Figure 4
From: BRAF inhibition sensitizes melanoma cells to α-amanitin via decreased RNA polymerase II assembly
Inhibition of oncogenic activated MAPK signaling creates a collateral vulnerability towards α-amanitin, similar as POLR2A hemizygous deletion. (A) POLR2A expression in melanoma cell lines with two copies of POLR2A (A375-P, UACC-62) or a monoallelic loss of one copy (IGR-37, SK-MEL-2). Each value represents the amount of mRNA relative to that in A375-P cells, which was arbitrarily defined as 1. TBP was used as the invariant control. Data are mean ± SD (n = 3 biological replicates). (B) Representative immunoblot for POLR2A in melanoma cell lines used in (A) (n = 3). α-Tubulin served as a loading control. (C) Drug response curves of indicated melanoma cell lines treated with increasing concentrations of α-amanitin. Data are mean ± SD (n = 3 biological replicates). (D) Drug response curves to α-amanitin of A375-P and SK-MEL-2 pre-treated (for 16 h) either with the indicated MAP-Kinase inhibitor or DMSO as control. Data are mean ± SD (n = 3 biological replicates).
