A novel HBV integration site involved in hepatocarcinogenesis was investigated. The HBV DNA integration sites were detected by Alu-PCR in hepatocellular carcinoma tissues, matched surrounding liver tissues in 30 patie...A novel HBV integration site involved in hepatocarcinogenesis was investigated. The HBV DNA integration sites were detected by Alu-PCR in hepatocellular carcinoma tissues, matched surrounding liver tissues in 30 patients with hepatitis B-related hepatocellular carcinoma (HCC) and 3 cases of normal liver tissues. The integration sites and flanking sequences in human genome were sequenced and blasted, and the expression of integrated HBV genes was determined by reverse transcriptase-polymerase chain reaction (RT-PCR). The influence of the up-regulated expression of integrated genes on hepatocarcinogenesis was analyzed. Nineteen integration sites of HBV DNA into HCC tissues were obtained by RT-PCR and sequencing. These genes encoding proteins were: LOC51030, LOC157777, minichromosome maintenance complex component 3 associated protein (MCM3AP), MCTP1, SH3 and multiple ankyrin repeat domains 2 isoform 2, CCDC40, similar to HCG2033532, mitochondrial ribosomal S5 pseudogene 4. One of them was integrated into the intron of MCM3AP. RT-PCR demonstrated that the expression levels of MCM3AP mRNA in HCC tissues, matched surrounding liver tissues and normal liver tissues were in a descendent order. The ratio of MCM3AP mRNA to the GAPDH mRNA in these three tissues was 1.07375, 0.21573, 0.06747 respectively, with the difference being statistically significant among them (P<0.05). Meanwhile, the expression levels of MCM3AP mRNA from HCC tissues in which HBV DNA integrated into MCM3AP were still significantly higher than those without HBV DNA integrated into MCM3AP. It was concluded that the HBV DNA integration sites into human genome were random, and MCM3AP was a new site. The up-regulated MCM3AP mRNA may affect flanking sequences which promote the hepatocarcinogenesis.展开更多
Objective: To isolate human tumor metastasis suppressive DNA sequence and to study the molecular mechanisms regulating tumor metastasis. Methods: A mouse lung adenocarcinoma cell clone 12 derived from its parent cell ...Objective: To isolate human tumor metastasis suppressive DNA sequence and to study the molecular mechanisms regulating tumor metastasis. Methods: A mouse lung adenocarcinoma cell clone 12 derived from its parent cell line LM2, which had been transduced with normal human genomic DNA, was previously reported. Compared with LM2, the metastatic potential of clone 12 was very much decreased. Clone 12 was used in this study to amplify the human DNA fragments by Inter Alu PCR technique. The human DNA fragments obtained were then transfected into LM2 cells and their malignant phenotype was tested in vitro and in vivo, and compared with that of the untransfected LM2 cells.Results Three human DNA fragments of 700, 500 and 300 bp were isolated. DNA sequencing revealed that the 700bp fragment does not show homology with hitherto reported genes and was accepted by the Genbank (pt712 U67835). In vitro proliferation and colony formation in soft agar of the 700 bp fragment-transfected LM2 cells were significantly inhibited as compared to the untransfected LM2 cells. Upon subcutaneous inoculation to syngeneic T739 mice, the 700bp-transfected LM2 cells grew more slowly and smaller tumors developed compared to the untransfected ones. Moreover, lung metastasis was not found in 6 of 10 mice inoculated with the 700bp-transfected LM2 cells, while it was found in 9 of 10 mice inoculated with the untransfected LM2 cells. The difference was statistically significant (P<0.001). The frequency of lymph node metastasis was also statistically different between the 2 groups of mice.Conclusion The newly isolated 700bp human DNA fragment may be a metastasis suppressor gene of malignant tumor.展开更多
为了探讨Alu SINE RNA和HEXIM1蛋白之间是否存在相互作用.本实验构建了带有FLAG标签的HEXIM1真核表达载体,转染人胚肾293(HEK293)细胞,做anti-FLAG的RNA免疫共沉淀(RIP)后运用免疫印记和逆转录PCR(reverse transcription PCR,RTPCR)等...为了探讨Alu SINE RNA和HEXIM1蛋白之间是否存在相互作用.本实验构建了带有FLAG标签的HEXIM1真核表达载体,转染人胚肾293(HEK293)细胞,做anti-FLAG的RNA免疫共沉淀(RIP)后运用免疫印记和逆转录PCR(reverse transcription PCR,RTPCR)等方法检测.证明了Alu SINE RNA和HEXIM1蛋白之间存在相互作用,表明Alu SINE RNA和HEXIM1蛋白共同影响基因转录调控,以及细胞在应对外界刺激时能及时在基因水平做出有效反应的可能.展开更多
