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Scheda a cura di Marco Chilosi , Mattia Barbareschi e Claudio Doglioni (GYM) p63 BIBLIOGRAFIA ESSENZIALE
Mol Cell 1998 Sep;2(3):305-16 p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities. Yang A, Kaghad M, Wang Y, Gillett E, Fleming MD, Dotsch V, Andrews NC, Caput D, McKeon F. Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA. We describe the cloning of p63, a gene at chromosome 3q27-29 that bears strong homology to the tumor suppressor p53 and to the related gene, p73. p63 was detected in a variety of human and mouse tissues, including proliferating basal cells of epithelial layers in the epidermis, cervix, urothelium, and prostate. Unlike p53, the p63 gene encodes multiple isotypes with remarkably divergent abilities to transactivate p53 reporter genes and induce apoptosis. Importantly, the predominant p63 isotypes in many epithelial tissues lack an acidic N terminus corresponding to the transactivation domain of p53. We demonstrate that these truncated p63 variants can act as dominant-negative agents toward transactivation by p53 and p63, and we suggest the possibility of physiological interactions among members of the p53 family.
J Natl Cancer Inst 1999 Apr 7;91(7):594-8 The emerging p53 gene family. Kaelin WG Jr. Perturbation of p53 protein function is a common, if not universal, finding in human cancer. Tumor suppression by p53 is due, at least in part, to its ability to activate transcription of certain genes involved in cell cycle control and apoptosis (programmed cell death). Two additional members of the mammalian p53 family, p73 and p51, which is also known as p40, p63, KET, or p73L, were recently identified. Both of these proteins share substantial sequence homology with p53 and can, at least when overproduced, activate p53-responsive promoters and induce apoptosis. Nonetheless, data on differences between these proteins and p53 are emerging. For example, p73 is not induced by DNA damage and is not targeted for inactivation by viral oncoproteins such as simian virus 40 (SV40) T antigen, adenovirus E1B 55K, and human papillomavirus E6. In contrast to p53, neither p73 nor p51 appears to be frequently mutated in human cancers on the basis of the limited studies reported to date. Finally, unlike p53, cells produce multiple p73 and p51 isoforms as a result of alternative splicing, and production of p73 and p51 appears to be restricted to certain tissues. Additional studies are required to determine the role, if any, that p73 and p51 play in cell growth control and carcinogenesis.
Nature 1999 Apr 22;398(6729):708-13 p63 is a p53 homologue required for limb and epidermal morphogenesis. Mills AA, Zheng B, Wang XJ, Vogel H, Roop DR, Bradley A. Howard Hughes Medical Institute, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA. The p53 tumour suppressor is a transcription factor that regulates the progression of the cell through its cycle and cell death (apoptosis) in response to environmental stimuli such as DNA damage and hypoxia. Even though p53 modulates these critical cellular processes, mice that lack p53 are developmentally normal, suggesting that p53-related proteins might compensate for the functions of p53 during embryogenesis. Two p53 homologues, p63 and p73, are known and here we describe the function of p63 in vivo. Mice lacking p63 are born alive but have striking developmental defects. Their limbs are absent or truncated, defects that are caused by a failure of the apical ectodermal ridge to differentiate. The skin of p63-deficient mice does not progress past an early developmental stage: it lacks stratification and does not express differentiation markers. Structures dependent upon epidermal-mesenchymal interactions during embryonic development, such as hair follicles, teeth and mammary glands, are absent in p63-deficient mice. Thus, in contrast to p53, p63 is essential for several aspects of ectodermal differentiation during embryogenesis.
