Inhibitory effect of Rnai on AML1 -ETO fusion gene expression in leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>By inhibiting AML1 -ETO fusion gene expression in Kasumi-1 cells with RNAi, to investigate the changes in cell proliferation and cell cycle.</p><p><b>METHODS</b>The small interference RNAs (siRNAs) specifically targeting the AML1 -ETO fusion gene were synthesized in vitro and transfected into Kasumi-1 cells by electroporation, the non-specific siRNAs transfected cells were taken as control. EGFP plasmid was transfected into Kasumi-1 cell and the transfection efficiency was detected by FCM. Inhibitory effect of siRNAs were detected by real-time RT-PCR and Western blots. Cell proliferation was measured by CCK-8 assay. DNA content was detected by PI assay.</p><p><b>RESULTS</b>The transfection efficiency was 44.5%. The AML1 -ETO specific siRNAs inhibited AML1 -ETO expression at both mRNA and protein levels. The cell proliferation rate in siRNAs treated group was lower than that in control group 72 h after transfection [(47.90 +/- 0.02)% vs (66.90 +/- 0.08)% , P < 0.05]. The cell cycle was blocked at G1 phase 72 h after siRNAs treatment, the cell proportion in G1 phase being 38.3% and 31.6% in control group, while in G2/M phase being 1.8% and 2.4% respectively.</p><p><b>CONCLUSIONS</b>The synthesized siRNAs can inhibit AML1 -ETO fusion gene expression. AML1 -ETO specific siRNA induced the decline of AML1 -ETO fusion protein in Kasumi-1 cell, and then caused the cell cycle blocked in G1 stage and eventually inhibited the cell proliferation.</p>

Inhibitory effect of RNA interference on chronic myeloid leukemia bcr/abl oncogene expression / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of RNA interference on chronic myeloid leukemia (CML) bcr/abl oncogene expression.</p><p><b>METHODS</b>The small interference RNAs (siRNAs) were synthesized in vitro. K562 cells stably expressing bcr/abl gene were transfected with the siRNA by electroporation, both the non-transfected cells and non-specific siRNAs transfected cells were taken as controls. The enhanced green fluorescent protein (EGFP) plasmid was used as positive control and the transfection efficiency was detected by flow cytometry. Inhibitory effect of siRNAs was demonstrated by real-time quantitative RT-PCR and Western blots. Cell proliferation was measured by MTT assay and apoptosis by Annexin V-FITC assay.</p><p><b>RESULTS</b>The transfection efficiency was about 70%. The synthesized siRNAs inhibited CML bcr/abl oncogene expression at both mRNA and protein levels. siRNAs could inhibit K562 cell proliferation to 47% and 56% at 24 h and 48 h after transfection, respectively, and induce cell apoptosis from 1.00% in control group to 15.05% and 19.4% at 24 h and 48 h respectively.</p><p><b>CONCLUSION</b>At the cell level, inhibition of CML bcr/abl oncogene expression by chemically synthesized siRNAs provides the new method for anti-leukemia study.</p>

Effects of acrylamide on DNA damage in human keratinocytes / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the toxic and DNA damaging effect of acrylamide (AA) on human keratinocytes and its mechanism.</p><p><b>METHODS</b>(1) After the keratinocyte cell line HaCaT cells were exposed to AA with different concentrations for 44 hours, cell survival rate was detected by MTT method. (2) The effects of DNA damage of exposed cells were detected by comet assay. (3) After treating the cells with 2.00 mmol/L of AA plus 0.50 mmol/L of 1-aminobenzotriazole (1-ABT), an inhibitor of cytochrome P-450 enzymes (CYP-450), for 4 hours, the relationship between DNA damage and CYP-450 was studied.</p><p><b>RESULTS</b>(1) Cytotoxicity measurement of AA showed that cell survival rate decreased significantly after 44-hour treatment. (2) Cytotoxicity was not detected after 4-hour AA treatment, but significant DNA damage was observed in all treatment groups, and the degree of damage increased with the concentration of AA. Moreover, the tail lengths of comet cells were in dose-effect relationship. As for cells treated by 1-ABT with 2 mmol/L AA, comet rate and tail length were 15.4% and (8.2 +/- 2.0) micro m respectively, which were decreased significantly (P < 0.01) when compared with 2 mmol/L AA treatment group [80.6% and (44.3 +/- 4.0) micro m].</p><p><b>CONCLUSIONS</b>Acrylamide has significant cytotoxicity and genotoxicity on HaCaT cells. AA-induced DNA damage may be related to the oxidative metabolite(s) of AA through CYP-450.</p>