Regulation of low-dose bevacizumab on claudin5 through PI3K. A. Western blot showed that low-dose bevacizumab (bevacizumab 10 μg/mL) up-regulated P-JNK and P-PI3K in HUVECs. B. Western-blot showed the changes of claudin5 and P-PI3K protein levels after PI3K inhibitor (LY294002) and/or low-dose bevacizumab treatment in HUVECs. LY294002 inhibited both the expression of P-PI3K and claudin5. C. Changes of claudin5 mRNA levels after bevacizumab and/or LY294002 treatment, which were consistent with the western blot, **P < 0.005. D. Western blot showed the changes of claudin5 and P-PI3K protein levels under low-dose bevacizumab and/or PI3K siRNA treatment in HUVECs. E. mRNA levels of claudin5 following low-dose bevacizumab and/or siRNA of PI3K treatment in HUVECs, ***P < 0.0005, ****P < 0.0001. F. Changes of claudin5 and P-PI3K protein under LY294002 and/or low-dose bevacizumab treatment by western-blot in MRMECs, which were consistent with HUVECs. All data were expressed as mean ± SD, and all statistical analyses were performed by one-way ANOVA.