a, b, Hela (a) or NIH3T3 (b) cells were transfected with indicated siRNAs and then infected with VSV-G pseudotyped, integrase-deficient (IND184A) MLV-Luc virus. Luciferase activities were measured 40 h post infection and luciferase activity in non-targeting (NT) control siRNA transfected cells was set as 1 (top panels). Data presented are mean ± SD from three independent experiments (n = 3). The expression of NP220 was determined by Western blot (bottom panels). c, Hela cells were first transfected with indicated siRNAs targeting histone methyltransferases and then infected with VSV-G pseudotyped, integrase-deficient (IND184A) MLV-Luc virus. Luciferase activities were measured 40 h post infection and luciferase activity in non-targeting (NT) control siRNA transfected HeLa cells was set as 1. Data presented are mean ± SD from three independent experiments (n = 3). d, Knockdown efficiency of siRNAs used in (c). Hela cells were transfected with indicated siRNAs targeting histone methyltransferases and mRNA levels of siRNA targeted genes were measured by RT-qPCR. mRNA levels in non-targeting (NT) control siRNA transfected HeLa cells was set as 1. Data presented are mean ± SD from three independent experiments (n = 3).