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Background/aim Several studies have found elevated soluble CD40 Ligand (sCD40L) in the serum of patients with malignancies as well as those with inflammatory bowel disease (IBD). Our goal was to determine the possible causal role of sCD40L in colitis-associated colorectal cancer (CAC) by using the well-established azoxymethane/dextran sulfate sodium (AOM/DSS) protocol. Materials and methods Twelve wild type (WT) and twelve TLR4 knock out (KO) female C57BL6 mice were divided into 4 experimental groups. Six WT and six TLR4 KO mice were treated with a single intraperitoneal dose (10 mg/kg of body weight) of AOM followed by three 7-day cycles of oral 2.5% DSS. The other two groups included 6 WT and 6 TLR4 KO mice that received only water and served as the control groups. The mice were sacrificed after 84 days. Results All mice in the AOM/DSS WT group developed CAC while all mice from the AOM/DSS TLR4 KO group were protected from CAC. We measured the serum and pathologic tissue levels of sCD40L with quantitative sandwich enzyme-linked immunoassay (ELISA) and found that serum sCD40L was significantly higher in wild-type mice that developed CAC compared to their healthy counterparts (wild-type and TLR-4 KO controls). In comparison, serum sCD40L levels were comparable between TLR-4 KO mice, which are protected from developing CAC, and their healthy counterparts (wild-type and TLR-4 KO controls). Of note, tissue levels of sCD40L were not affected by the development of CAC. Conclusion Our findings point to the presence of an axis between TLR-4 and sCD40L, which may lead to decreased immunosurveillance and the subsequent development of colitis-associated cancer.

Background/aim TLR-4 Knock-out (KO) mice are protected from colitis-associated cancer in the established AOM/DSS mouse model. The aim of this study was to assess whether the TLR4 KO mice would still be protected from carcinogenesis after platelet depletion and transfusion with TLR4 wild-type platelets. Materials and methods Thirty-two female C57BL6 mice were divided into 6 groups. Among the three groups that received Azoxymethane/Dextran Sulfate Sodium (AOM/DSS), one group included TLR4KO mice, which were depleted of their platelets and were then transfused with platelets from TLR4 wild-type mice. The other two groups included wild-type and TLR-4KO mice that only received AOM/DSS. Results All 6 animals in the KO group that underwent platelet depletion/transfusion succumbed. Three of them died before the administration of DSS and three in the week following DSS administration. In contrast, mice in the other two groups experienced less weight loss and only 1 mouse died in each of them. Conclusion Platelet depletion/transfusion was detrimental in TLR-4 transgenic mice that received AOM/DSS.