bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2021: MicroRNA affinity assay
Authors: Shi Miao , Han Weiguo , Spivack Simon 
Published: February 2011

Abstract
Introduction: MicroRNAs (miRNAs) are small noncoding RNAs functioning in gene regulation. In animal cells, miRNAs bind to target sites in the 3’ UTR of mRNAs, causing posttranscriptional repression or degradation of mRNAs. The identification of specific miRNAs to target a 3′UTR of a given gene is essential for studies in gene regulation. However, the sequence software programs conventionally used to predict binding of individual microRNAs to a given mRNA transcript are notoriously unreliable, and specific microRNA-mRNA binding is very difficult to directly affirm using currently available techniques. We have developed a microRNA affinity assay that addresses this need. Methods: We chose a candidate gene that had been extensively studied experimentally for microRNA regulation; it is known that miR-200c and miR-200b can bind to 3′UTR RNA of TCF8 [Hurteau 2007]. Here, a 500bp fragment of the 3′UTR RNA of TCF8 was generated by IVT, and used as a bait sequence to identify miRNAs that bind a mixture of known miRNA composition, and alternately a naturally produced cellular miRNA pool. After separation, miRNA qPCR was used to check recovery rate of miRNA, and cloning and sequencing was used to identify miRNAs. Results: Specific miRNAs from a synthetic mixture miRNAs, miRNA qPCR results displayed excellent recovery rates (151.57% with pipetting error, for miR-200c), 88.88% for the closely related miR-200b, 0.31% for the sequence-unrelated miR-9, 0.67% (miR-10a), 0.1% (miR-20a), 8.78% (miR-34a with some 3′UTR homology), 0.11% (miR-100), 0.16% (miR-140-5p), 0.98% (miR-144), 0.33% (miR-802) and 1.58% (miR-1234). After cloning the captured miRNAs, there were 10 sequences from miR-200c, 7 sequences from miR-200b, and one other sequence in 18 sequenced clones. When separating specific miRNAs from naturally produced NHBE cell miRNA pool, miRNA qPCR results show that their recovery rates are 88.88% (miR-200c), 80% (miR-200b), 0.07% (miR-20a), less than 0.006% (miR-34a) and 0.01% (miR-100). Conclusions: For both simple known and complex unknown microRNA pools, this pull-down strategy is effective in determining microRNA-mRNA binding. In future work, we will use other 3′UTR RNA sequences of candidate genes as bait sequence, for microRNA-related discovery and confirmation.
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 2021.
Abstract 2025: Let-7 family miRNAs regulate estrogen signaling pathways mediated by ER alpha-66 and ER alpha-36 in breast cancer
Authors: Zhao Yingchun , Deng Caishu , Wang Jiarui , Xiao Jing , Zhang Hongwei , Gatalica Zoran , Recker Robert , Xiao Gary G. 
Published: February 2011

