Journal of Molecular Biomarkers and Clinical Trials
miRNA Roles: Sequence Analyses of Oncogenic and Tumor Suppressive miRNAs
Published on: 2018-04-27
MicroRNAs (miRNAs) are small (∼25 nucleotides) noncoding RNA molecules thought to play an important role in regulating gene expression. Knowledge of the biological functions of most miRNAs is still limited, but these miRNAs are thought to regulate the gene expression in various diseases. In this paper the relations between the sequences of cancer-related miRNAs (both oncogenic and tumor suppressive) and those of control miRNAs in human beings are examined from the viewpoint of nucleotide frequencies at individual positions. Oncogenic and tumor suppressive miRNAs are involved in the overexpression/upregulation and underexpression/downregulation of cancers, whereas control miRNAs are not involved in cancer development and progression. The 132 oncogenic, 111 tumor suppressive, and 1610 control miRNA sequences investigated in this work were collected from miRBase on the basis of the relations between miRNAs of Homo sapiens and various cancers in the literature. Statistical analyses of the positional nucleotide occurrence features revealed clear differences between the cancer-related and control miRNAs. This indicates that miRNAs can be used as biomarkers in human cancers.