Selective Inhibition of L-type Amino Acid Transporter 1 Suppresses Cell Proliferation in Ovarian Clear Cell Carcinoma.

BACKGROUND/AIM: Ovarian clear cell carcinoma (OCCC) is a histological type of ovarian cancer that is refractory to chemotherapy and has poor prognosis, which necessitates the development of novel treatment therapies. In this study, we focused on L-type amino acid transporter 1 (LAT1), which is involved in cancer growth, and investigated the effect of its selective inhibition on cell proliferation in OCCC. MATERIALS AND METHODS: The inhibitory effect of nanvuranlat (JPH203), a LAT1 selective inhibitor, on the cellular uptake of [3H] leucine was evaluated using the OCCC cell line JHOC9, which expresses the LAT1 protein. In addition, the kinetics of cell proliferation and changes in phosphorylation of the mTOR pathway were analyzed. The correlation between LAT1 expression and progression-free survival (PFS) was evaluated using clinical specimens of OCCC. RESULTS: Nanvuranlat inhibited [3H] leucine intracellular uptake and cell proliferation in a dose-dependent manner in JHOC9 cells. In addition, it suppressed the activity of the mTOR signaling pathway, which is thought to inhibit cancer cell proliferation. LAT1 expression was most frequent in OCCC among clinical specimens of epithelial ovarian cancer. A correlation between LAT1 expression and PFS was observed in OCCC. CONCLUSION: LAT1 selective inhibition suppresses cell proliferation via the mTOR pathway by inhibiting leucine uptake in OCCC. This study illustrates the potential of using LAT1 selective inhibition as a treatment strategy for OCCC.

Immunohistochemical Differentiation between Western and East Asian Types of CagA-Positive Helicobacter pylori in Gastric Biopsy Samples.

Background: Cag A-positive Helicobacter pylori isolated from human gastric mucosa is categorized as a Western or East Asian allele-type based on whether the cagA gene encodes an EPIYA-C or EPIYA-D motif. We aimed to differentiate between the 2 types of H. pylori by immunohistochemistry (IHC) using formalin-fixed paraffin-embedded (FFPE) gastric biopsy samples. Materials and Methods: We developed 2 monoclonal antibodies (mAbs) that detect either the EPIYA-C or EPIYA-D motif of the H. pylori CagA protein by IHC using FFPE tissues. FFPE tissue sections from 30 Japanese and 39 Brazilian gastric biopsy samples with H. pylori infection confirmed by Giemsa staining (moderate/severe in the Sydney classification system) were examined by IHC with the novel mAbs followed by polymerase chain reaction (PCR) for EPIYA-C or EPIYA-D using DNA extracted from adjacent tissue sections. Results: Differentiation among Western and East Asian types and CagA-negative H. pylori was successful in most (97%) samples by IHC with the novel mAbs and commercially available mAbs that react with a species-specific lipopolysaccharide or a common CagA motif of H. pylori. The detection status of EPIYA-C/D motifs by IHC with the novel mAbs was consistent with the PCR results in 61 (88%) of 69 samples: EPIYA-C(+)/D(-) in zero Japanese and 26 Brazilian samples, EPIYA-C(-)/D(+) in 26 Japanese and 1 Brazilian sample, and EPIYA-C(-)/D(-) in 1 Japanese and 7 Brazilian samples. The detection sensitivity and specificity of IHC with each novel mAb compared with the PCR results were, respectively, 84% and 97% for EPIYA-C, and 97% and 95% for EPIYA-D. Conclusions: The novel mAbs specific to each EPIYA-C or EPIYA-D motif differentiated between Western and East Asian types of CagA-positive H. pylori by IHC using FFPE tissues. Applying these novel mAbs to large numbers of archived pathology samples will contribute to elucidating the association of these allele types with gastric cancer.

Radiomic Analysis for Pretreatment Prediction of Recurrence Post-Radiotherapy in Cervical Squamous Cell Carcinoma Cancer.

