Reduced syndecan-1 expression is correlated with the histological grade of malignancy at the deep invasive front in oral squamous cell carcinoma

Identification of UNC5B as a novel aggressive biomarker for osteosarcoma based on basement membrane genes

BACKGROUND

The prognosis of patients with metastatic osteosarcoma is poor, and the variation of basement membrane genes (BMGs) is associated with cancer metastasis. However, the role of BMGs in osteosarcoma has been poorly studied.

METHODS

BMGs were collected and differentially expressed BMGs (DE-BMGs) were found through difference analysis. DE-BMGs were further screened by univariate Cox regression and Lasso regression analyses, and six key BMGs were identified and defined as basement membrane genes signatures (BMGS). Then, BMGS was used to construct the osteosarcoma BMGS risk score system, and the osteosarcoma patients were divided into high- and low-risk groups based on the median risk score. Single-sample gene set enrichment analysis (ssGSEA) and ESTIMATE scores were used to investigate the differences in immune infiltration between the two scoring groups. Additionally, we investigated whether UNC5B affects various features in tumors by bioinformatic analysis and whether UNC5B was involved in multiple biological functions of osteosarcoma cells by wound healing assay, transwell assay, and western blot.

RESULTS

The osteosarcoma BMGS risk score reliably predicts the risk of metastasis, patient prognosis, and immunity. UNC5B expression was elevated in osteosarcoma, and correlated with various characteristics such as immune infiltration, prognosis, and drug sensitivity. In vitro assays showed that UNC5B knockdown reduced osteosarcoma cells' capacity for migration and invasion, and EMT process.

CONCLUSION

A novel BMGS risk score system that can effectively predict the prognosis of osteosarcoma was developed and validated. The UNC5B gene in this system is one of the key aggressive biomarkers of osteosarcoma.

Targeting Syndecan-1: New Opportunities in Cancer Therapy

Syndecan-1 (SDC1, CD138) is one of the heparan sulfate proteoglycans and is essential for maintaining normal cell morphology, interacting with extracellular and intracellular protein repertoire as well as mediating signaling transduction upon environmental stimuli. The critical role of SDC1 in promoting tumorigenesis and metastasis has been increasingly recognized in various cancer types, implying a promising potential of utilizing SDC1 as a novel target for cancer therapy. This review summarizes the current knowledge on SDC1 structure and functions, including its role in tumor biology. We also discuss the highlights and limitations of current SDC1-targeted therapies as well as the obstacles in developing new therapeutic methods, offering our perspective on the future directions to target SDC1 for cancer treatment.

Follistatin-related protein 1 interacting partner of Syndecan-1 promotes an aggressive phenotype on Oral Squamous cell carcinoma (OSCC) models

Syndecans belong to the family of transmembrane heparan sulfate proteoglycans and are associated with many physiopathological processes, including oral cancer. As previously shown soluble syndecan-1 (SDC1) fragments and synthetic SDC1 peptide were able to induce cell migration in oral cancer cell lines. In order to explore the role of SDC1 in oral cancer, we have investigated SDC1 interacting partners and its functional role in oral cancer models. Here we have shown that SDC1 interacts with follistatin-related protein 1 (FSTL1) by its ectodomain (ectoSDC1) and extracellular juxtamembrane peptide (pepSDC1) and that their transcript levels can affect tumor events. Using orthotopic mouse model we identified that the knock-down for FSTL1 (shFSTL1) or for both FSTL1 and SDC1 (sh2KD) produced less aggressive and infiltrative tumors, with lower keratinization deposition, but with increased levels of epithelial-mesenchymal transition and proliferation compared to control and SDC1 knock-down. Based on cell culture assays, we suggest that the shFSTL1 effect on tumor tissues might be from significant increase of mRNA levels of Activin A (ActA) and its resceptors. This study shows for the first time two different complexes, SDC1 and FSTL1; pepSDC1 and FSTL1, exhibiting a close relationship in cell signaling events, as FSTL1 promotes a more aggressive phenotype. SIGNIFICANCE: This work contributes to the understanding of new SDC1 functions, based on the investigation of protein-protein complex formation in Oral Squamous cell carcinoma (OSCC) models. The FSTL1 identification, as an interacting partner of SDC1 ectodomain and of its derived peptide promotes molecular events that favors cancer development and progression, as highlighted by Activin A (ActA) and Epithelial-mesenchymal transition (EMT) gene expression and by changes in the phenotype of orthotopic OSCC mouse tumor tissues when SDC1-FSTL1 expression is modulated.

