Adenoid cystic carcinoma(ACC) is one of the most common malignant tumors of minor salivary glands and can also arise ina variety of sites in the head and neck including the major salivary glands, the esophagus, the lacrimal glands. ACC showsslow but relentless growth, so it shows long-term recurrence. The various reports about prognostic factors which influencethe recurrence pattern are introduced but the reports about prognostic factors are rare in Korean adenoid cystic carcinomapatients. We examined 40 ACC patients who finally diagnosed at Department of Oral Pathology, Seoul National UniversityDental Hospital. Clinicopathologic and immunohistochemical features were reviewed and factors correlated with recurrenceand survival were analyzed. The 5-year survival rate of T3,T4 stage was 31.2%, while that of the T1,T2 stage was 88.2%,and the difference 5-year survival and T stage was statistically significant. The rate of local recurrence was 20% and therate of distant metastasis was 27.5%. Mean recurrence time were 4.8 years and 5.2 years. There was no significant differencebetween age, sex, T stage, TNM stage, histologic type and recurrence. But the high T stage and the solid type recurredmore frequently. There was no significant difference between recurrence rate, 5-year survival rate and Ki-67, MVDexpression. But the higher expression of Ki-67, MVD show the higher recurrence rate and the lower 5-year survival rate.

System L amino acid transporter is a major route for providing living cells with neutral amino acids including several essentialamino acids. To elucidate the expression pattern of L-type amino acid transporter 1 (LAT1) in the bone formationprocess, the expressions of LAT1 and its subunit 4F2 heavy chain (4F2hc) were investigated in the healing process after theimplantation of bone graft materials in the calvarial osseous defected rats. Circular calvarial defects (1 cm in diameter) weremade midparietally. The rats were divided into 4 groups of 1 control group and 3 experimental groups. In the control group,the defect was only covered with soft tissue flap. In the experimental groups, they were filled with human particulate dentin(particulate dentin group), with plaster of Paris (plaster of Paris group) and with the mixture of human particulate dentinand plaster of Paris with ratio of 2 : 1 by weight (mixture group). The rats were sacrificed at the 1, 2, 4 and 8 weeks afteroperation and the RT-PCR analysis and immunohistochemical analysis were performed. In the RT-PCR analysis, the mRNAsof LAT1 and 4F2hc were strongly detected in all 4 groups. In the immunohistochemical analysis, at 1 week after operation,the LAT1 protein and its subunit 4F2hc protein were mainly expressed in the osteoblasts, osteocytes and interstitial tissuesof the around the defect and inner part of newly forming bone in all 4 groups. The expressions of LAT1 and 4F2hc proteinswere decreased at 2 and 4 weeks after operation. The LAT1 and 4F2hc proteins were scarcely expressed at 8 weeks after operationin all 4 groups.These results suggest that the LAT1 and its subunit 4F2hc highly expressed at the early stage of new bone formation andmay have an important role in providing cells with neutral amino acids including several essential amino acids at that stage.

It is well known that the imbalance between epithelial cell growth and inhibitor factors may cause human epithelialcancer. Over-expression of the epidermal growth factor receptor(EGFR) has been implicated in the development of oral squamouscell carcinoma. ZD1839 inhibits selectively the EGFR tyrosine kinase activity and is clinically used for cancerpatients. However the mechanisms by which it exerts its anti-tumor activity remains unclear. This study attempted to determinethe mechanisms underlying the effects of ZD1839 on the cellular level and to characterize the effects of ZD1839 withregard to human oral squamous cell carcinoma(OSCC) cell growth. The YD-10B and YD-38 cell lines established from OSCCin the department of Oral Pathology, Yonsei University College of Dentistry and ZD1839(Iressa) were used for this study. Theinhibition of cell proliferation induced by ZD1839 was reversible and the lowest dose of ZD1839 that produced statisticallysignificant growth inhibition in YD cell lines were 0.1 μM. The delay in cell cycle progression was induced by 0.1 μM ofZD1839 treatment after 24 hr. This reduction in cell proliferation and cell cycle delay were associated with up-regulation ofthe cyclin dependent kinase inhibitor(CDKI), P21CIP1/WAF1 and P27KIP1. Reduced expression of cyclin D1 was also observed aftertreatment with ZD 1839 to YD-38 cells but not to YD-38. The present results suggest that the antiproliferative effects ofZD1839, in vitro was associated with degradation of cyclin D1, which may be used as a possible indicator of a high cell sensitivityto ZD1839.

