Involvement of EphA2 in head and neck squamous cell carcinoma: mRNA expression, loss of heterozygosity and immunohistochemical studies

EphA2 is a 130-kDa transmembrane protein primarily found in adult human epithelial cells and is a member of one of the largest receptor tyrosine kinases. It is located on 1p36.1, a genetic hot spot in cancer. EphA2 overexpression has been observed in aggressive solid tumors and its potential role in tumorigenesis, which includes cell growth, survival, migration and angiogenesis have been reported. However, the role of EphA2 remains unknown in head and neck cancer. In this study, we investigated the genetic profile of EphA2 in primary head and neck squamous cell carcinoma (HNSCC) by determining mRNA level, status of loss of heterozygosity and protein expression. mRNA expression was also correlated with clinicopathological data. Infrequent loss of heterozygosity (20%) was observed, though a 10-fold increase of mRNA expression in tumors compared to normal tissues was noted. A significant number of samples with normal to high mRNA expression was observed among patients with regional metastasis, with T3-T4 tumor size and with moderate to poor differentiation. However, statistical studies did not show any correlation between mRNA expression and any of the clinicopathological parameters. Tumor cells expressed EphA2 protein, but only weakly. These results suggest that EphA2 might be involved in the early development of HNSCC although not directly responsible for its progression.

Localization of FAK is related with colorectal carcinogenesis

Focal adhesion kinase (FAK) is an important mediator functioning between cells and the extracellular matrix and is closely related with the integrin-signaling pathway. FAK has been reported to be involved in the proliferation, differentiation and apoptosis of cells. To date, no report has demonstrated the involvement of FAK in the carcinogenesis of the digestive tract. Therefore, we examined colorectal, esophageal, pancreatic and mammary cancers for expression of FAK and Phospho (P)-FAK by immunohistochemistry. Strong expression of FAK in the cytoplasm was detected in all 4 tumor types and expressions of FAK and P-FAK increased as the degree of cell differentiation became higher in colorectal and esophageal carcinomas. Interestingly P-FAK expression was confined to the nuclei, which was an unexpected result. No previous report of such a finding has been published for gastrointestinal cancer. All four of the organs investigated in the present study showed P-FAK expression in the nuclei, suggesting an association between FAK activation and abnormal cell proliferation. We also performed immunostaining of P-FAK in cell lines to examine the significance of its experience in the nuclei. However, unlike clinical specimens, the cell lines did not show P-FAK expression in the nuclei. Moreover, the injection of cancer cells into the peritoneal cavity of mice also failed to demonstrate P-FAK expression in the nuclei. These results may be related with the function of carrier proteins of FAK such as Hic-5 and Zyxin, which are found only in humans. Taken together, FAK and P-FAK are involved in the carcinogenesis of digestive organs.

Heparanase and vascular endothelial growth factor expression in the progression of oral mucosal melanoma

Oral mucosal melanoma is an aggressive neoplasm with poor prognosis. Heparanase is an endo-beta-d-glucuronidase, which cleaves heparan sulphate chains. The vascular endothelial growth factor (VEGF) is the most potent angiogenic mitogen and interaction with its receptor (VEGFR) has been associated with angiogenesis. We investigated the expression of these molecules in the progression of oral mucosal melanoma. Immunohistochemistry was carried out in 15 oral melanotic macules and 19 oral melanomas using heparanase, VEGF, VEGFR-2, CD34 and Ki-67. Microvessel density was determined and subjected to statistical analysis. Heparanase and VEGFR-2 were not expressed in the oral melanotic macule. Atypical melanocytes and melanoma cells expressed heparanase, VEGF and VEGFR-2. An intense expression was noted in the early invasive phase, which marks the crucial transition from in situ to the invasive phase. In the invasive component, heparanase was intense but selective in the invasive fronts and at the periphery of nests unlike the extensive expression of VEGF and VEGFR-2. However, hot spots were only observed at the periphery of the nests. In conclusion, melanoma cells expressed heparanase, VEGF and VEGFR-2. The coexpression of these molecules in atypical melanocytes and melanoma cells suggests their function in cell migration and invasion. Moreover, the intense expression in the crucial transition from in situ to the invasive phase suggests their role in the progression of the tumor. The role of VEGF and VEGFR-2 in angiogenesis was evident only at the periphery of the nests in the invasive components.

