Gene expression profiling of mesoblastic nephroma and Wilms tumors--comparison and clinical implications.
OBJECTIVE
To better understand the molecular mechanisms in the tumorigenesis and progression of mesoblastic nephroma (MN), we studied its gene expression profiles. MN is the most common tumor of the neonatal kidney. It occurs in a younger age group than the Wilms tumor (WT). To date, very little is known about the etiology and pathogenesis of MN.


METHODS
Using microarrays containing 22,943 cDNA, we analyzed the expression profiles of MN and compared its expression profiles with those of several other types of kidney tumors, including WT.


RESULTS
MN has a distinct molecular signature that clusters close to the WT, suggesting that both types of tumor share some similarity in gene expression and biology. When comparing the two profiles closely, we identified a number of genes that are commonly upregulated in both tumors, including insulin-like growth factor 2, thrombospondin 4, and mesenchyme homeo box 1. We also identified a set of genes that distinguish MN from WT, some of which may underlie the difference in their behaviors and can be used as diagnostic markers. Among this group of genes, topoisomerase II-alpha, highly expressed in WTs, is not overexpressed in MN. Immunohistochemical staining of topoisomerase II-alpha in additional cases of WTs and MNs confirmed this distinction further.


CONCLUSIONS
The results of our study demonstrated that MN has a distinct gene expression profile and that some of the newly identified genes can be potentially used as novel diagnostic markers.
Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Jun
J
Sugimura
Ximing J
XJ
Yang
Maria S
MS
Tretiakova
Masayuki
M
Takahashi
Eric J
EJ
Kort
Barbara
B
Fulton
Tomoaki
T
Fujioka
Nicholas J
NJ
Vogelzang
Bin Tean
BT
Teh
D000951:Antigens, Neoplasm; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007231:Infant, Newborn; D007680:Kidney Neoplasms / Q000235:genetics* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D018201:Nephroma, Mesoblastic / Q000235:genetics* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D009396:Wilms Tumor / Q000235:genetics* / Q000378:metabolism
D000951:Antigens, Neoplasm; D018076:DNA, Complementary; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D004250:DNA Topoisomerases, Type II