti-proliferative effect in H1975 xenograft model was observed after treatment. The tumor sizes between the control mice and the treated mice were significantly different on day 19 (714% vs 154%, p=0.02). Total EGFR, IRS-1 and RAF-1 were suppressed in the tumors of H1975 and RPC-9 one day after injection of miR-7.
Conclusion: MiR-7 by non-viral weekly delivery in two typical xenograft models of EGFR-TKI resistant cell lines was effective through downregulating EGFR, IRS-1, and RAF-1. The treatment with miR-7 expressing plasmid may be promising for the EGFR-TKI-resistant lung cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1158. doi:10.1158/1538-7445.AM2011-1158
Abstract 116: Methylcytosine binding domain protein 2(MBD2) dependent proliferation and survival of breast cancer cells
Authors: Mian Omar Y. , Wang Shou Z. , Zhu Sheng Z. , Bear Harry D. , Ginder Gordon D. 
Published: June 2012

Abstract
Methyl Cytosine Binding Domain Protein 2 (MBD2) functions as an interpreter of DNA methylation by binding promoter sequences with high methylated CpG content and recruiting a Nuclear Remodeling and Deacetylase (NuRD) co-repressor complex. MBD2 has been shown to bind to and mediate repression of methylated tumor suppressor genes in cancer cells where re-patterning of CpG methylation and associated gene silencing is common. We have investigated the role of MBD2 in breast cancer cell growth and tumor suppressor gene expression. We show that stable shRNA mediated knockdown of MBD2 leads to significant growth suppression of cultured human mammary epithelial cancer lines, SK-BR-3 (92%); MDA-MB-231 (77%); MDA-MB-435 (94%); with the peak anti-proliferative effect occurring only after sustained, stable knockdown and lasting over 4 weeks. MBD2 knockdown also leads to markedly decreased propensity for these aggressive breast cancer cell lines to form in vivo xenograft tumors in BALB/C nu/nu mice. The growth effects of MBD2 knockdown are accompanied by de-repression of specific tumor suppressor genes including DAPK1 and KLK10. Chromatin immunoprecipitation assays and bisulfite sequencing demonstrate MBD2 binding directly to the hyper-methylated CpG-rich promoters of both DAPK1 and KLK10. Expression of an shRNA-resistant MBD2 protein results in restoration of growth and re-silencing of the MBD2 dependent tumor suppressor genes. Our data suggest that uncoupling CpG-methylation from repressive chromatin remodeling and histone modifications by removing MBD2 is sufficient to initiate and maintain tumor suppressor gene transcription and suppress neoplastic cell growth. These results demonstrate a role for MBD2 in aggressive breast cancer cell growth and provide support for the prospect of targeting MBD2 therapeutically.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 116. doi:10.1158/1538-7445.AM2011-116
Abstract 1167: Fixation does not affect the integrity of microRNAs in archival colorectal cancer specimens over a period of 20 years
Authors: Bovell Liselle C. , Shanmugam ChandraKumar , Katkoori Venkat , Salih Chura , Grizzle William E. , Manne Upender 
Published: June 2012

