Microfluidic purification and concentration of malignant pleural effusions for improved molecular and cytomorphological diagnostics

Evaluation of pleural fluids for metastatic cells is a key component of diagnostic cytopathology. However, a large background of smaller leukocytes and/or erythrocytes can make accurate diagnosis difficult and reduce specificity in identification of mutations of interest for targeted anti-cancer therapies. Here, we describe an automated microfluidic system (Centrifuge Chip) which employs microscale vortices for the size-based isolation and concentration of cancer cells and mesothelial cells from a background of blood cells. We are able to process non-diluted pleural fluids at 6 mL/min and enrich target cells significantly over the background; we achieved improved purity in all patient samples analyzed. The resulting isolated and viable cells are readily available for immunostaining, cytological analysis, and detection of gene mutations. To demonstrate the utility towards aiding companion diagnostics, we also show improved detection accuracy of KRAS gene mutations in lung cancer cells processed using the Centrifuge Chip, leading to an increase in the area under the curve (AUC) of the receiver operating characteristic from 0.90 to 0.99. The Centrifuge Chip allows for rapid concentration and processing of large volumes of bodily fluid samples for improved cytological diagnosis and purification of cells of interest for genetic testing, which will be helpful for enhancing diagnostic accuracy.

Diagnostic and predictive role of cell-free midkine in malignant pleural effusions

PURPOSE

The detection of circulating nucleic acids has long been explored for the diagnosis and prognosis of a variety of clinical conditions. The aim of this study was to detect the cell-free mRNA expression of midkine (MK) in patients with effusions and its potential diagnostic and predictive value.

METHODS

Effusions were collected prospectively from 168 patients. The cell-free RNA was extracted from effusions, and the mRNA expression of MK was detected using real-time PCR. The expression of carcinoembryonic antigen (CEA) and biochemical markers in effusions were also assayed. Primary cancer cells were isolated from the malignant effusions (n = 46). Compared with culture cell lines, the response of these cancer cells to chemotherapeutic agents was determined by CCK-8 assay.

RESULTS

The expression of cell-free MK mRNA was significantly higher in the malignant group than in the benign group (0.13 vs 0.01, P < 0.001). The sensitivity and diagnostic accuracy of MK were 77.5 and 81.5 %, while a combination of CEA and MK reached 86.9 % sensitivity and 88.7 % accuracy. In addition, cell-free MK mRNA expression was significantly correlated with inhibitory rate of cisplatin (R = -0.72, P < 0.01).

CONCLUSIONS

Measurement of cell-free MK mRNA levels in effusion supernatant yields a high diagnostic accuracy and a potential predictive value.

[Establishment of primary Her-2 over- expression human breast cancer cell model]

AIM

Through isolation and purification pri-mary HER2 overexpression human breast cancer cells from malignant pleural effusion and identification the HER2 expression level of the cells to establish the primary HER2 overexpression human breast cancer cell model. METH-ODS: Malignant pleural effusion of HER2 overexpression breast cancer patient was collected. The primary cells were extracted from malignant pleural effusion by Lymphocyte separation medium and the method of density gradient centrifugation. When the primary cells were cultured and spreaded to the 5th generation, the HER2 expression level of the primary cells were detected by the methods of Q-PCR,Western blot and flow cytometry (FCM). Ability of tumor-bearing was detected by tumor-bearing nude mice assay.

RESULTS

The primary HER2 overexpression human breast cancer cells were extracted and identified by the methods of Q-PCR, Western blot and tumor-bearing nude mice assay,even though the FCM showed Negative results.

CONCLUSION

The primary HER2 overexpression human breast cancer cell model was established; Identification of primary cells need to be confirmed by different methods.

[Detection of epidermal growth factor receptor gene mutations in non-small cell lung cancer using bi-loop probe specific primer quantitative PCR]

OBJECTIVE

To investigate the sensitivity of bi-loop probe and specific primer quantitative PCR (BPSP-qPCR) in the detection of epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC).

METHODS

BPSP-qPCR was employed to examine the presence of mutations of EFGR exon 19 through 21. Correlation of the mutations with clinicopathological characteristics and types of tumor samples were performed.

RESULTS

In the cohort of 265 specimens, 30.2% (80/265) mutations were found to be 19-del and/or L858R. Females (39.7%, 31/78), non-smokers (41.0%, 43/105) and adenocarcinoma patients (37.8%, 51/135) had a higher mutation rate (P<0.05) among 184 patients whose profiles were available. T790M combined with 19-del and/or L858R accounted for 3.3% (6/184) of the mutations. Male metastatic tumors (29.6%, 8/27), pleural fluids of females (42.9%, 9/21) and non-smokers (40.7%, 11/27) were found to have higher percentage of 19-del and/or L858R mutations, in contrast, no mutations were found in the metastatic lesions of non-adenocarcinoma patients (P>0.05).

