Overexpression of microRNA-16 declines cellular growth, proliferation and induces apoptosis in human breast cancer cells.

MicroRNAs (miRNA) are a large family of small single-stranded RNA molecules found in all multicellular organisms. Early studies have been shown that miRNA are involved in cancer development and progression, and this role can be done by working as an oncogenes and tumor suppressor genes, so manipulation of this molecules can be a promising approach in cancer therapy, and experimental results represented that the modification in breast cancer phenotype is possible by miRNA expression alteration. miR-16, which is located in 13q14 chromosome, plays critical roles as a tumor suppressor by targeting several oncogenes which regulate cell cycle and apoptosis.

Targeting of the signal transducer Smo links microRNA-326 to the oncogenic Hedgehog pathway in CD34+ CML stem/progenitor cells.

Aberrant expression and function of microRNAs (miRNAs) in leukemia have added a new layer of complexity to the understanding of development and progression of the disease state. However, their targeting of specific signaling pathways responsible for the maintenance and survival properties of leukemic stem cell (LSC) still remains to be further clarified. Hedgehog (Hh) signaling, a highly conserved developmental pathway, has been proven as a functional pathway for LSCs, and loss of this pathway impairs the development of BCR-ABL-induced chronic myeloid leukemia (CML) and depletes CML stem cells.