| Autor: |
Flore Sneyers, Martijn Kerkhofs, Femke Speelman-Rooms, Kirsten Welkenhuyzen, Rita La Rovere, Ahmed Shemy, Arnout Voet, Guy Eelen, Mieke Dewerchin, Stephen W. G. Tait, Bart Ghesquière, Martin D. Bootman, Geert Bultynck |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Cell Death and Disease, Vol 14, Iss 9, Pp 1-17 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2041-4889 |
| DOI: |
10.1038/s41419-023-06120-4 |
| Popis: |
Abstract Intracellular Ca2+ signals control several physiological and pathophysiological processes. The main tool to chelate intracellular Ca2+ is intracellular BAPTA (BAPTAi), usually introduced into cells as a membrane-permeant acetoxymethyl ester (BAPTA-AM). Previously, we demonstrated that BAPTAi enhanced apoptosis induced by venetoclax, a BCL-2 antagonist, in diffuse large B-cell lymphoma (DLBCL). This finding implied a novel interplay between intracellular Ca2+ signaling and anti-apoptotic BCL-2 function. Hence, we set out to identify the underlying mechanisms by which BAPTAi enhances cell death in B-cell cancers. In this study, we discovered that BAPTAi alone induced apoptosis in hematological cancer cell lines that were highly sensitive to S63845, an MCL-1 antagonist. BAPTAi provoked a rapid decline in MCL-1-protein levels by inhibiting mTORC1-driven Mcl-1 translation. These events were not a consequence of cell death, as BAX/BAK-deficient cancer cells exhibited similar downregulation of mTORC1 activity and MCL-1-protein levels. Next, we investigated how BAPTAi diminished mTORC1 activity and identified its ability to impair glycolysis by directly inhibiting 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) activity, a previously unknown effect of BAPTAi. Notably, these effects were also induced by a BAPTAi analog with low affinity for Ca2+. Consequently, our findings uncover PFKFB3 inhibition as an Ca2+-independent mechanism through which BAPTAi impairs cellular metabolism and ultimately compromises the survival of MCL-1-dependent cancer cells. These findings hold two important implications. Firstly, the direct inhibition of PFKFB3 emerges as a key regulator of mTORC1 activity and a promising target in MCL-1-dependent cancers. Secondly, cellular effects caused by BAPTAi are not necessarily related to Ca2+ signaling. Our data support the need for a reassessment of the role of Ca2+ in cellular processes when findings were based on the use of BAPTAi. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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