There are two major classes of heat-stable microtubule-associated proteins (MAPs): MAP2 and tau (MAPT). Both bind microtubules and regulate their polymerization and stability—a critical process for maintaining cellular architecture and dynamics (1).
MAP2 exists in four main isoforms—MAP2A, MAP2B, MAP2C, and MAP2D—via alternative splicing. The high molecular weight isoforms MAP2A/B (~250 kDa) and lower molecular weight isoforms MAP2C/D (~70 kDa) all share a conserved microtubule-binding core domain, important for dendritic stabilization and neuritogenesis (2).
Since microtubule dynamics are central to cell division, migration, and morphology, aberrations in MAP2 and tau expression have been implicated in several types of cancer.
Consequently, MAP2 expression has diagnostic and prognostic relevance in neuro-oncology. MAP2 immunoreactivity helps distinguish glial neoplasms in neuropathology, and its expression tends to vary according to tumor grade (3). While classic low-grade gliomas often show robust MAP2 staining, higher-grade tumors may exhibit less-specific and more heterogeneous patterns. Moreover, in melanoma, reduced MAP2 expression correlates with increased tumor aggressiveness, underscoring its potential role as a tumor suppressive marker (4).