암세포에서 송엽의 AP-1(c-fos/c-jun)에 미치는 영향

Effect of Pini Folium Extract on AP-1 (c-fos/c-jun)in Cancer Cells

Phorbol ester, growth factors activities are mediated by nuclear transcription factors, the c-Fos and c-Jun, which can regulate transcriptional activation through specific DNA sites and by forming the transcription factor AP-1, which usually mediates cell proliferation and differentiation signals. We explored effects of Pini Folium extract (API-1) on AP-1 activity. Western blot analysis confirmed that API-1 decreased levels of c-Fos or c-Jun protein induced by the tumor promoter Phorbol 12-myristate 13-acetate (PMA; 200nM). Transient transfection assays with a c-fos promoter reporter construct showed that API-1 decreased transcription activity by more than 50-60%. However, treatment of API-1 did not reduce the abundance of nuclear proteins binding to an consensus AP-1 binding site. Partition of the API-1 extract in organic solvents yielded semi-purified fractions whose anti-AP-1 activity studied further. The main substances were fractionated into dichloromethane layer. Futhermore, API-1 extract repressed the [3H]-thymidine uptake in C6 glioma cells, indicating that this extract could be included in a new type of modulator in the mitogenesis.