Ampelopsis japonica enhances the effect of radiotherapy in non-small cell lung cancer

Abstract

Background: Radiotherapy is widely used in the clinical treatment of non-small cell lung cancer (NSCLC); however, its effectiveness often proves unsatisfactory. Ampelopsis japonica (AJ) is a traditional Chinese herb with anti-inflammatory and anticancer activities. However, whether AJ could enhance the effect of radiotherapy in NSCLC needs to be further explored.

Methods: In vivo, BALB/c nude mice were used for a xenograft tumor model to explore whether AJ could enhance the effect of radiation therapy (RT) in NSCLC. In vitro, human NSCLC cell lines HCC827 and H1299 were used to explore the effect of AJ on the cell proliferation and apoptosis of RT-treated NSCLC. Moreover, bioinformatic analysis was performed to analyze the signaling pathways regulated by AJ.

Results: Ampelopsis japonica enhanced the inhibitory effect of RT on NSCLC tumor growth in vivo. Simultaneously, AJ further enhanced the inhibitory effect of RT on NSCLC proliferation and the promoting effect of RT on NSCLC apoptosis. Bioinformatic analysis showed that AJ regulated the PI3K-Akt signaling pathway. We confirmed that AJ decreased the protein levels of the PI3K-Akt signaling pathway. Furthermore, the combination of AJ and RT suppressed activation of the PI3K-Akt signaling pathway.

Conclusion: Ampelopsis japonica augmented the inhibitory impact of RT on NSCLC cell proliferation and tumor growth by suppressing the PI3K-Akt signaling pathway.

Keywords: Tumor growth; Apoptosis; Medicine, Chinese traditional; PI3K-Akt signaling pathway; Radiation therapy.

Fig. 1

Ampelopsis japonica (AJ) suppresses cell survival and proliferation of NSCLC in vitro. a The cell survival rate of HCC827 and H1299 cells treated by different doses (0 ~ 400 μg/mL) of AJ was detected by CCK‑8 assay. *P < 0.05. b The cell survival rate of HCC827 and H1299 cells after treatment with AJ (25 μg/mL) and radiotherapy (RT; 8 Gy) was detected by CCK‑8 assay. c The proliferation of HCC827 and H1299 cells after treatment with AJ (25 μg/mL) and RT (8 Gy) was detected by colony formation assay. The results are presented as the mean ± standard deviation of three independent experiments, each preformed in triplicate. The differences among groups were analyzed using one-way ANOVA followed by Tukey’s test or by Kruskal–Wallis test followed by Dunn’s test (*P < 0.05 vs. the control group; ^#P < 0.05 vs. the RT group)

Fig. 2

Ampelopsis japonica (AJ) promotes cell apoptosis of NSCLC in vitro. a The apoptotic rate of HCC827 and H1299 cells after treatment with AJ (25 μg/mL) and radiotherapy (RT; 8 Gy) was detected by flow cytometry. b The protein expression of c‑caspase‑3, Bax, and Bcl‑2 in HCC827 and H1299 cells after treatment with AJ (25 μg/mL) and RT (8 Gy) was detected by western blot. The results are presented as the mean ± standard deviation of three independent experiments, each preformed in triplicate. The differences among groups were analyzed using one-way ANOVA followed by Tukey’s test or by Kruskal–Wallis test followed by Dunn’s test (*P < 0.05 vs. the control group; ^#P < 0.05 vs. the RT group)

Fig. 3

Detection and bioinformatic analysis of the active ingredients of Ampelopsis japonica (AJ). a The active components of AJ were analyzed using the TCMSP database. The screening criteria were oral bioavailability (OB) ≥ 30% and drug-likeness (DL) ≥ 0.18. b Venn diagram of the lung cancer-related genes and the Ampelopsis japonica target genes. The lung cancer-related genes were searched from the GeneCards, and the targets of AJ were analyzed in the DrugBank database. c The GO functional enrichment analysis for the selected targets was performed using R software (R Foundation, Vienna, Austria). d KEGG pathway enrichment analysis for the selected targets was performed using R software

Fig. 4

Ampelopsis japonica (AJ) inhibits the PI3K-Akt signaling pathway. a, b The protein expression of the PI3K-Akt signaling pathway in NSCLC cells after treatment with AJ (25 μg/mL) and radiotherapy (RT; 8 Gy) was detected by western blot. The results are presented as the mean ± standard deviation of three independent experiments, each preformed in triplicate. The differences among groups were analyzed using one-way ANOVA followed by Tukey’s test or by Kruskal–Wallis test followed by Dunn’s test (*P < 0.05 vs. the control group; ^#P < 0.05 vs. RT the group)

Fig. 5

Ampelopsis japonica (AJ) suppresses tumor growth of NSCLC in a xenograft model mice. a The administration process of the animal experiment. Mice were inoculated subcutaneously with NSCLC cells. Mice of the RT groups were treated with 8 Gy of local RT at day 10, day 12, and day 14. Mice of AJ groups were administered different doses of AJ daily by oral gavage on days 10–24. Tumor tissues were collected at the indicated timepoints for subsequent analysis. b Pictures of tumor tissues of each group. c Tumor weight of xenograft model mice. d Tumor volume of xenograft model mice. The results are presented as the mean ± standard deviation of three independent experiments, each preformed in triplicate. The differences among groups were analyzed using one-way ANOVA followed by Tukey’s test or by Kruskal–Wallis test followed by Dunn’s test (*P < 0.05 vs. the control group; ^#P < 0.05 vs. the RT group)