S100A6 (Calcyclin) is a prostate basal cell marker absent in prostate cancer and its precursors

S100A6 (Calcyclin) is a calcium-binding protein that has been implicated in a variety of biological functions as well as tumorigenesis. The aim of our study was to investigate the involvement of S100A6 during prostate cancer development and progression. Using immunohistochemistry, the expression of S100A6 was examined in benign (n=66), premalignant (n=10), malignant (n=66) and metastatic prostate (n=5) tissues arranged in a tissue-microarray or whole sections as well as in prostate cancer cell lines. The S100A6 immunostaining pattern in tissues was compared with that of cytokeratin 5 (a basal cell marker) and 18 (a benign luminal cell marker). In all cases of benign epithelium, intense S100A6 expression was seen in the basal cell layer with absent staining in luminal cells. In all cases of prostatic adenocarcinoma (matched), metastatic lesions and 3/10 high-grade prostatic intraepithelial neoplasia lesions, an absence of S100A6 was seen. Western blotting and RT–PCR analysis of cell lines showed S100A6 expression to be absent in LNCaP, LNCaP-LN3 and LNCaP-Pro5 but present in Du145, PC3, PC-3M and PC-3M-LN4. LNCaP cells treated with 5-Azacytidine, caused re-expression of S100A6 mRNA. Sequencing of bisulphite modified DNA showed CpG methylation within the S100A6 promoter region and exon 1 of LNCaP, LNCaP-LN3 and LNCaP-Pro5 cell lines but not in Du145 cells. Our data suggest that loss of S100A6 protein expression is common in prostate cancer development and may occur at an early stage. The mechanism of loss of expression may involve hypermethylation of CpG sites. The finding of intense S100A6 expression in the basal cells of benign glands but loss of expression in cancer could be useful as a novel diagnostic marker for prostate cancer.

Expression levels of cytoskeletal proteins indicate pathological aging of S100B transgenic mice: an immunohistochemical study of MAP-2, drebrin and GAP-43

S100B is a calcium-binding protein found within astroglial cells. When released, S100B has extracellular neurotrophic effects involving the neuronal cytoskeleton. The gene for S100B is located on chromosome 21 and levels of the protein are elevated in Down Syndrome (DS) and Alzheimer's Disease (AD). Thus, overexpression of S100B may be related to the cytoskeletal abnormalities seen in these disorders. Transgenic mice overexpressing human S100B were examined for cytoskeletal changes as young (70 days) and aged (200 days) adults, using immunochemical staining of the dendritic associated protein, MAP-2, the growth-associated protein-43 (GAP-43) and the dendritic spine marker, drebrin. As young adults, the S100B transgenic mice exhibited significantly greater MAP-2-immunoreactivity in the hippocampus, however as older adults, the animals exhibited less staining. In both the CD1 control animals and the S100B animals, the immunoreactivity of drebrin increased with age, however there were no significant between group differences. Finally, the older S100B animals showed more GAP-43 staining than the control animals, suggesting that synaptic remodeling could take place, possibly in response to the loss of MAP-2-ir dendrites. Overall, the data suggest that S100B overexpression leads to changes in cytoskeletal markers. The longitudinal effects of S100B overexpression are discussed with relevance to aging and pathology.

Involvement of interferon regulatory factor 1 and S100C/A11 in growth inhibition by transforming growth factor beta 1 in human hepatocellular carcinoma cells

Growth inhibition by transforming growth factor (TGF)-beta 1 has been attributed to the induction of cyclin-dependent kinase inhibitors, among which p21/Waf1 plays a major role in many biological contexts. In the present study, two new intracellular mediators for the induction of p21/Waf1 by TGF-beta 1 were identified in a human hepatocellular carcinoma cell line (JHH-5) expressing mutant-type p53. After addition of TGF-beta 1 to JHH-5 cells, a marked increase of the p21/Waf1 expression preceded the inhibition of DNA synthesis. Expression of IFN regulatory factor (IRF)-1, a known transacting factor for p21/Waf1 promoter, was elevated just before or in parallel with the increase of p21/Waf1. Transduction of antisense IRF-1 inhibited the increase in p21/Waf1 in JHH-5 cells treated with TGF-beta 1 and partially released the cells from the growth arrest by TGF-beta 1. Expression of S100C/A11, a member of the Ca(2+)-binding S100 protein family, also markedly increased after addition of TGF-beta 1. S100C/A11 protein was translocated to and accumulated in nuclei of TGF-beta 1-treated JHH-5 cells, where p21/Waf1 was concomitantly accumulated. When a recombinant S100C/A11 protein was introduced into nuclei of JHH-5 cells, DNA synthesis was markedly inhibited in a dose-dependent manner in the absence of TGF-beta 1. Prior transfection of p21/Waf1-targeted small interfering RNA efficiently blocked decrease of DNA synthesis in JHH-5 cells caused by TAT-S100C/A11 or TGF-beta 1 and markedly inhibited expression of p21/Waf1 protein in the cells. These results indicate that IRF-1 and S100C/A11 mediate growth inhibition by TGF-beta 1 via induction of p21/Waf1.

