Pro-apoptotic and pro-autophagic effects of the Aurora kinase A inhibitor alisertib (MLN8237) on human osteosarcoma U-2 OS and MG-63 cells through the activation of mitochondria-mediated pathway and inhibition of p38 MAPK/PI3K/Akt/mTOR signaling pathway

Abstract

Osteosarcoma (OS) is the most common malignant bone tumor occurring mostly in children and adolescents between 10 and 20 years of age with poor response to current therapeutics. Alisertib (ALS, MLN8237) is a selective Aurora kinase A inhibitor that displays anticancer effects on several types of cancer. However, the role of ALS in the treatment of OS remains unknown. This study aimed to investigate the effects of ALS on the cell growth, apoptosis, autophagy, and epithelial to mesenchymal transition (EMT) and the underlying mechanisms in two human OS cell lines U-2 OS and MG-63. The results showed that ALS had potent growth inhibitory, pro-apoptotic, pro-autophagic, and EMT inhibitory effects on U-2 OS and MG-63 cells. ALS remarkably induced G2/M arrest and down-regulated the expression levels of cyclin-dependent kinases 1 and 2 and cyclin B1 in both U-2 OS and MG-63 cells. ALS markedly induced mitochondria-mediated apoptosis with a significant increase in the expression of key pro-apoptotic proteins and a decrease in main anti-apoptotic proteins. Furthermore, ALS promoted autophagic cell death via the inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and p38 mitogen-activated protein kinase (p38 MAPK) signaling pathways, and activation of 5′-AMP-dependent kinase (AMPK) signaling pathway. Inducers or inhibitors of apoptosis or autophagy simultaneously altered ALS-induced apoptotic and autophagic death in both U-2 OS and MG-63 cells, suggesting a crosstalk between these two primary modes of programmed cell death. Moreover, ALS suppressed EMT-like phenotypes with a marked increase in the expression of E-cadherin but a decrease in N-cadherin in U-2 OS and MG-63 cells. ALS treatment also induced reactive oxygen species (ROS) generation but inhibited the expression levels of sirtuin 1 and nuclear factor-erythroid-2-related factor 2 (Nrf2) in both cell lines. Taken together, these findings show that ALS promotes apoptosis and autophagy but inhibits EMT via PI3K/Akt/mTOR, p38 MAPK, and AMPK signaling pathways with involvement of ROS- and sirtuin 1-associated pathways in U-2 OS and MG-63 cells. ALS is a promising anticancer agent in OS treatment and further studies are needed to confirm its efficacy and safety in OS chemotherapy.

Analyzing the disease module associated with osteosarcoma via a network‑ and pathway‑based approach

“…GO terms related to translation (e.g., cytoplasmic translation) were also enriched in OS genes. In line with previous studies, several pathways, such as mTOR signaling pathway (ranked 5th) ( 29 , 30 ), Hippo signaling pathway (ranked 9th) ( 31 ), PI3K-Akt signaling pathway (ranked 10th) ( 30 , 32 ), MAPK signaling pathway (ranked 11th) ( 33 ), Wnt signaling pathway (ranked 22nd) ( 34 , 35 ), p53 signaling pathway (ranked 24th) ( 36 – 38 ), and TGF-β signaling pathway (ranked 27th) ( 38 , 39 ), were enriched in OS genes. In addition, several cancer-related pathways were identified, such as Pathways in cancer, Proteoglycans in cancer, central carbon metabolism in cancer, and transcriptional misregulation in cancer.…”

Knockdown of SIRT1 Suppresses Bladder Cancer Cell Proliferation and Migration and Induces Cell Cycle Arrest and Antioxidant Response through FOXO3a-Mediated Pathways

“…And they are involved in many vital processes of cells including oxidative stress response, cell cycle regulation, aging, cell differentiation, energy metabolism, genomic stability, and tumorigenesis [11, 12]. Among them, Sirt1 deacetylates FOXO family members, p300, nuclear factor- κ B (NF- κ B), p53, and histones [12, 13], which regulate cell survival and cellular stress response. It also regulates Peroxisome Proliferator-Activated Receptor- γ , mTOR, and 5′-AMP-dependent kinase (AMPK), which play roles in cellular energy metabolism and autophagy [11, 12].…”

“…Among them, Sirt1 deacetylates FOXO family members, p300, nuclear factor- κ B (NF- κ B), p53, and histones [12, 13], which regulate cell survival and cellular stress response. It also regulates Peroxisome Proliferator-Activated Receptor- γ , mTOR, and 5′-AMP-dependent kinase (AMPK), which play roles in cellular energy metabolism and autophagy [11, 12]. SIRT1 is already known related to many metabolic diseases, such as obesity [14–16], diabetes [17–19], and nonalcoholic fatty liver [19–21].…”

Diosmetin inhibits cell proliferation and induces apoptosis by regulating autophagy via the mammalian target of rapamycin pathway in hepatocellular carcinoma HepG2 cells

“…mTOR is considered a critical inhibitor protein in the regulation of autophagy; therefore, inhibition of mTOR is associated with triggering autophagy in tumor cells (41). Pathways that regulate mTOR expression include the PI3K/Akt (42), mitogen-activated protein kinase/ERK 1/2 (41) and the AMPK (43) pathways. mTOR activity is stimulated by Akt and ERK 1/2 phosphorylation and inhibited by AMPK phosphorylation.…”