In order to unravel unidentified genes from human salivary gland, a cDNA library of human submandibular gland was constructed in the Uni‐ZAP XR vector by use of mRNA from human submandibular gland and ZAP‐cDNA® Gigapack® III Gold Cloning Kit. cDNA of salivary gland was subtracted with cDNA of immortalized human keratinocyte cell line, Rhim Human Epithelial Keratinocyte cell line. The phage cDNA library was converted into a pBluescript phagemid cDNA library, which was subsequently plated on LB plates with ampicillin, IPTG, and X‐gal, and white colonies were selected for sequencing. Among 200 clones analyzed, four clones containing C77‐091, C75‐014, C76‐022, and C76‐012 designated orphan genes that are intensely expressed in the interlobular ductal and serous acinar cells of human submandibular gland. Particularly C77‐091 gene expresses 46 amino acids peptide (pI=9.45). C75‐014 and C76‐022 genes were characterized as those expressing excretory basic proteins primarily consist of alanine, proline, and leucine residues, mimicking a basic proline‐rich protein (bPRP) showing helical structures and having multiple consensus sequences of phosphorylation sites. The strong expression of C76‐012 mRNA in the nuclei of salivary ductal and acinar cells suggests a role of C76‐012 gene as a DNA binding RNA/protein. These data suggest that the identification of four orphan genes from the human salivary glands may add further understanding of greater role of salivary proteins providing innate immunity by protecting and stabilizing the mucosal epithelium in the maintaining homeostasis of oral mucosa.

The transcription factor nuclear factor-kB (NF-kB) plays an important role in regulating cell growth, apoptosis, and metastatic functions. Constitutive activation of NF-KB has been observed in various cancers; however, molecular mechanisms resulting in such activation remain elusive. Numerous evidences showed that over expression of TGase 2 might be linked with constitutive activation of NF-KB. To understand the pathways responsible for constitutive activation of NF-kB is important for rational design of NF-kB inhibitors for cancer therapy. Human salivary gland adenocarcinoma has been most aggressive solid tumors. Current therapy does not significantly improve survival rates. Thus, to investigate new therapeutic modalities against this adenocarcinoma is necessary. The purpose of this study was to study a constitutive activation of NF-kB with the expression of TG2 in SGT cell line origianted from human salivary gland adenocarcinoma by TGase 2 activity, RT-PCR and immunoslot blotting method. SGT cell line showed the highest TGase 2 activity and NF-kB activation than any other cell line. All the cell lines showed increased NF-kB mRNA activation after A231027 treatment than that of control. In immunoslot blotting, SGT cell line showed NF-kB activation correlated with TGase 2 expression after A231027 and BSA. It suggested that there might be a direct correlation between TGase 2 expression and NF-kB activation in SGT cell line.

The role of Cl channels in regulatory volume decrease (RVD) in human salivary gland acinar cells was examined using a whole-cell patch clamp technique. Human tissues were obtained from healthy volunteers or from patients with oromaxillofacial tumors. During the measurements, K+-free solutions were employed to eliminate contamination of whole-cell conductance by K+ currents. When the cells were exposed to a 70% hypotonic solution, outward-rectifying currents, which were not observed in the resting state, were found to have significantly increased both in human labial and parotid gland acinar cells. The amplitudes of the currents were reduced in a low CI bath solution. Furthermore, the addition of 100μM 5-Nitro-2- (3-phenyl propylamino) benzoic acid (NPPB) or 100μM 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS), known to partially block Cl channels, significantly inhibited these currents. Its outward-rectifying current profile, shift in reversal potential in a low Cl bath solution and pharmacological properties suggest that this is a Cα2+ independent, volume activated Cl current. We conclude therefore that volume activated Cl channels play a putative role in RVD in human salivary gland acinar cells.

Epithelial-myoepithelial carcinoma (EMC) is uncommon, low-grade malignant epithelial neoplasm, and composed of ductal and large, clear-staining myoepithelial differentiated cells. we found four cases of EMC patients among those who visited the dental hospital of Seoul National University from 1998 to 2008. Immunohistochemical staining with epithelial and myoepithelial marker was done to verify the characteristic biphasic cell population. In our cases, the mean age of the patients was 61.5 years, which is consistent with previous reports. However, all the patients were female, and submandibular glands were the most affected sites. This is different from other reports that parotid gland was the most affected sites. There was recurrence and metastasis to lung in one out of four cases.