Nature 1999 Apr 22;398(6729):714-8 p63 is essential for regenerative proliferation in limb, craniofacial and epithelial development. Yang A, Schweitzer R, Sun D, Kaghad M, Walker N, Bronson RT, Tabin C, Sharpe A, Caput D, Crum C, McKeon F. Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA. The p63 gene, a homologue of the tumour-suppressor p53, is highly expressed in the basal or progenitor layers of many epithelial tissues. Here we report that mice homozygous for a disrupted p63 gene have major defects in their limb, craniofacial and epithelial development. p63 is expressed in the ectodermal surfaces of the limb buds, branchial arches and epidermal appendages, which are all sites of reciprocal signalling that direct morphogenetic patterning of the underlying mesoderm. The limb truncations are due to a failure to maintain the apical ectodermal ridge, a stratified epithelium, essential for limb development. The embryonic epidermis of p63-/- mice undergoes an unusual process of non-regenerative differentiation, culminating in a striking absence of all squamous epithelia and their derivatives, including mammary, lacrymal and salivary glands. Taken together, our results indicate that p63 is critical for maintaining the progenitor-cell populations that are necessary to sustain epithelial development and morphogenesis.
Trends Mol Med 2002 Mar;8(3):133-9 Mutations in the p53 homolog p63: allele-specific developmental syndromes in humans. van Bokhoven H, McKeon F. Dept of Human Genetics, University Medical Center Nijmegen, The Netherlands. p63 is the most recently discovered but most ancient member of the p53 family. In marked contrast to p53, p63 is highly expressed in embryonic ectoderm and in the basal, regenerative layers of many epithelial tissues in the adult. The p63-knockout mouse dies at birth and lacks limbs, epidermis, prostate, breast and urothelial tissues, apparently owing to the loss of stem cells required for these tissues. Significantly, several dominant human syndromes involving limb development and/or ectodermal dysplasia have been mapped to chromosome 3q27 and ultimately the gene encoding p63. The heterozygous p63mutations are distinct for each of the syndromes and are thought to act through both dominant-negative and gain-of-function mechanisms rather than a loss-of-function haploinsufficiency. The allele specificity of these syndromes offers unique molecular insights into the poorly understood actions of p63 in limb development, ectodermal-mesodermal interactions and stem cell maintenance.
Clin Cancer Res 2002 Feb;8(2):494-501 p63 expression profiles in human normal and tumor tissues. Di Como CJ, Urist MJ, Babayan I, Drobnjak M, Hedvat CV, Teruya-Feldstein J, Pohar K, Hoos A, Cordon-Cardo C. Division of Molecular Pathology, Department of Pathology, Sloan-Kettering Institute, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. PURPOSE: The p63 gene, located on chromosome 3q27-28, is a member of the p53 gene family. The product encoded by the p63 gene has been reported to be essential for normal development. EXPERIMENTAL DESIGN: In this study, we examined the expression pattern of p63 in human normal and tumor tissues by immunohistochemistry using a monoclonal antibody (clone 4A4) that recognizes all p63 splice variants, and by reverse transcription-PCR using isoform-specific primers. RESULTS: We found that p63 expression was restricted to the nucleus, with a nucleoplasmic pattern. We also observed that the expression was restricted to epithelial cells of stratified epithelia, such as skin, esophagus, exocervix, tonsil, and bladder, and to certain subpopulations of basal cells in glandular structures of prostate and breast, as well as in bronchi. Consistent with the phenotype observed in normal tissues, we found that p63 is expressed predominantly in basal cell and squamous cell carcinomas, as well as transitional cell carcinomas, but not in adenocarcinomas, including those of breast and prostate. Interestingly, thymomas expressed high levels of p63. Moreover, a subset of non-Hodgkin's lymphoma was also found to express p63. Using isoform-specific reverse transcription-PCR, we found that thymomas express all isoforms of p63, whereas the non-Hodgkin's lymphoma tended to express the transactivation-competent isoforms. We did not detect p63 expression in a variety of endocrine tumors, germ cell neoplasms, or melanomas. Additionally, soft tissue sarcomas were also found to have undetectable p63 levels. CONCLUSIONS: Our data support a role for p63 in squamous and transitional cell carcinomas, as well as certain lymphomas and thymomas.
