Kannen V, de Oliveira EC, Motta BZ, Chaguri AJ, Brunaldi MO, Garcia SB. Trypanosomiasis-induced megacolon illustrates how myenteric neurons modulate the risk for colon cancer in rats and humans.
PLoS Negl Trop Dis 2015;
9:e0003744. [PMID:
25884710 PMCID:
PMC4401552 DOI:
10.1371/journal.pntd.0003744]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/07/2015] [Indexed: 01/05/2023] Open
Abstract
Background
Trypanosomiasis induces a remarkable myenteric neuronal degeneration leading to megacolon. Very little is known about the risk for colon cancer in chagasic megacolon patients. To clarify whether chagasic megacolon impacts on colon carcinogenesis, we investigated the risk for colon cancer in Trypanosoma cruzi (T. cruzi) infected patients and rats.
Methods
Colon samples from T. cruzi-infected and uninfected patients and rats were histopathologically investigated with colon cancer biomarkers. An experimental model for chemical myenteric denervation was also performed to verify the myenteric neuronal effects on colon carcinogenesis. All experiments complied the guidelines and approval of ethical institutional review boards.
Results
No colon tumors were found in chagasic megacolon samples. A significant myenteric neuronal denervation was observed. Epithelial cell proliferation and hyperplasia were found increased in chagasic megacolon. Analyzing the argyrophilic nucleolar organiser regions within the cryptal bottom revealed reduced risk for colon cancer in Chagas’ megacolon patients. T. cruzi-infected rats showed a significant myenteric neuronal denervation and decreased numbers of colon preneoplastic lesions. In chemical myenteric denervated rats preneoplastic lesions were reduced from the 2nd wk onward, which ensued having the colon myenteric denervation significantly induced.
Conclusion/Significance
Our data suggest that the trypanosomiasis-related myenteric neuronal degeneration protects the colon tissue from carcinogenic events. Current findings highlight potential mechanisms in tropical diseases and cancer research.
The myenteric neuronal activity on colon carcinogenesis is a matter of debate. Chagas disease (a trypanosomiasis-related chronic infection) induces megacolon damaging myenteric neurons. Puzzling, tumors have been rarely reported in chagasic megacolon patients. We reveal here hyperplasia-related high-proliferation occurs in chagasic megacolon, although the risk for colon cancer is reduced. Having carcinogen-exposed rats infected with Trypanosoma cruzi reduced the numbers of myenteric neurons and colon preneoplastic lesions. An experimental model for chemical myenteric denervation was applied in carcinogen-exposed rats revealing that myenteric neurons promote the development of colon preneoplastic lesions. Yet, activity of the fecal content had to be secluded from the myenteric neuronal activity on colon carcinogenesis. Hartmann’s surgical procedure enabled that. This was applied together with carcinogenic exposure and myenteric neuronal denervation ensuring that the neuronal activity is associated with enhanced development of colon carcinogenesis. Taken together, we believe colon tumors are not found within the chagasic megacolon region because the myenteric neuronal density is impaired. These observations shed lights on novel potential cell to cell interactions promoting the colon cancer development.
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