Background & Aims: Micro-RNA (miRNA) are endogenous regulatory RNA molecules that modulate gene expression. Alterations in miRNA expression can contribute to tumor growth by modulating the functional expression of critical genes involved in tumor cell proliferation or survival. Our aims were to identify specific miRNA involved in the regulation of cholangiocarcinoma growth and response to chemotherapy.

Methods: miRNA expression in malignant and nonmalignant human cholangiocytes was assessed using a microarray. Expression of selected miRNA and their precursors was evaluated by Northern blots and real-time polymerase chain reaction, respectively. The effect of selected miRNA on cell growth and response to chemotherapy was assessed using miRNA-specific antisense oligonucleotides to decrease miRNA expression or with precursor miRNA to increase cellular expression.

Results: miRNA expression was markedly different in malignant cholangiocytes, with decreased expression of many miRNA compared with nonmalignant cells. A cluster of miRNA, including miR-320, miR-200b, miR-21, miR-23a, miR-141, miR-27a, and miR-34a, were expressed in all cell lines. MiR-21, miR-141, and miR-200b were highly over-expressed in malignant cholangiocytes. Inhibition of miR-21 and miR-200b increased sensitivity to gemcitabine, whereas inhibition of miR-141 decreased cell growth. Treatment of tumor cell xenografts with systemic gemcitabine altered the expression of a significant number of miRNA. miR-21 modulates gemcitabine-induced apoptosis by phosphatase and tensin homolog deleted on chromosome 10 (PTEN)-dependent activation of PI 3-kinase signaling. Potential target genes that were modulated by selected miRNA were identified.

Conclusions: Alterations in miRNA expression contribute to tumor growth and response to chemotherapy. Aberrantly expressed miRNA or their targets will provide mechanistic insight and therapeutic targets for cholangiocarcinoma.

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.gastro.2006.02.057DOI Listing

Publication Analysis

Top Keywords

mirna expression
20
growth response
16
mirna
15
response chemotherapy
12
selected mirna
12
expression
10
cell lines
8
alterations mirna
8
expression contribute
8
contribute tumor
8

Similar Publications

Objectives: This study aimed to comprehensively investigate the molecular landscape of gastric cancer (GC) by integrating various bioinformatics tools and experimental validations.

Methodology: GSE79973 dataset, limma package, STRING, UALCAN, GEPIA, OncoDB, cBioPortal, DAVID, TISIDB, Gene Set Cancer Analysis (GSCA), tissue samples, RT-qPCR, and cell proliferation assay were employed in this study.

Results: Analysis of the GSE79973 dataset identified 300 differentially expressed genes (DEGs), from which COL1A1, COL1A2, CHN1, and FN1 emerged as pivotal hub genes using protein-protein interaction network analysis.

View Article and Find Full Text PDF

The purpose of this review was to analyse the literature regarding the correlation between the level of tryptamine, aryl hydrocarbon receptor (AHR) signalling pathway activation, and monoamine oxidase (MAO)-A and MAO-B activity in health and conditions such as neurodegenerative, neurodevelopmental, and psychiatric disorders. Tryptamine is generated through the decarboxylation of tryptophan by aromatic amino acid decarboxylase (AADC) in the central nervous system (CNS), peripheral nervous system (PNS), endocrine system, and gut bacteria. Organ-specific metabolism of tryptamine, which is mediated by different MAO isoforms, causes this trace amine to have different pharmacokinetics between the brain and periphery.

View Article and Find Full Text PDF

Introduction: Ovarian cancer is a significant cause of death among females. MiRNAs, particularly the miR-196 family, can influence tumor progression by targeting specific pathways. Detecting ovarian cancer early is challenging, highlighting the need for additional biomarkers such as miRNAs to improve diagnosis and treatment strategies.

View Article and Find Full Text PDF

Neuropathic pain following peripheral nerve injury results from maladaptive changes in neurons and immune cells contribution to mechanisms underlying chronic pain. Specifically, in dorsal root ganglia (DRG), sensory neuron cell bodies release extracellular vesicles (EVs) which promote pro-inflammatory macrophage accumulation that facilitates nociceptive signalling. Here, we show that macrophages shuttle EVs to neurons.

View Article and Find Full Text PDF

Renal interstitial fibrosis (RIF) is a common pathway in chronic kidney disease (CKD) that ultimately leads to end-stage renal failure, worsening both glomerulosclerosis and interstitial fibrosis. Ten percent of the adult population in the world suffers from CKD, and as the ageing population continues to rise, it is increasingly regarded as a global threat-a silent epidemic. CKD has been discovered to be closely associated with both long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), while the precise molecular processes behind this relationship are still unclear.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!