Elevated Neuron-specific Enolase Research Articles

Receptor protein tyrosine phosphatase alpha signaling is involved in androgen depletion-induced neuroendocrine differentiation of androgen-sensitive LNCaP human prostate cancer cells.

The neuroendocrine (NE) cells represent the third cell population in the normal prostate. Results of several clinical studies strongly indicate that the NE cell population is greatly increased in prostate carcinomas during androgen ablation therapy that correlates with hormone-refractory growth and poor prognosis. However, the mechanism of NE cell enrichment in prostate carcinoma remains an enigma. We investigated the molecular mechanism by which androgen-sensitive C-33 LNCaP human prostate cancer cells become NE-like cells in an androgen-reduced environment, mimicking clinical phenomenon. In the androgen-depleted condition, androgen-sensitive C-33 LNCaP cells gradually acquired the NE-like morphology and expressed an increased level of neuron-specific enolase (NSE), a classical marker of neuronal cells. Several NE-like subclone cells were established. Biochemical characterizations of these subclone cells showed that receptor-type protein-tyrosine phosphatase alpha (RPTPalpha) is elevated and ERK is constitutively activated, several folds higher than that in parental cells. In androgen-depleted condition, PD98059, an MEK inhibitor, could efficiently block not only the activation of ERK, but also the acquisition of the NE-like morphology and the elevation of NSE in C-33 LNCaP cells. In RPTPalpha cDNA-transfected C-33 LNCaP cells, ERK was activated and NSE was elevated. In those cells in the presence of PD98059, the ERK activation and NSE elevation were abolished, following a dose-response fashion. Additionally, in constitutively active MEK mutant cDNA-transfected C-33 LNCaP cells, ERK was activated and NSE level was elevated, and cells obtained the NE-like phenotype. Our data collectively indicated that RPTPalpha signaling via ERK is involved in the NE transdifferentiation of androgen-sensitive C-33 LNCaP human prostate cancer cells in the androgen-depleted condition.

Cytosolic levels of neuron-specific enolase in squamous cell carcinomas of the lung.

To study the behavior and possible correlations of neuron-specific enolase (NSE) with other clinicobiological parameters, we measured the cytosolic levels of this marker by means of an immunoradiometric assay (IRMA) in 95 squamous cell lung carcinoma samples. We also analyzed the levels of pS2, tissue-type plasminogen activator (t-PA), hyaluronic acid (HA), free beta subunit of human chorionic gonadotropin (beta-HCG), CYFRA 21.1 and CA 125 in cytosol. On the cell surface we analyzed the concentrations of epidermal growth factor receptor (EGFR), HA, erbB-2 oncoprotein, CD44s, CD44v5 and CD44v6. Other parameters considered were clinical stage, lymph node involvement, histological grade (HG), ploidy and the cellular S-phase fraction measured by flow cytometry on nuclei obtained from fresh tissues. In the 95 squamous cell carcinomas the cytosolic levels of NSE varied from 4.5 to 2235 ng/mg protein (median: 267) and were significantly higher (p < 0.001) than those observed in 38 samples of normal pulmonary tissue obtained from the same patients (range: 56-657; median: 141.5). When classifying tumors according to the different parameters analyzed, we observed that the levels of NSE were higher in aneuploid than in diploid cases (p = 0.046) and in those that were HG3 than in those that were HG2 (p < 0.001). Tumors with high NSE levels (> 422 ng/mg protein; 75th percentile) were more likely to have high S-phase values (p = 0.012) and were more frequently aneuploid (p = 0.038) and HG3 (p < 0.001) than those with low levels of NSE (< 180 ng/mg protein; 25th percentile). These results lead us to the following conclusions: 1) the cytosolic concentrations of NSE are significantly higher in squamous cell carcinomas than in healthy pulmonary tissue, and 2) the cytosolic concentrations of NSE are not correlated with clinical stage or nodal involvement. However, in our study higher levels of the enzyme were statistically correlated with aneuploidy, histological grade 3 and S-phase. This may explain its association with poorer outcome and progression, but also the more favorable response of tumors with elevated NSE to chemotherapy, as suggested by other groups.