BACKGROUND: The current study aims to predict the recurrence of cervical cancer patients treated with radiotherapy from radiomics features on pretreatment T1- and T2-weighted MR images. METHODS: A total of 89 patients were split into model training (63 patients) and model testing (26 patients). The predictors of recurrence were selected using the least absolute shrinkage and selection operator (LASSO) regression. The machine learning used neural network classifiers. RESULTS: Using LASSO analysis of radiomics, we found 25 features from the T1-weighted and 4 features from T2-weighted MR images, respectively. The accuracy was highest with the combination of T1- and T2-weighted MR images. The model performances with T1- or T2-weighted MR images were 86.4% or 89.4% accuracy, 74.9% or 38.1% sensitivity, 81.8% or 72.2% specificity, and 0.89 or 0.69 of the area under the curve (AUC). The model performance with the combination of T1- and T2-weighted MR images was 93.1% accuracy, 81.6% sensitivity, 88.7% specificity, and 0.94 of AUC. CONCLUSIONS: The radiomics analysis with T1- and T2-weighted MR images could highly predict the recurrence of cervix cancer after radiotherapy. The variation of the distribution and the difference in the pixel number at the peripheral and the center were important predictors.

Propionibacterium acnes-Derived Circulating Immune Complexes in Sarcoidosis Patients.

Propionibacterium acnes is a potential etiologic agent of sarcoidosis and a dysregulated immune response to the commensal bacterium is suspected to cause granuloma formation. P. acnes-derived insoluble immune complexes were recently demonstrated in sinus macrophages of sarcoidosis lymph nodes, suggesting local proliferation of the bacterium in affected organs. In the present study, we developed a method for detecting P. acnes-derived immune complexes in human blood by measuring the concentration of P. acnes-specific lipoteichoic acid (PLTA) detectable after an antigen retrieval pretreatment of plasma samples. Before pretreatment, anti-PLTA antibody was detected and PLTA could not be detected, in all plasma samples from 51 sarcoidosis patients and 35 healthy volunteers. After pretreatment, however, a significant level of PLTA (>105 ng/mL) was detected in 33 (65%) sarcoidosis patients and 5 (14%) control subjects, with 86% specificity and 65% sensitivity for sarcoidosis. In both groups, plasma anti-PLTA antibody titers did not differ between samples with and without detection of PLTA. PLTA levels were abnormally increased (>202 ng/mL) in 21 (41%) sarcoidosis patients. These findings suggest that P. acnes-derived circulating immune complexes present in human blood are abnormally increased in many sarcoidosis patients, presumably due to local proliferation of the bacterium in the affected organs.

Cancer gland rupture as a potential risk factor for lymph node metastasis in early colorectal adenocarcinoma with deep submucosal invasion.

AIMS: Lymph node metastasis (LNM) has not been found in more than 85% of patients with early invasive colorectal adenocarcinoma (T1-CRAC) who undergo surgery after therapeutic endoscopy due to the risk for LNM. Better histological risk assessment for LNM of endoscopically resected T1-CRAC is important to avoid unnecessary additional surgery. METHODS AND RESULTS: We evaluated cancer gland rupture (CGR), i.e. cancer glands with a discontinuous epithelial lining, at the invasive front, as a potential risk factor for LNM by histological examination of differentiated T1-CRAC from 217 patients who underwent surgery with or without therapeutic endoscopy. CGR was represented by C-shaped neoplastic glands with a variable inflammatory or stromal reaction, and was occasionally accompanied by mucus lake or abscess formation. CGR was observed in 168 (77%) cases, including all 20 cases with LNM, and the odds ratio of LNM was higher for CGR than for deep invasion (depth of submucosal invasion ≥1000 µm). All cases with LNM were found among 148 cases with deep invasion and positive CGR, whereas no LNM was detected in 29 cases with deep invasion and negative CGR, regardless of vascular invasion or tumour budding. In the 148 cases, LNM was detected in 18 (19%) of 93 cases with positive vascular invasion or high-grade tumour budding, and in two (4%) of 55 cases without either. CONCLUSIONS: Our findings suggest that CGR is an easily applied and objective histological finding for predicting LNM that could be useful for assessing the risk for LNM of endoscopically resected T1-CRAC with deep invasion.

