IgG expression was strongly correlated to MTA1 expression and IgG down-regulation lowered MTA1 expression.

A, IgG was down-regulated with specific IGHG1 siRNA transfection with Real-time PCR. B, MTA1 expression was lowered following the decrease of IgG expression detected with Real-time PCR. C, typical bands represent the changes of IgG and MTA1 expressions after IGHG1 siRNA interference in A549 cell line. D, similar changes in SK-MES-1 cell line. E, Igγ (red, positive staining in cytoplasm) was mostly co-localized with MTA1 (purplish red, positive staining in nuclei) in lung cancers. Black arrows or arrowheads show typical cancer cells labeling with IgG and MTA1. F, lung cancers with weak IgG expression have a lower expression level of MTA1 in comparison to strong IgG expression cancers. G, lung cancers with lymph node metastasis have much higher MTA1 expression than non-metastatic cancers. The histograms represent the four independent assays. Data are presented as mean ± S.E. *, p<0.05. Scale bars: 20 µm.