Figure 3.

Interleukin-6 and Hyper-IL-6 suppress proliferation of PDT-treated HeLa cells. (A) HeLa cells were treated with increasing concentrations of HPPH and exposed to 1 J cm⁻² of light. After irradiation, cells were plated in 6 cm dishes in the presence or absence of IL-6 cytokines (IL-6 100 ng ml⁻¹; Hyper-IL-6 160 ng ml⁻¹). After 14 days, colonies were fixed, stained with crystal violet and counted (colonies with >25 cells). The values represent means of a single experiment performed in triplicate, representative of three performed. (B) [³H]thymidine incorporation into HeLa cells. Post –PDT, cells were treated or not treated with 160 ng ml⁻¹ Hyper-IL-6. [³H]Thymidine incorporation after 48 h of treatment is plotted as the mean±s.d. of a single experiment performed in triplicate, representative of three independent experiments. ^*P<0.05, compared with the corresponding value of PDT alone.