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. 2017 Jan 9;8(8):13464–13475. doi: 10.18632/oncotarget.14562

Figure 4. Differential regulation of resistance to [pemetrexed + sorafenib + sildenafil] by the PI3K, ERK1/2 and STAT signaling pathways.

Figure 4

(A) HCT116 cells (parental wild type; K-RAS D13 deleted, C2; C2 cells transfected to express H-RAS V12, C10; C2 cells transfected to express H-RAS V12 C10-35 that activates the ERK1/2 pathway; C2 cells transfected to express H-RAS V12 C10-40 that activates the PI3K pathway) were treated for 12 h with vehicle control or with pemetrexed (1.0 μM), sildenafil (2.0 μM), sorafenib (2.0 μM), alone or in combination as indicated. Floating cells were then cytospun onto the 96 well plate and cell viability determined. The percentage cell death under each transfection and treatment condition was calculated and values with a statistical significance lower than the corresponding value CMV cells are in red; those whose value is greater than in CMV cells are green (*p < 0.05 less than corresponding value in wild type cells; #p < 0.05 greater than corresponding value in wild type cells). (B) A549 cells were transfected with an empty vector plasmid (CMV) or with plasmids to express: activated AKT; activated MEK1; activated mTOR; activated p70 S6K; alone or in the indicated combinations. CMV transfected cells were treated with the JNK inhibitory peptide as indicated (10 μM). Twenty-four h after transfection were treated for 12 h with vehicle control or with pemetrexed (1.0 μM), sildenafil (2.0 μM), sorafenib (2.0 μM), alone or in combination as indicated. Floating cells were then cytospun onto the 96 well plate and cell viability determined. The percentage cell death under each transfection and treatment condition was calculated and values with a statistical significance lower than the corresponding value CMV cells (*p < 0.05 less than corresponding value in CMV cells). (C) H460 cells were transfected with an empty vector plasmid (CMV) or with plasmids to express: activated AKT and activated STAT3. Twenty-four h after transfection were treated for 12 h with vehicle control or with pemetrexed (1.0 μM), sildenafil (2.0 μM), sorafenib (2.0 μM), alone or in combination as indicated. Floating cells were then cytospun onto the 96 well plate and cell viability determined. The percentage cell death under each transfection and treatment condition was calculated and values with a statistical significance lower than the corresponding value CMV cells are in red; those whose value is greater than in CMV cells are green (*p < 0.05 less than corresponding value in CMV cells).