Fig. 7: JunB regulates expression and secretion of angiogenic factors and thereby BM angiogenesis in MM.
From: JunB is a key regulator of multiple myeloma bone marrow angiogenesis
In contrast to Hif-1α which is induced by hypoxia in MM BM microenvironment, JunB upregulation in MM cell is triggered predominantly by IL-6 secreted from bone marrow stroma cells (BMSC) and also by direct MM: BMSC cell-cell contact. Importantly, induced upregulation of JunB is a critical, MEK/MAPK- and NFκB- dependent but Ras status- independent mediator for the transcription of key angiogenic factors VEGF, VEGFB and IGF1, and thereby MM BM angiogenesis, particularly in early MM.
