Laminin-5 Γ2 Research Articles

Overexpression of Laminin 5γ2 Chain Correlates with Tumor Cell Proliferation, Invasion, and Poor Prognosis in Laryngeal Squamous Cell Carcinoma.

Objective Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor. Laminin 5γ2 chain (LAMC2) was reported to be associated with tumorigenesis. This study explored the role of LAMC2 on LSCC progression by regulating the integrinβ1/FAK/Src/AKT pathway. Methods The level of LAMC2 in 46 LSCC patients was detected by qRT-PCR and western blot. Then the relationship between LAMC2 expression and LSCC malignancy as well as prognosis was analyzed, and the effect of LAMC2 expression on LSCC patient survival was also analyzed using the Kaplan–Meier survival curves. Afterwards, the LSCC cells were transfected with LAMC2 overexpression and knockdown vectors, the effect of LAMC2 on LSCC cell viability, proliferation ability, cell cycle, cell migration, and invasion were detected by CCK-8, colony formation, flow cytometry, wound healing, and Transwell assays. The expression of EMT-related biomarkers and integrin β1/FAK/Src/AKT signaling-related proteins was detected by western blot. Moreover, the effect of LAMC2 on LSCC tumor growth was evaluated by in vivo xenograft experiments and western blot. Results LAMC2 was expressed at high level in LSCC tissues and associated with poor prognosis. LAMC2 overexpression increased TU177 cell viability, proliferation ability, promoted cell cycle, cell migration, and invasion capacity. The expression of N-cadherin, vimentin, and integrinβ1/FAK/Src/AKT related proteins was increased, while the expression of E-cadherin protein was decreased. When the LAMC2 knockdown in AMC-HN-8 cells had opposite effects. Furthermore, shLAMC2 decreased tumor volume and the expression of LAMC2, Ki-67 and integrinβ1, but increased the expression of E-cadherin in LSCC tumor-bearing mice. Conclusion The findings suggested that LAMC2 was overexpressed in LSCC and correlated with poor prognosis. LAMC2 knockdown inhibited LSCC progression by regulating the integrinβ1/FAK/Src/AKT signaling pathway. Therefore, LAMC2 could be a target for LSCC therapy.

Vascular Invasion and Stromal S100A4 Expression at the Invasive Front of Colorectal Cancer are Novel Determinants and Tumor Prognostic Markers.

Object: The aim of the present study was to investigate the clinicopathological characteristics and prognostic factors associated with sporadic colorectal cancer (CRC). We examined the clinicopathological findings and immunohistochemical expression of tumor prognostic markers at tumor budding sites to determine their predictive value for patient prognosis.Materials and Methods: Immunohistochemical examination was performed by tissue microarray (TMA) of specimens from 106 patients with CRC. On hematoxylin and eosin (H&E)-stained tumor tissue slides, a representative area of tumor budding at the invasive front was selected for the construction of a TMA. Immunostaining for matrix metalloproteinase-7 (MMP7), the laminin-5 (ln-5) γ2 chain and S100A4 was performed to determine the association between patient survival and these markers.Results: Clinicopathological variables were also assessed. Tumor location, histological type, degree of lymphatic invasion and vascular invasion, tumor stage, epithelial expression of S100A4, stromal cell expression of S100A4 and expression of the ln-5γ2 chain were associated with an increased risk of mortality. Five factors were retained in the multivariate logistic regression analysis. Specifically, the tumor location, degree of lymphatic invasion and vascular invasion, tumor stage and stromal cell expression of S100A4 remained significant predictors of patient survival after controlling for the other variables.Conclusion: Vascular invasion and stromal expression of S100A4 in the tumor budding areas correlated with patient survival. Stromal immunostaining of S100A4 may be useful for identifying high-risk patients with advanced CRC.

Sulfur mustard-stimulated proteases and their inhibitors in a cultured normal human epidermal keratinocytes model: A potential approach for anti-vesicant drug development.

