scispace - formally typeset
Search or ask a question
Author

Giuseppe Trigiante

Bio: Giuseppe Trigiante is an academic researcher from Ludwig Institute for Cancer Research. The author has contributed to research in topics: Medicine & Pandemic. The author has an hindex of 8, co-authored 8 publications receiving 1939 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: The expression of ASPP is frequently downregulated in human breast carcinomas expressing wild-type p53 but not mutant p53, therefore, ASPP regulate the tumor suppression function of p53 in vivo.

681 citations

Journal ArticleDOI
TL;DR: Polymorphism in p53 may influence individual responsiveness to cancer therapy, and clinical response following cisplatin-based chemo-radiotherapy for advanced head and neck cancer is influenced by this polymorphism, cancers expressing 72R mutants having lower response rates than those expressing 72P mutants.

432 citations

Journal ArticleDOI
TL;DR: iASPP is an evolutionarily conserved inhibitor of p53; inhibition of iASPP by RNA-mediated interference or antisense RNA in C. elegans or human cells, respectively, induces p53-dependent apoptosis and could provide an important new strategy for treating tumors expressing wild-type p53.
Abstract: We have previously shown that ASPP1 and ASPP2 are specific activators of p53; one mechanism by which wild-type p53 is tolerated in human breast carcinomas is through loss of ASPP activity. We have further shown that 53BP2, which corresponds to a C-terminal fragment of ASPP2, acts as a dominant negative inhibitor of p53 (ref. 1). Hence, an inhibitory form of ASPP resembling 53BP2 could allow cells to bypass the tumor-suppressor functions of p53 and the ASPP proteins. Here, we characterize such a protein, iASPP (inhibitory member of the ASPP family), encoded by PPP1R13L in humans and ape-1 in Caenorhabditis elegans. iASPP is an evolutionarily conserved inhibitor of p53; inhibition of iASPP by RNA-mediated interference or antisense RNA in C. elegans or human cells, respectively, induces p53-dependent apoptosis. Moreover, iASPP is an oncoprotein that cooperates with Ras, E1A and E7, but not mutant p53, to transform cells in vitro. Increased expression of iASPP also confers resistance to ultraviolet radiation and to cisplatin-induced apoptosis. iASPP expression is upregulated in human breast carcinomas expressing wild-type p53 and normal levels of ASPP. Inhibition of iASPP could provide an important new strategy for treating tumors expressing wild-type p53.

387 citations

Journal ArticleDOI
22 Apr 2004-Oncogene
TL;DR: It is demonstrated that the in vitro response of cells exposed to anticancer agents is strongly influenced by this SNP in wild-type p53, and that the outcome of chemo-radiotherapy of squamous carcinomas is more favourable in cancers retaining a wild- type 72R allele.
Abstract: A single-nucleotide polymorphism (SNP) in exon 4 results in expression of either arginine (72R) or proline (72P) at codon 72 of p53. We demonstrate that the in vitro response of cells exposed to anticancer agents is strongly influenced by this SNP in wild-type p53. In inducible systems and in cells expressing the endogenous protein, expression of 72P wild-type p53 results in a predominant G1 arrest, with only a minor apoptosis, at drug concentrations causing extensive apoptosis in cells expressing the 72R wild-type variant. The superior apoptosis-inducing activity of the 72R form correlates with more efficient induction of specific apoptosis-associated genes, and is maximal in the presence of serine 46 (S46). In vivo, the outcome of chemo-radiotherapy of squamous carcinomas is more favourable in cancers retaining a wild-type 72R allele, such cases having higher response rates and longer survival than those with wild-type 72P. Together, these results reveal that this SNP is an important determinant of response to anticancer agents in cells expressing wild-type p53. Analysis of complete p53 genotype (mutation and SNP) merits detailed investigation as a simple means for prediction of treatment response and survival in clinical oncology.

253 citations

Journal ArticleDOI
TL;DR: The identification of a new family of proteins, known as ASPPs, has led to the discovery of a novel mechanism that selectively regulates the apoptotic function, but not the cell-cycle-arrest function, of p53 and gives an insight into how p53 responds to different stress signals.
Abstract: One of the most frequently mutated genes in human cancers, tumour suppressor p53 (TP53), can induce cell-cycle arrest and apoptosis. The apoptotic function of p53 is tightly linked to its tumour-suppression function and the efficacy of many cancer therapies depends on this. The identification of a new family of proteins, known as ASPPs (ankyrin-repeat-, SH3-domain- and proline-rich-region-containing proteins), has led to the discovery of a novel mechanism that selectively regulates the apoptotic function, but not the cell-cycle-arrest function, of p53, and gives an insight into how p53 responds to different stress signals. ASPPs might be new molecular targets for cancer therapy.

