Isolation of a novel human lung-specific gene, LUNX, a potential molecular marker for detection of micrometastasis in non-small-cell lung cancer

Chimeric Antigen Receptor (CAR) T-Cell Therapy for Patients with Lung Cancer: Current Perspectives

Immunotherapy using chimeric antigen receptor (CAR)-engineered T-cells has achieved unprecedented efficacy in selected hematological cancers. However, solid tumors such as lung cancer impose several additional challenges to the attainment of clinical success using this emerging therapeutic modality. Lung cancer is the biggest cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths worldwide each year. Obstacles to the development of CAR T-cell immunotherapy for lung cancer include the selection of safe tumor-selective targets, accounting for the large number of candidates that have been evaluated thus far. Tumor heterogeneity is also a key hurdle, meaning that single target-based approaches are susceptible to therapeutic failure through the emergence of antigen null cancers. There is also a need to enable CAR T-cells to traffic efficiently to sites of disease, to infiltrate tumor deposits and to operate within the hostile tumor microenvironment formed by solid tumors, resisting the onset of exhaustion. Multiple immune, metabolic, physical and chemical barriers operate at the core of malignant lesions, with potential for further heterogeneity and evolution in the face of selective therapeutic pressures. Although the extraordinarily adaptable nature of lung cancers has recently been unmasked, immunotherapy using immune checkpoint blockade can achieve long-term disease control in a small number of patients, establishing clinical proof of concept that immunotherapies can control advanced lung carcinomas. This review summarizes pre-clinical CAR T-cell research that is specifically focused on lung cancer in addition to published and ongoing clinical trial activity. A number of advanced engineering strategies are also described which are designed to bridge the gap to the attainment of meaningful efficacy using genetically engineered T-cells.

Molecular Profile Study of Extracellular Vesicles for the Identification of Useful Small “Hit” in Cancer Diagnosis

Tumor-secreted extracellular vesicles (EVs) are the main mediators of cell-cell communication, permitting cells to exchange proteins, lipids, and metabolites in varying physiological and pathological conditions. They contain signature tumor-derived molecules that reflect the intracellular status of their cell of origin. Recent studies have shown that tumor cell-derived EVs can aid in cancer metastasis through the modulation of the tumor microenvironment, suppression of the immune system, pre-metastatic niche formation, and subsequent metastasis. EVs can easily be isolated from a variety of biological fluids, and their content makes them useful biomarkers for the diagnosis, prognosis, monitorization of cancer progression, and response to treatment. This review aims to explore the biomarkers of cancer cell-derived EVs obtained from liquid biopsies, in order to understand cancer progression and metastatic evolution for early diagnosis and precision therapy.

Immunogenic senescence sensitizes lung cancer to LUNX-targeting therapy

The higher immunogenicity of tumors usually predicts favorable therapeutic responses. Tumor antigens dominate the immunogenic character within tumors. We investigated if there was a targetable tumor antigen during immunogenic chemotherapy within lung cancer. Chemotherapy-induced immunogenic senescence was demonstrated using a multi-marker, three-step workflow, and RNA-sequencing data. The ability of anti-lung-specific X protein (LUNX) antibody to suppress the survival of senescent lung cancer cells was evaluated in vitro and in vivo using real-time cytotoxicity analysis and xenograft mouse models, respectively. The induction of cellular senescence by immunogenic chemotherapy boosted cell-surface shuttling of LUNX and enhanced the immunogenic features of senescent tumor cells, which sensitized lung cancer cells to anti-LUNX antibody-mediated therapy and contributed to tumor suppression. The immunogenic senescence-mediated anti-tumor response was triggered by the direct action of antibody on tumor cells, strengthened by natural-killer cells through an antibody-dependent cell-mediated cytotoxicity response, and ultimately, led to tumor control. Our findings suggest that LUNX is a lung cancer targetable-immunogenic antigen. The proportion of lung cancers responding to LUNX-targeting therapy could be expanded substantially by immunogenic chemotherapy that induces senescence-associated translocation of LUNX to the plasma membrane.

Immunotherapy for lung cancer: Focusing on chimeric antigen receptor (CAR)-T cell therapy

Besides traditional treatment strategies, including surgery, radiotherapy, and chemotherapy for lung cancer as the leading cause of cancer incidence and death, immunotherapy has also emerged as a new treatment strategy. The goal of immunotherapy is to stimulate the immune system responses against cancer, using various approaches such as therapeutic vaccines, monoclonal antibodies, immune checkpoint inhibitors, and T-cell therapy. Chimeric antigen receptor (CAR)-T cells, one of the most popular cancer immunotherapy approaches in the last decade, are genetically engineered T-cells to redirect patients' immune responses to recognize and eliminate tumor-associated antigens (TAA)-expressing tumor cells. CAR-T cell therapy provides promising benefits in lung tumors. In this review, we summarize different immunotherapy approaches for lung cancer, the structure of CAR-T cells, currently undergoing CARs in clinical trials, and various TAAs are being investigated as potential targets in designing CAR-T cells for lung cancer.

Functional Study of Polymorphism 1888 C>T in the Promoter Region of Human PLUNC Gene

BACKGROUND

Our previous study showed that a single nucleotide polymorphisms (SNP) of 1888 C>T located at promoter region of human PLUNC gene might affect the susceptibility of nasopharyngeal carcinoma (NPC) in a Chinese population. This study aims to analyze the effect of the genetic variant on PLUNC promoter activity.

MATERIALS AND METHODS

The DNA fragments of the PLUNC promoter region including the SNP 1888 C>T were obtained by polymerase chain reaction (PCR). The recombinant plasmid of the fragment and the pGL3-Enhancer firefly luciferase reporter vector were cloned and identified. Relative luciferase activity (RLA) was measured and electrophoretic mobility shift assay (EMSA) was analyzed.

RESULTS

Luciferase reporter assays demonstrated that luciferase activity of the 1888 T-allele was significantly higher, compared with the C-allele. EMSA experiment proved that the PLUNC gene promoter region SNP 1888 TT genotype had the ability to bind the nucleus protein with the human NPC CEN2 cell, whereas the CC genotype had not.

CONCLUSIONS

SNP 1888 C>T in the promoter region of PLUNC gene might be a functional mutant locus, indicating that individuals carrying SNP 1888 C-C genotype might be more likely to develop NCP due to the reduced expression of the PLUNC gene. Further functional studies on PLUNC genetic variants are warranted to verify our findings.

LunX-CAR T Cells as a Targeted Therapy for Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) carries a high mortality, and efficacious therapy is lacking. Therapy using chimeric antigen receptor (CAR) T cells has been used efficaciously against hematologic malignancies, but the curative effect against solid tumors is not satisfactory. A lack of antigen targets is one of the main reasons for this limited efficacy. Previously, we showed that lung-specific X (LUNX; also known as BPIFA1, PLUNC, and SPLUNC1) is overexpressed in lung cancer cells. Here, we constructed a CAR-T-cell-based strategy to target LunX (CAR^LunX T cells). CAR T cells were developed so that, upon specific recognition of LunX, they secreted cytokines and killed LunX-positive NSCLC cells. In vitro, CAR^LunX T cells displayed enhanced toxicity toward NSCLC lines and production of cytokines and showed specific LunX-dependent recognition of NSCLC cells. Adoptive transfer of CAR^LunX T cells induced regression of established metastatic lung cancer xenografts and prolonged survival. CAR^LunX T cells could infiltrate into the tumor. Also, we constructed a patient-derived xenograft model of lung cancer. After therapy with CAR^LunX T cells, tumor growth was suppressed, and survival was prolonged significantly. Together, our findings offer preclinical evidence of the immunotherapeutic targeting of LunX as a strategy to treat NSCLC.

