Immune response in lung cancer mouse model mimics human anti-Hu reactivity

Prognostic value of the common tumour-infiltrating lymphocyte subtypes for patients with non-small cell lung cancer: A meta-analysis

Background

Many previous studies have revealed that tumour-infiltrating lymphocytes (TILs) are significantly associated with prognosis in various tumours. However, this finding remains controversial in non-small cell lung cancer (NSCLC). We performed this meta-analysis systematically to evaluate the prognostic value of TILs in NSCLC.

Methods

The references were collected by searching the PubMed, EMBASE and Web of Science databases. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were summarized using random or fixed effects models to evaluate the association between TILs and NSCLC survival outcomes.

Results

A total of 45 interrelated studies were eligible that included 11,448 patients. Pooled analysis showed that a high density of TILs indicated a better overall survival (HR = 0.80, 0.70–0.89) and progression-free survival (HR = 0.73, 0.61–0.85) for patients with NSCLC; a high density of CD3+ TILs in the tumour nest indicated a better overall survival (HR = 0.84, 0.69–0.99) and disease-specific survival (HR = 0.57, 0.34–0.80); a high density of CD4+ TILs in the tumor nest indicated a favourable overall survival (HR = 0.86, 0.76–0.96); a high density of CD8+ TILs indicated a favourable overall survival (HR = 0.995, 0.99–1.0), progression-free survival (HR = 0.52, 0.34–0.71), disease-free survival (HR = 0.64, 0.43–0.85), relapse/recurrence-free survival (HR = 0.42, 0.18–0.67) and disease-specific survival (HR = 0.56, 0.35–0.78); and a high density of CD20+ TILs in the tumour nest indicated a favourable overall survival (HR = 0.65, 0.36–0.94). However, a high density of Foxp3+ TILs in the tumour stroma indicated a worse relapse/recurrence-free survival (HR = 1.90, 1.05–2.76) in NSCLC.

Conclusions

Our meta-analysis confirmed that high densities of TILs, CD3+TILs, CD4+TILs, CD8+TILs and CD20+TILs in the tumour nest are favourable prognostic biomarkers for patients with NSCLC, and Foxp3+TILs in the tumour stroma are a poor prognostic biomarker.

Synchronous Adie's syndrome and type 1 antineuronal nuclear antibody (anti-Hu)-related paraneoplastic neurological syndromes as predictors of complete response in limited-stage small-cell lung cancer: A case report

Adie's syndrome (AS) and paraneoplastic sensorimotor neuropathy with cerebellar ataxia (PSN CA) are extremely rare, rapidly progressive, autoimmune diseases associated with the development of antibodies against neuronal-specific Hu proteins that are abnormally expressed in small-cell lung cancer (SCLC). We herein present the unique case of a 55-year-old obese woman, previous heavy smoker, who, during treatment with standard cisplatin-etoposide chemotherapy for limited-stage SCLC, developed simultaneous AS and worsening symptoms consistent with PSN CA that led to significant neurological disability and severe axonal electrophysiological pattern on nerve conduction studies. Serology confirmed the presence of low-titre type 1 antineuronal nuclear antibodies (ANNA-1), previously referred to as anti-Hu antibodies. Following plasmapheresis, immunosuppressive therapy and physical rehabilitation, the neurological symptoms progressively improved. The tumour completely regressed, with no recurrence detected on subsequent radiological examinations. The aim of this case was to highlight the importance of a multidisciplinary team approach for early recognition and rapid treatment of paraneoplastic neurological syndromes (PNS) as key to achieving significant recovery and marked improvement of the neurological deficit. This report extends the literature by confirming earlier studies showing that the presence of serum ANNA-1 in SCLC, an aggressive type of pulmonary carcinoma that is challenging to treat, may portend a more favourable prognosis and response to chemotherapy. Thus, patients with SCLC and new-onset neurological symptoms should be tested for ANNA-1. The role of a multimodality approach to treating PNS is also emphasized.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature: Part 3: Neurological paraneoplastic syndromes, involving the central nervous system

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes that can complicate lung cancer appears useful. This article is the third of a series of five and deals mainly with neurological paraneoplastic syndromes involving the central nervous system.