Regulation of REG4 Expression and Prediction of 5-Fluorouracil Sensitivity by CDX2 in Ovarian Mucinous Carcinoma.

BACKGROUND/AIM: The biological importance of the caudal-related homeobox transcription factor CDX2 in acquiring resistance to anticancer drugs has been studied in ovarian mucinous carcinoma. CDX2 promotes the expression of multidrug resistance 1 (MDR1) and confers resistance to paclitaxel. The regenerating islet-derived family member 4 (REG4) gene is a potential target gene of CDX2. In this study, we investigated the relationship between the expression of CDX2 and Reg IV and the regulation of Reg IV expression and examined novel chemotherapeutic regimens. MATERIALS AND METHODS: The regulation of Reg IV expression by CDX2 and sensitivity of 5-fluorouracil (5-FU) were evaluated using ovarian mucinous cancer cell lines. RESULTS: The correlation of CDX2 with Reg IV expression was demonstrated in ovarian mucinous carcinoma. Reg IV expression was enhanced by transfection of CDX2 and was suppressed by inhibition of CDX2 expression. OMC-3 cells with ectopically overexpressed CDX2 showed enhanced apoptosis and sensitivity to 5-FU. CONCLUSION: CDX2 promotes resistance to paclitaxel and sensitivity to 5-FU. Novel 5-FU-based chemotherapy based on CDX2 may be used in ovarian mucinous carcinoma.

The quantitative analysis of the human papillomavirus DNA load in submandibular gland lesions with droplet digital polymerase chain reaction.

BACKGROUND: The relationship between infection with human papillomavirus (HPV) and tumorigenesis of salivary gland remains controversial. OBJECTIVES: This study explored the relationship between HPV and salivary gland lesions as well as that of the HPV infection status and p16INK4A immunoreactivity. The HPV DNA loads were also quantitatively evaluated. MATERIALS AND METHODS: Tissue samples from 31 submandibular gland lesions were evaluated. p16INK4A immunohistochemical (IHC) staining, nested polymerase chain reaction (PCR), DNA sequencing, and droplet digital PCR (ddPCR) were performed. RESULTS: Non-neoplastic lesion, benign tumors, and malignant tumors were noted in 9, 16, 6 cases, respectively. p16INK4A immunoreactivity was higher in malignant tumors than in benign tumors (50.0% vs. 6.3%). Single PCR with MY09/11 found that all samples were negative. Nevertheless, nested PCR revealed a high HPV-DNA positivity rate of 96.8%. No relationship between the HPV status and p16INK4A immunoreactivity was shown. HPV-18 was the only subtype identified in this study. ddPCR showed significantly lower HPV-18 DNA loads in submandibular gland lesions than in oropharyngeal cancers. CONCLUSIONS: HPV-DNA positivity and p16INK4A-immunoreactivity were not correlated in submandibular gland lesions. The loads of HPV DNA detected in this study were small. HPV positivity therefore may not be associated with tumorigenesis of the submandibular gland.

Useful Application of Immunostaining to Malignant Pleural Effusion among Lao People in Vientiane Capital, Lao PDR

