TCH1036, a indeno[1,2-c]quinoline derivative, potentially inhibited the growth of human brain malignant glioma (GBM) 8401 cells via suppression of the expression of Suv39h1 and PARP.

ABSTRACT

A newly synthesized Indeno[1,2-c]quinoline derivative, which has previously been found to potentially trap DNA-topoisomerase cleavage complexes more effectively than camptothecin, could effectively inhibit the proliferation of a variety of cancers, such as breast cancer treated with TCH1030. In this study, we further explore the activity of the TCH1036, TCH1259 and TCH1030 compounds in suppressing the growth of human brain malignant glioma (GBM) 8401 cells, in addition to elucidating the related mechanisms. According to tests of cytotoxicity, the GBM cells were more sensitive to the inhibitory effects of the TCH1036 compound than to those of the other two compounds. Moreover, the accumulation of GBM cells in the sub-G1 and G2/M phases was clearly induced by the TCH1036 compound in a dose-dependent manner. A screening of the majority of histone-modifier enzymes indicated that the expression of Suv39h1 in the GBM cells was attenuated by treatment with each of the TCH compounds, an observation which was further confirmed by Western blotting. The increase in active-form caspase 3 in the GBM cells treated with TCH compounds caused a high degree of poly (ADP-ribose) polymerase (PARP) cleavage and also enhanced the high ratio of hypodiploid GBM cells in the sub-G1 phase. In molecular docking simulations, it was observed that the stable forms of the TCH compounds could successfully insert into the catalytic pocket of PARP, with the highest affinity being between PARP and the TCH1036 compound. These findings suggested that the TCH1036 compound would be a promising compound in the treatment of brain malignant glioma.