Immunohistochemical localization of pulmonary surfactant apoproteins in various lung tumors. Special reference to nonmucus producing lung adenocarcinomas

Surfactant protein A down-regulates epidermal growth factor receptor by mechanisms different from those of surfactant protein D

We recently reported that the lectin surfactant protein D (SP-D) suppresses epidermal growth factor receptor (EGFR) signaling by interfering with ligand binding to EGFR through an interaction between the carbohydrate-recognition domain (CRD) of SP-D and N-glycans of EGFR. Here, we report that surfactant protein A (SP-A) also suppresses EGF signaling in A549 human lung adenocarcinoma cells and in CHOK1 cells stably expressing human EGFR and that SP-A inhibits the proliferation and motility of the A549 cells. Results with ¹²⁵I-EGF indicated that SP-A interferes with EGF binding to EGFR, and a ligand blot analysis suggested that SP-A binds EGFR in A549 cells. We also found that SP-A directly binds the recombinant extracellular domain of EGFR (soluble EGFR or sEGFR), and this binding, unlike that of SP-D, was not blocked by EDTA, excess mannose, or peptide:N-glycosidase F treatment. We prepared a collagenase-resistant fragment (CRF) of SP-A, consisting of CRD plus the neck domain of SP-A, and observed that CRF directly binds sEGFR but does not suppress EGF-induced phosphorylation of EGFR in or proliferation of A549 cells. These results indicated that SP-A binds EGFR and down-regulates EGF signaling by inhibiting ligand binding to EGFR as well as SP-D. However, unlike for SP-D, SP-A lectin activity and EGFR N-glycans were not involved in the interaction between SP-A and EGFR. Furthermore, our results suggested that oligomerization of SP-A is necessary to suppress the effects of SP-A on EGF signaling.

Cytological markers for predicting ALK-positive pulmonary adenocarcinoma

BACKGROUND

ALK gene rearrangement is an important class of gene mutations in pulmonary adenocarcinoma. ALK-positive pulmonary adenocarcinoma exhibits characteristic histological features, such as signet ring cell carcinoma (SRCC) and a mucinous cribriform structure. However, when insufficient histological specimens are obtained, ALK-positivity must be predicted based on cytological features. The purpose of this study was to clarify the cytological characteristics of ALK-positive pulmonary adenocarcinoma.

METHODS

We compared the cytological findings of 16 ALK-positive cases with 40 ALK-negative cases. We examined various cytoplasmic features of SRCC, including the presence of pink, yellow, or orange mucin; green, vacuolar, or vesicular cytoplasm; and green globular cytoplasmic secretions. We also examined whether the SRCC cells exhibited a pattern of individually scattered cells, the formation of cell clusters, and formation of a mucinous cribriform pattern.

RESULTS

A univariate analysis showed that significantly frequent cytological findings included pink mucin, green cytoplasm, vacuolar cytoplasm, vesicular cytoplasm, green globular cytoplasmic secretions, an individually scattered pattern, cluster formation, and a mucinous cribriform structure (all, P < .05). A stepwise multivariate logistic regression analysis identified three significant contributing factors: pink mucin (P = .03), vesicular cytoplasm (P = .06), and an individually scattered pattern (P = .01) of SRCC. If the specimens showed two or three of these features, the sensitivity and specificity were both 88% for the prediction of ALK-positive cancers.

CONCLUSION

Three cytological features of SRCC (pink mucin, vesicular cytoplasm, and an individually scattered pattern) could be useful cytological markers for the prediction of ALK-positive pulmonary adenocarcinoma.

Evidence of surfactant protein A and D expression decrement and their localizations in human prostate adenocarcinomas

AIM

Surfactant proteins (SP-A and SP-D) were originally described in the lung; however, they are also present in the prostate. Purpose of this study, therefore, was to determine how surfactant proteins are altered in prostate adenocarcinomas (PCa) and find out any connection exists between their expressions and their staining patterns, prostate-specific antigen (PSA) values, Gleason score, age, tumor volume and tumor, node, metastases (TNM) clinical stage.

METHODS

Thirty-five tissue samples were obtained during radical prostatectomy. All specimens were classified to three groups based on the Gleason score <7, 7 and Gleason score >7. Surfactant proteins' expressions were tested by immunohistochemical and Western blotting methods.

RESULTS

Immunoreactivity was detected in the cytoplasm from both basal cells and secretory epithelial cells in malignant and non-malignant areas. About 80% of the malignant basal cells were characterized as either weak or strong while non-malignant epithelial cells demonstrated strong immunoreactivity for SP-A. Also malignant (81.8%) and non-malignant cells (90.6%) were characterized as either weak or strong for SP-D. Decrement of SP-A and SP-D immunostaining tended to associate with an increasing Gleason score (p > 0.05, p < 0.05), tumor volume (p < 0.05, p > 0.05) and age (p > 0.05, p > 0.05). There was a strong positive correlation between Gleason score and tumor volume (p < 0.01). Also, either none or weak SP-A and SP-D immunoreactivity was observed specimens with Gleason score 7 or higher. SP-A and SP-D reacted with 34 kDa (SP-A) and 43 kDa (SP-D) immunoreactive single bands were decreased in tumor tissues.

CONCLUSIONS

The development of prostate cancer may be related to decreased level of surfactant protein A and D.

Surfactant protein-A concentration in sera from dogs with pulmonary parenchymal diseases

Pulmonary surfactant protein A (SP-A) is used as a biomarker to understand the clinical features of pulmonary diseases and associated prognostic indices in human medicine. This study was conducted to investigate whether or not serum SP-A concentration can be used as a biomarker for identifying pulmonary parenchymal diseases in dogs. Thirty-two dogs with pulmonary parenchymal diseases, 34 with nonrespiratory diseases and 57 healthy dogs were included. Serum SP-A concentration was measured in all dogs using sandwich enzyme linked immunosorbent assay with an anti-dog SP-A polyclonal antibody. Median serum SP-A concentration in healthy dogs was <2.0 ng/ml, whereas that in dogs with aspiration pneumonia (n=11), primary lung tumors (n=9) and blunt traumatic lung injury (BTLI; n=12) was 3.1, 7.2 and 2.6 ng/ml, respectively; these values were significantly higher than those in healthy dogs. The serum SP-A concentration in dogs with nonrespiratory diseases was comparable with that in healthy dogs. No correlation was observed between the serum SP-A and plasma C-reactive protein concentrations in dogs with aspiration pneumonia and BTLI. There was a significant correlation between the serum SP-A concentration and thoracic radiographic changes in dogs with BTLI. These findings suggest that the serum SP-A concentration may be a useful clinical biomarker of alveolar damage that can be used for differential diagnosis of pulmonary parenchymal diseases and nonrespiratory diseases in dogs.

Comparison of monoclonal napsin A, polyclonal napsin A, and TTF-1 for determining lung origin in metastatic adenocarcinomas

Thyroid transcription factor 1 (TTF-1) is currently the best immunohistochemical marker for carcinomas of lung origin. Our aim was to compare napsin A to TTF-1 for identifying pulmonary origin in metastatic adenocarcinoma and its mimics. One hundred fifty-five metastatic carcinomas (55 pulmonary, 100 nonpulmonary) were stained with monoclonal napsin A and TTF-1, and most also with polyclonal napsin A. The sensitivity of monoclonal napsin A, polyclonal napsin A, and TTF-1 for metastatic adenocarcinomas of pulmonary origin was 76%, 81%, and 82%, respectively. Two lung carcinomas were diffusely positive for monoclonal napsin A, but negative or equivocal for TTF-1. TTF-1 stained 9 of 100 nonpulmonary carcinomas (all thyroid), monoclonal napsin A stained 12 of 100 (4 sites), and polyclonal napsin A stained 27 of 91 (8 sites). Napsin A is expressed in a wider variety of metastatic nonpulmonary carcinomas than TTF-1, and the monoclonal antibody is more specific. Napsin A is a useful adjunct to TTF-1, because occasional lung adenocarcinomas are TTF-1 negative but napsin A positive.

