Serum neuron-specific enolase: a marker for disease extent and response to therapy of small-cell lung cancer

Immunoaffinity Intact-Mass Spectrometry for the Detection of Endogenous Concentrations of the Acetylated Protein Tumor Biomarker Neuron Specific Enolase

Intact-mass spectrometry has huge potential for clinical application, as it enables both quantitative and qualitative analysis of intact proteins and possibly unlocks additional pathophysiological information via, e.g., detection of specific post-translational modifications (PTMs). Such valuable and clinically useful selectivity is typically lost during conventional bottom-up mass spectrometry. We demonstrate an innovative immunoprecipitation protein enrichment assay coupled to ultrahigh performance liquid chromatography quadrupole time-of-flight high resolution mass spectrometry (UPLC-QToF-HRMS) for the fast and simple identification of the protein tumor marker Neuron Specific Enolase Gamma (NSEγ) at low endogenous concentrations in human serum. Additionally, using the combination of immunoaffinity purification with intact mass spectrometry, the presence of NSEγ in an acetylated form in human serum was detected. This highlights the unique potential of immunoaffinity intact mass spectrometry in clinical diagnostics.

Label-Free Assessment of Neuron-Specific Enolase via Polydopamine over a Carbon-Nanotube-Based Flexible Immunosensor

A label-free electrochemical immunosensor was developed for the rapid and sensitive detection of neuron-specific enolase (NSE). The electropolymerization of dopamine in conjunction with highly conductive carbon nanotubes offers a simple and quick platform for the direct anchoring of antibodies without the assistance of any coupling agent as well as a blocking agent. The developed immunosensor exhibited a wider detection range from 120 pM (9 ng mL-1) to 3 nM (200 ng mL-1) for NSE with a high sensitivity of 3.9 μA pM-1 cm-2 in 0.1 M phosphate-buffered saline (PBS) at physiological pH (7.4). Moreover, the short recognition time (15 min) for the antigen enabled the detection to be fast and less invasive. Additionally, the evaluation of a rate constant at various concentrations of NSE via feedback mode of scanning electrochemical microscopy (SECM) explained the profound effect of antigen concentration on the rate of flow of electrons. Therefore, the proposed immunosensor can be a promising tool for the early detection of small cell lung cancer in a very short period of time with consistent accuracy.

Crosstalk between small-cell lung cancer cells and astrocytes mimics brain development to promote brain metastasis

Brain metastases represent an important clinical problem for patients with small-cell lung cancer (SCLC). However, the mechanisms underlying SCLC growth in the brain remain poorly understood. Here, using intracranial injections in mice and assembloids between SCLC aggregates and human cortical organoids in culture, we found that SCLC cells recruit reactive astrocytes to the tumour microenvironment. This crosstalk between SCLC cells and astrocytes drives the induction of gene expression programmes that are similar to those found during early brain development in neurons and astrocytes. Mechanistically, the brain development factor Reelin, secreted by SCLC cells, recruits astrocytes to brain metastases. These astrocytes in turn promote SCLC growth by secreting neuronal pro-survival factors such as SERPINE1. Thus, SCLC brain metastases grow by co-opting mechanisms involved in reciprocal neuron-astrocyte interactions during brain development. Targeting such developmental programmes activated in this cancer ecosystem may help prevent and treat brain metastases.

Post-translational modifications and their implications in cancer

Post-translational modifications (PTMs) are crucial regulatory mechanisms that alter the properties of a protein by covalently attaching a modified chemical group to some of its amino acid residues. PTMs modulate essential physiological processes such as signal transduction, metabolism, protein localization, and turnover and have clinical relevance in cancer and age-related pathologies. Majority of proteins undergo post-translational modifications, irrespective of their occurrence in or after protein biosynthesis. Post-translational modifications link to amino acid termini or side chains, causing the protein backbone to get cleaved, spliced, or cyclized, to name a few. These chemical modifications expand the diversity of the proteome and regulate protein activity, structure, locations, functions, and protein-protein interactions (PPIs). This ability to modify the physical and chemical properties and functions of proteins render PTMs vital. To date, over 200 different protein modifications have been reported, owing to advanced detection technologies. Some of these modifications include phosphorylation, glycosylation, methylation, acetylation, and ubiquitination. Here, we discuss about the existing as well as some novel post-translational protein modifications, with their implications in aberrant states, which will help us better understand the modified sites in different proteins and the effect of PTMs on protein functions in core biological processes and progression in cancer.

Analysis of Neuron-Specific enolase isozymes in human serum using immunoaffinity purification and liquid chromatography-tandem mass spectrometry quantification

Neuron-specific enolase (NSE) is a promising small-cell lung cancer (SCLC) biomarker composed of αγ and γγ isozyme dimers. As the conventional immunoassays are prone to interferences and cannot differentiate between the isozymes, we developed a multiplex immunoaffinity (IA) liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the quantification of NSEα and NSEγ in human serum. A calibrator was prepared by performing cold denaturation of recombinantly expressed αα and γγ enolase dimers to induce a new dimer equilibrium that was determined to be approximately 1αγ:1γγ:1αα. Selective sample purification was achieved by performing IA extraction using an antibody specific towards NSEγ. The isolated αγ and γγ dimers were denatured and trypsin digested to allow quantification of the selected signature peptides and their corresponding isotopically labelled peptide internal standard. The obtained linear dynamic ranges were determined to be 1.5-56 ng/mL and 0.64-167 ng/mL for NSEα and NSEγ (R² = 0.88 and 0.97 respectively). Validation of the assay showed acceptable accuracy and precision for NSEα and NSEγ. The method was successfully applied to patient serum in which both isozymes were detected. Compared to the conventional immunoassay, substantially lower total NSE concentrations were measured in IA LC-MS/MS. With this multiplex IA LC-MS/MS assay, the clinical value of quantifying the individual isozymes can be explored. In addition, together with the calibrator described here, it may be applied to standardize NSE immunoassays across different platforms.

Protein acylation: mechanisms, biological functions and therapeutic targets

Metabolic reprogramming is involved in the pathogenesis of not only cancers but also neurodegenerative diseases, cardiovascular diseases, and infectious diseases. With the progress of metabonomics and proteomics, metabolites have been found to affect protein acylations through providing acyl groups or changing the activities of acyltransferases or deacylases. Reciprocally, protein acylation is involved in key cellular processes relevant to physiology and diseases, such as protein stability, protein subcellular localization, enzyme activity, transcriptional activity, protein-protein interactions and protein-DNA interactions. Herein, we summarize the functional diversity and mechanisms of eight kinds of nonhistone protein acylations in the physiological processes and progression of several diseases. We also highlight the recent progress in the development of inhibitors for acyltransferase, deacylase, and acylation reader proteins for their potential applications in drug discovery.

