Fig. 2.

HCC827 parental cells barely express ACE2. (A) Flow cytometry results show that ACE2 is clearly expressed at the protein level in HCC827 GR2 cells while it is barely expressed in the parental cells. (B) Conventional and quantitative RT-PCR for the expression of ACE2 mRNA in HCC827 parental and GR2 cells. bp, base pair; P, parent; G, GR2. (C) Viability of HCC827 parental cells and GR2 cells incubated with control IgG-DT3C conjugate or H8R64-DT3C conjugate for 72 h. Results are presented as means ± SD from triplicate cultures. **P < 0.01. (D) Flow cytometry results reveal that ACE2 is hardly expressed in parental cells or TKI-resistant cells derived from HCC4006 and H1975 cells.