Methylation Assessment for the Prediction of Malignancy in Mediastinal Adenopathies Obtained by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Patients with Lung Cancer

The evaluation of mediastinal lymph nodes is critical for the correct staging of patients with lung cancer (LC). Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for mediastinal staging, though unfortunately lymph node micrometastasis is often missed by cytological analysis. The aim of this study was to evaluate the predictive capacity of methylation biomarkers and provide a classification rule for predicting malignancy in false negative EBUS-TBNA samples. The study included 112 patients with a new or suspected diagnosis of LC that were referred to EBUS-TBNA. Methylation of p16/INK4a, MGMT, SHOX2, E-cadherin, DLEC1, and RASSF1A was quantified by nested methylation-specific qPCR in 218 EBUS-TBNA lymph node samples. Cross-validated linear regression models were evaluated to predict malignancy. According to EBUS-TBNA and final diagnosis, 90 samples were true positives for malignancy, 110 were true negatives, and 18 were false negatives. MGMT, SHOX2, and E-cadherin were the methylation markers that better predicted malignancy. The model including sex, age, short axis diameter and standard uptake value of adenopathy, and SHOX2 showed 82.7% cross-validated sensitivity and 82.4% specificity for the detection of malignant lymphadenopathies among negative cytology samples. Our results suggest that the predictive model approach proposed can complement EBUS-TBNA for mediastinal staging.

Three Markers in Cancerous and Healthy Cells of Patients with Non-Small-Cell Lung Carcinoma (NSCLC)

Introduction: Lung cancer is the most common cause of cancer-related death among males and females. The diagnosis of lung cancer is of great importance for clinical considerations and follow-up treatment. This study aimed to examine the expression of CEA, LUNX, and CK19 biomarkers in the cancerous and healthy tissues of patients suffering from NSCLC. Methods: In this study, 30 patients with NSCLCs referring to Masih Daneshvari Hospital in Tehran were voluntarily selected prior to taking any treatment. A tissue sample from the center and a sample of healthy tissues close to the cancerous masses were prepared by a specialist in the bronchoscopy sector and tested using real-time RT-PCR. Results: Positive CEA mRNA was observed in cancerous tissues in the center of tumors of 25 out of 30 cases. In the healthy tissue group, the same was found in 10 out of 30 cases (P<0.001). The markers CK19 and LUNX mRNAs showed to be positive in cancerous samples in the center of tumors of 15 and 22 out of 30 cases, and in the healthy tissue group, the expression was observed in 5 and 4 out of 30 cases, respectively(P<0.001). Conclusion: This study confirms that the aformentioed markers are the ones with a relatively appropriate sensitivity and specificity for the diagnosis of lung cancer.

Multi-Gene Expression in Anthracosis of the Lungs as One of the Risk Factors for Non-Small Cell Lung Cancer

Background: Anthracosis of the lung occurs due to the deposition of carbon and silica in the mucosa and submucosa, manifested as black lesions. The association of anthracosis with lung cancer has remained to be clearly elucidated The current study aimed to assess the P16, CDH1 and LUNX genes expression level to evaluate the association of anthracotic lesions in the lungs with the occurrence of non-small cell lung cancer. Methods: Forty biopsy samples were taken from the center and 40 from the margins of black anthracotic lesions in the lungs; RNA was extracted from the samples and cDNA was synthesized. Real-time reverse-transcription polymerase chain reaction (RT-PCR) was performed to assess the expression of P16, CDH1 and LUNX genes. All steps were performed in triplicate. Results: A significant reduction in P16 gene expression was noted at the center compared to the margins of the lesions (P<0.001). expression level of CDH1 at the center of lesions was significantly lower than margins (P<0.001). However, LUNX gene had significantly higher expressionlevel at the center compared to margins (P<0.001). Conclusion: Decreased expression of P16 and CDH1 and increased expression of LUNX tumor genes were noted at the center of anthracotic lesions. Significant increase in expression of LUNX gene in NSCLC indicates an association between anthracosis and NSCLC, according to which, anthracotic patients may carry a high risk for NSCLC.

Increased expression of BPI fold-containing family A member 1 is associated with metastasis and poor prognosis in human colorectal carcinoma

Bactericidal or permeability-increasing protein fold-containing family A member 1 (BPIFA1) has been demonstrated to be involved in inflammatory responses in the upper airway and the progression of non-small cell lung cancer. However, the expression levels of BPIFA1 and its clinical prognostic significance in colorectal carcinoma (CRC) has not yet been elucidated. Reverse transcription-polymerase chain reaction and immunohistochemistry were used to analyze the expression levels of BPIFA1 in CRC and normal mucosal tissues. The associations between BPIFA1 expression levels and clinicopathological characteristics, and its predictive value for prognosis in CRC, were statistically evaluated as appropriate. The expression levels of BPIFA1 were revealed to be upregulated at the transcriptional and translational levels in CRC tissues, compared with in normal mucosal tissues. A high expression level of BPIFA1 is significantly associated with invasion depth (P=0.040), lymph node metastasis (P=0.035) and distant metastasis (P=0.010). Furthermore, Kaplan-Meier analysis indicated that BIPFA1 overexpression is associated with short survival time, and the Cox proportional hazards model of risk analysis indicated that BPIFA1 is an independent prognostic factor for patients with CRC. The results of the present study suggested that BPIFA1 expression is upregulated in CRC tissues, and that an increased expression level of BPIFA1 is associated with tumor invasion, metastasis and poor prognosis, indicating that BPIFA1 may be a potential clinical prognostic predictor and therapeutic target for patients with CRC.

Identification of novel SNPs in differentially expressed genes and its association with horn cancer of Bos indicus bullocks by next-generation sequencing

The use of polymorphic markers like SNPs promises to provide comprehensive tool for analysing genome and identifying genomic regions that contribute to cancer phenotype. Horn cancer is the most common cancer among Bos indicus animals. Increased expression of some genes due to polymorphisms increases risk of HC incidence. We successfully amplified 91 SNPs located in 69 genes in 52 samples, each of HC and HN. Equimolar concentration of amplicons from 69 PCR products of each sample was pooled and subjected to sequencing using Ion Torrent PGM. Data obtained were analysed using DNASTAR software package and case control analysis using SAS software. We found SNP present in BPIFA1 gene of B. indicus shows association with event of HC which reflects its potential to be a genetic marker. Bioinformatic analysis to detect structural and functional impact nsSNP of BPIFA1 added another layer of confirmation to our result. We successfully identified SNP associated with HC as well as demonstrated efficient approach for limited number of SNP discovery and validation in targeted genomics regions in large number of samples combining PCR amplification and Ion Torrent PGM sequencing which suits small-scale laboratories with limited budget.

New insights on the palate, lung, and nasal epithelium clone (PLUNC) proteins: Based on molecular and functional analysis of its homolog of YH1/SPLUNC1

The palate, lung, and nasal epithelium clone (PLUNC) proteins are intricate immune molecules and arisen questions from them are still unresolved. In order to identify the role of PLUNC family proteins, we had analyzed its homolog protein YH1/SPLUNC1, which highly expresses in nontumor nasopharyngeal epithelium while expresses weakly in nasopharyngeal carcinoma (NPC) tissues. It is found that YH1/SPLUNC1 protein expression level was higher in chronic normal nasopharynx inflammatory cells compared to NPC tissue cells. An approach to produce active YH1/SPLUNC1 protein had been established and recombinant YH1/SPLUNC1 protein could bind to all four Gram-positive and four Gram-negative bacteria we tested, and triggered the aggregation of those bacteria. Interestingly, YH1/SPLUNC1 protein has antimicrobial activity, and it can directly kill Escherichia coli and Acinetobacter haemolyticus. The microorganism cell showed morphological changes in cell wall such as cell damage and cytoplasmic leakage after exposure to YH1/SPLUNC1 protein, indicating that YH1/SPLUNC1 directly killed the microorganisms by cell wall permeabilization. All these results indicated that YH1/SPLUNC1 might be an important antimicrobial protein involved in innate immunity defense.

