Figure 2.

Overexpression of DDAH I increases the in vivo tumour growth rate. (A) In vivo, overexpression of DDAH I caused an increase in the growth rate of D20, D26 and D27 tumours compared to M4 and C6 tumours. Results are means±s.e.m. of at least two different inoculations of six mice. (B) Western blot analysis of tumours (100 μg protein per lane) confirmed that the overexpressing DDAH tumours had higher amounts of DDAHI protein in vivo. (C) Assessment of DDAH activity in tumour homogenates by the conversion of [¹⁴C] L-NMMA to L-citrulline. Tumour homogenates derived from D26 and D27 revealed a two- and a half-fold increase in their DDAH activity compared to C6 tumours. Results are means+s.e.m. of duplicates from two separate experiments (**P<0.02 compared to control, Student's t-test).