The objective of this study, a parallel study to global gene expression profiling, was to identify dysregulated microRNAs (miRNAs) associated with endometrioid endometrial adenocarcinoma (EEC), examine their correlation with clinico‐pathological characteristics and identify predicted target genes of the dysregulated miRNAs. Using real‐time quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR), profiling of miRNA expression was performed in 30 EECs and 22 normal counterparts in which genome‐wide gene expression had been previously profiled and reported. Clustering analysis identified 30 miRNAs which were significantly dysregulated in EEC. The expression of a sub‐group of miRNAs was significantly correlated with clinico‐pathological characteristics including stage, myometrial invasion, recurrence and lymph node involvement. By searching for predicted miRNA targets that were linked to the dysregulated genes previously identified, 68 genes were predicted as candidate targets of these 30 dysregulated miRNAs. miR‐205 was significantly overexpressed in EECs compared with normal controls. After transfection of a miR‐205 inhibitor, the expression of miR‐205 in endometrial cancer cell line RL95‐2 cells decreased whereas its predicted target gene, JPH4, showed increased protein expression. JPH4 seems to be a real miR‐205 target in vitro and in vivo, and a candidate tumor suppressor gene in EEC. Based on this study in EEC, miRNAs predicted to be involved in tumorigenesis and tumor progression have been identified and placed in the context of the transcriptome of EEC. This work provides a framework on which further research into novel diagnosis and treatment of EEC can be focused. © 2008 Wiley‐Liss, Inc.

TXMicroRNAs (miRNAs) regulate mRNA stability and protein expression, and certain miRNAs have been demonstrated to act either as oncogenes or tumor suppressors. Differential miRNA expression signatures have been documented in many human cancers but the role of miRNAs in endometrioid endometrial cancer (EEC) remains poorly understood. This study identifies significantly dysregulated miRNAs of EEC cells, and characterizes their impact on the malignant phenotype. We studied the expression of 365 human miRNAs using Taqman low density arrays in EECs and normal endometriums. Candidate differentially expressed miRNAs were validated by quantitative real-time PCR. Expression of highly dysregulated miRNAs was examined in vitro through the effect of anti-/pre-miRNA transfection on the malignant phenotype. We identified 16 significantly dysregulated miRNAs in EEC and 7 of these are novel findings with respect to EEC. Antagonizing the function of miR-7, miR-194 and miR-449b, or overexpressing miR-204, repressed migration, invasion and extracellular matrix-adhesion in HEC1A endometrial cancer cells. FOXC1 was determined as a target gene of miR-204, and two binding sites in the 3 0 -untranslated region were validated by dual luciferase reporter assay. FOXC1 expression was inversely related to miR-204 expression in EEC. Functional analysis revealed the involvement of FOXC1 in migration and invasion of HEC1A cells. Our results present dysfunctional miRNAs in endometrial cancer and identify a crucial role for miR-204-FOXC1 interaction in endometrial cancer progression. This miRNA signature offers a potential biomarker for predicting EEC outcomes, and targeting of these cancer progression-and metastasis-related miRNAs offers a novel potential therapeutic strategy for the disease.Endometrial cancer is a common cause of gynecological cancer death. The most dominant subtype, endometrioid endometrial cancer (EEC), accounts for >80% of this cancer. Menopause and unopposed estrogenic stimulation are typical risk factors. Patients are generally treated with surgery, radiation, chemotherapy or hormone therapy. Patients with early stage disease have 5-year survival rates over 80%, however, about 15-20% develop metastasis. 1 These patients and those with advanced stage disease or recurrence have poor prognosis due to limitation of effective treatment. 2 Understanding the pathogenesis of this disease may provide insights for the development of novel therapeutic strategies.MicroRNAs (miRNAs) are small noncoding RNA molecules of 19-24 nucleotides that regulate gene expression posttranscriptionally through imperfect base pairing with the 3 0 -untranslated region (3 0 UTR) of target mRNAs, causing transcript degradation and translational inhibition. 3 Approximately 20-30% of all genes are targeted by miRNAs and a single miRNA may target as many as 200 genes. 4 In human cancers, >50% of the miRNA genes are located in chromosomal fragile sites, minimal regions containing loss of heterozygosity, minimal amplicons or common breakpoint regions. 5 DNA ...

