The roles of tight junction protein cingulin in human endometrioid endometrial cancer.

The bicellular tight junction molecule cingulin (CGN) binds to microtubules in centrosomes. Furthermore, CGN contributes to the tricellular tight junction (tTJ) proteins lipolysis-stimulated lipoprotein receptor (LSR) and tricellulin (TRIC). CGN as well as LSR decreased during the malignancy of endometrioid endometrial cancer (EEC). Although tTJ protein LSR is involved in the malignancy of some cancers, including EEC, the role of CGN is unknown. In this study, we investigated the roles of CGN with tTJ proteins in human EEC cells by using the CGN-overexpressing EEC cell line Sawano. In 2D cultures, CGN was colocalized with LSR and TRIC at tTJ or at γ-tubulin-positive centrosomes. In immunoprecipitation with CGN antibodies, CGN directly bound to LSR, TRIC, and ß-tubulin. Knockdown of CGN by the siRNA decreased the epithelial barrier and enhanced cell proliferation, migration and invasion, as well as knockdown of LSR. In the Sawano cells cocultured with normal human endometrial stromal cells, knockdown of CGN decreased expression of LSR and TRIC via MAPK and AMPK pathways. In 2.5D cultures, knockdown of CGN induced the formation of abnormal cysts and increased the permeability of FD-4 to the lumen. In 2D and 2.5D cultures, treatment with ß-estradiol with or without EGF or TGF-ß decreased CGN expression and the epithelial permeability barrier and enhanced cell migration, and pretreatment with EW7197+AG1478, U0126 or an anti-IL-6 antibody prevented this. In conclusion, CGN, with tTJ proteins might suppress the malignancy of human EEC and its complex proteins are sensitive to estrogen and growth factors derived from stromal cells.

Therapeutic Outcome of Multidisciplinary Treatment in Unresectable Biliary Tract Cancer: A Multicenter Retrospective Analysis.

Background: There is little established evidence regarding treatment strategies for unresectable biliary tract cancer (BTC). This study aimed to clarify the situation of multidisciplinary treatment for unresectable BTC in the 2000s when there was no international standard first-line therapy. Methods: We retrospectively reviewed 315 consecutive patients with unresectable BTC who had been treated at seven tertiary institutions in Kanagawa Prefecture, Japan between 1999 and 2008. Results: The unresectable factors were as follows: locally advanced, 101 cases (32.1%); hematogenous metastases, 80 cases (25.4%); and peritoneal dissemination, 30 cases (9.5%). Chemotherapy or radiation therapy was administered to 218 patients (69.2%). The best supportive care was provided in 97 cases (30.8%). The most common regimen was gemcitabine monotherapy, followed by gemcitabine combination therapy and S-1 monotherapy. The 1- and 2-year survival rates of all patients were 34.6% and 12.2%, respectively. The median survival time (MST) was 8 months in all patients. The 1-year survival rate was 65%, and the MST was 12 months among the locally advanced patients, whereas patients with peritoneal dissemination had the worst outcome; the 1-year survival rate was 7%, and the MST was 5 months. Among treated 90 cases of perihilar cholangiocarcinoma, patients who received chemoradiotherapy (n = 24) had a significantly better outcome than those who received chemotherapy alone (MST: 20 vs. 11 months, P < 0.001). Conclusions: Unresectable BTC has heterogeneous treatment outcomes depending on the mode of tumor extension and location. Multidisciplinary treatment seems useful for patients with locally advanced BTC, whereas patients with metastatic disease still have a poor prognosis.

The interplay between the epithelial permeability barrier, cell migration and mitochondrial metabolism of growth factors and their inhibitors in a human endometrial carcinoma cell line.