CONCLUSIONS

BPSP-qPCR is a robust method in detection of EGFR mutations with high consistency and sensitivity. The difference of EGFR mutations in primary tumors, metastatic lesions and pleural fluids suggests that EGFR tyrosine kinase inhibitors (EGFR-TKI) treatment may have variable treatment effects depending on the tumor sites.

Evaluation of the phenotype pattern of macrophages isolated from malignant and non-malignant pleural effusions

Macrophages are among the infiltrate components of most malignant tumors. Tumor-associated macrophages (TAMs) may secrete a variety of humoral factors, which promote or inhibit tumor growth. In general, depending on their activation pathway, macrophages exhibit two different patterns of phenotype, M1 or M2. It is assumed that TAMs comprise pattern M2. In the malignant pleural effusion, macrophages are a frequent component of cytological evaluation. In this microenvironment, TAMs could be involved in the development of immunity. The phenotype of macrophages represented in malignant and non-malignant pleural effusions is unknown. In this study, macrophages were isolated from 38 pleural effusions (15 malignant and 23 non-malignant) and the expression of a variety of immune mediators and their receptors was assessed to determine the type of activation (M1 vs. M2). The expression of mRNA was analyzed for IL-1β, IL-4, IL-6, IL-10, IL-11, IL-18, TNFα, TGFβ1, IL1R1, IL1RAP, TLR2, TLR4, VLA4, CD62L, MMP2, MMP9, VEGFA, PDGFA, and PDGFB. In immunohistochemical evaluation, the expressions of CD68, mesothelin, MAC387, IL-1β, IL-6, IL-10, IL-12, TNFα, and CD105 were assessed. The cytoplasmic expression of IFNγ, TNFα, IL-6, and IL-10 and the surface expression of CD11a, CD14, CD15, CD16, CD23, CD25, CD45, CD54, CD62L, CD69, VLA2, VLA3, VLA4, VLA6, TLR2, TLR4, and CCR7 were tested using flow cytometry. In supernatants from macrophages cultures, TNFα, IL-1β, IL-6, IL-8, IL-10, IL-12, MCP1, and VEGF were investigated by cytometric beads array method (CBA flex sets) and TGFβ1 by ELISA. Our results indicate that macrophages from malignant and non-malignant pleural effusions differ from each other and suggest that macrophages isolated from non-malignant effusions show a pattern comparable to M1 while those isolated from malignant effusions express similarity to M2 phenotype, but they have not shown a classical M2 pattern.

Spheres derived from lung adenocarcinoma pleural effusions: molecular characterization and tumor engraftment

Malignant pleural effusions (MPEs) could represent an excellent source to culture a wide variety of cancer cells from different donors. In this study, we set up culture conditions for cancer cells deriving from MPEs of several patients affected by the most frequent form of lung cancer, namely the subset of non small cell lung cancers (NSCLC) classified as Lung Adenocarcinomas (AdenoCa) which account for approximately 40% of lung cancer cases. AdenoCa malignant pleural effusions gave rise to in vitro cultures both in adherent and/or in spheroid conditions in almost all cases analyzed. We characterized in greater detail two samples which showed the most efficient propagation in vitro. In these samples we also compared gene profiles of spheroid vs adherent cultures and identified a set of differentially expressed genes. Finally we achieved efficient tumor engraftment in recipient NOD/SCID mice, also upon inoculation of small number of cells, thus suggesting indirectly the presence of tumor initiating cells.

[Value of detecting p16 gene methylation in the diagnosis of malignant pleural effusion]

OBJECTIVE

To investigate aberrant methylation in the promoter of p16 gene in the sediment cells of pleural effusion and evaluate its clinical significance in the differentiating benign and malignant pleural effusion.

METHODS

Using methylation-specific PCR (MSP), aberrant promoter methylation of p16 gene was detected in the sedimental cells of pleural effusion samples from 66 patients with pleural effusion.

RESULTS

Of the 66 patients with pleural effusion, 36 had a definite diagnosis of malignant pleural effusion, and the rest were confirmed to have benign pleural effusion. The positivity rate of p16 gene promoter methylation was 69.4% (25/36) in malignant pleural effusion and 13.3% (4/30) in benign pleural effusion specimens, showing a significant difference between them (χ² = 20.915, P < 0.01). The diagnostic sensitivity, specificity and accuracy of aberrant promoter methylation of p16 gene in the 36 malignant cases were 69.4%, 86.7% and 77.3%, respectively. The positive expression of p16 gene promoter methylation in malignant pleural effusion was not correlated to the histological type or the pathological grade of the tumor (P > 0.05).

