Diagnostic effects of prolonged storage on fresh effusion samples

The effects on morphology and diagnostic interpretation of delayed processing of refrigerated effusion samples have not been well documented. The potential for cellular degeneration has led many laboratories to reflexively fix samples rather than submit fresh/refrigerated samples for cytologic examination. We sought to determine if effusion specimens are suitable for morphologic, immunocytochemical, and DNA-based molecular studies after prolonged periods of refrigerated storage time. Ten fresh effusion specimens were refrigerated at 4 degrees C; aliquots were processed at specific points in time (days 0, 3, 5, 7, 10, 14). Specimens evaluated included four pleural (3 benign, 1 breast adenocarcinoma) and six peritoneal (2 ovarian adenocarcinomas, 1 malignant melanoma, 2 mesotheliomas, 1 atypical mesothelial) effusions. The morphology of the cytologic preparations from the 10 effusions was preserved and interpretable after 14 days of storage at 4 degrees C. The immunocytochemical profile of the samples (AE1/AE3, EMA, calretinin, and LCA) was consistent from day 0 to day 14. Amplifiable DNA was present in all samples tested on day 14. We conclude that cytopathologic interpretation of effusion samples remains reliable with refrigeration at 4 degrees C even if processing is delayed.

The utility of fluorescence in-situ hybridization in the diagnosis of malignant pleural effusion

PURPOSE OF REVIEW

Molecular tools are used to refine the diagnosis of malignancy in pleural fluids. This review discusses the rationale and recent findings of the application of one of these tools, fluorescence in-situ hybridization, in pleural effusions.

RECENT FINDINGS

Aneuploidy (i.e., pronounced numeric and structural chromosomal changes) is a recurrent finding in cells of solid tumors. Different methods attempt to detect tumor-associated aneuploidy to prove micrometastasis in different compartments, such as urine, cerebrospinal fluid, bone marrow, and body fluids. In recent years, fluorescence in-situ hybridization analysis has proved viable for detecting metastasis based on the observation of matching patterns of chromosomal aneusomies in primary tumors and corresponding metastasis.

SUMMARY

Fluorescence in-situ hybridization analysis using specific probes for visualizing numeric aberrations in a microscopic evaluation (thus complementing routine cytologic evaluation) has been shown to be relatively simple, very robust, and thus applicable in material of lesser quality and more sensitive than routine cytology. Remarkably, dual-color fluorescence in-situ hybridization analysis allows for an efficient analysis in effusions, and the approach presented in this review proved to be more specific than other molecular procedures applied in effusions to detect malignancy, such as polymerase chain reaction. Prospective studies are needed to demonstrate that refinement of staging by fluorescence in-situ hybridization or polymerase chain reaction ('molecular upstaging') will translate into meaningful therapeutic consequences.

Image cytometry: an aid for cytological diagnosis of pleural effusions

The conventional cytology rate for identification of neoplastic cells in effusions is about 60%. The rate of diagnostically equivocal effusions in routine cytology is dependent on the volume of effusion examined, type of preparation and staining, experience of the examiner, and application of ancillary methods. The aim of our study was to confirm the role of image cytometry analysis (DNA-ploidy) on pleural effusions. In this retrospective study based on 42 available cases with a histological diagnosis, we have examined 13 reactive mesothelial proliferations and 29 cases of malignant tumors (adenocarcinoma [ACA] or mesothelioma). The smears collected were submitted to the image analysis following a-three step protocol (smears stained with the Papanicolaou method were destained and then restained with Feulgen staining and finally analysed using image analysis cytometry). The results have shown that nonmalignant cases (reactive mesothelial proliferation) were all diploid and in contrast all aneuploid cases corresponded to malignant tumors. Only three mesotheliomas showed a diploid profile. In conclusion, these results confirm data from literature and indicate that cytometric analysis of nuclear content is a useful marker for identification of malignant cells in equivocal effusions and can be used to increase the cytological sensitivity in doubtful mesothelial proliferations.

[Expressions of 8-OH-dG, k-ras, and p53 genes in pleural effusion cells and their clinical significances]

BACKGROUND & OBJECTIVE

Oxidative DNA damage plays an important role in carcinogens-induced carcinogenesis. 8-hydoxy-2deoxy-guanosine (8-OH-dG), a biomarker of oxidative DNA damage, plays important roles in initiation, progression, and prognosis of lung cancer, and closely relates with mutations of k-ras and p53 genes in carcinogenesis of lung tissue. This study was to detect protein expressions of 8-OH-dG, k-ras, and p53 genes in lung cancer tissues, and to analyze their values in distinguished diagnosis of lung cancer.

METHODS

Protein levels of 8-OH-dG, k-ras, and p53 in pleural effusion cells from 53 patients with lung cancer, and 53 patients with other benign lung diseases were detected by immunocytochemistry.

