DEMONSTRATION OF ISOFORMS OF THE ESTROGEN-RECEPTOR IN THE BONE TISSUES AND IN OSTEOBLASTIC CELLS

作者：HOSHINO S; INOUE S; HOSOI T; SAITO T; IKEGAMI A; KANEKI M; OUCHI Y; ORIMO H

来源：Calcified Tissue International, 1995, 57(6): 466-468.

DOI：10.1007/BF00301952

• ESTROGEN RECEPTOR
• ISOFORM
• POLYMERASE CHAIN REACTION
• BONE
• OSTEOBLAST

Expression of isoforms of estrogen receptor (ER) was examined in the bone tissues. Reverse transcriptase-polymerase chain reaction (RT-PCR) using specific primers for rat ER cDNA was performed with total RNA from rat bone tissues. Then, we sequenced the amplified products after cloning and identified two isoforms of the ER and the wildtype ER. One of the ER mRNA isoforms did not have the region corresponding to exon 4 and the other isoform did not have the region corresponding to both exon 3 and exon 4. These isoforms were designated as ER Delta 4 isoform and ER Delta 3/4 isoform, respectively. The existence of these isoforms was also confirmed in ROS-17/2.8 osteoblastic osteosarcoma cells. Chloramphenicol acetyltransferase assay showed that these isoforms lost estrogen dependent transactivation activities. We suggest that the ER isoforms may play some roles in the bone metabolism in which estrogen is essential to maintain bone density.

• 出版日期1995-12