Abstract
Recently, there has been a growing interest in the importance of stem cells (SCs) in the development/progression of gastric neoplasms. In this study, we performed a comprehensive analysis of different populations of bone-marrow-derived stem cells (BMSCs) in patients with various types of gastric malignancies, including gastric cancer, gastrointestinal stromal tumors (GISTs), neuroendocrine neoplasms (NENs), and lymphomas. We found significantly lower numbers of circulating Lin-/CD45 +/ CD133 + hematopoietic stem/progenitor cells (HSPCs), and intensified peripheral trafficking of both Lin-/CD45-/CXCR4+/CD34+/CD133+ very small embryonic/epiblast-like stem cells (VSELs) and CD105 + /STRO-1 +/ CD45- mesenchymal SCs (MSCs) in patients with gastric cancer, but not in those with other types of gastric neoplasms. No significant differences in the absolute numbers of circulating CD34 +/ KDR +/ CD31 +/ CD45- endothelial progenitor cells (EPCs) were observed between the groups. This abnormal balance in the peripheral trafficking of BMSCs in patients with gastric cancer was neither associated with clinical stage of the disease nor with systemic levels of stromal-derived factor-1 (SDF-1), as these were comparable to the values observed in control individuals. Interestingly, the absolute numbers of circulating BMSCs correlated with the concentrations of complement cascade-derived anaphylatoxins/molecules (mainly C5b-9/membrane attack complex-MAC) and sphingosine-1-phosphate (S1P). In summary, our translational study revealed that abnormal peripheral trafficking of BMSCs occurs in patients with gastric cancer, but not in those with other types of gastric neoplasms. Further, our findings indicate that highlighted complement cascade-derived molecules and S1P, but not SDF-1, are significant players associated with this phenomenon.