Abstract
Background
Patients with inflammatory bowel disease (IBD) are at a higher risk of developing colitis-associated colorectal cancer. The aim of the present study was to investigate the role of CD73 in IBD-associated tumourigenesis.
Methods
A mouse model of colitis-associated tumourigenesis (CAT) induced by azoxymethane and dextran sulphate sodium (AOM/DSS) was successfully constructed. Model mice were injected with CD73 inhibitor or adenosine receptor agonist. Colon length, body weight loss and tumour formation were assessed macroscopically. Measurement of inflammatory cytokines and RNA sequencing on colon tissues were performed.
Results
Inhibition of CD73 by adenosine 5′-(α,β-methylene) diphosphate (APCP) suppressed the severity of CAT with attenuated weight loss, longer colons, lower tumour number and smaller tumour size when compared with the model group. On the other hand, activation of adenosine receptors using 1-(6-amino-9H-purin-9-yl)-1-deoxy-N-ethyl-β-d-ribofuranuronamide (NECA) exacerbated CAT. Histological assessment indicated that inhibition of CD73 reduced while activation of adenosine receptors exacerbated the histological damage of the colon compared with the model group. Increased expression of pro-inflammatory cytokines (tumour necrosis factor-α and interleukin-6) in colonic tissue was detected in the NECA group. According to the results of RNA sequencing, potential oncogenes such as ALOX15, Bcl2l15 and Nat8l were found to be downregulated in the APCP group and upregulated in the NECA group compared with the model group.
Conclusion
Therefore, inhibition of CD73 attenuated IBD-associated tumourigenesis, while activation of adenosine receptors exacerbated tumourigenesis in a C57BL/6J mouse model. This effect may be associated with the expression of pro-inflammatory cytokines and the regulation of ALOX15, Bcl2l15 and Nat8l.
Analyses of mRNA Profiling through RNA Sequencing on a SAMP8 Mouse Model in Response to Ginsenoside Rg1 and Rb1 Treatment