Discovery of YS-1 as a cell line of gastric inflammatory cancer-associated fibroblasts.

BACKGROUND: Inflammatory cancer-associated fibroblasts (iCAFs) was first identified by co-culture of pancreatic stellate cells and tumor organoids. The key feature of iCAFs is IL-6high/αSMAlow. We examine this phenomenon in gastric cancer using two cell lines of gastric fibroblasts (HGF and YS-1). METHODS AND RESULTS: HGF or YS-1 were co-cultured with MKN7 (a gastric adenocarcinoma cell line) in Matrigel. IL-6 protein levels in the culture supernatant were measured by ELISA. The increased production of IL-6 was not observed in any of the combinations. Instead, the supernatant of YS-1 exhibited the higher levels of IL-6. YS-1 showed IL-6high/αSMA (ACTA2)low in real-time PCR, mRNA-seq and immunohistochemistry. In mRNA-seq, iCAFs-associated genes and signaling pathways were up-regulated in YS-1. No transition to myofibroblastic phenotype was observed by monolayer culture, or the exposure to sonic hedgehog (SHH) or TGF-ß. YS-1 conditioned medium induced changes of morphology and stem-ness/differentiation in NUGC-3 (a human gastric adenocarcinoma cell line) and UBE6T-15 (a human bone marrow-derived mesenchymal stem cell line). CONCLUSIONS: YS-1 is a stable cell line of gastric iCAFs. This discovery will promote further research on iCAFs for many researchers.

Histopathology of pulmonary thromboembolism in a patient with Behçet's disease.

Pulmonary involvement in vascular Behçet's disease (BD) (VBD) is a serious manifestation. Among the pulmonary manifestations, pulmonary embolism is considered a rare manifestation because deep vein thrombosis (DVT) has been thought to detach from the vessel wall, whereas pulmonary thrombus has been suggested to result from in situ pulmonary arteritis.In this case report, we present histopathological evidence of pulmonary embolism derived from DVT in an autopsy case of VBD. This observation emphasises that DVT causes pulmonary embolism in BD, indicating that anticoagulants are required for its prevention.

Cytological features of BCOR-CCNB3 sarcoma: Comparison with Ewing sarcoma and synovial sarcoma.

INTRODUCTION: BCOR-CCNB3 sarcoma (BCS) is one of the histological types classified as an undifferentiated small round cell sarcoma of bone and soft tissue. This sarcoma frequently develops in males under 20 years of age. Histologically, a delicate capillary network has been reported as a conspicuous finding. In this study, the cytological findings of BCS were observed in two cases of primary lesions and one case of a lung metastatic lesion. The cytological findings of BCS were compared with its histological mimics, and the characteristic findings of BCS were examined. METHODS: Three cases of BCS were studied, and a cytological comparison was performed with 8 cases of Ewing sarcoma (ES) and 10 cases of synovial sarcoma (SS; monophasic type: 7 cases, biphasic type: 2 cases, poorly differentiated: 1 case). RESULTS: In all BCS cases, small clusters with thin and delicate vascular cores and tiny vascular fragments were conspicuous. In ES and SS cases, although small clusters with vascular cores were observed, the vascular cores were thicker than in BCS, and no tiny vascular fragments appeared in most cases. Cytomorphological differences of tumour cells were also observed among BCS, ES, and SS. Predominantly rounded nuclei with fine chromatin and inconspicuous nucleoli can be cytological clues for BCS. CONCLUSIONS: BCS shows characteristic cytological findings that make the diagnosis of BCS more likely than that of ES and SS. Cytological evaluation is a useful tool for appropriate differential diagnosis that leads to a more accurate final diagnosis and rapid treatment.

Cancer stem cells in Epstein-Barr virus-associated gastric carcinoma.

