Carcinomas induced by cell lines cultivated from normal mouse placentas

Area of Science:

• Cell Biology
• Immunology
• Oncology

Background:

• Cell lines derived from mouse placentas can serve as models for studying trophoblast biology.
• Trophoblast cells play crucial roles in pregnancy and have unique immunological properties.

Purpose of the Study:

• To establish and characterize novel mouse placental trophoblast cell lines.
• To investigate the immunological and viral resistance properties of these cell lines.
• To assess the tumorigenic potential and transplantation genetics of the established cell lines.

Main Methods:

• In vitro cultivation of mouse placental cells to establish cell lines.
• Characterization of cell surface markers (H-2 antigen, Fc receptor, Thy 1, surface immunoglobulin).
• Assessment of hormone production (gonadotropin-like substance, steroid hormones).
• Evaluation of resistance to murine type-C RNA tumor virus infection.
• Tumor induction studies via injection into adult mice and subsequent transplantation experiments.
• Genetic analysis of tumor transplantation susceptibility in different mouse strains.

Main Results:

• Established cell lines exhibit trophoblast characteristics, including hormone production.
• The cell lines lack specific cell surface antigens and are resistant to murine type-C RNA tumor virus infection due to a post-adsorption/penetration replication block.
• Injection of cell lines induced carcinomas in adult mice, with tumor formation requiring approximately 2 x 10^6 cells.
• Tumor transplantation varied between mouse strains, indicating genetic control of susceptibility.
• Genetic crosses revealed that tumor transplantation acceptance is controlled by a single pair of dominant autosomal genes.

Conclusions:

• Novel mouse placental trophoblast cell lines have been successfully established and characterized.
• These cell lines possess unique immunological and viral resistance properties, offering a valuable model for further research.
• The tumorigenicity and transplantation genetics of these cells provide insights into host-tumor interactions and genetic control of tumor acceptance.