ABSTRACT
Objective To investigate the effect of ginsenoside Rg3 on immune checkpoint PD-L1 in Lewis cells (LLC) and to explore the related mechanism. Methods The effects of ginsenoside Rg3 on the proliferation of LLC were observed by MTT assay and cell long-term dynamic monitoring. LLC cells treated with 20 ng/mL IFN-γ were used to construct experimental model with high expression of PD-L1 in vitro. The effect of ginsenoside Rg3 on expression of PD-L1 was detected by flow cytometry and immunofluorescence. The effect of ginsenoside Rg3 on the protein expression of PI3K/Akt/mTOR pathway was verified by Western blotting. Results Ginsenoside Rg3 at 16, 32, 64, and 128 μmol/L significantly inhibited the proliferation of LLC (P < 0.01) and reduced the expression of PD-L1 induced by IFN-γ (P < 0.05). Ginsenoside Rg3 at 32 and 64 μmol/L significantly decreased the protein expression of PI3K and mTOR (P < 0.01), and ginsenoside Rg3 at 16, 32, and 64 μmol/L significantly inhibited the phosphorylation of Akt proteins (P < 0.05). Conclusion Ginsenoside Rg3 significantly inhibited the expression of PD-L1 in LLC cells by inhibiting PI3K/Akt/mTOR pathway. Ginsenoside Rg3 blocked the tumor cells escaping immune response by PD-L1 over-expression, enhanced the immune response of T cells, and inhibited the growth of non-small cell lung cancer cells.
ABSTRACT
Platycodin D(PD) has a significantly inhibitory effect on multiple malignant tumors, and can inhibit the proliferation of leukemia cells K562 and induce apoptosis. However, its effect in improving the sensitivity of drug-resistant cells to imatinib and their molecular mechanism remained unclear. To investigate the effect and mechanism of PD alone or combined with imatinib (IM) in inhibiting CML imatinib resistant cell line K562/R, the cell proliferation was examined by CCK8 assay to reveal the effect of PD on the inhibitory function of imatinib. Cell apoptosis was detected by Annexin V-FITC/PI double staining. Protein expressions of cleaved caspase-3, cleaved caspase-9, PARP, cleaved PARP, Bcr/abl, p-AKT and p-mTOR were detected by Western blot. The results showed that the inhibitory effect of PD combined with imatinib on the proliferation and apoptosis of K562/R cells was significantly higher than that of the control group and the single drug group. Protein expressions of cleaved caspase-3, cleaved caspase-9 and cleaved PARP were significantly up-regulated in the combination group, and protein expressions of PARP, Bcr/abl, p-AKT and p-mTOR were down-regulated. The results indicated that PD increased the sensitivity of drug-resistant cells to imatinib, and the inhibitory effect of PD combined with imatinib was significantly better than the single drug on cell proliferation, induction of apoptosis, inhibition of Bcr/abl protein and PI3K/AKT/mTOR signaling pathway.
Subject(s)
Humans , Antineoplastic Agents , Pharmacology , Apoptosis , Cell Proliferation , Drug Resistance, Neoplasm , Imatinib Mesylate , Pharmacology , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Drug Therapy , Pathology , Saponins , Pharmacology , Signal Transduction , Triterpenes , PharmacologyABSTRACT
The phosphoinositide-3 kinase (PI3K)/protein kinase B (PKB/AKT)/mammalian target of rapamycin (mTOR) pathway is asso-ciated with cell growth, proliferation, differentiation, apoptosis and metabolism. The abnormalities of this signal pathway are found in various malignant tumors. This pathway has also been investigated as an anti-tumor target. Recently, novel inhibitors have been stud-ied in clinical trials of lymphoma. This review summarizes the activation status of the PI3K/AKT/mTOR pathway and its use for targeted therapy of lymphoma.
ABSTRACT
Protein kinase B( Akt)is an intermediate signal molecule in PI3K-Akt-mTOR signaling pathway which plays an important role in development and incidence of colorectal cancer when activated by phosphorylation. As target of drugs,Akt has become a focus in the treatment of colorectal cancer. Clinical trials research proves that many kinds of Akt inhibitors have good antitumor activity. In recent years,the Akt inhibi-tors are more and more be taken seriously in colorectal cancer treatment.
ABSTRACT
Phosphoinositide-3 kinase (PI3K)/protein kinase B (PKB/AKT)/mammalian target of rapamycin (mTOR) pathway is associated with cell proliferation, survival and migration. It plays an important role in the process of tumorgenesis. As a kind of antitumor target, numerous researches have focused on this pathway in recent years. This review summarizes the advances in regulation, protein expression and targeted therapy of PI3K-AKT/mTOR pathway for gastric cancer, and predicts the hot spots of this pathway in gastric cancer in the future studies. Copyright © 2014 by TUMOR.