RESULTS

Positive rates of 8-OH-dG, k-ras, and p53 protein in cancer group were significantly higher than those in benign disease group [75.5% (40/53) vs. 15.1% (8/53), P < 0.01; 64.2% (34/53) vs. 3.8% (2/53), P < 0.01; and 69.8% (37/53) vs. 18.9% (10/53), P < 0.01; respectively]. Protein levels of 8-OH-dG, k-ras, and p53 protein in cancer group were 1.68+/-1.21, 1.32+/-1.06, and 1.57+/-1.15,respectively. Rank correlation analysis showed that protein expression of 8-OH-dG positively correlated with those of k-ras (RS=0.643, P < 0.01), and p53 (RS=0.827, P < 0.01)u protein expression of k-ras positively correlated with that of p53 (RS=0.897, P < 0.01).

CONCLUSIONS

Protein expressions of 8-OH-dG, k-ras, and p53 are up-regulated in pleural effusion cells of lung cancer, and have mutual relations. They may be used as reference markers in diagnosing and screening for lung cancer.

Primary effusion lymphoma of the pericardial cavity carrying t(1;22)(q21;q11) and t(14;17)(q32;q23)

We report a case of primary effusion lymphoma (PEL) in a 75-year-old woman without human immunodeficiency virus or hepatitis C virus, which presented as fever, chest pain, and pericardial effusion. The lymphoma cells were positive for CD20 and CD79a, and were negative for CD3 and CD10. Genomic human herpes virus 8 (HHV-8) and Epstein-Barr virus were not detected in the lymphoma cells. Cytogenetic analysis showed complex abnormalities by the G-banding technique, and spectral karyotyping (SKY) analysis provided more detailed characterization of the chromosomal aberrations, including t(1;22)(q21;q11) and t(14;17)(q32;q23). We did not detect C-MYC gene rearrangement or BCL-2 expression. She was treated successfully with six courses of the CHOP regimen. The present case demonstrated a rare category of PEL that is not associated with HHV-8 or C-MYC gene rearrangement. In addition, SKY analysis disclosed cryptic chromosomal abnormalities involving 1q21 and 17q23.

The diagnostic significance of the detection of cytokeratin 19 mRNA by quantitative RT-PCR in benign and malignant pleural effusions

OBJECTIVE

To evaluate the diagnostic significance of detecting cytokeratin 19 (CK19) mRNA by quantitative reverse transcription polymerase chain reaction (RT-PCR) in benign and malignant pleural effusions.

METHODS

CK19 mRNA was examined by quantitative RT-PCR and CK19 was detected by Enzyme-linked immunoadsorbent assay (ELISA) in 32 patients with malignant pleural effusions and 35 patients with benign pleural effusions.

RESULTS

On the threshold of 200 copies/microl, the positive rate of CK19 mRNA in patients with malignant pleural effusions was 62.5%. The positive rates of CK19 mRNA and CK19 in the malignant pleural effusions were significantly higher than those in the benign group (P<0.01). Furthermore, the positive rate of CK19 mRNA was higher than that of CK19 in the malignant group (P<0.05).

CONCLUSION

Detection of CK19 mRNA can be a promising diagnostic marker in differential diagnosis of benign and malignant pleural effusions.

Establishment of permanent cell lines purified from human mesothelioma: morphological aspects, new marker expression and karyotypic analysis

This study reports the establishment of three major subtypes of human mesothelioma cells in tissue culture, i.e. the epithelioid, sarcomatoid and biphasic forms, and compares their phenotypic and biological characteristics. Primary cells isolated from biopsies or pleural exudates were subcultured for over 50 passages. We evaluated immunoreactivity using various mesothelial markers related to histological patterns of these cell lines. For epithelioid cells, calretinin and cytokeratin were found to be useful and easily interpretable markers as for control mesothelial cells. The biphasic form was only partially positive and the sarcomatoid type negative. Vimentin was expressed by all cell lines. BerEP4, a specific marker for adenocarcinoma, was negative. Interestingly, while the macrophage marker CD14 was negative, immunoreactivity for a mature macrophage marker (CD68) was expressed by all cell types, suggesting that this marker might constitute an additional tool useful in the differential diagnosis of mesothelioma. At the ultrastructural level, a cell surface rich in microvilli confirmed their mesothelial origin. PCR analysis revealed that none of the cell lines contained SV40 DNA. Karyotypic analyses showed more complex abnormalities in the epithelioid subtype than in the sarcomatoid form. These cell lines may be useful in the study of cellular, molecular and genetic aspects of the disease.

