Author index

Abstract

Our previous work showed that melatonin (N-acetyl-5-methoxytryptamine) inhibits proliferation of the human endometrial cancer cell line, Ishikawa, which is estrogen receptor-positive. The aim of the present study was to determine whether Ishikawa cells possess membrane melatonin receptors. Binding of the radioligand 2-[125I]-iodomelatonin to membrane preparations obtained from Ishikawa cells was detectable, saturable and stable. Scatchard analysis revealed that the dissociation constant (Kd) of the binding sites was 179.0 pm (similar to that of the MT2 [Mel1b] melatonin receptor subtype), and that the concentration (Bmax) of the binding sites was 12.9 fmol/mg protein. Luzindole, a selective MT2 melatonin receptor antagonist, significantly suppressed binding of 2-[125I]-iodomelatonin at all concentrations tested (10(-8) to 10(-4) m). These results suggest that the MT2 melatonin receptor subtype is present in the membranes of Ishikawa cells, and that the antiproliferative effect of melatonin on Ishikawa cells is mediated via the MT2 receptor. This may have implications for the use of melatonin in endometrial cancer therapy.

Melatonin membrane receptors in peripheral tissues: Distribution and functions

“…The expression of these receptors is up-regulated by the melatonin treatment and is associated with the down-regulation of the ER-beta and PRB (Chuffa et al, 2011). Influence of the melatonin on the incidence of endometrial cancer has been suggested (Sandyk et al, 1992) and the presence of the functional MT2 receptor was detected in the estrogen positive cell line derived from patient with endometrial carcinoma (Kobayashi et al, 2003). …”

Night Shift Work and the Risk of Endometrial Cancer

“…An MT2 melatonin receptor subtype that may mediate the cancer-protective effect of melatonin has been described in a human endometrial cancer cell line (15,16). This report presents the first evaluation of the relationship between night work and endometrial cancer risk in a large prospective cohort of pre-and postmenopausal women.…”

Antiproliferative effects of melatonin on the growth of rat pituitary prolactin‐secreting tumor cells in vitro

“…Melatonin has also showed to suppress tumor growth in a number of experimental models, including undifferentiated neoplasms, sarcomas and carcinomas, such as squamous cell cervical carcinomas, prostate cancer, endometrial cancer, colon cancer, trophoblastoma, choriocarcinoma, neuroblastoma, hepatocarcinoma, ovarian carcinoma, melanoma and mammary carcinoma [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Melatonin has been given to patients with solid tumors for many years with inconsistent results.…”