Expression of DNA topoisomerase II alpha and multidrug resistance p-glycoprotein in acute leukemia.
BACKGROUND
Drug resistance is a major cause of treatment failure in acute leukemia. Overexpression of multidrug resistance gene and decreased activity of topoisomerase II alpha are suggested as two important mechanisms for this resistance.


METHODS
We used immunohistochemical method to determine the expressions of both topoisomerase II alpha (topo II alpha) and p-glycoprotein (gp-170) in bone marrow biopsy specimens from 68 cases of acute leukemia. Patients were divided into four groups: (1) leukemia cells with high score for topo II alpha and negative for gp-170; (2) leukemia cells with high score for topo II alpha and positive for gp-170; (3) leukemia cells with low score for topo II alpha and negative for gp-170; and (4) leukemia cells with low score for topo II alpha and positive for gp-170. The clinical responses were then followed as routine, and the clinical correlation was evaluated by analysis of variance and Pearson Chi-Square test.


RESULTS
The measure of the single parameter (either topo II alpha or gp-170 alone) did not show a significant difference in the overall survival. However, the complete response rate was much higher in the first group patients whose bone marrow reading score was high in topo II alpha and negative for gp-170 expression. Survival duration increased with the increase in the complete response rate.


CONCLUSIONS
Combined parameters of topo II alpha and gp-170 are more useful than any individual parameter for the prognosis of acute leukemia.
Chiu
C F
CF
Department of Internal Medicine, Veterans General Hospital-Taipei, Taiwan, R.O.C.
Chow
K C
KC
Lin
F M
FM
Lin
C K
CK
Liu
S M
SM
Chen
K Y
KY
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000032:analysis*; D000208:Acute Disease; D000328:Adult; D000368:Aged; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007938:Leukemia / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015996:Survival Rate
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004250:DNA Topoisomerases, Type II