Expression data from functional studies using RNAi on Lamin B1 in BL2 cells

Lamin B1 is a component of the nuclear envelope involved in epigenetic chromatin regulation and is reduced during B cell activation and formation of lymphoid germinal centres. RNAi-mediated reduction of Lamin B1 results in spontaneous SHM as well as kappa-light chain aberrant surface expression showing that Lamin B1 is a negative epigenetic regulator of SHM. We used Affymetrix Exon 1.0 ST microarrays to detail the global programme of gene expression underlying changes induced in siRNA-treated Lamin B1low BL2 cells. siRNA-mediated reduction of nuclear Lamin B1 incorporation resulted in a general upregulation of positive cell cycle regulatory genes which in turn occurred alongside an upregulation of genes responsible for cell cycle checkpoint execution or cell cycle arrest, and were specific for LMNB1 reduction. Gene expression profiling on BL2 cell line was conducted for 2 independently cultured passages with 4 experimental approaches each, with 1) control with non-targeting siRNA 2) control with non-targeting siRNA and after induction of SHM 3) LMNB1 RNAi transfected 4) LMNB1 RNAi transfected and after induction of SHM. For siRNA treated samples, SMARTpool LMNB1 siRNA mixture of three siRNAs in equimolar concentration was used.