TGF-β1 signaling pathway serves a role in HepG2 cell regulation by affecting the protein expression of PCNA, gankyrin, p115, XIAP and survivin

Abstract

Abstract.The transforming growth factor-β (TGF-β) signaling pathway serves a key role in the pathogenesis of liver cancer. To investigate the association between TGF-β1 and the following proteins: Proliferating cell nuclear antigen (PCNA), gankyrin, general vesicular transport factor p115 (p115), X-linked inhibitor of apoptosis protein (XIAP) and survivin, HepG2 liver cancer cells were transfected with small interfering RNA (siRNA) directed against TGF-β1, or were treated with exogenous TGF-β1. TGF-β1 protein expression levels were assessed at 72 and 96 h using western blotting, cell growth was evaluated using a Cell Counting kit-8 assay, and flow cytometry was used to examine cell cycle distribution and apoptosis. In addition, PCNA, gankyrin, p115, XIAP and survivin protein levels were evaluated using western blotting. TGF-β1 protein expression levels were decreased at 72 and 96 h following siRNA transfection, indicating that the siRNA against TGF-β1 was effective. In the TGF-β1-knockdown group, the HepG2 cells exhibited G 1 or S-phase cell cycle arrest; therefore, the number of G 2 -phase cells was decreased, cell growth was inhibited and apoptotic peaks were observed. By contrast, no significant alteration in cell cycle distribution or apoptosis was observed in the cells treated with exogenous TGF-β1. In the exogenous TGF-β1 group, PCNA and XIAP protein expression levels were increased, whereas gankyrin, p115 and survivin protein expression was observed to be dependent on the duration of treatment. By contrast, PCNA, gankyrin, XIAP and survivin protein expression decreased following TGF-β1 knockdown; however, p115 protein expression increased. In conclusion, the TGF-β1 signaling pathway may affect cell growth, cell cycle distribution and apoptosis through the regulation of PCNA, gankyrin, p115, XIAP and survivin protein expression in liver cancer. The results of the present study may improve the current understanding of the role of the TGF-β signaling pathway during the pathogenesis of liver cancer.

Development of human liver extracellular matrix hydrogel for three dimensional cell culture and cell transplantation

“…Live/dead analysis of the samples after TGF-1 treatment showed a lower number of alive cells and an increased number of dead cells in treated samples compared to untreated control samples. This result is consistent with other published studies where it was shown that TGF-1 reduced SNU-449 cell growth and increased the percentage of apoptotic cells compared to untreated samples [430]. Gene expression analysis was performed to investigate the effect of TGF-1 on Vimentin, E-Cadherin, β-Catenin and Twist1 gene levels.…”

A Functional SMAD2/3 Binding Site in the PEX11β Promoter Identifies a Role for TGFβ in Peroxisome Proliferation in Humans

“…It contributes to hepatocyte proliferation and differentiation, but also to all stages of disease progression, from initial liver injury through inflammation and fibrosis to cirrhosis and hepatocellular carcinoma (Fabregat et al, 2016). HepG2 cells have been shown to express TGFβ and to respond to TGFβ treatment or silencing of TGFβ with alterations in cell growth, apoptosis and the cell cycle (Wang et al, 2017). We assume that TGFβ signaling in our experimental system contributes to the proliferation and/or differentiation of HepG2 cells as peroxisome elongation is a hallmark of cell growth and proliferation (Schrader et al, 1999).…”

The Curious Case of the HepG2 Cell Line: 40 Years of Expertise

“…The case of liver cancer focuses on the following pathways: the transforming growth factor β (TGF-β) [ 157 ], proto-oncogene Wnt/β-catenin [ 158 ], phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) [ 159 ], c-Jun N-terminal kinase (JNK)/signal transducer and activator of transcription (STAT) [ 160 ], Hedgehog and tumor protein 53 transduction pathways [ 161 ].…”