CLONING OF HUMAN BONE MORPHOGENETIC PROTEIN TYPE IB RECEPTOR (BMPR-IB) AND ITS EXPRESSION IN PROSTATE-CANCER IN COMPARISON WITH OTHER BMPRS

Bone metastasis is a common event in prostate cancer, and it is known that some of the bone morphogenetic proteins (BMPs) are expressed in p rostate cancer cells, while no study on the expression of their recept ors, BMPRs, has been reported, Here we report cloning and sequence ana lysis of the human BMPR-IB cDNA. We also analysed the expression of tr anscripts of three types of the BMPR genes in human tissues and prosta te cancer cell lines, The BMPR-IB mRNA was present in various organs, but the highest level was found in the prostate. Moreover, the amount of BMPR-IB mRNA was significantly low in prostate cancer tissues after androgen withdrawal and was also low in prostate cancer cell lines. R T-PCR analysis showed that the BMPR-IB message was upregulated by andr ogen stimulation in the LNCaP cell line which expresses the androgen r eceptor, By contrast, the mRNA levels of BMPR-IA and BMPR-II were not significantly different among non-cancerous and cancerous prostate tis sues. It was also suggested that human BMPR-IA and BMPR-IB might have different biological functions in the prostate, although their sequenc es were 85.3% identical in the serine-threonine kinase domain.