Fig. 6

Netrin-1 promotes the motility of the primary glioblastoma stem-like cells. a Primary human GBM stem-like cells, GBM9, were mixed with GFP positive U251MG cells, that were either wildtype (U251), full length NTN1 producing (U251-NTN1FH) or NTN1 central domain producing (NTN1(II)FH). The spheroids were implanted into 3D Matrigel and their growth was monitored with Cell-IQ imaging system for 24 h. Gray arrows mark sprouts that are led by GBM9 cells. Green arrows mark sprouts that are led by GFP-positive U251MG cells. The invasion of the spheroids is presented also on Additional file 6: Video3, Additional file 7: Video4 and Additional file 8: Video5. b The number of sprouts led by the GFP-negative (GFP-) primary cells or GFP-positive (GFP+) U251MG cells were quantitated. The distribution as percentage is presented. Error bars represent SD. * = p < 0,05. c After 24 h 3D Matrigel invasion spheroids consisting of GBM9 cells mixed with U251-NTN1FH or U251-NTN1(II)FH were fixed and used for immunofluorescence staining against Nestin and HA. HA marks either full-length NTN1 (NTN1FH) or the central fragment of NTN1 (NTN1(II)FH)