YEN-HUI CHENChen T.-M.CHANG-YAO HSIEH2020-11-272020-11-2719960263-6484https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029844709&doi=10.1002%2fcbf.686&partnerID=40&md5=d8c14dbc02a6030ee76e3b3198a4ec4chttps://scholars.lib.ntu.edu.tw/handle/123456789/522757Transcription of the human chorionic gonadotropin (hCG) genes begins in the very early embryo stage and decreases or even disappears in nonplacental tissues. We have studied the regulation of hCG-beta genes by cell fusion and by the reverse transcription-polymerase chain reaction (RT-PCR). The choriocarcinoma cell lines, JAR and JEG-3, express high levels of the hCG-beta subunit while HeLa cells express extremely low levels of it. Most HeLa x JAR and HeLa x JEG-3 fusion clones expressed only a trace of the hCG-beta subunit mRNA, while JAR x JEG-3 fusion clones still expressed high levels of the hCG-beta subunit, Most transcripts of the hCG-beta subunit genes in JAR and JEG-3 came from the hCG-beta 5 subunit. Even the trace amount of hCG-beta transcripts from fusion clones came mainly from the beta-5 gene. The results suggest that the expression of the hCG-beta subunit genes depends on negative control. Probably when embryonic cells differentiate to form nonplacental tissues, specific inhibitors may appear and inhibit the expression of the hCG-beta subunit genes.[SDGs]SDG3chorionic gonadotropin beta subunit; messenger RNA; article; cancer cell culture; cell fusion; choriocarcinoma; controlled study; gene repression; HeLa cell; human; human cell; priority journal; reverse transcription polymerase chain reactionjournal article10.1002/cbf.68689520492-s2.0-0029844709