Altered expression and activation of the nerve growth factor receptors TrkA and p75 provide the first evidence of tumor progression to effusion in breast carcinoma

The aim of this study was to characterize phenotypic alterations along the progression of breast carcinoma from primary tumor to pleural effusion through analysis of the expression of nerve growth factor (NGF) and its receptors phospho-TrkA (p-TrkA activated receptor) and p75. Sections from 42 malignant pleural effusions from breast cancer patients and 65 corresponding solid tumors (34 primary, 31 metastatic) were evaluated for protein expression of the activated p-TrkA receptor. The majority of lesions were additionally studied for NGF and p75 expression. Six effusions and four breast carcinoma cell lines were studied for expression of p-TrkA using immunoblotting (IB). Membrane expression of p-TrkA was high in carcinoma cells in effusions (39/42, 93%) and locoregional recurrences (12/13, 92%), with significantly lower expression in both primary tumors (14/34, 41%) and lymph node metastases (8/18, 44%), respectively (p < 0.001 for effusions vs. primary tumors; p = 0.001 for effusions vs. lymph nodes). In contrast, p75 expression was less frequent in effusions compared to both primary tumors and lymph node metastases, significantly so for the latter (p = 0.019). NGF expression was comparable at all sites, but its expression in tumor cells in effusions (7/21 cases) was limited to cases in which time to progression (TTP) to effusion occurred within 5 years or less from primary operation. In univariate analysis of survival, mean and median TTP were 6.3 and 6 years for NGF-negative effusions, compared to 3 and 4 years for NGF-positive cases (p = 0.013). IB confirmed expression of p-TrkA in five of six effusions, while all four breast cancer cell lines were p-TrkA-negative. Our data provide the first documented evidence of molecular events that occur along tumor progression of breast carcinoma from primary tumors to effusion. The almost universal expression of p-TrkA in cancer cells in effusions and late recurrences is in full agreement with our recent report linking this factor with poor prognosis in ovarian cancer. Furthermore, the rapid progression to effusion in cases showing NGF expression in tumor cells underscores the aggressive clinical behavior of tumors that are able to utilize this pathway in an autocrine manner.

Alterations of mRNA splicing in primary effusion lymphomas

Primary effusion lymphoma (PEL) is a unique form of malignant lymphoma associated with infection by the Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8). The majority of PELs also contain the EBV genome. Although viral infection is believed to play a critical role in the pathogenesis of PEL, it has been suggested that additional molecular lesions are required for the development of PEL. Alternative splicing of pre-mRNA is an important mechanism in the regulation of cellular and viral gene expression. Deregulation of pre-mRNA splicing may shift the gene expression balance and lead to the development of cancer. In order to investigate mRNA splicing in PELs, we examined mRNA splicing of three genes, DNA polymerase beta (pol beta), Bcl-x and CD45, in eight PEL cell lines. We found that the average variant percentage of pol beta in PEL cell lines is two times higher than in peripheral blood mononuclear cells (PBMC) and that the variant pattern of genes bcl-x and CD45 is quite different in PEL cell lines than in PBMC. In addition, we also found that the percentage of variant pol beta increased two-fold in PBMC following Epstein-Barr virus (EBV) infection. Therefore, viral infection may contribute to mRNA alternative splicing in PEL. In order to explore the mechanism by which viral infection affects mRNA splicing, we also examined the roles of genes KS-SM, SM and EBERs and viral copies in mRNA splicing. Our findings indicate that various factors acting as positive or negative regulators may be involved in mRNA alternative splicing caused by viral infection. In conclusion, mRNA splicing in PEL can be altered by viral infection and this alteration may contribute to the pathogenesis of PEL.

Evaluation of breast cancer metastases in pleural effusions by molecular biology techniques

The aim of this study was to evaluate the presence of allelic loss in chromosomal regions previously described as exhibiting loss of heterozygosity (LOH) during breast carcinogenesis, in pleural effusions of breast cancer patients. LOH was analyzed in three loci (1p32, 7q31, and 17q21). We studied 41 samples of pleural effusions from breast cancer patients (24 positive for neoplastic cells, 14 suspected, and 3 negative cases) and breast tissues from the patients (primary tumors and nonneoplastic adjacent tissue). DNA was extracted from pleural effusions, primary tumor, and adjacent normal tissue. LOH was evaluated by polymerase chain reaction assay and was observed in 38% of pleural effusions positive for neoplastic cells, and in 36% of suspected cases where morphology only did not allow the diagnosis of malignancy. We conclude that LOH analysis in pleural effusions of breast cancer patients is able to identify metastases in cases where morphologic analysis becomes difficult.