Protease stimulation in cultured normal human epidermal keratinocytes (NHEK) due to sulfur mustard (SM) exposure is well documented. However, the specific protease(s) stimulated by SM and the protease substrates remain to be determined. In this study, we observed that SM stimulates several proteases and the epidermal-dermal attachment protein laminin-5 is one of the substrates. We propose that following SM exposure of the skin, laminin-5 degradation causes the detachment of the epidermis from the dermis and, therefore, vesication. We utilized gelatin zymography, Western blotting, immuno-fluorescence staining, and real-time polymerase chain reaction (RT-PCR) analyses to study the SM-stimulated proteases and laminin-5 degradation in NHEK. Two major protease bands (64 kDa and 72 kDa) were observed by zymography in SM-exposed cells. Addition of serine protease inhibitor (aprotinin, 100 μM), or the metalloprotease inhibitor (amastatin, 100 μM) to NHEK cultures prior to SM exposure decreased the SM-stimulated protease bands seen by zymography. These inhibitors completely or partially prevented SM-induced laminin-5 γ2 degradation as seen by Western blotting as well as immuno-fluorescence staining. Our results from Western blotting and RT-PCR studies also indicated that the membrane-type matrix metalloproteinase-1 (MT-MM-1) may be involved in SM-induced skin blistering.To summarize, our results in the NHEK model indicate the following: (a) SM stimulates multiple proteases including serine protease(s), and metalloproteases; (b) SM decreases the level of laminin-5 γ2, which is prevented by either a serine protease inhibitor or a metalloprotease inhibitor and (c) MT-MMP-1 maybe one of the proteases that is involved in skin blistering due to SM exposure.

High-mobility group box 1 promotes extracellular matrix synthesis and wound repair in human bronchial epithelial cells.

High mobility group box 1 (HMGB1) is a damage-associated molecular pattern (DAMP) protein that binds Toll-like receptors (e.g., TLR4) and the receptor for advanced glycated end products (RAGE). The direct effects of HMGB1 on airway structural cells are not fully known. As epithelial cell responses are fundamental drivers of asthma, including abnormal repair-restitution linked to changes in extracellular matrix (ECM) synthesis, we tested the hypothesis that HMGB1 promotes bronchial epithelial cell wound repair via TLR4 and/or RAGE signaling that regulates ECM (fibronectin and the γ2-chain of laminin-5) and integrin protein abundance. To assess impact of HMGB1 we used molecular and pharmacological inhibitors of RAGE or TLR4 signaling in scratch wound, immunofluorescence, and immunoblotting assays to assess wound repair, ECM synthesis, and phosphorylation of intracellular signaling. HMGB1 increased wound closure, and this effect was attenuated by blocking RAGE and TLR4 signaling. HMGB1-induced fibronectin and laminin-5 (γ2 chain) was diminished by blocking RAGE and/or blunting TLR4 signaling. Similarly, induction of α3-integrin receptor for fibronectin and laminin-5 was also diminished by blocking TLR4 signaling and RAGE. Lastly, rapid and/or sustained phosphorylation of SMAD2, ERK1/2, and JNK signaling modulated HMGB1-induced wound closure. Our findings suggest a role for HMGB1 in human airway epithelial cell repair and restitution via multiple pathways mediated by TLR4 and RAGE that underpin increased ECM synthesis and modulation of cell-matrix adhesion.

