• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.12
• /
• pp.4773-4780
• /
• 2014

Background: To investigate the effects of small interference RNA (siRNA) targeting BCR/ABL mRNA on proliferation and apoptosis in the K562 human chronic myeloid leukemia (CML) cell line and to provide a theoretical rationale and experimental evidence for its potential clinical application for anti-CML treatment. Materials and Methods: The gene sequence for BCR/ABL mRNA was found from the GeneBank. The target gene site on the BCR/ABL mRNA were selected according to Max-Planck-Institute (MPI) and rational siRNA design rules, the secondary structure of the candidate targeted mRNA was predicted, the relevant thermodynamic parameters were analyzed, and the targeted gene sequences were compared with BLAST to eliminate any sequences with significant homology. Inhibition of proliferation was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry (FCM) and the morphology of apoptotic cells was identified by Giemsa-Wright staining. Western blotting was used to analyze the expression of BCR/ABL fusion protein in K562 cells after siRNA treatment. Results: The mRNA local secondary structure calculated by RNA structure software, and the optimal design of specific siRNA were contributed by bioinformatics rules. Five sequences of BCR/ABL siRNAs were designed and synthesized in vitro. Three sequences, siRNA1384, siRNA1276 and siRNA1786, which showed the most effective inhibition of K562 cell growth, were identified among the five candidate siRNAs, with a cell proliferative inhibitory rate nearly 50% after exposure to 12.5nmol/L~50nmol/L siRNA1384 for 24,48 and 72 hours. The 50% inhibitory concentrations ($IC_{50}$) of siRNA1384, siRNA1276 and siRNA1786 for 24hours were 46.6 nmol/L, 59.3 nmol/L and 62.6 nmol/L, respectively, and 65.668 nmol/L, 76.6 nmol/L, 74.4 nmol/L for 72 hours. The colony-formation inhibiting test also indicated that, compared with control, cell growth of siRNA treated group was inhibited. FCM results showed that the rate of cell apoptosis increased 24 hours after transfecting siRNA. The results of annexinV/PI staining indicated that the rate of apoptosis imcreased (1.53%, 15.3%, 64.5%, 57.5% and 21.5%) following treamtne with siRNAs (siRNA34, siRNA372, siRNA1384, siRNA1276 and siRNA1786). Morphological analysis showed td typical morphologic changes of apoptosis such as shrunken, fragmentation nucleus as well as "apoptotic bodies" after K562 cell exposure to siRNA. Western blot analysis showed that BCR/ABL protein was reduced sharply after a single dose of 50nmol/L siRNA transfection. Conclusions: Proliferation of K562 cells was remarkbly inhibited by siRNAs (siRNA1384, siRNA1276 and siRNA1786) in a concentration-dependent manner in vitro, with effective induction of apoptosis at a concentration of 50 nmol/L. One anti-leukemia mechanism in K562 cells appeared that BCR/ABL targeted protein was highly down-regulated. The siRNAs (siRNA1384, siRNA1276 and siRNA1786) may prove valuable in the treatment of CML.

• Journal of Life Science
• /
• v.19 no.11
• /
• pp.1581-1590
• /
• 2009

Hizikia fusiforme is a kind of brown edible seaweed that mainly grows in the temperate seaside areas of the northwest pacific, including Korea, Japan and China, and has been widely used as a health food for hundreds of years. Recently, H. fusiforme has been known to exert pharmacological activities including antioxidant, antimutagenic and anticoagulant activities. However, the molecular mechanisms of H. fusiforme in malignant cells have not been clearly elucidated yet. In this study, the effects of ethyl alcohol extract of H. fusiforme (EAHF) on the anti-proliferative effects of MDA-MB-231 and MCF-7 human breast cancer cells were investigated. EAHF treatment resulted in a concentration-dependent growth inhibition by including apoptosis in MDA-MB-231 cells and G1 phase arrest in MCF-7 cells, which could be proved by MTT assay, DAPI staining, agarose gel electrophoresis and flow cytometry analysis. In MDA-MB-231 cells, the increase in apoptosis induced by EAHF treatment correlated with up-regulation of pro-apoptotic Bax expression. EAHF treatment induced the proteolytic activation of caspase-3 and caspase-9, and a concomitant inhibition of poly (ADP-ribose) polymerase, $\beta$-catenin, phospholipase-${\gamma}1$ protein and DNA fragmentation factor 45/inhibitor of caspase-activated DNase. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. fusiforme.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.4
• /
• pp.395-401
• /
• 2006

