Transcription of cytokeratins 8, 18, and 19 in bone marrow and limited expression of cytokeratins 7 and 20 by carcinoma cells: Inherent limitations for RT-PCR in the detection of isolated tumor cells

Citation
A. Dimmler et al., Transcription of cytokeratins 8, 18, and 19 in bone marrow and limited expression of cytokeratins 7 and 20 by carcinoma cells: Inherent limitations for RT-PCR in the detection of isolated tumor cells, LAB INV, 81(10), 2001, pp. 1351-1361
Citations number
43
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Medical Research General Topics
Journal title
LABORATORY INVESTIGATION
ISSN journal
0023-6837 → ACNP
Volume
81
Issue
10
Year of publication
2001
Pages
1351 - 1361
Database
ISI
SICI code
0023-6837(200110)81:10<1351:TOC81A>2.0.ZU;2-A
Abstract
The suitability of "real-time" quantitative reverse transcriptase polymeras e chain reaction (RT-PCR) for the detection of isolated carcinoma cells in bone marrow was investigated by evaluating the expression of cytokeratin (C K)7, CK8, CK18, CK19, and CK20 in 17 gastrointestinal cancer cell lines, 64 control bone marrow specimens from noncancer patients, and 30 bone marrow specimens from patients with gastric or colorectal cancer. RT-PCR products for CK8 and CK18 were detected in all cancer cell lines, but only 16, 5, an d 11 cell lines provided evidence for CK19, CK7, and CK20 transcription. Va riable numbers of bone marrow specimens from noncancer patients demonstrate d background transcription of CK8 (78.1%), CK18 (95.3%), CK19 (35.9%), CK20 (29.6%), and CK7 (16.7%). Maximal background transcription for CK8, CK18, and CK19 ranged from 52.2 to 56.1 copies/10(3) copies g lyceraldehyde-3-pho sphate dehydrogenase (GAPDH), the corresponding values of 0.06 and 0.76 cop ies for CK7 and CK20 being distinctly lower. When maximal background values were used as a threshold value to define positivity in tumor cell dilution experiments, sensitivity levels of one tumor cell in 10(4) bone marrow cel ls were determined for CK7 and CK20 RT-PCR assays. Maximal background expre ssion values of the different CKs as obtained in the control series were ex ceeded once (CK20), twice (CK18 and CK19), and 18 times (CK7) in bone marro w specimens from cancer patients, with none of these specimens exceeding th e maximal background expression value of CK8. We conclude that RT-PCR for C K8, CK18, and CK19 cannot be recommended for the detection of isolated tumo r cells in bone marrow of cancer patients. On the other side, the limited n umber of gastric and colorectal cancer cell lines expressing CK7 and CK20 i ndicates that assay sensitivity for these CKs might be limited because of t heir selective expression by carcinoma cells.