Single-cell transcriptomics reveal metastatic CLDN4+ cancer cells underlying the recurrence of malignant pleural effusion in patients with advanced non-small-cell lung cancer

BACKGROUND

Recurrent malignant pleural effusion (MPE) resulting from non-small-cell lung cancer (NSCLC) is easily refractory to conventional therapeutics and lacks predictive markers. The cellular or genetic signatures of recurrent MPE still remain largely uncertain.

METHODS

16 NSCLC patients with pleural effusions were recruited, followed by corresponding treatments based on primary tumours. Non-recurrent or recurrent MPE was determined after 3-6 weeks of treatments. The status of MPE was verified by computer tomography (CT) and cytopathology, and the baseline pleural fluids were collected for single-cell RNA sequencing (scRNA-seq). Samples were then integrated and profiled. Cellular communications and trajectories were inferred by bioinformatic algorithms. Comparative analysis was conducted and the results were further validated by quantitative polymerase chain reaction (qPCR) in a larger MPE cohort from the authors' centre (n = 64).

RESULTS

The scRNA-seq revealed that 33 590 cells were annotated as 7 major cell types and further characterized into 14 cell clusters precisely. The cell cluster C1, classified as Epithelial Cell Adhesion Molecule (EpCAM)+ metastatic cancer cell and correlated with activation of tight junction and adherence junction, was significantly enriched in the recurrent MPE group, in which Claudin-4 (CLDN4) was identified. The subset cell cluster C3 of C1, which was enriched in recurrent MPE and demonstrated a phenotype of ameboidal-type cell migration, also showed a markedly higher expression of CLDN4. Meanwhile, the expression of CLDN4 was positively correlated with E74 Like ETS Transcription Factor 3 (ELF3), EpCAM and Tumour Associated Calcium Signal Transducer 2 (TACSTD2), independent of driver-gene status. CLDN4 was also found to be associated with the expression of Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A) and Vascular Endothelial Growth Factor A (VEGFA), and the cell cluster C1 was the major mediator in cellular communication of VEGFA signalling. In the extensive MPE cohort, a notably increased expression of CLDN4 in cells from pleural effusion among patients diagnosed with recurrent MPE was observed, compared with the non-recurrent group, which was also associated with a trend towards worse overall survival (OS).

CONCLUSIONS

CLDN4 could be considered as a predictive marker of recurrent MPE among patients with advanced NSCLC. Further validation for its clinical value in cohorts with larger sample size and in-depth mechanism studies on its biological function are warranted.

TRIAL REGISTRATION

Not applicable.

Cell-free DNA methylation analysis as a marker of malignancy in pleural fluid

Diagnosis of malignant pleural effusion (MPE) is made by cytological examination of pleural fluid or histological examination of pleural tissue from biopsy. Unfortunately, detection of malignancy using cytology has an overall sensitivity of 50%, and is dependent upon tumor load, volume of fluid assessed, and cytopathologist experience. The diagnostic yield of pleural fluid cytology is also compromised by low abundance of tumor cells or when morphology is obscured by inflammation or reactive mesothelial cells. A reliable molecular marker that may complement fluid cytology for the diagnosis of malignant pleural effusion is needed. The purpose of this study was to establish a molecular diagnostic approach based on pleural effusion cell-free DNA methylation analysis for the differential diagnosis of malignant pleural effusion and benign pleural effusion. This was a blind, prospective case-control biomarker study. We recruited 104 patients with pleural effusion for the study. We collected pleural fluid from patients with: MPE (n = 48), indeterminate pleural effusion in subjects with known malignancy or IPE (n = 28), and benign PE (n = 28), and performed the Sentinel-MPE liquid biopsy assay. The methylation level of Sentinel-MPE was markedly higher in the MPE samples compared to BPE control samples (p < 0.0001) and the same tendency was observed relative to IPE (p = 0.004). We also noted that the methylation signal was significantly higher in IPE relative to BPE (p < 0.001). We also assessed the diagnostic efficiency of the Sentinel-MPE test by performing receiver operating characteristic analysis (ROC). For the ROC analysis we combined the malignant and indeterminate pleural effusion groups (n = 76) and compared against the benign group (n = 28). The detection sensitivity and specificity of the Sentinel-MPE test was high (AUC = 0.912). The Sentinel-MPE appears to have better performance characteristics than cytology analysis. However, combining Sentinel-MPE with cytology analysis could be an even more effective approach for the diagnosis of MPE. The Sentinel-MPE test can discriminate between BPE and MPE. The Sentinel-MPE liquid biopsy test can detect aberrant DNA in several different tumor types. The Sentinel-MPE test can be a complementary tool to cytology in the diagnosis of MPE.

Efficacy of osimertinib in patients with EGFR-mutation positive non-small cell lung cancer with malignant pleural effusion

BACKGROUND

As an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), osimertinib has emerged as a standard EGFR-mutation positive treatment for non-small cell lung cancer (NSCLC). However, the efficacy of osimertinib for malignant pleural effusion (MPE) remains understudied. This study aimed to evaluate the impact of osimertinib on time to treatment failure (TTF) and overall survival (OS) in patients with EGFR-mutation positive NSCLC, comparing those with and without MPE.

METHODS

This retrospective analysis included patients with advanced or recurrent NSCLC treated with osimertinib at our hospital between April 2016 and June 2021. TTF was defined as the duration from osimertinib initiation to discontinuation, and OS as the duration until death, irrespective of the reason.

RESULTS

Among 229 patients receiving osimertinib, 84 had MPE before administration, 39 acquired EGFR exon20 T790M mutation following previous EGFR-TKI therapy, and 45 were EGFR-TKI-naive. Among EGFR-TKI-naive patients, median TTF was 14.8 and 19.8 months for those with and without MPE, respectively (hazard ratio [HR] 1.40; 95% confidence interval [CI]: 0.90-2.18; p = 0.12). Median OS was 32.0 and 42.0 months for patients with and without MPE, respectively (HR 1.43; 95% CI: 0.86-2.38; p = 0.16). Among patients with T790M mutation, median TTF was 12.3 and 13.1 months for patients with and without MPE, respectively (HR 1.03; 95% CI: 0.69-1.55; p = 0.88). Median OS for patients with and without MPE was 23.2 and 24.7 months, respectively (HR 1.09; 95% CI: 0.72-1.67; p = 0.68).

CONCLUSION

Among patients with EGFR-mutation positive NSCLC, the evidence of MPE has little effect on survival with osimertinib.

Performance of SHOX2 and RASSF1A methylation assay in supernatants and matched cell pellets for the diagnosis of malignant pleural effusion

BACKGROUND

It is difficult to distinguish between malignant pleural effusion (MPE) and benign pleural effusion (BPE). The purpose of this study was to determine the best specimen type by evaluating the DNA methylation status of SHOX2 and RASSF1A in 3 matched PE components.

METHODS

In total, 94 patients were enrolled, including 45 MPE, 35 BPE, and 14 undefined PE (UPE) with malignancies. PE samples were processed into supernatants, fresh-cell pellets, and formalin-fixed and paraffin-embedded (FFPE) cell blocks, respectively. A quantitative real-time PCR was used to detect the methylation status of SHOX2 and RASSF1A.

RESULTS

SHOX2 and RASSF1A methylation levels were significantly higher in the 3 MPE sample types than those of BPE (P < 0.05). The area under the curve using cell-free DNA (cf-DNA) was the highest. The detection sensitivity of SHOX2 and RASSF1A in fresh-cell DNA, cf-DNA and FFPE cell-block were 71.1% (32/45), 97.8% (44/45) and 66.7% (28/42), respectively, with specificities of 97.1% (34/35), 94.3% (33/35), and 96.9% (31/32). Notably, a combination of the cytological analysis and cf-DNA methylation assay showed an increase in positivity rate from 75.6% to 100%.

