Surfactant Protein A Gene Deletion and Prognostics for Patients with Stage I Non–Small Cell Lung Cancer

A potential treatment option for transformed small-cell lung cancer on PD-L1 inhibitor-based combination therapy improved survival

OBJECTIVES

Transformed small-cell lung cancer (T-SCLC) has an extremely poor prognosis, and no remedies based on immunotherapy have been evaluated among T-SCLC patients. We retrospectively analysed the efficacy and safety of combining atezolizumab with chemotherapy for T-SCLC.

METHODS

Forty-seven patients harbouring EGFR mutations who developed T-SCLC were enrolled. Eleven patients who used immunotherapy were defined as the I/O group, and the remaining 36 were defined as the Non-I/O group. Clinical characteristics, pathological data, and survival outcomes were collected. RNA sequencing and whole-exome sequencing (WES) were performed for in-depth analysis.

RESULTS

All patients received at least one line of EGFR-TKI before rebiopsy to confirm T-SCLC. Nine patients received atezolizumab-bevacizumab-carboplatin-paclitaxel (albumin-bound) (ABCP), and the remaining 2 received atezolizumab-etoposide-carboplatin (ECT) in the I/O group. The objective response rate was 73 % (8/11). The median progression-free survival (mPFS) of T-SCLC on post-transformation therapy with I/O group and Non-I/O group was 5.1 m and 4.1 m, respectively. The median post-T-SCLC overall survival of the I/O group was significantly longer than that Non-I/O group (20.2 m vs 7.9 m, P ＜ 0.01). T-SCLC harbouring EGFR L858R tended to be longer than EGFR 19del (mPFS: not reached vs 3.7 m, P = 0.11). Positive PD-L1 status was also associated with PFS benefits (mPFS: 6.0 m vs 3.7 m, P = 0.20). Furthermore, RNA sequencing revealed that expression of SFTPA1 is significantly higher in the durable clinical benefit group. WES showed that STC2 mutation is more frequently observed at the time-point immunotherapy acquired resistance. Combination therapy based on a PD-L1 inhibitor was well tolerated, and the safety profile was consistent with previously reported studies.

CONCLUSION

Our study first demonstrated that a PD-L1 inhibitor combined with chemotherapy ± bevacizumab could be a potential safe option for specific SCLC-transformed patients. Subsequent studies with more patients are essential to verify the efficacy and potential biomarkers.

Differential Regulation of Human Surfactant Protein A Genes, SFTPA1 and SFTPA2, and Their Corresponding Variants

The human SFTPA1 and SFTPA2 genes encode the surfactant protein A1 (SP-A1) and SP-A2, respectively, and they have been identified with significant genetic and epigenetic variability including sequence, deletion/insertions, and splice variants. The surfactant proteins, SP-A1 and SP-A2, and their corresponding variants play important roles in several processes of innate immunity as well in surfactant-related functions as reviewed elsewhere [1]. The levels of SP-A have been shown to differ among individuals both under baseline conditions and in response to various agents or disease states. Moreover, a number of agents have been shown to differentially regulate SFTPA1 and SFTPA2 transcripts. The focus in this review is on the differential regulation of SFTPA1 and SFTPA2 with primary focus on the role of 5′ and 3′ untranslated regions (UTRs) and flanking sequences on this differential regulation as well molecules that may mediate the differential regulation.

SFTPA1 is a potential prognostic biomarker correlated with immune cell infiltration and response to immunotherapy in lung adenocarcinoma

Pulmonary surfactant protein A1 (SFTPA1) is a member of the C-type lectin subfamily that plays a critical role in maintaining lung tissue homeostasis and the innate immune response. SFTPA1 disruption can cause several acute or chronic lung diseases, including lung cancer. However, little research has been performed to associate SFTPA1 with immune cell infiltration and the response to immunotherapy in lung cancer. The findings of our study describe the SFTPA1 expression profile in multiple databases and was validated in BALB/c mice, human tumor tissues, and paired normal tissues using an immunohistochemistry assay. High SFTPA1 mRNA expression was associated with a favorable prognosis through a survival analysis in lung adenocarcinoma (LUAD) samples from TCGA. Further GeneOntology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that SFTPA1 was involved in the toll-like receptor signaling pathway. An immune infiltration analysis clarified that high SFTPA1 expression was associated with an increased number of M1 macrophages, CD8⁺ T cells, memory activated CD4⁺ T cells, regulatory T cells, as well as a reduced number of M2 macrophages. Our clinical data suggest that SFTPA1 may serve as a biomarker for predicting a favorable response to immunotherapy for patients with LUAD. Collectively, our study extends the expression profile and potential regulatory pathways of SFTPA1 and may provide a potential biomarker for establishing novel preventive and therapeutic strategies for lung adenocarcinoma.

Identification of circulating tumor cells using 4-color fluorescence in situ hybridization: Validation of a noninvasive aid for ruling out lung cancer in patients with low-dose computed tomography-detected lung nodules

BACKGROUND

Approximately one third of needle biopsies that are performed to rule out malignancy of indeterminate pulmonary nodules detected radiologically during lung cancer screening are negative, thus exposing cancer-free patients to risks of pneumothorax, bleeding, and infection. A noninvasive confirmatory tool (eg, liquid biopsy) is urgently needed in the lung cancer diagnosis setting to stratify patients who should receive biopsy versus those who should be monitored.

