[Correlation of DNA-dependent protein kinase catalytic subunit expression to radiosensitivity of non-small cell lung cancer cell lines].
OBJECTIVE
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) plays an important role in repairing irradiation-induced DNA double-strand break (DSB), and affects the radiosensitivity of tissue cells. This study was to detect the expression of DNA-PKcs in different non-small cell lung cancer (NSCLC) cell lines and evaluate its correlation to radiosensitivity.


METHODS
The content and activity of DNA-PKcs in five NSCLC cell lines A549, H1299, L78, PGCL3 and H460 were measured by Western blot and the DNA-PK activity assay. Cell survival was analyzed using clonogenic formation assay.


RESULTS
The radiosensitivities of five NSCLC cell lines were different. The values of survival fraction at 2 Gy (SF2) were 0.74 in A549 cells, 0.25 in H1299 cells, 0.21 in H460 cells, 0.48 in PGCL3 cells, and 0.58 in L78 cells. The protein levels of DNA-PKcs were 3.26+/-0.98 in A549 cells, 0.51+/-0.07 in L78 cells, 0.51+/-0.11 in H1299 cells, 0.86+/-0.23 in H460 cells, and 2.60+/-0.76 in PGCL3 cells. The activity values of DNA-PKcs were 8.30+/-1.03 in A549 cells, 2.45+/-0.52 in H1299 cells, 0.11+/-0.02 in H460 cells, 4.13+/-0.87 in PGCL3 cells, and 0.42+/-0.07 in L78 cells. In adenocarcinoma and large cell carcinoma cell lines, SF2 were correlated to DNA-PKcs content (P<0.05, r=0.95) and activity (P=0.03, r=0.98).


CONCLUSIONS
DNA-PKcs is an important factor to predict the radiosensitivity in adenocarcinoma and large cell lung cancer cell lines.
Pan
Yi
Y
Department of Radiation Oncology, Guangdong Provincial People's Hospital, Guangdong, 510080, People's Republic of China.
Li
Wei-Xiong
WX
Li
Jun-Ming
JM
Zhu
Jian-Quan
JQ
Liang
Yi-Qiang
YQ
Guo
Ai-Lin
AL
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D018287:Carcinoma, Large Cell / Q000378:metabolism / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects*; D051747:DNA-Activated Protein Kinase / Q000378:metabolism*; D004789:Enzyme Activation / Q000528:radiation effects; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D010315:Particle Accelerators; D011836:Radiation Tolerance
D051747:DNA-Activated Protein Kinase