CONCLUSION

Detection of aberrant methylation in p16 gene promoter in the sediment cells of pleural effusion specimens by MSP method allows differentiation between benign and malignant pleural effusion.

Neurotrophin system activation in pleural effusions

Neurotrophins (NTs) expression was assessed in malignant and non-malignant pleural effusions (inflammatory exudates and transudates). Enzyme-linked immunosorbent assay, in malignant exudates from small and non-small cell lung cancer (SCLC and NSCLC), detected nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), and their levels are higher as compared with inflammatory and transudative effusions. By immunoblots, in cultured cancer cells coming from malignant pleural effusions, NTs and low- and high-affinity NT receptors were detected in a percentage of SCLC and NSCLC. Proliferation assay demonstrated that BDNF significantly increased cancer cell proliferation in vitro, on the contrary, NT-3 reduced cancer cell growth rate and NGF did not modify cell growth. Moreover, NGF protects cells from death during starvation. These effects are reverted by the addition of NT receptor antagonists. Cultured cancer cells injected into the lung of immunodeficient mice generate lung tumors expressing NTs and NT receptors. These findings suggest that NTs may be able to modulate cancer cell behavior and their growth.

Antiapoptotic activity of autocrine interleukin-22 and therapeutic effects of interleukin-22-small interfering RNA on human lung cancer xenografts

PURPOSE

Non-small cell lung carcinoma (NSCLC) is one of most common malignant diseases and usually is resistant against apoptosis-inducing chemotherapy. This study is to explore the antiapoptotic mechanisms of interleukin (IL)-22 in human lung cancer.

EXPERIMENTAL DESIGN

Nineteen cases with stage I to III NSCLC were collected to determine the expression of IL-22. Stable transfection of human IL-22 cDNA into A549 and PG cells and transfection of IL-22-RNA interference (RNAi) into these cancer cell lines were done to reveal the molecular mechanisms of IL-22.

RESULTS

It was found that IL-22 was highly expressed in primary tumor tissue, malignant pleural effusion, and serum of patients with NSCLC. IL-22R1 mRNA was also detected in lung cancer tissues as well as lung cancer cell lines. Overexpression of IL-22 protected lung cancer cell lines from serum starvation-induced and chemotherapeutic drug-induced apoptosis via activation of STAT3 and its downstream antiapoptotic proteins such as Bcl-2 and Bcl-xL and inactivation of extracellular signal-regulated kinase 1/2. Exposure to blocking antibodies against IL-22R1 or transfection with the IL-22-RNAi plasmid in vitro resulted in apoptosis of these lung cancer cells via STAT3 and extracellular signal-regulated kinase 1/2 pathways. Furthermore, an in vivo xenograft study showed that administration of IL-22-RNAi plasmids significantly inhibited the human tumor cell growth in BALB/c nude mice.

CONCLUSIONS

Our study indicates that autocrine production of IL-22 contributes to human lung cancer cell survival and resistance to chemotherapy through the up-regulation of antiapoptotic proteins.

Osteopontin is involved in the formation of malignant pleural effusion in lung cancer

Malignant pleural effusion (MPE) is associated with advanced-stage lung cancer and is a poor prognostic sign for these patients. Osteopontin (OPN) is a multifunctional cytokine that is involved in the tumor progression and angiogenesis of lung cancer cells. The purpose of this study is to investigate and provide evidence for the role of OPN in the formation of MPE associated with lung cancer. In this study, we established an OPN knockdown murine lung cancer cell line, 3LL cells, utilizing the small interfering RNA (siRNA) technique. To reveal the effect of OPN on the formation of MPE associated with lung cancer, we directly injected OPN knockdown 3LL cells, 3LL/OPN siRNA, or control cells, 3LL/control siRNA, into the pleural space of C57BL/6 mice. OPN knockdown significantly reduced the formation of MPE, but did not inhibit in vivo tumor growth of 3LL cells in mice. Vascular endothelial growth factor (VEGF) concentration in MPE was markedly decreased in the 3LL/OPN siRNA in comparison with that of the 3LL/control siRNA. In vitro, recombinant OPN protein enhanced VEGF secretion from human umbilical vein endothelial cell (HUVEC) or human mesothelial cell line, Met5A cells, in a concentration-dependent manner. These results suggest that OPN is positively involved in the formation of MPE of lung cancer presumably by promoting VEGF secretion from vascular endothelial cells or mesothelial cells. OPN could be an effective target molecule for reducing MPE in lung cancer patients.

