Molecular characterization of congenital mesoblastic nephroma and its distinction from Wilms tumor.
BACKGROUND
Congenital mesoblastic nephroma (CMN) is a rare tumor of the neonatal kidney. It was once thought to be a variant of Wilms tumor that also arises from primitive renal cells.


METHODS
Molecular characteristics of two CMN were studied to clarify their potential relationship to Wilms tumors. Patterns of gene expression were assayed by Northern blot hybridization analysis. Tumors were tested for loss of heterozygosity (LOH) at chromosomes 11p13 and 11p15 using Southern blot analysis.


RESULTS
The CMN, like Wilms tumors, demonstrated high-level expression of insulin-like growth factor II. Unlike Wilms tumors, however, the CMN expressed neither the N-myc oncogene nor the putative Wilms tumor suppressor gene, WT1. Using a panel of probes spanning 11p13 and 11p15, no LOH was detected in the CMN, nor was there evidence of deletion or rearrangements of WT1.


CONCLUSIONS
Although Wilms tumor and CMN both arise from the developing kidney, molecular characterization suggests that different factors are involved in the pathogenesis of these two tumors.
Tomlinson
G E
GE
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235-9063.
Argyle
J C
JC
Velasco
S
S
Nisen
P D
PD
D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13; D004273:DNA, Neoplasm / Q000235:genetics; D015870:Gene Expression; D016162:Genes, Wilms Tumor / Q000235:genetics*; D016259:Genes, myc / Q000235:genetics; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D007680:Kidney Neoplasms / Q000151:congenital* / Q000235:genetics*; D008297:Male; D010641:Phenotype; D009396:Wilms Tumor / Q000151:congenital* / Q000235:genetics*
D004273:DNA, Neoplasm; D007335:Insulin-Like Growth Factor II