[CITATION][C] High expression of precursor microRNA‐155/BIC RNA in children with Burkitt lymphoma

M Metzler, M Wilda, K Busch… - Genes …, 2004 - Wiley Online Library
M Metzler, M Wilda, K Busch, S Viehmann, A Borkhardt
Genes, Chromosomes and Cancer, 2004Wiley Online Library
In a recent issue of Genes, Chromosomes & Cancer, van den Berg et al.(2003) reported on
the high expression of human BIC RNA in Hodgkin lymphoma by means of the serial
analysis of gene expression (SAGE) technique. In addition, using a combination of RNA in
situ hybridization and immunostaining, they found that the expression of BIC is specific for
Reed–Sternberg (RS) cells and that the BIC transcripts were in the nuclei of the RS cells. In
contrast to their findings in Hodgkin lymphoma, an analysis of 43 cases of non-Hodgkin …
In a recent issue of Genes, Chromosomes & Cancer, van den Berg et al.(2003) reported on the high expression of human BIC RNA in Hodgkin lymphoma by means of the serial analysis of gene expression (SAGE) technique. In addition, using a combination of RNA in situ hybridization and immunostaining, they found that the expression of BIC is specific for Reed–Sternberg (RS) cells and that the BIC transcripts were in the nuclei of the RS cells. In contrast to their findings in Hodgkin lymphoma, an analysis of 43 cases of non-Hodgkin lymphoma (NHL; 15 follicular lymphomas, 7 diffuse large B-cell lymphomas, 9 Burkitt lymphomas, 7 anaplastic large cell lymphomas, and 5 T-cell-rich B-cell lymphomas) did not reveal any remarkable up-regulation of BIC expression, although one case of Burkitt lymphoma (BL) showed weak expression of BIC in a minority of its tumor cells. The BIC locus was originally identified as a common retroviral integration site in avian-leukosis virus–induced B–cell lymphomas (Clurman and Hayward, 1989; Tam et al., 1997). It should be stressed that the human BIC gene encodes a microRNA, miR-155. This microRNA is encoded by nucleotides 241–262 of BIC, which spans 1,421 bp in total and is on chromosome 21 (GenBank accession number: AF402776). MicroRNAs (miRNAs) are an abundant class of noncoding RNAs that interact with coding mRNA and trigger either translation repression or direct RNA cleavage via RNA interference, depending on the degree of complementarity with the specific target mRNA (Ambros, 2001; Lagos-Quintana et al., 2001; Ruvkun, 2001; Lai, 2002; Pasquinelli, 2002; Ambros et al., 2003; Lagos-Quintana et al., 2003). Mature miRNAs are 21–23 nt long and are excised from an approximately 60-to 80-nt double-stranded RNA hairpin by Dicer RNase III (Hutvagner et al., 2001). In the last 2 years, more than 200 human microRNA genes have been described, but the prediction and validation of their target mRNAs by computerized means and experimental approaches is a tantalizing and still unresolved task (Ambros et al., 2003). Apart from this open question, it was recently hypothesized that microRNA genes might play an important role in oncogenesis (McManus, 2003).
We support the idea advanced by van den Berg et al. that BIC might play a role in the selection of B cells, but here we also extend their data by demonstrating that miR-155/BIC is highly expressed in pediatric BL but not in other hematologic malignancies, for example, pre-B/common or T-cell leukemia.
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