Expression of a photoreceptor protein, recoverin, as a cancer-associated retinopathy autoantigen in human lung cancer cell lines

Cancer-Associated Retinopathy during Treatment for Small-Cell Lung Carcinoma.

“…This protein is a member of the E-F hand family of calcium-binding proteins involved in the transduction of light by vertebrate photoreceptors and is also identified as an autoantigen in CAR (12,13). It has been reported that this photoreceptor-specific protein is expressed by the tumor in CARpatients (16) and by a human lung cancer cell line (MN-1112), which was established from tumors of small-cell lung carcinoma patients with CAR (17,26). In addition, expression of recoverin was not found in patients with diabetic retinopathy, age-related macular degeneration and in small-cell lung carcinoma patients without CAR (7,17).…”

“…It has been reported that this photoreceptor-specific protein is expressed by the tumor in CARpatients (16) and by a human lung cancer cell line (MN-1112), which was established from tumors of small-cell lung carcinoma patients with CAR (17,26). In addition, expression of recoverin was not found in patients with diabetic retinopathy, age-related macular degeneration and in small-cell lung carcinoma patients without CAR (7,17). On the other hand, Adamuset al reported serum antibodies to a 46 kDa protein in CARpatients with various types of cancer and that protein sequence analysis of the peptides from the protein revealed a high homology with human enolase, an important glycolytic enzyme (27 paraneoplastic neuropathy other than CAR.In patients with paraneoplastic sensory neuropathy (28) or paraneoplastic cerebellar degeneration (29), a polyclonal complement-fixing immunoglobulin G (IgG) antibody (anti-Hu) or anti-Purkinje cell antibodies are found in the serum and cerebrospinal fluid.…”

“…CAR is associated with epithelial neoplasm, mostly small-cell lung carcinoma and is characterized by the degeneration of retinal photoreceptors (2-1 1). A photoreceptor protein, recoverin, has been recognized as the autoantigen of this disorder (12)(13)(14)(15)(16)(17). It has been reported that CARis usually found before the diagnosis of primary cancer, but there have been some reports that this disorder occurred during the treatment of malignant diseases (9,18,19).…”

Clinicopathological Features of Gastric Cancer Cases and Aberrantly Expressed Recoverin

“…As a mechanism for the apoptotic cell death of photoreceptor cells observed in CAR, it has been postulated that anti-recoverin antibody generated by unknown mechanisms in some cancer patients penetrates into the photoreceptor cells via the peripheral circulation and causes misregulation of the phototransduction pathway by blocking recoverin function (Adamus et al 1998;Maeda et al 2001b). In the initial step of CAR pathogenesis, several studies suggested that aberrant expression of retina-specific recoverin, serving as a shared antigen between tumor cells and retina, was critical since such aberrant expression of recoverin had been identified in tumor cells in CAR patients but not in non-CAR cancerous patients (Polans et al 1995;Matsubara et al 1996;Yamaji et al 1996). However, in contrast, we have recently found that aberrant expression of retina-specific recoverin occurred in more than 50% of several kinds of cancer cells, and their cell lines obtained from non-CAR cancerous patients (Maeda et al 2000;Maeda et al 2001a).…”

Autoimmune Retinopathy in Benign Thymoma after Good Syndrome-associated Cytomegalovirus Retinitis

“…Four cases of thymomaassociated autoimmune retinopathy have been reported in the literature. [1][2][3][4] In thymoma CAR, antigens that cross-react with retinal antigens (molecular mimicry) may cause retinal apoptosis, [5][6][7][8] as evidenced by serum anti-recoverin antibodies being detected in 75% of reported cases and in 50% of resected thymomas. Interphotoreceptor retinoid-binding 80…”