Proteomic Analysis of Circulating Extracellular Vesicles Identifies Potential Biomarkers for Lymph Node Metastasis in Oral Tongue Squamous Cell Carcinoma

Lymph node metastasis is the most reliable indicator of a poor prognosis for patients with oral tongue cancers. Currently, there are no biomarkers to predict whether a cancer will spread in the future if it has not already spread at the time of diagnosis. The aim of this study was to quantitatively profile the proteomes of extracellular vesicles (EVs) isolated from blood samples taken from patients with oral tongue squamous cell carcinoma with and without lymph node involvement and non-cancer controls. EVs were enriched using size exclusion chromatography (SEC) from pooled plasma samples of patients with non-nodal and nodal oral tongue squamous cell carcinoma (OTSCC) and non-cancer controls. Protein cargo was quantitatively profiled using isobaric labelling (iTRAQ) and two-dimensional high-performance liquid chromatography followed by tandem mass spectrometry. We identified 208 EV associated proteins and, after filtering, generated a short list of 136 proteins. Over 85% of the EV-associated proteins were associated with the GO cellular compartment term "extracellular exosome". Comparisons between non-cancer controls and oral tongue squamous cell carcinoma with and without lymph node involvement revealed 43 unique candidate EV-associated proteins with deregulated expression patterns. The shortlisted EV associated proteins described here may be useful discriminatory biomarkers for differentiating OTSCC with and without nodal disease or non-cancer controls.

Syndecan-1 (CD138), Carcinomas and EMT

Cell surface proteoglycans are known to be important regulators of many aspects of cell behavior. The principal family of transmembrane proteoglycans is the syndecans, of which there are four in mammals. Syndecan-1 is mostly restricted to epithelia, and bears heparan sulfate chains that are capable of interacting with a large array of polypeptides, including extracellular matrix components and potent mediators of proliferation, adhesion and migration. For this reason, it has been studied extensively with respect to carcinomas and tumor progression. Frequently, but not always, syndecan-1 levels decrease as tumor grade, stage and invasiveness and dedifferentiation increase. This parallels experiments that show depletion of syndecan-1 can be accompanied by loss of cadherin-mediated adhesion. However, in some tumors, levels of syndecan-1 increase, but the characterization of its distribution is relevant. There can be loss of membrane staining, but acquisition of cytoplasmic and/or nuclear staining that is abnormal. Moreover, the appearance of syndecan-1 in the tumor stroma, either associated with its cellular component or the collagenous matrix, is nearly always a sign of poor prognosis. Given its relevance to myeloma progression, syndecan-1-directed antibody—toxin conjugates are being tested in clinical and preclinical trials, and may have future relevance to some carcinomas.

Syndecan-1 Promotes Hepatocyte-Like Differentiation of Hepatoma Cells Targeting Ets-1 and AP-1

Syndecan-1 is a transmembrane heparan sulfate proteoglycan which is indispensable in the structural and functional integrity of epithelia. Normal hepatocytes display strong cell surface expression of syndecan-1; however, upon malignant transformation, they may lose it from their cell surfaces. In this study, we demonstrate that re-expression of full-length or ectodomain-deleted syndecan-1 in hepatocellular carcinoma cells downregulates phosphorylation of ERK1/2 and p38, with the truncated form exerting an even stronger effect than the full-length protein. Furthermore, overexpression of syndecan-1 in hepatoma cells is associated with a shift of heparan sulfate structure toward a highly sulfated type specific for normal liver. As a result, cell proliferation and proteolytic shedding of syndecan-1 from the cell surface are restrained, which facilitates redifferentiation of hepatoma cells to a more hepatocyte-like phenotype. Our results highlight the importance of syndecan-1 in the formation and maintenance of differentiated epithelial characteristics in hepatocytes partly via the HGF/ERK/Ets-1 signal transduction pathway. Downregulation of Ets-1 expression alone, however, was not sufficient to replicate the phenotype of syndecan-1 overexpressing cells, indicating the need for additional molecular mechanisms. Accordingly, a reporter gene assay revealed the inhibition of Ets-1 as well as AP-1 transcription factor-induced promoter activation, presumably an effect of the heparan sulfate switch.

Involvement of Syndecan-1 and Heparanase in Cancer and Inflammation

The cell surface heparan sulfate proteoglycan Syndecan-1 acts as an important co-receptor for receptor tyrosine kinases and chemokine receptors, and as an adhesion receptor for structural glycoproteins of the extracellular matrix. It serves as a substrate for heparanase, an endo-β-glucuronidase that degrades specific domains of heparan sulfate carbohydrate chains and thereby alters the functional status of the proteoglycan and of Syndecan-1-bound ligands. Syndecan-1 and heparanase show multiple levels of functional interactions, resulting in mutual regulation of their expression, processing, and activity. These interactions are of particular relevance in the context of inflammation and malignant disease. Studies in animal models have revealed a mechanistic role of Syndecan-1 and heparanase in the regulation of contact allergies, kidney inflammation, multiple sclerosis, inflammatory bowel disease, and inflammation-associated tumorigenesis. Moreover, functional interactions between Syndecan-1 and heparanase modulate virtually all steps of tumor progression as defined in the Hallmarks of Cancer. Due to their prognostic value in cancer, and their mechanistic involvement in tumor progression, Syndecan-1 and heparanase have emerged as important drug targets. Data in preclinical models and preclinical phase I/II studies have already yielded promising results that provide a translational perspective.

