Immunophenotype of isolated tumour cells in the blood, bone marrow and lymph nodes of patients with gastric cancer.

Immunophenotype of isolated (disseminated or circulating) tumour cells (ITC) in the blood, bone marrow and lymph nodes were studied in patients with gastric cancer. Coexpression of metalloproteinases inducer (EMMPRIN), chemokine receptors (CCR6, CXCR4) and adhesion molecules (Ep-CAM, CD44) was determined on cytokeratin positive (CK+) cells in CD45- cell population sorted out from the blood and/or bone marrow. Eight cytospin samples of blood and 69 samples of bone marrow containing CK+ cells from patients with gastric cancer were included into study. Expression of EMMPRIN and CCR6 were noted in a half of CK+ samples (of blood/bone marrow) whereas the expression of CXCR4 and Ep-CAM was much lower. Analysis of paired data of these determinants expression on CK+ cells showed no association between them. Expression of EMMPRIN, Ep-CAM, CCR6, CCR7, CXCR1, and CXCR4 on ITC in lymph nodes was determined by flow cytometry. In 18 lymph nodes (out of 36 assayed) CK+ cells were found. The expression of CCR6 and Ep-CAM on CK+ cells was observed in almost all studied lymph nodes, CXCR1--in half of them. The expression of EMMPRIN and CCR7 cells was lower. These results suggest that ITC of gastric cancer express variably several molecules that may be involved in metastasis formation.