Expression of class III beta-tubulin in malignant epithelial tumours: an immunohistochemical study using TU-20 and TuJ-1 antibodies

Class III beta-tubulin has been discovered as a marker of early phases of neuronal differentiation in developmental conditions, as well as in different tumours of neuronal origin. More recently, the expression of class III beta-tubulin molecule has been described as a marker of different types of malignant epithelial tumours. This study attempts to compare the immunostaining features of two different mouse monoclonal antibodies TU-20 and TuJ-1, both detecting class III beta-tubulin, in a group of twenty bioptically evaluated carcinomas of various sites. The proposal that class III beta-tubulin expression can correlate with the degree of tumour differentiation and thus could be potentially used as predictive marker of prognosis has been previously done; one of aims of our study was to confirm this hypothesis. Our results showed that both TuJ- 1 and TU-20 antibodies displayed similar immunostaining profile and pattern within individual tumours. Surprisingly, we discovered that only 50% of tumours included in our group showed expression of class III beta-tubulin, however, positive immunoreaction did not correspond with the degree of differentiation of individual tumours. In our group of carcinomas, the class III beta-tubulin positivity was not related to the tumour site, histologic type of tumour or its grade.     

促泌素在胃肠道神经内分泌肿瘤中的表达及其临床意义

目的 比较促泌素(secretagogin,SCGN)与传统的神经内分泌标记物在胃肠道神经内分泌肿瘤中的表达差异.方法 收集胃肠道手术标本共88例,其中实验组为8例类癌和20例非典型类癌,对照组为40例腺癌伴神经内分泌分化和20例腺癌.所有标本均使用SCGN、PGP9.5、CD56、NSE、Syn及CgA进行免疫组织化学SP两步法染色.结果 SCGN可在胃肠道粘膜同有层腺体的弥散性神经内分泌细胞中表达,多显示“开放型”的神经内分泌细胞.除CD56和NSE各在1例胃肠道腺癌中阳性表达外,SCGN及其它标记物在20例腺癌中均无表达,所有标记物之间均无统计学差异(P＞0.05).SCGN在40例胃肠道腺癌伴神经内分泌分化、20例非典型类癌和8例类癌巾的阳性表达率均最高,分别为62.5％ (25/40)、90％(18/20)和100％(8/8),PGP9.5阳性表达率均最低分别为32.5％(13/40)、45％ (9/20)和37.5％(3/8),两标记物在这三组肿瘤中的表达均有显著统计学差异(P＜0.01),而CD56、NSE、Syn和CgA在以上三组肿瘤中的表达率均较高,与SCGN比较均无统计学差异(P＞0.05).所有标记物在腺癌伴神经内分泌分化、非典型类癌和类癌中的阳性表达率均明显高于腺癌(P＜0.01);SCGN、Syn和CgA在非典型类癌和类癌巾的阳性表达均高于腺癌伴神经内分泌分化(P＜0.05);所有标记物在非典型类癌和类癌之间的阳性表达率均无统计学差异(P＞0.05).结论 SCGN作为一种新型的神经内分泌标记物与传统标记物Syn和CgA联合,可应用于胃肠道神经内分泌肿瘤的临床病理诊断.     

Gastrointestinal carcinoid tumours. Histogenetic, histochemical, immunohistochemical, clinical and therapeutic aspects