CONCLUSIONS

The SHOX2 and RASSF1A methylation assay using cf-DNA, the primary recommended specimen type, can excellently increase the diagnostic sensitivity of MPE. A combination of methylation assay with cytological analysis can be used for auxiliary diagnosis of PE.

Single-cell RNA sequencing reveals immune microenvironment of small cell lung cancer-associated malignant pleural effusion

We used 10 × genomics single-cell transcriptome sequencing technology to reveal the tumor immune microenvironment characteristics of small cell lung cancer (SCLC) in a patient with malignant pleural effusion (MPE). A total of 8008 high-quality cells were finally obtained for subsequent bioinformatic analysis, which were divided into 10 cell clusters further identified as B cells, T cells, myeloid cells, NK cells, and cancer cells. Such SCLC related genes as NOTCH1, MYC, TSC22D1, SOX4, BLNK, YBX3, VIM, CD8A, CD8B, and KLF6 were expressed in different degrees during differentiation of T and B cells. Different ligands and receptors between T, B and tumor cells almost interact through MHC II, IL-16, galectin, and APP signaling pathway.

Study on the application of percutaneous closed pleural brushing combined with cell block technique in the diagnosis of malignant pleural effusion

INTRODUCTION

This study was to investigate the diagnostic value of percutaneous closed pleural brushing (CPBR) followed by cell block technique for malignant pleural effusion (MPE) and the predictive efficacy of pleural fluid carcinoembryonic antigen (CEA) for epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma patients with MPE.

METHODS

All patients underwent closed pleural biopsy (CPB) and CPBR followed by cell block examination. MPE-positive diagnostic rates between the two methods were compared. Univariate and multivariate analyses were performed to determine factors influencing the EGFR mutations. Receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of pleural fluid CEA for EGFR mutations.

RESULTS

The cumulative positive diagnostic rates for MPE after single and twice CPBR followed by cell block examination were 80.5% and 89.0%, higher than CPB (45.7%, 54.3%) (P < 0.001). Univariate analysis showed that EGFR mutation was associated with pleural fluid and serum CEA (P < 0.05). Multivariate analysis showed that pleural fluid CEA was an independent risk factor for predicting EGFR mutation (P < 0.001). The area under the curve (AUC) of pleural fluid CEA for EGFR mutation prediction was 0.774, higher than serum CEA (P = 0.043), but no difference with the combined test (P > 0.05).

CONCLUSION

Compared with CPB, CPBR followed by the cell block technique can significantly increase the positive diagnostic rate of suspected MPE. CEA testing of pleural fluid after CPBR has a high predictive efficacy for EGFR mutation in lung adenocarcinoma patients with MPE, implying pleural fluid extracted for cell block after CPBR may be an ideal specimen for genetic testing.

Differences in Pleural Fluid Amylase Levels in Patients with Malignant Pleural Effusion Based on Cancer Type, Histologic Type, and Epidermal Growth Factor Receptor Mutations

Objective High pleural amylase levels have been reported in patients with malignant pleural effusion; however, the characteristics of this association are uncertain. Therefore, this study investigated the factors, such as cancer type and oncogenic drivers, related to pleural amylase levels in patients with malignant pleural effusion. Methods We retrospectively collected the data of 362 cancer patients [lung adenocarcinoma (n=256), lung squamous carcinoma (n=12), small-cell lung carcinoma (n=32), other lung cancers (n=5), mesothelioma (n=31), and metastatic cancer (n=26)] with malignant pleural effusion at Fukujuji Hospital from January 2012 to October 2022. Pleural amylase levels were compared. Results Pleural amylase levels were significantly higher in patients with lung adenocarcinoma [median 58.6 IU/L (interquartile range (IQR) 33.8-139.3)] than in those with small-cell lung carcinoma [median 37.2 IU/L (IQR 26.3-63.7), p=0.012]. The median pleural amylase level was higher in patients with lung adenocarcinoma than in those with other cancer or histologic types, although the difference was not significant. Pleural amylase levels were higher in epidermal growth factor receptor (EGFR) mutation-positive patients than in EGFR mutation-negative patients [median 95.8 IU/L (IQR 52.7-246.5) vs. median 51.2 IU/L (IQR 27.8-96.9), p<0.001]. The Kaplan-Meier survival curves of pleural amylase ≥75 IU/L were higher than those of pleural amylase <75 IU/L [log-rank test p<0.001, hazard ratio 0.54 (95% confidence interval: 0.41-0.71)]. Conclusion This study demonstrates that pleural amylase levels were elevated in patients with lung adenocarcinoma and EGFR mutations. Furthermore, a high pleural amylase level was associated with a good prognosis.

CD39 identifies a specific CD8 + T cell population in lung adenocarcinoma-related metastatic pleural effusion

Malignant pleural effusion (MPE), which is a complex microenvironment that contains numerous immune and tumour signals, is common in lung cancer. Gene alterations, such as driver gene mutations, are believed to affect the components of tumour immunity in the microenvironment (TIME) of non-small-cell lung cancer. In this study, we have shown that pleural CD39 + CD8 + T cells are selectively elevated in lung adenocarcinoma (LUAD) with wild-type epidermal growth factor receptor (EGFRwt) compared to those with newly diagnosed mutant EGFR (EGFRmu). Furthermore, these CD39 + CD8 + T cells are more prevalent in MPE with acquired resistance to EGFR-tyrosine kinase inhibitors (AR-EGFR-TKIs). Our analysis reveals that pleural CD39 + CD8 + T cells exhibit an exhausted phenotype while still retaining cytolytic function. Additionally, they have a higher T cell receptor (TCR) repertoire clonality compared to CD39-CD8 + T cells, which is a unique characteristic of LUAD-related MPE. Further investigation has shown that TCR-Vβ clonality tends to be more enhanced in pleural CD39 + CD8 + T cells from MPE with AR-EGFR-TKIs. In summary, we have identified a subset of CD8 + T cells expressing CD39 in MPE, which may potentially be tumour-reactive CD8 + T cells. This study provides new insights into the dynamic immune composition of the EGFRmu tumour microenvironment.

Combined Methylation of SHOX2 and RASSF1A Genes in Diagnosing Malignant Pleural Effusion

BACKGROUND

It is a significant challenge to identify pleural effusion (PE) through differential diagnosis in clinical settings. The present study endeavors to devise a strategy to differentiate between malignant pleural effusion (MPE) and benign pleural effusion (BPE) by detecting gene methylation.

METHODS

This study recruited 214 patients with PE, among which 104 patients were identified with MPE, while the remaining 110 patients were categorized as having BPE. The methylation levels of short stature homeobox 2 (SHOX2) and RAS association domain family 1, isoform A (RASSF1A) genes were analyzed through methylation-specific polymerase chain reaction (MS-PCR).

RESULTS

The methylation status of either SHOX2 or RASSF1A genes was significantly elevated in MPE compared to BPE. The sensitivity and specificity of SHOX2 and RASSF1A methylation in diagnosing PE were 66.3% and 90.9%, respectively. The sensitivity of the combined methylation detection intended to diagnose pulmonary MPE was 73.5% and 52.8% in non-pulmonary MPE (p < 0.05), suggesting that combined detection of SHOX2 and RASSF1A methylation had high diagnostic value for lung cancer. In comparison to the results of cytology and DNA ploidy detection, methylation detection demonstrated a superior diagnostic efficiency in the diagnosis of lung cancer (p < 0.05). Additionally, the combined detection of SHOX2 and RASSF1A methylation was more potent in diagnosing BPE and MPE (p < 0.05), while compensating for the limitations of cytology and DNA ploidy detection.

