Expression of hypoxia-inducible factor-1 alpha is significantly associated with the progression and prognosis of oral squamous cell carcinomas in Taiwan.

BACKGROUND: Overexpression of hypoxia-inducible factor-1 alpha (HIF-1 alpha) has been found to be significantly associated with the tumor invasion, lymph node metastasis, clinical stage, and prognosis of a variety of human cancers. METHODS: This study examined the expression of HIF-1 alpha in 57 specimens of oral squamous cell carcinoma (OSCC), 41 specimens of oral epithelial dysplasia (OED, 12 mild, 17 moderate, and 12 severe OED cases), and 14 specimens of normal oral mucosa (NOM) by immunohistochemistry. RESULTS: We found that the mean nuclear HIF-1 alpha labeling indices (LIs) increased significantly from NOM (9 +/- 6%) through mild OED (25 +/- 18%), moderate OED (41 +/- 27%), and severe OED (42 +/- 22%) to OSCC samples (55 +/- 23%, P < 0.001). A significant correlation was found between the higher mean nuclear HIF-1 alpha LI and OSCCs with larger tumor size (P < 0.001), regional lymph node metastasis (P < 0.001), or more advanced clinical stages (P < 0.001). Only larger tumor size (P = 0.002) and nuclear HIF-1 alpha LI >or= 60% (P = 0.048) were identified as independent unfavorable prognosis factor by multivariate analyses with Cox regression model. Kaplan-Meier curve showed that OSCC patients with a nuclear HIF-1 alpha LI >or= 60% had a significantly poorer cumulative survival than those with a nuclear HIF-1 alpha LI < 60% (log-rank test, P = 0.022). CONCLUSIONS: We conclude that the expression of HIF-1 alpha is an early event in oral carcinogenesis. The nuclear HIF-1 alpha LI in OSCC samples can predict the progression of OSCCs and the survival of OSCC patients.

Oral verruciform xanthoma: a clinicopathologic study of 15 cases.

BACKGROUND/PURPOSE: Oral verruciform xanthoma (VX) is an uncommon oral mucosal lesion. This retrospective study evaluated the clinical and histopathologic features of 15 oral VXs occurring in Taiwanese patients. METHODS: Fifteen consecutive cases of oral VX were collected from January 1988 to December 2005. Clinical data and microscopic features of these cases were reviewed and analyzed. RESULTS: The mean age of patients was 45 years (range, 18-79 years). There were eight male and seven female patients. Seven (46.6%) cases occurred on the gingiva, four (26.7%) on the tongue, and four (26.7%) on the buccal or vestibular mucosa. The greatest mean dimension of the lesions was 0.8 cm (range, 0.3-2.0 cm). Three patients had concomitant other oral mucosal lesions such as oral submucous fibrosis, squamous cell carcinoma, and erosive oral lichen planus. Microscopically, all specimens showed varying degrees of surface parakeratosis and the accumulation of numerous foam cells in the connective tissue papillae among uniformly elongated epithelial ridges. Individuals or aggregates of foam cells were also found underneath the epithelial ridges in nine (60%) cases. When the oral VX lesions were further classified into three types according to the microscopic surface architecture, seven (47%) lesions were of the verrucous type, three (20%) the papillary type, and five (33%) the flat type. All patients received surgical excision of the lesions and no recurrence was noted during follow-up of up to 18 years. CONCLUSION: Oral VXs occur more frequently in the fifth decade of life. The more commonly affected site is the gingiva. The treatment of choice for oral VXs is surgical excision. The prognosis is excellent and recurrence was not seen in this study.

Expression of human telomerase reverse transcriptase (hTERT) protein is significantly associated with the progression, recurrence and prognosis of oral squamous cell carcinoma in Taiwan.