The increased knowledge of the pathobiology of gastrointestinal carcinoid (neuroendocrine) tumours and the improved therapeutic possibilities have brought a demand for more precise diagnosis. Although the carcinoid tumours can often be tentatively recognized in routinely processed microscopic slides, their more accurate identification requires additional diagnostic procedures. General neuroendocrine markers such as the argyrophil reaction of Grimelius and immunohistochemistry with application of antibodies against chromogranin A and of neuron-specific enolase are discriminatory staining methods which are used to reveal the neuroendocrine origin of almost all highly differentiated carcinoid tumours of the gastrointestinal tract. Mid-gut carcinoids, which predominate among these tumours almost unexceptionally contain serotonin. This biogenic amine can be demonstrated by the argentaffin reaction of Masson, serotonin immunoreactively or by formalin-induced fluorescence. The characteristic staining pattern of mid-gut carcinoids is almost invariably preserved in the metastatic deposits and consequently the staining methods for identifying serotonin can also be used on metastases to reveal a primary mid-gut carcinoid. The enterochromaffin-like (ECL) cell carcinoids of the body and fundic area of the stomach often seen in association with pernicious anaemia are argyrophil with the Sevier-Munger silver stain. Other neuroendocrine tumours, viz. antral, duodenal and rectal carcinoids should be studied by a battery of relevant peptide hormone antisera for adequate diagnosis. During the last decade new peptide hormones have been found in circulation in patients with carcinoid tumours, but serotonin and urinary 5-HIAA are still the most important markers for carcinoids of the mid-gut origin. Other clinically useful tumour markers are chromogranin A + B, pancreatic polypeptide, human chorionic gonadotropin alpha and beta subunits. For localizing procedures, angiography is the most reliable investigative method for primary tumours in the gut, whereas CT-scan and ultrasound investigations are good for detection of liver metastases. During the last five years, the therapy for malignant carcinoid tumours has been considerably improved. Chemotherapy has only revealed objective response rates in about 10-30% of the patients giving median survivals from start of therapy of about 10 months. Recently treatment with alpha interferons and the new somatostatin analogue octreotide have given objective responses in 50-75% of patients with malignant mid-gut carcinoid tumours. These patients have now a median survival from start of therapy of 70 months when treated with alpha interferons. In the future new therapies will come into use such as monoclonal antibodies and perhaps also agents blocking different growth factors.     

Neuron-specific enolase in mucosal endocrine cells and carcinoid tumours of the small intestine: A comparative study with neuron-specific enolase immunocytochemistry and silver stains

Summary Endocrine cells of human small intestinal mucosa, small intestinal carcinoids and carcinoid liver metastases were stained with an immunocytochemical technique using an antiserum against neuron-specific enolase (NSE), with the argyrophil technique of Grimelius and with the argentaffin technique of Masson. In the normal mucosa, scattered NSE-immunoreactive cells were seen mainly in the deeper parts of the crypts. These cells, as shown in the same sections, corresponded to the argentaffin and/or argyrophil cells indicating that they were of endocrine type.All intestinal carcinoids (16 cases) displayed NSE immunoreactivity. However, this reaction did not correlate on the cellular level with the silver techniques employed. Thus, many tumour cells were NSE immunoreactive but lacked an argentaffin or argyrophil reaction and vice versa. On the light microscopical level the silver techniques reveal the presence of neurohormonal granules in the tumour cells, while the NSE immunoreactivity appears to disclose neuroendocrine differentiation of the tumour cells irrespective of their hormone and granular content.Out of 13 carcinoid liver metastases, eight displayed strong NSE immunoreactivity, three were weakly stained and two were unreactive. Consecutive or the same tumour sections showed an argentaffin and argyrophil reaction in all carcinoid metastases. Since silver staining provides one type of information and NSE immunocytochemistry another, they provide in combination a good discriminator for neuroendocrine tumours.     

Expression of class III β-tubulin in normal and neoplastic human tissues

 The class III β-tubulin isotype is widely used as a neuronal marker in normal and neoplastic tissues. This isotype was, however, also immunodetected in certain tumours of non-neuronal origin such as squamous cell carcinoma. Using a newly described monoclonal antibody we compared the distribution of class III β-tubulin in normal and neoplastic tissues. The TU-20 mouse monoclonal antibody was prepared against a conserved synthetic peptide from the C-terminus of the human class III β-tubulin isotype, and its specificity was confirmed by immunoblotting, by competitive enzyme-linked immunosorbent assay and by immunofluorescence microscopy on cultured cells. In different cell lines of various origins the antibody reacted only with neuroblastoma Neuro-2a cells and with embryonal carcinoma P19 cells stimulated to neuronal differentiation by retinoic acid. Immunohistochemistry on formaldehyde-fixed paraffin-embedded normal human tissues revealed the presence of the class III β-tubulin isotype in cell bodies and processes of neuronal cells in the peripheral and central nervous systems. In other tissues, this β-tubulin isotype was not immunodetected. Class III β-tubulin was found in all cases of ganglioneuroblastoma, ganglioneuroma, medulloblastoma, neuroblastoma, sympathoblastoma and in one case of teratoma. In contrast, no reactivity was detected in tumours of non-neuronal origin, including 32 cases of squamous cell carcinoma. The results indicate a specific TU-20 epitope expression exclusively in neuronal tissues. The antibody could thus be a useful tool for the probing of class III β-tubulin functions in neurons as well as for immunohistochemical characterisation of tumours of neuronal origin. Accepted: 29 July 1997     