Cancer Res. 2003 May 15;63(10):2351-7. DeltaNp63alpha and TAp63alpha regulate transcription of genes with distinct biological functions in cancer and development. Wu G, Nomoto S, Hoque MO, Dracheva T, Osada M, Lee CC, Dong SM, Guo Z, Benoit N, Cohen Y, Rechthand P, Califano J, Moon CS, Ratovitski E, Jen J, Sidransky D, Trink B. Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA. The p63 gene shows remarkable structural similarity to the p53 and p73 genes. Because of two promoters, the p63 gene generates two types of protein isoforms, TAp63 and DeltaNp63. Each type yields three isotypes (alpha, beta, gamma) because of differential splicing of the p63 COOH terminus. The purpose of this study was to determine whether there is a functional link between the distinct p63 isotypes in their transcriptional regulation of downstream targets and their role in various cellular functions. TAp63alpha and DeltaNp63alpha adenovirus expression vectors were introduced into Saos2 cells for 4 and 24 h, and then gene profiling was performed using a DNA microarray chip analysis. Seventy-four genes (>2-fold change in expression) were identified that overlapped between two independent studies. Thirty-five genes were selected for direct expression testing of which 27 were confirmed by reverse transcription-PCR or Northern blot analysis. A survey of these genes shows that p63 can regulate a wide range of downstream gene targets with various cellular functions, including cell cycle control, stress, and signal transduction. Our study thus revealed p63 transcriptional regulation of many genes in cancer and development while often demonstrating opposing regulatory functions for TAp63alpha and DeltaNp63alpha.
PATOLOGIA POLMONARE
Lab Invest 2002 Oct;82(10):1335-45 Abnormal re-epithelialization and lung remodeling in idiopathic pulmonary fibrosis: the role of deltaN-p63. Chilosi M, Poletti V, Murer B, Lestani M, Cancellieri A, Montagna L, Piccoli P, Cangi G, Semenzato G, Doglioni C. Department of Pathology, University of Verona, Verona, Italy. Products of the p63 gene, a recently described member of the p53 family, are constitutively expressed in the basal cells of human bronchi and bronchioli. The truncated isoforms of the p63 gene (deltaN-p63 proteins) counteract the apoptotic and cell cycle inhibitory functions of p53 after DNA damage, and this property is likely to be central in the cell renewal strategy of stratified epithelial tissues. To investigate the dysfunctional repair processes that characterize idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP), we immunohistochemically analyzed the expression of the transactivating and dominant-negative isoforms of the p63 gene on 16 tissue samples obtained from patients suffering from this disorder. In most IPF cases herein investigated, epithelial cells expressing deltaN-p63 were observed at sites of abnormal proliferation at the bronchiolo-alveolar junctions, characterized by epithelial hyperplasia, squamous metaplasia, bronchiolization, and abnormal p53 nuclear accumulation. Similar features were not observed in normal lung and in samples taken from other pulmonary diseases used as controls, including acute interstitial pneumonia, idiopathic bronchiolitis obliterans organizing pneumonia, nonspecific interstitial pneumonia, and desquamative interstitial pneumonia. On the basis of these findings, we can hypothesize a new model for UIP pathogenesis, involving a deregulated development of mesenchymal-epithelial interactions and abnormal proliferation of epithelial cells at the bronchiolo-alveolar junction after cell injury. In our view, the progressive loss of alveolar tissue and lung remodeling after injury in IPF/UIP is concomitantly produced by pneumocyte loss and alveolar collapse on one hand and by progressive bronchiolar proliferation and architectural distortion on the other.
