RESUMEN
A high level of apoptotic activity and an independence of apoptosis from the expression of p53 and bcl-2 have been observed in non-small-cell lung carcinoma. We examined 44 samples of normal, metaplastic and premalignant (i.e. mild, moderate and severe dysplasias and carcinoma in situ) bronchial epithelia to evaluate whether differences in the apoptotic activity could already be seen in the stages preceding squamous cell carcinoma of the lung (SQCLC). Apoptotic cells and bodies were visualized by 3' end labelling. The expression of p53 and members of the bcl-2 gene family, such as bcl-2, bax and mcl-1, were determined immunohistochemically with specific antibodies. The relative number of apoptotic cells and bodies [apoptotic index (AI%)] was already increased threefold as the normal bronchial epithelium changed to squamous metaplasia, and the AIs of the dysplastic lesions were about four times higher than those of the normal epithelium. Apoptosis was significantly associated with cell proliferation, as determined by proliferating cell nuclear antigen (PCNA) immunohistochemistry. However, the extent of apoptosis did not correlate with the expression of p53, bcl-2, bax and mcl-1. We conclude that, in the metaplasia-dysplasia-carcinoma sequence in the lung, the elevation of the AI% is an early event associated with cell proliferation activity, but is independent of the expression of p53, bcl-2, mcl-1 and bax.
Asunto(s)
Apoptosis , Bronquios/patología , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/patología , Neoplasias Pulmonares/patología , Lesiones Precancerosas/patología , Biomarcadores de Tumor/análisis , Bronquios/citología , Fragmentación del ADN , Células Epiteliales/citología , Epitelio/patología , Humanos , Inmunohistoquímica , Metaplasia , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Proteínas de Neoplasias/análisis , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Valores de Referencia , Estudios Retrospectivos , Proteína p53 Supresora de Tumor/análisis , Proteína X Asociada a bcl-2RESUMEN
A series of 85 lung/bronchial tissue samples from 76 patients consisting of normal, metaplastic and dysplastic epithelium and different types of lung carcinomas were analyzed for the distribution of hyaluronan (HA), using a biotinylated hyaluronan binding complex as an HA-specific probe. The normal pseudo-stratified columnar bronchial epithelium was either negative for HA or displayed a weak staining around the basal cells. The epithelia of serous and mucous bronchial glands were HA negative whereas the submucosal connective tissue was strongly positive. In metaplastic, dysplastic and carcinoma in situ lesions the whole epithelium from basal to uppermost cells expressed HA on plasma membranes. Epithelial HA was also found in squamous cell carcinomas, but not in adenocarcinomas, carcinoid tumors or small cell carcinomas of the lung. Whereas epithelial HA was present in all lesions of the squamous cell type, the staining intensity displayed great local variability in 50% of the cases with severe dysplasia, carcinoma in situ and squamous cell carcinomas. In squamous cell carcinomas, such an irregular staining pattern was significantly associated with poor differentiation. Our results indicate that the expression of HA in different bronchial lesions and lung tumors is restricted to those showing squamous cell differentiation, being absent from other types of lung carcinomas. The increase of HA depleted areas in poorly differentiated squamous cell carcinomas emphasizes the important role of HA in tumor differentiation. HA on carcinoma cell surface may influence tumor growth and metastatic behavior.
Asunto(s)
Bronquios/metabolismo , Carcinoma de Células Escamosas/metabolismo , Ácido Hialurónico/metabolismo , Neoplasias Pulmonares/metabolismo , Adenocarcinoma/metabolismo , Neoplasias de los Bronquios/metabolismo , Tumor Carcinoide/metabolismo , Carcinoma de Células Pequeñas/metabolismo , Humanos , Metaplasia/metabolismo , Lesiones Precancerosas/metabolismoRESUMEN
AIMS: We investigated the extent of apoptosis in 55 benign and malignant salivary gland tumours and its association with the immunohistochemical expression of bcl-2 and bax. METHODS AND RESULTS: Apoptosis was detected in histological sections by the 3'-end DNA labelling method. bcl-2 and bax protein expression was determined by immunohistochemistry. The frequency of apoptosis was clearly higher in malignant than in benign tumours. In pleomorphic adenomas and Warthin's tumours the average apoptotic index was 0.01% (range 0.00-0.07%) while in the malignant salivary gland tumours it was 0.42% (range 0.00-1.75%). Immunohistochemical bcl-2 expression was observed in all pleomorphic adenomas and Warthin's tumours and in most cases the expression was strong. In malignant tumours, 9/25 cases showed no expression and in the rest of the cases, apart from adenoid cystic carcinomas, the bcl-2 expression was often weak. There were significantly more cases with no or weak bcl-2 positivity in malignant than in benign salivary gland tumours (P = 0.001). There was a statistically significant association between a weak bcl-2 expression and a high frequency of apoptosis (P = 0.02). In contrast to bcl-2, strong bax expression was found in both benign and malignant tumours and was not associated with the frequency of apoptosis. CONCLUSIONS: The low bcl-2 expression in malignant tumours suggests that down-regulation of its expression might contribute to their higher frequency of apoptosis.
