Transcription of genes encoding matrix metalloproteinases (MMPs) in HepG2 cells. HepG2 cells were cultured for 6 days in HepG2 cell culture medium and the mRNA levels of MMPs (MMP1, MMP2, MMP3, MMP8, MMP9, MMP10, and MMP13) were quantitatively monitored using real-time PCR. MMP3 exhibited the highest mRNA level; the expression of the remaining MMP genes decreased in the following order: MMP2 > MMP10 > MMP1 > MMP13 > MMP8 > MMP9. Data are shown as the mean ± standard deviation (SD) of four independent experiments. *p < 0.05.