Sarcoidosis Vasc Diffuse Lung Dis 2001 Mar;18(1):23-6 Constitutive p63 expression in airway basal cells. A molecular target in diffuse lung diseases. Chilosi M, Doglioni C. The p63 gene has high homology with p53, but more complex physiologic functions, including the regulation of the maintenance of basal cells in stratified epithelia. These cells in fact express high levels of the deltaN-terminal truncated isoforms of the p63 gene that can act as dominant-negative inhibiting the activity of p53. Basal cells in human bronchi and bronchioli seem to use the same strategy, since they constitutively express high levels of p63, at variance with alveolar pneumocytes. Over-expression of these isoforms in airway basal cells can inhibit important functions of the p53-pathway, including cell cycle arrest and apoptosis. This finding underlines the key role of p63 in epithelial renewal in human lung, with important implications in the understanding of the mechanisms of tissue remodelling occurring in diffuse lung diseases.
J Pathol 2002 Sep;198(1):100-9 p63 immunoreactivity in lung cancer: yet another player in the development of squamous cell carcinomas? Pelosi G, Pasini F, Olsen Stenholm C, Pastorino U, Maisonneuve P, Sonzogni A, Maffini F, Pruneri G, Fraggetta F, Cavallon A, Roz E, Iannucci A, Bresaola E, Viale G. Department of Pathology and Laboratory Medicine, European Institute of Oncology and University of Milan School of Medicine, Milan, Italy. The p63 protein, a member of the p53 family of nuclear transcription factors, is characterized by different capabilities of transactivating reporter genes, inducing apoptosis, and functioning as dominant-negative agent. This study evaluated the prevalence and prognostic implications of p63 immunoreactivity in 221 patients with stage I non-small cell lung carcinoma (NSCLC) and in 57 patients with stage I-IV neuroendocrine tumours (NET). The results were correlated with the tumour proliferative fraction, the accumulation of p53 protein, and with patient survival. p63 immunoreactivity was seen in 109/118 squamous cell carcinomas, 15/95 adenocarcinomas, 2/2 adenosquamous carcinomas, 4/6 large cell carcinomas, 9/20 poorly differentiated NET, and 1/37 typical and atypical carcinoids (p < 0.001). Furthermore, the prevalence of p63-immunoreactive cells increased progressively from pre-neoplastic and pre-invasive lesions to invasive squamous cell carcinomas. In these latter tumours, but not in adenocarcinomas, p63 immunoreactivity correlated directly with the tumour proliferative fraction (p = 0.028), and inversely with the tumour grade (p = 0.004). No relationship was found with p53 protein immunoreactivity or the other clinico-pathological variables examined. Although p63 is likely to be involved in the development of pulmonary squamous cell carcinoma, it does not carry any prognostic implication for NSCLC patients.
Mod Pathol 2001 May;14(5):521-6 Pulmonary epithelial-myoepithelial tumor of unproven malignant potential: report of a case and review of the literature. Pelosi G, Fraggetta F, Maffini F, Solli P, Cavallon A, Viale G. Department of Pathology and Laboratory Medicine, European Institute of Oncology and University of Milan School of Medicine, Italy. Epithelial-myoepithelial tumors of the lung are rare neoplasms whose biological behavior and clinical course still remain to be defined. A case of epithelial-myoepithelial tumor of the lung arising from bronchial mucosa-submucosa and occurring as a polypoid lesion of the upper left bronchus in a 47-year-old man is reported. The tumor did not infiltrate the cartilaginous wall of the bronchus and showed a biphasic histological appearance with a double layering of epithelial and myoepithelial cells. Myoepithelial spindle cells with eosinophilic cytoplasm were also observed. Mitotic figures were very rare and necrosis absent. Immunohistochemical study for epithelial and muscular markers confirmed the presence of a double-cell component in the tumor, namely epithelial and myoepithelial. The patient is alive and well, with no evidence of recurrent or metastatic disease 6 months after surgery. On the basis of the present case and the six previously reported cases, we suggest using the noncommittal term pulmonary epithelial-myoepithelial tumor of unproven malignant potential (PEMTUMP) for this type of neoplasm. In addition, we first introduce p63 as a novel marker for highlighting the myoepithelial cells of the respiratory tract and speculate on the role of these cells in the development of this unusual tumor.
