A 30-year-old man has a routine health maintenance examination. A stool sample is positive for occult blood. On colonoscopy, an ulcerative lesion is seen projecting into the cecum. The microscopic appearance of a section of the excised lesion is shown in the figure. Which of the following molecular biologic events is thought to be most critical in the development of such lesions?
A.
Overexpression of E-cadherin gene
B.
Amplification of ERBB2 gene
C.
Germline transmission of a defective RB gene
D.
A defective DNA mismatch-repair gene
E.
Translocation of retinoic acid receptor α gene