Upregulation of S100A4 after spinal cord transection in adult rats

AIM

To investigate whether spinal cord transection induces changes of gene expression of S100A4 protein.

METHODS

In a spinal cord transection model, S100A4 expression and cellular localization were examined using cDNA microarray, Northern blot, immunohistochemistry, and immunofluorescence double-labeling methods.

RESULTS

There was very limited S100A4 mRNA expression in the control spinal cord. However, S100A4 mRNA expression was increased significantly in both the rostral and caudal spinal cord segments adjacent to the injury site. Specifically, S100A4 gene expression was substantially increased at d 2, peaked at d 7 and d 14, and remained high up to 28 d post-injury. During its peak expression, S100A4 protein was localized in astrocytes of the spinal cord within 5 mm from the site of spinal transection.

CONCLUSION

Spinal cord transection induces prolonged S100A4 expression at both mRNA and protein levels in areas close to the injury site. Increased expression of S100A4 in astrocytes after spinal cord transection may indicate that this molecule may play a role in astrocytic responses to injury.

Expression of S100A4 combined with reduced E-cadherin expression predicts patient outcome in malignant melanoma

The aim of the present study was to analyze the expression of S100A4 and E-cadherin in a panel of primary and metastatic malignant melanoma, and to correlate the expression level to clinicopathological parameters. The expression of S100A4 was examined by immunohistochemistry in 99 superficial spreading and 60 nodular primary melanomas, while the expression of E-cadherin was analyzed in 92 superficial spreading and 52 nodular lesions from the same panel. The expression levels of S100A4 and E-cadherin in the biopsies were inversely correlated, with S100A4 being expressed at the highest frequency in the nodular and E-cadherin in the superficial spreading lesions, respectively. When analyzing the melanoma subgroups separately, it was revealed that expression of S100A4 had a more significant impact on patient outcome in early superficial spreading melanomas than in the nodular subtype, while E-cadherin expression did not predict patient outcome in any of the subgroups. When examining all the patients, both markers give clinical information as predictors for disease-free survival, but when combining the expression of the two markers, a stronger significant correlation between high E-cadherin expressing/S100A4 negative biopsies and increased disease-free survival (P=0.002) was revealed, demonstrating the importance of examining the expression of more than one factor involved in the metastatic cascade when predicting patient outcome. We have also evaluated the relationship between the expression of these two antigens and cell cycle and signal transduction factors.

S100 protein is a useful and specific marker for hair cells of the lateral line system in postembryonic zebrafish

The neuromast of the lateral line system of zebrafish has become an ideal model for the study of both developmental genetics and the vertebrate auditory system. Interestingly, the hair cells of this system have been found to selectively display immunoreactivity for S100 protein in some teleosts. In order to provide a selective marker for the sensory cells of the lateral line system, we have analyzed immunohistochemically the expression of S100 protein in zebrafish from the larval to the adult stage. In larval and adult animals S100 protein immunoreactivity was detected restricted to the hair cells of both superficial and canal neuromasts. Apparently the expression of S100 protein by hair cells was independent of the age, but it was expressed heterogeneously in the hair cells of canal neuromasts. The results of this work provide a feasible method to easily identify sensory cells in the neuromasts, and may be of interest in studies regarding development, differentiation or turnover of hair cells.

