Select microRNA Profiles of Patients with Chronic Lymphocytic Leukemia.
Prabhjot Kaur, Claudine L Bartels, Heather A Bentley, Gregory J Tsongalis. Dartmouth-Hitchcock Medical Center, Lebanon, NH
Background: MicroRNAs (miRNAs) are small endogenous, non-coding 22-nucleotide regulatory RNAs found in plants and animals. miRNAs modulate hematopoietic lineage differentiation and play important gene-regulatory roles during development by pairing with target mRNAs to specify posttranscriptional repression of these messages. In human chronic lymphocytic leukemia (CLL), the most common leukemia in the western world, mice- model studies have shown dysregulated expression of miR-15a, miR-16, and mir 29-a to cause a disease simulating human CLL. MiRNA 181, is a putative regulator of B-cell differentiation in mice and its dysregulated expression has been associated with disease progression in a select population of human CLL. In this study we evaluated these miRNA profiles from B-cell enriched prospective CLL samples.
Design: In the present study, nineteen RNA samples, representing 18 CLL patients, were extracted from fresh peripheral blood specimens. The patient's ages ranged from 46 to 90 years and ten of these were treated previously while 8 were untreated. Samples were collected at different time points between August 2009 and September of 2010. The samples were enriched for B-cells using the RosetteSep Human B Cell Enrichment Cocktail (StemCell Technologies, Vancouver, BC, Canada) and total RNA was extracted using the mirVana™ miRNA Isolation Kit (Ambion). Expression of miR15a, miR16-1, miR29a, miR181a, and U47 (an endogenous control) in each sample was determined using TaqMan® MicroRNA Assays (Applied Biosytems). In addition, expression of these miRNAs was determined in B cells from normal samples. The DCT of the normal (CTnormal – CTendogenous control) and CLL samples (CTCLL sample - CTendogneous control) were calculated, and relative comparison of normal and CLL samples was made using the DDCTmethod (DCTCLL sample – DCTnormal).
Results: In this study, we found that there is an upregulation of miR29a and, down-regulation of miR15a and miR16-1 expression. Interestingly, miR 181a was downregulated in all CLL patients compared to normal.
Conclusions: Our preliminary results show that miRNA 181a expression levels in CLL patients differs from that of normal patients and is a likely candidate for further evaluation for its role in disease progression in CLL.
Monday, February 28, 2011 1:00 PM
Poster Session II # 266, Monday Afternoon