Carcinoma of Unknown Primary Origin: Application of Immunohistochemistry With Emphasis to Different Cytokeratin 7 and 20 Staining Patterns

BACKGROUND

Although the primary origin of some carcinomas may be obscure to clinicians, its identification is crucial as it affects prognosis and treatment (especially novel targeted therapies). Immunohistochemistry (IHC) may be helpful in identifying the primary origin of carcinomas. This retrospective survey aimed to evaluate the frequency and accuracy of each IHC marker used to determine the origin of carcinomas.

METHODS

The review of pathology department archives revealed 307 cases of cancer of unknown primary origin (CUP) between 2015 and 2020, which were accessible in the department archives. Demographic information, site of biopsy, clinical and pathologic diagnoses, and IHC results of the patients were collected.

RESULTS

The patients included 157 (51.15%) men and 150 (48.85%) women. The age of the patients ranged from 14 to 92 years, including 106 (34.5%) expired cases. In 27% of cases, the primary origin of carcinoma remained unknown. The agreement between pathologic and clinical diagnoses was 59%. The most common pattern of cytokeratin (CK) expression in CUP was CK7+/CK20- (55.3%), followed by CK7-/CK20- (19%), CK7+/CK20+ (15%), and CK7-/CK20+ (10.7%), respectively.

CONCLUSION

The IHC analysis may improve the diagnosis of CUPs. However, the origin of some cases remains unknown despite an IHC analysis, thereby necessitating the use of more diagnostic procedures or gene expression studies for reaching a definitive diagnosis.

Filaggrin and atopic march

There is an increasing number of experimental, genetic and clinical evidence of atopic dermatitis expression as a pre-condition for later development of other atopic diseases such as asthma, food allergy and allergic rhinitis. Atopic dermatitis is a heterogeneous, recurrent childhood disease, also present in the adult age. It is increasingly attributed to systemic features and is characterized by immunological and skin barrier integrity and function dysregulation. To maintain the protective function of the skin barrier, in particular the maintenance of pH, hydration and antimicrobial functions, the filaggrin, among others, plays a significant role. Filaggrin is a multifunctional, histidine-rich, insoluble protein. The lack of filaggrin is associated with various cutaneous (e.g. ichthyosis vulgaris, allergic contact dermatitis) and non-cutaneous (e.g. diabetes, inflammatory conditions of the gastrointestinal tract) diseases and may be a result of genetic, immunological factors combined with environmental factors. In this review we summarised (emphasized) recent findings in understanding the role of filaggrin in atopic dermatitis and other diseases, participants in the atopic march.

Quantitative Analysis of Nuclear Lamins Imaged by Super-Resolution Light Microscopy

The nuclear lamina consists of a dense fibrous meshwork of nuclear lamins, Type V intermediate filaments, and is ~14 nm thick according to recent cryo-electron tomography studies. Recent advances in light microscopy have extended the resolution to a scale allowing for the fine structure of the lamina to be imaged in the context of the whole nucleus. We review quantitative approaches to analyze the imaging data of the nuclear lamina as acquired by structured illumination microscopy (SIM) and single molecule localization microscopy (SMLM), as well as the requisite cell preparation techniques. In particular, we discuss the application of steerable filters and graph-based methods to segment the structure of the four mammalian lamin isoforms (A, C, B1, and B2) and extract quantitative information.

Secondary Colonic Adenocarcinoma of the Prostate Histologically Mimicking Prostatic Ductal Adenocarcinoma

Purpose

To study the clinical presentation and pathological features of secondary colonic adenocarcinoma of the prostate.

Materials and methods

Six cases of colonic adenocarcinoma extending into the prostate were retrieved from the surgical pathology and autopsy files of the period 1985-1999. Immunostaining for prostatic acid phosphatase (PAP), prostate specific antigen (PSA), cytokeratin 7 (CK7), cytokeratin 20 (CK20) and carcinoembryonic antigen (CEA) was carried out in all cases. Clinical charts were also reviewed.

Results

Secondary colonic carcinoma spread into the prostatic stroma and along the prostatic ducts. In all four surgical cases, patients with a known history of rectal carcinoma presented with symptoms of urinary obstruction after 12 to 36 months of being free of recurrent or metastatic disease. In three surgical cases the secondary carcinoma involved the prostatic urethra in a form mimicking endometriod carcinoma, which led to an incorrect diagnosis of prostatic endometrioid carcinoma in one case. The tumor cells were immunoreactive to CK20 and CEA and not reactive to CK7, PAP and PSA.

Conclusions

Colonic carcinoma involving the prostate may mimic prostatic duct carcinoma due to the ductal and urethral involvement. Using a panel of immunostaining and clinical history is helpful in the differential diagnosis.

Glial Fibrillary Acidic Protein (GFAP) in Human Cerebral Tumors. An Immunohistochemical Study

Glial fibrillary acidic protein (GFAP) was studied in 160 cerebral tumors, mostly of neuro-epithelial nature. It was positive in astroglial tumors with an intensity proportional to the degree of cell differentiation. It was sometimes positive also in non-astroglial tumors, such as oligodendrogliomas and ependymomas, and this finding is discussed in relation to genesis and diagnostic value. In medulloblastomas, there were also positive cells, which could be reactive glia cells included in the tumors or subependymal cells. The demonstration of GFAP is very useful in gliosarcomas for identifying the glial component. It was sometimes positive in hemangioblastomas, and it is discussed in view of the nature of the stromal cells of this tumor.

Immunohistochemistry and Reverse Transcriptase Polymerase Chain Reaction on Sentinel Lymph Nodes can Improve the Accuracy of Nodal Staging in Breast Cancer Patients

In this study the nodal staging sensitivity of sentinel lymph node biopsy (SLNB) with detailed pathological and molecular biological examination has been investigated and compared to that of axillary lymph node dissection (ALND) with routine histological evaluation. Sentinel lymph nodes (SLNs) were removed by the dual-agent injection technique in 68 patients with primary, clinically node-negative breast cancer. Forty-seven patients had negative SLNs according to hematoxylin and eosin (H&E) staining. These H&E-negative SLNs were serially sectioned and examined at 250 μm levels by anticytokeratin immunohistochemistry (IHC). In 14 patients the SLNs were also investigated by cytokeratin 20 (CK20) reverse transcriptase polymerase chain reaction (RT-PCR). SLNB with IHC increased the node-positive rate by 26% (by 40% in tumors less than or equal to 2 cm in size (pT1) and by 9% in tumors more than 2 cm but less than or equal to 5 cm in size (pT2)). The sensitivity of SLNB with IHC was superior to that of ALND with routine histology in pT1 tumors and identical in pT2 tumors. The concordance between histology and RT-PCR was only 21%, and in two of three cases with positive histological results RT-PCR was negative. In conclusion, SLNB with detailed pathological and/or molecular biological evaluation can improve the sensitivity of regional staging. ALND can probably be abandoned in patients with pT1 SLN-negative breast cancer. Further prospective studies are required to determine the clinical significance of these detailed SLN evaluation techniques, but at present these methods are still investigational.