Napsin A expression in lung and kidney neoplasia: a review and update

Napsin A is an aspartic protease present in the epithelial cells of the lung and kidney. Recent studies have shown that, in lung tumors, napsin A expression is restricted to lung adenocarcinomas, whereas among renal tumors, it is frequently expressed in renal cell carcinomas, especially the papillary and clear cell subtypes. Owing to its restricted expression, napsin A is a useful marker that can assist in the diagnosis of both lung adenocarcinomas and renal cell carcinomas.

Generation and evaluation of a monoclonal antibody, designated MAdL, as a new specific marker for adenocarcinomas of the lung

Background:

Different therapy regimens in non-small-cell lung cancer (NSCLC) are of rising clinical importance, and therefore a clear-cut subdifferentiation is mandatory. The common immunohistochemical markers available today are well applicable for subdifferentiation, but a fraction of indistinct cases still remains, demanding upgrades of the panel by new markers.

Methods:

We report here the generation and evaluation of a new monoclonal antibody carrying the MAdL designation, which was raised against primary isolated human alveolar epithelial cells type 2.

Results:

Upon screening, one clone (MAdL) was identified as a marker for alveolar epithelial cell type II, alveolar macrophages and adenocarcinomas of the lung. In a large-scale study, this antibody, with an optimised staining procedure for formalin-fixed tissues, was then evaluated together with the established markers thyroid transcription factor-1, surfactant protein-A, pro-surfactant protein-B and napsin A in a series of 362 lung cancer specimens. The MAdL displays a high specificity (>99%) for adenocarcinomas of the lung, together with a sensitivity of 76.5%, and is capable of delivering independent additional diagnostic information to the established markers.

Conclusion:

We conclude that MAdL is a new specific marker for adenocarcinomas of the lung, which helps to clarify subdifferentiation in a considerable portion of NSCLCs.

Metastatic carcinoma to subcutaneous tissue and skeletal muscle: clinicopathological features in 11 cases

OBJECTIVE

Metastatic carcinoma to subcutaneous tissue or skeletal muscle is relatively rare. The present study aimed to clarify the clinicopathological features for confirming the diagnosis as soft tissue metastasis and determining the primary site.

METHODS

We reviewed records of 11 patients with soft tissue metastasis who were in our institution from 1996 to 2009.

RESULTS

In 9 of 10 patients who underwent magnetic resonance imaging, findings consisted of poorly circumscribed high-intensity lesions around the tumor on T2-weighted images, irregular peritumoral enhancement and poorly enhanced lesions at the center of the tumor on T1-weighted images. Systematic immunohistochemical examination was more valuable for diagnosing as soft tissue metastasis and confirming the primary site. The expression patterns of cytokeratins 7 and 20 and tissue-specific antibodies such as thyroid transcription factor-1, MUC5AC and CDX2 were useful diagnostic markers. The primary site could be determined in five patients with cytokeratin 7/20 immunophenotype and positivity for tissue-specific antibodies. In four cases, determination of the primary site finally became possible by comparison with the histological findings of operative specimens in past carcinoma and/or in consideration of radiological findings and the results of cytokeratin 7/20 phenotyping.

CONCLUSIONS

Systematic immunohistochemical examination is helpful for confirmation of the primary origin in soft tissue metastasis of carcinoma in addition to clinical information such as the history and condition of past carcinoma, radiological findings and comparison between the histology of biopsy specimens and past carcinoma.

Pax8: a marker for carcinoma of Müllerian origin in serous effusions

PAX8 is a nuclear transcription factor with limited expression in normal and neoplastic tissues in a cell lineage-dependent manner. PAX8 has been detected in embryonic Müllerian ducts, human fallopian tubes, and ovarian carcinomas. However, little is known about its expression in other areas of the female genital tract. In this study, we used immunohistochemistry (IHC) to examine PAX8 expression in the normal uterine corpus and cervix, malignant tumors arising from these sites, and malignant effusions. We reported here that PAX8 was also detected in endometrial epithelial cells and endocervical glands, with a lower expression level in the latter, but not in the stromal cells of these areas. All endometrial carcinomas (N = 52) were positive for PAX8, whereas endocervical adenocarcinomas (N = 5) and uterine leiomyosarcomas (N = 3) were negative for PAX8. PAX8 was detected in 70% (22/31) and 68.8% (11/16) of metastatic carcinomas of the ovary and endometrium in serous effusions, respectively. No PAX8 was detected in carcinomas of nongynecologic origin or noncarcinomas (N = 71) in serous effusions except in one renal-cell carcinoma and one carcinoma of unknown primary in a woman. In addition, papillary serous carcinomas of the peritoneum (N = 10) were diffusely positive for PAX8, implying a Müllerian origin similar to malignant tumors in the female genital tract. Our findings suggest that PAX8 is an additional IHC marker for carcinomas of Müllerian origin hence we recommend including PAX8 for evaluation of malignant serous effusions in women, especially when tumors of Müllerian origin are in the differential diagnosis.

A study of immunohistochemical differential expression in pulmonary and mammary carcinomas

The risk of developing a second primary cancer is increased in patients with breast cancer, and the lung is one of the major sites involved. Moreover, the lung is the major metastatic site for breast cancers. A distinction between metastatic breast cancer and primary lung cancer can be histologically difficult, and both show an overlapping CK7+/CK20- immunoprofile in a majority of cases. The degree of difficulty increases with poorly differentiated tumors. We investigated differential expressions of TTF-1, Napsin A, surfactant apoprotein A, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 immunostains in 197 pulmonary carcinomas (158 adenocarcinomas, 39 squamous) and 115 invasive mammary carcinomas (91 ductal, 24 lobular type). In mammary carcinomas, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 were expressed in 74, 72, 64, and 62%, respectively, whereas TTF-1, Napsin A, and surfactant apoprotein A were all negative. The expressions were diffuse in estrogen receptor and GATA-3, and variable in mammaglobin and GCDFP-15. For a combination of estrogen receptor/mammaglobin or GATA-3/mammaglobin, 83% of mammary carcinomas were positive, and the detection rate was not improved by using all three markers. All lung squamous cell carcinomas were negative for all markers studied. TTF-1, Napsin A, and surfactant apoprotein A were positive in 80, 77, and 45% of pulmonary adenocarcinomas. None of the TTF-1-negative tumors expressed surfactant apoprotein A. GCDFP-15 was focally expressed in 2.5% of pulmonary adenocarcinomas, and estrogen receptor was focally expressed in one case (1.2%) of pulmonary adenocarcinoma. When metastasis from breast cancer is suspected in the lung, a combination of either estrogen receptor/mammaglobin or GATA-3/mammaglobin as breast markers, and a combination of TTF-1 and Napsin A as lung markers may be helpful for differentiating between the two. Caution should be taken in the interpretation of GCDFP-15 due to its occasional expression in pulmonary adenocarcinomas.

DC-LAMP stains pulmonary adenocarcinoma with bronchiolar Clara cell differentiation

DC-LAMP is a molecule expressed in mature dendritic cells, but its mRNA is also found in the lung. This study compares the immunostaining spectrum of PE-10, an antisurfactant protein monoclonal antibody; thyroid transcription factor-1 (TTF-1); and DC-LAMP in normal and neoplastic lung in an attempt to characterize the cell type(s) that express DC-LAMP. Electron microscopy was used to define cell types. DC-LAMP marks pulmonary adenocarcinomas that show Clara cell characteristics by electron microscopy. In contrast, PE-10 labels tumors that have Clara cell and type II pneumocyte differentiation. DC-LAMP staining was lost in solid type adenocarcinomas but persisted in well-differentiated areas. CC-10, an antibody that marks Clara cells, was also positive in tumors that labeled for DC-LAMP. There was no prognostic difference in tumors that reacted with DC-LAMP. DC-LAMP and CC-10 reactivity was also observed in endometrial adenocarcinomas but not in other tumor types.