Untargeted metabolomics and lipidomics identified four subtypes of small cell lung cancer

INTRODUCTION

Small cell lung cancer (SCLC) is a heterogeneous malignancy with dismal prognosis. However, few studies have conducted on the metabolic heterogeneity in SCLC.

OBJECTIVE

We therefore identify SCLC classifications using untargeted metabolomics and lipidomics. We also compared their survival and the immunotherapy responses.

METHODS

Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (LC-MS/MS) analysis was performed in 191 SCLC serum samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was conducted to identify metabolic pathways. The Kaplan-Meier and log-rank test were used to analyze the survival curves. The univariate and multivariate Cox proportional hazards regression models were used to evaluate prognostic factors for OS in patients with SCLC.

RESULTS

Distinct subtypes of SCLC were identified by consensus clustering algorithm using partioning around medoids (pam) based on untargeted metabolomics and lipidomics. Four distinct subtypes of SCLC were identified, with distinct metabolic pathways. Subgroup 2 had the longest survival whereas Subgroup 1 had the shortest. Subtype 2 benefited most from immunotherapy in OS, as in contrast to Subtype 3 with shortest survival.

CONCLUSION

Our study revealed the metabolic heterogeneity in SCLC and identified four subtypes with distinct metabolic features. It indicates promising therapeutic and prognostic value that may guide treatment for SCLC. The subtype-specific clinical trials may be designed and would be instructive for drug development.

Metastatic small-cell carcinoma of the bladder that maintains a complete response to chemoradiation therapy

Introduction

Small-cell carcinoma of the urinary bladder has a poor prognosis, and no standard treatment has been established. We encountered a case of a patient with metastasis in which complete response and long-term survival were obtained by treating the primary lesion with a combination of irinotecan, carboplatin chemotherapy, and radiation therapy.

Case presentation

An 83-year-old man was diagnosed with a bladder tumor with liver metastasis. Small-cell carcinoma was diagnosed via transurethral resection. Second-line chemotherapy with irinotecan and carboplatin and irradiation of the primary lesion were significantly effective. The imaging evaluation showed a complete response. The therapeutic effect was maintained for 1 year, even after the discontinuation of chemotherapy.

Conclusion

Irinotecan and carboplatin should be considered for the treatment of small-cell carcinoma of the bladder. Irradiation of the primary lesion may also be useful if the extent of metastasis is low.

ENO2 Promotes Colorectal Cancer Metastasis by Interacting with the LncRNA CYTOR and Activating YAP1-Induced EMT

The glycolytic enzyme enolase 2 (ENO2) is dysregulated in many types of cancer. However, the roles and detailed molecular mechanism of ENO2 in colorectal cancer (CRC) metastasis remain unclear. Here, we performed a comprehensive analysis of ENO2 expression in 184 local CRC samples and samples from the TCGA and GEO databases and found that ENO2 upregulation in CRC samples was negatively associated with prognosis. By knocking down and overexpressing ENO2, we found that ENO2 promoted CRC cell migration and invasion, which is dependent on its interaction with the long noncoding RNA (lncRNA) CYTOR, but did not depend on glycolysis regulation. Furthermore, CYTOR mediated ENO2 binding to large tumor suppressor 1 (LATS1) and competitively inhibited the phosphorylation of Yes-associated protein 1 (YAP1), which ultimately triggered epithelial–mesenchymal transition (EMT). Collectively, these findings highlight the molecular mechanism of the ENO2–CYTOR interaction, and ENO2 could be considered a potential therapeutic target for CRC.

Role of Neuron-Specific Enolase in the Diagnosis and Disease Monitoring of Sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology. The diagnosis of sarcoidosis is based on clinicopathologic findings accompanied by the formation of granulomas in multiple organs, including the lung. Although angiotensin-converting enzyme (ACE) and soluble interleukin 2 receptor (sIL-2R) are traditionally used for the diagnosis of sarcoidosis, specific diagnostic markers remain to be determined. In the current study, we found that serum neuron-specific enolase (NSE) levels were elevated in patients with sarcoidosis. Serum NSE levels were positively correlated with serum ACE and sIL-2R levels. The sensitivity of NSE alone was modest, but its combination with sIL-2R and ACE had the highest sensitivity compared to those of each single marker. When comparing serum NSE and pro-gastrin-releasing peptide (ProGRP) levels in SCLC patients with those in patients with sarcoidosis and nonsarcoidotic benign diseases, serum NSE could be used to distinguish SCLC from sarcoidosis and nonsarcoidosis by setting at a cutoff value of 17.0 ng/ml with a sensitivity of 73.5% and a specificity of 90.2%, which were comparable to those of ProGRP. Serum NSE levels were associated with organ involvement and were higher in sarcoidosis patients who had been treated with oral corticosteroid (OCS) than in those who had never received OCS therapies; there was a positive association between elevated serum NSE levels and OCS use. Increased concentrations of serum NSE in patients at the nonremission phase decreased after spontaneous remission, whereas serum NSE levels fluctuated in accordance with serum ACE or sIL-2R levels during the follow-up period in patients with sarcoidosis. These findings suggest that NSE could be a marker for the diagnosis and monitoring of the clinical outcome of patients with sarcoidosis.

Anti-alpha enolase multi-antibody specificity in human diseases. Clinical significance and molecular mechanisms

Alpha-enolase (Eno) is an ubiquitary glycolytic enzyme playing multiple functions that go well beyond its principal metabolic role of energy supplier during glycolysis. Eno is localized in the cytoplasm, but also expressed on the cell membrane, where it binds plasminogen allowing its activation. Its shorter form, in the nucleus, acts as transcription factor. In inflammatory conditions, Eno undergoes post-translational modifications, such as citrullination, oxidation and phosphorylation. Eno is also an autoantigen in different disorders. In fact, autoantibodies to Eno have been detected in rheumatoid arthritis, lupus nephritis, primary glomerulonephritis, cancer, infections and other disorders, and in many cases they represent specific markers to be utilized in clinical practice. Anti-Eno antibodies in the different clinical conditions are not equal: they differ in isotype and often recognize different epitopes on the enzyme. IgG1 and IgG3 are prevalent in Rheumatoid Arthritis, IgG2 in Lupus nephritis and IgG4 in primary autoimmune glomerulopathy. This review analyzes the characteristics of anti-Eno autoantibodies in autoimmune disorders and cancer, describing their fine specificity and isotype restriction. The post-translational modifications that are target of autoantibodies are also discussed, as they represent the basis for elucidating the molecular mechanisms responsible for epitope generation. Despite an impressive amount of experimental work on anti-Eno antibodies, it is still necessary to validate the use of anti-Eno antibodies as biomarkers of selected diseases and extend the knowledge on the mechanisms of anti-Eno autoantibody production. Strategies that downmodulate the immune response to Eno may represent in the future novel approaches in the treatment of autoimmune disorders.

