This study aims to construct the recombinant lentivirus vector containing specific small interfering RNA (siRNA) targeting rat CREB binding protein(CBP)gene and to identify its function of inhibiting the expressions of acetylated histone in primarily cultured hippocampal neurons. Firstly, we constructed four kinds of recombinant lentivirus siCBP. And then we used them to infect the primarily cultured hippocampal neurons, and performed real-time PCR, western blot respectively to detect the expressions of CBP. Afterwards, the most effective lentivirus siCBP was used to infect the primarily cultured hippocampal neurons, and then the HAT activity and protein expressions of acetylated histone Ac-H3, Ac-H4 of the neurons were examined. By using PCR, endonuclease cutting and gene sequencing, we confirmed that the target genes were correctly cloned in lentivirus vector. Besides, CBP mRNA and protein expressions in neurons were found to be with varying degrees of decreases after infections of the four kinds of lentivirus siCBP. Furthermore, the representative and most effective lentivirus GR806 could effectively inhibit the HAT activity and the protein expressions of Ac-H3, Ac-H4 in neurons. It provides the experimental basis for the subsequent application of siCBP to clarify the effects and corresponding molecular mechanism of the CBP-dependent histone acetylation on learning and memory function in hippocampus.
Objective To investigate the radiation-sensitizing effects of Ku80 silencing by siRNA interference for A549 lung cancer cells. Methods The sequences of Ku80 siRNA and negative siRNA were chemically synthesized and transfected into A549 lung cancer cells by lipofectamine. RT-PCR and Western bolt analysis were used to determine Ku80 gene expression. The transfected cells in culture dishes were irradiated with X ray at doses of 2 Gy, 4 Gy, 6 Gy, 8 Gy, 10 Gy, respectively. Once all treatments were completed, the cells were processed with the colony formation assay. Results RT-PCR detection showed that Ku80 mRNA levels in A549 lung cancer cells were reduced after transfected with Ku80 siRNA at 24 h, 48 h and 72 h time points. Western blot analysis showed that Ku80 protein content decreased at 48 h and 72 h time points compared with the control group ( P lt; 0. 05 ) . Cloning formation assay indicated that radiosensitivity of A549 lung cancer cells was enhanced after transfected with Ku80 siRNA. Conclusion Ku80 siRNA can effectively inhibit Ku80 gene expression of A549 lung cancer cells, and therefore enhance its radiosensitivity.
ObjectiveTo explore the influence mechanism of proliferation and invasion in colon cancer cell after silence of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene. MethodsRT-PCR or Western blot method was used to detect the expression of PTEN mRNA or protein among four colon cancer cell lines (HT-29, WiDr, CaCo-2, and Colo320 cell lines). small interfering RNA (siRNA) was used to synthetize PTEN siRNA and transfect it into colon cancer cells. The expression of PTEN protein after transfecting was detected by Western blot. WsT-1 and invasion assay were used to examine the effects of PTEN siRNA silence on proliferation and invasion in colon cancer cells. ResultsPTEN mRNA and protein were expressed in all the four colon cancer cell lines. After PTEN siRNA transfected into the colon cancer cells, the expressions of PTEN proteins were inhibited in all the four colon cancer cell lines (P < 0.01), and the proliferation and invasion of colon cancer cells were enhanced significantly (P < 0.01). ConclusionsPTEN siRNA play an important role in metastasis process of colon cancer via enhanced its proliferation and invasion. Therefore, the understanding biologic mechanisms for regulation of PTEN might enable better molecular target therapy of treating the colon cancer patients with metastasis.