Frequent deletions and down-regulation of micro- RNA genes miR15 and miR16 at 13q14 in chronic lymphocytic leukemia

doi:10.1073/pnas.242606799

Frequent deletions and down-regulation of micro- RNA genes miR15 and miR16 at 13q14 in chronic lymphocytic leukemia

^*Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107 USA; ^†Clinical Immunology, National Institute for Research on Cancer, 16132 Genoa, Italy Europe; ^‡Department of Leukemia, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030 USA; ^§Long Island Jewish Medical Center, New Hyde Park, NY 11040 USA; and ^¶Department of Medicine, University of California at San Diego, La Jolla, CA 92093 USA

Contributed by Carlo M. Croce

Abstract

Micro-RNAs (miR genes) are a large family of highly conserved noncoding genes thought to be involved in temporal and tissue-specific gene regulation. MiRs are transcribed as short hairpin precursors (≈70 nt) and are processed into active 21- to 22-nt RNAs by Dicer, a ribonuclease that recognizes target mRNAs via base-pairing interactions. Here we show that miR15 and miR16 are located at chromosome 13q14, a region deleted in more than half of B cell chronic lymphocytic leukemias (B-CLL). Detailed deletion and expression analysis shows that miR15 and miR16 are located within a 30-kb region of loss in CLL, and that both genes are deleted or down-regulated in the majority (≈68%) of CLL cases.

Footnotes

↵ ∥ To whom correspondence should be addressed at: Kimmel Cancer Center, Thomas Jefferson University, 233 South 10th Street, 1050 Bluemle Life Science Building, Philadelphia, PA 19107. E-mail: Carlo.Croce{at}mail.tju.edu.
Abbreviations:
1. CLL, chronic lymphocytic leukemia
2. LOH, loss of heterozygosity
3. miRNA, micro-RNA