Polypeptide growth factors in gastroenteropancreatic neuroendocrine tumours

Polypeptide growth factors form a potent class of extracellular signal molecules in the regulation of cellular differentiation and proliferation. Disturbances in the expression of growth factors influence the normal pathway of differentiation and lead to cellular transformation and tumour progression. Contemporary medical studies report that various growth factors such as those for platelet-derived growth factor, vascular endothelial growth factor, epidermal growth factor, hepatocyte growth factor and insulin-like growth factor are expressed in gastroenteropancreatic neuroendocrine tumours (GEP/NET). Polypeptide growth factors have great significance in the growth, progression and development of metastases by various tumours. We describe the role of growth factors in GEP/NET on the basis of the available reports of medical research.     

Transcription factor snail1 expression and poor survival in pharyngeal squamous cell carcinoma

Snail1, a key regulator of epithelial-mesenchymal transition (EMT), plays an important role in tumour progression. Previous studies of snail1 have mainly focused on the epithelial tumour cells. The objective of this study was to evaluate the expression of snail1 protein in endothelial cells, stromal myofibroblasts and malignant epithelial cells of pharyngeal squamous cell carcinomas (PSCC), as well as its relation to clinicopathological features and survival. One hundred and ten tissue microarray samples were analyzed for snail1 expression using immunohistochemistry. In endothelial cells snail1 expression was observed in 51 (48%) of 107 cases and it predicted reduced disease specific survival (DSS) (p=0.009). In 49 (46%) tumour samples snail1 immunostaining was detected in stromal myofibroblasts and there was a tendency to poorer DSS in that group (p=0.067). Snail1 expression in endothelial cells and stromal myofibroblasts is also associated with hypopharyngeal tumours (p=0.01 and p=0.038 respectively), increasing T category (T3-4) (p=0.005, p=0.037 respectively) and poorer general condition of the patient (Karnofsky performance status score <70; p=0.029, p=0.039 respectively). Moreover endothelial expression correlated with advanced stage (III-IV) (p=0.005) and poorer differentiation (grade 2-3; p=0.012). In malignant epithelial cells snail1 immunostaining was detected in 75 of 110 cases (68%). Expression of the protein was more common in hypopharyngeal tumours (p=0.044). Snail1 positive tumours associated with a lower Karnofsky performance status score (p=0.039) and regional failure (p=0.042). Our findings indicate that snail1 protein expression in endothelial cells and to some extent also in tumour stromal myofibroblasts seems to be a predictor of poor survival in PSCC. The presence of snail1 protein in tumour microenvironment rather than in malignant epithelial tumour cells may induce tissue remodelling and tumour progression.     

Evaluation of PD-L1 expression in a large set of gastroenteropancreatic neuroendocrine tumours and correlation with clinicopathological data

BackgroundTargeting programmed death protein 1 (PD-1) or its ligand PD-L1 is a promising therapeutic approach for many types of cancer in which PD-L1 is overexpressed. However, data on PD-L1 expression levels in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are limited and contradictory.MethodsWe evaluated PD-L1 expression in 457 archived, formalin-fixed, paraffin-embedded GEP-NEN samples from 175 patients by immunohistochemistry using the highly sensitive monoclonal anti-PD-L1 antibody 73-10. The immunostaining was semiquantitatively evaluated using a 12-point immunoreactivity score (IRS) taking both PD-L1-positive tumour cells and immune cells into account. Tumour samples with an IRS ≥ 3 were considered PD-L1-positive. Results were correlated with clinicopathological data and with the expression of several typical markers and receptors for neuroendocrine tumours.ResultsOf the GEP-NEN samples, 73% were PD-L1-positive. The median IRS value across all samples was 4.0, corresponding to low expression. PD-L1 immunostaining was predominantly localised at the plasma membrane of the tumour cells. Positive correlations were observed between PD-L1 expression and tumour grading or Ki-67 index, between PD-L1 expression and the expression of chromogranin A, and between PD-L1 expression and the expression of each of the five somatostatin receptors. PD-L1 expression was lower in tumours with lymph node metastases at diagnosis than in those without regional metastasis and lower in high-stage than in earlier-stage tumours. No association was noted between PD-L1 expression and patient survival.ConclusionsPD-L1 expression is common in GEP-NENs and increases with malignancy. Therefore, especially in high-grade GEP-NENs, targeting the PD-1/PD-L1 axis could be a promising additional therapeutic strategy.     