Lung specific X protein as a novel therapeutic target for lung cancer

The identification of novel therapeutic targets in lung cancer is an urgent challenge. We found lung-specific X protein (LunX) is overexpressed in lung cancer and promotes primary tumor growth and metastatic colonization. The antibody against LunX appears to be potentially applicable for therapeutic use in the future, given its efficacy in preclinical models.

Expression of two basic mRNA biomarkers in peripheral blood of patients with non-small cell lung cancer detected by real-time rt-PCR, individually and simultaneously

Introduction: Although extensive research has been conducted on lung cancer markers, a singular clinically applicable marker has not been found yet. The objective of this study was to evaluate the sensitivity and the specificity of carcinoembryonic antigen (CEA) mRNA and lung-specific X protein (LUNX) mRNA biomarkers in peripheral blood to detect lung cancer individually and simultaneously. Methods: Thirty patients affected by lung cancer and 30 healthy individuals were studied in this research. Three vials of cDNA were made from each sample after taking peripheral blood samples and extracting total RNA. Each sample was examined by the real-time RT-PCR technique. The result from each vial was then compared with the sensitivity of overall marker. Results: The CEA mRNA was positive in 24 out of 30 lung cancer patients. Hence, its sensitivity was determined at 80%, differing significantly from that observed in healthy individuals, where 11 positive cases were seen. The overall sensitivity of this marker was significantly associated with positivity in vials 2 and 3 but not in vial 1. The LUNX mRNA was positive in 21 out of 30 patients, indicating 70% sensitivity. This finding significantly differed from that in healthy individuals. The overall sensitivity of this marker was significantly associated with positivity in vials 1 and 3, but not in vial 2. In 93.3% of the patients, at least one positive marker was observed. Conclusion: The mentioned mRNA could be suggested as sensitive and specific markers in peripheral blood for primary diagnosis of lung cancer.

Bactericidal/Permeability-increasing protein fold-containing family member A1 in airway host protection and respiratory disease

Bactericidal/permeability-increasing protein fold-containing family member A1 (BPIFA1), formerly known as SPLUNC1, is one of the most abundant proteins in respiratory secretions and has been identified with increasing frequency in studies of pulmonary disease. Its expression is largely restricted to the respiratory tract, being highly concentrated in the upper airways and proximal trachea. BPIFA1 is highly responsive to airborne pathogens, allergens, and irritants. BPIFA1 actively participates in host protection through antimicrobial, surfactant, airway surface liquid regulation, and immunomodulatory properties. Its expression is modulated in multiple lung diseases, including cystic fibrosis, chronic obstructive pulmonary disease, respiratory malignancies, and idiopathic pulmonary fibrosis. However, the role of BPIFA1 in pulmonary pathogenesis remains to be elucidated. This review highlights the versatile properties of BPIFA1 in antimicrobial protection and its roles as a sensor of environmental exposure and regulator of immune cell function. A greater understanding of the contribution of BPIFA1 to disease pathogenesis and activity may clarify if BPIFA1 is a biomarker and potential drug target in pulmonary disease.

SPLUNC1 Is a Significant Marker in Pleural Effusion from Lung Cancer Compared to Tuberculosis

SPLUNC1 (Short palate, lung and nasal epithelium clone1) protein is an abundant secretory product of epithelia present throughout the conducting airways. Although its function is still not fully known, most studies have focused on its defensive effect in the infection of human airways and its potential to serve as a molecular marker for lung cancer. In this study, we further evaluated the SPLUNC1 expression in patients with lung disease to explore its role in cancer or tuberculosis at the protein level. We generated a panel of antibodies by using protein from a eukaryotic expression system as the immunogen to mice. It was the panel of SPLUNC1 monoclonal antibodies that allowed us to comparatively determine SPLUNC1 protein in lung cancer and tuberculosis infection by detecting sera and pleural effusion other than airway surface. The results showed that the SPLUNC1 level was not significantly changed either from sera of lung cancer or control. There was a significant increase in pleural effusion from lung cancer when compared to tuberculosis. These results indicate that SPLUNC1 may be a useful marker for tracing lung cancer cells, based on its epithelial origin property in pleural effusion.

Targeting LUNX inhibits non-small cell lung cancer growth and metastasis

There remains a great need for effective therapies for lung cancer, the majority of which are non-small cell lung cancers (NSCLC). Here, we report the identification of a novel candidate therapeutic target, LUNX, as a molecule overexpressed in primary NSCLC and lymph node metastases that is associated with reduced postoperative survival. Functional studies demonstrated that LUNX overexpression promoted lung cancer cell migration and proliferation by interactions with the chaperone protein 14-3-3. Conversely, LUNX silencing disrupted primary tumor growth, local invasion, and metastatic colonization. The finding that LUNX was expressed on cell membranes prompted us to generate and characterize LUNX antibodies as a candidate therapeutic. Anti-LUNX could downregulate LUNX and reduce lung cancer cell proliferation and migration in vitro. Administered in vivo to mice bearing lung cancer xenografts, anti-LUNX could slow tumor growth and metastasis and improve mouse survival. Together, our work provides a preclinical proof of concept for LUNX as a novel candidate target for immunotherapy in lung cancer.

Diagnostic utility of LUNX mRNA and VEGF mRNA in pleural fluid for differentiating benign from malignant origin

OBJECTIVE

The purpose of this study was to evaluate the diagnostic utility of lung-specific X protein (LUNX) mRNA and vascular endothelial growth factor mRNA in differentiating pleural effusion of different origin.

METHODS

A total of 136 patients with pleural effusion (46 cases of malignant pleural effusion caused by lung cancer, 30 cases of malignant pleural effusion caused by other cancers and 60 cases of benign pleural effusion) were enrolled in this study. Levels of LUNX mRNA and vascular endothelial growth factor mRNA in pleural fluid were detected by real-time quantitative polymerase chain reaction. Pleural fluid carcinoembryonic antigen and Cyfra21-1 were also measured simultaneously.

RESULTS

The LUNX mRNA level was significantly higher in malignant pleural effusion caused by lung cancer than in malignant pleural effusion caused by other cancers and in benign pleural effusion. In malignant pleural effusion caused by cancers of different origin, the vascular endothelial growth factor mRNA level was significantly higher than in benign pleural effusion. For the diagnosis of malignant pleural effusion caused by lung cancer, LUNX mRNA exhibited higher sensitivity (80%), when compared with vascular endothelial growth factor mRNA (65%), carcinoembryonic antigen (67%) and Cyfra21-1 (61%), with the same specificity (95%). The combination of LUNX mRNA and cytology achieved a sensitivity of 85%. The combined use of LUNX mRNA and vascular endothelial growth factor mRNA and cytology raised the sensitivity to 89%, with 95% specificity. In initial cytology-negative pleural effusion from lung cancer, LUNX mRNA achieved the highest positive result (65%) among the four markers.

CONCLUSIONS

The detection of LUNX mRNA and vascular endothelial growth factor mRNA in pleural fluid may be a complementary tool for the diagnosis of malignant pleural effusion. In particular, pleural fluid LUNX mRNA provided a valuable adjunct in distinguishing malignant pleural effusion caused by lung cancer from benign pleural effusion.