Gefitinib-induced interstitial lung disease showing improvement after cessation: disassociation of serum markers

Gefitinib (ZD1839), a small-molecule epidermal growth factor receptor tyrosine kinase inhibitor, is an anticancer agent for patients with non-small cell lung carcinoma. Recently, however, as a result of accumulating evidence, it has been recognized that gefitinib can give rise to lethal lung toxicity. The authors report a case of interstitial lung disease (ILD) induced by gefitinib, which improved promptly following cessation of the administration of the agent. Clinical signs suggesting a good prognosis were noted, namely, findings similar to acute eosinophilic pneumonia on CT and a disassociation in the elevation of specific serum markers of ILD. At the time of onset of ILD, serum concentrations of surfactant protein (SP)-A and SP-D were significantly increased, whereas that of KL-6 was not increased. A previous study of three cases of lethal lung toxicity resulting from gefitinib administration revealed a significant and almost equal increase in KL-6, SP-A and SP-D. These results suggest that SP-A and SP-D may be indicators of gefitinib-induced ILD and that KL-6 is a predictor of outcome. Using a combination of these markers may help to establish a differential prognosis in patients with gefitinib-induced ILD.

Surfactant Protein A Detection in Large Cell Carcinoma of the Lung

Large cell carcinomas of the lung are undifferentiated malignant epithelial tumors that lack cytologic features of small cell carcinoma, glandular cell carcinoma, or squamous cell differentiation. Lung surfactant protein A (SP-A) is produced by alveolar type II cells and Clara cells. Most bronchioloalveolar carcinomas of the lung react positively for SP-A. Positive SP-A staining of large cell carcinoma of the lung could indicate that at least part of these tumors have the same cellular origin or differentiation as bronchioloalveolar carcinoma. The authors determined the SP-A staining of 63 large cell carcinomas of the lung by IHC. In 20 of the 63 (32%), the tumors stained positive for SP-A. This may imply that about one third of large cell carcinomas of the lung have a similar cellular origin or differentiation as bronchioloalveolar carcinoma. The significance of this finding for prognosis and new forms of treatment remains to be determined.

Napsin A is useful to distinguish primary lung adenocarcinoma from adenocarcinomas of other organs

The aim of the present study was to compare the usefulness of the peripheral airway cell markers, naspin A and surfactant protein A (SP-A), for distinguishing primary lung adenocarcinoma from adenocarcinomas of other organs in various clinical conditions. Immunohistochemical expression of napsin A and SP-A was analyzed at primary sites of 120 lung carcinomas and 40 adenocarcinomas of other organs, at lung metastatic sites of 32 adenocarcinomas of other organs, and in metastatic lymph nodes of 21 lung adenocarcinomas and 45 adenocarcinomas of other organs. Napsin A and SP-A expressions were compared between primary and recurrent sites in 8 lung adenocarcinomas. Napsin A and SP-A expressions were noted in 84.3% and 53.0% of primary sites of 83 lung adenocarcinomas, respectively, but neither napsin A nor SP-A was expressed at primary sites of other histological types of lung carcinomas or at primary or metastatic sites of adenocarcinomas of other organs. In lung adenocarcinomas, napsin A and SP-A were expressed in metastatic lymph nodes in 81.0% and 19.0%, respectively, and at recurrent sites in 87.5% and 37.5%, respectively. Napsin A is superior to SP-A for distinguishing primary lung adenocarcinoma from adenocarcinomas of other organs at primary, metastatic, and recurrent sites.

Papillary adenocarcinoma of the lung is a more advanced adenocarcinoma than bronchioloalveolar carcinoma that is composed of two distinct histological subtypes

To clarify the clinicopathological nature of papillary adenocarcinoma (PA) of the lung, 20 cases of PA were collected consecutively from resected adenocarcinoma of the lung, studied immunohistochemically and, using molecular techniques, compared with bronchioloalveolar carcinoma (BAC). Clinicopathologically, PA occurred in 7.4% and dominantly in female patients. Morphologically, PA was divided into two subtypes according to the presence of residual alveolar structures, detected by elastica van Gieson stain. One of these subtypes was closely related to the morphology of BAC and might be diagnosed as adenocarcinoma with mixed subtypes. The other PA subtype was composed of tall columnar cells and grew compressively, which was similar to type F adenocarcinoma previously reported by Noguchi et al. Immunohistochemical studies using lung tissue-specific antigens, progression markers and tumor suppressor products found that PA seemed a more advanced adenocarcinoma than BAC, but no differences were observed among PA subtypes. Molecular biological analysis using three microsatellite markers at chromosome 3p revealed more frequent loss of heterozygosity in PA than BAC, with no differences among PA subtypes. These findings suggest that PA is a more advanced adenocarcinoma subtype than BAC. Further investigations are needed to clarify true PA as clinicopathologically and biologically independent from other histological subtypes of adenocarcinoma of the lung.

Surfactant protein gene expressions for detection of lung carcinoma cells in peripheral blood

BACKGROUND

Inflow of tumor cells to circulation is an essential step for metastasis of primary tumors. To know its state may contribute to therapeutic strategy. However, methodology to detect lung carcinoma cells floating in peripheral blood has not been established. Pulmonary surfactant protein (SP)-A, SP-C and Clara cells-10 kd protein (CC10) are specific to the lung and often expressed in primary lung carcinomas. We evaluated the worth of these gene expressions for the detection of carcinoma cells in peripheral blood.

METHODS

The expressions in 5 ml of venous blood were tested by RT-PCR. Ninety-nine patients with non-small cell lung carcinoma (NSCLC) and 17 with small cell lung carcinoma (SCLC) were compared to 13 with secondary lung tumor, 48 with non-malignant respiratory diseases and 19 healthy volunteers.

RESULTS

The mRNA expressions of SP-A and SP-C were completely specific to NSCLC when compared to SCLC and secondary lung tumors. All of the healthy volunteers and patients with non-malignant respiratory diseases showed negative for these mRNA expressions, except for one sample. The positive rate of SP-A, SP-C and CC10 mRNA in patients with NSCLC was 33.3%, 14.1%, 3.3%, respectively. The rates of SP-A and SP-C mRNA were higher than that (11.1%) in CEA mRNA. The increased positive rate of mRNA of SP-A and SP-C was significantly dependent on the clinical stage and the existence of distant metastasis.

CONCLUSION

These results demonstrate that the detection of mRNA of SP-A and SP-C would give clinicians valuable information suggesting the presence of blood-floating carcinoma cells as a step toward metastasis.

Identification of a novel adhesion molecule involved in the virulence of Legionella pneumophila

Legionella pneumophila is an intracellular bacterium, and its successful parasitism in host cells involves two reciprocal phases: transmission and intracellular replication. In this study, we sought genes that are involved in virulence by screening a genomic DNA library of an L. pneumophila strain, 80-045, with convalescent-phase sera of Legionnaires' disease patients. Three antigens that reacted exclusively with the convalescent-phase sera were isolated. One of them, which shared homology with an integrin analogue of Saccharomyces cerevisiae, was named L. pneumophila adhesion molecule homologous with integrin analogue of S. cerevisiae (LaiA). The laiA gene product was involved in L. pneumophila adhesion to and invasion of the human lung alveolar epithelial cell line A549 during in vitro coculture. However, its presence did not affect multiplication of L. pneumophila within a U937 human macrophage cell line. Furthermore, after intranasal infection of A/J mice, the laiA mutant was eliminated from lungs and caused reduced mortality compared to the wild isolate. Thus, we conclude that the laiA gene encodes a virulence factor that is involved in transmission of L. pneumophila 80-045 and may play a role in Legionnaires' disease in humans.

