[Inhibition of mutant CD59 protein on proliferation of ovarian cancer A2780 cells].
OBJECTIVE
Overexpression of CD59 is found in a variety of solid tumor cells, which is related to the uncontrolled cell growth of tumors and malignant transformation. This study was to investigate the anti-complement capacity of mutant CD59 (at the W40 site), and its inhibitory effect on ovarian cancer cell line A2780 in combination with lip polysaccharide (LPS).


METHODS
The pIRES-WTCD59 plasmid and the pIRES-M1CD59 plasmid were transfected into A2780 cells. Stable expression clones were selected by G418. CD59 gene and protein were successfully expressed in A2780 cells. The anti-complement capacity of wide-type CD59 and mutant CD59, and the effect of combination treatment with mutant CD59 protein and LPS on A2780 cells were both detected by MTT assay.


RESULTS
Stable expressions of wild type and mutant CD59 were established in A2780 cells. Mutant CD59 lost its inhibition of human complements compared with wide-type CD59 (P<0.05), but this was not significantly different compared with the control group. After incubation with 5 mg/L LPS for half an hour, the inhibition rates were (26.9+/-2.95)%, (36.3+/-4.87)%, (29.6+/-3.16)% in A2780 cells transfected with wide-type CD59, mutant CD59, and without transfection respectively (P<0.05).


CONCLUSIONS
The W40 site is important to the activity of human CD59 protein. Inhibition of the W40 site may be a potential method to increase the complement capacity and promote the anti-proliferation activity of LPS.
Li
Jian-Min
JM
Department of Immunology, Medical College of Qingdao University, Qingdao, Shandong, 266071, PR China.
Gao
Mei-Hua
MH
Zhang
Bei
B
D018957:CD59 Antigens / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003165:Complement System Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology*; D010957:Plasmids; D012333:RNA, Messenger / Q000378:metabolism; D014162:Transfection
D018957:CD59 Antigens; D008070:Lipopolysaccharides; D050505:Mutant Proteins; D012333:RNA, Messenger; C051590:CD59 protein, human; D003165:Complement System Proteins