METHODS

A novel antigen-independent, 4-color fluorescence in situ hybridization (FISH)-based method was developed to detect circulating tumor cells (CTCs) with abnormalities in gene copy numbers in mononuclear cell-enriched peripheral blood samples from patients with (n = 107) and without (n = 100) lung cancer.

RESULTS

Identification of CTCs using FISH probes at 10q22.3/CEP10 and 3p22.1/3q29 detected lung cancer cases with 94.2% accuracy, 89% sensitivity, and 100% specificity compared with biopsy.

CONCLUSION

The high accuracy of this liquid biopsy method suggests that it may be used as a noninvasive decision tool to reduce the frequency of unnecessary needle biopsy in patients with benign pulmonary lesions.

MiR-629-3p-induced downregulation of SFTPC promotes cell proliferation and predicts poor survival in lung adenocarcinoma

The long-term prognosis of patients with lung cancer remains poor and thus it is imminent to further elucidate the molecular mechanism for the oncogenesis of lung cancer. In this study, we observed that surfactant protein C (SFTPC) expression was downregulated in human lung adenocarcinoma tissues and cell lines, and low SFTPC expression correlated with poor overall survival of lung adenocarcinoma patients. Moreover, we found that overexpression of SFTPC could inhibit lung cancer cell proliferation in vitro and in vivo, but downregulation of SFTPC showed the opposite results. Besides, it was observed that miR-629-3p expression was upregulated in human lung adenocarcinoma tissues and cell lines. More importantly, we found that miR-629-3p could downregulate SFTPC expression by directly binding to the SFTPC 3'-UTR and inhibit the regulatory effect of SFTPC on lung adenocarcinoma cell proliferation. In conclusion, these data suggested that miR-629-3p-meditated downregulation of SFTPC may promote lung adenocarcinoma progression.

The CD26/DPP4-inhibitor vildagliptin suppresses lung cancer growth via macrophage-mediated NK cell activity

CD26/dipeptidyl peptidase 4 (DPP4) is a transmembrane protein which is expressed by various malignant cells. We found that the expression of CD26/DPP4 was significantly higher in lung adenocarcinoma samples in our own patient cohort compared to normal lung tissue. We therefore hypothesize that the inhibition of CD26/DPP4 can potentially suppress lung cancer growth. The CD26/DPP4 inhibitor vildagliptin was employed on Lewis Lung Carcinoma (LLC) cell line and a human lung adenocarcinoma (H460) cell line. Two weeks after subcutaneous injection of tumor cells into C57BL/6 and CD1/nude mice, the size of LLC and H460 tumors was significantly reduced by vildagliptin. Immunohistochemically, the number of macrophages (F4/80+) and NK cells (NKp46+) was significantly increased in vildagliptin-treated tumor samples. Mechanistically, we found in vitro that lung cancer cell lines expressed increased levels of surfactant protein upon vildagliptin treatment thereby promoting the pro-inflammatory activity of macrophages. By the depletion of macrophages with clodronate and by using NK cell deficient (IL-15-/-) mice, tumors reversed to the size of controls, suggesting that indeed macrophages and NK cells were responsible for the observed tumor-suppressing effect upon vildagliptin treatment. FACS analysis showed tumor-infiltrating NK cells to express tumor necrosis-related apoptosis-inducing ligand (TRAIL) which induced the intra-cellular stress marker γH2AX. Accordingly, we found upregulated γH2AX in vildagliptin-treated tumors and TRAIL-treated cell lines. Moreover, the effect of vildagliptin-mediated enhanced NK cell cytotoxicity could be reversed by antagonizing the TRAIL receptor. Our data provide evidence that the CD26/DPP4-inhibitor vildagliptin reduces lung cancer growth. We could demonstrate that this effect is exerted by surfactant-activated macrophages and NK cells that act against the tumor via TRAIL-mediated cytotoxicity.

Alteration of surfactant protein A expression in renal cell carcinoma

Surfactant protein-A (SP-A) belongs to a family of collagen-containing C-type lectins called collectins. SP-A is expressed by renal tubule epithelial cells. We investigated the distribution of SP-A in renal cell carcinomas (RCC) using immunohistochemical techniques and western blotting. We used 35 formalin fixed, paraffin embedded (FFPE) RCC tissue samples. We compared results with clinico-pathological parameters of RCC including age, sex, Fuhrman grade, tumor volume, tumor node metastasis (TNM) and clinical stage. SP-A was localized in the glomerulus and renal tubule epithelium in nontumor tissue and strong SP-A immunoreactivity was observed in tumor tissue. SP-A was expressed in the RCC tumor cells (64%) and nontumor cells (34%) in males and RCC tumor cells (90%) and nontumor cells (30%) in females. There was a significant correlation between SP-A immunoreactivity in tumor cells and gender, age, tumor diameter, Fuhrman grade and tumor diameter. Western blot analysis supported the immunohistochemical findings. We present evidence for involvement of SP-A in RCC and suggest that increased SP-A expression in RCC is associated with favorable prognosis.

Non-invasive early detection of malignant pulmonary nodules by FISH-based sputum test

BACKGROUND

Early detection decreases lung cancer mortality. The Target-FISH Lung Cancer Detection (LCD) Test is a non-invasive test designed to detect chromosomal changes (deletion or amplification) via Fluorescence in situ Hybridization (FISH) in sputum specimens from persons suspected of having lung cancer. We evaluated the performance of the LCD test in patients with highly suspicious pulmonary nodules who were scheduled for a biopsy procedure.

