Profiling of nuclear extract proteins from human neuroblastoma cell lines: the search for fingerprints

Neuroblastoma (NB) commonly presents with advanced disease at diagnosis and is associated with poor survival. If identified early, however, survival is improved suggesting a benefit of early detection. The authors have used proteomics technology in an attempt to identify novel markers that permit early detection of NB and characterize its molecular makeup.

Three different human NB cell lines SK-N-AS, SK-N-DZ, and SK-N-FI were subjected to series of biochemical fractionation steps to extract nuclear proteins. These proteins were analyzed for differential expression by 2-dimensional polyacrylamide gel electrophoresis. Polypeptides of interest were subsequently identified by liquid chromatography-linked tandem mass spectrometry.

Multiple proteins were identified in these human NB cell lines including SET (a ubiquitous nuclear protein), stathmin (a cytosolic signal transduction protein), and grp94 (a heat shock protein). SET is a putative oncogene associated with the chromosomal translocation (6;9) leading to acute undifferentiated leukemia. Stathmin is an oncogene found in greater abundance in leukemic cells compared to nonleukemic cells. A total of 94-kDa glucose-regulated protein has been shown to be protective in human breast cancer cells in vitro and related with the occurrence, differentiation, and progression of human lung cancer. The first protein has not been previously associated with NB.

The identification of these 3 previously unrecognized cancer-related potential biomarkers in human NB cell lines may prove useful in developing diagnostic tests. The proteomic methodology of 2-dimensional polyacrylamide gel electrophoresis/mass spectrometry also provides an improved opportunity to understand the natural history of NB and develop novel chemotherapeutic agents for this prevalent childhood malignancy with a dismal outcome.