The effect of Eosinophil cationic protein (ECP) on Hodgkin lymphoma cell lines
2011 (English)In: Experimental Hematology, ISSN 0301-472X, E-ISSN 1873-2399, Vol. 39, no 8, 850-858 p.Article in journal (Refereed) Published
Background In classical Hodgkin lymphoma (HL), many eosinophils in tumour tissue indicate poor prognosis, probably caused by stimulation of the tumour cells, the Hodgkin Reed Sternberg (HRS) cells. However, eosinophils are primarily known for their role in innate immunity, where one function is to secrete the toxic substances eosinophil cationic protein (ECP), and eosinophil protein X (EPX). The aim of this study was to investigate the effects of ECP on HRS cells in vitro.
Method The fluorometric microculture cytotoxicity-assay (FMCA) measured survival index (SI) of cells from the HL cell lines HDLM-2, KMH2, and L428 after incubation with ECP or EPX. The gene products of a coding ECP polymorphism, ECP97arg and ECP97thr, and ECPs, with different levels of glycosylation were investigated. Flow cytometry was used to monitor the effects of ECP on markers of cell death.
Results A concentration dependent reduction of SI was seen after ECP treatment. For the B-cell derived cell lines, KMH2 and L428, ECP was cytotoxic with a dose response relationship similar to a previously investigated small-cell lung cancer cell-line. In contrast, for HDLM-2, which is a cell line of T-cell origin, the cytotoxicity was even more pronounced at the lowest concentrations tested, and then reached a plateau at about 0.018µM. At a concentration of 0.14µM of ECP, an SI of 71%±1.9 was recorded for HDLM-2, which did not accentuate despite higher concentrations of ECP. ECP97arg and ECP97thr displayed similar cytotoxicity, and the level of glycosylation did not affect cytotoxicity for HDLM-2, in contrast to the small-cell lung cancer cell-line. For EPX, no or very limited reduction in SI was seen, compared to ECP (p<0.001). The majority of cells that died from ECP (the HDLM-2 cell line) were PI positive, and only a few were annexin V positive.
Conclusions ECP is cytotoxic for HRS cells, but heterogeneity between cell lines was seen. The two cell lines of B-cell origin, KMH2 and L428, were sensitive to high ECP concentrations, but for HDLM-2, of T-cell origin, the cytotoxicity reached a plateau at higher concentrations. Thus, even at presumably high concentrations, ECP can be present around HRS cells without eradicating all cells.
Place, publisher, year, edition, pages
2011. Vol. 39, no 8, 850-858 p.
Hodgkin lymphoma, Eosinophil cationic protein, cytotoxicity, HDLM-2, eosinophils
Hematology Cancer and Oncology
Research subject Oncology
IdentifiersURN: urn:nbn:se:uu:diva-100590DOI: 10.1016/j.exphem.2011.05.006ISI: 000293801600005PubMedID: 21679745OAI: oai:DiVA.org:uu-100590DiVA: diva2:210605
First two authors contributed equally.2009-04-022009-04-022014-08-15Bibliographically approved