Effects of Sinopodophyllum hexundrum on apoptosis in K562 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of Sinopodophyllum hexundrum on apoptosis in K562 cells.</p><p><b>METHODS</b>K562 cells were treated with Sinopodophyllum hexundrum at different concentrations and for different lengths of time to determine the optimal conditions of SinoPodophyllum hexandrum treatment for K562 cells using CCK8 assay. The cell apoptotic rate was detected by flow cytometry, and the cell morphology and nuclear morphology of K562 cells were observed with Wright staining and DPAI staining, respectively. The protein expressions of BCR/ABL, p-BCR/ABL, STAT5, p-STAT5 and the apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were determined with Western blotting.</p><p><b>RESULTS</b>The cell proliferation was inhibited in a concentration-and time-dependent manner by 1, 2, and 3 µg/mL Sinopodophyllum hexundrum. The treatment was optimal with a Sinopodophyllum hexundrum concentration of 2 µg/mL a treatment time of 48 h, and the cell apoptotic rate increased in a time-dependent manner and significantly increased at 48 h (P<0.001). The expression of apoptosis-related proteins PARP, caspase-3 and cleaved-caspase-3 were also activated in a time-dependent manner. The cells showed typical apoptotic changes after treatment with 2 µg/mL Sinopodophyllum hexundrum for 48 h with significantly reduced expressions of BCR/ABL, p-BCR/ABL, STAT5, AND p-STAT5.</p><p><b>CONCLUSION</b>Sinopodophyllum hexundrum promotes K562 cell apoptosis possibly by inhibiting BCR/ABL-STAT5 survival signal pathways and activating the mitochondrion-associated apoptotic pathways.</p>

Prokaryotic expression of Trx-apoptosis-inducing factor-defected mitochondria localization sign fusion protein and its effect on cell-free system of leukemia K5 62 cells / 肿瘤

Objective: To express the fusion protein-thioredoxin-apoptosisinducing factor-defected mitochondria localization sign (Trx-DMLS-AIF) in prokaryotic cells and to detect its effect on cell-free system of leukemia K562 cells. Methods: The recombinant plasmid expressing Trx-DMLS-AIF fusion protein was established and transformed into E.coli BL21. The expression of Trx-DMLS-AIF fusion protein was induced by isopropyl β-D-1-thiogalactopyranoside (IPTG) and purified by Ni-NTA Spin Columns. The cell-free system of leukemia K562 cells was established. The effect of Trx-DMLS-AIF fusion protein on cell-free system of K562 cells was detected by acridine orange (AO) staining. The effect of plasmosin on the ability of Trx-DMLS-AIF fusion protein entering into nuclei of K562 cells was detected by immunofluorescent staining. Results: The expression of Trx-DMLS-AIF fusion protein was successfully induced by IPTG, and the purified Trx-DMLS-AIF fusion protein was obtained. The result of AO staining showed that Trx-DMLS-AIF fusion protein could induce the nucleus apoptosis in cell-free system of K562 cells. The result of immunofluorescent staining showed that the plasmosin of K562 cells could prevent Trx-DMLS-AIF fusion protein from entering into the nuclei of K562 cells. Conclusion: The expression of Trx-DMLS-AIF fusion protein is successfully induced. TrxDMLS-AIF can induce the nucleus apoptosis of K562 cells, and the plasmosin of K562 cells can prevent Trx-DMLS-AIF fusion protein from entering into the nuclei of K562 cells.