KSHV-infected cells express enhanced levels of VEGF-A. (A) An ELISA was performed to quantify levels of VEGF-A present in the culture supernatant of various target cells. Each reaction was done in triplicate and each point represents the average ± SD of 3 experiments. (B) Northern blot analysis of VEGF-A expression in cells. Target cells were either untreated or treated with 50 μM of PD98059 at 37°C. After 1 hour incubation, the cells were lysed and total RNA was isolated from the cells. The total RNA was subjected to Northern blotting as per standard protocols to monitor VEGF-A and β-actin mRNA.