Abstract
To understand how microRNAs (miRNAs) regulate breast cancer tumorigenesis, a miRNA expression microarray screening was performed using RNAs from formalin-fixed paraffin-embedded (FFPE) breast tissues, which included benign (n=13), ductal carcinoma in situ (DCIS) (n=16), and invasive ductal carcinoma (IDC) (n=15). Twenty miRNAs that were differentially expressed (p&lt;0.01) were identified, of which let-7 family miRNAs were down-regulated in human breast cancer tissues at stages of DCIS and IDC compared to benign stage. To understand the role of let-7 miRNAs further, we performed bioinformatics analysis and found that let-7 miRNA sequences match sequences in the 3’-UTRs of estrogen receptor alpha 66 (ER-α66) and another novel receptor ER-α36. The targeting of let-7 miRNAs on ER-α66 and ER-α36 was further confirmed by a number of experimental assays, including luciferase assay, protein expression, and mRNA expression. Overexpression of let-7 miRNAs in ER-α66-positive breast cancer MCF7 cell line negatively affected ER-α66 mediated genomic estrogen pathway. As expected, down-regulation of the ER-α66 signaling by let-7 miRNAs inhibited cell proliferation, and subsequently triggered the cell apoptotic process in MCF7 cells. On the other hand, overexpression of let-7 miRNAs in ER-α66-negative cell line MB-MDA-231 negatively affected ER-α36 mediated non-genomic estrogen pathway. Besides, down-regulation of let-7 is correlated with up-regulation of ER-α36 in tamoxifen (Tam) and ICI-182780 (ICI) resistance in MCF7 cell line. Forced overexpression in Tam-and ICI-resistant MCF7 cells dampened ER-α36 expression. In conclusion, our findings not only indicate a new regulatory mechanism of let-7 miRNAs in ER mediated cellular malignant growth of breast cancer, and but also provide potential biomarkers and/or surrogate therapeutic targets useful for early diagnosis and/or therapeutic options for breast 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 2025.
Abstract 2026: MicroRNA-214 is a negative regulator of p53
Authors: Yang Hua , Kong William , Williams Kendra , He Lili , Cheng Jin Q. 
Published: February 2011

Abstract
The p53 transcription factor mediates multiple cellular functions including the response to genotoxic stress, differentiation, cell cycle and apoptosis. Since p53 inactivation is a critical event in tumor development, the regulation of p53 and its pathway is of prime importance in the understanding of tumorigenesis. While a number of microRNAs have been shown to be regulated by p53, microRNA regulation of p53 is still not well documented. Here we demonstrate that miR-214, a putative oncogenic miRNA, regulates p53 protein but not mRNA level by direct targeting 3′UTR of p53. Ectopic expression of miR-214 represses p53 and enhances the resistance to radiation- or chemotherapeutic agent-induced cell cycle arrest and apoptosis in wild-type but not mutated p53 cells. Introduction of p53 cDNA lacking 3′UTR largely abrogates miR-214-induced cell growth and survival. Depletion of endogenous miR-214 elevates protein level of p53 and induces apoptosis in human cancer cell lines expressing wild-type p53. These findings indicate that miR-214 is an important posttranscriptional regulator of p53 and exerts its oncogenic activity through targeting p53.
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 2026.
Abstract 2032: MicroRNA control of tumor cell plasticity in a new tumor metastasis model
Authors: Banyard Jacqueline , Wilson Arianne M. , Bielenberg Diane R. , Zetter Bruce R. 
Published: February 2011

Abstract
We have developed a new prostate cancer model to discover the molecular changes underlying metastasis. A series of cell lines were developed by isolating metastatic cells from lymph nodes of nude mice following orthotopic injection of DU145 human prostate cancer cells and expression changes analyzed using gene chips. We found that these DU145-LN cells exhibit a mesenchymal-epithelial transition (MET). Repeated rounds of in vivo metastatic selection progressively increased the expression of epithelial markers including E-cadherin, cytokeratin-18 and EpCAM, and decreased mesenchymal markers such as vimentin. Despite being more epithelial, DU145-LN cells are more migratory and show reduced proliferation in vitro. However, they show increased tumorigenesis when reinjected into nude mice. Interestingly, clinical metastases are frequently epithelial, despite strong evidence that EMT enhances metastasis. To explain this, current models of metastasis invoke EMT with subsequent MET at the secondary site. Our cells appear to demonstrate this plasticity making them an ideal model system for studying MET regulation.
The MET changes in the DU145-LN cells suggested a coordinated mechanism of regulation. MicroRNA arrays revealed several candidates which correlated with the epithelial phenotype. DU145-LN cells showed increased expression of the miR-200 family (a, b, c and miR-141), and treatment with synthetic miR-200 inhibitors resulted in reduced cell-cell interactions and decreased E-cadherin levels. Our data complement recent evidence showing down-regulation of miR-200 by EMT. miR-200 acts in a feedback loop with the transcription factor ZEB1 to regulate EMT. We also observed significantly reduced expression of an additional microRNA not previously linked to cell morphology in the DU145-LN cells. Transfection of precursor miRNA to this target altered the epithelial morphology and reduced E-cadherin levels, suggesting an additional pathway of MET/EMT control. We are currently determining the mechanism of action of this new microRNA target.
Our data support a role for MET in tumor metastasis, and indicate that microRNAs are an important mechanism mediating tumor cell plasticity and EMT/MET.
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 2032.
Abstract 2035: The levels of miR-145 are regulated by DNA methylation and p53 gene status in prostate cancer
Authors: Suh Seong O , Zaman Mohd Saif , Shahryari Varahram , Chen Yi , Liu Jan , Tabatabai Z. Laura , Kakar Sanjay , Deng Guoren , Dahiya Rajvir 
Published: February 2011

