Effect of irradiation on transforming growth factor-beta secretion by malignant glioma cells.
Glioblastoma cells secrete transforming growth factor-beta (TGF-beta), which has a variety of immunosuppressive properties. We investigated the effect of irradiation TGF-beta secretion by malignant glioma cells. Three malignant glioma cell lines (T98G, A172, KG-1-C) were cultured and irradiated using 10 and 50 Gy Linac radiation. After further culture for 36 hours in serum-free culture medium, the supernatants were collected. The TGF-beta activity in the culture supernatants was determined using a specific bioassay. The levels of the active form and total TGF-beta in the supernatants from irradiated malignant glioma cells decreased compared to those from un-irradiated cells. However, since irradiation inhibited the growth of tumor cells, the amount of TGF-beta secretion per cell in irradiated cells tended to increase after irradiation. These results suggest that malignant glioma cells can still secrete TGF-beta and activate latent TGF-beta even after large dose irradiation, despite the inhibition of tumor growth.
Satoh
E
E
Department of Neurosurgery, Yamanashi Medical University, Japan.
Naganuma
H
H
Sasaki
A
A
Nagasaka
M
M
Ogata
H
H
Nukui
H
H
D000818:Animals; D016895:Culture Media, Serum-Free; D005909:Glioblastoma / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D005910:Glioma / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007108:Immune Tolerance; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D016895:Culture Media, Serum-Free; D016212:Transforming Growth Factor beta