Nestin, a neuroectodermal stem cell marker molecule, is expressed in Leydig cells of the human testis and in some specific cell types from human testicular tumours

The intermediate filament protein nestin is predominantly expressed in some stem/progenitor cells and appears to be a useful molecular tool to characterise tumours originating from precursor cells of neuroectodermal and mesenchymal lineages. Leydig cells originate in the adult testis by differentiation from stem cells and express a variety of neural and neuroendocrine markers. The possible expression of the neural stem cell marker nestin in Leydig cells and testicular tumour cells was determined by analysing the patterns of nestin expression in normal and pathological human testes by Western blot and immunohistochemical methods. In normal testis, nestin was found in some vascular endothelial cells, a subset of peritubular spindle-shaped cells and some Leydig cells; spermatogenic and Sertoli cells were unstained. In normal Leydig cells, nestin was distributed in the perinuclear cytoplasm and accumulated in the crystalloids of Reinke with ageing. In non-tumour pathologies (cryptorchidism, impaired spermatogenesis), the seminiferous tubules were immunonegative, whereas hyperplastic Leydig cells showed cytoplasmic immunolabelling. In testicular malignancies, nestin was localised in the Sertoli cells of the seminiferous tubules affected with intratubular germ cell neoplasia, in the hyperplastic Leydig cells associated with these tumours and in some components (mesenchymal and neuroepithelial cells) of teratomas; spermatocytic and non-spermatocytic seminomas were unstained. Some vascular endothelial cells were immunolabelled in all tumour samples. Thus, nestin is expressed in a population of normal and hyperplastic Leydig cells and in Sertoli cells in the presence of intratubular germ-cell neoplasia. Nestin may be a good marker for identifying components of testicular teratomas.The two first authors participated equally in this workThis work was supported by a grant from the Fondo de Investigaciones Sanitarias (FIS 02/3003 to M.V.T. Lobo)     

Heterogeneous phenotype of human glioblastoma: In vitro study

Glioblastomas (GBMs) are the most lethal primary brain tumours. Increasing evidence shows that brain tumours contain the population of stem cells, so‐called cancer stem cells (CSCs). Stem cell marker CD133 was reported to identify CSC population in GBM. Further studies have indicated that CD133 negative cells exhibiting similar properties and are able to initiate the tumour, self‐renew and undergo multilineage differentiation. GBM is a highly heterogeneous tumour and may contain different stem cell populations with different functional properties. We characterized five GBM cell lines, established from surgical samples, according to the marker expression, proliferation and differentiation potential. CD133 positive cell lines showed increased proliferation rate in neurosphere condition and marked differentiation potential towards neuronal lineages. Whereas two cell lines low‐expressing CD133 marker showed mesenchymal properties in vitro, that is high proliferation rate in serum condition and differentiation in mesenchymal cell types. Further, we compared therapy resistance capacity of GBM cell lines treated with hydroxyurea. Our results suggest that CSC concept is more complex than it was believed before, and CD133 could not define entire stem cell population within GBM. At least two different subtypes of GBM CSCs exist, which may have different biological characteristics and imply different therapeutic strategies. Copyright © 2013 John Wiley & Sons, Ltd.     

Proteomic evaluation of sheep serum proteins

Background

Mammary tumours frequently develop in female domestic cats being highly malignant in a large percentage of cases. Chemokines regulate many physiological and pathological processes including organogenesis, chemotaxis of inflammatory cells, as well as tumour progression and metastasization. In particular, the chemokine/receptor pair SDF-1/CXCR4 has been involved in the regulation of metastatic potential of neoplastic cells, including breast cancer. The aim of this study was the immunohistochemical defininition of the expression profile of CXCR4 in primary and metastatic feline mammary carcinomas and the evaluation of the role of SDF-1 in feline mammary tumour cell proliferation.

