Figure 4.

Overexpression of the Mmp inhibitor Timp or Mmp RNAi suppresses invasiveness of ras^V12, scrib^−/− tumors but does not interfere with tumor growth. Fluorescent microscopy of eye/antennal/brain complexes (8 days AEL) (A–C) and live 9-day-old larvae (D, F), carrying GFP-marked clones of the indicated genotypes shows that suppression of Mmp function by Timp expression or RNAi does not interfere with the growth of malignant eye disc tissue. The extent of clonal overgrowth in ras^V12, scrib^−/−, timp eye/antennal discs (B) and of ras^V12, scrib^−/− discs expressing Mmp1 and Mmp2 RNAi (C) exceeds that of the entire ras^V12, scrib^−/− eye/antennal/brain complex (A). (D–G′) Examination of dissected eye/antennal/brain complexes (8 days AEL) by confocal microscopy reveals no invasive clonal tissue in the VNC (arrows) in the ras^V12, scrib^−/−, timp genotype (G′) as opposed to ras^V12, scrib^−/− (E′). The clones are marked with GFP (green), the actin cytoskeleton is visualized using phalloidin staining (white) and Elav marks differentiated neurons (red). The arrows and arrowheads indicate VNC and brain optic lobes, respectively. Images C, C′ and G, G′ represent projections of multiple confocal sections. Scale bars=50 μm.