General Innervation Pattern and Sensory Corpuscles in the Scapholunate Interosseous Ligament

The scapholunate interosseous ligament (SLIL) is biomechanically important in maintaining wrist motion and grip strength in the hand, but its possible sensory role in the dynamic muscular stability of the wrist joint has not been examined. The aim of this study was to use immunohistochemical methods to analyze the general innervation and the possible existence of sensory corpuscles in the SLIL. The ligament was excised in its entirety from 9 patients. Antibodies against the low-affinity p75 neurotrophic receptor (p75) were used to reveal sensory corpuscles as well as general innervation. Furthermore, antibodies against the general nerve marker protein gene product 9.5 (PGP 9.5) and the glial marker S-100 were used to additionally depict innervation and corpuscular structures. Blood vessels occurred in areas interspersed throughout the homogeneous collagenous structure. In these vascularized areas, the SLIL was found to be supplied with nerve fascicles and sensory corpuscles of both the Ruffini and lamellated type. p75 immunoreactivity (IR) was detected in association with the nerve fascicles and the corpuscles, particularly in their capsule. S-100 IR was found in the Schwann cells in the central regions of the corpuscle, and PGP 9.5 IR marked the axonal structures in the corpuscles. New information on neurotrophin receptor distribution in ligaments has been obtained here. The presence of nerve fascicles and particularly sensory corpuscles in the SLIL suggests that the ligament has a proprioceptive role in the stability of the wrist. The marked p75 IR further indicates that neurotrophins play a part in a proprioceptive system in the ligament, given the importance of neurotrophins in maintaining sensory function.

Metastasis-associated S100A4 (Mts1) protein is expressed in subpopulations of sensory and autonomic neurons and in Schwann cells of the adult rat

S100A4 (Mts1) is a member of a family of calcium-binding proteins of the EF-hand type, which are widely expressed in the nervous system, where they appear to be involved in the regulation of neuron survival, plasticity, and response to injury or disease. S100A4 has previously been demonstrated in astrocytes of the white matter and rostral migratory stream of the adult rat. After injury, S100A4 is markedly up-regulated in affected central nervous white matter areas as well as in the periventricular area and rostral migratory stream. Here, we show that S100A4 is expressed in a subpopulation of dorsal root, trigeminal, geniculate, and nodose ganglion cells; in a subpopulation of postganglionic sympathetic and parasympathetic neurons; in chromaffin cells of the adrenal medulla; and in satellite and Schwann cells. In dorsal root ganglia, S100A4-positive cells appear to constitute a subpopulation of small ganglion neurons, a few of which coexpressed calcitonin gene-related peptide (CGRP) and Griffonia simplicifolia agglutinin (GSA) isolectin B4 (B4). S100A4 protein appears to be transported from dorsal root ganglia to the spinal cord, where it is deposited in the tract of Lissauer. After peripheral nerve or dorsal root injury, a few S100A4-positive cells coexpress CGRP, GSA, or galanin. Peripheral nerve or dorsal root injury induces a marked up-regulation of S100A4 expression in satellite cells in the ganglion and in Schwann cells at the injury site and in the distal stump. This pattern of distribution partially overlaps that of the previously studied S100B and S100A6 proteins, indicating a possible functional cooperation between these proteins. The presence of S100A4 in sensory neurons, including their processes in the central nervous system, suggests that S100A4 is involved in propagation of sensory impulses in specific fiber types.

[Expression of S100 protein in renal cell carcinoma and its relation with P53]

OBJECTIVE

To investigate the expression of S100 in renal cell carcinoma (RCC) and its relation with P53.

METHODS

Immunohistochemical method was used to detect the expressions of S100A1, S100B and the mutant P53 in 36 RCC and 14 normal kidney tissues. The associations of S100 protein expression with the tumor pathological types, clinical stages and P53 expression were analyzed.

RESULTS

The positive rates of S100A1 expression in RCC and normal kidney tissues were 72.2% and 21.4%, respectively (P <0.01); S100A1 expression in RCC was significantly correlated with its stage and degree of malignancy. The positive rates of the mutant P53 expression in RCC and normal kidney tissues were 30. 6% and zero respectively (P <0.05), and its expression was not associated with the stage and degree of malignancy degree of RCC (P > 0.05). There was no significant difference in S100B expression between RCC (36.1%) and normal kidney tissues (64.3%, P >0.05). There was no significant correlation between the mutant P53 and S100A1 or S100B expression (P > 0.05).

CONCLUSION

S100A1 may serve as a new useful marker in judging the degree of malignancy and invasion of RCC.

