Immunologic classification of acute lymphocytic leukemia (ALL) was carried out by using 11 - 13 kinds of monoclonal antibodies against human leucocyte differentiation antigens in 19 cases. The results showed that of these 19 cases, there were T-ALL in 4, B-ALL in 4, C-ALL in 7, AUL in 2 and hybrid type of ALL (H-ALL) in 2. The 5 types mentioned above could also be classified, according to the immunologic criteria described by Foon in 1986, into 3 major groups: T-ALL, non-T-ALL and H-ALL. The Foon's classification method is useful for judgement of malignant cell source and differentiated stage, and for further understanding the nature of ALL cells.

OBJECTIVETo investigate the in vitro killing efficiency of D-amino acid oxidase (DAAO)/D-alanine (D-Ala) system on K562e cells.

METHODSK(DfGC) cell line stably expressing DAAO was obtained by retrovirus transfection technique. The integration and expression of DAAO gene were identified by PCR and in situ hybridization. The killing activities of D-Ala to DAAO(+) cells alone or the mixtures of DAAO(+) and DAAO(-) cells in different ratios were observed. H(2)O(2) production by K(DfGC) cell was measured by phenol red oxidation assay.

RESULTSPCR and in situ hybridization analysis confirmed the integration of DAAO gene in positive clone and its mRNA expression. There was no significant difference in cell proliferation between the two kinds of K562 cells. Ninety percent of K(DfGC) cells was killed by 12.5 mmol/L D-Ala after 24 hour-treatment and the H(2)O(2) levels were in accord with the killing activities of D-Ala. When K(DfGC) was mixed with K562e at different ratio, no significant bystander effect could be found after treating with 15.0 mmol/L D-Ala for 24 hours.

CONCLUSIONThe leukemia cell line K562e was sensitive to DAAO/D-Ala system and there was no significant bystander effects observed within this cells.

Alanine ; metabolism ; pharmacology ; Cell Survival ; drug effects ; D-Amino-Acid Oxidase ; genetics ; metabolism ; Gene Expression ; Humans ; Hydrogen Peroxide ; metabolism ; K562 Cells ; cytology ; drug effects ; metabolism ; Plasmids ; genetics ; RNA, Messenger ; genetics ; metabolism ; Transfection