Merlin Expression in Pediatric Anaplastic Ependymomas Real Time PCR Study

Most frequent molecular and immunohistochemical markers present in selected types of brain tumors

“…The NF2 gene is located on 22q, which is often lost in ependymomas in spinal localization. However, most of these tumors in intracranial localization do not have alterations of this chromosome (Buccoliero et al 2010). There have also been reported cases of ependymoma in patients with Li-Fraumeni syndrome, Turcot syndrome (Mullins et al 1998) and multiple endocrine neoplasia type 1 syndrome (Al-Salameh et al 2010).…”

Molecular genetics of ependymoma

“…Unlike many other cancers for which existing familial cancer syndromes provided important clues for our initial understanding of tumorigenic mechanisms, there are few known familial ependymoma syndromes. We do know, however, that there is increased incidence of spinal intramedullary ependymomas in patients with neurofibromatosis type 2 (NF2)[24],[25].The NF2 gene is located on chromosome 22q, which is frequently lost in patients with spinal ependymomas[25]–[27]. However, many of these tumors, especially those that occur intracranially, do not harbor NF2 mutations.…”

“…However, many of these tumors, especially those that occur intracranially, do not harbor NF2 mutations. Thus, despite that the NF2 gene may be important in the formation of some spinal ependymomas, it is probably not the critical tumor suppressor gene on chromosome 22q that is involved in sporadic intracranial ependymoma tumorigenesis[25]–[27]. Ependymoma has also been reported in patients with Li-Fraumeni syndrome, i.e.…”

“…Initial quests for tumor suppressor genes present on 22q focused on NF2 located at 22q12; however, NF2 mutation is not associated with the majority of ependymoma cases[25]–[27].Another potential tumor suppressor gene is hSNF5/INI1 at 22q11.23. Kraus et al [55] found no mutations or homozygous deletions of this gene in a series of 53 ependymomas, and this gene has not been shown to be silenced by DNA promoter methylation[56].…”

Estudo das alterações na expressão gênica dos ependimomas

“…Alterações no cromossomo 22, como monossomia ou perdas alélicas, variam nas casuísticas de ependimoma (tanto intracraniano como intramedular) de 26 a 71%, sugerindo a presença de outro gene supressor de tumor, distinto de NF2, nessa região (Weremowicz, Kupsky et al 1992;Rubio, Correa et al 1994;Hulsebos, Oskam et al 1999;Ward, Harding et al 2001;Ammerlaan, de Bustos et al 2005;Buccoliero, Castiglione et al 2010;Yao, Mack et al 2011). …”