Fig. 5. The protamine-conjugated EGFR-monoclonal antibody complex binds siRNA, internalises via the endosomal pathway specifically into EGFR-expressing cells, inhibits KRAS expression upon KRAS-siRNA transport, and specifically inhibits cellular colony formation.

A Vesicular tracking in A549 NSCLC cells. Cells treated with αEGFR-mAB-P/Alexa488-siRNA/P were subjected to Lysotracker red staining. The vesicles containing Alexa488 rarely colocalized with Lysotracker staining (merged picture see white arrows for green Alexa-siRNA fluorescence outside red lysosomes). B Western blot for KRAS of two NSCLC cell lines treated with PBS, carrier-control-siRNA and carrier-KRAS siRNA accompanied by blot for actin as loading control (same blot). C–E In vitro response of colony growth to treatment with KRAS mutation-specific siRNAs. Cell lines indicated were pre-incubated with antibody-conjugates coupled to siRNAs, resuspended in soft agar and cultivated for ~1 week. Cntr-siRNA, control-siRNA; PBS, vehicle control without active treatment. Mean ± SD of three independent experiments. Two-sided t-test, *p < 0.05. Specific molecular characteristics of the cell lines are given in parenthesis.