The suppressive effect on CD4 T cell alloresponse against endothelial HLA-DR via PD-L1 induced by anti-A/B ligation.

While donor-specific human leukocyte antigen (HLA) antibodies are a frequent cause for chronic antibody-mediated rejection in organ transplantation, this is not the case for antibodies targeting blood group antigens, as ABO-incompatible (ABO-I) organ transplantation has been associated with a favorable graft outcome. Here, we explored the role of CD4 T cell-mediated alloresponses against endothelial HLA-D-related (DR) in the presence of anti-HLA class I or anti-A/B antibodies. CD4 T cells, notably CD45RA-memory CD4 T cells, undergo extensive proliferation in response to endothelial HLA-DR. The CD4 T cell proliferative response was enhanced in the presence of anti-HLA class I, but attenuated in the presence of anti-A/B antibodies. Microarray analysis and molecular profiling demonstrated that the expression of CD274 programmed cell death ligand 1 (PD-L1) increased in response to anti-A/B ligation-mediated extracellular signal-regulated kinase (ERK) inactivation in endothelial cells that were detected even in the presence of interferon-γ stimulation. Anti-PD-1 antibody enhanced CD4 T cell proliferation, and blocked the suppressive effect of the anti-A/B antibodies. Educated CD25+ CD127- regulatory T cells (edu.Tregs ) were more effective at preventing CD4 T cell alloresponses to endothelial cells compared with naive Treg ; anti-A/B antibodies were not involved in the Treg -mediated events. Finally, amplified expression of transcript encoding PD-L1 was observed in biopsy samples from ABO-I renal transplants when compared with those from ABO-identical/compatible transplants. Taken together, our findings identified a possible factor that might prevent graft rejection and thus contribute to a favorable outcome in ABO-I renal transplantation.

The effect of aprepitant and dexamethasone combination on paclitaxel-induced hypersensitivity reaction.

PURPOSE OF INVESTIGATION: Dexamethasone (DEX) is often administered to prevent paclitaxel (PTX)-induced hypersensitivity reactions (HSR). The DEX dose is reduced when administered in combination with aprepitant (APR). However, the influence of that dose reduction on PTX-induced HSR has not been thoroughly studied. The present authors aimed to investigate the effects of the combined administration of APR and DEX on PTX-induced HSR. MATERIALS AND METHODS: Fifty-one patients who received a three-week PTX regimen in combination with APR and DEX were retrospectively analysed. The authors compared the dose of DEX with the incidence of HSR and other toxicities. RESULTS: Patients were stratified into two groups depending on the DEX dose, > 20 mg (group D, 33 patients), and < 12 mg (group reD, 26 patients). The incidence of HSR in Groups D and reD were 51.5% (17/33) and 53.8% (14/26), respectively. The frequencies of other toxicities between the groups were comparable. CONCLUSION: The findings suggest that although a reduction in DEX dose is possible when APR is co-administered, this does not affect the PTX-induced HSR. However, adverse effect should be closely monitored.

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a ferret (Mustela putorius furo).

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a 4-month-old ferret are reported. Clinical signs including neurological symptoms appeared at 3 months of age and progressed rapidly. By magnetic resonance imaging, severe cerebral atrophy was recognized. Histopathologically, there was severe neuronal loss and diffuse astrogliosis with macrophage accumulations; lesions were found predominantly in the cerebral cortex. Intracytoplasmic pigments were observed in surviving neurons and macrophages throughout the brain. The pigments were intensely positive for periodic acid-Schiff, Luxol fast blue, and Sudan black B and exhibited a green autofluorescence. Electron microscopic examination revealed the accumulation of electron-dense granular material within lysosomes of neurons and macrophages. Immunohistochemically, a large number of saposin-positive granules accumulated in the neuronal cells, astrocytes, and macrophages of the lesions, but significant immunoreactivity for subunit c of mitochondrial adenosine triphosphate synthase was not observed. Based on these findings, the animal was diagnosed as affected by neuronal ceroid-lipofuscinosis.