Laminin‐5 gamma 2 chain expression is associated with intensity of tumor budding and density of stromal myofibroblasts in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide. Laminin-5 gamma 2 chain (laminin-5 γ2) is a protein associated to a migratory phenotype in epithelial neoplastic cells. Stromal myofibroblasts also play a significant role in tumor invasion, due to its ability to modify the extracellular matrix. Tumor budding is a morphologic marker of tumor invasion. The aim of this study was to evaluate the expression of laminin-5 γ2 in OSCC and its association with intensity of tumor budding and density of stromal myofibroblasts. Paraffin-embedded archival samples of 57 OSCC patients were evaluated. Immunohistochemistry was employed to detect laminin-5 γ2, alpha smooth muscle actin (marker of stromal myofibroblasts), and multicytokeratin (to identify OSCC cells in tumor budding evaluation). Laminin-5 γ2 expression and its association with intensity of tumor budding and density of stromal myofibroblasts were analyzed. Association among intensity of tumor budding and density of stromal myofibroblasts was also evaluated. Higher laminin-5 γ2 expression was associated with high-intensity tumor budding (P < 0.05) and with higher density of stromal myofibroblasts (P < 0.05). Moreover, high-intensity tumor budding was associated with higher density of stromal myofibroblasts (P < 0.05). In OSCC, higher laminin-5 γ2 expression is associated with high-intensity tumor budding and with higher density of stromal myofibroblasts, suggesting that this expression is related to the establishment of an invasive phenotype of neoplastic cells and a permissive environment for tumor invasion in this neoplasia.

Assessment of Laminin-5 in Oral Dysplasia and Squamous Cell Carcinoma

Laminin-5 is an important protein in the establishment of an intact basement membrane. The aims of this study were to assess the expression of laminin-5 (γ2 chain) using cyclin D1 and Ki-67 in hyperplastic oral mucosal lesions, oral dysplasia, and squamous cell carcinoma (SCC). Paraffin-embedded tissue blocks of 134 patients were stained for laminin-5, cyclin D1, and Ki-67 using immunohistochemistry and assessed by virtual microscopy. Statistical analysis was performed using Kruskal-Wallis tests and Mann-Whitney U tests for post hoc assessment. Laminin-5, cyclin D1, and Ki-67 were found to have significant differences in expression for the different categories of dysplasia, SCC, and hyperplasia (P < .001). Cyclin D1 and Ki-67 expression levels were significantly increased in moderate and severe dysplasia and SCC, with no significant difference in expression between hyperplasia and mild dysplasia or between biopsies of severe dysplasia and SCC. Laminin-5 expression was only significantly increased in SCC, confirming it as a marker of malignant transformation and invasion. The results of this study indicate that overexpression of laminin-5 is found only in SCC and not dysplastic lesions. Therefore, laminin-5 has potential as a marker for the intraoperative assessment of cancer excision margins and could be used as a target for chemotherapeutic agents.

Clinicopathological significance of laminin-5γ2 chain expression in superficial esophageal cancer

The glycoprotein laminin 5γ2 chain (LN-5γ2) has recently become a focus of increased interest and investigation as a marker of invasion in gastrointestinal malignancies. We investigated the significance of LN-5γ2 expression as a prognostic factor in superficial esophageal cancer. The study population consisted of 87 patients who had undergone a transthoracic esophagectomy and three-field lymphadenectomy for the treatment of superficial esophageal cancer at Tokai University Hospital. Formalin-fixed, paraffin-embedded sections of the resected specimens were examined using immunohistochemical staining and hematoxylin and eosin staining to assess the correlations between the LN-5γ2 expression pattern and the clinicopathological factors (age, sex, T-factor, N-factor, ly-factor, v-factor, degree of differentiation, infiltrative growth pattern, tumor node metastasis classification of malignant tumors [TNM] stage, etc.) and the patient outcome. The expression pattern of LN-5γ2 was classified into an extracellular type (E type), characterized by the staining of extracellular matrix such as the basement membrane and the stroma (31 cases, 35.6%), and a cytoplasmic type (C type), characterized by the staining of the cytoplasm in the cancer cells (56 cases, 64.6%). The expression pattern was not correlated with any of the clinicopathological factors that were assessed. However, univariate analyses of the survival analysis data showed that the N-factor (P = 0.011), TNM stage (P = 0.011), and LN-5γ2 C type (P = 0.017) were prognostic factors. A multivariate analysis revealed that the N-factor (P = 0.049) and LN-5γ2 C type (P = 0.048) were prognostic factors. In the survival analysis, a univariate analysis of the 75 T1b cases also showed that the N-factor (P = 0.048), TNM stage (P = 0.048), and LN-5γ2 C type (P = 0.029) were prognostic factors, while a multivariate analysis showed that the LN-5γ2 C type (P = 0.035) was a prognostic factor. The C type expression of LN-5γ2, i.e. confined to the cytoplasm, was correlated with an unfavorable outcome among the patients with superficial esophageal cancer in the present series. Observation of the LN-5γ2 expression pattern may be useful for the diagnosis of highly malignant tumors.