CONCLUSIONS

The detection of SHOX2 and RASSF1A methylation can effectively differentiate between BPE and MPE, especially in diagnosing pulmonary MPE.

EGFR Mutation is a Prognostic Factor in Lung Cancer Patients with Pleural Dissemination Detected During or After Surgery

BACKGROUND

Primary lung tumors are sometimes resected when either pleural dissemination (PD) or malignant pleural effusion (MPE) exists. This study clarified the prognostic factors for non-small cell lung cancer (NSCLC) with either PD and MPE, or both, detected during or after surgery.

PATIENTS AND METHODS

We examined patients with NSCLC from a multicenter database who had either PD, MPE, or both, detected during or after surgery between 2005 and 2015. Hazard ratios and 95% confidence intervals were estimated using the Cox proportional hazards model adjusted for potential confounding factors.

RESULTS

Among 9463 registered patients, PD, MPE, or both, were found in 114 patients with NSCLC during or after surgery. Primary tumor resection and exploratory thoracotomy were performed in 65 and 49 patients, respectively. In univariate analysis, adenocarcinoma, clinically undetected lymph node metastasis (c-N0 or unknown), EGFR mutation, and combination of chemotherapy or tyrosine kinase inhibitors after surgery were better prognostic factors for overall survival (OS), whereas in the multivariate analysis, adenocarcinoma, clinically undetected lymph node metastasis, and EGFR mutation were favorable independent prognostic factors in OS. Additionally, limited to patients with EGFR mutation, patients with primary lung tumor resection showed a significantly better 5-year OS than those with exploratory thoracotomy (86.4 vs. 44.8%; p < 0.001).

CONCLUSION

Our findings show that surgical resection of primary tumors could improve the prognosis of patients with PD, MPE, or both, detected during or after surgery when the tumors harbor an EGFR mutation.

Simultaneous diagnosis of tuberculous pleurisy and malignant pleural effusion using metagenomic next-generation sequencing (mNGS)

BACKGROUND

Metagenomic next-generation sequencing (mNGS) has become a powerful tool for pathogen detection, but the value of human sequencing reads generated from it is underestimated.

METHODS

A total of 138 patients with pleural effusion (PE) were diagnosed with tuberculous pleurisy (TBP, N = 82), malignant pleural effusion (MPE, N = 35), or non-TB infection (N = 21), whose PE samples all underwent mNGS analysis. Clinical TB tests including culture, Acid-Fast Bacillus (AFB) test, Xpert, and T-SPOT, were performed. To utilize mNGS for MPE identification, 25 non-MPE samples (20 TBP and 5 non-TB infection) were randomly selected to set human chromosome copy number baseline and generalized linear modeling was performed using copy number variant (CNV) features of the rest 113 samples (35 MPE and 78 non-MPE).

RESULTS

The performance of TB detection was compared among five methods. T-SPOT demonstrated the highest sensitivity (61% vs. culture 32%, AFB 12%, Xpert 35%, and mNGS 49%) but with the highest false-positive rate (10%) as well. In contrast, mNGS was able to detect TB-genome in nearly half (40/82) of the PE samples from TBP subgroup, with 100% specificity. To evaluate the performance of using CNV features of the human genome for MPE prediction, we performed the leave-one-out cross-validation (LOOCV) in the subcohort excluding the 25 non-MPE samples for setting copy number standards, which demonstrated 54.1% sensitivity, 80.8% specificity, 71.7% accuracy, and an AUC of 0.851.

CONCLUSION

In summary, we exploited the value of human and non-human sequencing reads generated from mNGS, which showed promising ability in simultaneously detecting TBP and MPE.

MicroRNAs Present in Malignant Pleural Fluid Increase the Migration of Normal Mesothelial Cells In Vitro and May Help Discriminate between Benign and Malignant Effusions

The sensitivity of pleural fluid (PF) analyses for the diagnosis of malignant pleural effusions (MPEs) is low to moderate. Knowledge about the pathobiology and molecular characteristics of this condition is limited. In this study, the crosstalk between stromal cells and tumor cells was investigated in vitro in order to reveal factors that are present in PF which can mediate MPE formation and aid in discriminating between benign and malignant etiologies. Eighteen PF samples, in different proportions, were exposed in vitro to mesothelial MeT-5A cells to determine the biological effects on these cells. Treatment of normal mesothelial MeT-5A cells with malignant PF increased cell viability, proliferation, and migration, and activated different survival-related signaling pathways. We identified differentially expressed miRNAs in PF samples that could be responsible for these changes. Consistently, bioinformatics analysis revealed an enrichment of the discovered miRNAs in migration-related processes. Notably, the abundance of three miRNAs (miR-141-3p, miR-203a-3, and miR-200c-3p) correctly classified MPEs with false-negative cytological examination results, indicating the potential of these molecules for improving diagnosis. Malignant PF produces phenotypic and functional changes in normal mesothelial cells. These changes are partly mediated by certain miRNAs, which, in turn, could serve to differentiate malignant from benign effusions.

Construction and analysis of expression profile of exosomal lncRNAs in pleural effusion in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is a highly malignant tumor with a very low five-year survival rate. In this study, we aimed to identify differentially expressed long-chain non-coding RNA (lncRNAs) and mRNAs from benign and malignant pleural effusion exosomes.

METHODS

We used gene microassay and quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) to detect and verify differentially expressed mRNAs and lncRNAs in benign and malignant pleural effusion exosomes. Gene Ontology (GO) functional significance and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway significance enrichment analyses were performed to identify the difference in biological processes and functions between different mRNAs. We selected the lncRNA ZBED5-AS1 with an upregulated differential fold of 3.003 and conducted a preliminary study on its cellular function.

RESULTS

Gene microassay results revealed that 177 differentially expressed lncRNAs were upregulated, and 215 were downregulated. The top 10 upregulated were FMN1, AL118505.1, LINC00452, AL109811.2, CATG00000040683.1, AC137932.1, AC008619.1, AL450344.1, AC092718.6, and ZBED5-AS1. The top 10 downregulated were TEX41, G067726, JAZF1-AS1, AC027328.1, AL445645.1, AL022345.4, AC008572.1, AC123777.1, AC093714.1, and PHKG1. For the mRNAs, 79 were upregulated, and 123 were notably downregulated. GO analysis revealed that the upregulated differential mRNAs were mainly involved in "cellular response to acidic pH" (biological processes), "endoplasmic reticulum part" (cellular components), and "at DNA binding, cyclase activity" (molecular functions). KEGG pathways were found to be related to V. cholerae infection, Parkinson's disease, and cell adhesion molecules. RT-qPCR showed that ZBED5-AS1 was highly expressed in LUAD tissues, cells, and benign and malignant pleural fluid exosomes. Overexpression of ZBED5-AS1 could significantly promote the proliferation, migration, invasion, and colony formation of LUAD cells, and knockdown had the opposite consequence.

CONCLUSION

The pleural effusion exosomes from patients with LUAD include several improperly expressed genes, and lncRNA-ZBED5-AS1 is a new biomarker that aids in our understanding of the occurrence and progression of LUAD.

