Fig. 4: CEACAM6 expression enhances EGFR stability in lung adenocarcinoma.

A RNA-seq analysis evaluating the correlation of CEACAM5 (left) and CEACAM6 (right) expression with EGFR status [wild-type (n = 193) versus mutant (n = 20) EGFR] in lung cancer cells from the CCLE database. *P < 0.05. B RNA-seq analysis assessing the correlation of CEACAM5 (left) and CEACAM6 (right) expression with EGFR status [wild-type (n = 444) versus mutant (n = 73) EGFR] in lung adenocarcinoma (n = 517) from the TCGA-LUAD database. C Dot-plot analysis assessing the correlation between p-EGFR (pY1068) and CEACAM6 by RPPA profiling and RNA-seq, respectively, from the TCGA-LUAD database (n = 357). D Co-immunoprecipitation analysis using an anti-CEACAM6 antibody to assess the interaction of CEACAM6 with EGFR in HCC827 and HCC827GR cells. E Immunoblotting analysis assessing EGFR and p-EGFR expression in HCC827 versus HCC827GR cells treated with cycloheximide (CHX, 50 ng/ml) for the indicated periods. F Immunoblotting analysis assessing CEACAM6 expression in HCC827GR cells transduced with the lentiviral vector encoding Flag-CEACAM6 or control vector. G Immunoblotting analysis assessing EGFR and p-EGFR expression in HCC827GR cells transduced with Flag-CEACAM6 or control vector followed by treatment with cycloheximide (CHX, 50 ng/ml) for the indicated periods. H Clonogenic assays of HCC827 cells transduced shCEACAM6 or scramble control in the presence of gefitinib (100 nM) for 14 days. The mean colony area (%) is presented relative to shCEACAM6-transduced cells treated with gefitinib (set as 100%), with error bars representing the standard deviation. *P < 0.05. I Clonogenic assays in HCC827GR cells transduced with Flag-CEACAM6 or control vector in the presence or absence of gefitinib (1 μM) for 14 days. The mean colony area (%) is presented relative to control or CEACAM6-overexpressing cells in the absence of gefitinib (set as 100%), with error bars representing the standard deviation. **P < 0.01.