Altered Differentiation of Cns Neural Progenitor Cells after Transplantation into the Injured Adult Rat Spinal Cord

Denervation of CNS neurons and peripheral organs is a consequence of traumatic SCI. Intraspinal transplantation of embryonic CNS neurons is a potential strategy for reinnervating these targets. Neural progenitor cell lines are being investigated as alternates to embryonic CNS neurons. RN33B is an immortalized neural progenitor cell line derived from embryonic rat raphé nuclei following infection with a retrovirus encoding the temperature-sensitive mutant of SV40 large T-antigen. Transplantation studies have shown that local epigenetic signals in intact or partially neuron-depleted adult rat hippocampal formation or striatum direct RN33B cell differentiation to complex multipolar morphologies resembling endogenous neurons. After transplantation into neuron-depleted regions of the hippocampal formation or striatum, RN33B cells were relatively undifferentiated or differentiated with bipolar morphologies. The present study examines RN33B cell differentiation after transplantation into normal spinal cord and under different lesion conditions. Adult rats underwent either unilateral lesion of lumbar spinal neurons by intraspinal injection of kainic acid or complete transection at the T10 spinal segment. Neonatal rats underwent either unilateral lesion of lumbar motoneurons by sciatic nerve crush or complete transection at the T10 segment. At 2 or 6-7 wk postinjury, lacZ-labeled RN33B cells were transplanted into the lumbar enlargement of injured and age-matched normal rats. At 2 wk posttransplantation, bipolar and some multipolar RN33B cells were found throughout normal rat gray matter. In contrast, only bipolar RN33B cells were seen in gray matter of kainic acid lesioned, sciatic nerve crush, or transection rats. These observations suggest that RN33B cell multipolar morphological differentiation in normal adult spinal cord is mediated by direct cell-cell interaction through surface molecules on endogenous neurons and may be suppressed by molecules released after SCI. They also indicate that the fate of immortalized neural progenitor cell lines in injured CNS must be stringently characterized.

Nestin expression as an indicator of cervical cancer initiation

Nestin is an intermediate filament protein expressed in proliferating cells during embryonic development of the central nervous system (CNS) and considered to be a neuronal stem cell/progenitor cell marker. This study investigated the difference of nestin expression between pre-cancer (carcinoma in situ - CIS) and cancer of cervix in 129 tissues (49 normal cervix, 41 CIS, and 39 invasive cervical cancer) through the use of a paraffin-embedded tissue array. Immunostaining was evaluated by intensity, proportion of stained cells, and pattern of expression. The expression of nestin was positive in 63.4% (26/41) for CIS and 43.6% (17/39) for invasive cervical cancer, but only 26.5% (13/49) for normal tissues (p = 0.002). Strong positive staining/large proportion staining were 53.7% (22/41) / 36.6% (15/41), 15.4% (6/39) / 61.5% (24/39) in the CIS and invasive cervical cancer tissues, respectively (p = 0.043, p < 0.001). The diffuse stain with basal layer was positive in 90.2% (37/41) for CIS, but only 24.5% (12/49) of the samples were positive in normal tissues (p < 0.001). Based on these results, the authors suggest that nestin expression seems to participate in the step of cancer initiation and could potentially be a useful marker in the early detection of cervical cancer.

Effect of hyperbaric oxygen on neurological recovery of neonatal rats following hypoxic-ischemic brain damage and its underlying mechanism

OBJECTIVE

To investigate the mechanism underlying the effect of hyperbaric oxygen (HBO) on hypoxic/ischemic brain damage (HIBD) in a neonatal rat model.

METHODS

A total of 30 neonatal SD rats aged 7 days were randomly assigned into control group, HIBD group and HBO group (n=10 per group). Following HIBD modeling in neonatal rats, HBO treatment was performed for consecutive 7 days. Immunohistochemistry was done to measure the expression of bone morphogenetic protein-4 (BMP-4) and nestin in the hippocampus. In situ hybridization was employed to detect the mRNA expression of BMP-4 and nestin in the hippocampus. TUNEL staining was done to detect the apoptosis of nerve cells.

RESULTS

HIBD was successfully established in the present study. Among three groups, the protein expression of BMP-4 in the hippocampus was the highest in the HBO group, and the smallest in the HIBD group. The BMP-4 expression in the HIBD group was significantly lower than that in the control group. The protein expression of nestin in the hippocampus was the highest in the HBO group, and the smallest in the HIBD group. The nestin protein expression in the hippocampus of HIBD group was significantly lower than that in the control group. The mRNA expression of BMP-4 in the hippocampus was the highest in the HBO group, and the smallest in the HIBD group. The mRNA expression of nestin in the hippocampus was the highest in the HBO group, and the smallest in the HIBD group. The number of apoptotic cells was the largest in the HIBD group, and the number of apoptotic cells in the HBO group was still larger than that in the control group (P<0.01).

CONCLUSION

HBO may promote the neurological recovery in neonatal rats with HIBD, which may be attributed to the increased protein and mRNA expression of BMP-4 and nestin in the hippocampus and the inhibition of neural apoptosis.

Immunolocalization of nestin, mesothelin and epithelial membrane antigen (EMA) in developing and adult serous membranes and mesotheliomas

The spatial and temporal distribution of epithelial membrane antigen (EMA), mesothelin and nestin was immunohistochemically analyzed in developing and adult human serous membranes and mesotheliomas in order to detect possible differences in the course of mesenchymal to epithelial transformation, which is associated with differentiation of mesothelial cells during normal development and tumorigenesis. Pleura and pericardium developing from the visceral mesoderm gradually transform into mesothelial cells and connective tissue. EMA appeared in mesothelium of both serous membranes during the early fetal period, whereas during further development, EMA expression was retained only in the pericardial mesothelium. It increased in both pleural mesothelium and connective tissue. Mesothelin appeared first in pericardial submesothelial cells and later in surface mesothelium, while in pleura it was immediately localized in mesothelium. In adult serous membranes, EMA and mesothelin were predominantly expressed in mesothelium. Nestin never appeared in mesothelium, but in connective tissues and myocardial cells and subsequently decreased during development, apart from in the walls of blood vessels. Mesothelial cells in the two serous membranes developed in two separate developmental pathways. We speculate that submesothelial pericardial and mesothelial pleural cells might belong to a population of stem cells. In epithelioid mesotheliomas, 13% of cells expressed nestin, 39% EMA and 7% mesothelin.

Nestin and other putative cancer stem cell markers in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a high incidence of distant metastasis. Recent studies have shown that cancer stem cells (CSCs), which have the potential to self-renew and are pluripotent, are crucially important in cancer cell growth, invasion, metastasis, and recurrence. Recently, several CSC-specific markers for pancreatic cancer have been reported, including CD133, CD24, CD44, CXCR4, EpCAM, ABCG2, c-Met, ALDH-1, and nestin, but their use is controversial. Nestin is one of the class VI intermediate filament proteins and a marker of exocrine progenitors of normal pancreatic tissue. Activated mutations of K-ras in nestin-positive progenitors of pancreatic tissue have been reported to induce cell growth in vitro and induce the formation of precancerous pancreatic lesions. We have reported that downregulation of nestin in PDAC cells inhibits liver metastasis in vivo. Nestin may modulate the invasion and metastasis of nestin-positive progenitor cells during PDAC development and may serve as a novel target for suppressing invasion and metastasis in PDAC. In this review, we summarize what is known about the correlation between PDAC and CSC markers, including nestin.