Vasculogenic mimicry and its clinical significance in medulloblastoma

Vasculogenic mimicry (VM), a process involving the formation of a tubular structure by highly invasive and genetically dysregulated tumor cells, can supplement the function of blood vessels to transport nutrients and oxygen to maintain the growth of tumor cells in many malignant tumors. We aimed to explore the existence of VM and its clinical significance in medulloblastoma in this study. VM was identified in 9 out of 41 (22%) medulloblastoma tissues. Immunohistochemical studies revealed that the presence of VM was associated with the expression of MMP-2, MMP-14, EphA2 and laminin 5γ2. Tumor tissues with VM were associated with lower microvessel density (MVD), which was indirect evidence of the blood supply function of VM. Survival analysis and log-rank tests showed that patients with VM had shorter overall survival time than those without VM. Multivariate analysis and the Cox proportional hazards model identified VM as independent prognostic factor for overall survival. Our results confirmed the existence of VM for the first time and revealed that VM is a strong independent prognostic factor for survival in patients with medulloblastoma.

Immunohistochemical expression profile of β-catenin, E-cadherin, P-cadherin, laminin-5γ2 chain, and SMAD4 in colorectal serrated adenocarcinoma

The immunohistochemical expression of cell adhesion molecules in colorectal serrated adenocarcinoma is still unknown. The immunostaining patterns of β-catenin, E-cadherin, P-cadherin, laminin 5γ2, and SMAD4 and their relationship to survival were studied in different tumor areas, namely, tumor center and invasive front, the latter comprising tumor bud and non-tumor bud clusters, as described in a previous study of 66 serrated adenocarcinomas and matched conventional carcinomas. Compared with conventional carcinomas, serrated adenocarcinomas showed significantly reduced nuclear β-catenin, membranous E-cadherin, and nuclear SMAD4 but an increased cytoplasmic expression of laminin-5γ2 at the invasive front that was particularly pronounced in the tumor buds. E-cadherin loss at the invasive front was identified as an independent prognostic factor for a poorer outcome in serrated adenocarcinoma. Serrated adenocarcinoma shows a distinct immunohistochemical profile at the invasive front compared with conventional carcinoma, which may account for its less favorable outcome. The lower frequency of nuclear β-catenin in SAC, especially in right-sided tumors, suggests that molecular mechanisms other than the canonical Wnt/β-catenin pathway may have a role in tumor bud formation.

Expression of laminin-5 γ2 chain in cutaneous pseudocarcinomatous hyperplasia

Since the use of laminin-5 as a marker of invasiveness has been proposed by several authors, our objective was to compare the expression of this protein in pseudocarcinomatous hyperplasia and squamous cell carcinoma (SCC). Sixty-four paraffin-embedded skin biopsy samples with diagnosis of epidermal hyperplasia (non-pseudocarcinomatous), pseudocarcinomatous hyperplasia, actinic keratosis/carcinoma in situ, microinvasive and frankly invasive SCC were obtained for immunohistochemical study. Adjacent normal epithelium and epidermal hyperplasia (non-pseudocarcinomatous) showed no staining. In pseudocarcinomatous hyperplasia, laminin-5 was positive, at least focally, in 14 of 16 (87.5%) samples and was concentrated in peripheral cells of elongated rete pegs and in migrating cells in dermis. In samples of microinvasive carcinoma (n = 7), the expression was observed in all cases and was concentrated in the leading edge of the tumor. All cases (n = 21) of frankly invasive SCC showed cells expressing laminin-5, at least focally. Well-differentiated areas of the tumor presented a pattern of expression in peripheral cells of tumor nests while a diffuse pattern of expression was observed in less differentiated areas. We showed that cytoplasmic laminin-5 expression should not be used as a criterion of malignancy and is not useful in distinguishing pseudocarcinomatous hyperplasia from microinvasive and well-differentiated SCC.

