PAX6 Promoter Methylation Correlates with MDA-MB-231 Cell Migration, and Expression of MMP2 and MMP9

Document Type: Research Articles

Authors

1 IHEM, National University of Cuyo, CONICET, Mendoza, Argentina.

2 IHEM, National University of Cuyo, CONICET, Faculty of Exact and Natural Sciences, Mendoza, Argentina.

3 IHEM, National University of Cuyo, CONICET, Faculty of Medical Sciences, Mendoza, Argentina.

Abstract

Objective: Breast cancer is a heterogeneous disease characterized by an accumulation of genetic and epigenetic
alterations that lead tumor cells to acquire characteristics like the capacity for invasion and metastasis. Metastasis
remains a major challenge in cancer management and understanding of its molecular basis should result in improved
prevention, diagnosis, and treatment of breast cancer patients. The aim of this study was to investigate how promoter
DNA methylation regulates PAX6 gene expression and influences breast carcinoma cell migration. Methods: PAX6
promoter methylation was detected by Methyl Specific-Multiplex Ligation Probe Amplification (MS-MLPA). Gene
expression was evaluated using qRT-PCR, while the effect of PAX6 on migration was ssessed by wound healing assay.
In addition, MMP2 and MMP9 genes were studied using different bioinformatic tools. Results: The PAX6 promoter is
methylated in breast cancer cell lines and methylation in this region impacts on its expression. Migration assays revealed
that PAX6 overexpression promotes cell migration, while PAX6 inhibition decreases it. More importantly, we found
that migration is affected by PAX6 methylation status. Employing bioinformatic analysis, binding sites for PAX6 on
the regulatory regions of the MMP2 and MMP9 genes were established, PAX6 overexpression increasing MMP2 and
MMP9 expression at the mRNA level. Conclusion: Our study provides novel insights into epigenetic events that regulate
PAX6 expression and molecular mechanisms by which PAX6 modifies the migration capacity of breast cancer cells.

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