1. ¹Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
2. ²Oncology Unit, St Olavs Hospital HF, Trondheim, Norway
3. ³Department of Mathematical Sciences, Norwegian University of Science and Technology, Trondheim, Norway
4. ⁴Department of Food and Medical technology, Sør-Trøndelag University College, Trondheim, Norway

Correspondence: Dr E Hofsli, Oncology Unit, St Olavs University Hospital HF, Olav Kyrresgt. 17, N-7006 Trondheim, Norway. E-mails: eva.hofsli@stolav.no or eva.hofsli@ntnu.no

Received 27 June 2008; Accepted 21 July 2008; Published online 30 September 2008.

Abstract

Neuroendocrine tumours (NETs) comprise a heterogenous group of malignancies with an often unpredictable course, and with limited treatment options. Thus, new diagnostic, prognostic, and therapeutic markers are needed. To shed new lights into the biology of NETs, we have by cDNA transcript profiling, sought to identify genes that are either up- or downregulated in NE as compared with non-NE tumour cells. A panel of six NET and four non-NET cell lines were examined, and out of 12 743 genes examined, we studied in detail the 200 most significantly differentially expressed genes in the comparison. In addition to potential new diagnostic markers (NEFM, CLDN4, PEROX2), the results point to genes that may be involved in the tumorigenesis (BEX1, TMEPAI, FOSL1, RAB32), and in the processes of invasion, progression and metastasis (MME, STAT3, DCBLD2) of NETs. Verification by real time qRT–PCR showed a high degree of consistency to the microarray results. Furthermore, the protein expression of some of the genes were examined. The results of our study has opened a window to new areas of research, by uncovering new candidate genes and proteins to be further investigated in the search for new prognostic, predictive, and therapeutic markers in NETs.