Abstract 3614: 3D model to study migration and invasion of lung cancer

Background: In 2D cell cultures, migration of tumor cells is characterized by epithelial-to-mesenchymal transition (EMT), whereby tumor cells loose epithelial and express mesenchymal markers and very often change into a spindle cell phenotype. In contrast to 2D cultures, in 3D cultures tumor cells do not lose their differentiation. Small cell lung cancer usually moves as single cells or in small clusters, squamous cell and adenocarcinomas preferentially move in large clusters of cells. In tissue specimen, all of these carcinomas migrate in a hybrid EMT, not loosing their cytokeratin and E-cadherin expression. In AC and SCC also polarity and specification do occur, as some tumor cells act as leaders, providing orientation for the followers. However, 3D culture system might better depict real migration and come closer to the in vivo system as 2D cell culture systems.

Material and Method: A 3D bioprinter (TissueLabsR) was used to spot an alveolar-mimicking lung-specific matrix on cell culture wells. Microscopic channels out of pluronicsR are created within the matrix. Pluronics is removed by cooling, leaving empty channels within the protein matrix. These channels can be filled with different interleukins, such as IL23, which will direct migration of the tumor cells. Cultured cell lines from an adenocarcinoma (A549) and small cell carcinoma (NCI-H82) are layered on top of the matrix and migration into the matrix is studied using different time points.

Results and Discussion: A matrix simulating an alveolar structure was created with MatrigelR. The A549 cells were seeded on the matrix and grown for 2,5, 10, and 14 days. The cells formed cell clusters on the matrix and after one week started to invade the matrix in cell complexes. By immunohistochemistry we could show, that the A549 cells retained their epithelial differentiation. The H82 cells showed a different behavior. They did not form large clusters, but started to invade in small groups. The use of the bioprinter enabled us not only to create a 3D tumor culture system to simulate the in vivo conditions but also to create matrix structures for studying invasion and migration and to stimulate carcinoma cells with migration-activating substances.

Citation Format: Melina Hardt, Kurt Zatloukal, Helmut H. Popper. 3D model to study migration and invasion of lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3614.

Genomic and transcriptional alterations in first-line chemotherapy exert a potentially unfavorable influence on subsequent immunotherapy in NSCLC

Background: Recent studies in non-small cell lung cancer (NSCLC) patients have demonstrated that first-line immunotherapy is associated with better therapeutic response than second-line treatment. So far, the mechanisms need to be explored. It prompted us to evaluate the association between first-line chemotherapy and subsequent immunotherapy in NSCLC as well as its underlying mechanisms at the genomic and transcriptomic level.

Methods: We launched a prospective, observational clinical study, paired tumor biopsies before and after chemotherapy were collected from NSCLC patients without tyrosine kinase inhibitor (TKI)-related driver gene mutations. The analyses included genomic and transcriptional changes performed by next-generation sequencing (NGS)-based whole-exome sequencing (WES) and messager ribonucleic acid (mRNA) sequencing. Characteristic mutational alterations in 1574 genes were investigated based on mutational status, clinicopathological factors, and chemotherapy responses. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, neoantigen prediction and intratumoral heterogeneity evaluation were also performed.

Results: Samples and information from 32 NSCLC patients without TKI-related driver gene mutations were obtained. We found that the total number of single nucleotide variants (SNV)/insertion-deletion (INDEL) mutations did not change significantly after chemotherapy. The tumor mutation burden (TMB) decreased significantly after chemotherapy in smoking patients and the decreased TMB correlated with a better survival of smoking patients. The change in copy number variations (CNVs) exhibited a decreasing trend during chemotherapy. Subsequent analysis at mRNA level revealed a significant decrease in the expression levels of genes related to antigen processing and presentation as well as other factors relevant for response to immunotherapy. Pathway enrichment analysis confirmed that the immune-related signaling pathways or biological processes were decreased after first-line chemotherapy.

Conclusions: Our study presents an explanation for the unsatisfactory results of immunotherapy when given after chemotherapy, and suggests that first-line chemotherapy is able to influence the tumor microenvironment and decrease the efficacy of subsequent immunotherapy. The study was registered at ClinicalTrials.gov, number NCT03764917, and has completed enrolment; patients are still in follow-up.

Distribution and prognostic significance of gluconeogenesis and glycolysis in lung cancer

Inhibition of glycolysis has been considered as a therapeutic approach in aggressive cancers including lung cancer. Abbreviated gluconeogenesis, mediated by phosphoenolpyruvate carboxykinase (PEPCK), was recently discovered to partially circumvent the need for glycolysis in lung cancer cells. However, the interplay of glycolysis and gluconeogenesis in lung cancer is still poorly understood. Here, we analyzed the expression of GLUT1, the prime glucose transporter, and of PCK1 and PCK2, the cytoplasmic and mitochondrial isoforms of PEPCK, in 450 samples of non‐small cell lung cancer (NSCLC) and in 54 NSCLC metastases using tissue microarrays and whole tumor sections. Spatial distribution was assessed by automated image analysis. Additionally, glycolytic and gluconeogenic gene expression was inferred from The Cancer Genome Atlas (TCGA) datasets. We found that PCK2 was preferentially expressed in the lung adenocarcinoma subtype, while GLUT1 expression was higher in squamous cell carcinoma. GLUT1 and PCK2 were inversely correlated, GLUT1 showing elevated expression in larger tumors while PCK2 was highest in smaller tumors. However, a mixed phenotype showing the presence of both, glycolytic and gluconeogenic cancer cells was frequent. In lung adenocarcinoma, PCK2 expression was associated with significantly improved overall survival, while the opposite was found for GLUT1. The metabolic tumor microenvironment and the 3‐dimensional context play an important role in modulating both pathways, since PCK2 expression preferentially occurred at the tumor margin and hypoxia regulated both, glycolysis and gluconeogenesis, in NSCLC cells in vitro, albeit in opposite directions. PCK1/2 expression was enhanced in metastases compared to primary tumors, possibly related to the different environment. The results of this study show that glycolysis and gluconeogenesis are activated in NSCLC in a tumor size and oxygenation modulated manner and differentially correlate with outcome. The frequent co‐activation of gluconeogenesis and glycolysis in NSCLC should be considered in potential future therapeutic strategies targeting cancer cell metabolism.

