Journal: Cancer cell
Article Title: RAC1 P29S Induces a Mesenchymal Phenotypic Switch via Serum Response Factor to Promote Melanoma Development and Therapy Resistance.
doi: 10.1016/j.ccell.2019.05.015
Figure Lengend Snippet: Figure 1. Effect of Activation of RAC1P29S on Survival of Melanocytes (A) Schematic of the ER-RAC1P29S fusion protein system. ER, estrogen receptor; 4OHT, 4-hydroxytamoxifen; HSP, heat shock protein. (B) RAC1-GTP assay in MCF10A cells (left) and mouse melanocyte cell line melan-a (right) stably expressing ER-RAC1P29S. Cells were treated with 500 nM 4OHT for 24 h and ER-RAC1P29S binding to the PAK1 RAC1 binding domain was assessed using a pull-down assay. (C) PAK1/2 and ERK1/2 phosphorylation by ER-RAC1P29S in melanocytes. Cells were treated with 500 nM 4OHT for 24 h. (D) Quantification of phospho-PAK1/2 and phospho-ERK1/2 levels detected by immunoblotting, normalized using vinculin loading control (n = 3 or more in- dependent experiments); t test versus 0 h was used with Holm-Sidak correction for multiple testing; *p < 0.05, ***p < 0.001; n.s., not statistically significant. (E) Morphological changes induced by ER-RAC1P29S activation in melan-a melanocytes treated with 500 nM 4OHT. (F) Viability of melan-a melanocytes with ER-RAC1P29S in growth factor-reduced medium (fetal calf serum [FCS] 0.25%, 12-O-tetradecanoylphorbol-13-acetate [TPA]-free). Cells were treated with 1 mM 4OHT and viability was quantified using CellTiter-Glo (n = 3 independent experiments); t test was used for statistical comparison. (G) Soft agar sphere formation of melan-a melanocytes with activated ER-RAC1P29S. Cells were grown in full medium containing 1 mM 4OHT for 3 weeks before staining, imaging, and automated counting (n = 3 biological replicates). (H) Effect of activation of ER-RAC1P29S on apoptosis in melan-a melanocytes. Cells were treated with 1 mM 4OHT. Cleaved caspase-3 was quantified and normalized to cell viability (n = 2 independent experiments, three biological replicates per experiment). Bars represent means ± SD. See also Figure S1.
Article Snippet: REAGENT or RESOURCE SOURCE IDENTIFIER Antibodies phospho-AKT (T308) CST #13038 phospho-AKT (S473) CST #9271 phospho-AKT (S473) CST #4060 AKT CST #2920 phospho-ERK1/2 (T202/T204) CST #9101 ERK1/2 CST #9107 phospho-PAK1/2 (S199/192) CST #2605 phospho-PAK1/2 (T423/402) CST #2601 PAK1/2/3 CST #2604 phospho-MEK1/2 (S217/221) CST #9145 RAC1 (23A8) Merck Millipore 05-389 Vinculin (hVIN-1) Sigma-Aldrich V9131 Myc (9E10) In-house (CRUK LRI) N/A Vimentin (EPR3776) Abcam ab92547 N-cadherin CST #13116 c-Jun CST #9165 phospho-c-Jun (S73) CST #9164 ER (MC-20) Santa Cruz sc-542 Fibronectin Abcam ab2413 phospho-BRAF (S445) CST #2696 phospho-CRAF (S338) CST #9427 S100 (4C4.9) Abcam ab4066 SOX10 (A2) Santa Cruz sc-365692 p16 (EPR1473) Abcam ab108349 p27 (F-8) Santa Cruz sc-1641 B220 (RA3-6B2) BD Biosciences 553086 B220-BV510 Biolegend RA3-6B2 CD19-BV605 Biolegend 6D5 CD38-APC Biolegend 90 CD95-BV421 BD Biosciences Jo2 CD138-BV786 BD Biosciences 281-2 NK1.1-PE Biolegend PK136 CD44-APC Ebioscience IM7 CD62L-PeCy7 Ebioscience MEL-14 CD3e-PerCPEFluor710 Ebioscience 145-2C11 CD4-BV421 Biolegend GK1.5 CD8a-FITC Ebioscience 53-6.7 PTEN CST #9559 Chemicals, Peptides, and Recombinant Proteins 4OH-tamoxifen Sigma-Aldrich H6278 Tamoxifen Sigma-Aldrich T5648 CCG-1423 Selleckchem S7719 CCG-203971 Tocris 5277 (Continued on next page) e1 Cancer Cell 36, 68–83.e1–e9, July 8, 2019
Techniques: Activation Assay, Stable Transfection, Expressing, Binding Assay, Pull Down Assay, Phospho-proteomics, Western Blot, Control, Comparison, Staining, Imaging