novH: differential expression in developing kidney and Wilm's tumors

Area of Science:

• Developmental Biology
• Oncology
• Molecular Genetics

Background:

• The human nov gene (novH) expression is altered in Wilms' tumors, inversely correlating with WT1 mRNA levels.
• novH is a known target of WT1 regulation, implying a role in nephrogenesis and Wilms' tumor development.

Purpose of the Study:

• To investigate the role of novH during normal kidney development and its expression patterns in Wilms' tumors.
• To determine if novH serves as a differentiation marker in renal and tumor tissues.

Main Methods:

• Analysis of novH protein and mRNA expression in normal kidney tissues during nephrogenesis.
• Examination of novH expression in various types of Wilms' tumors, including WAGR and DDS-associated cases.
• Correlation of novH expression with WT1 levels and specific mutations.

Main Results:

• novH protein is closely associated with glomerular podocyte differentiation in normal kidneys.
• Altered novH expression (mRNA and protein) is a consistent feature of Wilms' tumors.
• Highest novH expression was observed in WAGR-associated Wilms' tumors.
• novH protein is prominent in abnormal podocytes in Denys-Drash syndrome cases and adjacent to tumors.
• novH is expressed in tumor-derived striated muscle and cartilage, indicating a role in heterotypic differentiation.
• Absence or low WT1 levels correlate with higher novH expression.

Conclusions:

• novH functions as a marker for podocytic differentiation in the kidney.
• novH also serves as a marker for heterotypic mesenchymal differentiation within Wilms' tumors.
• WT1's transcriptional functions on novH depend on the specific mutation, influencing expression variability.