Laminin-5 immunohistochemical mapping for analysis of local extension in hypopharyngeal cancer: A preliminary report

Laminin-5 γ2 chain (LNγ2) plays an important role in cancer differentiation and migration. Using a novel immunohistochemical mapping technique to investigate whole mucosal strips of total laryngopharyngectomy specimens using iodine, H-E, and LNγ2 stainings, we investigated the locoregional behavior of hypopharyngeal cancer. Surgical specimens from two patients with pyriform sinus cancer were investigated. Three percent iodine was applied to the tumor-bearing laryngopharynx during surgery and photographed. Stainabilities of H-E and LNγ2 on pathologic sections from all mucosal strips were scored and coordinated with the laryngopharyngeal photograph to illustrate the immunohistochemical map. In both patients, the main tumor of invasive squamous cell carcinoma was circumferentially surrounded by a superficial lesion characterized by high grade intraepithelial neoplasia that remained unstained by iodine. On LNγ2 immunohistochemical mapping, the main tumor was demonstrated by Score 2 staining and the superficial lesion by a stronger Score 3 staining. The finding of neoplastic cells at the periphery demonstrating a higher potential than the cancer cells at the tumor center is suggestive of impending progression from neoplasia to carcinoma. The current preliminary report suggested morphological evidence of intraepithelial infiltration and lateral invasion in hypopharyngeal cancer.

Aberrant up-regulation of LAMB3 and LAMC2 by promoter demethylation in gastric cancer

The LAMB3 and LAMC2 genes encode the laminin-5 β3 and γ2 chains, respectively, which are parts of laminin-5, one of the major components of the basement membrane zone. Here, we report the frequent up-regulation of LAMB3 and LAMC2 by promoter demethylation in gastric cancer. Gene expression data analysis showed that LAMB3 and LAMC2 were up-regulated in various tumor tissues. Combined analyses of DNA methylation and gene expression of both genes in gastric cancer cell lines and tissues showed that DNA hypomethylation was associated with the up-regulation of both genes. Treatment with a methylation inhibitor induced LAMB3 and LAMC2 expression in gastric cancer cell lines in which both genes were silenced. By chromatin immunoprecipitation assay, we showed the activation histone mark H3K4me3 was associated with the expression of both genes. The expression level of LAMB3 affected multiple malignant phenotypes in gastric cancer cell lines. These results suggest that epigenetic activation of LAMB3 and LAMC2 may play an important role in gastric carcinogenesis.

Tumour budding correlates with local recurrence of rectal cancer

Predictive tools for local recurrence (LR) of rectal cancer are needed. This study assessed the predictive value of tumour budding detected by MNF-116 and laminin-5 γ2 chain (Ln-5 γ2). In a case-control study, the surgical specimens of 48 patients with LR after from primary resection of rectal carcinoma and 82 control patients matched for gender and preoperative radiation from a population of 1180 patients operated with total mesorectal excision were studied. The presence of budding was examined using immunohistochemistry with Ln-5 γ2 and pan-cytokeratin staining with MNF-116. Tumour budding counts ranged from 0 to 106 buds (mean 43, median 38) for all patients. Significantly more tumours with more than 35 buds were seen in the LR than in the control group (67 vs 44%; P = 0.02). The spread of budding was also more extensive in the LR than in the control group (63 vs 49%, P = 0.03). In a multivariate analysis with tumour, node, metastasis stage, MNF-116-stained budding was an independent predictor of local failure (P = 0.02). The budding frequency was higher in irradiated tumours in comparison with tumours that had not received irradiation (mean 53 vs 38, P = 0.03). For Ln-5 γ2, more tumours with ≥ 10 buds were seen in the group with LR than among the control patients, but this difference was not statistically significant (73 vs 57%; P = 0.09). No additive value was found in the multivariate logistic regression model when Ln-5 γ2-stained budding frequency was added to MNF-116 and tumour, node, metastasis stage. The agreement between budding frequency determined by MNF-116 and Ln-5 γ2 was moderate, with a κ-coefficient of 0.34 (0.16-0.51). Tumour budding determined by MNF-116 staining may serve as a predictive marker for LR in rectal cancer.