Abstract
Background: MicroRNAs (miRNAs) have potential prognostic and therapeutic value in human malignancies, including colorectal cancer (CRC). Many human tumor tissues are available as formalin-fixed paraffin-embedded (FFPE) specimens, which are an excellent source for biomarker discovery. However, the stability of miRNAs and the reliability of measurements of miRNA expression in archival samples stored for long periods of time (&gt; 20 years) are not known. Therefore, we evaluated the stability and expression levels of miRNAs in FFPE CRC specimens and compared their expression levels to those in CRC cell lines.
Methods: A panel of seven miRNAs (RNU6B, miR-20a, miR-21, miR-106a, miR-181b, miR-203, and miR-324-5p) in 219 CRC archival tissue samples, stored for 6 to 28 years (1982 through 2004) in a dark, cool place, and 11 CRC cell lines (LoVo, HCT116, HCT116 (p53-/-), RKO, LS174T, CaCo-2, Colo205, SW480, WiDr, HCT-15, and DLD-1) were evaluated by the use of TaqMan® microRNA assays and by quantitative real-time polymerase chain reactions. In CRCs, these miRNAs, excluding RNU6B (an endogenous reference molecule), are candidate prognostic or predictive biomarkers. All assay reagents used were from Applied Biosystems Inc., (Carlsbad, CA). From each block, tissue sections, 10-microns thick, were used for extraction of miRNAs. miRNA expression was measured as threshold cycle (Ct) values. Triplicate reactions were averaged for each miRNA, and the raw Ct values were determined. The Kruskal-Wallis one-way analysis of variance was employed to analyze the miRNA expression difference among archived samples from different years. Correlation coefficient analysis was performed to compare the expression levels of miRNA in archival tissues and cell lines.
Results: In both CRC archival tissues and cell lines, the median Ct values of all miRNAs ranged from 19 to 32. All seven miRNAs were stable in CRC tissues stored for up to 28 years; their expression levels were similar across all ages of blocks. (Kruskall-Wallis P values for all 7 miRNAs ranged from 0.627 to 1.000.) There was good correlation between the levels of expression of all seven miRNAs in FFPE tissues and in the CRC cell lines (correlation coefficient R2 range, 0.784 to 0.937).
Conclusions: Since miRNAs are stable in archival CRC samples stored for over 20 years, FFPE samples can be used to evaluate miRNAs as biomarkers. These studies were supported by grants 2U54-CA118948-03, R01-CA98932, and R03-CA139629 from the NCI/NIH.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1167. doi:10.1158/1538-7445.AM2011-1167
Abstract 1170: MicroRNA gene polymorphisms in cancer susceptibility loci 5p12, 8q24 and 11q13
Authors: Kim Hye Kyung , Chanock Stephen J. , Fang Jun , Collins Irene , Amundadottir Laufey 
Published: June 2012

Abstract
Using Genome Wide Association Studies (GWAS), we and others have previously identified and replicated genetic variations in chromosome 5p12, 8q24 and 11q13. Interestingly, the majority of risk-associated variations map to non-coding regions of the genome and thus, the molecular mechanism of single nucleotide polymorphisms (SNPs) underlying increased cancer risk remains unknown. To assess whether these SNPs could affect the biogenesis and function of non-coding RNA species, such as microRNAs (miRNA), here we assessed miRNA gene polymorphisms in these cancer susceptibility loci. We catalogued two miRNA genes in 5p12, sixteen miRNA genes in 8q24, and seven miRNA genes in 11q13. We re-sequenced the pri- and pre-miRNA genomic sequences in these loci using HapMap DNA samples. As a result, in 8q24 miRNA genes, we identified three new SNPs and confirmed two previously reported SNPs. In 11q13, we identified four genetic variations within different miRNA genes. However, linkage disequilibrium plot analysis of both loci didn't show any statistically significant association of any of these SNPs with their corresponding GWAS signals. Thus, we consider it unlikely that miRNA in these regions are direct downstream effectors of cancer-associated genetic variations. Nevertheless, because these risk loci are prone to genomic instability, we assessed whether the SNPs could affect miRNA gene expression since indirect associations with increased cancer susceptibility can't be excluded. To address this question, we cloned pre-miRNA genes from these loci, with or without genetic variations, into miRNA expression vectors and determined their relative expression in transfected 293T cells. We tested for an 8q24-encoded miRNA (miR-1206) or an 11q13 encoded-miRNA (miR-612) expression using miRNA TaqMan assays, and we found that the G allele polymorphism (rs2114358) in miR-1206 significantly downregulated miRNA expression levels compared to the reference A allele. On the other hand, an rs550894 (C/A) in miR-612 significantly upregulated miRNA expression levels compared to that of the reference C allele. These data indicate that the miRNA SNPs in these loci have indeed functional consequences that lead to dysregulation of miRNA biogenesis. Whether such changes in miRNA expression could also result in increased cancer risk needs to be assessed in future studies by identifying the downstream target genes of these miRNAs.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1170. doi:10.1158/1538-7445.AM2011-1170
Abstract 1186: Identification of p53 regulatory microRNAs
Authors: Zhang Xin , Dobbelstein Matthias 
Published: June 2012

