Luciferase assay

HeLa229 cells were transfected with luciferase reporter plasmids pGL3-MUC1-promoter (500 ng) or pGL3-ABCB1-promoter (500 ng) together with pGL3-SV40-Renilla (10 ng). Thirty-six hours later, cells were collected and analyzed by the Dual-Luciferase Assay system (Promega) according to the manufacturer's instructions.

pGL3-MUC1-promoter luciferase reporter plasmid was generously provided by Dr. Donald Kufe at Dana-Farber Cancer Institute Harvard Medical School Boston, MA, USA.

The human ABCB1 promoter (-2500 to +700) was amplified with primers (up: 5′-GGGGTACCGCAAGGGGACCAGGTAGGTTTCATC-3′, down: 5′-CTAGCTAGCCTAGTTACCTTTTATTGT-3′), the human ABCB1 promoter (−200 to +200) was amplified with primers (up: 5′-CTAGCTAGCAGGAAATCTGAAAGCCTGAC-3′, down: 5′-GGGGTACCCCCTTTCTAGAGAGGTGCA-3′), and then cloned into pGL3-basic vector (Promega) to construct pGL3-ABCB1-promoter (−2500 to +700) luciferase reporter and pGL3-ABCB1-promoter (−200 to +200) luciferase reporter.