SLAMF1/CD150 expression and topology in prostate and breast cancer cell lines.

Background: SLAMF1/CD150 receptor is aberrantly expressed in malignant hematopoietic cells compared to ubiquitous expression in their normal analogues. However, the data about CD150 expression and function outside the hematopoietic system are limited. The aim of this pilot study was to examine the profile of mRNA expression of CD150 isoforms and the protein topology in highly and low malignant breast (BC) and prostate cancer (PC) cell lines.

Materials and methods: The study was performed on BC T47D, MDA-MB-231, ВСС/Р and BC/ML cell lines and PC LNCap, Du-145 and PC-3 cell lines. The quantitative polymerase chain reaction was applied for study of CD150 isoforms mRNA expression and flow cytometry was used for determination of protein localization.

Results: Analyzed BC cell lines did not express CD150 on the cell surface membrane (csCD150^-), but more than 45% of cells were positive for CD150 cytoplasmic reaction (cyCD150⁺). The cyCD150 expression level in T47D cells of luminal BC subtype was higher than in basal BC cell lines MDA-MB-231, ВСС/Р and BC/ML. The PC cell lines expressed CD150 both on the cell surface and in cytoplasm. The highest number of csCD150⁺ and cyCD150⁺ cells was revealed in less aggressive androgen responsive, non-metastatic LNCap cell line. All studied BC and PC cell lines expressed mRNA of canonical transmembrane mCD150 and novel nCD150 isoforms but with different pattern of prevalence. Soluble CD150 isoform was revealed at the low level only in BCC/P BC cell line and LNCap, PC-3 PC cell lines.

Conclusions: We have shown that BC and PC cell lines differentially expressed multifunctional receptor CD150 at the mRNA and protein levels that may indicate its association with the degree of their malignancy.