Mammalian short palate lung and nasal epithelial clone 1 (SPLUNC1) in pH-dependent airway hydration

The epithelia that line the conducting airways are the lung's first point of contact with inhaled pathogens and toxicants. As such, they are known to play an important role in the lung's innate defense system, which includes (i) the production of airway surface liquid (ASL) that helps cleanse the airways through the physical removal of pathogens and toxicants on the mucociliary escalator and (ii) the secretion of anti-microbial proteins into the ASL to kill inhaled pathogens. Interestingly, the recently crystallized short palate lung and nasal epithelial clone 1 (SPLUNC1) protein appears to be a multi-functional protein. That is, it not only acts as an anti-microbial agent, but also modulates ASL homeostasis by acting as an endogenous inhibitor of the epithelial Na(+) channel (ENaC). This review will focus on the latter function of SPLUNC1, and will discuss new structural and physiological data regarding SPLUNC1's failure to function as a regulator of ASL hydration in CF airways.

Significance of combined detection of LunX mRNA and tumor markers in diagnosis of lung carcinoma

OBJECTIVE

To evaluate the significance of combined detection of LunX mRNA, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 21-1 fragment (CYFRA21-1) in clinical diagnosis of lung carcinoma.

METHODS

Based on the quantitative RT-PCR and chemiluminescence immunoassay, the expression levels of LunX mRNA, CEA, NSE, and CYFRA21-1 in 113 patients with lung carcinoma (case group) and 30 healthy participants (control group) were detected. Meantime, the sensitivity, specificity, and accuracy of the combination detection were also explored.

RESULTS

The positive rates of LunX mRNA in peripheral blood and CEA, NSE, and CYFRA21-1 in serum were significantly higher in case group than those in control group ((χ) (2)=17.295, 16.825, 19.148, and 17.450; P<0.05). There was no statistical significance when positive rate of LunX mRNA was evaluated among different pathological types ((χ) (2)=0.047, P>0.05). The positive rate of LunX mRNA in stage I + II, III, and IV had a significantly increasing tendency ((χ) (2)=10.565, 32.462, P<0.05). The positive rate of CYFRA21-1 was highest in squamous carcinoma (78.5%), the positive rate of NSE was highest in small cell carcinoma (86.7%), and the positive rate of CEA wag highest in lung adenocarcinoma (80.4%). The sensitivity and accuracy of the combination detection were 91.1% and 88.1%, respectively.

CONCLUSIONS

The combined detection of LunX mRNA and tumor markers (TMs) including CEA, NSE, and CYFRA21-1 in peripheral blood is helpful to increase the diagnostic accuracy of lung cancer. Also, it can inform the pathological typing of lung carcinoma.

mRNA expression of CK19, EGFR and LUNX in patients with lung cancer micrometastasis

To evaluate the clinical significance of mRNA expression of cytokeratin 19 (CK19), epidermal growth factor receptor (EGFR) and lung-specific X protein (LUNX), a total of 42 patients who were diagnosed with non-small cell lung cancer (NSCLC) by pathology were studied retrospectively. The messenger RNA (mRNA) expression levels of CK19, EGFR and LUNX in the peripheral blood were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). The expression of CK19 mRNA did not differ significantly according to the location, size, clinical stage or differentiation of the primary tumor (all P>0.05). However, there was a significant difference in the level of CK19 mRNA expression between squamous carcinoma and adenocarcinoma. The positive rates of EGFR mRNA in the patient and the healthy control groups were 69.0 and 12.5%, respectively, and were significantly different (P<0.05). The positive rates of LUNX mRNA in the two groups were 40.5 and 0%, respectively, and were significantly different (P<0.05). The results indicate that the mRNA expression of CK19, EGFR and LUNX in the peripheral blood is of significant clinical value for the diagnosis of micrometastasis and the prognosis of lung cancer.

LUNX mRNA-positive cells at different time points predict prognosis in patients with surgically resected nonsmall cell lung cancer

LUNX is a lung-specific gene whose messenger ribonucleic acid (mRNA) expression is strictly limited to normal lung tissue and nonsmall cell lung cancer (NSCLC) tissue. The aim of this study was to investigate whether the detection of LUNX mRNA-positive circulating tumor cells (CTC)s in peripheral blood at different time points is useful for predicting disease recurrence, disease-free survival (DFS), and overall survival (OS) in NSCLC patients undergoing surgery. Serial blood samples from 68 patients with stage I-IIIA NSCLC were examined by real-time quantitative polymerase chain reaction assay targeting LUNX mRNA before (T0) and after surgery (T1) and after the completion of adjuvant chemotherapy (T2). Results showed that LUNX mRNA-positive CTCs were detected in 40 of 68 NSCLC patients (58.8%) before surgery; the detection rates of LUNX mRNA-positive CTCs at T1 and T2 time points were 32.4% (22/68) and 33.3% (20/60), respectively. The detection of LUNX mRNA-positive CTC at 3 time points was associated with lymph node status and pathologic stage. During the follow-up period, patients with LUXN mRNA-positive CTC at 3 time points had a higher relapse rate and a shorter DFS and OS than those without. Multivariate analysis revealed that presence of LUNX mRNA-positive CTC at T1 and T2 time points was an independent unfavorable factor for DFS and OS. In conclusion, detection of LUNX mRNA-positive CTC after surgery and the completion of adjuvant chemotherapy in patients with stage I-IIIA NSCLC are highly predictive for DFS and OS. This technique could aid in the prediction of prognosis and design of tailored treatment.

Dual acute proinflammatory and antifibrotic pulmonary effects of short palate, lung, and nasal epithelium clone-1 after exposure to carbon nanotubes

Carbon nanotubes (CNTs; allotropes of carbon with a cylindrical nanostructure) have emerged as one of the most commonly used types of nanomaterials, with numerous applications in industry and biomedicine. However, the inhalation of CNTs has been shown to elicit pulmonary toxicity, accompanied by a robust inflammatory response with an early-onset fibrotic phase. Epithelial host-defense proteins represent an important component of the pulmonary innate immune response to foreign inhalants such as particles and bacteria. The short palate, lung, and nasal epithelium clone-1 (SPLUNC1) protein, a member of the bactericidal/permeability-increasing-fold (BPIF)-containing protein family, is a 25-kD secretory protein that is expressed in nasal, oropharyngeal, and lung epithelia, and has been shown to have multiple functions, including antimicrobial and chemotactic activities, as well as surfactant properties. This study sought to assess the importance of SPLUNC1-mediated pulmonary responses in airway epithelial secretions, and to explore the biological relevance of SPLUNC1 to inhaled particles in a single-walled carbon nanotube (SWCNT) model. Using Scgb1a1-hSPLUNC1 transgenic mice, we observed that SPLUNC1 significantly modified host inflammatory responses by increasing leukocyte recruitment and enhancing phagocytic activity. Furthermore, we found that transgenic mice were more susceptible to SWCNT exposure at the acute phase, but showed resistance against lung fibrogenesis through pathological changes in the long term. The binding of SPLUNC1 also attenuated SWCNT-induced TNF-α secretion by RAW 264.7 macrophages. Taken together, our data indicate that SPLUNC1 is an important component of mucosal innate immune defense against pulmonary inhaled particles.

Foxm1 transcription factor is required for the initiation of lung tumorigenesis by oncogenic Kras(G12D.)

Lung cancer is the leading cause of deaths in cancer patients in the United States. Identification of new molecular targets is clearly needed to improve therapeutic outcomes of this devastating human disease. Activating mutations in K-Ras oncogene and increased expression of FOXM1 protein are associated with poor prognosis in patients with non-small-cell lung cancer. Transgenic expression of activated Kras(G12D) in mouse respiratory epithelium is sufficient to induce lung adenocarcinomas; however, transcriptional mechanisms regulated by K-Ras during the initiation of lung cancer remain poorly understood. Foxm1 transcription factor, a downstream target of K-Ras, stimulates cellular proliferation during embryogenesis, organ repair and tumor growth, but its role in tumor initiation is unknown. In the present study, we used transgenic mice expressing Kras(G12D) under control of Sftpc promoter to demonstrate that Foxm1 was induced in type II epithelial cells before the formation of lung tumors. Conditional deletion of Foxm1 from Kras(G12D)-expressing respiratory epithelium prevented the initiation of lung tumors in vivo. The loss of Foxm1 inhibited expression of K-Ras target genes critical for the nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathways, including Ikbkb, Nfkb1, Nfkb2, Rela, Jnk1, N-Myc, Pttg1 and Cdkn2a. Transgenic overexpression of activated FOXM1 mutant was sufficient to induce expression of these genes in alveolar type II cells. FOXM1 directly bound to promoter regions of Ikbkb, Nfkb2, N-Myc, Pttg1 and Cdkn2a, indicating that these genes are direct FOXM1 targets. FOXM1 is required for K-Ras-mediated lung tumorigenesis by activating genes critical for the NF-κB and JNK pathways.