Spontaneous oral tumours in 18 rabbits (2005-2015).

This retrospective study of a series of 18 cases aimed to describe the clinical and pathological findings of oral tumours in rabbits, as there have been few reports detailing spontaneous oral tumours in this species. A total of 13 different tumour types were diagnosed: squamous cell carcinoma (three), ameloblastoma (two), fibrosarcoma (two), osteosarcoma (two), cementoma (one), complex odontoma (one), giant cell epulis (one), sarcoma (one), chondrosarcoma (one), trichoepithelioma (one), papilloma (one), malignant melanoma (one) and basal cell carcinoma (one). Odontogenic tumours were relatively common in this study as compared to the oral tumours typically identified in dogs and cats. The most common clinical sign in this study was feeding abnormalities. Surgical excision and radiation therapy were found to be effective in rabbits.

Spontaneous intranasal tumours in rabbits: 7 cases (2007-2019).

OBJECTIVES: Neoplasms that arise in the nasal cavity are reported infrequently in rabbits. This case series aims to review and determine the clinical behaviour of neoplasms in the nasal cavity in rabbits. MATERIALS AND METHODS: A retrospective study was conducted on seven pet rabbits diagnosed with intranasal tumours to describe the clinical and histopathological findings and prognoses after surgery and/or radiotherapy. RESULTS: The most common clinical signs were nasal snoring when breathing, nasal discharge, and subsequent dyspnoea and anorexia. Six different histopathological types of tumours were diagnosed: intranasal adenocarcinoma, squamous cell carcinoma, osteosarcoma, carcinoid tumour, osteoma, and lymphoma. Skull radiography only revealed the abnormalities in three of seven cases but on CT, the intranasal masses were more clearly identified in all cases. All cases received tumour resection through rhinostomy and four cases received radiotherapy after surgery. In the six cases with a known outcome, the survival time after surgery was more than 13 months. CLINICAL SIGNIFICANCE: This case series provides an insight of the behavior of intranasal neoplasms in rabbits. Surgical treatment and radiotherapy could improve their clinical sings.

Histological and Immunohistochemical Features of Normal Histiocytes and Langerhans Cells, and Histiocytic Sarcomas in Four-Toed Hedgehogs (Atelerix albiventris).

Histiocytic sarcoma (HS) is a haematopoietic tumour of histiocyte origin that has been sporadically reported in four-toed hedgehogs (Atelerix albiventris). The present study aimed to investigate clinical, gross, histopathological and immunohistochemical features of HS in eight hedgehogs. Histological and immunohistochemical features of normal histiocytes and Langerhans cells (LCs) of hedgehogs were also investigated. HLA-DR-, Iba-1- and E-cadherin-positive LCs were observed in the epidermis, while Iba-1- and CD204-positive histiocytes were detected in the lymph nodes and spleen of normal hedgehogs. Localized HS (six cases) developed in the skin and spleen, while disseminated HS (two cases) occurred in the intestine. Tumour cells of disseminated HS were also distributed within the mesenteric lymph nodes, liver, kidney, spleen, lung and adrenal glands. Tumour cells of both localized and disseminated HS were composed of histiocytic cells, spindle to pleomorphic cells, multinucleated giant cells and erythrophagocytic cells. Most tumour cells were immunopositive for Iba-1, CD204 and lysozyme. A small number of tumour cells were positive for E-cadherin and CD208, and the tumour cells in one case were positive for HLA-DR. These results suggest that the tumour cells have variable features of histiocyte origin, including dendritic cells, LCs and macrophages. The behaviour of HS in the hedgehog was very aggressive, and 50% of cases died within 90 days of resection. The present study also highlighted the tendency for local tumour recurrence in localized cutaneous HS cases, suggesting a requirement for a long-term follow-up after excision.

