Expression of plasma cell markers in colon cancer and lung adenocarcinoma

Certain clusters of differentiation that are markers of plasma cells (CD38 and CD138) can be expressed not only on plasma cells infiltrating the tumor and its microenvironment, but also on the tumor cells themselves and in the stroma of malignant neoplasms. The literature is divided on the expression of the proteoglycan CD138 (syndecan-1), which can be detected on the cells and structures of colon cancer and lung adenocarcinoma. Most publications claim that this proteoglycan delays tumor development, and that its loss is associated with epithelial-mesenchymal transition, decreased in the degree of cancer differentiation, and an unfavorable prognosis for patients. At the same time, there are also directly contradictory observations, testifying that patients with high levels of syndecan-1 have a poor prognosis, suppression of its expression weakens the invasive capacity of cultured tumor cells, inhibits tumor growth and metastasis. Some human cell lines and tissue samples of lung adenocarcinoma have increased expression of the characteristic plasma cell differentiation cluster CD38, which, according to the general opinion of researchers, is associated with a poor prognosis for patients. Such marked inconsistency in publications may serve as evidence that the issue of plasma cell marker expression in malignant tissues is advisable to study in more detail and more widely. Only a comprehensive approach to this problem can lead to significant results in the study of the fundamental mechanisms of adhesion and functioning of tumor cells, which may have not only theoretical but also practical significance due to the possibility of influencing the pathogenetic mechanisms of cancer progression.