Multiplex PCR-based detection of circulating tumor cells in lung cancer patients using CK19, PTHrP, and LUNX specific primers

INTRODUCTION

The aim of this study was to develop a multiplex polymerase chain reaction (PCR)-based method for detection of circulating tumor cells in peripheral blood of lung cancer (LC) patients.

PATIENTS AND METHODS

Peripheral blood was collected from 71 healthy donors and 125 LC patients at different pathological stages. Samples were analyzed using multiplex PCR, and specific primers for CK19, PTHrP, and LUNX mRNA. The sensitivity of our method was set at 10 LC cells (A549 cells) in 3 mL of peripheral blood of healthy donors using spiking experiments.

RESULTS

The detection rates in LC patients for CK19, PTHrP, and LUNX were 45.6%, 64.8%, and 28%, and in healthy individuals were 7%, 7%, and 5.6%, respectively. Overall, our method produced 77.8% positive detections for at least 1 molecular marker. Twenty-eight (22.2%) were negative for expression of all markers, 39 (31.2%) were positive for expression of 1 marker, 42 (33.6%) were positive for expression of 2 markers, and 17 (13.6%) were positive for expression of all 3 markers. Detection of CK19 mRNA expression positively correlated with LC stage and distant metastases. PTHrP mRNA detection correlated positively with LC stage, presence of bone metastasis, and squamous cell carcinoma, and LUNX mRNA detection correlated with lymph node involvement. Combined detection of 2 or 3 markers was significantly correlated with metastatic disease, and negative detection of all 3 molecular markers was correlated with early stage nonmetastatic disease.

CONCLUSION

Multiple PCR-based detection of CK19, PTHrP, and LUNX mRNA expression provides useful information for disease stage and dissemination in LC patients.

Superiority and clinical significance of Lunx mRNA in the diagnosis of malignant pleural effusion caused by pulmonary carcinoma

Background

Pulmonary carcinoma is the main cause of malignant pleural effusions (MPEs). However, there is no satisfactory marker for diagnosing MPEs caused by pulmonary carcinoma. The purpose of this study is to assess the clinical significance of Lunx mRNA detection in diagnosing MPEs caused by pulmonary carcinoma.

Methods

A total of 209 patients with pleural effusions were recruited. The patients were diagnosed by cast-off cells, bronchoscopy, and pleural biopsy. The levels of Lunx mRNA in the pleural effusions were determined by real-time PCR. The levels of PH, LDH, glucose, albumin, and CEA were also determined. Patients who accepted chemotherapy underwent Lunx mRNA detection before and after the first chemotherapy session. The patients were divided into four groups according the effect of chemotherapy: complete remission (CR), partial remission (PR), no change (NC), and progressive disease (PD). The patients were also divided into two groups according the change in direction of Lunx mRNA expression after chemotherapy: increased group and decreased group. The patients were followed up to determine survival.

Results

Lunx mRNA was positive in 89 of 106 patients with pleural effusions caused by pulmonary carcinoma. The specificity and sensitivity were 95.9% and 84.9%. The area under the ROC curve was 0.922. Lunx mRNA detection was better than detection using cast-off cells and CEA. All of the Lunx-positive patients with MPEs were diagnosed with pulmonary carcinoma, and all extrapulmonary carcinoma patients were Lunx-negative. The positive predictive value of Lunx mRNA for the source of tumor cells was 100%. Lunx mRNA expression decreased after the first session of chemotherapy in the CR and PR groups, increased in the PD group, there was no change in the NC group. Further analysis indicated the change in direction of Lunx mRNA expression was associated with the overall survival of patients. The patients in the increased group had longer overall survival times than those in the decreased group.

Conclusion

Lunx mRNA is a specific tumor gene that is highly expressed in MPEs caused by pulmonary carcinoma. The changes in Lunx mRNA levels after chemotherapy can predict the prognosis of patients with MPEs caused by pulmonary carcinoma.

Integrating genomics and proteomics-oriented biomarkers to comprehend lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer deaths worldwide. Recent years have brought tremendous progress in the development of genomic and proteomic platforms to study lung cancer progression and biomarker identification.

OBJECTIVE

To evaluate and integrate potential innovations of 'omics' (e.g., genomics and proteomics) technologies in dissecting biomarkers for lung cancer.

METHODS

Omics technologies permit simultaneous monitoring of many hundreds or thousands of macro and small molecules, as well as functional monitoring of multiple pivotal cellular pathways. Discussion follows to explore the principal challenges in the development of cancer biomarkers integrating genomics with proteomics data sets with their functional counterparts in conjunction with clinical data.

RESULTS/CONCLUSION

Sets of genes and gene interactions affecting different subsets of cancers can be determined using genomics in lung cancer. Proteomic studies have generated numerous functional data sets of potential diagnostic, prognostic and therapeutic significance in lung cancer. It is likely that omics will take a central place in the understanding, diagnosis, monitoring and treatment of lung cancer. Here the potential benefits and pitfalls of these methodologies are reviewed for the faster discovery of therapeutically valuable biomarkers for lung cancer.

Lung cancer screening: from imaging to biomarker

Despite several decades of intensive effort to improve the imaging techniques for lung cancer diagnosis and treatment, primary lung cancer is still the number one cause of cancer death in the United States and worldwide. The major causes of this high mortality rate are distant metastasis evident at diagnosis and ineffective treatment for locally advanced disease. Indeed, approximately forty percent of newly diagnosed lung cancer patients have distant metastasis. Currently, the only potential curative therapy is surgical resection of early stage lung cancer. Therefore, early detection of lung cancer could potentially increase the chance of cure by surgery and underlines the importance of screening and detection of lung cancer. In the past fifty years, screening of lung cancer by chest X-Ray (CXR), sputum cytology, computed tomography (CT), fluorescence endoscopy and low-dose spiral CT (LDCT) has not improved survival except for the recent report in 2010 by the National Lung Screening Trial (NLST), which showed a 20 percent mortality reduction in high risk participants screened with LDCT compared to those screened with CXRs. Furthermore, serum biomarkers for detection of lung cancer using free circulating DNA and RNA, exosomal microRNA, circulating tumor cells and various lung cancer specific antigens have been studied extensively and novel screening methods are being developed with encouraging results. The history of lung cancer screening trials using CXR, sputum cytology and LDCT, as well as results of trials involving various serum biomarkers, are reviewed herein.