Manipulation of the immune system by non-small cell lung cancer and possible therapeutic interference

Pulmonary carcinomas have developed mechanisms by which they escape the attack of immune cells. Immune checkpoint molecules programmed death 1 - programmed death ligand 1 (PD1-PDL1) and the cytotoxic T-lymphocyte antigen 4 system have gained attention. The expression of PDL1 by tumor cells causes immune tolerance, and further influences the microenvironment via orchestration by cytokines. Therapy with PDL1 antibodies could restore the cytotoxicity of T-lymphocytes towards tumor cells. Many patients will respond to this treatment. However, resistance mechanisms will counteract this therapy. New investigations have identified additional immune checkpoint inhibitors such as lymphocyte activation gene 3 and T cell immunoglobulin and mucin-domain containing-3. Tumor cells also induce tolerance by manipulating cells of the innate immune system. Macrophages are polarized to tumor-friendly M2, neutrophils into N2 types, and dendritic cells and myeloid suppressor cells are switched to assist tumor cells. Regulatory T cells enter the tumor microenvironment and signal tolerance to cytotoxic cells, inhibiting the influx of NK cells. Soluble mediators either released by tumor cells or cells of the tumor stroma induce immune tolerance, examples including tryptophan and indolamine dioxygenases, arginine and adenosine. Treatment options to counteract these molecules are currently being tested. The tumor stroma has been classified as immune-inflamed, immune-excluded, and immune-desert types. The latter might be switched to an inflamed type by induction of tertiary lymph follicles. Dendritic cells and macrophages normally phagocytose tumor antigens, but inhibitors of phagocytosis can block this. Interference with these molecules is another option for re-establishing the cytotoxic action of the immune system against tumor cells. In this review we will discuss these aspects with a special emphasis on non-small cell lung cancer.

Novel stereotactic body radiation therapy (SBRT)-based partial tumor irradiation targeting hypoxic segment of bulky tumors (SBRT-PATHY): improvement of the radiotherapy outcome by exploiting the bystander and abscopal effects

Background

Despite the advances in oncology, patients with bulky tumors have worse prognosis and often receive only palliative treatments. Bulky disease represents an important challenging obstacle for all currently available radical treatment options including conventional radiotherapy. The purpose of this study was to assess a retrospective outcome on the use of a newly developed unconventional stereotactic body radiation therapy (SBRT) for PArtial Tumor irradiation of unresectable bulky tumors targeting exclusively their HYpoxic segment (SBRT-PATHY) that exploits the non-targeted effects of radiotherapy: bystander effects (local) and the abscopal effects (distant).

Materials and methods

Twenty-three patients with bulky tumors received partial bulky irradiation in order to induce the local non-targeted effect of radiation (bystander effect). The hypoxic tumor segment, called the bystander tumor volume (BTV), was defined using PET and contrast-enhanced CT, as a hypovascularized-hypometabolic junctional zone between the central necrotic and peripheral hypervascularized-hypermetabolic tumor segment. Based on tumor site and volume, the BTV was irradiated with 1–3 fractions of 10–12 Gy prescribed to 70% isodose-line. The pathologic lymph nodes and metastases were not irradiated in order to assess the distant non-targeted effects of radiation (abscopal effect). No patient received any systemic therapy.

Results

At the time of analysis, with median follow-up of 9.4 months (range: 4–20), 87% of patients remained progression-free. The bystander and abscopal response rates were 96 and 52%, respectively. Median shrinkage of partially irradiated bulky tumor expressing intensity of the bystander effect was 70% (range 30–100%), whereas for the non-irradiated metastases (intensity of the abscopal effect), it was 50% (range 30–100%). No patient experienced acute or late toxicity of any grade.

Conclusions

SBRT-PATHY showed very inspiring results on exploitation of the radiation-hypoxia-induced non-targeted effects that need to be confirmed through our ongoing prospective trial.

Present study has been retrospectively registered by the local ethic committee under study number A 26/18.

Primary patient-derived lung adenocarcinoma cell culture challenges the association of cancer stem cells with epithelial-to-mesenchymal transition

The cancer stem cell (CSC) and epithelial-to-mesenchymal transition (EMT) models have been closely associated and used to describe both the formation of metastasis and therapy resistance. We established a primary lung cell culture from a patient in a clinically rare and unique situation of primary resistant disease. This culture consisted of two biologically profoundly distinct adenocarcinoma cell subpopulations, which differed phenotypically and genotypically. One subpopulation initiated and sustained in spheroid cell culture (LT22s) whereas the other subpopulation was only capable of growth and proliferation under adherent conditions (LT22a). In contrast to our expectations, LT22s were strongly associated with the epithelial phenotype, and expressed additionally CSC markers ALDH1 and CD133, whereas the LT22a was characterized as mesenchymal with lack of CSC markers. The LT22s cells also demonstrated an invasive behavior and mimicked gland formation. Finally, LT22s were more resistant to Cisplatin than LT22a cells. We demonstrate a primary lung adenocarcinoma cell culture derived from a patient with resistant disease, with epithelial aggressive subpopulation of cells associated with stem cell features and therapy resistance. Our findings challenge the current model associating CSC and disease resistance mainly to mesenchymal cells and may have important clinical implications.

