Sinclair miniature swine: an animal model of human melanoma

Gene expression in Sinclair swine with malignant melanoma

“…The downregulation of TYR, TACSTD1, GPNMB and CYP4A22 during regression and progression of the disease at a later age may be the result of a cell-mediated response that attacks metastatic melanocytes as the animals become older (Greene et al, 1997), and is consistent with the observation that animals with melanoma develop vitiligo with age (Misfeldt and Grimm, 1994).…”

“…Cutaneous malignant melanoma in Sinclair swine may have multiple primary sites and usually disseminates in the lymph nodes and visceral organs (Das Gupta et al, 1989;Greene et al, 1994;Greene et al, 1997). Some pigs may die because of widespread disease but a majority develop a cell-mediated immune response that causes complete regression of the tumors (Misfeldt and Grimm, 1994;Greene et al, 1997), although the immune response also attacks melanocytes in the skin, resulting in varying degrees of vitiligo that may progress to complete depigmentation (Misfeldt and Grimm, 1994).…”

Congenital and hereditary tumours in domestic animals. 2. Pigs. A review

“…The majority of PBLs in melanoma swine was of CD4+ T lymphocyte phenotype (59). In vitro experiments suggested that gamma-delta T, non-MHC restricted cytotoxic lymphocytes play an important immunodefensive role (57). Natural killer (NK) cytotoxicity against allogeneic swine melanoma cells was found to be significantly lower when compared to lysis of control, xenogeneic target cells (68).…”

“…Generalized depigmentation, including uveal vitiligo, appears to be associated with a cellular lymphocytic response (68) and immune response (21). Whether both types of response function alone or in combination remains unanswered (57). When' vitiligo develops early after a the occurrence of a primary melanoma in human patients, the outcome is good, but when it appears several years later, it frequently heralds metastasis (46), The storage of melanin (melanosis), often in macrophages, is another frequent feature in swine, particularly after regression.…”

“…) pigmented lesions in a heritable way in humans (18). Since Sinclair swine melanoma is an inherited neoplasm and as selective breeding increases the incidence of pigmented tumours, this animal model provides an unique opportunity yo determine the mode of inheritance (54,57). Although two loci being involved in the expression of melanomas in swine were discovered, the complete mode of inheritance has not yet been elucidated (7,73).…”