Two intertwined compartments coexisting in sporadic conventional colon adenomas

Area of Science:

• Gastroenterology
• Cell Biology
• Oncology

Background:

• Sporadic conventional colon adenomas consist of two distinct microscopic compartments.
• The upper compartment contains dysplastic tissue, while the lower compartment features non-dysplastic crypts with corrupted shapes (CCS).

Purpose of the Study:

• To investigate the histo-biological characteristics of CCS in colon adenomas.
• To determine the relationship between CCS and dysplastic tissue development.
• To explore the potential interdependence of the two compartments in adenoma formation.

Main Methods:

• Microscopic examination of 306 colon adenomas to analyze CCS and proliferating cell-domains (PC).
• Assessment of p53 expression in dysplastic tissue and CCS of sporadic adenomas.
• Comparison of adenoma crypts with normal colon crypts and crypts in carcinogen-treated rats.

Main Results:

• CCS in colon adenomas exhibited asymmetric, haphazardly-distributed PC-domains, unlike symmetric domains in normal controls.
• Foci of p53-upregulated dysplastic tissue were observed in 28% of adenomas.
• p53-upregulated single cells were found in CCS of 30% of adenomas, indicating somatic mutations.
• CCS with asymmetrical PC-domains and p53-upregulated cells were present in polypoid adenoma stalks, suggesting CCS development precedes dysplastic growth.
• CCS were also identified in rats with induced colon adenomas.

Conclusions:

• The two compartments of sporadic conventional colon adenomas are likely interdependent.
• CCS development may precede or occur concurrently with dysplastic tissue growth.
• These findings suggest a potential link between normal colonic mucosa alterations and conventional adenoma histogenesis.