Systemic delivery of miR-204 suppresses tumor metastasis.

<p>A, injection of miR-204 oligonucleotide into tail vein suppressed lung metastasis. Live bioluminescence images of mice injected with miR-204 (<i>n</i> = 6) or miR-204 mutant (neg. control; <i>n</i> = 6) oligonucleotides using the Xenogen In Vivo Imaging System (IVIS) (Xenogen). Images were taken after subcutaneously injecting 150 mg/kg D-luciferin substrate in PBS to anesthetized mice. B, tumor metastasis volume was assessed starting from day 10 until animals were sacrificed at day 60. Using ROI analysis, tumor light intensity was calculated in photon/s, which corresponds with the number of live cells in vivo. C, representative lung images showing GFP^+ve foci (red circle) in neg. control groups. D, representative lung sections showing metastatic foci in neg. control groups. E, no hepatotoxicity in miR-204 injected mice. Sections of liver from miR-204 injected mice show no signs of hepatotoxicity. The presence of multifocal periportal lymphocytes is not unusual and is a common finding in young animals.