Combing metabolomics with bioanalysis methods to study the antitumor mechanism of the new acridone derivative 8q on CCRF-CEM cells: 8q induced mitochondrial-mediated apoptosis and targeted the PI3K/AKT/FOXO1 pathway

A comprehensive review on acridone based derivatives as future anti-cancer agents and their structure activity relationships

The development of drug resistance and severe side-effects has reduced the clinical efficacy of the existing anti-cancer drugs available in the market. Thus, there is always a constant need to develop newer anti-cancer drugs with minimal adverse effects. Researchers all over the world have been focusing on various alternative strategies to discover novel, potent, and target specific molecules for cancer therapy. In this direction, several heterocyclic compounds are being explored but amongst them one promising heterocycle is acridone which has attracted the attention of medicinal chemists and gained huge biological importance as acridones are found to act on different therapeutically proven molecular targets, overcome ABC transporters mediated drug resistance and DNA intercalation in cancer cells. Some of these acridone derivatives have reached clinical studies as these heterocycles have shown huge potential in cancer therapeutics and imaging. Here, the authors have attempted to compile and make some recommendations of acridone based derivatives concerning their cancer biological targets and in vitro-cytotoxicity based on drug design and novelty to increase their therapeutic potential. This review also provides some important insights on the design, receptor targeting and future directions for the development of acridones as possible clinically effective anti-cancer agents.

A Novel Methoxybenzyl 5-Nitroacridone Derivative Effectively Triggers G1 Cell Cycle Arrest in Chronic Myelogenous Leukemia K562 Cells by Inhibiting CDK4/6-Mediated Phosphorylation of Rb

Chronic myeloid leukemia (CML) is a malignant tumor caused by the abnormal proliferation of hematopoietic stem cells. Among a new series of acridone derivatives previously synthesized, it was found that the methoxybenzyl 5-nitroacridone derivative 8q has nanomolar cytotoxicity in vitro against human chronic myelogenous leukemia K562 cells. In order to further explore the possible anti-leukemia mechanism of action of 8q on K562 cells, a metabolomics and molecular biology study was introduced. It was thus found that most of the metabolic pathways of the G1 phase of K562 cells were affected after 8q treatment. In addition, a concentration-dependent accumulation of cells in the G1 phase was observed by cell cycle analysis. Western blot analysis showed that 8q significantly down-regulated the phosphorylation level of retinoblastoma-associated protein (Rb) in a concentration-dependent manner, upon 48 h treatment. In addition, 8q induced K562 cells apoptosis, through both mitochondria-mediated and exogenous apoptotic pathways. Taken together, these results indicate that 8q effectively triggers G1 cell cycle arrest and induces cell apoptosis in K562 cells, by inhibiting the CDK4/6-mediated phosphorylation of Rb. Furthermore, the possible binding interactions between 8q and CDK4/6 protein were clarified by homology modeling and molecular docking. In order to verify the inhibitory activity of 8q against other chronic myeloid leukemia cells, KCL-22 cells and K562 adriamycin-resistant cells (K562/ADR) were selected for the MTT assay. It is worth noting that 8q showed significant anti-proliferative activity against these cell lines after 48 h/72 h treatment. Therefore, this study provides new mechanistic information and guidance for the development of new acridones for application in the treatment of CML.

Lappaconitine sulfate induces apoptosis and G0/G1 phase cell cycle arrest by PI3K/AKT signaling pathway in human non-small cell lung cancer A549 cells

Lappaconitine sulfate (LS) has good solubility and bioavailability. We have previously studied the anti-proliferative activity of LS on colon cancer HT-29 cell, but its anti-proliferative activity and molecular mechanism on human non-small cell lung cancer A549 cells are still unclear. This study was to investigate the effects of LS on proliferation, cell cycle and apoptosis in human non-small cell lung cancer A549 cells, and its possible molecular mechanisms. Cell proliferation activity was measured by Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'- deoxyuridine (EdU) cell proliferation kit. Cell cycle was detected by propidium iodide (PI) flow cytometry. Apoptosis was detected by Annexin-V-FITC/PI method. Western blot was used to detect cycle and apoptosis-related proteins expression. These results showed that the proliferation activity of LS was significantly decreased in A549 cells, showing a dose- and time-dependent manner (p < 0.05). LS could increase the proportion of G0/G1 phase cells and decrease the proportion of cells in S phase, showing obvious G0/G1 phase arrest. LS significantly inhibited the expression of p-PI3K/PI3K, p-AKT/AKT, Cyclin D1 and Bcl-2 proteins (p < 0.05), and increased the expression of p53, p21, Bax, caspase 3 and caspase 9 (p < 0.05). Moreover, PI3K inhibitor (LY294002) significantly decreased A549 cell viability rate induced by LS, abrogated the activation of p-PI3K/PI3K and p-AKT/AKT in the presence of LS. These results indicated that LS could block A549 cells in the G0/G1 phase, induce apoptosis, and inhibit cell proliferation through the PI3K/AKT signaling pathway.