Abstract
MiR-145 is down-regulated in various cancers. However, the regulation of miR-145 and its role in the prostate cancer is not known. We analyzed the expression of miR-145 in microdissected prostate cancers and adjacent normal prostate tissues. In 17 of 21 (81%) prostate cancers, the levels of miR-145 (measured by qRT-PCR) were significantly lower than those in the adjacent normal tissues. Down-regulated miR-145 levels correlated with DNA methylation (identified by methylation-specific PCR and sequencing) in the upstream region of miR-145, indicating that methylation may be involved in its regulation. The levels of miR-145 were also measured in 49 cancer cell lines, including 4 prostate cancer, 3 kidney cancer, 11 breast cancer, 23 colorectal cancer and 8 pancreatic cancer cell lines. In cancer cell lines, the down-regulation of miR-145 was also significantly correlated with its methylation. In seven cancer cell lines (3 prostate cancer, 2 kidney cancer and 2 colorectal cancer cell lines) with methylated miR-145, treatment with the demethylation agent, 5-aza-deoxycytidine significantly induced miR-145 expression. We also found a significant correlation between miR-145 expression and the status of the p53 gene in 49 cancer cell lines. In 31 cell lines with a p53 gene mutation, miR-145 levels were low in 30 cell lines (97%) while in 18 cell lines with wild type p53, miR-145 levels were low in only 6 cell lines (33%, p&lt;0.001). There is a potential p53 protein binding site upstream of miR-145 flanked by methylated CpG sites. The binding ability of wild type and mutant p53 to this site with or without methylation, and the effects on the expression of miR-145 were tested by electrophoretic mobility shift assay (EMSA) and luciferase assay. In summary, this is the first report on miR-145 regulation by p53 mutation and DNA hypermathylation in prostate 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 2035.
Abstract 2038: miR-149* induces apoptosis by inhibiting Akt1 and E2F1 in human cancer cells
Authors: Lin Ruey-Jen , Lin You-Chin , Yu Alice L. 
Published: February 2011

