M. Koshiyama et al., Correlation between Topo II alpha expression and chemosensitivity testing for Topo II-targeting drugs in gynaecological carcinomas, ANTICANC R, 21(2A), 2001, pp. 905-910
Background: The purpose of this study was to investigate the correlation be
tween topoisomerase II alpha (Topo II alpha) expression and the chemosensit
ivity to Topo II-targeting drugs in gynaecological carcinomas. Materials an
d Methods: We analysed the expression of Topo II alpha, and then correlated
this with the in vitro chemosensitivities of 43 gynaecological tumors usin
g immunohistochemistry and a tetrazolium dye (MTT) assay. Results. There wa
s a significant correlation between the Topo II alpha index (the number of
positive cells per 100 cells: %) and the tumor cell growth inhibition rate
in culture (I.R.: %) for doxorubicin and etoposide (r=0.631, p <0.001 and r
=0.645, p<0.001, respectively). The I.Rs for doxorubicin and etoposide in e
ndometrial carcinomas were lower than those in ovarian carcinomas [38.2<plu
s/minus>22.8 vs 54.6 +/- 29.8, 37.3 +/- 19.8 vs 59.3 +/- 30.6](p<0.05, resp
ectively). Furthermore, the number of high Topo II-alpha index (over 30%) t
umors in the ovarian carcinoma cases was higher than that in the endometria
l carcinoma cases (63.1% vs 45.8%, p<0.05). Conclusions. Our data suggest t
hat the Topo II-alpha index of a tumor is a reflection of its chemosensitiv
ity to Topo II-targeting drugs. The use of this index may enable prediction
of a clinical response to chemotherapy using Topo II-targeting drugs in gy
naecological malignancies.