Quantitative determination of high-temperature requirement protein A1 and its possible associated molecules during induced reparative dentin formation

INTRODUCTION

The equilibrium of inhibitors and inducers plays an important role in the mineralization of dentin during dentinogenesis. High-temperature requirement protein A1 (HtrA1) is a novel bone mineralization inhibitor involved in physiological and pathological bone formation. However, the expression of HtrA1 in tooth mineralization is unknown. The purpose of the present study was to investigate the localization and quantity of HtrA1 and its possible related molecules during induced reparative dentin formation.

METHODS

Rats were randomly sacrificed after direct pulp capping on days 0, 7, 14, and 21. Maxillary segments were obtained and routinely prepared for histological analysis, immunohistochemistry, quantum dots-based double immunofluorescence, and CRi's Nuance imaging system (CRI, Woburn, MA)-based quantitative determination.

RESULTS

The square measure values of reparative dentin significantly increased on day 7 and continued to increase until day 21. HtrA1, matrix Gla protein (MGP), nestin, and bone sialoprotein were positively stained and colocalized in the odontoblasts and/or odontoblast-like cells zone and reparative dentin during induced reparative dentin formation. The expressions of HtrA1 and MGP were significantly enhanced after direct pulp capping on day 7 and did not significantly change between days 7, 14, and day 21. Both expressions of HtrA1 and MGP were positively correlated with the square measure values of reparative dentin; however, no correlation was found between the expressions of HtrA1 and MGP.

CONCLUSIONS

HtrA1 could be observed and might possibly be involved in the process of reparative dentin formation associated with MGP.

Low-intensity low-frequency ultrasound promotes proliferation and differentiation of odontoblast-like cells

INTRODUCTION

Ultrasound is a potential therapeutic tool for dental tissue repair, but its biological effects on odontoblasts have not been well characterized. In this study, the effects of low-intensity low-frequency ultrasound on the viability, proliferation, and differentiation of odontoblast-like cells were investigated.

METHODS

Cell viability and proliferation were assessed after the treatment of adherent clonal MDPC-23 odontoblast-like cells with a 25-mW/cm(2) 45-kHz ultrasound. An in vitro scratch wound healing assay was used to investigate the ultrasound effects on cell migration. Long-term cultures were used to study odontogenic differentiation and extracellular mineralization.

RESULTS

Ultrasound exposure for up to 30 minutes did not significantly affect odontoblast-like cell viability but significantly increased cell numbers after 2 days in culture. Ultrasound did not influence the scratch wound closure rate in the absence or presence of the mitogen inhibitor mitomycin C, indicating that ultrasound did not influence cellular migration. Single and consecutive exposures to ultrasound resulted in the enhancement of in vitro mineralization after 14 days in culture with an osteogenic differentiation medium. This coincided with the up-regulation of gene expression of collagen type I, osteoadherin, dentine matrix protein 1, and osteocalcin as well as the expression of cell markers alkaline phosphatase and nestin.

CONCLUSIONS

These findings indicate that low-frequency ultrasound is able to influence proliferation and differentiation of odontoblast-like cells and may potentially be considered as a therapeutic tool for dental pulp and dentine repair.

Detection of cancer stem cell markers in sarcomas

The identification of cancer stem cell markers represents one of the very relevant research topics because cancer stem cells play important roles in tumour initiation and progression, as well as during metastasis formation and in relapse of the disease. This article summarises recent knowledge on well-known and putative cancer stem cell markers in various types of bone and soft-tissue sarcomas. Special attention is paid to the detection of CD133, ABC transporters, nestin and aldehyde dehydrogenase that have been intensively studied both in tumour tissues and in sarcoma cell lines during the past few years. Finally, an overview is given of the possible CSC phenotypes provided by functional assays of tumourigenicity.

HDAC inhibitor 4-phenylbutyrate preserves immature phenotype of human embryonic midbrain stem cells: implications for the involvement of DNA methyltransferase

Cell replacement and gene therapy using neural stem cells (NSCs) have been widely touted as a promising treatment for CNS diseases including brain tumors. Histone deacetylase (HDAC) inhibitors have been used to explore mechanisms behind the lineage-specific differentiation of NSCs and as modulators of gene therapy. We have used the human embryonic midbrain stem cell line NGC-407 and the HDAC inhibitor 4-phenylbutyrate (4-PB) to investigate the differentiation from epigenetic perspectives. NGC-407 cells can differentiate into both neurons and glial cells, evidenced by morphological characteristics as well as up-regulation of the respective markers β-tubulin III and glial fibrillary acidic protein (GFAP) and simultaneous down-regulation of the NSC-marker nestin. Genomic DNA extracted from the differentiating cells was globally more methylated than that of the proliferating cells. The differentiating cells showed increased expression of the de novo DNA methyltransferase DNMT3B along with strong immunoreactivity in the cell nuclei. When these cells were treated with 4-PB, both the astrocytic and the neuronal differentiation phenotypes were suppressed, which paralleled a substantially weakened DNMT3B immunoreactivity in the cell nuclei. Importantly, 4-PB treatment preserves the immature phenotype of these differentiating cells as indicated by Western blot analysis and immunocytochemical analyses of the NSC markers, nestin and CD133. Nestin becomes entirely degraded 5 days after induction of differentiation, but upon exposure to 4-PB, some of the differentiating cells retain the integrity of nestin and concurrently, CD133 is also up-regulated. Taken together, the data suggests that HDAC activity is necessary for human embryonic NSC differentiation.

Clinicopathological correlations of nestin expression in surgically resectable pancreatic cancer including an analysis of perineural invasion

BACKGROUND AND AIMS

Nestin is considered to be a marker of stem/progenitor cells in different tissues. Nestin expression was also described in various tumors. In pancreatic ductal adenocarcinoma (PDAC), its role in cancer cell migration, invasion, and metastases has been suggested. The study aimed at examining the expression of nestin in PDAC, and to evaluate its clinicopathological correlations.

METHODS

The expression of nestin was immunohistochemically examined in 117 PDAC resection specimens, analyzed, and correlated with clinico-pathological parameters including perineural invasion (PNI). Analysis of nestin expression in nerve fibers in tissues of chronic pancreatitis (CP) was added.

RESULTS

Immunohistochemical analysis of nestin expression showed 79 nestin negative (67.5 %) and 38 nestin positive (32.5 %) PDACs. No significant correlations of nestin expression in tumor cells with the analyzed clinicopathological parameters were demonstrated. Tumor grade (p<0.001) and nodal status (p=0.009) proved to represent independent prognostic factors. PNI was identified in 94 PDAC (80.3 %), and did not correlate with nestin expression. Nestin immunostaining was displayed in nerve fibers of both CP and PDAC tissues.

CONCLUSION

An intimate link of nestin to a biological process of pancreatic cancer was confirmed. The expression of nestin did not prove to be a valuable prognostic factor and an immunohistochemical assessment of nestin expression is not superior to conventional prognostic factors in PDAC. A correlation between nestin expression in tumor cells and PNI was not confirmed and expression of nestin in nerve fibers of both PDAC and CP tissues seems to reflect the process of neural remodeling responsible for pancreatic neuropathy.