Abstract
microRNAs (miRNAs) play vital roles in several biological processes, including apoptosis, by negatively regulating the expression of target genes. The molecular mechanisms of the key survival signal, Akt family, have been extensively investigated, but whether is regulated by miRNA remains unknown. In a recent study of neuroblastoma samples, we found the expression of miR-149 to be lower in the high-risk group than the low- and intermediate-risk groups. Upon transfection of Be2C, a neuroblastoma cell line and HeLa cells with miR-149 oligo, no changes in cell growth were observed. On the other hand, ectopic expression of miR-149*, the cognate miRNA of miR-149, inhibited the growth and induced apoptosis in these two cancer cell lines. By TargetScan screening, Akt1, the predominant Akt isoform in most tissue, E2F1, and b-Myb were predicted as possible target genes of miR-149*. In Be2C and HeLa cells transfected with miR-149* oligo, reduced expressions of Akt1, E2F1, and b-Myb at protein level were detected by Western blotting, and decreased mRNA levels of Akt1 and E2F1 were also noted by RT-qPCR. Using luciferase reporter assay, the target sites were verified in the 3′UTRs of Akt1 and E2F1, but not in b-Myb, suggesting that Akt1 and E2F1 were the direct target and b-Myb was an indirect target of miR-149*. Silencing of Akt1 or E2F1 expression also led to similar apoptotic changes as miR-149* transfection in these two cell lines, suggesting that the pro-apoptotic effects of miR-149* was exerted at least in part by repressing Akt1 and E2F1 expressions. Importantly, analysis of primary neuroblastoma samples (n=56) revealed a significant inverse correlation of miR-149* with E2F1 expressions (p=0.026). Furthermore in stage1 samples, the mean expression level of miR-149* was significantly higher than in stage 2/3 (p&lt;0.05), and that of E2F1 appeared to be lower. The results provide further support of an important role of miiR-149* in regulation of E2F1, especially in stage1 neuroblastoma tumors. Interestingly, using the reporter assays, excess miR-149 introduced by transfection to simulated its preponderance in the in vivo condition, could not overcome the repressive function of miR-149* on the target genes. This implies that the pro-apoptotic function of miR-149* may not be dampened by its predominant cognate, miR-149, in vivo. Our findings not only provided the first evidence that Akt1 is a direct target of a miRNA but also demonstrated that miR-149* is a pro-apoptotic miRNA by repressing the expression of Akt1 and E2F1.
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 2038.
Abstract 2044: Altered microRNA expression induced by tumorigenic conazoles in mouse liver
Authors: Ross Jeffrey A. , Blackman Carl F. , Thai Sheau-Fung , Li Zhiquan , Kohan Michael , Jones Carlton P. , Chen Tao 
Published: February 2011

Abstract
Triadimefon, propiconazole, and myclobutanil are conazoles, an important class of agricultural and therapeutic fungicides. Triadimefon and propiconazole are mouse liver tumorigens, while myclobutanil is not. As part of a coordinated study to understand the molecular determinants of conazole tumorigenicity, we analyzed the microRNA expression levels in control and conazole treated mice after 90 days of administration in feed. Groups of mice were fed either control diet or diet containing 1800 p.p.m. triadimefon, 2500 p.p.m. propiconazole or 2000 p.p.m. myclobutanil. MicroRNA was isolated from livers and analyzed using Superarray whole mouse genome miRNA PCR arrays from SABioscience. Data were analyzed using the Significance Analysis of Microarrays (SAM) procedure. We identified those miRNAs whose expression was either increased or decreased relative to untreated controls with q ≤ 0.01. The tumorigenic conazoles induced many more changes in miRNA expression than the non-tumorigenic conazole. A group of 19 miRNAs was identified whose expression was significantly altered in both triadimefon and propiconazole treated animals but not in myclobutanil treated animals. All but one of the altered miRNAs were downregulated compared to controls. The greatest fold-changes in miRNA expression were observed for mmu-mir-135b and mmu-mir-684. Among the putative targets of the miRNAs altered by tumorigenic conazoles are genes involved in regulation of apoptosis and cell proliferation. This abstract does not reflect US EPA policy.
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 2044.
Abstract 2049: Post transcriptional regulation of RhoB expression
Authors: Glorian Valerie , Maillot Gerard , Poles Sophie , Favre Gilles , Vagner Stephan 
Published: February 2011

