STAT1 and STAT2 participate in growth inhibition of human hepatoma HepG2 cells induced by phosphatidylethanolamine / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the roles of STAT1 and STAT2 in growth inhibition induced by phosphatidylethanolamine (PE) in human hepatoma HepG2 cells.</p><p><b>METHODS</b>The growth of HepG2 cells exposed to 0.125, 0.25, 0.5 and 1.0 mmol/L PE was assessed by MTT assay, and the expressions of STAT1 and STAT2 were analyzed using immunocytochemical assay.</p><p><b>RESULTS</b>PE inhibited the growth of HepG2 cells in a dose-dependent manner and increased the expression of STAT1 and STAT2 in comparison with those in the control group. AG490, an inhibitor of JAKs, partially reversed PE-induced growth inhibition of HepG2 cells.</p><p><b>CONCLUSION</b>STAT1 and STAT2 are involved in the growth inhibition of human hepatoma HepG2 cells induced by PE.</p>

Small interfering RNA-mediated nuclear factor-kappaB P65 suppression induces apoptosis of hepatic carcinoma SMMC-7721 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the mechanism of hepatic carcinoma cell apoptosis induced by small interfering RNA (siRNA)-mediated nuclear factor-kappaB (NF-kappaB) P65 silencing.</p><p><b>METHODS</b>Hepatic carcinoma SMMC-7721 cells were exposed to liposome-mediated transfection with NF-kappaB P65 siRNA synthesized by in vitro transcription, and the cells with empty liposome transfection and those without particular treatment served as the control groups. The expression of NF-kappaB P65 in the cells was detected by Western blotting, the cell viability examined by MTT assay, and the cell apoptosis assessed by flow cytometry. Immunohistochemistry was used to examine the expressions of Bcl-2 and Bax.</p><p><b>RESULTS</b>siRNA transfection significantly inhibited the expression of NF-kappaB P65 in SMMC-7721cells, with inhibition rates of 64.74% compared with the untreated cells and of 34.52% compared with the liposome-treated cells. The siRNA-treated SMMC-7721 cells also exhibited significant decrease in cell proliferation by 33.39% and 27.23% in comparison with the untreated and liposome-treated cells, respectively. NF-kappaB P65 siRNA induced obvious cell apoptosis with down-regulated Bcl-2 and up-regulated Bax expressions.</p><p><b>CONCLUSION</b>NF-kappaB p65 siRNA can induce SMMC-7721 cell apoptosis via the Bcl-2/Bax pathway.</p>

Small interfering RNA-mediated MAPK p42 silencing induces apoptosis of HeLa cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of small interfering RNA (siRNA)-induced MAPK p42 silencing on the survival of HeLa cells.</p><p><b>METHODS</b>Two siRNAs targeting at the MAPK p42 gene and one random siRNA were synthesized respectively by Silencer siRNA Construction Kit and transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) in the transfected HeLa cells was analyzed by Western blotting and immunohistochemistry, and the morphology of cells were observed with electron microscope. TUNEL assay and Annexin V/PI staining were employed for detecting the cell apoptosis.</p><p><b>RESULTS</b>The expression of p42(MAPK) in the HeLa cells was remarkably suppressed after transfection with the two siRNAs, reduced by about 2.5 and 3.2 folds respectively in comparison with the negative control. Chromatin margination in the cell nuclei were observed in the transfected cells, and TUNEL assay and Annexin V/PI staining further confirmed the occurrence of cell apoptosis.</p><p><b>CONCLUSION</b>In vitro MAPK p42 siRNA-1 and siRNA-2 transfection can specifically silence the gene expression and induce apoptosis of HeLa cells.</p>

Inhibition of the expression of p42MAPK in HeLa cell line by RNA interference / 中华病理学杂志

<p><b>OBJECTIVE</b>To screen for siRNAs that inhibit the expression of p42(MAPK) in HeLa cell line.</p><p><b>METHODS</b>Three p42(MAPK) siRNAs and one random siRNA were synthesized using Silencer siRNA Construction Kit, and labeled with Cy-3 for measurement of transfection effect. SiRNAs were transfected into HeLa cells by Lipofectamin 2000. The expression of p42(MAPK) was analyzed by Western blot. The biological effect of siRNAs on HeLa cell growth was monitored by MTT and flow cytometry.</p><p><b>RESULTS</b>Two siRNAs (siRNA-2 and siRNA-3) among three tested were identified to be able to downregulate the p42(MAPK) expression. A concurrent growth retardation of HeLa cell line was observed in comparison with the control.</p><p><b>CONCLUSION</b>Inhibition of p42(MAPK) expression with siRNA technique can inhibit the proliferation of HeLa cells.</p>

Mechanism of apoptosis induced by indole-3-acetic acids combined with horseradish peroxidase in leukemia cell line K562 / 中国实验血液学杂志

To investigate the possible mechanism of apoptosis induced by indole-3-acetic acid (IAA) combined with horseradish peroxidase in leukemia cell line K562, cell proliferation and apoptosis of K562 cell were examined by MTT assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), respectively; the activity of superoxide dismutase (SOD) and the quantitative change of MDA were measured by biochemical method; changes of free radical were determined by 2, 7-dichlorofluorescin diacetate (DCFH-DA) probe with confocal microscopy. The results showed that of MTT assay and TUNEL indicated that IAA/HRP could significantly inhibit cell proliferation (P < 0.05) and induce apoptosis of K562 cell (P < 0.01), at the same time a positive correlation was found between apoptosis rate and IAA concentration (r = 0.971, P < 0.01). The activity of SOD and the quantitative of MDA increased, accompanied with a rise in IAA concentration. Results detected by DCFH-DA probe indicated that the fluorescence intensity of intracellular free radical increased, as compared with control, and a positive correlation was found. It is concluded that IAA/HRP can inhibit proliferation of K562 cells and induce K562 cell apoptosis, its mechanism may be related with the increase of intracellular free radical due to the effects of IAA/HRP.

Genetic polymorphism of 3 STR loci of CSF1PO, TPOX and TH01 in Chinese Sibo population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To obtain allele and genotype frequencies and related forensic data of CF1PO, TPOX and TH01 loci in Chinese Xinjiang Sibo population.</p><p><b>METHODS</b>Genomic DNA from peripheral blood mononuclear cells of normal Chinese Xinjing Sibo population was used as template, and CSF1PO, TPOX and TH01 fragments were amplified by PCR. The PCR products were analyzed by 4% denaturing PAGE and detected using silver stain detection.</p><p><b>RESULTS</b>Nine alleles were found at CSF1PO locus, eight alleles at TPOX locus and eight alleles at TH01 locus in Chinese Sibo population. All the 3 loci complied with Hardy-Weinberg equilibrium. The heterozygosities were 0.9426, 0.8361 and 0.8853, and the polymorphism information contents were 0.8298, 0.7213 and 0.7626 for CSF1PO, TPOX and TH01, respectively.</p><p><b>CONCLUSION</b>The data on the alleles frequency of these 3 STR loci might be used for individual identification and paternity identification and for genetic researches in Chinese Sibo population.</p>