Otoraplin (OTOR)

Otoraplin (OTOR) is a secreted, evolutionarily conserved protein and a member of the melanoma-inhibiting activity (MIA) gene family, characterized by an SH3-like domain[1][2][3][4][6]. It is predominantly expressed in the inner ear—particularly the cochlea—where it participates in the chondrogenesis of the otic capsule, contributing to normal auditory function and cartilage maintenance[1][2][4]. While its main physiological role is believed to be in cartilage development, especially of the inner ear, altered OTOR expression has also been noted in various cancer tissues, notably breast carcinoma, where it correlates with enhanced tumor proliferation, migration, and invasiveness, as well as poor prognosis[3]. Functional genomic studies suggest OTOR may modulate oncogenic signaling via the MAPK–ERK pathway[3]. A polymorphism in the OTOR gene affecting translation initiation has been associated with hereditary forms of deafness[6]. Otoraplin is the subject of ongoing research as both a potential therapeutic target in select cancers, especially melanoma and breast tumors, and as a genetic risk factor for sensory hearing loss, but no approved drugs currently target OTOR directly[3][5][6].

Other names

Fibrocyte-derived proteinMelanoma inhibitory activity-like proteinFDPMIALMIAL1OTORfibrocyte-derived proteinmelanoma inhibitory activity-like proteinMGC126737MGC126739

Not defined; potential pro- or anti-tumorigenic effects via MAPK–ERK pathway modulation - Promotes “suicide gene therapy” in melanoma models (proposed mechanism, not clinically validated)