PNA-PCR amplified KRAS mutant DNA of FFPE sample exclusively.

<p>A Tumor tissue contains a GGT→GCT mutation. B Tumor tissue contains a GGT→GAT mutation. C Tumor tissue contains a GGC→GAC mutation.</p

Quantification of KRAS mutant DNA.

<p>Varying amounts of KRAS mutant DNA were plotted against Ct values (threshold cycle). Slope, r value and regression line are shown.</p

PNA-PCR assay could suppress wild-type DNA more completely in the existence of KRAS mutant DNA.

<p>(A) There are wild-type PCR products when adding 100 ng KRAS wild-type DNA in PNA-PCR assay. (B) There are only KRAS mutant PCR products when adding 100 ng wild-type DNA and 0.01 ng KRAS mutant DNA.</p

Calculation of KRAS mutation abundance in tumor cells.

<p>Calculation of KRAS mutation abundance in tumor cells.</p

Correlation between percentage of KRAS mutation in tumor cells and disease control rate.

<p>Correlation between percentage of KRAS mutation in tumor cells and disease control rate.</p

Patients’ mutation type and response to therapy.

<p>Patients’ mutation type and response to therapy.</p

Patients’ characteristics of the 35 patients receiving cetuximab.

<p>Patients’ characteristics of the 35 patients receiving cetuximab.</p

Influence of exosomes on expression of miRNAs and mRNAs detected in this study.

<p>Expression levels of (A) miRNAs and (B) mRNAs under normal conditions with and without exosome pretreatment. Fold-changes in expression of (C) miRNAs and (D) mRNAs under cisplatin with and without exosome pretreatment. Bars indicate mean ± SD of three replicates. *indicates p<0.05 versus control groups.</p

Isolation and characterization of exosomes.

<p>(A) Exosome isolation method used in this study. (B, C) Transmission electron microscopic image of the exosomes. Exosomes are small vesicles measuring from 30nm to 100 nm in diameter. (D) Western blot of CD63 and β-actin in exosomes and cells.</p

Influence of exosomes on sensitivity of cells to cisplatin.

<p>(A) Pretreatment of A549 cells with exosomes released during cisplatin (3 µg/mL) exposure decreases the sensitivity of cells to cisplatin by about 20% compared with those without pretreatment for 48 h. (B) Uptake of exosomes (red) by A549 cells after incubation for 3 h was visualized by microscopy. Scale bar: 50 µm. (C) Microscopic image of A549 cells cultured under four conditions [control, exosomes, DDP (3 µg/mL), exosomes+DDP] for 48 h. Images were obtained at a magnification of 100×. *in (A) indicates p<0.05 versus control groups.</p