24 citations,
June 1999 in “Mechanisms of Development” The study demonstrated that ornithine decarboxylase (ODC) played a significant role in hair follicle development and hair growth by being associated with cell proliferation and commitment. ODC was expressed in embryonic epidermis at sites of follicle development and persisted in proliferating bulb cells of anagen follicles, except at the base of the bulb. Its expression decreased as follicles entered catagen and resumed with new follicle initiation. In vibrissae, ODC showed a complex expression pattern, being present in both the bulb and hair shaft, and in outer root sheath cells near the follicle bulge, suggesting a link to hair follicle stem cells.
88 citations,
August 1998 in “Carcinogenesis” The study demonstrated that elevated levels of ornithine decarboxylase (ODC) and polyamines, when combined with a mutant Ha-ras gene, led to spontaneous tumor development in double transgenic mice. These mice, which were bred to carry both K6/ODC and v-Ha-ras transgenes, developed well-differentiated keratoacanthomas, some of which progressed to carcinomas within 2 months. The tumor development was dependent on ODC, as the use of the ODC inhibitor DFMO prevented tumor formation and caused regression. This indicated that ODC overexpression and activated Ha-ras were sufficient for malignant transformation, providing a model to study epithelial tumor development without chemical carcinogens or tumor promoters.
42 citations,
February 1996 in “Journal of Investigative Dermatology” The study investigated the role of polyamines in hair follicle function and fiber composition in sheep. It found that inhibiting ornithine decarboxylase with alpha difluoromethylornithine altered fiber characteristics but did not inhibit wool follicle growth in culture. Conversely, inhibiting S-adenosylmethionine decarboxylase with methylglyoxal (bis)guanylhydrazone completely inhibited fiber growth, which could be reversed by adding spermidine, but not spermine. The study concluded that polyamines, particularly spermidine, were crucial for hair growth, as evidenced by the ability of spermidine to partially counteract growth depression in methionine-deficient conditions.
