Therapeutic efficacy of the angiogenesis inhibitor O- (Chloroacetyl- carbamoyl) fumagillol (TNP-470; AGM-1470) for human anaplastic thyroid carcinoma in nude mice

TNP-470 (AGM-1470), a synthetic analog of fumagillin (6-chloroacetyl-carbamoyloxy-4-( 1,2-epoxy-1,5-dimethyl- 4-hexenyl)-5-methoxy-1-oxaspiro [2,5] octane), has been reported to reduce the supply of nutrients to experimental tumors by inhibiting angiogenesis. In this study, we investigated anti-tumor activity of TNP-470 against human thyroid anaplastic carcinoma with a view to developing a new treatment for this thyroid tumor. A transplantable tumor was established from thyroid anaplastic carcinoma of a 78-year- old woman, as a xenograft in nude mice (BALB/c, nu/nu, male). This transplantable tumor, with chromosomal abnormality was shown to be non-functional in excretory hormones and to preserve morphological characteristics of the original anaplastic tumor tissue. TNP-470 was given at a dose of 50 mg/kg b.w. to nude mice transplanted with human thyroid anaplastic carcinoma by different routes of administration: intratumoral, peritumoral, subcutaneous and intraperitoneal. Intratumoral and peritumoral administration were effective, and especially the TNP-470 administered by the former route completely inhibited tumor growth. Immunohistochemical analysis using anti-factor VIII antibody revealed the density of microvessels to be significantly decreased by local administration of TNP-470 (intratumoral administration, 7.8 ± 2.9/mm 2, control, 27.0 ± 6.3/mm 2; peritumoral administration, 9.7 ± 2.6/mm 2, control, 21.1 ±5. 1/mm 2). Our findings suggested the possibility of clinical application of TNP-470 to control the growth of human anaplastic thyroid carcinoma.