ORIGINAL PAPER Expression of small nucleolar RNAs in leukemic cells Kaisa J. Teittinen & Asta Laiho & Annemari Uusimäki & Juha-Pekka Pursiheimo & Attila Gyenesei & Olli Lohi Accepted: 5 November 2012 # International Society for Cellular Oncology 2012 Abstract Purpose Small nucleolar RNAs (snoRNAs) direct sequence-specific modifications to ribosomal RNA. We hy- pothesized that the expression of snoRNAs may be altered in leukemic cells. Methods The expression of snoRNAs was analyzed in vari- ous leukemic cell lines by massive parallel sequencing (SOLiD). Quantitative real-time PCR (RT-qPCR) was used to validate the expression profiles. Results Our results show characteristic differences in the expression patterns of snoRNAs between cell lines repre- senting the main subgroups of leukemia, AML, pre-B-ALL and T-ALL, respectively. In RT-qPCR analyses, several snoRNAs were found to be differentially expressed in T- ALL as compared to pre-B-ALL cell lines. Conclusions snoRNAs are differentially expressed in vari- ous leukemic cell lines and could, therefore, be potentially useful in the classification of leukemia subgroups. Keywords Leukemia . snoRNA . SOLiD . Nucleolus Abbreviations ALL Acute lymphoblastic leukemia AML Acute myeloid leukemia APL Acute promyeloid leukemia BLL Burkitt’ s lymphoma/leukemia DE Differentially expressed FC Fold change miRNA Micro-RNA ncRNA Non-protein-coding RNA NSCLC Non-small cell lung cancer RT-qPCR Quantitative real-time PCR scaRNA Cajal body-specific RNA siRNA Small interfering RNA snRNA Small nuclear RNA snoRNA Small nucleolar RNA snoRNP Small nucleolar ribonucleoprotein 1 Introduction The discovery that the majority of the mammalian genome is transcribed into non-protein-coding RNAs (ncRNAs) has changed the landscape of human genetics [1]. Recent work has established that these RNAs are involved in normal cel- lular processes as well as pathological conditions such as cancer, heart diseases, immune disorders, and various neuro- degenerative and metabolic diseases [2]. Several classes of ncRNA have been identified, including small interfering RNAs (siRNA), microRNAs (miRNA), PIWI-associated RNAs (piRNA), small nucleolar RNAs (snoRNA), and vari- ous species of long ncRNA. The small non-coding RNA molecules of the nucleolus, snoRNAs, can be grouped into two main classes. One class Electronic supplementary material The online version of this article (doi:10.1007/s13402-012-0113-5) contains supplementary material, which is available to authorized users. K. J. Teittinen (*) : A. Uusimäki : O. Lohi Tampere Center for Child Health Research, University of Tampere School of Medicine and Tampere University Hospital, FM-3, Biokatu 10, 3rd Floor, FIN-33520 Tampere, Finland e-mail: kaisa.teittinen@uta.fi A. Laiho : J.-P. Pursiheimo : A. Gyenesei Turku Centre for Biotechnology and the Finnish Microarray and Sequencing Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland Cell Oncol. DOI 10.1007/s13402-012-0113-5