Browsing by Author "Shih, Jou-Ho"

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PSPC1 mediates TGF-beta 1 autocrine signalling and Smad2/3 target switching to promote EMT, stemness and metastasis
(2018-04-01)
Yeh, Hsi-Wen
;
Hsu, En-Chi
;
Lee, Szu-Shuo
;
Lang, Yaw-Dong
;
Lin, Yuh-Charn
Activation of metastatic reprogramming is critical for tumour metastasis. However, more detailed knowledge of the underlying mechanism is needed to enable targeted intervention. Here, we show that paraspeckle component 1 (PSPC1), identified in an aberrant 13q12.11 locus, is upregulated and associated with poor survival in patients with cancer. PSPC1 promotes tumorigenesis, epithelial-to-mesenchymal transition (EMT), stemness and metastasis in multiple cell types and in spontaneous mouse cancer models. PSPC1 is the master activator for transcription factors of EMT and stemness and accompanies c-Myc activation to facilitate tumour growth. PSPC1 increases transforming growth factor-ss 1 (TGF-ss 1) secretion through an interaction with phosphorylated and nuclear Smad2/3 to potentiate TGF-ss 1 autocrine signalling. Moreover, PSPC1 acts as a contextual determinant of the TGF-ss 1 pro-metastatic switch to alter Smad2/3 binding preference from tumour-suppressor to pro-metastatic genes. Having validated the PSPC1-Smads-TGF-ss 1 axis in various cancers, we conclude that PSPC1 is a master activator of prometastatic switches and a potential target for anti-metastasis drugs.
PSPC1-interchanged interactions with PTK6 and beta-catenin synergize oncogenic subcellular translocations and tumor progression
(2019-12-16)
Lang, Yaw-Dong
;
Chen, Hsin-Yi
;
Ho, Chun-Ming
;
Shih, Jou-Ho
;
Hsu, En-Chi
Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide due to metastasis. Paraspeckle component 1 (PSPC1) upregulation has been identified as an HCC pro-metastatic activator associated with poor patient prognosis, but with a lack of targeting strategy. Here, we report that PSPC1, a nuclear substrate of PTK6, sequesters PTK6 in the nucleus and loses its metastasis driving capability. Conversely, PSPC1 upregulation or PSPC1-Y523F mutation promotes epithelial-mesenchymal transition, stemness, and metastasis via cytoplasmic translocation of active PTK6 and nuclear translocation of p-catenin, which interacts with PSPC1 to augment Wnt3a autocrine signaling. The aberrant nucleocytoplasmic shuttling of active PTK6/beta-catenin is reversed by expressing the PSPC1 C-terminal interacting domain (PSPC1-CT131), thereby suppressing PSPC1/PTK6/beta-catenin-activated metastasis to prolong the survival of HCC orthotopic mice. Thus, PSPC1 is the contextual determinant of the oncogenic switch of PTK6/beta-catenin subcellular localizations, and PSPC1-CT131 functions as a dual inhibitor of PSPC1 and PTK6 with potential for improving cancer therapy.