Killing Glioblastoma Cells with Glycosylated Indolocarbazole-Based Derivative LCS1269: A Potential Crosstalk Between Micronuclei Formation and the Concurrent Induction of Apoptosis, Necroptosis, and Pyroptosis

Background/Objectives: Glioblastoma multiforme (GBM) is the most infiltrative, treatment-resistant, and deadly brain tumor in adults. Given the extremely malignant phenotype of the GBM cells, the high intratumoral heterogeneity, and the limited efficacy of the vast majority of chemotherapeutics due to the restrictive nature of the blood–brain barrier, GBM remains largely incurable. Methods: Utilizing the U87, U251, and T98G GBM cell lines, diverse in vitro approaches (Western blotting, quantitative real-time PCR, flow cytometry, immunofluorescence, Luc-reporter analysis, microscopic examination, and scanning electron microscopy), and pharmacological inhibition, we investigated for the first time the cell death decisions in the GBM cells in response to the LCS1269 treatment. Results: We showed that LCS1269 collapsed the mitochondrial potential and triggered both intrinsic and extrinsic apoptosis. Importantly, our findings demonstrated that LCS1269-mediated apoptosis was paralleled by an induction of both MLKL-dependent necroptosis and caspase-3/GSDME-dependent pyroptosis. Using a combination of specific inhibitors, we further demonstrated that apoptosis, necroptosis, and pyroptosis provoked by LCS1269 occur simultaneously and orchestrate a peculiar form of programmed cell death, which is known as PANoptosis. We subsequently found that LCS1269-induced PANoptosis may be initiated either through the RIPK1-PANoptosome alone or through the integrated ZBP1-, AIM2-, and RIPK1-PANoptosomes. Additionally, we revealed that LCS1269-mediated PANoptosis may be closely related to micronuclei formation. Conclusions: Taken together, our results confirm that LCS1269 is a promising anti-glioblastoma agent that is capable of effectively promoting GBM cell death via PANoptosis.