Reticular crypt epithelium and intra-epithelial lymphoid cells in the hyperplastic human palatine tonsil: An immunohistochemical analysis

Extensive immunohistochemical analyses of the hyperplastic human palatine tonsil disclosed variegated B cell phenotypes on the lymphoid cells among the crypt epithelium. The reticular epithelial network was evident by cytokeratin immunostaining. The reticular epithelium near the crypt Iumen was positive for Iysozyme. Secretory component was negative, while HLA-DR was frequently expressed. Intramucosal small Iymphocytes, densely distributed in the Iuminal side, consisted mainly of B cells expressing CD19, CD20, CD21, CD22, CD45R, CD74, DBB42, HLA-DR, HLA-DQ, bcl-2 protein and surface lgM. Some B cells revealed mantle zone phenotypes (surface IgD+, CD5+, CD24+, DBA44+, CD10^--, DNA7^--). Cells of germinocyte phenotype (CD10+, DNA7+) were sparsely seen. A good number of intramucosal lymphoid cells were further labeled for CD11b, a phenotype of so-called B-1 cells. Plasma cells were clustered within the basal half. IgG was their major immunoglobulin class, followed by IgA, IgM and lgD classes. A smaller number of T cells (CD2+, CD3+, CD5+, CD45RO+, TCR αβ+) were identified among the epithelium. CD4+ cells predominated over CD8+ cells. TCR γΔ + cells were rare. Macrophages (CD68+), dendritic histio-cytes (S-100 protein+, CD1+), and natural killer cells (CD16+ or CD57+) were also dispersed. Another unique feature of this lymphoepithelial complex was the existence of HLA-DR intramucosal microvasculature, where lymphocyte recirculation was suggested. Proliferating cell nuclear antigen was detected commonly in the epithelial cells but rarely in the lymphoid cells. Possible lymphoepithelial interactions and morphologic similarities to the thymic medulla are discussed.     

Ubiquitinated cytokeratin inclusions in lichen amyloidosus: An immunohistochemical analysis

Eosinophilic hyaline inclusions were consistently seen in the perinuclear cytoplasm of suprabasal keratinocytes in lichen amyiddosus. The inclusions, negative with amylold staining, were immunoreective for ubiquitin and cytokeratin, and uitrastructuraliy showed aggregations of fine filaments of two size (central thin and peripheral thick). The thin filaments were the main component in the upper epidermal layer. Four monoclonal antibodies (AE1, AE3, KL1 and CAM5.2) and om antiserum (WSS) were used for characterizing cytokeratin expression. The AE1 antibody normally stained the basal cells, but in lichen amyloidosus basal staining mostly disappeared. Instead, groups of suprabasal keratrnocytss were labeled, with AE1 -reactive inclusions disfributed therein. In contrast, the KL1 antibody, showing suprabasal staining, failed to react with the inclusions. The includms were weakly reactive with the AE3 and WSS antibodies, which stained all keratinocytes. The CAM5.2 antibody was unreactive. The subepidermal amyloid deposits were negative with all the antibodies. The inclusions were ubiquitinated especialty in the granular layer. Immuno-electron microscopy disclosed that ubiquitin was more denseiy localized in the thin filaments than in the thick ones. This indicated that cytokeratin expression and metabolism are altered in the affected epidermis, and that ubiquitin functions in the process of degradation of abnormal cytokeratin filaments.     

Synergism of cytotoxicity between cis-diaminedichloro-platinum-(ii) and cis-diamine(1,1-cyclobutanedicarboxylate)-platinum-(ii)

In an attempts to increase the antitumor effect and to reduce normal tissue toxicity, the combined cytotoxic effect of cis-Diamminedichloroplatinum (II) (CDDP) and cis-diammine(1,1-cyclobutane dicarboxylate) platinum (II) (CBDCA) was investigated using HeLa and colon 26 cell lines and the combination index (CI). Cytotoxicity of the combination of CDDP and CBDCA on 27 surgically resected specimens of human gastric and colorectal adenocarcinomas was also evaluated using the in vitro succinate dehydrogenase inhibition (SDI) test. The CI values varied with the dose ratio examined (1:1-1:6) of CDDP and CBDCA, with findings that CI<1, synergy, was obtained at fraction affected (Fa)>0.75 for HeLa cells and at Fa<0.9 for colon 26 cells in cases of a dose ratio of 1:1 to 1:2. Of all 27 clinical human adenocarcinomas, the succinate dehydrogenase (SD) activity was significantly lower in cancer cells concomitantly exposed to both CDDP and CBDCA than in those exposed to either drug alone. These positive effects of a combination of two platinum analogues on human malignant tissues have heretofore not been reported, which would warrant the clinical application of this combination for human malignant tumors.     

