Journal: Frontiers in Oncology
Article Title: Disrupting PTPRJ transmembrane-mediated oligomerization counteracts oncogenic receptor tyrosine kinase FLT3 ITD
doi: 10.3389/fonc.2022.1017947
Figure Lengend Snippet: Signaling analysis of THP-1 (A) MV4-11 (B) and 32D FLT3 ITD cells expressing TMD mutant PTPRJ. (A) THP-1 PTPRJ KO cells or cells re-expressing PTPRJ wt, G979L, or G983L were starved for 4 h in serum-free medium, then stimulated with 200 ng/ml FLT3 ligand for 5 min (+FL) or left unstimulated (–FL) and lysed in RIPA buffer. (B, C) MV4-11 and 32D FLT3 ITD PTPRJ KO cells or cells re-expressing PTPRJ wt, G979L, G983L, or G987L were starved for 4 h in serum-free medium and treated with DPI (0.5 µM), AC220 (20 nM), or mock (DMSO), as indicated, then lysed in RIPA buffer. Equivalent amounts of protein samples were separated by SDS-PAGE and blotted to a nitrocellulose membrane. Blots were first probed by phospho-site specific antibodies recognizing pSTAT5 (Y694), pAKT (S473), and pERK1/2 (T202/Y204). Blots were re-probed for total STAT5, AKT, and ERK1/2 and subsequently analyzed with antibodies recognizing vinculin (124 kDa) and beta-actin (42 kDa) as a loading control. Left : Representative immunoblots are shown. Dashes indicate positions of molecular weight standard bands. 79 – G979L; 83 – G983L; 87 – G987L Right : Quantification of specific phosphorylation of AKT, ERK1/2, and STAT5 in relation to the total protein level. Values were normalized to FL-stimulated or DPI treated wt and are given as mean ± standard deviation, n = 3 - 4. Statistics: two-way ANOVA and Dunnett’s multiple comparisons test; *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001 compared to respective wt.
Article Snippet: The IL-3-dependent murine myeloid cell line 32D clone 3 (32D) (German Collection of Microorganisms and Cell Cultures (DSMZ), Braunschweig, Germany) was maintained in RPMI 1640 medium supplemented with sodium pyruvate (5 mg/ml), 10% heat-inactivated fetal calf serum (FCS), L-glutamine (2 mM), and IL-3 (1 ng/ml).
Techniques: Expressing, Mutagenesis, SDS Page, Membrane, Control, Western Blot, Molecular Weight, Phospho-proteomics, Standard Deviation