Expression of nestin, mesothelin and epithelial membrane antigen (EMA) in developing and adult human meninges and meningiomas

The spatial and temporal pattern of appearance of nestin, epithelial membrane antigen (EMA) and mesothelin proteins was immunohistochemically determined in the cells of normal developing and adult human meninges and meningiomas. Human meninges developed as two mesenchymal condensations in the head region. The simple squamous epithelium on the surface of leptomeninges developed during mesenchymal to epithelial transformation. Nestin appeared for the first time in week 7, EMA in week 8, while mesothelin appeared in week 22 of development. In the late fetal period and after birth, nestin expression decreased, whereas expression of EMA and mesothelin increased. EMA appeared in all surface epithelial cells and nodules, while mesothelin was found only in some of them. In adult meninges, all three proteins were predominantly localized in the surface epithelium and meningeal nodules. In meningothelial meningiomas (WHO grade I), EMA was detected in all tumor cells except in the endothelial cells, mesothelin characterized nests of tumor cells, while nestin was found predominantly in the walls of blood vessels. The distribution pattern of those proteins in normal meningeal and tumor cells indicates that nestin might characterize immature cells, while EMA and mesothelin appeared in maturing epithelial cells. Neoplastic transformation of these specific cell lineages contributes to the cell population in meningiomas.

Clinicopathologic significance of putative stem cell markers, CD44 and nestin, in gastric adenocarcinoma

Cancer stem cells (CSC) are unique subpopulations that have the capacity to drive malignant progression and mediate radio/chemoresistance. The role of nestin as a CSC marker in gastric adenocarcinoma is largely unknown. Our objective was to evaluate immunoexpression of CSC markers CD44 and nestin in gastric adenocarcinoma versus non-neoplastic gastric mucosae (NNGM) and correlate it with various clinicopathologic factors. Tissue microarray blocks from 174 cases of gastric adenocarcinoma and 41 samples of adjacent NNGM were assembled. Clinical data including patient's age and sex, tumor histologic subtype and grade, and disease stage were obtained. Expression of CD44 and nestin was assessed by immunohistochemistry. Expression of membranous CD44 (51%, 78/152) and cytoplasmic nestin (25%, 43/174) was significantly greater in gastric adenocarcinoma than in NNGM (P<0.001). A subset of cases (n=15) that co-expressed membranous CD44 and cytoplasmic nestin were significantly more frequent in Lauren intestinal histologic subtype than in diffuse subtype (P<0.05). Foci of intestinal metaplasia (n=6) showed either CD44 (3/6) or nestin (2/6) expression. This is the first study to report the clinicopathologic significance of nestin expression in gastric cancers, and to correlate the nestin expression with CD44, another stem cell marker. The study shows that nestin and CD44, are significantly expressed in a subset of gastric adenocarcinoma, particularly co-expression of nestin and CD44 is significantly revealed in Lauren intestinal histologic subtype. Their expression is also increased in intestinal metaplasia, a premalignant lesion. These findings suggest that CSCs may have a pathogenetic role in the pathway of intestinal metaplasia-intestinal type gastric adenocarcinoma.

[Culture and identification of neural stem cells from mouse embryos]

OBJECTIVE

The purpose of this study was to culture and identify neural stem cells from mouse embryos in vitro using a modified method and provide a basis for further study of the biology of neural stem cells under hypoxia.

METHODS

The cells were isolated mechanically from the front cortex of fetal Institute of Cancer Research (ICR) mice on embryonic day 14. They were passaged by mechanical dissociation and enzymatic digestion. The neurospheres were identified by immunofluorescent staining of nestin. Cell differentiation was induced by 1% fetal bovine serum and then the cells were identified by immunohistochemistry of β-tubulin III and GFAP.

RESULTS

The cells obtained from the front cortex of fetal ICR mice had the capacity of forming neurospheres which showed nestin immunoreactive positivity. After being induced by 1% fetal bovine serum, the cells were differentiated into β-tubulin III-positive cells and GFAP-positive cells.

CONCLUSIONS

Using mechanical dissociation of primary cells and mechanical dissociation with enzymatic digestion of primary cells, the NSCs from the front cortex of mouse embryos can be obtained.

Analysis of nuclear nestin localization in cell lines derived from neurogenic tumors

Nestin is a class VI intermediate filament protein expressed in the cytoplasm of stem and progenitor cells in the mammalian CNS during development. In adults, nestin is present only in a small subset of cells and tissues, including the subventricular zone of the adult mammalian brain, where neurogenesis occurs. Nestin expression has also been detected under such pathological conditions as ischemia, inflammation, and brain injury, as well as in various types of human solid tumors and their corresponding cell lines. Furthermore, nestin was recently found in the nuclei of glioblastoma, neuroblastoma, and angiosarcoma cells and it was proved to interact directly with the nuclear DNA in neuroblastoma cells. Here, we perform the first study of the intracellular distribution of nestin in cell lines derived from neurogenic tumors. Using immunodetection methods, we examined nestin expression in tumor-derived cell lines obtained from 11 patients with neuroblastoma, medulloblastoma, or glioblastoma multiforme. Besides its standard cytoplasmic localization, nestin was present in the nuclei of two neuroblastoma cell lines and one medulloblastoma cell line. Nestin was only present in the nuclei of cells with diffuse cytoplasmic staining for this protein, and the proportion of cells positive for nestin in nuclei, as well as the intensity of staining, varied. The presence of nestin in the nuclei was confirmed by both transmission electron microscopy and Western blotting. Our results indicate that the presence of nestin in the nuclei of tumor cells is not very rare, especially under in vitro conditions.

A novel terminal web-like structure in cortical lens fibers: architecture and functional assessment

This study describes a novel cytoskeletal array in fiber cells of the ocular lens of the rat and shows its relationship to the classical terminal web of other epithelial tissues. Naive adult Sprague-Dawley rats (n = 28) were utilized. F-actin, fodrin, myosin IIA, and CP49 distribution was assessed in anterior and posterior polar sections. For functional analysis, lenses were cultured with or without cytochalasin-D for 3 hr, then processed for confocal microscopy or assessed by laser scan analysis along sutures. Phalloidin labeling demonstrated a dense mesh of F-actin adjacent to posterior sutural domains to a subcapsular depth of 400 μm. Anterior polar sections revealed a comparable actin structure adjacent to anterior suture branches however, it was not developed in superficial fibers. Fodrin and myosin were localized within the web-like actin apparatus. The data was used to construct a model showing that the cytoskeletal array is located within the blunt, variable-width fiber ends that abut at sutures such that the "terminal web" flanks the suture on either side. Treatment with cytochalasin-D resulted in partial disassembly of the "terminal web" and perturbed cellular organization. Laser scan analysis revealed that cytochalasin-D treated lenses had significantly greater focal variability than control lenses (P = 0.020). We conclude that cortical fibers of rat lenses contain a bipolar structure that is structurally and compositionally analogous to classical terminal webs. The results indicate that the lens "terminal web" functions to stabilize lens fiber ends at sutures thus minimizing structural disorder, which in turn, promotes the establishment and maintenance of lens transparency.

Impact of nestin analysis in multiple myeloma

Nestin, a marker of multipotent precursor cells, is an important dynamic structure; its polymerization/depolymerization influences intracellular signaling and participates in key cell processes such as proliferation, migration and cell survival. It is presumed that nestin plays a central role in carcinogenesis. It is suggested that nestin might be a suitable diagnostic and prognostic indicator of malignancy and a potential marker of cancer stem cells. Unexpectedly, nestin has been identified in mature CD138+CD38+ plasma cells (PC) of multiple myeloma patients (MM). Expression of nestin, a marker of stem/progenitor cells, in malignant PC, that are considered to be terminally differentiated, indicates that nestin might play a unique role in pathology of MM.

