1.Cloning, expression and purification of novel gene NBEAL1 and its relationship with pathological grades of glioma
Chenchen BAO ; Hao YANG ; Na LI ; Bin LIU ; Hua SONG ; Ping SHENG ; Guohan HU ; Daxiang CUI
Chinese Journal of Cancer Biotherapy 2010;17(1):77-81
Objective: To construct the expression plasmid of a novel gene human NBEAL1 (neurobeachin like 1), and to study its relationship with the pathological grades of glioma. Methods: Total RNA of human glioma cell line U251 was extracted. NBEAL1 expression plasmid pGEX-KG/NBEAL1 was constructed and transferred into E. coli BL21. Recombinant NBEAL1 protein was induced by IPTG and further purified by GST affinity chromatographic column. The purity of recombinant NBEAL1 protein was examined by Western blotting analysis. A NBEAL1 protein specific monoclonal antibody was prepared and was used to study the relationship of NBEAL1 expression with pathological grades of glioma. Results: The NBEAL1 gene fragment was successfully cloned into pGEX-KG expression plasmid and verified by DNA sequencing. The recombinant NBEAL1 protein was expressed in inclusion bodies, with a yield of more than 30% of total bacterial proteins; the purity of purified NBEAL1 protein was above 95%. Western blotting analysis confirmed that the purified protein containing GST tag and NBEAL protein. NBEAL1 protein was lowly expressed in normal brain tissues and highly expressed in low grade glioma tissues; and the expression of NBEAL1 decreased with the increase of glioma malignancy. Conclusion: The NBEAL1 protein has been successfully cloned, expressed and purified. NBEAL1 protein expression in glioma tissues is negatively associated with the pathological grades of glioma.
2.Preparation of human malignant melanoma ganglioside ScFv antibody-conjugated quantum dot nanoprobe and its specific binding with human malignant melanoma cells
Xiaomin ZHANG ; Tangde ZHANG ; Chenchen BAO ; Hua SONG ; Na LI ; Bin LIU ; Rong HE ; Zhiming LI ; Daxiang CUI ; Qiushi REN
Chinese Journal of Cancer Biotherapy 2010;17(1):30-35
Objective: To prepare a nanoprobe, anti-human melanoma ganglioside single chain variable fragment (GD/ScFvMEL) antibody conjugated with CdTe quantum dot, and to observe its ability to specifically bind human malignant melanoma cells. Methods: The GD/ScFvMEL gene was cloned into pET32a (+), and the plasmid was then transformed into E. coli BL21 (DE3) for GD/ScFvMEL protein antibody expression. The expressed GD/ScFvMEL antibody was purified by denaturing method and further refolded by modified dialysis method. The purified GD/ScFvMEL antibody was analyzed by SDS-PAGE. The GD/ScFvMEL-QDs nanoprobe was prepared by conjugating GD/ScFvMEL antibody with CdTe quantum dot, and its specificity was observed by incubating with MGC-803 cells and melanoma A375 cells. Results: The recombinant pET32a-GD/ScFvMEL was constructed and confirmed by PCR, restriction endonuclease analysis and DNA sequencing. The proportion of expressed GD/ScFvMEL antibody in total bacteria proteins was about 40% as detected by SDS-PAGE. The purified- and refolded-GD/ScFvMEL antibody was effectively conjugated with CdTe quantum dot, and the resulting GD/ScFvMEL-QDs nanoprobe was successfully prepared. The GD/ScFvMEL-QDs nanoprobe could specifically bind melanoma A375 cells, but could not bind stomach cancer MGC-803 cells. Conclusion: We have successfully prepared an anti-human melanoma ganglioside single-chain antibody-CdTe quantum dot nanoprobe, which can specifically bind melanoma cells.
3.Establishment of adipocytokine CTRP4 transgenic mouse
Daxiang NA ; Zhuang MA ; Yang LUO ; Qi LI ; Weifeng TAN ; Lanlan WANG ; Guoying ZHANG ; Ang YIN ; He HUANG ; Xiaotong WU ; Lu WANG
Chinese Journal of Comparative Medicine 2014;(7):1-6
Objective To establish the CTRP4 transgenic mouse model and investigate the function of the novel adipocytokine CTRP4.Methods CTRP4 overexpressing vector in pCAGGS was firstly constructed and then microinjected into zygote to establish the founder transgenic mice .F1 heterozygotes were generated by founder mice mating with wildtype mice, and the CTRP4 transgenic homozygotes were generated by F 1 littermates.The genotype was confirmed by PCR and test cross method .The expression level of CTRP 4 in transgenic mice was detected by western blot .Result The human CTRP4 transgenic homozygote mice line was established , and the expression level of CTRP 4 was confirmed raletively high in detected tissues including heart , liver, brain and kidney . Conclusion The human CTRP4 transgenic mice was successfully established .