This experiment was performed to study the biocompatibility of xenograft materials (ABBM. coralline HA). Both autogenousbone grafts and allogenic banked bone were frequently and successfully used to promote regeneration of parts ofskeleton. The use of these types of grafts were limited by the cost of donor site operation for autogenous boneor by fear ofthe risk of infection of allogenic materials. Another type of graft is xenograft which include ABBM and coralline HA. For investigatingthe biocompatibility, generally many investigators used cancer cell lines or animal cell lines. But cancer cell linesand animal cell lines had functioned different metabolism from normal human cell. So the experiment used normal humanosteoblast for compare the biocompatibility of ABBM with coralline HA which were fixed in 24 well base contained culturemedium. After 1st, 3rd, 7th, 14th, 28th days, the culture medium were taken out and checked the concentrations ofcalcium(Ca), inorganic phosphate(IP) and alkaline phosphatase(ALP). In another method, histologic samples were investigatedafter 8weeks of xenograft materials implantated on rabbit's tibia, the bone was cut and made undecalcified ground samplesand checked with fluorecent microscope, polarizing microscope, reflection electron microscope and electron probemicroanalysis. The statistical results of concentrations (Ca, IP, ALP) of materials in the culture medium have decreasedbyday's, which meant that xenograft materials were effective for bone remodelling. The concentrations in the culture mediumof ABBM were lower than that of coralline HA, that meant that biocompatibility of ABBM were superior than that of corallineHA. Histologic samples showed that ABBM had better bone remodelling effect than coralline HA. ABBM showed good alizarinred marking lines, more deposition of Ca, IP, and dense color of bone around newly formed osteon and bonetrabeculae. it was concluded that ABBM was more biocompatible than corallineHA in vivo and in vitro test.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatoryeffects of LED irradiation such as promotion of wound healing have been well known, there are few reports aboutmolecular mechanisms associated with wound healing by LED irradiation. The purpose of the present study was to investigatethe expression pattern of various extracellular matrix(ECM) molecules in relation to wound healing after LED irradiationon primary human gingival fibroblasts(hGFs) in vitro. The source of light for irradiation was a continuous-wave LEDemitting at a wavelength of 635 nm, and manufactured that energy density was 5 mW/cm2 on sample surfaces. The hGFswere irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation),24 and 48 hour after irradiation. To investigate the molecular mechanisms associated with wound healing, we examinedthe mRNA expression of 6 types of collagens, 7 types of matrix metalloproteinases(MMPs) and 4 types of tissue inhibitionof metalloproteinases(TIMPs) after LED irradiation by RT-PCR. The mRNA expression of collagen 4, MMP-3, 9, and16, and TIMP-3 was influenced by LED irradiation. Generally, the collagen expression of the irradiation group was slightlyincreased, particularly collagen 4 was significantly increased at 0 hour. The expression of MMP-3 was increased at 0 and 24hours and MMP-16 was increased at 24 hours, respectively. The expression of MMP-9 was decreased at 0 hour and increasedat 24 and 48 hours. The mRNA expression of TIMP-3 was significantly decreased at 24 and 48 hours after irradiation. Theseresults suggest that the altered expression of ECM molecules after LED irradiation may contribute to the accelerated woundhealing.