In this study, we investigated anticarcinogenic effects of extracts from Gloiopeltis tenax (GT). GT was extracted with methanol (GTM), which was then further fractionated into four fractions by using solvent fractionation method, affording methanol (GTMM), hexane (GTMH), butanol (GTMB) and aqueous (GTMA) soluble fractions. We determined the cytotoxic effects of these fractions on cancer cells by MTT assay. Among various fractions of GT, the GTMM showed the strongest cytotoxic effect at concentration of $150{\mu}g/mL$, displaying 95.97% on HepG2 cell lines and 93.64% on HT-29 cell lines, respectively. And, the anti-proliferative effect of GT was accompanied by a marked in increase of levels of Bad, Bax, Bok and Bak protein and activation of caspase-3, caspase-7 and PARP protein. Also, we observed quinone reductase (QR) induced effects in all fraction layers of GT on HepG2 cells. The QR induced effects of the GTMM and GTMB on HepG2 cells at concentration of $60{\mu}g/mL$ showing inductive indexes of 2.86 and 2.04 compared to the control value of 1.0.

• Journal of Life Science
• /
• v.21 no.7
• /
• pp.961-968
• /
• 2011

The formation of reactive lipid aldehydes, 4-hydroxynonenal (HNE) is shown to be derived from fatty acid hydroperoxides through the oxidative process. Among its known effects in cytotoxicity, HNE has been implicated in apoptotic cell death. To delineate its putative role as a potential mediator, we investigated the mechanism by which HNE induces apoptosis of endothelial cells (ECs). The anti-proliferative effects of HNE were tested through MTT assay after exposure to various concentrations ($5\sim15\;{\mu}M$) of HNE. We observed apoptotic bodies with propidium iodide staining, and measured the HNE induction of endothelial apoptosis by flow cytometry assay. We observed that cells exposed to HNE for 24 hr resulted in increased poly(ADP-ribose) polymerase cleavage and up-regulation of Bax. Data on the HNE action strongly indicated the involvement of reactive species, namely, intracellular ROS, nitrite, and peroxynitrite. To obtain evidence on the implication of ROS and peroxynitrite in HNE-induced apoptosis, a ROS scavenger, N-acetylcysteine (NAC), and a peroxynitrite scavenger, penicillamine, were tested. Results clearly indicate that the induction of apoptosis by HNE was effectively inhibited by NAC and penicillamine. Based on the present data, we conclude that the endothelial apoptosis induced by HNE involves both ROS generation and peroxynitrite activity. Our new data could lead to a redefinition of HNE action on apoptosis in ECs.

• Journal of Preventive Medicine and Public Health
• /
• v.27 no.1 s.45
• /
• pp.11-24
• /
• 1994

The studies reported here were undertaken to investigate the effects of mercury chloride on immune system of Balb/c mouse employing a flexible tier of in vitro and in vivo assays. Mercury chloride inhibited the proliferative responses of spleen cells to lipopolysaccharide, pokeweed mitogen, and phytohemagglutinin as a dose-dependent manner. This inhibitory effect was observed not only when $HgCl_2$ was added 2nd or 3rd day of 3 days culture period but also when spleen cells was pretreated with $HgCl_2$ for 2 hours. Mercury chloride, however, potentiated the production of IgM and IgG from spleen cells. During the $HgCl_2$ administration by drinking for 3 weeks, the weight gain of mice was significantly blunted than that o control group mice, while no overt signs related to mercury toxicity were noted in any mice of experimental group. There was no change in thymus and spleen weights, and in histological findings of kidney, bone marrow of femur, thymus, spleen, and popliteal lymph node after 3 weeks of mercury exposure. However, $HgCl_2$ induced a significant increase of total serum IgM, IgG including $IgG_1,\;IgG_{2a}\;and\;IgG_{2b}$, and IgE in Balb/c mice. Treatment in vivo with anti-IL-4 monoclonal antibody significantly abrogated the $HgCl_2$-induced increase in total serum IgG1 and IgE. Whereas $HgCl_2$ potentiated total serum IgM and IgG, there was no difference in total serum hemagglutinin to SRBC (Sheep Red Blood Cell) between experimental and control group mice when these mice were immunized with SRBC. All these findings observed in Balb/c mice suggest that mercury perturbates well-orchestrated regulation of immune responses before developing histopathological changes in lymphoid tissues.