Surfactant Protein A Detection in Primary Pulmonary Adenocarcinoma without Bronchioloalveolar Pattern

BACKGROUND

Immunohistochemical studies in human lung carcinoma reported positive staining of tumor cells for surfactant protein A (SP-A), especially in peripheral airway cell carcinoma, which include bronchioloalveolar carcinoma and in some reports also papillary subtypes.

OBJECTIVE

The purpose of this study was to determine the SP-A expression in tumor cells of lung adenocarcinoma without a bronchioloalveolar pattern, classified according to the WHO.

METHODS

In total, 169 primary adenocarcinomas of the lung (109 acinar, 32 solid with mucin, 24 papillary and 4 mucinous) were examined by immunohistochemistry for SP-A expression.

RESULTS

Twenty-five percent of acinar, 38% of papillary and 3% of solid adenocarcinoma with mucin showed a positive intracytoplasmic SP-A reaction of the tumor cells. None of the mucinous adenocarcinomas stained for SP-A. This study included the largest number of acinar adenocarcinomas and solid adenocarcinomas with mucin studied for SP-A. We clearly demonstrated that also primary lung adenocarcinoma without a bronchioloalveolar pattern can express SP-A. A positive staining of hyperplastic type II cells surrounding the tumors or entrapped in the tumor could clearly be differentiated from the SP-A-positive stain of tumor cells.

CONCLUSION

These results support the theory that SP-A-producing cells may generate not only bronchioloalveolar and papillary carcinoma, but also other subtypes of lung adenocarcinoma.

Phenotypic characteristics of mouse lung adenoma induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone

The expression profile of adenoma induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in A/J mice was compared with that of normal lung tissue by suppression subtractive hybridization (SSH). The mRNAs of surfactant-associated protein A (SP-A) and lysozyme showed characteristically higher transcription in the adenoma tissue than in normal lung. High expression of both SP-A and lysozyme in tumor cells was confirmed by in situ hybridization (ISH). In normal lung, alveolar type II pneumocytes were positive for both SP-A and lysozyme, indicating that tumor cells retained the phenotypic characteristics of the murine alveolar type II pneumocytes. Previous studies of human adenocarcinomas have shown that the two proteins are expressed reciprocally; SP-A and lysozyme are differential markers of atypical adenomatous hyperplasia (AAH) and non-goblet cell type adenocarcinoma, and of goblet cell type adenocarcinoma, respectively. Thus, the present results indicate that the phenotype of NNK-induced A/J mouse adenoma differs from that of AAH, which is thought to be a preinvasive lesion of human adenocarcinoma.

Hunting the primary: novel strategies for defining the origin of tumours

In 1995, two methods of genome-wide expression profiling were first described: expression microarrays and serial analysis of gene expression (SAGE). In the subsequent 10 years, many hundreds of papers have been published describing the application of these technologies to a wide spectrum of biological and clinical questions. Common to all of this research is a basic process of data gathering and analysis. The techniques and statistical and bio-informatic tools involved in this process are reviewed. The processes of class discovery (using clustering and self-organizing maps), class prediction (weighted voting, k nearest neighbour, support vector machines, and artificial neural networks), target identification (fold change, discriminant analysis, and principal component analysis), and target validation (RT-PCR and tissue microarrays) are described. Finally, the diagnostic problem of adenocarcinomas that present as metastases of unknown origin is reviewed, and it is demonstrated how integration of expression profiling techniques promises to throw new light on this important clinical challenge.

Immunohistochemical panel of antibodies in the diagnosis of brain metastases of the unknown primary

The primary tumor of brain metastases (BM) is unknown in up to one-half of BM at the time of neurosurgery. Fifty-four consecutive unselected BM were investigated immunohistochemically using antibodies against different intermediate filaments and tumor markers. By correlating the immunohistochemical results with the location of the primary tumor, a staining pattern characteristic of the most frequent BM could be established. Subsequently, 40 cases with known primary tumor were blinded and re-evaluated based on their immunohistochemical staining pattern. Lung (20.4%), colorectum (11.1%), melanoma (7.4%), and breast (7.4%) were the most common primaries. In 14 (25.9%) cases, the primary was unknown. The characteristic immunohistochemical profiles of BM were found to be positivity of cytokeratin 7 and thyroid transcription factor-1 (TTF-1) pointing to the lung, positivity of cytokeratin 20 and negativity of cytokeratin 7 pointing to the colorectum, positivity of vimentin and protein S100 and negativity of cytokeratins (CK) pointing to a melanoma, and positivity of cytokeratin 7 and CA 15-3 with negativity of TTF-1, CA 125 and CA 19-9 pointing to the breast. These primaries comprise the majority in our series. Using the established panel of immunohistochemical markers, we were able to identify the primary in 29 out of 40 (72.5%) BM correctly. To predict the primaries of BM, a combination of antibodies against different CK, vimentin, protein S100, TTF-1, and CA 15-3 is able to point to the primary site in BM of the unknown primary.

Combined status of MUC1 mucin and surfactant apoprotein A expression can predict the outcome of patients with small-size lung adenocarcinoma

AIM

Lung cancer is still a disease of high mortality, despite advanced diagnostic techniques. Here, we aim to report a unique method to predict the recurrence and outcome of patients with pulmonary adenocarcinomas.

METHODS AND RESULTS

Immunohistochemical expression of MUC1 mucin and surfactant apoprotein A (SP-A) was examined in 185 cases of surgically removed lung adenocarcinomas of non-bronchioloalveolar type smaller than 30 mm. Staining results were evaluated semiquantitatively, and the expression of MUC1 and SP-A was compared in each case. There were 140/185 (76%) cases showing MUC1 expression higher than SP-A expression (MUC1>SP-A), and 45/185 (24%) cases showing MUC1 expression lower than or equal to SP-A expression (MUC1<or =SP-A). Recurrence was observed in 24% (34/140) of the patients with a MUC1>SP-A pattern, but in 7% (3/45) of the patients with a MUC1< or =SP-A pattern after the median observation period of 41 months (1-99 months) (P < 0.01). The MUC1>SP-A group showed higher recurrence and worse survival than the MUC1<or =SP-A group by Kaplan-Meier's method (P < 0.01 and P < 0.005). Even in the patients with apparently favourable prognostic factors (well-differentiated adenocarcinoma or no lymph node metastasis), recurrence and survival were different between the two groups.

CONCLUSIONS

A high MUC1/SP-A ratio is strongly associated with a poor outcome in patients with small-size lung adenocarcinoma.

Aspartic proteinase napsin is a useful marker for diagnosis of primary lung adenocarcinoma

Napsin A is an aspartic proteinase expressed in lung and kidney. We have reported that napsin A is expressed in type II pneumocytes and in adenocarcinomas of the lung. The expression of napsin was examined in 118 lung tissues including 16 metastases by in situ hybridisation. Napsin was expressed in the tumour cell compartment in 33 of 39 adenocarcinomas (84.6%), in two of 11 large cell carcinomas and in one lung metastasis of a renal cell carcinoma. Expression of napsin was found to be associated with a high degree of differentiation in adenocarcinoma. Immunohistochemistry was performed for three proteins currently used as markers for lung adenocarcinoma : surfactant protein-A, surfactant protein-B and thyroid transcription factor-1. Thyroid transcription factor-1 showed the same sensitivity (84.6%) as napsin for adenocarcinoma, whereas surfactant protein-A and surfactant protein-B showed lower sensitivities. Among these markers, napsin showed the highest specificity (94.3%) for adenocarcinoma in nonsmall cell lung carcinoma. We conclude that napsin is a promising marker for the diagnosis of primary lung adenocarcinoma.

Lung carcinoma metastasis presenting as a pineal region tumor

An autopsy case is reported of pineal metastasis from lung adenocarcinoma, which is a rare manifestation of the disease. A 75-year-old man who had been found to have a lesion in the lung by chest CT 2 years previously, became aware of head heaviness and then suffered consciousness disturbance. Brain MRI revealed a solitary mass in the pineal region with hydrocephalus. At autopsy a midsagittal section of the brain disclosed a well-circumscribed mass consisting of epithelial cells occupying the third ventricle. Although it should be recognized that such metastasis is very rare, the present case provides further information that might be useful for diagnosis.