EBV-negative lymphoepithelial-like carcinoma of the lower lip

Lymphoepithelial-like carcinoma (LEC) is a rare malignant neoplasm, which can be associated with Epstein-Barr virus (EBV) infection. Histologically, LEC is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. LEC appears to be an uncommon tumor type of lip carcinoma. An 82-year-old white woman presented a lesion on her lower lip that developed over the last year. The lesion was characterized by ulceration with flat edges, hardened base, painful, and absence of regional lymphadenopathy. Microscopical analysis evidenced an intense inflammatory infiltrate, composed of lymphoplasmacytic cells, associated with scarce pleomorphic epithelial cells. Immunohistochemistry highlighted the LEC cells with strong expression of pan-CK AE1/AE3, EMA, p63, and p53. CD138 was also faintly positive. Ki-67 was >85%. In situ hybridization analysis did not show evidence of EBV. A diagnostic of EBV-negative LEC was made. We present an uncommon type of lip carcinoma, which can represent a diagnostic challenge for clinicians and pathologists.

Detection of Micro-invasion in Sudanese Oral Verrucous Carcinoma Samples Using Syndecan-1 Stain

Aim:

Verrucous carcinoma (VC) is a low-grade rare variant of squamous cell carcinoma (SCC). Syndecan-1 (CD138) is a heparan sulfate proteoglycan which participates in cell-to-cell adhesion and cell-matrix interaction. Being misled by the apparent non-aggressive nature of VC, some clinicians and pathologists believe that this tumor is not an aggressive tumor, not realizing the fact that some of these lesions may contain nests or foci of well-differentiated SCC. This study aimed to assess syndecan-1 expression of VC and detection of micro-invasion in VC using syndecan-1 immunohistochemical (IHC) stain.

Methods:

Observational analytical study of 34 paraffin block of VC cases and 24 cases of variable grades of oral epithelial dysplasia. Cases were stained by hematoxylin and eosin (H&E) and then IHC stain for syndecan-1 was applied. Nine paraffin blocks from specimens of normal oral mucosa were used as the reference group for syndecan-1 stain positivity.

Results:

In this study, we found that 32 (94.1%) out of 34 of verrucous carcinoma cases showed loss of syndecan-1 expression. Moreover, highly statistically significant association was found between the presence of suggestive micro-invasion in H&E and loss of syndecan-1 expression in micro-invasive area in the same case.

Conclusions:

In conclusion, syndecan-1 stain can be used as a biomarker in detection of micro-invasion in verrucous carcinoma.

Primordial odontogenic tumor: Subepithelial expression of Syndecan-1 and Ki-67 suggests origin during early odontogenesis

Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation. Ki-67 is considered the gold standard as a cell proliferation marker. The aim of this study was to examine the expression of Syndecan-1 and Ki-67 proliferation index in POT and normal tooth germs to better understand the biological behavior of this tumor. Results showed that Syndecan-1 was more intensely expressed in subepithelial mesenchymal areas of POT, in a pattern that resembles the early stages of tooth development. The cell proliferation index (4.1%) suggests that POT is a slow growing tumor. Syndecan-1 expression in tooth germs in late cap and early bell stages was similar to POT, showing immunopositivity in subepithelial mesenchymal condensed areas. The immunohistochemical findings showed a pattern in which the population of subepithelial mesenchymal cells exhibited greater proliferative activity than the central portion of the dental papilla.

Integrin α11 is overexpressed by tumour stroma of head and neck squamous cell carcinoma and correlates positively with alpha smooth muscle actin expression

Background

Cancer‐associated fibroblasts (CAFs) were shown to be important for tumour progression in head and neck squamous cell carcinomas (HNSCCs). Their heterogeneity and lack of specific markers is increasingly recognized. Integrin α11 was recently shown to be expressed by CAFs and might serve as a specific CAF marker.

Aim

To investigate integrin α11 expression and its correlation with the expression of a well‐known marker of CAF, alpha smooth muscle actin (α‐SMA), in HNSCC.

Methods

Fresh frozen (FF) and formalin‐fixed paraffin‐embedded (FFPE) samples from healthy volunteers (n = 24), oral lichen planus (OLP) (n = 32) and HNSCC (n = 106) were collected together with clinical data after ethical approval. Immunohistochemistry to detect integrin α11 and α‐SMA was performed on FF and FFPE samples. qPCR for integrin α11 (ITGA11) and α‐SMA(ACTA2) was performed on FF samples. Data were analysed using chi‐square test and Kaplan–Meier survival analysis.

