[Correlations of S100A4 and MMP9 expressions to infiltration, metastasis and prognosis of non-small cell lung cancer]

OBJECTIVE

To observe the expressions of metastasis-associated protein (S100A4) and matrix metalloproteinase 9 (MMP9) in human non-small cell lung cancer (NSCLC) and investigate their correlations to the infiltration, metastasis and prognosis of NSCLC.

METHODS

The expressions of S100A4 and MMP9 were detected in 41 NSCLC specimens and 6 normal lung tissue specimens using immunohistochemistry with SP method. Univariate and multivariate survival analysis were used to analyze the correlations of S100A4 and MMP9 to the clinicopathological characteristics and progrnosis of NSCLC.

RESULTS

Compared with normal lung tissues, NSCLC showed significantly increased positivity for S100A4 and MMP9 expression (P<0.05); their expression were significantly higher in adenocarcinoma than in squamous cell carcinoma (P<0.01), and higher in metastatic NSCLC than in that without lymphatic metastasis (P<0.01). The positive expression rates of S100A4 and MMP9 were significantly higher in tumors in TNM stages III +IV than in stages II+I (P<0.05). S100A4 expression was positively correlated to tumor size (P<0.001), while MMP9 was inversely correlated to tumor differentiation (P<0.05). The expressions of S100A4 and MMP9 were both correlated to lymphatic metastasis, TNM stages and pathological types (P<0.05), and they also showed a mutual correlation (P<0.01). Univariate survival analysis confirmed the effects of histological types, lymphatic metastasis, clinical TNM stages and expressions of S100A4 and MMP9 on the survival time of NSCLC patients (P<0.001). Multivariate survival analysis identified clinical TNM stages and expressions of S100A4 and MMP9 as the independent factors affecting the prognosis of NSCLC (P<0.05).

CONCLUSION

The expressions of S100A4 and MMP9 are up-regulated in NSCLC and have significant correlations to the clinical and biological behaviors of NSCLC. S100A4 and MMP9 status are independent prognostic predictors of NSCLC, and detection of their expressions may help evaluate the prognosis of NSCLC.

Value of serum S-100B for prediction of distant relapse and survival in stage III B/C melanoma

BACKGROUND

The biochemical marker serum S-100B has been proven to reflect the stage of melanoma and to be useful for disease monitoring and prediction of survival, mainly in stage IV disease. For stage III melanoma, limited data are available and its predictive value for relapse is unknown. Serum S-100B was evaluated prospectively for monitoring response and its predictive value for relapse and overall survival in stage IIIB/C melanoma patients.

PATIENTS AND METHODS

Treatment consisted of one cycle of neoadjuvant and adjuvant chemo(immuno)therapy, around surgery. S-100B was measured at enrollment and prior to and following surgery. The levels of S-100B in serum were compared to the pattern and intensity of the expression of S-100B in the melanoma tissue.

RESULTS

Some patients with normal initial S-100B values (n=18) showed responses (3 complete remission and 2 partial remission), in contrast to patients with elevated S-100B values. Distant relapse within one year was found in 11/23 (48%) patients with increased S-100B versus 2/18 (11%) patients with a normal value (p=0.01). Overall survival was decreased in patients with increased S-100B compared to those with normal S-100B (p=0.02). Correlations between the pattern and intensity of S-100B expression in the tumor specimen and the value of serum the S-100B did not reach statistical significance.

CONCLUSION

Serum S-100B is a valuable biomarker for the evaluation of response to treatment and prediction of early distant relapse and survival in stage IIIB/C melanoma. The marginal correlation between serum S-100B values and expression of S-100B in the tumor specimens needs further study.

Validity of S-100 B in patients after brain radiation

BACKGROUND

S-100B is a calcium binding acute phase protein and a potential biomarker for brain injury. In prior studies elevated plasma S-100B levels were detected in stroke and severe head trauma. The aim of this study was to evaluate whether S-100 B is elevated during cerebral radiotherapy and whether that is associated with adverse outcomes.

MATERIAL AND METHODS

In this prospective pilot study, 45 patients (25 males, 20 females, median age 58 (17-81)) underwent cerebral radiation therapy because of a primary or metastaic cerebral malignancy. 39 patients were included in the evaluation. 6 patients died during the study period. S-100 plasma concentrations were measured with an electrochemiluminescence immunoassay on admission and weekly during radiation therapy for the duration of 6 weeks. In 10 healthy young volunteers (5 males, 5 females, median age 32 (28-36)) S-100 B plasma levels were measured weekly for 6 weeks as a negative control. Furthermore, in an active control 10 patients (4 males, 6 females, median age 68 (64-76)) with stroke (7 = major stroke, 3 = lacunar infarct) S- 100 B plasma levels were measured for 7 consecutive days after the event.

