Journal: Cancer letters
Article Title: Human papillomavirus insertions identify the PIM family of serine/threonine kinases as targetable driver genes in head and neck squamous cell carcinoma
doi: 10.1016/j.canlet.2020.01.012
Figure Lengend Snippet: (A) Western blot analysis of PIM1 expression and (B) cell proliferation curves (y-axis, Log10 average cell count) of parental UPCI:SCC090 cell line, 2 negative controls (empty vector mock-edited by CRISPR, clones C1, C2), and 5 PIM1 knockout clones (gene edited by CRISPR, clones C9, C2, C5, C4, C11) cultured over time (x-axis, days). Key: colors, symbols: cell clones. Slopes of linear regression lines indicative of growth rates are: parental, 0.157; empty C1,0.156; empty C2, 0.157; PIM1 C9, 0.135; PIM1 C2, 0.148; PIM1 C5, 0.104; PIM1 C4, 0.121; and PIM1 C11, 0.066. Error bars, range of cell counts in duplicate wells. (C) Western blot analysis of downstream proteins and phosphorylation targets of PIM1, in a selected PIM1 knockout clone derived from UPCI:SCC090 cells by CRISPR gene editing, compared with parental UPCI:SCC090 control cells. (D) Schematic of possible mechanism of resistance in response to PIM inhibition in HNSCC cells such as CAL 27 cells, through feedback loops involving increased expression of PIM protein through STAT activation. Downstream targets of PIM kinases are displayed showing activating (green) and inactivating (orange) phosphorylation, and biological responses associated with these signaling interactions. GF, growth factor ligand, e.g. EGF, epidermal growth factor; RTK, receptor tyrosine kinase, e.g. EGFR, epidermal growth factor receptor; STAT, signal transducer and activator of transcription. See also Supp. Figs. S6 and S11.
Article Snippet: Dual inhibition of PIM and EGFR pathways To assay effects of PIM pathway inhibition on cell viability, cell lines were treated with pan-PIM inhibitor INCB053914 (Incyte Corp.) [ 18 ], or the PIM1 inhibitors Quercetagetin (Santa Cruz Technologies) or PIM1 Inhibitor 2 (Santa Cruz Technologies), or a negative control, DMSO, as described in Supplementary Methods .
Techniques: Western Blot, Expressing, Cell Counting, Plasmid Preparation, CRISPR, Clone Assay, Knock-Out, Cell Culture, Phospho-proteomics, Derivative Assay, Control, Inhibition, Activation Assay