Extracellular Vesicle MicroRNA in Malignant Pleural Effusion

Lung and breast cancer are the two most common causes of malignant pleural effusion (MPE). MPE diagnosis plays a crucial role in determining staging and therapeutic interventions in these cancers. However, our understanding of the pathogenesis and progression of MPE at the molecular level is limited. Extracellular Vesicles (EVs) and their contents, including microRNAs (miRNAs), can be isolated from all bodily fluids, including pleural fluid. This study aims to compare EV-miRNA patterns of expression in MPE caused by breast (BA-MPE) and lung (LA-MPE) adenocarcinomas compared to the control group of heart-failure-induced effusions (HF-PE). We conducted an analysis of 24 pleural fluid samples (8 LA-MPE, 8 BA-MPE, and 8 HF-PE). Using NanoString technology, we profiled miRNAs within EVs isolated from 12 cases. Bioinformatic analysis demonstrated differential expression of miR-1246 in the MPE group vs. HF-PE group and miR-150-5p and miR-1246 in the BA-MPE vs. LA-MPE group, respectively. This difference was demonstrated and validated in an independent cohort using real-time PCR (RT-PCR). miRNA-1246 demonstrated 4-fold increased expression (OR: 3.87, 95% CI: 0.43, 35) in the MPE vs. HF-PE group, resulting in an area under the curve of 0.80 (95% CI: 0.60, 0.99). The highest accuracy for differentiating MPE vs. HF-PE was seen with a combination of miRNAs compared to each miRNA alone. Consistent with prior studies, this study demonstrates dysregulation of specific EV-based miRNAs in breast and lung cancer; pleural fluid provides direct access for the analysis of these EV-miRNAs as biomarkers and potential targets and may provide insight into the underlying pathogenesis of tumor progression. These findings should be explored in large prospective studies.

Phenotypic and functional characterizations of CD8+ T cell populations in malignant pleural effusion

Malignant pleural effusions (MPE) are a common terminal pathway for many types of cancer, especially non-small cell lung cancer (NSCLC). However, the phenotype and differentiation status of MPE-infiltrating CD8⁺ T cells have not yet been systematically addressed. In this study, the surface molecules and cytokine secretion of T cells in MPE and peripheral blood (PB) were analyzed using flow cytometry. We found an increased frequency of CD8⁺ T cells in MPE compared to PB among lung cancer patients, of which the effector memory subset (Tem, CCR7^- CD45RA^-) and central memory subset (Tcm, CCR7⁺ CD45RA^-) were upregulated. MPE-derived Tem and Tcm subsets expressed more PD1 or CD39, and there was a greater population of cells in these subsets that co-expressed them. In addition, Tem and Tcm cells from MPE had higher cytokine production than terminally differentiated effector memory cells (TemRA, CCR7^- CD45RA⁺) and naïve cells (Tnaive, CCR7⁺CD45RA⁺). Our results demonstrate that the Tem and Tcm cells in MPE may have advantages in both tumor reactivity and immune functionality. Altogether, these findings help to characterize the phenotype of MPE-derived CD8⁺ T cells in terms of differentiation and tumor reactivity and reveal their potential as a target for immunotherapy.

Intrapleural nano-immunotherapy promotes innate and adaptive immune responses to enhance anti-PD-L1 therapy for malignant pleural effusion

Malignant pleural effusion (MPE) is indicative of terminal malignancy with a uniformly fatal prognosis. Often, two distinct compartments of tumour microenvironment, the effusion and disseminated pleural tumours, co-exist in the pleural cavity, presenting a major challenge for therapeutic interventions and drug delivery. Clinical evidence suggests that MPE comprises abundant tumour-associated myeloid cells with the tumour-promoting phenotype, impairing antitumour immunity. Here we developed a liposomal nanoparticle loaded with cyclic dinucleotide (LNP-CDN) for targeted activation of stimulators of interferon genes signalling in macrophages and dendritic cells and showed that, on intrapleural administration, they induce drastic changes in the transcriptional landscape in MPE, mitigating the immune cold MPE in both effusion and pleural tumours. Moreover, combination immunotherapy with blockade of programmed death ligand 1 potently reduced MPE volume and inhibited tumour growth not only in the pleural cavity but also in the lung parenchyma, conferring significantly prolonged survival of MPE-bearing mice. Furthermore, the LNP-CDN-induced immunological effects were also observed with clinical MPE samples, suggesting the potential of intrapleural LNP-CDN for clinical MPE immunotherapy.

Development of a novel ALK rearrangement screening test for non-small cell lung cancers

Approximately 5–7% of non–small cell lung cancer (NSCLC) cases harbor an anaplastic lymphoma kinase (ALK) fusion gene and may benefit from ALK inhibitor therapy. To detect ALK fusion genes, we developed a novel test using reverse transcription polymerase chain reaction (RT-PCR) for the ALK kinase domain (KD). Since ALK expression is mostly silenced in the adult with the exception of neuronal tissue, the normal lung tissue, mesothelial lining, and inflammatory cells are devoid of ALK transcript, making ALK KD RT-PCR an ideal surrogate test for ALK fusion transcripts in lung or pleural effusion. The test was designed with a short PCR product (197 bp) to work for both malignant pleural effusion (MPE) and formalin-fixed, paraffin-embedded (FFPE) NSCLC samples. Using ALK IHC as a reference, the sensitivity of the test was 100% for both MPE and FFPE. The specificity was 97.6% for MPE and 97.4% for FFPE. Two false positive cases were found. One was a metastatic brain lesion which should be avoided in the future due to intrinsic ALK expression in the neuronal tissue. The other one resulted from ALK gene amplification. Due to potential false positivity, subsequent confirmation tests such as fluorescence in situ hybridization or multiplex PCR would be preferable. Nevertheless, the test is simple and inexpensive with no false negativity, making it a desirable screening test. It also offers an advantage over multiplex RT-PCR with the capability to detect novel ALK fusions. Indeed through the screening test, we found a novel ALK fusion partner (sperm antigen with calponin homology and coiled-coil domains 1 like gene, SPECC1L) with increased sensitivity to crizotinib in vitro. In summary, a novel RNA-based ALK KD analysis was developed for ALK rearrangement screening in MPE and FFPE specimens of NSCLC. This simple inexpensive test can be implemented as routine diagnostics.

Using Disposable Membrane Cell Collector to Enrich Lung Adenocarcinoma Cells in Bloody Pleural Effusion for Anaplastic Lymphoma Kinase Fusion Gene Detection

PURPOSE

For anaplastic lymphoma kinase (ALK) gene detection, the centrifugal sedimentation method (CSM) and cell block method (CBM) are commonly used to process samples of bloody pleural effusions (BPEs). However, in practice, the impurity content in the processed samples often affects the results and even leads to the detection failure. The purpose of this study was to establish a cell enrichment method (CEM) by using a disposable membrane cell collector to remove blood and inflammatory cells and enrich lung adenocarcinoma cells in BPE for more efficient RNA extraction and ALK gene detection.

MATERIALS AND METHODS

CEM proposed in this study and the traditional CSM and CBM were used to treat BPE samples collected from 37 lung adenocarcinoma patients. A DeNovix DS-11 ultraviolet spectrophotometer was used to measure the concentration and purity of extracted RNA. Amplification refractory mutation systems (ARMS) and ABI 7500 fluorescence qPCR were used to detect ALK gene. Through statistical analysis, the CEM was compared with the CSM and CBM in RNA concentration, purity, and ALK gene detection results.

RESULTS

The concentration of RNA extracted by using the CEM was significantly higher than that extracted by using the CBM and CSM (p < 0.001). The purity of RNA extracted by using the CEM was significantly higher than that by the other 2 methods (p = 0.011, p = 0.005). ALK gene testing with PCR was successful in all the samples using the CEM, but 2 cases by the CSM and 1 case by the CBM failed.

