[Objective] The aim was to study cloning and prokaryotic expression of P23 major surface protein gene of Theileria sergenti. [Method] A pair of specific primers was designed according to the sequence of P23 major surf...[Objective] The aim was to study cloning and prokaryotic expression of P23 major surface protein gene of Theileria sergenti. [Method] A pair of specific primers was designed according to the sequence of P23 major surface protein of T. sergenti (D84447).The P23 gene was amplified by PCR from genomic DNA of T. sergenti and cloned into pMD18-T vector to construct recombinant clonal vector pMD18-P23. Positive clones were identified by PCR screening and restriction digestion. A recombinant expression plasmid pGEX-4T-P23 was constructed by subcloning the cloned P23 gene into the linearized pGEX-4T-1 vector and transformed into E. coli BL21. After introduction by IPTG,the expressed fusion protein was identified by SDS-PAGE and Western-blotting. [Result] The cloned gene has a total length of 507 bp. Sequencing result showed that the nucleotide sequence of the cloned P23 gene shared 99.4% identity with that of P23 published in GenBank (D84447). The expressed fusion protein was 46 ku in molecular mass. Induction opportunity of zhours after culture inoculation was the best,the induction time of 6 h was the best,and induction temperature of 34 ℃ was the best as well,IPTG of 1 mmol/L had little effect on the expression. Western-blotting indicated that recombinant protein was recognized by specific antibody. [Conclusion] This study would lay a foundation for further research on the prevention and diagnose of T. sergenti.展开更多
Objective: To investigate the role of nm23 gene expression in human lung cancer. Methods: Forty human lung cancer tissues and 19 non-cancer pulmonary tissues were studied for their nm23-H1 and nm23-H2 mRNA expression ...Objective: To investigate the role of nm23 gene expression in human lung cancer. Methods: Forty human lung cancer tissues and 19 non-cancer pulmonary tissues were studied for their nm23-H1 and nm23-H2 mRNA expression with non-radioactive Northern blot hybridization. The correlation of nm23 mRNA expression with clinical features of lung cancer was analyzed. Results: The mRNA expression of nm23-H2 gene in poorly differentiated squamous cell carcinoma was significantly decreased compared to that in moderate-high differentiated squamousd cell carcinoma. The mRNA expression of nm23-H1 and nm23-H2 gene in small cell lung cancer was significantly decreased compared to that in squamous cell carcinoma. No significant difference in nm23 mRNA expression was observed between lung cancer with and without lymph node metastasis, nor was there significant difference between tumor stage. Conclusion: The mRNA expression of nm23 gene is correlated with the degree of differentiation of lung cancer, but there is no evidence of metastasis suppression effect by nm23 gene.展开更多
We have studied the expression of nm23(NDP) in 50 cases nasopharyngeal biopsies with anti-nm23(NDP) antibodies. As a result, the NDP positive rate in nasopharyngeal carcinoma (NPC) (95.54%) markedly increased (P<0....We have studied the expression of nm23(NDP) in 50 cases nasopharyngeal biopsies with anti-nm23(NDP) antibodies. As a result, the NDP positive rate in nasopharyngeal carcinoma (NPC) (95.54%) markedly increased (P<0.05), as compared with that in the normal nasopharyngeal epithelia (50.00-60.00%) and lymphocytes (52.00%). There were cytopfasmic type, nucleus type and mixed cytoplasmonucleus type according to NDP location in a cell. Their positive rates were 64.44%, 15.56% and 20.00% respectively in nasopharyngeal carcinoma. The expression of NDP had no relation with cervical lymphometastases in NPC, and the NDP positive rates had no significance between bilateral cervical lymphometastases and unilateral (P<0.05). But the NDP expression had most relation with the NPC staging. The expression rate and the intensity in Ⅲ or Ⅳ stage patients were markedly higher than that in II stage. It points out that the high-level expression of NDP had relation with the rapid cellular proliferation in NPC, and it may indicate the bad prognoses.展开更多
Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells...Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells to synthesized cDNA. The synthesized cDNA encoding pre-miRNA-451 was amplified by polymerase chain reaction （PCR）. The PCR product was separated by electrophoresis on 1% agarose gel and then recovered and purified. The purified cDNA fragments of miRNA-451 precursor sequence was then ligated with vector pLMP for 1 h by using DNA ligase to form pLMP- miRNA-451 plasmid. After that, the pLMP-miRNA-451 plasmid was transformed into E. coli DH5a strain expression system to clone and amplificate. The purified pLMP-miRNA-451 extracted from E. coli DH5a via transformation and clone screening was identificatied with restriction enzyme digestion and DNA sequencing. At last, pLMP-miRNA-451 was transfected into SGC-7901 cells with lip2000. Real-time PCR was used for detection of the miRNA-451, the transfection efficiency was ob- served under fluorescence microscopy and cell counting kit-8 assay was conduced to evaluate the effect of miRNA-451 on SGC-7901 cell proliferation. Results： Our results showed that pLMP-miRNA-451 expression vector was not only constructed successfully and effectively infected SGC-7901 cells, but also could repress the SGC-7901 cell proliferation. Conclusion： The constructed plasmid pLMP-miRNA-451 could used for further studies of miRNA-451 in SGC-7901 cell lines.展开更多
MicroRNAs (miRNAs) are small endogenous RNAs molecules,approximately 21–23 nucleotides in length,which regulate gene expression by base-pairing with 3′ untranslated regions (UTRs) of target mRNAs.However,the functio...MicroRNAs (miRNAs) are small endogenous RNAs molecules,approximately 21–23 nucleotides in length,which regulate gene expression by base-pairing with 3′ untranslated regions (UTRs) of target mRNAs.However,the functions of only a few miRNAs in organisms are known.Recently,the expression vector of artificial miRNA has become a promising tool for gene function studies.Here,a method for easy and rapid construction of eukaryotic miRNA expression vector was described.The cytoplasmic actin 3 (A3) promoter and flanked sequences of miRNA-9a (miR-9a) precursor were amplified from genomic DNA of the silkworm (Bombyx mori) and was inserted into pCDNA3.0 vector to construct a recombinant plasmid.The enhanced green fluorescent protein (EGFP) gene was used as reporter gene.The Bombyx mori N (BmN) cells were transfected with recombinant miR-9a expression plasmid and were harvested 48 h post transfection.Total RNAs of BmN cells transfected with recombinant vectors were extracted and the expression of miR-9a was evaluated by reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot.Tests showed that the recombinant miR-9a vector was successfully constructed and the expression of miR-9a with EGFP was detected.展开更多
基金Supported by Science and Technology Development Program of Jilin Province (20050703-4)~~
文摘[Objective] The aim was to study cloning and prokaryotic expression of P23 major surface protein gene of Theileria sergenti. [Method] A pair of specific primers was designed according to the sequence of P23 major surface protein of T. sergenti (D84447).The P23 gene was amplified by PCR from genomic DNA of T. sergenti and cloned into pMD18-T vector to construct recombinant clonal vector pMD18-P23. Positive clones were identified by PCR screening and restriction digestion. A recombinant expression plasmid pGEX-4T-P23 was constructed by subcloning the cloned P23 gene into the linearized pGEX-4T-1 vector and transformed into E. coli BL21. After introduction by IPTG,the expressed fusion protein was identified by SDS-PAGE and Western-blotting. [Result] The cloned gene has a total length of 507 bp. Sequencing result showed that the nucleotide sequence of the cloned P23 gene shared 99.4% identity with that of P23 published in GenBank (D84447). The expressed fusion protein was 46 ku in molecular mass. Induction opportunity of zhours after culture inoculation was the best,the induction time of 6 h was the best,and induction temperature of 34 ℃ was the best as well,IPTG of 1 mmol/L had little effect on the expression. Western-blotting indicated that recombinant protein was recognized by specific antibody. [Conclusion] This study would lay a foundation for further research on the prevention and diagnose of T. sergenti.
文摘Objective: To investigate the role of nm23 gene expression in human lung cancer. Methods: Forty human lung cancer tissues and 19 non-cancer pulmonary tissues were studied for their nm23-H1 and nm23-H2 mRNA expression with non-radioactive Northern blot hybridization. The correlation of nm23 mRNA expression with clinical features of lung cancer was analyzed. Results: The mRNA expression of nm23-H2 gene in poorly differentiated squamous cell carcinoma was significantly decreased compared to that in moderate-high differentiated squamousd cell carcinoma. The mRNA expression of nm23-H1 and nm23-H2 gene in small cell lung cancer was significantly decreased compared to that in squamous cell carcinoma. No significant difference in nm23 mRNA expression was observed between lung cancer with and without lymph node metastasis, nor was there significant difference between tumor stage. Conclusion: The mRNA expression of nm23 gene is correlated with the degree of differentiation of lung cancer, but there is no evidence of metastasis suppression effect by nm23 gene.