RESULTS

During radiotherapy S-100 B plasma concentrations increased from median baseline values of 0.030 microg/l to 0.044 microg/l. For the time of radiation therapy most patients showed a mild increase, but absolute plasma values were still within the normal range. In the control group of healthy volunteers S-100 B remained unchanged. In stroke patients S-100 B increased to maximum values of 1.7 microg/l three days after the event. In the 3 patients with lacunar infarcts no increase of S-100 B levels could be detected.

CONCLUSION

Brain irradiation leads to a mild increase of S-100 B plasma levels. However, the absolute rise was far weaker compared to that seen in major brain injuries.

S100B is expressed in, and released from, OLN-93 oligodendrocytes: Influence of serum and glucose deprivation

S100B (member of a family of proteins that are 100% soluble in ammonium sulfate at neutral pH) has been widely used as astrocyte marker in animal models and in human brain diseases. Recent studies revealed S100B-immunopositivity in oligodendrocytes and O2A oligodendroglial progenitor cells. It is unknown, however, if oligodendrocytes produce S100B themselves, or if the S100B-immunolabeling is caused by binding or absorption of the protein. To address this question, S100B expression and protein release were analyzed in a highly pure oligodendrocytic OLN-93 cell line (from rat), in the astrocytic C6 cell line (from rat) and primary astrocytes. S100B was gene expressed in all cultures, as revealed by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. OLN-93 cells and glial fibrillary acidic protein (GFAP)-negative astrocytes expressed the multiligand receptor for advanced glycation end products (RAGE). S100B protein levels were determined in supernatants and cell homogenates by immunoluminometry under normal conditions and after serum and glucose deprivation (SGD). SGD led to a several-fold increased release of S100B (after 6 and 24 h), which was particularly pronounced in primary astrocytes. Increased S100B in cell homogenates was most notable in OLN-93 cells under SGD, indicating activated S100B synthesis. These cells also showed the highest percentage of dead cells, as determined by propidium iodide-positivity, after SGD. Incubation with 0.5, 2 and 5 microg/l exogenous S100B was not toxic to OLN-93 cells. In conclusion, OLN-93 cells produce more S100B under SGD than astrocytes and are more susceptible to cell death upon SGD, which provokes leakage of S100B. Our data indicate active S100B secretion from astrocytes under SGD since highly elevated levels of S100B were detected in the supernatant despite a low percentage of dead cells. The experimental results provide further evidence for a production/release of S100B in/from oligodendrocytes, e.g. in metabolic stress conditions like cerebral ischemia. Studies on S100B in bodily fluids should be carefully interpreted in order to avoid misleading hypotheses concerning the specific involvement of astrocytes, due to the various cellular sources of S100B.

[Expression of CD117, CD34, SMA, S-100 protein, Vim and desmin in patients with gastrointestinal stromal tumors]

OBJECTIVE

To investigate the clinicopathological diagnosis and expressions of CD117, CD34, SMA, S-100 protein, Vimentin(Vim) and desmin in gastrointestinal stromal tumors (GISTs).

METHODS

A retrospective analysis of the clinical data and the results of various examinations was conducted among 35 patients with pathologically confirmed GISTs undergoing surgical resection. The expressions of CD117, CD34, SMA, S-100, Vim and desmin in the tumor tissues were detected by immunohistochemistry with SP method.

RESULTS

In these GIST cases, the tumors were located mostly in the stomach (n=11), small intestines (n=11), and abdominal cavity (n=5). The main clinical manifestations included abdominal distension, abdominal pain, gastrointestinal bleeding, and abdominal masses. The positivity rates of CD117 and CD34 in the tumors were 94.3% and 91.4%, respectively, both significantly higher than those of SMA, S-100, Vim and Desmin (P<0.001), and also higher than that in leiomyoma (P<0.0001). The positivity rate of Desmin was only 2.9% in the tumors, significantly lower than those of CD117 and CD34 (P<0.05) and that in liomyoma (P<0.001).

CONCLUSIONS

GISTs occur mostly in the stomach and small intestines, and endoscopy, ultrasound endoscope and CT examination are effective modalities for diagnosis of GISTs. A definite diagnosis of GISTs can be established in the presence of positive expression of CD117 and CD34 and negative expression of Desmin in the tumor.