Microchip-associated sarcoma in a shrew (Suncus murinus)

A 16-mo-old female house musk shrew (Suncus murinus) with a 1-wk history of a rapidly growing subcutaneous mass in the interscapsular region was euthanized and submitted for necropsy. Macroscopic examination identified an irregular, well-demarcated, solid, tan-white subcutaneous mass. A small cavity containing a microchip device was present at the center of the mass. In addition, massive splenomegaly was evident grossly. Histologically, the subcutaneous mass comprised spindle cells arranged in a storiform pattern of interweaving bundles, consistent with a high-grade soft tissue sarcoma with multifocal necrosis. Immunohistochemical investigation suggested that the neoplastic cells were positive for neuron-specific enolase and (rarely) α-smooth muscle actin and negative for cytokeratin, desmin, S100, and vimentin. In light of the mesenchymal histopathologic phenotype and the lack of specific immunoreactivity pattern, the mass was considered to be most consistent with a poorly differentiated sarcoma. To our knowledge, this is the first report of a microchip-associated soft tissue sarcoma in a shrew.

Basic study of retinal stem/progenitor cell separation from mouse iris tissue

We described the possibility of retinal regeneration using a novel and efficient technique for culturing and separating retinal stem/progenitor cells from iris tissue. Immunohistochemical staining of adult agouti mouse iris tissue revealed the presence of nestin/low-affinity neurotrophin receptor p75 (p75(NTR))-positive cells on the endothelium camerae anterioris side. Cultured mouse iris-derived cells contained little or no melanin and were found to be positive for nestin. Most nestin-positive cells were analyzed for the coexpression of p75(NTR) as a cell membrane protein. When the p75(NTR) was used as a marker to sort the cells, we obtained a dense population of nestin-positive cells. Furthermore, the nestin/p75(NTR)-positive cells were able to differentiate into neural retina cells. Thus, this culture and separation technique is useful for obtaining retinal stem/progenitor cells from adult mouse iris tissue and for the efficient production of neural retina cells.

Reduced hypocretin (orexin) levels in dementia with Lewy bodies

Sleep disorders are observed in Parkinson's disease, dementia with Lewy bodies, and Alzheimer's disease; however, the underlying mechanisms are unclear. Reduced hypocretin (orexin) levels are reported in Parkinson's disease and sleep disorders, including narcolepsy; however, its levels in dementia with Lewy bodies and Alzheimer's disease and its relationship with sleep disturbances in these disorders remain undetermined. We examined hypocretin levels in dementia with Lewy bodies and Alzheimer's disease cases and correlated these with sleep habits and clinical characteristics. Although limited hypocretin alterations were observed in Alzheimer's disease, we show reduced neocortical hypocretin immunoreactivity in dementia with Lewy bodies patients correlating with hypersomnolence and alpha-synuclein levels. These results suggest the involvement of hypocretin in sleep disorders in dementia with Lewy bodies.

Culture of newborn monkey liver epithelial progenitor cells in chemical defined serum-free medium

Studies with hepatic progenitor cells from non-human primates would allow better understanding of their human counterparts. In this study, rhesus monkey liver epithelial progenitor cells (mLEPCs) were derived from a small piece of newborn livers in chemical defined serum-free medium. Digested hepatic cells were treated in Ca(2+)-containing medium to form cell aggregates. Two types of cell aggregates were generated: elongated spindle cells and polygonal epithelial cells. Elongated spindle cells were expressed as vimentin and brachyury, and they were disappeared within 5 d in our cultures. The remaining type consisted of small polygonal epithelial cells that expressed cytokeratin 7 (CK7), CK8, CK18, nestin, CD49f, and E-cad, the markers of hepatic stem cells, but were negative for alpha-fetoprotein, albumin, and CK19. They can proliferate and be passaged, if on laminin or rat tail collagen gel, to initiate colonies. When cultured with dexamethasone and oncostatin M, the expression of mature hepatocyte markers, such as alpha-1-antitrypsin, intracytoplasmic glycogen storage, indocyanine green uptake, and lipid droplet generation, were induced in differentiated cells. If transferred onto mouse embryonic fibroblasts feeders, they gave rise to CK19-positive cholangiocytes with formation of doughnut-like structure. Thus, mLEPCs with bipotency were derived from newborn monkey liver and may serve as a preclinical model for assessment of cell therapy in humans.

Novel association of APC with intermediate filaments identified using a new versatile APC antibody

BACKGROUND

As a key player in suppression of colon tumorigenesis, Adenomatous Polyposis Coli (APC) has been widely studied to determine its cellular functions. However, inconsistencies of commercially available APC antibodies have limited the exploration of APC function. APC is implicated in spindle formation by direct interactions with tubulin and microtubule-binding protein EB1. APC also interacts with the actin cytoskeleton to regulate cell polarity. Until now, interaction of APC with the third cytoskeletal element, intermediate filaments, has remained unexamined.

RESULTS

We generated an APC antibody (APC-M2 pAb) raised against the 15 amino acid repeat region, and verified its reliability in applications including immunoprecipitation, immunoblotting, and immunofluorescence in cultured cells and tissue. Utilizing this APC-M2 pAb, we immunoprecipitated endogenous APC and its binding proteins from colon epithelial cells expressing wild-type APC. Using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), we identified 42 proteins in complex with APC, including beta-catenin and intermediate filament (IF) proteins lamin B1 and keratin 81. Association of lamin B1 with APC in cultured cells and human colonic tissue was verified by co-immunoprecipitation and colocalization. APC also colocalized with keratins and remained associated with IF proteins throughout a sequential extraction procedure.

CONCLUSION

We introduce a versatile APC antibody that is useful for cell/tissue immunostaining, immunoblotting and immunoprecipitation. We also present evidence for interactions between APC and IFs, independent of actin filaments and microtubules. Our results suggest that APC associates with all three major components of the cytoskeleton, thus expanding potential roles for APC in the regulation of cytoskeletal integrity.

[Effects of ganglioside 1 and nerve growth factor on the proliferation of neural stem cells in vitro]

OBJECTIVE

To study the effects of ganglioside 1 (GM1) and nerve growth factor (NGF) on neural stem cells (NSCs) proliferation in vitro.

METHODS

NSCs were isolated and cultured in vitro. NSCs were cultured in the medium containing epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) or without the two agents. Different concentrations of GM1 and NGF were added into the two different medium. MTT and cell ball counting methods were used to ascertain the proliferation of NSCs. Immunohistochemical technology was used to observe the effect of GM1 and NGF on the proliferation of NSCs.

RESULTS

High concentrations of GM1 (100 ng/L and 200 ng/L) promoted significantly the proliferation of NSCs in the medium containing EGF and bFGF (p<0.05). In the differentiation medium containing serum but no EGF and bFGF, NSCs proliferation increased with increasing concentration of GM1; the proportion of neurons and gliacytes increased with increasing concentration of NGF.

CONCLUSIONS

High concentration of GM1 can promote NSCs proliferation and NGF can promote NSCs differentiation.

