Abstract: FR-PO221
Aberrant SIX2 Expression in Neonatal Kidney Stem Progenitor Cells Is Sufficient to Drive Malignant Transformation
Session Information
- Onconephrology: Immunotherapy Nephrotoxicity and Assessment of GFR
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Lantermans, Hildo C., Amsterdam UMC Locatie AMC, Amsterdam, Noord-Holland, Netherlands
- Kraan, Willem, Amsterdam UMC Locatie AMC, Amsterdam, Noord-Holland, Netherlands
- Van den Heuvel, Lambertus P.W.J., Radboud Universitair Medisch Centrum, Nijmegen, Netherlands
- Arcolino, Fanny Oliveira, Amsterdam UMC Locatie AMC, Amsterdam, Noord-Holland, Netherlands
- Levtchenko, Elena, Amsterdam UMC Locatie AMC, Amsterdam, Noord-Holland, Netherlands
Group or Team Name
- Paediatric Nephrology.
Background
Wilms tumor (WT) is the most common paediatric renal tumor with an annual incidence of 4 to 10 per million children. WT is thought to arise in renal progenitor cells as it resembles nephrogenic cells both morphologically and transcriptionally. Although the underlying genetic causes of WT are diverse, in vitro models to study WT are largely restricted to a few WT cell lines which do not fully represent the diversity observed in patients. In order to expand the in vitro models of WT and improve the knowledge on its molecular pathogenesis we investigated whether we could induce malignant transformation of healthy non-immortalized neonatal kidney stem progenitor cells.
Methods
We have previously isolated and characterized kidney stem progenitor cells from the urine of preterm neonates (nKSPC). We transduced nKSPC with retroviral particles encoding for SIX2, a transcription factor that is crucial during nephrogenesis and aberrantly upregulated in most WT cases. We monitored changes in cell growth and viability by flow cytometric analysis and investigated molecular reprogramming on both the RNA and protein level.
Results
Intriguingly, overexpression of solely SIX2 in a minor fraction of nKSPC (~5 %) provided the overexpressing cells with a growth advantage that was sufficient to outcompete most non-transduced cells within two weeks. Moreover, the growth of SIX2 overexpressing nKSPC is no longer contact-inhibited and their cellular morphology resembles that of primary WT cells. Whereas the parental nKSPC maintain self-renewing for more than 20 passages, SIX2 overexpressing nKSPCs grow rapidly up to more than 30 passages. On both protein and RNA level we show that SIX2 overexpression results in downregulation of Wnt signaling with concurrent strong upregulation of the oncogene Myc and the cell cycle regulator cyclin D1, which have both been implied in WT pathogenesis.
Conclusion
We show that nKSPCs can serve as a valuable tool to establish in vitro WT models and to study WT pathogenesis. As proof of principle we show that overexpression of a single gene involved in WT pathogenesis, SIX2, is sufficient to drive malignant transformation and immortalization of nKSPCs.
Funding
- Government Support – Non-U.S.