Recognizing genes differentially regulated in vitro by the multiple endocrine neoplasia type 1 (MEN1) gene, using RNA interference and oligonucleotide microarrays.
BACKGROUND
Data on downstream effects of MEN1 gene inactivation is scarce. In an effort to identify genes regulated by MEN1, we designed a silencing experiment in a human endocrine pancreatic tumor cell line (BON1).


METHODS
By using RNA interference, MEN1 mRNA expression was knocked-down by >85%. Gene expression was assessed by oligonucleotide microarrays and compared to expression in nonsilenced controls. We also investigated if genes were differentially expressed in 6 malignant endocrine pancreatic tumors (EPTs) with homozygous MEN1 inactivation compared to 2 without MEN1 gene alterations.


RESULTS
Using a cut-off of > or =2 times, 66 genes were found to be upregulated, and 22 were downregulated in the MEN1-silenced clones. We corroborated the microarray findings by performing quantitative-PCR on the RNA from the silencing experiments for 7 of the 88 differentially regulated genes. Genes involved in endocrine cell fate determination, as well as genes known to be involved in NFkappaB, Notch, and Wnt signaling pathways, were among genes verified as differentially regulated in vitro.


CONCLUSIONS
The demonstration of pathways affected by silencing of MEN1 in vitro provides novel insight into neoplastic processes of potential importance in vivo, which warrants further study.
Stålberg
Peter
P
Department of Surgical Sciences, University Hospital, Uppsala, Sweden.
Santesson
Mårten
M
Ekeblad
Sara
S
Lejonklou
Margareta Halin
MH
Skogseid
Britt
B
D045744:Cell Line, Tumor; D004273:DNA, Neoplasm / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D052138:Genes, Neoplasm / Q000235:genetics* / Q000502:physiology; D006801:Humans; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism
D004273:DNA, Neoplasm; C105373:MEN1 protein, human; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D051880:Receptors, Notch; D051153:Wnt Proteins