Neuron-specific Enolase in Testicular Cancer

The clinical significance of serum neuron-specific enolase (NSE) was evaluated at diagnosis (before orchiectomy) in 132 patients, and in the follow-up of 236 men with germ cell tumours of the testis. The purpose of the study was to determine whether serum NSE was a more clinically useful tumour marker than the existing tumour markers β-hCG, AFP and LDH. The mean observation time was 4.3 years. At orchiectomy, serum NSE levels were raised in 38 (29%) of all the patients, and in 8/53 (15%) of the patients with clinical stage 1 seminoma. NSE had the same sensitivity as β-hCG in seminoma. There were very few false-positive values for the classic markers β-hCG and AFP, but 117 out of 219 patients (53.5%) did experience false-positive serum NSE levels at least once during follow-up. The false-positive values were wide ranging [13-70 μg/L]. None of the four evaluable patients with seminoma who experienced relapse had increased levels of serum NSE at relapse. Two out of 14 non-seminoma patients who experienced relapse had elevated serum NSE levels at the time of relapse, but increased NSE was not the first sign of relapse in any of them. It is concluded that serum NSE is of no clinical value in monitoring patients with testicular cancer.

Cytosolic levels of neuron-specific enolase in squamous cell carcinomas of the lung

To study the behavior and possible correlations of neuron-specific enolase (NSE) with other clinicobiological parameters, we measured the cytosolic levels of this marker by means of an immunoradiometric assay (IRMA) in 95 squamous cell lung carcinoma samples. We also analyzed the levels of pS2, tissue-type plasminogen activator (t-PA), hyaluronic acid (HA), free beta subunit of human chorionic gonadotropin (beta-HCG), CYFRA 21.1 and CA 125 in cytosol. On the cell surface we analyzed the concentrations of epidermal growth factor receptor (EGFR), HA, erbB-2 oncoprotein, CD44s, CD44v5 and CD44v6. Other parameters considered were clinical stage, lymph node involvement, histological grade (HG), ploidy and the cellular S-phase fraction measured by flow cytometry on nuclei obtained from fresh tissues. In the 95 squamous cell carcinomas the cytosolic levels of NSE varied from 4.5 to 2235 ng/mg protein (median: 267) and were significantly higher (p < 0.001) than those observed in 38 samples of normal pulmonary tissue obtained from the same patients (range: 56-657; median: 141.5). When classifying tumors according to the different parameters analyzed, we observed that the levels of NSE were higher in aneuploid than in diploid cases (p = 0.046) and in those that were HG3 than in those that were HG2 (p < 0.001). Tumors with high NSE levels (> 422 ng/mg protein; 75th percentile) were more likely to have high S-phase values (p = 0.012) and were more frequently aneuploid (p = 0.038) and HG3 (p < 0.001) than those with low levels of NSE (< 180 ng/mg protein; 25th percentile). These results lead us to the following conclusions: 1) the cytosolic concentrations of NSE are significantly higher in squamous cell carcinomas than in healthy pulmonary tissue, and 2) the cytosolic concentrations of NSE are not correlated with clinical stage or nodal involvement. However, in our study higher levels of the enzyme were statistically correlated with aneuploidy, histological grade 3 and S-phase. This may explain its association with poorer outcome and progression, but also the more favorable response of tumors with elevated NSE to chemotherapy, as suggested by other groups.