Recent Advances in Biomarkers and Regenerative Medicine for Diabetic Neuropathy

Diabetic neuropathy is one of the most common complications of diabetes. This complication is peripheral neuropathy with predominant sensory impairment, and its symptoms begin with hyperesthesia and pain and gradually become hypoesthesia with the loss of nerve fibers. In some cases, lower limb amputation occurs when hypoalgesia makes it impossible to be aware of trauma or mechanical stimuli. On the other hand, up to 50% of these complications are asymptomatic and tend to delay early detection. Therefore, sensitive and reliable biomarkers for diabetic neuropathy are needed for an early diagnosis of this condition. This review focuses on systemic biomarkers that may be useful at this time. It also describes research on the relationship between target gene polymorphisms and pathological conditions. Finally, we also introduce current information on regenerative therapy, which is expected to be a therapeutic approach when the pathological condition has progressed and nerve degeneration has been completed.

Neuron specific enolase promotes tumor metastasis by activating the Wnt/β-catenin pathway in small cell lung cancer

Neuron-specific enolase (NSE) has been used as a specific biomarker for small cell lung cancer (SCLC) patients. Nevertheless, the biological function and mechanism of NSE in SCLC are still unclear. In this study, we clarified the role of NSE in the progression of SCLC and found that NSE expression was positively correlated with distant metastasis. Functional analysis showed that overexpression of NSE promoted migration and invasion of SCLC cells. Mechanism analysis showed that NSE overexpression induced epithelial-mesenchymal transition (EMT) of SCLC cells. Moreover, overexpression of NSE increased the protein expression of β-catenin and its downstream target genes, and silencing β-catenin eliminated NSE-mediated cell migration, invasion and EMT process. Furthermore, NSE interacted with β-catenin and inhibited the degradation of β-catenin. Besides, the animal experiments also indicated that NSE could promote the EMT process and distant metastasis of SCLC cells in vivo. In summary, our results revealed that NSE could promote the EMT process of SCLC cells by activating the Wnt/β-catenin signaling pathway, thereby promoting cell migration, invasion and distant metastasis, which might serve as a potential target for the therapy of SCLC patients.

Effect of photobiomodulation on serum neuron specific enolase (NSE) among patients with diabetic peripheral neuropathy - A pilot study

BACKGROUND AND AIM

Photobiomodulation is an emerging therapy for Diabetic peripheral neuropathy (DPN) of which the management is still a dilemma for clinicians. Elevated Neuron Specific Enolase (NSE) is associated with neuropathy. We aimed this study to assess the effect of Low Level Laser Therapy (LLLT) on Serum Neuron Specific Enolase in Type II Diabetes Mellitus patients with DPN.

METHODOLOGY

Pre post interventional study was done on 50 patients with DPN. DPN was confirmed using 10g Monofilament test, Vibration perception threshold (VPT) and Michigan Neuropathy Screening Instrument. All patients were provided with LLLT for 9 min on dorsal and plantar of foot with a dosage of 3.1 J/cm ² for 10 days. A blood sample was collected at baseline and 4 weeks after LLLT for NSE estimation.

RESULT

A significant reduction in serum NSE levels (0.006) after 4 weeks of laser therapy was observed in 42 patients when compared with baseline. A significant reduction in the vibration perception threshold (p = 0.003) and Numeric pain rating scale (p = 0.004) were observed.

CONCLUSION

In this pilot study, we have assessed the effect of LLLT on serum NSE levels among patients with DPN and showed improved quality of life and decrease in serum NSE levels. These findings should be investigated in larger trials.

Correction of the NSE concentration in hemolyzed serum samples improves its diagnostic accuracy in small-cell lung cancer

Neuron-specific enolase (NSE) is a well-known biomarker for the diagnosis, prognosis and treatment monitoring of small-cell lung cancer (SCLC). Nevertheless, its clinical applicability is limited since serum NSE levels are influenced by hemolysis, leading to falsely elevated results. Therefore, this study aimed to develop a hemolysis correction equation and evaluate its role in SCLC diagnostics. Two serum pools were spiked with increasing amounts of hemolysate obtained from multiple individuals. A hemolysis correction equation was obtained by analyzing the relationship between the measured NSE concentration and the degree of hemolysis. The equation was validated using intentionally hemolyzed serum samples, which showed that the correction was accurate for samples with an H-index up to 30 μmol/L. Correction of the measured NSE concentration in patients suspected of lung cancer caused an increase in AUC and a significantly lower cut-off value for SCLC detection when compared to uncorrected results. Therefore, a hemolysis correction equation should be used to correct falsely elevated NSE concentrations. Results of samples with an H-index above 30 μmol/L should not be reported to clinicians. Application of the equation illustrates the importance of hemolysis correction in SCLC diagnostics and questions the correctness of the currently used diagnostic cut-off value.

Prognostic value of neuron-specific enolase for small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Neuron-specific enolase (NSE) has become a widely used and easily attainable laboratory assay of small cell lung cancer (SCLC). However, the prognostic value of NSE for SCLC patients remains controversial. The aim of the study was to evaluate the correlation between elevated serum NSE before therapy and survival of SCLC patients.

METHODS

We performed a systematic review and meta-analysis. A systematic literature search was conducted in PubMed, Embase, and the Cochrane Central Register from the inception dates to December 2019. Eligible articles were included according to inclusion and exclusion criteria; then, data extraction and quality assessment were performed. The primary outcome was overall survival (OS), and the secondary endpoint was progression-free survival (PFS).

RESULTS

We identified 18 studies comprising 2981 patients. Pooled results revealed that elevated NSE was associated with worse OS (HR = 1.78, 95% CI 1.55-2.06, p < 0.001) and PFS (HR = 1.50, 95% CI 1.16-1.93, p = 0.002). In subgroup analysis, elevated NSE did not predict worse OS in patients who received only chemotherapy (HR 1.22, 95% CI 0.96-1.55, p = 0.10) or part of whom received surgical resection before chemotherapy and radiotherapy (HR = 2.16, 95% CI 0.82-5.69, p = 0.12).

CONCLUSION

Elevated serum NSE before any therapy of SCLC patients may be a negative prognostic factor for OS and PFS. The prognostic value of NSE for OS was particularly observed in patients treated by standard management.

