Figure 4

Silencing of NURR1 expression inhibits in growth of mammary xenograft tumors. A) Cell lines stably transfected with plasmids expressing GFP with (4A2KD-) or without (Vec-) shRNA against NURR1 were generated from MDA-MB-468 and highly invasive MDA-MB-231 breast cancer cell lines. NURR1 silencing efficiency was ascertained by Western blot. Athymic nude mice were inoculated by injection with 5×10⁵, and tumor growth was monitored over 35 days by GFP fluorescence using a Maestro Flex small animal imager (Vec-468 and 4A2KD-468 upper panels, Vec-231 and 4A2KD-231 lower panels). In MDA-MB-231 derived cell lines, stable silencing of NURR1 resulted in decreased contralateral metastases (arrow). B) Quantification of the tumor associated fluorescence was quantified, and NURR1 silencing resulted in significant (*two-way analysis of variance, p < 0.01) inhibition in tumor growth by 35 days post inoculation in both cell lines).