METHODS

Induced sputum was collected from patients who were scheduled for biopsy of a solitary pulmonary nodule (0.8-3 cm) in one of 6 tertiary medical centers in the US and Israel. The lung cancer detection (LCD) Test combined sputum cytology and Target-FISH analysis on the same target cells and the results were compared to the pathology. Participants with non-surgical negative biopsy results were followed for 2 years to determine their final diagnosis.

RESULTS

Of the 173 participants who were evaluated, 112 were available for analysis. Overall, the LCD test had a sensitivity of 85.5% (95% CI, 76.1-92.3), specificity of 69% (95% CI, 49.2-84.7) and an accuracy of 81.3% (95% CI, 72.8-88). The positive and negative predictive values (PPV, NPV) were 88.8% and 62.5%, respectively. The LCD test was positive in 9 of 11 lung cancer patients who had an initial negative biopsy.

CONCLUSIONS

In a cohort of patients with highly suspicious lung nodules, the LCD test is a non-invasive option with good sensitivity and a high positive predictive value. A positive LCD test reinforces the need to aggressively pursue a definitive diagnosis of suspicious nodules.

Concentrations of SP-A and HSP70 are associated with polarization of macrophages in pleural effusions of non-small cell lung cancer

Damage-associated molecular pattern (DAMP) molecules can initiate an immune response through Toll-like receptors (TLRs). DAMPs are released from cells as a response to the extracellular danger and can be by-products of tissue damage. In cancer microenvironment necrotic cells release debris which has potency to become DAMPs. Non-small cell lung cancer (NSCLC) is often accompanied by pleural effusion (PE), which contains a variety of DAMPs. Surfactant protein A (SP-A) and heat shock protein 70 (Hsp70) are important DAMPs in the respiratory tract. The aim of this study was to determine a correlation between SP-A or Hsp70 and development of PE in the course of NSCLC. Moreover, we aimed to determine relationships between DAMPs and certain humoral factors associated with formation and persistence of PE as well as pleural-residing macrophages. In 34 PE samples, we estimated concentration of SP-A, Hsp70, IL-6, IL-18, G-CSF, M-CSF, SCF, SDF1α, VEGF as well as the fraction of macrophages and their pattern of polarization. We have found correlations between the concentration of the SP-A and Hsp70 and the percentage of PE-derived macrophages, also between concentrations of SP-A and Hsp70, and cytokines which participate in inflammation and processes involved in remodeling of extracellular matrix (ECM). Our data indicate an important role of SP-A during the development of PE associated with NSCLC. We suggest that measurement of concentration level of SP-A can be helpful in the course of diagnosis of malignant PE associated with NSCLC.

A prediction model for distinguishing lung squamous cell carcinoma from adenocarcinoma

Accurate classification of squamous cell carcinoma (SCC) from adenocarcinoma (AC) of non–small cell lung cancer (NSCLC) can lead to personalized treatments of lung cancer. We aimed to develop a miRNA-based prediction model for differentiating SCC from AC in surgical resected tissues and bronchoalveolar lavage (BAL) samples. Expression levels of seven histological subtype-associated miRNAs were determined in 128 snap-frozen surgical lung tumor specimens by using reverse transcription-polymerase chain reaction (RT-PCR) to develop an optimal panel of miRNAs for acutely distinguishing SCC from AC. The biomarkers were validated in an independent cohort of 112 FFPE lung tumor tissues, and a cohort of 127 BAL specimens by using droplet digital PCR for differentiating SCC from AC. A prediction model with two miRNAs (miRs-205-5p and 944) was developed that had 0.988 area under the curve (AUC) with 96.55% sensitivity and 96.43% specificity for differentiating SCC from AC in frozen tissues, and 0.997 AUC with 96.43% sensitivity and 96.43% specificity in FFPE specimens. The diagnostic performance of the prediction model was reproducibly validated in BAL specimens for distinguishing SCC from AC with a higher accuracy compared with cytology (95.69 vs. 68.10%; P < 0.05). The prediction model might have a clinical value for accurately discriminating SCC from AC in both surgical lung tumor tissues and liquid cytological specimens.

Surfactant protein A: A key player in lung homeostasis

The respiratory tract is continually exposed to various insults that are a permanent threat to the maintenance of lung homeostasis. Repair of the parenchyma structure, particularly of the alveolar epithelium, requires complex cellular strategies. Among the molecular components that play an important role in these processes are the surfactant proteins (SPs), particularly SP-A. The present review examines current evidence regarding the role of SP-A in lung host defence mechanisms through its implication in innate/adaptive immunity of the lung and epithelium integrity and repair. New information on SP-A deficiency in various forms of pulmonary diseases could help define therapeutic strategies aimed at restoring functional SP-A within the alveolar structure.

Integrating DNA methylation and microRNA biomarkers in sputum for lung cancer detection

Background

Abnormal microRNA (miRNA) expressions and promoter methylation of genes detected in sputum may provide biomarkers for non-small lung cancer (NSCLC). Here, we evaluate the individual and combined analysis of the two classes of sputum molecular biomarkers for NSCLC detection.