Merkel Cells, Normal and Neoplastic: An Update

Merkel cells (MC) occur in the basal epidermal layer, hair follicles, and oral mucosa, as complexes with sensory axons. The axons transduce slowly adapting type I mechanoreception, and MC modulate their sensitivity. MC also determine and maintain the 3-dimensional epidermal structure. They have neuroendocrine granules, rigid spinous processes, and desmosomal junctions with each other and with keratinocytes. Rare MC are dermaWl. Current evidence supports a basal cell origin. Merkel cell carcinomas (MCC) occur mostly in sun-exposed skin in old age. Trabecular, intermediate, or small cell in pattern, MCC have neuroendocrine granules, intercellular junctions, rigid spinous processes, and a paranuclear collection of intermediate filaments staining for cytokeratin 20. Most MCC behave indolently, but those with the small cell pattern, and some with the intermediate pattern, are aggressive and rapidly fatal.

Isolation and partial characterization of a new human glioblastoma cell line

Although significant progresses were made in the field of molecular biology of malignant cerebral gliomas, the prognostic of these tumors continues to be reserved. One of the therapeutic failure reasons is the incomplete knowledge regarding the origin of these tumors and cells features, which in fact represent an obstacle in developing a cell and molecular therapy guided against malignant cells responsible for the tumor development and for the therapeutic resistance. Initiation and characterization of glioblastoma cell lines represents an essential step in order to obtain a better in vitro and in vivo experimental model for glioblastoma. We describe here a new glioblastoma line, named T11, which was successfully isolated in our laboratories starting with a tumor sample obtained intraoperative from a 58 years-old female patient. The histopathological evaluation showed a grad IV WHO glioma (glioblastoma). The sample was prepared by manual fragmentation, followed by enzymatic digestions using different concentration of trypsin. The cell line has been cultivated for more than 150 passages. The characterization of the glioblastoma line consisted in the evaluation of cells proliferation capacity (growth curve), morphological features, karyotyping and identification of specific markers. We found that T11 expressed specific markers for glial progenitors and astrocytes (glial fibrillary acidic protein-GFAP); oligodendrocites (A2B5; O4), and microglia (CD45, CD 11b). Cells were negative for neuronal lineage markers like beta3-tubulin and NCAM. In order to evaluate the differentiation grade of T11 cell line, the presence of stem cell markers (nestin, CD133) was explored. T11l cells expressed higher level of nestin and lower level of CD133 comparing with standard glioblastoma cell line U87. T11 cell line expressed VEGF and Bcl-2, but not EGFR and Mdrl and Bax. This new line has distinct and unique characteristics when compared with standard glioblastoma cell line (e.g., U87) and may become a new and useful in vitro model for glioblastoma.

Nestin, PDGFRbeta, CXCL12 and VEGF in glioma patients: different profiles of (pro-angiogenic) molecule expression are related with tumor grade and may provide prognostic information

Angiogenesis is a key event in the natural progression of gliomas. Nestin, a marker for multipotential neuroepithelial stem cells, is detected in neuroepithelial tumors and in proliferating endothelial cells (ECs) and is involved in the early stages of lineage commitment, proliferation and differentiation. Nestin expression is correlated with proangiogenic chemokines (CXCL12 and its receptor CXCR4) and growth factors (VEGF, PDGF-B and its receptor PDGFRbeta). VEGF expression upregulates CXCR4 on endothelial cells, binding the chemokine SDF1/CXCL12 (Stromal Derived Factor) that has a role on angiogenesis and chemotaxis of endothelial cells; PDGF (platelet-derived growth factor) and PDGFRbeta are also crucial by increasing the expression of VEGF. We performed a retrospective study on the presence and role of nestin-expressing cells in 102 patients with glioma, relating the findings to VEGF, CXCL12, PDGFRbeta expression and to clinical outcome (time to tumor progression-TTP and survival time-ST). Our results suggest that in gliomas the detection of proliferating ECs expressing nestin correlates to histological malignancy grade and clinical outcome. Also, the expression of CXCL12 in low-grade gliomas was the only factor associated with a significantly shorter TTP, suggesting a role of this chemokine in angiogenic shift and/or disease progression.

Protein expression in orthocortical and paracortical cells of merino wool fibers

Crimp and bulk, important wool fiber properties, are thought to be related to differences in the protein composition of the orthocortex and paracortex. Fiber morphological studies have demonstrated that the paracortex has a higher proportion of matrix and cysteine than the orthocortex. While there is some evidence for the differential expression of genes between these cell types in the follicle, this has not been demonstrated satisfactorily in the mature fiber. Using proteolytic digestion of wool fibers, followed by ultrasonic disruption to obtain relatively pure fractions of both cell types, the KAP3 high sulfur protein family was found to be present in higher concentrations in the paracortex. This significant finding provides an explanation for the higher cysteine content reported in the paracortex. This represents an advance in our understanding of protein expression variation in the orthocortex and paracortex, and how this relates to key physical and mechanical properties of wool fibers.

Unique and recurrent mutations in the filaggrin gene in Singaporean Chinese patients with ichthyosis vulgaris

Filaggrin is an abundant protein of the outer epidermis that is essential for terminal differentiation of keratinocytes and formation of an effective barrier against water loss and pathogen/allergen/irritant invasion. Recent investigations in Europe and Japan have revealed null mutations in the filaggrin gene (FLG) as the underlying cause of ichthyosis vulgaris (IV), a common skin disorder characterised by dry skin, palmar hyperlinearity and keratosis pilaris. Following the development of a strategy for the comprehensive analysis of FLG, we have identified five unique mutations and one recurrent mutation in Singaporean Chinese IV patients. Mutation 441delA is located in the profilaggrin S100 domain, whereas two additional frameshift mutations, 1249insG and 7945delA, occur in the first partial filaggrin repeat ("repeat 0") and in filaggrin repeat 7, respectively. Both nonsense mutations Q2147X and E2422X are found in filaggrin repeat 6, whereas R4307X was found on one of the longer size variant alleles of FLG, within duplicated repeat 10.2. Mutation E2422X, previously found in a single Dutch patient, was found in one Singaporean IV patient and at a low frequency in Asian population controls. Our study confirms the presence of population-specific as well as recurrent FLG mutations in Singapore.

Development of a high-throughput screening assay for chemical effects on proliferation and viability of immortalized human neural progenitor cells

There is considerable public concern that the majority of commercial chemicals have not been evaluated for their potential to cause developmental neurotoxicity. Although several chemicals are assessed annually under the current developmental neurotoxicity guidelines, time, resource, and animal constraints prevent testing of large numbers of chemicals using this approach. Thus, incentive is mounting to develop in vitro methods to screen chemicals for their potential to harm the developing human nervous system. As an initial step toward this end, the present studies evaluated an automated, high-throughput method for screening chemical effects on proliferation and viability using ReNcell CX cells, a human neural progenitor cell (hNPC) line. ReNcell CX cells doubled in approximately 36 h and expressed the neural progenitor markers nestin and SOX2. High-throughput assays for cell proliferation (5-bromo-2'-deoxyuridine incorporation) and viability (propidium iodide exclusion) were optimized and tested using known antiproliferative compounds. The utility of this in vitro screen was evaluated further using a set of compounds containing eight known to cause developmental neurotoxicity and eight presumably nontoxic compounds. Six out of eight developmental neurotoxicants significantly inhibited ReNcell CX cell proliferation and/or viability, whereas two out of eight nontoxic chemicals caused only minimal effects. These results demonstrate that chemical effects on cell proliferation and viability can be assessed via high-throughput methods using hNPCs. Further development of this approach as part of a strategy to screen compounds for potential effects on nervous system development is warranted.