This study used an immunohistochemical technique to examine the expression of human telomerase reverse transcriptase (hTERT) protein in 82 specimens of OSCC, 116 specimens of oral epithelial dysplasia (OED), and 21 specimens of normal oral mucosa (NOM). The cytoplasmic and nuclear hTERT staining intensity (SI; 0, no staining; 1, weak; 2, moderate; 3, strong), labeling indices (LIs, defined as the percentage of positive cells in total cells), and labeling scores (LSs, defined as LI x SI) in OSCC, OED, and NOM samples were calculated and compared among groups. The correlation between the cytoplasmic or nuclear hTERT LS in OSCCs and clinicopathological parameters or survival of OSCC patients was analyzed statistically. The mean cytoplasmic hTERT LSs increased significantly from NOM (87+/-17%) through OED (95+/-18%) to OSCC samples (114+/-33%, p=0.000). The mean nuclear hTERT LSs also increased from NOM (80+/-14%) to OED (91+/-20%) and then decreased to OSCC samples (86+/-35%) with no statistically significant difference among the 3 groups. A significant correlation was found between the higher mean cytoplasmic hTERT LSs and OSCCs occurring in male patients (p=0.023), with larger tumor sizes (T3 and T4, p=0.048), with more advanced clinical stages (stages 3 and 4, p=0.033), or from patients with areca quid chewing (p= 0.029), cigarette smoking (p=0.027), or alcohol drinking habit (p=0.025). In addition, OSCC patients with nuclear hTERT LSs greater than 100% were prone to have a higher recurrence rate (p=0.044) and a lower 5-year survival rate (p=0.011). Our results indicate that the increased expression of hTERT protein is an early event in oral carcinogenesis and hTERT may be a biomarker for OSCCs. Measuring the amount of cytoplasmic or nuclear expression of hTERT in OSCC samples may predict the oral cancer progression, recurrence, and prognosis in Taiwan.

Levamisole can modulate the serum tumor necrosis factor-alpha level in patients with recurrent aphthous ulcerations.

BACKGROUND: Recurrent aphthous ulcerations (RAU) are common oral inflammatory lesions. Tumor necrosis factor (TNF)-alpha is an important inflammatory mediator and a critical cytokine for adequate host defense. Our previous studies have shown that 14-43% and 59-63% of patients in the ulcerative stage of major, minor or herpetiform RAU have significantly higher than normal serum levels of interleukin (IL)-6 and IL-8, respectively. In this study, we examined whether RAU patients in the ulcerative stage had a significantly higher than normal serum level of TNF-alpha and assessed whether treatment with levamisole can modulate serum TNF-alpha levels in RAU patients. METHODS: This study used a solid phase, two-site sequential chemiluminescent immunometric assay to determine the baseline serum levels of TNF-alpha in 146 patients with RAU, nine patients with traumatic ulcers (TU), and 54 normal control subjects. Fifty-five RAU patients with serum TNF-alpha levels higher than 5.0 pg/ml were treated with levamisole for 0.5-4 months and their serum TNF-alpha levels were measured after treatment. RESULTS: We found that 29% (42 of 146) RAU patients as well as 39% (24 of 61) major type, 20% (14 of 69) minor type, and 25% (four of 16) herpetiform type RAU patients had a serum level of TNF-alpha greater than the upper normal limit of 7.4 pg/ml. The mean serum level of TNF-alpha in patients with RAU (9.1 +/- 1.0 pg/ml, P < 0.001), major type RAU (11.6 +/- 1.9 pg/ml, P < 0.001), minor type RAU (6.9 +/- 0.9 pg/ml, P < 0.005), or herpetiform type RAU (9.6 +/- 2.7 pg/ml, P < 0.001) was higher than that (3.8 +/- 0.2 pg/ml) in normal control subjects. The mean serum TNF-alpha level was significantly higher in patients with major type RAU than in patients with minor type RAU (P < 0.05) and was significantly higher in major type RAU patients in the exacerbation stage than in the post-exacerbation stage (P < 0.05). In 55 RAU patients with serum TNF-alpha levels higher than 5.0 pg/ml, treatment with levamisole for a period of 0.5-4 months could significantly reduce the serum TNF-alpha level from 16.4 +/- 1.9 to 5.8 +/- 0.6 pg/ml (P < 0.001). CONCLUSIONS: We conclude that a significantly higher than normal serum level of TNF-alpha can be detected in 20-39% of patients in the ulcerative stage of major, minor or herpetiform RAU. The serum TNF-alpha level may be associated with the severity and the stage of RAU. Levamisole can modulate serum TNF-alpha levels in RAU patients.

HMB-45 may be a more sensitive maker than S-100 or Melan-A for immunohistochemical diagnosis of primary oral and nasal mucosal melanomas.