Isoaspartylation appears to trigger small cell lung cancer-associated autoimmunity against neuronal protein ELAVL4

Autoantibodies against SCLC-associated neuronal antigen ELAVL4 (HuD) have been linked to smaller tumors and improved survival, but the antigenic epitope and mechanism of autoimmunity have never been solved. We report that recombinant human ELAVL4 protein incubated under physiological conditions acquires isoaspartylation, a type of immunogenic protein damage. Specifically, the N-terminal region of ELAVL4, previously implicated in SCLC-associated autoimmunity, undergoes isoaspartylation in vitro, is recognized by sera from anti-ELAVL4 positive SCLC patients and is highly immunogenic in subcutaneously injected mice and in vitro stimulated human lymphocytes. Our data suggest that isoaspartylated ELAVL4 is the trigger for the SCLC-associated anti-ELAVL4 autoimmune response.

Paraneoplastic Hu and CRMP5 antibodies are present in smokers without cancer or neurological disease

BACKGROUND AND OBJECTIVE

We investigated if the paraneoplastic Hu and collapsin response mediator protein 5 (CRMP5) antibodies could be used as early markers for lung cancer in smokers with or without chronic obstructive pulmonary disease (COPD).

METHODS

Hu and CRMP5 antibodies were measured by radioimmunoprecipitation assay (RIPA) in sera from 552 smokers; 379 with and 173 without COPD. Three hundred blood donors served as controls. The positive sera were also tested by indirect immunofluorescence and line blot with recombinant proteins. The 552 smokers were matched with data from the Cancer Registry of Norway, and the hospital medical records from the subjects positive for Hu and CRMP5 antibodies were reviewed. The mean follow-up time was 4.4 years (range 2.5-5.7 years).

RESULTS

The RIPA showed that 5/379 (1.3%) smokers with COPD had Hu antibodies and 1/379 (0.3%) smokers with COPD had CRMP5 antibodies. Only the smoker with the highest RIPA index had Hu antibodies also detected by immunofluorescence and line blot. One of 173 (0.6%) smokers without COPD had Hu antibodies, but none had CRMP5 antibodies. None of the 300 controls had Hu antibodies, but 2/300 (0.7%) had CRMP5 antibodies. Hu antibodies remained positive for more than 5 years. No cancer or neurological disease was recorded in the Hu or CRMP5 positive patients. The total cancer frequency in the smokers with and without COPD was 70/552 (13%).

CONCLUSIONS

Hu and CRMP5 antibodies were not associated with cancer or neurological disease in a large cohort of smokers and are therefore not always paraneoplastic.

Animal models of autoimmune neuropathy

The peripheral nervous system (PNS) comprises the cranial nerves, the spinal nerves with their roots and rami, dorsal root ganglia neurons, the peripheral nerves, and peripheral components of the autonomic nervous system. Cell-mediated or antibody-mediated immune attack on the PNS results in distinct clinical syndromes, which are classified based on the tempo of illness, PNS component(s) involved, and the culprit antigen(s) identified. Insights into the pathogenesis of autoimmune neuropathy have been provided by ex vivo immunologic studies, biopsy materials, electrophysiologic studies, and experimental models. This review article summarizes earlier seminal observations and highlights the recent progress in our understanding of immunopathogenesis of autoimmune neuropathies based on data from animal models.

Immunopathogenesis of paraneoplastic neurological syndromes associated with anti-Hu antibodies: A beneficial antitumor immune response going awry

Paraneoplastic neurological disorders (PNDs) are syndromes that develop in cancer patients when an efficient antitumor immune response, directed against antigens expressed by both malignant cells and healthy neurons, damages the nervous system. Herein, we analyze existing data on the mechanisms of loss of self tolerance and nervous tissue damage that underpin one of the most frequent PNDs, the anti-Hu syndrome. In addition, we discuss future directions and propose potential strategies aimed at blocking deleterious encephalitogenic immune responses while preserving the antineoplastic potential of treatment.

Serum markers in small cell lung cancer: opportunities for improvement

Lung cancer is one of the leading causes of death from malignancy worldwide. In particular small cell lung cancers, which comprise about 15-20% of all lung cancers, are extremely aggressive and cure rates are extremely low. Therefore, new treatment modalities are needed and detection at an early stage of disease, as well as adequate monitoring of treatment response is essential in order to improve outcome. In this respect, the use of non-invasive tools for screening and monitoring has gained increasing interest and the clinical applicability of reliable, tumor-related substances that can be detected as tumor markers in easily accessible body fluids is subject of intense investigation. Some of these indicators, such as high LDH levels in serum as a reflection of the disease, have been in use for a long time as a general tumor marker. To allow for improved monitoring of the efficacy of new therapeutic modalities and for accurate subtyping, there is a strong need for specific and sensitive markers that are more directly related to the biology and behavior of small cell lung cancer. In this review the current status of these potential markers, like CEA, NSE, ProGRP, CK-BB, SCC, CgA, NCAM and several cytokeratins will be critically analyzed with respect to their performance in blood based assays. Based on known cleavage sites for cytoplasmic and extracellular proteases, a prediction of stable fragments can be obtained and used for optimal test design. Furthermore, insight into the synthesis of specific splice variants and neo-epitopes resulting from protein modification and cleavage, offers further opportunities for improvement of tumor assays. Finally, we discuss the possibility that detection of SCLC related autoantibodies in paraneoplastic disease can be used as a very early indicator of SCLC.