β-catenin is a cytoplasmic protein that participates in the assembly of cell-cell adherens junctions by binding cadherinsto the cytoskeleton. In addition, it is a key component of the Wnt signaling pathway. Activation of this pathway triggers theaccumulation of β-catenin in the nucleus, where it activates the transcription of target genes. Abnarmal accumulation of β-catenin is characteristic of polyposis coli(APC) or Axin tumor suppressor proteins, which regulates β-catenin degradation,or activating mutations in β-catenin molecule itself. Here we show that overexpression of Sox4 down-regulates wild typeβ-catenin in HEK 293 cells. The inhibitory effect of Sox4 on wild type β-catenin is apparently mediated by the ubiquitin-proteasoem system and requires an active glycogen synthase kinase 3β(GSK3β). Mutations in the N-terminus of β-catenin(S33Y) which compromise its degradation by the proteasomes or inhibition of GSK3β activity rendered β-cateninresistant to down-regulation by Sox4. In light of recent evidence that Sox4 expression is activated in colon and other tumorswith β-catenin dysregulation, our findings suggest that Sox4 is part of a feedback inhibitory pathway for Wnt signalingin normal cells. Moreover, the mutations in APC, Axin or β-catenin in cancer cells appear to render β-catenin resistantto the effects of Sox4 inhibition.

Pro-inflammatory cytokines are important mediators of cutaneous cellular activities during many oral mucosal diseases.IHOK culture model transfected by E6/E7 genes provide further evidence for the role of HPV in tumorogenesis. It is interestingto investigate cytokine expression of immortalized human oral keratinocyte(IHOK). The purpose of this study were toanalysis cytokine mRNA expression levels of NHOK and IHOK by RT-PCR. IHOK showed about 5 fold increases of IL-6 comparedwith NHOK, while TNF-α was the lowest. It suggested that immortalization of NHOK with E6/E7 could result in elevatedexpression of IL-6, and IHOK be in the intermediate stage of oral carcinogenesis.

Epithelium maintains homeostasis by the signaling balance of growth stimulation and inhibition. Recently, loss of growthinhibitory effects of transforming growth factor-β(TGF-β) on epithelial cells is regarded as a possible mechanism ofcancer. Although the genomic mutation in type I and type Ⅱ receptors of TGF-β is considered one of important mechanismof these inactivation, there might be another inactivation mechanism because the mutation rate is relatively low and inhibitoryeffect is not associated with the mutation. The purpose of this study is evaluating controlling mechanism type Ⅱreceptor of TGF-β by detecting effects of TGF-β on growth inhibition and on expression of cell cycle regulatory proteinp21CIP1. Eight cancer cell lines derived from oral squamous cell carcinoma(OSCC) were examined. There was no growth inhibitioneffects by TGF-β except YD-8 cells. YD-8 cells which showed growth inhibition expresses p21CIP1 by TGF-βwhether refractory cell lines, YD-9, did not. All of the tumor cells express mRNA of type Ⅱ receptor by RT-PCR and northernblot analysis, especially on YD-8 and YD-17M. From these results, most of oral cancer cell lines might loose the growthinhibitory effects by TGF-β, and the growth inhibition on YD-8 cells was mediated by expression of p21CIP1.

Genomic imprinting is defined as parent-of-origin expression of specific genes and may play an important role in embryonaldevelopment of mammals. Loss of imprinting(LOI), biallelic expression of the imprinted genes, have been observed in avariety of human tumors and syndromes. H19, a paternally imprinted gene, is transcribed as an untranslated RNA thatserves as a riboregulator. LOI of H19 is observed in a variety of human malignancies. In this study, LOI of H19 was examinedin head and neck squamous cell carcinomas(HNSCCs). Four(28.6%) of the 14 HNSCCs and 8(28.6%) of the 28 inflammatoryoral lesions were informative for imprinting analysis of H19. H19 was imprinted in all inflammatory oral lesions,however, 2(50%) of the 4 informative HNSCCs manifested LOI. These data suggest that LOI of the H19 may play a role in theoncogenesis of HNSCC.

