[In vitro study on the transduction of mutant human dihydrofolate reductase cDNA into human umbilical cord blood CD34+ cells].

OBJECTIVE

To explore whether human umbilical cord blood hematopoietic progenitor cells transduced with mutant dihydrofolate reductase(mDHFR) gene increase resistance to metrotrexate(MTX).

METHODS

Cord blood CD34+ cells were enriched with a high-gradient magnetic cell sorting system(MACS), and then transfected with supernatant of retrovirus containing human mDHFR cDNA. Hematopoietic progenitor clonogenic assay was used to evaluate mDHFR-conferred resistance to MTX.

RESULTS

The purity of cord blood CD34+ cells was approximately 90% and recovery rate was 71.1%. The transduced and mock-transduced CD34+ cells were cultured in mediums containing 20 nmol/L MTX for 14 days. The percentages of progenitor colonies of transduced and mock-transduced CD34+ cells were higher than that of non-transduced (P < 0.01), obviously. The resistance of the former to MTX is nearly twofold of the latter.

CONCLUSION

Transduction of mDHFR gene could confer the resistance of human hematopoietic progenitor cells to MTX toxicity.