Cell-free Circulating miRNA Biomarkers in Cancer.

Considerable attention and an enormous amount of resources have been dedicated to cancer biomarker discovery and validation. However, there are still a limited number of useful biomarkers available for clinical use. An ideal biomarker should be easily assayed with minimally invasive medical procedures but possess high sensitivity and specificity. Commonly used circulating biomarkers are proteins in serum, most of which require labor-intensive analysis hindered by low sensitivity in early tumor detection. Since the deregulation of microRNA (miRNA) is associated with cancer development and progression, profiling of circulating miRNAs has been used in a number of studies to identify novel minimally invasive miRNA biomarkers. In this review, we discuss the origin of the circulating cell-free miRNAs and their carriers in blood. We summarize the clinical use and function of potentially promising miRNA biomarkers in a variety of different cancers, along with their downstream target genes in tumor initiation and development. Additionally, we analyze some technical challenges in applying miRNA biomarkers to clinical practice

implications for health and disease

Many aspects of human physiology and behavior display rhythmicity with a period of approximately 24 h. Rhythmic changes are controlled by an endogenous time keeper, the circadian clock, and include sleep-wake cycles, physical and mental performance capability, blood pressure, and body temperature. Consequently, many diseases, such as metabolic, sleep, autoimmune and mental disorders and cancer, are connected to the circadian rhythm. The development of therapies that take circadian biology into account is thus a promising strategy to improve treatments of diverse disorders, ranging from allergic syndromes to cancer. Circadian alteration of body functions and behavior are, at the molecular level, controlled and mediated by widespread changes in gene expression that happen in anticipation of predictably changing requirements during the day. At the core of the molecular clockwork is a well-studied transcription-translation negative feedback loop. However, evidence is emerging that additional post-transcriptional, RNA-based mechanisms are required to maintain proper clock function. Here, we will discuss recent work implicating regulated mRNA stability, translation and alternative splicing in the control of the mammalian circadian clock, and its role in health and disease

miR-638 mediated regulation of BRCA1 affects DNA repair and sensitivity to UV and cisplatin in triple negative breast cancer

Introduction Triple-negative breast cancer (TNBC) represents 15 to 20% of all types of breast cancer; however, it accounts for a large number of metastatic cases and deaths, and there is still no effective treatment. The deregulation of microRNAs (miRNAs) in breast cancer has been widely reported. We previously identified that miR-638 was one of the most deregulated miRNAs in breast cancer progression. Bioinformatics analysis revealed that miR-638 directly targets BRCA1. The aim of this study was to investigate the role of miR-638 in breast cancer prognosis and treatment. Methods Formalin-fixed, paraffin-embedded (FFPE) breast cancer samples were microdissected into normal epithelial and invasive ductal carcinoma (IDC) cells, and total RNA was isolated. Several breast cancer cell lines were used for the functional analysis. miR-638 target genes were identified by TARGETSCAN-VERT 6.2 and miRanda. The expression of miR-638 and its target genes was analyzed by real-time qRT-PCR and Western blotting. Dual-luciferase reporter assay was employed to confirm the specificity of miR-638 target genes. The biological function of miR-638 was analyzed by MTT chemosensitivity, matrigel invasion and host cell reactivation assays. Results The expression of miR-638 was decreased in IDC tissue samples compared to their adjacent normal controls. The decreased miR-638 expression was more prevalent in non-TNBC compared with TNBC cases. miR-638 expression was significantly downregulated in breast cancer cell lines compared to the immortalized MCF-10A epithelial cells. BRCA1 was predicted as one of the direct targets of miR-638, which was subsequently confirmed by dual-luciferase reporter assay. Forced expression of miR-638 resulted in a significantly reduced proliferation rate as well as decreased invasive ability in TNBC cells. Furthermore, miR-638 overexpression increased sensitivity to DNA-damaging agents, ultraviolet (UV) and cisplatin, but not to 5-fluorouracil (5-FU) and epirubicin exposure in TNBC cells. Host cell reactivation assays showed that miR-638 reduced DNA repair capability in post UV/cisplatin-exposed TNBC cells. The reduced proliferation, invasive ability, and DNA repair capabilities are associated with downregulated BRCA1 expression. Conclusions Our findings suggest that miR-638 plays an important role in TNBC progression via BRCA1deregulation. Therefore, miR-638 might serve as a potential prognostic biomarker and therapeutic target for breast cancer

miR-671-5p inhibits epithelial-to-mesenchymal transition by downregulating FOXM1 expression in breast cancer.

MicroRNA (miRNA) dysfunction is associated with a variety of human diseases, including cancer. Our previous study showed that miR-671-5p was deregulated throughout breast cancer progression. Here, we report for the first time that miR-671-5p is a tumor-suppressor miRNA in breast tumorigenesis. We found that expression of miR-671-5p was decreased significantly in invasive ductal carcinoma (IDC) compared to normal in microdissected formalin-fixed, paraffin-embedded (FFPE) tissues. Forkhead Box M1 (FOXM1), an oncogenic transcription factor, was predicted as one of the direct targets of miR-671-5p, which was subsequently confirmed by luciferase assays. Forced expression of miR-671-5p in breast cancer cell lines downregulated FOXM1 expression, and attenuated the proliferation and invasion in breast cancer cell lines. Notably, overexpression of miR-671-5p resulted in a shift from epithelial-to-mesenchymal transition (EMT) to mesenchymal-to-epithelial transition (MET) phenotypes in MDA-MB-231 breast cancer cells and induced S-phase arrest. Moreover, miR-671-5p sensitized breast cancer cells to cisplatin, 5-fluorouracil (5-FU) and epirubicin exposure. Host cell reactivation (HCR) assays showed that miR-671-5p reduces DNA repair capability in post-drug exposed breast cancer cells. cDNA microarray data revealed that differentially expressed genes when miR-671-5p was transfected are associated with cell proliferation, invasion, cell cycle, and EMT. These data indicate that miR-671-5p functions as a tumor suppressor miRNA in breast cancer by directly targeting FOXM1. Hence, miR-671-5p may serve as a novel therapeutic target for breast cancer management