基金supported by grants from the National Natural Sciences Foundation of China (No. 30872237)the National Program on Key Basic Research Project (973 Program) (No. 2007CB512900)
文摘A novel HBV integration site involved in hepatocarcinogenesis was investigated. The HBV DNA integration sites were detected by Alu-PCR in hepatocellular carcinoma tissues, matched surrounding liver tissues in 30 patients with hepatitis B-related hepatocellular carcinoma (HCC) and 3 cases of normal liver tissues. The integration sites and flanking sequences in human genome were sequenced and blasted, and the expression of integrated HBV genes was determined by reverse transcriptase-polymerase chain reaction (RT-PCR). The influence of the up-regulated expression of integrated genes on hepatocarcinogenesis was analyzed. Nineteen integration sites of HBV DNA into HCC tissues were obtained by RT-PCR and sequencing. These genes encoding proteins were: LOC51030, LOC157777, minichromosome maintenance complex component 3 associated protein (MCM3AP), MCTP1, SH3 and multiple ankyrin repeat domains 2 isoform 2, CCDC40, similar to HCG2033532, mitochondrial ribosomal S5 pseudogene 4. One of them was integrated into the intron of MCM3AP. RT-PCR demonstrated that the expression levels of MCM3AP mRNA in HCC tissues, matched surrounding liver tissues and normal liver tissues were in a descendent order. The ratio of MCM3AP mRNA to the GAPDH mRNA in these three tissues was 1.07375, 0.21573, 0.06747 respectively, with the difference being statistically significant among them (P<0.05). Meanwhile, the expression levels of MCM3AP mRNA from HCC tissues in which HBV DNA integrated into MCM3AP were still significantly higher than those without HBV DNA integrated into MCM3AP. It was concluded that the HBV DNA integration sites into human genome were random, and MCM3AP was a new site. The up-regulated MCM3AP mRNA may affect flanking sequences which promote the hepatocarcinogenesis.
基金the National Natural Science Foundation of China (No. 39370761 ).
文摘Objective: To isolate human tumor metastasis suppressive DNA sequence and to study the molecular mechanisms regulating tumor metastasis. Methods: A mouse lung adenocarcinoma cell clone 12 derived from its parent cell line LM2, which had been transduced with normal human genomic DNA, was previously reported. Compared with LM2, the metastatic potential of clone 12 was very much decreased. Clone 12 was used in this study to amplify the human DNA fragments by Inter Alu PCR technique. The human DNA fragments obtained were then transfected into LM2 cells and their malignant phenotype was tested in vitro and in vivo, and compared with that of the untransfected LM2 cells.Results Three human DNA fragments of 700, 500 and 300 bp were isolated. DNA sequencing revealed that the 700bp fragment does not show homology with hitherto reported genes and was accepted by the Genbank (pt712 U67835). In vitro proliferation and colony formation in soft agar of the 700 bp fragment-transfected LM2 cells were significantly inhibited as compared to the untransfected LM2 cells. Upon subcutaneous inoculation to syngeneic T739 mice, the 700bp-transfected LM2 cells grew more slowly and smaller tumors developed compared to the untransfected ones. Moreover, lung metastasis was not found in 6 of 10 mice inoculated with the 700bp-transfected LM2 cells, while it was found in 9 of 10 mice inoculated with the untransfected LM2 cells. The difference was statistically significant (P<0.001). The frequency of lymph node metastasis was also statistically different between the 2 groups of mice.Conclusion The newly isolated 700bp human DNA fragment may be a metastasis suppressor gene of malignant tumor.
文摘为了探讨Alu SINE RNA和HEXIM1蛋白之间是否存在相互作用.本实验构建了带有FLAG标签的HEXIM1真核表达载体,转染人胚肾293(HEK293)细胞,做anti-FLAG的RNA免疫共沉淀(RIP)后运用免疫印记和逆转录PCR(reverse transcription PCR,RTPCR)等方法检测.证明了Alu SINE RNA和HEXIM1蛋白之间存在相互作用,表明Alu SINE RNA和HEXIM1蛋白共同影响基因转录调控,以及细胞在应对外界刺激时能及时在基因水平做出有效反应的可能.
