COX-2 induction by heparanase in the progression of breast cancer

Breast cancer confined within the lactiferous duct or lobule, without invading the stroma, is called ductal carcinoma in situ (DCIS), whereas breast cancer that has invaded the stroma through the basal membrane is called invasive cancer. Heparanase, an endo-beta-D-glucuronidase that specifically degrades heparan sulfate proteoglycans (HSPGs) in the extracellular matrix (ECM), plays an important role when breast cancer cells breach the basal membrane. Recently, we have reported that heparanase is involved in angiogenesis through direct induction of cyclo-oxygenase-2 (COX-2). COX-2 induces vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and is thus involved in neovascularization. The present study was undertaken to analyze surgically resected breast cancer specimens for heparanase and COX-2 expression, using specimens from 59 patients with invasive cancer and 85 patients with DCIS (including 41 cases of DCIS adjacent to invasive cancer). This study yielded the following results: a) the distribution of heparanase within tumor tissue was identical to that of COX-2; b) heparanase expression was more frequent in invasive cancer than in non-invasive cancer; c) a close positive correlation was noted between heparanase and COX-2 expression (this correlation was particularly strong in cases of invasive cancer); and d) COX-2 expression was always seen in cases positive for heparanase expression. Our results indicate that heparanase expression increases during the progression of breast cancer into invasive cancer, and that this change is accompanied by increased COX-2 expression. They also suggest that heparanase may play a novel role for COX-2 mediated tumor angiogenesis in breast-cancer progression.     

Expression of protein arginine methyltransferase‐5 in oral squamous cell carcinoma and its significance in epithelial‐to‐mesenchymal transition

Protein arginine methyltransferases (PRMT) 5, a member of type II arginine methyltransferases, catalyzes the symmetrical dimethylation of arginine residues on histone and non‐histone substrates. Although the overexpression of PRMT5 has been reported in various cancers, its role in oral squamous cell carcinoma (OSCC) has not been elucidated. In the present study, we immunohistochemically examined the expression of PRMT5 in surgically resected oral epithelial dysplasia (OED, n = 8), oral intraepithelial neoplasia (OIN)/carcinoma in situ (CIS) (n = 11) and OSCC (n = 52) with or without contiguous OED lesions. In the normal epithelium, PRMT5 was weakly expressed in the cytoplasm of basal layer cells. In OED, OIN/CIS, and OSCC, its expression consistently and uniformly increased in the cytoplasm of dysplastic and cancer cells. Moreover, nuclear and cytoplasmic localization was detected in the invasive front of cancer cells, particularly in cases showing poor differentiation or aggressive invasion patterns. The concomitant nuclear and cytoplasmic expression of PRMT5 correlated with the loss of E‐cadherin and cytokeratin 17, and the upregulation of vimentin, features that are both indicative of epithelial‐to‐mesenchymal transition. PRMT5 may play a role from early oncogenesis through to the progression of OSCC, particularly in the aggressive mode of stromal invasion.     

Visualization of INT2 and HST1 Amplification in oral squamous cell carcinomas

Oral squamous cell carcinoma (OSCC) develops along a multistep genetic pathway including loss of tumor suppressor genes and alteration of oncogenes. We characterized seven OSCC cell lines by classical and molecular cytogenetic analysis and fresh tumor and adjacent oral mucosa corresponding to three of the cell lines by molecular cytogenetics. We observed homogeneously staining regions (hsrs) in four of the seven cell lines, at 11q13 in three and at 11q23 and in an unidentified marker chromosome in the fourth. Amplification of band 11q13 occurs in 30–60% of head and neck squamous cell carcinomas. To determine whether INT2 and HST1, both located in band 11q13, are amplified in the tissues and cell lines and to confirm the chromosomal location(s) of the amplification, we used dual-color fluorescence in situ hybridization (FISH) with DNA probes for these genes and the chromosome 11 centromere. We report chromosomal localization of INT2/HST1 amplification in OSCC. Coamplification of INT2 and HST1 was detected in the hsrs in cultured tumor cells from the four hsr-containing tumors and in directly harvested tumor cells, which were available from only two of these tumors. Amplification was not present in tumors lacking hsrs or adjacent oral mucosa corresponding to any of the seven tumors. The observation of amplification in fresh tumor cells suggests that the amplification was present in the patients, may play a key role in the development and/or progression of OSCC, and is not due to karyotypic evolution in vitro. The absence of amplification in the adjacent mucosa suggests that 11q13 amplification is a relatively late event in OSCC tumorigenesis.     