TRIM28, a new molecular marker predicting metastasis and survival in early-stage non-small cell lung cancer

TRIM28 is a universal corepressor for Kruppel-associated box zinc finger proteins. In this study, we demonstrated the expression of TRIM28 gene was significantly higher in cancerous tissues than in noncancerous tissues (P < 0.001). TRIM28 knockdown resulted in a decrease in cell proliferation in liquid media as well as in soft agar. The proliferation rate was impaired and the cell cycle progression was inhibited after knockdown of TRIM28 in non-small cell lung cancer cell lines PAa and SK-MES-1. We used real-time polymerase chain reaction to detect circulating cancer cells in 138 non-small cell lung cancer patients. The overall positive detection rate was 30.4% (42 of 138) in peripheral blood of NSCLC patients and was 29.9% (29 of 97) in early-stage patients. In a 70-month follow-up study, 20 of 29 patients (69.0%) in TRIM28 positive group had recurrence and/or metastasis, significantly higher (P = 0.004) than in the TRIM28 negative group (25 of 68, 36.8%). In addition, non-small cell lung cancer patients whose circulating cancer cells expressed TRIM28 suffered shorter tumor-specific survival compared with those with absent TRIM28 expression (P < 0.001). Results of our study showed that TRIM28 provides a survival advantage to lung cancer cells and may be a new marker to predict metastasis and prognosis in early-stage non-small cell lung cancer patients.

Expression pattern of PLUNC proteins as an auxiliary tool for the diagnosis of high-grade mucoepidermoid carcinoma of the salivary gland

BACKGROUND

Mucoepidermoid carcinomas are the most frequent malignant neoplasia of the salivary glands and are histologically classified as low, intermediate, and high grade. At present, histochemical stains such as periodic acid-Schiff or mucicarmine are useful tools in making a diagnosis. Recently, expression of the PLUNC proteins has been described in mucin-producing salivary gland tumors, with the suggestion that they could provide a powerful tool for the diagnosis of difficult cases.

METHODS

This study evaluates the expression of PLUNC proteins in 30 cases of salivary gland mucoepidermoid carcinomas. Tumors were reviewed and classified according to histological grade. Periodic acid-Schiff, mucicarmine, and immunohistochemical staining for SPLUNC1, LPLUNC1, SPLUNC2, and LPLUNC2 were carried out. Immunostaining was classified as positive or negative.

RESULTS

The majority of the tumors (63%) were classified as low grade, 13% were intermediate grade, and 23% were high grade. SPLUNC1 (90%) and LPLUNC1 (93%) were positive in the majority of cases, mainly in mucous cells, mucin plugs, and intermediate cells. SPLUNC2 and LPLUNC2 did not present significative expression within the tumors; however, LPLUNC2 was found to stain positively in mast cells in 83% of the samples.

CONCLUSIONS

SPLUNC1 and LPLUNC1 showed a similar pattern of expression and could prove useful in the diagnosis of high-grade cases because of the differential staining in intermediate and epidermoid cells. The expression of LPLUNC2 in mast cells has not previously been reported, but further studies are necessary to validate this finding and to determine its significance.

Expression and clinical significance of lung-specific X protein mRNA in bronchial brushing specimens from patients with or without lung cancer

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the diagnostic utility of lung-specific X protein (LUNX) mRNA expression in bronchial brushing specimens from patients with lung cancer.

METHODS

LUNX mRNA levels were assessed by performing RT-PCR on liquid-based cytology bronchial brushing specimens from patients with lung cancer (n=104) or benign lung disease (n=91).

RESULTS

  LUNX mRNA expression was significantly more frequent in patients with all carcinomas, squamous cell carcinomas, adenocarcinomas, as well as patients with central, peripheral and diffuse carcinomas (P<0.01), and non-small cell lung carcinomas (P<0.05) compared with patients with benign disease. The diagnostic performance of RT-PCR analysis of LUNX mRNA was significantly better than that of cytology in terms of sensitivity (93.3±4.8% vs 64.4±9.2%), negative predictive value (91.6±6.0% vs 71.1±7.9%) and accuracy (88.7±4.4% vs 81.0±5.5%), whereas specificity (83.5±7.6%) and positive predictive value (86.6±6.3%) were lower than those of cytology (100%).

CONCLUSIONS

  Liquid-based cytology and RT-PCR can be performed to detect LUNX mRNA expression in bronchial brushing specimens, and this technique may be a useful adjunct to cytological diagnosis of lung cancer. The sensitivity of the technique was greater than that of cytology but its lower specificity should be taken into account.

Quantitation of SPLUNC1 in saliva with an xMAP particle-based antibody capture and detection immunoassay

The short palate lung and nasal epithelial clone 1 (SPLUNC1) protein may be differentially expressed in oral infections, oral inflammatory disorders, or oral malignancies and may be involved in innate immune responses in the oral cavity. However, the actual concentration of SPLUNC1 in saliva has not previously been determined. In this study, we determined the concentrations of SPLUNC1 in saliva using a particle-based antibody capture and detection immunoassay. A commercial goat anti-rhSPLUNC1 polyclonal antibody (AF1897) was linked to fluorescent polystyrene microspheres and used as the capture antibody. A commercial mouse IgG2b anti-rhSPLUNC1 monoclonal antibody (MAB1897) was biotinylated and used as the detection antibody. Western blot and 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) analysis of immunoprecipitated rhSPLUNC1 and SPLUNC1 from saliva were used to show that the capture AF1897 and detection MAB1897 antibodies both recognized SPLUNC1. Protein concentrations in saliva from 20 subjects ranged from 0.9 to 23.9mg/ml; SPLUNC1 concentrations ranged from 34.7ng/ml to 13.8μg/ml; and SPLUNC concentrations normalized per mg of total salivary protein ranged from 4.7ng/ml to 5.3μg/ml. These results show that SPLUNC1 is detected in saliva in a variety of concentrations. This immunoassay may prove to be useful in determining the concentration of SPLUNC1 in saliva for assessing its role in the pathogenesis of oral infections, oral inflammatory disorders, or oral malignancies.

Distribution of human PLUNC/BPI fold-containing (BPIF) proteins

Although gene expression studies have shown that human PLUNC (palate, lung and nasal epithelium clone) proteins are predominantly expressed in the upper airways, nose and mouth, and proteomic studies have indicated they are secreted into airway and nasal lining fluids and saliva, there is currently little information concerning the localization of human PLUNC proteins. Our studies have focused on the localization of three members of this protein family, namely SPLUNC1 (short PLUNC1), SPLUNC2 and LPLUNC1 (long PLUNC1). Western blotting has indicated that PLUNC proteins are highly glycosylated, whereas immunohistochemical analysis demonstrated distinct patterns of expression. For example, SPLUNC2 is expressed in serous cells of the major salivary glands and in minor mucosal glands, whereas SPLUNC1 is expressed in the mucous cells of these glands. LPLUNC1 is a product of a population of goblet cells in the airway epithelium and nasal passages and expressed in airway submucosal glands and minor glands of the oral and nasal cavities. SPLUNC1 is also found in the epithelium of the upper airways and nasal passages and in airway submucosal glands, but is not co-expressed with LPLUNC1. We suggest that this differential expression may be reflected in the function of individual PLUNC proteins.

New biomarkers for lung cancer

IMPORTANCE OF THE FIELD

Despite many efforts to improve early detection, lung cancer remains the leading cause of cancer deaths. Stage is the main determinant of prognosis and the basis for deciding treatment options. Screening tests for lung cancer have not been successful so far.

AREAS COVERED IN THE REVIEW

The article reviews the available literature related to biomarkers in use at present and those that could be used for early diagnosis, staging, prognosis, response to therapy and prediction of recurrence. The single biomarkers are analysed, divided according to the technological methods used and the locations of sampling.

WHAT THE READER WILL GAIN

The reader will gain knowledge on biomarkers in use and those now under study. The reader will also gain insights into the difficulties pertaining to the development of biomarkers, results reproducibility and clinical application.

TAKE HOME MESSAGE

Although some markers seem to be promising, at present there is no consensus on the proven value of their clinical use in lung cancer. The future lies probably in a panel of biomarkers instead of individual assays, or in predictive models derived from the integration of clinical variables and gene expression profiles.

