Potential Role for the Metnase Transposase Fusion Gene in Colon Cancer through the Regulation of Key Genes

<div><p>The Metnase fusion gene consists of a SET histone methyltransferase domain and a transposase domain from Mariner transposase. This transposable element is involved in chromosome decatenation, enhances DNA repair, promotes foreign DNA integration, and assists topoisomerase II function. This study investigates the role of Metnase in colon cancer homeostasis and maintenance of the stemness phenotype in colon cancer stem cells (CSCs). Silencing of Metnase was performed in human cancer cell lines before and after treatment with cisplatin, and in colon CSCs. Subsequent changes in the expression of genes involved in repair mechanisms, DNA synthesis, topoisomerase II function, and metastasis as well stemness transcription factors were studied with RT-qPCR experiments. Cellular viability and apoptosis were evaluated by flow cytometry. The results suggest that Metnase influences the expression of many genes involved in the above processes. Furthermore, Metnase levels appear to impact upon expression of NANOG, OCT3/4, and SOX2. Suppression of Metnase also led to an increase in apoptosis. Therefore, Metnase may possess an important role in DNA repair, topoisomerase II function, and the maintenance of stemness during colon cancer development.</p></div

Percentage of dead cells and cells undergoing apoptosis before and after Metnase Knockdown.

<p>Percentage of dead cells and cells undergoing apoptosis before and after Metnase Knockdown.</p

Primer pairs that were used in qPCR.

<p>Primer pairs that were used in qPCR.</p

Metnase regulates gene expression of stemness markers.

<p>Relative gene expression analysis of the stemness transcription factors NANOG, OCT3/4, and SOX2 following Metnase knockdown.</p

Metnase regulates gene expression in HCT-116 cell line.

<p>Relative gene expression of transcription factors in HCT-116 cells following Metnase knockdown. The percentage of knockdown reached 65%.</p

Metnase regulates gene expression in colon CSCs.

<p>Relative gene expression of transcription factors in Colon CSCs following Metnase knockdown. The percentage of Metnase knockdown reached 40%. The ΔΔCt method was used to perform the analysis. Each bar represents the average of the Ct values. The assays were performed in triplicate and a p-value <0.05 was considered significant. In the control sample the average value is 1.00 indicating that there is no change in gene expression. Values>1 indicate an increase in gene expression while values <1 indicate a decrease in gene expression. The conditions for subsequent experiments were the same.</p