Primary orbital mesenchymal chondrosarcoma: a case report and literature review

BACKGROUND

Mesenchymal chondrosarcoma (MC) is a subtype of chondrosarcoma, with an incidence varying from 1 to 8% of all chondrosarcomas. It is an aggressive neoplasm with a high tendency for late recurrence and occasional delayed distant metastasis. Orbital MC is very rare, and only approximately 30 cases have been described in the literature. We describe here one case of primary orbital MC.

CASE REPORT

A 14-year-old boy without a past medical history presented with a 1-month history of progressive proptosis on the right eye. Computed tomography (CT) scans of the orbit revealed a right intraconic lesion, with areas of calcification. The lesion was excised. Histopathological analysis revealed that the tumor had a biphasic pattern, showing a combination of small cell malignancy and well-differentiated cartilage. Immunohistochemistry examination revealed a diffuse membrane expression of CD99 on the small cell malignancy; S-100 was positive only within the cartilage component. The patient received chemotherapy, and no metastatic disease was found at the 2-month follow-up.

CONCLUSION

Although rare, MC should be considered in the differential diagnosis of a well-circumscribed orbital lesion in young adults, especially when CT scans reveal areas of calcification within the tumor.

The role of S100P in the invasion of pancreatic cancer cells is mediated through cytoskeletal changes and regulation of cathepsin D

Up-regulation of S100P, a member of the S100 calcium-binding protein family, is an early molecular event in the development of pancreatic cancer and it is expressed at high levels in both precursor lesions and invasive cancer. To gain more insight into the molecular mechanisms underlying the functional roles of this protein, we stably overexpressed S100P in the Panc1 pancreatic cancer cell line and identified the consequent changes in global protein expression by two-dimensional difference in-gel electrophoresis. The observed changes in target proteins were confirmed by Western blot analysis and immunofluorescence, whereas their functional effect was investigated using motility and invasion assays. In this study, we have shown that overexpression of S100P led to changes in the expression levels of several cytoskeletal proteins, including cytokeratins 8, 18, and 19. We have also shown disorganization of the actin cytoskeleton network and changes in the phosphorylation status of the actin regulatory protein cofilin. Additionally, we have shown that overexpression of S100P leads to increased expression of another early pancreatic cancer marker, S100A6, as well as the aspartic protease cathepsin D, both of which are involved in cellular invasion. Functional studies showed that the increased invasive potential of S100P-overexpressing cells was at least partially due to the increase in cathepsin D expression. In summary, our data suggest that these changes could contribute to the metastatic spread of pancreatic cancer and may explain the devastating prognosis of this disease.

Expression of S100A4 by a variety of cell types present in the tumor microenvironment of human breast cancer

The S100A4 protein, which is involved in the metastasis process, is a member of the S100 superfamily of Ca-binding proteins. Members of this family are multifunctional signaling proteins with dual extra and intracellular functions involved in the regulation of diverse cellular processes. Several studies have established a correlation between S100A4 protein expression and worse prognosis for patients with various malignancies including breast cancer. In this article, we have used specific antibodies in combination with immunohistochemistry (IHC) to identify the cell types that express S100A4 in human breast cancer biopsies obtained from high-risk patients. IHC analysis of 68 tumor biopsies showed that the protein is expressed preferentially by various cell types present in the tumor microenvironment (macrophages, fibroblasts, activated lymphocytes), rather than by the tumor cells themselves. Moreover, we show that the protein is externalized by the stroma cells to the fluid that bathes the tumor microenvironment, where it is found in several forms that most likely correspond to charge variants. Using a specific ELISA test, we detected a significant higher concentration of S100A4 in the tumor interstitial fluid (TIF) as compared to their corresponding normal counterparts (NIF).

Gene expression profiling of nonhuman primates exposed to aerosolized Venezuelan equine encephalitis virus

Host responses to Venezuelan equine encephalitis viruses (VEEV) were studied in cynomolgus macaques after aerosol exposure to the epizootic virus. Changes in global gene expression were assessed for the brain, lungs, and spleen. In the brain, major histocompatibility complex (MHC) class I transcripts were induced, while the expression of S100b, a factor associated with brain injury, was inhibited, as was expression of the encephalitogenic gene MOG. Cytokine-mediated signals were affected by infection, including those involving IFN-mediated antiviral activity (IRF-7, OAS, and Mx transcripts), and the increased transcription of caspases. Induction of a few immunologically relevant genes (e.g. IFITM1 and STAT1) was common to all tested tissues. Herein, both tissue-specific and nontissue specific transcriptional changes in response to VEEV are described, including induction of IFN-regulated transcripts and cytokine-induced apoptotic factors, in addition to cellular factors in the brain that may be descriptive of the health status of the brain during the infectious process. Altogether, this work provides novel information on common and tissue-specific host responses against VEEV in a nonhuman primate model of aerosol exposure.