Assessment of differentiation in adenocarcinoma cells from pleural effusion by peripheral airway cell markers and their diagnostic values

Ultrastructural studies have shown that Clara cell-type is a more common type of adenocarcinoma than alveolar type II cell-type, and that both types may provide better prognosis than other types, indicating an importance of differentiation toward peripheral airway cells. Pulmonary surfactant protein (SP)-A is a specific marker for both alveolar type II cells and Clara cells in peripheral lung tissues, while SP-C and Clara cell 10 kD protein (CC10) may be particularly and highly specific to alveolar type II cells and Clara cells, respectively. The aims of this study were to assess the differentiation of adenocarcinoma cells in pleural effusions by evaluating the expression of these cell markers and to evaluate their values as diagnostic tools for judging the cause of pleural effusion. We examined pleural effusions from 52 patients; 20 with primary lung adenocarcinomas, 6 with small cell lung carcinomas, 11 with metastatic malignant tumors and 15 with non-neoplastic diseases. The cell pellets from effusions were subjected to immunocytochemical staining for SP-A, proSP-C, a precursor of SP-C, and CC10. By this immunocytochemical study for SP-A and proSP-C, 10 (50%) and 6 (30%) of 20 adenocarcinomas, respectively, showed a positive immunoreactivity in their effusion cells, while none of them expressed CC10. Alveolar type II cells therefore may be the main progenitor cells of some adenocarcinomas. In pleural effusions from patients with primary lung adenocarcinomas, reverse transcriptase-polymerase chain reaction (RT-PCR) for SP-A mRNA showed a sensitivity of 83%, while, in all remaining patients, these assays were negative. In conclusion, we demonstrated that lung adenocarcinomas, which are partially differentiated toward alveolar type II cells, are not as rare as previously thought, and that both the RT-PCR and immunocytochemical analyses for SP-A and pro-SP-C could be worthy indicators of differential diagnosis.

Surfactant protein A expression in human normal and neoplastic breast epithelium

We studied the presence of surfactant protein A (Sp-A) immunoreactivity and messenger RNA in 62 normal and abnormal breast samples. Sections were immunostained with polyclonal anti-Sp-A antibody. The association between Sp-A immunoreactivity and histologic grade of 32 invasive ductal carcinomas was assessed by 3 pathologists who scored the intensity of Sp-A immunoreactivity times the percentage of tumor immunostained; individual scores were averaged, and the final scores were correlated with tumor grade, proliferative index, and expression of estrogen and progesterone receptors. Strong Sp-A immunoreactivity was present at the luminal surface of ductal epithelial cells in normal breast samples and in benign lesions; carcinomas displayed variable immunoreactivity, inversely proportional to the degree of differentiation. Sp-A messenger RNA was detected by reverse transcriptase-polymerase chain reaction in 3 of 3 normal breast samples and 9 of 9 carcinomas. The significance of Sp-A expression in breast epithelium requires further study; possibly it has a role in native host defense or epithelial differentiation.

Use of thyroid transcription factor 1, PE-10, and cytokeratins 7 and 20 in discriminating between primary lung carcinomas and metastatic lesions in fine-needle aspiration biopsy specimens

BACKGROUND

The distinction of a primary lung carcinoma from a metastatic lesion is important, because the treatment and prognosis differ for patients with these malignancies. Such a distinction can be difficult because of overlapping cytologic features. It has been shown that antibodies to thyroid transcription factor 1 (TTF-1) and PE-10 are fairly specific markers for primary lung tumors in histologic specimens. TTF-1 regulates the expression of surfactant protein production, and PE-10 is a monoclonal antibody against components of human surfactant proteins. The combination of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) immunoprofiling has been helpful in the identification of the primary site of origin of lung tumors.

METHODS

In the current study, the authors evaluated the utility of TTF-1 and PE-10 immunostaining and also compared the staining with expression of CK7 and CK20 in the discrimination between primary lung tumors and metastatic lesions in 55 specimens from fine-needle aspiration (FNA) biopsies of the lung. Formalin fixed, paraffin embedded cell blocks from 35 primary lung tumors (16 adenocarcinomas, 8 squamous cell carcinomas, 6 large cell undifferentiated carcinomas, and 5 small cell carcinomas) and 20 metastatic carcinomas (6 breast lesions, 6 colon lesions, 3 urinary bladder lesions, 2 kidney lesions, 1 biliary tract lesion, 1 endometrial lesion, and 1 thyroid lesion) were immunostained with monoclonal antibodies to TTF-1, PE-10, CK7, and CK 20. Positive immunostaining for CK7, CK20, and PE-10 was based on cytoplasmic staining, whereas TTF-1 positive staining was based on nuclear staining of the neoplastic cells.

RESULTS

Positive immunostaining with TTF-1 and PE-10 was noted in six primary lung tumors (17%). One metastatic lesion (5%) and two metastatic lesions (10%) were positive for TTF-1 and PE-10, respectively. The CK7 positive/CK20 negative immunophenotype was noted in 30 primary lung tumors (86%) and in 11 metastatic lesions (55%). The CK7 negative/CK20 negative immunophenotype was seen in four metastatic lesions and in the remaining five primary lung tumors. The CK7 negative/CK20 positive and CK7 positive/CK20 positive immunophenotypes were seen in two and three metastatic lesions, respectively, but in none of the primary lung tumors. When a CK7 positive/CK20 negative adenocarcinoma also demonstrated either TTF-1 positive or PE-10 positive staining, it was likely that the adenocarcinoma was of pulmonary origin (P < 0.035; Fisher exact test). The specificity of such a combination for discriminating between primary and metastatic adenocarcinomas was 94%.

CONCLUSIONS

The results suggest that TTF-1, PE-10, or CK7/CK20 alone did not distinguish reliably between primary pulmonary tumors carcinomas and metastatic neoplasms of the lung in FNA biopsy specimens because of low sensitivity and specificity. The use of a panel of antibodies that includes CK7/CK20, TTF-1, and PE-10 may be helpful in discriminating between primary and metastatic adenocarcinomas of the lung. An adenocarcinoma is likely a primary lung tumor when it is of the CK7 positive/CK20 negative phenotype and demonstrates either TTF-1 positive or PE-10 positive staining.

Prognostic significance of frequent acidophilic nuclear inclusions in adenocarcinoma of the lung with immunohistochemical and ultrastructural studies

BACKGROUND

Adenocarcinoma of the lung occasionally has acidophilic nuclear inclusions (ANIs). Some studies have reported that the incidence of ANIs was higher in well differentiated tumor types and have suggested that adenocarcinoma patients with ANIs might have a more favorable prognosis; however, to the authors' knowledge, statistically significant prognostic findings were not reported. The objective of the current study was to assess the prognostic significance of ANI in patients with pulmonary adenocarcinoma and, moreover, to characterize ANI immunohistochemically and ultrastructurally.

METHODS

Surgically resected tumor specimens from 147 patients with primary pure adenocarcinoma of the lung were examined. Only obvious ANIs surrounded by a clear halo on hematoxylin and eosin-stained slides were counted; the authors classified cases with > or = 10 ANIs per 10 high-power fields (/10 HPF) as frequent-ANI cases, cases with < 10 ANIs/10 HPF as infrequent-ANI cases, and cases without ANIs as non-ANI cases in the current study.

RESULTS

Nineteen frequent-ANI cases (12.9%) and 16 infrequent-ANI cases (10.9%) were found; the remaining 112 cases (76.2%) were considered to be non-ANI cases. The majority of ANIs immunohistochemically contained surfactant apoprotein and ultrastructurally corresponded to invagination of the inner nuclear membrane, showing a tubular or amorphous configuration. Frequent-ANI patients showed significantly better prognosis than the other two groups on both overall univariate analysis and univariate analysis limited to patients with International Union Against Cancer Stage I disease (P = 0.0096 and P = 0.0095, respectively). However, on the multivariate analysis only disease stage was shown to be a significant prognostic factor and frequent-ANI showed borderline significance (P = 0.0956).