Results

Significantly higher levels of integrin α11 and α‐SMA at both protein and mRNA levels were found in HNSCC vs. normal controls and OLP. A strong correlation was found between integrin α11 and α‐SMA expression, and double staining showed their colocalization. Both integrin α11 and α‐SMA were detected surrounding metastatic islands. Expression of α‐SMA at tumour front but not tumour centre correlated with patient survival.

Conclusion

Integrin α11 was overexpressed in HNSCC stroma and colocalized with α‐SMA. Expression of α‐SMA at tumour front but not tumour centre had prognostic value for survival, pinpointing the importance of assessing tumour front when evaluating stromal molecules as prognostic biomarkers.

Molecular and clinical profiles of syndecan-1 in solid and hematological cancer for prognosis and precision medicine

Syndecan-1 (SDC1, CD138) is a key cell surface adhesion molecule essential for maintaining cell morphology and interaction with the surrounding microenvironment. Deregulation of SDC1 contributes to cancer progression by promoting cell proliferation, metastasis, invasion and angiogenesis, and is associated with relapse through chemoresistance. SDC1 expression level is also associated with responses to chemotherapy and with prognosis in multiple solid and hematological cancers, including multiple myeloma and Hodgkin lymphoma. At the tissue level, the expression levels of SDC1 and the released extracellular domain of SDC1 correlate with tumor malignancy, phenotype, and metastatic potential for both solid and hematological tumors in a tissue-specific manner. The SDC1 expression profile varies among cancer types, but the differential expression signatures between normal and cancer cells in epithelial and stromal compartments are directly associated with aggressiveness of tumors and patient's clinical outcome and survival. Therefore, relevant biomarkers of SDC signaling may be useful for selecting patients that would most likely respond to a particular therapy at the time of diagnosis or perhaps for predicting relapse. In addition, the reciprocal expression signature of SDC between tumor epithelial and stromal compartments may have synergistic value for patient selection and the prediction of clinical outcome.

Syndecan-1 in Cancer: Implications for Cell Signaling, Differentiation, and Prognostication

Syndecan-1, a cell surface heparan sulfate proteoglycan, is critically involved in the differentiation and prognosis of various tumors. In this review, we highlight the synthesis, cellular interactions, and the signalling pathways regulated by syndecan-1. The basal syndecan-1 level is also crucial for understanding the sequential changes involving malignant transformation, tumor progression, and advanced or disseminated cancer stages. Moreover, we focus on the cellular localization of this proteoglycan as cell membrane anchored and/or shed, soluble syndecan-1 with stromal or nuclear accumulation and how this may carry different, highly tissue specific prognostic information for individual tumor types.

Proteoglycan-based diversification of disease outcome in head and neck cancer patients identifies NG2/CSPG4 and syndecan-2 as unique relapse and overall survival predicting factors

Background

Tumour relapse is recognized to be the prime fatal burden in patients affected by head and neck squamous cell carcinoma (HNSCC), but no discrete molecular trait has yet been identified to make reliable early predictions of tumour recurrence. Expression of cell surface proteoglycans (PGs) is frequently altered in carcinomas and several of them are gradually emerging as key prognostic factors.

Methods

A PG expression analysis at both mRNA and protein level, was pursued on primary lesions derived from 173 HNSCC patients from whom full clinical history and 2 years post-surgical follow-up was accessible. Gene and protein expression data were correlated with clinical traits and previously proposed tumour relapse markers to stratify high-risk patient subgroups.

Results

HNSCC lesions were indeed found to exhibit a widely aberrant PG expression pattern characterized by a variable expression of all PGs and a characteristic de novo transcription/translation of GPC2, GPC5 and NG2/CSPG4 respectively in 36%, 72% and 71% on 119 cases. Importantly, expression of NG2/CSPG4, on neoplastic cells and in the intralesional stroma (Hazard Ratio [HR], 6.76, p = 0.017) was strongly associated with loco-regional relapse, whereas stromal enrichment of SDC2 (HR, 7.652, p = 0.007) was independently tied to lymphnodal infiltration and disease-related death. Conversely, down-regulated SDC1 transcript (HR, 0.232, p = 0.013) uniquely correlated with formation of distant metastases. Altered expression of PGs significantly correlated with the above disease outcomes when either considered alone or in association with well-established predictors of poor prognosis (i.e. T classification, previous occurrence of precancerous lesions and lymphnodal metastasis). Combined alteration of all three PGs was found to be a reliable predictor of shorter survival.

Conclusions

An unprecedented PG-based prognostic portrait is unveiled that incisively diversifies disease course in HNSCC patients beyond the currently known clinical and molecular biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1336-4) contains supplementary material, which is available to authorized users.

