OBJECTIVETo detect mutations of human telomeric repeat binding factor 1 (TERF1) gene in 11 malignant hematopoietic cell lines, which have positive telomerase activity, and evaluate the significance of the mutations.

METHODSGenome structure of TERF1 was predicted by using biology information program, and verified by PCR and sequencing. Telomerase activity was detected by telomeric repeat amplification (TRAP)-ELISA. PCR and sequencing were used to detect mutation of each exon of TERF1 in 11 cell lines, including myelogenous leukemia cell lines K562, HL-60, U-937, NB4, THP-1, HEL and Dami; lymphoblastic leukemia cell lines 6T-CEM, Jurkat and Raji and MDS-RAEB cell line MUTZ-1. Five DNA samples from healthy volunteers were detected as normal controls.

RESULTSTERF1 gene has 10 exons and spans 38.6 kb. All the 11 cell lines showed positive telomerase activity. No mutation was found in all exons of TERF1 in the 11 cell lines. However, 4 variants were found in intron1, 2 and 8 near exon1, exon2 and exon9, respectively. The variants in MUTZ-1 was different from those in leukemia cell lines; but no difference was found between the variants in myelogenous and lymphoblastic leukemia cell lines.

CONCLUSIONTERF1 mutation is probably not among the main factors of the gene dysfunction in malignant hematopoietic diseases.