BACKGROUND: Primary mucosal melanomas (MMs) of the head and neck are a rare entity. Melanomas with characteristic melanin-pigmented tumor cells are easy to diagnose, but those without melanin-pigmented tumor cells, amelanotic melanomas, are difficult to identify and need immunohistochemistry (IHC) to confirm the final diagnosis. In this study, we examined the expression of three melanocytic differentiation markers, HMB-45, S-100, and Melan-A in primary oral and nasal MMs. We tried to evaluate whether HMB-45, S-100, and Melan-A were useful for diagnosis of primary oral and nasal MMs and to find out which marker was the best of the three. METHODS: This study used IHC to examine the expression of HMB-45, S-100, and Melan-A in 17 formalin-fixed paraffin-embedded specimens of primary oral and nasal MMs. The staining intensities (SIs) and labeling indices (LIs) of HMB-45, S-100, and Melan-A in 17 MMs were calculated and compared between any two markers. RESULTS: Immunostaining results showed that the positive rate was 94% (16 of 17) for HMB-45, 88% (15 of 17) for S-100, and 71% (12 of 17) for Melan-A in 17 MMs. The SI of HMB-45 was significantly higher than that of S-100 (P = 0.0011) or of Melan-A (P = 0.0034). In addition, the mean LI of Melan-A (59 +/- 43%) was significantly lower than that of HMB-45 (83 +/- 28%, P = 0.0065) or of S-100 (79 +/- 33%, P = 0.0237). CONCLUSIONS: Our results indicate that both HMB-45 and S-100 show a high positive rate and LI in MMs and therefore may be good markers for immunohistochemical diagnosis of primary oral and nasal MMs. In addition, HMB-45 may be a more sensitive marker than S-100 because HMB-45 shows a significantly higher SI than S-100 in this study.

Expression of hepatocyte growth factor and c-met protein is significantly associated with the progression of oral squamous cell carcinoma in Taiwan.

BACKGROUND: Hepatocyte growth factor (HGF) is a pleotropic growth factor that regulates cell proliferation, migration, survival, tumor angiogenesis, and tumor cell invasion and metastasis. Its diverse biological effects are mediated through its interaction with its receptor, c-met protein. METHODS: In this study, we examined the expression of HGF and c-met protein in 93 specimens of oral squamous cell carcinoma (OSCC), 10 specimens of oral epithelial dysplasia (OED), 14 specimens of oral epithelial hyperkeratosis (OEH), and 16 specimens of normal oral mucosa (NOM) by immunohistochemistry. The HGF and c-met labeling indices (LIs) in OSCC, OED, OEH, and NOM groups were calculated and compared between groups. The correlation between the expression of HGF or c-met in OSCCs and clinicopathological parameters, or survival of OSCC patients was analyzed statistically to investigate the possible influence of HGF or c-met on the progression and prognosis of OSCCs in Taiwan. RESULTS: Positive HGF or c-met staining was mainly cytoplasmic. The mean HGF LI increased significantly from NOM (3.1 +/- 5.1%) through OEH (32.5 +/- 19.8%) and OED (52.0 +/- 19.3%) to OSCC (71.9 +/- 28.6%; P = 0.000). The mean c-met LI also increased significantly from NOM (25.8 +/- 30.8%) and OEH (34.4 +/- 19.3%) through OED (53.0 +/- 20.0%) to OSCC (73.0 +/- 29.4%; P = 0.000). Statistical analysis showed that the c-met LI in either the tumor center or invasion front was significantly associated with T status, N status, and clinical staging of OSCC. However, only the HGF LI in the tumor invasion front was significantly correlated with N status and clinical staging of OSCC. CONCLUSION: Our results suggest that the expression of HGF and c-met protein is an early event in oral carcinogenesis in Taiwan. The HGF LI in the tumor invasion front and the c-met LI in either the tumor center or invasion front can predict the progression of OSCCs in Taiwan.

Characteristics of calcifying odontogenic cyst in Taiwanese.

