Depletion of the Human Ion Channel TRPM2 in Neuroblastoma Demonstrates Its Key Role in Cell Survival through Modulation of Mitochondrial Reactive Oxygen Species and Bioenergetics

Abstract

Edited by Xiao-Fan WangTransient receptor potential melastatin 2 (TRPM2) ion channel has an essential function in modulating cell survival following oxidant injury and is highly expressed in many cancers including neuroblastoma. Here, in xenografts generated from neuroblastoma cells in which TRPM2 was depleted with CRISPR/Cas9 technology and in in vitro experiments, tumor growth was significantly inhibited and doxorubicin sensitivity increased. The hypoxia-inducible transcription factor 1/2␣ (HIF-1/2␣) signaling cascade including proteins involved in oxidant stress, glycolysis, and mitochondrial function was suppressed by TRPM2 depletion. TRPM2-depleted SH-SY5Y neuroblastoma cells demonstrated reduced oxygen consumption and ATP production after doxorubicin, confirming impaired cellular bioenergetics. In cells in which TRPM2 was depleted, mitochondrial superoxide production was significantly increased, particularly following doxorubicin. Ectopic expression of superoxide dismutase 2 (SOD2) reduced ROS and preserved viability of TRPM2-depleted cells, however, failed to restore ATP levels. Mitochondrial reactive oxygen species (ROS) were also significantly increased in cells in which TRPM2 function was inhibited by TRPM2-S, and pretreatment of these cells with the antioxidant MitoTEMPO significantly reduced ROS levels in response to doxorubicin and protected cell viability. Expression of the TRPM2 pore mutant E960D, in which calcium entry through TRPM2 is abolished, also resulted in significantly increased mitochondrial ROS following doxorubicin treatment, showing the critical role of TRPM2-mediated calcium entry. These findings demonstrate the important function of TRPM2 in modulation of cell survival through mitochondrial ROS, and the potential of targeted inhibition of TRPM2 as a therapeutic approach to reduce cellular bioenergetics, tumor growth, and enhance susceptibility to chemotherapeutic agents.

Resveratrol attenuates hypoxia-induced neuronal cell death, inflammation and mitochondrial oxidative stress by modulation of TRPM2 channel

“…Groups. Naturel presence of TRPM2 channel in SH-SY5Y but not in the HEK293 cells were indicated by the expression studies 29,47,48 . The SH-SY5Y cells as neuronal disease models have been used in several studies 13,29,43 .…”

Crosstalk between calcium and reactive oxygen species signaling in cancer

“…In essence, these studies suggest that the expression of TRPM2-S may be beneficial to rapidly proliferating cells under optimal conditions, including adequate oxygen and nutrients supply, while under stress conditions the expression of TRPM2-L is essential in initiating pro-survival pathways such as HIF and antioxidant enzyme expression. This was further demonstrated in TRPM2-L CRISPR/Cas9 deleted cells, which were less tumorigenic and more susceptible to doxorubicin cytotoxicity [143]. The pro-tumorigenic action of TRPM-L was again shown to be due to its role in maintaining HIF stabilization, and by maintaining mitochondrial redox balance through expression of FOXO3 and Sod2.…”

“…The pro-tumorigenic action of TRPM-L was again shown to be due to its role in maintaining HIF stabilization, and by maintaining mitochondrial redox balance through expression of FOXO3 and Sod2. This preserved mitochondrial function and ATP production [143]. The complex, yet intriguing, relationship between the TRPM2 isoforms requires further investigation to ascertain if the ratio of TRPM2-L to TRPM2-S is altered in cancers and if this is associated with patient outcome and chemoresistance.…”

Neuroblastoma: Genetic, Epigenetic Mechanisms and Targeted Therapy Approaches: Review

“…88 Mitokondri yoluyla hücre proliferasyonunu düzen-leyen TRPM2, nöroblastomda potansiyel bir terapötik hedeftir. 89 Nöroblastom tedavisinde umut verici yaklaşımlardan biri de HNET, ALK, NTRK2 ve NCAM gibi hücre yüzey proteinlerini hedeflemektir. 90,91 Kimerik antijen reseptör modifiye T-hücreleri, hem nöroblastom hücrelerine immünolojik bir yanıt oluşturmak hem de yanıt düzeyini artırmak amacıyla aşılamada umut vadeden bir yaklaşım-dır.…”