The purpose of this study was to evaluate the role of survivin in various salivary gland tumors. For this study, total 18 cases of salivary gland tumors; 6 cases of benign and 12 cases of malignant tumors were used as experimental group. In benign tumors; pleomorphic adenoma, oncocytoma, and in malignant tumors; adenoid cystic carcinoma, mucoepidermoid tumor, high grade and low grade malignancy each, adenocarcinoma, acinic cell adenocarcinoma cases were included. And for the control group, fresh submandibular glands were attained from gnathosurgical specimen. All the specimens, experimental, control group were fixed in 10% neutral formalin solutions, embedded in paraffin, sectioned 5um or more in thickness, stained with the hematoxylin and eosin, mounted and examined under the microscope. For the immunohistochemical studies, all the specimens were activated with survivin monoclonal, and secondary antibodies as usual manners, and taken photos on various pathologic fields analysed with the image analysis system, and evaluated the positive and negative stained area in the tumors on each images and statistically analyzed with SPSS 15.0 program. Attained result as follows. In control group, in part, acini cells show positive reaction on the nuclei, negative on the all most of the cytoplasm, more intense reaction on the cytoplasm and nuclei on the serous demilune (47.33%). In experimental group, all the specimens show survivin positive reaction on the cytoplasm with/or without positive reaction on nuclei according to the tumors, in benign tumors; pleomorphic adenoma (63.48%), oncocytoma (56.31%), each and in malignant tumors; adenoid cystic carcinoma (87.6%), acinic cell adenocarcinoma (56.35%). adenocarcinoma (67.47%), mucoepidermoid carcinoma, low grade (70.76%). high grade (55.23%). Survivin expression shows higher in tumors compare to that on the control group (p<0.05), but between the malignant tumors no significant are not noted(p>0.005). Survivin expression is strongly related to the malignancy of salivary gland tumors

The sodium bicarbonate cotransporter (NBC) protein is functionally expressed in salivary glands. In this experiment, we examined the role of NBC in HCO₃-formation in human parotid gland acinar cells. Intracellular pH (pHi) was measured in 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF)-loaded cells. Acetazolamide (0.1 mM) and 4,4'-diisothio cyanatostilbene-2,2'-disulphonic acid (DIDS, 0.5 mM) were used as specific inhibitors of carbonic anhydrase and NBC, respectively. The degree of inhibition was assessed by measuring the pHi recovery rate (△pHi/min) after cell acidification using an ammonium prepulse technique. In control experiments, △pHi/min was 1.40±0.06. Treatment of cells with 0.5 mM DIDS or 0.1 mM acetazolamide significantly reduced △pHi/min to 1.14±0.14 and 0.74±0.15, respectively. Simultaneous application of DIDS and acetazolamide further reduced △pHi/min to 0.47±0.10. Therefore, DIDS and acetazolamide reduced △pHi/min by 19% and 47%, respectively, while simultaneous application of both DIDS and acetazolamide caused a reduction in △pHi/min of 67%. These results suggest that in addition to carbonic anhydrase, NBC also partially contributes to HCO₃- formation in human parotid gland acinar cells.

Inositol 1,4,5-trisphosphate (IP₃) plays an important role in the release of Cα²+ from intracellular stores into the cytoplasm in a variety of cell types. IP₃ translocation dynamics have been studied in response to many types of cell signals. However, the dynamics of cytosolic IP₃ in salivary acinar cells are unclear. A green fluorescent protein (GFP)-tagged pleckstrin homology domain (PHD) was constructed and introduced into a phospholipase C δ1 (PLC δ1) transgenic mouse, and then the salivary acinar cells were isolated. GFP-PHD was heterogeneously localized at the plasma membrane and intracellular organelles in submandibular gland and parotid gland cells. Application of trypsin, a G protein-coupled receptor activator, to the two types of cells caused an increase in GFP fluorescence in the cell cytoplasm. The observed time course of trypsin-evoked IP₃movement in acinar cells was independent of cell polarity, and the fluorescent label showed an immediate increase throughout the cells. These results suggest that GFP-PHD in many tissues of transgenic mice, including non-cultured primary cells, can be used as a model for examination of IP₃intracellular dynamics.