CONCLUSIONS

Using the disposable membrane cell collector to process BPE of lung adenocarcinoma patients for RNA extraction and ALK gene detection is more effective and successful compared with the traditional methods, and it is suggested to be further applied and popularized in clinical practice.

Distinct profile of cell-free DNA in malignant pleural effusion of non-small cell lung cancer and its impact on clinical genetic testing

Cell-free DNA (cfDNA) in supernatant of pleural effusion from advanced NSCLC patients has been proved as surrogate sample detecting therapeutic targets as well as tumor mutation burden (TMB). As recently reported, cfDNA in pleural effusion supernatant is superior to plasma in TMB evaluation. It is reasonable to hypothesize that cfDNA profile in pleural effusion (PE) and plasma might be different. It remains to be elucidated why cfDNA in PE supernatant impacts on genetic analysis. Consequently, the approach dealing with cfDNA from PE supernatant might need to be different from that for plasma cfDNA in order to obtain accurate clinical genetic testing result. Methods: Pleural effusion samples from 32 patients with stage IV lung adenocarcinoma were collected. Supernatant and sediment were processed separately to extract Cell-free DNA as well as sediment DNA (PE-S). cfDNA from pleural effusion was analyzed by Agilent 2100 bioanalyzer. Libraries were prepared by 1) direct use of the total cfDNA without fragmentation step (PE-FL) or 2) use of full-length cfDNA fragmented to 150-250bp (PE-F), 3) use of cfDNA fragments enriched to ~167bp (PE-E167) as well as 4) use of cfDNA fragments larger than 500bp enriched (PE-E500). All samples were subjected to targeted next-generation sequencing (NGS) with a panel of 448 cancer-related genes as well as a panel of 10 NSCLC driver genes. Results: cfDNA were successfully extracted from 30 MPE samples. cfDNA displayed distinct profile in supernatant of malignant pleural effusion from that of plasma cfDNA. No statistical difference in detection of hotspot variations between PE-E167 and PE-F by 448-gene or 10-gene panel. While TMB from PE-F samples was significantly higher than that from PE-E167 and PE-FL. Higher TMB from PE-F was resulted from cancer-unspecific variants with low allele frequency (0.1%-1%) which were mainly introduced by long-fragment cfDNA. Similar genetic profile was observed between paired cfDNA of PE-FL and cfDNA of PE-E167. Conclusion: Long-fragment cfDNA in the PE supernatant will introduce low abundant cancer unrelated variants which leads overestimation of TMB. Paired PE-FL and PE-E167 gave comparable outcomes. Direct use of the total cfDNA without fragmentation step (PE-FL) is recommended for library preparation of NGS testing in clinical practice to exclude interference from long fragments of the cfDNA.

Cytokine/Chemokine/Growth Factor Levels in Malignant Pleural Effusion of Non-small Cell Lung Cancer

OBJECTIVE

Malignant pleural effusions (MPEs) deteriorate the quality of life in patients with advanced stages of cancer. Although vascular endothelial growth factor (VEGF) is known to be a key factor for MPE formation, it is not fully clarified whether there are other components related to its appearance.

METHODS

Pleural effusion and serum samples were collected from patients with MPEs of non-small cell lung cancer. Cellular analysis of pleural effusion was performed using fluorescence flow cytometry. The concentrations of 12 cytokines, chemokines, and growth factors in MPEs and serum samples were analyzed using the cytometric bead array method.

RESULTS

Fifteen patients (median age: 70 years, 11 males) with non-small cell lung cancer (13 adenocarcinoma, 2 squamous cell carcinoma) were enrolled in this study. Concentrations of VEGF, interleukin (IL)-5, IL-6, IL-8, IL-12/IL-23p40, and C-C motif chemokine ligand (CCL) 2 were significantly higher in MPE than in serum. Pleural IL-5 levels correlated with malignant cell numbers in MPE. There was no factor related to the total amount of drained effusion or period of chest tube insertion.

CONCLUSIONS

Production of six molecules were increased in the pleural cavity with MPE of non-small cell lung cancer. Complex interactions among these molecules may regulate MPE formation.

High frequency of exon 20 S768I EGFR mutation detected in malignant pleural effusions: A poor prognosticator of NSCLC

BACKGROUND

Lung cancer is the cause of a fourth of all cancer-related deaths. About a third of all lung adenocarcinoma tumours harbour mutations on exons 18 to 21 of the epidermal growth factor receptor (EGFR) gene. Detection of these mutations allows for targeted therapies in the form of EGFR Tyrosine kinase inhibitors. Recently, "liquid biopsies" have emerged as an alternative to conventional tissue mutation detection.

AIM

In this pilot study, we attempted to optimize EGFR mutation detection from malignant pleural effusions (MPEs) as "liquid biopsies" when tissue biopsies were unavailable. Resulting mutations were then to be mapped on the EGFR gene and explored using cBioPortal, a public cancer genomic database.

METHODS AND RESULTS

We first attempted a direct sequencing approach and showed that single nucleotide variants (SNVs) were likely to be missed in MPEs. We then switched to and optimized an EGFR mutant-specific quantitative polymerase chain reaction-based assay. This assay was piloted on n = 10 pleural effusion samples (one non-malignant pleural effusion as a negative control). 5/9 (55.55%) samples harboured EGFR mutations with 2/9 (22.22%) being exon 19 deletions and 3/9 (33.33%) the S768I mutation. The frequency of the S768I SNV in our study was significantly higher than that observed in other studies (~0.2%). Utilizing cBioPortal data, we report that patients with S768I have a shorter median survival time (6 months vs 38 months), progression-free survival time (8 months vs 44 months) and lower tumor mutation count compared to patients with other EGFR mutations.

CONCLUSIONS

The shorter survival of patients with the S768I SNV predicts aggressive disease and poor prognosis as a result of this mutation. Studies in larger cohorts and/or animal models are necessary to confirm these findings.

Effect of malignant-associated pleural effusion on endothelial viability, motility and angiogenesis in lung cancer

Malignant pleural effusion (MPE) and paramalignant pleural effusion (PPE) remain debilitating complications in lung cancer patients with poor prognosis and limited treatment options. The role of vascular endothelial cells has not been explored in the pleural environment of lung cancer. By integrating MPE and PPE as malignant-associated pleural fluid (MAPF), the current study aimed to evaluate the effect of MAPF on cell proliferation, migration and angiogenesis of HUVEC. First, increased capillaries were identified in the subpleural layer of lung adenocarcinoma. Compatible with pathological observations, the ubiquitous elevation of HUVEC survival was identified in MAPF culture regardless of the underlying cancer type, the driver gene mutation, prior treatments and evidence of malignant cells in pleural fluid. Moreover, MAPF enhanced HUVEC motility with the formation of lamellipodia and filopodia and focal adhesion complex. Tube formation assay revealed angiogenic behavior with the observation of sheet-like structures. HUVEC cultured with MAPF resulted in a significant increase in MAPK phosphorylation. Accompanied with VEGFR2 upregulation in MAPF culture, there was increased expressions of p-STAT3, HIF-1α and Nf-kB. VEGF/VEGFR2 blockade regressed endothelial migration and angiogenesis but not cell proliferation. Our data indicate the angiogenic activities of MAPF on vascular endothelial cells that revealed increased pleural capillaries in lung cancer. Targeting the VEGF/VEGFR2 pathway might modulate the angiogenic propensity of MAPF in future clinical investigations.

