Colon-derived liver metastasis, colorectal carcinoma, and hepatocellular carcinoma can be discriminated by the Ca(2+)-binding proteins S100A6 and S100A11.
BACKGROUND
It is unknown, on the proteomic level, whether the protein patterns of tumors change during metastasis or whether markers are present that allow metastases to be allocated to a specific tumor entity. The latter is of clinical interest if the primary tumor is not known.


RESULTS
In this study, tissue from colon-derived liver metastases (n = 17) were classified, laser-microdissected, and analysed by ProteinChip arrays (SELDI). The resulting spectra were compared with data for primary colorectal (CRC) and hepatocellular carcinomas (HCC) from our former studies. Of 49 signals differentially expressed in primary HCC, primary CRC, and liver metastases, two were identified by immunodepletion as S100A6 and S100A11. Both proteins were precisely localized immunohistochemically in cells. S100A6 and S100A11 can discriminate significantly between the two primary tumor entities, CRC and HCC, whereas S100A6 allows the discrimination of metastases and HCC.


CONCLUSIONS
Both identified proteins can be used to discriminate different tumor entities. Specific markers or proteomic patterns for the metastases of different primary cancers will allow us to determine the biological characteristics of metastasis in general. It is unknown how the protein patterns of tumors change during metastasis or whether markers are present that allow metastases to be allocated to a specific tumor entity. The latter is of clinical interest if the primary tumor is not known.
Melle
Christian
C
Core Unit Chip Application, Institute of Human Genetics and Anthropology, Medical Faculty at the Friedrich Schiller University, Jena, Germany.
Ernst
Günther
G
Schimmel
Bettina
B
Bleul
Annett
A
von Eggeling
Ferdinand
F
D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism*; D002277:Carcinoma / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D018797:Cell Cycle Proteins / Q000032:analysis / Q000378:metabolism*; D045744:Cell Line, Tumor; D003106:Colon / Q000473:pathology; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary*; D020543:Proteome; D000075383:S100 Calcium Binding Protein A6; D009418:S100 Proteins / Q000032:analysis / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D020543:Proteome; D000075383:S100 Calcium Binding Protein A6; D009418:S100 Proteins; C055351:S100A6 protein, human; C072337:S100A11 protein, human