It is known that there are abnormalities of tight junction functions, cell migration and mitochondrial metabolism in human endometriosis and endometrial carcinoma. In this study, we investigated the effects of growth factors and their inhibitors on the epithelial permeability barrier, cell migration and mitochondrial metabolism in 2D and 2.5D cultures of human endometrioid endometrial carcinoma Sawano cells. We also investigated the changes of bicellular and tricellular tight junction molecules and ciliogenesis induced by these inhibitors. The growth factors TGF-ß and EGF affected the epithelial permeability barrier, cell migration and expression of bicellular and tricellular tight junction molecules in 2D and 2.5D cultures of Sawano cells. EW-7197 (a TGF-ß receptor inhibitor), AG1478 (an EGFR inhibitor) and SP600125 (a JNK inhibitor) affected the epithelial permeability barrier, cell migration and mitochondrial metabolism and prevented the changes induced by TGF-ß and EGF in 2D and 2.5D cultures. EW-7197 and AG1478 induced ciliogenesis in 2.5D cultures. In conclusion, TGF-ß and EGF promoted the malignancy of endometrial cancer via interplay among the epithelial permeability barrier, cell migration and mitochondrial metabolism. EW-7197 and AG1478 may be useful as novel therapeutic treatments options for endometrial cancer.

Mailing human papillomavirus self-sampling kits to women under-screened for cervical cancer improved detection in cervical cancer screening in a general population study in Japan.

BACKGROUND: One cause of the increase in cervical cancer rates in Japan is the long-term stagnation in the cervical cancer screening consultation rate. Therefore, improving the screening consultation rate is of urgent concern to reduce cervical cancer incidence. Self-collected human papilloma virus (HPV) tests have been successfully adopted in several countries, such as the Netherlands and Australia, as a measure of individuals who have not undergone cervical cancer screening in national programs. This study aimed to verify whether self-collected HPV tests presented an effective countermeasure for individuals who had not undergone the recommended cervical cancer screenings. METHODS: This study was conducted from December 2020 to September 2022 in Muroran City, Japan. The primary evaluated endpoint was the percentage of citizens who underwent cervical cancer screening at a hospital with positive self-collected HPV test results. The secondary endpoint was the percentage of included participants who were diagnosed with cervical intraepithelial neoplasia (CIN) or higher among those who visited a hospital and underwent cervical cancer screening. RESULTS: The included study participants were 7,653 individuals aged 20-50 years with no record of previous cervical cancer examination in the past 5 years. We mailed these participants information on self-administered HPV tests as an alternative screening procedure and sent the kit to 1,674 women who requested the test. Among them, 953 returned the kit. Among the 89 HPV-positive individuals (positive rate, 9.3%), 71 (79.8%) visited the designated hospital for an examination. A closer examination revealed that 13 women (18.3% of hospital visits) had a CIN finding of CIN2 or higher, among whom one each had cervical cancer and vulvar cancer, eight presented with CIN3, and three presented with CIN2; two cases of invasive gynecologic cancer were also identified. CONCLUSIONS: We conclude that the self-collected HPV tests showed a certain efficacy as a measure of individuals who had not undergone the recommended cervical cancer screening. We devised ways to have the unexamined patients undergo HPV testing and ensure that HPV-positive individuals visited the hospital. Despite a few limitations, our findings suggest the effectiveness of this public health intervention.

LSR antibody promotes apoptosis and disrupts epithelial barriers via signal pathways in endometrial cancer.

Lipolysis-stimulated lipoprotein receptor (LSR), a lipid metabolism-related factor localized in tricellular tight junctions (tTJs), plays an important role in maintaining the epithelial barrier. LSR is highly expressed in well-differentiated endometrial endometrioid carcinoma (EEC), and its expression decreases during malignancy. Angubindin-1, a novel LSR ligand peptide, regulates tTJs without cytotoxicity, enhances paracellular permeability, and regulates epithelial barrier via c-Jun N-terminal kinase (JNK)/cofilin. In this study, we investigated the immune-modulatory roles of an anti-LSR antibody in the treatment of EEC in vitro compared to those of angubindin-1. We prepared an antibody against the extracellular N-terminal domain of human LSR (LSR-N-ab) and angubindin-1. EEC cell-line Sawano cells in 2D and 2.5D cultures were treated with 100 µg/ml LSR-N-ab or 2.5 µg/ml angubindin-1 with or without protein tyrosine kinase 2ß inhibitor PF431396 (PF43) and JNK inhibitor SP600125 (SP60) at 10 µM. Treatment with LSR-N-ab and angubindin-1 decreased LSR at the membranes of tTJs and the activity of phosphorylated LSR and phosphorylated cofilin in 2D culture. Treatment with LSR-N-ab and angubindin-1 decreased the epithelial barrier measured as TEER values in 2D culture and enhanced the epithelial permeability of FD-4 in 2.5D culture. Treatment with LSR-N-ab, but not angubindin-1, induced apoptosis in 2D culture. Pretreatment with PF43 and SP60 prevented all the changes induced by treatment with LSR-N-ab and angubindin-1. Treatment with LSR-N-ab and angubindin-1 enhanced the cell metabolism measured as the mitochondrial respiration levels in 2D culture. LSR-N-ab and angubindin-1 may be useful for therapy of human EEC via enhanced apoptosis or drug absorption.

