Characterization of a small-cell-lung-carcinoma cell line from a patient with cancer-associated retinopathy.
We examined the biologic properties of a small-cell-lung-carcinoma (SCLC) cell line (designated MN-1112) established from a patient with SCLC who showed paraneoplastic retinopathy syndrome. Morphologic and immunocytochemical analyses showed that MN-1112 cells possess features of the classic type of SCLC. MN-1112 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 Western-immunoblot 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.
Yamaji
Y
Y
First Department of Internal Medicine, Kagawa Medical School, Japan.
Matsubara
S
S
Yamadori
I
I
Sato
M
M
Fujita
T
T
Fujita
J
J
Takahara
J
J
D000368:Aged; D000782:Aneuploidy; D001483:Base Sequence; D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins / Q000235:genetics; D018288:Carcinoma, Small Cell / Q000473:pathology*; D002455:Cell Division; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D005136:Eye Proteins; D015972:Gene Expression Regulation, Neoplastic; D051597:Hippocalcin; D006801:Humans; D007621:Karyotyping; D008074:Lipoproteins; D008297:Male; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger / Q000235:genetics; D051603:Recoverin; D012162:Retinal Degeneration / Q000473:pathology*; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D005136:Eye Proteins; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; C496731:RCVRN protein, human; D012333:RNA, Messenger; D051603:Recoverin; D051597:Hippocalcin