Complementary roles of pro-gastrin-releasing peptide (ProGRP) and neuron specific enolase (NSE) in diagnosis and prognosis of small-cell lung cancer (SCLC)

In this study, we evaluated the clinical usefulness of ProGRP and NSE for diagnosis and prognosis of small-cell lung cancer (SCLC). Serum levels of ProGRP and NSE were determined in 108 healthy subjects, 103 patients with benign pulmonary diseases, 142 with non-small cell lung cancer (NSCLC), and 114 with SCLC. Sensitivity of ProGRP in diagnosis of SCLC was significantly higher than that of NSE (64.9 vs. 43.0%, P<0.001). The difference was substantial in patients with limited disease (56.5 vs. 20.3%, P<0.001). However, 11 of 40 SCLC patients with normal levels of serum ProGRP (27.5%) showed elevated levels of serum NSE. In the SCLC patients receiving chemotherapy, the CR rate in patients with elevated NSE levels was significantly lower than in patients with normal levels of NSE (18.5 vs. 61.7%, P<0.001). Elevation of both ProGRP and NSE was a poor prognostic factor, and patients with elevated levels of either ProGRP or NSE showed shorter survival than those without. From multivariate analysis, NSE was found to have a greater effect on survival of SCLC patients than ProGRP. These findings indicate that ProGRP is more sensitive than NSE for diagnosis of SCLC, while NSE is superior to ProGRP as a prognostic factor. In conclusion, both ProGRP and NSE are useful tumor markers and they have a complementary role for each other in diagnosis and prognosis of SCLC.

Prognostic value of neuroendocrine serum markers and PSA in irradiated patients with pN0 localized prostate cancer.

The prognosis of patients with localized prostate cancer depends on clinical stage, histological grade, and pretreatment prostate-specific antigen (PSA). We evaluated the additional prognostic impact of serum levels of neuron-specific enolase (NSE) and chromograninA (CgA) after curative radiotherapy and the importance of serum PSA, analyzed 3 months after irradiation. From 1988 to 1995, 161 patients with localized T1-4, pN0M0, prostate adenocarcinoma were treated with external radiation (66Gy, 2Gy/5 fractions per week). Frozen serum samples were assessed for CgA, NSE, and PSA before and 3 months after radiotherapy. CgA was analyzed in only 100 patients. NSE and CgA were determined by a immunometric assay. Total PSA was measured by a time-resolved fluoro-immunometric assay. Prior to radiotherapy CgA was elevated in 16 of 100 patients, and NSE was elevated in 33 of the 161 patients. There was no association between grade, T category or pretreatment PSA and the levels of neuroendocrine markers. Pretreatment-elevated serum NSE, but not initial CgA, identified patients with an unfavorable prognosis. A < 50% reduction of PSA 3 months after radiotherapy was associated with decreased failure-free 10 years urvival. Multivariate analysis demonstrated an increased risk of failure for patients with elevated pretreatment NSE and PSA values, T3 category, and decline of PSA less than 50% 3 months after radiotherapy. The presence of none or several risk factors (1-4) defined clearly separable groups. Together with T category and pretreatment serum PSA values, serum NSE values before radiotherapy and decrease of serum PSA 3 months after radiotherapy represent easily assessable prognostic parameters in patients undergoing curative radiation treatment for prostate cancer.

Enolasa específica neuronal sanguínea en neonatos con asfixia perinatal

Neuron-specific enolase (NSE) is a sensitive marker of brain injury after hypoxia or ischemia. There are few studies about its usefulness in asphyctic newborns. To study the correlation between blood NSE levels and neurological outcome in newborns with hypoxic ischemic encephalopathy. We have determined the blood values of NSE by radioimmunoassay in 25 asphyctic term-newborns with clinical encephalopathy (of mild, moderate and severe degree) and in 22 healthy term newborns (control group). Blood samples were obtained between 24 and 72 hours after birth in all neonates. Surviving infants were followed for a variable time (median: 3.5 years; range: 1-6) and the neurological status was determined. NSE levels in the group of asphyctic neonates who died or developed neurological sequelae (n= 6; mean: 116.4 ng/ml; range: 42-226) were significantly higher than NSE values in the group of asphyctic neonates who were neurologically normal at follow-up (n= 19; mean: 21.3 ng/ml; range: 7.4-40), with p< 0.001. There were not differences between NSE values in the group of asphyctic neonates who developed neurologically normal and the control group (mean: 7.6 ng/ml; range: 10.3-28.3). Sensitivity and specificity of blood NSE as predictor of poor outcome were, respectively, 100% and 78%. The combined specificity for blood NSE together with a moderate/severe encephalopathy was 95%. The presence of elevated NSE values in blood after perinatal asphyxia can be a sensitive indicator of conspicuous brain damage. The combined information provided by the severity of the encephalopathy together with the blood NSE values have shown a high predictive value for neurological outcome.

