One stone two birds: conjugation of graphene oxide with Rg3-doxorubicin reduces its toxicity and downregulates metallothionein expression for improved liver-targeted therapy

Abstract

Although the role of metallothionein (MT) in various cancers has been extensively studied, its expression upon treatment with the ginsenoside Rg3 and doxorubicin-coated graphene-based nanoparticles (GO-Rg3-DOX) has not yet been elucidated. Using RNA sequencing, we elucidated how GO-Rg3-DOX arrested cell growth by modulating Wnt signaling and the cell cycle pathway. For this purpose, RNA-seq datasets of graphene oxide (GO), GO-Rg3, and GO-Rg3-DOX were used to explore the expression of MT genes and cell growth-dependent pathways in Huh7 cells, a human liver cancer cell line. Our analysis revealed that the MT gene family plays a major role in the induction of oxidative stress in Huh7 cells. In particular, cell-metal association triggered oxidative stress in the GO-treated group via MT gene downregulation, upregulation of the extracellular matrix-receptor interaction pathway, and downregulation of the Wnt signaling pathway and oxidative phosphorylation, resulting in cancer cell growth inhibition. In contrast, the GO-Rg3 combination group showed an upregulation of MT genes, indicating reduced toxicity and oxidative stress upon Rg3 conjugation. Finally, the GO-Rg3-DOX complex exhibited significant cellular association with minimal toxicity in Huh7 cells, leading to the downregulation of Wnt signaling and cell cycle pathways. Overall, our study clearly demonstrates that the GO-Rg3-DOX complex has significant anticancer therapeutic potential, which warrants further in vivo studies.