Chapter 16.4, Problem 4R

Summary Introduction

To review:

The inactivation of tumor-suppressing genes in colorectal cancer, whose two possible explanations are given below:

a. Mutations in the coding regions, resulting in inactive proteins.

b. Epigenetic silencing at the promoters of the genes, resulting in reduced transcription.

Given:

Figure shows two possibilities including mutations and epigenetic silencing that are to be explained.

Introduction:

Certain tumor suppressor genes are inactive in colorectal cancer. This further results in a condition characterized by an uncontrolled cell division commonly referred to as cancer. There are two possible reasons behind this cancerous condition including mutations in coding regions and epigenetic silencing at the promoters of genes.

Mutations are defined as the alternations in the sequence of the genetic material of a cell in an organism. On the other hand, the inactivation of a nonmutational gene that propagates from precursor cells to the daughter clone cells.