Value of anti-survivin in early diagnosis of malignant tumors / 第三军医大学学报

ABSTRACT

Objective To establish a soluble expression of recombinant survivin in E. coli, and evaluate the role of anti-survivin in tumor diagnosis. Methods The recombinant survivin was screened by ampicillin resistance, identified by PCR and double digestion of endonucleases. The sequenced DNA of survivin was analyzed by BLAST. The survivin/Trx fusion protein expressed in E.coli BL21 (DE3) was induced with IPTG, identified by Western blot and purified with Ni-NTA agarose respectively. The anti-survivin antibodies in serum were detected with an indirect ELISA. By the methods above, 144 serum samples from cancer patients and 300 serum samples from normal subjects were analyzed. Meanwhile, the joint detection of anti-survivin, AFP, CEA, CA199, CA125 in blood sera from cancer patients was detected. Results After PCR and double digestion with endonucleases, the survivin gene was inserted into the prokaryotic expression vector PET 32a(+). After DNA sequencing, the constructed expression plasmid was transformed into competent cells E.coli BL21(DE3). Western blot identified that the recombinant survivin/Trx fusion protein was specific against survivin antibody. The purity of the protein was over 96% after purified by Ni-NTA agarose. Anti-survivin was expressed in the sera of different cancer patients, but the positive rate varied. Conclusion Prokaryotic expression plasmid PET 32a(+)/survivin was successfully constructed and highly purified survivin/Trx fusion protein was obtained. The detection results of anti-survivin, AFP, CEA, CA199, CA125 in blood serum show in the diagnosis of tumors, the joint detection can overcome the shortfall of each gene and enhance the diagnostic rate.