Identification of Epithelial-Mesenchymal Transition-related Target Genes Induced by the Mutation of Smad3 Linker Phosphorylation

J Cancer Prev. 2018 Mar;23(1):1-9. doi: 10.15430/JCP.2018.23.1.1. Epub 2018 Mar 30.

Abstract

Background: Smad3 linker phosphorylation plays essential roles in tumor progression and metastasis. We have previously reported that the mutation of Smad3 linker phosphorylation sites (Smad3-Erk/Pro-directed kinase site mutant constructs [EPSM]) markedly reduced the tumor progression while increasing the lung metastasis in breast cancer.

Methods: We performed high-throughput RNA-Sequencing of the human prostate cancer cell lines infected with adenoviral Smad3-EPSM to identify the genes regulated by Smad3-EPSM.

Results: In this study, we identified genes which are differentially regulated in the presence of Smad3-EPSM. We first confirmed that Smad3-EPSM strongly enhanced a capability of cell motility and invasiveness as well as the expression of epithelial-mesenchymal transition marker genes, CDH2, SNAI1, and ZEB1 in response to TGF-β1 in human pancreatic and prostate cancer cell lines. We identified GADD45B, CTGF, and JUNB genes in the expression profiles associated with cell motility and invasiveness induced by the Smad3-EPSM.

Conclusions: These results suggested that inhibition of Smad3 linker phosphorylation may enhance cell motility and invasiveness by inducing expression of GADD45B, CTGF, and JUNB genes in various cancers.

Keywords: Epithelial-mesenchymal transition; Pancreatic cancer; Prostate cancer; RNA sequence analysis; Smad3.