Dynamic molecular changes associated with epithelial–mesenchymal transition and subsequent mesenchymal–epithelial transition in the early phase of metastatic tumor formation

Metastatic tumor formation via vessel route begins with cancer cell extravasation from vessel lumen, migration into the connective tissue surrounding vessels, and invasion into target organ parenchyma. Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) have been recognized to play an important role in metastatic process, however, how and where these biological changes take place in the early phase of metastatic tumor development has never been clarified. We morphologically evaluated 34 small intrapulmonary metastases formed after cancer cell extravasation from lymphatics (lymphogenic metastasis) and 40 formed in the absence of extravasation (aerogenous metastasis) in human specimens and found that isolated or small clusters of invasive cancer cells (tumor budding) were frequently observed in lymphogenic metastasis (24/34; 71%), but were never observed within aerogenous metastasis. We immunostained 34 lymphogenic metastases for 13 molecular markers of EMT and MET and scored the immunostaining intensity of cancer cells floating in lymphatic vessels (LVs), migrating into the connective tissue surrounding vessels [bronchovascular bundle (BVB)], and growing in lung parenchyma (LP). Cancer cells within BVBs stained more weakly for E-cadherin (p < 0.001), β-catenin (p < 0.001), and Geminin (p < 0.001) and more strongly for MMP-7 (p = 0.046) and Laminin-5 γ2 (p = 0.037) than tumor cells in LVs. However, cancer cells in LP exhibited resurgent E-cadherin (p = 0.011), β-catenin (p < 0.001), and Geminin (p = 0.037) expression and reduced MMP-7 (p = 0.038) and Laminin-5 γ2 (p = 0.001) expression in comparison with cancer cells in BVBs. Our results suggested that in the early phase of metastatic tumor formation cancer cells undergo dynamic phenotypic change associated with EMT and subsequent MET.

Expressions of the gamma2 chain of laminin-5 and secreted protein acidic and rich in cysteine in esophageal squamous cell carcinoma and their relation to prognosis

Previous studies have shown that the expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess the expressions of laminin-5 γ2 chain and SPARC in esophageal squamous cell carcinoma (SCC), and to clarify the prognostic significance of the expressions of laminin-5 γ2 chain and SPARC in esophageal SCC, we detected the expressions of laminin-5 γ2 chain and SPARC in cancer tissue and corresponding normal mucosa from 116 patients with advanced (stages II–IV) esophageal SCC using the tissue microarray-based immunohistochemistry and analyzed the correlation of the expressions with clinicopathologic characteristics and survival. We found that in normal esophageal tissues, laminin-5 γ2 chain was expressed in the basement membrane, whereas in esophageal SCC tissues, laminin-5 γ2 chain was expressed in the cytoplasm of carcinoma cells, with a positive rate of 72.4%. SPARC was not detected in normal esophageal mucosa, but was expressed in stromal fibroblasts in 84.6% of esophageal SCC cases and in cancer cells in 7.8% of esophageal SCC cases. There was a significant correlation between laminin-5 γ2 chain and stromal SPARC expression in esophageal SCC (Spearman' s rho = 0.423, P < 0.001). The expressions of both laminin-5 γ2 chain and stromal SPARC were correlated with survival (P = 0.032 and P = 0.034, respectively). In stage-II esophageal SCC, the expression of laminin-5 γ2 chain was significantly correlated with survival (P = 0.023), while the expression of SPARC was not significantly correlated with survival (P = 0.154). Patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis than did those lacking elevated levels of laminin-5 γ2 chain expression and/or elevated levels of SPARC expression (P = 0.001). In stage-II esophageal SCC, patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis (P < 0.001). These results suggest that laminin-5 γ2 chain and SPARC may play roles in the progression of esophageal SCC and their simultaneous expression is correlated with poorer prognosis, especially in patients with stage-II SCC.

