Figure 1. GKN1 induces telomeres shortening in gastric cancer cells.

(A) Stable GKN1 transfectants, AGS^GKN1 and MKN1^GKN1 (left panel), and transient GKN1 transfectants (right panel), showed marked expression of GKN1 by Western blot analysis. (B) In the MTT assay, GKN1 stable cells showed time-dependent inhibition of cell viability. (C) Telomere length and telomerase activity decreased significantly in AGS and MKN1 cells transiently transfected with GKN1, compared with those in non-transfected negative control and mock-transfected cells. (D) AGS^Mock, MKN1^Mock, AGS^GKN1, and MKN1^GKN1 cells were serially cultivated for 13 passages until the cells reached the end of their lifespan. The cumulative PDL diminished significantly after passage 1 and exhibited minimal proliferative activity after passage 4 in GKN1 stable transfectants. (E) A steady decline in telomere length and telomerase activity was observed with advancing passages in AGS^GKN1 and MKN1^GKN1 cells. (F) Stable transfectants from passage 5 showed significant shortening of telomeres, as well as decreased telomerase activity and hTERT mRNA expression in a time-dependent manner.