Background: Pathology and laboratory medicine (PALM) services are limited in low-resource countries, such as Lao PDR. Patients with malignant pleural effusion (MPE) are not properly diagnosed and treated in these situations. The purpose of this study is to confirm the usefulness of immunocytochemistry in MPE to identify the histological type and probable primary site of cancer of MPE and to discuss its usefulness in low-resource countries, such as Laos. Methods: We retrospectively reviewed glass slides of pleural effusion sent to the Department of Pathology at the University of Health Sciences from the central hospitals for cytological screening from January 2012 to December 2016. The cytological review, cell transfer and immunocytochemical staining were performed at Tokyo Medical and Dental University. Among 81 cases of MPE from Laos, 66 cases of malignant tumors that contained enough tumor cells were included in this study, and the slides were screened with 14 primary antibodies to classify the histological type and identify the probable primary site of carcinoma. Results: Among the 66 cases, 34 cases (52%) were of female patients, and 32 cases (48%) were of male patients. The patients' ages ranged from 28 to 88 years with an average of 58 years. The immunocytochemical study identified 32 cases (49%) of primary lung adenocarcinoma, two cases (3%) of malignant mesothelioma, one case (1.5%) of breast/gynecological carcinoma, one case (1.5%) of T cell lymphoma, and one case (1.5%) of B cell lymphoma. Twenty-nine cases (43.5%) were classified as carcinoma not otherwise specified. Pulmonary small cell carcinoma/squamous cell carcinoma and metastatic colon, prostate, and liver carcinoma were not identified among the cases. Conclusions: Immunocytochemistry is a useful ancillary method in MPE diagnostics. This method could be applied in the pathological laboratories in low- or middle-resource countries, such as Laos.

Progressive Encephalomyelitis with Rigidity and Myoclonus Resolving after Thymectomy with Subsequent Anasarca: An Autopsy Case.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is an autoimmune disorder involving the brainstem and spinal cord and is sometimes associated with thymoma. We encountered a 75-year-old woman with typical PERM features, glycine receptor antibody, and thymoma. Her neurologic symptoms improved after thymectomy, but she unexpectedly developed anasarca with massive pleural effusions and hypoalbuminemia and finally succumbed to death. The autopsy showed edema and mononuclear infiltration in the pleura but no neuropathological findings typical of PERM. Effective treatment of PERM can reverse the neuropathological signs of encephalomyelitis. The autoimmune nature of anasarca is possible but not proven.

Propionibacterium acnes-derived insoluble immune complexes in sinus macrophages of lymph nodes affected by sarcoidosis.

BACKGROUND: Propionibacterium acnes is thought to be a causative agent of sarcoidosis. Patients with sarcoidosis have circulating immune complexes. We attempted to detect P. acnes-derived immune complexes in sarcoid lesions. METHODS: We evaluated formalin-fixed and paraffin-embedded lymph node samples from 38 sarcoidosis patients and 90 non-sarcoidosis patients (27 patients with necrotizing lymphadenitis, 28 patients with reactive lymphadenitis, 16 patients with colon cancer, 19 patients with gastric cancer) by immunohistochemistry using anti-human immunoglobulins (IgG, IgA, and IgM) and complement (C1q and C3c) antibodies, and a P. acnes-specific monoclonal antibody (PAB antibody) that reacts with the membrane-bound lipoteichoic acid of P. acnes. RESULTS: Small round bodies (SRBs) bound to IgA, IgM, or IgG were detected in sinus macrophages, in 32 (84%), 32 (84%), or 11 (29%) sarcoid samples, respectively, and in 19 (21%), 26 (29%), or no (0%) control samples, respectively. Some of these insoluble immune complexes (IICs) also bound to C1q and C3c. We developed a microwave treatment followed by brief trypsin digestion (MT treatment) to detect PAB-reactive SRBs bound to immunoglobulins (IIC-forming P. acnes). MT treatment revealed abundant IIC-forming P. acnes in most (89%) of the sarcoid samples and sparse distribution in some (20%) of the control samples with lymphadenitis, but no IIC-forming P. acnes was detected in control samples without inflammation. IIC-forming P. acnes were mostly bound to both IgA and IgM. The PAB-reactive antigen and immunoglobulins were both located at the peripheral rim of the IIC-forming P. acnes. Conventional electron microscopy identified many SRBs (0.5-2.0 µm diameter) in sinus macrophages of sarcoid lymph nodes with many IIC-forming P. acnes, some of which were in phagolysosomes with a degraded and lamellar appearance. CONCLUSIONS: P. acnes-derived IICs in sinus macrophages were frequent and abundant in sarcoid lymph nodes, suggesting a potential etiologic link between sarcoidosis and this commensal bacterium.

