The DNMT3A Knockout MCF-7 Polyclonal Cells are a polyclonal knockout cell population derived from MCF-7 breast adenocarcinoma cells, generated via CRISPR/Cas9-mediated disruption of the DNMT3A gene. This loss-of-function model provides a genetically tractable system for studying de novo DNA methylation in a hormone-responsive epithelial context, without the selection biases of monoclonal expansion.
The parental MCF-7 line is a human breast adenocarcinoma model derived from a metastatic pleural effusion of a 69-year-old female. Cells are ER??+, PR+, and HER2?, reflecting a luminal A molecular subtype. MCF-7 is widely used to investigate estrogen-dependent growth, endocrine therapy resistance, and hormonal regulation of gene expression.
DNMT3A catalyzes de novo CpG methylation, establishing epigenetic silencing patterns critical for development, X-chromosome inactivation, and genomic imprinting. The enzyme functions through interactions with cofactors DNMT3L, DNMT3B, HDAC1, and EZH2, and is recruited to chromatin by UHRF1 and PCNA. Its activity is regulated upstream by RAS-MAPK and PI3K-AKT cascades, estrogen receptor alpha (ESR1) signaling, and transcription factors MYC and E2F1. Downstream targets including tumor suppressors CDKN2A, MLH1, BRCA1, CDH1, and RASSF1A are transcriptionally silenced by DNMT3A-dependent methylation, and knockout leads to their derepression alongside pluripotency genes such as OCT4 and NANOG.
In the MCF-7 background, DNMT3A knockout disrupts methylation-dependent repression of estrogen-responsive and tumor-suppressor gene networks, directly impacting hormone signaling pathways that govern cell proliferation and survival. The polyclonal design maintains population diversity, enabling robust assessment of functional consequences such as altered drug sensitivity and pathway rewiring, free from clonal artefacts.
This model supports applications in epigenetic regulation of breast cancer, hormone signaling dissection, drug resistance studies, and hypomethylating agent evaluation. Key assays include western blotting, RT-qPCR, bisulfite sequencing, ChIP-qPCR, immunofluorescence, and proliferation or apoptosis assays. High-content approaches such as RNA-seq and chromatin accessibility profiling can further elucidate genome-wide effects. For further information or project discussions, contact Ascent Research.