Role of deregulated microRNAs in breast cancer progression Using FFPE tissue

MicroRNAs (miRNAs) contribute to cancer initiation and progression by silencing the expression of their target genes, causing either mRNA molecule degradation or translational inhibition. Intraductal epithelial proliferations of the breast are histologically and clinically classified into normal, atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). To better understand the progression of ductal breast cancer development, we attempt to identify deregulated miRNAs in this process using Formalin-Fixed, Paraffin-Embedded (FFPE) tissues from breast cancer patients. Following tissue microdissection, we obtained 8 normal, 4 ADH, 6 DCIS and 7 IDC samples, which were subject to RNA isolation and miRNA expression profiling analysis. We found that miR-21, miR-200b/c, miR-141, and miR-183 were consistently up-regulated in ADH, DCIS and IDC compared to normal, while miR-557 was uniquely down-regulated in DCIS. Interestingly, the most significant miRNA deregulations occurred during the transition from normal to ADH. However, the data did not reveal a step-wise miRNA alteration among discrete steps along tumor progression, which is in accordance with previous reports of mRNA profiling of different stages of breast cancer. Furthermore, the expression of MSH2 and SMAD7, two important molecules involving TGF-β pathway, was restored following miR-21 knockdown in both MCF-7 and Hs578T breast cancer cells. In this study, we have not only identified a number of potential candidate miRNAs for breast cancer, but also found that deregulation of miRNA expression during breast tumorigenesis might be an early event since it occurred significantly during normal to ADH transition. Consequently, we have demonstrated the feasibility of miRNA expression profiling analysis using archived FFPE tissues, typically with rich clinical information, as a means of miRNA biomarker discovery

Surficial geologic map of the Des Moines Lobe of Iowa, Phase 5: Polk County

https://ir.uiowa.edu/igs_ofm/1030/thumbnail.jp

Cell-free Circulating miRNA Biomarkers in Cancer

Considerable attention and an enormous amount of resources have been dedicated to cancer biomarker discovery and validation. However, there are still a limited number of useful biomarkers available for clinical use. An ideal biomarker should be easily assayed with minimally invasive medical procedures but possess high sensitivity and specificity. Commonly used circulating biomarkers are proteins in serum, most of which require labor-intensive analysis hindered by low sensitivity in early tumor detection. Since the deregulation of microRNA (miRNA) is associated with cancer development and progression, profiling of circulating miRNAs has been used in a number of studies to identify novel minimally invasive miRNA biomarkers. In this review, we discuss the origin of the circulating cell-free miRNAs and their carriers in blood. We summarize the clinical use and function of potentially promising miRNA biomarkers in a variety of different cancers, along with their downstream target genes in tumor initiation and development. Additionally, we analyze some technical challenges in applying miRNA biomarkers to clinical practice.</p

Engineering a biomimetic three-dimensional nanostructured bone model for breast cancer bone metastasis study.

Traditional breast cancer (BrCa) bone metastasis models contain many limitations with regards to controllability, reproducibility and flexibility of design. In this study, a novel biomimetic bone microenvironment was created by integrating hydroxyapatite (HA) and native bioactive factors deposited by osteogenic induction of human bone marrow mesenchymal stem cells (MSCs) within a cytocompatible chitosan hydrogel. It was found that a 10% nanocrystalline HA (nHA) chitosan scaffold exhibited the highest BrCa adhesion and proliferation when compared to chitosan scaffolds with 20% nHA, 10% and 20% microcrystalline HA as well as amorphous HA. This 3-D tunable bone scaffold can provide a biologically relevant environment, increase cell-cell and cell-matrix interactions as found in native bone, and retain the behavior of BrCa cells with different metastasis potential (i.e. highly metastatic MDA-MB-231, less metastatic MCF-7 and transfected MDA-MB-231). The co-culture of MSCs and MDA-MB-231 in this bone model illustrated that MSCs have the capacity to upregulate the expression of the well-known metastasis-associated gene metadherin within BrCa cells. In summary, this study illustrates the ability of our 3-D bone model to create a biomimetic environment conducive to recapitulating the behavior of metastatic BrCa cells, making it a promising tool for in vitro BrCa cell bone metastasis study and for the discovery of potential therapeutics

Genome-wide analysis of BP1 transcriptional targets in breast cancer cell line Hs578T

Homeobox genes are known to be critically important in tumor development and progression. The BP1 (Beta Protein 1) gene, an isoform of DLX4, belongs to the Distal-less (DLX) subfamily of homeobox genes and encodes a homeodomain-containing transcription factor. Our studies have shown that the BP1 gene was overexpressed in 81% of primary breast cancer and its expression was closely correlated with the progression of breast cancer. However, the exact role of BP1 in breast has yet to be elucidated. Therefore, it is important to explore the potential transcriptional targets of BP1 via whole genome-scale screening. In this study, we used the chromatin immunoprecipitation on chip (ChIP-on-chip) and gene expression microarray assays to identify candidate target genes and gene networks, which are directly regulated by BP1 in ER negative (ER-) breast cancer cells. After rigorous bioinformatic and statistical analysis for both ChIP-on-chip and expression microarray gene lists, 18 overlapping genes were noted and verified. Those potential target genes are involved in a variety of tumorigenic pathways, which sheds light on the functional mechanisms of BP1 in breast cancer development and progression. © Ivyspring International Publisher. All rights reserved