Exon 19 of EGFR mutation in relation to the CA-repeat polymorphism in intron 1

Epidermal growth factor receptor (EGFR) mutations in lung cancer enhance tyrosine kinase activity and increase sensitivity to the EGFR tyrosine kinase inhibitor, gefitinib. Mutation analysis of the EGFR gene is therefore indispensable for predicting gefitinib response. We investigated a CA-repeat polymorphism in the EGFR gene related to EGFR mutations. Because an increasing number of CA-repeats at intron 1 of the EGFR gene has been reported to reduce transcription activity, we examined the relationship between EGFR mutations and this CA-repeat polymorphism. EGFR mutations at exon 19 were closely associated with shorter CA-repeat length in the shorter allele, but this was not the case for EGFR mutations at exons 18 or 21. Increased intrinsic EGFR mRNA expression in non-cancerous lung tissues from lung adenocarcinoma patients was also significantly associated with shorter CA-repeat length. A higher frequency of EGFR mutations at exon 19 was associated with shorter CA-repeat length only in patients with high levels of EGFR mRNA expression. To determine the phenotypes of cells possessing shorter CA-repeats, an in vitro study using human bronchial epithelial cells with different CA-repeat lengths was performed; more rapid cell growth and activated EGF/EGFR signaling were found more often in the cells having both shorter CA-repeats and increased EGFR mRNA expression. These results suggest that CA-repeat length in the EGFR gene may be a genetic factor related to cancer in the case of EGFR mutations at exon 19. The mechanism likely involves enhanced intrinsic expression of EGFR mRNA and activated EGF/EGFR signaling that accompany shorter CA-repeats.

Establishment and characterization of a new Ewing's sarcoma cell line from a malignant pleural effusion

BACKGROUND

Ewing's sarcoma cell lines may represent a good in vitro model for the understanding of tumor biology in this heterogeneous group of diseases. In the present study, we report the establishment and characterization of a primary Ewing's sarcoma cell line (LDS-Falck 01).

MATERIALS AND METHODS

LDS-Falck 01 was generated from a malignant pleural effusion of a patient with metastatic peripheral primitive neuroectodermal tumor arising from the chest wall. Extensive characterization of the cells was accomplished using immunocytochemical, RT-PCR and cytogenetic studies.

RESULTS

In vitro LDS-Falck 01 cells had both anchorage-dependent and -independent growth patterns. Immunocytochemical studies showed that cells were PAS-, vimentin-, CD99- and NSE-positive, EGFR- and CD117-negative. Cytogenetic analysis revealed a complex hyperdiploid karyotype with multiple chromosomal aberrations including an unbalanced translocation t(11;22)(q24;q12). The EWS/FLI1 chimeric transcript type 1 was detected.

CONCLUSION

This cell line may represent a valid tool for investigating the biomolecular characteristics of this group of neoplasms and their sensitivity to therapeutic agents.

Characterization of novel transforming growth factor-beta type I receptors found in malignant pleural effusion tumor cells

Background

Tumors expressing a transforming growth factor-beta type I receptor (TβRI) mutant with sequence deletions in a nine-alanine (9A) stretch of the signal peptide are reported to be highly associated with disease progression. Expression of this mutant could interfere with endogenous TGFβ signaling in the cell. However, little is known about the importance of the remaining part of the signal peptide on the cellular function of TβRI.

Results

We cloned and identified four new in-frame deletion variants of TβRI, designated DM1 to DM4, in pleural effusion-derived tumor cells. Intriguingly, DM1 and DM2, with a small region truncated in the putative signal peptide of TβRI, had a serious defect in their protein expression compared with that of the wild-type receptor. Using serial deletion mutagenesis, we characterized a region encoded by nucleotides 16–51 as a key element controlling TβRI protein expression. Consistently, both DM1 and DM2 have this peptide deleted. Experiments using cycloheximde and MG132 further confirmed its indispensable role for the protein stability of TβRI. In contrast, truncation of the 9A-stretch itself or a region downstream to the stretch barely affected TβRI expression. However, variants lacking a region C-terminal to the stretch completely lost their capability to conduct TGFβ-induced transcriptional activation. Intriguingly, expression of DM3 in a cell sensitive to TGFβ made it significantly refractory to TGFβ-mediated growth inhibition. The effect of DM3 was to ablate the apoptotic event induced by TGFβ.

