The establishment of supramolecular immunobead real-time PCR and the             identification of Cox-2 as a metastasis-related marker in colorectal carcinoma.
Cyclooxygenase-2 (Cox-2) is an inducible enzyme that converts arachidonic             acid to prostaglandins, and it is hypothesized to induce carcinogenesis and metastasis             in colorectal cancer. Our previous data also indicated that a higher expression             level of Cox-2 was correlated with colorectal cancer metastasis. The Cox-2 protein             was detected in the glandular cavity of colorectal cancer and the surrounding             interstitial tissues. The usefulness of the Cox-2 gene as a gene therapy target             and diagnostic marker remains unknown. In this study, a method using immuno-PCR             and real-time PCR followed by supramolecular immunobead real-time PCR was established             and used to detect the expression of Cox-2 in serum samples of nude mice with             colorectal carcinoma. In addition, we established a Cox-2 gene stable knockdown             colorectal cell line (SW480-EGFP-Cox-2 shRNA) using lentiviral vector-mediated             RNA interference (RNAi) technology and established an imageable colorectal cancer             metastasis mouse model. We found that the proliferation, invasion and tumorigenesis             of SW480-EGFP-Cox-2 shRNA cells were attenuated compared with SW480 cells. In vivo             experiments also demonstrated that angiogenesis in the Cox-2 knockdown colorectal             cancer cells was decreased. The whole body optical imaging revealed that the SW480-EGFP-Cox-2             shRNA cells had an abrogated ability to develop metastases in the lymph nodes,             lungs or liver in vivo. The improved immunobead PCR assay detected significantly             lower Cox-2 protein levels in the serum samples of the SW480-EGFP-Cox-2 shRNA             group compared with those of the SW480-EGFP-Cox-2-Ctrl shRNA group. In conclusion,             our results indicated that the knockdown of Cox-2 expression suppressed the proliferation             and invasion of colorectal cancer cells both in vitro and in vivo. This study             also demonstrated that silencing Cox-2 in vivo reduced the metastastic potential             of colorectal cancer. Thus, Cox-2 is a promising marker for the diagnosis of colorectal             metastasis and a potential therapeutic target for colorectal cancer.
Department of Pathology, Nanfang Hospital, and Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, PR China.
Zu-Guo
ZG
Li
Xiao-Yan
XY
Wang
Jian-Lan
JL
Chang
Wei-Bing
WB
Xie
Teng-Fei
TF
Liu
Qing-Ling
QL
Zhang
Yong-Jian
YJ
Deng
Yan-Qing
YQ
Ding
D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D002277:Carcinoma / Q000097:blood / Q000201:enzymology / Q000556:secondary*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000097:blood / Q000201:enzymology / Q000473:pathology*; D051546:Cyclooxygenase 2 / Q000097:blood* / Q000235:genetics; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D007118:Immunoassay; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D034622:RNA Interference; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D051598:Whole Body Imaging
D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human