Related Experiment Video
Updated: Aug 16, 2026
The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers
Published on: January 22, 2013
Alteration of frizzled expression in renal cell carcinoma
Nico Janssens1, Luc Andries, Michel Janicot
1Department of Biochemistry, University of Antwerp, Wilrijk, Belgium. njansse9@prdbe.jnj.com
Abstract:
To evaluate the involvement of frizzled receptors (Fzds) in oncogenesis, we investigated mRNA expression levels of several human Fzds in more than 30 different human tumor samples and their corresponding (matched) normal tissue samples, using real-time quantitative PCR. We observed that the mRNA level of Fzd5 was markedly increased in 8 of 11 renal carcinoma samples whilst Fzd8 mRNA was increased in 7 of 11 renal carcinoma samples. Western blot analysis of crude membrane fractions revealed that Fzd5 protein expression in the matched tumor/normal kidney samples correlated with the observed mRNA level. Wnt/beta-catenin signaling pathway activation was confirmed by the increased expression of a set of target genes. Using a kidney tumor tissue array, Fzd5 protein expression was investigated in a broader panel of kidney tumor samples. Fzd5 membrane staining was detected in 30% of clear cell carcinomas, and there was a strong correlation with nuclear cyclin D1 staining in the samples. Our data suggested that altered expression of certain members of the Fzd family, and their downstream targets, could provide alternative mechanisms leading to activation of the Wnt signaling pathway in renal carcinogenesis. Fzd family members may have a role as a biomarker.
Insights
Altered expression of frizzled receptors (Fzd) is implicated in kidney cancer. Fzd5 and Fzd8 show increased levels in renal carcinomas, suggesting their potential as biomarkers for Wnt signaling pathway activation.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Frizzled receptors (Fzds) are key regulators of the Wnt signaling pathway.
- Aberrant Wnt signaling is frequently observed in various cancers, including renal carcinoma.
- The specific role of Fzd family members in renal carcinogenesis requires further elucidation.
Purpose of the Study:
- To investigate the expression levels of specific Frizzled receptors (Fzds) in human renal tumors.
- To determine the correlation between Fzd expression and Wnt/beta-catenin signaling pathway activation.
- To explore the potential of Fzd family members as biomarkers in renal cancer.
Main Methods:
- Real-time quantitative PCR (qPCR) to assess mRNA expression levels of Fzd family members.
- Western blot analysis to evaluate Fzd protein expression in matched tumor and normal kidney tissues.
- Analysis of a kidney tumor tissue array to examine Fzd5 protein expression in a broader sample set.
Main Results:
- Fzd5 mRNA levels were significantly elevated in 8 out of 11 renal carcinoma samples.
- Fzd8 mRNA levels were increased in 7 out of 11 renal carcinoma samples.
- Fzd5 protein expression correlated with mRNA levels, and Fzd5 membrane staining was observed in 30% of clear cell carcinomas, correlating with cyclin D1 expression.
Conclusions:
- Altered expression of Fzd family members, particularly Fzd5, is associated with renal carcinogenesis.
- These findings suggest alternative mechanisms for Wnt signaling pathway activation in kidney cancer.
- Fzd family members may serve as potential biomarkers for renal cancer diagnosis and prognosis.
Related Concept Videos
02:23Abnormal Proliferation
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...