Nuclear expression of Rac1 in squamous intraepithelial lesions and cervical cancer cell lines. A. Representative images showing nuclear Rac1 expression in low-grade squamous intraepithelial lesions (L-SIL) and high-grade squamous intraepithelial lesions (H-SIL) but not in epithelium without squamous SIL. B. Representative images of immunocytochemical analysis showing nuclear Rac1 expression in cervical cancer cells C33A and SiHa, but not in non-tumorigenic Hacat cells. Magnification: 40×. C. Western blot analysis of Rac1 protein levels in cytoplasmic (C) and nuclear (N) protein extracts from HaCat, C33A and SiHa cells. D. Western blot analysis of Rac1 and Tiam1 protein levels in whole-cell extracts from HaCat, C33A and SiHa cells.