Figure 4.

Expression of urokinase type plasminogen (uPA) activator in EMT6 murine mammary carcinoma cells by northern blot analysis of mRNA from transfected EMT6. (A) Poly (A⁺) RNA (8 μg/lane) derived from cells from the cytomegalovirus control transfected clone (lane 1) and from cells from clones H (lane2), J (lane 3), and O (lane 4) carrying the antisense insulin-like growth factor I receptor (IGF-IR) construct was analysed using a uPA cDNA hybridisation probe. (B) Rehybridisation of the same filter was performed with a β actin probe. The mRNA signals were scanned using the laser densitometer SciScan 5000, and the difference in the expression of mRNA transcripts was calculated relative to the β actin standards. Results of analysis for uPA are shown in the bar graph (C). The numbers under the bar graph correspond to the numbers used in A and B.