A Histopathological and Immunohistochemical Study of Basal Membrane Alterations, with Special Reference to Advance of Dysplastic Grading

A histopathological and immunohistochemical study was conducted to elucidate the alteration of the basement membranes (BMs) and important related factors in oral precursor lesions and oral squamous cell carcinoma (OSCC). Gingivae from 36 cases (5 normal epithelium, 7 hyperkeratosis, 7 mild dysplasia, 7 moderate dysplasia, 5 severe dysplasia, 5 OSCC) were examined. As for histopathological findings of BMs, periodic acid-methenamine-silver stain (PAM) displayed continuous liner appearances in all cases except for OSCC. Reticulin silver impregnation showed discontinuous and irregular distributions were admitted in severe dysplasia and OSCC. From immunohistochemical analysis, laminin 5γ2 and collagen IV appeared thicker and more irregularity attitude in moderate, severe and OSCC, while thinner, linear and continuous appearance in control, hyperkeratosis and mild dysplasia. As for integrin α6, it was increased obviously from hyperkeratosis to mild dysplasia, but it was decreased in severe dysplasia and OSCC on the contrary. Expression of tenascin was gradually increased underlying BMs from hyperkeratosis to OSCC. As for oral precursor lesion, instability of BMs components and up-regulation of BMs related proteins have reinforced from moderate dysplasia. Based on these results, it was supposed that moderate dysplasia became the switch to malignant transformation occurs.

Investigation of vasculogenic mimicry in sebaceous carcinoma of the eyelid

Vasculogenic mimicry (VM) is a newly proposed pattern of tumour angiogenesis that has been identified in some malignancies and is associated with poor prognosis. The purpose of this study was to investigate whether sebaceous carcinomas of the eyelid exhibit VM and to determine whether these fluid-conducting patterns are associated with clinicopathologic features, the number of microvessels and the levels of endothelial growth factor (VEGF) and matrix metalloprotease-2 (MMP-2) in tumours. Forty paraffin-embedded samples of sebaceous carcinoma of the eyelid were collected, along with complete clinical and pathologic data for all the cases. Tissue sections were stained for CD34, periodic acid and Schiff (PAS), VEGF and MMP-2. VM was identified by the presence of PAS-positive and CD34-negative loops lined by tumour cells. The VM status of tumour samples was compared with the clinical and pathological data using statistical tests. The levels of VEGF, MMP-2 and the number of microvessels were compared between patients with and without VM. VM was detected in 14 of 40 (35%) tumour samples. The existence of VM in tumours was associated with tumour size (p=0.007) and recurrence (p=0.021). The number of microvessels was lower in tumours with VM (13.03+/-4.02 versus 22.99+/-7.72; p<0.0001). The staining index of MMP-2 was higher in tumours with VM (27.43, range: 0-5.3) compared to tumours without VM (16.77, range: 0-2.7; p=0.004). However, there was no difference in the expression of VEGF between groups with and without VM (p=0.244). Vasculogenic mimicry is present in sebaceous carcinoma of the eyelid making it an unfavourable prognosis sign. MMP-2 is associated with VM formation in sebaceous carcinoma of the eyelid.

