Paavo Pääkkö

Cell specific expression of peroxiredoxins in human lung and pulmonary sarcoidosis

Background: Six proteins of the peroxiredoxin (Prx) family have recently been characterised which have the capacity to decompose hydrogen peroxide in vivo and in vitro. These proteins may have an important role in the protection of human lung against endogenous and exogenous oxidant stress. However, the expression and distribution of these proteins in healthy human lung and diseased lung tissue is unknown. Methods: The cell specific expression of Prxs in healthy lung tissue from four non-smokers and in parenchymal tissue from 10 subjects with pulmonary sarcoidosis was investigated by immunohistochemistry, and expression of these proteins in various cultured lung cells and cells of bronchoalveolar lavage (BAL) fluid of controls and patients with sarcoidosis was assessed by Western blot analysis. Results: All six Prxs could be synthesised in cultured human lung cells. The bronchial epithelium showed moderate to high expression of Prxs I, III, V and VI, the alveolar epithelium expressed mainly Prxs V and VI, and alveolar macrophages expressed mainly Prxs I and III. Granulomas of subjects with sarcoidosis expressed mainly Prxs I and III. Samples of BAL fluid from controls and from subjects with sarcoidosis had very similar findings, except that Prxs II and III had a tendency for increased immunoreactivity in sarcoidosis tissue. Conclusions: Prxs I, III, V, and VI, in particular, have prominent and cell specific expression in human lung tissue. High expression of Prxs I and III in granulomas and alveolar macrophages of sarcoidosis parenchyma may have a significant effect on the oxidant burden and the progression of lung injury in this disease.

Expression of matrix metalloproteinase-9 in head and neck squamous cell carcinoma: a potential marker for prognosis.

Purpose: Previous studies have shown that matrix metalloproteinase-9 (MMP-9) is expressed in malignant head and neck squamous cell carcinoma. The prognostic role of MMP-9 is still unclear. The aim of this study was to investigate the role of MMP-9 immunoreactive protein as a prognostic marker for survival in head and neck squamous cell carcinoma. Experimental Design: Overexpression of the immunoreactive protein for MMP-9 was evaluated in tissue sections of 74 primary head and neck carcinomas with a monoclonal antibody using a biotin-streptavidin immunohistochemical staining method. The staining results were compared with the clinical data and to the patients’ outcome. Results: Positive immunostaining for MMP-9 was observed in 82% of the head and neck carcinomas, 39% of the cases being extensively positive. MMP-9 protein expression was independent of the stage or the grade of the tumor. The expression of MMP-9 was prognostic for shortened survival, the 5-year cause-specific survival being 45% in MMP-9 positive cases, and 92% in cases negative for MMP-9 (P = 0.013). MMP-9 positivity also correlated to the relapse-free survival (P = 0.019). At the 5-year follow-up, the cumulative relapse-free survival rate was 79% for patients with MMP-9-negative tumor and 42% for the patients with positive immunostaining for MMP-9. High expression of MMP-9 seemed to be linked with more aggressive relapses, appearing in 33% of the cases in local relapses, in 52% of cases with lymph node relapses, and in 60% of the cases with hematogenic relapses. Conclusions: This is the first study with a long follow-up showing that the immunoreactive protein of MMP-9 in head and neck carcinoma is associated with shortened relapse-free and cause-specific survival, suggesting that MMP-9 has a role in tumor progression of head and neck carcinomas, as well as in estimation of the prognosis of these diseases.

Cadmium and chromium as markers of smoking in human lung tissue.

The pulmonary cadmium (Cd) and chromium (Cr) contents from 45 decreased persons from Northern Finland were determined by plasma emission spectrometry (DCP-AES). These subjects did not have any malignant diseases or known occupational exposure to heavy metals. The pulmonary metal concentrations were compared with smoking history, pulmonary emphysema, age, and occupation. The mean Cd concentrations for the nonsmokers, smokers, and exsmokers were 0.4 (SD +/- 0.4), 3.0 (SD +/- 2.2), and 1.1 (SD +/- 1.0) micrograms/dry wt, and the corresponding values for Cr were 1.3 (SD +/- 0.9), 4.3 (SD +/- 3.3), and 4.8 (SD +/- 4.0) micrograms/g dry wt, respectively. The pulmonary Cr content increased with age and smoking time, but showed no connection with occupation. The Cd content was dependent only on smoking-related variables, increasing with the amount of tobacco smoked. The pulmonary Cd was seen to return to the level of nonsmokers in 21-22 years after cessation of smoking, whereas Cr showed no decreasing tendency with the time since smoking stopped.

