Amonafide Induces HUVEC Senescence by Inhibiting Autophagy

Abstract

Background: Amonafide (Amo), due to hematotoxicity and digestive tract symptoms, the clinical application of which is limited. Several studies have reported that chemotherapy side effects are closely related to cellular senescence accumulation. Our study aims to examine whether amonafide causes senescence in human umbilical vein endothelial cell (HUVEC) lines and investigate its mechanisms associated with senescence.

Methods: The experiments of expression of genes and proteins associated with aging were carried out with HUVEC cell lines. The experiments were divided into a control group and an amonafide group with different days. The HUVEC senescence cells were detected by SA-β-Gal staining, Western blotting detected the protein levels of p16, p53, AMPK (Adenosine 5'-Monophosphate (AMP)-Activated Protein Kinase), mTOR (mechanistic Target of Rapamycin), p62, and LC3 (microtubule-associated protein1 light chain 3, MAP1LC3). Fluorescence detected the expression of mRFP (monomeric Red Fluorescent Protein)-GFP (Green Fluorescent Protein)-LC3 and LC3 puncta of HUVEC cells. RT-qPCR (Real-Time Quantitative Polymerase Chain Reaction) tested the expressions of p53, p21, IL (Interleukin)-1β, IL-6 (Interleukin-6), IL-8 (Interleukin-8), and MCP-1 (Monocyte Chemoattractant Protein-1). CCK-8 (Cell Counting Kit-8) assessed the HUVEC cell viability.

Results: Here, we reported that amonafide resulted in an increased proportion of SA-β-Gal positive cells, high expression of aging-related proteins (p53 p < 0.05; p16 p < 0.05), and aging-related genes (p53 p < 0.05; p21 p < 0.05; IL-1β p < 0.05; IL-6 p < 0.05; IL-8 p < 0.05; MCP-1 p < 0.05) on the 3rd day. Mechanistically, amonafide could cause an increase in the levels of the mTOR (p < 0.05) on days 1 and 3, and p62 protein (p < 0.05) on day 1, and a decline in LC3II (microtubule-associated protein1 light chain 3Ⅱ)/LC3I levels (p < 0.05) on day 3, which is associated with the regulation of senescence. Additionally, the viability of HUVECs (human umbilical vein endothelial cells) was significantly inhibited by amonafide starting with a concentration of 0.8 μm (p < 0.05).

Conclusions: We first discovered that amonafide caused normal cellular senescence in our experiments. Amonafide-induced cellular aging by inhibiting autophagy and activating the mTOR pathway. The findings may offer new strategies for managing adverse reactions to amonafide.

Keywords: amonafide; autophagy; mTOR; senescence.