Characterization and establishment of an immortalized rabbit ovary granulosa cell line for reproductive biology experiments

Granulosa cells (GCs) are the key components of ovarian follicles and regulate the maturation, communication, growth, and development of oocytes. GCs have great potential as human therapeutic models and in livestock breeding. In this study, we established an immortalized cell line (Im-RGCs) by transforming primary rabbit granulosa cells (Pri-RGCs) with lentivirus-mediated simian virus 40 Large T (SV40LT). Morphologically, Im-RGCs were indistinguishable from Pri-RGCs and maintained intact cell structure as observed by H&E staining. Also, Im-RGCs exhibited no significant change in cell proliferation, viability, and growth. Furthermore, GC-specific markers, such as FSHR, StAR, CYP11A1, and CYP19A1, were examined by PCR, immunofluorescence, and Western blotting. ELISA and karyotype analysis showed that Im-RGCs can synthesize steroid hormones and maintain the normal number of chromosomes during the infinite passage. Furthermore, soft-agar cloning and nude mice tumorigenic experiments indicated the absence of any malignancy transformation in Im-RGCs. In conclusion, we successfully established the immortalized granulosa cell line of rabbit follicles that can be used for biological, animal husbandry, and female reproductive research.