Regulation of leukemic cell adhesion, proliferation, and survival by β-catenin

• DOI: 10.1182/blood.v100.3.982
• Publication Date: 2002-10-11T18:33:52Z
• Authors: Eun Joo Chung; Sang-Gu Hwang; PhuongMai Nguyen; Sunmin Lee; Jung-Sik Kim; Jin Woo Kim; Pierre A. Henkart; Donald P. Bottaro; Lilian Soon; Paolo Bonvini; Su-Jae Lee; Judith E. Karp; Ho Jung Oh; Jeffrey S. Rubin; Jane B. Trepel
• Keywords: Jurkat cells

Abstract In epithelial cells β-catenin plays a critical role as a component of the cell-cell adhesion apparatus and as a coactivator of the TCF/LEF (T-cell transcription factor/lymphoid enhancer binding factor) family of transcription factors. Deregulation of β-catenin has been implicated in the malignant transformation of cells of epithelial origin. However, a function for β-catenin in hematologic malignancies has not been reported. β-Catenin is not detectable in normal peripheral blood T cells but is expressed in T–acute lymphoblastic leukemia cells and other tumor lines of hematopoietic origin and in primary lymphoid and myeloid leukemia cells. β-Catenin function was examined in Jurkat T–acute lymphoblastic leukemia cells. Overexpression of dominant-negative β-catenin or dominant-negative TCF reduced β-catenin nuclear signaling and inhibited Jurkat proliferation and clonogenicity. Similarly, these constructs inhibited proliferation of K562 and HUT-102 cells. Reduction of β-catenin expression with β-catenin antisense down-regulated adhesion of Jurkat cells in response to phytohemagglutinin. Incubation of Jurkat cells with anti-Fas induced caspase-dependent limited proteolysis of β-catenin N- and C-terminal regions and rapid redistribution of β-catenin to the detergent-insoluble cytoskeleton, concomitant with a marked decline in nuclear β-catenin signaling. Fas-mediated apoptosis was potentiated by inhibition of β-catenin nuclear signaling. The data suggest that β-catenin can play a significant role in promoting leukemic cell proliferation, adhesion, and survival.