title: Induction of cell differentiation and promotion of endocan gene expression in stomach cancer by melatonin.
abstract: The pineal hormone melatonin has been shown to have anticancer therapeutic properties in patients with gastric cancer, the mechanisms, however, remain largely unknown. The present study examined the effects of melatonin on cell differentiation related factors, namely, endocan, alkaline phosphatase, and lactate dehydrogenase, in gastric adenocarcinoma cell line SGC7901. Expression of endocan was significantly decreased in tissue of gastric cancer as compared to normal stomach tissue, as determined by immunohistochemical staining, and there is correlation between the degree of the decrease of endocan expression and the degree of differentiation of the cancer. Treatment of cultured gastric adenocarcinoma cells with 10(-4) mol/l melatonin significantly increased the gene expression of endocan and down-regulated the activity of alkaline phosphatase and lactate dehydrogenase, two enzymes that promote de-differentiation in gastric tissue; and there was a negative correlation between the level of endocan expression and the activities of differentiation marker enzymes in the melatonin treated cancer cells. Gastric cancer cells treated with melatonin show more differentiated morphologic phenotype as compared the untreated cells. The findings indicate that melatonin may play its anticancer role in gastric adenocarcinoma by acting as a differentiation inducer.
authors.affiliation: Institute of Clinical Pharmacology, Anhui Medical University, Hefei, 230032 Anhui, People's Republic of China.
authors.forename: Sumei
authors.initials: S
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Zuo
authors.forename: Shuyu
authors.initials: S
authors.lastname: Gui
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000704:Analysis of Variance; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor; D003124:Colorimetry; D017931:DNA Primers / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000378:metabolism*
chemical_list: D017931:DNA Primers; C101134:ESM1 protein, human; D009363:Neoplasm Proteins; D011509:Proteoglycans; D007770:L-Lactate Dehydrogenase; D000469:Alkaline Phosphatase; D008550:Melatonin