MicroRNAs (miRNAs) play an important role in a variety of physiological as well as pathophysiological processes, including carcinogenesis. The aim of this study is to identify a distinct miRNA expression signature for cervical intraepithelial neoplasia (CIN) and to unveil individual miRNAs that may be involved in the development of cervical carcinoma. Expression profiling using quantitative real-time RT-PCR of 202 miRNAs was performed on micro-dissected high-grade CIN (CIN 2/3) tissues and compared to normal cervical epithelium. Unsupervised hierarchical clustering of the miRNA expression pattern displayed a distinct separation between the CIN and normal cervical epithelium samples. Supervised analysis identified 12 highly differentially regulated miRNAs, including miR-518a, miR-34b, miR-34c, miR-20b, miR-338, miR-9, miR-512-5p, miR-424, miR-345, miR-10a, miR-193b and miR-203, which distinguished the high-grade CIN specimens from normal cervical epithelium. This miRNA signature was further validated by an independent set of high-grade CIN cases. The same characteristic signature can also be used to distinguish cervical squamous cell carcinoma from normal controls. Target prediction analysis revealed that these dysregulated miRNAs mainly control apoptosis signaling pathways and cell cycle regulation. These findings contribute to understanding the role of microRNAs in the pathogenesis and progression of cervical neoplasm at the molecular level.

Alternative splicing (AS) allows increased diversity and orthogonal regulation of the transcriptional products of mammalian genomes. To assess the distribution and variation of alternative splicing across cell lineages of the immune system, we comprehensively analyzed RNA sequencing and microarray data generated by the Immunological Genome Project Consortium. AS is pervasive: 60% of genes showed frequent AS isoforms in T or B lymphocytes, with 7,599 previously unreported isoforms. Distinct cell specificity was observed, with differential exon skipping in 5% of genes otherwise coexpressed in both B and T cells. The distribution of isoforms was mostly all or none, suggesting on/off switching as a frequent mode of AS regulation in lymphocytes. From the identification of differential exon use in the microarray data, clustering of exon inclusion/exclusion patterns across all Immunological Genome Project cell types showed that ∼70% of AS exons are distributed along a common pattern linked to lineage differentiation and cell cycling. Other AS events distinguished myeloid from lymphoid cells or affected only a small set of exons without clear lineage specificity (e.g., Ptprc). Computational analysis predicted specific associations between AS exons and splicing regulators, which were verified by detection of the hnRPLL/ Ptprc connection.A lternative splicing (AS), the process of selectively including or removing exons to create a variety of transcripts from the same pre-mRNA, plays an important role in amplifying the diversity and flexibility of genome-encoded molecules (1, 2). AS can result in different protein isoforms or generate mRNAs of identical coding sequence but varying in their stability, localization, susceptibility to translational control, or microRNA regulation. AS is frequent and ubiquitous, affecting 55-95% of multiexon genes in mammals in different estimates (3-6). It is involved in a wide range of biological phenomena, ranging from sex determination to apoptosis or tumor formation. It also allows evolutionary tinkering with transcript structure and gradual transitions in gene function (7).Splicing events are overrepresented in genes involved in signaling and transcriptional regulation (receptors, signaling transduction, and transcription factors) and immune and nervous system processes. It has been hypothesized that alternative splicing is particularly valuable in complex systems, where information is processed differently at different times (immune response) or fine-tuning of signal integration is important (5). In the immune system, the first instance of AS recognized was the now textbook case of differential processing of primary Ig transcripts generating either a membrane receptor in naïve B cells or a secreted protein after antigen-induced differentiation (8). Other notable examples are the splicing of transcripts encoding adhesion molecules such as PECAM1 or CD44, which modulate cell-stroma interactions, or the extracellular domain of the coinhibitory molecule CTLA4 (9). A particularly well-studie...

Small interfering RNAs (siRNAs) are powerful RNA interference (RNAi) reagents for directed post- transcriptional gene silencing. Exogenous siRNA is frequently used in RNAi studies. However, due to profound differences in the activity of siRNAs targeted to different regions of a gene, several reagents may have to be screened for optimal activity. This approach is expensive due to the cost of chemical synthesis of RNAs. We report a technically simple, quick and cost-effective method for the production of siRNAs that makes use of in vitro transcription and deoxyribozyme digestion of the transcripts to produce the desired sequence and length. The method allows for several siRNAs to be produced in parallel at much reduced costs. The siRNAs produced with this method were tested in MDA-MB-231 human breast cancer cells for efficacy against the type 1 insulin-like growth factor receptor (IGF1R) mRNA and they caused dose-dependent inhibition of IGF1R expression comparable to that induced by chemically synthesised siRNAs of the same sequence. This method is also useful for producing long RNA fragments of defined length and sequence that may be difficult to synthesise chemically, and also for producing large quantities of RNAs for applications including structural studies and the study of interactions between RNA and other molecules, such as proteins, other nucleic acids and drugs.