A strong association has been identified between miR-569 and 3q26.2, a chromosomal locus that is amplified in some breast cancers. Altered expression of the miR-569 gene has been demonstrated to affect growth and proliferation of breast epithelial cells. Ectopic expression of miR-569 resulted in tumor cell proliferation and metastasis. This occurs through miR-569 inhibition of TP53INP1, a tumor suppressor gene. In comparison to normal tissues and less malignant tumors, TP53INP1 occurs at lower levels in more invasive cancers, presumably in part due to the role played by miR-569.