Frequency of Propionibacterium acnes Infection in Prostate Glands with Negative Biopsy Results Is an Independent Risk Factor for Prostate Cancer in Patients with Increased Serum PSA Titers.

BACKGROUND: Propionibacterium acnes has recently been implicated as a cause of chronic prostatitis and this commensal bacterium may be linked to prostate carcinogenesis. The occurrence of intracellular P. acnes infection in prostate glands and the higher frequency of P. acnes-positive glands in radical prostatectomy specimens from patients with prostate cancer (PCa) than in those from patients without PCa led us to examine whether the P. acnes-positive gland frequency can be used to assess the risk for PCa in patients whose first prostate biopsy, performed due to an increased prostate-specific antigen (PSA) titer, was negative. METHODS: We retrospectively collected the first and last prostate biopsy samples from 44 patients that were diagnosed PCa within 4 years after the first negative biopsy and from 36 control patients with no PCa found in repeated biopsy for at least 3 years after the first biopsy. We evaluated P. acnes-positive gland frequency and P. acnes-positive macrophage number using enzyme-immunohistochemistry with a P. acnes-specific monoclonal antibody (PAL antibody). RESULTS: The frequency of P. acnes-positive glands was higher in PCa samples than in control samples in both first biopsy samples and in combined first and last biopsy samples (P < 0.001). A frequency greater than the threshold (18.5 and 17.7, respectively) obtained by each receiver operating characteristic curve was an independent risk factor for PCa (P = 0.003 and 0.001, respectively) with odds ratios (14.8 and 13.9, respectively) higher than those of serum PSA titers of patients just before each biopsy (4.6 and 2.3, respectively). The number of P. acnes-positive macrophages did not differ significantly between PCa and control samples. CONCLUSIONS: These results suggested that the frequency of P. acnes-positive glands in the first negative prostate biopsy performed due to increased PSA titers can be supportive information for urologists in planning repeated biopsy or follow-up strategies.

Intracellular Propionibacterium acnes infection in glandular epithelium and stromal macrophages of the prostate with or without cancer.

BACKGROUND: Recent reports on Propionibacterium acnes (P. acnes) suggest that this bacterium is prevalent in the prostate, is associated with acute and chronic prostatic inflammation, and might have a role in prostate carcinogenesis. METHODS: To evaluate the pathogenic role of this indigenous bacterium, we screened for the bacterium in radical prostatectomy specimens using enzyme immunohistochemistry with a novel P. acnes-specific monoclonal antibody (PAL antibody), together with an anti-nuclear factor-kappa B (NF-κB) antibody. We examined formalin-fixed and paraffin-embedded tissue sections of radical prostatectomy specimens from 28 patients with prostate cancer and 18 age-matched control patients with bladder cancer, but without prostate cancer. RESULTS: Immunohistochemistry with the PAL antibody revealed small round bodies within some non-cancerous glandular epithelium and stromal macrophages in most prostate samples. Prostate cancer samples had higher frequencies of either cytoplasmic P. acnes or nuclear NF-κB expression of glandular epithelium and higher numbers of stromal macrophages with P. acnes than control samples. These parameters were also higher in the peripheral zone than in the transitional zone of the prostate, especially in prostate cancer samples. Nuclear NF-κB expression was more frequent in glands with P. acnes than in glands without P. acnes. The number of stromal macrophages with the bacterium correlated with the grade of chronic inflammation in both the PZ and TZ areas and with the grade of acute inflammation in the TZ area. CONCLUSIONS: Immunohistochemical analysis with a novel monoclonal antibody for detecting P. acnes in the prostate suggested that intraepithelial P. acnes infection in non-cancerous prostate glands and inflammation caused by the bacterium may contribute to the development of prostate cancer.

