Overcoming Basal Autophagy, Kangai Injection Enhances Cisplatin Cytotoxicity by Regulating FOXO3a-Dependent Autophagic Cell Death and Apoptosis in Human Lung Adenocarcinoma A549/DDP Cells

Abstract

Cisplatin resistance is one of the major obstacles in the treatment of nonsmall cell lung cancer (NSCLC). Kangai injection (KAI), a Chinese herbal medicine, has been used in tumors as adjuvant treatment, but its exact antitumor mechanism is still unclear. In this study, we first demonstrated that cisplatin-resistant A549/DDP cells showed a higher level of basal autophagy in response to cisplatin treatment with increasing autophagic protein expression levels of Beclin 1, p62, and LC3 compared to cisplatin-sensitive A549/DDP cells; then, we assessed the antitumor effect of KAI in cisplatin-resistant lung adenocarcinoma A549/DDP cells. Our results showed that KAI exhibited direct cytotoxic and chemosensitizing effects in A549/DDP cells. Combining KAI with cisplatin promoted A549/DDP cell apoptosis, which was confirmed by cell cycle arrest, condensed nuclear chromatin, annexin V fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining, and apoptosis-related protein expression. In addition, combining KAI with cisplatin induced autophagic cell death in A549/DDP cells with a high level of basal autophagy, as indicated by an increase in LC3 spot count, an accumulation of Beclin 1 and LC3 II, and reduced p62 protein expression. We also found that the apoptosis and autophagic cell death induced by cotreatment of KAI and cisplatin in A549/DDP cells were FOXO3a-dependent as indicated by decreased p-FOXO3a expression and increased FOXO3a nuclear localization, respectively. Furthermore, the FOXO3a gene knockdown assay further confirmed that KAI enhanced cisplatin cytotoxicity in A549/DDP cells with a high level of basal autophagy by inducing apoptosis and autophagic cell death in a FOXO3a-dependent manner. These findings suggest that the combination of KAI and cisplatin might support the potential clinical treatment as a novel strategy to overcome cisplatin resistance.

Cinobufotalin effect and mechanism on serum MMP-2, MMP-9, Beclin1, LC3-II in advanced NSCLC patients

“…The main obstacle of platinum-based chemotherapy for advanced NSCLC is chemotherapy resistance. Zhou et al (10) showed higher basal autophagy levels in cisplatin-resistant A549/DDP cells treated with cisplatin, and cisplatin resistance (12). The occurrence and development of tumors are significantly influenced by autophagy.…”

“…(A) Patients comply with the relevant diagnostic criteria of the NCCN Clinical Practice Guidelines: Non-Small Cell Lung Cancer (2020. V8) (10)…”

Study the inhibitory effect and mechanism of the ethanol extract of deziyangxin on LLC cells

“…Apoptosis and autophagy are two distinct mechanisms involved in programmed cell death and regulate important intracellular physiological processes. Studies have shown that herbal components can effectively induce apoptosis and autophagy in the treatment of non-small cell lung cancer [ [10] , [11] , [12] ]. Caspase is a type of cysteine protease, and its activation serves as an important biochemical marker of apoptosis.…”