Clinical Manifestations of Respiratory Bronchiolitis as an Incidental Finding in Surgical Lung Biopsies: A Retrospective Analysis of a Large Austrian Registry

BACKGROUND

While respiratory bronchiolitis (RB) is a frequent histopathological finding in smoker's lungs, RB-associated interstitial lung disease (RB-ILD) remains a rare disease.

OBJECTIVES

We analyzed how the histological finding of RB was associated with clinical information in a series of 684 consecutive surgical lung biopsies.

METHODS

Retrospective analysis with delineation of clinical manifestations, smoking habits, pulmonary function test, and blood gas analysis in patients with RB in surgical lung biopsy. In 240 of these biopsies, RB was diagnosed, and in 146 of these cases a full clinical dataset was available.

RESULTS

The final diagnosis of these 146 patients was consistent with RB-ILD (n = 18), pulmonary Langerhans cell histiocytosis (n = 7), various ILD (n = 9), spontaneous pneumothorax (n = 43), traumatic pneumothorax (n = 5), lung cancer (n = 41), various benign lung tumors (n = 8), and chronic pulmonary effusion (n = 15). Smoking history was positive in 93% of patients, 72% revealed centrilobular emphysema in their biopsy, and 58% described dyspnea as the main symptom. Amongst these diagnoses there were significant differences in age and smoking habits, but only small distinctions in pulmonary function test and blood gas analysis. Out of the patients with RB-ILD, 17% developed lung cancer in the later course.

CONCLUSION

RB is strongly related to smoking, emphysema, and dyspnea and frequently associated with lung cancer. RB-ILD is a rare disease that may represent a considerable risk for lung cancer. Pulmonary function testing and blood gas analysis do not differ between RB-associated diseases. The finding of RB should prompt further diagnostic workup, and in case of RB-ILD, entail regular screening for lung cancer.

Subtype Classification of Lung Adenocarcinoma Predicts Benefit From Adjuvant Chemotherapy in Patients Undergoing Complete Resection

PURPOSE

The classification for invasive lung adenocarcinoma by the International Association for the Study of Lung Cancer, American Thoracic Society, European Respiratory Society, and WHO is based on the predominant histologic pattern-lepidic (LEP), papillary (PAP), acinar (ACN), micropapillary (MIP), or solid (SOL)-present in the tumor. This classification has not been tested in multi-institutional cohorts or clinical trials or tested for its predictive value regarding survival from adjuvant chemotherapy (ACT).

PATIENTS AND METHODS

Of 1,766 patients in the IALT, JBR.10, CALGB 9633 (Alliance), and ANITA ACT trials included in the LACE-Bio study, 725 had adenocarcinoma. Histologies were reclassified according to the new classification and then collapsed into three groups (LEP, ACN/PAP, and MIP/SOL). Primary end point was overall survival (OS); secondary end points were disease-free survival (DFS) and specific DFS (SDFS). Hazard ratios (HRs) and 95% CIs were estimated through multivariable Cox models stratified by trial. Prognostic value was estimated in the observation arm and predictive value by a treatment effect interaction with histologic subgroups. Significance level was set at .01 for pooled analysis.

RESULTS

A total of 575 patients were included in this analysis. OS was not prognostically different between histologic subgroups, but univariable DFS and SDFS were worse for MIP/SOL compared with LEP or ACN/PAP subgroup (P < .01); this remained marginally significant after adjustment. MIP/SOL patients (but not ACN/PAP) derived DFS and SDFS but not OS benefit from ACT (OS: HR, 0.71; 95% CI, 0.51 to 0.99; interaction P = .18; DFS: HR, 0.60; 95% CI, 0.44 to 0.82; interaction P = < .01; and SDFS: HR, 0.59; 95% CI, 0.42 to 0.81; interaction P = .01).

CONCLUSION

The new lung adenocarcinoma classification based on predominant histologic pattern was not predictive for ACT benefit for OS, but it seems predictive for disease-specific outcomes.

[Pulmonary Langerhans cell histiocytosis]

Pulmonary Langerhans cell histiocytosis is regarded as a reactive proliferation of the dendritic Langerhans cell population stimulated by chronic tobacco-derived plant proteins due to incomplete combustion but can also occur in childhood as a tumor-like systemic disease. Currently, both these forms cannot be morphologically distinguished. In the lungs a nodular proliferation of Langerhans cells occurs in the bronchial mucosa and also peripherally in the alveolar septa with an accompanying infiltration by eosinophilic granulocytes and destruction of the bronchial wall. Langerhans cells can be selectively detected with antibodies against CD1a and langerin. In the reactive isolated pulmonary form, abstinence from tobacco smoking in most patients leads to regression of infiltration and improvement of symptoms. In high-resolution computed tomography (HRCT) the small star-like scars can still be detected even after complete cessation of tobacco smoking.