Results

We analyze expression of 3 miRNAs (miR-21, miR-31, and miR-210) and methylation of 3 genes (RASSF1A, PRDM14, and 3OST2), which were previously identified as potential biomarkers for NSCLC, in sputum of a set of 117 stage I NSCLC patients and 174 cancer-free smokers. The results are validated in a different set of 144 stage I NSCLC patients and 171 controls. The panel of 3 miRNA biomarkers has 81.5 % sensitivity and 85.9 % specificity; the panel of 3 methylation biomarkers displays 82.9 % sensitivity and 76.4 % specificity for NSCLC detection. Integrated analysis of 2 miRNAs (miR-31 and miR-210) and 2 genes (RASSF1A and 3OST2) yields higher sensitivity (87.3 %) and specificity (90.3 %) compared with the individual panels of the biomarkers (P < 0.05). Combined analysis of all the 3 miRNAs and 3 genes does not have performance superior to that of the panel of 2 miRNAs and 2 genes (P > 0.05). The performance of combined use of the two classes of biomarkers was confirmed in the validation set.

Conclusions

The integration of two different classes of biomarkers synergistically improves both the sensitivity and the specificity for the early detection of NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-016-0275-5) contains supplementary material, which is available to authorized users.

Role of surfactant protein A in non-infectious lung diseases

Surfactant protein A (SP-A) is a large multimeric protein found in the airways and alveoli of the lungs. SP-A is a member of the collectin family of proteins, characterized by NH2-terminal collagen-like regions and COOH-terminal lectin domains. Although other surfactant proteins such as SP-B function to reduce surface tension in the lungs, SP-A as well as SP-D regulates the pulmonary immune response. To date, a number of studies have shown the immunoregulatory function of SP-A, mainly in the field of infectious diseases. By binding to a wide variety of pathogens, SP-A opsonizes and enhances pathogen uptake by phagocytes. In addition to the effect on pathogens, recent studies have shown that SP-A also modulates lung immune system in the area of non-infectious lung diseases. In this review, the potential role of SP-A in the multiple aspects of pulmonary host defense will be discussed, focusing mainly on non-infectious lung diseases such as acute and chronic pulmonary fibrosis and lung cancer. J. Med. Invest. 61: 1-6, February, 2014.

Visualization of phosphatidylcholine (16:0/16:0) in type II alveolar epithelial cells in the human lung using imaging mass spectrometry

Imaging mass spectrometry (MS) is an emerging technique that can detect numerous biomolecular distributions in a non-targeting manner. In the present study, we applied a mass imaging modality, mass microscopy, to human lung tissue and identified several molecules including surfactant constituents in a specific structure of the lung alveoli. Four peaks were identified using imaging MS, and the ion at m/z 772.5, in particular, was localized at some spots in the alveolar walls. Using an MS/MS analysis, the ion was identified as phosphatidylcholine (PC)(16:0/16:0), which is the main component of lung surfactant. In a larger magnification of the lung specimen, PC (16:0/16:0) was distributed in a mottled fashion in a section of the lung. Importantly, the distribution of PC (16:0/16:0) was identical to that of anti-SLC34A2 antibody immunoreactivity, which is known to be a specific marker of type II alveolar epithelial cells, in the same section. Our experience suggests that imaging MS has excellent potential in human pathology research.

Surfactant protein A suppresses lung cancer progression by regulating the polarization of tumor-associated macrophages

Surfactant protein A (SP-A) is a large multimeric protein found in the lungs. In addition to its immunoregulatory function in infectious respiratory diseases, SP-A is also used as a marker of lung adenocarcinoma. Despite the finding that SP-A expression levels in cancer cells has a relationship with patient prognosis, the function of SP-A in lung cancer progression is unknown. We investigated the role of SP-A in lung cancer progression by introducing the SP-A gene into human lung adenocarcinoma cell lines. SP-A gene transduction suppressed the progression of tumor in subcutaneous xenograft or lung metastasis mouse models. Immunohistochemical analysis showed that the number of M1 antitumor tumor-associated macrophages (TAMs) was increased and the number of M2 tumor-promoting TAMs was not changed in the tumor tissue produced by SP-A-expressing cells. In addition, natural killer (NK) cells were also increased and activated in the SP-A-expressing tumor. Moreover, SP-A did not inhibit tumor progression in mice depleted of NK cells. Taking into account that SP-A did not directly activate NK cells, these results suggest that SP-A inhibited lung cancer progression by recruiting and activating NK cells via controlling the polarization of TAMs.

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

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

Determination of the differential expression of mitochondrial long non-coding RNAs as a noninvasive diagnosis of bladder cancer

Background

Bladder cancer is a significant cause of morbidity and mortality with a high recurrence rate. Early detection of bladder cancer is essential in order to remove the tumor, to preserve the organ and to avoid metastasis. The aim of this study was to analyze the differential expression of mitochondrial non-coding RNAs (sense and antisense) in cells isolated from voided urine of patients with bladder cancer as a noninvasive diagnostic assay.

Methods

The differential expression of the sense (SncmtRNA) and the antisense (ASncmtRNAs) transcripts in cells isolated from voided urine was determined by fluorescent in situ hybridization. The test uses a multiprobe mixture labeled with different fluorophores and takes about 1 hour to complete. We examined the expression of these transcripts in cells isolated from urine of 24 patients with bladder cancer and from 15 healthy donors.

Results

This study indicates that the SncmtRNA and the ASncmtRNAs are stable in cells present in urine. The test reveals that the expression pattern of the mitochondrial transcripts can discriminate between normal and tumor cells. The analysis of 24 urine samples from patients with bladder cancer revealed expression of the SncmtRNA and down-regulation of the ASncmtRNAs. Exfoliated cells recovered from the urine of healthy donors do not express these mitochondrial transcripts. This is the first report showing that the differential expression of these mitochondrial transcripts can detect tumor cells in the urine of patients with low and high grade bladder cancer.

