Submitted to: Journal of Cellular Biochemistry
Publication Type: Proceedings
Publication Acceptance Date: February 1, 1995
Publication Date: N/A
Technical Abstract: We report the sequence of porcine Fas antigen, which has overall identity of 60, 48, and 65% with the proteins from human, mouse, and cow, respectively. The predicted porcine Fas protein is 332 amino acids in length. In comparison to the human protein, the three cysteine-rich domains show 88% identity (70% homology); the signal transduction domain shows 93% identity (65% homology); and the negative regulation domain shows 73% identity (47% homology).Thus far, we have detected Fas mRNA in porcine corpus luteum, lung, ovary, spleen, testicle, and thymus via RT-PCR, but have failed to observe expression in brain, liver, or heart muscle. We have examined the expression of Fas mRNA in tumors taken from Sinclair miniature swine that display an inherited form of melanoma. In this animal model, tumors on animals that survive to weaning invariably regress spontaneously, a phenomenon that may proceed via apoptosis. Lesions from all stages of tumor development, from dysplastic nevi to regression phase, were examined for Fas mRNA expression via RT-PCR. Surprisingly, we detected Fas mRNA in the majority of early stage (rapidly growing) tumors, while only 3 out of 15 tumors in the regression phase tested positive. In contrast, we detected Fas mRNA in all 6 available miniature swine melanoma cell lines that were derived from tumors at various stages of development.