S100A5: a marker of recurrence in WHO grade I meningiomas

Some WHO grade I intracranial meningiomas resected from the same sites and with the same quality of resection (Simpson's grading scale) recur, while others do not. The reasons for this variability in occurrence of recurrence have not yet been determined. We therefore investigated the prognostic recurrence value of seven biological markers on a series of completely resected WHO grade I meningiomas. For this purpose, we analysed a series of 33 WHO grade I meningiomas totally resected between 1980 and 1990 (a follow-up of 10 years), including 14 cases of recurrence. The fixed tumour material from each meningioma was submitted to histochemical analyses targeting galectin-3 and its binding sites, the S100A5, S100A6 and S100B proteins, and cathepsin-B and -D. The levels of expression were assessed semi-quantitatively (in terms of the staining intensity and the labelling index) and submitted to uni- and multivariate analyses. Of all the markers investigated, only S100A5 expression can be associated with any significant prognostic value in the matter of recurrence. More particularly, the meningiomas with high levels of S100A5 staining intensity either did not recur, or recurred later than those with a low immunopositive S100A5 intensity (P = 0.004). Cox regression analyses demonstrated that this latter marker was associated with significant prognostic values independent of the patients' ages. Furthermore, the combination of the patients' ages and S100A5 staining intensity permitted the identification of a group with a particularly high risk of recurrence, that is, the patients younger than 55 and with meningiomas exhibiting low S100A5 intensities (P = 0.001). In conclusion, the S100A5 protein could play a role in the recurrence of totally resected WHO grade I meningiomas.

Target validation in hypoxia-induced vascular remodeling using transcriptome/metabolome analysis

The present study describes combined transcriptome and metabolome analysis for therapeutic target validation in hypoxia-induced vascular remodeling. Exposure to hypoxic conditions resulted in the upregulation of S100C mRNA and increased taurine (2-aminoethanesulfonic acid) content in the rat lung, as demonstrated by differential display and amino-acid content analysis. Hypoxia resulted in transcriptional activation of the S100C promoter through hypoxia-inducible factor-1 (HIF-1). Taurine suppressed HIF-1-mediated increases in S100C transcription. Moreover, oral taurine administration attenuated vascular remodeling in hypoxic rat lung, whereas depletion of endogenous taurine by administration of beta-alanine resulted in increased vascular remodeling. Inhibition of HIF transcription by taurine may be of therapeutic benefit in preventing hypoxia-induced vascular remodeling. In conclusion, we used transcriptome and metabolome analysis to identify a therapeutic low-molecular-weight ligand that plays a critical role in hypoxia-induced vascular remodeling. These techniques provided an excellent strategy for screening and validation of targets.

Over-expression of S100B protein in children with cerebral palsy or delayed development

S100B protein plays a role in promoting the maturation of a variety of neurons in many different CNS regions. Behavioral dysfunction in S100B over-expressed transgenic mice and the chronic elevation of S100B in Down's syndrome and in schizophrenia suggest that S100B over-expression is related to abnormal brain function. Therefore, we believed that the over-expression of S100B protein might be implicated in developmental brain dysfunction. The purpose of this study was to evaluate the serum S100B protein levels in patients with developmental brain dysfunction, such as cerebral palsy and delayed development, and to determine the clinical relevance of serum S100B protein in these patients. The mean values of serum S100B protein were significantly increased in both conditions. Patients with cerebral palsy had a S100B protein level of 3455.8 +/- 5004.6 ng/L and those with delayed development of 2557.0 +/- 2321.0 ng/L, compared with a normal control level of 583.8 +/- 483.0 ng/L (P < 0.05). The over-expression of S100B (defined as the normal mean plus three standard deviations) was found in 47.1% of the total patient group (delayed development (47.5%) and cerebral palsy (47.0%)). The frequency of over-expression was not significantly related to clinical diagnosis, disease severity or to brain MRI findings. However, patients who had periventricular leukomalacia by brain MRI showed a wide range and very high levels of S100B exceeding 10,000 ng/L in some cases. These findings suggest that the pathogenesis implied by the over-expression of S100B protein during brain development may play a role in developmental brain dysfunction.

