Knockdown of GRHL3 Inhibits Activities and Induces Cell Cycle Arrest and Apoptosis of Human Colorectal Cancer Cells

The Grainyhead-like 3（GRHL3） is involved in epidermal barrier formation, neural tube closure and wound repair. Previous studies have suggested that GRHL3 has been linked to many different types of cancers. However, to date, its effects on human colorectal cancer（CRC） has not been clarified yet. Our microarray analysis has indicated predominant GRHL3 expression in CRC. The purpose of this study was to investigate the expression and significance of GRHL3 in CRC tumorigenesis using CRC tissues and paired paracancerous tissues, as well as using distinct CRC cell lines（HT29 and DLD1）. We observed increased GRHL3 expression at both m RNA and protein levels in CRC tissues and CRC cell lines using quantitative real-time polymerase chain reaction（q RT-PCR） and Western blotting. Moreover, silencing GRHL3 with si RNA could suppress CRC cell proliferation, viability and migration in vitro. We also found that knockdown of GRHL3 could promote cell cycle arrest at G0/G1 phase in HT29 cells and DLD1 cells, and induce cell apoptosis in HT29 cells. Together, our study revealed the down-regulation of GRHL3 in vitro could inhibit CRC cell activity and trigger cell cycle arrest at G0/G1 phase and apoptosis.

Modulating effects of survivin antisense oligonucleotide on changes of apoptosis and cell cycle of human hepatocellular carcinoma cell line SMMC-7721

To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.

Gambogic acid induces mitochondria-dependent apoptosis by modulation of Bcl-2 and Bax in mantle cell lymphoma JeKo-1 cells

Objective： To study the mechanisms in gambogic acid （GA） -induced JeKo-1 human Mantle Cell Lymphoma cell apoptosis in vitro. Methods： The proliferation of GA-treated JeKo-1 cells was measured by CCK-8 assay and Ki-67 immunocytochemical detection. Apopt0sis, cell cycle and mitochondrial membrane potential were measured by flow cytometric analysis. Caspase-3, -8 and -9 were detected by colorimetric assay. Bcl-2 and Bax were analyzed by Western blotting. Results： GA inhibited cell growth in a time- and dose- dependent manner. GA induces apoptosis in JeKo- 1 cells but not in normal bone marrow cells, which was involved in reducing the membrane potential of mitochondria, activating caspases-3, -8 and -9 and decreasing the ratio of Bd-2 and Bax without cell cycle arresting. Conclusions： GA induced apoptosis in human MCL JeKo-1 cells by regulating Bcl-2/Bax and activating caspase-3, -8 and -9 via mitochondrial pathway without affecting cell cycle.

Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling

Objective To investigate microwave-induced morphological and functional injury of natural killer（NK） cells and uncover their mechanisms. Methods NK-92 cells were exposed to 10, 30, and 50 m W/cm^2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2 D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK（p-ERK） was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126. Results Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis（P 〈 0.001） and cell cycle arrest（P 〈 0.001） were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 m W/cm^2 microwave exposure（P 〈 0.01）. In the 30 m W/cm^2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure（P 〈 0.05）. Furthermore, p-ERK was down regulated at 1 h after exposure（P 〈 0.05）, while ERK blockade significantly promoted microwave-induced apoptosis（P 〈 0.05） and downregulation of perforin（P 〈 0.01）. Conclusion Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Effect of Trichosanthin on Cell Cycle and Apoptosis of Murine Melanoma Cells

Objective:To study thei nhibitory effect of purified trichosanthin component on the proliferation of malignant melanoma.Methods:The effect of purified trichosanthin componenton the DNA synthesis,cell cycle and cell apoptos is of murinemelanomacellsweredetected by flow cytometry when culture dinvitro.Results:The significantG0/G1phasearrest was revealed by the inc rease of cellsinG0/G1 phase and decrease of cell sinS phase.The obviousapoptosis of melanoma cells was in duced bypuri fied trichos anthin component.G0/G1phase arrest was high lycorrelated withapop to sis(r=0.8705).Conclusion:The purified trichos anthin component can markedly inhibit melanoma cells by the suppression of DNA syn the sisin S phaseand cell mitosisas well as induction of cell apoptosis.

Anti-apoptosis Effect of Decoy Receptor 3 in Cholangiocarcinoma Cell Line TFK-1

Background： Decoy receptor 3 （DcR3） is a protein with anti-apoptotic effect that belongs to the tumor necrosis factor receptor superfamily. DcR3 is highly expressed in a variety of malignant tumors including cholangiocarcinoma and its expression was found to be related to the clinical stage, the invasion, and tile metastasis of the tumor. This in vitro study aimed to investigate the effect ofdownregulated expression of DcR3 on cell viability, cell apoptosis, and cell cycle in cholangiocarcinoma cell line TFK-1. Methods： Three different cell lines were cultured： human cholangiocarcinoma TFK-I, human biliary epithelial carcinoma HuCCT-1, and human cholangiocarcinoma RBE. The cholangiocarcinoma cell line with the highest expression of DcR3 was selected for further investigation. The expression of DcR3 was silenced/knocked down by transfection with DcR3-siRNA in the selected cell line. Various biological phenotype parameters such as cell viability, apoptosis, and cell cycle were observed. Results： The mRNA and protein levels of DcR3 were measured in the three cell lines, and TFK-1 was selected. After the treatment with DcR3-siRNA for 48 h, DcR3 mRNA and protein expression in the treatment group were 38.45% （P 〈 0.01 ） and 48.03% （P 〈 0.05） of that of＇the control, respectively. It was found that the cell viability decreased to 61.87% of the control group （P 〈 0.01 ） after the downregulation of DcR3 in cholangiocarcinoma cell line TFK- 1 by transfection with DcR3-siRNA, while tile percentage ofapoptotic cells was 2.98 times as compared with the control group （P 〈 0.05）. Compared with the control group the ratio of G0/G1 increased, and the ratio of G2/M dccreased in the treatment group. However, the differences were not statistically significant. Conclusions： The effect of DcR3 on the growth and apoptosis ofcholangiocarcinoma has been demonstrated. DcR3 is not only a predictive marker for malignant tumor but it is also likely to be a potential target for cancer gene therapy. Further studies should focus on exploring the binding ligand of DcR3, the signaling pathway involved, and the molecular mechanism for the regulation of DcR3 expression in cholangiocarcinoma.