Stable suppression of HER-2 gene expression using siRNA increases the lysis of human ovarian carcinoma cells mediated by NK-92 cell line.
The overexpression and amplification of HER-2 gene is associated with the malignant biological behavior of ovarian carcinoma and these tumor cells expressing elevated levels of HER-2 appear to be resistant to the cytolysis of NK-92. In this study, we analyzed the cytolysis effects of NK-92 on human ovarian carcinoma cells (SK-OV-3) after inhibition the expression of HER-2 mRNA by siRNA. Human ovarian carcinoma cell line SK-OV-3 was transfected with siRNA-hairpin expression retroviral vector (HER-2/siRNA) designed to target HER-2 mRNA. A negative control was established utilizing a vector lacking the antisense component (HER-2/negative). The expression levels of HER-2 gene in SK-OV-3/siRNA, and SK-OV-3/negative cell lines were evaluated by semi-quantitative RT-PCR and immunohistochemistry. The growth and the early apoptosis of these cells were assayed by MTT and flow cytometry, respectively. The cytotoxicity of NK-92 against target cells was investigated by LDH. SK-OV-3/siRNA and SK-OV-3 cells were injected subcutaneously into BALB/c nude mice respectively and NK-92 cells were intraperitoneally injected to examine the anti-tumor activity in vivo. The stable cell line (SK-OV-3/siRNA) with a persistent silence of HER-2 was established. The inhibited expression of HER-2 gene was exhibited by semi-quantitative RT-PCR and immunohistochemistry. The suppressed proliferation and the elicitation of early apoptosis cells were observed in SK-OV-3/siRNA cell line. NK-92 cell line can efficiently lyse the SK-OV-3/siRNA cells in vitro and significantly inhibit the growth of tumors xenografted with SK-OV-3/siRNA cells. Suppression of HER-2 gene expression using siRNA combined treatment of NK-92 presents a new strategy for NK-92 biological treatment on the HER-2 expression epithelial tumors.
Zhou
Ying
Y
Anhui Province Key Laboratory of Molecular Medicine, Hefei 230001, P.R. China.
Cheng
Zhixiang
Z
Zhu
Huaiping
H
Feng
Dingqing
D
Zhao
Weidong
W
Ling
Bin
B
Wei
Haiming
H
Tian
Zhigang
Z
D000818:Animals; D017209:Apoptosis; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010051:Ovarian Neoplasms / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*
D034741:RNA, Small Interfering; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human; C524056:Erbb2 protein, mouse