Wilms tumor and the WT1 gene

Area of Science:

• Oncology
• Developmental Biology
• Genetics

Background:

• Wilms tumor (nephroblastoma) is a pediatric kidney cancer originating from embryonic renal precursors.
• The WT1 tumor suppressor gene, located at chromosome 11p13, is crucial for normal genitourinary development.
• WT1 mutations are found in hereditary and sporadic Wilms tumors, as well as other malignancies.

Purpose of the Study:

• To elucidate the role of the WT1 gene in Wilms tumorigenesis and normal genitourinary development.
• To investigate the functional differences between WT1 isoforms and their implications in cancer.
• To explore WT1's involvement in other cancers, including leukemia and desmoplastic small round cell tumor.

Main Methods:

• Positional cloning to identify the WT1 gene.
• Analysis of germline and somatic mutations in WT1.
• Study of WT1 expression patterns in developing kidneys and other tissues.
• Investigation of WT1 alternative splicing isoforms and their functions.
• Examination of WT1's role in mouse models (wt1-null mice).

Main Results:

• Germline WT1 mutations cause severe genitourinary abnormalities, underscoring its developmental importance.
• WT1 inactivation is observed in a subset of Wilms tumors and other cancers.
• Two major WT1 isoforms, (-KTS) and (+KTS), exhibit distinct functions in gene regulation and possibly mRNA processing.
• WT1 is implicated in hematopoiesis and mesothelial cell function, with specific translocations found in desmoplastic small round cell tumors.

Conclusions:

• WT1 is a critical tumor suppressor essential for normal kidney and sexual development.
• Understanding WT1 isoform function and mutations provides insights into the link between differentiation and cancer.
• WT1's multifaceted roles extend beyond kidney development to other cellular processes and malignancies.