Transcriptome dissection of gastric cancer: identification of novel diagnostic and therapeutic targets from pathology specimens

Gastric cancer is the fourth most common malignancy in the world, and mortality due to gastric cancer is second only to that from lung cancer. 'Transcriptome dissection' is a detailed analysis of the entire expressed transcripts from a cancer, for the purpose of understanding the precise molecular mechanism of pathogenesis. Serial analysis of gene expression (SAGE) is a suitable technique for performing transcriptome dissection. Gastric cancers of different stages and histology were analyzed on SAGE, and one of the largest gastric cancer SAGE libraries in the world was created (GEO accession number GSE 545). Through SAGE, many candidate genes have been identified as potential diagnostic and therapeutic targets for the treatment of gastric cancer. Regenerating islet-derived family, member 4 (Reg IV) participated in 5-fluorouracil (5-FU) resistance and peritoneal metastasis, and its expression was associated with an intestinal phenotype of gastric cancer and with endocrine differentiation. GW112 expression correlated with advanced tumor stage. Measurement of Reg IV and GW112 levels in sera indicated a sensitivity of 57% for detection of cancer. SPC18 participated in tumor growth and invasion through transforming tumor growth factor-alpha upregulation. Palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) was a useful marker for gastric hepatoid adenocarcinoma. Expression of SOX9, HOXA10, CDH17, and loss of claudin-18 expression were associated with an intestinal phenotype of gastric cancer. Information obtained from transcriptome dissection greatly contributes to diagnosis and treatment of gastric cancer.

Diagnostic utility of LunX mRNA in peripheral blood and pleural fluid in patients with primary non-small cell lung cancer

Background

Progress in lung cancer is hampered by the lack of clinically useful diagnostic markers. The goal of this study was to provide a detailed evaluation of lung cancer tumor markers indicative of molecular abnormalities and to assess their diagnostic utility in non-small cell lung cancer (NSCLC) patients.

Methods

Quantitative real-time RT-PCR was used to determine LunX, CK19, CEA, VEGF-C and hnRNP A2/B1 mRNA levels in peripheral blood and pleural fluid from NSCLC patients, compared with those from patients with other epithelial cancer (esophagus cancer and breast cancer), benign lung disease (pneumonia and tuberculo pleurisy) and from healthy volunteers.

Results

In peripheral blood LunX mRNA was detectable in 75.0% (33/44) of patients with NSCLC, but not in patients with other epithelial cancer (0/28), benign lung disease (0/10) or in healthy volunteers (0/15). In contrast, all other genetic markers were detected in patients with either NSCLC, other epithelia cancer or benign lung disease, and in healthy volunteers. The expression level and positive rate of LunX mRNA in peripheral blood correlated with the pathologic stage of NSCLC (P < 0.001 and P = 0.010 respectively). Furthermore, LunX mRNA was detected in 92.9% (13/14) of malignant pleural fluid samples and was the only marker whose expression level was significantly different between malignant and benign pleural fluid (P < 0.001). Additionally, expression of LunX mRNA in the peripheral blood of NSCLC patients decreased shortly after clinical treatment (P = 0.005).

Conclusion

Of several commonly used genetic markers, LunX mRNA is the most specific gene marker for lung cancer and has potential diagnostic utility when measured in the peripheral blood and pleural fluid of NSCLC patients.

Gene expression profiling with microarray and SAGE identifies PLUNC as a marker for hepatoid adenocarcinoma of the stomach

Gastric cancer is one of the most common malignancies worldwide. In this study, we screened for genes upregulated in gastric cancer by comparing gene expression profiles from serial analysis of gene expression and microarray and identified the palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) gene. Immunostaining for PLUNC in 140 gastric cancer cases revealed strong and extensive staining of PLUNC in hepatoid adenocarcinoma of the stomach, whereas 7% of conventional gastric cancer cases showed focal immunostaining of PLUNC. Gastric hepatoid adenocarcinoma is an extrahepatic tumor characterized by morphologic similarities to hepatocellular carcinoma. To investigate the utility of PLUNC immunostaining in the diagnosis of gastric hepatoid adenocarcinoma, six cases of gastric hepatoid adenocarcinoma (six primary tumors and two associated liver metastases) were studied further. PLUNC staining was observed in all six primary hepatoid adenocarcinomas. PLUNC staining was observed in both the hepatoid adenocarcinoma and tubular/papillary adenocarcinoma components of primary tumors, although PLUNC staining was preferentially localized in tubular/papillary adenocarcinoma components. Staining of PLUNC was also detected in both liver metastases. PLUNC staining was not observed in 52 cases of primary hepatocellular carcinoma or in normal adult or fetal liver. These results indicate that PLUNC is a novel marker that distinguishes gastric hepatoid adenocarcinoma from primary hepatocellular carcinoma.

Expression of PLUNC family members in benign and malignant salivary gland tumours

OBJECTIVES

The aim of this study was to determine the expression of PLUNC proteins in benign and malignant salivary gland tumours and thus their potential use as diagnostic and / or prognostic tools.

MATERIALS AND METHODS

A tissue microarray was assembled from 64 salivary gland tumours including adenoid cystic carcinoma, carcinoma ex-pleomorphic adenoma, mucoepidermoid carcinoma, polymorphous low-grade adenocarcinoma, pleomorphic adenoma, acinic cell carcinoma, myoepithelial carcinoma and papillary cystadenocarcinoma. Clinicopathological data were collected retrospectively and immunohistochemical analysis of three PLUNC proteins (SPLUNC1, SPLUNC2 and LPLUNC1) was performed. Immunoreactivity was assessed as positive or negative.

RESULTS

PLUNC expression was only found in mucoepidermoid carcinomas and papillary cystadenocarcinoma; all other tumours studied were negative. Mucin plugs, mucous and intermediate cells of mucoepidermoid carcinomas were positive for LPLUNC1 and SPLUNC2, but areas composed of epidermoid and clear cells were negative for all PLUNCs. Papillary cystadenocarcinoma was positive for all PLUNCs. No correlation was found with tumour grade or outcome.

CONCLUSIONS

Intense expression of two PLUNC proteins in mucous cells and mucin plugs of mucoepidermoid carcinoma and papillary cystadenocarcinoma indicate that they could be used as additional diagnostic tools in some equivocal cases, but further studies are needed to understand the biological processes involved in PLUNC expression.

Expression of nicotinic acetylcholine receptor subunit genes in non-small-cell lung cancer reveals differences between smokers and nonsmokers

Nicotine and its derivatives, by binding to nicotinic acetylcholine receptors (nAChR) on bronchial epithelial cells, can regulate cellular proliferation and apoptosis via activating the Akt pathway. Delineation of nAChR subtypes in non-small-cell lung cancers (NSCLC) may provide information for prevention or therapeutic targeting. Expression of nAChR subunit genes in 66 resected primary NSCLCs, 7 histologically non-involved lung tissues, 13 NSCLC cell lines, and 6 human bronchial epithelial cell lines (HBEC) was analyzed with quantitative PCR and microarray analysis. Five nonmalignant HBECs were exposed to nicotine in vitro to study the variation of nAChR subunit gene expression with nicotine exposure and removal. NSCLCs from nonsmokers showed higher expression of nAChR alpha6 (P < 0.001) and beta3 (P = 0.007) subunit genes than those from smokers, adjusted for gender. In addition, nAChR alpha4 (P < 0.001) and beta4 (P = 0.029) subunit gene expression showed significant difference between NSCLCs and normal lung. Using Affymetrix GeneChip U133 Sets, 65 differentially expressed genes associated with NSCLC nonsmoking nAChR alpha6beta3 phenotype were identified, which gave high sensitivity and specificity of prediction. nAChR alpha1, alpha5, and alpha7 showed significant reversible changes in expression levels in HBECs upon nicotine exposure. We conclude that between NSCLCs from smokers and nonsmokers, different nAChR subunit gene expression patterns were found, and a 65-gene expression signature was associated with nonsmoking nAChR alpha6beta3 expression. Finally, nicotine exposure in HBECs resulted in reversible differences in nAChR subunit gene expression. These results further implicate nicotine in bronchial carcinogenesis and suggest targeting nAChRs for prevention and therapy in lung cancer.