Prognostic and predictive values of SPP1, PAI and caveolin-1 in patients with oral squamous cell carcinoma

SPP1, PAI and caveolin-1 are known to be closely associated with tumor progression in several kinds of human tumors. This study aimed to investigate the expression of SPP1, PAI and caveolin-1 in oral squamous cell carcinoma (OSCC), and to evaluate their association with the prognosis in oral carcinoma. Immunohistochemical staining was used to examine the expression of SPP1, PAI and caveolin-1 in 17 normal oral mucosa, 6 oral epithelial dysplasia and 43 OSCC specimens by tissue microarrays. High expression of SPP1, PAI and caveolin-1 was found in OSCC patients, and SPP1 and PAI expression were significantly higher in OSCC than in normal oral mucosa. No significant correlations were found between SPP1, PAI and caveolin-1 expression and clinicopathological factors. Expression of SPP1, PAI and caveolin-1 was also not associated with overall survival. Moreover, SPP1 was closely correlated with PAI, caveolin-1 and Keap1, and PAI had significant correlations with caveolin-1, Keap1 and Nrf2, and caveolin-1 was associated with Keap1 by using the Pearson correlation coefficient test. Our findings suggest that overexpressed SPP1, PAI and caveolin-1 were linked to carcinogenesis and progression, and thus they may serve as potential prognostic factors in OSCC.     

Differential expression of basement membrane collagen-IV α1 to α6 chains during oral carcinogenesis

This study aimed to resolve if basement membrane (BM) collagen α chains undergo remodeling during oral carcinogenesis. Using immunohistochemistry and transmission electron microscopy, we found that BMs in oral epithelial dysplasias (OED: mild, n=10; moderate, n=10; severe, n=10) and carcinoma in situ (CIS) (n=10) differed from normal mucosa (n=6) and oral epithelial hyperplasia (n=5) in showing: (1) excessive lamina densa-like material ultrastructurally, and (2) stronger immunoexpression for α5(IV) than for α1(IV), α2(IV), and α6(IV) chains—findings that implicate these molecules’ role as an adhesive template for the attachment and persistence of basal dysplastic cells. Incipient loss of BM integrity in CIS, where α5(IV)/α6(IV) chains were more frequently absent than α1(IV)/α2(IV) chains, suggests that α(IV) network disruption is crucial for progression of dysplastic cells into the extracellular compartment, marking transition into the invasive phase. In carcinomatous BM, the disappearance of α(IV) chains was more severe in poorly differentiated oral squamous cell carcinoma (OSCC) (n=10) than in well-differentiated OSCC (n=10). In all samples examined, α3(IV) and α4(IV) chains were absent. These findings taken together suggest that BM collagen-IV α chains undergo remodeling where selective increase and loss of these molecules are probably early and late events, respectively, during progression of oral dysplasia to cancer.     