Conclusion

This pilot study indicates that fluorescent in situ hybridization of cells from urine of patients with different grades of bladder cancer confirmed the tumor origin of these cells. Samples from the 24 patients with bladder cancer contain cells that express the SncmtRNA and down-regulate the ASncmtRNAs. In contrast, the hybridization of the few exfoliated cells recovered from healthy donors revealed no expression of these mitochondrial transcripts. This assay can be explored as a non-invasive diagnostic tool for bladder cancer.

Stromal micropapillary component as a novel unfavorable prognostic factor of lung adenocarcinoma

BACKGROUND

Pulmonary adenocarcinomas with a micropapillary component having small papillary tufts and lacking a central fibrovascular core are thought to result in poor prognosis. However, the component consists of tumor cells often floating within alveolar spaces (aerogenous micropapillary component [AMPC]) rather than invading fibrotic stroma observed in other organs like breast (stromal invasive micropapillary component [SMPC]). We previously observed cases of lung adenocarcinoma with predominant SMPC that was associated with micropapillary growth of tumors in fibrotic stroma observed in other organs. We evaluated the incidence and clinicopathological characteristics of SMPC in lung adenocarcinoma cases.

PATIENTS AND METHODS

We investigated the clinicopathological characteristics and prognostic significance of SMPC in lung adenocarcinoma cases by reviewing 559 patients who had undergone surgical resection. We examined the SMPC by performing immunohistochemical analysis with 17 antibodies and by genetic analysis with epidermal growth factor receptor (EGFR) and KRAS mutations.

RESULTS

SMPC-positive (SMPC(+)) tumors were observed in 19 cases (3.4%). The presence of SMPC was significantly associated with tumor size, advanced-stage disease, lymph node metastasis, pleural invasion, lymphatic invasion, and vascular invasion. Patients with SMPC(+) tumors had significantly poorer outcomes than those with SMPC-negative tumors. Multivariate analysis revealed that SMPC was a significant independent prognostic factor of lung adenocarcinoma, especially for disease-free survival of pathological stage I patients (p = 0.035). SMPC showed significantly higher expression of E-cadherin and lower expression of CD44 than the corresponding expression levels shown by AMPC and showed lower surfactant apoprotein A and phospho-c-Met expression level than corresponding expression levels shown by tumor cell components without a micropapillary component. Fourteen cases with SMPC(+) tumors (74%) showed EGFR mutations, and none of them showed KRAS mutations.

CONCLUSIONS

SMPC(+) tumors are rare, but they may be associated with a poor prognosis and have different phenotypic and genotypic characteristics from those of AMPC(+) tumors.

Pulmonary Collectins in Diagnosis and Prevention of Lung Diseases

Pulmonary surfactant is a complex mixture of lipids and proteins, and is synthesized and secreted by alveolar type II epithelial cells and bronchiolar Clara cells. It acts to keep alveoli from collapsing during the expiratory phase of the respiratory cycle. After its secretion, lung surfactant forms a lattice structure on the alveolar surface, known as tubular myelin. Surfactant proteins (SP)-A, B, C and D make up to 10% of the total surfactant. SP-B and SPC are relatively small hydrophobic proteins, and are involved in the reduction of surface-tension at the air-liquid interface. SP-A and SP-D, on the other hand, are large oligomeric, hydrophilic proteins that belong to the collagenous Ca²⁺-dependent C-type lectin family (known as “Collectins”), and play an important role in host defense and in the recycling and transport of lung surfactant (Awasthi 2010) (Fig. 43.1). In particular, there is increasing evidence that surfactant-associated proteins A and -D (SP-A and SP-D, respectively) contribute to the host defense against inhaled microorganisms (see 10.1007/978-3-7091-1065_24 and 10.1007/978-3-7091-1065_25). Based on their ability to recognize pathogens and to regulate the host defense, SP-A and SP-D have been recently categorized as “Secretory Pathogen Recognition Receptors”. While SP-A and SP-D were first identified in the lung; the expression of these proteins has also been observed at other mucosal surfaces, such as lacrimal glands, gastrointestinal mucosa, genitourinary epithelium and periodontal surfaces. SP-A is the most prominent among four proteins in the pulmonary surfactant-system. The expression of SP-A is complexly regulated on the transcriptional and the chromosomal level. SP-A is a major player in the pulmonary cytokine-network and moreover has been described to act in the pulmonary host defense. This chapter gives an overview on the understanding of role of SP-A and SP-D in for human pulmonary disorders and points out the importance for pathology-orientated research to further elucidate the role of these molecules in adult lung diseases. As an outlook, it will become an issue of pulmonary pathology which might provide promising perspectives for applications in research, diagnosis and therapy (Awasthi 2010).