Insulin-like growth factor 1-induced enolase 2 deacetylation by HDAC3 promotes metastasis of pancreatic cancer

Enolase 2 (ENO2) is a key glycolytic enzyme in the metabolic process of glycolysis, but its potential function in pancreatic ductal adenocarcinoma (PDAC) is unclear. In this study, we observed a significant overexpression of ENO2 in PDAC tissues, and its expression was correlated with metastasis and poor prognosis in PDAC patients. K394 was identified as a major acetylation site in ENO2 that regulates its enzymatic activity, cell metabolism and PDAC progression. Knockdown of ENO2 suppressed tumor growth and liver metastasis in PDAC. Re-expression of wild-type (WT) ENO2, but not the K394 acetylation mimetic mutant, could reverse the decreased tumor malignancy. We further characterized histone deacetylase 3 (HDAC3) and P300/CBP-associated factor (PCAF) as the potential deacetylase and acetyltransferase for ENO2, respectively. HDAC3-mediated deacetylation was shown to lead to ENO2 activation and enhancement of glycolysis. Importantly, insulin-like growth factor-1 (IGF-1) was found to decrease K394 acetylation and stimulate ENO2 activity in a dose- and time-dependent manner. The PI3K/AKT/mTOR pathway facilitated the phosphorylation of HDAC3 on S424, which promoted K394 deacetylation and activation of ENO2. Linsitinib, an oral small-molecule inhibitor of IGF-1R, could inhibit IGF-1-induced ENO2 deacetylation by HDAC3 and the PI3K/AKT/mTOR pathway. Furthermore, linsitinib showed a different effect on the growth and metastasis of PDAC depending on the overexpression of WT versus K394-mutant ENO2. Our results reveal a novel mechanism by which acetylation negatively regulates ENO2 activity in the metastasis of PDAC by modulating glycolysis. Blockade of IGF-1-induced ENO2 deacetylation represents a promising strategy to prevent the development of PDAC.

Axon-like protrusions promote small cell lung cancer migration and metastasis

Metastasis is the main cause of death in cancer patients but remains a poorly understood process. Small cell lung cancer (SCLC) is one of the most lethal and most metastatic cancer types. SCLC cells normally express neuroendocrine and neuronal gene programs but accumulating evidence indicates that these cancer cells become relatively more neuronal and less neuroendocrine as they gain the ability to metastasize. Here we show that mouse and human SCLC cells in culture and in vivo can grow cellular protrusions that resemble axons. The formation of these protrusions is controlled by multiple neuronal factors implicated in axonogenesis, axon guidance, and neuroblast migration. Disruption of these axon-like protrusions impairs cell migration in culture and inhibits metastatic ability in vivo. The co-option of developmental neuronal programs is a novel molecular and cellular mechanism that contributes to the high metastatic ability of SCLC.

Serum SP70 is a sensitive predictor of chemotherapy response in patients with advanced nonsmall cell lung cancer

SP70 is a novel tumor biomarker in patients with nonsmall cell lung cancer (NSCLC). However, its role as a marker for predicting the response to chemotherapy for patients with advanced NSCLC has not been investigated. A total of 152 patients were enrolled. Serum SP70, carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), and neuron-specific enolase (NSE) were detected before and after 2 cycles of chemotherapy. The correlation between serum tumor biomarker levels and chemotherapy responses and their association with epidermal growth factor receptor (EGFR) mutation status and progression-free survival (PFS) were analyzed. Serum SP70 levels were significantly decreased after chemotherapy in the partial remission (PR) group (P < .001) and increased in the progressive disease (PD) group (P < .001), but not significantly changed in the stable disease (SD) group (P = .114). Although similar changes were observed on CEA and CYFRA21-1 levels but not NSE, ROC analysis demonstrated that SP70 is superior to the others. Additionally, patients with EGFR mutation had higher serum SP70 levels and tissue SP70 expression than patients without EGFR mutation (P = .014 and P = .002, respectively). The median PFS of patients with decreased SP70 levels after chemotherapy was longer than that of patients with stable or increased serum SP70 level (24 months vs 12 months vs 2 months, P < .001), and the differences of all other 3 tumor markers were not obvious. Serum SP70 is a sensitive and real-time indicator of chemotherapeutic efficacy in patients with advanced NSCLC and related to PFS.

Lung Cancer-Associated Keratin 19 Fragments: Development and Biochemical Characterisation of the New Serum Assay Enzymun-Test® Cyfra 21–1

From a panel of 4 murine monoclonal antibodies directed against keratin 19 various antibody combinations were evaluated in solid-phase enzyme-linked sandwich immunoassays for detection of soluble keratin 19 fragments in patient sera. One of these antibody combinations, comprised of the monoclonal antibodies Ks 19.1 and BM 19.21, was selected for further development to a routine test (Enzymun-Test® CYFRA 21–1) because of its high diagnostic sensitivity and specificity for non-small cell lung carcinoma (NSCLC). Both antibodies are specific for keratin 19, no reactivity could be observed with cytokeratin 8 or 18. The epitopes of the two antibodies were determined to be within helix 2B of the rod romain. The epitope sequences lie within the sequence 311–335 for the catcher antibody Ks 19.1 and 346–367 for the detector antibody BM 19.21. These sequences are unique, as could be confirmed from sequence databases. The standard material for the assay was prepared from a cytoskeleton fraction of cultivated MCF-7 cells. Subsequent digestion of this fraction with chymotrypsin yielded a soluble and stable standard material. Both the standard material and the serum analyte appeared as oligomers when analysed on gel chromatography: the serum analyte appeared exclusively at a Mr of 100 ± 10 kD, whereas the standard material eluted in fractions corresponding to 100 ±10 kD and 450 kD. Due to the precise definition of the antigen and the localisation of the antibody binding sequences, Enzymun-Test® CYFRA 21–1 is one of the best characterised tumor markers so far.

Neuron-Specific Enolase

The clinical value of neuron-specific enolase as a marker in small cell lung cancer, neuroblastoma, melanoma and seminoma has been reviewed The role of serum and cerebrospinal NSE in benign and malignant disease of the central nervous sytem is discussed.