Human papillomavirus testing and cytology using physician-collected uterine cervical samples vs. self-collected vaginal samples and urine samples.

BACKGROUND: Human papillomavirus (HPV) testing using self-collected vaginal samples and urine samples is convenient and effective for improving the screening rate. But, to serve as an alternative cervical cancer screening technique, such tests must offer sensitivity equivalent to the HPV testing of physician-collected cervical samples. To examine the effectiveness of HPV testing using self-collected samples and urine samples, we compared the results of HPV testing using these samples with those of HPV testing using physician-collected samples and cytological examinations. METHODS: The study population included 300 women (age: 20-50 years) with abnormal cervical cytology. The results of HPV testing using self-collected samples and urine samples and physician-collected samples and cervical cytology were compared. RESULTS: For all HPV types, the κ-value was 0.773 for physician- and self-collected samples and 0.575 for physician-collected and urine samples. The κ-value for HPV type 16-positive samples was 0.988 for physician- and self-collected samples and 0.896 for physician-collected and urine samples. The κ-value for HPV type 18-positive samples was 0.856 for physician- and self-collected samples and 0.831 for physician-collected and urine samples. For other HPV types, the value was 0.809 for physician- and self-collected samples and 0.617 for physician-collected and urine samples. CONCLUSIONS: The obtained results were consistent between physician- and self-collected samples as well as between physician-collected and urine samples. Considering that the agreement rate was particularly high for the high-risk HPV types 16 and 18, HPV testing using physician-collected samples, self-collected samples, and urine samples was equally effective for the types with high carcinogenicity.

The Roles of Tricellular Tight Junction Protein Angulin-1/Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Endometriosis and Endometrioid-Endometrial Carcinoma.

Tight junction proteins play roles beyond permeability barriers functions and control cell proliferation and differentiation. The relation between tight junctions and the signal transduction pathways affects cell growth, invasion and migration. Abnormality of tight junction proteins closely contributes to epithelial mesenchymal transition (EMT) and malignancy of various cancers. Angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) forms tricellular contacts that has a barrier function. Downregulation of angulin-1/LSR correlates with the malignancy in various cancers, including endometrioid-endometrial carcinoma (EEC). These alterations have been shown to link to not only multiple signaling pathways such as Hippo/YAP, HDAC, AMPK, but also cell metabolism in ECC cell line Sawano. Moreover, loss of angulin-1/LSR upregulates claudin-1, and loss of apoptosis stimulating p53 protein 2 (ASPP2) downregulates angulin-1/LSR. Angulin-1/LSR and ASPP2 concentrate at both midbody and centrosome in cytokinesis. In EEC tissues, angulin-1/LSR and ASPP2 are reduced and claudin-2 is overexpressed during malignancy, while in the tissues of endometriosis changes in localization of angulin-1/LSR and claudin-2 are seen. This review highlights how downregulation of angulin-1/LSR promotes development of endometriosis and EEC and discusses about the roles of angulin-1/LSR and its related proteins, including claudins and ASPP2.

Analysis of the diagnostic capabilities of urinary neutrophil gelatinase-associated lipocalin and serum procalcitonin for acute kidney injury at the early stage of critical care intensive care unit admission.

