[Effects of AML1-ETO on transcription activity of p21WAF1/CIP1 gene promoter].

OBJECTIVE

To observe the effects of AML1-ETO fusion gene on the transcription activity of p21WAF1/CIP1 gene. And to explore the enhancement of leukemia pathogenesis of AML1-ETO.

METHODS

The luciferase reporter plasmids of p21WAF1/CIP1 gene promoter were constructed, and co-transfected into CV-1 cells with AML1-ETO, AML1b and AML1a expression plasmids. The trans-activity of p21WAF1/CIP1 gene promoter was assayed by luminometer.

RESULTS

AML1-ETO exhibited a distinct inhibition activity of p21WAF1/CIP1 gene promoter with a sequence-specificity and dosage-dependent manner. The trans-activity of p21WAF1/CIP1 gene promoter decreased to (19 +/- 4)% compared to control group, when 1000 ng pCMV5-AML1-ETO plasmid was used. AML1b and AMLla showed less inhibition activity. The trans-activity of p21WAF1/CIP1 gene promoter decreased to (61 +/- 16)% and (59 +/- 16)% compared to control group, respectively, when 1000 ng plasmid was used.

CONCLUSION

AML1-ETO exhibits more inhibition activity of p21WAF1/CIP1 gene promoter than AML1b and AMLla, results from recruiting transcription co-repression complex efficiently by ETO. Based on previous researches, the effects of exogenous AML1-ETO on p21WAF1/CIP1 gene promote may be dependent on the type of cell lines.