Neuron-Specific Enolase in the Diagnosis and Therapy Monitoring of Lung Cancer: A Comparison with Cea, Tpa, Ferritin and Calcitonin

The significance of neuron-specific enolase (NSE) in the diagnosis and treatment monitoring of lung cancer was investigated in comparison with such established tumour markers as carcinoembryonic antigen (CEA), tissue polypeptide antigen (TPA), ferritin and calcitonin. We determined the serum concentrations of these tumour markers in 25 patients with small cell lung cancer (SCLC), 30 patients with non small cell lung cancer (NSCLC), and 38 patients with benign pulmonary diseases (BPD). In 14 patients with lung cancer, it was possible to follow up the behaviour of the tumour markers under treatment for up to 16 months. Calcitonin proved to have a surprisingly low sensitivity for SCLC. The utility of TPA and of ferritin was restricted, although the sensitivity was comparably high, by the high rate of false positive results. For NSCLC, CEA proved to be the best tumour marker. At present, NSE appears to be the tumour marker with the greatest specificity and sensitivity for SCLC. Its determination in the diagnosis, treatment and follow-up of SCLC makes good sense.

Serum NSE, CEA, CT, CA 15-3 Levels in Human Lung Cancer

The significance of neuron specific enolase (NSE) was investigated in comparison with other tumor markers (CEA, CT, CA 15-3) used in the diagnosis and treatment monitoring of lung cancer.

As previously described, the calcitonin assay proved to have very low sensitivity for small cell lung cancer (SCLC). The serum NSE assay was, however, shown to be a useful diagnostic aid for discrimination between histologically different lung cancers, and therefore this assay may be a valuable tool for treatment monitoring in SCLC patients.

CA 15-3, also an unspecific marker, showed similar sensitivity to the NSE assay in SCLC patients, the sensitivity being higher than CEA in non small cell lung cancer (NSCLC)

Reevaluation of the Usefulness of Systematic Bone Scanning in Initial Staging and follow-up of Small Cell Lung Carcinoma, Taking into Account the Serum Levels of Neuron-Specific Enolase

The prescription of bone scans (BS) in the initial staging and follow-up of small cell lung carcinoma (SCLC) is a traditional attitude. The availability of the serum neuron-specific enolase (NSE) assay and budget limitations led us to evaluate retrospectively, in 57 patients, the consequences of a more selective attitude, namely to perform BS only in those patients with abnormal serum NSE levels. Both BS and NSE assays were performed in 47 patients referred for initial staging of SCLC; NSE levels were normal in 8 but in 2 of these cases (25%) secondary bone localizations with great clinical significance were discovered at BS. During follow-up, 59 BS were performed in conjunction with NSE assays; 45 NSE levels were in the normal range whereas 17 (38%) corresponding BS were suggestive of bone metastases. In conclusion, due to the frequent occurrence of false-negative results in patients with bone metastases, serum NSE levels proved to be useless in the selection for BS of patients suffering from SCLC.

Preoperative CEA, NSE, SCC, TPA and CYFRA 21.1 Serum Levels as Prognostic Indicators in Resected Non-Small Cell Lung Cancer

In 62 patients affected by resectable non-small cell lung cancer (NSCLC) submitted to radical surgery we evaluated the prognostic significance of CEA, NSE, SCC, TPA and CYFRA 21.1 serum levels at diagnosis, as well as the predictive ability of these tumor markers with respect to histological type and pathological stage. The group was composed of 56 male and 6 female patients; the median age was 62 years (range 29–73 years). Thirty-four patients had a histological diagnosis of adenocarcinoma and 28 of squamous cell carcinoma; with regard to pathological stage, 32 patients had stage I, 4 patients stage II and 23 patients stage IIIA disease. A good predictive ability with respect to histological type was obtained with SCC serum levels; as for pathological stage, TPA and CYFRA 21.1 were found to have moderate predictive ability. In this series of patients, at a median follow-up of 55 months after surgery, we found that both TPA and CYFRA 21.1 serum levels at diagnosis were reliable predictors of overall survival, high values of these markers being associated with a worse prognosis.

A Case of Small Cell Carcinoma of the Prostate and Review of the Literature

Aim and background

Small cell carcinoma of the prostate (SCCP) is a relatively rare entity, an aggressive tumor with a tendency to metastasize early. There is no standard chemotherapy regimen for SCCP. We report the case of a 67-year-old man with an initial diagnosis of prostate adenocarcinoma with bone metastases who subsequently developed a small cell carcinoma of the prostate with liver metastases.

Methods and study design

A review of this case and of the current literature was done with a view to highlighting the ideal approach to such an unusual tumor.

Results and conclusion

The patient was treated with carboplatin and etoposide and after 3 cycles achieved a good response. Unfortunately he developed massive pulmonary embolism which impeded the continuation of treatment and caused his death. By reviewing the literature we found there is no standard of care and new targeted therapies have failed to prove any benefit so far. It is mandatory to persevere in planning trials and exploring new drugs to improve the outcome of patients with SC-C P. It might also be worth creating a register for SCCP where data can be collected to coordinate the management of these patients and to establish better connections among cancer centers.

Evaluation of quantitative parameters for distinguishing pheochromocytoma from other adrenal tumors

Adrenal tumors are increasingly found incidentally during imaging examinations. It is important to distinguish pheochromocytomas from other adrenal tumors because of the risk of hypertensive crisis. Although catecholamines and their metabolites are generally used to diagnose pheochromocytoma, false-positive test results are common. An effective screening method to distinguish pheochromocytoma from adrenal incidentalomas is needed. We analyzed 297 consecutive patients with adrenal incidentalomas. Our findings included 162 non-functioning tumors, 47 aldosterone-producing adenomas, 26 metastases, 22 cases of subclinical Cushing's syndrome, 21 pheochromocytomas, 12 cases of Cushing's syndrome, and 7 adrenocortical cancers. We checked quantitative parameters such as age, blood, and urine catecholamines and their metabolites, neuron-specific enolase, size and computed tomography (CT) attenuation values. Among catecholamine-related parameters, the sum of urine metanephrine and normetanephrine (urineMNM) levels produced the highest area under the receiver operating characteristic curve regarding discrimination of pheochromocytoma from other lesions. Size and CT attenuation values also differed significantly. However, size was correlated with catecholamine levels. CT attenuation was not correlated with other factors. The optimal thresholds were 19 Hounsfield units (HU) for CT attenuation (sensitivity, 100%; specificity, 60%) and 0.43 mg/24 h for urineMNM (sensitivity, 89%; specificity, 96%). No pheochromocytomas were evident when CT attenuation values were under 19 HU. Even in adrenal tumors with CT attenuation values ≥ 19 HU, when urineMNM was < 0.43 mg/24 h, the frequency of pheochromocytoma was only 4.3%, when urineMNM was ≥ 0.43 mg/24 h, the frequency of pheochromocytoma was 93% and when urineMNM was > 0.77 mg/24 h the frequency of pheochromocytoma was 100%. CT attenuation value and urineMNM represented the most useful combination for diagnosis of pheochromocytoma.