The purpose of this study was to evaJ uate the role of integrin a 3 and integrin ß 1 expression in the saivary gJand tumors. For this study, 11 specimens diagnosed as pleomorpic adenoma, adenoid cystic carcinoma, adenocarcinoma, mucoe pidermoid carcimoma referred to the Dept. of Oral Pathology‘ School of Dentistry, Kyung Hee University, 2 specimens 01' normaJ submandibular gland tissues were used as experimental, control groups respectively, All the tissues experimental and control group wel'e fixed in neutral formaJin solution and embedded in paraffin, seriaJ tissue section were made 511m in thickness and processed in the standard way for immunohistochemical method, using primary antibody against integrin a 3, and integrin ß 1 each was diluted at 1;100 followed by the poly- horse radish peroxidase detection system with DAB as chormogen counterstained with Mayel ’s hematoxylin stain method and mounted And examined unde1' the biologic micro scope with the criteria of no epitheliaJ stain, weak 01' focal epithelial stain, moderate 01' focal intensive epithelial s tain. intense generalized epithelial staining for the epithelial, and connective tissue components in no1'mal salivary gland, and saivary g land tumors : pleomorphic adenoma‘ adenoid cystic carcinoma, adenoca1'cinoma, mucoepide1'moid ca1'cinoma on each On the integ1'in α 3 reaction, negative to minimal posit ive reaction was noted on the salivary gland twnors and nor mal subma ndibular gland tlssues On the integrin ß 1 reactions, intense 1'eaction is shown on the serous demilune and ductal cells , and partly on the serous acini in submandibula1' gland tlssues On the integrin ß 1 reactions to pleomorphic adenoma tissues, moderate reactions were noted on the ductal celJs and myoepithelial cells. On the integrin ß 1 reactions to adenoid cystic ca rci noma‘ adenocarcinoma, mucoepidermoid ca1'cinoma tissues, intense reactions were shown on the neo plastic cell s , This resuJt suggest that integrin a 3. integrin ß 1 could be a 1'ole inducing the tumorigenesis.

Epithelial myoepithelial carcinoma(EMC) is an uncommon malignant sali va ry gland neoplasm, compri sing about 1% 。f salivar y gland neoplasms, They are histologically composed 01' biphasic cell s such as myoepithelial cells and ductal cells EMC occurs predominantly in the major salivary glands, par t icularly in the par otid gland, They have been reported to occur onJy 10-15% in t he intraoral minor salivary glands, The authors experi enced 4 cases of EMC in Department of Oral Pathology in Seoul National University Dental Hospital from 1995 to 2007‘ and reported them with revi ew of li terature, They occurred at the age [rom 34 to 75 years with average age of 54, Three cases occurred in f'emale and 1 in male, showing predominant occurrence in female, Al I of them occurred in the f100r of mouth Three patients presented localized swollen mass at the time of admission, One patient manifested pain with surface n ecrotic ulcer, and others did not complain any symptoms, The duration of symptoms before diagnosis has ranged f rom three mont hs to 2 years in our cases Microscopically, they growed in double layered ductal structure composed 。f' ductal cells of the inner luminal layer which showed positive immunohistochemical reaction to cytokeratin and rnyoepithelial cells 01' the outer peripheral layer identifi ed by the positive reactivity to S-100 and srnooth muscle ac tin antibody, They did not show perinem al invasion‘ but invasíve growth into adjacent tissue, AII of them did not show in vasion into t he underlying bOl1e While 3 pat ients were treated with total excision of tω110 1' mass wi thout n。 evidence of recurrence a ncl metastasis, a 75 year old patient gave up receiving t reatment at the t irne of diagnos is, and then died 01' the cancer 5 years after init ial diagnosis, It seems that EMC of the intraoral minor salivary gland is a tumor 01' low grade malignancy with low potent ial of recurrence and metastasis

