topoisomerase ii beta

Chloroquinoxaline sulfonamide (Chloroquinoxaline) 是拓扑异构酶 II alpha/beta 毒物，具有抗肿瘤活性和免疫抑制特性，可抑制小鼠 B16 黑色素瘤细胞的增殖，可用于研究转移性结直肠癌。

Ethonafide is an anthracene-containing derivative of amonafide that belongs to the azonafide series of anticancer agents. The lack of cross-resistance in multidrug-resistant cancer cell lines and the absence of a quinone and hydroquinone moiety make ethonafide a potentially less cardiotoxic replacement for existing anthracene-containing anticancer agents. Ethonafide was cytotoxic against three human prostate cancer cell lines at nanomolar concentrations. Ethonafide was found to be better tolerated and more effective at inhibiting tumor growth compared with mitoxantrone in a human xenograft tumor regression mouse model. Mechanistically, we found that ethonafide inhibited topoisomerase II activity by stabilizing the enzyme-DNA complex, involving both topoisomerase IIalpha and -beta. In addition, ethonafide induced a potent G(2) cell cycle arrest in the DU 145 human prostate cancer cell line. By creating stable cell lines with decreased expression of topoisomerase IIalpha or -be......

XK489 is a synthetic quinoxaline phenoxypropionic acid derivative with proapoptotic and antiproliferative activities. R(+)XK469 selectively inhibits topoisomerase II-beta, blocks activation of MEK/MAPK signaling kinases, stimulates caspases, and upregulates p53-dependent proteins, including cyclins A and B1, thereby arresting cancer cells in the G2/M phase of the cell cycle. Both R(+) and S(-) isomers of this agent are cytotoxic, although the R-isomer is more potent.