Alterations in Keratin Levels and Modifications in Colorectal Adenomagenesis

A cancerized field is an area of abnormal tissue in the vicinity of a cancer but
appearing to be macroscopically normal. Identification of these has important
clinical implications as abnormal tissues could be left in situ following
polypectomy or surgical resection, leading to neoplastic recurrence in the same
area. Up to 60% of patients develop metachronous adenomas following
adenoma excision, the observed high rate of metachronous adenoma formation
could be due to field changes analogous to cancerized fields around an adenoma.
Keratins are important regulators of colonocyte physiology and their regulatory
role is, in part, influenced by post-translational modifications and butyrate
exposure. Butyrate has been shown to have a protective effect in the colon to
prevent colorectal carcinoma. Alterations in keratin levels have been shown
between the cancerized field and normal tissue. The investigation of keratins as a
marker for a cancerized field and how they are influenced by butyrate may
provide clues in the prevention of and treatment of adenomagenesis and the
early stages of carcinogenesis.
This thesis examines the involvement of keratins in adenoma fields and their
response to butyrate exposure; the available evidence for these associations is
reviewed.