Figure 4.

Aspirin plus erlotinib inhibited invasion and migration of cancer cells. (A) Cancer cells were gently scratched with a sterile pipette tip and then washed with PBS three times. Next, cancer cells were incubated with 2 mM aspirin, 2.5 µM erlotinib or the combination for indicated times. Photographs were taken by microscope. (B) Cancer cells were seeded in the upper chamber and then cells were incubated with 2 mM aspirin, 2.5 µM erlotinib or the combination for 24 h. Cancer cells invaded the underside of the membrane were fixed in 1% methanol and stained by crystal violet. Quantification of invaded A549 (C) and SGC-7901 (D) cells were counted in Matrigel Transwell invasion assays.