Molecular changes in invasive front of oral cancer

Treatment planning for oral squamous cell carcinoma (OSCC) is based on the clinical TNM (Tumor, Node and Metastasis) classification. This system operates on the assumption that small tumours without clinical spread have a better prognosis than larger tumours with metastases. However, it is a well-known fact that some tumours with the same clinical staging show different growth patterns and clinical behaviour. This makes the prognosis for patients with OSCC difficult to predict on the basis of clinical staging alone. Although many histopathological characteristics of OSCC have been identified as prognostic factors, none is believed to be completely infallible. Therefore, a great need exists for more reliable prognostic markers, which will assist in treatment decisions. It is now well documented that several molecular events of significance for tumour spread, such as gain and loss of adhesion molecules, secretion of proteolytic enzymes, increased cell proliferation and initiation of angiogenesis occur at the tumour–host interface or invasive front, where the deepest and presumably most aggressive cells reside. This review describes the various molecular events and interactions, which take place in the invasive front of the OSCC, and elucidates their role as prognostic markers.

A rare Japanese case with a NUT midline carcinoma in the nasal cavity: a case report with immunohistochemical and genetic analyses

BACKGROUND

NUT (nuclear protein in testis) midline carcinoma (NMC) is a recently described aggressive malignancy that is genetically defined by rearrangements of the NUT locus at 15q14. In approximately two-thirds of cases, the characteristic t(15;19) results in the fusion oncogene BRD4-NUT. Only 10 sinonasal NMCs have been documented, none of which were Japanese cases.

CASE PRESENTATION

An 18-year-old woman was admitted because of a rapidly progressing tumor in the nasal cavity. A biopsy revealed an undifferentiated neoplasm without squamous differentiation. The tumor cells had round to oval nuclei with vesicular chromatin, prominent nucleoli, and scant cytoplasm. Immunohistochemical staining demonstrated a strong positivity for vimentin and NUT, with focal CD138 and only spotty EMA and cytokeratin AE1/AE3 staining. Cytogenetic and fluorescence in situ hybridization analyses revealed a t(15;19) and BRD4-NUT gene rearrangement. Direct sequencing identified the in-frame fusion of exon11 of BRD4 with exon2 of NUT. The patient was transferred to another hospital for chemoradiotherapy.

CONCLUSION

We herein describe the first Japanese case with an NMC of the sinonasal cavity, providing detailed and unambiguous cyto- and molecular genetic information on BRD4-NUT-rearrangement. The accumulation of cases with well-documented genetic data should provide clues to the treatment of this tumor entity.

Epithelial and stromal syndecan-1 and -2 are distinctly expressed in oral- and cutaneous squamous cell carcinomas

BACKGROUND

Oral squamous cell carcinoma (OSCC) and cutaneous squamous cell carcinoma (CSCC) are epithelial neoplasms of which OSCC has worse survival and higher risk of metastasis than CSCC. The aim of this study was to explore the differences of immunoexpressions between syndecan-1 and -2 in OSCC and head and neck CSCC.

METHODS

A total of 35 patients diagnosed with OSCC and 25 with CSCC, presented T1 and T2 tumors and treated at Helsinki University Central Hospital between years 2001 and 2009, were selected into this study. The levels and locations of syndecan-1 and -2 immunostainings were analyzed using formalin-fixed and paraffin-embedded tissue samples of OSCC and CSCC cases together with clinical data.

RESULTS

Cell membrane epithelial syndecan-1 expression decreased significantly compared to normal tissue in both cancer types. Cell membrane syndecan-1 expression in the invasive front had negative correlation with invasion depth of both tumors (OSCC, r = -0.339, P = 0.025; CSCC, r = -0.469, P = 0.004). In cancers over 4-mm invasion depth, the number of stromal syndecan-1-positive collagen fibers and inflammatory cells were higher in OSCC than in CSCC. Syndecan-2 expression in non-malignant stroma was higher in CSCC than in OSCC tumors. In addition, unlike syndecan-1, syndecan-2 was more often and more intensively expressed in the tumor inflammatory cells in CSCC than in OSCC.

CONCLUSION

Our results suggest that variable stromal expression of syndecan-1 and -2 in OSCC compared to CSCC may at least partially explain the differences in their clinical behavior.

Novel processed form of syndecan-1 shed from SCC-9 cells plays a role in cell migration