The prognostic value of Stathmin-1, S100A2, and SYK proteins in ER-positive primary breast cancer patients treated with adjuvant tamoxifen monotherapy: an immunohistochemical study

INTRODUCTION

We recently found that DNA methylation of S100A2, spleen tyrosine kinase (SYK), and Stathmin-1 (STMN1) correlates with response to tamoxifen therapy in metastatic breast cancer. In this retrospective study, we investigated immunohistochemically whether these three markers are predictors of relapse in early breast cancer (EBC) patients treated with adjuvant tamoxifen alone.

METHODS

Immunohistochemical staining was performed for S100A2, SYK and STMN1 on a tissue microarray containing ER-positive invasive breast carcinomas from a study cohort of 215 operable breast cancer patients, who underwent radical local therapy and who were treated with adjuvant tamoxifen monotherapy. Cox regression was used to correlate staining intensity of the three markers with main endpoints in our study; disease-free survival (DFS), and disease-specific survival (DSS).

RESULTS

In univariate analysis, only STMN1 staining intensity strongly correlated with DFS (P = 0.014) and DSS (P = 0.002). In the groups of low and high STMN1 intensity, DFS was 84% and 63%, and DSS was 89% and 70%. STMN1 retained its prognostic value for DFS (P = 0.002) and DSS (<0.001) in the multivariate model together with lymph node status. We found also a trend to better DFS in patients with low STMN1 intensity in both lymph node-positive (P = 0.001) and -negative patients (P = 0.065). As the tumour cells did not express S100A2 (except in one case) the potential prognostic value of this marker was not evaluated.

CONCLUSIONS

Staining intensity of STMN1, but not SYK, predicted outcome in our collective of ER- positive tamoxifen treated EBC patients.

Expression of S100 protein family members in the pathogenesis of bladder tumors

The S100 proteins act as multifactional signaling factors that are involved in the regulation of diverse cellular processes. To explore the involvement of S100 genes in bladder cancers, S100 gene expressions were systematically evaluated at the RNA level by microarray and real-time PCR. Total RNAs were obtained from 4-hydroxybutyl(butyl)nitrosamine (OH-BBN)-induced mouse and rat bladder cancers, human bladder cancers and matched normal bladder urothelium. Microarray analysis was performed on mouse and rat bladder cancers; real-time PCR was performed in mouse, rat and human bladder cancers and their matched normal urothelium for confirmation. Microarray analysis revealed that 9 and 6 members of the S100 gene family were differentially expressed in mouse and rat bladder cancers, respectively. Thirteen members of the S100 gene family were confirmed by real-time PCR to be differentially expressed in human bladder cancers, with overexpression of S100A2, S100A3, S100A5, S100A7, S100A8, S100A9, S100A14, S100A15, S100A16 and S100P, and underexpression of S100A1, S100A4 and S100B. S100A1, S10OA3, S100A8, S10A9, S100A14, S100A15 and S100A16 showed similar patterns of differential expression in bladder cancers from mouse, rat and human. To our knowledge this is the first report of systematic evaluation of S100 gene expressions in bladder cancers. Our results indicate that differential expression of S100 gene family members is characteristic of bladder cancers and these genes may play important roles in bladder tumorigenesis and progression.

S100A10 expression in thyroid neoplasms originating from the follicular epithelium: contribution to the aggressive characteristic of anaplastic carcinoma

BACKGROUND

S100A10, a member of the S100 family, forms a heterotetramer with annexin IIH and promotes carcinoma invasion and metastasis by plasminogen activation. In this study, S100A10 and annexin II expression in thyroid neoplasms were demonstrated.

PATIENTS AND METHODS

The expression levels of S100A10 and annexin II in 193 thyroid neoplasms were immunohistochemically investigated.

RESULTS

S10A10 and annexin II were not expressed in normal follicular cells or any follicular adenomas. Cells stained positively in 14.6% and 20.8% of follicular carcinomas for S100A10 and annexin II, respectively, but their expression levels were always low. S100A10 and annexin II were expressed in all papillary carcinomas, but 88.2% and 82.8% ofpapillary carcinomas were classified in the low group. These expression levels were not linked to any clinicopathological features. S100S10 and annexin II were also expressed in all anaplastic carcinomas, with 83.3% of these lesions were classified in the high group.

