Figure 1. Nuclear irregularity of RCCs is responsible for progerin. (A) The irregularity of the nuclear membrane in human RCC cell line UMRC2 (C2). C2 cells were fixed and stained with Lamin A/C (LMA; green). Nuclear DNA was stained with DAPI (blue). Left panel shows the nuclear morphology of normal fibroblasts (29-y-old healthy subject). (B) Nuclear deformation in HGPS (HS). Cells were also stained with Lamin A/C (LMA; green) and DAPI. (C) Transcriptional expression of progerin (PG) in human cancer cell lines. Expression of progerin was determined by RT-PCR in RCC cell lines (Caki-2, C2, C2V, ACHN, A498, and A704) and non-RCC cell lines (A549 and HCT116) or normal fibroblasts (81-y-old and 29-y-old subjects) compared with HGPS cells (positive control). Because progerin is partially deleted from Lamin A (intra-deletion of 150 bp; arrow), the smaller Lamin A PCR product is progerin (arrowhead). We also confirm that this small band is progerin by cloning-sequencing method. In addition, we showed the relative expression of progerin regarding GAPDH as a graph using a densitometer (see below). (D) Progerin (PG) expression at the translational level in RCC cell lines. WB analysis showed the expression of progerin in C2, Caki-2, A704, and A498 cell lines, but not in A549 and HCT116 at the translation level. HGPS and normal fibroblasts were used for positive and negative controls for PG. We also showed the expression of pVHL and Lamin A/C. Actin was used as a loading control. (E) Si-progerin (Si-PG) ameliorates the nuclear deformation of HGPS (HS). HGPS cells were stained with Lamin A/C after transfection with si-progerin (Si-PG). Si-C indicates scrambled si-RNA. In contrast, progerin transfection induces nuclear deformation in 293 cells (bottom). (F) Si-progerin (Si-PG) ameliorates the nuclear deformation of RCCs. C2 and Caki-2 cells were transfected with si-progerin for 24 h and stained with Lamin A/C and DAPI.