Cancer stem cells (CSCs) play a decisive role in the development and progression of cancer. To investigate CSCs in Epstein-Barr virus (EBV)-associated carcinoma (EBVaGC), we screened previously reported stem cell markers of gastric cancer in EBV-infected gastric cancer cell lines (TMK1 and NUGC3) and identified CD44v6v9 double positive cells as candidate CSCs. CD44v6/v9+/+ cells were sorted from EBVaGC cell line (SNU719) cells and EBV-infected TMK1 cells and these cell populations showed high spheroid-forming ability and tumor formation in SCID mice compared with the respective CD44v6/v9-/- cells. Sphere-forming ability was dependent on the nuclear factor-κB (NF-κB) signaling pathway, which was confirmed by decrease of sphere formation ability under BAY 11-7082. Small interfering RNA knockdown of latent membrane protein 2A (LMP2A), one of the latent gene products of EBV infection, decreased spheroid formation in SNU719 cells. Transfection of the LMP2A gene increased the sphere-forming ability of TMK1 cells, which was mediated through NF-κB signaling. Together, these results indicate that CD44v6v9+/+ cells are CSCs in EBVaGC that are maintained through the LMP2A/NF-κB pathway. Future studies should investigate CD44v6/v9+/+ cells in normal and neoplastic gastric epithelium to prevent and treat this specific subtype of gastric cancer infected with EBV.

Loss of the cell polarity determinant human Discs-large is a novel molecular marker of nodal involvement and poor prognosis in endometrial cancer.

BACKGROUND: Recent Drosophila studies showed that Discs-large (Dlg) is critical for regulation of cell polarity and tissue architecture. We investigated the possibility that loss of the human homologue of Drosophila Dlg (DLG1) is involved in endometrial carcinogenesis. METHODS: We analysed DLG1 expression in 160 endometrial cancers by immunohistochemical staining. Its expression was confirmed by quantitative real-time PCR (RT-PCR). We investigated the roles of DLG1 in growth and invasion by knockdown experiment in endometrial cancer cell lines. RESULTS: Human DLG1 localises at cellular membrane in normal endometrial tissues. Loss of DLG1 was observed in 37 cases (23.1%). Loss of DLG1 was observed in patients with advanced stage and high-grade histology. It was also observed in patients with nodal metastasis, deep myometrial invasion, and negative oestrogen and progesterone receptors. Patients with loss of DLG1 showed poorer overall survival (P=0.0019). Immunohistochemistry data correlated with RT-PCR data. Knockdown of Dlg1 in endometrial cancer cells resulted in accelerated tumour migration and invasion in vitro. CONCLUSIONS: Tissue polarity disturbance because of loss of DLG1 was shown to confer more aggressive characteristics to endometrial cancer cells. Our study revealed that DLG1 expression is a novel molecular biomarker of nodal metastasis, high-grade histology, and poor prognosis in endometrial cancer.

Both cancerous miR-21 and stromal miR-21 in urothelial carcinoma are related to tumour progression.

AIMS: Urothelial carcinoma (UC) is a globally common cancer. miR-21 appears to be important in the tumorigenesis of almost all types of human cancer. However, its precise localization and significance in UC have yet to be clarified. The aim of this study was to examine miR-21 expression in UC and reveal its clinicopathological importance. METHODS AND RESULTS: Tissue arrays of 232 UCs were examined for miR-21 by the use of in-situ hybridization. One hundred and forty-eight transurethral resection specimens and 84 surgically resected specimens were used. After miR-21 positivity had been evaluated separately in tumour cells and the tumour stroma, it was compared with clinicopathological factors and overall survival. miR-21 was strongly expressed in tumour cells in 9% of cases and in the tumour stroma in 6% of cases. Stromal miR-21 positivity was lower than that of cancerous miR-21. Both miR-21s were correlated with each other and related to tumour stage, locus, and histological grade. In addition, strong positivity of miR-21 in cancer and the stroma was significantly related to poorer prognosis among surgically resected cases. In a Cox proportional hazard model, cancerous miR-21 was the only independent prognostic factor except for tumour stage. CONCLUSIONS: miR-21 in both cancer and stromal cells is closely related to tumour progression in UC. miR-21 may be a prognostic marker for cancer progression.