Lack of B-RAF mutations in head and neck squamous cell carcinoma

B-RAF is one of the most commonly mutated oncogenes in human cancer. However, the mutation status of B-RAF has not been established completely in HNSCC. We have analysed the mutation status of the kinase domain of the B-RAF gene (exons 11 and 15) in 91 Japanese HNSCC patients as well as 12 HNSCC cell lines. DNA was extracted and amplified by PCR. Mutations were then analysed by SSCP mutation detection method. Since V600EB-RAF constitutes 90 % of the mutations identified in B-RAF in human cancers, we also used MASA analysis to specifically detect this mutation in exon 15 of B-RAF. Using both methods, no mutation was found in both exon 11 and 15 in all patients and cell lines. Mu tations are absent or rare in the kinase domain of B-RAF in Japanese HNSCC. However, more studies are still needed to determine its usefulness as a target for molecular therapy in these patients.

Deletion mapping of chromosome 4q22-35 and identification of four frequently deleted regions in head and neck cancers

Head and neck squamous cell carcinoma (HNSCC) is a diverse group of cancers that are frequently aggressive in their biologic behavior. Inactivation of tumor suppressor gene (TSG) is one of the most critical steps leading to HNSCC. Loss of heterozygosity analysis is very sensitive method for the detection of frequent allelic loss in a chromosomal locus. This method has been considered as an important evidence for the localization of TSGs. We analyzed loss of heterozygosity (LOH) at chromosome 4q22-35 region by using 14 polymorphic microsatellite markers in 83 matched normal and HNSCC tissues. LOH was detected at least in one location in 71 of 83 (86%) tumor tissues. Frequent deletions were detected at the location of microsatellite markers, D4S2909 (46%), D4S2623 (51%), D4S406 (48%), D4S1644 (45%) and D4S2979 (40%). Four different frequently deleted regions at 4q22, 4q25, 4q31 and 4q34-35 were observed. These regions include several putative TSGs such as Caspase-6, SMARCAD1, SMARCA5, SAP30 and ING2. Further molecular analysis of each gene should be performed to clarify their roles in head and neck squamous cell carcinogenesis.

Immobilized rhBMP-2/succinylated type I atelocollagen gene expression of intracellular signaling molecules on ST2 cells

Recombinant human bone morphogenetic protein-2 (rhBMP-2) chemically-bonded to succinylated type I atelocollagen, a biomaterial carrier with a porous structure, was reported to augment cellular activity of ST2 cells. The Smad protein family has been suggested to play an important role in the intracellular signaling pathway of BMP by its binding to receptors on target cells. However, there has been no study analyzing the downstream genes of the rhBMP-2 induced intracellular signal transduction pathway. The purpose of this study was to examine the effect of immobilized rhBMP-2 on gene expression of intracellular signaling molecules on ST2 cells. Our study showed two expression patterns of downstream genes of rhBMP-2 intracellular signal transduction pathway. In the first pattern, BMPR-IA, Smad 1, and Smad 5 genes showed high basic expression before the addition of rhBMP, and the high level of gene expression continued for long period and decreased in the late stage when rhBMP-2 was immobilized. In the second pattern, Smad 6, Smad 7, and Smad 8 genes showed low basic expression before the addition of rhBMP-2 and a continuous increase from the beginning was followed by a decrease in the late stage when rhBMP-2 was immobilized. Our results also showed that intracellular signaling continued for prolonged period when rhBMP-2 was immobilized to succinylated type I atelocollagen. This study indicated that immobilizing rhBMP-2 is an efficient method to increase bone induction.

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

Background

Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.

Methods

A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.

Results

The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.

Conclusion

The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.