Asunto(s)
Apoptosis/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas/genética , Neoplasias de las Glándulas Salivales/genética , Expresión Génica/genética , Humanos , Inmunohistoquímica , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Neoplasias de las Glándulas Salivales/química , Proteína X Asociada a bcl-2RESUMEN
The present study was undertaken to analyse the extent of apoptosis in operated small cell lung carcinoma (SCLC) by using in situ labelling of the oligonucleosomal DNA fragments by terminal transferase. The extent of apoptosis was compared with the cell proliferation activity, as determined by Ki-67 immunohistochemistry; with the volume density of necrosis (per cent), as determined by the morphometric point counting method; and with the occurrence of immunohistochemically detectable p53 and bcl-2 proteins. By in situ labelling, remarkably high apoptotic indices (from 0.08 to 8.10 per cent) were seen in SCLC. A high percentage of SCLSs also showed an exceptionally high proliferation activity. Aberrant accumulation of p53 protein was seen in 37.5 per cent and bel-2 overexpression in 50 per cent of SCLCs. Necrosis was seen in 82.5 per cent of SCLCs. The extent of apoptosis was inversely related to the extent of tumour necrosis (P = 0.05) and to p53 protein accumulation (P = 0.008). A positive association was found between the extent of apoptosis and bel-2 immunoreactivity (P = 0.02). The apoptotic indices (per cent) correlated with the age (P < 0.05) and total smoking time of the patients (P = 0.06).
Asunto(s)
Apoptosis , Carcinoma de Células Pequeñas/patología , Neoplasias Pulmonares/patología , Proteína p53 Supresora de Tumor/metabolismo , Carcinoma de Células Pequeñas/metabolismo , Carcinoma de Células Pequeñas/cirugía , División Celular , Humanos , Técnicas para Inmunoenzimas , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/cirugía , Necrosis , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismoRESUMEN
This study was undertaken to determine the extent of apoptosis in lung carcinoma and to evaluate it as a prognostic marker. A series of 75 lung carcinomas (47 squamous cell carcinomas, 24 adenocarcinomas, 3 small cell carcinomas, and 1 large cell carcinoma) was analyzed for the extent of apoptosis by using the 3' end-labeling method of DNA in tissue sections. Apoptosis was correlated with the rate of cell proliferation, the immunohistochemically detectable p53 and bcl-2, the extent of tumor necrosis, and the survival data. The end-labeling method allowed a precise evaluation of the extent of apoptosis. In tumor tissue, the number of apoptotic bodies was roughly 2-fold greater than the number of apoptotic cells, whereas in nonneoplastic control tissues, the ratio was 1:1. The apoptotic indexes (percentages of apoptotic cells and bodies among tumor cells) were slightly higher in adenocarcinoma than in squamous cell carcinoma. There was no association between the extent of apoptosis and the expression of proliferating cell nuclear antigen or p53. On the other hand, tumor necrosis correlated significantly with proliferating cell nuclear antigen and p53 positivity (P = 0.00025 and 0.00087, respectively). Surprisingly, the extent of apoptosis was also found to be independent of the expression of bcl-2. Patients with apoptotic indexes greater than 1.5% had significantly shorter survival time than patients with apoptotic indexes equal to 1.50% or less (P < 0.01 by log rank). Aberrant p53 positivity also predicted a poor prognosis (P < 0.002 by log rank). By multivariate analysis, enhanced apoptosis showed a 1.9-fold risk (P = 0.04), and p53 positivity showed a 2.3-fold risk (P = 0.005) for a shortened survival. We conclude that both enhanced apoptosis and p53 positivity are independent prognostic markers in non-small cell lung carcinoma, predicting shortened survival time of the patients.