Lentivirus-mediated shRNA (small hairpin RNA) knockdown of
gene expression
We knocked down the expression of the human ERLIN2 gene in
human breast cancer cell lines SUM225 and SUM44 or human
hepatoma cell line Huh-7 by using the Expression Arrest GIPZ
lentiviral shRNAmir system (OpenBiosystems). Lentivirus was
produced by transfecting HEK (human embryonic kidney)-293FT
cells with a combination of the lentiviral expression plasmid
DNA and the Trans-Lentiviral packaging mix (OpenBiosystems).
For cell infection, viral supernatants were supplemented with
6 μg/ml polybrene and incubated with the cells for 24 h. The cells
expressing shRNA were selected with puromycin for 2–3 weeks
for functional studies (cell proliferation assays) and for 4–10 days
after infection for RNA extraction.