Figure 6: HMGA1 regulates drug resistance in NSCLC.

(a) Validation of HMGA1 through western blotting using an HMGA1-pS102 site-specific antibody and an HMGA1 antibody. (b) Knockdown of CK2 reduces HMGA1 phosphorylation. (b) Confirmation that HMGA1 is a CK2 substrate through an in vitro kinase assay using synthetic peptides of HMGA1 and CK2 kinase, followed by detection via MALDI-TOF MS. (d) RT-PCR analysis of the efficiency of HMGA1 knockdown in PC9 and PC9/gef cells; shLacZ virus infection was used as a negative control. (e) Histogram of the cell survival rate (%) after knockdown using control shRNA, shLacZ and shHMGA1 (C1-2 and E1-2) (mean ± SE in triplicate experiments). (f) Cytotoxicity assays for various concentrations of gefitinib in HMGA1-knockdown PC9 and PC9/gef cells.