BACKGROUND AND PURPOSE: Calcifying odontogenic cyst (COC) is a rare type of odontogenic cyst. This retrospective study analyzed the clinical, radiographic, and histopathologic features of COC in Taiwanese. METHODS: Ten cases of COC in 2 male and 8 female patients with a mean age of 29 years (range, 11 to 48 years) treated from January 1985 to December 2002 were included. Microscopic slides, clinical histories, and radiographic features of these 10 COC cases were reviewed and analyzed. RESULTS: COCs occurred in the maxilla in 3 cases and in the mandible in 7 cases. COCs were associated with impacted teeth in 6 cases and with odontomas in 3 cases. All COCs appeared as either unilocular (9 cases) or multilocular (1 case) radiolucencies. In 7 cases, spotty radiopaque materials were scattered throughout the radiolucency. Histologically, all of the lesions were at least partially lined by epithelium with cuboidal to columnar basal cells and stellate reticulum-like suprabasal cells. Variable numbers of ghost cells, some of which were calcified, were observed in the lining epithelium or in the fibrous connective tissue wall of all 10 cases. Juxta-epithelial dentinoid was also found in all cases. However, proliferation of ameloblastoma-like tumor nests was observed in only 1 case. Based on the above histologic findings, 6 COC lesions were classified as simple unicystic type, 3 as unicystic odontoma-producing type, and 1 as unicystic ameloblastomatous proliferating type. CONCLUSIONS: COC occurs frequently in the second and third decades and is commonly associated with an impacted tooth or an odontoma. It usually appears as a mixed radiolucent and radiopaque lesion radiographically. Simple unicystic type is the most common type of COC. No recurrences were found after conservative surgical removal in this series.

Odontoma: a clinicopathologic study of 81 cases.

BACKGROUND AND PURPOSE: Odontoma is the most common odontogenic tumor. It includes 2 types, the compound and complex odontomas. There has not been a series study of the clinical and histologic features of odontomas from Taiwan. This study evaluated the clinicopathologic features of odontoma in Taiwanese. METHODS: Cases of odontoma treated from 1998 to 2002 identified from medical records were included. The microscopic features, radiographic features, and clinical history of the patients were reviewed and analyzed. RESULTS: A total of 81 odontomas in 81 patients (36 males and 45 females) were included. There were 62 compound and 19 complex odontomas. The mean age of the patients was 18 years with the majority of odontomas occurring in the first (32%) and second decade (38%) of life. Odontomas had a marked predilection for the maxilla (70%) and for the anterior region of the jaw (83%), particularly for the anterior maxilla (62%). Sixty four (79%) of the 81 odontomas were associated with 80 impacted teeth, including 71 permanent teeth, 2 deciduous teeth, and 7 supernumerary teeth. Of the 71 impacted permanent teeth, the maxillary central incisor (27%) was most commonly affected, followed by the maxillary canine (26%) and mandibular canine (24%). Histologic examination revealed enamel matrix in 90%, dentin in 100%, cementum in 88%, pulp tissue in 96%, fibrous capsule in 93%, ghost cells in 83%, reduced enamel epithelium in 86%, and nests of odontogenic epithelium in 58% of odontomas. Dentigerous cyst was associated with 9% of odontomas. CONCLUSIONS: In this series, odontomas occurred most often in the first and second decade of life. Although complex odontomas are usually found in the posterior jaw, in this Taiwanese series they were most commonly found in the anterior maxilla. Odontoma is frequently associated with an impacted tooth and occasionally with a dentigerous cyst. No recurrence of odontomas was found after surgical excision with follow-up of 1 to 15 years.

Sequential expressions of MMP-1, TIMP-1, IL-6, and COX-2 genes in induced periapical lesions in rats.

To elucidate the pathogenesis of periapical lesion-associated bone resorption, a disease model of Wistar rat molar was employed. After lesion induction, the mRNAs encoding for matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2) in the developing lesions were detected by in situ hybridization at day 5, 10, 15 and 20, respectively. At day 5, MMP-1, IL-6 and COX-2 mRNAs appeared predominantly in macrophages. During day 15 to day 20, increased expressions of these mediators were also found in osteoblasts but to a lesser extent compared with those in macrophages. MMP-1 mRNA was also detected in osteoclasts. In contrast, expression of the TIMP-1 gene was noted primarily in osteoblasts and was less pronounced compared with that of MMP-1. The mediator-expressing cells aggregated in the vicinity of bone resorption areas and their numbers increased with time. These data suggest that macrophages and osteoblasts are involved in the development of periapical lesions, and that they promote bone resorption by producing MMP-1, IL-6 and COX-2. In addition, administration of a specific COX-2 inhibitor, meloxicam, reduced the extent of periapical bone resorption by 43% and simultaneously diminished the numbers of cells synthesizing MMP-1 and IL-6 mRNAs. These results further elucidate the significance of COX-2 in disease progression of periapical lesions as it modulates indirectly the production of MMP-1 and IL-6.