Activation of metalloproteinases-2 and -9 by interleukin-1alpha in S100A4-positive liposarcoma cell line: correlation with cell invasiveness

BACKGROUND

The S100A4 gene may affect the invasive properties of tumor cells through modulation of metalloproteinases (MMPs) and their inhibitors (TIMPs).

MATERIALS AND METHODS

In the human liposarcoma cell line, SW872, we analyzed the expression of S100A4 protein by immunohistochemistry and flow cytometry. The production of MMP2, MMP9, TIMP1 and TIMP2 was assessed by gelatin zymography and enzyme-linked immunoabsorbent assay before and after interleukin-1alpha (IL-1alpha) and interleukin-6 (IL-6) stimulation; cell invasiveness was measured by Matrigel invasion assay.

RESULTS

S100A4-positive SW872 cells responded to IL-1alpha with induction of immunoreactive MMP2 and TIMP1 and with activation of both MMPs, the latter significantly associated with an increase of cell invasiveness. Treatment with IL-6 induced less significant variations resulting in a more stable invasive behavior.

CONCLUSION

These data show that S100A4-positive SW872 respond to interleukins by influencing the behavior of factors involved in extracellular matrix degradation and emphasize the predominant role of MMP activity status on the positive regulation of cell migration mechanisms.

S100A4/Mts1 produces murine pulmonary artery changes resembling plexogenic arteriopathy and is increased in human plexogenic arteriopathy

S100A4/Mts1 confers a metastatic phenotype in tumor cells and may also be related to resistance to apoptosis and angiogenesis. Approximately 5% of transgenic mice overexpressing S100A4/Mts1 develop pulmonary arterial changes resembling human plexogenic arteriopathy with intimal hyperplasia leading to occlusion of the arterial lumen. To assess the pathophysiological significance of this observation, immunohistochemistry was applied to quantitatively analyze S100A4/Mts1 expression in pulmonary arteries in surgical lung biopsies from children with pulmonary hypertension secondary to congenital heart disease. S100A4/Mts1 was not detected in pulmonary arteries with low-grade hypertensive lesions but was expressed in smooth muscle cells of lesions showing neointimal formation and with increased intensity in vessels with an occlusive neointima and plexiform lesions. Putative downstream targets of S100A4/Mts1 include Bax, which is pro-apoptotic, and the pro-angiogenic vascular endothelial growth factor (VEGF). The increase in S100A4/Mts1 expression precedes heightened expression of Bax in progressively severe neointimal lesions but in non-S100A4/Mts1-expressing cells. VEGF immunoreactivity did not correlate with severity of disease. The relationship of increased S100A4/Mts1 to pathologically similar lesions in the transgenic mice and patients occurs despite differences in localization (endothelial versus smooth muscle cells).

Microphthalmia transcription factor and NKI/C3 expression in cellular neurothekeoma

While the usual or myxoid-type neurothekeoma has been reasonably well established as being a tumor of neural origin, the cellular neurothekeoma remains in disputed histogenesis. We studied a series of 11 cellular neurothekeomas using paraffin immunoperoxidase staining with microphthalmia transcription factor (Mitf), NKI/C3, and S-100. The majority of the tumors in our series stained with NKI/C3 (9/11) and Mitf (9/11). All failed to stain with S-100. Furthermore, we divided our series of cellular neurothekeomas according to cytomorphology; tumors demonstrating predominantly spindled morphology, predominantly epithelioid morphology, and mixed spindle and epithelioid morphology. The two tumors that failed to stain with NKI/C3 both demonstrated predominantly spindled morphology. One of the tumors that failed to stain with Mitf showed exclusive spindled morphology, while the other showed mixed morphology (spindle and epithelioid). Two of the tumors, which stained strongly with Mitf, however, showed exclusive epithelioid morphology. This current study furthers the concept that cellular neurothekeoma is a tumor of neuroectodermal origin, and further suggests that it may express some component of melanocytic differentiation.

Accuracy of the determination of S100B protein expression in malignant melanoma using polyclonal or monoclonal antibodies

AIMS

To compare the routinely used polyclonal anti-S100 and a mouse monoclonal anti-S100B antibody for their accuracy in the detection of the S100B expression profile (pattern and intensity) in a series of 67 primary (n = 37) and lymph node metastatic (n = 30) melanoma tissues. S100B is the lineage marker of malignant melanoma. Antibodies routinely used for melanoma diagnosis are not necessarily specific for this protein. Furthermore, clinical monitoring of melanoma progression is mostly based on the determination of serum S100B protein levels without knowing the actual expression level in the primary and/or metastatic tissue.