Anaplastic plasmacytoma with malignant pleural effusion lacking evidence of monoclonal gammopathy

A case of plasmacytoma of the pleural cavity is reported with massive malignant pleural effusion, which, most unusually, lacked monoclonal gammopathy, thereby making it difficult to distinguish from lymphoma. The pleural tumor and pleural effusion contained large mononuclear lymphoma-like cells with distinct nucleoli. Immunohistochemistry revealed neither lymphoma markers nor clonal cytoplasmic nor cell surface immunoglobulins. Tumor cells were stained with vimentin and the plasma cell markers, VS38c, CD138 (syndecan-1), and MUM1 antibodies. Bone marrow contained small amounts of tumor consisting of similar cells. Electron microscopy showed well developed rough endoplasmic reticulum and peripherally positioned nuclei with euchromatin. Flow cytometry of bone marrow revealed a minimal involvement of CD38-positive cells. Chromosomal analysis of marrow cells revealed a complex abnormal karyotype. A polymerase chain reaction demonstrated clonal re-arrangement of the immunoglobulin heavy-chain gene. The overall results indicate a clonal expansion of tumor cells with primitive plasma cell differentiation with the highly unusual feature of absent monotypic immunoglobulin. The study illustrates the need for a comprehensive array of techniques to distinguish such rare non-synthesizing and non-secretory plasmacytomas from lymphoma.

Chromosomal and comparative genomic analyses of HHV-8-negative primary effusion lymphoma in five HIV-negative Japanese patients

A rare subset of HIV lymphoma, known as primary effusion lymphoma (PEL), is a high-grade tumour carrying human herpes virus 8 (HHV-8). Very little is known about genomic aberration in PEL, and only a few HIV-negative PEL have been reported. Here we report the results of chromosomal analysis and comparative genomic hybridisation (CGH) conducted to detect regions of gain and loss, in five HIV-negative Japanese cases of HHV-8-negative PEL. All patients except one (35-year-old female) were elderly men and the morphologic examination showed large cell type. PEL expressed B-cell-associated and activation-associated antigens, and exhibited clonal immunoglobulin genes. No HHV-8 was detected in all four examined cases, but Epstein-Barr virus (EBV) was detected in one case. Genomic abnormalities and aberrations were identified in all HHV-8/HIV-negative PEL. CGH studies showed gain in 19 of 24 chromosomes. Gains of 3q13-27, 8q24, 10q21-23 and Yq were detected in two of the five cases, but other gains were noted in each case. Chromosomal analysis revealed complex abnormalities both in numbers and structures. Burkitt lymphoma-associated t(8;22) was detected in one case, but +8 chromosome and c-myc amplification were detected in the other three cases by Southern blot and/or fluorecence in situ hybridization (FISH). Abnormality of chromosome 8, which associates with c-myc, was detected in four of the five HHV-8/HIV-negative PEL. However, the other common genomic abnormalities of HHV-8/HIV-negative PEL were not detected in our study, but the complex abnormalities seemed to be true rather than the usual large B-cell lymphoma. Our results suggest that multi-step genomic abnormalities might be associated in HHV-8/HIV-negative PEL tumorigenesis.

Immunoglobulin and T-cell receptor gene-gene rearrangement in pleural cavity-based T-cell rich B-cell lymphoma in an immunocompetent patient

Body cavity-based lymphomas are fluid-based lymphomas that are not associated with a tumor mass or adenopathy which could explain the origin of the lymphomatous effusion. A distinct lymphoma that grows in the body cavity as a lymphomatous effusion in the absence of a tumor mass has been identified as a primary effusion lymphoma. This almost exclusively occurs in patients with acquired immunodeficiency syndrome (AIDS), who invariably have a history of Kaposi sarcoma. We report a rare case of a recurrent pleural effusion in an immunocompetent patient. There was no evidence of lymphadenopathy or an associated mass on computerized tomography of the chest, abdomen and pelvis. Serology for HIV, HHS-8, EBV and HTLV-1 were negative. Cytologic examination of the pleural fluid showed an elevated white cell count with 97% lymphocytes, mostly with T-cell markers. Bone marrow aspirate and biopsy were negative and bronchoscopy was unrevealing. Pleural biopsy was significant for >70% T-lymphocytes and some large atypical cells. Which had CD19, CD20 and weak bcl-2 positivity. Kappa and lambda light chains did not show distinct clonality. A preliminary diagnosis of T-cell rich B-cell lymphoma (TCRBCL) of the pleural cavity was made. The diagnosis was confirmed with DNA studies done on the pleural biopsy specimen using PCR and southern blot. Dual rearrangement of Ig heavy chain region and TCR-beta genes were identified. The patient responded to combination chemotherapy with cyclophosphamide, adriamycin, vincristine and prednisone. Our case is the first known case of pleural cavity-based TCRBCL and illustrates the role of gene rearrangement studies in such patients.

[Clinical significance of MDR gene expression in malignant pleural effusion and ascites and solid tumors]

OBJECTIVE

To discuss the guiding significance of multidrug resistance (MDR) gene expression for monitoring the clinical effectiveness of chemotherapy upon cancer, and to analyze the MDR1 and glutnthione-s-transferase(GST-pi) mRNA expression rates in primary breast cancer, and their correlation with the clinical outcome and prognosis.