Pulmonary surfactant: an immunological perspective

Pulmonary surfactant has two crucial roles in respiratory function; first, as a biophysical entity it reduces surface tension at the air water interface, facilitating gas exchange and alveolar stability during breathing, and, second, as an innate component of the lung's immune system it helps maintain sterility and balance immune reactions in the distal airways. Pulmonary surfactant consists of 90% lipids and 10% protein. There are four surfactant proteins named SP-A, SP-B, SP-C, and SP-D; their distinct interactions with surfactant phospholipids are necessary for the ultra-structural organization, stability, metabolism, and lowering of surface tension. In addition, SP-A and SP-D bind pathogens, inflict damage to microbial membranes, and regulate microbial phagocytosis and activation or deactivation of inflammatory responses by alveolar macrophages. SP-A and SP-D, also known as pulmonary collectins, mediate microbial phagocytosis via SP-A and SP-D receptors and the coordinated induction of other innate receptors. Several receptors (SP-R210, CD91/calreticulin, SIRPalpha, and toll-like receptors) mediate the immunological functions of SP-A and SP-D. However, accumulating evidence indicate that SP-B and SP-C and one or more lipid constituents of surfactant share similar immuno-regulatory properties as SP-A and SP-D. The present review discusses current knowledge on the interaction of surfactant with lung innate host defense.

Aldehyde dehydrogenase 1 is a tumor stem cell-associated marker in lung cancer

Tumor contains small population of cancer stem cells (CSC) that are responsible for its maintenance and relapse. Analysis of these CSCs may lead to effective prognostic and therapeutic strategies for the treatment of cancer patients. We report here the identification of CSCs from human lung cancer cells using Aldefluor assay followed by fluorescence-activated cell sorting analysis. Isolated cancer cells with relatively high aldehyde dehydrogenase 1 (ALDH1) activity display in vitro features of CSCs, including capacities for proliferation, self-renewal, and differentiation, resistance to chemotherapy, and expressing CSC surface marker CD133. In vivo experiments show that the ALDH1-positive cells could generate tumors that recapitulate the heterogeneity of the parental cancer cells. Immunohistochemical analysis of 303 clinical specimens from three independent cohorts of lung cancer patients and controls show that expression of ALDH1 is positively correlated with the stage and grade of lung tumors and related to a poor prognosis for the patients with early-stage lung cancer. ALDH1 is therefore a lung tumor stem cell-associated marker. These findings offer an important new tool for the study of lung CSCs and provide a potential prognostic factor and therapeutic target for treatment of the patients with lung cancer.

Combined genetic analysis of sputum and computed tomography for noninvasive diagnosis of non-small-cell lung cancer

CT plays an important role in diagnosis of lung cancer, however has been limited by uncertain detection rate for early stage of non-small-cell lung cancer (NSCLC), particularly central tumors. Genetic analysis of sputum has proven to be useful in diagnosis of NSCLC. We proposed to evaluate efficacy of combing CT and genetic analysis of sputum for noninvasive diagnosis of stage I NSCLC. Genomic copy changes of a panel of lung cancer-related genes, HYAL2, FHIT, p16, and SP-A were analyzed by a mini-chip in sputum from 33 patients with stage I NSCLC and 49 cancer-free controls. The genetic and CT diagnoses were compared with surgical-pathologic stage. CT had higher sensitivity (85%) in detection of lung cancer compared with the mini-chip (70%) (p<0.05), while there was no significant difference in specificity between the two tests (89% vs. 92%, p=0.09). Similarly, CT showed considerably higher sensitivity (93%) in identifying peripheral tumors than did the mini-chip (64%) (p<0.05), whereas there was no difference in specificity between them (98% vs. 96%, p=0.28). However, in detecting central tumors, CT had lower specificity (90%) compared with the mini-chip (98%) (p<0.05), although its sensitivity (79%) was higher than that of the mini-chip (73%) (p=0.05). Combining both tests offered higher sensitivity (91%) than did any single one (85%, 70%, all <0.05), while still keeping 92% sensitivity. In particular, this combined approach yielded higher sensitivity, specificity, and accuracy for diagnosing central cancers compared with CT alone (all p<0.05). The integration of the genetic assay with CT led to improvements in noninvasive diagnosis of stage I NSCLCs, especially central tumors.

3p22.1 and 10q22.3 deletions detected by fluorescence in situ hybridization (FISH): a potential new tool for early detection of non-small cell lung Cancer (NSCLC)

BACKGROUND

Our objective was to study the feasibility of detecting chromosomal deletions at 3p22.1 and 10q22.3 by fluorescent in situ hybridization (FISH) and to examine their distribution in different areas of the airway in patients with non-small cell lung cancer.

METHODS

Brush biopsies from the mainstem bronchus on the normal side contralateral to the tumor (NBB) and mainstem bronchus on the tumor side (TBB) were obtained from 122 patients who underwent surgical resection. Touch preparations from the tumor (TTP), normal lung parenchyma, and bronchi adjacent to the tumor were also obtained. Two FISH assays using probes complementary to 3p22.1 and 10q22.3 were used to detect deletions.

RESULTS

NBB showed a relatively low deletion rate of 3p22.1 and 10q22.3 compared with TTP (p < 0.0001). TBB showed a significantly higher rate of deletions compared with NBB but lower than TTP from the tumor (p < 0.05) for both 3p22.1 and 10q22.3. A significantly higher deletion rate was seen at TTP compared with normal lung parenchyma at both the 3p22.1 and 10 q22.3 (p < 0.0001). Correlations were seen between the deletion rates of TTP and TBB at 3p22.1 (rho = 0.61, p < 0.0001) and between TTP and bronchi adjacent to the tumor at 10q22.3 (rho = 0.64, p < 0.0001).