Prognostic factors in advanced non-small cell lung cancer: elevated serum levels of neuron specific enolase indicate poor prognosis.

Non-small cell lung cancer (NSCLC) is resistant to chemotherapy and prognosis of advanced NSCLC patients is considered to be dependent on various prognostic factors. We analyzed prognostic factors in patients with advanced NSCLC who had been enrolled in clinical trials conducted by the Okayama Lung Cancer Study Group between 1978 and 1992 using two kinds of multivariate analysis, Cox's multivariate analysis and recursive partitioning and amalgamation (RPA) analysis. The first analysis was performed on 261 patients using 28 variables. Performance status (PS), clinical stage, liver metastasis or serum albumin level was an independent prognostic factor by Cox's analysis. In the second analysis performed on 128 patients having data on neuron specific enolase (NSE), NSE was the most important prognostic factor. Using the RPA method, three subgroups with significantly different survival potentials were defined. Among them, patients with normal serum NSE levels and good PS were found to obtain a markedly favorable prognosis [median survival time (MST) 22.1 months, 3-year survival rate 42.9%], whereas the survival of patients with elevated serum NSE levels and bone metastasis was extremely short (MST 4.7 months, 3-year survival rate 0%). These results indicate that analysis of prognostic factors including serum levels of NSE is useful for predicting the survival of patients with advanced NSCLC.

Screening for multiple endocrine neoplasia type 1 and hormonal production in apparently sporadic neuroendocrine tumors.

Screening was performed in 130 consecutive patients with apparently sporadic neuroendocrine tumors (NET) to assess the prevalence of multiple endocrine neoplasia type 1 (MEN1) and hormonal production. Screening for MEN1 included measurement of serum calcium and PTH [PTH-(1-84)], gastrin, PRL, and insulin-like growth factor type I (IGF-I) levels. MEN1 genetic testing was performed in patients with two components of the MEN1 syndrome. Screening for hormonal production included measurement of serum neuron-specific enolase (NSE), calcitonin (CT), glycoprotein alpha-subunit (GP alpha), hCG beta-subunit (free hCG beta), and somatostatin levels. Twenty-four-hour urinary free cortisol (UFC) and 5-hydroxyindolacetic acid (5-HIAA) determinations were also performed. Four patients had hyperparathyroidism, none of whom had pituitary or familial disease. Hyperprolactinemia was compatible with a pituitary disease in one patient. No acromegalic feature or any increase in IGF-I was found. Hypergastrinemia, compatible with an associated pancreatic NET, was found in one patient. Genetic screening of the MEN1 gene was performed in five of the six patients with two components of the MEN1 syndrome. A nonsense mutation (Arg108stop) was identified in the tumor of one patient. Elevated NSE, 5-HIAA, CT, GP alpha, free hCG beta, SMS, and nonsuppressible UFC were found in 47%, 46%, 14%, 19%, 12%, 3%, and 6% of NET patients, respectively. Production of CT, GP alpha, and free hCG beta was highly related to the primary site: all but two of these secretions originated in foregut NET. 5-HIAA secretion was found in 27% of foregut-derived and 85% of midgut-derived NET. In conclusion, MEN1 is a rare event in patients presenting with apparently sporadic NET. It occurred mainly in foregut NET and should be screened for by serum calcium and PTH-(1-84) measurements. Routine hormonal measurements should depend on the primary site. NSE, 5-HIAA, CT, and alphaGP should be routinely measured in foregut-derived NET; only serum NSE and 5-HIAA measurements are recommended in midgut-derived NET.

Neuron-specific enolase and chromogranin A as markers of neuroendocrine tumours.