Results

A total of 45 mammary surgical samples, including 33 primary tumours (31 carcinomas and 2 adenomas), 6 metastases, and 4 normal mammary tissues were anlyzed. Tumor samples were collected from a total number of 26 animals, as in some cases concurrent occurrence of neoplasm in more than one mammary gland was observed. Tissues were processed for standard histological examination, and all lesions were classified according to the World Health Organization criteria. CXCR4 expression in neoplastic cells was evaluated by immunohistochemistry. The level of CXCR4 immunoreactivity was semi-quantitatively estimated as CXCR4 score evaluating both the number of positive cells and the intensity of staining. Six primary, fibroblast-free primary cultures were obtained from fresh feline mammary carcinomas and characterized by immunofluorescence for CXCR4 and malignant mammary cell marker expression. SDF-1-dependent in vitro proliferative effects were also assayed. CXCR4 expression was observed in 29 out of 31 malignant tissues with a higher CXCR4 score observed in 4 out of 6 metastatic lesions than in the respective primary tumours. In 2 benign lesions analyzed, only the single basaloid adenoma showed a mild positive immunostaining against CXCR4. Normal tissue did not show CXCR4 immunoreactivity. CXCR4 score was statistically significantly associated with the histological features of the samples, showing an increase accordingly with the degree of neoplastic transformation (from normal tissue to metastatic lesions). Finally, in the primary cultures obtained from 6 primary feline mammary carcinomas CXCR4 expression was detected in all cells and its activation by SDF-1 in vitro treatment caused a significant increase in the proliferation rate in 5 out of 6 tumours.

Conclusions

These results indicate that malignant feline mammary tumours commonly express CXCR4, with a higher level in malignant tumours, and, in most of the cases analysed, metastatic cells display stronger immunoreactivity for CXCR4 than the corresponding primary tumours. Moreover, CXCR4 activation in primary cultures of feline mammary carcinomas causes increase in the proliferative rate. Thus, SDF-1/CXCR4 system seems to play a tumorigenic in feline mammary gland malignancy and in vitro cultures from these tumour samples may represent an experimental model to investigate the biological and pharmacological role of this chemokinergic axis.     

Protein kinase D2 regulates chromogranin A secretion in human BON neuroendocrine tumour cells

Chromogranin A is a member of the granin family of acidic secretory glycoproteins that is found in secretory granules of many endocrine cells including neuroendocrine tumour cells. This hormone serves as a model system for autonomous hormone secretion by the so called functional neuroendocrine tumours of the gastrointestinal tract. The precise regulation of chromogranin secretion at the level of the Golgi apparatus is a subject of intense research. The protein kinase D (PKD) family of serine threonine kinases has so far been implicated in the regulation of constitutive secretion in epithelial cells. Here we examined whether PKD2 expression and activity could also play a role in the release of secretory granules from the trans Golgi network (TGN) in neuroendocrine tumour cells and hence be a target to block autonomous secretion by these tumours. Our data show that expression and catalytic activity of PKD2 are required for the release of chromogranin A containing secretory vesicles. Inhibition of PKD2 activity or siRNA knockdown of PKD2 resulted in a marked perinuclear retention of chromogranin A immunofluorescence in the trans Golgi network and led to a marked reduction in basal as well as phorbol ester stimulated secretion of chromogranin A into the supernatant of cells. Thus, PKD2 controls the release of secretory granules in neuroendocrine tumour cells at the level of the Golgi apparatus and could hence serve as a novel target to block hormone secretion in functional neuroendocrine tumours.     

S-100 protein in human lung neuroendocrine neoplasms. Immunohistochemical study of 14 cases and review of the literature

A group of lung neuroendocrine (NE) neoplasms are investigated in view of the possible presence of S-100 protein immunoreactivity in their cells. The selected tumours were classified according to Gould et al. (1983a) and Mosca et al. (1985). They comprise 5 carcinoids, 3 neuroendocrine carcinomas of the well-differentiated type, or peripheral carcinoids, 5 neuroendocrine carcinomas of the intermediate cell type, or intermediate-cell, poorly differentiated carcinomas, 3 neuroendocrine carcinomas of the microcytoma type, or small cell carcinomas-SCC and a nodal metastasis of microcytoma. All but 2 tumours were immunoreactive for neuron specific enolase (NSE). Few S-100 immunoreactive cells were detected in 4 out of 5 carcinoids, in 1 out of 3 peripheral carcinoids, in 4 out of 5 poorly differentiated carcinomas and in the 3 microcytomas examined. No S-100 positive cells were found in the SCC's nodal metastasis. The S-100 immunolabelled cells can be interpreted as dendritic reticulum cells migrating through the tumours. However, in one case of typical carcinoid, abundant S-100 positive cells were detected: their stellate morphology and their intimate relation with neoplastic cells suggest that they are part of the neoplasia as a sort of satellite cell.     