Identification of HLA-A*2402-restricted epitope peptide derived from ERas oncogene expressed in human scirrhous gastric cancer

ERas is a recently identified oncogene involved in the tumorgenic growth of embryonic stem cells. We examined the significance of ERas expression in scirrhous gastric carcinoma, and the possibility of ERas as a tumor-associated antigen of gastric cancer for developing a cancer vaccine. ERas expression was determined in scirrhous gastric carcinoma specimens by immunohistochemical staining. To assess the possibility of the ERas protein as an anticancer vaccine target, we examined whether ERas for HLA-A-restricted epitope peptides were capable of eliciting cytotoxic T lymphocyte activity. Immunohistochemical analysis identified ERas protein in the nucleus and cytoplasm of cancer cells, yet ERas was not expressed in normal gastric epithelium. By western blotting, lysates of the scirrhous gastric cancer cell lines, OCUM-8, OCUM-2MD3 and OCUM-2M were shown to contain a 25-kDa band of ERas protein. ERas mRNA was detected in these cell lines by RT-PCR. To investigate cytotoxicity, we successfully established cytotoxic T lymphocyte clones stimulated by HLA-A*2402-restricted ERas peptides (FALDDPSSL). These peptides have specific cytotoxicity against corresponding HLA-A*2402-positive target cells pulsed with the candidate peptide. We found that the cytotoxic T lymphocyte clones demonstrated cytotoxic activity against OCUM-8 cells that endogenously express ERas. Our results suggest that ERas is a novel tumor-associated antigen with the potential application to be a vaccine against scirrhous gastric cancer.     

Tumor-associated MUC5AC stimulates in vivo tumorigenicity of human pancreatic cancer

MUC5AC, a high molecular weight glycoprotein, is overexpressed in the ductal region of human pancreatic cancer but is not detectable in the normal pancreas, suggesting its association with disease development. In the present study, we investigated the in vitro and in vivo effects of MUC5AC knockdown by short interfering RNA (siRNA) in the MUC5AC-overexpressing SW1990 and BxPC3 human pancreatic cancer cell lines in order to clarify its function. Significant decreases in the expression levels of MUC5AC mRNA and protein were observed in SW1990 and BxPC3 cells that had been stably transfected with a MUC5AC siRNA expression vector (SW1990/si-MUC5AC and BxPC3/si-MUC5AC cells) compared to those in cells transfected with an si-mock vector (SW1990/si-mock and BxPC3/si-mock cells). In in vitro studies, neither type of MUC5AC-knockdown cell showed any difference in cell survival, proliferation, or morphology from the si-mock cells or parental cells. However, in vivo xenograft studies demonstrated that MUC5AC knockdown significantly reduced the tumorigenicity and suppressed the tumor growth of si-MUC5AC cells compared to those of the si-mock cells. Immunohistochemical analysis revealed that CD45R/B220+ and Gr-1+ cells had infiltrated into the tumor tissue of the SW1990/si-MUC5AC cells. Furthermore, cancer-associated antigen specific antibodies were detected at high levels in the sera from the SW1990/si-MUC5AC cell-bearing mice. These results suggest that tumor-associated MUC5AC expressed on the surface of pancreatic cancer cells supports the escape of pancreatic cancer cells from immunosurveillance. The present findings highlight a new dimension of MUC5AC as a functional immunosuppressive agent and its important role in pancreatic cancer progression.     

The effects of dutasteride on voiding and storage symptoms in men with benign prostatic hyperplasia

We investigated the effects of dutasteride on voiding and storage symptoms by a post-hoc analysis from two randomized, placebo-controlled, parallel-group studies (Japanese phase II study and phase III study) which assessed the efficacy and safety of dutasteride in Japanese men with benign prostatic hyperplasia (BPH). Men aged 50 years and older, with a prostate volume of 30 cc or greater, an International Prostate Symptom Score (IPSS) of 8 or higher and maximal urinary flow rate of 15 ml/sec or lower were randomized to placebo or dutasteride groups. The number of subjects for the placebo and dutasteride groups was respectively 72 and 72 in the phase II study, and 185 and 193 in the phase III study. Questions 1, 3, 5 and 6 of IPSS were related to voiding symptoms, and Questions 2, 4 and 7 were related to storage symptoms. Changes between pre- and post-treatments were evaluated. In the phase II study, dutasteride significantly improved voiding symptoms and numerically improved storage symptoms compared with the placebo at week 24. In the phase III study, dutasteride significantly improved voiding and storage symptoms compared with the placebo after 52 weeks. These consistent results suggest that dutasteride is effective for both voiding and storage symptoms in Japanese men with BPH.     

