Graphene Oxide Enhanced Cisplatin Cytotoxic Effect in Glioblastoma and Cervical Cancer.

Graphene oxide (GO) is an oxidized derivative of graphene. So far, GO has mostly been studied as a drug delivery method rather than a standalone drug for treating cancers like glioblastoma or cervical cancer. However, we propose a promising new approach-using GO as a sensitizer for cisplatin chemotherapy. Here, we analyze the effects of triple GO pretreatment, followed by cisplatin treatment, on cancerous cell lines U87 and HeLa, as well as the noncancerous cell line HS-5, through morphology analysis, viability assay, flow cytometry, and LDH release assay. The viability assay results showed that GO treatment made U87 and HeLa cells more responsive to cisplatin, leading to a significant reduction in cell viability to 40% and 72%, respectively, without affecting HS-5 cells viability, while the Annexin V/Propidium iodine assay showed that GO pretreatment did not cause a change in live cells in all three examined cell lines, while GO-pretreated HeLa cells treated with cisplatin showed significant decrease around two times compared to cells treated with cisplatin standalone. The U87 cell line showed a significant increase in LDH release, approximately 2.5 times higher than non-GO-pretreated cells. However, GO pretreatment did not result in LDH release in noncancerous HS-5 cells. It appears that this phenomenon underlays GO's ability to puncture the cell membrane of cancerous cells depending on its surface properties without harming noncancerous cells.

Reduced Graphene Oxide Modulates the FAK-Dependent Signaling Pathway in Glioblastoma Multiforme Cells In Vitro.

Aggressive invasiveness is a common feature of malignant gliomas, despite their high level of tumor heterogeneity and possible diverse cell origins. Therefore, it is important to explore new therapeutic methods. In this study, we evaluated and compared the effects of graphene (GN) and reduced graphene oxides (rGOs) on a highly invasive and neoplastic cell line, U87. The surface functional groups of the GN and rGO flakes were characterized by X-ray photoelectron spectroscopy. The antitumor activity of these flakes was obtained by using the neutral red assay and their anti-migratory activity was determined using the wound healing assay. Further, we investigated the mRNA and protein expression levels of important cell adhesion molecules involved in migration and invasiveness. The rGO flakes, particularly rGO/ATS and rGO/TUD, were found highly toxic. The migration potential of both U87 and Hs5 cells decreased, especially after rGO/TUD treatment. A post-treatment decrease in mobility and FAK expression was observed in U87 cells treated with rGO/ATS and rGO/TUD flakes. The rGO/TUD treatment also reduced ß-catenin expression in U87 cells. Our results suggest that rGO flakes reduce the migration and invasiveness of U87 tumor cells and can, thus, be used as potential antitumor agents.