Since ancient Eygypt, various dental materials were used for lost teeth including gold. The key point of this materialswere nontoxic to human body. Since early of 1990's, dental implant was done for recovery of maxillofacial defects. Frommiddle of 1970's, osseointergation concept of implant was introduced and performed in dental field. Biocompatibility of titaniumshowed good effect for osseointergration but had some problems (Galvance current and toxic corrosion) with suprastructuressuch as gold crowns. This study was performed to make safe dental implants which have reduced Galvanic currentsand corrosion. 3 kind of dental casting gold alloys (different Gold contents, 1㎝×1㎝×0.1㎝ plates.) were used as experimentalgroup, while Titanium were used as control group. Normal human osteoblasts(NHOsts)were cultured during1-4weeks for histologic study. For analysing the calcium(Ca), Phosphorus(P) and alkaline phosphatase(ALP), NHosts werecultred during 2-23days. After experiments, histologic finding were observed by LSM and SEM. Ca, P, ALP concentration byautomatic biochemical analyzer were analyzed by ANOVA test and linear regression method. The results were as follows.Biocompatibility of dental casting gold alloys were similar to titianium alloys histolgically. Biochemical analysis of dentalcasting gold alloys had no significant difference to titianium alloy except AIGIS-Fine. We could conclude that biocompatibilityof dental casting gold alloys with high contents of gold were superior to that of low contents and alloys withhigh contents of gold had no significant difference from titanium on NHost culture. Gold dental implant might be better thantitanium implant due to similar biocompatibility and no galvanic currency.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatoryeffects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reportsabout molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examinethe molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of lightfor irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental sampleswere acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanismsassociated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclinD1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstratedthe percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiatedby LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation,cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cellsthrough transition from S to G2 phase.

Adenocarcinoma NOS of salivary glands is characterized by a high rate of local recurrences and metastasis. Long-termsurvival rate of Adenocarcinoma NOS lis not promising. Thus, different chemotherapeutical approaches had been proposedfor this neoplasm, including apoptosis induction by drugs. The current treatment of choice of adenocarcinoma NOS is controversible,and an effective treatment for them is not yet available. Chemotherpeutic agents that can be inhibit or reversethe tumor growth by targeting apoptotic pathways will be new candidates for cancer prevention and therapy. The purpose ofthis study were to study the effect of Brefeldin A(BFA) as apoptotic inducing agent in SGT cell line from human submandibularadenocarcinoma NOS and apply these results to make a plan of treatment and prognosis of salivary gland tumorsinvolving adenocarcinoma NOS. SGT cells were treated with a 300μM BFA solution in serum-free medium during 18hours. SGT cells were grown in DMEM with 10% fetal bovine serum served as controls. The growth curve and MTT assay forsuccinyl dehydrogenase activity were performed. For apoptotic analysis, fragmentation of genomic DNA was confirmed withgel electrophoresis. Transmission electron microscopy was assessed for the effect of BFA on SGT cells phenotype. Apoptoticcell recognition and counting were carried out with Annexin-V, caspase 3 and APo2.7 antibody through flow cytometry.Growth of SGT cell line was abrutply decreased after 1 day of BFA treatment. MTT assay for succinyl dehydrogenase activityof the cells showed about 55% after 300μM BFA treatment. Destruction of cellular organells, numerous vacuolation in thecytoplasm & nucleus, chromatin margination, & fragments of nucleus were seen with TEM after 300μM BFA treatment. DNAfragmentation of SGT cell line was induced by 300μM BFA treatment and confirmed by gel electrophoresis from genomicDNA extraction. Late apoptosis of the cells through flow cytometric analysis of Annexin-V staining as induced by 300μMBFA treatment. Early apoptosis of the cells through flow cytometric analysis of caspase 3 and Apo 2.7 staining was inducedby 300μM BFA treatment. It suggested that early and late apoptosis of SGT cell line would be induced by Brefeldin A treatmentin vitro study. This work evaluated the efficacy of BFA, a potent apoptosis inducer, on SGT cultured cell line. And BFAas chemotherapeutic agent will be used as the treatment choice for adenocarcinoam NOS, and be need to apply BFA to invivo study & clinical approach in future.