Characterization of a small-cell-lung-carcinoma cell line from a patient with cancer-associated retinopathy

✍ Scribed by Yasufumi Yamaji; Shuji Matsubara; Ichiro Yamadori; Makoto Sato; Toshikazu Fujita; Jiro Fujita; Jiro Takahara

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: French
• Weight: 805 KB
• Volume: 65
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19960301)65:5<671::aid-ijc18>3.0.co;2-a

✦ Synopsis

We examined the biologic properties of a small-cell-lungcarcinoma (SCLC) cell line (designated MN-I I 12) established from a patient with SCLC who showed paraneoplastic retinopathy syndrome. Morphologic and immunocytochemical analyses showed that MN-I I I2 cells possess features of the classic type of SCLC. MN-I I I 2 cells grew in suspension forming relatively large clumps of cells with a doubling time of 72 hr. By light-microscope examination, the cells were relatively small and had scanty cytoplasm. The cells produced NSE, ACTH and CK (BB isozyme); they also expressed recoverin, a novel photoreceptor protein, detected by Northern-blot and Westernimmunoblot analysis using human-recoverin-specific DNA probe and anti-bovine-recoverin polyclonal antibody. This report shows that human recoverin is expressed in cultured SCLC cells. Our results support the hypothesis that, in cancer-associated retinopathy (CAR) patients, auto-immune antibody targeting for ectopic recoverin in SCLC is initially produced and cross-reacts with the retinal protein, resulting in the retinal degeneration that occurs in CAR patients.