Inferior ectopic bone formation of mesenchymal stromal cells from adipose tissue compared to bone marrow: rescue by chondrogenic pre-induction.

Human mesenchymal stromal cells derived from bone marrow (BMSC) and adipose tissue (ATSC) represent a valuable source of progenitor cells for cell therapy and tissue engineering. While ectopic bone formation is a standard activity of human BMSC on calcium phosphate ceramics, the bone formation capacity of human ATSC has so far been unclear. The objectives of this study were to assess the therapeutic potency of ATSC for bone formation in an ectopic mouse model and determine molecular differences by standardized comparison with BMSC. Although ATSC contained less CD146(+) cells, exhibited better proliferation and displayed similar alkaline phosphatase activity upon osteogenic in vitro differentiation, cells did not develop into bone-depositing osteoblasts on ß-TCP after 8weeks in vivo. Additionally, ATSC expressed less BMP-2, BMP-4, VEGF, angiopoietin and IL-6 and more adiponectin mRNA, altogether suggesting insufficient osteochondral commitment and reduced proangiogenic activity. Chondrogenic pre-induction of ATSC/ß-TCP constructs with TGF-ß and BMP-6 initiated ectopic bone formation in >75% of samples. Both chondrogenic pre-induction and the osteoconductive microenvironment of ß-TCP were necessary for ectopic bone formation by ATSC pointing towards a need for inductive conditions/biomaterials to make this more easily accessible cell source attractive for future applications in bone regeneration.

An approach to the serodiagnosis of human lung cancer. Cell culture lines reactive as antigens with tumor patients' sera.

A solid-phase radioimmunoassay technique was used to quantitate antigen-antibody reactions between various human cell lines and lung cancer patients' sera. Four human fetal lung cell lines and four human tumor cell lines were more or less reactive as antigens. Failure to obtain exact correspondence between reactions with these cell lines indicates that more than one antigen may be required for detecting specific antibodies to the various lung tumor types. These results suggest that serum antibody detection might be a feasible approach to the immunodiagnosis of lung cancer at stages when the tumor masses are relatively small.