Question

Describe genetic events and epigenetic factors that are important in tumorigenesis.

Answer 1

Tumorigenesis comprises genetic and epigenetic alterations.

Genetic changes are the changes in genomic DNA sequence.

• Poiint mutation
• Single nucleotide polymorphism (SNP)
• Copy number variability (CNV)

This is usually achieved by environmental factors such as smoking, alcohol, hereditary, etc which may lead to loss of heterozygosity, homo deletion or gain copy number.

Epigenetic changes is responsible for regulation of gene expression without any alteration in the underlying DNA sequence.

• DNA methylation
• Modifications of the histone proteins
• Micro RNA instability

This results in selective gene activation or inactivation which allows proliferative activity to occur at an higher rate.

This is usually achieved by acetylation, methylation, sumolation, ubiquination, and phosphorylation.