Colorectal Neoplasms/metabolism; CpG Islands; DNA Methylation; MicroRNAs/metabolism; Sp1 Transcription Factor/metabolism; Azacitidine/analogs & derivatives; Azacitidine/pharmacology; Base Sequence; Cell Proliferation; Chi-Square Distribution; Colorectal Neoplasms/genetics; Colorectal Neoplasms/mortality; Colorectal Neoplasms/pathology; CpG Islands/drug effects; DNA Methylation/drug effects; DNA Modification Methylases/antagonists & inhibitors; DNA Modification Methylases/genetics; DNA Modification Methylases/metabolism; Decitabine; Down-Regulation; Enzyme Inhibitors/pharmacology; Female; Gene Expression Profiling/methods; Gene Knockdown Techniques; Gene Silencing; HCT116 Cells; HT29 Cells; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Molecular Sequence Data; Multivariate Analysis; Neoplasm Invasiveness; Oligonucleotide Array Sequence Analysis; Polymerase Chain Reaction; Prognosis; Proportional Hazards Models; Risk Assessment; Risk Factors; Signal Transduction; Sp1 Transcription Factor/genetics; Time Factors; Transfection