Pharmacokinetics, Pharmacodynamic Efficacy Prediction Indexes and Monte Carlo Simulations of Enrofloxacin Hydrochloride Against Bacterial Strains That Induce Common Clinical Diseases in Broiler Chickens.

Pharmacokinetic parameters and efficacy prediction indexes (Cmax/MIC90 and AUC0-24/MIC90) of an enrofloxacin hydrochloride (ENR-HCl) veterinary product soluble in water were determined in healthy broiler chickens of both sexes after a single oral dose of ENR-HCl (equivalent to 10 mg ENR base/kg bw). Monte Carlo simulations targeting Cmax/MIC90 = 10 and AUC0-24/MIC90 =125 were also performed based on a set of MIC (minimum inhibitory concentration) values of bacterial strains that induce common clinical diseases in broiler chickens and that showed to be susceptible to ENR-HCl. Plasma concentrations of ENR and its main metabolite ciprofloxacin (CIP) were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma concentration-time curves were found to fit a non-compartmental open model. The ratio of the area under the plasma concentration-time curve (AUC) of CIP/ENR was 4.91%. Maximum plasma concentrations of 1.35 ± 0.15 µg/mL for ENR-HCl and 0.09 ± 0.01 µg/mL for CIP were reached at 4.00 ± 0.00 h and 3.44 ± 1.01 h, respectively. Areas under the plasma vs. time concentration curve in 24 h (AUC0-24) were 18.91 ± 1.91 h × µg/mL and 1.19 ± 0.12 h × µg/mL for ENR-HCl and CIP, respectively. Using a microbroth dilution method, the minimum inhibitory concentration (MIC90) values were determined for ENR-HCl for 10 bacterial strains (Mycoplasma gallisepticum, Mycoplasma synoviae, Avibacterium paragallinarum, Clostridium perfringens, Escherichia coli, Pseudomonas aeruginosa, Salmonella ser. Enteritidis, Salmonella ser. Gallinarum, Salmonella ser. Pullorum, and Salmonella ser. Typhimurium), which are the most common causes of infectious clinical diseases in broiler chickens. In summary, the PK/PD ratios and Monte Carlo simulation were carried out for ENR-HCl in poultry, which due to its solubility was administered in drinking water. The PK/PD efficacy prediction indexes and Monte Carlo simulations indicated that the ENR-HCl oral dose used in this study is useful for bacterial infections in treating C. perfringens (Gram-positive), E. coli and S. ser. Enteritidis (Gram-negative) and M. gallisepticum bacteria responsible for systemic infections in poultry, predicting a success rate of 100% when MIC ≤ 0.06 µg/mL for E. coli and S. ser. Enteritidis and MIC ≤ 0.1 µg/mL for M. gallisepticum. For C. perfringens, the success rate was 98.26% for MIC ≤ 0.12. However, clinical trials are needed to confirm this recommendation.

Elevated serum levels of soluble CX3CL1 in patients with microscopic polyangiitis.

OBJECTIVES: To test the hypothesis that CX3CL1 contributes to the pathogenesis of microscopic polyangiitis. METHODS: Serum samples from 18 patients with microscopic polyangiitis (MPA), who fulfilled the revised criteria of the American College of Rheumatology (ACR), were collected during both the newly diagnosed, untreated active disease states and inactive disease states. Also serum was from patients with large vessel vasculitis (LVV), including giant cell arteritis (n=4) and Takayasu arteritis (n=3), and from 52 healthy individuals. Soluble (s)CX3CL1 levels in serum were measured using an enzyme-linked immunosorbent assay. Disease activity was assessed using Birmingham vasculitis activity scores (BVAS). Expression of CX3CR1 was examined by flow cytometry. RESULTS: Serum sCX3CL1 levels were significantly higher in MPA patients than in either LVV group or healthy individuals. The elevated sCX3CL1 levels seen in MPA patients correlated positively with BVAS, as well as with CRP levels and ESR, and similarly increased expression of cell-surface CX3CR1 was seen on peripheral blood CD4 and CD8 T cells from patients with MPA. Notably, sCX3CL1 levels and CX3CR1 expression were diminished during clinical remission following treatment. CONCLUSION: Our findings suggest that CX3CL1 may be involved in the pathogenesis of MPA, and may serve as a useful serologic marker of disease activity in systemic vasculitis.