METHODS

The mRNA expression levels of MDR1 in 16 cases with malignant pleural effusion and ascites and 102 cases of solid tumors were measured using semiquantitative RT-PCR assay. The MDR1 and GST-pi mRNA expression rates in 84 cases of breast cancer, out of the 102 cases of solid tumors, were also studied in the same way.

RESULTS

(1) An average coincidence rate of 84.5% was found between the mRNA expression level of MDR1 and the clinical response to chemotherapy in the 16 cases with malignant pleural effusion and ascites and 18 cases of solid tumors. (2) The positive rate of MDR1 mRNA expression in primary breast cancer tissue was 79.7%, with the medium and high levels as high as 33.3%, while the positive rate of GST-pi mRNA expression was 33.3%, with the medium and high expression levels being as low as 4.8%. There was a highly significant difference between the two groups (P < 0.01). The positive rates of MDR1 mRNA in the group having received chemotherapy before surgery and the group not receiving chemotherapy before surgery were 87.8% and 68.6% respectively, showing a lymph nodes and in the group without metastases in axillary lymph nodes were 89.1% and 68.4% respectively, indicating a significant difference (P < 0.05). The positive rates of GST-pi mRNA in the group suffering distant metastases and the group not suffering distant metastases were 71.4% and 20.6% respectively, showing a significant difference (P < 0.05). The GST-pi mRNA expression rates in the estrogen receptor (ER)- and progesterone receptor (PR)-positive groups were higher than those in the ER- and PR-negative groups, indicating a significant difference (P < 0.05) .

CONCLUSION

The mRNA expression level of MDR1 has a relatively high correlation with the clinical response to chemotherapy, and thus can be used to monitor the effectiveness of chemotherapy. MDR1 is the main drug resistance mechanism in breast cancer. Chemotherapy before surgery induces MDR1 mRNA expression. MDR1 e xpression and GST-pi mRNA expression serve as a significant prognostic indicator for breast cancer, thus having guiding significance for assessing prognosis.

Expression levels of the nerve growth factor receptors TrkA and p75 in effusions and solid tumors of serous ovarian carcinoma patients

PURPOSE

The purpose of this study was to analyze the expression of the high- and low-affinity nerve growth factor (NGF) receptors TrkA and p75 in effusions and in primary and metastatic tumors of serous ovarian carcinoma patients, as well as to evaluate their association with clinicopathological parameters and disease outcome.

EXPERIMENTAL DESIGN

Sections from 77 malignant effusions and 78 primary and metastatic lesions were evaluated for protein expression of TrkA and p75 using immunohistochemistry (IHC). Expression of the phosphorylated form of TrkA (p-TrkA) was evaluated in 75 effusions using IHC. TrkA and p75 mRNA expression was studied in 44 effusions using reverse transcription-PCR (RT-PCR).

RESULTS

TrkA protein membrane expression was detected in carcinoma cells in 30 of 77 (39%) effusions and 64 of 78 (82%) solid tumors. The decrease in TrkA expression in effusions approached, but did not reach, statistical significance when only corresponding lesions were analyzed (P = 0.06 in the comparison of effusions and primary tumors, P = 0.09 for effusions and metastases). Conversely, p75 protein membrane expression was more common in effusions, which was detected in 16 of 77 (21%) effusions as compared with 6 of 78 (8%) solid tumors (P > 0.05 in analysis of corresponding lesions). Expression of p-TrkA in carcinoma cells was limited to 5 of 75 effusions. Interestingly, 11 of 16 p75-positive effusions were also immunoreactive for the antibody against TrkA (P = 0.001), suggesting NGF activation using two signaling pathways. TrkA and p75 protein expression in tumor cells was similar in pleural and peritoneal effusions (P > 0.05). Using reverse transcription-PCR, TrkA mRNA was detected in 2 of 45 effusions, whereas p75 mRNA was present in 3 of 45 specimens. TrkA and p75 showed no association with tumor grade, Fédération Internationale des Gynaecologistes et Obstetristes stage, chemotherapy status, the extent of residual disease, or survival (P > 0.05).

CONCLUSIONS

TrkA and p75 are both expressed in advanced-stage ovarian carcinoma, but whereas p75 expression is elevated in effusions, TrkA shows an opposite trend. The different expression of NGF receptors in effusions may relate to the different microenvironment and growth factor availability in body cavities, as also supported by the infrequent activation of TrkA in effusions. The similar expression of TrkA and p75 in carcinoma cells in pleural and peritoneal effusions provides further evidence for our hypothesis that there are few, if any, phenotypic differences between ovarian carcinoma cells at these two sites. TrkA and p75 expression in effusions does not appear to be a predictor of disease outcome in advanced-stage serous ovarian carcinoma.