Minimal requirements for the molecular testing of lung cancer

From the aspect of the contemporary pathologic diagnostics of lung cancer, it is a key issue of the tissue obtained since small biopsies and cytology still play a major role. In the non-small cell lung cancer era, cytology considered equal to biopsy. However, in recent years it is unable to provide quality diagnosis and must be replaced by biopsy. Various molecular techniques can handle various different tissue samples which must be considered during molecular pathology diagnosis. Besides, tumor cell-normal cell ratio in the obtained tissue as well as the absolute tumor cell number have great significance whose information must be provided in the primary lung cancer diagnosis. Last but not least, for continuous sustainable molecular diagnostics of lung cancer rational algorythms, affordable technology and appropriate reimbursement are equally necessary.

Molecular testing in lung cancer in the era of precision medicine

The clinical expectations how pathologists should submit lung cancer diagnosis have changed dramatically. Until mid 90-ties a clear separation between small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC) was mostly sufficient. With the invention of antiangiogenic treatment a differentiation between squamous and non-squamous NSCLC was requested. When epidermal growth factor receptor (EGFR) mutation was detected in patients with pulmonary adenocarcinomas and subsequent specific treatment with tyrosine kinase inhibitors (TKIs) was invented, sub-classification of NSCLC and molecular analysis of the tumor tissue for mutations was asked for. Pathologists no longer submit just a diagnosis, but instead are involved in a multidisciplinary team for lung cancer patient management. After EGFR several other driver genes such as echinoderm microtubule associated protein like 4-AL-Kinase 1 (EML4-ALK1), c-ros oncogene 1, receptor tyrosine kinase (ROS1), discoidin domain receptor tyrosine kinase 2 (DDR2), fibroblast growth factor receptor 1 (FGFR1) were discovered, and more to come. Due to new developments in bronchology (EUS, EBUS) the amount of tissue submitted for diagnosis and molecular analysis is decreasing, however, the genes to be analyzed are increasing. Many of these driver gene aberrations are inversions or translocations and thus require FISH analysis. Each of these analyses requires a certain amount of tumor cells or one to two tissue sections from an already limited amount of tissues or cells. In this respect new genetic test systems have been introduced such as next generation sequencing, which enables not only to detect multiple mutations in different genes, but also amplifications and fusion genes. As soon as these methods have been validated for routine molecular analysis this will enable the analysis of multiple genetic changes simultaneously. In this review we will focus on genetic aberrations in NSCLC, resistance to new target therapies, and also to methodological requirements for a meaningful evaluation of lung cancer tissue and cells.

Lung adenocarcinomas: comparison between mice and men

A few human tumor types have been modeled in mice using genetic or chemical tools. The final goal of these efforts is to establish models that mimic not only the location and cellular origin of human cancers but also their genetic aberrations and morphologic appearances. The latter has been neglected by most investigators, and comparative histopathology of human versus mouse cancers is not readily available. This issue is exacerbated by the fact that some human malignancies comprise a whole spectrum of cancer subtypes that differ molecularly and morphologically. Lung cancer is a paradigm that appears not only as non-small cell and small-cell lung cancer but comprises a plethora of subtypes with distinct morphologic features. This review discusses species-specific and common morphological features of non-small cell lung cancer in mice and humans. Potential inconsistencies and the need for refined genetic tools are discussed in the context of a comparative analysis between commonly employed RAS-induced mouse tumors and human lung cancers.

Abstract 1209: Comparison of lung adenocarcinoma development in genetically engineered mouse and in humans - similarities and differences

Lung adenocarcinoma (AC) induced by carcinogen inhalation never came close to the human counterpart. This has changed with the creation of genetically engineered models.

Different types of mouse AC were studied, some of them with a KRAS codon12 mutation background, others with HRAS mutants inserted; in most additional hits were introduced (ATG5, PTEN, PI3K, p53). Development of AC was followed for 28 weeks. Human lung AC subtypes and precursor lesions served for comparison.

AC in mice starts with papillary growth at the bronchoalveolar junction (baJ). Tumor spreads into the alveolar periphery. Due to different cell to alveolar size alveoli are filled almost completely, simulating solid growth. At a certain size hypoxic necrosis is seen in centers, followed by neoangiogenesis and desmoplastic stroma formation. Finally invasion of tumor cells into stroma occur. Metastasis is rare, due to high tumor load, causing early death. Vascular invasion is seen, if second carcinogenic hits are applied.

Dissimilarities with human precursor and AC types are: AC in mice are all non-mucinous, they are predominant papillary or solid, often with a high degree of signet ring cell formation; in addition there seems to be a requirement of large tumor size before invasion and metastasis occur. To understand AC development knowledge of the anatomy and histology of mouse and human lung is necessary, but these models open a new way of investigating lung AC.

Citation Format: Helmut H. Popper, Beatrice Grabner, Emilio Casanova, Robert Eferl, Rao Shuan, Josef Penninger. Comparison of lung adenocarcinoma development in genetically engineered mouse and in humans - similarities and differences. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1209. doi:10.1158/1538-7445.AM2014-1209

Hypoxia increases membrane metallo-endopeptidase expression in a novel lung cancer ex vivo model - role of tumor stroma cells

Background

Hypoxia-induced genes are potential targets in cancer therapy. Responses to hypoxia have been extensively studied in vitro, however, they may differ in vivo due to the specific tumor microenvironment. In this study gene expression profiles were obtained from fresh human lung cancer tissue fragments cultured ex vivo under different oxygen concentrations in order to study responses to hypoxia in a model that mimics human lung cancer in vivo.