CONCLUSIONS

Frequent ANIs appear to be of limited value in clarifying the prognosis of patients with lung adenocarcinoma.

Different subtypes of human lung adenocarcinoma caused by different etiological factors. Evidence from p53 mutational spectra

Human lung adenocarcinomas are only relatively weakly associated with tobacco smoke, and other etiological factors need to be clarified. These may also vary with the histopathology. Because the p53 mutation status (frequency and spectrum) of a carcinoma can provide clues to causative agents, we subclassified 113 adenocarcinomas into five cell types: hobnail, columnar/cuboidal, mixed, polygonal, and goblet (54, 23, 18, 13, and 5, respectively) and investigated relationships with p53 mutations and smoking history. In the hobnail cell type, a low mutational frequency (37%) and a high proportion of transitions (65%), especially G:C to A:T transitions at CpG dinucleotides (45%) associated with spontaneous mutations, were found with a weak relation to tobacco smoke. In contrast, a high mutation frequency (70%) with a higher proportion of transversions (50%), especially G:C to T:A (44%) on the nontranscribed DNA strand, caused by exogenous carcinogenic agents like tobacco smoke, were observed for the columnar cell type, as with squamous cell carcinomas. These results indicate that two major subtypes of lung adenocarcinoma exist, one probably caused by tobacco smoke, and the other possibly due to spontaneous mutations. For the prevention of lung adenocarcinomas, in addition to stopping tobacco smoking, the elucidation of endogenous mechanisms is important.

Tumor uptake of radioiodinated anti-human pulmonary surfactant-associated protein monoclonal antibody PE10 in nude mice bearing human pulmonary adenocarcinoma in combination with an unlabeled preload

This study assessed the potential use of radioimmunoscintigraphy of pulmonary alveolar Type II cells tumor with the radiolabeled anti-human surfactant-associated protein (SP) monoclonal antibody (MAb) PE 10 in combination with preloads of unlabeled MAb. The in vitro binding of iodine-125 ((125)I)-labeled MAb PE 10 (1 microg), which had a specific radioactivity of 400 MBq/mg, on human pulmonary papillary adenocarcinoma NCI-H441 cells that produced SP was investigated. In NCI-H441 tumor-bearing nude mice, the tumor uptake of (125)I-MAb PE 10 (5 microg) was examined in combination with preloads of unlabeled MAb PE 10 (0, 5, 10, and 50 microg). An isotype-matched unassociated murine MAb was used as a control both in vitro and in vivo. (125)I-MAb PE 10 showed specific cell binding compared with (125)I-control MAb. Tumor uptake of (125)I-MAb PE 10 in vivo reached a peak of 4.97+/-0.33% injected dose per gram (%ID/g) at 48 h postinjection. Preloads of 5 and 10 microg unlabeled MAb PE 10 significantly enhanced tumor uptake at 48 h postinjection ( 5.94+/-0.29% ID/g and 5.72+/-0.29% ID/g, respectively), whereas preload of 50 microg unlabeled MAb PE 10 significantly decreased tumor uptake ( 2.75+/-0.32% ID/g) at 48 h. Preload of 5 microg unlabeled MAb PE 10 significantly increased the tumor-to-blood radioactivity ratio at 48 h ( 2.39+/-0.16). Preloads of unlabeled control MAb did not cause any significant change in tumor uptake. Immunohistochemistry showed the intracellular and pericellular patterns of SP expression in tumor cells. In conclusion, radioimmunoscintigraphy with MAb PE 10 labeled with a gamma-emitting radioiodine such as (123)I might be a useful means of targeting pulmonary alveolar Type II tumor cells in combination with preloading with an optimal dose of the unlabeled MAb.

Cancer proteomics: from identification of novel markers to creation of artifical learning models for tumor classification

Studies of global protein expression in human tumors have led to the identification of various polypeptide markers, potentially useful as diagnostic tools. Many changes in gene expression recorded between benign and malignant human tumors are due to post-translational modifications, not detected by analyses of RNA. Proteome analyses have also yielded information about tumor heterogeneity and the degree of relatedness between primary tumors and their metastases. Results from our own studies have shown a similar pattern of changes in protein expression in different epithelial tumors, such as decreases in tropomyosin and cytokeratin expression and increases in proliferating cell nuclear antigen (PCNA) and heat shock protein expression. Such information has been used to create artificial learning models for tumor classification. The artificial learning approach has potential to improve tumor diagnosis and cancer treatment prediction.

Surfactant protein C expression in urethane-induced murine pulmonary tumors

Mice injected with urethane develop tumors with distinct histological patterns, which are classified as solid, papillary, or a mixture of these two patterns within the same tumor. Most investigators agree that solid tumors arise from alveolar type II cells, but the cellular origin of papillary tumors is less certain, being attributed to either type II cells or nonciliated bronchiolar epithelial (Clara) cells. To characterize the state of differentiation of these tumors more precisely and to provide additional information on gene expression, we used immunocytochemistry and/or in situ hybridization to determine the cellular localization of surfactant-associated proteins A (SP-A), SP-B, SP-C, and SP-D; Clara cell-associated protein CC-10; and thyroid transcription factor-1. In normal mouse lung, the messenger RNAs (mRNAs) for SP-A, SP-B, and SP-D were expressed in both type II cells and Clara cells. SP-C mRNA, however, was expressed only in type II cells, and CC-10 expression of mRNA was restricted to Clara cells. All tumors examined, both solid and papillary, expressed SP-A, SP-B, SP-C, SP-D, and thyroid transcription factor-1, but not CC-10. However, SP-C expression was slightly diminished in larger (older) papillary tumors. These results demonstrate that urethane-induced murine lung tumors express the type II cell phenotype.

Thyroid transcription factor-1 is the superior immunohistochemical marker for pulmonary adenocarcinomas and large cell carcinomas compared to surfactant proteins A and B

AIMS

Antibodies against the thyroid transcription factor-1 (TTF-1) and the surfactant proteins A and B (SPA, SPB) were compared as paraffin-reactive immunohistochemical markers for non-small cell carcinomas of pulmonary origin.

METHODS AND RESULTS

We studied 138 carcinomas of pulmonary origin (98 adenocarcinomas, 20 non-neuroendocrine large cell carcinomas, 20 squamous cell carcinomas) and a total of 276 extrapulmonary carcinomas of various primary origins. Using the monoclonal antibody 8G7G3/1, TTF-1 was detectable in 75% of non-mucinous pulmonary adenocarcinomas and in 40% of large cell carcinomas but in only 10% of mucinous adenocarcinomas and not in squamous cell carcinomas. In contrast, both SPA and SPB were positive in only 45% of pulmonary adenocarcinomas and in 10% and in 5% of the large cell carcinomas, respectively. TTF-1 had a specificity of 0.98 for pulmonary carcinomas as 5/7 thyroid carcinomas were the only TTF-1-positive extrapulmonary tumours. Anti-SPB and anti-SPA had specificities of 1. 00 and 0.97, respectively.

CONCLUSIONS

The monoclonal antibody 8G7G3/1 against TTF-1 should be the first choice as a component of an antibody panel aiming to prove or to exclude the pulmonary origin of non-mucinous adenocarcinomas and non-neuroendocrine poorly differentiated carcinomas, especially in patients presenting with metastatic carcinomas of unknown primary site.

