Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Jan;136(1):48-62.
doi: 10.1111/jnc.13383. Epub 2015 Nov 6.

Vinorelbine and Epirubicin Share Common Features With Polysialic Acid and Modulate Neuronal and Glial Functions

Affiliations
Free PMC article

Vinorelbine and Epirubicin Share Common Features With Polysialic Acid and Modulate Neuronal and Glial Functions

Gabriele Loers et al. J Neurochem. .
Free PMC article

Abstract

Polysialic acid (PSA), a large, linear glycan composed of 8 to over 100 α2,8-linked sialic acid residues, modulates development of the nervous system by enhancing cell migration, axon pathfinding, and synaptic targeting and by regulating differentiation of progenitor cells. PSA also functions in developing and adult immune systems and is a signature of many cancers. In this study we identified vinorelbine, a semi-synthetic third generation vinca alkaloid, and epirubicin, an anthracycline and 4'-epimer of doxorubicin, as PSA mimetics. Similar to PSA, vinorelbine and epirubicin bind to the PSA-specific monoclonal antibody 735 and compete with the bacterial analog of PSA, colominic acid in binding to monoclonal antibody 735. Vinorelbine and epirubicin stimulate neurite outgrowth of cerebellar neurons via the neural cell adhesion molecule, via myristoylated alanine-rich C kinase substrate, and via fibroblast growth factor receptor, signaling through Erk pathways. Furthermore, the two compounds enhance process formation of Schwann cells and migration of cerebellar neurons in culture, and reduce migration of astrocytes after injury. These novel results show that the structure and function of PSA can be mimicked by the small organic compounds vinorelbine and epirubicin, thus raising the possibility to re-target drugs used in treatment of cancers to nervous system repair. Vinorelbine and epirubicin, identified as PSA mimetics, enhance, like PSA, neuronal migration, neuritogenesis, and formation of Schwann cell processes, and reduce astrocytic migration. Ablating NCAM, inhibiting fibroblast growth factor (FGFR) receptor, or adding the effector domain of myristoylated alanine-rich C kinase substrate (MARCKS) minimize the vinorelbine and epirubicin effects, indicating that they are true PSA mimetics triggering PSA-mediated functions.

Keywords: epirubicin; migration; neural cell adhesion molecule; neurite outgrowth; polysialic acid; vinorelbine.

