Background: Multidrug resistance (MDR) is a critical reason of cancer chemotherapy failure. Babao dan (BBD) is a classical and famous traditional Chinese patent medicine, which has been reported to has anti-gastric cancer activity. However, the roles and molecular mechanisms of the reversal of MDR of gastric cancer by BBD have not been well described until now. Methods: SGC-7901 and SGC-7901/DDP cells were used in this study, and drug resistance and evaluation of the reversal effect of BBD was determined using MTT assays in SGC7901/DDP cells. Doxorubicin (DOX) and Rhodamin123 (Rho123) staining was performed to assess BBD effects on drug accumulation and efflux of drug-resistant gastric cancer cells. Cell apoptosis was directly assessed using DAPI staining. Apoptotic and dead cells were detected by flow cytometry after staining with Annexin V-FITC and propidium iodide (PI). Cyto-ID assays were performed to examine cellular autophagy. Changes in cell protein expression of ABCB1, ABCC1, ABCG2, Bax, Bcl-2, caspase-3, cleaved-caspase-3, LC3, p62, Beclin1 and the PI3K/AKT/mTOR pathway were detected by Western blot. Inhibition of autophagy with 3-MA, chloroquine (CQ) and PI3K antagonist (LY294002) or agonist (740Y-P) , uncovered a role for the potentially downregulated signaling pathway, PI3K/AKT/mTOR.Results: The SGC7901/DDP cell line exhibited multi-drug resistance to DDP, DOX and 5-fluorouracil (5-FU) and the drug resistant index (RI) of DDP, DOX and 5-FU were 1.86, 1.50 and 47.70, respectively. BBD reversed the MDR of SGC7901/DDP cells by increasingDOX accumulation, reducing Rh123 efflux and down-regulating the expression of ABCB1, ABCC1, ABCG2. Furthermore, BBD induced apoptosis in SGC7901/DDP cells through regulating caspase-3, cleaved-caspase-3, Bax and Bcl-2. Moreover, BBD induced autophagy in DDP-resistant gastric cancer cells via regulating p62, LC3 and Beclin1. Pathway analyses suggested BBD may inhibit PI3K/AKT/mTOR pathway activity and subsequent autophagy induction. Conclusions: BBD may reverse the MDR of gastric cancer cells, and promote autophagic death via inactivation of the PI3K/AKT/mTOR signaling pathway.

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive hematopoietic malignancy that is most common in children. Alantolactone (ALT) has been reported to have antitumor activity in different types of cancers. This study aimed to investigate the antitumor activity and molecular mechanism of ALT in ALL. Methods: The ALL cell lines were treated with 1, 5 and 10μM of ALT, and then subjected to MTT assay and RNA sequencing. Flow cytometry, JC-1 staining and immunofluorescence staining assays were employed to measure cell apoptosis and autophagy. Meanwhile, Western blot analysis was used to detect apoptosis and autophagy related proteins. Finally, the effect of ALT on tumor growth was measured in BV173 xenograft nude mouse model. Results: In this study, we demonstrated that ALT inhibited the proliferation of ALL cells in does-dependent manner. A series of experiments demonstrated that ALT inhibited cell proliferation, colony formation, autophagy, induced apoptosis and restained tumor growth in vivo through upregulating adaptor related protein complex 2 subunit mu 1 (AP2M1). Moreover, autophagy activator rapamycin attenuated the pro-apoptotic effect of ALT on BV173 and NALM6 cell lines. Further, overexpressed AP2M1 decreased the expression of Beclin1, LC3-II/LC3-1 ratio and increased p62 expression. Fianally, knockdown of Beclin1 increased the levels of bax, cleaved caspase 3 and cytochrome C and decreased bcl-2 expression. Conclusions: This study demonstrated that ALT exerts antitumor activity through inducing apoptosis and inhibiting autophagy by upregulating AP2M1 in ALL, indicating a potential therapeutic strategy for ALL treatment.