MiR-509-3-5p represses PLK1 expression by targeting PLK1 3ʹ-UTR.
Expression of miR-509-3-5p is induced and PLK1 repressed upon DNA damage.
Overexpression of miR-509-3-5p induces G2/M arrest and aberrant mitosis.
MiR-509-3-5p inhibits cell proliferation and sensitizes cells to DNA damage agents.