A tubulin binding peptide targets glioma cells disrupting their microtubules, blocking migration, and inducing apoptosis.

Despite aggressive treatment regimes, glioma remains a largely fatal disease. Current treatment limitations are attributed to the precarious locations within the brain where such tumors grow, their highly infiltrative nature precluding complete resection and lack of specificity among agents capable of attenuating their growth. Here, we show that in vitro, glioma cells of diverse origins internalize a peptide encompassing a tubulin-binding site (TBS) on the neurofilament light protein. The internalized peptide disrupts the microtubule network, inhibits migration and proliferation, and leads to apoptosis. Using an intracerebral transplant model, we show that most, if not all, of these responses to peptide exposure also occur in vivo. Notably, a single intratumor injection significantly attenuates tumor growth, while neither peptide uptake nor downstream consequences are observed elsewhere in the host nervous system. Such preferential uptake suggests that the peptide may have potential as a primary or supplementary glioblastoma treatment modality by exploiting its autonomous microtubule-disrupting activity or engaging its capacity to selectively target glioma cells with other cell-disrupting cargos.

Extra neurofilament NF-L subunits rescue motor neuron disease caused by overexpression of the human NF-H gene in mice.

Previous studies demonstrated that transgenic mice overexpressing human neurofilament heavy (hNF-H) protein develop a progressive motor neuron disease characterized by the perikaryal accumulations of neurofilaments resembling those found in amyotrophic lateral sclerosis (ALS). To further investigate this neurofilament-induced pathology, we generated transgenic mice expressing, solely or concomitantly, the hNF-H and the human neurofilament light (hNF-L) proteins. We report here that the motor neuron disease caused by excess hNF-H proteins can be rescued by overexpression of hNF-L in a dosage-dependent fashion. In hNF-H transgenic mice, the additional hNF-L led to reduction of perikaryal swellings, relief of axonal transport defect and restoration of axonal radial growth. A gene delivery approach based on recombinant adenoviruses bearing the hNF-L gene also demonstrated the possibility to reduce perikaryal swellings after their formation in adult mice. The finding that extra NF-L can protect against NF-H-mediated pathogenesis is of potential importance for ALS, particularly for cases with NF-H abnormalities.

The NFL-TBS.40-63 anti-glioblastoma peptide disrupts microtubule and mitochondrial networks in the T98G glioma cell line.

Despite aggressive therapies, including combinations of surgery, radiotherapy and chemotherapy, glioblastoma remains a highly aggressive brain cancer with the worst prognosis of any central nervous system disease. We have previously identified a neurofilament-derived cell-penetrating peptide, NFL-TBS.40-63, that specifically enters by endocytosis in glioblastoma cells, where it induces microtubule destruction and inhibits cell proliferation. Here, we explore the impact of NFL-TBS.40-63 peptide on the mitochondrial network and its functions by using global cell respiration, quantitative PCR analysis of the main actors directing mitochondrial biogenesis, western blot analysis of the oxidative phosphorylation (OXPHOS) subunits and confocal microscopy. We show that the internalized peptide disturbs mitochondrial and microtubule networks, interferes with mitochondrial dynamics and induces a rapid depletion of global cell respiration. This effect may be related to reduced expression of the NRF-1 transcription factor and of specific miRNAs, which may impact mitochondrial biogenesis, in regard to default mitochondrial mobility.