1. DNA METHYLATION Guided by: Presented by: SUSHMA MARLA M.PHARM (First Sem) DEPT. OF BIOTECH. PROF. KALPANA JOSHI PROF. & HEAD BIOTECH. DEPT. SCOE. PUNE.

12. PRE-IMPLANTATION Genome undergoes Demethylation AFTER IMPLANTATION OF EMBRYO AND DURING CARCINOGENESIS New Methylation patterns are set by de-novo methylation. DURING REPLICATION Methylation patterns must be maintained. Therefore, DNMT1, methylates the hemimethylated DNA after strand synthesis.

15. CpG ISLANDS PROMOTER REGIONS NON-PROMOTER REGIONS Non-methylated Methylated Binding of TF Transcription Inhibition of TF binding Transcriptional silencing Methylated Non-methylated Silence parasitic genetic elements Genomic stability Binding of TF Transcription

20. METHYLATION IMBALANCE may contribute to TUMOR PROGRESSION GLOBAL HYPOMETHYLATION DNA HYPERMETHYLATION Observed in neoplastic cells May induce neoplastic transformation Genomic instability, Abnormal chromosomal structures and Activating oncogenes. Inactivation of tumor-suppressor genes: p16, BRCA1 Inactivation of DNA repair genes: MLH1, MGMT

21. A CpG island hypermethylation profile of human cancer

27. Major Advance: Conversion of unmethylated cystosines to uracil using sodium bisulfite Sequencing: unemethylated cytosines read as thymidine in sense strand; adenine in the anti-sense strand. Other technologies evolved from here.

30. Methylation specific PCR