Figure 4: Apoptotic induction by the knockdown of lamin A/C and cytokeratin 18 with small interfering RNAs (siRNA). (A) Silencing effects of irrelevant (control) siRNA, lamin A/C siRNA alone, cytokeratin 18 siRNA alone and both in the HCC2998 cells. The down-regulation of lamin A/C and cytokeratin 18 was determined by Western blots. (B) Cytoplasmic histone-associated DNA fragments released from the nuclei of apoptotic HCC2998 cells after respective siRNA silencing were measured by the Cell Death Detection™ ELISA kit (Bars: SD).