CONCLUSION

Deletions of the 3p22.1 and 10q22.3 regions can be reliably detected by FISH. As one progresses from the contralateral normal bronchus to the bronchus on the side of tumor and the tumor itself, the percentage of chromosomal deletions increases in a statistically significant fashion. This suggests that, FISH analysis of bronchoscopic brushes may be useful for identifying patients at high risk for developing non-small cell lung cancer.

Magnetic enrichment of bronchial epithelial cells from sputum for lung cancer diagnosis

BACKGROUND

Sputum is an easily accessible diagnostic material for lung cancer early detection by cytologic and molecular genetic analysis of exfoliated airway epithelial cells. However, the use of sputum is limited by its cellular heterogeneity, which includes >95% macrophages and neutrophils and only about 1% bronchial epithelial cells. We propose to obtain concentrated and purified bronchial epithelial cells to improve early detection of lung cancer in sputum samples.

METHODS

Sputum was collected from patients with stage I nonsmall-cell lung cancer, cancer-free smokers, and healthy nonsmokers. Magnetic-assisted cell sorting (MACS) with anti-CD14 and anti-CD16 antibody beads were used to enrich bronchial epithelial cells by depleting macrophages and neutrophils from sputum. Fluorescence in situ hybridization (FISH) analysis for detection of FHIT deletion and cytology were evaluated in the enriched specimens.

RESULTS

The bronchial epithelial cells were concentrated to 40% purity from 1.1% of the starting population, yielding an average of 36-fold enrichment and at least 2.3 x 10(5) cells per sample. Detecting FHIT deletions for lung cancer diagnosis produced 58% sensitivity in the enriched sputum, whereas there was 42% sensitivity in the unenriched samples (P = .02). Cytologic examination of the enriched sputum resulted in 53% sensitivity, as compared with 39% sensitivity in unenriched sputum (P = .03). Furthermore, only 2 cytocentrifuge slides of the unenriched sputum were needed for the analyses, as compared with up to 10 cytocentrifuge slides required from the unprocessed specimens.

CONCLUSIONS

The enrichment of bronchial epithelial cells could improve the diagnostic value of sputum and the efficiency of genetic and cytologic analysis of lung cancer.

Automated detection of genetic abnormalities combined with cytology in sputum is a sensitive predictor of lung cancer

Detection of lung cancer by sputum cytology has low sensitivity but is noninvasive and, if improved, could be a powerful tool for early lung cancer detection. To evaluate whether the accuracy of diagnosing lung cancer by evaluating sputa for cytologic atypia and genetic abnormalities is greater than that of conventional cytology alone, automated scoring of genetic abnormalities for 3p22.1 and 10q22.3 (SP-A) by fluorescence in situ hybridization (FISH) and conventional cytology was done on sputa from 35 subjects with lung cancer, 25 high-risk smokers, and 6 healthy control subjects. Multivariate analysis was performed to select variables that most accurately predicted lung cancer. A model of probability for the presence of lung cancer was derived for each subject. Cells exfoliated from patients with lung cancer contained genetic aberrations and cytologic atypias at significantly higher levels than in those from control subjects. When combined with cytologic atypia, a model of risk for lung cancer was derived that had 74% sensitivity and 82% specificity to predict the presence of lung cancer, whereas conventional cytology achieved only 37% sensitivity and 87% specificity. For diagnosing lung cancer in sputum, a combination of molecular and cytologic variables was superior to using conventional cytology alone.

A micropapillary pattern is predictive of a poor prognosis in lung adenocarcinoma, and reduced surfactant apoprotein A expression in the micropapillary pattern is an excellent indicator of a poor prognosis

A micropapillary pattern is defined as papillary tufts without a fibrovascular core and is known to be a factor that indicates a poor prognosis in numerous cancers. However, their role in lung adenocarcinoma has not been investigated widely. In 185 cases of small-size lung adenocarcinoma (< or =3 cm), cases with a micropapillary pattern ratio of more than 1% (analyzed by NIH image) were defined as micropapillary pattern positive. Correlations between the micropapillary pattern and clinicopathological factors were investigated and immunohistochemical expression of mucin and various antigens was examined in regions with and without micropapillary patterns. Micropapillary pattern-positive tumors (micropapillary pattern ratio > or =1%) were observed in 11.4% of cases (21/185) and the micropapillary pattern ratio correlated with TNM stage (P=0.0002), lymphatic invasion (P=0.0002) and lymph node metastasis (P=0.03). Disease-free interval (P<0.0002) and survival (P=0.027) were significantly shorter for micropapillary pattern-positive patients, and micropapillary pattern-positive stage IA cases also had a significantly shorter disease-free interval (P<0.0001). MUC1 was expressed strongly across the surface of the micropapillary structure, whereas MUC4 tended to show lower expression in the micropapillary pattern. It was noteworthy that the disease-free interval in patients with high surfactant apoprotein A expression was significantly better than in patients with low surfactant apoprotein A expression (P=0.03), and no recurrence or death occurred in patients with high surfactant apoprotein A expression. Our results show that the micropapillary pattern ratio correlates with lymphatic invasion and lymph node metastasis, and that a high micropapillary pattern ratio leads to a poor prognosis. High MUC1 expression on the surface is an important characteristic of a micropapillary pattern, and reduced surfactant apoprotein A expression in the micropapillary pattern may be an excellent indicator for poor prognosis in small-size lung adenocarcinoma.

