Effects of Methionine Restriction on Proliferation, Cell Cycle, and Apoptosis of Human Acute Leukemia Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of methionine restriction on proliferation, cell cycle and apoptosis of human acute leukemia cells.@*METHODS@#Cell Counting Kit-8 (CCK-8) assay was used to detect the effect of methionine restriction on HL-60 and Jurkat cells proliferation. The effect of methionine restriction on cell cycle of HL-60 and Jurkat cells was examined by PI staining. Annexin V-FITC / PI double staining was applied to detect apoptosis of HL-60 and Jurkat cells following methionine restriction. The expression of cell cycle-related proteins cyclin B1, CDC2 and apoptosis-related protein Bcl-2 was evaluated by Western blot assay.@*RESULTS@#Methionine restriction significantly inhibited the proliferation of HL-60 and Jurkat cells in a time-dependent manner (HL-60: r =0.7773, Jurkat: r =0.8725), arrested the cells at G2/M phase (P < 0.001), and significantly induced apoptosis of HL-60 and Jurkat cells (HL-60: P < 0.001; Jurkat: P < 0.05). Furthermore, Western blot analysis demonstrated that methionine restriction significantly reduced the proteins expression of Cyclin B1 (P < 0.05), CDC2 (P < 0.01) and Bcl-2 (P < 0.001) in HL-60 and Jurkat cells.@*CONCLUSION@#Acute leukemia cells HL-60 and Jurkat exhibit methionine dependence. Methionine restriction can significantly inhibit the proliferation, promote cell cycle arrest and induce apoptosis of HL-60 and Jurkat cells, which suggests that methionine restriction may be a potential therapeutic strategy for acute leukemia.

The inhibitory effect of a novel phosphodiesterase 4 inhibitor ZL-n-91 on proliferation of osteosarcoma U20S cells / 中国药理学通报

Aim To explore the anti-cancer effects of ZL-n-91, a novel and highly selective phosphodiesterase 4 inhibitor, on the osteosarcoma U2OS cells.Methods CCK-8 assay was used to detect the inhibitory effect of ZL-n-91 with different concentrations(0, 20, 40, 80, 160, 240, 320, 400, 480 μmol·L-1)and different intervention time(0, 24, 48, 72, 96 h)on the proliferation of U2OS cells.Tablet clone forming experiment was used to detect the effect of ZL-n-91 on the clonality of U2OS cells.Flow cytometry was used to detect the cell apoptosis and cell cycle distribution.Western blot was employed to detect the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 protein.Results The inhibitory rate of ZL-n-91 on U2OS cells was concentration- and time-dependent(P<0.05), and its half inhibition rate IC50 was 174.1 μmol·L-1.ZL-n-91 significantly inhibited the clonality of U2OS cells(P<0.01).ZL-n-91 significantly induced cell apoptosis, and caused cell cycle arrest at G0/G1 phase in U2OS cells(P<0.01).The results of Western blot showed that ZL-n-91 significantly down-regulated the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 proteins in U2OS cells(P<0.05).Conclusions The novel selective phosphodiesterase 4 inhibitor, ZL-n-91, can significantly inhibit the proliferation of osteosarcoma U2OS cells with induction of cell cycle arrest and cell apoptosis, and may become a potential anti-cancer agent.

1 kHz, 96 W pulse-burst picosecond laser system with six equal spacing and amplitude pulses.

An average power of 96 W pulse-bursts picosecond laser system at a pulse repetition frequency of 1 kHz was reported with six pulses in bursts. Pulses in bursts have equal spacing and amplitude; spacing between each pulse was 800 ps, which repetition rate was up to gigahertz. The beam quality of M2 factor was less than 3, and pulse width was 50 ps. Pulses from a Nd:YVO4 mode-locked laser were broadened to 115 ps by a volume-Bragg grating and each pulse was divided into six pulses by beam splitter mirrors to obtain seed bursts. A Nd:YAG regenerative amplifier and two stages of single passed high gain Nd:YAG amplifier with serrated aperture were applied to achieve high power.

Compact KGd(WO4)2 picosecond pulse-train synchronously pumped broadband Raman laser.

We demonstrate an efficient approach to realizing an extra-cavity, synchronously pumped, stimulated Raman cascaded process under low repetition frequency (1 kHz) pump conditions. We also construct a compact KGd(WO4)2 (KGW) crystal picosecond Raman laser that has been configured as the developed method. A pulse-train green laser pumped the corresponding 70 mm long KGW crystal Raman cavity. The pulse train contains six pulses, about 800 ps separated, for every millisecond; thus, it can realize synchronous pumping between pump pulse and the pumped Raman cavity. The investigated system produced a collinear Raman laser output that includes six laser lines covering the 532 to 800 nm spectra. This is the first report on an all-solid-state, high-average-power picosecond collinear multi-wavelength (more than three laser components) laser to our knowledge. This method has never been reported on before in the synchronously pumped stimulated Raman scattering (SRS) realm.