Background: Gastric cancer accounts 8% of the total cancer cases and 10% of total cancer deaths worldwide. The indoleamine N-acetyl-5-methoxytryptamine, better known as melatonin, is the principal hormone produced by the pineal gland. Recently, it has shown some anticancer role in some malignancies such as breast and colon cancer; also, some of its protective roles in the GI tract are as free radical scavenger and as antimitogenic and apoptotic agents. Based on the anticancer effects of melatonin and wide distribution of this neurohormone in the GI tract and some proposed physiologic and pharmacologic roles for this neurohormone, this study is initially scheduled to determine the expression of melatonin receptor MT2 in tissue samples of adenocarcinoma cancer patients.
Methods: For this aim, a total of 30 gastric adenocarcinoma patients and 30 normal individuals were selected and examined for MT2 gene expression by real-time PCR.
Results: Our results have shown interestingly high expression for MT2 receptor in cancer and marginal cancer tissues compared with normal people.
Conclusions: According to our results, it is concluded that for the first time, the expression of MT2 receptor in gastric adenocarcinoma tissues which was in parallel with breast and colon cancer studies and high expression of this receptor in the marginal tissues indicate refractory mechanism which shows the defending role of melatonin in the GI system. Our experiments has not shown any relationship between MT2 receptor expression and grade and clinicopathological features of gastric tumor, so we cannot conclude any relationship between this receptor expression and progression of the tumor, although this expression can be considered as an etiology.