Figure 6.

Targeted intervention of the expression of mitogen‐activated protein kinase 4 (MAPK4) could inhibit the growth of non‐small cell lung cancer (NSCLC) tumor in vivo. Lewis lung carcinoma (LLC) cells (5 × 10⁵) were subcutaneously injected into the right flanks of wild‐type (WT) C57BL/6 mice. Tumors were collected on day 21. (a) Schematic diagram showing subcutaneously injection of LLC cells (5 × 10⁵) into the right flanks of WT mice. Seven days later, the constructed PGL3.0 basic‐CD34 promoter‐MAPK4 RNA interference (RNAi) eukaryotic expression vectors (termed as p‐siMAPK4) or p‐cont given by subcutaneous injection into the left flank of murine NSCLC tumor model three times every 3 days. Tumor growth was monitored every 2 days to generate the growth curve, and tumors were collected on day 14. (b) Tumor size. (c) Tumor volume and (d) tumor weight. (e) Tumor pathology was analyzed by hematoxylin‐eosin (H&E) staining. The arrows indicate neovascularization. (f–h) The expression of MAPK4 and CD34 in tumors was analyzed by immunofluorescence and quantitated. (i, j) Cell proliferation nuclear antigen (Ki67) expression in tumors was analyzed by immunofluorescence and quantitated. Representative data from three independent experiments were shown. *p < 0.05, **p < 0.01.