Naturally occurring miRNAs that regulate human oncogenes and methods of use thereof are described. Suitable nucleic acids for use in the methods and compositions described herein include, but are not limited to, pri-miRNA, pre-miRNA, mature miRNA or fragments of variants thereof that retain the biological activity of the mature miRNA and DNA encoding a pri-miRNA, pre-miRNA, mature miRNA, fragments or variants thereof, or regulatory elements of the miRNA. The compositions containing nucleic acids are administered to a patient in need of treatment or prophylaxis of at least one symptom or manifestation of cancer. In one embodiment, the compositions are administered in an effective amount to inhibit gene expression of one or more oncogenes. Methods for treatment or prevention of at least one symptom or manifestation of cancer are also described.