Design, Synthesis, and In Vitro Evaluation of Benzofuro[3,2-c]Quinoline Derivatives as Potential Antileukemia Agents.

Herein, we design and synthesize an array of benzofuro[3,2-c]quinolines starting from 3-(2-methoxyphenyl)quinolin-4(1H)ones via a sequential chlorination/demethylation, intramolecular cyclization pathway. This sequential transformation was efficient, conducted under metal-free and mild reaction conditions, and yielded corresponding benzofuro[3,2-c]quinolines in high yields. In vitro biological evaluation indicated that such type of compounds showed excellent antileukemia activity and selectivity, and therefore may offer a promising hit compound for developing antileukemia compounds.

[The Mechanism of Artesunate Combined with Cytarabine and/or Daunorubicin on the Apoptosis of MV4-11 MLL-rearranged Acute Myeloid Leukemia Cell Line].

OBJECTIVE: To investigate the effect and mechanism of artesunate (ARTS) combined with cytarabine(Ara-C) and/or daunorubicin (DNR) on the proliferation and apoptosis of MV4-11 human mixed-lineage leukemia rearranged（MLL-r） acute myeloid leukemia (AML) cell line. METHODS: CCK-8 assay was used to detect the proliferation effect of individual or in combination of ARTS, DNR, Ara-C on MV4-11 cells. The IC50 of ARTS, DNR and Ara-C was calculated separately. The cell apoptosis and expression of receptors DR4 and DR5 were detected by flow cytometry. Western blot was used to detect the expression of Caspase-3 and Caspase-9 in each groups. RESULTS: The inhibition effect of ARTS, Ara-C and DNR on the proliferation of MV4-11 were all dose-dependently (r=0.99, 0.90 and 0.97, respectively). The IC50 of ARTS, Ara-C and DNR on MV4-11 for 48 hours were 0.31 µg/ml, 1.43 µmol/L and 22.47 nmol/L, respectively. At the dose of ARTS 0.3 µg/ml， Ara-C 1.0 µmol/L and DNR 15 nmol/L, the proliferation rate for 48 hours of the tri-combination treatment was significantly lower than that of the bi-combination treatment, while both were significantly lower than that of the individual treatment (all P＜0.05). In terms of bi-combination treatment, the cells proliferation rate for 48 hours of the ARTS+Ara-C group was significantly lower than that of the ARTS+DNR group, while both were significantly lower than that of the Ara-C+DNR group (all P＜0.05). The cooperativity index (CI) of bi- and tri-combination treatment were all less than 1. After 48 hours of drug action, the cell apoptosis rate of the ARTS+DNR+Ara-C group was significantly higher than that of the Ara-C+DNR group, while both were significantly higher than that of the ARTS+DNR group (all P＜0.05). Meanwhile, the was no statistical difference between the cells apoptotic rate of the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (P>0.05). The expression of DR4 and DR5 also showed no difference between control group and drug group. Compared with the DNR+Ara-C group, the expressions of Caspase-3 were significantly down-regulated in both the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (all P＜0.05). The down-regulation of Caspase-3 expression was the most significantly in the combination group of three drugs, while the Caspase-9 expressions in different groups showed no apparent change. CONCLUSION: The in vitro study showed that tri-combination of ARTS+Ara-C+DNR and bi-combination of ARTS+Ara-C could inhibit the proliferation and promote apoptosis of MV4-11 cell line. The inhibition effect of these two combinations were significantly superior to that of the traditional Ara-C+DNR treatment. The mechanism underlying this finding may be identified by the down regulation of Caspase-3, while no altered expression was observed of Caspase-9, DR4 and DR5.

[Effects of artesunate combined with bortezomib on apoptosis and autophagy of acute myeloid leukemia cells in vitro and its mechanism].

Objective: To investigate the effects of artesunate combined with bortezomib on the proliferation, apoptosis and autophagy of human acute myeloid leukemia cell lines MV4-11, and its mechanisms. Methods: MTT method was used to determine the anti-proliferation effect of different concentrations of artesunate, bortezomib and their combination on MV4-11 cells. The cell apoptosis were analyzed by flow cytometry. The expression of cleaved-Caspase-3, Bcl-2 family protein (Bcl-2, Mcl-1, Bim, Bax) and autophagy-related protein LC3B were assayed by Western blot. Results: Artesunate displayed a proliferation inhibition effect on MV4-11 with dose- and time-dependent manner, the IC(50) of artesunate on MV4-11 after 48 hours was 1.44 µg/ml. Bortezomib displayed a proliferation inhibition effect on MV4-11 with dose-dependent manner, the IC(50) of bortezomib on MV4-11 after 48 hours was 8.97 nmol/L. The combination of artesunate (0.75, 1.0 µg/ml) and Bortezomib (6, 8 nmol/L) showed higher inhibition on MV4-11 than artesunate or bortezomib alone in the same concentration gradient after 48 hours (P<0.05) . The cooperation index of the two drugs were all less than 1. The 48 h apoptotic rate of artesunate (1.5 µg/ml) on MV4-11 was (15.27±2.18) %, (19.85±3.23) % of bortezomib (8 nmol/L) , (81.67±5.96) % of combination of the two drugs, significantly higher than the single group (P<0.05) . When combination of the two drugs on MV4-11 after 24 hours, the levels of pro-apoptotic protein Bim and the cleaved activation of Caspase-3 and autophagy-related protein LC3B were up-regulated and the anti-apoptotic protein Bcl-2 expressions was down-regulated. Conclusion: Combination of artesunate with bortezomib shows a significant synergistic effects on proliferation, apoptosis and autophagy of MV4-11 cell lines, which may be associated with Bcl-2 family proteins expression.