Figures

Fig. 1
Fig. 1. Structure models of PSA and vinorelbine and epirubicin
(A) Chemical structures of vinorelbine and epirubicin. (B) Configuration of PSA, shown as a surface, superimposed with the 3D structure of epirubicin (right) showing that epirubicin can adopt a conformation compatible with that of PSA when bound to antibody 735. No significant structural similarity with vinorelbine is observed. (C) Structure models of complexes between antibody 735 and vinorelbine (left) or epirubicin (right) suggest that the two compounds bind to a hydrophobic region that appears critical for interactions with PSA.
Fig. 2
Fig. 2. Vinorelbine and epirubicin compete with colominic acid for binding to the PSA-specific antibody 735
(A) Colominic acid coupled to catalase was immobilized in 384-wells and incubated with antibody 735 in the presence of vinorelbine (light gray line) or epirubicin (dark grey line) at 100 nM – 100 μM concentrations (means ± SEM). The signal from antibody binding to colominic acid was set to 100%. Vinorelbine and epirubicin compete with colominic acid for binding to antibody 735 in a concentration dependent manner reaching a maximal effect at 40 to 80 μM concentrations. * p < 0.05, ** p < 0.005; two-way analysis of variance (ANOVA) followed by Tukey's post hoc testing. (B) Representative images of cerebellar neurons stained with PSA antibody mAb 735 (Cy3; red) alone or in the presence of vinorelbine or epirubicin, PSA peptide (positive control) or nocodazole (negative control). Nuclei are shown in blue. Scale bar: 50 μm. (C) Histogram showing the quantification of immunostainings from 50 cells (means + SEM). * p < 0.05, ** p < 0.005 (one-way ANOVA).
Fig. 3
Fig. 3. Vinorelbine and epirubicin stimulate neurite outgrowth from wild-type neurons
(A) Vinorelbine and epirubicin but not nocodazole stimulate concentration dependent neurite outgrowth from wild-type cerebellar neurons (left). Neurite outgrowth from NCAM-deficient cerebellar neurons in the absence (poly-L-lysine; PLL) or presence of colominic acid (CA), vinorelbine, epirubicin and nocodazole (small organic compounds at 1 nM concentration, CA at 30 μg/ml; right). (B) Representative images of cerebellar neurons, motor neurons and dorsal root ganglion (DRG) neurons grown in the absence (untr) or presence of vinorelbine (vino). Scale bars: 20 μm. The bar diagram shows the comparison of neurite lengths of cerebellar, motor and dorsal root ganglion (DRG) neurons in the absence (poly-L-lysine; PLL) or presence of colominic acid (CA), vinorelbine, epirubicin and nocodazole (small organic compounds at 1 nM concentration, CA at 30 μg/ml). (A-B) Data represent means of neurite lengths per cell + SEM as compared with PLL from three independent experiments. Asterisks denote significant differences from control. ** p < 0.001; one-way or two-way (3A left panel) ANOVA followed by Tukey's post hoc testing.
Fig. 4
Fig. 4. Vinorelbine and epirubicin stimulate process formation of wild-type Schwann cells
Representative images of Schwann cells grown in the absence (untr) or presence of 10 nM vinorelbine (vino). Scale bar: 20 μM. Histogram shows that vinorelbine and epirubicin but not nocodazole stimulate concentration dependent process formation of Schwann cells. Data represent means of process lengths per cell + SEM as compared with PLL from three independent experiments. Asterisks denote significant differences from control. * p < 0.01, ** p < 0.001; two-way ANOVA followed by Tukey's post hoc testing.
Fig. 5
Fig. 5. Vinorelbine and epirubicin bind with and stimulate neurite outgrowth via MARCKS
(A) Neurite lengths of cerebellar neurons in the presence of 1 nM vinorelbine, 1 nM epirubicin and 30 μg/ml colominic acid, and the MARCKS-ED and control peptides (20 μg/ml). Data represent mean values of neurite lengths per cell + SEM as compared with PLL from three independent experiments. Asterisks denote significant differences from control, * p < 0.001; one-way analysis of variance (ANOVA). Hatches denote differences within a group, # p < 0.001. (B) MARCKS-ED was incubated with PBS (without competitor), colominic acid (CA), vinorelbine or epirubicin followed by addition of PSA mimicking peptide coupled to biotin. Binding of PSA mimicking peptide was detected with Streptavidin-HRP. Means + SD from triplicates and three independent experiments are shown. * p < 0.05.
Fig. 6
Fig. 6. Vinorelbine and epirubicin stimulate neurite outgrowth via FGF receptor and Erk signaling pathways
Neurite length of cerebellar neurons grown in the presence of 1 nM vinorelbine, 1 nM epirubicin and colominic acid (CA at 30 μg/ml) and in the presence of the Erk inhibitor CAS 865362-74-9 (1 μM) and the FGFR receptor tyrosine kinase inhibitor CAS 192705-79-6 (100 nM). Data represent means of neurite lengths per cell + SEM as compared with PLL from three independent experiments. Asterisks denote significant differences from control, * p < 0.001; one-way ANOVA. Hatches denote differences within a group, # p < 0.001.
Fig.7
Fig.7. Vinorelbine and epirubicin increase migration of neurons out of cerebellar explants and of cortical neurons, and inhibit migration of astrocytes
(A, B) Migration of cells out of cerebellar explants was determined 32 h after compound application (0.1 to 100 nM concentrations (A), 1 nM (B)) and the total number of migrating cells was determined. (C) Confluent monolayers of wild-type astrocytes were scratched resulting in a gap of approximately 800 μm (gap width was set to 100%). Closure of the gap was measured by inverted phase-contrast microscopy from 0 to 48 h. Histograms show data representing mean values + SEM from three independent experiments. Asterisks denote significant differences from control. * p< 0.01; one-way ANOVA. (D, E) Monolayers of cortical neurons were injured by applying a scratch and treated with 10 nM vinorelbine, 10 nM epirubicin, and the control compounds 10 nM nocodazole and nitrendipine or vehicle control (control). Phase contrast images are shown for 0 h and 24 h after scratching. Scale bar = 200 μm. Histograms represent the gap widths in percent of the original gap width (gap size at 0 h was set to 100%) (means+ SEM, from three independent experiments).

Similar articles

See all similar articles

Cited by 2 articles

Publication types

MeSH terms

Feedback