Methods

Non-small cell lung cancer (NSCLC) fragments from altogether 70 patients were maintained ex vivo in normoxia or hypoxia in short-term culture. Viability, apoptosis rates and tissue hypoxia were assessed. Gene expression profiles were studied using Affymetrix GeneChip 1.0 ST microarrays.

Results

Apoptosis rates were comparable in normoxia and hypoxia despite different oxygenation levels, suggesting adaptation of tumor cells to hypoxia. Gene expression profiles in hypoxic compared to normoxic fragments largely overlapped with published hypoxia-signatures. While most of these genes were up-regulated by hypoxia also in NSCLC cell lines, membrane metallo-endopeptidase (MME, neprilysin, CD10) expression was not increased in hypoxia in NSCLC cell lines, but in carcinoma-associated fibroblasts isolated from non-small cell lung cancers. High MME expression was significantly associated with poor overall survival in 342 NSCLC patients in a meta-analysis of published microarray datasets.

Conclusions

The novel ex vivo model allowed for the first time to analyze hypoxia-regulated gene expression in preserved human lung cancer tissue. Gene expression profiles in human hypoxic lung cancer tissue overlapped with hypoxia-signatures from cancer cell lines, however, the elastase MME was identified as a novel hypoxia-induced gene in lung cancer. Due to the lack of hypoxia effects on MME expression in NSCLC cell lines in contrast to carcinoma-associated fibroblasts, a direct up-regulation of stroma fibroblast MME expression under hypoxia might contribute to enhanced aggressiveness of hypoxic cancers.

Abstract 5267: STAT signaling is totally deregulated in malignant pleural mesothelioma: What are the reasons

Malignant pleural mesothelioma (MPM) is an aggressive tumor caused by former asbestos exposure with a mean overall survival of 12 months from diagnosis. The knowledge about predictive factors of outcome is poor and MPM is resistant to conventional therapy. The long latency period in MPM pathogenesis as well as the absence of early symptoms is responsible for the late diagnosis of this disease.

From our recent study and published data we know that the regular rapid progressive type of MPM uses several signaling pathways regulating cell growth and survival. Asbestos causes genetic modifications, most notably the upregulation of cell survival and growth signaling pathways as well as the expression of other proteins that favor the resistance of MPM to apoptosis and chemotherapy. In order to develop more effective therapy than the currently used chemotherapy, novel targets have to be identified in MPM.

The JAK/STAT signaling pathway is the principal signaling mechanism for lots of cytokines or growth factors in mammalians. JAK activation induces a variety of biological responses like cell proliferation, differentiation, cell migration, and apoptosis.

Our investigations demonstrate that the STAT signaling pathway is totally deregulated: STAT1 is upregulated, whereas STAT3 is downregulated. SOCS1 and SOCS3 - which represent a negative feedback loop and which are regulators of STAT1 and STAT3 - are totally missing in MPM. Investigations in six mesothelioma cell lines showed that STAT1 is highly expressed and that SOCS1 is missing whereas the expression of pSTAT1 (Tyr701) can be stimulated and therefore be increased by Interferon-gamma treatment. The expression levels of other components of the STAT signaling pathway in these cell lines are currently under investigation.

It is known that protein expression is controlled by noncoding RNAs, e.g. microRNAs (miRNA) and we investigated the possible impact of miRNAs on the STAT signaling pathway in MPM. We identified miR-30d* as a regulator of phosphorylated STAT1 (Ser727). Furthermore we found that miR-19b, miR-30b, miR-30c and miR-222 are upregulated which are predicted to target SOCS1 and SOCS3 - this could be an explanation for the missing expression of these proteins. MiR-21 is extremely upregulated in MPM, a miRNA that is associated with a wide variety of human tumors and which targets STAT3.

Understanding the role of STATs in MPM could be the first step into the development of a targeted therapy for these tumors.

Citation Format: Lisa Arzt, Franz Quehenberger, Iris Halbwedl, Helmut H. Popper. STAT signaling is totally deregulated in malignant pleural mesothelioma: What are the reasons. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5267. doi:10.1158/1538-7445.AM2013-5267

Interstitial lung diseases-can pathologists arrive at an etiology-based diagnosis? A critical update

Interstitial lung diseases (ILD) encompass a group of diseases with a wide range of etiologies and a variety of tissue reactions within the lung. In many instances, a careful evaluation of the tissue reactions will result in a specific diagnosis or at least in a narrow range of differentials, which will assist the clinician to arrive at a definite diagnosis, when combining our interpretation with the clinical presentation of the patient and high-resolution computed tomography. In this review, we will exclude granulomatous pneumonias as well as vascular diseases (primary arterial pulmonary hypertension and vasculitis); however, pulmonary hypertension as a complication of interstitial processes will be mentioned. Few entities of pneumoconiosis presenting as an interstitial process will be included, whereas those with granulomatous reactions will be excluded. Drug reactions will be touched on within interstitial pneumonias, but will not be a major focus. In contrast to the present-day preferred descriptive pattern recognition, it is the author's strong belief that pathologists should always try to dig out the etiology from a tissue specimen and not being satisfied with just a pattern description. It is the difference of sorting tissue reactions into boxes by their main pattern, without recognizing minor or minute reactions, which sometimes will guide one to the correct etiology-oriented interpretation. In the author's personal perspective, tissue reactions can even be sorted by their timeliness, and therefore, ordered by the time of appearance, providing an insight into the pathogenesis and course of a disease. Also, underlying immune mechanisms will be discussed briefly as far as they are essential to understand the disease.