Pleural metastasis from auricular melanoma: A brief report

Primary auricular melanoma is rarely reported. Approximately, it accounts for 1% to 4% of all cutaneous melanoma. Early literature suggested that melanoma of the ear is more aggressive than other melanomas, with a propensity for spreading to both regional lymph nodes and distant sites. Here, we present a case of cytological pleural metastasis from auricular melanoma in a 43-year-old woman. Immunohistochemical staining showed that the tumors cells were positive for S-100 protein and Melan-A. The mutation of the v-raf murine sarcoma viral oncogene homolog B (BRAF)V600E was demonstrated on Sanger sequencing. To our knowledge, this is the first report describing the cytomorphology of metastatic auricular melanoma in pleural effusion.

Rationale and Design of a Phase II Trial of Osimertinib Combined With Bevacizumab in Patients With Untreated Epidermal Growth Factor Receptor-mutated Non-small-cell Lung Cancer and Malignant Pleural and/or Pericardial Effusion (SPIRAL II Study)

Progression-free survival (PFS) of patients with non-small-cell lung cancer with pleural or pericardial effusion is expected to be prolonged with combination use of an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor plus bevacizumab compared with that with an EGFR-tyrosine kinase inhibitor alone. Phase I clinical trial data have been reported for combined treatment with osimertinib plus bevacizumab and demonstrated their safety, but the efficacy remains unclear, particularly in patients with pleural or pericardial effusion. This is an ongoing single arm, prospective, open-label, multicenter, phase II trial to evaluate the efficacy and safety of osimertinib plus bevacizumab combination therapy in EGFR mutation-positive patients with untreated or recurrent non-small-cell lung cancer and pleural and/or pericardial effusion. Osimertinib will be administered orally once daily at a dose of 80 mg. One cycle consists of 21 days. Bevacizumab 15 mg/kg will be administered by drip infusion on Day 1 of each cycle. Treatment will be continued until progressive disease or any of the discontinuation criteria are met. The primary endpoint will be the 1-year PFS rate. Secondary endpoints are response rate, PFS, overall survival, survival not requiring pleural/pericardial drainage, and safety. Osimertinib plus bevacizumab combination therapy is expected to prolong PFS and reduce adverse events. TRIAL REGISTRATION NUMBER: UMIN000028071.

Pleural effusion as a substitute for tumor tissue in detecting EGFR/ALK mutations in non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Pleural effusion (PE) has been reported useful in many studies for testing epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) with variable results. This systematic review and meta-analysis was performed to elucidate whether PE could be used as a surrogate for tumor tissue to detect EGFR mutations.

METHODS

We extracted 2 × 2 diagnostic table from each included study and calculated data on specificity, sensitivity, negative likelihood ratio (NLR), positive likelihood ratio (PLR) ,and diagnostic odds ratio (DOR). We used the area under curve (AUC) and summary receiver operating characteristic curve (SROC) to summarize the overall diagnostic performance and assessed publication bias by Deeks' funnel plot.

RESULTS

Our meta-analysis included 15 eligible publications. The following summary estimates for diagnostic parameters of the EGFR mutations detection in PE were made: sensitivity, 0.86 (95%CI 0.83-0.89); specificity, 0.93 (95%CI 0.91-0.95); PLR, 8.53 (95%CI 5,94-12.25); NLR, 0.18 (95%CI 0.13-0.25); DOR, 63.40 (95%CI 38.83-103.51); and AUC, 0.94. Funnel plot indicated publication bias insignificant.

CONCLUSIONS

The meta-analysis suggests that EGFR mutation detecting in PE, especially supernatants, is a promising surrogate for tumor tissue in EGFR mutations testing of patients with NSCLC.

Comparison of PANAMutyper and PNAClamp for Detecting KRAS Mutations from Patients With Malignant Pleural Effusion

BACKGROUND/AIM

KRAS is one of the frequently mutated genes in human cancers and often relates with drug resistance and poor prognosis. PANAMutyper™ is a novel technology that integrates PNAClamp™ and PANA S-Melting™. In the present study, PANAMutyper™ and PNAClamp™ were compared for the detection of KRAS mutations using different samples of patients with malignant pleural effusion.

PATIENTS AND METHODS

A total of 103 patients (including 56 lung adenocarcinoma, 10 lung squamous carcinoma, 17 small cell lung cancer, 3 large cell lung cancer, 3 stomach cancer, 2 ovarian cancer, and others) with malignant pleural effusion were investigated using matched tumor tissue, cell block, and pleural effusion samples. The diagnostic performance of these two methods was compared.

RESULTS

KRAS mutations were detected in 18 (17.5%) of 103 patients using tissue, cell block, and pleural effusion samples. All 18 patients with KRAS mutations were detected by PANAMutyper™ using any sample type, however, only 7 cases were detected by PNAClamp™. Among the subtypes of KRAS mutations, substitution in codon 12, 35G>T was the most frequent, followed by substitution in codon 12, 35G>A and codon 12, 34G>A. In pleural effusion specimens, PANAMutyper™ showed a better diagnostic performance compared to PNAClamp™.

CONCLUSION

PANAMutyper™ had a diagnostic superiority for the detection of KRAS mutations in patients with malignant pleural effusion compared to PNAClamp™, although there was a concordance between PANAMutyper™ and PNAClamp™ results. Therefore, PANAMutyper™ can be used for a more sensitive and accurate detection of KRAS mutations.

Role of Ancillary Techniques in Fluid Cytology

The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.

Reactive oxygen species modulator 1, a novel protein, combined with carcinoembryonic antigen in differentiating malignant from benign pleural effusion

The differential diagnosis of malignant pleural effusion and benign pleural effusion remains a clinical problem. Reactive oxygen species modulator 1 is a novel protein overexpressed in various human tumors. The objective of this study was to evaluate the diagnostic value of joint detection of reactive oxygen species modulator 1 and carcinoembryonic antigen in the differential diagnosis of malignant pleural effusion and benign pleural effusion. One hundred two consecutive patients with pleural effusion (including 52 malignant pleural effusion and 50 benign pleural effusion) were registered in this study. Levels of reactive oxygen species modulator 1 and carcinoembryonic antigen were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Results showed that the concentrations of reactive oxygen species modulator 1 both in pleural fluid and serum of patients with malignant pleural effusion were significantly higher than those of benign pleural effusion (both p < 0.05). The diagnostic sensitivity and specificity of pleural fluid reactive oxygen species modulator 1 were 61.54% and 82.00%, respectively, with the optimized cutoff value of 589.70 pg/mL. However, the diagnostic sensitivity and specificity of serum reactive oxygen species modulator 1 were only 41.38% and 86.21%, respectively, with the cutoff value of 27.22 ng/mL, indicating that serum reactive oxygen species modulator 1 may not be a good option in the differential diagnosis of malignant pleural effusion and benign pleural effusion. The sensitivity and specificity of pleural fluid carcinoembryonic antigen were 69.23% and 88.00%, respectively, at the cutoff value of 3.05 ng/mL, while serum carcinoembryonic antigen were 80.77% and 72.00% at the cutoff value of 2.60 ng/mL. The sensitivity could be raised to 88.17% in parallel detection of plural fluid reactive oxygen species modulator 1 and carcinoembryonic antigen concentration, and the specificity could be improved to 97.84% in serial detection.

Molecular Alterations in Patients with Pulmonary Adenocarcinoma Presenting with Malignant Pleural Effusion at the First Diagnosis

OBJECTIVES

The aim of this study was to report cytologic and molecular features of pulmonary adenocarcinoma patients presenting with a malignant pleural effusion at the first diagnosis.

STUDY DESIGN

Patients who had a cytopathologic diagnosis conclusive for lung adenocarcinoma for the first time on their pleural fluid specimen, and molecular testing done, were studied. The control group consisted of patients with a malignant pleural effusion that developed during disease progression.