Abstract
Purpose: microRNAs (miRNAs) play very important roles in gene regulation, by interfering with target mRNA stability and/or translation. A number of specific miRNAs have been identified to function as oncogenes or tumor suppressors. We originally found that miR-192/-215 constitute part of the p53 tumor suppressor network and can act as effectors and regulators of p53. In this project, we aim to identify more p53-regulatory miRNAs to gain deeper insight into p53 regulation.
Experiments: We developed an immunofluorescence-based screen to identify p53-regulatory miRNAs. Briefly, U2OS cells, an osteosarcoma cell line with wild type p53, were transfected with a collection of miRNA expression plasmids. The cellular levels of p53 were then evaluated by subsequent immunofluorescence analysis via high content BD pathway.
Results: From our screen, we identified the known p53-regulatory miRNA miR-125b (Le et al., 2009), that can reduce the levels of p53, which in turn validated our screen method. Several other candidates identified from this screen are undergoing study in the context of the p53 tumor suppressor pathway. These miRNAs might be novel therapeutic targets for diagnosis and treatment of human cancers.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1186. doi:10.1158/1538-7445.AM2011-1186
Abstract 119: MiR-1 downregulation plays a critical role in thyroid cell proliferation
Authors: Leone Vincenza , D'angelo Daniela , Pallante Pierlorenzo , Ferraro Angelo 
Published: June 2012

Abstract
MiR-1 downregulation plays a critical role in thyroid cell proliferation
V. Leone, D. D'Angelo, PL. Pallante, A. Ferraro.
Istituto di Endocrinologia ed Oncologia Sperimentale del CNR c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli “Federico II”, Naples, Italy.
MicroRNAs have emerged as an important class of short endogenous RNAs that act as post-transcriptional regulators of gene expression, and their expression is constantly deregulated in human cancer.
MiR-1 has been found downregulated in lung, colon and prostate cancer. The aim of our work has been to investigate the possible role of miR-1 in thyroid carcinogenesis. Therefore, we have analysed miR-1 expression in a panel of thyroid neoplasias including benign and malignant lesions. Our results show that miR-1 expression is drastically downregulated in thyroid adenomas and carcinomas in comparison with normal thyroid tissue. Interestingly, miR-1 downregulation was also found in thyroid hyperproliferative non neoplastic lesions such as goiters. These results suggested a general role of miR-1 downregulation in the control of thyroid cell proliferation. This suggestion was then confirmed by the drastic decrease in miR-1 expression following exposure of rat thyroid cells to thyrotropin (TSH), the physiological thyroid stimulator. Searching for miR-1 targets, we identified CREB1 transcriptional factor, that is the main effector of the TSH-induced thyroid cell growth, as miR-1 target, suggesting the presence of a regulatory synergistic loop including TSH, CREB1 and the miR-1. Moreover, we have demonstrated that also the CXCR4 protein and its ligand SDF1α, that are involved in cell migration and are constantly overexpressed in human thyroid carcinoma, are targets of miR-1. Functional studies demonstrate that miR-1 is able to inhibit thyroid carcinoma cell proliferation and migration validating a critical role of miR-1 downregulation in thyroid carcinogenesis.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 119. doi:10.1158/1538-7445.AM2011-119
Abstract 1190: Integration of mRNA and miRNA signatures induced by BRCA1 gene
Authors: Tanic Miljana , Zajac Magdalena , Gomez-Lopez Gonzalo , Benitez Javier , Martinez-Delgado Beatriz 
Published: June 2012

Abstract
During the past years it has been well established that microRNAs (miRNAs) modulate the activity of mRNAs. Microarray-based techniques are being useful to obtain miRNA and gene expression signatures associated to different samples. The aim of this study is to integrate data from both types of microarray experiments to obtain significant relationships between miRNA profile and gene expression signature associated to the absence or presence of BRCA1 gene in a cellular system. Whole genome transcriptional mRNA profiling and global miRNA expression profiling was performed on a BRCA1 deficient, HCC1937 breast cancer cell line, and the isogenic HCC1937 expressing BRCA1. We have related each differentially expressed miRNA and their miRanda predicted transcripts targets obtained from miRBase and TargetScan, to find consistent pairs of downregulated targets for upregulated miRNAs and viceversa, which were non randomly associated (Fisher, FDR&lt;0.05).
In our study we found over 8000 differentially expressed genes and 9 differentially expressed miRNAs between HCC1937 and HCC1937/BRCA1 cells (FDR p&lt;0.05). Integration of these data revealed significant interactions between three differentially upregulated microRNAs and their downregulated targets. Moreover, we have evaluated the role of these experimentally consistent pairs at the biological pathways level (Ingenuity Pathway Analysis). We identified potential signaling pathways significantly repressed associated with miRNA upregulation in BRCA1-expressing HCC1937 cells, which included MAPK or NFκB pathway. Down regulation of these pathways was experimentally validated by luciferase assays.
Integration analysis between miRNA-mRNA data allows us to define genes and pathways controlled by differentially expressed miRNA upon BRCA1 expression.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1190. doi:10.1158/1538-7445.AM2011-1190
Abstract 1196: FZD7 plays a critical role in triple negative breast cancer proliferation
Authors: Yang Lixin , Wu Xiwei , Deng Xutao , Lau Sean , Somlo George , Yen Yun 
Published: June 2012

