Cumulus cells conditioned medium facilitates germ cell differentiation from human embryonic stem cells: An experimental study

Background: Studies have shown that embryonic stem cells can differentiate into germ cells either spontaneously or directed by the defined factors or by applying a co-culture method or conditioned medium of stromal cells. Objective: Here, Yazd4 (human embryonic stem cells [hESC] line; 46, XX) was used to evaluate the effect of human cumulus cells conditioned medium (CCCM) on in vitro germ cell production and development. Materials and Methods: In this experimental study 2 different complete media were applied, Dulbecco's modified eagle's medium + 20% fetal bovin serum and embryoid body (EB) medium (KnockOut serum replacement- hESC without basal fibroblast growth factor). Thus, there are 2 control groups for spontaneous differentiation (SD) (SD-EB and SD-DM) and 2 types of CCCM (CCCM-DM and CCCM-EB) as test groups. 40% dilution of the conditioned medium was applied according to previous reports. Results: Reverse transcription-quantitative polymerase chain reaction and immunofluorescent staining assays revealed that between groups with similar complete medium, CCCM provides a better condition for in vitro germ cell differentiation from hESCs. Moreover, a comparison between the 2 types of complete media showed that EB medium is more supportive than Dulbecco's modified eagle's medium +20% fetal bovin serum. Conclusion: CCCM with EB medium as a complete medium provides a better condition for in vitro germ cell differentiation from hESCs.