The predominant cause of death in cancer patients is metastasis, the formation of secondary tumors in other organs like the brain, liver, and lungs. Cancer cells detach from the original primary tumor and reach a single cell or group of cells in another organ. The cells of the body normally remain in place through adhering to an extracellular substance. However, cancer cells learn how to release themselves from these bonds and invade surrounding tissues, blood, and the lymphatic system.
The transformation of sedentary, specialized cells into wandering, invasive, and unspecialized cells is called epithelial-mesenchymal transition (EMT), which is central to metastasis. EMT is a multistage process, which is accompanied by a fundamental change in cell morphology and number of genetic programs. The molecular processes that govern EMT, however, are still poorly understood.
Main Switch Found
The research groups of Prof. Gerhard Christofori of the Department of Biomedicine at the University of Basel; Prof. Erik van Nimwegen from the Biozentrum, University of Basel; and Prof. Dirk Schuebeler from the Friedrich Miescher Institute have discovered a master regulator of EMT and metastasis: the transcription factor Sox4 is upregulated in its activity and triggers the expression of a number of genes that play an important role during EMT and metastasis.
In particular, Sox4 promotes the expression of the enzyme Ezh2, a methyltransferase, which generally influences methylation of specific proteins (histones), the packaging of the genetic material, and thus its readability and gene expression. Due to this change in genetic information, the behavior and function of cells are reprogrammed – a process that is currently observed during metastasis. Such a change in gene expression is also found in patients with malignant cancer and metastasis and correlates with a poor prognosis.
These findings point to the possibility that the inhibition of the transcription factor Sox4 and especially the methyltransferase Ezh2 could hinder metastasis in cancer patients. Appropriate medications are currently being developed but they need to undergo clinical trials before being used in patients. The research was implemented within the framework of the SystemsX.ch-RTD Project “Cell Plasticity.”
Neha Tiwari, Vijay K. Tiwari, Lorenz Waldmeier, Piotr J. Balwierz, Phil Arnold, Mikhail Pachkov, Nathalie Meyer-Schaller, Dirk Schübeler, Erik van Nimwegen, and Gerhard Christofori (2013)
Sox4 Is a Master Regulator of Epithelial-Mesenchymal Transition by Controlling Ezh2 Expression and Epigenetic Reprogramming Cancer Cell; Published online June 10, 2013 | doi:
University of Basel