Causes of pulmonary granulomas: a retrospective study of 500 cases from seven countries

BACKGROUND

The frequencies of various causes of pulmonary granulomas in pathological material are unknown, as is the influence of geographical location on aetiology. The aim of this study was to identify the causes of pulmonary granulomas in pathological specimens, to define their frequencies, and to determine whether these causes vary by geographical location.

METHODS

500 lung biopsies and resections containing granulomas were reviewed retrospectively by expert pulmonary pathologists from 10 institutions in seven countries. Fifty consecutive cases from each location were assigned a diagnosis based on histological features and available clinical/microbiological data.

RESULTS

A specific cause was identified in 58% of cases (290/500), most commonly sarcoidosis (136, 27%) and mycobacterial or fungal infections (125, 25%). Mycobacteria were identified in 19% of cases outside the USA versus 8% within the USA. In contrast, fungi accounted for 19% cases in the USA versus 4% in other locations. Fungi were mostly detected by histology, whereas most mycobacteria were identified in cultures. In 42% of cases (210/500) an aetiology could not be determined.

CONCLUSIONS

Across several geographical settings, sarcoidosis and infections are the most common causes of pulmonary granulomas diagnosed in pathological specimens. Fungi are more commonly identified than mycobacteria in the USA, whereas the reverse is true in other countries. A definite aetiology cannot be demonstrated in more than a third of all cases of pulmonary granulomas, even after histological examination. These findings highlight the need to submit material for histology as well as cultures in all cases in which granulomatous disease enters the differential diagnosis.

Comparison of formalin-free tissue fixatives: a proteomic study testing their application for routine pathology and research

CONTEXT

Formalin-fixed, paraffin-embedded tissue is the routine processing method for diagnostics practiced in pathology departments worldwide.

OBJECTIVE

To determine the potential value of non-cross-linking, formalin-free tissue fixation for diagnostics in pathology and proteomic investigations.

DESIGN

We tested 3 commercially available, formalin-free tissue fixatives-FineFIX, RCL2, and HOPE-in lung cancer specimens from 10 patients. The fixatives were evaluated for their effects on tissue morphology, protein recovery, and immunoreactivity for a selected panel of proteins differently expressed in lung cancer, using immunohistochemistry and Western blotting.

RESULTS

Tumor-cell analysis with hematoxylin-eosin worked equally well for all tested fixatives when compared with the standard formalin-fixed, paraffin-embedded procedure. Movat pentachrome stains showed comparable results for the different matrices and cellular proteins analyzed. The RCL2 (P = .01) and HOPE fixatives (P = .03) improved protein recovery when compared with formalin-fixed, paraffin-embedded or frozen tissues. Our data clearly show that the fixatives evaluated influenced immunoreactivity to matched, formalin-fixed, paraffin-embedded lung cancer tissue. In particular, membrane-bound proteins, such as epidermal growth factor receptor EGFR, can be detected more efficiently by immunohistochemistry and Western blotting.

CONCLUSION

We have demonstrated that formalin-free fixatives have the potential in routine pathology and research to replace formalin in histomorphology and protein preservation.

MicroRNA expression and clinical outcomes in patients treated with adjuvant chemotherapy after complete resection of non-small cell lung carcinoma

This study determined whether expression levels of a panel of biologically relevant microRNAs can be used as prognostic or predictive biomarkers in patients who participated in the International Adjuvant Lung Cancer Trial (IALT), the largest randomized study conducted to date of adjuvant chemotherapy in patients with radically resected non-small cell lung carcinoma (NSCLC). Expression of miR-21, miR-29b, miR-34a/b/c, miR-155, and let-7a was determined by quantitative real-time PCR in formalin-fixed paraffin-embedded tumor specimens from 639 IALT patients. The prognostic and predictive values of microRNA expression for survival were studied using a Cox model, which included every factor used in the stratified randomization, clinicopathologic prognostic factors, and other factors statistically related to microRNA expression. Investigation of the expression pattern of microRNAs in situ was performed. We also analyzed the association of TP53 mutation status and miR-34a/b/c expression, epidermal growth factor receptor and KRAS mutation status, and miR-21 and Let-7a expression. Finally, the association of p16 and miR-29b expression was assessed. Overall, no significant association was found between any of the tested microRNAs and survival, with the exception of miR-21 for which a deleterious prognostic effect of lowered expression was suggested. Otherwise, no single or combinatorial microRNA expression profile predicted response to adjuvant cisplatin-based chemotherapy. Together, our results indicate that the microRNA expression patterns examined were neither predictive nor prognostic in a large patient cohort with radically resected NSCLC, randomized to receive adjuvant cisplatin-based chemotherapy versus follow-up only.

Epithelial Repair and Regeneration

Contact with the environment positions the respiratory epithelium at risk for acute and chronic injury from infectious pathogens, noxious agents, and inflammatory processes. Thus, to protect gas transfer within the lung the epithelium is programmed for routine maintenance and repair. Programs for repair are directed by epithelial, mesenchymal, and inflammatory signals that collectively constitute highly regulated networks. Principal components of the repair network are developmental morphogens, integrin and growth factor signaling molecules, and transcription factors. The epithelium responds to these signals with a remarkable plasticity and is bulwarked by a population of lung progenitor cells to ensure maintenance and repair for fluid balance and host defense functions.

Abstract 2995: MicroRNA expression and outcome of adjuvant chemotherapy in patients with completely resected non-small cell lung cancer: International Adjuvant Lung Cancer Trial Biologic Program (IALT-Bio)

The aim of our study was to assess whether expression levels of a panel of biologically relevant microRNAs can be used as prognostic and/or predictive biomarkers in patients who participated in the International Adjuvant Lung Cancer Trial (IALT), the largest randomized study conducted so far of adjuvant chemotherapy in patients with radically resected NSCLC stage I-III.