Analysis of the neoplastic nature and biological potential of sporadic and nevoid basal cell carcinoma syndrome-associated keratocystic odontogenic tumor

BACKGROUND

Keratocystic odontogenic tumor (KCOT), also known as odontogenic keratocyst, is a benign cystic neoplasm, which may be associated with nevoid basal cell carcinoma syndrome (NBCCS) and if it does, will occur as multiple cystic lesions. KCOT is locally destructive despite its bland histological features. However, the neoplastic nature of KCOT is not well established. Heparanase is an endo-d-glucuronidase enzyme that specifically cleaves heparan sulfate (HS) and the increase of its level in tumors promotes invasion, angiogenesis, and metastasis.

METHODS

To investigate the neoplastic character of KCOT, we studied the localization patterns of heparanase in KCOT, focusing on the differences between sporadic and NBCCS-associated KCOTs, by immunohistochemistry and in situ hybridization. To compare the expression pattern of these cysts with non-tumorous odontogenic developmental cyst, dentigerous cyst was included.

RESULTS

All the odontogenic cysts showed positive immunoreaction for heparanase protein in various intensities. The expression pattern of heparanase gene corresponded to that of protein expression. Interestingly, intense gene and protein expressions were observed in KCOT associated with NBCCS compared with sporadic ones and dentigerous cyst.

CONCLUSIONS

The results implied that heparanase expression may be correlated with the neoplastic properties of KCOT, particularly in NBCCS-associated cases.

Comprehensive loss of heterozygosity analysis and identification of a novel hotspot at 3p21 in salivary gland neoplasms

OBJECTIVES

We sought to assess loss of heterozygosity (LOH) profiles of 3p, 6q, 8q, 10q, 12q, 13q, and 17p and to identify the tumor suppressor genes involved in salivary gland neoplasms.

STUDY DESIGN

LOH analysis was performed using 26 microsatellite markers by polymerase chain reaction-polyacrylamide gel electrophoresis method in 20 benign and 6 malignant salivary gland tumors.

RESULTS

Overall, LOH was detected in at least one informative locus in 18 of 20 (90%) of benign tumors and in all of 6 cases of malignant tumors. High LOH frequencies were revealed at the loci D3S1307 (22%, 3p26), D3S966 (41%, 3p21), D6S255 (27%, 6q25), D8S166 (25%, 8q12), D8S199 (21%, 8q24), and D10S1765 (28%, 10q23) in benign tumors, defining the hotspot regions for putative tumor suppressor genes.

CONCLUSIONS AND SIGNIFICANCE

The hotspot regions defined by the present study suggest that new tumor suppressor genes related to the development of salivary gland tumors may reside at several chromosomal loci, including loci at 3p, 6q, 8q and 10q.

Effects of a Novel Palatinose Based Enteral Formula (MHN-01) Carbohydrate-Adjusted Fluid Diet in Improving the Metabolism of Carbohydrates and Lipids in Patients with Esophageal Cancer Complicated by Diabetes Mellitus

BACKGROUND

During perioperative management of patients with gastrointestinal cancer complicated by diabetes mellitus, adequate alimentation is required, but we often face difficulties associated with hyperglycemia and other accompanying complications. Recently, we investigated the effects of a novel palatinose based enteral formula (MHN-01) in suppressing post-prandial hyperglycemia and improving lipid metabolism in experimental animals and perioperative management of patients with esophageal cancer complicated by diabetes mellitus.

MATERIALS AND METHODS

We gave normal rats and rats with type 2 diabetes mellitus a single oral dose of fluid diet, and analyzed comparatively the time course of blood glucose level in each group until 3 h after the dose. In both the normal rat group and the type 2 diabetes group, peak blood glucose level after the MHN-01 dose was significantly lower than after a dose of ordinary fluid diet and was comparable to the peak level after a dose of a fluid diet rich in MUFA (monounsaturated fatty acid). We allowed normal mice free access to fluid diet for 43 days, and measured their body fat levels. Fat accumulation was significantly lower in mice given MHN-01 than in mice given ordinary fluid diet. We also analyzed the respiratory quotient and resting energy expenditure of normal Sprague-Dawley rats fed by MHN-01 or an ordinary fluid diet. The respiratory quotient of the MHN-01 group was significantly lower than the ordinary fluid group, although the resting energy expenditure of both groups was almost the same level. The effect of MHN-01 was estimated to be based on improvement of lipid metabolism.

