This study sought to evaluate short-term treatment with COX-2 inhibitors and acute changes in colonic PGE2 levels as predictors of long-term efficacy in a genetic model of colorectal cancer.
In the COS-treated CRC group (CMCOS), COS protected mice from CRC by decreasing the disease activity index, tumor incidences and multiplicity, and the mRNA levels of COX-2, IL-6, TNF-α, IL-1β, IL-10, and IKK-β mRNA in colonic epithelial cells.
The CRC condition was produced in response to COX-2 and IL-6 induced activation of JAK2/STAT3 which, in turn, was due to the enhanced phosphorylation of JAK2 and STAT3.
Increased synthesis of PGE<sub>2</sub> in CRC has been shown to occur through COX-2-dependent mechanisms; however, loss of the PGE<sub>2</sub>-catabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (15-PGDH, HPGD), in colonic tumors contributes to increased prostaglandin levels and poor patient survival.
The CRC protective effects of apiaceous vegetables are mainly due to the inhibitory effect of FaOH and FaDOH on NF-κB and its downstream inflammatory markers, especially COX-2.
Therefore, the present study was designed to assess the prophylactic potentials of probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus GG) in conjunction with celecoxib, a selective cox-2 inhibitor in 1,2 dimethylhydrazine dihydrochloride (DMH)-induced experimental colon carcinogenesis, a well-established, well appreciated and widely used model for colorectal cancer that shares many similarities to human sporadic colorectal cancer with respect to response to some promotional and preventive agents.
COX-2 and proliferating cell nuclear antigen (PCNA) expression were assessed immunohistochemically. lncRNA-CCHE1 expression was upregulated in CRC tissues compared to adjacent non-cancerous tissues, and was significantly associated with larger tumor size, less differentiated histology, advanced dukes' stage, positive lymph node involvement and vascular invasion.
A mechanistic analysis revealed that YAP1 promoted CRC-derived MDSC induction by suppressing PTEN expression to up-regulate COX-2, P-AKT and P-p65 in CRC-derived cells, leading to secretion of the cytokine granulocyte-macrophage colony-stimulating factor.
On the other hand, NPX and other NSAIDs are extensively studied in terms of colorectal cancer (CRC) prevention and inhibition, since it has been evidenced that COX-2 corresponds with the risk of the tumor occurrence and growth.
In conclusion, our study provided the evidence towards better antiproliferative effect of AR13 and AR15 in DMH-induced CRC through the blockade of COX-2/JAK-2/STAT-3 signal transduction pathway and could be demonstrated as useful anti-CRC candidate molecules for future anticancer therapy.
In the prostaglandin-dependent pathways, inhibition of cyclooxygenase (COX), particularly COX-2, is the primary mechanism known to be involved in aspirin-induced CRC suppression.
Here we showed that the addition of the COX-2 inhibitor celecoxib improved the antitumor efficacy in colorectal cancer (CRC) of the monoclonal anti-EGFR antibody cetuximab.