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Updated: May 25, 2026
Radiosensitivity of Cancer Stem Cells in Lung Cancer Cell Lines
Published on: August 21, 2019
Basal HIF-1α expression levels are not predictive for radiosensitivity of human cancer cell lines
D Schilling1, C Bayer, K Emmerich
1Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
Background And Purpose:
High levels of hypoxia inducible factor (HIF)-1α in tumors are reported to be associated with tumor progression and resistance to therapy. To examine the impact of HIF-1α on radioresistance under normoxia, the sensitivity towards irradiation was measured in human tumor cell lines that differ significantly in their basal HIF-1α levels.
Material And Methods:
HIF-1α levels were quantified in lysates of H1339, EPLC-272H, A549, SAS, XF354, FaDu, BHY, and CX- tumor cell lines by ELISA. Protein levels of HIF-1α, HIF-2α, carbonic anhydrase IX (CA IX), and GAPDH were assessed by Western blot analysis. Knock-down experiments were performed using HIF-1α siRNA. Clonogenic survival after irradiation was determined by the colony forming assay.
Results:
According to their basal HIF-1α status, the tumor cell lines were divided into low (SAS, XF354, FaDu, A549, CX-), intermediate (EPLC-272H, BHY), and high (H1339) HIF-1α expressors. The functionality of the high basal HIF-1α expression in H1339 cells was proven by reduced CA IX expression after knocking-down HIF-1α. Linear regression analysis revealed no correlation between basal HIF-1α levels and the survival fraction at either 2 or 4 Gy in all tumor cell lines investigated.
Conclusion:
Our data suggest that basal HIF-1α levels in human tumor cell lines do not predict their radiosensitivity under normoxia.