CONCLUSION

These findings suggest that S100A10 and annexin II contribute to the aggressive characteristics of anaplastic carcinoma, while playing a constitutive role in papillary carcinoma.

Expression of insulin-like growth-factor-1 receptor (IGF-1R) in peripheral nerve sheath tumors in neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is an autosomal-dominant inherited disease, characterised by the development of nerve sheath tumors. NF1 is the most frequently inherited disease associated with a predisposition for cancer (in particular malignant peripheral nerve sheath tumors: MPNST). NF1 is a progressive disease with phase-like growth spurts of dermal or plexiform neurofibroma (PNF). These tumors can cause severe disfigurement of patients. Growth control of these tumors is poorly understood. The aim of this study was to identify the expression of insulin-like growth factor 1-receptor (IGF-1R) in peripheral nerve sheath tumors. Factor and receptor are involved in the growth control of numerous physiological and pathological processes, including Schwann cell development.

MATERIALS AND METHODS

The investigation included tumors of NF1-patients only (neurofibroma, MPNST). Sections of the specimens were immunohistochemically typed for several antigens (target antigens: IGF-1R, S-100, EMA, CD34, MIB-1), using both single and double-staining methods. Double-staining allowed the sub-typing of the IGF-1R-expressing cells in the mixed nerve sheath tumors. The expression was also investigated in Schwann cell cultures and co-cultures with fibroblasts.

RESULTS

Staining of S-100 and IGF-1R, PNF were more intensely marked than MPNST (r = -0.439, p < 0.002, N = 49). The proliferation index was tumor-type dependent: MPNST > neurofibroma. The IGF-1R-expression correlated positively with the MIB-1 index in neurofibroma (r = 0.372, p = 0.021, N = 38). The receptor expression was higher in PNF than in dermal neurofibroma (r = 0.335, p = 0.040, N = 38). IGF-1R was detected in Schwann cells (S-100 positive) and in perineurial cells (EMA-positive) of all nerve sheath tumors. However, the receptor was also identified in CD34-marked endothelia of neurofibromas but not in endothelia of MPNST. In Schwann cell cultures, a strong receptor-expression became evident. This expression was independent of co-cultivation of tumor cells with fibroblasts. The statistical calculations excluded the impact of gender on the receptor expression.

CONCLUSION

This investigation provides evidence for the expression of IGF-1R in nerve sheath tumors in NF1. The expression pattern varied between the tumor types, the cell types, and between tumors of the same type. IGF and IGF-1R are a prerequisite to maintain Schwann cell stability in the postnatal period and to prevent Schwann cell apoptosis. The first evidence for IGF-1R expression in mutated Schwann cells may indicate a tumor-type associated receptor expression in NF1.

A review of the S100 proteins in cancer

AIM

In the quest to reduce mortality and morbidity from cancer, there is continued effort to identify novel biomarkers to aid in the early detection and the accurate prediction of tumour behaviour. One group of proteins that is emerging as a potentially important group of markers in multiple tumour types is the S100 family. This review summarises the biological and clinical relevance of these proteins in relation to different tumour types.

METHODS

A literature search was performed using the PubMed database and the reference lists of relevant articles. Single case studies were excluded and only reports with a clinical relevance from 1961 to 2007 were included.

RESULTS

The search yielded over 1000 published articles and reports. Important reports and studies were reviewed, screened and tracked for further relevant publications. Only the most relevant publications are discussed with relation to individual members of the S100 family.

CONCLUSION

There is increasing evidence that altered expression of S100 family members is seen in many cancers including breast, lung, bladder, kidney, thyroid, gastric, prostate and oral cancers. S100 proteins are commonly up-regulated in tumours and this is often associated with tumour progression. In contrast S100A2, S100A11 and S100A9 have been documented as tumour suppressors in some cancers but as tumour promoters in others. This demonstrates the complexity of the family and variability of their functions. Although the precise roles of these proteins in cancer is still to be discovered many of the family are associated with promoting metastases through interactions with matrix metalloproteinases or by acting as chemoattractants. There is also evidence that some members can regulate transcription factors such as p53. S100B already has a role in a clinical setting in the diagnosis and therapeutic monitoring of malignant melanoma. As our understanding of this family develops it is likely that many more members will aid the diagnosis, monitoring and potential treatment of cancers in the future.

