Endothelin receptor expression in colorectal cancer

The distribution of endothelin-A- and B- (ETA, ETB)receptor subtypes was co mpared in colorectal cancer to that in normal colon and their. expression i n the colorectal cancer cell lines LIM1215. HT29, SKCO1, SKCO17 and LoVo wa s determined, using gross and high resolution autoradiography and quantifie d by densitometry. ETA and ETB binding sites were expressed by all the cell lines. There was significantly (p=0.008) higher expression of ETA-receptor s by cancers (205.95 dpm x 1000/mm(2)) compared to normal colon (129.19 dpt n x 1000/mm(2)). However. for ETB-receptors, this was reversed, with signif icantly (p = 0.008) higher expression of ETB binding in normal colon (207.0 0 dpm x 1000/mm(2)) than in tumours (122.35 dpm x 1000/mm(2)).