METHODS AND RESULTS

The profile of expression patterns (focal, heterogenous and diffuse) as well as intensity ranges (+, ++ and +++) were similar for the two antibodies in melanoma tissues. However, comparison of the patterns and intensities on the basis of individual cases revealed a high frequency of discrepancies (50.7 and 58.2%, respectively). Severe discrepancy between the two antibodies in the determination of the S100B protein expression pattern (focal versus diffuse or focal versus heterogeneous) was relatively frequent; 13.4 and 11.9%, respectively. Furthermore, a similar rate of severe discrepancy was observed between the two antibodies in the determination of the intensity of S100B expression levels (+ versus +++ or + versus ++); 19.4 and 8.9%, respectively. Separate analysis of the primary tumours and metastases gave similar results.

CONCLUSION

For the accurate determination of S100B protein expression in malignant melanoma it is highly recommended that a monospecific antibody is used.

[Giant leiomyoma of the ovary]

Most of benign and malignant mesenchimal tumors may develop in the ovary. A case of 58 years old female, operated for ovary tumor is presented. A large soft mase 10-7-5 cm with in semilucent capsule is resected. Different (small and large) nodules with in edematous stroma constitute the tumor and imitate a large ovarian cancer. After histologic examination the nodules are composed of criss-crossing and whirling bundles of smooth muscle cells. Immunohistochemically they express Desmin diffusely and don't express Vimentin and S100 protein. Smooth muscle cells bundles in large amount of edematous, colagenous stroma look like islands. Stromal cells are Vimentin positive. Operation in this case is just limited to the tumor.

The regulation of EN-RAGE (S100A12) gene expression in human THP-1 macrophages

EN-RAGE is a ligand for the receptor for advanced glycation end products (RAGE) and may be involved in the development of diabetic macro- and micro-angiopathy. This study is designed to investigate the regulation of EN-RAGE gene expression in human macrophages. The amounts of EN-RAGE mRNA were measured in cultured human THP-1 macrophages after treatment with various stimuli known to modulate atherosclerosis. First, interleukin-6 (IL-6), a proinflammatory cytokine, increased the level of EN-RAGE mRNA by approximately 2-fold in a time- and a dose-dependent fashion. EN-RAGE protein was detected in the cultured medium and increased significantly by the addition of IL-6. The induction was abolished by pretreatment with the JAK kinase inhibitor and cycloheximide, but not with the MEK kinase inhibitor. Second, pioglitazone (PIO), a thiazolidinedione, decreased the level of EN-RAGE mRNA by approximately 25% of the basal in a time- and a dose-dependent fashion. Pioglitazone also inhibited the induction of EN-RAGE mRNA by IL-6. These results indicate the production of EN-RAGE is induced by IL-6 through de novo protein synthesis via the JAK-STAT kinase pathway and inhibited by the activation of peroxisome proliferator-activated receptor-gamma (PPARgamma) in human macrophages.

Cryopreservation of human brain tissue allowing timely production of viable adult human brain cells for autologous transplantation

BACKGROUND

Autologous transplantation is an attractive approach to treat some neurological diseases. A major obstacle is the capacity to produce cells for transplantation at the appropriate time. We describe a cryopreservation procedure for adult human brain tissue allowing the generation of cells in vitro.

METHODS

Neurological resections were dissected to separate white and grey matter. Fractions were frozen in a specific cryopreservation medium containing a selected serum and stored in liquid nitrogen. Tissue was thawed, cells were mechanically dissociated, expanded in culture and characterized by immunochemistry.

RESULTS

Adult human brain tissue cryopreserved for up to two years was successfully used to generate brain cells that could be maintained in culture for up to 100 days. Cells expressed a variety of neuroectodermal markers including GFAP, S100beta, and neurofilament.

CONCLUSION

A successful procedure for cryopreservation of adult human brain tissue has been established that might facilitate future autologous transplantation strategies.

