ag-213 and Syndrome

The major manifestations of Rieger syndrome (RS), an autosomal dominant disorder, include absent maxillary incisor teeth, malformations of the anterior chamber of the eye, and umbilical anomalies [Aarskog et al., 1983: Am J Med Genet 15:29-38; Gorlin et al., 1990: "Syndromes of the Head and Neck" 3rd ed.]. Linkage of RS to human chromosome 4q markers has been identified with tight linkage to epidermal growth factor (EGF) [Murray et al., 1992: Nat Genet 2:46-48]. Mutations associated with genes of the EGF superfamily are implicated in malformations arising from abnormal development of the first branchial arch [Ardinger et al., 1989: Am J Hum Genet 45:348-353; Sassani et al., 1993: Am J Med Genet 45:565-569]. Down-regulation of EGF during early mouse development results in ablation of tooth formation [Kronmiller et al., 1991: Dev Biol 147:485-488]. Since EGF, TGF-alpha, and EGF receptor (EGFr) transcripts are expressed in the mouse first branchial arch and derivatives, experimental strategies were employed to investigate the consequences of down-regulation of EGF translation and inhibition of EGF receptor during embryonic mandibular morphogenesis. Antisense inhibition of EGF expression produces mandibular dysmorphogenesis with decreased tooth bud size; these effects are reversed by the addition of exogenous EGF to the culture medium [Shum et al., 1993: Development 118:903-917]. Tyrphostin RG 50864, which inhibits EGF receptor kinase activity, inhibits EGF or TGF-alpha stimulation of tyrosine phosphorylation in a concentration-dependent manner and severely retards mandibular development [Shum et al., 1993: Development 118:903-917].(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Base Sequence; Catechols; Disease Models, Animal; DNA, Antisense; Epidermal Growth Factor; ErbB Receptors; Facial Bones; Gene Expression; Humans; Mice; Molecular Sequence Data; Nitriles; Protein-Tyrosine Kinases; Signal Transduction; Skull; Syndrome; Tooth Abnormalities; Transforming Growth Factor alpha; Tyrphostins