Expression of miR-21, miR-29b, miR-34a/b/c, miR-155 and Let-7a was determined by quantitative real-time PCR in paraffin embedded formalin fixed tumor specimens from 639 IALT patients, using small nuclear RNA U66 as the endogenous normalization control. From 79 patients sufficient tumor adjacent normal tissue was available as well. The prognostic and predictive value of microRNA expression and chemotherapy for survival were studied using a Cox model, which included every factor used in the stratified randomization plus clinical and histological prognostic factors as well as other factors statistically related to microRNA expression. Association of p53 mutation status and miR-34a/b/c expression was analyzed, as well as association of EGFR and K-Ras mutation status with miR-21 and Let-7a expression, respectively. Finally association of p16 and miR-29b expression was assessed. In situ hybridization was performed for validation and to determine histological expression patterns.

Overall, we found that there was no significant association between the expression profile of any of the tested microRNAs and survival. However, for miR-21, miR-34b and miR-34c, there is a suggested deleterious prognostic effect of lower values on survival. No single microRNA expression profile or a combination of microRNA expression profiles, as determined by cluster analysis, predicted response to adjuvant cisplatin-based chemotherapy.

Concluding, expression levels of the tested microRNAs were neither predictive nor prognostic in this patient cohort.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2995.

An Integrative Approach for Analyzing the Interplay of Genetic and Epigenetic Changes in Tumors

The accumulation of chromosomal aberrations is a characteristic feature of tumor development. However, an understanding of tumorigenesis that assumes that changes in DNA copy number always cause equivalent changes in the corresponding RNA and protein levels is an oversimplification and completely ignores the individual genetic and epigenetic context in which an aberration has to be evaluated. We present a brief introduction to various techniques dedicated to the genome-wide analysis of genetic and epigenetic changes, and illustrate how complementary information derived from these various DNA array-based technologies can lead to a better understanding of the consequences of chromosomal aberrations.

Multidrug resistance proteins do not predict benefit of adjuvant chemotherapy in patients with completely resected non-small cell lung cancer: International Adjuvant Lung Cancer Trial Biologic Program

PURPOSE

The purpose of our study was to determine whether multidrug resistance proteins (MRP) are of prognostic and/or predictive value in patients who were enrolled into the International Adjuvant Lung Cancer Trial (IALT).

EXPERIMENTAL DESIGN

Expression of MRP1 and MRP2 was immunohistochemically assessed in tumor specimens obtained from 782 IALT patients. Prognostic and predictive analyses were based on Cox models adjusted for clinical and pathologic variables.

RESULTS

MRP1 expression was considered positive in 364 (47%) patients and MRP2 expression in 313 (40%) patients. MRP2-positive patients had a significantly shorter overall survival than MRP2-negative patients in the total patient population [adjusted hazard ratio for death, 1.37; 95% confidence interval (95% CI), 1.09-1.72; P = 0.007]. There was no significant association between MRP1 expression and overall survival. Neither MRP1 nor MRP2 predicted response to adjuvant cisplatin-based chemotherapy.

CONCLUSIONS

MRP2 expression is an independent prognostic factor in patients with completely resected non-small cell lung cancer but neither MRP1 nor MRP2 was of predictive value in patients enrolled into the IALT.

Cell cycle regulators and outcome of adjuvant cisplatin-based chemotherapy in completely resected non-small-cell lung cancer: the International Adjuvant Lung Cancer Trial Biologic Program

PURPOSE

The International Adjuvant Lung Cancer Trial (IALT) demonstrated that adjuvant cisplatin-based chemotherapy improves the survival of patients with completely resected non-small-cell lung cancer (NSCLC). The purpose of our study was to determine whether cell cycle regulators are of prognostic and/or predictive value in patients who were enrolled onto the IALT.

PATIENTS AND METHODS

Expression of p27Kip1, p16INK4A, cyclin D1, cyclin D3, cyclin E, and Ki-67 was immunohistochemically assessed in tumor specimens obtained from 778 IALT patients. Prognostic and predictive analyses were based on Cox models adjusted for clinical and pathologic parameters.

RESULTS

There was a relationship between p27Kip1 status and benefit of cisplatin-based chemotherapy (test for interaction, P = .02). Among patients with p27Kip1-negative tumors, cisplatin-based chemotherapy resulted in longer overall survival compared with controls (adjusted hazard ratio [HR] for death = 0.66; 95% CI, 0.50 to 0.88; P = .006). In patients with p27Kip1-positive tumors, overall survival was not different between patients treated with cisplatin-based chemotherapy and controls (adjusted HR for death = 1.09; 95% CI, 0.82 to 1.45; P = .54). The other cell cycle regulators and Ki-67 did not predict benefit of adjuvant cisplatin-based chemotherapy. None of these biomarkers was significantly associated with overall survival of the patients in the total study population.

CONCLUSION

NSCLC patients with p27Kip1-negative tumors benefit from adjuvant cisplatin-based chemotherapy after complete tumor resection. Before establishing p27Kip1 as a routine marker for selection of patients for adjuvant chemotherapy, the predictive value of p27Kip1 has to be confirmed in patients from other trials.

