These findings indicate that the TSSC3 gene is silenced through hypermethylation of the promoter regions, a mechanism commonly associated with gene silencing in cancer.
Our laboratory has found genomic imprinting of a large genomic domain of human 11p15.5, identifying six imprinted genes within this domain: (a) insulin-like growth factor II (IGF-II), an important autocrine growth factor in a wide variety of malignancies; (b) H19, an untranslated RNA that is a putative growth suppressor gene regulating IGF-II; (c) p57KIP2, a cyclin-dependent kinase inhibitor that causes G1-S arrest; (d) KvLQT1, a voltage-gated potassium channel; (e) TSSC3, a gene that is homologous to mouse TDAG51, which is implicated in Fas-mediated apoptosis; and (f) TSSC5, a putative transmembrane protein-encoding gene.