In:
Endocrine-Related Cancer, Bioscientifica, Vol. 16, No. 2 ( 2009-06), p. 549-564
Abstract:
Lytic peptide Hecate (23-amino acid (AA)) fused with a 15-AA fragment of human chorionic gonadotropin-β (CG-β), Hecate-CGβ conjugate (H-CGβ-c) selectively binds to and destroys tumor cells expressing LH/chorionic gonadotropin receptor (Lhcgr). Transgenic mice (6.5 month old) expressing SV40 T-antigen under the inhibin-α promoter (inhα/Tag) presenting with Lhcgr expressing adrenal tumors were treated either with H-CGβ-c, GnRH antagonist (GnRH-a), estradiol (E 2 ; only females) or their combinations for 1 month. We expected that GnRH-a or E 2 in combination with H-CGβ-c could improve the treatment efficacy especially in females by decreasing circulating LH and eliminating the potential competition of serum LH with the H-CGβ-c. GnRH-a and H-CGβ-c treatments were successful in males (adrenal weights 14±2.8 mg and 60±26 vs 237±59 mg in controls; P 〈 0.05). Histopathologically, GnRH-a apparently destroyed the adrenal parenchyma leaving only the fibrotic capsule with few necrotic foci. In females, H-CGβ-c was totally ineffective, whereas GnRH-a (19±5 mg) or E 2 (77±50 mg) significantly reduced the adrenal weights compared with controls (330±70 mg). Adrenal morphometry, cell proliferation markers, post-treatment suppression of serum progesterone, and quantitative RT-PCR of GATA-4, Lhcgr, and GATA-6 further supported the positive outcome. H-CGβ-c selectively killed the Lhcgr expressing tumor cells, whereas GnRH-a blocked tumor progression through gonadotropin suppression, emphasizing the gonadotropin dependency of these adrenocortical tumors. If extrapolated to humans, H-CGβ-c could be considered for the treatment of gonadotropin-dependent adrenal tumors in males, whereas in females gonadotropin suppression, but not H-CGβ-c, would work better.
Type of Medium:
Online Resource
ISSN:
1351-0088
,
1479-6821
Language:
Unknown
Publisher:
Bioscientifica
Publication Date:
2009
detail.hit.zdb_id:
2010895-3
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