MCF-7 breast cancer cells express normal forms of all vasopressin receptors plus an abnormal V2R

We have previously provided evidence that an autocrine loop involving vasop ressin is present in perhaps all breast cancers. This study now shows MCF-7 breast cancer cells express mRNAs for all currently recognized vasopressin receptor subtypes (V-1a, V-1b, and V-2). Cloning and DNA sequencing over t he entire open reading frame of each mRNA revealed that normal sequences re presenting each receptor were present. However, in addition, an abnormal mR NA for the V-2 receptor, expected to give rise to a truncated 'diabetic' pr otein, was also expressed. Western analysis revealed that all three normal mRNAs gave rise to proteins of sizes compatible with them being functional receptors. The abnormal V-2 receptor mRNA also gave rise to proteins. (C) 1 999 Elsevier Science Inc. All rights reserved.