Genetic deletions in sputum as diagnostic markers for early detection of stage I non-small cell lung cancer

PURPOSE

Analysis of molecular genetic markers in biological fluids has been proposed as a powerful tool for cancer diagnosis. We have characterized in detail the genetic signatures in primary non-small cell lung cancer, which provided potential diagnostic biomarkers for lung cancer. The aim of this study was to determine whether the genetic changes can be used as markers in sputum specimen for the early detection of lung cancer.

EXPERIMENTAL DESIGN

Genetic aberrations in the genes HYAL2, FHIT, and SFTPC were evaluated in paired tumors and sputum samples from 38 patients with stage I non-small cell lung cancer and in sputum samples from 36 cancer-free smokers and 28 healthy nonsmokers by using fluorescence in situ hybridization.

RESULTS

HYAL2 and FHIT were deleted in 84% and 79% tumors and in 45% and 40% paired sputum, respectively. SFTPC was deleted exclusively in tumor tissues (71%). There was concordance of HYAL2 or FHIT deletions in matched sputum and tumor tissues from lung cancer patients (r = 0.82, P = 0.04; r = 0.84, P = 0.03), suggesting that the genetic changes in sputum might indicate the presence of the same genetic aberrations in lung tumors. Furthermore, abnormal cells were found in 76% sputum by detecting combined HYAL2 and FHIT deletions whereas in 47% sputum by cytology, of the cancer cases, implying that detecting the combination of HYAL2 and FHIT deletions had higher sensitivity than that of sputum cytology for lung cancer diagnosis. In addition, HYAL2 and FHIT deletions in sputum were associated with smoking history of cancer patients and smokers (both P < 0.05).

CONCLUSIONS

Tobacco-related HYAL2 and FHIT deletions in sputum may constitute diagnostic markers for early-stage lung cancer.

Computed Tomography–Diagnosed Emphysema, Not Airway Obstruction, Is Associated with the Prognostic Outcome of Early-Stage Lung Cancer

PURPOSE

Because both emphysema and lung cancer can arise from biological damage caused by cigarette smoking, we investigated if the development of emphysema is associated with the clinical features of smoker's lung cancer.

EXPERIMENTAL DESIGN

The subjects were a consecutive series of 100 smokers who underwent lobectomy with hilar and mediastinal dissection for clinical stage I non-small cell lung cancer. We studied the relationship between the presence or absence of emphysema at the onset of the lung cancer and clinicopathologic features. Emphysema was diagnosed by measuring the low-attenuation area using computed tomography densitometry.

RESULTS

There were no differences in clinicopathologic variables, including the degree of smoking exposure between the patients with (n=58) and those without (n=42) emphysema, although male gender and airflow limitation were predominant in the patients with emphysema. The presence of emphysema, but neither male gender nor airflow limitation, adversely affected both overall and disease-specific survival. According to Cox regression analysis, emphysema was an independent prognosticator among age, gender, degree of smoking exposure, tumor size, nodal status, histologic subtype, histologic grade, and microvessel invasion. These results were stabilized by a bootstrap sampling model.

CONCLUSIONS

Computed tomography-diagnosed emphysema, but not airway obstruction, is associated with poor prognosis in smokers with early-stage lung cancer. Thus, routine computed tomography densitometry in smokers with lung cancer should be mandatory.

A novel multiple FISH array for the detection of genetic aberrations in cancer

Interphase multicolor fluorescence in situ hybridization (IM-FISH) has great promise for improving cancer diagnosis because it can directly visualize multiple changes in chromosomes and gene copy number on a cell-to-cell basis. However, no more than four targets can be detected simultaneously by current commercially available IM-FISH protocols, and the DNA probes used are too large to detect the single-gene aberrations that characterize tumorigenesis. As a result, multiple FISH has a low sensitivity in detecting cancer cells. To overcome such limitations, we first developed specific genomic probes for the genes relevant to primary lung cancer. We next designed a multiple FISH array by arranging four different compositions of cocktails of four probes for each gene on a coverslip, which allowed four four-color FISH experiments to be performed in parallel on a single slide. We then tested the multiple FISH array on bronchial brushing samples from lung cancer patients to determine its ability to detect genetic abnormalities. A comparison of the data with the results of cytology and commercial four-color FISH suggested that the multiple FISH array had the highest sensitivity for cancer detection. The technique may thus be a powerful laboratory strategy for cancer prevention and early detection and for improved patient management.

Analysis of paired primary lung and lymph node tumor cells: a model of metastatic potential by multiple genetic programs

BACKGROUND

The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. We tested this hypothesis by examining the molecular differences, if any, between primary tumor cells and matched lymph node metastatic cells in human non-small-cell lung carcinoma specimens.

METHODS

We performed transcriptional profiling studies on malignant cells from 11 pairs of stage III tumors and their tumor-positive lymph nodes using multiple, complementary analytic techniques. To confirm the overall validity of microarray data, we used real-time polymerase chain reaction.

RESULTS

The molecular signature of nodal metastasis was a composite of two paradoxical, but not mutually exclusive, expression patterns: metastatic cells are: (1) different from their primary tumor cells based on a few genes and (2) genetically similar, overall, to their primary tumor cells. Consequently, we found a 27-gene subset sufficient to differentiate nodal metastatic cells from primary tumor cells.

CONCLUSIONS

Thus, we concluded that a more accurate model of metastatic potential is based on a global primary tumor expression pattern along with the appearance of distinct metastatic variants. The 27-gene signature differentiating primary tumors from their metastatic cells may define non-small-cell lung carcinoma nodal metastatic potential.