RESULTS

We identified 18 patients (9 males and 9 females). Micropapillary and/or solid adenocarcinoma type features predominated among cytologic specimens (n = 15), while acinar patterns predominated in controls. Survival was not significantly different from that of the control group (mean 13.8 vs. 13.9 months, respectively; p = 0.61). Ten (55%) cases had mutations in EGFR (n = 6; 60%), KRAS (n = 3; 30%), or ALK translocation (n = 1; 10%). No mutations were identified in BRAF, AKT, ERBB2, NRAS, or PIK3CA (tested in 7 patients). Patients positive for the tested mutations had a better overall survival than patients negative for the mutations (mean survival 16.2 vs. 6.05 months, respectively; p = 0.006, log-rank test). Ten (84%) control patients were positive for mutations in EGFR (n = 5; 42%), KRAS (n = 4; 34%), or ALK translocation (n = 1; 8.4%).

CONCLUSION

In our series, a micropapillary-like and solid-like morphology, common in cytologic specimens, and alterations in EGFR were the most frequent identifiable molecular changes.

Genetic profiling of putative breast cancer stem cells from malignant pleural effusions

A common symptom during late stage breast cancer disease is pleural effusion, which is related to poor prognosis. Malignant cells can be detected in pleural effusions indicating metastatic spread from the primary tumor site. Pleural effusions have been shown to be a useful source for studying metastasis and for isolating cells with putative cancer stem cell (CSC) properties. For the present study, pleural effusion aspirates from 17 metastatic breast cancer patients were processed to propagate CSCs in vitro. Patient-derived aspirates were cultured under sphere forming conditions and isolated primary cultures were further sorted for cancer stem cell subpopulations ALDH1⁺ and CD44⁺CD24^-/low. Additionally, sphere forming efficiency of CSC and non-CSC subpopulations was determined. In order to genetically characterize the different tumor subpopulations, DNA was isolated from pleural effusions before and after cell sorting, and compared with corresponding DNA copy number profiles from primary tumors or bone metastasis using low-coverage whole genome sequencing (SCNA-seq). In general, unsorted cells had a higher potential to form spheres when compared to CSC subpopulations. In most cases, cell sorting did not yield sufficient cells for copy number analysis. A total of five from nine analyzed unsorted pleura samples (55%) showed aberrant copy number profiles similar to the respective primary tumor. However, most sorted subpopulations showed a balanced profile indicating an insufficient amount of tumor cells and low sensitivity of the sequencing method. Finally, we were able to establish a long term cell culture from one pleural effusion sample, which was characterized in detail. In conclusion, we confirm that pleural effusions are a suitable source for enrichment of putative CSC. However, sequencing based molecular characterization is impeded due to insufficient sensitivity along with a high number of normal contaminating cells, which are masking genetic alterations of rare cancer (stem) cells.

Epidermal Growth Factor Receptor Mutation and Anaplastic Lymphoma Kinase Gene Fusion: Detection in Malignant Pleural Effusion by RNA or PNA Analysis

Analyzing EGFR mutations and detecting ALK gene fusion are indispensable when planning to treat pulmonary adenocarcinoma. Malignant pleural effusion (MPE) is a devastating complication of lung cancer and sometimes the only source for mutation analysis. The percentage of tumor cells in the pleural effusion may be low; therefore, mutant enrichment is required for a successful analysis. The EGFR mutation status in MPE was determined using three methods: (1) PCR sequencing of genomic DNA (direct sequencing), (2) mutant-enriched PCR sequencing of genomic DNA using peptide nucleic acid (PNA-sequencing), and (3) PCR sequencing of cDNA after reverse transcription for cellular RNA (RNA-sequencing). RT-PCR was also used to test cases for ALK gene fusion.

PNA-sequencing and RNA-sequencing had similar analytical sensitivities (< 1%), which indicates similar enrichment capabilities. The clinical sensitivity in 133 cases when detecting the common EGFR exon 19 and exon 21 mutations was 56.4% (75/133) for direct sequencing, 63.2% (84/133) for PNA-sequencing, and 65.4% (87/133) for RNA-sequencing. RT-PCR and sequencing showed 5 cases (3.8%) with ALK gene fusion. All had wild-type EGFR. For EGFR analysis of MPE, RNA-sequencing is at least as sensitive as PNA-sequencing but not limited to specific mutations. Detecting ALK fusion can be incorporated in the same RNA workflow. Therefore, RNA is a better source for comprehensive molecular diagnoses in MPE.

Mast cells mediate malignant pleural effusion formation

Mast cells (MCs) have been identified in various tumors; however, the role of these cells in tumorigenesis remains controversial. Here, we quantified MCs in human and murine malignant pleural effusions (MPEs) and evaluated the fate and function of these cells in MPE development. Evaluation of murine MPE-competent lung and colon adenocarcinomas revealed that these tumors actively attract and subsequently degranulate MCs in the pleural space by elaborating CCL2 and osteopontin. MCs were required for effusion development, as MPEs did not form in mice lacking MCs, and pleural infusion of MCs with MPE-incompetent cells promoted MPE formation. Once homed to the pleural space, MCs released tryptase AB1 and IL-1β, which in turn induced pleural vasculature leakiness and triggered NF-κB activation in pleural tumor cells, thereby fostering pleural fluid accumulation and tumor growth. Evaluation of human effusions revealed that MCs are elevated in MPEs compared with benign effusions. Moreover, MC abundance correlated with MPE formation in a human cancer cell-induced effusion model. Treatment of mice with the c-KIT inhibitor imatinib mesylate limited effusion precipitation by mouse and human adenocarcinoma cells. Together, the results of this study indicate that MCs are required for MPE formation and suggest that MC-dependent effusion formation is therapeutically addressable.

Sea-urchin-like Au nanocluster with surface-enhanced raman scattering in detecting epidermal growth factor receptor (EGFR) mutation status of malignant pleural effusion

Somatic mutations in the epidermal growth factor receptor (EGFR) gene are common in patients with lung adenocarcinomas and are associated with sensitivity to the small-molecule tyrosine kinase inhibitors (TKIs). For 10%-50% of the patients who experienced malignant pleural effusion (MPE), pathological diagnosis might rely exclusively on finding lung cancer cells in the MPE. Current methods based on polymerase chain reaction were utilized to test EGFR mutation status of MPE samples, but the accuracy of the test data was very low, resulting in many patients losing the chance of TKIs treatment. Herein, we synthesized the sea-urchin-like Au nanocluster (AuNC) with an average diameter of 92.4 nm, composed of 15-nm nanopricks. By introducing abundant sharp nanopricks, the enhancement factor of AuNC reached at 1.97 × 10(7). After capped with crystal violet (CV), polyethylene glycol, and EGFR mutation specific antibody, the AuNC-EGFR had excellent surface-enhanced Raman scattering (SERS) activity and EGFR mutation targeted recognition capability in lung cancer cells. Characteristic SERS signal at 1617 cm(-1) of CV was linear correlation with the number of H1650 cells, demonstrating the minimum detection limit as 25 cells in a 1-mL suspension. The gold mass in single H1650 cells exposed to AuNC-E746_750 for 2 h ranged from 208.6 pg to 231.4 pg, which approximately corresponded to 56-62 AuNCs per cell. Furthermore, SERS was preclinically utilized to test EGFR mutation status in MPE samples from 35 patients with lung adenocarcinoma. Principal component analysis (PCA) and the support vector machine (SVM) algorithm were constructed for EGFR mutation diagnostic analysis, yielding an overall accuracy of 90.7%. SERS measurement based on sea-urchin-like AuNC was an efficient method for EGFR mutation detection in MPE, and it might show great potential in applications such as predicting gene typing of clinical lung cancer in the near future.