Iron-catalyzed allylic arylation of olefins via C(sp3)-H activation under mild conditions.

An aryl Grignard reagent in the presence of mesityl iodide converts an allylic C-H bond of a cycloalkene or an allylbenzene derivative into a C-C bond in the presence of a catalytic amount of Fe(acac)(3) and a diphosphine ligand at 0 °C. The stereo- and regioselectivity of the reaction, together with deuterium labeling experiments, suggest that C-H bond activation is the slow step in the catalytic cycle preceding the formation of an allyliron intermediate.

"Crawling-type" adenocarcinoma of the stomach: a distinct entity preceding poorly differentiated adenocarcinoma.

BACKGROUND: Gastric "crawling-type" adenocarcinoma (CTAC) is a neoplasm histologically comprising irregularly fused glands with low-grade cellular atypia that tends to spread laterally in the mucosa. It is necessary to elucidate the clinicopathological characteristics of CTAC. METHODS: We evaluated 25 CTACs-16 intramucosal (M-) and 9 submucosal invasive (SM-) cancers-clinicopathologically and immunohistochemically. RESULTS: CTAC was most frequently located in the lesser curvature of the middle-third of the stomach. Macroscopically, 21 lesions were superficial-depressed and 4 were superficial-flat type. Histologically, all CTACs had cystic dilated glands and 16 lesions had focal signet-ring cells. All invasive areas of the SM-CTACs were occupied by poorly differentiated adenocarcinoma with an infiltrative growth pattern and abundant stroma. Fifteen CTACs were surrounded by mucosa with partial or no intestinal metaplasia. In the intramucosal area, 24 lesions were mixed phenotype with mucin and brush border immunoexpression. SM-CTAC was frequent in lesions with an intramucosal poorly differentiated component (PDC) greater than 10 mm in size (P = 0.041), and lymph node metastasis (LNM) was frequent in lesions with a PDC greater than 20 mm (P = 0.039). The frequency of an expanded pattern (Ki-67-positive cells occupying > 50 % of the mucosa) was higher in SM-CTAC than in M-CTAC (P = 0.027). p53 overexpression was not detected in the intramucosal areas of any of the lesions. CONCLUSION: CTAC is a distinct subgroup of gastric adenocarcinoma in the early phase. A larger PDC and a Ki-67 expanded pattern were predictive of submucosal invasion or LNM.

[Immunohistochemical detection of Helicobacter pylori with a novel monoclonal antibody: Its clinicopathological significance and validity in the routine pathological diagnosis].

The immunological mechanism of Helicobacter pylori-induced chronic gastritis is still unknown. In our previous study using a novel anti-H. pylori monoclonal antibody and surgically resected stomachs from gastric cancer patients, we succeeded to detect H. pylori captured by macrophages in gastric lamina propria and lymph nodes, and proved that the H. pylori-positive macrophages correlated with chronic gastritis. To elucidate this correlation in the cases without gastric cancer, we examined H. pylori in 519 gastric biopsy specimens of 242 cases using immunohistochemistry with the novel antibody. Also, we evaluated the validity of the novel antibody in the routine pathological diagnosis. In 402 specimens from the cases without gastric tumors, the bacteria were detected not only in the mucous layer of 148 specimens but also in the lamina propria of 144 specimens. The specimens only with the intramucosal bacteria showed high-grade chronic and low-grade acute inflammation, whereas the specimens only with the intra-mucous bacteria tended to show the low-grade chronic and high-grade acute inflammation. Statistically, H. pylori in the lamina propria correlated with chronic gastritis. When compared to commercially available anti-H. pylori antibody and Giemsa staining, the novel antibody showed the highest sensitivity to detect the bacteria in the lamina propria. These results suggest that H. pylori in the lamina propria is thought to be deeply related with the development of H. pylori-induced chronic gastritis also in the cases without gastric cancer. And, the novel antibody is proved to be very useful in the routine pathological assessment of H. pylori infection.

