Expression profiling after induction of demethylation in MCF-7 breast cancer cells identifies involvement of TNF-α mediated cancer pathways.
Epigenetic methylation change is a major process that occurs during cancer development. Even though many tumor-related genes have been identified based on their relationship between methylation and expression, few studies have been conducted to investigate the relevant biological pathways involved in these changes. To identify essential pathways likely to be affected by methylation in breast cancer, we examined a pool of genes in which expression was upregulated after induction of demethylation by 5-Aza-2'-deoxycytidine (Aza) in the MCF-7 breast cancer cell line. Genome-wide demethylation was confirmed by monitoring the demethylation of a previously known gene, SULT1A1. Overall, 210 and 213 genes were found to be upregulated and downregulated (fold change ≥ 2), respectively, in common in cells treated with 5 and 10 μM of Aza. Network analysis of these 423 genes with altered expression patterns identified the involvement of a cancer related network of genes that were heavily regulated by TNF-α in breast tumorigenesis. Our results suggest that epigenetic dysregulation of cellular processes relevant to TNF-α-dependent apoptosis may be intimately involved in tumorigenesis in MCF-7 cells.
Department of Life Science, Dongguk University-Seoul, Seoul, 100-715, Korea.
Ju Hee
JH
Kim
Seongeun
S
Kang
Tae Woo
TW
Kim
Lihong
L
Yin
Ran
R
Liu
Sun Jung
SJ
Kim
D001372:Aza Compounds / Q000494:pharmacology; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002273:Carcinogens / Q000494:pharmacology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000235:genetics / Q000473:pathology; D019295:Computational Biology; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D046228:Microarray Analysis; D015398:Signal Transduction / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D001372:Aza Compounds; D002273:Carcinogens; D014409:Tumor Necrosis Factor-alpha