MicroRNAs (miRNAs) are small, non-coding RNAs that negatively regulate the expression of protein coding genes. In this study, we screened highly informative prostate cancer cell lines and xenografts (n = 42) for miRNA gene copy number and expression changes. The expression profiling showed distinction between cell lines and xenografts as well as between androgen sensitive and independent models. Only a few copy number alterations that were associated with expression changes were identified. Most importantly, the miR-15a-miR-16-1 locus was found to be homozygously deleted in two samples leading to the abolishment of miR-15a, but not miR-16, expression. miR-16 is also expressed from another genomic locus. Mutation screening of the miR-15a-miR-16-1 gene in the model systems as well as clinical samples (n = 50) revealed no additional mutations. In conclusion, our data indicate that putative tumor suppressors, miR-15a and miR-16-1, are homozygously deleted in a subset of prostate cancers, further suggesting that these miRNAs could be important in the development of prostate cancer.

dx.doi.org/10.1002/gcc.20873, hdl.handle.net/1765/91358
Genes, Chromosomes & Cancer
Department of Urology

Porkka, K, Ogg, E.-L, Saramäki, O.R, Vessella, R.L, Pukkila, H, Lähdesmäki, H, … Visakorpi, T. (2011). The miR-15a-miR-16-1 locus is homozygously deleted in a subset of prostate cancers. Genes, Chromosomes & Cancer, 50(7), 499–509. doi:10.1002/gcc.20873