Conclusion

We identified four new transcript variants of TβRI in malignant effusion tumor cells and characterized two key elements controlling its protein stability and transcriptional activation. Expression of one of variants bestowed cancer cells with a growth advantage in the presence of TGFβ. These results highlight the potential roles of some naturally occurring TβRI variants on the promotion of tumor malignancy.

Chromosomal aberrations of malignant pleural effusions of lung adenocarcinoma: different cytogenetic changes are correlated with genders and smoking habits

Chromosomal aberrations of malignant cells from pleural effusions of 31 cases of lung adenocarcinoma were analyzed. Pooled CGH results showed frequent amplifications on chromosome arms 1p (22.6%), 1q (35.5%), 2q (25.8%), 3q (38.7%), 4q (41.9%), 5p (41.9%), 5q (51.6%), 6p (19.4%), 6q (25.8%), 7p (41.9%), 7q (35.5%), 8q (32.3%), 12q (38.7%), 13q (22.6%), 14q (35.5%), 17q (19.4%), Xp (22.6%), and Xq (38.7%). Frequent deletions were found on 1p (19.4%), 3p (16.1%), 4q (16.1%), 8p (25.8%), 9p (22.6%), 9q (29.0%), 10q (22.6%), 13q (22.6%), 16p (19.4%), 16q (22.6%), 17p (29.0%), 18q (16.1%), 19p (41.9%), 19q (32.3%), 20p (19.4%) and 22q (29%). These genomic changes were generally found consistent with previous reports of CGH analysis of primary tumors of lung adenocarcinoma. Loss of 19q and 22q were more frequently found in our studies (32.3% and 29.0%, respectively) than studies of primary tumors (less than 7% for both genetic changes). Gain of 11p, although not a frequent finding, was relatively more common in this (16%) than other studies (range, 2.9-11.8%). Interestingly, occurrences of 3p loss and 11p gain were higher in smokers than non-smokers, and deletion of 3p and increased copy number of 11p and Xp appeared more often in male than female patients. Among 17 male patients, gain of chromosomal 11p was a frequent aberration in tumors of smokers, while gain of Xp was more easily found in tumors of non-smokers. One candidate gene located within 11p15, lactate dehydrogenase C (LDHC), was selected for further study. Three cases with 11p gain had amplified FISH signals of LDHC. Also tumors from smokers or male had significantly higher transcript level of LDHC than non-smokers or female, respectively. The results demonstrate that different cytogenetic changes of malignant pleural effusions from lung adenocarcinoma are correlated with genders and smoking habits. The role of LDHC in the carcinogenesis of smoking-related lung adenocarcinoma, especially in male patients with pleural effusions, deserves further investigations.

EGFR mutation status in pleural fluid predicts tumor responsiveness and resistance to gefitinib

It has been reported that the threonine-to-methionine substitution at amino acid position 790 (T790M) of the epidermal growth factor receptor (EGFR) gene is correlated with acquired resistance to gefitinib. We previously reported that there was some population that harbored the EGFR T790M mutation as a minor clone of tumor cells prior to drug treatment, may be causing resistance to gefitinib during treatment. This fact also suggests that the detection of the EGFR T790M mutation prior to treatment may predict the development of resistance. We also showed that pleural fluid is a useful specimen for detection of EGFR mutation using sensitive assays. In this study, we reported a female patient who was treated with gefitinib because an EGFR L858R mutation was found in her pleural fluid. Our patient showed partial response to gefitinib, but she had progressive disease only 4 months after the start of treatment. Furthermore, the EGFR T790M mutation was detected in the pleural fluid before gefitinib treatment by the mutant-enriched PCR assay. Our findings confirmed that the EGFR T790M mutation was occasionally present as a minor population in tumor cells before treatment and caused resistance after gefitinib administration. The detection of a small fraction of T790M-positive alleles may be useful to predict the clinical course of the gefitinib-treated non-small-cell lung cancer patients.

Aberrant promoter methylation profile in pleural fluid DNA and clinicopathological factors in patients with non-small cell lung cancer

The aim of this study was to investigate the prognostic value of hypermethylation of tumor suppressor genes in patients with non-small cell lung cancer (NSCLC). In samples from 34 lung patients with malignant pleural effusions, we used a methylation-specific polymerase chain reaction to detect aberrant hypermethylation of the promoters of the DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT), p16INK4a, ras association domain family 1A (RASSF1A), apoptosis-related genes, death-associated protein kinase (DAPK), and retinoic acid receptor beta(RARbeta). There is no association between methylation status of five tumor suppressor genes including MGMT, p16INK4a, RASSF1A, DAPK and RARbeta in pleural fluid DNA and clinicopathological parameters including clinical outcome. Aberrant promoter methylation of tumor suppressor genes in pleural fluid DNA could not be a valuable prognostic marker of NSCLC patients with malignant pleural effusion.