Circulating neuron-specific enolase (NSE) and chromogranin A (CgA) were measured in 128 patients with neuroendocrine tumours (NET) to compare their sensitivity and specificity, to investigate factors associated with elevated serum levels and to determine the usefulness of these markers in the follow-up of NET patients. NSE (Cispack NSE, Cis Bio International, Gif-sur-Yvette, France; normal <12.5 microg l(-1)), and chromogranin A (CgA-Riact, Cis Bio International, normal <100 microg l(-1)) were measured in 128 patients without renal insufficiency. There were 99 patients with gastroenteropancreatic (GEP) NET, 19 with medullary thyroid carcinoma and ten with phaeochromocytoma. Fifty-three patients with non-NET were studied as controls. Serum NSE and CgA levels were elevated in 48 (38%) and 76 (59%) of the 128 NET patients respectively. In all groups of NET patients, CgA proved to be more sensitive than NSE. NSE and CgA had a specificity of 73% and 68% respectively. Immunostaining for NSE was positive in three out of eight controls with elevated CgA levels, whereas immunostaining for CgA and synaptophysin was negative in all cases. Elevated CgA levels were significantly associated with two independent parameters, namely the presence of other secretions (P = 0.0001) and a heavy tumour burden (P = 0.001). Elevated NSE levels were exclusively associated with poor tumour differentiation (P = 0.01). Among six patients with NET followed for 11-37 months, CgA appeared to be a better marker of tumour evolution than NSE. We suggest that CgA ought to be the only general marker screened in NET patients.

Neuron-specific enolase in non-neoplastic lung diseases, a marker of hypoxemia?

Neuron-specific enolase (NSE) is a glycolytic enzyme localized within neuronal and neuroendocrine tissues. Serum NSE is widely used as a marker of neuroendocrine tumors. Moderate serum NSE elevation has been reported in some patients with benign lung diseases. We decided to investigate whether the elevation of serum NSE in non-neoplastic lung diseases is connected with hypoxemia and to what extent the recovery of sufficient ventilation with a respirator may influence NSE concentrations. Serum NSE was estimated by means of radioimmunoassay in 83 patients with various non-neoplastic lung diseases. Serum NSE exceeding 12.5 micrograms/L was significantly more frequent in patients with marked hypoxemia (PaO2 < 6.67 kPa; p = 0.03) than in others. The median NSE value in the group of patients without respiratory failure (Ro) was 7.2 micrograms/L (10% > 12.5 micrograms/L), in the group of patients with respiratory failure not requiring mechanical ventilation (Rf) it was 8.5 micrograms/L (24% > 12.5 micrograms/L), and in the group of patients with respiratory failure requiring mechanical ventilation (Rfv) 13.1 micrograms/L (60% > 12.5 micrograms/L). The differences between the Rfv group and the other two groups (Rf and Ro) were significant (P = 0.049 and p = 0.0004, respectively). During successful mechanical ventilation elevated serum NSE decreased to values below the cutoff in 8/10 patients. We conclude that serum NSE elevation is a frequent event in patients with terminal hypoxemia in the course of benign lung diseases. Normalization of serum NSE is observed in the majority of patients during the first week of mechanical ventilation.

Neuron-specific enolase: reference values in cord blood.

With foetal sonography prenatal detection of tumours has become more frequent. To evaluate and treat these infants it is necessary to identify the tumour postnatally. Elevated neuron-specific enolase is a biochemical marker of neuroblastoma. Since conditions during birth may influence neuron-specific enolase concentration in foetal serum, specific reference values in cord blood are required. Cord blood samples were taken from 192 healthy term newborns and concentration of neuron-specific enolase was measured by enzyme immunoassay (EIA). Median neuron-specific enolase concentration in the reference group was 8.0 micrograms/l and the 5th-95th percentiles were 4.8-19.4 micrograms/l. No differences between male and female newborns were detected (p = 0.13). Measurement of neuron-specific enolase in cord blood, in comparison with our reference values, offers an early postnatal possibility of confirming the diagnosis of neuroblastoma.

