The effect of type beta transforming growth factor on proliferation of clonogenic cells from human gliomas.
Type beta transforming growth factor (B-TGF) is a potent regulator of cell growth and differentiation. Growth of many human tumour cell lines are inhibited by B-TGF. The effect of B-TGF on proliferation of clonogenic cells from 12 human glioma biopsies was registrated in a thymidine incorporation assay. B-TGF appeared to be a potent growth inhibitor for some gliomas, while it had no effect on others. Maximum inhibition was about 60%. Though not significant, glioblastomas appeared to be less sensitive to inhibition by B-TGF than astrocytomas and oligodendrogliomas. Very little is known about the growth inhibitory action of B-TGF. The negative autocrine growth theory for cancer cells postulates that a reduced production, or production of a defective growth inhibitor normally found in the cell, may account for the autonomous nature of some cancer cells. In view of this theory, we searched for B-TGF in protein extracts from a glioblastoma cell line, T-MGl, whose growth was inhibited by B-TGF. Protein extract from T-MGl cells was analysed for B-TGF activity using a soft agar colony formation assay with normal rat kidney fibroblasts. B-TGF was not found in the extract. Since, according to the literature B-TGF has been found in all other cell lines examined, we believe that there may be a lack of B-TGF or an altered B-TGF in the gliomas whose growth are inhibited by B-TGF. This problem will be studied further.
Helseth
E
E
Brain Tumour Research Laboratory, University Hospital of Trondheim, Norway.
Unsgaard
G
G
Dalen
A
A
Vik
R
R
D001932:Brain Neoplasms / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002999:Clone Cells; D003470:Culture Media; D005910:Glioma / Q000032:analysis / Q000473:pathology*; D006801:Humans; D012685:Sepharose; D015291:Transforming Growth Factors / Q000032:analysis / Q000494:pharmacology*
D003470:Culture Media; D015291:Transforming Growth Factors; D012685:Sepharose