Effect of tumour necrosis factor-alpha and irradiation alone or in combination on the viability of hepatocellular and biliary adenocarcinoma cell lines in vitro.
BACKGROUND
Tumour necrosis factor alpha (TNF-alpha) may exhibit antitumoral activity and can influence the reaction of both tumour and normal tissue to radiation.


OBJECTIVE
To test the effect of TNF-alpha and/or irradiation on hepatocellular (HepG2, Hep3B, Sk-Hep1, HuH7) and cholangiocellular (Sk-chA1, Mz-chA1) tumour cell lines.


METHODS
Colony formation, apoptosis analysis and trypan blue exclusion were used to assess cell viability. Doses of radiation (2-25 Gy) and TNF-alpha (100-50,000 U) as well as their respective sequencing were varied (24 and 12 h before and 6 h after). The expression of TNF-alpha and TNF receptors 1/2 was determined using real-time polymerase chain reaction and IkappaBalpha protein expression was detected by Western blot.


RESULTS
Sole irradiation induced a reduction in colony formation in all cell lines and sole TNF-alpha in HepG2 and Sk-chA1 cells only. No difference in apoptosis induction after TNF-alpha or irradiation was observed. Cellular death induced by the combination of TNF-alpha and radiation was not superior to the use of any of the two agents alone. All cell lines revealed that radiation induced upregulation of TNF-alpha whereas the extent of TNF receptor-specific transcription did not change. Furthermore, radiation-induced changes in IkappaBalpha expression were not detectable.


CONCLUSIONS
Our data suggest that both TNF-alpha and radiation may be treatment options for hepatocellular and cholangiocellular carcinomas. Because TNF-alpha and radiation do not interact in terms of radiosensitization, anti-TNF-alpha treatment may have the potential to protect against hepatocellular injury after abdominal irradiation. However, further in vivo studies are needed to confirm that anti-TNF-alpha treatment does not compromise tumour control and actually attenuates radiation-induced liver injury.
Qesaraku
Blendi
B
Department of Radiotherapy, University Hospital Goettingen, Goettingen, Germany.
Dudas
Joszef
J
Rave-Fränk
Margret
M
Hess
Clemens Friedrich
CF
Ramadori
Giuliano
G
Saile
Bernhard
B
Christiansen
Hans
H
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000532:radiotherapy*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D001661:Biliary Tract Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014343:Trypan Blue; D014409:Tumor Necrosis Factor-alpha / Q000627:therapeutic use*; D014410:Tumor Stem Cell Assay
D000970:Antineoplastic Agents; D017931:DNA Primers; D014409:Tumor Necrosis Factor-alpha; D014343:Trypan Blue