Synergistic tumour suppressor activity of E-cadherin and p53 in a conditional mouse model for metastatic diffuse-type gastric cancer.

BACKGROUND: Gastric cancer is the second most frequent cause of death from cancer in the world, diffuse-type gastric cancer (DGC) exhibiting a poor prognosis. Germline mutations of CDH1, encoding E-cadherin, have been reported in hereditary DGC, and genetic and/or epigenetic alterations of CDH1 are frequently detected in sporadic DGC. Genetic alterations of TP53 are also frequently found in DGC. To examine the synergistic effect of the loss of E-cadherin and p53 on gastric carcinogenesis, a mouse line was established in which E-cadherin and p53 are specifically inactivated in the stomach parietal cell lineage. METHODS: Atp4b-Cre mice were crossed with Cdh1(loxP/loxP) and Trp53(loxP/loxP) mice, and the gastric phenotype of Atp4b-Cre(+);Cdh1(loxP/loxP);Trp53(loxP/loxP) double conditional knockout (DCKO) mice was examined. RESULTS: Non-polarised E-cadherin-negative parietal cells and proton pump-negative atypical foci were observed in DCKO mice. Intramucosal cancers and invasive cancers composed of poorly differentiated carcinoma cells and signet ring cells, histologically very similar to those in humans, were found from 6 to 9 months, respectively. Fatal DGC developed at 100% penetrance within a year, frequently metastasised to lymph nodes, and had tumourigenic activity in immunodeficient mice. Gene expression profiles of DGC in DCKO mice also resembled those of human DGC, and mesenchymal markers and epithelial-mesenchymal transition-related genes were highly expressed in mouse DGC as in human DGC. CONCLUSION: This mouse line is the first genetically engineered mouse model of DGC and is very useful for clarifying the mechanism underlying gastric carcinogenesis, and provides a new approach to the treatment and prevention of DGC.

Reduced expression of cytokeratin 4 and 13 is a valuable marker for histologic grading of esophageal squamous intraepithelial neoplasia.

Histologic evaluation of low-grade or high-grade intraepithelial neoplasia (LG-IN or HG-IN) of the esophagus is important for estimating the risk of progression to invasive carcinoma. Discrimination between LG-IN and HG-IN, or neoplasia and non-neoplastic lesion (NNL), however, is occasionally difficult. This study was designed to evaluate whether cytokeratin expression can be used for discrimination of these lesions. Esophageal Iodine-unstained lesions (n=154), less than 10 mm, were classified into HG-IN, LG-IN, and NNL. These lesions together with 154 foci of normal esophageal epithelium (NEE) were examined by immunohistochemistry for cytokeratins (CK4 and CK13), p53 overexpression, and the MIB-1 labeling index. The ratios of CK4- and CK13-positive staining were scored from 1 to 3. The CK4- and CK13-positive staining ratios were decreased in NNL (73% and 78%), LG-IN (55% and 69%), and HG-IN (33% and 48%), compared to NEE (91% and 95%). The differences between LG-IN and HG-IN, neoplasia and NNL, and among these three lesions and NEE were statistically significant (p < 0.005). The cytokeratin scores correlated with the MIB-1 labeling index (both: p < 0.0001), but not with p53 overexpression. CK4 and CK13 immunohistochemistry could be an objective method for evaluating the risk for progression to invasive carcinoma.

Relationship between mucin expression of gastric intramucosal signet ring cell carcinoma and its background mucosa.