Pro-gastrin-releasing peptide (ProGRP) as a biomarker in small-cell lung cancer diagnosis, monitoring and evaluation of treatment response

Lung cancer belongs to malignant tumors that possess the highest rates of morbidity and mortality in the world. A number of morphological, biological and clinical features justify the distinction of small-cell carcinoma with respect to the other histological types of lung cancer. The predominant neuroendocrine phenotype is critical for the selection of biomarkers used in diagnostics, monitoring and evaluation of treatment response; early onset relapses in patients with small-cell lung cancer (SCLC) and the evaluation of their prognosis. Although for a long time the neuron-specific enolase (NSE) was considered to be the marker of choice for this tumor, it is now increasingly important to pay attention to concentrations of pro-gastrin-releasing peptide (ProGRP). The results of this marker have been implicated in the differential diagnosis of non-small lung cancer and SCLC, chemotherapy and radiotherapy monitoring as well as evaluation of treatment response. The subject of this series of studies is to determine the usefulness of ProGRP in the evaluation of patients’ prognosis and its predictive value. The current aim for the optimization of the effectiveness of biochemical diagnostics of SCLC is recommended by complementary ProGRP and NSE studies. The present work is a summary of the latest reports regarding diagnostic utility of these markers in SCLC.

The prognostic value of the serum neuron specific enolase and lactate dehydrogenase in small cell lung cancer patients receiving first-line platinum-based chemotherapy

The aim of this study was to investigate the associations of serum levels of neuron-specific enolase (NSE), pro-gastrin releasing peptide (ProGRP), and lactate dehydrogenase (LDH) with clinical response and survival in small cell lung cancer (SCLC) patients receiving first-line platinum-based chemotherapy.One hundred thirty-six patients with SCLC were recruited in this study. All the patients received first-line platinum-based chemotherapy. Clinical efficacy was assessed according to Response Evaluation Criteria in Solid Tumors v1.1 criteria. Serum samples were collected from SCLC patients before chemotherapy. NSE, ProGRP, and LDH levels were measured by commercial electrochemiluminescence immunoassay, enzyme-linked immune sorbent assay, and kinetic spectrophotometric method, respectively.Overall response rate was 71.3% with 97 patients who achieved complete response (CR) +  partial response (PR). NSE and LDH level declined in patients who achieved CR + PR compared with patients in stable disease (SD) and progress disease (PD). Multivariate logistic regression analysis revealed that NSE > 50.324 ng/mL, stage ED, and distant metastases were independent risk factors for patients achieving CR + PR, and chemotherapy > 4 cycles was an independent protective factor in predicting CR + PR. Receiver operating characteristic (ROC) curves presented that expression of NSE, ProGRP, and LDH are of good predicting value for patients achieving CR + PR. Patients with a higher level of NSE and LDH presented worse progression-free survival and overall survival. In addition, multivariate Cox regression analysis showed that NSE level > 50.324 ng/mL and distant metastasis were independently correlated with worse OS.Serum NSE and LDH could be promising biomarkers for predicting therapy response and survival of SCLC patients receiving first-line platinum-based chemotherapy.

Systematic review and meta-analysis of the efficacy of serum neuron-specific enolase for early small cell lung cancer screening

We performed a pooled analysis of the efficacy of serum neuron-specific enolase (NSE) levels for early detection of small cell lung cancer (SCLC) in patients with benign lung diseases and healthy individuals. Comprehensive searches of several databases through September 2016 were conducted. The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Ultimately, 33 studies containing 9546 samples were included in the review. Pooled sensitivity of NSE for detecting SCLC was 0.688 (95%CI: 0.627-0.743), specificity was 0.921 (95%CI: 0.890-0.944), positive likelihood ratio was 8.744 (95%CI: 6.308-12.121), negative likelihood ratio was 0.339 (95%CI: 0.283- 0.405), diagnostic odds ratio was 25.827 (95%CI: 17.490- 38.136) and area under the curve was 0.88 (95%CI: 0.85- 0.91). Meta-regression indicated that study region was a source of heterogeneity in the sensitivity and joint models, while cut-off level was a source in the joint model. Subgroup analysis showed that enzyme linked immunosorbent assays had the highest sensitivity and radioimmunoassay assays had the highest specificity. The diagnostic performance was better in Europe [sensitivity: 0.740 (95%CI: 0.676-0.795), specificity: 0.932 (95%CI: 0.904-0.953)] than in Asia [sensitivity: 0.590 (95%CI: 0.496- 0.678), specificity: 0.901 (95%CI: 0.819-0.948)]. In Europe, 25 ng/ml is likely the most suitable NSE cut-off level. NSE thus has high diagnostic efficacy when screening for SCLC, though the efficacy differs depending on study region, assay method and cut-off level. In the clinic, NSE measurements should be considered along with clinical symptoms, image results and histopathology.

Meta-Analysis of Serum Gastrin-Releasing Peptide Precursor as a Biomarker for Diagnosis of Small Cell Lung Cancer

Background:

The serum level of gastrin-releasing peptide precursor (proGRP) is generally? elevated in patients with small cell lung cancer (SCLC). However, the diagnostic sensitivity and specificity of serum proGRP in SCLC cases remains controversial. The study aimed to assess the diagnostic value of this biomarker by meta-analysis.

Materials and Methods:

The Cochrane, Clinical trials, Pubmed, Web of Science and Embase databases were searched and diagnostic values were calculated or extracted. Statistical analysis was accomplished with RevMan 5.3 and STATA 12.0 software.

Results:

A total of 27 studies with 7268 participants were included. The pooled sensitivity, specificity, PLR, NLR and DOR were 0.754 (95% CI: 0.700-0.802), 0.945 (95% CI: 0.916-0.965), 13.804 (95% CI: 9.096-20.948), 0.260 (95% CI: 0.213-0.317) and 53.101 (95% CI: 34.327-82.145) respectively. The AUC was 0.910 (95% CI: 0.880-0.930). Significant publication bias was not found (P =0.622).

Conclusions:

The meta-analysis indicated that serum proGRP is indeed a useful biomarker with goodsensitivity and high specificity for diagnosis of SCLC. Therefore proGRP can be expected to be widely applied in the clinic for identification of lung cancer patients.

Drebrin: A new oncofetal biomarker associated with prognosis of lung adenocarcinoma

OBJECTIVES

With the aim of searching for novel oncofetal tumor biomarkers of lung adenocarcinoma other than carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP), we developed a strategy involving monoclonal antibodies generated from embryonic tissue of miniature swine.

