Figure 5. Silica gel immobilization selects for cells that are more chemoresistant even while proliferative.

(A) Timeline for cisplatin treatment studies of cells either (i) surviving silica gel immobilization or (ii) recovered from hypoxia treatment or serum starvation. Recovery periods of three days after hypoxia or serum starvation and one week post-extraction allowed for similar cell densities and return to a proliferative state at the start of cisplatin treatment. (B) Response to cisplatin treatment of cells surviving silica gel immobilization (“Extracted+Cisplatin”) relative to cells maintained in 2-D culture conditions (“2-D+Cisplatin”). Fold change in viable cell number indicates cell number at Day 3 post-cisplatin treatment relative to cell number before drug treatment (*P < 0.05 relative to 2-D). (C,D) Fold change in viable cell number for cells recovered from (C) hypoxia (“Recovered Hyp+Cisplatin”) or (D) serum starvation (“Recovered SS+Cisplatin”) and treated with 0.5 μM cisplatin for 24 hours relative to proliferating cells grown in standard culture conditions (“Cisplatin”) after treatment. Fold change in viable cell number indicates cell number at Day 3 post-cisplatin treatment relative to untreated controls for each respective condition (*P < 0.05 compared to “Cisplatin”).