Cutaneous Rosai-Dorfman disease

Rosai-Dorfman disease (RDD) is a rare benign proliferative disorder of histiocytes in the lymph nodes with or without extranodal involvement. RDD limited to the skin without nodal involvement, known as cutaneous Rosai-Dorfman disease, is very rare. We describe a 34-year-old female with RDD of the skin over the chest. A large nodule with satellite lesions was excised for histopathological examination. Microscopically, there were many large histiocytes (Rosai-Dorfman cells) exhibiting emperipolesis, among many plasma cells, lymphocytes and neutrophils throughout the dermis and the subcutaneous tissue. The histiocytes were immunohistochemically positive for S-100 protein but negative for CD 1a. Physical examination showed no lymphadenopathy or any extra-cutaneous lesions. Serological tests indicated a past infection with Epstein-Barr virus and cytomegalovirus. The diagnosis of cutaneous RDD may be difficult in the absence of associated lymphadenopathy or any specific features of the skin lesion. Hence, not only is histopathological examination required for definitive diagnosis but a high index of suspicion by the clinicians and pathologists is essential to help diagnose this very rare disease.

Neutrophil-derived S100A12 in acute lung injury and respiratory distress syndrome

OBJECTIVE

Both persistent accumulation and activation of neutrophils may contribute to the most severe form of acute lung injury, acute respiratory distress syndrome. We analyzed the expression of neutrophil-derived S100A12 and the proinflammatory receptor for advanced glycation end products (RAGE) in patients with acute respiratory distress syndrome. Additional in vivo and in vitro experiments were performed to further analyze the contribution of S100A12 to pulmonary inflammation.

SUBJECTS

We included 14 patients with acute respiratory distress syndrome and eight controls. In addition, 16 healthy subjects were included in an experimental lipopolysaccharide challenge model.

INTERVENTIONS

Concentrations of S100A12 and soluble RAGE were analyzed in bronchoalveolar lavage fluid. The expression of S100A12 and RAGE in lung biopsies from patients was analyzed by immunohistochemistry. S100A12 was also analyzed in bronchoalveolar lavage fluid from eight healthy subjects after challenge with lipopolysaccharide and compared with eight controls who received placebo inhalation. Effects of S100A12 on endothelial cells were analyzed in vitro.

MAIN RESULTS

Patients with acute respiratory distress syndrome had significantly enhanced pulmonary S100A12 expression and higher S100A12 protein concentrations in bronchoalveolar lavage fluid than controls. Levels of soluble RAGE were not significantly elevated in acute respiratory distress syndrome. S100A12 concentrations decreased with time from disease onset. In healthy volunteers, S100A12 was elevated in bronchoalveolar lavage fluid after lipopolysaccharide inhalation. In vitro experiments confirmed strong proinflammatory effects of human S100A12.

CONCLUSIONS

S100A12 and its receptor RAGE are found at high concentrations in pulmonary tissue and bronchoalveolar lavage fluid in acute lung injury. S100A12 expression may reflect neutrophil activation during lung inflammation and contribute to pulmonary inflammation and endothelial activation via binding to RAGE.

Up-regulation of loricrin expression by cell adhesion molecule nectin-1 through Rap1-ERK signaling in keratinocytes

Nectin is an immunoglobulin-like cell-cell adhesion molecule, which plays essential roles in the initial step of formation of adherens junctions and tight junctions. We demonstrate here the role of nectin-1 in the epidermis using nectin-1-/- mice. Newborn nectin-1-/- pups showed shiny and slightly reddish skin; the amount of loricrin, one of the differentiation markers and also a major component of cornified cell envelopes, was markedly reduced in the epidermis of nectin-1-/- mice. The amounts of repetin and SPRRP, other components of cornified cell envelopes, were markedly elevated probably due to a compensatory mechanism to overcome the impaired expression of loricrin. However, cornified cells from nectin-1-/- mice were sensitive to mechanical stress. Moreover, Ca2+-induced activation of ERK through Rap1 and expression of loricrin were reduced in primary cultured nectin-1-/- keratinocytes; in turn, the inhibition of ERK activation reduced the amount of loricrin in wild-type keratinocytes. These results indicate that nectin-1 plays a key role in the expression of loricrin in the epidermis.

Differential expression of periodontal ligament-specific markers and osteogenic differentiation in human papilloma virus 16-immortalized human gingival fibroblasts and periodontal ligament cells

BACKGROUND AND OBJECTIVE

Periodontal ligament cells and gingival fibroblasts are important in the remodeling of periodontal tissue, but human papilloma virus (HPV)16-immortalized cell lines derived from human periodontal ligament cells and gingival fibroblasts has not been characterized. The purpose of this study was to establish and differentially characterize the immortalized cell lines from gingival fibroblasts and periodontal ligament by HPV16 transfection.