MATERIALS AND METHODS

Using immunohistochemistry, we selected suitable hybridoma clones that were reactive against swine fetal lung but not adult lung using tissue microarray loading of human normal lung, lung cancer, and fetal and adult swine tissues.

RESULTS

The selected clones included several that were uniquely reactive against both swine fetal lung and human lung adenocarcinoma, and protein microarray revealed that the antigen they recognized was "drebrin" (DBN1). We then examined the association between the pattern of drebrin expression and the clinicopathological characteristics of lung adenocarcinoma using surgically resected samples of human lung adenocarcinoma. Two hundred formalin-fixed and paraffin-embedded tumor samples were immunostained for drebrin using clone B246, one of the clones that were reactive against drebrin. The cases were divided into those with strong (n=85) and weak (n=115) drebrin expression. In terms of disease-free survival, cases showing strong drebrin expression had a significantly poorer prognosis than those with weak drebrin expression (p=0.033).

CONCLUSION

The present findings indicate that "drebrin" is a unique oncofetal protein that can be applied as a new biomarker of lung adenocarcinoma.

Association between serum tumor markers and metabolic tumor volume or total lesion glycolysis in patients with recurrent small cell lung cancer

The aim of the present study was to investigate the association between serum tumor markers and the metabolic tumor volume (MTV) or total lesion glycolysis (TLG), as determined by fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography-computed tomography (PET/CT) in patients with recurrent small cell lung cancer (SCLC). Data from 21 patients with recurrent SCLC were collected. The levels of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and cytokeratin 19 fragment 21-1 were measured at the time of the ¹⁸F-FDG PET/CT examination. The MTV and TLG of all lesions were calculated. Pearson correlation analyses were used to estimate the correlations between NSE level and PET findings. Pearson correlation analyses showed that NSE was the only tumor marker to have a strong correlation with MTV or TLG (r=0.787, P<0.001; r=0.866, P<0.001, respectively). In patients with a normal NSE level, no correlation was found between NSE and MTV or TLG (r=0.018, P=0.958; r=-0.003, P=0.92, respectively), but a significant correlation was found in patients with an abnormal NSE level (r=0.789, P<0.01; r=0.872, P=0.01, respectively). Therefore, TLG and MTV may serve as sensitive markers of tumor burden in patients with recurrent SCLC, with TLG showing greater sensitivity. In patients with an abnormal NSE level, a higher NSE level indicates greater MTV and TLG.

CEA, SCC and NSE levels in exhaled breath condensate--possible markers for early detection of lung cancer

Lung cancer (LC) is the leading cause of cancer-related death. The sensitive and non-invasive diagnostic tools in the early stage are still poor. We present a pilot study on the early diagnosis of LC by detecting markers in exhaled breath condensate (EBC). EBC samples were collected from 105 patients with LC and 56 healthy controls. We applied chemiluminescence immunoassay to detect CEA (carcinoembryonic antigen), SCC (squamous cell carcinoma) antigen and NSE (neuron specific enolase) in EBC and serum. Concentrations of markers were compared between independent groups and subgroups. A significantly higher concentration level of each marker was found in patients with LC than healthy controls. The areas under curve of receiver operating characteristic (ROC) curves were 0.800, 0.771, 0.659, 0.679, 0.636 and 0.626 for EBC-CEA, serum-CEA, EBC-SCC, serum-SCC, EBC-NSE and serum-NSE, respectively. Markers in EBC had a higher positive rate (PR) and were more specific to histologic types than markers in serum. In addition, multivariate analysis was performed to evaluate the association of presenting markers with the stages of non-small cell lung cancer (NSCLC). EBC-CEA showed the best predictive characteristic (p < 0.006) of early-NSCLC. Our study suggested that tumor markers in EBC may have a better diagnostic performance for LC than those in serum. With further investigation on the combination of markers in EBC, detection of EBC could probably be a novel and non-invasive method to detect NSCLC earlier.

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.

Identification of Autoantibodies for α and γ-Enolase in Serum from a Patient with Melanoma

Melanoma is one of lethal malignant skin tumors and the sole effective cure for the disease can be achieved by surgical resection of primary tumor and early diagnosis for melanoma is crucial for patients’ prognosis. Detection of novel tumor-related antibodies would aid in the diagnosis of early-stage cancer, in the detection of recurrence and in the development of a more effective immunotherapy. In the middle of the exploration of a candidate of biomarker for melanoma by proteomics-base technique, we encountered the coexistence of autoantibodies for α-enolase and γ-enolase in serum derived from a patient with melanoma, who had received the repeated treatments with alkylating agents and interferon β. Although melanoma is known to be a highly antigenic tumor, it is still unclear why these autoantibodies appeared. To evaluate the usefulness in detecting the circulating α-enolase or γ-enolase autoantibodies in serum from melanoma patients for biomarkers for tumor progression, more studies are needed.

Definitive chemoradiotherapy of limited-disease small cell lung cancer: Retrospective analysis of new predictive factors affecting treatment results

The aim of this study was to evaluate potential predictive factors in the treatment of limited-disease small cell lung cancer (LD-SCLC). A total of 33 patients with LD-SCLC who underwent definitive chemoradiotherapy at our institute between April 1996 and May 2007 were enrolled in our retrospective study. The relationship between a range of potential predictive factors and the initial response, time to progression and pattern of failure was analyzed. The factors evaluated included the tumor markers Pro-gastrin-releasing peptide (Pro-GRP) and neuron-specific enolase; net tumor size (sum of each lesion mass on computed tomography at 1-cm intervals); total radiation dose; biological effective dose (BED); overall treatment time (OTT); time between the start of any type of treatment and the end of radiation therapy (SER). In addition, the novel factors of radiation dose-intensity (RDI = BED/OTT) and RDI/NTS (= RDI/net tumor size) were defined. Of the 33 patients evaluated in our study, 22 (67%) achieved a complete response (CR) and 27 (82%) experienced treatment failure or recurrence. High RDI/NTS values showed a significant correlation with CR (P=0.043). Prolonged OTT and lower values of RDI and RDI/NTS showed a significant correlation with recurrence within 12 months (P=0.022, 0.033 and 0.015, respectively). The lower values of RDI and RDI/NTS showed a significant correlation with distant metastasis as a first failure site (P=0.038 and 0.044, respectively). Patients with RDI/NTS ≥0.08 had a more favorable prognosis (P=0.045). Thus, RDI and RDI/NTS may become beneficial predictive factors in the treatment of LD-SCLC. However, further studies are required to confirm our preliminary results.

