[Detection of cytokeratin20 mRNA in peripheral blood from colonic cancer patients by fluorescence quantitative polymerase chain reaction].
OBJECTIVE
To investigate the expression level of cytokeratin20 mRNA (CK20 mRNA) of cancer cells in peripheral blood from colorectal cancer patients, detected by fluorescence quantitative polymerase chain reaction (FQ-PCR), and to evaluate its clinical value.


METHODS
To systemically study the reproducibility, quantitative range and amplification efficiency of CK20 mRNA detection by FQ-PCR, analyze and compare the result consistency with conventional RT-PCR and immunohistochemistry, separately. The expression level of CK20 mRNA of cancer cells in peripheral blood was examined in 136 colorectal cancer cases with or without hepatic metastasis.


RESULTS
The within-run and between-run CV of FQ-PCR to assay CK20 mRNA were 3.6% and 5.3%, respectively, quantitative range was from 10(3) copies/ml to 10(8) copies/ml and amplification efficiency was 87.4%. Comparing with traditional RT-PCR and immunohistochemistry, the Kappa value was 0.87 and 0.83, respectively. The expression level of CK20 mRNA of cancer cells in peripheral blood from colorectal cancer patients was (3.52 +/- 1.47) x 10(4) copies/ml, and the expression positive rate was 48.5%. None was found among the 75 cases in the control group. The positive rate of CK20 mRNA of cancer cells in peripheral blood was 9.5%, 25.0%, 48.8% and 87.5% in the patients at Dukes stage A, B, C and D, respectively (P < 0.05). The positive rate of CK20 mRNA was 87.5% in patients with hepatic metastasis and 32.3% in patients without hepatic metastasis (P < 0.05). CK20 mRNA showed a tendency to decline in 35 cases of colorectal cancer within the 1st, 3rd and 5th week after operation. There was no difference among the data of pre-operation cases and on the 1st, 3rd week (P > 0.05), but a significant difference between pre-operation and the 5th week (P < 0.05).


CONCLUSIONS
FQ-PCR is a rapid and sensitive method for quantitating CK20 mRNA. The expression of CK20 mRNA of cancer cells in peripheral blood from colorectal cancer patients has a correlation with recurrence and metastasis of the tumors. Detection of CK20 mRNA is helpful to monitor hematogenous dissemination of colorectal cancers.
Wang
Zhong-cheng
ZC
Department of Clinical Laboratory, Chongqing Emergency Medical Center, Chongqing 400014, China. zgcgwg@163.com
Wang
Can
C
Zeng
Qing-gui
QG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D005260:Female; D005453:Fluorescence; D006801:Humans; D007150:Immunohistochemistry; D053554:Keratin-20 / Q000235:genetics / Q000378:metabolism*; D008113:Liver Neoplasms / Q000097:blood* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D012004:Rectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D053554:Keratin-20; D012333:RNA, Messenger