The extracellular milieu is comprised in part by products of cellular secretion and cell surface shedding. The presence of such molecules of the sheddome and secretome in the context of the extracellular milieu may have important clinical implications. In cancer they have been hypothesized to play a role in tumor growth and metastasis. The objective of this study was to evaluate whether the sheddome/secretome from two cell lines could be correlated with their potential for tumor development. Two epithelial cell lines, HaCaT and SCC-9, were chosen based on their differing abilities to form tumors in animal models of tumorigenesis. These cell lines when stimulated with phorbol-ester (PMA) showed different characteristics as assessed by cell migration, adhesion and higher gelatinase activity. Proteomic analysis of the media from these treated cells identified interesting, functionally relevant differences in their sheddome/secretome. Among the shed proteins, soluble syndecan-1 was found only in media from stimulated tumorigenic cells (SCC-9) and its fragments were observed in higher amount in the stimulated tumorigenic cells than stimulated non-tumorigenic cells (HaCaT). The increase in soluble syndecan-1 was associated with a decrease in membrane-bound syndecan-1 of SCC-9 cells after PMA stimuli. To support a functional role for soluble syndecan-1 fragments we demonstrated that the synthetic syndecan-1 peptide was able to induce cell migration in both cell lines. Taken together, these results suggested that PMA stimulation alters the sheddome/secretome of the tumorigenic cell line SCC-9 and one such component, the syndecan-1 peptide identified in this study, was revealed to promote migration in these epithelial cell lines.

Review article: Current concepts of ameloblastoma pathogenesis

Ameloblastoma is a locally destructive and invasive tumour that can recur despite adequate surgical removal. Molecular studies have offered interesting findings regarding ameloblastoma pathogenesis. In the present review, the following topics are discussed regarding its molecular nature: clonality, cell cycle proliferation, apoptosis, tumour suppressor genes, ameloblastin and other enamel matrix proteins, osteoclastic mechanism and matrix metalloproteinases and other signalling molecules. It is clear from the literature reviewed that translational studies are necessary to identify prognostic markers of ameloblastoma behaviour and to establish new diagnostic tools to the differential diagnosis of unicystic from multicystic ameloblastoma. Finally, molecular biology studies are also important to develop more effective alternative approaches to the treatment of this aggressive odontogenic tumour.

The prognostic value of intraepithelial and stromal CD3-, CD117- and CD138-positive cells in non-small cell lung carcinoma

The major value of prognostic markers in potentially curable non-small cell lung carcinoma (NSCLC) should be to guide therapy after surgical treatment. Although tumor-infiltrating T lymphocytes and plasma cells have been documented in NSCLC, a clear association with clinical outcome, especially for the stromal component, has not been well established. The aim of this study was to elucidate the prognostic significance of these cells/markers in the epithelial and stromal compartments of NSCLC. Tissue microarrays from 335 resected, stage I-IIIA, NSCLC were constructed by duplicate cores from viable neoplastic epithelial and stromal areas. Immunohistochemistry was used to evaluate the infiltration of CD3(+), CD117(+) as well as CD138(+) cells in epithelial and stromal areas. In univariate analyses, increasing numbers of stromal CD3(+) (p = 0.001) and epithelial CD3(+) cells (p = 0.004) correlated significantly with an improved disease-specific survival. No such relation was noted with CD3(+) or CD117(+) cells. In the multivariate analysis, stromal CD3(+) cells was an independent prognostic factor for disease-specific survival (HR 1.925, CI 1.21-3.04, p = 0.005). Increased presence of the pan T-cell marker, CD3, which is an independent factor, correlates with improved clinical outcome in NSCLC. This prognostic impact of T cells is clearer in the tumor stroma. Neither plasma cells nor mast cells were prognostic indicators in our cohort.

Potential biomarkers in saliva for oral squamous cell carcinoma

Sensitive and reliable early diagnostic markers for oral squamous cell carcinoma (OSCC) remain unavailable. Early identification of recurrence for OSCC is also a challenge. Unlike the other deep cancers, OSCC is located in oral cavity. The DNA, RNA, and protein derived from the living cancer cells and inflammatory cells then can be conveniently obtained from saliva. High-throughput genomic and proteomic approaches have been carried out to identify the potential biomarkers in body fluids such as saliva and blood for diagnosis and prognosis of OSCC. This article reviewed the recently identified biomarkers from saliva for OSCC. In addition, the biomarkers which have been correlated with OSCC tumor malignancy by molecular pathology analysis are also described. Finally, the potential biomarkers that have been demonstrated to associate with the malignant OSCC may be used for salivary screening for high-risk patients are suggested. This article may help to identify the potential biomarkers for screening and the molecular pathology analysis for high-risk patients of OSCC. Effective screening to identify high-risk patients can allow the clinician to provide the appropriate treatment without delay and to reduce the recurrence of OSCC.

Sdc1 negatively modulates carcinoma cell motility and invasion

During cancer progression, tumor cells eventually invade the surrounding collagen-rich extracellular matrix. Here we show that squamous cell carcinoma cells strongly adhere to Type I collagen substrates but display limited motility and invasion on collagen barriers. Further analysis revealed that in addition to the alpha2beta1 integrin, a second collagen receptor was identified as Syndecan-1 (Sdc1), a cell surface heparan sulfate proteoglycan. We demonstrate that siRNA-mediated depletion of Sdc1 reduced adhesion efficiency to collagen I, whereas knockdown of Sdc4 was without effect. Importantly, silencing Sdc1 expression caused reduced focal adhesion plaque formation and enhanced cell spreading and motility on collagen I substrates, but did not alter cell motility on other ECM substrates. Sdc1 depletion ablated adhesion-induced RhoA activation. In contrast, Rac1 was strongly activated following Sdc1 knockdown, suggesting that Sdc1 may mediate the link between integrin-induced actin remodeling and motility. Taken together, these data substantiate the existence of a co-adhesion receptor system in tumor cells, whereby Sdc1 functions as a key regulator of cell motility and cell invasion by modulating RhoA and Rac activity. Downregulation of Sdc1 expression during carcinoma progression may represent a mechanism by which tumor cells become more invasive and metastatic.