Preserved or enhanced OATP1B3 expression in hepatocellular adenoma subtypes with nuclear accumulation of ß-catenin.

AIM: Recent studies have indicated that hepatocellular adenoma (HCA) is a heterogenous group of benign tumors with various genetic and clinicopathological characteristics. We delineated the clinicopathological characteristics of HCA subtypes and evaluated the expression of transporter protein OATP1B3 in HCA. METHODS: HCA in 34 Japanese patients were investigated immunohistochemically and classified into four subtypes (HNF1α-inactivated type, H-HCA; ß-catenin-activated type, b-HCA; inflammatory type, I-HCA; unclassified type, u-HCA). Immunostaining of OATP1B3 protein in HCA tissue sections was performed to determine the association between OATP1B3 expression and HCA subtypes. RESULTS: HCA was categorized into the following four subtypes and two combined subtypes: 10 H-HCA (29%), 10 I-HCA (29%), seven b-HCA (21%), two b-HCA/H-HCA (6%), two b-HCA/I-HCA (6%) and three u-HCA (9%). The male-to-female ratio was 18:16. Oral contraceptive use was rare but seven HCA were found in patients with glycogen storage disease, congenital absence of the portal vein and idiopathic portal hypertension. OATP1B3 expression was decreased in 24 HCA but was preserved or increased in 10 HCA. All nine HCA with nuclear staining for ß-catenin showed preserved or enhanced OATP1B3 expression, indicating a significant association between nuclear ß-catenin accumulation and OATP1B3 expression in HCA. CONCLUSION: HCA subtype classification was validated in 91% of our Japanese subjects although their clinical backgrounds including rare contraceptive use were different from European subjects. A close association between preserved or enhanced OATP1B3 expression and b-HCA subtype indicated important modalities for clinical decisions in the treatment and follow up of patients with HCA.

Stromal miR-21 is more important than miR-21 of tumour cells for the progression of gastric cancer.

BACKGROUND: Gastric cancer (GC) is a common cancer globally. miRNA-21 (miR-21) appears to be important in the tumourigenesis of almost all types of human cancer. However its precise localization in GC has yet to be clarified. We thus examined miR-21 localization in GC and revealed its clinicopathological importance. METHODS: Tissue arrays of 469 GCs from 454 patients were examined for miR-21 using in situ hybridization (ISH). The positivity was evaluated separately in tumour cells and stromal cells. Conventional sections of 10 GCs were also stained. Eight cases were examined by quantitative RT-PCR (qRT-PCR). RESULTS: miR-21 was highly expressed in tumour cells of 44% of cases and in cancer stroma of 51% of cases. miR-21 of tumour cells was not related to clinicopathological factors, whereas stromal miR-21 was related to many factors including tumour stage, size, and nodal metastasis. Stromal miR-21 gradually increased during tumour progression. ISH of whole sections showed stronger stromal positivity in invasive areas with desmoplastic reaction. Cancer stroma also showed higher miR-21 expression than tumour and non-tumourous tissue in the qRT-PCR study. CONCLUSION: Stromal miR-21 is closely related to tumour progression in GC. Stromal miR-21 of tumours might be a target of treatment.

Integrins αvß6, α6ß4 and α3ß1 are down-regulated in cholangiolocellular carcinoma but not cholangiocarcinoma.

