The monoamine oxidase-A inhibitor clorgyline promotes a mesenchymal-to-epithelial transition in the MDA-MB-231 breast cancer cell line.

Monoamine oxidase-A (MAO-A) dysfunction has been historically associated with depression. Recently, depression as well as altered MAO-A expression have both been associated with a poor prognosis in cancers, although the mechanism involved remains ambiguous. For example, MAO-A mRNA is repressed across cancers, yet MAO-A protein and levels of serotonin, a substrate of MAO-A implicated in depression, are paradoxically increased in malignancies, including breast cancer.

Aspartic acid substitutions in monoamine oxidase-A reveal both catalytic-dependent and -independent influences on cell viability and proliferation.

Post-translational influences could underlie the ambiguous roles of monoamine oxidase-A (MAO-A) in pathologies such as depression, cancer and Alzheimer disease. In support of this, we recently demonstrated that the Ca²⁺-sensitive component of MAO-A catalytic activity is inhibited by a pro-survival p38 (MAPK)-dependent mechanism. We substituted three aspartic acid (D) residues in human MAO-A that reside in putative Ca²⁺-binding motifs and overexpressed the individual proteins in the human HEK293 cell line.

Alzheimer disease-related presenilin-1 variants exert distinct effects on monoamine oxidase-A activity in vitro.

Monoamine oxidase-A (MAO-A) has been associated with both depression and Alzheimer disease (AD). Recently, carriers of AD-related presenilin-1 (PS-1) alleles have been found to be at higher risk for developing clinical depression. We chose to examine whether PS-1 could influence MAO-A function in vitro.