The anticancer activity of lytic peptides is inhibited by heparan sulfate on the surface of the tumor cells

BACKGROUND

Cationic antimicrobial peptides (CAPs) with antitumor activity constitute a promising group of novel anticancer agents. These peptides induce lysis of cancer cells through interactions with the plasma membrane. It is not known which cancer cell membrane components influence their susceptibility to CAPs. We have previously shown that CAPs interact with the two glycosaminoglycans (GAGs), heparan sulfate (HS) and chondroitin sulfate (CS), which are present on the surface of most cells. The purpose of this study was to investigate the role of the two GAGs in the cytotoxic activity of CAPs.

METHODS

Various cell lines, expressing different levels of cell surface GAGs, were exposed to bovine lactoferricin (LfcinB) and the designer peptide, KW5. The cytotoxic effect of the peptides was investigated by use of the colorimetric MTT viability assay. The cytotoxic effect on wild type CHO cells, expressing normal amounts of GAGs on the cell surface, and the mutant pgsA-745, that has no expression of GAGs on the cell surface, was also investigated.

RESULTS

We show that cells not expressing HS were more susceptible to CAPs than cells expressing HS at the cell surface. Further, exogenously added heparin inhibited the cytotoxic effect of the peptides. Chondroitin sulfate had no effect on the cytotoxic activity of KW5 and only minor effects on LfcinB cytotoxicity.

CONCLUSION

Our results show for the first time that negatively charged molecules at the surface of cancer cells inhibit the cytotoxic activity of CAPs. Our results indicate that HS at the surface of cancer cells sequesters CAPs away from the phospholipid bilayer and thereby impede their ability to induce cytolysis.

Comparative expression of syndecan-1 and Ki-67 in peripheral and desmoplastic ameloblastomas and ameloblastic carcinoma

The aims of the present study were to examine whether the pattern of syndecan-1 expression correlates with cellular proliferation index in desmoplastic ameloblastomas (DA), peripheral ameloblastomas (PA) and ameloblastic carcinomas (AC), and to compare with that previously reported for solid (SA) and unicystic (UA) variants of ameloblastoma. Immunohistochemistry was performed for syndecan-1 and Ki-67 in seven ameloblastomas (four DA and three PA) and three AC. Expression of syndecan-1 was related to the histological subtype of tumors and, in the case of malignancy, to lower expression levels observed in AC (22.5%) than in PA (47.5%) or DA (77.5%) (P < 0.05). Syndecan-1 expression correlated inversely with Ki-67 proliferative index: the expression was lower in both types of ameloblastomas (1.5% in DA and 6.4% in PA) than in AC (41.2%; P < 0.05). The present results suggest that the decrease in syndecan-1 expression and increase in the Ki-67 index observed in AC is in accordance with its higher aggressiveness as compared to the rare DA and PA. Interestingly, DA had a lower proliferation index as well as the highest levels of syndecan-1 expression. These data suggest that DA differ from the other types of intraosseous ameloblastomas but more studies are necessary to better understand the role of this protein as a marker in the biological behavior of the epithelial odontogenic neoplasms.

Relationship between cell adhesion molecules expression and the biological behavior of gastric carcinoma

AIM: To evaluate the relationship between the expression of cell adhesion molecules (CAMs) and the biological behavior of gastric carcinoma.

METHODS: Expression of syndecan-1, E-cadherin and integrin β3 were evaluated by immunohistochemical study in a total of 118 gastric carcinomas and 20 non-tumor gastric mucosas.

RESULTS: The expressions of syndecan-1 and E-cadherin were significantly lower in gastric carcinoma compared to non-tumor gastric mucosa, and the low expression rates were positively correlated to the tumor invasion depth, vessel invasion, lymph node metastasis and distant metastasis (P < 0.01 in all cases). However, the expression of integrin β3 was significantly higher in gastric carcinoma compared to non-tumor gastric mucosa, and the high expression rates were positively correlated to the tumor invasion depth, vessel invasion, lymph node metastasis and distant metastasis (P < 0.01 in all cases). In addition, the three protein expressions were correlated to the tumor growth pattern (P < 0.01, P < 0.01, and P < 0.05 respectively), but not correlated to tumor differentiation (P > 0.05, P > 0.05 and P > 0.05 respectively). Positive correlation was observed between the expressions of syndecan-1 and E-cadherin, but they which were negatively correlated to the expression of integrin β3 (P < 0.01 in all cases). Univariate analysis demonstrated that the mean survival time and 5-year survival rate were lower in the cases with low expressions of syndecan-1 and E-cadherin and high expression of integrin β3 (P < 0.01, in all cases). COX multivariate analysis showed that the expression level of syndecan-1 could be an independent prognostic index of gastric carcinoma (P < 0.01), whereas E-cadherin and integrin β3 could not be independent indexes (P > 0.05, P > 0.05 respectively).

