A New Anorectal Melanoma Cell Line Derived from a Primary Human Rectal Tumor

Abstract

Background: Anorectal melanoma is a rare disease with poor prognosis and nonspecific symptoms, leading to difficulties in preoperative diagnosis. Here, we describe the establishment of MELS, a novel anorectal melanoma cell line derived from tumor resection of the rectum in a 40-year-old Japanese man.Methods: Histological, electron microscopic, and immunohistochemical features of S-100, HMB-45, Melan-A, and NSE positivity in the patient's tumor were confirmed as typical of surgically resected anorectal melanoma.Results: MELS cells are round or oval cells with sharp thorn-like protrusions on some or all of the cell membrane. They form irregular attached colonies with numerous floating cells in two-dimensional culture. Transmission electron microscopy revealed that some MELS cells possess cytoplasmic melanosomes. Immunocytochemically, MELS cells showed the same staining patterns as surgical tissues. MELS cells had lower growth rates than Caco-2 (a colon adenocarcinoma cell line) and A375 (a cutaneous melanoma cell line) cells. Oxaliplatin and irinotecan were more effective in MELS cells than in Caco-2 and A375 cells.

Effects of Exogenous Melatonin on Colon Glial Cells in Experimental Desynchronosis

“…Известно, что S-100 является неспецифическим биомаркером астроцитов в нервной ткани и в собственной пластинке слизистой толстой кишки выявляет их аналоги [6]. В эпителии кишки S-100 позитивные клетки имеют базальное расположение, округлую или треугольную форму и, вероятно, являются клетками диффузной эндокринной системы, так как белок S-100 встречается в нейроэндокринных опухолях кишечника [16]. В дальнейшем мы будем рассматривать только клетки собственной пластинки слизистой оболочки.…”