K-ras and rho A mutations in malignant pleural effusion

Mutations of the Kristen ras (K-ras) gene have been implicated in the pathogenesis of human lung cancer, especially adenocarcinoma, and have been proposed to be a prognostic factor. The K-ras mutation in codon 12 is detectable even in cell-free fluids by using the enriched polymerase chain reaction (PCR) technique. On the other hand, based on experimental results, the rho A mutation in codon 14 is also proposed to be oncogenic as observed in the K-ras mutation. Malignant pleural effusion is a common complication of lung cancer. We studied the point mutation of K-ras codon 12 and rho A codon 14 using enriched PCR in specimens of pleural effusion. Forty patients with pleural effusion were enrolled in this study. The causes of pleural effusion were non-small cell lung cancer (18 cases), small cell lung cancer (6 cases), malignant mesothelioma (2 cases), metastatic lung tumor (5 cases), thymoma (1 case), malignant lymphoma (1 case), and pleuritis tuberculosa (7 cases). The K-ras mutation was detected in 4 of 14 cases with adenocarcinoma, 1 of 3 cases with squamous cell carcinoma, 1 of 1 case with large cell carcinoma, and 1 of 5 cases with metastatic lung tumor, respectively. The rho A mutation was not detected in any pleural effusion examined in this study. Our study demonstrates the usefullness of pleural effusion as a clinical specimen for a search of point mutation of oncogenes. The K-ras codon 12 mutation is readily detected in pleural effusion, and the demonstration of this mutation has potentially important implications for the diagnosis of malignant pleural effusion.

Pitfalls in TRAP assay in routine detection of malignancy in effusions

Telomerase has been found to be reactivated in a majority of cancers but is inactive in most somatic cells. Our principal goal was to determine the potential use of the telomeric repeat amplification protocol (TRAP) assay as marker for malignancy in cytological effusions. The simple selection criterion was the cytological diagnosis, and routine samples were classified into malignant (58 samples) and nonmalignant (233 samples). Of the malignant samples, 44/58 (76%) were positive by TRAP assay. Of the 14 telomerase-negative cytology-positive samples, RNA integrity was poor in 9, indicating suboptimal sample conservation for molecular analysis. In 3 of the remaining 5 samples with a negative TRAP assay, a high number of malignant cells was observed, and these cells might have been telomerase-negative. Thus, the sensitivity of TRAP assay for the presence of malignant cells was about 76%. In the cytologically nonmalignant effusions, the presence of telomerase activity was observed in 24% (55/233). Of these, 6% were highly suspicious for malignancy, 9% were doubtful, and 9% were cytologically nonmalignant effusions confirmed by a follow-up of 12 mo or more. According to these data, the specificity of the TRAP assay to detect tumor cells in effusions ranged only between 82-91%. Our results indicate that, although the TRAP assay is positive in 6-15% of putative malignant effusions, the relatively high number of TRAP false-negative and false-positive cases renders this test unsuitable for routine diagnostic purposes.

Quantitative fluorescence in situ hybridization in lung cancer as a diagnostic marker

The diagnosis of lung cancer is quite often hampered by the existence of various cell types within samples such as biopsies or pleural effusions. We have established a new marker for image cytometry of interphase tumor cells of the lung by using the most recurrent and early cytogenetic event in lung cancer, the loss of the short arm of chromosome 3. The method is based on the detection of the imbalance between the long and the short arms of chromosome 3 by performing two-color fluorescence in situ hybridization on both arms. Fourteen tumors were analyzed after short-term culture and compared with the corresponding cytogenetic data obtained from metaphase analysis. Results on interphase nuclei and control experiments on metaphases were the same, with imbalance ratios ranging from 1.0 to 2.0 (mean value 1.6, median 1.5). To assess the clinical significance of this approach, three pleural effusions were analyzed. Data showed that normal cells within the sample could have been distinguished from the tumor cells based on different imbalance values between the long and the short arms. Thus, our method allows refined detection of lung tumor cells within samples containing heterogeneous cell populations.

Gene expression analysis of the catalytic subunit of human telomerase (hEST2) in the differential diagnosis of serous effusions

Diagnostic accuracy in effusion cytology based on morphologic examination is not always satisfactory. Therefore, various diagnostic adjuncts such as immunocytochemistry or deoxyribonucleic acid cytometry are employed in this diagnostic field. Recently, demonstration of telomerase activity has been proposed as a possible marker for malignancy. In this study a seminested reverse transcription-polymerase chain reaction (RT-PCR) strategy for expression analysis of the catalytic subunit of human telomerase (hEST2) was used in 58 serous effusions. RT-PCR results correlated with cytologic diagnoses in 14 of 17 malignant effusions. In eight effusions cytologically suspicious for malignancy, PCR results were in accordance with the clinical follow-up. However, hEST2 RT-PCR was also positive in six of 15 cytologically benign effusions that consisted predominantly of inflammatory and mesothelial cells. Using the telomeric repeat amplification protocol, it could be demonstrated that cultured, proliferating benign mesothelial cells may present a weak telomerase activity, as is known in other benign cells including activated lymphocytes. In conclusion, the simple and rapid method of hEST2 RT-PCR serves to support the cytologic diagnosis of malignancy, but false-positive PCR results resulting from activated lymphocytes and proliferating mesothelial cells must be considered.

