Research Paper Volume 11, Issue 1 pp 33—47

HPV-18 E2 protein downregulates antisense noncoding mitochondrial RNA-2, delaying replicative senescence of human keratinocytes

Figure 7. Lentiviral transduction of HPV-18 E2 induces downregulation of both ASncmtRNA-1 and ASncmtRNA-2 in HFK. In consequence, replicative lifespan is extended from 8 to 26 passages, when cells become senescent. HFK, at passage 8 (p8), arrest at G1, concomitant with increase of the p21 tumor suppressor protein. In contrast, E2-expressing HFK arrest at p26 in G2/M, while p21 decreases and cells are binucleated. Remarkably, in both cases, ASncmtRNA-2 is upregulated and SncmtRNA is downregulated upon senescence, while ASncmtRNA-1 remains downregulated in HFK-E2 and constant in HFK and HFK-ZsG.