Exogenous C8-Ceramide Induces Apoptosis by Overproduction of ROS and the Switch of Superoxide Dismutases SOD1 to SOD2 in Human Lung Cancer Cells

Abstract

Ceramides, abundant sphingolipids on the cell membrane, can act as signaling molecules to regulate cellular functions including cell viability. Exogenous ceramide has been shown to exert potent anti-proliferative effects against cancer cells, but little is known about how it affects reactive oxygen species (ROS) in lung cancer cells. In this study, we investigated the effect of N-octanoyl-D-erythro-sphingosine (C8-ceramide) on human non-small-cell lung cancer H1299 cells. Flow cytometry-based assays indicated that C8-ceramide increased the level of endogenous ROS in H1299 cells. Interestingly, the ratio of superoxide dismutases (SODs) SOD1 and SOD2 seem to be regulated by C8-ceramide treatment. Furthermore, the accumulation of cell cycle G1 phase and apoptotic populations in C8-ceramide-treated H1299 cells was observed. The results of the Western blot showed that C8-ceramide causes a dramatically increased protein level of cyclin D1, a critical regulator of cell cycle G1/S transition. These results suggest that C8-ceramide acts as a potent chemotherapeutic agent and may increase the endogenous ROS level by regulating the switch of SOD1 and SOD2, causing the anti-proliferation, and consequently triggering the apoptosis of NSCLC H1299 cells. Accordingly, our works may give a promising strategy for lung cancer treatment in the future.

SOD1 Promotes Cell Proliferation and Metastasis in Non-small Cell Lung Cancer via an miR-409-3p/SOD1/SETDB1 Epigenetic Regulatory Feedforward Loop

“…Our results demonstrate that down-regulation of SOD1 can significantly inhibit the proliferation, invasion, and migration of NSCLC, whereas SOD1 over-expression had opposite effects. Our flow cytometry analysis verifies that alterations in SOD1 expression can promote tumor cell proliferation and metastasis by influencing the cell cycle and apoptosis, consistent with previous research results (Glasauer et al, 2014;Chang et al, 2018).…”

“…Chang et al found that upregulation of SOD2 could increase ROS levels and decrease SOD1 expression, leading to cyclin D1 up-regulation and G1-phase cell cycle arrest. Eventually, activated caspase-3 and subsequent apoptosis in H1299 cells (Chang et al, 2018). SOD1 deficiency was shown to leads to increased oxidative stress, which can induce DNA hypomethylation in prostate tissue (Bhusari et al, 2010).…”

“…Other mechanisms also regulate SOD1, including oxidative stress and phosphorylation. Chang et al (2018) reported that up-regulation of SOD2 can increase ROS levels and decrease SOD1 expression in NSCLC H1299 cells. While, Tsang et al (2018) found that the mechanistic target of rapamycin complex 1 (mTORC1) regulates SOD1 activity through reversible phosphorylation at S39 in yeast and T40 in humans in response to nutrient availability.…”

Synergistic effects of ascorbic acid and plant‐derived ceramide to enhance storability and boost antioxidant systems of postharvest strawberries

“…Natural ceramides can be transported into cells, and the changes in ceramide concentration trigger many biological effects, such as regulation of cell cycle arrest, cell senescence and apoptosis, programmed cell death, and abscisic acid-dependent stomatal closure. [50][51][52] In this experiment, the addition of exogenous ceramide could have the potential to increase intracellular ceramide content required for biological action, which is comparable to the cellular concentration of ceramide under physiological and stimulating conditions, 53 can cause spontaneous anti-reverse defense mechanism of fruit tissue.…”

<p>Ethyl acetate extracts of <em>Nepenthes ventricosa x sibuyanensis</em> leaves cause growth inhibition against oral cancer cells via oxidative stress</p>

“…In contrast, 3 hrs incubation of EANS (40 μg/mL) maintained basal level of ROS generation in normal oral cells (HGF-1) (Figure 5C), suggesting on differential ROS induction between oral cancer and normal oral cells. Since ROS may induce apoptosis43 and DNA damage,44 this differential ROS induction may partly explain the differential killing against oral cancer cells but less cytotoxic effects on normal oral cells.…”