Pnm. Konings et al., REVERSAL BY NGF OF CYTOSTATIC DRUG-INDUCED REDUCTION OF NEURITE OUTGROWTH IN RAT DORSAL-ROOT GANGLIA IN-VITRO, Brain research, 640(1-2), 1994, pp. 195-204
Cytostatic drugs, like cisplatin, vincristine and taxol, when given to
cancer patients may cause peripheral neuropathies. We were interested
in the potential neuroprotective effects of neurotrophic factors agai
nst such neuropathies. To this aim we studied the effects of these cyt
ostatic agents on sensory fibers located in the dorsal root ganglia (D
RG) in vitro and studied whether nerve growth factor (NGF) could rever
se the cytostatic induced morphological changes on intact DRG (1 DRG/w
ell, n = 10 per dose). Neuritogenesis from DRG was measured with an im
age analysis system following exposure to different concentrations of
cytostatic drugs in the presence of 3 ng NGF/ml and cytosine arabinosi
de (Ara-C, 10(-6) M). Relative neurite outgrowth in intact DRG in cult
ure was reduced dose-dependently, (a) by vincristine starting at a dos
e of 0.4 ng/ml for 2 days (-33% as compared to control; P < 0.001, Stu
dent's t-test); (b) by taxol 10 ng/ml (-60%; P < 0.001), and (c) by ci
splatin 3 mug/ml (-47%, P < 0.001). Cisplatin also prevented the migra
tion of satellite cells away from the intact DRG along the extending n
eurites into the well in contrast to control, vincristine, or taxol. T
o evaluate the neuroprotective potential of NGF in this in vitro cytos
tatic neuropathy model, we incubated intact DRG with cytostatic agents
in combination with increasing amounts of NGF. Neurite outgrowth from
DRG treated with vincristine (0.5 ng/ ml) + NGF (3 ng/ml) for 2 days
was significantly higher (+87%) than after treatment with vincristine
+ 1 ng NGF/ ml (P < 0.001). Neurite outgrowth from DRG treated with ta
xol (20 ng/ ml) + NGF (3 ng/ ml) for 2 days was significantly higher (
+228%) than after taxol + 1 ng NGF/ ml (P < 0.05). Neuritogenesis from
DRG treated with cisplatin (2.5 mug/ml) + NGF (3 ng/ ml) for 2 days w
as significantly increased (+105%) compared to treatment with cisplati
n + 1 ng NGF/ ml (P < 0.001). DRG thus appear to be a very suitable mo
del for studying cytostatic drug-induced neuropathies in vitro and NGF
has a clear neuroprotective effect on the vincristine-, taxol-, and c
isplatin-induced neuropathies in this in vitro model.