Osteopontin: a marker for invasive oral squamous cell carcinoma but not for potentially malignant epithelial dysplasias

This study aimed to evaluate and correlate osteopontin (OPN) expression in oral squamous cell carcinoma (OSCC) and potentially malignant disorders including oral leukoplakia and oral submucous fibrosis (OSMF). Expression of OPN was investigated in 140 samples including OSCC, oral leukoplakia, and OSMF with or without dysplasia and normal oral mucosa. By using immunohistochemistry. Both intercellular and intracellular staining of the keratinocytes was considered to be positive, and intensity grading was assessed. Statistical analysis was done using analysis of variance. OPN positivity was detected in 85% cases of OSCC, 55% cases of oral leukoplakia, 35% cases of OSMF, and 60% cases of normal mucosa. These study highlights OPN as a biomarker for malignancy in the form of invasion but not to study progression from dysplasia to malignant transformation.     

Cyclooxygenase-2 is expressed frequently and early in Barrett's oesophagus and associated adenocarcinoma

AIMS: To establish the prevalence of cyclooxygenase-2 (COX-2) expression in a large series of resected Barrett's adenocarcinoma and associated preneoplastic lesions and to correlate this expression with clinicopathological data and prognosis. METHODS: COX-2 expression was assessed by immunohistochemistry in resected surgical specimens of 66 Barrett's adenocarcinomas and 32 cases of Barrett's mucosa (with dysplasia in 17 cases). RESULTS: Epithelial expression of COX-2 protein was increased in Barrett's mucosa compared with normal oesophagus. Epithelial expression of COX-2 was found in 91% of Barrett's specialized mucosa negative for dysplasia, 94% of Barrett's mucosa with dysplasia, and 97% of Barrett's adenocarcinoma. COX-2 expression was significantly higher in the well-differentiated adenocarcinomas when compared with the poorly differentiated tumours. There was no significant correlation between COX-2 expression and the other pathological features of the tumours. Survival analysis showed no significant prognostic value for COX-2. CONCLUSION: Our results confirm up-regulation of COX-2 in Barrett's oesophagus-metaplastic and dysplastic-and in Barrett's adenocarcinoma. Increased COX-2 expression did not differ during the progression from Barrett's oesophagus negative for dysplasia to Barrett's adenocarcinoma and is related to adenocarcinoma whose histology is well differentiated. This suggests that enhanced expression of COX-2 may occur early during Barrett's-associated neoplastic transformation.     

Spatial and temporal heparanase expression in colon mucosa throughout the adenoma-carcinoma sequence.

Heparanase is a mammalian endo-beta-D-glucuronidase that cleaves heparan sulfate side chains at a limited number of sites. Such enzymatic activity is thought to participate in degradation and remodeling of the extracellular matrix and to facilitate cell invasion associated with tumor metastasis, angiogenesis and inflammation. Traditionally, heparanase activity was well correlated with the metastatic potential of a large number of tumor-derived cell types. More recently, heparanase upregulation has been documented in an increasing number of primary human tumors, correlating with poor postoperative survival and increased tumor vascularity. Here, we employed anti-heparanase 733 polyclonal antibody that preferentially recognizes the 50 kDa active heparanase subunit over the 65 kDa proenzyme, as well as anti-heparanase 92.4 monoclonal antibody that recognizes both the latent and the active enzyme, to follow heparanase expression, processing and localization throughout the adenoma-carcinoma transition of the colon epithelium. Normal (nondysplastic) mucosa of the large bowel near epithelial neoplasms, as well as areas of mild dysplasia in adenomas, exhibited a strong reactivity with antibody 733 that became even stronger in foci of moderate dysplasia. Interestingly, although reactivity with antibody 733 was markedly reduced in severe dysplasia and in colorectal carcinoma, response to antibody 92.4 exhibited the opposite trend and staining intensities increased in parallel with tumor stage, the highest being in carcinoma cells. Involvement of latent heparanase (detected by 92.4, but not by 733 antibody) in tumor progression was suggested by activation of the Akt/PKB signal transduction pathway upon heparanase overexpression or exogenous addition to HT29 human colon carcinoma cells. These results suggest that heparanase expression is induced during colon carcinogenesis, and that its processing, conformation and localization are tightly regulated during the course of colon adenoma-carcinoma progression.     

