title: Critical evaluation of real-time reverse transcriptase-polymerase chain reaction for the quantitative detection of cytokeratin 20 mRNA in colorectal cancer patients.
abstract: We evaluated the usefulness of cytokeratin 20 (CK20) mRNA expression in the quantitative detection of circulating tumor cells in the blood of patients with colorectal cancer (CRC). Blood samples from healthy volunteers (HVs; n = 37), patients with localized (n = 42) and metastatic colorectal cancer (n = 40), and patients with chronic inflammatory bowel disease (CID; n = 15) were examined. After immunomagnetic enrichment using microbeads against human epithelial antigen, total RNA was extracted, reverse transcribed, and analyzed by real-time reverse transcriptase-polymerase chain reaction using the LightCycler instrument. CK20 expression in peripheral blood was found in 46 of 82 (56%) patients with CRC, 8 of 37 (22%) HVs, and 9 of 15 (60%) patients with CID. Levels of CK20 mRNA were significantly higher in blood samples from CRC patients (median 681) than in blood samples from HVs (median 0) (P = 0.001), whereas no difference could be detected between patients with CRC and CID. Although the present technique could not distinguish CRC from CID, the method warrants further efforts to improve sample preparation and tumor cell enrichment, which may render real-time CK20 reverse transcriptase-polymerase chain reaction a feasible technique in identifying circulating tumor cells in peripheral blood of cancer patients.
authors.affiliation: Division of Clinical Oncology, Department of Internal Medicine, Medical University Graz, Avenbruggerplatz 15, A-8036 Graz, Austria. nadia.dandachi@meduni-graz.at
authors.forename: Nadia
authors.initials: N
authors.lastname: Dandachi
authors.forename: Marija
authors.initials: M
authors.lastname: Balic
authors.forename: Stefanie
authors.initials: S
authors.lastname: Stanzer
authors.forename: Michael
authors.initials: M
authors.lastname: Halm
authors.forename: Margit
authors.initials: M
authors.lastname: Resel
authors.forename: Thomas Anton
authors.initials: TA
authors.lastname: Hinterleitner
authors.forename: Hellmut
authors.initials: H
authors.lastname: Samonigg
authors.forename: Thomas
authors.initials: T
authors.lastname: Bauernhofer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D019073:HT29 Cells; D006262:Health; D006801:Humans; D011163:Hydroxymethylbilane Synthase / Q000235:genetics; D015212:Inflammatory Bowel Diseases / Q000235:genetics; D053554:Keratin-20; D007633:Keratins / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012372:ROC Curve; D012015:Reference Standards; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000592:standards*; D012680:Sensitivity and Specificity
chemical_list: C507499:KRT20 protein, human; D053554:Keratin-20; D012333:RNA, Messenger; D007633:Keratins; D011163:Hydroxymethylbilane Synthase