Figure 5.

Inhibition of PRMT5 or its activity upregulates BTG2 expression through the phosphorylation of ERK. (A and B) Western blot showed that knockdown of PRMT5 increased the phosphorylation of Raf and ERK and protein level of BTG2 in HCC cells, while inhibition of ERK phosphorylation by 24 h pretreatment with 20 μM p‐ERK inhibitor PD184352 in shPRMT5 cells led to downregulation of BTG2 and p‐ERK. (C) Treatment of HCC cells with 500 nmol/L GSK591 for 4 days led to significant loss of PRMT5‐catalyzed methylarginine on H4 (H4R3me2s), the upregulation of BTG2, and the phosphorylation of ERK. Inhibition of ERK phosphorylation by PD184352 treatment reversed these effects. H4R3me2s was used to detect the PRMT5 activity. Histone 3 was used as nuclear loading control