Abstract
Breast cancer is genetically and clinically heterogeneous. Triple negative cancer is a subtype of breast cancer, most of which is associated with poor outcome and the lack of benefit from target therapy. A pathway analysis in a microarray study was performed using triple negative breast tumor cells compared with non-triple negative breast tumor cells. Overexpression among several Wnt pathway genes, such as FZD7, LRP6 and TCF7 has been observed in triple negative breast tumors. To validate their function, inhibition of FZD7 using FZD7-shRNA was carried out. Noticeably decreased cell proliferation, suppressed invasiveness and colony formation in triple negative MDA-MB-231 and BT-20 cells were observed. Mechanism study indicated that these effects occurred through silencing the canonical Wnt signaling pathway, as evidenced by loss of nuclear accumulation of β-catenin and decreased transcriptional activity of TCF7. Our finding suggests that FZD7 involved canonical Wnt signaling pathway is essential for tumorigenesis of triple negative breast tumor. Thus, FZD7 may be a biomarker and a potential therapeutic target for triple negative breast cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1196. doi:10.1158/1538-7445.AM2011-1196
Abstract 1199: Implications of protein kinase C (PKC)α and PKCΔ on murine mammary tumor growth and metastatic dissemination; effect of retinoids
Authors: Berardi Damian E. , Bessone María Inés Díaz , Campodónico Paola B. , Motter Andrea , Bal de Kier Joffé Elisa D. , Urtreger Alejandro J. , Todaro Laura B. 
Published: June 2012

Abstract
The retinoid system exerts some of its effects on cell differentiation and malignant phenotype reversion through the interaction of its receptors (RAR) with different PKC isoforms.
In this work, using a murine mammary tumor cell line (LM3), we studied the interaction between RARs and PKC in vitro as well as whether the overexpression of α and Δ PKC isoforms could influence the effect of retinoids on cell proliferation both in vivo and in vitro.
Western blot assays showed that the pharmacological inhibition of PKCΔ (Rottlerin 5μM, 24h) impaired all trans retinoic acid (ATRA)-induced RARα1 translocation to the nucleus while the pharmacological inhibition of PKCα (Gö6976 5μM, 24h) did not affect this translocation. Moreover, immunoprecipitation assays showed that only PKCΔ co-immunoprecipitated with RARα1 after ATRA treatment, suggesting a physical interaction between both molecules. However, both PKC isoforms seemed to be necessary for RARs activation as determined by a gene reporter assay.
Next, by a stable transfection procedure, we overexpressed PKCα and PKCΔ in LM3 cell line. In vitro assays showed that LM3-PKCα cells presented the highest proliferative rate and were highly responsive to ATRA treatment reducing their growth capability. These genetically modified lines were also inoculated orthotopically into the mammary glands of female BALB/c mice. Ten days later, when tumors were palpable, mice were implanted with ATRA pellets (10 mg/mouse). Tumors overexpressing PKCα presented a higher growth rate and were more metastatic than control vector-transfected LM3 cells, but showed a significant response to ATRA treatment, impairing primary tumor growth and reducing lung metastases number [Md (range) 55 (20-75) vs. 16 (0-27) in non-treated and ATRA-treated LM3-PKCα cells respectively (P&lt;0.05 Mann-Whitney test)]. Both control and PKCΔ overexpressing tumors were unresponsive to retinoid treatment.We can conclude that, while PKCα overexpressing cells were more aggressive than control ones, they showed an important response to retinoid treatment both in vivo and in vitro, indicating that a retinoid therapy could be successful in human mammary tumors with high PKCα levels. On the other hand, while we found an in vitro clear interaction between PKCΔ and RARα1, the overexpression of PKCΔ did not to modulate their response to the retinoid therapy.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1199. doi:10.1158/1538-7445.AM2011-1199