The intramucosal lesion of gastric signet ring cell carcinoma (SIG) is known to form a layered structure (LS) that simulates mucin expression in ordinary gastric mucosa. In this study, we suspected the influence of background mucosa on the formation of LS and performed histopathological analysis. We examined 35 cases of intramucosal SIG with a maximum diameter of 30 mm or less. The LS patterns were classified into those with a layer of MUC6-positive cells (complete pattern, CP) and those lacking this layer (incomplete pattern, ICP). The relationship between LS patterns and the characteristics of the background mucosa, the expression of MUC2 (intestinal-type mucin antigen), MUC5AC (foveolar-type mucin antigen), and Ki-67 (the marker of cell proliferation activity) was examined by histochemistry and immunohistochemistry. Intestinal metaplasia in the background mucosa and MUC2 expression were frequently observed in cases with ICP. Ki-67-positive cells were much more and they were distributed more widely in the lesion of cases with ICP alone than in the other cases. Mucin expression and LS formation of gastric SIG are strongly influenced by its background mucosa. The cases completely lacking MUC6 expression may have higher malignant potential.

Helicobacter pylori invades the gastric mucosa and translocates to the gastric lymph nodes.

Helicobacter pylori has been considered to be non-invasive and to rarely infiltrate the gastric mucosa, even though there is an active Th1 immune response in the lamina propria of the H. pylori-infected stomach. To elucidate whether H. pylori invades the lamina propria and translocates to the gastric lymph nodes, we examined H. pylori in formalin-fixed and paraffin-embedded tissue sections of stomach and gastric lymph nodes obtained from 51 cancer patients using real-time PCR and immunohistochemistry (IHC) with a novel anti-H. pylori monoclonal antibody that recognizes lipopolysaccharides. Fresh gastric lymph nodes were used to culture for H. pylori. In 46 patients with H. pylori in the stomach, the bacterium was found in the lymph nodes from 21 patients by culture, 37 patients by PCR, and 29 patients by IHC. H. pylori captured by macrophages was found in the lamina propria of 39 patients. In the lymph nodes, the bacterium was found in many macrophages and a few interdigitating dendritic cells at the paracortical areas. H. pylori was also found in the intracellular canaliculi of parietal cells in 21 patients, but intracytoplasmic invasion into gastric epithelial cells was not identified. When compared to the commercially available anti-H. pylori antibodies, the novel antibody showed the highest sensitivity to detect H. pylori-positive macrophages, whereas no difference was found for H. pylori in the mucous layer. The H. pylori-positive macrophages in the lamina propria correlated with chronic gastritis as well as translocation of such cells to the lymph nodes. These results suggest that H. pylori-induced gastric epithelial damage allows the bacteria to invade the lamina propria and translocate to the gastric lymph nodes, which may chronically stimulate the immune system. The bacteria captured by macrophages, whether remaining alive or not, may contribute to the induction and development of H. pylori-induced chronic gastritis.

Expression and intracellular localization of matrix metalloproteinases in intraductal papillary mucinous neoplasms of the pancreas.

To analyze the expression of matrix metalloproteinases (MMPs) and their relationships with the histological grades of the intraductal papillary mucinous neoplasm (IPMN) of the pancreas, we examined the frequency of expression and intracellular localization of MMP1, MMP2, MMP3, MMP7, and MMP9 in IPMN by immunohistochemistry. A total of 45 IPMN lesions (14 adenomas, 17 borderline lesions, nine noninvasive carcinomas, and five invasive lesions) from 21 patients were examined. MMP1, MMP2, MMP7, and MMP9 were expressed in tumor cells. Frequency of tumor cells expressing MMP7 was low in adenomas (median, 5.0%), higher in borderline lesions (median, 30.0%), in noninvasive carcinomas (median, 50.0%), and in invasive lesions (median, 80.0%), with a significant trend (P < 0.0001). Such a trend was also observed when the lesions were classified into gastric and intestinal subtypes (P < 0.0001 and P = 0.011, respectively). Basolateral expression of MMP7 in tumor cells was more prominent in lesions with higher histological grades (P < 0.0001). The frequency and the localization of MMP1, MMP2, and MMP9 did not correlate to the histological grades. MMP7 may contribute to the process by which IPMN advances from adenoma to carcinoma and to subsequent invasion of tumor cells in IPMN.