MATERIAL AND METHODS

Cell growth, cell cycle analysis, western blot for cell cycle regulatory proteins and osteogenic differentiation markers, and reverse transcription-polymerase chain reaction for periodontal ligament-specific markers were performed.

RESULTS

Both immortalized cell lines (immortalized gingival fibroblasts and immortalized periodontal ligament cells) grew faster than primary cultured gingival fibroblasts or periodontal ligament cells. Immortalized gingival fibroblasts and immortalized periodontal ligament cells overexpressed proteins p16 and p21, and exhibited degradation of proteins pRb and p53, which normally cause cell cycle arrest in G2/M-phase. Western blotting and reverse transcription-polymerase chain reaction for periodontal ligament-specific and osteogenic differentiation marker studies demonstrated that a cell line, designated IPDL, mimicked periodontal ligament gene expression for alkaline phosphatase, osteonectin, osteopontin, bone sialoprotein, bone morphogenic protein-2, periostin, S-100A4 and PDLs17.

CONCLUSION

These results indicate that IPDL and immortalized gingival fibroblast cell lines consistently retain normal periodontal ligament and gingival fibroblast phenotypes, respectively, and periodontal ligament markers and osteogenic differentiation in IPDL are distinct from immortalized gingival fibroblast cells.

Downregulation of an astrocyte-derived inflammatory protein, S100B, reduces vascular inflammatory responses in brains persistently infected with Borna disease virus

Borna disease virus (BDV) is a neurotropic virus that causes a persistent infection in the central nervous system (CNS) of many vertebrate species. Although a severe reactive gliosis is observed in experimentally BDV-infected rat brains, little is known about the glial reactions contributing to the viral persistence and immune modulation in the CNS. In this regard, we examined the expression of an astrocyte-derived factor, S100B, in the brains of Lewis rats persistently infected with BDV. S100B is a Ca(2+)-binding protein produced mainly by astrocytes. A prominent role of this protein appears to be the promotion of vascular inflammatory responses through interaction with the receptor for advanced glycation end products (RAGE). Here we show that the expression of S100B is significantly reduced in BDV-infected brains despite severe astrocytosis with increased glial fibrillary acidic protein immunoreactivity. Interestingly, no upregulation of the expression of S100B, or RAGE, was observed in the persistently infected brains even when incited with several inflammatory stimuli, including lipopolysaccharide. In addition, expression of the vascular cell adhesion molecule 1 (VCAM-1), as well as the infiltration of encephalitogenic T cells, was significantly reduced in persistently infected brains in which an experimental autoimmune encephalomyelitis was induced by immunization with myelin-basic protein. Furthermore, we demonstrated that the continuous activation of S100B in the brain may be necessary for the progression of vascular immune responses in neonatally infected rat brains. Our results suggested that BDV infection may impair astrocyte functions via a downregulation of S100B expression, leading to the maintenance of a persistent infection.

2,3,7,8-Tetrachlorodibenzo-p-dioxin induces premature activation of the KLF2 regulon during thymocyte development

The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) causes numerous and diverse toxic events via activation of the aryl hydrocarbon receptor, including atrophy of the thymus. Exposure to TCDD induces acute thymocyte cell loss, which occurs concomitantly with proliferation arrest and premature emigration of triple negative (TN; CD4(-), CD8(-), CD3(-)) T cell progenitors. In this report, we demonstrate that TCDD exposure results in dysregulation of KLF2 (Kruppel-like factor 2) expression in developing thymocytes. The Klf2 gene encodes an Sp1-like zinc finger transcription factor that functions as a central regulator of T lymphocyte proliferation and trafficking. During normal thymocyte development, KLF2 is expressed exclusively in CD4 and CD8 single positive T cells and promotes a nonproliferative, promigratory phenotype. In mice exposed to TCDD, however, the Klf2 gene is prematurely expressed in TN thymocytes. Administration of a 100 microg/kg dose of TCDD results in a approximately 15-fold induction of KLF2 as early as the TN2 (CD44(+), CD25(+)) stage of development and immediately precedes acute cell loss in the TN3, TN4, and double positive (CD4(+), CD8(+)) cell stages. Induction of KLF2 occurs within 12 h of TCDD exposure and is fully dependent on expression of the aryl hydrocarbon receptor. In addition, TCDD exposure alters the expression of several factors comprising the KLF2 regulon, including Edg1/S1P(1), beta(7) integrin, CD52, Cdkn2d (cyclin-dependent kinase inhibitor 2D), s100a4, and IL10R alpha. These findings indicate that the pollutant TCDD interferes with early thymopoeisis via ectopic expression of the KLF2 regulon.

