New miRNAs cloned from neuroblastoma.
BACKGROUND
MicroRNAs (miRNAs) are a novel class of gene expression regulators implicated in cancer biology. Neuroblastoma (NB) is an embryonal tumour consisting of neural crest-derived undifferentiated cells and is characterised by variable clinical courses ranging from spontaneous regression to therapy-resistant progression. Recent advances identified a subset of miRNAs with putative function in NB biology. However, the full repertoire of miRNAs expressed in NBs is not available.


RESULTS
We describe miRNA profiles of 13 NB specimens and 2 NB cell lines as determined by miRNA cloning. A total of 3153 sequences were sequenced and analysed by a miRNA prediction tool (miRpredict). Our library covered 27% miRNAs known to date. 39 reads corresponding to 25 individual sequences were classified as novel miRNAs, including miRNA* species of 10 known miRNAs. Expression of 5 new miRNA* forms and 8 individual sequences was supported by Northern blotting. Most of the novel miRNA genes are not related to each other and do not share homology with the annotated sequences in the public miRNA database, but they are conserved within mammals or have close homologues in primates genomes.


CONCLUSIONS
We provide evidence for 29 new miRNA and miRNA-like sequences (24 novel sequences and 5 miRNAs discovered initially in other species). Some of these newly identified sequences reside within frequently altered chromosomal regions in NB tumours and may play a role in NB biology.
Afanasyeva
Elena A
EA
Department of Tumour Genetics, B030, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany. e.afanasyeva@dkfz-heidelberg.de
Hotz-Wagenblatt
Agnes
A
Glatting
Karl-Heinz
KH
Westermann
Frank
F
D001483:Base Sequence; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D006801:Humans; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000235:genetics*; D009690:Nucleic Acid Conformation; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics; D012334:RNA, Neoplasm / Q000737:chemistry / Q000235:genetics*
D035683:MicroRNAs; D012322:RNA Precursors; D012334:RNA, Neoplasm