Combined affinity labelling and mass spectrometry analysis of differential cell surface protein expression in normal and prostate cancer cells

Abstract

Differences in the expression of cell surface proteins between a normal prostate epithelial (1542-NP2TX) and a prostate cancer cell line (1542-CP3TX) derived from the same patient were investigated. A combination of affinity chromatographic purification of biotin-tagged surface proteins with mass spectrometry analysis identified 26 integral membrane proteins and 14 peripheral surface proteins. The findings confirm earlier reports of altered expression in prostate cancer for several cell surface proteins, including ALCAM/CD166, the Ephrin type A receptor, EGFR and the prostaglandin F2 receptor regulatory protein. In addition, several novel findings of differential expression were made, including the voltagedependent anion selective channel proteins Porin 1 and 2, ecto-5 0 -nucleotidase (CD73) and Scavenger receptor B1. Cell surface protein expression changed both qualitatively and quantitatively when the cells were grown in the presence of either or both interferon INFa and INFc. Costimulation with type I and II interferons had additive or synergistic effects on the membrane density of several, mainly peripherally attached surface proteins. Concerted upregulation of surface exposed antigens may be of benefit in immuno-adjuvant-based treatment of interferon-responsive prostate cancer. In conclusion, this study demonstrates that differences in the expression of membrane proteins between normal and prostate cancer cells are reproducibly detectable following vectorial labelling with biotin, and that detailed analysis of extracellular-induced surface changes can be achieved by combining surfacespecific labelling with high-resolution two-dimensional gel electrophoresis and mass spectrometry.

Ecto-5′-nucleotidase expression is associated with the progression of renal cell carcinoma

“…Previous studies have revealed that CD73 is applicable as a cell-surface marker of malignant tumors, including those in bladder cancer (22), leukemia (23), glioma (24), melanoma (25), and ovarian (26), colon, breast (7,24,(27)(28)(29), thyroid (30), esophageal (31) and prostate cancers (32). However, to the best of our knowledge, the present study is the first to report that CD73 may also be a biomarker for clear cell RCC.…”

A2B adenosine receptor blockade inhibits growth of prostate cancer cells

“…In addition to the high expression level of the A 2B AR, P2Y 1 receptors [4], which are activated by endogenous adenine nucleotides, and ectonucleotidases CD39 and CD73 [19], which together degrade adenine nucleotides to produce adenosine, are also abundantly expressed in prostate cancer cells. Stagg et al [20] recently reported that CD73 deficiency suppressed prostate tumorigenesis in a mouse transgenic model of prostate cancer.…”

CD73-Deficient Mice Are Resistant to Carcinogenesis

“…Previous studies suggested that CD73 is associated with malignant transformation of prostate epithelial cells (20). TRAMP transgenic mice develop mild to severe prostate hyperplasia by 12 weeks of age and by 24 weeks of age, approximately 100% of male mice have poorly differentiated and invasive adenocarcinomas (18).…”

“…Mean prostate weight AE SEM at various ages (13,20, and 25 weeks) were calculated and probability of significance determined using a Mann-Whitney rank-sum U test.…”