Safety studies of LP20 powder produced from heat-killed Lactobacillus plantarum L-137.

The safety of LP20 and its prototype, a powder, with potential use in food, produced from a mixture of dextrin and heat-killed Lactobacillus plantarum L-137, was assessed in an acute study in mice, and in an in vitro bacterial reverse mutation assay, an in vitro chromosome aberration assay, and an in vivo mouse micronucleus assay. LP20 prototype was not acutely toxic when administered to male and female Slc:ICR mice by single gavage at 2000mg/kg bw. Dosing was not associated with mortality, clinical signs, changes in bodyweight, or macroscopic abnormalities. The LD(50) in mice was greater than 2000mg/kg bw. There was no evidence of genotoxicity of LP20 in the Ames assay (0-5000microg/plate) or in the in vitro chromosome aberration assay with Chinese hamster lung fibroblasts (0-5000microg/mL). Administration of two consecutive daily doses of 500, 1000, or 2000mg/kg bw by gavage to male Crlj:CD-1 mice was not associated with an increased incidence of micronuclei and did not alter the ratio of polychromatic to normochromatic erythrocytes. These studies show that LP20 powder is not acutely toxic and is without genotoxic activity both in vitro and in vivo.

Broad-spectrum antibiotic prescriptions are discontinued unevenly throughout the week.

In order to investigate prescribing patterns of in-hospital broad-spectrum antibiotics (antimeticillin-resistant Staphylococcus aureus drugs, carbapenems and piperacillin/tazobactam), data on the distribution of antibiotic initiation and discontinuation throughout the week were analysed at Osaka University Hospital, Japan. No significant differences in the number of initiations were found between weekdays. However, broad-spectrum antibiotics were disproportionately discontinued on Tuesdays or on the second day after a holiday. This study suggests that broad-spectrum antibiotics tend to be continued over weekends or holidays and discontinued thereafter; this is likely to be due to behavioural factors beyond medical indications, and needs to be addressed in future antimicrobial stewardship initiatives.

Localised radiotherapy for a ferret with possible anal sac apocrine adenocarcinoma.

A seven-year-old, neutered male ferret was referred to our hospital with two perianal masses (2.4x3.0 and 2.4x3.5 cm, respectively) that had recurred after initial surgical excision. Complete resection of the masses was impossible as there was deep invasion along the rectum. On histopathology, the masses were diagnosed as apocrine adenocarcinoma possibly of anal gland origin based on tumour location. There was marked response to localised radiotherapy using an orthovoltage unit at 4 Gy, twice weekly. No visible mass was detectable after six doses of radiation. However, at that time, pleural effusion was diagnosed and radiotherapy was discontinued. Cytology of a sample of the pleural effusion suggested mesothelioma, and no obvious pulmonary metastasis of anal sac adenocarcinoma were identified on thoracic radiography. The ferret died at home on day 71 after the first admission.

Amyloid-producing Odontoameloblastoma in a Black-tailed Prairie Dog (Cynomys ludovicianus).

A 6-year-old female black-tailed prairie dog (Cynomys ludovicianus) was presented with a space-occupying lesion in the left submandibular region. On computed tomography, a low attenuating, poorly circumscribed mass infiltrated the left mandibular bone, with osteolytic change. Microscopically, the lesion was composed of odontogenic epithelium proliferating in nests and embedded in abundant dental papilla-like ectomesenchyme, including dentine and enamel. Multifocal amyloid deposition was observed. Immunohistochemically, the neoplastic epithelial cells were positive for cytokeratin (CK) AE1/AE3, CK14 and p63. Some epithelial cells were positive for amelogenin and some adjacent to the amyloid deposits co-expressed S100. The ectomesenchymal cells expressed vimentin and strong S100 immunoreactivity was observed in odontoblast-like cells. The amyloid was immunolabelled with amelogenin. The tumour was diagnosed as amyloid-producing odontoameloblastoma.