A predictive parameter in patients with brain related complications after cardiac surgery?

The prognostic estimation of cerebral complications after cardiac surgery is a major problem in the early postoperative period. Neuron specific enolase (NSE) is an enzyme involved in glycolysis, which is localized in neurons and axonal processes. It escapes into the blood and cerebrospinal fluid at the time of neural injury. Therefore we focused the study on the question of how far serum levels of neuron specific enolase can predict the neurological and neuropsychological outcome after cardiac surgery. We determined, with a prospective study design of NSE serum levels in 200 patients undergoing cardiac surgery preoperatively, right after the operation and 48 h later. The NSE was measured with a solid phase enzyme immuno assay which utilized a highly specific monoclonal antibody to NSE. We evaluated the neurological and neuropsychological status before and 72 h after surgical intervention. As a control group we recruited 50 patients undergoing general surgical treatment. The preoperative serum levels of NSE are constantly low in all patients with a mean value of 11.1 ng/ml (8.3-13.6) and a mean +/- S.D. of 3.12 in the main group and a mean value of 9.6 ng/ml (7.8-10.3) and a mean +/- S.D. of 1.84 in the control group. The early postoperative measurements indicated a significant increase to a mean value of 19.7 ng/ml (8.7-70.9) with a mean +/- S.D. of 2.89 in the main group. In contrast there is no increase of NSE serum levels after general surgery. The 48 h postoperative mean levels declined to 14.2 ng/ml (9.9-26.2), S.D. of 3.23. In 17 out of the 200 patients a neurological complication occurred. Elevated NSE levels were found in 16 of these 17 patients. The highest concentrations of NSE were measured in 7 patients with the most severe neurological complications being transient ischemic attack and stroke. The early serum levels of NSE after cardiopulmonary bypass, in those patients with severe neurological deficits, indicate that NSE is a suitable marker for the detection and quantification of cerebral injury after open heart surgery. Therefore, in addition NSE seems to be of predictive value for the clinical outcome and gives implications for the treatment and prognosis of patients with brain related complications in cardiac surgery.

Neuron-specific enolase as an aid to outcome prediction in head injury.

A statistically significant elevation was observed in serum and CSF neuron-specific enolase (NSE) levels in patients with major head injury, relative to control individuals. No correlation was noted between serum NSE and either APACHE II, Injury Severity Score (ISS), Glasgow Outcome Score (GOS) or Glasgow Coma Scale (GCS). A significant correlation was noted between CSF NSE levels and GCS, but not between CSF NSE and APACHE II, ISS or GOS. Of the patients with major head injury, 100% had NSE CSF levels above the normal level, while 47% had elevated serum NSE levels. In nine patients with major head injury, changes in CSF levels reflected changes in serum NSE levels. In all nine patients, serum NSE decreased to reach normal values, regardless of the outcome as predicted by the GOS. Therefore, while NSE would appear to be a marker of neuronal cell damage, other markers are also essential.

Do neuron-specific enolase levels discriminate between small-cell lung cancer and mediastinal tumors?

The capacity of pretherapeutically assessed neuron-specific enolase (NSE) to differentiate between small cell lung cancer (SCLC) and mediastinal tumors was investigated retrospectively in a series of 320 patients. NSE was found to be increased in 95/130 (73.1%) patients with SCLC, in 4/62 (6.5%) patients with Hodgkin's disease, in 10/58 (17.2%) patients with non-Hodgkin's lymphoma, in 5/16 (31.3%) patients with teratoma, and in 6/54 (11.1%) patients with thymoma. The cut-off value, defined as the 95% percentile of a reference population suffering from benign pulmonary disorders (n = 192), was set at 13.8 ng/ml. When this discrimination level was increased to 26.4 ng/ml, which corresponds to a 95% specificity versus the total group with mediastinal tumors, SCLC was recognized with a detection rate of only 49.2%. In conclusion, increased NSE concentrations in a patient with a hilar mass and/or mediastinal widening on X-ray are not always diagnostic of SCLC due to the high rate of elevated NSE values associated with mediastinal tumors. However, in a patient who presents with a hilar mass and a high NSE level, bronchoscopy is always indicated to obtain adequate specimens for histology in order to plan an appropriate therapeutic regimen.