137 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: Understanding the complex mechanisms that regulate whether or not a cell dies in response to p53 will ultimately contribute to the development of therapeutic strategies to repair the apoptotic p53 response in cancers.
Abstract: Compared with many normal tissues, cancer cells are highly sensitized to apoptotic signals, and survive only because they have acquired lesions — such as loss of p53 — that prevent or impede cell death. We are now beginning to understand the complex mechanisms that regulate whether or not a cell dies in response to p53 — insights that will ultimately contribute to the development of therapeutic strategies to repair the apoptotic p53 response in cancers.

3,242 citations

Journal ArticleDOI
17 May 2001-Nature
TL;DR: Deregulated cell proliferation provides a minimal 'platform' necessary to support further neoplastic progression and should be targeted withroit targeting to have potent and specific therapeutic consequences.
Abstract: Beneath the complexity and idiopathy of every cancer lies a limited number of 'mission critical' events that have propelled the tumour cell and its progeny into uncontrolled expansion and invasion One of these is deregulated cell proliferation, which, together with the obligate compensatory suppression of apoptosis needed to support it, provides a minimal 'platform' necessary to support further neoplastic progression Adroit targeting of these critical events should have potent and specific therapeutic consequences

3,151 citations

Journal ArticleDOI
TL;DR: This Review focuses on recent advances in the understanding of the regulation of p21 and its biological functions with emphasis on its p53-independent tumour suppressor activities and paradoxical tumour-promoting activities, and their implications in cancer.
Abstract: One of the main engines that drives cellular transformation is the loss of proper control of the mammalian cell cycle. The cyclin-dependent kinase inhibitor p21 (also known as p21WAF1/Cip1) promotes cell cycle arrest in response to many stimuli. It is well positioned to function as both a sensor and an effector of multiple anti-proliferative signals. This Review focuses on recent advances in our understanding of the regulation of p21 and its biological functions with emphasis on its p53-independent tumour suppressor activities and paradoxical tumour-promoting activities, and their implications in cancer.

2,247 citations

Journal ArticleDOI
TL;DR: What are the molecular mechanisms of tumour resistance to apoptosis and how can the authors use this knowledge to resensitize tumour cells to cancer therapy?
Abstract: Every cell in a multicellular organism has the potential to die by apoptosis, but tumour cells often have faulty apoptotic pathways. These defects not only increase tumour mass, but also render the tumour resistant to therapy. So, what are the molecular mechanisms of tumour resistance to apoptosis and how can we use this knowledge to resensitize tumour cells to cancer therapy?

1,948 citations

Journal ArticleDOI
18 Apr 2005-Oncogene
TL;DR: The p53 pathway responds to stresses that can disrupt the fidelity of DNA replication and cell division by activation of the p53 protein as a transcription factor that initiates a program of cell cycle arrest, cellular senescence or apoptosis.
Abstract: The p53 pathway responds to stresses that can disrupt the fidelity of DNA replication and cell division. A stress signal is transmitted to the p53 protein by post-translational modifications. This results in the activation of the p53 protein as a transcription factor that initiates a program of cell cycle arrest, cellular senescence or apoptosis. The transcriptional network of p53-responsive genes produces proteins that interact with a large number of other signal transduction pathways in the cell and a number of positive and negative autoregulatory feedback loops act upon the p53 response. There are at least seven negative and three positive feedback loops described here, and of these, six act through the MDM-2 protein to regulate p53 activity. The p53 circuit communicates with the Wnt-beta-catenin, IGF-1-AKT, Rb-E2F, p38 MAP kinase, cyclin-cdk, p14/19 ARF pathways and the cyclin G-PP2A, and p73 gene products. There are at least three different ubiquitin ligases that can regulate p53 in an autoregulatory manner: MDM-2, Cop-1 and Pirh-2. The meaning of this redundancy and the relative activity of each of these feedback loops in different cell types or stages of development remains to be elucidated. The interconnections between signal transduction pathways will play a central role in our understanding of cancer.

1,881 citations