Relation between PI3-kinase activity and HPV oncogene expression. (A) HPV16E7 mRNA expression in FK16A cells at immortal (p36) and anchorage independent (p99) stage as determined by qRT-PCR. (B) HPV16 mRNA expression in anchorage independent FK16A cells (p122) after PI3-kinase inhibition determined by Northern blot using an HPV16 radio-labeled probe. (C) HPV16E7 mRNA expression determined by qRT-PCR after PI3-kinase inhibition relative to mock treatment (p189). * Indicates a statistical significant difference. (D) hTERT mRNA expression determined by qRT-PCR in anchorage independent FK16A cells (p118) silenced for PIK3CA compared to FK16A cells transfected with non-targeting siRNAs. P: passage.