Inactivation of LLC1 gene in nonsmall cell lung cancer

Serial analysis of gene expression studies led us to identify a previously unknown gene, c20orf85, that is present in the normal lung epithelium but absent or downregulated in most primary nonsmall cell lung cancers and lung cancer cell lines. We named this gene LLC1 for Low in Lung Cancer 1. LLC1 is located on chromosome 20q13.3 and has a 70% GC content in the promoter region. It has 4 exons and encodes a protein containing 137 amino acids. By in situ hybridization, we observed that LLC1 message is localized in normal lung bronchial epithelial cells but absent in 13 of 14 lung adenocarcinoma and 9 out of 10 lung squamous carcinoma samples. Methylation at CpG sites of the LLC1 promoter was frequently observed in lung cancer cell lines and in a fraction of primary lung cancer tissues. Treatment with 5-aza deoxycytidine resulted in a reduced methylation of the LLC1 promoter concomitant with the increase of LLC1 expression. These results suggest that inactivation of LLC1 by means of promoter methylation is a frequent event in nonsmall cell lung cancer and may play a role in lung tumorigenesis.

Genome-wide array-based comparative genomic hybridization analysis of pancreatic adenocarcinoma: identification of genetic indicators that predict patient outcome

We analyzed the subchromosomal numerical aberrations of 44 surgically resected pancreatic adenocarcinomas by array-based comparative genomic hybridization. The aberration profile ranged widely between cases, suggesting the presence of multiple or complementary mechanisms of evolution in pancreatic cancer, and was associated with lymph node metastasis and venous or serosal invasion. A large number of small loci, previously uncharacterized in pancreatic cancer, showed non-random loss or gain. Frequent losses at 1p36, 4p16, 7q36, 9q34, 11p15, 11q13, 14q32-33, 16p13, 17p11-13, 17q11-25, 18q21-tel, 19p13, 21q22 and 22q11-12, and gains at 1q25, 2p16, 2q21-37, 3q25, 5p14, 5q11-13, 7q21, 7p22, 8p22, 8q21-23, 10q21, 12p13, 13q22, 15q13-22 and 18q11 were identified. Sixteen loci were amplified recurrently. We identified novel chromosomal alterations that were significantly associated with a range of malignant phenotypes. Gain of LUNX, HCK, E2F1 and DNMT3b at 20q11, loss of p73 at 1p36 and gain of PPM1D at 17q23 independently predicted patient outcome. Expression profiling of amplified genes identified Smurf1 and TRRAP at 7q22.1, BCAS1 at 20q13.2-3, and VCL at 10q22.1 as potential novel oncogenes. Our results contribute to a complete description of genomic structural aberrations and the identification of potential therapeutic targets and genetic indicators that predict patient outcome in pancreatic adenocarcinoma.

Molecular biomarkers for cancer detection in blood and bodily fluids

Cancer is a major and increasing public health problem worldwide. Traditionally, the diagnosis and staging of cancer, as well as the evaluation of response to therapy have been primarily based on morphology, with relatively few cancer biomarkers currently in use. Conventional biomarker studies have been focused on single genes or discrete pathways, but this approach has had limited success because of the complex and heterogeneous nature of many cancers. The completion of the human genome project and the development of new technologies have greatly facilitated the identification of biomarkers for assessment of cancer risk, early detection of primary cancers, monitoring cancer treatment, and detection of recurrence. This article reviews the various approaches used for development of such markers and describes markers of potential clinical interest in major types of cancer. Finally, we discuss the reasons why so few cancer biomarkers are currently available for clinical use.

Gene Expression Profiles from Needle Biopsies Provide Useful Signatures of Non-Small Cell Lung Carcinomas

Gene expression profiles from DNA microarrays can provide molecular signatures that improve tumor classification, prognosis, and treatment options. While much of this work has focused on isolation of RNA from the resected tumor, fewer studies have utilized RNA from fine needle aspirates (FNA). In this pilot study we examined whether the gene signatures obtained from FNA samples would correlate with signatures taken from the resected tumor. Based on NSCLC gene expression profiles obtained from eleven sets of FNA and tumor samples we obtained a high concordance of FNA profiles matching their matched tumor sample. These results suggest that FNA samples may provide informative gene expression signatures regarding the potential aggressiveness of non-small-cell lung carcinomas.

A combination of molecular markers accurately detects lymph node metastasis in non-small cell lung cancer patients

Occult lymph node metastasis (micrometastasis) is a good prognostic indicator in non-small cell lung cancer (NSCLC) and could be used to direct adjuvant chemotherapy in stage I patients. This study was designed to evaluate molecular markers for detection of occult lymph node metastasis in NSCLC, define the best marker or marker combination to distinguish positive from benign lymph nodes, and evaluate these markers in lymph nodes from pathologically node-negative (pN(0)) NSCLC patients. Potential markers were identified through literature and database searches and all markers were analyzed by quantitative reverse transcription-PCR in a primary screen of six NSCLC specimens and 10 benign nodes. Selected markers were further evaluated on 21 primary NSCLC specimens, 21 positive nodes, and 21 benign nodes, and the best individual markers and combinations were identified. A combination of three markers was further validated on an independent set of 32 benign lymph nodes, 38 histologically positive lymph nodes, and 462 lymph nodes from 68 pN(0) NSCLC patients. Forty-two markers were evaluated in the primary screen and eight promising markers were selected for further analysis. A combination of three markers (SFTPB, TACSTD1, and PVA) was identified that provided perfect classification of benign and positive nodes in all sample sets. PVA and SFTPB are particularly powerful in tumors of squamous and adenocarcinoma histologies, respectively, whereas TACSTD1 is a good general marker for NSCLC metastasis. The combination of these genes identified 32 of 462 (7%) lymph nodes from 20 of 68 (29%) patients as potentially positive for occult metastasis. Long-term follow-up will determine the clinical relevance of these findings.

Expression and regulation of PLUNC in human nasal epithelium

CONCLUSIONS

We demonstrated that PLUNC (palate, lung, and nasal epithelium clone) is secreted from nasal epithelial cells and is not influenced by differentiation or proinflammatory mediators. The functional role of PLUNC in the human airway has yet to be elucidated.

OBJECTIVES

The localization and regulation of PLUNC protein in human nasal epithelium was investigated. First, we located epithelial cells expressing PLUNC protein in human nasal mucosa. Secondly, we sought to identify PLUNC protein in either human nasal secretions from healthy volunteers or apical secretions from cultured human nasal epithelial cells. Lastly, we investigated whether epithelial differentiation and proinflammatory cytokines influence the expression of PLUNC in human nasal epithelial cells.

MATERIALS AND METHODS

Immunohistochemical staining for PLUNC was conducted on nasal turbinate specimens. Western blot analysis was conducted on nasal secretions from healthy volunteers, apical secretion from cultured human nasal epithelium, and on normal-appearing posterior ethmoid mucosa, inferior turbinate, and nasal polyp specimens. Reverse transcription-PCR (RT-PCR) of PLUNC was performed with mRNA from cultured human nasal epithelium cells treated with either interleukin-1beta or tumor necrosis factor-alpha.

RESULTS

PLUNC was expressed in ciliated cells of surface epithelium and serous cells of the submucosal gland in the human nasal mucosa, and was also found in the nasal secretions of healthy volunteers and apical secretions of cultured human nasal epithelial cells. The degree of mucociliary differentiation and proinflammatory mediators did not influence the expression of PLUNC gene and protein in nasal epithelium.