Peripheral blood DNA methylation markers for the early detection of colorectal carcinoma in the Egyptian population and its relation to high fiber diet / Omar Zaghloul Elshabacy ; Supervised Maissa Elsaid Elraziky , Said Ebraheem Shalaby , Dina Sabry Abdelfatah

Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Tropical Medicine

Background : DNA methylation is one of the most important epigenetic mechanisms. Aberrant promoter demethylation is usually associated with overexpression of genes that might participate in pathogenesis of many diseases. Alkylresorcinols are used as biomarkers of wholegrain intake and fiber diet which decrease risk of colorectal cancer.Aim of the work : to evaluate methylation level of serum SFRP2, CDH13 and Nurog1 genes as novel non-invasive markers in CRC among Egyptian patients and to verify the relation of diertry fibre intake to occurrence of CRC using plasma.Methods : A whole blood sample (10cc) will be collected and stored at 4C for a maximum of 24 hours. Samples will be delivered within this period to the molecular biochemistry lab for removal of the Buffy coat, DNA extraction and analysis. Alkylresorcinols homologues C17:0, C19:0 and C21:0 were detected. The molecular biologist will assess all samples in a blinded fashion.Results : CDH13 shows the highest performance with cut-off of 0.45 æg/L, followed by Neurog1 with cut-off of 0.22. CDH13 and Neurog1 shows sensitivity (91%) while CDH13 shows higher specificity (84%) then Neurog1 (69%). SFRP shows the least performance with the least sensitivity (76%) and specificity (46%) for detection of adenocarcinoma. Alkylresorcinols were significant higher in non-cancer group.Concluson : SFRP2, CDH13 and Nurog1 can be useful in prediction of colorectal carcinoma. High intake of whole grain may decrease risk of CRC

Issued also as CD