title: The gold (III) porphyrin complex, gold-2a, suppresses WNT1 expression in breast cancer cells by enhancing the promoter association of YY1.
abstract: The gold (III) porphyrin complex, gold-2a, elicits anti-tumor activity by targeting the Wnt/β-catenin signaling pathway [Chow KH et al, Cancer Research 2010;70(1):329-37]. Here, the molecular mechanisms underlying the inhibitory effects of this compound on WNT1 gene expression were elucidated further. A response element to gold-2a was identified located within the -1290 to -1112 nt region of the WNT1 promoter, containing a binding site for the transcription regulator Yin Yang 1 (YY1). Gold-2a promoted the association of YY1 and suppressor of zeste 12 (Suz12; a component of the polycomb repressor complex 2) with the WNT1 promoter. Under normal culture conditions, the intracellular translocalization of YY1 was synchronized with cell cycle progression and WNT1 expression. Gold-2a promoted the nuclear accumulation and abolished the nuclear exportation of YY1, resulting in a persistent inhibition of WNT1 expression and a cell cycle arrest at G1/S phase. A dimorphic role of YY1 in regulating cell proliferation and division was revealed. Thus, the present study extends the understanding of the anti-tumor mechanism of gold-2a to the epigenetic level, which involves the modulation of the dynamic interactions between YY1 and a specific region of the WNT1 promoter.
authors: Kim Hei-Man
authors: KH
authors: Chow
authors: Jing
authors: J
authors: Liu
authors: Raymond Wai-Yin
authors: RW
authors: Sun
authors: Paul M
authors: PM
authors: Vanhoutte
authors: Aimin
authors: A
authors: Xu
authors: Jie
authors: J
authors: Chen
authors: Chi-Ming
authors: CM
authors: Che
authors: Yu
authors: Y
authors: Wang