[Effects of guanine-quadruplexes formation induced by adriamycin on telomeric extension reaction mediated by telomerase of Tca8113 cells].
OBJECTIVE
To study the effects of adramycin to disturb telomeric extention reaction mediated by telomerase of Tca8113 cells by inducing oligonucleotides that contain telomeric repeats to form guanine-quadruplex (G4) structures.


METHODS
In the presence of adriamycin, d(TTAGGG)4, d(TTAGAG)4, d(TTAGGG)5 and d(TTAGGGT) were analyzed by electrophoretic mobility shift assay. The mobility of d(TTAGGG)3, d(TTAGGG)4 and d(TrAGGG)5 in native polyacrylamide electrophoresis were observed. Methylation protection experiments were performed to investigate the effects of adriamycin on methylation of guanine in d(TTAGGG)4 and d(TTAGAG)4. The traditional telomeric repeats amplification protocol (TRAP) and modified TRAP-G4 assays were, respectively, used to analyze the different characteristcs of adriamycin's inhibiting telomeric extension mediated by telomerase of Tca8113 cells.


RESULTS
At 5.00 microg/mL of adriamycin, conversion of some of linear d(TrAGGG)4 and d(TrAGGG)5to the new, high-mobility bands formed by complex with special second structures were found in the mobility shift assay. Adriamycin at 1.25 microg/mL protected the G in d(TIAGGG)4 from methylating. Adriamycin at 2.50 microg/mL or 1.25 microg/mL partially inhibited the telomeric extension lengthened by telomerase of Tca8113 cells in TRAP assay, but completely did so in TRAP-G4 assay.


CONCLUSIONS
Adriamycin is able to disturb telomeric extention mediated by telomerase of Tca8113 cells by inducing oligonucleotides that contain telomeric repeats to form intra-molecular G4 structures.
Hu
Xiao-wen
XW
Dept. of Oral and Maxillofacial Surgery, The Second Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
Huang
Hong-zhang
HZ
Yu
Dong-sheng
DS
D004247:DNA; D004317:Doxorubicin; D054856:G-Quadruplexes; D006147:Guanine; D009690:Nucleic Acid Conformation; D019098:Telomerase; D016615:Telomere
D006147:Guanine; D004317:Doxorubicin; D004247:DNA; D019098:Telomerase