Background:
The loss of differentiation is a key characteristic of colorectal cancer, and is associated with increased propensity for metastasis. Understanding the mechanistic basis for the loss of differentiation in colorectal cancer may inform strategies for re-inducing differentiation and consequently inhibiting metastatic spread. The goal of this study was to determine the role of the Ets Homology Factor (EHF) transcription factor in the regulation of the differentiation status and migration of colorectal cancer cells. EHF is a member of E26 transformation specific (ETS) transcription factors which are important regulators of differentiation and developmental programs in many tissues.
Methods:
Affymetrix microarrays were used to identify transcription factors which are significantly differentially expressed between moderately and poorly differentiated colorectal cancer cell lines. Differential gene expression was confirmed by q-RT-PCR and western blot. The moderately differentiated colorectal cancer cell line SW948 was transfected with EHF targeting siRNAs using lipofectamine. The poorly differentiated colon cancer cell line HCT116 was transfected with an exogenous EHF construct and single cell clones were selected with G418 resistance. Migration potential was analysed using the Boyden-Chamber assay and stained for migrated cells.
Results:
Analysis of microarray data demonstrated that EHF expression was significantly downregulated in poorly differentiated colorectal cancer cell lines compared to moderately differentiated lines. Knockdown of EHF in moderately differentiated SW948 colorectal cancer cells enhanced cell migration while conversely, EHF overexpression in poorly differentiated HCT116 cells inhibited cell migration, but had no effect on differentiation marker expression.
Conclusion:
This study identifies a novel role for the EHF transcription factor in the regulation of migration of colorectal cancer cells.