4-Nerolidylcatechol induces autophagy in human glioblastoma cells

Abstract

Gliomas account for the majority of primary malignant brain tumors and present invasive behavior into adjacent healthy tissue. While 4-NC had previously shown to induce apoptotic cell death in a melanoma model, for the glioma model described in this paper 4-NC is cytotoxic for the cells with the induction of the autophagic pathway. Trypan blue exclusion assay showed that 4-NC was cytotoxic in a dose-dependent manner for A172 and T98G cell lines. IC 10 and IC 50 values were at 32 µM and 41 µM for A172 and T98G respectively. Inhibition of cell proliferation was observed by total cell counts and by cell cycle analysis by flow cytometry, with cell cycle arrest of A172 and T98G cell lines respectively in the G1/G0 and S phases of the cell cycle. 4-NC induced up-regulation of autophagic pathways, as shown by immunoblotting for LC3-I/II, Real-Time PCR for ATG-7 and Beclin-1 genes, and by fluorescence microscopy observation of autophagic vacuoles in cells transfected with GFP-LC3 and electron microscopy. Glioma cells concomitantly treated with 4-NC and 3-MA, an inhibitor of the autophagic process, are more sensible to cell death, suggesting that autophagy protects the cells from the action of 4-NC.

Aptamer-Driven Toxin Gene Delivery in U87 Model Glioblastoma Cells

“…Cell death mediated by autophagy is one of the most widely studied non-apoptotic cell death mechanisms which has been reported in several types of cancer cells (Bursch et al, 2000), including glioblastoma, for instance after treatment with temozolomide (Würstle et al, 2017), 4-Nerolidylcatechol (Massaro et al, 2017), or with ionizing radiation (Yao et al, 2003) and the anti-angiogenic compound bevacizumab (Castro and Aghi, 2014); however it is not yet clear whether these increased autophagic activities are the primary cause for cell death.…”

Avaliação do potencial de superação da quimioresistência do melanoma aos inibidores de BRAF^V600E (Vemurafenibe) e de MEK (Trametinibe) utilizando terapia combinatória com 4-nerolidilcatecol (4-NC)

“…Por outro lado, o 4-NC apresentou efeitos citotóxicos contra glioblastoma (linhagens celulares A172 e T98G) e células leucêmicas K562 por mecanismos mitocondriais com parada do ciclo celular nas fases G1/G0 e S do ciclo celular promovendo apoptose (MASSARO et al, 2017;CORTEZ et al, 2015;BENFICA et al, 2017). Além disso, o 4-NC induziu autofagia nas células de glioma como resultado de estresse celular para proteção dos efeitos deletérios do composto (MASSARO, et al, 2017).…”

“…Por outro lado, o 4-NC apresentou efeitos citotóxicos contra glioblastoma (linhagens celulares A172 e T98G) e células leucêmicas K562 por mecanismos mitocondriais com parada do ciclo celular nas fases G1/G0 e S do ciclo celular promovendo apoptose (MASSARO et al, 2017;CORTEZ et al, 2015;BENFICA et al, 2017). Além disso, o 4-NC induziu autofagia nas células de glioma como resultado de estresse celular para proteção dos efeitos deletérios do composto (MASSARO, et al, 2017). Também já foi demonstrado por nosso grupo que o 4-NC possui alta citotoxicidade para células de melanoma, incluindo linhagens com mutações NRAS ou BRAF, induzindo apoptose dependente de caspase-3, provavelmente após parada na fase G1 do ciclo celular, por aumento na produção de ROS, dano ao DNA, aumento na expressão de supressores tumorais (p53) e alterações no potencial de membrana.…”