BACKGROUND: Acute kidney injury (AKI) is a disease that negatively affects patient prognosis and requires early diagnosis and treatment. Biomarkers that predict AKI are needed for early diagnosis of this disease. METHODS: We compared the AKI group and the non-AKI group in patients who were admitted to our critical care intensive care unit (ICU) and conducted a comparative study focusing on urinary neutrophil gelatinase-associated lipocalin (U-NGAL) and serum procalcitonin (PCT). RESULTS: Seventy-one out of 106 ICU inpatients were diagnosed with AKI in accordance with the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Among the patients who were diagnosed with AKI stages 1 to 3, 94.4% of all patients reached the maximum stage by day 5 after admission. Comparing the non-AKI group and AKI stage 1 to 3 on days 1 to 3 after admission, U-NGAL and PCT levels in the stage 3 group were significantly higher than those in the non-AKI group. Additionally, in receiver operating characteristic curve (ROC) analysis on days 1-3 after admission, U-NGAL and PCT levels can be used as biomarkers for the diagnosis of AKI, and in particular, AKI stage 3 can be predicted and diagnosed with high accuracy. U-NGAL and PCT levels were also significantly higher in AKI due to sepsis and acute pancreatitis and due to sepsis, respectively. CONCLUSIONS: Measuring U-NGAL and PCT levels as biomarkers for AKI may further improve the accuracy of AKI diagnosis in critical care ICU.

Optical coherence tomography and coronary angioscopy assessment of healed coronary plaque components.

PURPOSE: Histopathological or intracoronary image assessment of healed plaques (HPs) has been reported. However, the lesion characteristics of HPs remains undetermined yet. We assessed the healed plaque components in patients with coronary artery lesions using multiple imaging modalities. METHODS: We enrolled 33 stable angina pectoris (SAP) patients with 36 native coronary culprit lesions with angiography severe stenosis and without severe calcification undergoing pre-intervention optical coherence tomography (OCT) and coronary angioscopy (CAS). HPs were defined as layered phenotype on OCT. Lesion morphologies and plaque characteristics of HPs were assessed using OCT and CAS. RESULTS: HPs were observed in 19 lesions (52.8%). HP lesions had higher frequent B2/C lesions (89.4% vs. 52.9%, p = 0.02), worse pre-PCI coronary flow (corrected thrombolysis in myocardial infarction count 21.6 ± 13.5 vs. 13.8 ± 6.2, p = 0.047) and greater lumen-area stenosis (79.6 ± 10.6% vs. 68.0 ± 21.6%, p = 0.047) than non-HP lesions. HP lesions had higher prevalence of OCT-thin-cap fibroatheroma (TCFA) (31.6% vs. 0.0%, p = 0.02), OCT-macrophage (89.5% vs. 41.2%, p = 0.004), and CAS-red thrombus (89.5% vs. 41.2%, p = 0.004) than non-HP lesions. The combination of 3 features including OCT-TCFA, macrophages, and CAS-red thrombus showed higher predictive valuer for HPs on OCT than each single variable. Post-PCI irregular tissue protrusion was more frequently observed in lesions with HPs than in those without (52.6% vs. 13.3%, p = 0.03). CONCLUSIONS: SAP lesions with HPs might have more frequent vulnerable plaques with intraplaque inflammation and thrombus than those without, suggesting that layered phenotype on OCT might reflect not only healing process but also potential risks for future coronary events.

Possibility of Targeting Claudin-2 in Therapy for Human Endometrioid Endometrial Carcinoma.