Napsin A, a member of the aspartic protease family, is abundantly expressed in normal lung and kidney tissue and is expressed in lung adenocarcinomas

A pair of 35 kDa polypeptides (TAO1/TAO2) are expressed in more than 90% of all primary lung adenocarcinomas but not in other major malignancies. Mass spectrometry of tryptic peptides showed that TAO1/TAO2 is identical to napsin A, a recently described member of the aspartic proteinase family. The site of processing of pronapsin A to the mature form was located. Napsin expression was detected in human lung adenocarcinoma tumors, compatible with the marker nature of TAO1/TAO2 in the diagnosis of primary lung adenocarcinoma. This is important since identification of markers which can distinguish primary lung adenocarcinomas from distant metastases is desirable. Northern blot analysis showed expression of napsin also in normal lung and kidney tissue, and in situ hybridization showed expression in type II alveolar cells of the lung. This protease is concluded to have a specific functional role in the normal alveolar epithelium and is a candidate protease for the proteolytic processing of surfactant precursors.

Utility of surfactant protein B precursor and thyroid transcription factor 1 in differentiating adenocarcinoma of the lung from malignant mesothelioma

Differentiation of malignant mesothelioma from adenocarcinoma, particularly from a lung primary, remains a difficult diagnostic problem. Surfactant protein B precursor (pro-SP-B) and thyroid transcription factor 1 (ITF-1) are expressed selectively in the normal respiratory epithelium and in adenocarcinomas of the lung. In this study, we evaluated the utility of pro-SP-B and ITF-1 in distinguishing pulmonary adenocarcinomas and malignant mesotheliomas. Immunoreactivity for pro-SP-B and TTF-1 was examined in paraffin sections of 370 primary lung carcinomas (208 adenocarcinomas, 101 squamous cell carcinomas, and 61 large cell carcinomas) and 95 malignant mesotheliomas, using a pro-SP-B antiserum and a monoclonal TTF-1 antibody with a biotin-streptavidin detection system. Immunostaining for pro-SP-B was detected in 57% of adenocarcinomas, and 20% of large cell carcinomas. Immunoreactivity for TTF-1 was shown in 76% of adenocarcinomas and 26% of large cell carcinomas. Malignant mesotheliomas and squamous cell carcinomas did not stain with either antibody. The expression of pro-SP-B and TTF-1 in adenocarcinomas of the lung but not in malignant mesotheliomas shows that pro-SP-B and TTF-1 staining is useful in differentiating these neoplasms.

K-ras gene point mutation in neogenetic lesions of subpleural fibrotic lesions: either an early genetic event in lung cancer development or a non-specific genetic change during the inflammatory reparative process

In the present study, K-ras mutation was investigated in 156 neogenetic epithelia that appeared in the lesion of subpleural fibrosis in order to elucidate the close relationship of lung cancer development with pulmonary interstitial pneumonia. The neogenetic epithelia were histologically subclassified into six types: (i) ciliated bronchial epithelium (CBE); (ii) squamous metaplastic epithelium (SME); (iii) cuboidal immature epithelium (CIE); (iv) stratified immature epithelium (SIE); (v) mucus cell epithelium (MCE); and (vi) intestinal metaplastic epithelium (IME). K-ras mutation was detected in 9.6% of neogenetic epithelia overall; 21% of CIE, 12% of SIE, 16% of SME, but not in other types of neogenetic epithelia. Immunohistochemically, CIE and SIE frequently expressed surfactant apoprotein and SME was characteristic to carcinoembryonic antigen expression. According to Ki-67 immunostain, CIE, SIE and SME are likely to grow faster than other histological types of epithelia. K-ras mutation was seen exclusively in codon 12 with predominant G to A and G to C substitutions without any G to T transversions, results which are somewhat different to previous studies in lung cancers. The present study clearly demonstrated that K-ras mutation appeared in certain histological types of neogenetic epithelia, but raised the question of whether K-ras mutation in neogenetic epithelia during the inflammatory reparative process might be an early genetic event in lung carcinogenesis.

Surfactant proteins A and D: disease markers

The abundant and restricted expression of surfactant proteins SP-A and SP-D within the lung makes these collectins specific markers for lung diseases. The measurement of SP-A and SP-D in amniotic fluids and tracheal aspirates reflects lung maturity and the production level of the lung surfactant in infants with respiratory distress syndrome (RDS). The SP-A concentrations in bronchoalveolar lavage (BAL) fluids are significantly decreased in patients with acute respiratory distress syndrome (ARDS) and also in patients at risk to develop ARDS. The prominent increase of these proteins in BAL fluids and sputum is diagnostic for pulmonary alveolar proteinosis (PAP). The concentrations of SP-A and SP-D in BAL fluids from patients with idiopathic pulmonary fibrosis (IPF) and interstitial pneumonia with collagen vascular diseases (IPCD) are rather lower than those in healthy controls and the SP-A/phospholipid ratio may be a useful marker of survival prediction. SP-A and SP-D appear in the circulation in specific lung diseases. Their serum concentrations significantly increase in patients with PAP, IPF and IPCD. The successive monitoring of serum levels of SP-A and SP-D may predict the disease activity. The serum SP-A levels increase in patients with ARDS. SP-A is also a marker for lung adenocarcinomas and can be used to differentiate lung adenocarcinomas from other types and metastatic cancers from other origins, and to detect metastasis of lung adenocarcinomas.

Immunohistochemical, ultrastructural and molecular study of well differentiated adenocarcinomas of the lung predominantly composed of goblet cells

In order to clarify the morphological and biological characteristics of well differentiated adenocarcinoma of the lung predominantly composed of goblet cells (WDAG), histopathological examinations, including some molecular biological procedures, were carried out using 42 surgical specimens of primary lung carcinoma which were predominantly (>50% of the total cell population) or totally composed of goblet cells. The subjects included 19 men and 21 women, ranging in age from 41 to 81 (mean 60 years old) with predominantly nodular, peripherally located lesions. Ultrastructural examination revealed characteristic apical microvillous filamentous core rootless (AFCR) in some, but not all, cases. Histologically, these AFCR corresponded well with structures stained by phosphotungstic acid hematoxylin (PTAH). The goblet cells of WDAG were divided into PTAH-positive (26 cases) and -negative (16 cases) groups. The PTAH-positive group had larger tumor size, greater number of intrapulmonary and extrapulmonary metastases and shorter disease-free interval. The immunoexpression of p53 protein (60%) and rate of K-ras point mutation (84%) were also higher in the PTAH-positive group. Therefore the goblet cell population of WDAG, though it may appear morphologically homogeneous under light microscopy, is actually composed of heterogeneous groups of cells with different histopathological characteristics and biological behavior.

Immunohistochemical localization of surfactant apoproteins in usual interstitial pneumonia associated with pulmonary carcinoma

Surfactant apoproteins A and B (SP-A and SP-B) are antigenic determinants of pulmonary surfactant complexes. The role and functional significance of these proteins are largely unknown and the pattern of expression is probably related to the functional maturation of type II pneumocytes. Differential expression of SP-A and SP-B was reported in the developing human lung but little is known of their expression in the chronic injury. We studied 5 surgical cases of usual interstitial pneumonia (UIP) associated with carcinoma to evaluate the expression of pulmonary surfactant apoproteins. These cases were immunohistochemically examined by the streptavidin-biotin complex method using monoclonal antibodies HS-1 and HS-2 against pulmonary surfactant apoprotein A (SP-A) and B (SP-B), respectively. In UIP, SP-B was expressed strongly in type II pneumocytes and Clara cells but bronchiolar epithelium and metaplastic squamous cell lines in the honeycomb lesion were non-reactive. SP-A showed a similar pattern but much weaker reactivity when compared to that of SP-B. Type II pneumocytes in normal lung tissue exhibited weak immunoreactivity and no difference in the intensity of staining between SP-A and SP-B. Neither carcinomatous area nor metaplastic lining cells at honeycomb lesion show immunoreactivity to SP-A and SP-B. These results suggest that type II pneumocytes in the UIP are functionally immature in their expression of the apoprotein types and the metaplastic squamous cells or neoplastic transformed cells do not have molecular characteristics of type II pneumocytes.