VEGF expression and angiogenesis in oral squamous cell carcinoma: an immunohistochemical and morphometric study

Angiogenesis is involved in tumor progression of oral squamous cell carcinoma (OSCC). In this study, we have investigated by immunohistochemistry vascular endothelial growth factor (VEGF) expression in tumor cells and we have correlated VEGF expression to microvessel area, evaluated by using CD105 as a marker of endothelial cells, in bioptic specimens of 54 human OSCC. Results demonstrated that VEGF is highly expressed in OSCC tumor specimens when compared to pre-neoplastic and normal tissues, without differences between the edge and inside the tumor. Moreover, VEGF expression is reduced in poor differentiated OSCC tumors when compared to moderate and good differentiated forms, and tumor microvessel area is higher in tumors when compared to pre-neoplastic lesions and normal tissues. Finally, VEGF and CD105 may be considered as reliable markers of tumor angiogenesis and progression in OSCC, even if we did not demonstrate any correlation between VEGF expression, tumor microvascular area, clinical stage, and lymph node status.     

Expression of E-cadherin and vimentin in oral squamous cell carcinoma

The aim of the study is to determine the levels of E-cadherin, vimentin expression in tumor tissues from patients with oral squamous cell carcinoma (OSCC), and the relationship between the expression of E-cadherin, vimentin and epithelial-mesenchymal transition, in order to explore its values for predicting the invasion and metastasis of oral squamous cell carcinoma, short survival of patients in many types of cancer. E-cadherin and vimentin expression of 10 benign and 42 OSCC tumor tissues was examined by immunohistochemical staining. E-cadherin is positively expressed in normal oral mucosa epithelium, but vimentin expression is not found in normal oral mucosa epithelia; the E-cadherin and vimentin were expressed in 26 of 42 (61.9%) and 16 of 42 (38.1%), respectively. No statistically difference was found for E-cadherin and vimentin expression in patients with different age, gender and tumor location, E-cadherin and vimentin expression was significantly associated with lymph node metastasis and tissue location (P < 0.05); E-cadherin expression was also significantly associated with tumor stage (P < 0.05); there are significantly difference between infiltrative margin and central area in patients with oral squamous cell carcinoma for E-cadherin and vimentin positive expression (P < 0.05). E-cadherin and vimentin positive expression was associated with tumor metastasis of oral squamous cell carcinoma. Our study preliminarily confirmed that EMT phenomenon is existed during the development of oral squamous cell carcinoma. Co-evaluation of E-cadherin and vimentin might be a valuable tool for predicting OSCC patient outcome.     

Expression of heparanase in normal, dysplastic, and neoplastic human colonic mucosa and stroma. Evidence for its role in colonic tumorigenesis

The human heparanase gene, an endo-beta-glucuronidase that cleaves heparan sulfate at specific intrachain sites, has recently been cloned and shown to function in tumor progression and metastatic spread. Antisense digoxigenin-labeled heparanase RNA probe and monoclonal anti-human heparanase antibodies were used to examine the expression of the heparanase gene and protein in normal, dysplastic, and neoplastic human colonic mucosa. To our knowledge, this is the first systematic study of heparanase expression in human colon cancer. Both the heparanase gene and protein were expressed at early stages of neoplasia, already at the stage of adenoma, but were practically not detected in the adjacent normal-looking colon epithelium. Gradually increasing expression of heparanase was evident as the cells progressed from severe dysplasia through well-differentiated to poorly differentiated colon carcinoma. Deeply invading colon carcinoma cells showed the highest levels of the heparanase mRNA and protein associated with expression of both the gene and enzyme by adjacent desmoplastic stromal fibroblasts. A high expression was also found in colon carcinoma metastases to lung, liver, and lymph nodes, as well as in the accompanying stromal fibroblasts. Moreover, extracts derived from tumor tissue expressed much higher levels of the heparanase protein and activity as compared to the normal colon tissue. In all specimens, the heparanase gene and protein exhibited the same pattern of expression. These results suggest a role of heparanase in colon cancer progression and may have both prognostic and therapeutic applications.     

