肝细胞肝癌患者肿瘤/睾丸抗原SSX-1及NY-ESO-1mRNA的表达意义

Clinical implications of expression of MAGE-1 and NY-ESO-1 mRNAs in gastrointestinal stromal tumors

AIM: To evaluate the possibility of using melanoma antigen-1 (MAGE-1) and New York-esophageal-1 (NY-ESO-1) antigens as specific targets for immunotherapy of gastrointestinal stromal tumors (GISTs) and using MAGE-1 and NY-ESO-1 mRNA levels as auxiliary parameters for risk classification of GISTs.

METHODS: The expression of MAGE-1 and NY-ESO-1 mRNAs was detected by reverse transcription-polymerase chain reaction (RT-PCR) in 30 GIST tissue specimens. The correlation of MAGE-1 and NY-ESO-1 mRNA expression with pathological parameters was analyzed in GISTs.

RESULTS: The positive rates of MAGE-1 and NY-ESO-1 mRNA expression in GIST specimens were 30% and 47%, respectively. At least one of these two cancer-testis antigens (CTAs) was detected in 18 GIST tissue specimens. The expression of MAGE-1 and NY-ESO-1 mRNAs was not correlated with age, sex or pathologic type (P > 0.05), but correlated with tumor site, tumor diameter and risk grade (all P < 0.05). The expression levels of MAGE-1 and NY-ESO-1 mRNAs in GISTs of high risk grade were significantly higher than those in GISTs of low risk grade (P < 0.05). No negative correlation was noted between the expression of MAGE-1 and NY-ESO-1 mRNAs in GISTs (r = 0.018, P > 0.05).

CONCLUSION: MAGE-1 and NY-ESO-1 mRNAs are expressed specifically in GIST tissue and may be potentially promising targets for antigen-specific immunotherapy of GISTs. The expression of MAGE-1 and NY-ESO-1 mRNAs is correlated with the risk grade of GISTs. MAGE-1 and NY-ESO-1 mRNA levels are promising auxiliary parameters for risk classification of GISTs.

Prokaryotic expression of ropporin and generation of its rabbit polyclonal antisera

AIM: To prepare human ropporin (a novel cancer/testis antigen) recombinant protein using a prokaryotic expression system and generate its rabbit polyclonal antisera.

METHODS: The full-length cDNA of the human ropporin gene was subcloned into the pQE30 vector and transformed into competent Escherichia coli (E.coli) JM109 cells. After transformed E.coli was induced using IPTG (isopropyl β-D-1-thiogalactopyranoside), human recombinant ropporin protein was extracted, purified by Nickel sepharose affinity chromatography, and verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Rabbits were immunized with the purified protein to prepare antisera. The specificity of antisera was determined by Western blot.

RESULTS: SDS-PAGE analysis showed that a protein with similar molecular weight to mouse popporin protein was purified from transformed E.coli. Western blot using anti-His tag monoclonal antibody showed that the prepared protein contained a His-tag. Polyclonal antisera were successfully generated by immunization of rabbits with human recombinant ropporin protein. The titers of antisera were more than 1:512000. Western blot analysis confirmed the specificity of the antisera obtained.

CONCLUSION: Human recombinant ropporin protein was successfully prepared using a prokaryotic expression system, and its rabbit polyclonal antisera were also successfully generated. The antisera obtained can be used to detect the expression of ropporin protein in various types of tumors and investigate its role in malignant processes.