Retinoblastoma-related protein pRb2/p130 and its binding to the B-myb promoter increase during human neuroblastoma differentiation

Giuseppe Raschellà, Barbara Tanno, Francesco Bonetto, Roberto Amendola, Tullio Battista, Antonio De Luca, Antonio Giordano, Marco G. Paggi

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27 Citations (Scopus)

Abstract

Neuroblastoma cells can undergo neural differentiation upon treatment with a variety of chemical inducers and growth factors. During this process, many cell cycle-related genes are downregulated while differentiation- specific genes are triggered. The retinoblastoma family proteins, pRb, p107, and pRb2/p130, are involved in transcriptional repression of proliferation genes, mainly through their interaction with the E2F transcription factors. We report that pRb2/p130 expression levels increased during differentiation of neuroblastoma cell line LAN-5. On the other hand, both pRb and p107 decreased and underwent progressive dephosphorylation at late differentiation times. The expression of B-myb and c-myb, two targets of the retinoblastoma family proteins, were downregulated in association with the increase of pRb2/p130, which was detected as the major component of the complex with E2F on the E2F site of the B-myb promoter in differentiated cells. Interestingly, E2F4, a preferential partner of p107 and pRb2/p130, was upregulated and underwent changes in cellular localization during differentiation. In conclusion, our data suggest a major role of pRb2/p130 in the regulation of B-myb promoter during neural differentiation despite the importance of cofactors in modulating the function of the retinoblastoma family proteins.
Original languageEnglish
Pages (from-to)297 - 303
Number of pages7
JournalJournal of Cellular Biochemistry
Volume67
Issue number3
DOIs
Publication statusPublished - 1 Dec 1997
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Cell Biology

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