Lactate dehydrogenase as prognostic factor in limited and extensive disease stage small cell lung cancer - a retrospective single institution analysis

PURPOSE

The aim of this retrospective study is to present data on clinical significance of lactate dehydrogenase (LDH) serum levels in an unselected contemporary patient population with small cell lung cancer (SCLC) in limited disease (LD) and extensive disease stage (ED).

PATIENTS AND METHODS

From June 2004 to June 2008, our electronic database including all in-patient and out-patient contacts was searched for patients with newly diagnosed LD and ED SCLC. 397 cases were identified. We collected data on patient characteristics including clinical performance status and LDH serum levels, metastatic sites, efficacy of first line chemotherapy and survival.

RESULTS

In both limited and extensive disease SCLC, elevated LDH serum levels resulted in significantly shorter median survival. The effect was most pronounced if levels were 300 U/l or higher. In patients with limited disease and normal LDH levels, median survival was 18.0 months. If LDH was higher than 300 U/l, overall survival was reduced to 12 months. In cases with extensive disease, overall survival was significantly lower in patients with elevated LDH serum levels with an additional reduction in overall survival in patients with LDH levels above 300 U/l. (7.0 vs. 12.0 months, p = <0.001). Multivariate Cox regression analyses revealed LDH levels to be an independent predictor of mortality after adjustment for age and Performance Status in LD and ED SCLC (HR 1.003, p = 0.017; HR 1.001, p = 0.002 respectively). However, categorizing LDH levels revealed no significant difference in LD SCLC.

CONCLUSION

In our contemporary comprehensive patient population, LDH is proved to be a strong, independent predictive factor of median survival in patients with LD and ED SCLC.

SCG3 transcript in peripheral blood is a prognostic biomarker for REST-deficient small cell lung cancer

PURPOSE

Specific markers of circulating tumor cells may be informative in managing lung cancer. Because the RE-1 silencing transcription factor (REST/NRSF) is a transcriptional repressor that is inactivated in neuroendocrine lung cancer, we identified REST-regulated transcripts (CHGA, CHGB, SCG3, VGF, and PCSK1) for evaluation as biomarkers in peripheral blood.

EXPERIMENTAL DESIGN

Transcripts were screened across lung cancer and normal cell lines. Candidates were assessed by reverse transcription-PCR and hybridization of RNA extracted from the peripheral blood of 111 lung cancer patients obtained at clinical presentation and from 27 cancer-free individuals.

RESULTS

Expression profiling revealed multiple chromogranin transcripts were readily induced on REST depletion, most notably SCG3 was induced >500-fold. The SCG3 transcript was also overexpressed by 12,000-fold in neuroendocrine compared with nonneuroendocrine lung cancer cells. In peripheral blood of lung cancer patients and cancer-free individuals, we found that SCG3 was more tumor-specific and more sensitive than other chromogranin transcripts as a biomarker of circulating tumor cells. Overall, 36% of small cell lung cancer (SCLC) and 16% of non-SCLC patients scored positively for normalized SCG3 transcript. This correlated with worse survival among SCLC patients with limited disease (n = 33; P = 0.022) but not extensive disease (n = 29; P = 0.459). Interestingly, the subcohort of 6 SCLC patients with resistance to platinum/etoposide chemotherapy all scored positively for peripheral blood SCG3 transcript (P = 0.022).

CONCLUSIONS

SCG3 mRNA, a component of the REST-dependent neurosecretory transcriptional profile, provides a sensitive prognostic biomarker for noninvasive monitoring of neuroendocrine lung cancer.

Biochemical parameters in neuroblastoma

Apart from the biochemical parameters routinely used like Vanillyl Mandellic Acid for the patients with neuroblastoma the parameters like neuron specific enolase, ferritin, lactate dehydrogenase, gamma glutamyl transferase were also studied to assess the utility in diagnosing the patients with neuroblastoma. The study involved 40 healthy ambulatory subjects and 30 untreated cases of histologically proved neuroblastoma referred to the Tata Memorial Hospital for further management and treatment. The urinary Vanillyl Mandellic Acid levels and the serum levels of neuron specific enolase, ferritin, lactate dehydrogenase had increased significantly, p<0.001 whereas the gamma glutamyl transferase had decreased significantly p<0.001, as compared to the normal. Serum neuron specific enolase, ferritin, lactate dehydrogenase alongwith urinary Vanillyl Mandellic Acid could be of help in diagnosing the patients with neuroblastoma.

Targeted determination of the early stage SCLC specific biomarker pro-gastrin-releasing peptide (ProGRP) at clinical concentration levels in human serum using LC-MS

Pro-gastrin-releasing peptide (ProGRP) is used as a specific diagnostic marker for small cell lung cancer (SCLC), a rapidly growing neoplasm with high mortality. Our object was to develop an LC-MS method for the detection and quantification of ProGRP in human serum using the specific tryptic digestion product NLLGLIEAK (m/z 485.8 for [M + 2H](2+)). For this purpose the sample pretreatment, clean-up, enrichment, and LC-MS conditions were evaluated. Sample pretreatment was carried out using ACN precipitation to decrease the sample complexity. Although ProGRP (31-98) standards were soluble in 99% ACN, it showed that optimal signal intensities were obtained by adding ACN to the serum in a 1:1 ratio v/v. A simplified tryptic digest protocol was carried out using 100 mM triethanolamine buffer to ensure pH stability during the whole procedure. The simplified protocol also includes omission of reducing and alkylating reagents. Necessary additional sample clean-up was achieved by trapping NLLGLIEAK on a RAM column (ADS-C8) which was back-flushed onto the analytical BioBasic C8 column. Volume of injection, sample enrichment, and column capacity are among the factors optimized to reach a mass LOD of 150 pg on column (OC) ProGRP (31-98). Detection of ProGRP in the serum sample of a patient suffering from SCLC with a clinically relevant concentration shows the potential of the method in diagnosis, prognosis, and monitoring of the disease.

Tumor markers in detection of lung cancer

The expression of biomarkers by lung cancers is useful in the diagnosis and clinical management of patients with lung cancer. Biomarkers provide insight into histogenesis, interrelationships, and biological behavior of lung tumors. This chapter presents data on lung cancer detection, involving some of the most studied and interesting lung cancer biomarkers to date-CYFRA 21-1, NSE, ProGRP, SCC, CEA, Tumor M2-PK, as well as markers in clinical application such as CRP, LDH, tumor-suppressor genes and oncogenes, CA125, CgA, NCAM, and TPA. Biomarker profiles in combination with fuzzy logic techniques have also been addressed. Serum markers used alone or in combination with other indices might play an important role in monitoring response to therapy in early detection of tumor reactivation in new treatment strategies as well as in secondary prevention.