Antioxidant supplements promote tumor formation and growth and confer drug resistance in hepatocellular carcinoma by reducing intracellular ROS and induction of TMBIM1

Abstract

Background Controversy over the benefits of antioxidants supplements in cancers persists for long. Using hepatocellular carcinoma (HCC) as a model, we investigated the effects of exogenous antioxidants N-acetylcysteine (NAC) and glutathione (GSH) on tumor formation and growth. Methods Multiple mouse models, including diethylnitrosamine (DEN)-induced and Trp53KO/C-MycOE-induced HCC models, mouse hepatoma cell and human HCC cell xenograft models with subcutaneous or orthotopic injection were used. In vitro assays including ROS assay, colony formation, sphere formation, proliferation, migration and invasion, apoptosis, cell cycle assays were conducted. Western blot was performed for protein expression and RNA-sequencing to identify potential gene targets. Results In these multiple different mouse and cell line models, we observed that NAC and GSH promoted HCC tumor formation and growth, accompanied with significant reduction of intracellular reactive oxygen species (ROS) levels. Moreover, NAC and GSH promoted cancer stemness, and abrogated the tumor-suppressive effects of Sorafenib both in vitro and in vivo. Exogenous supplementation of NAC or GSH reduced the expression of NRF2 and GCLC, suggesting the NRF2/GCLC-related antioxidant production pathway might be desensitized. Using transcriptomic analysis to identify potential gene targets, we found that TMBIM1 was significantly upregulated upon NAC and GSH treatment. Both TCGA and in-house RNA-sequence databases showed that TMBIM1 was overexpressed in HCC tumors. Stable knockdown of TMBIM1 increased the intracellular ROS; it also abolished the promoting effects of the antioxidants in HCC cells. On the other hand, BSO and SSA, inhibitors targeting NAC and GSH metabolism respectively, partially abrogated the pro-oncogenic effects induced by NAC and GSH in vitro and in vivo. Conclusions Our data implicate that exogenous antioxidants NAC and GSH, by reducing the intracellular ROS levels and inducing TMBIM expression, promoted HCC formation and tumor growth, and counteracted the therapeutic effect of Sorafenib. Our study provides scientific insight regarding the use of exogenous antioxidant supplements in cancers.

Prediction Model of Lung Adenocarcinoma Sorafenib Response Based on Random Forest

“…Recent research reported that sorafenib can inhibit the expression of genes such as GCLC, SLC7A11 and reduce the level of glutathione (GSH), leading to the occurrence of cellular ferroptosis (Cui et al, 2022;Zhang et al, 2021). Besides nuclear events mediated by NFE2L2 and glutathione conjugation pathway, sensitive cells are active at respiratory electron transport and mitochondrial translation pathway, this means that they have more active mitochondrial reactions.…”

Design, Synthesis and Activity of New N1-Alkyl Tryptophan Functionalized Dendrimeric Peptides against Glioblastoma

“…Metabolically controlled accumulation of ROS, typical for cancer cells, induces oxidative stress and may lead to such pro-tumorigenic processes as phospholipid oxidation, DNA instability, and production of disadvantageous metal cations at a higher oxidation state. Furthermore, recent evidence has accumulated that ROS also have a role as signaling molecules in regulation cancer-cell proliferation, metastasis, angiogenesis, etc., [ 63 , 64 ] or inducing cancer-cell apoptosis [ 3 , 4 , 5 , 53 , 54 , 65 ]. It can be speculated that introduction of exogenous chemotherapeutics with antioxidant activity would affect GBM cells in a positive or negative way.…”

Natural product preferentially targets redox and metabolic adaptations and aberrantly active STAT3 to inhibit breast tumor growth in vivo

“…Mice were administered R001 (5 mg/kg, oral gavage, 100 μL PBS with 5% DMSO) every day, 5 times per week for 75 days. For the R001 combination with NAC treatment, NAC was orally given alone (120 mg/kg) [ 28 ], or combined with R001 (5 mg/kg) every day, 5 times per week for 60 days. Animals were monitored daily, tumor size was measured with calipers and body weight was taken every 3–4 days.…”