Fig. 4

Netrin-1 increases the invasiveness of GBM stem-like cells in vivo. a–c The tumor growth in xenograft models was evaluated by immunohistochemistry with human specific nestin antibody. Representative tile images of tissue sections of each U87MG xenograft group are presented. The area covered with tumor is surrounded with dashed line. d To evaluate the effect of NTN1FH or NTN1(II)FH on GBM cell invasiveness xenograft tissue section were stained with human specific Lamin A/C antibody and the invasive colonies were counted. The average number of invasive colonies in each group is presented. Error bars represent +/− standard error of the mean. * p value is <0,05. e–g Immunofluorescence microscopy images of the tumor border show the infiltrative growth of nestin positive GBM cells in each U87MG xenograft groups. Scale bars represent 100 μm. h–i The invasive tumor sprouts of U87MG-NTN1FH tumors were further characterized with immunofluorescence stainings of the tissue sections. Dashed line borders the tumor stroma and the white arrow points the direction of invasion. In (h) red arrows point NTN1 positive cells and green arrows Nestin positive cells. In (i) green arrows point NTN1 positive cells and red arrows the Notch2 positive cells. Scale bars represent 50 μm