Claudin-2 (CLDN-2) is a leaky-type tight junction protein, and its overexpression increases tumorigenesis of some types of cancer cells. In the present study, to examine the possibility of targeting CLDN-2 in the therapy for endometrioid endometrial adenocarcinoma, we investigated the regulation and role of CLDN-2 in endometriosis and endometrioid endometrial adenocarcinoma. In endometrioid endometrial adenocarcinoma tissues, marked upregulation of CLDN-2 was observed together with malignancy, while in endometriosis tissues, a change in the localization of CLDN-2 was observed. In cells of the endometrial adenocarcinoma cell line Sawano, which highly express CLDN-2, downregulation of CLDN-2 induced by the siRNA upregulated the epithelial barrier and inhibited cell migration. Furthermore, the downregulation of CLDN-2 affected the cell cycle and inhibited cell proliferation. In Sawano cells cultured with high-glucose medium, CLDN-2 expression was downregulated at the mRNA and protein levels. The high-glucose medium upregulated the epithelial barrier, cell proliferation, and migration, and inhibited cell invasion. The histone deacetylase (HDAC) inhibitor tricostatin A (TSA), which has antitumor effects, downregulated CLDN-2 expression, cell proliferation, invasion, and migration, and upregulated the epithelial barrier. The mitochondrial respiration level, an indicator of cancer metabolism, was downregulated by CLDN-2 knockdown and upregulated by the high-glucose condition. Taken together, these results indicated that overexpression of CLDN-2 closely contributed to the malignancy of endometrioid endometrial adenocarcinoma. Downregulation of CLDN-2 via the changes of the glucose concentration and treatment with HDAC inhibitors may be important in the therapy for endometrial cancer.

ASPP2 suppression promotes malignancy via LSR and YAP in human endometrial cancer.

Apoptosis-stimulating p53 protein 2 (ASPP2) is an apoptosis inducer that acts via binding with p53 and epithelial polarity molecule PAR3. Lipolysis-stimulated lipoprotein receptor (LSR) is an important molecule at tricellular contacts, and loss of LSR promotes cell migration and invasion via Yes-associated protein (YAP) in human endometrial cancer cells. In the present study, to find how ASPP2 suppression promotes malignancy in human endometrial cancer, we investigated its mechanisms including the relationship with LSR. In endometriosis and endometrial cancers (G1 and G2), ASPP2 was observed as well as PAR3 and LSR in the subapical region. ASPP2 decreased in G3 endometrial cancer compared to G1. In human endometrial cancer cell line Sawano, ASPP2 was colocalized with LSR and tricellulin at tricellular contacts and binding to PAR3, LSR, and tricellulin in the confluent state. ASPP2 suppression promoted cell migration and invasion, decreased LSR expression, and induced expression of phosphorylated YAP, claudin-1, -4, and -7 as effectively as the loss of LSR. Knockdown of YAP prevented the upregulation of pYAP, cell migration and invasion induced by the ASPP2 suppression. Treatment with a specific antibody against ASPP2 downregulated ASPP2 and LSR, affected F-actin at tricellular contacts, upregulated expression of pYAP and claudin-1, and induced cell migration and invasion via YAP. In normal human endometrial epithelial cells, ASPP2 was in part colocalized with LSR at tricellular contacts and knockdown of ASPP2 or LSR induced expression of claudin-1 and claudin-4. ASPP2 suppression promoted cell invasion and migration via LSR and YAP in human endometrial cancer cells.

Epithelial barrier dysfunction and cell migration induction via JNK/cofilin/actin by angubindin-1.

Angulin-1/LSR is a tricellular tight junction molecule, that plays an important role in maintaining the epithelial and endothelial barriers. The actin cytoskeleton at tricellular contacts also contributes to the maintenance of the epithelial barrier. Loss of angulin-1/LSR enhances the migration of various cancer cells. Angubindin-1 is a novel binder to angulin-1/LSR and angulin-3. It is a peptide generated from the angulin-1 binding site of Clostridium perfringens iota toxin, which affects the actin cytoskeleton and decreases the epithelial and endothelial barrier functions. However, its regulatory mechanisms are not well understood. To investigate the regulatory mechanisms of the epithelial barrier dysfunction and cell migration induction by angubindin-1, we used human endometrial cancer cell line Sawano, which has high LSR expression and the epithelial barrier function. Angubindin-1 decreased LSR expression and the epithelial barrier function and increased cell migration. It inhibited the recovery of the epithelial barrier function in a Ca-switch model. At tricellular contacts, sinking of the membrane and an increase of actin fibers near the junctions were caused by angubindin-1. It dynamically changed F-actin from lines to dot-like structures at tricellular contacts. Angubindin-1 transiently increased the phosphorylation of cofilin and JNK, which are involved in the regulation of the intracellular actin cytoskeleton. Furthermore, knockdown of JNK and the JNK inhibitor SP600125 prevented the decrease of the epithelial barrier function and the increase of cell migration induced by angubindin-1. These findings suggest that angubindin-1 might reversibly regulate the epithelial barrier and cell migration at tricellular contacts via JNK/cofilin/actin cytoskeleton dynamics.

