Combination DLL4 with Jagged1-siRNA can enhance inhibition of the proliferation and invasiveness activity of human gastric carcinoma by Notch1/VEGF pathway.
OBJECTIVE
To evaluate the effects of adenovirus- mediated gene transfer of DLL4 and Jagged1 siRNA on proliferation and invasion of SGC7901 cells by Notch/ VEGFR pathway.


METHODS
Plasmid of DLL4 and Jagged1 siRNA were constructed and transfected into SGC7901 cells. siRNA and endostatin (VEGF inhibitor) were designed as the control group. The mRNA and protein expressions of DLL4 and Jagged1 were respectively detected with RT-PCR and western blotting. In order to find out the changes of proliferation and invasion power of SGC7901 cell lines, we analyzed the data by MTT, Boyden chamber and evaluated apoptosis of cell with flow cytometry. We treated BALB/C nude mice with DLL4 and Jagged1-siRNA, and tumor control rate (%) in nude mice was calculated.


RESULTS
DLL4 and Jagged1 siRNA transfections specifically down-regulated the corresponding mRNA and protein levels in SGC7901 cells. The experiment of permeated artificial basal membrane showed that the invasion power of SGC7901 cell lines were on the decline after treatment of Ad-DLL4- Jagged1-siRNA (12.23±3.12 vs. 78.38±17.38, p<0.05). The values of 490nm wavelength light absorption were different in the five groups. The number of alive cells in the group of DLL4-Jagged1-siRNA was lower than others in the 6th d (0.77±0.01 vs. 3.00±0.11 p<0.05). The apoptosis rate of transfected DLL4 and Jagged1 group with FACS were 18.07%±0.98±1.78 and there were significant differences between treated and control groups (18.07%±0.98 vs. 1.08%±0.23, p<0.01). The tumor transplantation experiment in BALB/C nude mice showed that intratumoral injection of DLL4 and Jagged1 siRNA could inhibit tumor growth.


CONCLUSIONS
DLL4 and Jagged1 siRNA gene therapy mediated by adenovirus may be useful for inhibiting growth and invasion of SGC7901 through a Notch/VEGFR pathway. These results provided a novel therapeutic target in preventing gastric cancer cell invasion and metastasis.
Department of Gastrointestinal Surgery, Wuhan University, Wuhan, China. sunhuawenmail@gmail.com
Hua-Wen
HW
Sun
Chong
C
Wu
Hai-Yan
HY
Tan
Qiu-Shuang
QS
Wang
D048868:Adaptor Proteins, Signal Transducing; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D051881:Receptor, Notch1 / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D013997:Time Factors; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays
D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; C497761:NOTCH1 protein, human; D012333:RNA, Messenger; D051881:Receptor, Notch1; D000072099:Serrate-Jagged Proteins; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A