Chelerythrine Inhibits Stemness of Cancer Stem-Like Cells of Osteosarcoma and PI3K/AKT/mTOR Signal

Abstract

Chelerythrine (CHE) is widely found in many herbs and is the main alkaloid constituent of Toddalia asiatica (L.) LAM. It has been proved to exert remarkable antitumor, antifungal, anti-inflammatory, and antiparasitic effects. In osteosarcoma, CHE is reported to inhibit proliferation and promote apoptosis. However, the effect of CHE on cancer stem-like cells (CSCs), which contribute to metastasis and recurrence in osteosarcoma, is still largely unknown. In this study, we investigated the effects of CHE on the stemness and malignant behaviors of CSCs derived from osteosarcoma cells. CSCs were enriched by culturing in serum-free medium. The effects of CHE on stemness were measured by detecting stemness factors and sphere formation ability. The effects of CHE on chemosensitivity to doxorubicin and MTX were measured by Annexin V-FITC/PI double staining. The effects of CHE on CSC malignancy were measured by performing CCK-8, colony formation, tumor formation in soft agar, migration, and invasion assays. We first enriched CSCs from osteosarcoma cells, which were characterized by upregulated stemness markers, including Oct4, Nanog, and Nestin. The addition of CHE clearly decreased malignant behaviors, including colony formation, tumor formation in soft agar, migration, and invasion. CHE also inhibited stemness and thus induced the failure of sphere formation. Moreover, CHE promoted apoptosis induced by chemo agents, including doxorubicin (DOX) and methotrexate (MTX). After CHE treatment, the protein expression of MMP-2/9 was significantly decreased, potentially inhibiting invasion. CHE also exhibited an inhibitory effect on the phosphorylation of PI3K, AKT, and mTOR, which is an upstream regulatory signaling pathway of MMP-2/9. In summary, CSCs derived from U2OS and MG-63 cells, CHE could inhibit the stemness and malignant behaviors of CSCs potentially by inhibiting the PI3K/AKT/mTOR signaling pathway.

Effect of traditional Chinese medicine in osteosarcoma: Cross-interference of signaling pathways and potential therapeutic targets

“…Compound Chinese medicine Associated OS cell lines References PI3K/AKT pathway Alantolactone Aucklandia lappa Decne. U2OS, HOS [84] Chelerythrine Toddalia asiatica L. U2OS, MG-63 [85] Andrographolide Andrographis paniculata U2OS [86] Rhaponticin Rheum palmatum L. MC3T3-E1, MG-63 [87] Wnt/β-catenin pathway Piperine Piper nigrum L. U2OS, 143B [88] Icariin Epimedium brevicornu Maxim. 143B [89] Isoquercitrin Bidens pilosa L. 143B, U2OS [90] Polydatin Reynoutria japonica Houtt.…”

“…Chelerythrine (CHE) is widely present in many herbs and is the main alkaloid component of Toddalia asiatica (L.) LAM with significant anti-tumor, anti-fungal, anti-inflammatory and anti-parasitic effects. Chen et al [85] found that CHE significantly inhibited the stemness of OS cancer stem cell markers (including Nanog, Oct4 and nestin) by regulating the PI3K/AKT/mTOR signaling axis, and also decreased the expression of MMP-2/9 protein, so as to inhibit the malignant behavior of CSC. In addition, intervention with CHE also reversed the resistance of OS cells to chemotherapeutic agents (including doxorubicin, methotrexate and so on).…”

Reprogramming of glucose metabolism: Metabolic alterations in the progression of osteosarcoma

“…Therefore, exploring ways to enhance the anti-tumour activity of PTEN may lead to a new targeted therapy for OS. Chamomine can inhibit the PI3K/AKT/mTOR signaling pathway, weaken the expression of MMP-2/9, and inhibit the invasion and metastasis of OS [107] . It has been reported that 200 μm arbutin significantly inhibited the activity of OS cells, which resulted in a significant increase in the expression of miR-338-3p and a corresponding significant decrease in the expression of MTHFD1L [108] .…”

Functional role of MicroRNA/PI3K/AKT axis in osteosarcoma

“…Recently, it was found that Glaucocalyxin A can induce apoptosis in osteosarcoma cells by increasing the ratio of Bax to Bcl-2, triggering reactive oxygen species (ROS) generation, decreasing mitochondrial membrane potential and inducing caspase-3 and caspase-9 cleavage, as found by using PI3K activators and inhibitors This function of Glaucocalyxin A is mainly achieved by inhibiting the nuclear translocation of GLI1 through the regulation of PI3K/AKT pathway ( Figure 2F ) ( 99 ). Furthermore, it has been found that inhibition of the PI3K/AKT/mTOR signaling pathway promotes apoptosis in osteosarcoma cells induced by chemotherapeutic agents, including DOX and methotrexate (MTX) ( Figure 3A ) ( 124 ). This finding has positive implications for contributing to the current challenge of chemoresistance.…”

“… (A) After being cocultured using CHE with DOX or MTX, apoptosis was measured by performing Annexin V-FITC/PI double staining followed by flow cytometry assay ( 124 ). (B) The apoptosis ratios for each group (percentage of Annexin V+ cells) were determined by flow cytometry ( 125 ).…”