The 2.0-Å crystal structure of tachylectin 5A provides evidence for the common origin of the innate immunity and the blood coagulation systems

Because invertebrates lack an adaptive immune system, they had to evolve effective intrinsic defense strategies against a variety of microbial pathogens. This ancient form of host defense, the innate immunity, is present in all multicellular organisms including humans. The innate immune system of the Japanese horseshoe crab Tachypleus tridentatus, serving as a model organism, includes a hemolymph coagulation system, which participates both in defense against microbes and in hemostasis. Early work on the evolution of vertebrate fibrinogen suggested a common origin of the arthropod hemolymph coagulation and the vertebrate blood coagulation systems. However, this conjecture could not be verified by comparing the structures of coagulogen, the clotting protein of the horseshoe crab, and of mammalian fibrinogen. Here we report the crystal structure of tachylectin 5A (TL5A), a nonself-recognizing lectin from the hemolymph plasma of T. tridentatus. TL5A shares not only a common fold but also related functional sites with the gamma fragment of mammalian fibrinogen. Our observations provide the first structural evidence of a common ancestor for the innate immunity and the blood coagulation systems.     

Serum testosterone level of patients with gastric carcinoma before and after gastrectomy

The serum testosterone level (STL) was determined in 84 male and 32 female patients with gastric carcinoma and in 58 male and 20 female patients with benign diseases as a control group. The STL of the male patients with carcinoma was lower (446 +/- 149 ng/dl) than that of the male control group (532 +/- 132 ng/dl) (P less than 0.001). Even 17 male patients of the early carcinoma showed lower STL (440 +/- 117 ng/dl) than the normal group (P less than 0.001). In the female patients, it was also lower (31.6 +/- 16.0 ng/dl) than in the control group (46.3 +/- 15.3 ng/dl) (P less than 0.005). The postoperative STL of the cases surviving the gastrectomy was higher than the preoperative data in 32 male patients (P less than 0.005) as well as in 12 female patients (0.025 greater than P greater than 0.01), whereas it obviously decreased in the patients who died of recurrence. Therefore, it appears that gastric carcinoma decreases the STL by some mechanism.     

RNA interference suppression of mucin 5AC (MUC5AC) reduces the adhesive and invasive capacity of human pancreatic cancer cells

Background

MUC5AC is a secretory mucin normally expressed in the surface muconous cells of stomach and bronchial tract. It has been known that MUC5AC de novo expression occurred in the invasive ductal carcinoma and pancreatic intraepithelial neoplasm with no detectable expression in normal pancreas, however, its function remains uncertain. Here, we report the impact of MUC5AC on the adhesive and invasive ability of pancreatic cancer cells.

Methods

We used two MUC5AC expressing cell lines derived from human pancreatic cancer, SW1990 and BxPC3. Small-interfering (si) RNA directed against MUC5AC were used to assess the effects of MUC5AC on invasion and adhesion of pancreas cancer cells in vitro and in vivo. We compared parental cells (SW1990 and BxPC3) with MUC5AC suppressed cells by si RNA (si-SW1990 and si-BxPC3).

Results

MUC5AC was found to express in more than 80% of pancreatic ductal carcinoma specimens. Next we observed that both of si-SW1990 and si-BxPC3 showed significantly lower adhesion and invasion to extracellular matrix components compared with parental cell lines. Expression of genes associated with adhesion and invasion including several integerins, matrix metalloproteinase (MMP) -3 and vascular endothelial growth factor (VEGF) were down-regulated in both MUC5AC suppressed cells. Furthermore, production of VEGF and phosphorylation of VEGFR-1 were significantly reduced by MUC5AC down regulation. Both of si-SW1990 and si-BxPC3 attenuated activation of Erk1/2. In vivo, si-SW1990 did not establish subcutaneous tumor in nude mice.

Conclusions

Knockdown of MUC5AC reduced the ability of pancreatic cancer cells to adhesion and invasion, suggesting that MUC5AC might contribute to the invasive motility of pancreatic cancer cells by enhancing the expression of integrins, MMP-3, VEGF and activating Erk pathway.