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The bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1) provides long-term survival in a murine glioma
Eleonora Vannini, Anna Panighini, Chiara Cerri
1CNR Neuroscience Institute, Via Moruzzi 1, 56124 Pisa, Italy. caleo@in.cnr.it.
Background:
Glioblastomas are largely unresponsive to all available treatments and there is therefore an urgent need for novel therapeutics. Here we have probed the antineoplastic effects of a bacterial protein toxin, the cytotoxic necrotizing factor 1 (CNF1), in the syngenic GL261 glioma cell model. CNF1 produces a long-lasting activation of Rho GTPases, with consequent blockade of cytodieresis in proliferating cells and promotion of neuron health and plasticity.
Methods:
We have tested the antiproliferative effects of CNF1 on GL261 cells and human glioma cells obtained from surgical specimens. For the in vivo experiments, we injected GL261 cells into the adult mouse visual cortex, and five days later we administered either a single intracerebral dose of CNF1 or vehicle. To compare CNF1 with a canonical antitumoral drug, we infused temozolomide (TMZ) via minipumps for 1 week in an additional animal group.
Results:
In culture, CNF1 was very effective in blocking proliferation of GL261 cells, leading them to multinucleation, senescence and death within 15 days. CNF1 had a similar cytotoxic effect in primary human glioma cells. CNF1 also inhibited motility of GL261 cells in a scratch-wound migration assay. Low dose (2 nM) CNF1 and continuous TMZ infusion significantly prolonged animal survival (median survival 35 days vs. 28 days in vehicle controls). Remarkably, increasing CNF1 concentration to 80 nM resulted in a dramatic enhancement of survival with no obvious toxicity. Indeed, 57% of the CNF1-treated animals survived up to 60 days following GL261 glioma cell transplant.
Conclusions:
The activation of Rho GTPases by CNF1 represents a novel potential therapeutic strategy for the treatment of central nervous system tumors.
Insights
Cytotoxic necrotizing factor 1 (CNF1) shows promise as a novel glioblastoma treatment. This bacterial toxin effectively inhibited glioma cell proliferation and significantly extended survival in mouse models, offering a new therapeutic avenue.
Area of Science:
- Neuro-oncology
- Bacterial Toxin Therapeutics
- Cellular Biology
Background:
- Glioblastomas are highly resistant to current treatments, necessitating novel therapeutic strategies.
- The bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), activates Rho GTPases, impacting cell division and neuronal function.
- CNF1's potential as an antineoplastic agent against gliomas requires investigation.
Purpose of the Study:
- To evaluate the antineoplastic effects of CNF1 on the GL261 glioma cell model.
- To assess CNF1's efficacy in inhibiting glioma cell proliferation, migration, and survival.
- To compare CNF1's therapeutic potential with temozolomide (TMZ) in vivo.
Main Methods:
- In vitro testing of CNF1 antiproliferative effects on GL261 and primary human glioma cells.
- In vivo studies involving intracerebral injection of GL261 cells in mice, followed by CNF1 or vehicle administration.
- Comparison with temozolomide (TMZ) treatment using minipump infusions in a separate animal group.
Main Results:
- CNF1 effectively blocked proliferation, induced multinucleation, senescence, and death in GL261 and human glioma cells.
- CNF1 inhibited glioma cell motility in vitro.
- Low-dose CNF1 and TMZ significantly prolonged median animal survival; high-dose CNF1 dramatically enhanced survival, with 57% of animals surviving beyond 60 days without apparent toxicity.
Conclusions:
- CNF1 demonstrates significant antineoplastic activity against glioblastoma models.
- CNF1-mediated activation of Rho GTPases presents a novel therapeutic strategy for CNS tumors.
- Further research into CNF1 as a treatment for central nervous system tumors is warranted.
