Figure 2.

IL-8 mRNA production of stimulated and unstimulated metastatic and nonmetastatic cells. Total RNA was extracted from untreated (control) cells, and from cells that were stimulated for 3 hours with either 1 ng/ml IL-1β or 4 ng/ml TNF-α. First-strand cDNA was produced by amplification with 1 μg of RNA using oligo-dT primers. Thirty-five cycles of PCR were performed using primer sets amplifying a 289-bp segment of the human IL-8 gene (A). Twenty-five cycles of PCR were performed using a β-actin primer set amplifying a 643-bp segment of the human β-actin gene (B).