The effects of adenosine triphosphate(ATP) on salivary glands have been recognized since 1982. The presence of purinergic recepetors(P2Rs) that mediate the effects of ATP in various tissues, including parotid and submandibular salivary gland, has been supported by the cloning of receptor cDNAs and the expression of the receptor proteins. P2Rs have many subtypes, and the activation of these receptor subtypes increase intracellular Cα²+, a key ion in the regulation of the secretion in the salivary gland. The apical pores of taste buds in circumvallate and foliate papillae are surrounded by the saliva from von Ebner salivary gland(vEG). Thus, it is important how the secretion of vEG is controlled. This study was designed to elucidate the roles of P2Rs on salivary secretion of vEG. Male Sprague-Dawley rats (about 200 g) were used for this experiment. vEG-rich tissues were obtained from dissecting 500-1,000μm thick posterior tongue slices under stereomicroscope view. P2Rs mRNA in vEG acinar cells were identified with RT-PCR. To observe the change in intracellular Cα²+ activity, we employed Cα²+-ion specific fluorescence analysis with fura-2. Single acinar cells and cell clusters were isolated by a sequential trypsin/collagenase treatment and were loaded with 10 μM fura -2 AM for 60 minutes at room temperature. Several agonists and antagonists were used to test a receptor specificity. RT-PCR revealed that the mRNAs of P2X₄, P2Y₁, P2Y₂ and P2Y₃ are expressed in vEG acinar cells. The intracellular calcium activity was increased in response to 10 μM ATP, a P2Rs agonist, and 2-MeSATP, a P2Y₄ and P2Y₂R agonist. However, 300 μM αβ-MeATP, a P2X₁ and P2X₃R agonist, did not elicit the response. The responses elicited by 10 μM ATP and UTP, a P2Y₂R agonists, were maintained when extracellular calcium was removed. 10 μM suramin, a P2XR antagonist, and reactive blue 2, a P2YR antagonist, partially blocked ATP-induced response. However, when extracellular calciums were removed, suramin did not abolish the responses elicited by ATP. These results suggest that P2Rs play an important role in salivary secretion of vEG acinar cells and the effects of ATP on vEG salivary secretion may be mediated by P2X₄, P2Y₁, P2Y₂, and/or P2Y₃.

Adenocarcinoma NOS of salivary glands is characterized by a high rate of local recurrences and metastasis. Long-term survival rate of Adenocarcinoma NOS lis not promising. Thus, different chemotherapeutical approaches had been proposed for 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 reverse the tumor growth by targeting apoptotic pathways will be new candidates for cancer prevention and therapy. The purpose of this study were to study the effect of Brefeldin A(BFA) as apoptotic inducing agent in SGT cell line from human submandibular adenocarcinoma NOS and apply these results to make a plan of treatment and prognosis of salivary gland tumors involving adenocarcinoma NOS. SGT cells were treated with a 300μM BFA solution in serum-free medium during 18 hours. SGT cells were grown in DMEM with 10% fetal bovine serum served as controls. The growth curve and MTT assay for succinyl dehydrogenase activity were performed. For apoptotic analysis, fragmentation of genomic DNA was confirmed with gel electrophoresis. Transmission electron microscopy was assessed for the effect of BFA on SGT cells phenotype. Apoptotic cell 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 activity of the cells showed about 55% after 300μM BFA treatment. Destruction of cellular organells, numerous vacuolation in the cytoplasm & nucleus, chromatin margination, & fragments of nucleus were seen with TEM after 300μM BFA treatment. DNA fragmentation of SGT cell line was induced by 300μM BFA treatment and confirmed by gel electrophoresis from genomic DNA extraction. Late apoptosis of the cells through flow cytometric analysis of Annexin-V staining as induced by 300μM BFA treatment. Early apoptosis of the cells through flow cytometric analysis of caspase 3 and Apo 2.7 staining was induced by 300μM BFA treatment. It suggested that early and late apoptosis of SGT cell line would be induced by Brefeldin A treatment in vitro study. This work evaluated the efficacy of BFA, a potent apoptosis inducer, on SGT cultured cell line. And BFA as chemotherapeutic agent will be used as the treatment choice for adenocarcinoam NOS, and be need to apply BFA to in vivo study & clinical approach in future.