Fibroblast growth factor 2 maintains the neurogenic capacity of embryonic neural progenitor cells in vitro but changes their neuronal subtype specification

Many in vitro systems used to examine multipotential neural progenitor cells (NPCs) rely on mitogens including fibroblast growth factor 2 (FGF2) for their continued expansion. However, FGF2 has also been shown to alter the expression of transcription factors (TFs) that determine cell fate. Here, we report that NPCs from the embryonic telencephalon grown without FGF2 retain many of their in vivo characteristics, making them a good model for investigating molecular mechanisms involved in cell fate specification and differentiation. However, exposure of cortical NPCs to FGF2 results in a profound change in the types of neurons generated, switching them from a glutamatergic to a GABAergic phenotype. This change closely correlates with the dramatic upregulation of TFs more characteristic of ventral telencephalic NPCs. In addition, exposure of cortical NPCs to FGF2 maintains their neurogenic potential in vitro, and NPCs spontaneously undergo differentiation following FGF2 withdrawal. These results highlight the importance of TFs in determining the types of neurons generated by NPCs in vitro. In addition, they show that FGF2, as well as acting as a mitogen, changes the developmental capabilities of NPCs. These findings have implications for the cell fate specification of in vitro-expanded NPCs and their ability to generate specific cell types for therapeutic applications. Disclosure of potential conflicts of interest is found at the end of this article.

Hyperbaric oxygen induces endogenous neural stem cells to proliferate and differentiate in hypoxic-ischemic brain damage in neonatal rats

BACKGROUND AND PURPOSE

Studies suggest that after brain injury, hyperbaric oxygen (HBO2) is neuroprotective by stimulating cell proliferation. We examine whether HBO2 promotes neural stem cells (NSC) to proliferate and differentiate in neonatal hypoxic-ischemic (HI) rats.

METHODS

Seven-day-old rat pups were subjected to unilateral carotid artery ligation followed by 2 hours of hypoxia (8% O2). HBO2 was administered (2 ATA (atmospheres absolutes), once daily for 7 days) within 3 hours after HI. The proliferating neural stem cells in the subventricular zone (SVZ) and dentate gyrus (DG) were dynamically examined by 5-bromo-2-deoxyuridine (BrdU)/nestin immunofluorescence. Nestin protein was detected by western blot analysis at various time points (from 6 hours to 14 days) after HI. The migrating NSC were examined by BrdU/doublecortin (DCX) immunofluorescence 7 and 14 days after HI. The phenotype of the newborn cells was identified by BrdU/beta-tubulin, BrdU/ glial fibrillary acidic protein (GFAP) and BrdU/O4 (oligodendrocyte marker) immunofluorescence. Myelin basic protein (MBP) was examined by immunohistochemistry and pathological changes of the brain tissue were detected 28 days after HI.

RESULTS

In neonatal HI rats treated with HBO2, the proliferation of endogenous NSC was observed in the SVZ and DG. Cell numbers peaked 7 days after HI and proliferating NSC migrated to the cerebral cortex at 14 d after HI. Twenty-eight days after HI, an increase in newly generated neurons, oligodendrocytes and MBP was observed in the HBO2 group compared to the untreated and HI-treated rats.

CONCLUSIONS

This study suggests that HBO2 treatment may promote neurogenesis of the endogenous NSC in neonatal HI rats, contributing to repair of the injured brain.

[Electrophysiological properties of outward voltage-gated potassium channels of neural stem cells from adult rat hippocampus]

OBJECTIVE

To explore the electrophysiological properties of outward voltage-gated potassium channels of neural stem cells (NSCs) from adult rat hippocampus.

METHODS

NSCs were isolated from the hippocampus of adult SD rats with serum-free incubation and single-cell cloning technique. Immunochemistry technique was employed to identify the clone cells and clone cell-derived progeny. Electrophysiological recordings of various outward voltage-gated potassium channels were performed at room temperature using whole-cell patch clamp.

RESULTS

The floating neural spheres from the hippocampus showed the expression of nestin antigen, and were able to differentiate into neural cells expressing Yuj1 antigen and glial fibrillary acidic protein (GFAP) respectively in vitro. Three type specialized ion channels were find in cultured NSCs: The outward delayed rectifier outward K(+) currents (I(DR)) was characterized by a slow activation with depolarization and a sensitivity to tetraethylammonium (TEA). The current density of transient A type K(+) currents (I(A)) was 11 pA/pF +/- 3 pA/pF and 29 pA/pF +/- 7 pA/pF (n = 11) at +20 mV and +50 mV respectively, which was characterized by a rapid activation with depolarization and could be blocked by 4-AP. The large conductance calcium activated potassium (BKCa) channels was identified by the inhibition of iberiotoxin (IbTX). The current density of this channel at +80 mV was 56 pA/pF +/- 4 pA/pF and 45 pA/pF +/- 4 pA/pF (n = 6, P < 0.05) before and after application of 100 nM IbTX respectively.

CONCLUSION

The cultured NSCs of adult rat hippocampus express at least three kinds of outward voltage-gated potassium channels, I(DR), I(A), and BKCa in vitro.

Morphological changes in the tubulointerstitial compartment in primary glomerulopathies

The renal interstitium structurally supports the functional renal units and is involved in almost all renal functions. The degree of renal disfunction strongly correlates to the changes in the tubulointerstitial compartment present in almost all types of glomerular diseases. A phenomenon arising in such an environment is epithelial-mesenchymal transition, i.e. a change of the cell;s epithelial phenotype into a mesenchymal one. Histochemical, immunohistochemical and morphometric analyses were made of 50 renal biopsies with primary glomerulopathies, as well as light-microscopy analyses of semi-thin sections embedded in epoxy resin. Double immunohistochemical stainings with pairs of epithelial and mesenchymal antibodies were also done. The results were analyzed and correlated with the clinical data of the renal function of the patients. The immunohistochemical analyses of the atrophic tubular epithelial cells showed a loss of expression of Cytokeratin and E-cadherin, an enhanced expression of HLA-DRalpha, and a de novo expression of Vimentin and alphaSMA as markers for epithelial-mesenchymal transition. The double immunohistochemical stainings with Cytokeratin/Vimentin and Cytokeratin/alphaSMA showed a simultaneous expression of these antigens in atrophic tubular cells. Their proliferative index was mildly enhanced. Interstitial fibrosis was present in 98% of the analysed biopsies. The analyses show correlations among all the changes in the tubulointerstitial compartment as well as the concentration of creatinine in the serum as a parameter of renal function. The study emphasizes the usefulness of the implementation of histomorphometrical and immunohistochemical techniques as well as ultrastructural and molecular analyses in the process of nephropathological diagnosis.