文摘We have studied the expression of nm23(NDP) in 50 cases nasopharyngeal biopsies with anti-nm23(NDP) antibodies. As a result, the NDP positive rate in nasopharyngeal carcinoma (NPC) (95.54%) markedly increased (P<0.05), as compared with that in the normal nasopharyngeal epithelia (50.00-60.00%) and lymphocytes (52.00%). There were cytopfasmic type, nucleus type and mixed cytoplasmonucleus type according to NDP location in a cell. Their positive rates were 64.44%, 15.56% and 20.00% respectively in nasopharyngeal carcinoma. The expression of NDP had no relation with cervical lymphometastases in NPC, and the NDP positive rates had no significance between bilateral cervical lymphometastases and unilateral (P<0.05). But the NDP expression had most relation with the NPC staging. The expression rate and the intensity in Ⅲ or Ⅳ stage patients were markedly higher than that in II stage. It points out that the high-level expression of NDP had relation with the rapid cellular proliferation in NPC, and it may indicate the bad prognoses.
基金supported by a grant from the Natural Science Foundation of China (No. 8100098)
文摘Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells to synthesized cDNA. The synthesized cDNA encoding pre-miRNA-451 was amplified by polymerase chain reaction （PCR）. The PCR product was separated by electrophoresis on 1% agarose gel and then recovered and purified. The purified cDNA fragments of miRNA-451 precursor sequence was then ligated with vector pLMP for 1 h by using DNA ligase to form pLMP- miRNA-451 plasmid. After that, the pLMP-miRNA-451 plasmid was transformed into E. coli DH5a strain expression system to clone and amplificate. The purified pLMP-miRNA-451 extracted from E. coli DH5a via transformation and clone screening was identificatied with restriction enzyme digestion and DNA sequencing. At last, pLMP-miRNA-451 was transfected into SGC-7901 cells with lip2000. Real-time PCR was used for detection of the miRNA-451, the transfection efficiency was ob- served under fluorescence microscopy and cell counting kit-8 assay was conduced to evaluate the effect of miRNA-451 on SGC-7901 cell proliferation. Results： Our results showed that pLMP-miRNA-451 expression vector was not only constructed successfully and effectively infected SGC-7901 cells, but also could repress the SGC-7901 cell proliferation. Conclusion： The constructed plasmid pLMP-miRNA-451 could used for further studies of miRNA-451 in SGC-7901 cell lines.
基金Project supported by the National Basic Research Program (973) of China (No. 2005CB121004)the National High-Tech R & D Program (863) of China (No. 2006AA10A119)+1 种基金the Innovation Foundation for Graduate Students of Jiangsu Provincethe National Natural Science Foundation of China (No. 61001013)
文摘MicroRNAs (miRNAs) are small endogenous RNAs molecules,approximately 21–23 nucleotides in length,which regulate gene expression by base-pairing with 3′ untranslated regions (UTRs) of target mRNAs.However,the functions of only a few miRNAs in organisms are known.Recently,the expression vector of artificial miRNA has become a promising tool for gene function studies.Here,a method for easy and rapid construction of eukaryotic miRNA expression vector was described.The cytoplasmic actin 3 (A3) promoter and flanked sequences of miRNA-9a (miR-9a) precursor were amplified from genomic DNA of the silkworm (Bombyx mori) and was inserted into pCDNA3.0 vector to construct a recombinant plasmid.The enhanced green fluorescent protein (EGFP) gene was used as reporter gene.The Bombyx mori N (BmN) cells were transfected with recombinant miR-9a expression plasmid and were harvested 48 h post transfection.Total RNAs of BmN cells transfected with recombinant vectors were extracted and the expression of miR-9a was evaluated by reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot.Tests showed that the recombinant miR-9a vector was successfully constructed and the expression of miR-9a with EGFP was detected.
