Ubiquitin carboxyl-terminal hydrolase isozyme L5 inhibits human glioma cell migration and invasion via downregulating SNRPF

Ubiquitin C-terminal Hydrolase-L5 (UCH-L5/UCH37), a member of the deubiquitinases (DUBs), suppresses protein degeneration via removing ubiquitin from the distal subunit of the polyubiquitin chain. The activity of UCH-L5 is enhanced when UCH-L5 combines with proteasome 19S regulatory subunit by Rpn13/Admr1 receptor and inhibited when UCH-L5 interacts with NFRKB. But the role of UCH-L5 in gliomas remains unknown. In this study, analysis of 19 frozen and 51 paraffin-embedded clinic pathological cases showed that UCH-L5 expression in glioma tissues was lower than normal brain tissues. In vitro, we found that UCH-L5 could inhibit migration and invasion of U87MG and U251 cells. It has been reported that the expression of SNRPN, SNRPF, and CKLF was abnormal in gliomas or other tumors. We also found that SNRPF-siRNA, SNRPN-siRNA and CKLF-siRNA could inhibit migration and invasion of U87MG cells. And knockdown of UCH-L5 expression improved both mRNA expression and protein level of SNRPF. The relationship between UCH-L5 and SNRPF was further confirmed in 293T cells. Our study showed that UCH-L5 could inhibit migration and invasion of glioma cells via down regulating expression of SNRPF. And the above findings suggest that UCH-L5 may inhibit occurrence and metastasis of gliomas.