Discordant synthesis and secretion of human chorionic gonadotropin and subunits by cervical carcinoma cells

Epidermoid carcinoma of the cervix cell lines DoT and CaSki were examined for the production of human chorionic gonadotropin (HCG) and its subunits (HCG-alpha and HCG-beta). Additionally, the effect of butyrate and other regulatory agents on synthesis and secretion was investigated. Media and cell lysates were analyzed by radioimmunoassay for HCG and HCG-beta and by radioreceptor assay for intact HCG. Although DoT and CaSki cells secreted more HCG-beta than HCG, the cell lysates contained only one-half as much HCG-beta as HCG. This raises the possibility that HCG-alpha synthesis may be limiting to the formation of intact HCG in DoT and CaSki cell lines. Our results also indicate discordance in HCG and HCG-beta production in response to butyrate. Whereas the production of HCG-beta was increased by 5 mM sodium butyrate, the synthesis and secretion of intact hCG were decreased. These results support the concept of independent regulation of alpha- and beta-subunit synthesis and secretion.