Effect of zoledronate on LPA-induced stress fiber induction, a cellular effect dependent on RhoA geranylgeranylation. On D0, PNT1-A cells were seeded onto glass coverslips in 6-well plates to obtain 60% confluence on D3. On D1, the cells were serum-starved till fixation on D3. After treatment by the indicated drugs then stimulation by LPA (20 μM, 5 hours on D3), actin fibers were visualized by tetramethylrhodamine isothiocyanate-labeled phalloidin. Cells are viewed on a Zeiss Axiophot microscope (X 630), and pictures are taken with a Princeton camera.