The present study reports on the transplantability and immunogenic properties of a murine spontaneous mammary adenocarcinoma (AdCa) cultured under various conditions. When cultured under standard conditions for 300 days, AdCa cells became nononcogenic, and 74 % survived the effects of immune spleen cells. Cell cultures grown in presence of the « extracellular protease » retained their transplantability, and only 25 % survived the effects of immune spleen cells. In cotton-stoppered bottles without HEPES, the cells retained their transplantability and survived after incubation with immune spleen cells, whereas AdCa cells cultured in presence of human alpha-1-antitrypsin became less oncogenic and remained sensitive to the killing effects of immune spleen cells. When treated with serum of mice or rabbits immunized with AdCa cells, the cells cultured under standard conditions or grown in presence of the human antitrypsin became non-transplantable, whereas cells grown in cotton-stoppered glass bottles or in presence of the « extracellular protease » retained their oncogenicity. When cultured AdCa cells were incubated with cAMP and then used to immunize syngeneic hosts, tumors arising from a challenging dose of untreated AdCa cells grew faster in mice immunized with cAMP-treated cells than in mice immunized with untreated cells. On the other hand, immunization with AdCa cells treated with EDTA, iodoacetate, or heparin reduced the transplantability of the challenging AdCa cells. Treatment with vibrio cholera neuraminidase (VCN) at pH 5.6 increased the immunogenicity of AdCa cells: immunization with VCN-treated AdCa cells protected syngeneic hosts against challenge with untreated AdCa cells, whereas formalin-or glutaraldehydeflxed untreated AdCa cells gave a transient protection. Rabbit and mouse antisera raised against VCN-treated AdCa cells and against membrane glycoproteins of untreated AdCa cells showed definite though variable cytotoxic activity against cultured untreated AdCa cells.
Mesenchymal stem cells cultured under hypoxic conditions had a greater therapeutic effect on mice with liver cirrhosis compared to those cultured under normal oxygen conditions