Irradiation Decreases the Neuroendocrine Biomarker Pro-Opiomelanocortin in Small Cell Lung Cancer Cells In Vitro and In Vivo

Background

Small cell lung cancer (SCLC) is an extremely aggressive disease, commonly displaying therapy-resistant relapse. We have previously identified neuroendocrine and epithelial phenotypes in SCLC tumours and the neuroendocrine marker, pro-opiomelanocortin (POMC), correlated with worse overall survival in patients. However, the effect of treatment on these phenotypes is not understood. The current study aimed to determine the effect of repeated irradiation treatment on SCLC cell phenotype, focussing on the neuroendocrine marker, POMC.

Results

Human SCLC cells (DMS 79) were established as subcutaneous xenograft tumours in CBA nude mice and then exposed to repeated 2Gy irradiation. In untreated animals, POMC in the blood closely mirrored tumour growth; an ideal characteristic for a circulating biomarker. Following repeated localised irradiation in vivo, circulating POMC decreased (p< 0.01), in parallel with a decrease in tumour size, but remained low even when the tumours re-established. The excised tumours displayed reduced and distinctly heterogeneous expression of POMC compared to untreated tumours. There was no difference in the epithelial marker, cytokeratin. However, there were significantly more N-cadherin positive cells in the irradiated tumours. To investigate the tumour response to irradiation, DMS79 cells were repeatedly irradiated in vitro and the surviving cells selected. POMC expression was reduced, while mesenchymal markers N-cadherin, β1-integrin, fibroblast-specific protein 1, β-catenin and Zeb1 expression were amplified in the more irradiation-primed cells. There were no consistent changes in epithelial marker expression. Cell morphology changed dramatically with repeatedly irradiated cells displaying a more elongated shape, suggesting a switch to a more mesenchymal phenotype.

Conclusions

In summary, POMC biomarker expression and secretion were reduced in SCLC tumours which regrew after irradiation and in repeatedly irradiation (irradiation-primed) cells. Therefore, POMC was no longer predictive of tumour burden. This highlights the importance of fully evaluating biomarkers during and after therapy to assess clinical utility. Furthermore, the gain in mesenchymal characteristics in irradiated cells could be indicative of a more invasive phenotype.     

A morphometric analysis of individual cell death in bronchial carcinoids

Abstract. The incidence and morphometric characteristics of individual dead cells have been measured in 51 cases of broncho-pulmonary carcinoid tumours. In both typical and atypical carcinoids, these dead cells were distinguished by nuclei that were significantly smaller and less regular than those of 'intact' tumour parenchymal cells. The proportion of dead to all tumour cells was not significantly different for typical and atypical carcinoids (17 and 13%, respectively). For 33 of these tumours, their ploidy status had also been established. In diploid tumours, the proportion of dead cells was 18% and in aneuploid tumours 12%. The prognosis of patients with atypical carcinoids was significantly worse and such tumours were more commonly aneuploid. Thus the incidence of individual cell death does not appear to be positively associated with poor prognosis in this series. The association between 'necrosis' and poor prognosis commented on in the literature may relate more to a different form of cell death, expressed histopathologically as gross coagulative necrosis, the incidence of which is significantly higher among the atypical, aneuploid tumours.     

Discussion of Paper on “Brilliant-Green-Bile Media”

