Characterization of human prostate and breast cancer cell lines for experimental T cell-based immunotherapy.

Background: In order to develop experimental immunotherapy for prostate and breast cancer it is of outmost importance to have representative target cell lines that through human leukocyte antigen (HLA) class I molecules present relevant levels of peptides from tumor-associated antigens for cytotoxic T lymphocyte (CTL) recognition.

Methods: We sequenced the HLA-A and HLA-B loci of eight commonly used prostate and breast cancer cell lines and analyzed the surface expression of HLA-ABC, HLA-DR, CD40, CD80, CD86, and CD54 by flow cytometry. We also analyzed the cell lines for mRNA expression from 25 genes reported to be specifically or preferentially expressed by prostate cells.

Results: Among the analyzed cell lines we found that LNCaP, PC-346C and MCF-7 are HLA-A*0201 positive. However, the HLA-A2 expression level is low and only MCF-7 upregulates HLA-A2 in response to IFN-gamma stimulation. MCF-7 also expresses high levels of CD54, which further improve its value as a CTL target cell line. On the other hand, LNCaP and PC-346C express 25 and 23 out of 25 prostate-related genes, respectively, while MCF-7 expresses 16 out of 25 genes.

Conclusions: None of the analyzed prostate cancer cell lines are optimal CTL target cells. However, MCF-7 could in many cases be used as a complement to HLA-A*0201 positive prostate cancer cells. The LNCaP and PC-346C cell lines are rich sources of prostate-related antigens that may be valuable for cancer vaccine development.