Localization of Tricellular Tight Junction Molecule LSR at Midbody and Centrosome During Cytokinesis in Human Epithelial Cells.

Epithelial integrity and barrier function are maintained during cytokinesis in vertebrate epithelial tissues. The changes in localization and the roles of tricellular tight junction molecule lipolysis-stimulated lipoprotein receptor (LSR) during cytokinesis are not well known, although new tricellular tight junctions form at the flank of the midbody during cytokinesis. In this study, we investigated the changes in localization and the role of LSR at the midbody and centrosome during cytokinesis using human endometrial carcinoma cell line Sawano, comparing the tricellular tight junction molecule tricellulin; bicellular tight junction molecules occludin, claudin-7, zonula occludens-1, and cingulin; and the epithelial polarized related molecules apoptosis-stimulating of p53 protein 2, PAR3, and yes-associated protein. During cytokinesis induced by treatment with taxol, the epithelial barrier was maintained and the tricellular tight junction molecules LSR and tricellulin were concentrated at the flank of the acetylated tubulin-positive midbody and in γ-tubulin-positive centrosomes with the dynein adaptor Hook2, whereas the other molecules were localized there as well. All the molecules disappeared by knockdown using small interfering RNAs. Furthermore, by the knockdown of Hook2, the epithelial barrier was maintained and most of the molecules disappeared from the centrosome. These findings suggest that LSR may play crucial roles not only in barrier function but also in cytokinesis.

Overexpression of the protein disulfide isomerase AtCYO1 in chloroplasts slows dark-induced senescence in Arabidopsis.

BACKGROUND: Chlorophyll breakdown is the most obvious sign of leaf senescence. The chlorophyll catabolism pathway and the associated proteins/genes have been identified in considerable detail by genetic approaches combined with stay-green phenotyping. Arabidopsis CYO1 (AtCYO1), a protein disulfide reductase/isomerase localized in the thylakoid membrane, is hypothesized to assemble the photosystem by interacting with cysteine residues of the subunits. RESULTS: In this study, we report that ectopic overexpression of AtCYO1 in leaves induces a stay-green phenotype during darkness, where oxidative conditions favor catabolism. In AtCYO1ox leaves, Fv/Fm and both chlorophyll a and chlorophyll b content remained high during dark-induced senescence. The thylakoid ultrastructure was preserved for a longer time in AtCYO1ox leaves than in wild type leaves. AtCYO1ox leaves maintained thylakoid chlorophyll-binding proteins associated with both PSII (D1, D2, CP43, CP47, LHCB2, and Cyt f) and PSI (PSA-A/B), as well as stromal proteins (Rubisco and ferredoxin-NADP+ reductase). AtCYO1ox did not affect senescence-inducible gene expression for chlorophyll catabolism or accumulation of chlorophyll catabolites. CONCLUSIONS: Our results suggest that ectopic overexpression of AtCYO1 had a negative impact on the initiation of chlorophyll degradation and proteolysis within chloroplasts. Our findings cast new light on the redox regulation of protein disulfide bonds for the maintenance of functional chloroplasts.

Direct measurement of intercellular CO2 concentration in a gas-exchange system resolves overestimation using the standard method.