1'he purpose 0 1' this study was to evaluate the ro1e of c• fos and c-jun expression in the salivary gland tumol‘ s , For this study‘ 11 s ubj ects of sali vary gland tumors ; 4 su이 ects of p1eomorphic adenomas, 3 s ubj ects of adenoid cystic car cinomas , 2 s ubjects of adenocar cinomas, 2 subjects of mucoepidermoid tumors, referred to the Dept, of Ora l Path College of Dentis t l'Y, Kyung Hee Univer sity, were used as experimental group, and 2 subj ect s of normal minor salivary gla nds without a ny infla mmator y changes, were used as control group respectively, All the tissues experimenta l and control group were fixed in 10% neutral formalin solution and embedded in paraffin , serial ti ssue section were made 5 I1I1l in thickness a nd processed in the s t andard way for immunohistochemical method, using primary and secondar y a ntibodi es, for c-fos, c-jun, foll owed by the Streptavidin-Horse Radish Peroxidase, all BioGenex U,S,A, made, appli cat ion counter s t ained with Mayer's hematoxylin stain method, mounted And examined under the biologic mi croscope, with the criteria : -(no epitheli al s ta in), +(weak or focal epithelial stain), ++(moder a te or focal intensive epithelial sta in)‘ +++(intense generali zed epithelial staining) for the epithelial, and stromal ti ssues on each Attained results as follows : 1 1n nonna l minor saliva ry gla nds , it is noted that negative responses on the acini minimal res ponses in nucl ei and cytoplams of se rous demilun e, myoepi theli al cells, and intensive r esponses in nuclei and cytoplam of ducta l cells to c-fos and c-jun, 2 1n the res ponses to c-fos, positive responses in nuclei and cytoplasms of the lining cells o[ the ad e nαd tissues, e pidermoid, and mucous cells in mucoepidermoid tumors are noted and in other tumor tissuses, negative nuclei wi th pos itive cyto plasms are revealed 3 1n the responses to c- jun, it is noted that positive r es ponse in nuclei and cytolasm i n the cells of adenoid tissues in pl eomorphic adenoma, epidermoid cell s, mucous cell in mucoe pi dermoid tumor but in other tumor s, only positive responses in cytoplasm are noted, Intensive r esponses on c-fos‘ c-jun were noted on the high a typical cells 1'his results suggest that c-fos and c-jun may be affected t o the reactivation on growt h and development of the salivary gland tumors

Eugenol (4-allyl-2-methoxyphenol) is a phenol derivative and generally used in dental treatment. A few investigator reported that eugen이-induced C)πoto잉city by apopto디c pathway, but it is not yet well understood In the present study, to investigate the eugenol-induced cytoto잉city by apoptosis, we have examined the apoptotic molecules and pathway in primary human gingival fibroblast (HGF) and human salivary gland cells (HSG). To identify apoptotic cell death, 3-(4,5-dimethylthiazol-2-yl)-2 ,5-diphenyl tetrazolium bromide (MTT) reduction assay with or without N-acetylcysteine (NAC), and the morphological study by propidium iodide (pI) staining were screened. And to investigate the apoptotic pathway, reverse transcriptase-polymerase chain reaction (RT-PCR) for apoptotic molecules and caspase aαivity assay were performed. Both M1T reduction assay and an addition of NAC showed that eugenol act as a pro-oxidant led to cell death. With the morphological study, both cells showed apoptotic change by nuclear fragmentation and/or chromatin condensations. With the apoptotic machinery study, the Bax and Bcl-2 mRNA expression were not detected in HGF. But, for HSG, the increased expression of Bax with decreased of Bcl-2 was observed. And the expression of Apaf-l was not detected or nα significantly increased in HGF and HSG, respectively. With measure of caspase activity, there was no change of caspase activities in HGF. But, for HSG, there was decrease of caspase 9 activity and increased caspase 3 activity. We suggest eugenol-treated HGF underwent apoptosis independent of Bcl family and caspase. However, for eugenol-πeated HSG, apoptosis occurred via Bcl famiIy and caspase pathway.

