Objective To observe the anti-tumor effect of apatinib(APa) combined with paclitaxel(PTX) at different sequential dosing on lung cancer.

Methods A549 lung cancer nude mice model was established and randomly divided into six groups: A: Control group (0.9% NS, D1-8); B: Apatinib alone group (APa, D1-7); C: Paclitaxel alone group (PTX, D1); D: Combined group 1 (PTX, D1; APa, D2-8); E: Combined group 2 (PTX, D1; APa, D1-7); F: Combinaed group 3 (APa, D1-7; PTX, D8). The day after the end of treatment, we used ELISA to detect the VEGFR2 concentration of blood, immunohistochemistry was used to measure the microvessel number, TUNEL assay was employed to detect the apoptosis cells of tumor, and PET/CT was used to probe SUV value. We observed and drew the tumor growth curve, and then calculated the tumor inhibition rate.

Results The tumor growth rate of treatment groups were all significantly slowed, compared with the physiological saline group (P < 0.05), and the tumor inhibition rate of all combined groups had no statistically significance compared with each other, respectively. The Combined group 2 showed most apoptotic cells, lowest VEGFR-2 levels and SUV value (P < 0.05), while the lowest MVD-CD31 expression in Combined group 2 had statistically significance compared with the physiological saline group, except the Combined group 3 (P < 0.05).

Conclusion Apatinib combined with paclitaxel shows the best effect on treating lung cancer.