Yy. Xiang et al., ISOLATION OF COMPLEMENTARY-DNA ENCODING K-CADHERIN, A NOVEL RAT CADHERIN PREFERENTIALLY EXPRESSED IN FETAL KIDNEY AND KIDNEY CARCINOMA, Cancer research, 54(11), 1994, pp. 3034-3041
Complementary DNA for a novel member of the cadherin family, designate
d K-cadherin, was isolated from a rat renal cell carcinoma complementa
ry DNA library by screening it with a short complementary DNA probe wh
ich was initially obtained from the RNA of day 16 fetal Wistar rat sto
mach mucosa by the polymerase chain reaction. The deduced primary stru
cture of K-cadherin is 789 amino acid residues, which contain five int
ernal repeats in its extracellular domain, a single putative transmemb
rane domain, and a cytoplasmic tail characteristic of those of classic
type cadherins. K-cadherin exhibits low homology with mature proteins
of mouse N- (38%), E- (35%), and P-cadherin (32%), and high homology
with a partially identified human cadherin-6 protein (95%) at the amin
o acid level. Northern blot analysis revealed a high level of expressi
on of K-cadherin mRNA in fetal rat kidney and brain, and rat kidney ca
rcinoma with two major transcripts, 4.1 and 8.0 kilobases in size, whe
reas there was very weak or no expression in any organ of adult rats.
The level of K-cadherin expression was also elevated in some human kid
ney cancer tissues. In the developing kidney, in situ hybridization sh
owed localization of K-cadherin mRNA in the nephroblastic epithelial c
ells of comma bodies coinciding with those in the process of polarizat
ion during glomeruloneogenesis. These results demonstrate that K-cadhe
rin must have important functions in both the process of kidney develo
pment and tumorigenesis of some types of kidney cancer.