Max dimerization protein 3 (MXD3)

Max dimerization protein 3 (MXD3) is a basic helix-loop-helix leucine zipper (bHLHZ) transcription factor in the MAD/MXD family and the Myc superfamily. MXD3 heterodimerizes with MAX and binds E-box DNA sequences to regulate gene expression. Unlike canonical MAD family members that are expressed in postmitotic cells and act as Myc antagonists to inhibit cell proliferation, MXD3 is expressed in proliferating cells during the S-phase and paradoxically promotes cell proliferation, particularly in neural precursors and various cancers. Overexpression of MXD3 has been linked to tumorigenesis and poor prognosis in several cancers, including medulloblastoma, neuroblastoma, renal cell carcinoma, and hepatocellular carcinoma. MXD3’s activity appears to be context-dependent: moderate expression sustains cell proliferation, while persistent overexpression induces cell cycle arrest and apoptosis. Experimental knockdown of MXD3 reduces cancer cell proliferation and induces apoptosis, highlighting its emerging role as a prognostic biomarker and a potential, although not yet clinically targeted, cancer therapy[1][2][3][4][5].

Other names

MAD3BHLHC13MYXMax-associated protein 3Max-interacting transcriptional repressor MAD3class C basic helix-loop-helix protein 13max dimerizer 3

Inhibition of cell proliferation through gene knockdown (siRNA/antisense), likely by disrupting MXD3-mediated transcriptional activity and promoting apoptosis[1]