Neuron-specific enolase in gerbil brain and serum after transient cerebral ischemia.

The sensitivity and validity of serum neuron-specific enolase as a marker of brain injury were tested after global cerebral ischemia. Sixty-nine Mongolian gerbils were perfusion fixed after variable reperfusion after 5-minute (group 1) or 15-minute (group 2) bilateral carotid occlusion. Neuron-specific enolase was analyzed by an enzyme immunoassay in serum of control, sham-operated, and ischemic animals before euthanasia and in nonischemic gerbil brains. Brains were processed for histology, immunohistochemistry, and morphometric evaluation of ischemic neuronal damage. After cerebral ischemia, loss of neuronal immunoreactivity was closely associated with increased neuron-specific enolase serum levels, which were significantly elevated by 24 hours (group 1) or by 4 hours (group 2) of reperfusion (P < .001). Response of serum levels depended on the duration of preceding ischemia, and maximum concentrations were approximately 3-fold (group 1) or 20-fold (group 2) those of nonischemic control. Morphological damage became apparent 48 hours (group 1) or 12 hours (group 2) after ischemia, as indicated by histological and morphometric data. Significantly elevated neuron-specific enolase serum levels could be demonstrated as a consequence of ischemia-induced cytoplasmic loss of neuron-specific enolase in central nervous system neurons, corresponded quantitatively to the severity of cerebral ischemia, and were detectable before irreversible neuronal injury. Therefore, analysis of serum neuron-specific enolase is suggested to be both a valuable diagnostic tool in clinical management of the initial stages of global cerebral ischemia and a prognostic parameter during the postischemic course.

Terminal neuroendocrine differentiation of human prostate carcinoma cells in response to increased intracellular cyclic AMP.

Recent clinicopathologic studies have shown that many prostatic adenocarcinomas express focal neuroendocrine differentiation and that neuroendocrine differentiation is most apparent in advanced anaplastic tumors. While studying growth-regulatory signal transduction events in human prostate carcinoma cell lines, we found that in two of four cell lines, the androgen-sensitive line LNCaP and the highly metastatic androgen-independent line PC-3-M, elevation of cAMP through addition of cAMP analogues or phosphodiesterase inhibitors induced a markedly neuronal morphology. Also in LNCaP cells ultrastructural analysis showed that cAMP induced the appearance of neurosecretory cell-like dense-core granules. Phenotypic analysis of untreated LNCaP and PC-3-M cells showed that both cell lines express markers of the neural crest including S-100, chromogranin A, pp60c-src, and neuron-specific enolase as well as the epithelial marker KS1/4 and stage-specific embryonic antigen 4. In PC-3-M cells, cAMP markedly elevated neuron-specific enolase protein and caused an increase in the specific activity of the neuroendocrine marker pp60c-src, and in both cell lines expression of KS1/4 and stage-specific embryonic antigen 4 was down-regulated. In addition to effects on lineage markers, cAMP treatment induced G1 synchronization, growth arrest, and loss of clonogenicity, indicating terminal differentiation. Our data provide direct evidence of plasticity in the lineage commitment of adenocarcinoma of the prostate. We have shown that cell-permeant cAMP analogues can induce terminal differentiation, suggesting that hydrolysis-resistant cyclic nucleotides may present an additional approach to the treatment of advanced prostate cancer.

A more objective staging of advanced prostate cancer--routine recognition of malignant endocrine structures: the assessment of serum TPS, PSA, and NSE values.