Do cytogenetic abnormalities precede morphologic abnormalities in a developing malignant condition?

Cytogenetic evaluation of bone marrow and neoplastic tissues plays a critical role in determining patient management and prognosis. Here, we highlight two cases in which the cytogenetic studies challenge the common practice of using hematologic and morphologic changes as key factors in malignant disease management. The first case is that of a lymph node sample from a 40-yr-old non-Hodgkin's lymphoma (NHL) patient sent for determination of disease progress. Hematologic studies showed no evidence of transformation to high-grade NHL (>15% blasts with rare mitotic figures). Cytogenetic studies of lymph node showed multiple clonal abnormalities, most notably a der(18) from a t(14;18) which is associated with high-grade NHL. After two cycles of chemotherapy with fludarabine, the patient did not show any clinical response, suggesting possible progression to high-grade lymphoma. The second case is of a patient with a history of human immunodeficiency virus and blastic natural killer leukemia/lymphoma. Hematologic studies of ascitic fluid classified the patient as having pleural effusion lymphoma whereas bone marrow analysis showed no malignancy. Bone marrow cytogenetic studies showed multiple clonal abnormalities including a t(8;14), which is commonly associated with Burkitt's lymphoma (BL). To our knowledge, this is the first case wherein a morphologically normal bone marrow showed presence of clonal abnormalities consistent with BL or Pleural effusion lymphoma. After two cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy, the patient's general condition and ascitis improved and she was discharged. These studies clearly demonstrate that genetic changes often precede morphologic changes in a developing malignant condition. Therefore, the critical information needed for care of patients with malignant disorders may be incomplete or inaccurate if cytogenetic evaluation is overlooked.

Establishment of a human herpes virus-8-negative malignant effusion lymphoma cell line (STR-428) carrying concurrent translocations of BCL2 and c-MYC genes

A new cell line, STR-428 was established from ascites tumor cells of a malignant effusion lymphoma patient without human herpes virus-8 (HHV-8) infection. STR-428 cells showed an immunophenotype of mature B-cells and produced few cytokines related to lymphomatous effusion. Karyotypic and genetic analysis revealed complex translocations including t(14;18)(q32;q21) effecting IgH/BCL2 and der(8)t(3;8)(q27;q24) involving c-MYC. STR-428 represents a unique, B-cell lymphoma cell line carrying concurrent rearrangement of BCL2 and c-MYC genes with features distinct from those of HHV-8-related primary effusion lymphoma. This cell line may be a valuable tool, other than HHV-8, to investigate the pathogenesis of primary lymphomatous effusion.

Aberrant promoter methylation in pleural fluid DNA for diagnosis of malignant pleural effusion

Accumulating evidence implicates epigenetic changes such as hypermethylation in carcinogenesis. We investigated whether DNA methylation of 5 tumor suppressor genes in pleural fluid samples could aid in diagnosis of malignant effusion. In samples from 47 patients with malignant pleural effusions and 34 with nonmalignant effusions, we used a methylation-specific polymerase chain reaction to detect aberrant hypermethylation of the promoters of the DNA repair gene O(6)-methylguanine-DNA methyltransferase (MGMT), p16(INK4a), ras association domain family 1A (RASSF1A), apoptosis-related genes, death-associated protein kinase (DAPK), and retinoic acid receptor beta (RARbeta). Promoter hypermethylation was associated with malignant effusion for MGMT (Odds ratio (OR) = infinity), p16(INK4a) (OR = infinity), RASSF1A (OR = 13.8; CI, 1.71-112), and RARbeta (OR = 3.17; CI, 1.10-9.11), but not for DAPK. Instead, DAPK methylation was associated with the length of smoking (p < 0.05). Patients with hypermethylation of MGMT, p16(INK4a), RASSF1A or RARbeta were 5.68 times more likely to have malignant effusions than patients without methylation (p = 0.008). Methylations per patient were more numerous for lung cancer than nonmalignant pulmonary disease (0.915 vs. 0.206, p < 0.001). Sensitivity, specificity, and positive predictive value of methylation in one or more genes for diagnosis of malignant effusion were 59.6%, 79.4%, and 80.0% respectively. In conclusion, aberrant promoter methylation of tumor suppressor genes in pleural fluid DNA could be a valuable diagnostic marker for malignant pleural effusion.