We used three-dimensional Matrigel culture system to examine the morphognesis of normal and malignant salivary glands cell in vitro including acinar cells(AC), myoepithelial cell(MC), salivary gland adenocarcinoma cells(SGT), mucoepidermoid carcinoma cells(MEC), and immortalized human salivary gland cells(HSG). For this purpose, normal and salivary gland tumor cells cultured in 3-D Matrigel, and characterized histologically and immunohistochemically, compared with same cells grown on monolayer culture and patient tissue from biopsy. 1. In three-dimensional Matrigel culture, HSG cells form acinar structure, SGT cells shows duct like structure, and other AC, MC and MEC cells dont' form any structure , and their morphology was different from that of monolayer cells. 2. Matrigel involved cell proliferation at a similar pattern to cells on plastic monolayer cell cultures, and monolayer cell revealed higher cell viability than that of Matrigel cultured cells. 3. All salivary glands cells on Matrigel or monolayer showed strong PCNA expression, and there is no expression difference in these cells. But some cells including myoepithelial cells in normal and salivary gland tumor tissue showing PCNA lavelling, so there is PCNA expression difference among normal and tumor tissue cells. 4. Actin expression was noted in AC cells on Matrigel, were rare expressed in the other cells except in MEC cells, and was present in myoepithelial cell and ductal cells of normal gland tissue. There is actin expression difference between tissue and cultured cells . 5. S-100 immunoreaction was moderateively positive in MC cells of monolayer culture, myoepithelial cells of normal tissue and pleomorphic adenoma, all cancer cells of mucoepidermoid carcinoma tissue, but significantly decreased in all salivary cells on Matrigel. 6. TGase 2 expression was prominent in MC cells of monolayer and Matrigel cultured, in myoepithelial cells of normal gland and pleomorphic adenoma, epidermoid cells of mucoepidermopid carcioma, and strong reaction in MEC and AC cells of monolayer and Matrigel cultured. 7. Expression of CK in monolayer culture showed strong reaction to CK6 in all sailvary gland cells, and mild reaction to CK10 and CK16 for all salivary cells, CK16 and CK19 expression in monolayer culture was similar to that of Matrigel culture. 8. CK6 and CK10 expression was strongest in AC and MC cells on Matrigel, and CK 4 was negative reaction in AC, SGT, MEC cells, strong reaction in MC cells but mild in SGT cells on Matrigel. Expression of CK was rare in HSG cells compared with other salivary gland cells, CK16 was prominent in SGT cells, CK10 and CK16 showed strongest expression in MEC cells of Matrigel. 9. Monolayer culture of HSG cell shwoing strong reaction to CK6, moderate to CK19 and mild to the others CK, but 3D cultured HSG cells reveal mild expression to CK16, and rare to others CK, intercallated duct in normal gland tissue showing strong to CK19, and mild to the others Ck, so there are CK expression difference in tissue, monolayer and 3-D cultured cells. 10. Monolayer culture of MEC cells represent strong reaction to CK6, mild to other CK, 3-D cells showing increased CK expression including CK6, epidermoid cells and intermediate cells in mucoepidermoid carcinoma tissue reveal positive to CK6 and CK16, mucous cell positive to CK10 and CK19, so Matrigel showed similar CK pattern compared to mucoepidermoid carcinoma tissue rather than monolThese data indicate that the interaction of salivary gland cells with basement membrane is an important factor in salivary gland development and cytodifferentiation, so this model system will be useful to study acinar or ductal differentiation in vitro.ayer cultred.

Established SGT cell line from human submandibular gland adenocarcinoma was used to study the TGase expression on a cellular level in vitro. Transglutaminase 2(TGase 2) is assoacitated with apoptosis, GTP binding protein, and cell marix interaction. The role of TGase 2 in salivary gland tumors is not clear yet. The pupose of this study were to examine the TGase expression of SGT cell line compared to other tumor cell lines, and to apply these results to the pathogenesis of salivary gland tumor. TGase enzyme assay of SGT, SCC-15, HN 4 and HeLa tumor cell line was 3 times repeated, and calculated. Immunoslot blot for semiquantitative protein analysis was done. The obtained results were as follows. 1. SGT cell line showed the highest TGase 2 enzyme activity(about 6-16 folds) irrespective of pre or postconfluency. 2. HN 4 cell line showed the highest TGase 1 enzyme activity(about 2-3 folds) irrespective of pre or postconfluency. 3. Under postconfluency TGase 1 induction was not induced, but slightly increased in all tumor cell lines. 4. TGase enzyme activity in all tumor cell lines was accompanied with TGase protein formation. From the aboving results, the higher TGase 2 expression of SGT cell line suggested that they would come from submandibular ductal cells and have a important role in the pathogensis of salivary gland tumors.