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. 2023 Jan 18;120(4):e2218118120. doi: 10.1073/pnas.2218118120

Fig. 5.

Fig. 5.

BETi upregulate CBX5 expression and sensitize EGFRi-resistant LUAD cell lines to erlotinib. (A) Immunoblot analysis measuring expression of CBX5 in the indicated EGFRi-resistant LUAD cell lines treated with the BETi JQ1 (2 μM) or PFI-1 (2 μM) for 48 h. (B) The indicated EGFRi-resistant LUAD cell lines were treated with erlotinib (100 nm), JQ1 (1 μM), or PFI-1 (1 μM) alone, or with a combination of erlotinib (100 nM) + JQ1 (1 μM) or erlotinib (100 nM) + PFI-1 (1 μM), and survival was measured in clonogenic assays. Representative wells for cells grown under the indicated conditions are shown. (C) HCC827-R2 cells expressing an NS or CBX5 shRNA were treated with DMSO, erlotinib (25 nM), or JQ1 (0.125 μM) alone, or with a combination of erlotinib (25 nM) + JQ1 (0.125 μM), and survival was measured in clonogenic assays. Representative wells for cells grown under the indicated conditions are shown. (D) EGFRi-resistant PC9 cells (PC9-R2) were injected subcutaneously into the flank of NSG mice (n = 5), and mice were treated with vehicle (0.5% methylcellulose/5% dextrose), erlotinib (25 mg/kg), JQ1 (50 mg/kg), or erlotinib (25 mg/kg) + JQ1 (50 mg/kg). Average tumor volumes at the end of the experiment are shown. Data are presented as the mean ± SEM. ns = not significant; *P < 0.05, **P < 0.01.