TY - JOUR
T1 - Tumor suppressor microRNAs are downregulated in myelodysplastic syndrome with spliceosome mutations
AU - Aslan, Derya
AU - Garde, Christian
AU - Nygaard, Mette Katrine
AU - Helbo, Alexandra Søgaard
AU - Dimopoulos, Konstantinos
AU - Hansen, Jakob Werner
AU - Severinsen, Marianne Tang
AU - Treppendahl, Marianne Bach
AU - Sjø, Lene Dissing
AU - Grønbæk, Kirsten
AU - Sommer Kristensen, Lasse
PY - 2016
Y1 - 2016
N2 - Spliceosome mutations are frequently observed in patients with myelodysplastic syndromes (MDS). However, it is largely unknown how these mutations contribute to the disease. MicroRNAs (miRNAs) are small noncoding RNAs, which have been implicated in most human cancers due to their role in post transcriptional gene regulation. The aim of this study was to analyze the impact of spliceosome mutations on the expression of miRNAs in a cohort of 34 MDS patients. In total, the expression of 76 miRNAs, including mirtrons and splice site overlapping miRNAs, was accurately quantified using reverse transcriptase quantitative PCR. The majority of the studied miRNAs have previously been implicated in MDS. Stably expressed miRNA genes for normalization of the data were identified using GeNorm and NormFinder algorithms. High-resolution melting assays covering all mutational hotspots within SF3B1, SRSF2, and U2AF1 (U2AF35) were developed, and all detected mutations were confirmed by Sanger sequencing. Overall, canonical miRNAs were downregulated in spliceosome mutated samples compared to wild-type (P = 0.002), and samples from spliceosome mutated patients clustered together in hierarchical cluster analyses. Among the most downregulated miRNAs were several tumor-suppressor miRNAs, including several let-7 family members, miR-423, and miR-103a. Finally, we observed that the predicted targets of the most downregulated miRNAs were involved in apoptosis, hematopoiesis, and acute myeloid leukemia among other cancer- and metabolic pathways. Our data indicate that spliceosome mutations may play an important role in MDS pathophysiology by affecting the expression of tumor suppressor miRNA genes involved in the development and progression of MDS.
AB - Spliceosome mutations are frequently observed in patients with myelodysplastic syndromes (MDS). However, it is largely unknown how these mutations contribute to the disease. MicroRNAs (miRNAs) are small noncoding RNAs, which have been implicated in most human cancers due to their role in post transcriptional gene regulation. The aim of this study was to analyze the impact of spliceosome mutations on the expression of miRNAs in a cohort of 34 MDS patients. In total, the expression of 76 miRNAs, including mirtrons and splice site overlapping miRNAs, was accurately quantified using reverse transcriptase quantitative PCR. The majority of the studied miRNAs have previously been implicated in MDS. Stably expressed miRNA genes for normalization of the data were identified using GeNorm and NormFinder algorithms. High-resolution melting assays covering all mutational hotspots within SF3B1, SRSF2, and U2AF1 (U2AF35) were developed, and all detected mutations were confirmed by Sanger sequencing. Overall, canonical miRNAs were downregulated in spliceosome mutated samples compared to wild-type (P = 0.002), and samples from spliceosome mutated patients clustered together in hierarchical cluster analyses. Among the most downregulated miRNAs were several tumor-suppressor miRNAs, including several let-7 family members, miR-423, and miR-103a. Finally, we observed that the predicted targets of the most downregulated miRNAs were involved in apoptosis, hematopoiesis, and acute myeloid leukemia among other cancer- and metabolic pathways. Our data indicate that spliceosome mutations may play an important role in MDS pathophysiology by affecting the expression of tumor suppressor miRNA genes involved in the development and progression of MDS.
KW - Aged
KW - Aged, 80 and over
KW - Alternative Splicing
KW - Cluster Analysis
KW - Cohort Studies
KW - DNA Mutational Analysis
KW - Down-Regulation
KW - Female
KW - Gene Expression Profiling
KW - Genes, Tumor Suppressor
KW - Humans
KW - Male
KW - MicroRNAs
KW - Middle Aged
KW - Mutation
KW - Myelodysplastic Syndromes
KW - Phosphoproteins
KW - RNA Splicing Factors
KW - Reverse Transcriptase Polymerase Chain Reaction
KW - Serine-Arginine Splicing Factors
KW - Spliceosomes
KW - Splicing Factor U2AF
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
U2 - 10.18632/oncotarget.7127
DO - 10.18632/oncotarget.7127
M3 - Journal article
C2 - 26848861
SN - 1949-2553
VL - 7
SP - 9951
EP - 9963
JO - Oncotarget
JF - Oncotarget
IS - 9
ER -
