TM3

TM3 cells were originally derived from normal testicular tissue obtained from an immature BALB/c mouse. As Leydig cells synthesize the majority of testosterone within the testis, TM3 cells provide an appropriate cell line with which to study steroidogenesis and androgen regulation in vitro.

TM3 cells adhere to culture plates as fibroblast-like cells. They have been shown to express multiple enzymes essential for steroidogenesis including 3β-hydroxysteroid dehydrogenase (3β-HSD). While TM3 cells have relatively low basal levels of testosterone secretion when compared to primary Leydig cells, they have been successfully utilized in mechanistic studies as they can be hormonally stimulated and subjected to signaling pathway alterations. These cells are typically cultured in an equal mixture of DMEM and Ham's F-12 with serum.

Due to their derivation from Leydig cells, TM3 cells have been widely used to study male reproductive physiology, endocrine disruption, and toxicology. Specifically, they have been employed to assess cytotoxicity, steroidogenic potential, and cellular stress responses of environmental chemicals, pharmaceuticals, and hormonal regulators. TM3 cells have proven useful to study Leydig cell biology due to their robustness, ease of culture, and well-established phenotype.