Re-expression of procollagen type IIA in oral squamous cell carcinoma

There are two forms of procollagen type II (IIA and IIB), both of which are expressed during chondrogenesis. Procollagen type IIA also is present at sites of developmental epithelial-mesenchymal interaction. Malignant transformation is associated with disturbed epithelial-mesenchymal interaction and the reappearance of fetal characteristics. This study aims to determine whether or not procollagen type IIA is re-expressed in oral squamous cell carcinoma (OSCC). Immunoperoxidase techniques were applied to frozen and paraffin sections of OSCC (n = 30) and normal oral mucosa (n = 5). In the carcinoma group, strong cytoplasmic staining for collagen type II was present (25/30). Staining was weak or absent in the stroma, and absent from the normal oral mucosa. Frozen sections from 10 of the carcinoma cases which showed positive staining were incubated with antibodies specific for procollagen type IIA and visualised using immunofluorescence. Staining was evident in each case and was particularly strong in the region of the basement membrane. Slot-blot analysis of collagen extracts from OSCC supported the immunohistochemical findings. We conclude, therefore, that procollagen type IIA is re-expressed in OSCC.     

Up-regulation of cyclooxygenase-2 expression in lymphocytic thyroiditis and thyroid tumors: significant correlation with inducible nitric oxide synthase

To cast light on relations of cyclooxygenase-2 (COX-2) expression to lymphocytic thyroiditis and thyroid tumorigenesis, protein levels were immunohistochemically assessed and compared with inducible nitric oxide synthase (iNOS) in a total of 181 cases: follicular adenoma, 23; well-differentiated papillary carcinoma, 85; poorly differentiated papillary carcinoma, 25; anaplastic carcinoma, 7; and follicular carcinoma, 41. In addition, 72 specimens of normal follicular epithelia and 36 of lymphocytic thyroiditis were used as control samples. Immunohistochemical results were confirmed in 2 cases each of normal thyroid, lymphocytic thyroiditis, and well-differentiated and poorly differentiated papillary carcinoma, by Western blotting assay. Stepwise increments in overexpression of COX-2 and iNOS were revealed in epithelial cells of lymphocytic thyroiditis, follicular adenoma, and papillary carcinoma; normal thyroid epithelium showed little expression. A significant positive correlation between the 2 enzymes was found with all cases. Enhanced expression of both COX-2 and iNOS suggests important roles in the inflammatory processes underlying lymphocytic thyroiditis and thyroid tumorigenesis.     

p53 immunoexpression in non-malignant oral mucosa adjacent to oral squamous cell carcinoma: potential consequences for clinical management

p53 is a tumour suppressor gene encoding a protein whose function is impaired in a very large proportion of human cancers. The objectives of this study were to determine the natural history of p53 alterations during stages of oral carcinogenesis, by comparing p53 immunoexpression in oral squamous cell carcinomas (OSCCs), their non-malignant adjacent mucosa, and respective metastases; and to define the potential practical consequences for clinical management of p53 staining in the non-malignant adjacent mucosa. Forty-two samples of non-malignant mucosa adjacent to OSCCs, the respective carcinomas, and six lymph node metastases derived from six of the OSCCs were investigated for p53 protein expression by immunohistochemistry. Seven out of 42 (17%) non-malignant mucosal samples immediately adjacent to OSCC showed suprabasal p53 staining and this was significantly associated with moderate/severe dysplasia (p=0.02). In six of these cases (86%), the respective carcinoma showed p53 immunoexpression in more than 50% of the neoplastic cells and in the remaining case, p53 immunoexpression was found in more than 25% of the neoplastic cells. In all p53-negative carcinomas that showed p53 immunoexpression in the non-malignant adjacent mucosa, p53 staining was never detected above the basal cell layer. Lymph node metastases showed the same patterns of p53 immunoexpression as the carcinomas from which they were derived. When suprabasal p53 staining is present in non-malignant mucosa immediately adjacent to OSCCs, this suggests stable p53 alterations which are maintained upon progression to overt malignancy. The immunostaining in non-malignant mucosa of the resection margins of OSCCs might be a valuable predictor for local recurrences and may therefore have implications for the management of patients who have received surgical treatment for OSCC.     

