Fig 6. CB-5083-resistant MV4-11 cells exhibit features of permanent endoplasmic reticulum (ER) stress but no apoptosis.
(A) Immunoblot showing induction of ER stress in inhibitor-resistant cells after a few months of continuous treatment with 200 and 500 nM CB-5083. (B and C) Flow cytometry analysis using Annexin V and 7-AAD staining showed decreased apoptosis in CB-5083-resistant cell lines. (D and E) IC50 values for CB-5083 in the indicated cell lines upon withdrawal and re-treatment with CB-5083. (F) Analysis of the coding sequence of VCP identified a variant (c.1591C>A p.I531L) in the cell line treated with 1 μM CB-5083.