Bone scans, serum tissue-specific polypeptide antigen (TPS), prostate specific antigen (PSA), and neuron-specific enolase (NSE) were assessed in a total of 80 hormonally treated prostate cancer patients. Thirty-nine patients were free of osseous lesions; in 8 subjects, 3 or fewer scintigraphic hot spots were found; in 29 patients, more than 3 bone lesions were recorded. In 3 patients, a partial contribution of endocrine cell cancer structures was found, while in one patient, a homogeneous small cell carcinoma was detected at autopsy. Measurement of the serum PSA test showed a clear-cut rise from stage D0 subjects to stage D2 patients, with a small number of bone lesions (> or = 3). However, a relative decrease in the mean PSA level was measured with further progression in a number of hot spots in bone (> 3). Androgen threshold that is critical for the induction of the PSA (and PAP) expression seems to differ markedly in various cell subpopulations that arise during adenocarcinoma dedifferentiation. This fact explains not only the rise in serum PSA in the majority of progressive and previously castrated subjects after an initial period of hormonal responsiveness, but also a relative decline of androgen-dependent PSA expression with further tumor progression. Localized disease was accompanied with normal or just slightly elevated TPS concentration. In metastatic tumors, serum TPS values revealed a steady increase with the progression in bone. These data seem to reflect not only an increase in tumor proliferation rate with progressively transformed genome, but also the rise in the number of proliferating cells. The presence of nonepithelial transformed tumor structures, such as small cell cancer within a bulk of adenocarcinoma, reduces or normalizes numerical serotests values of both TPS and PSA even during tumor progression. The extent of such decline depends upon the bulk of the endocrine component. The assessment of the above parameters, especially when associated with elevated plasma NSE concentrations, may help in distinguishing an advanced adenocarcinoma with and without elements of malignant neuroendocrine structures. The proposed approach, modified by applying corresponding organ-specific markers, may be checked for its possible general use in staging protocols of various heterogeneous tumors.

Serum neuron-specific enolase and lactate dehydrogenase as predictors of response to chemotherapy and survival in non-small cell lung cancer.

The prognostic value of serum neuron-specific enolase (NSE) and lactate dehydrogenase (LDH) was prospectively assessed in 42 patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) treated within two chemotherapy trials. Pretreatment NSE levels ranged from 4.6 to 34.6 ng/mL (median value, 7.5) and were above 10 ng/mL in ten patients (23.8%). LDH levels varied between 85 U/L and 2,484 U/L (median value, 220) and were above 250 U/L in 12 patients (29.3%). Elevated levels of both enzymes were significantly more common in patients with metastatic disease than in those with locoregional disease (40% v 9% for NSE and 40% v 18% for LDH, respectively). Strong positive correlation (correlation factor 0.693) was found between NSE and LDH serum levels. The levels of both markers did not correlate with age, sex, previous therapy, performance status, or histology. Responses to chemotherapy were seen more frequently in patients with elevated NSE levels (six of ten, 60%) than in those with normal values (seven of 32, 22%; P = .02). Similar correlation was found for LDH: Response was seen in seven of 12 patients with elevated levels (58%) and in six of 29 (21%) of those with normal values (P = .02). In a logistic regression analysis, both markers considered individually remained significant when adjusted by sex, age, performance status, prior therapy, histology, and extent of disease. Three pretreatment characteristics, high levels of NSE and LDH (both considered as continuous variables) and metastatic disease, were found to be associated with shorter survival; with adjustment for extent of disease, however, NSE and LDH were no longer correlated with shorter survival. These data suggest potential clinical value of NSE and LDH determination in treatment selection of NSCLC patients.

Neuron-specific enolase as a prognostic factor in metastatic malignant melanoma

Serum neuron-specific enolase (NSE) was measured in 63 patients with metastatic malignant melanoma. 20 patients (32%) had elevated serum NSE (> 10 μg/l) before the start of treatment. Another 13 patients (21%) developed pathological NSE values during the course of the disease. In many patients, elevated NSE was related to a large tumour burden, and a gradual rise in serum NSE indicated disease progression. Patients with elevated pretreatment NSE had a median survival time of 3 months compared with 12 months for those with normal pretreatment NSE values. NSE thus proved to be a useful prognostic factor in metastatic malignant melanoma.