Intercellular CO2 concentration of leaves (Ci) is a critical parameter in photosynthesis. Nevertheless, uncertainties in calculating Ci arise as stomata close. Here, by modifying the assimilation chamber of a commercial gas-exchange equipment to directly measure Ci, we demonstrate overestimation of calculated Ci (i.e. Ci(c)) without stimulating stomatal closure. Gas exchange was measured on one side of the leaf while measured Ci (Ci(m)) was acquired simultaneously on the other side of the leaf in hypostomatous passion fruit (Passiflora edulis Sims) and amphistomatous sunflower (Helianthus annuus L.) and common bean (Phaseolus vulgaris L.). The adaxial surface showed comparable Ci(c) and Ci(m) in sunflower, whereas in common bean, where the adaxial surface has a low stomatal density, Ci(c) markedly differed from Ci(m) when the stomata remained open. However, the latter discrepancy disappeared when measuring the leaf flipped upside down so that the gas exchange was measured (i.e. Ci was calculated) on the abaxial side, which has a much higher stomatal density. The passion fruit showed the largest discrepancy on the astomatous side, indicating that the cuticle has a large impact on the calculation. Direct measurement of Ci is recommended as a more accurate estimate than the calculation when stomatal gas transport is restricted. Occurrence of overestimation and prospects for direct measurement are discussed.

Downregulation of lipolysis-stimulated lipoprotein receptor promotes cell invasion via claudin-1-mediated matrix metalloproteinases in human endometrial cancer.

Lipolysis-stimulated lipoprotein receptor (LSR) is a novel molecule present at tricellular contacts which recruits tricellulin (TRIC), a molecular component of tricellular tight junctions (tTJs). LSR and TRIC are colocalized with the bicellular tight junction (bTJ) protein claudin (CLDN)-1-based tight junction strands at tricellular corners. Knockdown of LSR in normal epithelial cells affects tTJ formation and the epithelial barrier function. In cancer cells knockdown of LSR has been demonstrated to increase cell invasion. However, the detailed mechanisms of how the downregulation of LSR enhances cell invasion in cancer remain unclear. In the present study, knockdown of LSR by small interfering RNA (siRNA) in Sawano human endometrial adenocarcinoma cells induced cell invasion. In LSR-knockdown Sawano cells, upregulation of CLDN-1 protein, which contributes to the cell invasion via matrix metalloproteinases (MMPs), was observed compared with the control group by western blotting and immunostaining. Knockdown of LSR significantly induced Sp1 transcription factor activity in the CLDN-1 promoter region. In LSR-knockdown Sawano cells, DNA microarray analysis demonstrated that MMP-1, MMP-2 and MMP-10 mRNA levels were increased, and the protein levels of membrane-type 1-MMP, MMP-2, MMP-9 and MMP-10 were shown to be increased on western blots. Knockdown of CLDN-1 with siRNA prevented the upregulation of cell invasion induced by the knockdown of LSR in Sawano cells. On the invasive front of human endometrial carcinoma tissue samples, a decrease in LSR and increase in CLDN-1 protein levels were observed using immunohistochemical methods. In conclusion, the results indicate that the downregulation of LSR promotes cell invasion of human endometrial cancer via CLDN-1 mediation of MMPs. This mechanism is important for studying the association of tTJs with the cellular invasion of cancer.

Immunohistochemical Comparison of Malignancy Between Radial Invasion and Mucosal Extension in Hilar Cholangiocarcinoma.

AIM: To compare the cells of mucosal extension (ME) and radial invasion (RI) in hilar cholangiocarcinoma (HCCA) for optimal resection. MATERIALS AND METHODS: Forty-six patients underwent surgery for HCCA between 1992 and 2004. Immunohistochemical expressions of p53, Ki-67, matrix metalloproteinase-7 (MMP7), mucin 1 (MUC1), and E-cadherin were assessed at five different sites of the tumour and compared between the recurrence and non-recurrence groups. RESULTS: Expression of E-cadherin was significantly lower in RI cells than in ME cells, and that of MMP7 and MUC1 was significantly higher in RI cells than in ME cells. Ki-67 expression was higher in ME cells than in RI cells. During the 11-year follow-up, recurrence in patients with R0 resection was associated with significantly lower E-cadherin, higher MMP7, and higher Ki-67 expression. CONCLUSION: Removal of as many RI cells as possible should be a priority in resection of HCCA, followed by removal of ME cells. E-Cadherin appears to be associated with recurrence of HCCA.

