Sensitization of human renal cell carcinoma cell lines to TRAIL-induced apoptosis by anthracyclines.
BACKGROUND
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a new member of the tumor necrosis factor family. The present study investigated whether anthracyclines enhance TRAIL-induced apoptosis and cytotoxicity in renal cell carcinoma (RCC) cells.


METHODS
Cytotoxicity was measured using the microtiter assay. Apoptosis was monitored using DNA ladder analysis. Caspase activity was determined using a quantitative colorimetric assay.


RESULTS
Treatment of ACHN and Caki-1 human RCC lines with TRAIL, in combination with subtoxic concentrations of epirubicin (EPI) or pirarubicin (THP), enhanced induction of apoptosis and cytotoxicity. Sequential treatment with EPI followed by TRAIL induced significantly more cytotoxicity than the inverse treatment. The combined cytotoxicity of TRAIL and EPI was significantly inhibited by the TRAIL-neutralizing fusion protein DR5:Fc, although EPI did not affect the mRNA expression of DR4, DR5, DcR1 or DcR2. The combination treatment with TRAIL and EPI activated caspase-6 and -3, which were downstream molecules of the death receptor. Furthermore, the combined cytotoxicity of TRAIL and EPI was almost completely inhibited by Z-VAD-FMK, and partly inhibited by Ac-DMQD-CHO.


CONCLUSIONS
These findings indicate that anthracyclines sensitize RCC cells to TRAIL-induced apoptosis and cytotoxicity through activation of caspases, suggesting that TRAIL, in combination with anthracyclines, has a therapeutic potential in the treatment of RCC.
Department of Urology, Kagawa Medical University, Kagawa Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Xiu-Xian
XX
Wu
Osamu
O
Ogawa
Yoshiyuki
Y
Kakehi
D018943:Anthracyclines / Q000494:pharmacology*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D002292:Carcinoma, Renal Cell / Q000473:pathology*; D045744:Cell Line, Tumor / Q000187:drug effects; D015251:Epirubicin / Q000494:pharmacology*; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D018943:Anthracyclines; D000903:Antibiotics, Antineoplastic; D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D015251:Epirubicin