Detection of cancer cells disseminated in bone marrow using real-time quantitative RT-PCR of CEA, CK19, and CK20 mRNA in patients with gastric cancer.
BACKGROUND
To determine the significance of bone marrow disseminated tumor cells in gastric cancer, we investigated the mRNA expression levels of carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and cytokeratin 20 (CK20) using the real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR).


METHODS
Bone marrow samples were aspirated from the sternum at the time of surgery in 65 patients with resectable gastric cancer. Total RNA was extracted from bone marrow; and the expression levels of CEA, CK19, and CK20 mRNA were determined by RQ-PCR using an ABI PRISM 7000 and quantified against the GAPDH mRNA level.


RESULTS
The detection limits of these genes were determined in the gastric cancer cell line MKN-45 and the colon cancer cell line C-1, which had been serially diluted in peripheral blood mononuclear cells (PBMCs). A rate of 1 cancer cell/million PBMCs was obtained by detecting CEA and CK19 mRNA in MKN-45 and by detecting CK20 mRNA in C-1. In the clinical samples, only 1 of the 65 gastric cancer patients (1.5%) who had stage IV disease was positive for CEA, CK19, and CK20 mRNA; none of CEA, CK19, or CK20 mRNA was positive in the remaining 64 patients. No significant correlation was observed between disseminated cancer cells in bone marrow and clinicopathological features, including simultaneous or metachronous hepatic metastasis and patient survival.


CONCLUSIONS
The incidence of disseminated cancer cells in bone marrow in our study appears low, unlike that in previous reports. The significance of disseminated cancer cells in bone marrow may also be quite low in gastric cancer.
Fujita
Yasuki
Y
Department of Surgery 1, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
Terashima
Masanori
M
Hoshino
Yutaka
Y
Ohtani
Satoshi
S
Kashimura
Seigo
S
Kanzaki
Norio
N
Osuka
Fumihiko
F
Kogure
Michihiko
M
Gotoh
Mitsukazu
M
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000231:Adenocarcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D019046:Bone Marrow Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000556:secondary; D002272:Carcinoembryonic Antigen / Q000235:genetics* / Q000378:metabolism; D018279:Carcinoma, Signet Ring Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D053539:Keratin-19 / Q000235:genetics* / Q000378:metabolism; D053554:Keratin-20 / Q000235:genetics / Q000378:metabolism; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000556:secondary; D012333:RNA, Messenger / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; C507499:KRT20 protein, human; D053539:Keratin-19; D053554:Keratin-20; D012333:RNA, Messenger; D012334:RNA, Neoplasm