Laminin-5 (γ2 chain) is a marker of invading cancer cells in human gallbladder carcinoma: Special emphasis on extension of carcinoma in situ along Rokitansky-Aschoff sinuses

Gallbladder carcinoma (GC) is a relatively uncommon malignancy and is often caused by diagnostic difficulties in distinguishing the extension of carcinoma in situ (CIS) from invasive carcinoma along Rokitansky-Aschoff sinuses (RAS). The laminin-5, a heterotrimer, is composed of alpha-3, beta-3 and gamma-2 chains. The gamma-2 chain is expressed in various invasive carcinoma cells. There are numerous reports that have described that laminin-5-gamma-2 is associated with tissue invasion in many organs. However, few studies are found in gallbladder carcinoma. To clarify the relationship between laminin-5-gamma-2 chain (LN-5) expression and the development of GCs, we performed an immunohistochemical study of 93 GCs. Cases were classified into three groups: CIS with/without the extension along RAS (Group A; n=17), carcinoma invading mucosa or muscular layer (Group B; n=5) and carcinoma invading beyond perimuscular connective tissue (Group C; n=71). The immunohistochemical intracytoplasmic expression was detected in the invasive fronts of the tumor. In the invasive components of Group B and C, LN-5 was expressed in 100 and 97% of cases, respectively, whereas in the CIS lesions of GCs, expression was not observed in Group A. LN-5 expression in the GCs tended to increase as tumors developed, which may be an indicator of the potential invasiveness of the tumor. Our results indicate that, in GCs, a strong intracytoplasmic expression of LN-5 was identified in the cancer cells whether in situ they extend along RAS or invading stroma.

Prognostic value of differential expression of Laminin-5 γ2 in oral squamous cell carcinomas: Correlation with survival

In oral squamous cell carcinomas of the head and neck, Laminin-5 gamma2 has been associated with tissue invasion, lymph node metastasis and histopathological grading. In the present study, we compared the expression of the subunit gamma2 of Laminin-5 under normal, dysplastic and invading epithelia in 65 biopsies previously diagnosed for oral squamous cell carcinoma. The number of gamma2-positive cells were analyzed in relation to patients' survival, tumor grading, size of the lesion, TNM stage, histopathological pattern of invasion and inflammatory reaction. Biopsies of oral squamous cell carcinomas were deparaffinised, processed for antigen unmasking procedures and stained with antibody anti-Laminin-5 gamma2. By light microscopy, 4 optical fields of x200 were selected in three different areas including normal, dysplastic and invading epithelia. Positive cells were counted and divided into three categories, which included <20 cells, between 21 and 50 cells and >50 stained cells. Patient survival was analyzed by Kaplan-Mayer curves. gamma2-positive cells were found in the basal layer of dysplastic epithelium, within inflammatory infiltrate, at the margins of differentiated invading islands and at the forefront of undifferentiated invading nests. Observations showed that an increased number of gamma2-positive cells correlated significantly with a shorter life expectancy under invading epithelia (log-rank test p<0.05), not when a count was performed under normal or dysplastic epithelia of the same patient. The number of gamma2-positive cells also correlated with the histopathological pattern of invasion. Our results show that gamma2 may be a reliable prognostic tool for oral squamous cell carcinomas.

Cytoplasmic Expression of Type VII Collagen Is Related to Prognosis in Patients with Esophageal Squamous Cell Carcinoma

Objective: Type VIIcollagen, the major component of anchoring fibrils, has been suggested to be involved with tumor cell invasion in a laminin-5-dependent manner in skin squamous cell carcinoma. However, the significance of type VII collagen expression in esophageal squamous cell carcinoma (ESCC) has been unknown to date. Therefore, we examined the expression of type VIIcollagen in ESCC, and confirmed the association between type VIIcollagen expression and clinicopathologic characteristics. Methods: We immunohistochemically examined the expression of type VII collagen and laminin-5 γ2 chain in surgical specimens of primary tumors in 109 patients with ESCC. Results: Positive cytoplasmic expression of type VII collagen was detected in 35%. Significant correlation between the expression of type VII collagen and laminin-5 γ2 chain expression was observed. In the type VII collagen-negative group, the 5-year survival rate was significantly better than in the positive group. Multivariate analysis indicated that the positive expression of type VII collagen was an independent prognostic factor. Conclusions: The expression of type VII collagen was closely related to poor prognosis. Type VII collagen cytoplasmic expression could be a useful marker for evaluating the tumor cell properties, including prognosis, in patients with ESCC.