Association of single nucleotide polymorphisms in endothelin family genes with the progression of atherosclerosis in patients with essential hypertension.

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide and its activity is mediated by the receptors ET type A (EDNRA) and ET type B (EDNRB). Although ET-1 is thought to play an important role in the development of atherosclerosis, it remains unclear whether polymorphisms of ET-1 family genes, including the ET-1 gene (EDN1), EDNRA, EDNRB and the genes for endothelin converting enzymes 1 and 2 (ECE1 and ECE2), are associated with the progression of atherosclerosis. We investigated the relationship between 11 single nucleotide polymorphisms (SNPs) of ET-1 family genes (including three in EDN1, one in EDNRA, two in EDNRB, four in ECE1 and one in ECE2) and atherosclerotic changes assessed using pulse wave velocity (PWV) and carotid ultrasonography in 630 patients with essential hypertension (EHT). In male subjects, we found significant differences in brachial-ankle PWV (baPWV) in additive and recessive models in EDNRB-rs5351 after Bonferroni correction. Also in male subjects, there were significant differences in mean intima-media thickness (IMT) in additive and recessive models in EDNRA-rs5333 after Bonferroni correction. We found no significant correlation between any SNPs in the ET family genes and baPWV, IMT and Plaque score (PS) in female subjects. Furthermore, after multiple logistic regression analysis, only EDNRB-rs5351 indicated as an independent risk of atherosclerosis in male hypertensive subjects. Of the endothelin-related genes, EDNRB-rs5351 was the most susceptible SNP associated with atherosclerosis in male hypertensives, and the genetic background may be involved in the progression of atherosclerosis in EHT patients.

Histopathological and Immunohistochemical Study of Trichoblastoma in the Rabbit.

Trichoblastoma is the most common skin tumour in the rabbit. The aim of the present study was to characterize the histological and immunohistochemical features of trichoblastoma in 27 rabbits. Common sites of tumour occurrence were the neck (6/30, 20%), head (5/30, 16.7%), flank (4/30, 13.3%) and hindlimb (4/30, 13.3%). Histologically, rabbit trichoblastoma was categorized into ribbon (10/30, 33.3%), trabecular (8/30, 26.7%) and mixed types (12/30, 40%). The tumour tissue showed close interaction with the surrounding stroma where prominent fibroblastic aggregation, known as papillary mesenchymal bodies, was frequently observed (24/30; 80%). Peritumoural stroma of all cases was stained by Alcian blue (at pH 2.5 with weaker staining at pH 1.0). Immunohistochemically, the peripheral palisading basal-type cells of the tumour were positive for cytokeratin (CK) 14 while the inner cells were typically positive for CK17, differing from the immunohistochemical profile of the rabbit epidermis and hair follicle. The present study suggests that uncontrolled embryonic trichogenesis is involved in the development of trichoblastoma in the rabbit.

Acetylcholinesterase inhibitor acting on the brain improves detrusor overactivity caused by cerebral infarction in rats.