Neuronal autoantigens--pathogenesis, associated disorders and antibody testing

The discovery of disorders that are associated with antibodies to neuronal cell-surface proteins has led to a paradigm shift in our understanding of CNS autoimmunity. These disorders can occur in patients with or without cancer-often children or young adults who develop psychosis, catatonic or autistic features, memory problems, abnormal movements, or seizures that were previously considered idiopathic. The autoantigens in such cases have crucial roles in synaptic transmission, plasticity and peripheral nerve excitability. Patients can be comatose or encephalopathic for months and yet fully recover with supportive care and immunotherapy. By contrast, disorders in which the antibodies target intracellular antigens, and in which T-cell-mediated irreversible neuronal degeneration occurs, show a considerably poorer response to treatment. In this article, we review the various targets of neuronal antibodies, focusing predominantly on autoantigens located on the cell surface or synapses-namely, N-methyl-D-aspartate receptors, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, γ-aminobutyric acid receptors, leucine-rich glioma-inactivated protein 1, contactin-associated protein-like 2, and metabotropic glutamate receptors. We also provide an algorithm to identify and assess antibodies that bind to cell-surface and synaptic antigens.

Identification of continuous epitopes of HuD antibodies related to paraneoplastic diseases/small cell lung cancer

HuD antibodies are associated with small cell lung cancer. To identify relevant epitopes of HuD antibodies, patient sera and a monoclonal antibody were analyzed for their reactivity to linear 20mer peptides spanning the human HuD protein. The HuD monoclonal antibody recognized a single fragment located in the first RNA recognition motif. Thorough analysis identified VRDKITQGSL as the actual epitope. Screening of anti-HuD positive patients and healthy controls identified eight peptides as potential subdominant epitopes. The majority of these peptides were located in the N-terminal end as well as in the linker region between the second and third RNA recognition motifs.

Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy

Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.

Paraneoplastic neurological disorders

The article provides an overview on the diagnosis and pathogenesis of paraneoplastic neurological disorders (PNDs), and subsequently the current therapeutic strategies in these patients. PNDs are nervous system dysfunctions in cancer patients, which are not due to a local effect of the tumor or its metastases. Most of these clinically defined syndromes in adults are associated with lung cancer, especially small-cell lung cancer, lymphoma and gynecological tumors. In a part of the PND, an overlapping of different clinical syndromes can be observed. Highly specific autoantibodies directed against onconeuronal antigens led to the current hypothesis of an autoimmune pathophysiology. Whereas the most central nervous PNDs are more T-cell-mediated, limbic encephalitis can be caused by pathogenic receptor autoantibodies. The PND of the neuromuscular junction and paraneoplastic autonomic neuropathy are mainly associated with receptor or ion channel autoantibodies. The childhood opsoclonus-myoclonus syndrome and the PNDs associated with receptor/ion channel autoantibodies often respond to immunosuppressive therapies, plasmapheresis and intravenous immunoglobulins. By contrast, most CNS PNDs associated with defined antineuronal antibodies directed against intracellular antigens only stabilize after tumor treatment.

A functional role for tumor cell heterogeneity in a mouse model of small cell lung cancer

Small cell lung cancer (SCLC) is the lung neoplasia with the poorest prognosis, due to its high metastatic potential and chemoresistance upon relapse. Using the previously described mouse model for SCLC, we found that the tumors are often composed of phenotypically different cells with either a neuroendocrine or a mesenchymal marker profile. These cells had a common origin because they shared specific genomic aberrations. The transition from neuroendocrine to mesenchymal phenotype could be achieved by the ectopic expression of oncogenic Ras(V12). Crosstalk between mesenchymal and neuroendocrine cells strongly influenced their behavior. When engrafted as a mixed population, the mesenchymal cells endowed the neuroendocrine cells with metastatic capacity, illustrating the potential relevance of tumor cell heterogeneity in dictating tumor properties.