A cancer biology topic Describte how ChIP chromatin immunopr

A cancer biology topic: Describte how ChIP (chromatin immunoprecipitation), DNA methylation array, and gene expression arrays are performed. What are the similarities?

Solution

DNA methylation is main epigenetic mechanism of gene expression regulation.Alteration in this leads to tumor. Various stimulant factors stimulate DNA methylation leads to generation of canceroua cells.

DNA methylation process do down regulation of gene.

Methylation of CpG sites blocks the binding of regulatory proteins resulting transcription modulation.

In CHIP DNA methylation stauninig of CHIP done by various stains. Stained CHIP show intensities of methylated and unmethylated bead types. Data analysis gives florescence intensity ratio between methylated and unmethylated group.

Value of ratio is 0, 1, 0.5 represents non methylation, total methylation and one copy methylated other not respectively.

DNA methylation measure by following other method also

Bisulfite treatment

Whole genomic DNA amplification

Hybridization and single base extension

In Gene expression two following procees take important part:-

TRANSCRIPTION:- DNA to RNA by RNA polymerase which use DNA as template and produce RNA.

TRANSLATION:- RNA to Protein translation (tRNA charged with amino acid enter in ribosome with correct mRNA triplet , ribisome then add aminoacid.

In cancer, gene promoter contain CpG island with numerous CpG sites. When CpG sitesethylated gene become silence.

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