PURPOSE: The functional contribution of the cholinergic pathway in the frontal cortex to micturition was evaluated following cerebral ischemia. Furthermore, it was examined whether reactivation of this regulatory system using acetylcholinesterase inhibitor could improve detrusor overactivity. METHODS: Left middle cerebral artery occlusion (MCAO) was performed in female Sprague-Dawley rats. Choline acetyltransferase (ChAT) activities after MCAO were assayed to assess the damage to cholinergic neurons. ChAT activities in the bilateral cortex, hippocampus, and pons were calculated by measuring the conversion of 1-[14C] acetyl-coenzyme A to [14C] acetylcholine. Effects on cystometrography of i.v. or i.c.v. donepezil hydrochloride (DON), a centrally acting acetylcholinesterase inhibitor, were investigated in conscious sham-operated (SO) and cerebral infarcted (CI) rats. To investigate whether DON in the forebrain was affected, we decerebrated rats after CI or SO, and investigated the effects on cystometrography of i.v. DON. RESULTS: Bladder capacity was markedly decreased after MCAO, and remained below half of the pre-occlusion capacity. The greatest increase in bladder capacity was attained at 1.2 x 10(-2) nM/kg of DON given i.v., with a change of 52.8% (P < 0.05). In cases of i.c.v. DON, the greatest increase in bladder capacity was at the dose of 6 x 10(-2) pmol with the change of 95.8% (P < 0.01). The activity of ChAT was decreased in the left cortex and hippocampus 24 h after MCAO (P < 0.05). In decerebrated rats, low dose of DON did not change micturition parameters. CONCLUSIONS: These results suggest that by upregulation of the forebrain muscarinic inhibitory mechanism, acetylcholinesterase inhibitor improves detrusor overactivity by cerebral infarction.

Fluid shear stress induces lipocalin-type prostaglandin D(2) synthase expression in vascular endothelial cells.

Ligands for peroxisome proliferator-activated receptor gamma, such as the thiazolidinedione class of antidiabetic drugs and 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), modulate various processes in atherogenesis. In search of cells that generate prostaglandin D(2) (PGD(2)), the metabolic precursor of 15d-PGJ(2), we identified PGD(2) from culture medium of endothelial cells. To study how PGD(2) production is regulated in endothelial cells, we investigated the role of fluid shear stress in the metabolism of PGD(2). Endothelial cells expressed the mRNA for the lipocalin-type PGD(2) synthase (L-PGDS) both in vitro and in vivo. Loading laminar shear stress using a parallel-plate flow chamber markedly enhanced the gene expression of L-PGDS, with the maximal effect being obtained at 15 to 30 dyne/cm(2). The expression began to increase within 6 hours after loading shear stress and reached the maximal level at 18 to 24 hours. In contrast, shear stress did not alter the expression levels of PGI(2) synthase and thromboxane A(2) synthase. In parallel with the increase in the expression level of L-PGDS, endothelial cells released PGD(2) and 15d-PGJ(2) into culture medium. These results demonstrate that shear stress promotes PGD(2) production by stimulating L-PGDS expression and suggest the possibility that a peroxisome proliferator-activated receptor gamma ligand is produced in vascular wall in response to blood flow.

Evaluation and characterization of catabolite-responsive elements (cre) of Bacillus subtilis.

A global mechanism of catabolite repression of the genus Bacillus comprises negative regulation exerted through the binding of the CcpA protein to the catabolite-responsive elements (cres) of the target genes. We searched for cre sequences in the Bacillus subtilis genome using a query sequence, WTGNAANCGNWNNCW (N and W stand for any base and A or T, respectively), picking out 126 putative and known cre sequences. To examine their cre function, we integrated spac promoter (P spac )-cre-lacZ fusions into the amyE locus. Examination of catabolite repression of beta-galactosidase synthesis in the integrants led us to the following conclusions: (i) lower mismatching of cre sequences to the query sequence is required for their function; (ii) although cre sequences are partially palindromic, low mismatching in the same direction as that of transcription of the target genes is more critical for their function than that in the inverse direction; and (iii) yet, a more palindromic nature of cre sequences is desirable for a better function. Furthermore, the alignment of 22 cre s that function in vivo implicated a consensus sequence, WWTGNAARCGNWWWCAWW (R stands for G or A). Interestingly, in the case where cre sequences are located in the protein-coding regions of the target genes, their conserved bases are preferentially the third bases of codons where base degeneracy is allowed.

Combined transcriptome and proteome analysis as a powerful approach to study genes under glucose repression in Bacillus subtilis.