Detection of EGFR mutation in supernatant, cell pellets of pleural effusion and tumor tissues from non-small cell lung cancer patients by high resolution melting analysis and sequencing

To determine epidermal growth factor receptor (EGFR) mutation in advanced non-small cell lung cancer (NSCLC) patients and compare the detection efficiency between different sample resources, both high resolution melting (HRM) analysis and direct sequencing method were used to analyze 36 pleural effusion samples and 22 matched biopsy tumor tissues collected from NSCLC patients. For each pleural effusion sample, the supernatant and the cell pellets were examined separately. Among all the 36 cases of pleural effusion samples, 18 mutations of EGFR were found in cell-free supernatant while 13 mutations were found in the cell pellets as detected by HRM analysis. In the 22 matched samples, 13 cases of EGFR mutations were identified in paraffin-embedded biopsy tissue samples, 12 cases in the cell-free supernatant and 9 cases in the cell pellets of pleural effusion. EGFR mutations in 15 cases out of the total 36 pleural effusion samples detected by direct sequencing were also identified by HRM analysis, giving 100% efficiency for HRM method. The results established the important role of HRM as a reliable and efficient method to determine EGFR mutation status and indicated the feasibility of using pleural effusion in replacement of biopsy tissues in particular clinical cases. Furthermore, the cell-free supernatant of pleural effusion might be a better resource for mutation detection than cell pellets.

Impact of cell arrangement of pleural effusion in survival of patients with breast cancer

OBJECTIVE

This study was performed to evaluate the potential influence of cytological differences between pleural effusions on the survival of women with metastatic breast cancer during 30 months of follow-up.

STUDY DESIGN

A hospital-based cohort study was performed. Pleural fluid cytology slides from patients with breast cancer were examined. Cases were grouped according to the pattern of tumor cells (spheroid and isolated), in order to access their prognostic value.

RESULTS

The study comprised 87 patients. An isolated cell pattern was associated with higher mortality 30 months after the pleural effusion when compared to a spheroid pattern (p = 0.038). Patients with an isolated cell pattern showed higher risk of dying than patients with spheroid formations. The relative risk after adjustment of intervening variables was 5.336 (95% CI 1.054-27.020). The presence of a triple-negative immunohistochemical pattern significantly increased the risk of mortality before 30 months.

CONCLUSION

Pleural effusion with isolated malignant cells is associated with worse prognosis after 30 months of follow-up.

Complementary value of DNA flow cytometry and image morphometry in detection of malignant cells in effusion fluids

BACKGROUND

In cytologic evaluation of body cavity effusions, the morphologic changes exhibited by reactive mesothelial cells often confound the diagnosis. This study investigates the role of DNA flow cytometry (DNA FCM) and image morphometry (IM) in improving diagnostic accuracy.

METHODS

53 pleural and 47 ascitic fluid samples were evaluated cytologically. All were also subjected to flow cytometry to assess DNA ploidy. Image morphometry was used to measure nuclear diameter, nuclear perimeter and nuclear area.

RESULTS

On cytomorphology 79% cases were diagnosed as benign, 19% as malignant and 2% as suggestive of malignancy. DNA FCM showed aneuploidy in 13 of 19 malignant cases and diploidy in 6 cases. The mean nuclear area of the benign group was 60.14 ± 39.91 µm² and that of malignant cases was 190.54 ± 56.06 µm². Using DNA FCM and IM, one of the two cases "suggestive of malignancy" was placed in the benign group and the other in the malignant group. Also, these modalities were able to pick up one case of malignancy that was diagnosed as benign on cytology.

CONCLUSIONS

Cytomorphology remains the foremost diagnostic modality in detecting malignant cells in effusions. DNA flow cytometry and image morphometry hold a valuable complementary value.

Malignant pleural effusion supernatants are substitutes for metastatic pleural tumor tissues in EGFR mutation test in patients with advanced lung adenocarcinoma

Background

Though the possibility of using malignant pleural effusions (MPEs) as alternatives for metastatic pleural tumor tissues (MPTTs) in epidermal growth factor receptor (EGFR) mutation test has been examined, due to the lack of studies comparing the results in matching MPEs and MPTTs, the clinical value of MPEs for advanced adenocarcinoma patients with pleural effusions is not confirmed.

Methods

EGFR mutation statuses in matching MPTTs, MPE supernatants and cell blocks, of 41 patients with advanced lung adenocarcinoma as diagnosed by thoracoscopy were analyzed using amplification refractory mutation system (ARMS).

Results

EGFR mutations were detected in 46.3% (19/41) of MPTTs, 43.9% (18/41) of MPE supernatants and 56.3% (18/32) of MPE cell blocks by ARMS analysis. Generally, the same EGFR statuses were identified in both MPTTs and matching MPE cell blocks of 81.3% patients (26/32), whereas MPTTs and matching MPE supernatants of 87.8% (36/41) patients shared the same EGFR status. Compared with EGFR mutation detection in MPTTs, the sensitivity of EGFR mutation detection in MPE-cell blocks was 87.5% (14/16), specificity was 75.0% (12/16), while the sensitivity of EGFR mutation detection in MPE-supernatants was 84.2% (16/19), specificity was 90.9% (20/22).

Conclusions

The high concordance of EGFR mutation statuses between MPEs and MPTTs in lung adenocarcinoma patients with pleural metastasis as determined by ARMS analysis suggests that MPEs, particularly MPE supernatants, may be substitutes for MPTTs in EGFR mutation test.

Diagnostic and prognostic value of SHOX2 and SEPT9 DNA methylation and cytology in benign, paramalignant and malignant pleural effusions

Pleural effusions (PE) are a common clinical problem. The discrimination between benign (BPE), malignant (MPE) and paramalignant (PPE) pleural effusions is highly important to ensure appropriate patient treatment. Today, cytology is the gold standard for diagnosing malignant pleural effusions. However, its sensitivity is limited due to the sometimes low abundance of tumor cells and the challenging assessment of cell morphology in cytological samples. This study aimed to develop and validate a diagnostic test, which allows for the highly specific detection of malignant cells in pleural effusions based on the DNA methylation biomarkers SHOX2 and SEPT9. A quantitative real-time PCR assay was developed which enabled the accurate and sensitive detection of SHOX2 and SEPT9 in PEs. Cytological and DNA methylation analyses were conducted in a case control study comprised of PEs from 114 patients (58 cases, 56 controls). Cytological analysis as well as SHOX2 and SEPT9 methylation resulted in 100% specificity. 21% of the cases were cytologically positive and 26% were SHOX2 or SEPT9 methylation positive. The combined analysis of cytology and DNA methylation resulted in an increase of 71% positively classified PEs from cancer patients as compared to cytological analysis alone. The absolute sensitivity of cytology and DNA methylation was not determinable due to the lack of an appropriate gold standard diagnostic for distinguishing between MPEs and PPEs. Therefore, it was unclear which PEs from cancer patients were malignant (containing tumor cells) and which PEs were paramalignant and resulted from benign conditions in cancer patients, respectively. Furthermore, DNA methylation analysis in PEs allowed the prognosis of the overall survival in cancer patients (Kaplan-Meier analysis, log rank test, p = 0.02 (SHOX2), p = 0.02 (SEPT9)). The developed test may be used as a diagnostic and prognostic adjunct to existing clinical and cytopathological investigations in patients with PEs of unclear etiology.

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.

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.