NOD1, RIP2 and Caspase12 are potentially novel biomarkers for oral squamous cell carcinoma development and progression

Although increasing studies have indicated that Nucleotide-oligomerization domain-containing protein 1 (NOD1) signaling could play an important role in gastrointestinal tumorigenesis, the protein expression and function of NOD1 signaling have not been understood well in oral squamous cell carcinoma (OSCC) progression. The objective of this study is, thus, to examine protein expression of NOD1 signaling immunohistochemically in normal, premalignant and malignant specimens of oral cavity, and to take insights into the association between the protein expression of NOD1 signaling pathway and OSCC precession. In this study immunohistochemical expression of NOD1, Receptor-interacting protein 2 (RIP2), Caspase12, human β Defensin1, 2 and 3 (hBD1, 2, 3) was examined in 15 normal controls, 30 cases of oral leukoplakia (OLK) and 60 cases of OSCC. The immunostaining score was assessed by 2 pathologists, respectively. We found that the expression of NOD1, RIP2, Caspase12, hBD1, 2, and 3 decreased along with the progression of OSCC. NOD1 expression was correlated significantly to tumor differentiation, lymph node metastasis, and tumor size. Our results also showed the correlation of hBD2, 3 to lymph node metastasis of OSCC. These results suggest that the dysfunction of NOD1 signaling pathways could be associated with OSCC development and progression. NOD1, RIP2 and Caspase12 could be used as potentially novel biomarkers for oral carcinogenesis.     

Bmi1 expression in oral lichen planus and the risk of progression to oral squamous cell carcinoma

Oral lichen planus (OLP) is a potentially malignant disorder associated with an increased risk of progression to oral squamous cell carcinoma (OSCC). The objective of this study was to determine protein expression of cancer stem cell factor Bmi1 in a longitudinal series of patients with OLP and evaluate the correlation between Bmi1 expression and the risk of progression to OSCC. In a retrospective study, Bmi1 expression was determined using immunohistochemistry in samples from 96 patients with OLP who received a mean follow-up of 54 months, including patients who did not progress to OSCC (n = 87) and patients who had progressed to OSCC (n = 9). Analysis of 10 cases of normal oral mucosa and 6 cases of postmalignant OSCC form previously diagnosed OLP was also performed. The results showed that Bmi1 expression was observed in 32 (36.8%) of 87 cases of nonprogressing OLP and in 8 (88.9%) of 9 cases of progressing OLP. Bmi1 was not expressed in normal oral mucosa, but it was positively expressed in the 6 (100%) cases of OSCC. Multivariate analysis revealed that the risk of malignant progression in the patients with Bmi1-positive expression was significantly higher than those with Bmi1 negativity (odds ratio, 20.75; 95% confidence interval, 2.21-194.57; P = .008). Collectively, Bmi1 expression was significantly associated with malignant transformation in a large series of patients with OLP who received a longitudinal observation. Our findings suggested that Bmi1 may serve as a useful marker for the identification of a high risk of malignant progression of OLP.     

