Related Experiment Video
Updated: Jun 27, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
TGF-beta repressors SnoN and Ski are implicated in human colorectal carcinogenesis
Vasiliki Bravou1, Anna Antonacopoulou, Helen Papadaki
1Clinical Oncology Laboratory, School of Medicine, University of Patras, Rio Patras, Greece.
Background:
The TGF-beta signaling repressors SnoN and Ski have been critically implicated in human cancer.
Methods:
To explore the role of SnoN and Ski in the development and progression of colorectal cancer we examined their protein expression profile by immunohistochemistry in a series of human colorectal adenomas, carcinomas and lymph node metastases. The mRNA expression of SnoN was also quantified by Real-Time RT-PCR.
Results:
SnoN and Ski were overexpressed both in adenomas with severe dysplasia and colorectal carcinomas. Protein expression was cytoplasmic and nuclear with predominant cytoplasmic localization. The subcellular localization was related differently to pathologic variables of colorectal carcinomas. Although there was no significant association of protein levels with tumor invasion and metastasis, a significant correlation of nuclear SnoN and Ski with beta-catenin pathway was observed. Moreover, SnoN mRNA did not differ in carcinomas as compared to normal control and there was no correlation between SnoN protein and mRNA levels.
Conclusion:
Our findings suggest that SnoN and Ski exert oncogenic effects in human colorectal carcinogenesis and their overexpression is implicated in early stage disease.
Related Concept Videos
TGF - β Signaling Pathway
The 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,...
Non-LTR Retrotransposons
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
Cancer-Critical Genes II: Tumor Suppressor Genes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...

