Old enemies meet new friends for colon cancer prevention

Peri‐weaning cholera toxin consumption suppresses chemically‐induced carcinogenesis in mice

“…The exception being a study from our group where BALB/cJ male mice and the AOM/DSS protocol for inflammation-promoted colonic neoplasia were used to show that oral administration of CT suppresses colonic polyp formation, through mechanisms involving significant modulations of local intestinal immunity. 8,9 An independent reproduction of our experiment in C57BL/6J female mice using only the B subunit of CT (CT-B), which carries powerful adjuvant properties, 24,25 led to similar observations. 10 These findings, however, could raise the argument that CT works to reduce only inflammationassociated carcinogenesis, and that its antitumor effect is merely local, restricting to the gastrointestinal tract.…”

“…By altering the neoplastic lesion macro-and microenvironment, they may either promote or suppress tumor growth and evolution, as well as affect cancer treatment. 1,4,8,[28][29][30] For the survival curve, mice were humanely killed upon the presence of clinical endpoints, which were by large dictated by the size of mammary tumors or the detrimental consequences of mammary, lung or stomach cancer expansion and local infiltration. Given the aggressive chemical carcinogenesis protocol used 14,32 and the induction of more than one types of tumors, the effect of CT on promoting the survival of mice was remarkable.…”

“…9 It follows that CT does not prevent preneoplastic lesions but it rather changes their environment, making it less favorable for their evolution and growth into tumors. 8,9,28 With our short-term experiment, we were able to probe genotoxically compromised epithelia and their environment without the confounding effects of neighboring tumors. Importantly, we found that CT pretreatment universally increased apoptosis in the cancer prone mammary, lung and nonglandular stomach.…”

“…4,7,15,[28][29][30] Our previous studies using the probiotic bacterium Lactobacillus reuteri, 7,15 as well as the present study using CT, suggest that exposure to certain gut bacterial antigens during the early life may contribute to the establishment of a well-balanced, long-lasting immune tone that lowers the probability of cancer development later in life. 4,7,8,15,26,[28][29][30] In cancer prevention, however, translating such and breast 13 survival outcomes demonstrated that patients who received the vaccine were presented with significantly lower mortality rates in all three types of cancer as compared to the nonvaccinated ones. [11][12][13] On the other hand, a similar retrospective population-based study testing the effects of various travel vaccines on the overall mortality of prostate cancer patients, claimed that reduced mortality correlated not only with the cholera vaccine, but also with vaccines against malaria, Salmonella typhi and several other, yet not all, vaccines against viral pathogens.…”

“…It should rather expand to pathogens that have been banned from the industrialized world as well. 8 Following this line of reasoning, we tested cholera-toxin (CT), the major pathogenic factor of the cholera-causing bacterium Vibrio cholerae. Using the azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse model of inflammation-induced colon cancer, we demonstrated that oral administration of CT suppressed colonic polyp formation, through mechanisms that involved significant alterations in intestinal immunity networks.…”