We used 2D protein gel electrophoresis and DNA microarray technologies to systematically analyze genes under glucose repression in B:acillus subtilis. In particular, we focused on genes expressed after the shift from glycolytic to gluconeogenic at the middle logarithmic phase of growth in a nutrient sporulation medium, which remained repressed by the addition of glucose. We also examined whether or not glucose repression of these genes was mediated by CcpA, the catabolite control protein of this bacterium. The wild-type and ccpA1 cells were grown with and without glucose, and their proteomes and transcriptomes were compared. 2D gel electrophoresis allowed us to identify 11 proteins, the synthesis of which was under glucose repression. Of these proteins, the synthesis of four (IolA, I, S and PckA) was under CcpA-independent control. Microarray analysis enabled us to detect 66 glucose-repressive genes, 22 of which (glmS, acoA, C, yisS, speD, gapB, pckA, yvdR, yxeF, iolA, B, C, D, E, F, G, H, I, J, R, S and yxbF ) were at least partially under CcpA-independent control. Furthermore, we found that CcpA and IolR, a repressor of the iol divergon, were involved in the glucose repression of the synthesis of inositol dehydrogenase encoded by iolG included in the above list. The CcpA-independent glucose repression of the iol genes appeared to be explained by inducer exclusion.

Apocrine adenocarcinoma of possible sweat gland origin in a male rabbit.

A five-year-old, male crossbreed rabbit was referred for acute caudal abdominal swelling. On physical examination, the rabbit was slightly depressed and showed an enlarged subcutaneous cyst in the caudal abdomen and an adjacent small, ulcerated solid mass. A drainage tube was placed in the cystic area, and surgical resection of the solid mass was performed. The histopathological diagnosis of the mass was apocrine adenocarcinoma. To the authors' knowledge, this report describes the first case of spontaneous apocrine adenocarcinoma of possible sweat gland origin in a male rabbit.

Down-regulation of TSC-22 (transforming growth factor beta-stimulated clone 22) markedly enhances the growth of a human salivary gland cancer cell line in vitro and in vivo.

We have recently isolated TSC-22 (transforming growth factor beta-stimulated clone 22) cDNA as a new anticancer drug (Vesnarinone)-inducible gene in a human salivary gland cancer cell line, TYS. We conducted the present study to examine whether up-regulation or down-regulation of TSC-22 can affect the growth of TYS cells in vitro and in vivo. We constructed an expression vector containing sense- or antisense-oriented human TSC-22 cDNA under the transcriptional control of the SR alpha promoter. We cotransfected TYS cells with the sense or antisense expression vector and pSV2neo and obtained more than 200 G418-resistant colonies in each sense or antisense transfectant. Approximately 80% of representative G418-resistant clones expressed the transcripts from transfected sense or antisense TSC-22 cDNA. To avoid the clonal heterogeneity of the cells, we mixed all of the G418-resistant colonies together in each sense or antisense transfectant and examined the expression of TSC-22 protein, in vitro growth, and the tumorigenicity in nude mice. The expression of TSC-22 protein was examined by solid-phase ELISA using a specific antibody against recombinant TSC-22 protein. The expression of TSC-22 protein was up-regulated in the sense transfectants and down-regulated in the antisense transfectants. Contrary to our expectation, up-regulation of TSC-22 protein did not affect both in vitro and in vivo growth of TYS cells. However, down-regulation of TSC-22 markedly enhanced the growth of TYS cells in vitro and in vivo. Furthermore, we examined the expression of TSC-22 mRNA in several human salivary gland tumors. The mRNA expression of TSC-22 in benign and malignant salivary gland tumors was significantly decreased when compared to that in tumor-free salivary glands (P < 0.05; one-way ANOVA), and in some salivary gland tumors, the expression of TSC-22 mRNA was not detectable by reverse transcription-PCR. These results suggest that down-regulation of TSC-22 may play a major role on salivary gland tumorigenesis.