[Significance of FCM-DNA ploidy pattern, AgNOR counting, hTERT and PCNA expression in differentiating malignant from benign serous effusion]

BACKGROUND & OBJECTIVE

Differentiating malignant from benign serous effusion is still a difficulty in clinic at present. This study was to explore the clinical value of flow cytometry (FCM)-DNA ploidy, argyrophilic nucleolar organizer region (AgNOR) staining, human telomerase reverse transcriptase (hTERT) and proliferating cell nuclear antigen (PCNA) expression in differentiating malignant from benign serous effusion.

METHODS

Sixty-seven patients with serous effusion, treated in People's Hospital of Huaibei City from Jun. 2004 to Jun. 2005, were selected. Besides routine exfoliated cytology examination, FCM-DNA ploidy analysis and AgNOR staining was performed, hTERT and PCNA expression were detected by SP immunocytology.

RESULTS

There were significant differences in FCM-DNA ploidy, AgNOR staining, hTERT and PCNA expression between malignant and benign serous effusion. Compared with exfoliated cytology, the sensitivity of AgNOR staining was the highest (89.1%), the specificity of cytology, hTERT and PCNA expression was the highest (100%), and the accuracy of AgNOR staining and hTERT expression was the highest (89.6%). According to combination examination, the sensitivity was increased to 91.3% through combining cytology with hTERT expression.

CONCLUSION

DNA aneuploidy, hTERT and PCNA expression and AgNOR counting increase are correlated to malignant serous effusion, and can be important auxiliary measures for serous cytology.

Detection of mRNAs of GA733 genes by RT-PCR in exfoliated cells of pleural and peritoneal effusions and its clinical values

OBJECTIVE

To evaluate the diagnostic values of the detection of mRNAs of GA733 gene family in exfoliated cells of pleural and peritoneal effusions.

METHODS

Sixty specimens of pleural and peritoneal fluids from 60 patients were collected. GA733-1 and GA733-2 mRNA in the exfoliated cells were detected by qualitative RT-PCR, and their diagnostic values were assessed. Patients Sixty patients with pleural or peritoneal effusions, from May 2003 and August 2004, aged 23-85 (average 56.5 years).

RESULTS

GA733-1 and GA733-2 mRNA were positive in 5 (13.9%) and 27 (75.0%) of 36 malignant specimens, and in 1 and 7 of 11 cause-unknown specimens, respectively, but both of them were negative in all 13 benign specimens, and the difference of GA733-2 mRNA positive rates among the three groups was significant (P<0.005), but that of GA733-1 mRNA was not (P>0.05). GA733-1 and GA733-2 mRNA were positive in 4 (15.4%) and 22 (84.6%) of 26 cytological positive specimens, and in 1 and 6 of 6 suspicious specimens, and in 1 (3.5%) and 6 (21.4%) of 28 negative specimens, respectively and the difference of GA733-2 mRNA positive rates among the three groups was significant (P<0.005), but that of GA733-1 mRNA was not (P>0.05). Sensitivity, specificity and accuracy of detection for GA733-2 mRNA for diagnosis of malignant effusions were 75.0%, 100% and 81.6%, respectively.

CONCLUSIONS

The detection of GA733-2 mRNA by qualitative RT-PCR is sensitive and highly specific for the diagnosis of malignant pleural and peritoneal effusions, while the diagnostic value of GA733-1 mRNA needs to be further investigated.

Clinical significance of the detection of the homozygous deletion of P16 gene in malignant pleural effusion

OBJECTIVE

To assess the role of the p16 gene exon 2 homozygous deletion in malignant pleural effusions.

METHODS

The homozygous deletion of p16 gene was determined in 34 pleural effusions due to non-small cell lung cancer (NSCLC) and in 21 cases with tuberculous pleuritis by polymerase chain reaction (PCR), compared with the determination of exfoliated cytology in the same specimens.

RESULTS

The PCR analysis showed that the homozygous deletion of p16 exon 2 was identified in 15 of 34 malignant pleural effusions (44.11%), including 8 negative cytology and it was not found any tuberculous pleural effusions. The exfoliated cytology of pleural effusion was positive in 19 of 34 malignant cases (55.88%). By combining two methods, the diagnostic sensitivity was enhanced, from 55.88% (19/34) to 79.41% (27/34), whose positive rate was higher than only determination of p16 exon2 homozygous deletion or exfoliated cytology in malignant pleural effusions (p<0.001, p<0.05 respectively).