Role of Wnt5a in the proliferation of human glioblastoma cells

Wnt5a operates as either a tumor suppressor or a tumor stimulator, according to tumor type. The functions of Wnt5a in human glioblastoma (GBM) have yet to be determined. We initially evaluated the expression of Wnt5a in human glioma. The results of immunohistochemical analyses have revealed that Wnt5a expression was higher in human GBM than in normal brain tissue and low-grade astrocytoma. In order to assess the role of Wnt5a on proliferation in human glioblastoma cells, we employed U87MG and GBM-05, a newly established GBM cell line. GBM-05 was established from a patient diagnosed with GBM. GBM-05 cells were shown to express Nestin, but did not express GFAP and Map2ab. GBM-05 cells formed infiltrating brain tumors after being intracerebrally transplanted into nude mice, and xenotransplanted GBM-05 cells were observed to differentiate into neuronal and astrocyte lineages. Wnt5a expression in the xenotransplanted tumors was higher than that detected in the surrounding brain tissues. The overexpression of Wnt5a increased the proliferation of GBM-05 and U87MG in vitro. By way of contrast, the downregulation of Wnt5a expression as the result of RNA interference reduced proliferation from GBM-05 and U87MG cells in vitro, and reduced tumorigenicity in vivo. Our data indicate that Wnt5a signaling is an important regulator in the proliferation of human glioma cells.

Immunohistochemical analysis of nestin and c-kit and their significance in pancreatic tumors

The purpose of the present study was to clarify the difference of expression of two stem cell markers, nestin and c-kit, among various pancreatic epithelial tumors and evaluate their utility. Immunohistochemistry was done for 99 surgically resected pancreatic tumor specimens, including 20 ductal adenocarcinoma (DAC), two undifferentiated carcinomas (UC), 31 intraductal papillary-mucinous neoplasms (IPMN), six mucinous cystic neoplasms (MCN), five serous cystadenomas (SCA), six acinar cell carcinomas, two pancreatoblastoma (PB), eight solid-pseudopapillary neoplasms (SPN), and 19 endocrine neoplasms (EN). Nestin was widely expressed in four SPN, one PB, one SCA, sarcoma areas in two UC, one MCN, and one DAC, and an area of oncocytic component in one IPMN. Some of these SPN, SCA and sarcomatous or oncocytic components in which nestin was expressed, also coexpressed c-kit. Additionally, partial (scattered) expression of c-kit was observed in ductal elements of 16 DAC, eight IPMN, five MCN, and one UC, one SCA, and three EN. The eight c-kit-positive IPMN included four of 23 adenoma-to-border lesions and four of eight non-invasive-to-invasive carcinomas. The three EN were all carcinomas. These indicate that expression of two stem cell markers is different by tumor type, but the utility of judging direction or degree of differentiation and malignant grade on the basis of their expression status is suggested.

Consistent expression of the stem cell renewal factor BMI-1 in primary and metastatic melanoma

Stem cell-like cells have recently been identified in melanoma cell lines, but their relevance for melanoma pathogenesis is controversial. To characterize the stem cell signature of melanoma, expression of stem cell markers BMI-1 and nestin was studied in 64 cutaneous melanomas, 165 melanoma metastases as well as 53 melanoma cell lines. Stem cell renewal factor BMI-1 is a transcriptional repressor of the Ink4a/Arf locus encoding p16(ink4a) and p14(Arf). Increased nuclear BMI-1 expression was detectable in 41 of 64 (64%) primary melanomas, 117 of 165 melanoma metastases (71%) and 15 of 53 (28%) melanoma cell lines. High nestin expression was observed in 14 of 56 primary melanomas (25%), 84 of 165 melanoma metastases (50%) and 21 of 53 melanoma cell lines (40%). There was a significant correlation between BMI-1 and nestin expression in cell lines (p = 0.001) and metastases (p = 0.02). These data indicate that cells in primary melanomas and their metastases may have stem cell properties. Cell lines obtained from melanoma metastases showed a significant higher BMI-1 expression compared to cell lines from primary melanoma (p = 0.001). Further, primary melanoma lacking lymphatic metastases at presentation (pN0, n = 40) was less frequently BMI-1 positive than melanomas presenting with lymphatic metastases (pN1; n = 24; 52% versus 83%; p = 0.01). Therefore, BMI-1 expression appears to induce a metastatic tendency. Because BMI-1 functions as a transcriptional repressor of the Ink4a/Arf locus, p16(ink4a) and p14(Arf) expression was also analyzed. A high BMI-1/low p16(ink4a) expression pattern was a significant predictor of metastasis by means of logistic regression analysis (p = 0.005). This suggests that BMI-1 mediated repression of p16(ink4a) may contribute to an increased aggressive behavior of stem cell-like melanoma cells.

Downregulation of desmuslin in primary vein incompetence

OBJECTIVE

Primary vein incompetence is one of the most common diseases of the peripheral veins, but its pathogenesis is unknown. These veins present obvious congenital defects, and examination of gene expression profiles of the incompetent vein specimens may provide important clues. The aim of this study was to screen for genes affecting the primary vein incompetence phenotype and test the differential expression of certain genes.

METHODS

We compared gene expression profiles of valvular areas from incompetent and normal great saphenous veins at the saphenofemoral junctions by fluorescent differential display reverse-transcription polymerase chain reaction (FDD RT-PCR). Differentially expressed complimentary DNAs (cDNAs) were confirmed by Northern blotting and semi-quantitative RT-PCR. Similarity of the cDNAs sequences to GenBank sequences was determined. Gene expression status was then determined by Western blot analysis and immunohistochemical techniques.

RESULTS

There were >30 differentially expressed cDNA bands. Sequence analysis revealed that a cDNA fragment obviously downregulated in incompetent great saphenous vein was a portion of the messenger RNA (mRNA) encoding desmuslin, a newly discovered intermittent filament protein. Northern blotting and semi-quantitative RT-PCR analysis revealed a similar mRNA expression profile of the desmuslin gene in other samples. Western blotting and immunohistochemical techniques localized the desmuslin protein mainly in the cytoplasm of venous smooth muscle cells. The amount of desmuslin was greatly decreased in the smooth muscle cells of incompetent veins.

CONCLUSIONS

The expression of many genes is altered in primary vein incompetence. Up- or downregulation of these genes may be involved in the pathogenesis of this disease. Desmuslin expression is downregulated in the abnormal veins. Its effect on the integrity of smooth muscle cells might be related to malformation of the vein wall. Further studies are needed to investigate other differentially expressed cDNAs and the exact role of desmuslin in this disease.

CLINICAL RELEVANCE

Primary vein incompetence is a frequent and refractory disease of the peripheral veins. Exploring its pathogenesis may enhance our comprehension and management of this disease. We used reliable techniques to detect disease-related genes and confirmed downregulation of desmuslin in abnormal veins. Alteration of these genes might be used as disease markers or gene therapy targets.

Oral leiomyosarcomas: report of two cases with immunohistochemical profile

Leiomyosarcoma of the oral cavity is a very rare tumor associated with aggressive clinical behavior and low survival. In this paper, we report 2 cases of leiomyosarcoma, affecting the gingival mucosa of a 54-year-old female and the maxillary bone of a 63-year-old male. Histologically, the tumors were composed of variably oriented fascicles of spindle-shaped cells with cigar-shaped nuclei and eosinophilic cytoplasm. The lesions were treated by surgical resection. Immunoreactivity to anti-vimentin, anti-smooth muscle actin, anti-desmin, anti-laminin, and anti-muscle-specific actin antibodies were found; conversely, the tumor cells were negative for anti-S100 and AE1/AE3 proteins. This report emphasizes the role of immunohistochemical study for correct diagnosis of leiomyosarcoma.