Abstract

Insulin-like growth factor II-messenger RNA-binding protein 3 (IMP3) is an oncofetal RNA-binding protein that promotes tumor cell proliferation by enhancing IGF-II protein synthesis and inducing cell adhesion and invasion by stabilizing CD44 mRNA. IMP3 expression has been studied in many human neoplasms with growing evidence that IMP3 is a biomarker of enhanced tumor aggressiveness. IMP3 expression has been correlated with a poorer phenotypic profile including increased risk of metastases and decreased survival. Only a few studies have examined IMP3 expression in lung cancers. We review here the literature concerning IMP3 expression in lung neoplasms, specifically adenocarcinoma, squamous cell carcinoma, and neuroendocrine tumors of the lung. IMP3 immunohistochemical expression was reported in 27-55% of cases of primary pulmonary adenocarcinoma and in 75-90% of cases of squamous cell carcinoma of the lung. In adenocarcinoma, IMP3 expression was reported to be correlated with more poorly differentiated histological grade, advanced stage of disease and lymph node metastases. IMP3 expression also may be a marker of high grade pre-invasive squamous lesions including high grade dysplasia and carcinoma in situ. In neuroendocrine tumors of the lung, IMP3 expression was expressed in all reported cases of large cell neuroendocrine carcinoma and small cell lung carcinoma, but expression was limited in carcinoid tumors. Overall, IMP3 appears to be a useful diagnostic marker for lung cancer pathology including for discriminating high grade neuroendocrine tumors and low grade carcinoids and for identifying high grade pre-invasive squamous lesions.     

A morphometric analysis of individual cell death in bronchial carcinoids

The incidence and morphometric characteristics of individual dead cells have been measured in 51 cases of broncho-pulmonary carcinoid tumours. In both typical and atypical carcinoids, these dead cells were distinguished by nuclei that were significantly smaller and less regular than those of 'intact' tumour parenchymal cells. The proportion of dead to all tumour cells was not significantly different for typical and atypical carcinoids (17 and 13%, respectively). For 33 of these tumours, their ploidy status had also been established. In diploid tumours, the proportion of dead cells was 18% and in aneuploid tumours 12%. The prognosis of patients with atypical carcinoids was significantly worse and such tumours were more commonly aneuploid. Thus the incidence of individual cell death does not appear to be positively associated with poor prognosis in this series. The association between 'necrosis' and poor prognosis commented on in the literature may relate more to a different form of cell death, expressed histopathologically as gross coagulative necrosis, the incidence of which is significantly higher among the atypical, aneuploid tumours.     

Ghrelin in neuroendocrine tumors

Ghrelin is a 28 amino acid peptide, primarily produced by the oxyntic mucosa X/A like neuroendocrine cells in the stomach. It is also found in the small intestine, hypothalamus, pituitary gland, pancreas, heart, adipose tissue, and immune system. In gastrointestinal neuroendocrine tumors (NETs) ghrelin release has been well documented. Ghrelin is a brain-gut circuit peptide with an important role in the physiological regulation of appetite, response to hunger and starvation, metabolic and endocrine functions as energy expenditure, gastric motility and acid secretion, insulin secretion and glucose homeostasis, as well as in the potential connection to the central nervous system. Recently, there has been a significant interest in the biological effects of ghrelin in NETs. In this article, we present a comprehensive review of ghrelin's expression and a brief summary of ghrelin's physiological role in NETs patients with carcinoids, type A chronic atrophic gastritis (CAG), with or without MEN-1, and with and without liver metastases. We hope, with the research reviewed here, to offer compelling evidence of the potential significance of ghrelin in NETs, as well as to provide a useful guide to the future work in this area.     

Prognostic significance of metallothionein expression in correlation with Ki-67 expression in adenocarcinomas of large intestine

The study aimed at determining levels of metallothionein (MT) and Ki-67 antigen expression in adenocarcinomas of large intestine and examining relation of the expression levels with various clinical and pathological variables. The studies were performed on 81 cases of large intestine adenocarcinoma. Using immunocytochemistry, expressions of MT (positive reaction in 73 cases) and of Ki-67 (positive reaction in 79 cases) antigen were examined and the obtained results were compared with, i.a., grade (G) of the tumour and depth to which intestinal wall was infiltrated by individual tumours. Patient survival analysis was also performed, as correlated to expression levels of the two antigens. The obtained results permitted to disclose that the lower was grade of histological differentiation (G2, G3), the more pronounced was expression of MT and Ki-67. Also, the deeper was neoplastic infiltration of intestinal wall, the more pronounced was MT and Ki-67 expression. Despite the relatively strong correlation between MT expression and Ki-67 expression (r=0.536; p<0.05), only Ki-67 antigen expression in large intestine adenocarcinomas was inversely correlated to survival of the patients. Ki-67 proved to be a better prognostic marker, as compared to MT, in large intestine adenocarcinomas.