Download Supplemental Figure Legends

1
SUPPLEMENTAL FIGURES
2
Figure S1. PREX1 and PREX2 display distinct expression and mutation patterns
3
in breast cancer, prostate cancer, and melanoma. cBioPortal was used to generate:
4
(A) Alignment of PREX1 and PREX2 proteins with their mutation profiles in cutaneous
5
melanoma. Distribution of PREX1 (B) and PREX2 (C) mRNA expression and mutation
6
status in breast cancer, prostate cancer, and cutaneous melanoma TCGA samples.
7
Figure S2. PREX1 is differentially amplified in breast cancer, prostate cancer and
8
cutaneous melanoma. PREX1 copy number analysis for TCGA melanoma (A),
9
prostate (B), and breast cancer subtypes (C), generated from Oncomine.
10
Figure S3. PREX1 levels are regulated by ERK both transcriptionally and post-
11
transcriptionally. (A) BRAF-mutant SK-MEL-28 cells were treated with or without
12
vemurafenib or SCH772984 for 24 h and PREX1 mRNA levels were measured by
13
Taqman qPCR using two independent probes. (B) NRAS-mutant SK-MEL-147 cells
14
were treated with trametinib or SCH772984 for 24 h, and PREX1 mRNA levels were
15
measured as above. (C) NRAS-mutant SK-MEL-119 cells were treated with vehicle or
16
trametinib in the presence of 50 µg/ml cycloheximide for the indicated time points, and
17
lysates were probed by western blot for PREX1, pERK/total ERK and MYC. Results
18
were quantified using ImageJ (D). Data are represented as mean ± SD.
19
Figure S4. Loss of PREX1 does not alter ERK phosphorylation. Cells were first
20
treated with siRNA against PREX1 or a mismatch control (MM) for 48 h. Lysates of
21
BRAF-mutant cell lines A375 (panel A) and WM2664 (panel B), and NRAS-mutant cell
22
lines SK-MEL-119 (panel C) and Mel224 (panel D), were analyzed by western blot for
ERK regulates PREX1 expression in human melanoma
23
PREX1 and pERK/total ERK. Apparent molecular weights are indicated to the right of
24
each panel; vinculin served as a loading control.
25
Figure S5. ERK differentially regulates PREX1 in breast and prostate cancer cells.
26
T47D (A,B) and MCF7 (C,D) breast cancer cells and PC-3 (E,F) prostate cancer cells
27
were treated with or without trametinib or SCH772984 for 24 or 48 h. Lysates were
28
probed by western blot for PREX1, pERK/total ERK and MYC (A,C,E). Apparent
29
molecular weights are indicated to the right of each panel; vinculin served as a loading
30
control. Fold-change in PREX1 protein levels are indicated by the numbers under the
31
PREX1 panels. PREX1 mRNA levels were measured by Taqman qPCR after 24 h of
32
drug treatment (B,D,F). Data are represented as mean ± SD.
2