[Bcl-2 antisense oligodeoxynucleotide enhances araninosyl cytosine-induced apoptosis of primary leukemia cells].
OBJECTIVE
The previous study has identified two novel antisense oligonucleotides (AS-ODN) of new target point in the translation initiation and the coding region of bcl-2 mRNA that could increase the sensitivity of HL-60 and K562 cells lines to etoposide, daunorubicin, and araninosyl cytosine (Ara-C). This study was designed to investigate whether the two novel bcl-2 AS-ODNs could increase Ara-C-induced apoptosis of cultured primary acute leukemia (AL) and chronic lymphocytic leukemia (CLL) Cells.


METHODS
Cell surviving fraction was determined using the trypan blue dye exclusion assay. The expression levels of bcl-2 protein were assayed by immunofluorescence using fluorescein isothiocyanate label. Apoptosis was detected by Giemsa staining and flow cytometry.


RESULTS
Treatment with the two AS-ODNs/Ara-C combination respectively for 48 h significantly inhibited the growth of AL and CLL cells. There was significant difference on AL and CLL cells survival between nonsense oligodeoxynucleotide(NS-ODN)/Ara-C combination and Ara-C treated cells alone (P < 0.05). It was found that the two AS-ODNs respectively combined with Ara-C could significantly downregulate bcl-2 protein expression (P < 0.05). There was a significant increase in apoptotic rates of AL or CLL cells after treatment with the two AS-ODNs respectively combined with Ara-C as respectively compared with the NS-ODN/Ara-C combination and Ara-C treated cells alone; and the effect had statistical difference (P < 0.05). Compared to the AS-ODN directed against the translation initiation of bcl-2 mRNA, the AS-ODN directed against the coding region showed stronger effect in the aspects of increasing the sensitivity of AL cells to Ara-C (P < 0.05).


CONCLUSIONS
The two novel AS-ODNs of new target point in the translation initiation and the coding region of bcl-2 mRNA could enhance Ara-C induced apoptosis of AL and CLL cells.
Lei
Xiao-yong
XY
Institute of Hematology, Jinan University Medical College, Guangzhou 510632, P. R. China.
Zhang
Huan
H
He
Dong-mei
DM
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis; D003561:Cytarabine / Q000494:pharmacology*; D004347:Drug Interactions; D018922:HL-60 Cells; D006801:Humans; D020014:K562 Cells; D007938:Leukemia / Q000473:pathology; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors* / Q000235:genetics
D000964:Antimetabolites, Antineoplastic; D020319:Oligodeoxyribonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D003561:Cytarabine