Expression of the B-cell proliferation marker MUM1 by melanocytic lesions and comparison with S100, gp100 (HMB45), and MelanA

The diagnosis of malignant melanoma remains one of the most difficult to render in surgical pathology, partially because of its extreme histologic variability. Limits in the sensitivity and/or specificity of the currently available melanocytic markers such as anti-S100, HMB45, and anti-MelanA further complicate this problem. Previous work has demonstrated that the B-cell proliferation/differentiation marker MUM1/IRF4 is detected in malignant melanoma and hematolymphoid malignancies, but not in any other neoplasm tested (including colonic, lung, breast, and ovarian carcinomas). In the current study, we have examined MUM1 protein expression in 61 melanocytic lesions and compared the diagnostic usefulness of this marker with that of anti-S100, HMB45, and anti-MelanA. The results indicate that MUM1 is positive in 33/36 (92%) cases of melanoma (21/22 [95%] conventional primary melanomas and 12/14 [86%] metastatic melanomas). In comparison, positivity was seen with anti-S100 in 36/36 cases (100%, 22 primary and 14 metastatic), HMB45 in 28 cases (78%, 17 primary and 11 metastatic), and anti-MelanA in 27 cases (75%, 19 primary and 8 metastatic). Although negative in schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors, MUM1 is detected in only one in eight cases of spindle cell and desmoplastic melanomas. With the exception of desmoplastic and spindle cell melanomas, MUM1 appears to be a sensitive and specific immunohistochemical stain for melanocytic lesions and may prove to be a useful addition to the current panel of melanoma markers.

Primary intraosseous malignant fibrous histiocytoma of the skull: a case report

Malignant fibrous histiocytoma (MFH) is a rare primary neoplasm that constitutes less than 1% of the malignant tumors of bone, and involvement of the skull is very rare. We present a case of malignant fibrous histiocytoma of the skull, presenting an intraosseous lesion in a 43-yr-old woman. She had a rapidly growing, tender mass in the right parietal region. A plain radiograph showed an osteolytic lesion of the right parietal bone. Magnetic resonance imaging revealed that the lesion showed heterogeneous low signal intensity on T1-weighted images and slightly high signal intensity on T2-weighted images. No evidence of an extraosseous extension to the adjacent dura and soft tissue was found, and a wide excision of the parietal bone was performed. Histologically, the tumor was a typical MFH displaying pleomorphic spindle cells in a storiform pattern. The results of immunohistochemical stainings revealed that the tumor cells were positive for vimentin, alpha-1-antitrypsin, and p53, and negative for smooth muscle actin, S100 protein, desmin, and MyoD1. Three months later, a mainly cystic, recurrent mass was developed at the previously operated site. Before the resection, we first performed the percutaneous aspiration cytology, revealing diagnostic multinucleated pleomorphic cells. Thereafter, she had to receive repetitive resections of recurrent or residual lesions, and she died of postoperative meningoencephalitis two years after the first operation.

ATP triggers intracellular Ca2+ release in type II cells of the rat carotid body

Using a Ca2+-imaging technique, we studied the action of ATP on the intracellular Ca2+ concentration ([Ca2+]i) of fura-2-loaded mixtures of type I and type II cells dissociated from rat carotid bodies. ATP (100 micro M) triggered a transient rise in [Ca2+]i in the spindle-shaped type II (sustentacular) cells, but not the ovoid type I (glomus) cells. When challenged with ionomycin (1 micro M), no amperometry signal could be detected from the ATP-responsive type II cells, suggesting that these cells lacked catecholamine-containing granules. In contrast, KCl depolarization triggered robust quantal catecholamine release from type I cells that were not responsive to ATP. In type II cells voltage clamped at -70 mV, the ATP-induced [Ca2+]i rise was not accompanied by any current change, suggesting that P2X receptors are not involved. The ATP-induced Ca2+ signal could be observed in the presence of Ni2+ (a blocker of voltage-gated Ca2+ channels) or in the absence of extracellular Ca2+, indicating that Ca2+ release from intracellular stores was the dominant mechanism. The order of purinoreceptor agonist potency in triggering the [Ca2+]i rise was UTP > ATP > 2-methylthioATP >> alpha,beta-methyleneATP, implicating the involvement of P2Y2 receptors. In carotid body sections, immunofluorescence revealed localization of P2Y2 receptors on spindle-shaped type II cells that partially enveloped ovoid type I cells. Since ATP is released from type I cells during hypoxia, we suggest that the ATP-induced Ca2+ signal in type II cells can mediate paracrine interactions within the carotid bodies.

