title: iASPP: a novel protein involved in pituitary tumorigenesis?
abstract: Pituitary tumors can be morphologically classified as microadenomas (diameter<1 cm) or macroadenomas (>1 cm), which can be enclosed, invasive and/or expansive. Functionally, they are classified as secreting tumors and clinically non-secreting or 'non-functioning' tumors. Several molecular mechanisms have been studied acting in uncontrolled cell proliferation and the acquisition of resistance to apoptosis. A potential mechanism related to apoptosis control has been found following the isolation and characterization of the ASPP proteins family. All these proteins share sequence similarities in their C-termini, which contains their signature sequences of Ankyrin repeats, SH3 domain and proline-rich region. Recent investigations reported that the expression of iASPP mRNA and protein was increased in non-transformed cells induced to undergo apoptosis and inhibition of iASPP expression in these cells by siRNA reduced apoptosis. Thus, modulation of iASPP expression seems to be an integral part of the apoptotic response. The ASPP proteins family binds to proteins that are key players in controlling apoptosis (P53 and NFkappaB p65 subunit). It has been speculated that the iASPP protein product induces apoptosis by blocking NFkappaB or inhibits apoptosis by blocking P53. By either mechanism, the gene could influence the survival of precancerous lesions.
authors.forename: Emilia M
authors.initials: EM
authors.lastname: Pinto
authors.forename: Nina Rosa C
authors.initials: NRC
authors.lastname: Musolino
authors.forename: Valter A S
authors.initials: VAS
authors.lastname: Cescato
authors.forename: Iberê C
authors.initials: IC
authors.lastname: Soares
authors.forename: Alda
authors.initials: A
authors.lastname: Wakamatsu
authors.forename: Evandro
authors.initials: E
authors.lastname: de Oliveira
authors.forename: Luiz Roberto
authors.initials: LR
authors.lastname: Salgado
authors.forename: Marcello D
authors.initials: MD
authors.lastname: Bronstein
mesh_terms: D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D016328:NF-kappa B / Q000502:physiology; D010911:Pituitary Neoplasms / Q000209:etiology*; D012097:Repressor Proteins / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; C119612:PPP1R13L protein, human; D012097:Repressor Proteins; D016159:Tumor Suppressor Protein p53