Simian virus-40 sequences are a negative prognostic cofactor in patients with malignant pleural mesothelioma

Several biochemical and clinical factors have been shown to correlate with survival in human malignant pleural mesothelioma (MM). Nevertheless, average survival of 4 to 10 months from diagnosis is sometimes not sufficient for full expression of these factors. Several studies have reported SV40 sequences in MM, suggesting a possible pathogenic role. We investigated whether the presence of these sequences had any effect on MM patient survival. For this study, we used polymerase chain reaction and Southern blot analysis to search for and identify SV40 DNA in biopsy samples from 83 MM patients. These cases were divided according to histology: 62/83 (74. 7%) had epithelioid morphology (EMM) and 21/83 (25.3%) had either biphasic or sarcomatous morphology (B/SMM). SV40 positivity was significantly associated with B/SMM growth pattern (chi-squared test = 5.03, P = 0.025). Kaplan-Meier univariate analysis confirmed the independent effect of histology on MM survival (log-rank test = 13.9, P < 0.001) and showed a trend for increased survival in SV40-negative patients (log-rank test = 2.83, P = 0.09). Most importantly, Cox's regression model showed that SV40-positive status affected the predictive value of histology on patient survival. In particular, when SV40 expression was added to the B/SMM histotype, Cox's regression model showed a significant increase in hazard ratio (HR) with respect to SV40-negative B/SMM (HR = 4.25, 95% CI = 2.00-9. 00, likelihood ratio test = 14.31, P < 0.001). We conclude that SV40 expression is significantly associated with B/SMM histology and represents an important prognostic cofactor when associated with the tumor subtype in MM patients.

Routine DNA cytometry of benign and malignant pleural effusions by means of the remote quantitation server Euroquant: a prospective study

AIM

To analyse the practicability and potential assistance of static DNA cytometry performed by means of the remote quantitation server Euroquant and the internet in routine diagnostic analysis of pleural effusions, and to outline the role of DNA cytometry on pleural effusions in distinguishing between benign and malignant (and herein primary versus metastatic) effusions.

MATERIALS AND METHODS

Cytological smears of 294 pleural effusions were stained with the Feulgen method. The DNA content of a minimum of 300 randomly chosen analysis nuclei and 30 reference nuclei (lymphocytes) was measured by internet connection to the remote quantitation server Euroquant. Cytometric features were derived from the histograms, and the time needed for case evaluation, the reliability of staining and measurement procedures, and the contribution to the final diagnosis were evaluated.

RESULTS

Only 120 of 294 pleural effusions could be measured. The total measurement time for each specimen was 60 minutes. The guidelines of the consensus report on DNA measurements were fulfilled. Seventy eight malignant (18 mesotheliomas, 60 metastatic tumours) and 42 benign effusions were measured. Seven of 78 malignant effusions were euploid and none of 42 benign effusions were aneuploid. The sensitivity and specificity were 91% and 100%, respectively, for distinguishing benign from malignant effusions, and 95% and 100%, respectively, for discriminating between benign and malignant effusions caused by metastatic malignant tumours.

CONCLUSIONS

Static DNA cytometry using the remote quantitation server Euroquant can be performed reliably in the routine diagnosis of pleural effusions; however, only 40% of effusions meet the technical requirements for static DNA cytometry. Within the measurable cases, static DNA cytometry made an important contribution to the confirmation/exclusion of malignancy.

Application of the p53 and K-ras gene mutation patterns for cytologic diagnosis of recurrent lung carcinomas

BACKGROUND

Cytologic specimens are one of the most important materials for lung carcinoma diagnosis, because they can be used in mass screening for lung carcinoma and early detection of cancer recurrence by examination of sputum and pleural fluid.

METHODS

To prove the potentiality of the cytologic specimens to be subjected to molecular detection of recurrent lung carcinomas, the authors enrolled 16 patients who had undergone surgical treatment for lung carcinoma with recurrence detected by malignant pleural fluid. First, they examined K-ras gene and p53 tumor suppressor gene abnormalities in resected tumors by polymerase chain reaction-based single-strand conformation polymorphism (PCR-SSCP) analysis. Next, using a microdissection method, they investigated the use of cytologic specimens such as pleural fluid for the detection of recurrence by finding the same mutations observed in the initially resected tumor.

RESULTS

Seven abnormally shifted bands were detected among six patients by PCR-SSCP analysis of surgical materials. Five of 7 abnormally shifted bands (71.4%) also were detected from microdissected malignant cells in cytologic smears. In two cases, they detected mutations by using single malignant cells in pleural fluid.

