Design, synthesis, and biological evaluation of novel 7-substituted 10,11-methylenedioxy-camptothecin derivatives against drug-resistant small-cell lung cancer in vitro and in vivo.
Zhang G, Yin R, Dai X, Wu G, Qi X, Yu R, Li J, Jiang T.
A series of novel 7-substituted 10,11-methylenedioxy-camptothecin (FL118) derivatives were designed, synthesized, and biologically evaluated. All the FL118 analogues showed significant cytotoxic activities in vitro with IC<sub>50</sub> values in the nanomolar range and were more potent than topotecan. The most active compound 9c exhibited more significant anti-tumor activity against small-cell lung cancer (NCI-H446, H69, drug-resistant H69AR cells, drug-resistant NCI-H446/Irinotecan cells and drug-resistant NCI-H446/EP cells) in vitro. Additionally, 9c could also induce the expression of apoptosis proteins such as caspase-3, caspase-9, and PARP in small-cell lung cancer. Further studies showed that 9c induced apoptosis by inhibiting the expression of Mcl-1, Bcl-2, XIAP and survivin in small-cell lung cancer. In vivo9c also showed better anti-tumor efficacy, with the tumor growth inhibition rates were 40.4% (0.75 mg/kg), 73.7% (1.5 mg/kg), and 95.5% (3 mg/kg). It is noteworthy that 9c also demonstrated potent inhibition of drug-resistant tumor growth in NCI-H446/Irinotecan and NCI-H446/EP xenograft models, the tumor growth inhibition rates were 93.42% and 84.46%, respectively. Taken together, these findings indicated that compound 9c displays outstanding antitumor activity and drug-resistance in small-cell lung cancer both in vivo and in vitro, which could be worth further research as a novel anti-tumor drug against small-cell lung cancer.