by Lynn Lamoreux
Let's talk pigs
The well known but under utilized Sinclair Swine herd developed by Max Amoss is characterized by a high incidence of melanomas that are present at birth or soon thereafter. In these pigs, the relationship between melanoma and vitiligo is potentially illuminating of both phenomena., If the melanoma stimulates accompanying vitiligo, then commonly the melanoma regresses over the course of the first few months of the pig's life, and the vitiligo progresses to the eventual destruction of most of the skin pigmentation so that the black pigs become white by the time they are a year or two old. Interestingly, pheomelanic piglets rarely are born with the melanoma, if they are, the melanomas quickly regress, and also these pheomelanic pigs do not exhibit vitiligo.
Work with these pigs suggests three genetic loci share major responsibility for the formation of the melanoma.
The only large herd of Sinclair swine selected for melanoma is housed at Texas A&M University, where it has most recently been used to map genes related to melanoma incidence. And of course has also been used by our member John Pawelek to test some of his esoteric theories relaavent to melanoma. Many of you had a chance to admire these pigs while attending the PASPCR meeting in College Station.
The Sinclair pig is one of our best models for both melanoma and vitiligo, and the Texas A&M colony is threatened with extinction. Also it is true that Texas A&M has been able to clone several litters of pigs (other kinds of pigs) using fibroblast cells. Therefore several members of the pigment cell community have offered to obtain tissues from this herd of pigs, grow up fibroblast cells, and store them for the future. We also hope to preserve the melanoma cell lines. References below represent some of the work of Dr. Max Amoss, who has maintained these pigs for many years.
1. Spontaneous Regression of Sinclair Swine Cutaneous Malignant Melanoma Amoss, MS, Fadok, VA, Multani, AS, Pathak, S, Greene, JF, Jr., Measel, JW, Jr., Morgan, CD. In ďAdvances in Swine Biomedical Research eds Tumbleson and Schook Plenum Press, NY 1996.
1. What is Inherited in Neoplastic systems? Animal Models of Cutaneous malignant Melanoma. Clark, WH, Jr., Laboratory Investigation 711, 1994
1. Histopathology of Regression in Sinclair Swine Model of Melanoma.
Greene, JF, Jr., Townsend, JS, IV, Amoss, MS, Jr. Laboratory Investigation 7117, 1994.
2. Regression by Differentiation in the Sinclair Swine Model of Cutaneous Melanoma. Greene, JF, Jr., Morgan, CD, Rao, Amoss, MS, Jr., Arguello, F.
Melanoma Research 7471, 1997.
3. Genetic Determinants of Cutaneous malignant Melanoma in Sinclair Swine.
Blangero, J, Tissot, RG, Beattie, Amoss, MS, Jr. British Journal of Cancer 73667, 1996.
4. Genetic Predisposition and Specific Chromosomal Defects Associated with Sinclair Swine Malignant Melanomas, Pathak, S, Amoss, MS, Jr. International Journal of Oncology 1153, 1997.
5. Spontaneous Regression of Cutaneous Melanomas in Sinclair Swine is Associated with Defective Telomerase Activity and Extensive Telomere Erosion. Pathak, S, Multani, AS, McConkey DJ, Amoss, MS, Jr. International Journal of Oncology 171219, 2000.
6. Immunophenotypic Characterization of Tumor Infiltrating Lymphocytes and
peripheral Blood Lymphocytes Isolated from
Melanomatous and non-Melanomatous Sinclair Miniature Swine. Morgan, CD,
MS, Jr., Rao, A, Greene, JF, Jr. Veterinary Immunology and Immunopathology
7. Cycloheximide-induced Apoptosis in Melanoma Cells Derived from Regressing Cutaneous Tumors of
Sinclair Swine. Gossett, R, Kier, AB, Schroeder, F, McConkey, D, Fadok, V, Amoss, MS, Jr. Journal of
Comparative Pathology 115353, 1996.