CONCLUSION

Our data suggested that combining the examination of exfoliated cytology and homozygous deletion of p16 gene exon2 in pleural effusion can recruit and enhance the diagnostic value of pleural effusion cytology. The detection of the homozygous deletion of the p16 gene in pleural effusion may be a useful adjunct to the cytological and histological examinations of pleural effusion. In cases of undiagnosed exudative pleural effusion with a high clinical suspicion for malignancy, it is reasonable to examine the homozygous deletion of pleural fluid p16 gene. With p16 gene homozygous deletion in pleural effusion, it may be strongly highly likely to be malignant and have a higher metastatic potential.

Lymphangioleiomyomatosis diagnosed by immunocytochemical and genetic analysis of lymphangioleiomyomatosis cell clusters found in chylous pleural effusion

A 37-year-old woman presented with a cough and discomfort in the chest. Computed tomography revealed the right pleural effusion and a number of cysts in the lungs. Thoracentesis revealed LAM cell clusters (LCC) in chylous pleural effusion, confirmed by immunocytochemical examinations showing that the cells at the center of cluster were LAM cells positive for alpha-smooth muscle actin and HMB45 and the outer layer was lymphatic endothelium cells. When LCC were cultured in vitro, the loss of heterozygosity of TSC2 markers was detected. This case illustrates that LAM can be diagnosed by the identification of LCC without an invasive biopsy if complicated with chylous effusion.

Potential diagnostic value of methylation profile in pleural fluid and serum from cancer patients with pleural effusion

BACKGROUND

The objective of this study was to investigate the diagnostic value of methylation profiles for discrimination between malignant and benign pleural effusions. A secondary objective was to examine the concordance of methylation in samples of serum and pleural fluid.

METHODS

The authors used methylation-specific polymerase chain reaction (MSP) analysis to examine the promoter methylation status of 4 genes in patients with pleural effusion: death-associated protein kinase (DAPK), Ras association domain family 1A (RASSF1A), retinoic acid receptor beta (RARbeta), and p16/INK4a. Pleural effusions were collected from 87 patients who had their diagnoses confirmed on cytologic and/or histologic examinations and clinical evolution. Pleural effusions were classified as malignant (n = 53 patients) or benign (n = 34 patients).

RESULTS

Methylation was detected in serum from 45.3% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions, and it was detected in pleural fluid samples from 58.5% of patients with malignant pleural effusions and from 0% of patients with benign pleural effusions (P = .001). The sensitivity of MSP was greater than that of cytologic examination alone (39.1%; P = .001). When MSP was used together with cytologic examination, sensitivity increased to 69.8% (P = .001).

CONCLUSIONS

Cell-free methylated DNA in pleural fluid can be detected in patients with neoplastic malignancy in a single extraction by thoracocentesis. Adequate management of the extracted pleural fluid can provide a rapid and reliable diagnosis in patients with pleural effusions who have suspected malignancy. MSP, used together with cytologic examination, may obviate the need for other invasive diagnostic tests.

Usefulness of EGFR mutation screening in pleural fluid to predict the clinical outcome of gefitinib treated patients with lung cancer

The importance of epidermal growth factor receptor (EGFR) gene mutation has been recognized in nonsmall cell lung cancer (NSCLC), requiring the standardization of mutation screening system including the kind of samples. Here, we examined the EGFR mutation status in 61 pleural fluid samples from NSCLC cases using direct sequencing, nonenriched PCR, mutant-enriched PCR and peptide nucleic acid-locked nucleic acid (PNA-LNA) PCR clamp assay. The mutant-enriched PCR assay detected 16 mutant cases. Among them, the nonenriched PCR assay failed to detect 3 mutant cases. Regarding the discrepancy between mutant-enriched PCR and PNA-LNA PCR clamp assays, 3 cases of exon19-deletions were detected only by mutant-enriched PCR assay and no difference at the L858R mutation. There was no difference in results between direct sequencing and nonenriched PCR assay. We also correlated the EGFR mutation with clinical outcome of gefitinib-treated 29 cases. EGFR mutations were present in 10 cases, revealing 7 partial response and 3 no change (NC). In EGFR wild-type cases, 10 revealed NC and 9 progressive disease. The responders were significantly more frequent among the EGFR mutant cases than among the wild-type (p < 0.0001). Overall survival (p = 0.0092) and progression-free survival (p = 0.018) were significantly longer among the EGFR mutant cases than among the wild-type. In summary, we evaluated the utility of EGFR mutation screening in pleural fluid using 4 assays that showed some discrepancies arising from the designs of the assays. As clinical importance, the EGFR mutation status in pleural fluid can be a biomarker for the favorable outcome of gefitinib-treated NSCLC cases.