<p>Synergistic Effect of 3-Bromopyruvate in Combination with Rapamycin Impacted Neuroblastoma Metabolism by Inhibiting Autophagy</p>

Abstract

Background Alterations in the cell metabolism, such as enhanced aerobic glycolysis, have been identified as a prominent hallmark of cancer cells. 3-Bromopyruvate (3-BrPA) is a proverbial hexokinase (HK)-II inhibitor, which can inhibit cancer cell energy metabolism. Rapamycin is a new type macrocyclic lactone, which can inhibit the serine/threonine protein kinase mTOR. In order to comprehend the influence of 3-BrPA on autophagy activity in vitro, we conducted a series of experiments using different human neuroblastoma (NB) cell lines. Materials and Methods The human NB cell lines were exposed to 3-BrPA and/or rapamycin, and the proliferation activity of the cells was detected by Cell Counting Kit-8 (CCK-8) assay. The mRNA expression of the cells treated with 3-BrPA and/or rapamycin was analyzed by quantitative real-time polymerase chain reaction (QPCR) assay. The protein expression of the cells was analyzed by Western Blotting (WB) assay. The effects of 3-BrPA and/or rapamycin treatment on cell cycle and cell apoptosis were analyzed by flow cytometry assay. Meanwhile, the cellular glucose absorption rate, lactate secretion rate and ATP content were also analyzed through the relevant metabolic analysis kits. Results Our results showed that 3-BrPA can induce growth inhibition in a dose-dependent pattern by cell apoptosis. 3-BrPA combined with rapamycin played a synergistic suppression role in NB cells, affected the cell apoptosis, cell cycle and the metabolic pathway. Up-regulated LC3-II accumulation was conscious in NB cells incubated with 3-BrPA and rapamycin. Rapamycin individually discourages the mTOR signaling pathway, while combined with 3-BrPA can enhance this phenomenon and influence cell metabolism of the NB cells. Conclusion The results suggested that 3-BrPA combined with rapamycin could induce cell apoptosis in NB cells by inhibiting mTOR activity. In conclusion, our research proposed that the dual inhibitory effect of the mTOR signaling pathway and the glycolytic activity may indicate a valid therapeutic tactic for NB chemoprevention.

3-Bromopyruvate Suppresses the Malignant Phenotype of Vemurafenib-Resistant Melanoma Cells

“…Interestingly, 3BP decreased proliferation and colony formation, in addition to triggering cell death regardless of PLX presence, indicating that 3BP presents cytostatic and cytotoxic effects on melanoma cells. These results agree with the literature, which shows that 3BP can both arrest the cell cycle [ 50 , 51 , 52 ] and trigger apoptosis/necrosis [ 53 , 54 ] in various types of tumors. However, as concentrations of 3BP greater than 60 μM can completely deplete cellular ATP [ 55 ], we hypothesized that necrosis might be the principal mechanism of 3BP in the SKMEL28R cell line.…”

Antitumor effects of the small molecule DMAMCL in neuroblastoma via suppressing aerobic glycolysis and targeting PFKL

“…Gan et al . reported that 3-bromopyruvate (3-BrPA), a hexokinase (HK)-II inhibitor, combined with rapamycin, synergistically suppressed aerobic glycolysis in NB cells [ 41 ]. Song et al .…”

Latest advances in cell-death pathway approaches in treating high-risk neuroblastoma

“…Further pre-clinical studies also showed that 3-BP enhance apoptotic cell death in doxorubicin-resistant NB cell lines (Bean et al, 2014), and combination treatment of 3-BP + rapamycin synergistically induced apoptosis, cell cycle arrest and inhibition of cytoprotective autophagy (which will be discussed in Section 5.0) in NB cells (Gan et al, 2020). The second generation of 3-BP, known as 177 Lu-3BP-227 in Phase I clinical trial (NCT03525392) for adult solid tumour expressing neurotensin receptor type 1 (NTR1) and showed an anti-tumour effect in metastatic pancreatic adenocarcinoma (Baum et al, 2018).…”

“…Pre-clinical NB (Bean et al, 2014;Gan et al, 2020;Matsushita et al, 2012) Phase I Adult solid tumours…”