Lowp53 protein expression in salivary gland tumours compared with lung carcinomas

Fifty-one salivary gland tumours (23 pleomorphic adenomas, 5 Warthins tumours, 12 mucoepidermoid carcinomas, 7 adenoid cystic carcinomas, 3 undifferentiated carcinomas and 1 acinic cell tumour) and 27 lung carcinomas (18 squamous cell carcinomas, 6 adenocarcinomas and 3 small cell carcinomas) were analysed immunohistochemically for the expression ofp53 nuclear phosphoprotein. Eight out of 51 (16%) salivary gland tumours werep53 positive. Three of these were benign and 5 malignant. All 3 benign salivary gland tumours were pleomorphic adenomas and expressed only occasional nuclear positivity with less than 1% of tumour cells positive. Of the 5p53-positive malignant tumours, 3 were mucoepidermoid carcinomas and 2 undifferentiated carcinomas. The malignant salivary gland tumours expressed more than 1% of positive nuclei in every case. Seventeen lung carcinomas werep53 positive (63%). Thirteen of these were squamous cell carcinomas, 3 were adenocarcinomas and 1 small cell lung carcinoma. The results show that mutations of thep53 gene may be infrequent in salivary gland tumours when compared with lung carcinomas. The relatively indolent course of some histological types of malignant salivary gland tumours could be associated with the preservation of the non-mutatedp53 gene in most of these tumours. The presence ofp53 positivity in some pleomorphic adenomas might, on one hand, suggest thatp53 gene alterations are also present in these tumours; on the other hand, the accumulation of thep53 protein in these tumours might also be due to some unknown mechanism, not necessarily related top53 gene mutation.

Open lung biopsy of patients with rheumatoid arthritis

SummaryIn order to shed light on the histological changes occurring in the lungs of patients with rheumatoid arthritis (RA), we scrutinized an open lung biopsy file of 199 patients and selected the patients with RA. The histopathological patterns observed were: pulmonary rheumatoid nodules (4 cases, including one with rheumatoid pneumoconiosis); usual interstitial pneumonia (UIP) (2 cases); desquamative interstitial pneumonia (2 cases); bronchiolitis obliterans with patchy organizing pneumonia (2 cases); follicular brochiolitis (1 case); organizing pneumonia always associated with bronchiolitis (3 cases); granulomatous reaction (3 cases); obliterating vasculitis (3 cases); granulomatous vasculitis (1 case); lymphoid hyperplasia (2 cases); and localized pulmonary fibrosis (1 case). The clinical data and laboratory findings for the histopathological groups overlapped and did not properly predict the anatomical picture. Both patients with UIP died of lung disease. Otherwise the prognosis in the series was good.

ABERRANT ACCUMULATION OF P53 ASSOCIATES WITH KI67 AND MITOTIC COUNT IN BENIGN SKIN LESIONS

Sixty‐two skin samples from patients with a variety of benign disorders (20 cases of psoriasis, 14 cases of chronic dermatitis, 11 seborrhoeic keratoses, 11 cases of lichen planus), and seven normal skin samples, were stained immunohistochemically with a polyclonal antibody (CM‐1) to p53, and a monoclonal antibody to Ki67, using the avidin‐biotin complex method, p53‐positive keratinocytes could be found in most of these lesions. The percentage of p53‐positive cells was, however, far lower than usually seen in p53‐positive malignant tumours. No p53 reactivity was observed in the normal skin samples. Variable Ki67 reactivity was observed in all skin samples. Overall, the number of Ki67‐positive cells was higher in skin samples in which the proportion of p53‐positive cells was high (>0.5% of total epidermal cell population) (P=0.004). This also applied separately to psoriatic and non‐psoriatic lesions (P=0.028 and P=0.033, respectively). In cases with >10% of Ki67‐positive cells, there were significantly more mitoses (P<0.001). This association applied to both psoriasis and the other lesions studied (P=0.024 and P <0.001, respectively). The results show that immunohistochemically detectable accumulation of p53 is a frequent finding in non‐neoplastic skin lesions. As p53 positivity was associated with the proliferation marker Ki67, the accumulation of p53 is possibly a response to an increased proliferation rate of the keratinocytes in these skin diseases, or alternatively it may be associated with apoptosis.

