Studies on the anticancer mechanisms of synthetic I6, YJC-1 and HKL-1 in human leukemia HL-60 cells

• Main Authors: Mei-Hua Hsu, 徐美華
• Other Authors: Li-Jiau Huang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/06603186903911385357

博士 === 中國醫藥大學 === 藥物化學研究所博士班 === 95 === The purpose of this study was to search novel anticancer agents and elucidating their action mechanisms. There were three parts in this thesis in which we elucidated the anticancer mechanisms of I6, YJC-1 and HKL-1 in human leukemia HL-60 cells. In the first part, we showed that the anti-leukemia mechanisms of I6. 1-(3,4-Dimethoxyphenyl)-3,5-dodecenedione (I6), a gingerdione deriva- tive, was synthesized in our laboratory, has been demonstrated to be an effective anti-tumor agent in human leukemia cells. In the present study, we found that I6 could inhibit cell proliferation in the time- and dose- dependent manner in human promyelocytic leukemia HL-60 cells. To investigate the anti-proliferation mechanism of I6, cell cycle analysis was performed. Results showed that I6 induced significant G1 arrest and apoptosis in HL-60 cells. It was proved by the reverse transcriptase- polymerase chain reaction (RT-PCR) analysis of regulatory on G1 arrest that the levels of p15 and p27 increased after treatment and mRNA levels of cyclin D2, cyclin E, and cdc25A were decreased. The I6-induced apoptosis was further confirmed by morphological observation and DNA fragmentation assay. I6-induced apoptosis was accompanied by up- regulation of caspase-3, and down-regulation of Bcl-2. Taken together, these results suggest that up-regulation of CDKI (p15 and p27) and down-regulation of cdc25A to cause suppression of cyclin D2 cyclin E may contribute to I6-mediated cell cycle arrest. Furthermore, the mitochondria permeability changes (the ratio of Bax/Bcl-2 increased) and caspase-3 activation may be the plausible mechanism by which I6 induced apoptosis. These results suggest that I6 is a potent anti-HL-60 drug and possess a significant action on cell cycle before commitment for apoptosis occurrence. In the second part, we showed that the anti-cancer mechanisms of YJC-1. 2-(3-Fluorophenyl)-6-methoxyl-4-oxo-1,4-dihydroquinoline-3- carboxylic acid (YJC-1), a 2-phenyl-4-quinolone (2-PQ) derivative, was synthesized in our laboratory, has been demonstrated to be an effective anti-mitotic agent. In the present study, YJC-1 displayed anti-mitosis and apoptosis effects against variety cancer cells including HL-60, K562, A549, CH27, NCI-H226, HA22T, Hep 3B, J5, Colo 205 and HeLa cells. Among these cancer cell lines, YJC-1 induced most typical mitosis phenotype in A549 lung cancer cells, and most typical apoptosis phenotype in HL-60 leukemia cells. In A549 cells, YJC-1 induced the spindle poles not oriented on opposite side of chromosomes, but did not affect the microtubule polymerization, thus the cell cycle progression stopped at early mitosis (prophase). In the meanwhile, YJC-1 suppressed cdc25C and activated p21 to change the expression levels of CDK1 and cyclin B. In HL-60 cells, YJC-1 also activated p21 to increase Bax expression to induce caspase-9 and caspase-3 cleavage, thus apoptosis occurred. Taken together, it is suggested that YJC-1 induced cell cycle arrest at prophase and apoptosis might be a crucial response to its anticancer effect. In the third part, we showed that the anti-leukemia mechanisms of HKL-1. 2-(3-Methoxyphenyl)-5-methyl-1,8-naphthyridin-4-one (HKL- 1), a 2-phenyl-1,8-naphthyridine-4-one (2-PN) derivative, was synthe- sized in our laboratory, has also been demonstrated to be an effective anti- mitotic agent. In the present study, HKL-1 displayed significantly anti-cancer activities against variety cancer cells including HL-60, A549, CH27, NCI-H226, MCF-7, HA22T, Colo 205 and HeLa cells. Among these cancer cell lines, YJC-1 induced most anti-cancer activity in HL-60 leukemia cells, with an IC50 value approximate to 0.0441 μM. HKL-1 inhibited the activity of CENP-E to cause spindle-pole fragmentation, loss of chromosome alignment during congression and reduced spindle tension, to inhibit microtubule polymerization, thus the cell cycle progression stopped at middle mitosis (metaphase). In addition, HKL-1 suppressed cdc25C and activated p21 to down-regulated the expression CDK1 and cyclin B. p21 activated also enhanced the activity of Bax to induce caspase-9 and caspase-3 cleavage, thus apoptosis occurred. Taken together, it is suggested that HKL-1 induced cell cycle arrest at metaphase and apoptosis might be a crucial response to its anticancer effect.