Dynamic changes in cell-surface expression of mannose in the oral epithelium during the development of graft-versus-host disease of the oral mucosa in rats.

BACKGROUND: The role of cell-surface glycoconjugates in oral mucosal graft-versus-host disease (GVHD) is still unclear, even though molecular changes in the oral epithelium are essential for the pathogenesis of these lesions. In this study, we investigated changes in the binding of mannose (Man)-specific Lens culinaris lectin (LCA) in the oral mucosa of rats with GVHD. METHODS: Lewis rat spleen cells were injected into (Lewis x Brown Norway) F1 rats to induce systemic GVHD, including oral mucosal lesions. Tongue and spleen samples were evaluated using lectin histochemistry, immunohistochemistry, Western blotting, transwell migration assays and Stamper-Woodruff binding assays. RESULTS: Binding of Man-specific LCA expanded to the epithelial layers of the tongue in GVHD-rats. An expansion of LCA binding was related to the increased expression of mannosyltransferase in the oral mucosa. CD8+ cells, effector cells of oral mucosal GVHD, expressed mannose-binding protein (MBP) and migrated to the medium containing Man in the transwell migration assay. Adherence of CD8+ cells to the oral epithelium could be inhibited by pretreating CD8+ cells with MBP antibody and/or by pretreating sections with Man-specific LCA. CONCLUSIONS: Increased expression of Man on keratinocytes leads to the migration and/or adhesion of CD8+ cells in the surface epithelium, which is mediated in part by the MBP/Man-binding pathway during the development of oral mucosal GVHD.

In vitro and in vivo expression of aldehyde dehydrogenase 1 in oral squamous cell carcinoma.

Aldehyde dehydrogenase isoform 1 (ALDH1) is a useful marker of cancer-initiating cells (CICs) in various organs. In this study, we investigated whether alterations in ALDH1 immunostaining and enzymatic activity in tumor cell populations predicted clinicopathological factors of prognostic importance for cancer progression and contributed to the characteristics of CICs in cisplatin-treated oral squamous cell cancer (OSCC) cells. We evaluated the association between the proportion of ALDH1-positive tumor cells and the clinicopathological features in 90 patients with OSCC. We also examined ALDH1 enzymatic activity, ABCG2 expression, invasive capacity and the ability to self-renew in OSCC cells treated with or without cisplatin. The clinicopathological results showed that elevated ALDH1 expression correlated with local recurrence. In in vitro experiments, the percentage of cells exhibiting ALDH1 enzymatic activity significantly increased among cisplatin-surviving cells (CiSCs) according to flow cytometry. Furthermore, CiSCs demonstrated upregulated expression of ABCG2, their invasive capacity increased, and their ability to generate cancer spheres was enhanced. An increased population of cells exhibiting ALDH1 immunostaining is a predictive marker of local recurrence. ALDH1 expression and activity contributes to the characteristics of CICs in OSCC.

Lupus-like oral mucosal lesions in mercury-induced autoimmune response in Brown Norway rats.

BACKGROUND: Administration of mercury at nontoxic doses induces systemic autoimmune disease in Brown Norway (BN) rats. The pathogenesis of lupus-like oral mucosal lesion by mercury-induced autoimmunity is still unclear, even though the oral mucosa is observed to be commonly affected in mercury-treated BN rats. In this study, we investigated the immunopathology of lupus-like oral mucosal lesions in a model of mercury-induced systemic autoimmunity. METHODS: Brown Norway male rats were injected subcutaneously with either phosphate-buffered saline (control) or mercury at a dose of 1.0 mg per kilogram of body weight on days 0, 3, 5, and 7. Blood, kidney, and tongue samples were taken at various timepoints for evaluation by immunohistochemistry, RT-PCR, and lupus band test (LBT). RESULTS: Oral mucosal lesions were classified according to three consecutive temporal phases on the basis of infiltration of immunocompetent cells as follows: (phase I) infiltration of MHC class II+ dendritic cells (DC) and macrophages; (phase II) addition of ED1+ macrophage infiltrates; and (phase III) focal infiltration of pan T cells following increased infiltration of DC and macrophages. Dense infiltration of DC and macrophages was observed in the basement membrane (BM) zone of the oral epithelium. Tissue expression of IL-4 mRNA was detected in early lesions (phase I), suggesting that locally produced IL-4 may be responsible for Th2-mediated immune response. A linear and continuous smooth pattern of fluorescence was observed in the oral epithelial BM in addition to renal glomeruli, indicating immune complex deposits. CONCLUSIONS: Local autoimmune responses are involved in the pathogenesis of mercury-induced lupus-like lesions of the oral mucosa.

Bladder recurrence of upper urinary tract cancer after laparoscopic surgery.

PURPOSE: We reviewed our cases to determine whether laparoscopic nephroureterectomy is a risk factor for the bladder recurrence. MATERIALS AND METHODS: From 1996 to 2003, 65 nephroureterectomies were performed: 47 by open and 18 by laparoscopic surgery. In 43 (28 by open, 15 by laparoscopic surgery), bladder cancer was not observed at the time of the operation. Two laparoscopic operations were converted to open surgery because of technical problems. The other 13 with laparoscopic and 28 with open surgery were enrolled into this study. RESULTS: Significantly higher recurrence rate was observed in laparoscopic cases (69.2%) than that in open cases (35.7%, P = 0.0484) by log rank test. However, the operation time required in laparoscopic surgery (371.5 +/- 90.8 min) was significantly longer than that in the open surgery (229.9 +/- 46.6 min, P < 0.0001). In multivariate analysis (Cox proportional hazards model), only the longer operation time (>250 min) was a significant variable (P = 0.0305), and laparoscopic surgery in itself was not a significant risk factor (P = 0.5011). CONCLUSIONS: Although frequent bladder recurrence was observed in laparoscopic cases, the most important risk factor was the longer operation time. Technical improvements including shortening of operation time and earlier ureteral ligation may decrease the bladder recurrence.