Relationship between histopathological features and the course of idiopathic pulmonary fibrosis/usual interstitial pneumonia

Background: Fibroblastic focus (FF) is the typical histopathological feature of idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP). A study was undertaken to analyse FF at diagnosis, to analyse the histopathological findings at necropsy, and to examine their association with the course of the disease. Methods: A retrospective study was made of 76 UIP cases collected over a period of 30 years from one university hospital; 64 had idiopathic IPF. The surface area of one slide of each lung biopsy specimen was defined by image analysis and the total number of FF was quantified. The histological features of necroscopic lung samples were re-analysed in 11 cases. Clinical follow up information was obtained from the registers. Results: Patients with ⩽50 FF/cm2 (nu200a=u200a34) in the lung biopsy specimen had a median survival of 89 months (95% CI 38 to 140) compared with 49 months (95% CI 36 to 62) in those with >50 FF/cm2 (nu200a=u200a42, pu200a=u200a0.0358). Diffuse alveolar damage (DAD) was detected in 10 necropsy samples and almost prevented the histopathological confirmation of UIP in six cases. Accumulation of neutrophils occurred in nine cases. There was no association between FF at diagnosis and DAD at necropsy, or between FF and exacerbation of the disease before death. Conclusions: The number of FF in lung samples before death is associated with poor survival but not with DAD, which is a common feature in necropsy specimens of patients with UIP. FF cannot predict an acute exacerbation of IPF.

Expression of the laminin γ2 chain in different histological types of lung carcinoma. A study by immunohistochemistry and in situ hybridization

Sixty‐four malignant lung tumours and 12 of their regional lymph node metastases were analysed for expression of the laminin γ2 chain by immunohistochemistry and in situ hybridization. Expression of the laminin γ2 chain was strongest in squamous cell carcinomas, followed by adenocarcinomas and large cell carcinomas. Positive cells, except for large cell carcinomas, were located at the epithelial–stromal interface of tumour clusters. An important exception was small cell lung carcinoma, with only a low level of laminin γ2 chain expression. Apart from tumour type, this may reflect the relatively scanty fibrous stroma in these tumours and supports previous observations that small cell lung carcinoma cells, contrary to other types, lack surface expression of α6β4 integrin, the specific laminin‐5 binding receptor. In frozen sections, immunohistochemistry showed linear basement membranes around tumour clusters in squamous cell carcinomas and adenocarcinomas. This shows that carcinoma cells are capable of heavy deposition of the laminin γ2 chain around tumour clusters and suggests that a laminin γ2 chain‐containing substrate may be of significance for the spread and growth of malignant tumours. Copyright

Presence of human papillomavirus DNA and abnormal p53 protein accumulation in lung carcinoma.

BACKGROUND: In some carcinomas inactivation of the tumour suppressor gene product p53, either by point mutation or indirectly by the human papillomavirus (HPV), has been suggested as two alternative routes to malignant transformation. To test this hypothesis in lung tumours, 43 lung carcinomas were analysed by in situ hybridisation and polymerase chain reaction (PCR) for the presence of HPV DNA, and the results were compared with p53 protein immunohistochemical analysis. METHODS: The presence of HPV DNA in lung carcinoma was detected by nucleic acid in situ hybridisation for HPV types 6, 11, 16, 18, 31, and 33 using nonradioactively labelled DNA probes. Polymerase chain reaction (PCR) analysis was performed on all cases showing positive HPV DNA labelling by in situ hybridisation and in an additional 13 negative cases. Abnormal nuclear accumulation of the p53 protein was revealed by immunohistochemistry using the avidin-biotin-peroxidase complex method and a CM-1 polyclonal anti-human p53 antibody and a monoclonal mutation-specific Pab 240 p53 antibody. RESULTS: HPV DNA was found by in situ hybridisation in 13 lung carcinomas (30%). In all these cases subtype-specific HPV DNA could also be detected by PCR. Abnormal p53 protein accumulation was seen in 21 of the 43 carcinomas (49%), of which 18 were HPV negative. Twelve (57%) of the CM-1 positive cases were also positive for the mutation-specific antibody Pab 240. There was an obvious inverse relationship between the presence of papilloma viral DNA and abnormal p53 protein accumulation. CONCLUSIONS: p53 plays an important part in the development of lung carcinomas and, in some cases, HPV may contribute to it by binding and inactivating the p53 protein.

Apoptosis in operated small cell lung carcinoma is inversely related to tumour necrosis and p53 immunoreactivity

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 bcl‐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 bcl‐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).