Abstract
Rho GTPases contribute to most steps of cancer initiation and progression, including the acquisition of unlimited proliferation potential, survival, tissue invasion and the establishment of metastases. By contrast to RhoA and RhoC, RhoB has been proposed to act as a tumor suppressor as it is activated in response to various stresses including UV exposure, and since it has been reported to inhibit tumor growth, cell migration and invasion. Unlike RhoA and RhoC, RhoB is often down regulated in human tumour tissues including lung and head and neck cancer and its expression is inversely correlated with tumor aggressiveness. However, the epigenetic regulation of RhoB expression in cancer cells remains to be elucidated. Since several recent works demonstrate that post-transcriptional deregulation of gene expression is involved in carcinogenesis, we have investigated the post-transcriptional regulation of RhoB expression. The RhoB 3’ untranslated region is well conserved between species and has numerous putative binding sites for post-transcriptional regulators such as mRNA binding proteins and microRNAs. By using luciferase assays and polysome analysis, we have found that the translation of the RhoB mRNA is regulated upon UV exposure. One specific miRNA, miR-19b whose expression is regulated by UV, directly targets the RhoB mRNA to control RhoB expression and UV-induced apoptosis. Interestingly, other post-transcriptionnal regulators involved in RhoB expression, such as the mRNA binding proteins HuR and TiaR were also indentified by functional assays using RNA interference strategy. Immunohistochemical analysis on a cohort of human lung tissues ranging from normal to invasive carcinoma are underway to detect a possible correlation between the expression of these proteins and RhoB downregulation in tumor.
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 2049.
Abstract 205: Bortezomib and paclitaxel synergistically induce apoptosis in chronic myelogenous leukemia cells
Authors: Bucur Octavian , Stancu Andreea L. , Petrescu Stefana M. , Khosravi-Far Roya 
Published: February 2011

Abstract
Bcr-Abl fusion protein plays a critical role in the pathogenesis and progression of Chronic Myelogenous Leukemia (CML) and in some of the Acute Lymphocytic Leukemia (ALL) cases. Current inhibitors of Abl kinases, such as Imatinib, have shown great promise in the treatment of CML, however, the emergence of the resistance and the persistence of the residual disease have underlined the importance of finding new ways of treatment CML and especially of the resistant forms of CML. We and others have previously shown that Bortezomib (FDA approved for the treatment of Multiple Myeloma), a selective proteasome inhibitor, efficiently induces apoptosis in Imatinib resistant Bcr-Abl T315I cells, and established Bortezomib as a potential important treatment in Bcr-Abl positive leukemias, determining the initiation of at least five different clinical trials for the treatment of CML, alone or in combination.
We are further showing here that Bortezomib in combination with the mitotic inhibitor Paclitaxel act synergistically in inducing apoptosis in Bcr-Abl positive cells. Paclitaxel, a mitotic inhibitor drug (FDA approved drug for the treatment of lung, ovarian, breast, head and neck cancers, and advanced forms of Kaposi's sarcoma) is also now in clinical trials for the treatment of CML. However, to our knowledge, there are no clinical trials or other studies regarding the combined treatment of Bortezomib and Paclitaxel in Bcr-Abl positive CML.
RESULTS: Combined treatment of Bortezomib and Paclitaxel synergistically induces cell death in human Bcr-Abl positive K562 cell line, by activating the initiator caspase 9 and effector caspase 3, which leads to the cleavage of a number of substrates, such as Poly ADP Ribose Polymerase (PARP), and results in apoptosis. Additionally, the exposure of the Bcr-Abl positive leukemia cells to the Bortezomib/Paclitaxel regimen results in an increase in the activation of the stress-related MAP kinases (such as p38 MAPK and JNK) versus the cytoprotective kinases (ERK1, ERK2), suggesting a possible implication of JNK and p38 MAPK in mediating the effect of the combined treatment. Moreover, we also show that the combined treatment is effective in inducing apoptosis in the murine Baf3 Bcr-Abl and Imatinib resistant Baf3 Bcr-Abl T315I cell lines, suggesting a potential use of the regimen in Imatinib resistant forms of CML.
CONCLUSION: Taken together, these findings underline that the combined treatment with Bortezomib and Paclitaxel represents a potentially promising strategy for the treatment of Chronic Myelogenous Leukemia in general, and of Imatinib resistant CML in particular.
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 205.