Hum Pathol 2002 Sep;33(9):921-6 P63 in pulmonary epithelium, pulmonary squamous neoplasms, and other pulmonary tumors. Wang BY, Gil J, Kaufman D, Gan L, Kohtz DS, Burstein DE. Department of Pathology and Ruttenberg Cancer Center, Mount Sinai School of Medicine, the Mount Sinai Medical Center, New York, NY 10029, USA. p63 is a p53-homologous nuclear protein that appears to play a crucial role in regulation of stem cell commitment in squamous and other epithelia. In this study, p63 expression was examined in benign lung and in neoplasms of pulmonary origin. Eighty sections from routinely fixed and processed archival bronchoscopic biopsy or lobectomy specimens were pretreated with citric acid (pH 6.0) for antigen retrieval, then incubated overnight with anti-p63 monoclonal antibody 4A4. Slides were stained using a streptavidin-biotin kit and diaminobenzidine as chromagen, and were counterstained with hematoxylin. In normal lung, p63 intensely stained nuclei of bronchial reserve cells but did not stain ciliated cells, alveolar epithelial cells, or nonepithelial cells. The lower strata of squamous metaplastic bronchial epithelium stained positively. All squamous-cell carcinomas stained positively (n = 30). In some well-differentiated carcinomas, staining was found at the periphery of tumor nests but was negative in central zones showing squamous maturation. Poorly differentiated carcinomas showed very high proportions (80% to 100%) of p63-positive nuclei. All small-cell carcinomas were p63 negative (n = 9). Staining of bronchioloalveolar carcinomas (n = 7) and adenocarcinomas (n = 23) was variable: some tumors showed no detectable staining, others showed heterogeneously positive staining. Adenosquamous carcinomas (n = 5) displayed a unique basalar staining pattern. Carcinoid tumors were almost entirely negative (n = 5). We conclude that p63 is expressed in benign bronchial stem cells, in neoplastic cells with either squamous differentiation or squamous differentiating potential, and in a subpopulation of adenocarcinomas. p63 immunostaining may also aid in some histopathologic distinctions, such as in small biopsies where the differential diagnosis is poorly differentiated squamous carcinoma versus small-cell carcinoma. A stem cell biology-based classification system for squamous carcinomas is proposed.
Proc Natl Acad Sci U S A 2000 May 9;97(10):5462-7 AIS is an oncogene amplified in squamous cell carcinoma. Hibi K, Trink B, Patturajan M, Westra WH, Caballero OL, Hill DE, Ratovitski EA, Jen J, Sidransky D. Department of Otolaryngology-Head and Neck Surgery, Division of Head and Neck Cancer Research, Johns Hopkins University School of Medicine, We and others recently isolated a human p53 homologue (p40/p51/p63/p73L) and localized the gene to the distal long arm of chromosome 3. Here we sought to examine the role of p40/p73L, two variants lacking the N-terminal transactivation domain, in cancer. Fluorescent in situ hybridization (FISH) analysis revealed frequent amplification of this gene locus in primary squamous cell carcinoma of the lung and head and neck cancer cell lines. (We named this locus AIS for amplified in squamous cell carcinoma.) Furthermore, amplification of the AIS locus was accompanied by RNA and protein overexpression of a variant p68(AIS) lacking the terminal transactivation domain. Protein overexpression in primary lung tumors was limited to squamous cell carcinoma and tumors known to harbor a high frequency of p53 mutations. Overexpression of p40(AIS) in Rat 1a cells led to an increase in soft agar growth and tumor size in mice. Our results support the idea that AIS plays an oncogenic role in human cancer.
