Use of nested polymerase chain reaction (PCR) for detection of retroviruses from formalin‐fixed, paraffin‐embedded uveal melanomas in cats

Abstract

Thirty‐six formalin‐fixed, paraffin‐embedded enucleated globes from cats with a diagnosis of diffuse anterior uveal melanoma were obtained. Sections of tumor were excised, deparaffinized, and subjected to nested polymerase chain reaction (PCR) to identify proviral DNA sequences from the feline leukemia virus (FeLV)–feline sarcoma virus (FeSV; 36 eyes), and the feline immunodeficiency virus (FIV; 18 eyes). All samples tested were negative for FIV DNA. Three samples were positive for FeLV–FeSV DNA. This is the first reported evidence of a possible link between naturally occurring feline anterior uveal melanoma and the presence of FeLV–FeSV DNA.

Lack of Detection of Feline Leukemia and Feline Sarcoma Viruses in Diffuse Iris Melanomas of Cats by Immunohistochemistry and Polymerase Chain Reaction

“…1,5,7,13,16,17,19 Diffuse iris melanoma is the most common primary intraocular neoplasm in cats. 5,7 While the factors involved in the induction of feline DIM have yet to be elucidated, there may be a role for the feline leukemia virus (FeLV).…”

“…6 Nested PCR for detection of FeLV/FeSV and feline immunodeficiency virus (FIV) has been performed in a group of diffuse anterior uveal melanomas/DIMs in cats. 19 The purpose of the present study was to determine if FeLV/FeSV was present in 10 feline DIMs using IHC and PCR for FeLV antigen and DNA detection, respectively.…”

“…1,5,7,13,16,17,19 Although morphologic and clinical features predictive of the biologic behavior of these neoplasms have been described, 5,13 the mechanisms of tumorigenesis of feline DIM are unknown. Feline uveal melanoma 2,18 and subcutaneous and intramuscular melanomas 15 have been experimentally induced with FeSV.…”

“…10 Feline leukemia virus/FeSV DNA has recently been detected in 3/36 feline anterior uveal melanomas/DIMs using nested PCR. 19 However, experimental data demonstrating the significance of FeLV/FeSV in the tumorigenesis of these 3 neoplasms was lacking, and the serological FeLV status of the 36 cats was unknown. The 10 feline DIMs in the present study did not demonstrate either FeLV antigen or FeLV DNA; the use of IHC and PCR provided complementary results.…”

“…Polymerase chain reaction is a highly sensitive and specific technique that can detect FeLV genomes in low copy number, latent FeLV, and replication-defective FeLV, such as FeSV. 6,12 Although nested PCR may be more sensitive than regular PCR, 19 the danger of contamination may also be greater. 8 Immunohistochemical staining detects FeLV antigen that is derived from replication of the virus and transcription and translation of viral proteins.…”