Pleuropulmonary desmoid tumors: immunohistochemical comparison with solitary fibrous tumors and assessment of beta-catenin and cyclin D1 expression

CONTEXT

Desmoid tumors arising in the lung and pleura are extremely rare and can resemble other, more common neoplasms native to these sites. Alterations of the adenomatous polyposis coli/beta-catenin pathway have been detected in sporadic desmoid tumors and have been associated with nuclear accumulation of beta-catenin and overexpression of cyclin D1.

OBJECTIVE

To analyze the expression of beta-catenin and cyclin D1 in desmoid tumors and solitary fibrous tumors (SFTs), and to compare the utilities of these substances for distinguishing between these entities with those of other, more commonly used stains.

DESIGN

Formalin-fixed, paraffin-embedded sections of 4 desmoid tumors (1 pulmonary, 1 pleural, 2 pleural/chest wall), and 5 benign and 6 malignant SFTs of the pleura were immunostained for beta-catenin, cyclin D1, ALK1, CD34, vimentin, desmin, smooth muscle actin, muscle-specific actin, S100, and pancytokeratin. Staining intensity and the percentage of stained tumor cells were assessed semiquantitatively.

RESULTS

Diffuse moderate or strong nuclear staining for beta-catenin was found in all desmoid tumors, 4 of 5 benign SFTs, and 2 of 6 malignant SFTs. All cases except 1 benign SFT showed concurrent cytoplasmic staining. Nuclear and cytoplasmic cyclin D1 staining was increased in all groups. The best distinction between desmoid tumors and SFTs was provided by CD34 (desmoid tumors, 0/4; SFTs, 8/11) and smooth muscle actin (desmoid tumors, 4/4; SFTs, 0/11).

CONCLUSIONS

Our findings suggest that alterations in the adenomatous polyposis coli/beta-catenin pathway and cyclin D1 dysregulation may contribute to the pathogenesis of pleuropulmonary desmoid tumors and SFTs. CD34 and smooth muscle actin stains are particularly useful for differentiating between pleuropulmonary desmoid tumors and SFTs.

Enhanced proliferation and decreased apoptosis in lung lavage cells of sarcoidosis patients

BACKGROUND

Sarcoidosis is a systemic autoimmune disease where an inflammatory reaction involving alveolar macrophages, T-helper lymphocytes, and epitheloid cells is mounted against unknown antigens. A genetic predisposition for sarcoidosis is supposed by studies in twins, by geographical and racial distribution. In the current investigation we compared the expression patterns between slow onset and acute sarcodosis using a whole-genome cDNA array.

METHODS

Bronchoalveolar lavage was performed in six patients with slow onset sarcoidosis and four patients with acute sarcoidosis (Löfgren's disease) and obtained cells were used for gene expression profiling. The results were confirmed by RT- and Taqman-PCR. In addition, protein expression was examined on paraffin sections of sarcoid granulomas by immunohistochemistry.

RESULTS

In T-helper lymphocytes and alveolar macrophages we found an upregulation of genes belonging to the phosphoinositol-3-kinase/v-akt murine thymoma viral oncogene homolog/signal transducer and activator of transcription 3 pathway, as well as a downregulation of genes of the extrinsic and intrinsic apoptotic signaling cascades. In addition an upregulation of the genes encoding fatty acid binding protein 4 and 5, as well as peroxisome proliferative activated receptor delta in Löfgren's disease was detected. Differences in gene expression between slow onset sarcoidosis and Löfgren's syndrome were found mainly within genes of the major histocompatibility complex.

CONCLUSIONS

In sarcoidosis enhanced cell proliferation and decreased apoptosis result in accumulation and prolonged survival of antigen-primed T-helper lymphocytes and activated macrophages. This is enhanced in Löfgren's disease, probably by hyper-stimulation via the peroxisome proliferation signaling, providing a larger pool of antigen-primed immune cells.

DNA repair by ERCC1 in non-small-cell lung cancer and cisplatin-based adjuvant chemotherapy

BACKGROUND

Adjuvant cisplatin-based chemotherapy improves survival among patients with completely resected non-small-cell lung cancer, but there is no validated clinical or biologic predictor of the benefit of chemotherapy.

METHODS

We used immunohistochemical analysis to determine the expression of the excision repair cross-complementation group 1 (ERCC1) protein in operative specimens of non-small-cell lung cancer. The patients had been enrolled in the International Adjuvant Lung Cancer Trial, thereby allowing a comparison of the effect of adjuvant cisplatin-based chemotherapy on survival, according to ERCC1 expression. Overall survival was analyzed with a Cox model adjusted for clinical and pathological factors.

RESULTS

Among 761 tumors, ERCC1 expression was positive in 335 (44%) and negative in 426 (56%). A benefit from cisplatin-based adjuvant chemotherapy was associated with the absence of ERCC1 (test for interaction, P=0.009). Adjuvant chemotherapy, as compared with observation, significantly prolonged survival among patients with ERCC1-negative tumors (adjusted hazard ratio for death, 0.65; 95% confidence interval [CI], 0.50 to 0.86; P=0.002) but not among patients with ERCC1-positive tumors (adjusted hazard ratio for death, 1.14; 95% CI, 0.84 to 1.55; P=0.40). Among patients who did not receive adjuvant chemotherapy, those with ERCC1-positive tumors survived longer than those with ERCC1-negative tumors (adjusted hazard ratio for death, 0.66; 95% CI, 0.49 to 0.90; P=0.009).

CONCLUSIONS

Patients with completely resected non-small-cell lung cancer and ERCC1-negative tumors appear to benefit from adjuvant cisplatin-based chemotherapy, whereas patients with ERCC1-positive tumors do not.