Effect of ethylnitrosourea on HPRT gene in human promyelocytic leukemia cells.

OBJECTIVE

To explore the molecular spectra and mechanism of human hypoxanthine guanine phosphoribosyl transferase (HPRT) gene mutation induced by ethyluitrosourea (ENU).

METHODS

Single cell cloning culture, two-way screening, multiple PCR amplification and electrophoresis technique were used.

RESULTS

With dose of ENU increasing, cell plating efficiency reduced (in the group with 100-200 micro g/ml doses, P < 0.01) and mutation frequency increased (in the group with 12.5-200.0 micro g/ml doses, P < 0.05) significantly. There was no all exons deletion in spontaneous mutations, and only 7.7% of them were detected as single exon deletion. But, deletion was found in 79.7% of ENU-induced mutations (62.5%-89.4%, P < 0.01), and deletion mutations in all nine exons of HPRT gene. Most of ENU-induced mutations were chain deletion with multiple exons (88.1%).

CONCLUSIONS

The spectra in spontaneous mutations differed completely from ENU-induced ones. ENU was liable to cause bigger changes in genetic structure, which suggested a stronger ENU's mutagenesis.