Down-regulation of keratin 4 and keratin 13 expression in oral squamous cell carcinoma and epithelial dysplasia: a clue for histopathogenesis

Sakamoto K, Aragaki T, Morita K‐i, Kawachi H, Kayamori K, Nakanishi S, Omura K, Miki Y, Okada N, Katsube K‐i, Takizawa T & Yamaguchi A
(2011) Histopathology 58, 531–542
Down‐regulation of keratin 4 and keratin 13 expression in oral squamous cell carcinoma and epithelial dysplasia: a clue for histopathogenesis Aims: This study aimed to identify relevant keratin subtypes that may associate with the pathogenesis of oral epithelial neoplasms. Methods and results: Expression of all the keratin subtypes was examined by cDNA microarray analysis of 43 oral squamous cell carcinoma (OSCC) cases. Immunohistochemical expression of the major keratins was examined in 100 OSCC and oral epithelial dysplasia (OED) cases. Many changes in keratin expression were observed and, significantly, consistent down‐regulation of keratin 4 (K4) and K13 expression was observed. Aberrant expression of K4 and K13 was associated with morphological changes in the affected oral epithelium. Experiments with cell cultures transfected with various keratin subtypes suggested that alterations in keratin subtype expression can cause changes in cell shape and movement. Conclusions: Aberrant expression of K4 and K13, which are the dominant pair of differentiation‐related keratins in oral keratinocytes, indicates dysregulation of epithelial differentiation in OSCC and OED. These keratins, especially K4, may be useful for pathological diagnosis. We propose that the aberrant expression of K4 and K13 and concomitant up‐regulation of the other keratins may be one of the causative factors for morphological alterations in the affected epithelium.     

CD133 expression in oral lichen planus correlated with the risk for progression to oral squamous cell carcinoma

Oral lichen planus (OLP) is a potentially malignant disorder associated with an increased risk for progression to oral squamous cell carcinoma (OSCC). The objective of this study to determine protein expression of cancer stem cell marker CD133 in tissue samples of patients with OLP and evaluate the correlation between CD133 expression and the risk of progression to OSCC. In this longitudinal case-control study, a total of 110 patients with OLP who received a mean follow-up of 56 months were enrolled, including 100 patients who did not progress to OSCC and 10 patients who had progressed to OSCC. CD133 expression was determined using immunohistochemistry in samples from these patients. Analysis of 10 cases of normal oral mucosa and 6 cases of postmalignant OSCC form previously diagnosed OLP was also performed. The results showed that CD133 expression was observed in 29% cases of nonprogressing OLP and in 80% cases of progressing OLP (P = .002). CD133 was not expressed in normal oral mucosa, but it positively expressed in the 100% cases of OSCC. Logistic regression analysis revealed that the risk of malignant progression in the patients with CD133-positive expression was significantly higher than those with CD133 negativity (odds ratio, 9.79; 95% confidence interval, 1.96-48.92; P = .005). Collectively, CD133 expression was significantly associated with malignant progression in a longitudinal series of patients with OLP. Our findings suggested that CD133 may serve as a novel candidate biomarker for risk assessment of malignant potential of OLP.     

Heparanase expression correlates with invasion and poor prognosis in gastric cancers

Degradation of basement membrane and extracellular matrix structures are important features of the metastatic process of malignant tumors. Human heparanase degrades heparan sulfate proteoglycans, which represent the main components of basement membranes and the extracellular matrix. Because of the role of heparanase in tumor invasion and metastasis, we examined heparanase expression in primary gastric cancers and in cell lines derived from gastric cancers by immunohistochemistry and RT-PCR, respectively. Four of seven gastric cancer cell lines showed heparanase mRNA expression by RT-PCR. Heparanase protein was detected in both the cytoplasm and the nucleus of heparanase mRNA-positive cells by immunohistochemical staining. Heparanase expression was confirmed in 35 (79.5%) of 44 gastric tumor samples by immunohistochemical staining. However, no or weak heparanase expression was detected in normal gastric mucosa. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Analysis of the clinicopathologic features showed stronger heparanase expression in cases of huge growing tumors, extensive invasion to lymph vessels, and regional lymph node metastasis. In gastric cancer, patients with heparanase expression showed significantly poorer prognosis than those without such expression (p = 0.006). In conclusion, our findings suggest that high expression of heparanase in gastric cancer is a strong predictor of poor survival.