Objective To investigate the radiosensitizing effects of gefitinib at different administration time. Methods Gefitinib was administered to A549 lung cancer cells in three different ways (method 1, 24 h before irradiation ;method 2, upon irradiation and method 3, 24 h after irradiation). Cell-surviving rates were evaluated by the colony-forming assays. Cell apoptnsis and cell-cycle distributions were detected by the flow cytometry (FCM). Protein expression of p21, Cdc25c, Bcl-2, Bax, Rad51 and phosphorylated DNA - PKcs (phnspho - DNA - PK) were measured with the Western blot analysis. Results The sensitizing effect ratio (ratio of D_0 value) was 2.23, 1.51 and 1.30 with method 1, 2 and 3, respectively. A higher apoptosis rate and more G_2/M phase arrest were observed with method 1 when compare with method 2 or 3. With the similar tendency, the protein level of p21, Cdc25c, Bcl-2, Bax, RadSl and phospho-DNA-PK changed distinctly. Conclusions Radiosensitizing effects are obtained in all three methods, with gefitinib delivered before irradiation being the best.

ObjectiveTo investigate the material basis and mechanism of Arnebia euchroma against hepatocarcinoma by network pharmacology， and to verify the potential targets of A. euchroma against hepatocarcinoma by molecular docking and experiments. MethodThe main active ingredients of A. euchroma were collected by retrieving the literature through China National Knowledge Network （CNKI） and Traditional Chinese Medicine System Pharmacology Database and Analysis Platform（TCMSP）. The active ingredients were screened out by FAFDrug4 platform according to the pharmacokinetics （ADME） properties of the drugs. The screening compounds and liver cancer targets were collected by using several databases and analyzed by drawing Venn diagrams. The protein-protein interaction （PPI） network was constructed by Cytoscape and STRING database. DAVID database was used to perform Gene Ontology （GO） functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis of key targets. Autodock was used to perform molecular docking of targets on core pathways. Cell counting kit-8 （CCK-8） experiment was carried out to validate the activities of five naphthoquinones. Based on the predicted results in the H22 tumor-bearing mouse model， the key targets of isovalerylshikonin against hepatocarcinoma were verified by hematoxylin-eosin （HE） staining， enzyme-linked immunosorbent assay （ELISA）， and Western blot assay. ResultFifty-five active ingredients and 34 targets of active ingredients against hepatocarcinoma were screened out. The active molecules with high degree values in the “drug-active ingredient-target-disease” network were mainly naphthoquinones. PPI network obtained several core targets of A. euchroma against hepatocarcinoma. Twenty-two pathways were screened out by KEGG analysis， mainly involving phosphatidylinositol 3-kinase/protein kinase B （PI3K/Akt）， vascular endothelial growth factor （VEGF）， tumor necrosis factor （TNF）， and other signaling pathways. The results of molecular docking showed that the five naphthoquinones had a good affinity with the targets of the PI3K/Akt signaling pathway. The results of CCK-8 and animal experiments showed that the lipid-soluble component isovalerylshikonin had good anti-cancer potential， and the high-dose group reduced the serum levels of VEGF and alpha fetoprotein （AFP） levels and elevated interferon-γ （IFN-γ） level （P<0.05， P<0.01）. The high-dose group also down-regulated phosphorylate（p）-Akt （Ser473） and B-cell lymphoma （Bcl）-2 protein expressions and up-regulated Bcl-2-antagonist of cell death （Bad） protein expression （P<0.01）. ConclusionA. euchroma can inhibit hepatocarcinoma cell proliferation and tumor angiogenesis and induce cancer cell apoptosis through the PI3K/Akt signaling pathway， which provides ideas and clues for the subsequent in-depth investigation of its specific mechanism.