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Scheda a cura di Marco Chilosi , Mattia Barbareschi e Claudio Doglioni (GYM) p63 PATOLOGIA POLMONARE
L'espressione di p63 (isoforme DN-p63) è caratteristica delle cellule basali del bronco e del bronchiolo. p63 è un ottimo marcatore (insieme alla CK5) per studiare la differenziazione e la patologia delle cellule basali, le cellule staminali delle vie aeree prossimali. Il comparto alveolare per la sua rigenerazione non utilizza la pathway p63.
figura 1. polmone fetale: espressione di p63 (isoforma DN-p63) nelle cellule basali di un bronco. Gli abbozzi alveolari sono negativi
figura 2. Nel polmone normale la isoforma DN-p63 è espressa nelle cellule basali bronco-bronchiolari, mentre l'isoforma TA-p63 è espressa nei pneumociti II
figura 3. espressione di TA-p63 nei pneumociti II iperplastici (danno alveolare diffuso)
figura 4. anomalie di espressione di DN-p63 nella componente bronchiolare della UIP
figura 5. intensa espressione di DN-p63 in un carcinoma squamoso del polmone
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.
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.
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.
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