Cannabidiol and fluorinated derivative anti-cancer properties against glioblastoma multiforme cell lines, and synergy with imidazotetrazine agents

Abstract

Abstract Background Glioblastoma multiforme (GBM) is an aggressive cancer with poor prognosis, partly due to resistance to the standard chemotherapy treatment, temozolomide (TMZ). Phytocannabinoid cannabidiol (CBD) has exhibited anti-cancer effects against GBM, however, the ability of CBD to overcome common resistance mechanisms to TMZ have not yet been investigated. 4’-Fluoro-cannabidiol (4’-F-CBD, or HUF-101/PECS-101) is a derivative of CBD, that exhibits increased activity compared to CBD during in vivo behavioural studies. Methods This work investigated the anti-cancer activity of cannabinoids against GBM cells sensitive to and representing major resistance mechanisms to TMZ. The cannabinoids were also studied in combination with imidazotetrazine agents, and the OrbiSIMS technique was used to investigate the mechanism of action of CBD. Results CBD and 4’-F-CBD were found to overcome two major resistance mechanisms (methylguanine DNA-methyltransferase (MGMT) activity and DNA mismatch repair (MMR)-deficiency). Synergistic responses were observed when cells were exposed to cannabinoids and imidazotetrazine agents. Synergy was increased with T25 and 4’-F-CBD. OrbiSIMS analysis highlighted the presence of methylated-DNA, a previously unknown anti-cancer mechanism of action of CBD. Conclusions This work demonstrates the anti-cancer activity of 4’-F-CBD and the synergy of cannabinoids with imidazotetrazine agents for the first time and expands understanding of CBD mechanism of action.