Loss of tricellular tight junction protein LSR promotes cell invasion and migration via upregulation of TEAD1/AREG in human endometrial cancer.

Lipolysis-stimulated lipoprotein receptor (LSR) is a unique molecule of tricellular contacts of normal and cancer cells. We investigated how the loss of LSR induced cell migration, invasion and proliferation in endometrial cancer cell line Sawano. mRNAs of amphiregulin (AREG) and TEA domain family member 1 (TEAD1) were markedly upregulated by siRNA-LSR. In endometrial cancer tissues, downregulation of LSR and upregulation of AREG were observed together with malignancy, and Yes-associated protein (YAP) was present in the nuclei. siRNA-AREG prevented the cell migration and invasion induced by siRNA-LSR, whereas treatment with AREG induced cell migration and invasion. LSR was colocalized with TRIC, angiomotin (AMOT), Merlin and phosphorylated YAP (pYAP). siRNA-LSR increased expression of pYAP and decreased that of AMOT and Merlin. siRNA-YAP prevented expression of the mRNAs of AREG and TEAD1, and the cell migration and invasion induced by siRNA-LSR. Treatment with dobutamine and 2-deoxy-D-glucose and glucose starvation induced the pYAP expression and prevented the cell migration and invasion induced by siRNA-LSR. siRNA-AMOT decreased the Merlin expression and prevented the cell migration and invasion induced by siRNA-LSR. The loss of LSR promoted cell invasion and migration via upregulation of TEAD1/AREG dependent on YAP/pYAP and AMOT/Merlin in human endometrial cancer cells.

The roles of tricellular tight junction protein lipolysis-stimulated lipoprotein receptor in malignancy of human endometrial cancer cells.

Lipolysis-stimulated lipoprotein receptor (LSR) has been identified as a novel molecular constituent of tricellular contacts that have a barrier function for the cellular sheet. LSR recruits tricellulin (TRIC), which is the first molecular component of tricellular tight junctions. Knockdown of LSR increases cell motility and invasion of certain cancer cells. However, the behavior and the roles of LSR in endometrial cancer remain unknown. In the present study, we investigated the behavior and roles of LSR in normal and endometrial cancer cells in vivo and in vitro. In endometriosis and endometrial cancer, LSR was observed not only in the subapical region but also throughout the lateral region as well as in normal endometrial epithelial cells in the secretory phase, and LSR in the cancer was reduced in correlation with the malignancy. Knockdown of LSR by the siRNA in cells of the endometrial cancer cell line Sawano, induced cell migration, invasion and proliferation, while TRIC relocalized from the tricellular region to the bicellular region at the membrane. In Sawano cells and normal HEEs, a decrease of LSR induced by leptin and an increase of LSR induced by adiponectin and the drugs for type 2 diabetes metformin and berberine were observed via distinct signaling pathways including JAK2/STAT. In Sawano cells, metformin and berberine prevented cell migration and invasion induced by downregulation of LSR by the siRNA and leptin treatment. The dissection of the mechanism in the downregulation of endometrial LSR during obesity is important in developing new diagnostic and therapy for endometrial cancer.

In vitro and in vivo evidence for oxalate oxidase activity of a germin-like protein from azalea.

Germins and germin-like proteins (GLPs) comprise large families of extracellular plant glycoproteins that are structurally similar, yet they have been reported to have distinct biochemical activities: oxalate oxidase and superoxide dismutase activities, respectively. We expressed an azalea GLP (RmGLP2) in cultured cells of tobacco, and determined that the extracellular protein fraction and the recombinant RmGLP2 protein purified from these cells catalyzed the oxidation of oxalate. Notably, this activity is purportedly restricted to germin and has not been demonstrated for a GLP. Although the specific activity of the purified RmGLP2 protein was low compared with that of a previously characterized barley germin/oxalate oxidase, tobacco cells expressing RmGLP2 exhibited significantly reduced oxalate levels. Thus, RmGLP2 represents the first reported GLP with oxalate oxidase activity.