Transplanted neuronal progenitor cells in a peripheral nerve gap promote nerve repair

A basic experiment of peripheral nerve regeneration using neuronal progenitor cells embedded in collagen gel was performed in a rat sciatic nerve defect. First, when neuronal progenitor cells derived from the fetal rat hippocampus were cultured in atelocollagen-containing medium, neurospheres positive for anti-nestin antibody were confirmed after 8 days. These cells differentiated into astrocytes positive for anti-glial fibrillary acidic protein (GFAP) antibody, oligodendrocytes positive for anti-galactocerebroside (GalC) antibody and neurons positive for anti-neurofilament 200 (NF200) antibody, and they were capable of extending axons. They also differentiated into Schwann-like supportive cells positive for anti-s100 and anti-p75 antibody. Next, a 15-mm defect was prepared in the sciatic nerve of mature rats, and the nerve was bridged with a silicone tube filled with neuronal progenitor cells (1 x 10(5)) embedded in collagen gel. The transplanted neuronal progenitor cells were labeled in advance with 5-bromo-2-deoxyuridine (BrdU). When the regenerated tissue was examined 6 weeks and 10 weeks after grafting, the number and diameter of myelinated fibers were significantly increased compared with a control tube without neuronal progenitor cells. Action potentials were detected in the regenerated nerve. Also, cells positive for both anti-BrdU antibody and anti-S100 or anti-p75 antibody were observed in the regenerated tissue, and part of the grafted neural stem cells were considered to have differentiated into Schwann cell-like supportive cells. From these results neuronal progenitor cells derived from the fetal rat hippocampus are considered to retain their proliferative and differentiating abilities in collagen gel, and when transplanted to a site of peripheral nerve defect, part of them differentiate into supportive cells and they contributed to promotion of axonal regeneration.

Characterization of social behaviors and oxytocinergic neurons in the S-100 beta overexpressing mouse model of Down Syndrome

S-100 beta, a gene triplicated in Down Syndrome (DS), is thought to play a role in development of the brain in general, and in the serotonergic neuronal system in particular. We have been studying an animal model of DS, based on overexpression of this gene. In the current study, we report on the social behaviors of these animals, both in same-strain and mixed-strain pairings. In addition, as the neuropeptide oxytocin is often thought to be involved in social behaviors, we have looked at oxytocin-containing cells. In non-social behaviors, such as grooming and line-crossing, the S-100 beta animals were more active than the CD-1 control animals and showed significantly less social sniffing. In mixed-strain studies, these differences became more pronounced, with the CD-1 animals showing significantly greater levels of sniffing and anogenital sniffing. As well, the CD-1 animals showed more rearing and an increase in line crossings, suggesting a heightened level of vigilance or awareness of novelty. The S-100 beta animals, conversely, did not appear to respond to the novelty of the CD-1 animals. In mixed pair studies, the S-100 beta animals more frequently took submissive postures, while the CD-1 animals more frequently took dominant postures, and showed a significant increase in biting the S-100 beta partner. The S-100 beta animals showed less rearing, perhaps a further indication that they were inhibited by the CD-1 animals. Analysis of oxytocin-containing neurons showed comparable levels in the supraoptic and paraventricular nuclei of the hypothalamus, but significantly reduced numbers of cells in the bed nucleus of the stria terminalis of the S-100 beta animals. These results are discussed in terms of oxytocin contributions to socialization and fear responding and the significance of these findings to DS.

Transient expression of S-100beta immunostaining in developing thalamus and somatosensory cortex of rat

Serotonin is thought to affect the development of barrel fields in somatosensory cortex of rat and transient expression of the serotonin transporter has been reported in relevant thalamic (ventral posterior) and cortical (layer IV of parietal) regions in support of this. Much of the developmental role of serotonin is mediated by release of the neurotrophic protein S-100beta. The current work was thus undertaken to determine if S-100beta also shows a transient expression pattern in thalamus and barrel fields. Male Sprague-Dawley rats were examined immunocytochemically for S-100beta expression on postnatal days (PD) 1, 7, 15 and 22. Expression of S-100beta selectively peaked in the ventral posterior nucleus of the thalamus at PD 7, and in layer IV of the parietal cortex from PD 7 to 15, in a 'barrel-like' pattern. Our findings suggest that S-100beta could indeed be the mediator of serotonin's effects on barrel field formation.