CONCLUSIONS

The authors successfully detected the same mutations in recurrent cytologic specimens as those in the initially resected tumors by PCR-SSCP analysis. These findings suggest that the p53 and K-ras gene mutation patterns are effective markers for the detection of recurrent lung carcinoma in cytologic specimens. Cancer (Cancer Cytopathol)

Characterization of a novel HHV-8-positive cell line reveals implications for the pathogenesis and cell cycle control of primary effusion lymphoma

Primary effusion lymphoma (PEL) represents a peculiar type of B cell lymphoma which associates with HHV-8 infection and preferentially grows in liquid phase in the serous body cavities. In this report, we provide the detailed characterization of a newly established PEL cell line, termed CRO-AP/6. The cell line was obtained from the pleural effusion of a HIV-positive patient with PEL. Its derivation from the tumor clone was established by immunogenotypic analysis. Detailed phenotypic investigations defined that CRO-AP/6 reflects pre-terminally differentiated B cells expressing the CD138/syndecan-1 antigen. Karyotypic studies of CRO-AP/6 identified several chromosomal abnormalities, whereas genotypic studies ruled out the involvement of molecular lesions associated with other types of B cell lymphoma. Both CRO-AP/6 and the parental tumor sample harbored infection by HHV-8. Conversely, EBV infection was present in the parental tumor sample although not in CROAP/6, indicating that CRO-AP/6 originated from the selection of an EBV-negative tumor subclone. The pattern of viral (HHV-8 v-cyclin) and cellular (p27Kip1) regulators of cell cycle expressed by CRO-AP/6, together with the results of growth fraction analysis, point to abrogation of the physiological inverse relationship between proliferation and p27Kip1 expression. Also, both CRO-AP/6 and the parental tumor sample display biallelic inactivation of the DNA repair enzyme gene O6-methylguanine-DNA methyltransferase (MGMT) by promoter methylation. Overall, the CRO-AP/6 cell line may help understand cell cycle control of PEL cells, may clarify the relative contribution of HHV-8 and EBV to the disease growth and development and may facilitate the identification of recurrent cytogenetic abnormalities highlighting putative novel cancer related loci relevant to PEL.

Adenoviral gene transfer is inhibited by soluble factors in malignant pleural effusions

Direct in vivo gene delivery is a prerequisite for many gene therapy strategies; however, efficacy has been limited by a lack of therapeutic gene transfer. In studying intrapleural malignancy as a model for the gene therapy of non-small cell lung cancer, we previously identified soluble chondroitin sulfate-proteoglycans/glycosaminoglycans (CS-PG/GAGs) in malignant pleural effusions (MPE) as factors that inhibit retroviral vector (RV) transduction. Similarly, we have observed inhibition to gene transfer in the fluid component of MPE using adenoviral (Ad) vectors. Analyses indicate that the factors responsible for the block are filterable, soluble, titrable, and heat stable (56 degrees C). Passage through microporous membranes fractionates the inhibitory factors into large (> 100 kD) components of the effusions. In contrast to RV transduction, hyaluronic acid or CS-PG/GAGs are not the inhibitors because the block is not reversed by pretreatment of the effusions with mammalian hyaluronidase, and exogenous addition of GAGs into the transduction media does not diminish Ad transduction. In considering the mechanism of action of the inhibitory factors, we observe that Ad entry, and specifically the binding of radiolabeled Ad to its target cell, is inhibited in the presence of MPE. Ad internalization may also be impaired; however, these studies exclude soluble fibronectin in MPE as a competitive inhibitor of Ad transduction. Lastly, sepharose A- mediated immunoglobulin depletion of MPE only partially reverses the block, and significant inhibition to Ad gene transfer persists at lower adenovirus:target cell ratios. Identifying the structural and functional basis for inhibition to Ad gene transfer may yield specific strategies to enable better in vivo translation of gene therapy approaches.

A new bioassay using transient transfection for invasion-related gene analysis

To understand the mechanisms of tumor invasion and metastasis, model systems are required that isolate the individual steps of these complicated, multifaceted processes. We propose a new procedure to identify genes involved in cell invasion and/or motility that features the combined advantages of transient gene transfection and Matrigel invasion assays. Cancer cells were transiently cotransfected with two vectors expressing the gene of interest and luciferase, as a marker of transfected cells, and then assayed for Matrigel invasion. Luciferase cotransfection appeared to be a sensitive semiquantitative assay for transfected cells and was maximal throughout the invasion assay. The proposed transfection procedure, using calcium phosphate precipitation, did not affect cell invasiveness and allowed cellular coexpression of both genes. When applying this method, we found that transient expression of the unliganded and liganded human estrogen receptor alpha prevented invasiveness of MDA-MB-231 breast cancer cells. In conclusion, we propose rapid and versatile in vitro procedure for studying the effects of individual cloned genes on cellular processes, such as invasion and motility.