Estrogen blocks parathyroid hormone-stimulated osteoclast-like cell formation in modulating differentiation of mouse marrow stromal cells in vitro.

BACKGROUND AND PURPOSE: During skeletal development and bone remodeling, bone marrow stromal cells give rise to osteoblasts and provide a critical microenvironment to support osteoclast formation. Estrogen is important for the maintenance of bone balance in adult animals by either increasing bone mass or inhibiting osteoclastic bone resorption. This study sought to determine the role that estrogen plays in coordinating osteogenic differentiation of bone marrow stromal cells and the ability of these cells to support osteoclast formation. METHODS: A conditionally immortalized mouse bone marrow stromal cell line, MS1, was used to examine the effects of estrogen on stromal cell differentiation and on stromal cell-supported osteoclast formation. RESULTS: On treatment of MS1 cells with 17 beta-estradiol (E2) (10(-12)-10(-8) M), alkaline phosphatase activity and bone nodule formation were increased in a dose-dependent manner, while the proliferation of MS1 cells was dose-dependently inhibited. 17 beta-E2 (10(-12)-10(-8) M) also caused a concentration-dependent inhibition of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cell (MNC) formation in parathyroid hormone (PTH)-stimulated MS1 and spleen cell cocultures. Furthermore, estrogen pretreatment of MS1 cells also decreased the number of TRAP-positive MNCs in cocultures. Culturing in PTH-treated conditioned media did not rescue the loss of activity supporting osteoclast-like cell formation in MS1 cells. CONCLUSION: These results indicate that 17 beta-E2-stimulated osteoblastic differentiation of mouse marrow stromal cells results in bone matrix mineralization and a decrease in activity of supporting PTH-induced osteoclast-like cell formation.

Estrogen inhibition of PTH-stimulated osteoclast formation and attachment in vitro: involvement of both PKA and PKC.

Estrogens modulate the catabolic effects of PTH on bone in vivo and in vitro. PTH-stimulated cAMP accumulation in osteoblasts is thought to be linked to increased osteoclastic activity, but the precise mechanism is still unknown. In cocultures of clonal marrow stromal cells (MS1) and normal mouse spleen cells, both 1,25-dihydroxyvitamin D3 and rat PTH (rPTH)-(1-34) can induce the formation of tartrate-resistant acid phosphatase- and calcitonin receptor-positive multinucleated osteoclast-like cells, which can attach to dentine slices and produce resorption pits. In this system, osteoclastogenesis stimulated by PTH, but not by 1,25-dihydroxyvitamin D3, was suppressed by 17beta-E2 (10(-10)-10(-8) M), whereas 17alpha-E2 (10(-8) M) had no effect. Exposure to 10(-8) M 17beta-E2, but not 17alpha-E2, also significantly decreased the PTH-induced attachment of osteoclast-like cells to dentine slices. 17beta-E2 inhibited osteoclast-like cell formation induced by 8-bromo-cAMP (10(-4) M), 12-O-tetradecanoylphorbol 13-acetate (10(-8) M), or rat PTH-(1-34) (10(-7) M) in combination with either rp-adenosine-3',5'-cyclic monophosphorothioate (10(-4) M) or 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (10(-5) M). 17beta-E2 suppressed the partial stimulation of tartrate-resistant acid phosphatase-positive multinucleated osteoclast-like cell formation induced by [Arg(2)]human (h) PTH-(1-34) (10(-7) M) or hPTH-(3-34) (10(-7) M), but not that caused by 10(-7) M hPTH-(53-84). We conclude that estrogens suppress PTH-stimulated osteoclast-like cell formation by blocking both the cAMP-dependent PKA pathway and the PLC-coupled calcium/PKC pathway. In addition to inhibiting formation of osteoclasts and promoting their apoptosis, estrogen may regulate bone resorption by blocking attachment of osteoclasts to bone.