Figure 2.

Reconstitution of HACE1 in a HACE1-null NK cell line induces apoptosis and cell cycle arrest. A: Vector or HACE1-transduced KAI3 cells were stained with Annexin V-PE and tested with fluorescence-activated cell sorting. B: Ectopic expression of HACE1 caused apoptosis in the KAI3 cell line (vector: 9.74% ± 0.92%, n = 2; HACE1: 89.04% ± 0.21%, n = 2). The rate of apoptosis was determined by measuring the proportion of Annexin V⁺ cells in the GFP⁺ population 2 days after transduction. Data are means ± SDs of two independent experiments. *P < 0.001 versus vector. C: Vector- or HACE1-transduced KAI3 cells were stained with Hoechst 33342, and the cell cycle profile on the GFP-gated population of vector- or HACE1-transduced KAI3 cells was determined with fluorescence-activated cell sorting. D: Ectopic HACE1 expression causes G₂/M cell cycle arrest in the KAI3 cell line [(%HACE1 − %Vector); (ΔG₀/G₁ = −23%, ΔS = 1%, ΔG₂/M = 12.9%)]. Data are means ± SDs of two independent experiments. E: HACE1 mRNA expression was determined in IL-2–activated PB NK cells. RPL13A was used as the housekeeping gene for normalization. F: HACE1 mRNA expression in cocultured primary NK cells is shown. *P < 0.05 versus Resting NK cells. G: Ectopic expression of HACE1 in KAI3 cells. RT-qPCR was applied on GFP⁺ KAI3 cells sorted 42 hours after transduction with vector or HACE1. RPL13A was used as the housekeeping gene for normalization. Data are means ± SDs of two independent experiments. *P < 0.001 versus vector.