PATOLOGIA PROSTATICA
Am J Pathol 2000 Dec;157(6):1769-75 p63 is a prostate basal cell marker and is required for prostate development. Signoretti S, Waltregny D, Dilks J, Isaac B, Lin D, Garraway L, Yang A, Montironi R, McKeon F, Loda M. Department of Adult Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA. The p53 homologue p63 encodes for different isotypes able to either transactivate p53 reporter genes (TAp63) or act as p53-dominant-negatives (DeltaNp63). p63 is expressed in the basal cells of many epithelial organs and its germline inactivation in the mouse results in agenesis of organs such as skin appendages and the breast. Here, we show that prostate basal cells, but not secretory or neuroendocrine cells, express p63. In addition, prostate basal cells in culture predominantly express the DeltaNp63alpha isotype. In contrast, p63 protein is not detected in human prostate adenocarcinomas. Finally, and most importantly, p63(-/-) mice do not develop the prostate. These results indicate that p63 is required for prostate development and support the hypothesis that basal cells represent and/or include prostate stem cells. Furthermore, our results show that p63 immunohistochemistry may be a valuable tool in the differential diagnosis of benign versus malignant prostatic lesions.
Cancer Res 2002 Apr 15;62(8):2220-6 Alpha-methylacyl-CoA racemase: a new molecular marker for prostate cancer. Luo J, Zha S, Gage WR, Dunn TA, Hicks JL, Bennett CJ, Ewing CM, Platz EA, Ferdinandusse S, Wanders RJ, Trent JM, Isaacs WB, De Marzo AM. Department of Pathology, Brady Urological Institute, Johns Hopkins University, School of Medicine, Baltimore, MD 21287, USA. Identification of genes that are dysregulated in association with prostate carcinogenesis can provide disease markers and clues relevant to disease etiology. Of particular interest as candidate markers of disease are those genes that are frequently overexpressed. In this study, we describe a gene, alpha-methylacyl-CoA racemase (AMACR), whose expression is consistently up-regulated in prostate cancer. Analysis of mRNA levels of AMACR revealed an average up-regulation of approximately 9 fold in clinical prostate cancer specimens compared with normal. Western blot and immunohistochemical analysis confirms the up-regulation at the protein level and localizes the enzyme predominantly to the peroxisomal compartment of prostate cancer cells. A detailed immunohistochemical analysis of samples from 168 primary prostate cancer cases using both standard slides and tissue microarrays demonstrates that both prostate carcinomas and the presumed precursor lesion (high-grade prostatic intraepithelial neoplasia) consistently scored significantly higher than matched normal prostate epithelium; 88% of the carcinomas had a staining score higher than the highest score observed for any sample of normal prostate epithelium. Both untreated metastases (n = 32 patients) and hormone refractory prostate cancers (n = 14 patients) were generally strongly positive for AMACR. To extend the utility of this marker for prostate cancer diagnosis, we combined staining for cytoplasmic AMACR with staining for the nuclear protein, p63, a basal cell marker in the prostate that is absent in prostate cancer. In a simple assay that can be useful for the diagnosis of prostate cancer on both biopsy and surgical specimens, combined staining for p63 and AMACR resulted in a staining pattern that greatly facilitated the identification of malignant prostate cells. The enzyme encoded by the AMACR gene plays a critical role in peroxisomal beta oxidation of branched chain fatty acid molecules. These observations could have important epidemiological and preventive implications for prostate cancer, as the main sources of branched chain fatty acids are dairy products and beef, the consumption of which has been associated with an increased risk for prostate cancer in multiple studies. On the basis of its consistency and magnitude of cancer cell-specific expression, we propose AMACR as an important new marker of prostate cancer and that its use in combination with p63 staining will form the basis for an improved staining method for the identification of prostate carcinomas. Furthermore, the absence of AMACR staining in the vast majority of normal tissues coupled with its enzymatic activity makes AMACR the ideal candidate for development of molecular probes for the noninvasive identification of prostate cancer by imaging modalities.
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