S100A4 protein and mesothelin expression in dysplasia and carcinoma of the extrahepatic bile duct

We evaluated the expression of S100A4 protein and mesothelin in dysplasia and carcinoma of the extrahepatic bile duct (EBD) and their potential use as adjuncts for differentiating carcinomatous and significant high-grade dysplastic epithelium from reactive or inflammatory glandular atypia of the EBD. We used immunohistochemical analysis on formalin-fixed tissue sections from 10 cases of carcinoma, 6 cases of high-grade dysphasia (HGD), 4 cases of low-grade dysplasia (LGD), and 10 cases of benign or reactive or inflammatory epithelium from the EBD. Expression of S100A4 protein was observed in 8 invasive carcinomas (80%), 5 HGD/carcinoma in situ cases (83%), and 0 LGDs. Mesothelin was expressed in 5 (50%) of 10 adenocarcinomas, 1 (17%) of 6 HGD/adenocarcinoma in situ cases, and 0 LGDs. No case of normal or reactive epithelium was positive for S100A4 protein or mesothelin. Mesothelin has moderate sensitivity and high specificity, whereas S100A4 protein is sensitive and specific for the identification of carcinoma and HGD of the EBD. S100A4 protein alone or combined with mesothelin can be used as an adjunct in differentiating carcinomatous and significant high-grade dysplastic epithelium from LGD and reactive or inflammatory glandular atypia of the EBD.

Direct comparison of [18F]FDG PET/CT with PET alone and with side-by-side PET and CT in patients with malignant melanoma

PURPOSE

The purpose of this retrospective, blinded study was to evaluate the additional value of [18F]FDG PET/CT in comparison with PET alone and with side-by-side PET and CT in patients with malignant melanoma (MM).

METHODS

A total of 127 consecutive studies of patients with known MM referred for a whole-body PET/CT examination were included in this study. PET alone, side-by-side PET and CT and integrated PET/CT study were independently and separately interpreted without awareness of the clinical information. One score each was applied for certainty of lesion localisation and for certainty of lesion characterisation. Verification of the findings was subsequently performed using all available clinical, pathological (n=30) and follow-up information.

RESULTS

The number of lesions with an uncertain localisation was significantly (p<0.001) reduced by PET/CT and side-by-side PET and CT (p<0.05) in comparison with PET alone. In line with this increase in certainty integrated PET/CT reading also improved certainty in characterisation of lesions, however, this did not reach significance (p=0.057) compared versus PET alone. Respectively, PET, side-by-side PET and CT and PET/CT showed a sensitivity of 86%, 89% and 91%, a specificity of 94%, 94% and 94%, a positive predictive value of 96%, 96% and 96% and a negative predictive value of 80%, 83% and 87%.

CONCLUSION

Integrated PET/CT offers a significant benefit in lesion localisation and an improvement in lesion characterisation compared with PET alone or with side-by-side PET and CT. The benefit is not as great as that reported for other tumour entities, which may be due to the high avidity of MM for [18F]FDG.

Evaluation of S100A10, annexin II and B-FABP expression as markers for renal cell carcinoma

This study aimed to analyze expression of S100A10, annexin II and B-FABP genes in renal cell carcinoma (RCC) and their potential value as tumor markers. Furthermore, any correlation between the gene expression and prognostic indicators of RCC was analyzed. Expression of each gene was estimated by RT-PCR in the non-neoplastic (normal) and tumorous parts of resected kidney samples. Also, each antigen was immunostained in RCC and normal kidney tissues. Expression of the S100A10 gene averaged 2.5-fold higher in the tumor than that in the normal tissues (n = 47), after standardization against that of beta-actin. However, expression of annexin II, a natural ligand of S100A10, was only 1.64-fold higher. In the tissue sections of RCC, S100A10 and annexin II were immunostained in membranes. In the normal renal epithelia, however, both antigens were stained in the Bowman's capsule and the tubules from Henle's loop through the collecting duct system, but not in the proximal tubules, from where most RCC are derived. In contrast, expression of the B-FABP gene was 20-fold higher in the tumor. No B-FABP was immunohistochemically detected in normal kidney sections, but it was stained in the cytoplasm of RCC tissue sections. S100A10 and B-FABP genes were overexpressed regardless of nuclear grade and stage of RCC. Immunopositivity in RCC tissues (n = 13) was 100% for S100A10 and annexin II, and 70% for B-FABP; however, no clear relationship was observed in either antigen with nuclear grade and stage. It was found that all three performed well as RCC markers. B-FABP was most specific to RCC, as it was expressed little in normal kidney tissues.