CONCLUSION: The low expression of syndecan-1 and E-cadherin and the high expression of integrin β3 are significantly correlated with the invasion and metastasis of gastric carcinoma, and they are highly correlated with each other. Therefore they may serve as important prognostic markers of gastric carcinoma.

Reduced migration, altered matrix and enhanced TGFbeta1 signaling are signatures of mouse keratinocytes lacking Sdc1

We have reported previously that syndecan-1 (Sdc1)-null mice show delayed re-epithelialization after skin and corneal wounding. Here, we show that primary keratinocytes obtained from Sdc1-null mice and grown for 3-5 days in culture are more proliferative, more adherent and migrate more slowly than wt keratinocytes. However, the migration rates of Sdc1-null keratinocytes can be restored to wild-type levels by replating Sdc1-null keratinocytes onto tissue culture plates coated with fibronectin and collagen I, laminin (LN)-332 or onto the matrices produced by wild-type cells. Migration rates can also be restored by treating Sdc1-null keratinocytes with antibodies that block alpha6 or alphav integrin function, or with TGFbeta1. Antagonizing either beta1 integrin function using a function-blocking antibody or TGFbeta1 using a neutralizing antibody reduced wild-type keratinocyte migration more than Sdc1-null keratinocyte migration. Cultures of Sdc1-null keratinocytes accumulated less collagen than wild-type cultures but their matrices contained the same amount of LN-332. The Sdc1-null keratinocytes expressed similar total amounts of eight different integrin subunits but showed increased surface expression of alphavbeta6, alphavbeta8, and alpha6beta4 integrins compared with wild-type keratinocytes. Whereas wild-type keratinocytes increased their surface expression of alpha2beta1, alphavbeta6, alphavbeta8, and alpha6beta4 after treatment with TGFbeta1, Sdc1-null keratinocytes did not. Additional data from a dual-reporter assay and quantification of phosphorylated Smad2 show that TGFbeta1 signaling is constitutively elevated in Sdc1-null keratinocytes. Thus, our results identify TGFbeta1 signaling and Sdc1 expression as important factors regulating integrin surface expression, activity and migration in keratinocyte and provide new insight into the functions regulated by Sdc1.

Quantitative analysis of syndecan-1 expression in dysplasia and squamous cell carcinoma of the oral cavity

INTRODUCTION

Decreased expression of syndecan-1 has been reported in dysplasia and squamous cell carcinoma (SCCA) of the oral cavity and appears to correlate with decreasing histological differentiation and poor clinical outcome. Assays of syndecan-1 expression to date have utilized manual microscopic analysis with qualitative grading of immunohistochemical staining intensity, which may introduce observer bias. We evaluated syndecan-1 expression in dysplasia and squamous cell carcinoma (SCCA) of the oral cavity, using a novel automated cellular imaging system that incorporates both staining intensity as well as the percentage of positively stained cells to yield a quantitative value for syndecan-1 expression.

MATERIALS AND METHODS

We performed a quantitative immunohistochemical analysis of syndecan-1 expression using an automated cellular image analysis system. We analyzed specimens from cases of mild dysplasia (N = 55), moderate dysplasia (N = 38), severe dysplasia (N = 25), carcinoma in situ (CIS) (N = 43), and SCCA of the oral cavity (N = 45), using normal mucosal epithelium (N = 21) as a positive control. The SCCA specimens were further subdivided by degree of differentiation. We retrospectively reviewed patient charts to identify tumor stage at diagnosis, recurrence, and disease-specific survival.

RESULTS

Syndecan-1 expression was significantly greater in normal controls than in specimens of mild, moderate, or severe dysplasia, CIS, or invasive SCCA (P < .05). Syndecan-1 expression did not differ significantly among specimens of mild, moderate, or severe dysplasia, CIS or SCCA. There was no significant difference in syndecan-1 expression between specimens from patients with no evidence of disease at 3 years follow-up and patients with local, regional, or distant recurrence.

CONCLUSIONS

Syndecan-1 expression does not appear to be useful as a marker of differentiation or as a prognostic indicator in dysplasia and SCCA of the oral cavity. The search for a suitable and reliable marker of biological aggressiveness is ongoing.