This Article Full Text Full Text (PDF) Supplementary Data Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Huppi, K. Articles by Caplen, N. J. Search for Related Content PubMed PubMed Citation Articles by Huppi, K. Articles by Caplen, N. J.

---

Cancer Genes and Genomics

The Identification of MicroRNAs in a Genomically Unstable Region of Human Chromosome 8q24

¹ Gene Silencing Section, Genetics Branch and ² Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland; and ³ Advanced Biomedical Computing Center, National Cancer Institute-Frederick/Science Applications International Corporation-Frederick, Inc., NIH, Frederick, Maryland

Requests for reprints: Konrad Huppi, Gene Silencing Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, NIH, Building 37, Room 6128, Bethesda, MD 20892. Phone: 301-402-7506; Fax: 301-402-3241. E-mail: huppi{at}helix.nih.gov

The PVT1 locus is identified as a cluster of T(2;8) and T(8;22) "variant" MYC-activating chromosomal translocation breakpoints extending 400 kb downstream of MYC in a subset (20%) of Burkitt's lymphoma (vBL). Recent reports that microRNAs (miRNA) may be associated with fragile sites and cancer-associated genomic regions prompted us to investigate whether the PVT1 region on chromosome 8q24 may contain miRNAs. Computational analysis of the genomic sequence covering the PVT1 locus and experimental verification identified seven miRNAs. One miRNA, hsa-miR-1204, resides within a previously described PVT1 exon (1b) that is often fused to the immunoglobulin light chain constant region in vBLs and is present in high copy number in MYC/PVT1–amplified tumors. Like its human counterpart, mouse mmu-miR-1204 represents the closest miRNA to Myc (50 kb) and is found only 1 to 2 kb downstream of a cluster of retroviral integration sites. Another miRNA, mmu-miR-1206, is close to a cluster of variant translocation breakpoints associated with mouse plasmacytoma and exon 1 of mouse Pvt1. Virtually all the miRNA precursor transcripts are expressed at higher levels in late-stage B cells (including plasmacytoma and vBL cell lines) compared with immature B cells, suggesting possible roles in lymphoid development and/or lymphoma. In addition, lentiviral vector-mediated overexpression of the miR-1204 precursor (human and mouse) in a mouse pre–B-cell line increased expression of Myc. High levels of expression of the hsa-miR-1204 precursor is also seen in several epithelial cancer cell lines with MYC/PVT1 coamplification, suggesting a potentially broad role for these miRNAs in tumorigenesis. (Mol Cancer Res 2008;6(2):212–21)