Epigenetics and pancreatic cancer: Pathophysiology and novel treatment aspects

Table 5 Overview of Epigenetic mechanisms - see text for details and references

Mechanism	Enzyme	Subclasses/components	Effect on target gene expression
DNA (de-) methylation	DNMT	DNMT1 (methylation maintenance)	↓
		DNMT3A and -3B (de novo methylation)
	DNA de-methylase	Not known	↑
Histone (de-) acetylation	HAT	e.g., CBP, p300	↑
Histone methylation	HDAC	Class I (HDACs-1-3, -8), class IIa (HDACs-4, -5, -7, -9), class IIb (HDACs-6, -10), class III (SIRT1-7), class IV (HDAC-11)	↑
	PcG→ H3-K27-me3	PRC1: CBX-2, 4, or 9, PHC-1, 2, or 3, BMI1, RING1A/B or RNF2	↓
		→ H3-K27-me3 maintenance
		PRC2: EZH2, SUZ12, EED
		→de novo H3-K27-me3 maintenance
	TrxG → H3-K4-me3	Several members	↑
Post-transcriptional	miRNAs	2578 mature miRNA (miRBase v20)	↓

HAT: Histone acetylase; HDAC: Histone deactylase; DNMT: DNA methyltransferase.