RESULTS

Between 2003 and 2005, among 164 patients who underwent radical thoracic esophagectomy and/or reconstruction for esophageal carcinoma at Okayama University Hospital, nine patients (5.5%) were diagnosed with diabetes mellitus in pre-operative screening and were treated with MHN-01. Clinical courses of two cases with severe status of diabetes mellitus were presented as successful case reports of MHN-01.

CONCLUSION

MHN-01 was very useful in perioperative management of patients complicated by diabetes mellitus, unable to ingest food p.o. such as esophageal cancer or other diseases.

Translocation of heparanase into nucleus results in cell differentiation

We recently reported that heparanase, one of the extracellular matrix-degrading enzymes, which plays a critical role in cancer progression, is located not only in the cytoplasm but also in the nucleus. Here we identified nuclear translocation of heparanase as a key step in cell differentiation. We applied an in vitro differentiation model of HL-60 cells with 12-0-tetradecanoylphorbol-13-acetate (TPA), in which nuclear translocation of heparanase was observed using immunohistochemical analysis. In this system, nuclear translocation of heparanase was abolished by inhibitors of heat shock protein 90 (HSP90), suggesting the involvement of HSP90 in translocation of heparanase. We further confirmed that overexpression of active form of heparanase induced differentiation of HL-60 cells, although the catalytic negative form of heparanase did not. Therefore we speculate that nuclear translocation of enzymatically active heparanase may be involved in cellular differentiation. Our results suggest that a novel function of heparanase upon cell differentiation would raise a potential new strategy for cancer therapy of promyeloid leukemia and other types of cancer.

Heparanase promotes angiogenesis through Cox-2 and HIF1α

Heparanase has been given attention for its role in the invasion and metastasis of various cancers for years. We have also investigated and reported the role of heparanase in several human cancers, including gastric, esophageal and colon carcinomas. Other than the critical role of heparanase in tumor invasion and metastasis, it is also believed that heparanase is involved in angiogenesis, another feature of tumor progression which is complicatedly mediated by many molecules, including cyclooxygenese-2 (Cox-2). Thus, our recent study elucidated a possible relationship of heparanase with Cox-2 upon tumor angiogenesis. Based upon our study, three major transcription factor binding sites containing NF-kappaB, NF-IL-6 and CRE sites seemed to have a compensative and cooperative role in heparanase-induced Cox-2 upregulation. On the other hand, tumor hypoxia often occurs in most tumors and Cox-2-induced HIF1alpha overexpression has recently been shown in various cancers. Here we believe that heparanase may also be involved in tumor hypoxia through the induction of HIFalpha either directly or indirectly through the Cox-2 pathway. This hypothesis indicates a possible novel function of heparanase and its link to HIF1alpha and Cox-2, and therefore this function would give us a clue about potential new strategies for cancer therapy.

Microcystic Adnexal Carcinoma with Mandibular Bone Marrow Involvement

Microcystic adnexal carcinoma is a rare, locally aggressive cutaneous neoplasm with a high probability of persistence locally but a low probability of metastasis. We report a case of a 69-year-old female patient with an indurated plaque at the mental region. Histologically, the tumor cells invaded the subcutaneous tissue and mandibular bone. The tumor consisted mainly of squamous and basaloid epithelial nests and cords embedded in a desmoplastic stroma. A few keratin-filled microcysts and ductal structures were also observed. Perineural encroachment was also noted but there was no mitosis, cytologic features of malignancy, or metastasis. The epithelial nests were positive to various cytokeratins except for CK20 and the lumina of the ductal structures were positive to carcinoembryonic antigen. Our results indicate that microcystic adnexal carcinoma consists of tumor cells capable of both follicular and eccrine differentiation. It is locally aggressive, extends far beyond its clinical presentation and may involve the bone. It may persist and remain asymptomatic for so many years without metastasis. A lifetime postsurgery monitoring is mandatory to ensure early and proper management.