Entry and intracellular growth of Legionella dumoffii in alveolar epithelial cells

We have found that Legionella dumoffii strain Tex-KL (ATCC 33343) invades into and proliferates in the human lung alveolar epithelial-cell line A549 in vitro. The organism associated with the A549 cells at a 10-fold greater magnitude than L. pneumophila Philadelphia-1 during in vitro coculture for 1 h. Thereafter, L. dumoffii Tex-KL invaded the cells at a significantly higher rate (100- to 1,000-fold) than did L. pneumophila Philadelphia-1. After internalization, however, both bacteria proliferated at the same rate. This in vitro finding led us to examine the bacterial localization in lungs in a fatal case of L. dumoffii pneumonia. Double immunostaining revealed the bacteria in surfactant apoprotein A-positive cells (i.e., type II alveolar epithelial cells). Next, we infected guinea pigs intratracheally with L. dumoffii Tex-KL. The animals became sick with a fever from 24 h to 48 h after infection with 10(4) to 10(9) cfu of L. dumoffii Tex-KL. The lung tissues were examined through electron microscopy at definite intervals. Many bacteria were found not only inside phagocytic cells in the alveolar space, but also in type I and type II alveolar epithelial cells. These findings strongly suggest that L. dumoffii has an ability to invade into and proliferate in human alveolar epithelial cells, which may explain the rapid and fulminant progress of pneumonia caused by L. dumoffii.

Pathological-radiological correlations: pathological and radiological correlation of endobronchial neoplasms: part II, malignant tumors

The majority of lung neoplasms are malignant. Many of these are central and have an associated endobronchial component. Most such neoplasms are of surface epithelial origin; however, neoplasms of submucosal gland, mesenchymal, and lymphoreticular origin may also demonstrate an endobronchial component. Because of their endobronchial location and associated symptoms, these patients often present at an earlier stage than purely parenchymal lung malignancies. The radiographic features in such cases may be similar to those associated with benign endobronchial tumors; however, there are certain radiological signs that are more suggestive of a malignant process. Despite these circumstances, conservative management such as endoscopic excision are inappropriate in most instances. The clinicopathologic and radiological features of these lesions are detailed.

Detection of surfactant protein-A gene transcript in the cells from pleural effusion for the diagnosis of lung adenocarcinoma

PURPOSE

To determine whether detecting surfactant protein-A (SP-A) gene transcript in the cells from pleural effusion is useful for the diagnosis of lung adenocarcinoma.

PATIENTS AND METHODS

We performed reverse transcription polymerase chain reaction (RT-PCR) analysis of SP-A gene transcript in the cells of pleural effusion from 42 consecutive patients with pleural effusion, including 7 patients with primary lung adenocarcinoma before their treatments.

RESULTS

A cDNA segment of SP-A was amplified from the pleural fluid cells of all patients with primary lung adenocarcinoma, indicating the presence of the SP-A gene transcript. None of the remaining patients, including those with metastatic lung adenocarcinoma, showed positive for the SP-A gene transcript.

CONCLUSION

These findings indicate that RT-PCR analysis of the SP-A gene transcript in pleural effusion is useful for the diagnosis of primary lung adenocarcinoma.

Mucin-producing adenocarcinoma of the lung, with special reference to goblet cell type adenocarcinoma: immunohistochemical observation and Ki-ras gene mutation

To clarify its biological nature, 10 samples of goblet cell-type adenocarcinoma of the lung were collected and compared with 10 other pulmonary mucin-producing adenocarcinomas with respect to immunohistochemical features and the presence of Ki-ras gene mutation in codons 12 and 13. Goblet cell-type adenocarcinomas lacked immunoreactivity for surfactant apoprotein and S-100 protein-positive Langerhans cells, which was in marked contrast to other mucin-producing adenocarcinomas. In addition, the mucin gene products, MUC-1 and MUC-2 glycoproteins were immunohistochemically stained. The results showed that MUC-1 glycoprotein is frequently expressed by mucin-producing adenocarcinomas except the goblet cell-type. Ki-ras gene mutation was detected in 12 of 20 (60%) mucin-producing adenocarcinomas. These mutations were exclusively found in codon 12 and G to A transitions were the most frequent type of alteration in the Ki-ras gene. In goblet cell-type adenocarcinomas, the frequency of Ki-ras gene mutation was 80% consisting of G to A transitions and G to T transversions in six and two tumors, respectively. Therefore, goblet cell-type adenocarcinomas differed from other mucin-producing adenocarcinomas in terms of immunohistochemical and molecular biological features, suggesting that goblet cell-type adenocarcinomas are distinctly different from other subtypes of adenocarcinomas.

Association of p53 protein expression in stage I lung adenocarcinoma with reference to cytological subtypes

Since the nuclear accumulation of p53 protein is known to correspond well with mutation of the p53 tumor-suppressor gene, we analyzed the p53 protein immunohistochemically with the anti-p53 mouse monoclonal antibody, DO-7, in 105 stage I lung adenocarcinomas. The p53 immunoreactivity was detected in the nuclei of cancer cells in 51 cases (49%). The p53-positive cases had a significantly poorer prognosis compared with the p53-negative cases (log-rank test; P < .001) When p53 expression was compared among the cytological subtypes of adenocarcinoma, the incidence of p53 expression in the bronchial surface epithelial cell type (11 of 15) was significantly higher than in the goblet cell type (1 of 6) and tended to be higher than the Clara cell/alveolar type II pneumocyte type (27 of 59). These findings indicate that immunohistochemical examination of the p53 protein is a potential prognostic factor in stage 1 lung adenocarcinomas, and that p53 expression has been associated with the cytological subtype.

Bronchogenic squamous cell carcinomas with invasion along alveolar walls

In bronchogenic squamous cell carcinoma, a growth pattern along the alveolar walls of the peripheral lung parenchyma is unusual. In order better to understand the way tumour cells invade the peripheral lung parenchyma, we studied two cases of squamous cell carcinoma with invasion along the alveolar walls (in 30% to 40% of the area surrounding the tumour). We used immunohistochemical staining with antibodies against pulmonary surfactant, apoproteins (PE-10) and collagen type IV, and electron microscopy. Tumour cells invading the peripheral lung tissue were located between one layer of type II alveolar epithelial cells and the basement membrane of the alveolar walls. These results suggest that the cells of a squamous carcinoma (unlike an adenocarcinoma) have the ability to spread along the basement membrane of the alveolar walls without destroying pre-existing normal peripheral lung parenchyma.

KM195 as an immunohistochemical marker of adenocarcinoma of the lung

In order to improve the diagnosis of lung carcinoma, in which a complicated histologic pattern is present, the immunohistochemistry of 119 adenocarcinomas, 65 squamous cell carcinomas, 12 small cell carcinomas, 18 large cell carcinomas, and 15 metastatic adenocarcinoma in the lung were evaluated using a monoclonal antibody, KM195, against lung carcinoma, and compared with the immunohistochemical results using anti-human cytokeratin (CAM 5.2) and other monoclonal antibodies. Formalin-fixed, paraffin-embedded tissues were stained using the labeled streptavidin-biotin method. Extracts from fresh tissue homogenate, after fractionation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were transferred by Western blotting and stained with KM195. The anti-lung adenocarcinoma, murine, monoclonal antibody KM195 (IgG), was positive in 107 of 119 adenocarcinomas (90%), in 15 of 18 large cell carcinoma (83%), in three of 65 squamous cell carcinomas (5%), 13 of 15 (87%) metastatic adenocarcinoma in the lung, and was negative in 12 small cell carcinomas (P < 0.001). KM195-bound protein of primary and metastatic adenocarcinoma in the lung cases concentrated at about 40 kDa. In contrast, CAM 5.2 was positive in 52 of 67 (78%) adenocarcinomas, 10 of 62 (16%) squamous cell carcinomas, and was negative in six small cell carcinomas. These results suggest that the immunohistochemistry for KM195 may be a more useful marker over CAM 5.2 for the diagnosis of pulmonary adenocarcinoma.