AIM: The aim of this study was to evaluate integrin expression and immunolocalization of the extracellular matrix proteins in cholangiolocellular carcinoma (CoCC). METHODS: Tissue specimens of 23 CoCC, 28 cholangiocarcinomas (CCC), 42 hepatocellular carcinomas (HCC) and 11 classical type combined hepatocellular cholangiocarcinomas (CHC) were immunostained for ß6, ß4 and α3 integrins, fibronectin and laminin. ITGB6, B4 and A3 mRNA levels in six HCC cell lines, five CCC cell lines and two CHC cell lines were quantified by quantitative reverse transcription polymerase chain reaction. RESULTS: Little or no positivity for ß6, ß4 and α3 integrins was shown in 91%, 91% and 52% of CoCC and 100%, 98% and 81% of HCC, respectively, according to immunostaining, whereas intense positive staining for these integrins was demonstrated in 64%, 96% and 75% of CCC, respectively. There was a close correlation between ß4 and α3 integrin expression and intracytoplasmic laminin in CoCC, CCC and HCC, but not between ß6 expression and its ligand, fibronectin. Integrin mRNA levels were increased in four of five CCC cell lines, but nearly undetectable in five of six HCC cell lines and one CHC cell line. Tubular differentiation of a CHC cell line cultured in collagen gel matrix induced upregulation of these integrins. CONCLUSION: Our results first indicated downregulation of αvß6, α6ß4 and α3ß1 integrins in CoCC, in contrast to its high expression in CCC, suggesting a diagnostic value of integrins in the differential diagnosis of CoCC and CCC, as well as a useful inducible marker of the intermediate features of CoCC.

Japanese herbal medicines shosaikoto, inchinkoto, and juzentaihoto inhibit high-fat diet-induced nonalcoholic steatohepatitis in db/db mice.

Few studies have investigated the effects of Japanese herbal medicines on nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). To the best of our knowledge, only one study has examined whether high-fat (HF) diet-fed db/db mice are appropriate animal models of NASH. We investigated the effects of four types of Japanese herbal medicines (shosaikoto (TJ-9), inchinkoto (TJ-135), juzentaihoto (TJ-48), and keishibukuryogan (TJ-25)) on hepatic lesions of HF diet-fed db/db mice. Db/db mice were divided into six groups: control diet (control); HF diet (HF); and HF diet supplemented with TJ-9, TJ-135, TJ-48, or TJ-25 (TJ-9, TJ-135, TJ-48, and TJ-25, respectively). Mice were killed after 6 weeks of treatment, and biochemical and pathological analyses were performed. Mice in the HF group consistently developed histopathological features consistent with definite NASH, and marked necroinflammation occurred. Serum alanine aminotransferase levels in the TJ-9, TJ-135, and TJ-48 groups were significantly improved compared with those in the HF group. With regard to liver histology, TJ-9 and TJ-48 significantly improved lobular inflammation, and TJ-135 significantly improved ballooning degeneration. We have shown that HF diet-fed db/db mice are animal models that correctly recapitulate the histopathology of human NASH and that TJ-9, TJ-135, and TJ-48 inhibit necroinflammatory activity in this model.

Gastric Cancer With the Increased Nicotinamide N-methyltransferase-positive Stromal Cells Includes Unfavorable Prognosis-related Cancer-associated Fibroblasts.

BACKGROUND/AIM: "Stromal high expression" of Nicotinamide N-methyltransferase (NNMT), previously reported as a poor prognostic factor of gastric cancer, was based on immunohistochemical H-score. However, this could simply indicate an increase in cancer-associated fibroblasts (CAFs) because NNMT is positive for fibroblasts. To verify this, the proportion and staining intensity of stromal NNMT-positive stellate/spindle cells were evaluated separately and examined for its association with related proteins (H3K4me3, H3K27me3, and LOXL2). PATIENTS AND METHODS: Immunohistochemistry for NNMT, H3K4me3, H3K27me3, and LOXL2 was performed on 521 tissue microarrays of gastric cancer. Cancer stromal stellate/spindle cells were evaluated according to morphology, proportion, and stain intensity of NNMT, loss of H3K4me3 and H3K27me3, and stain intensity of LOXL2. Their associations with clinicopathological characteristics and overall survival were examined. RESULTS: Higher staining intensity of NNMT was not related to a poorer prognosis. However, higher proportion of NNMT-positive stellate/spindle cells indirectly contributed to a poor prognosis. It was associated with CAF-like morphology and a global decrease in H3K4me3/H3K27me3, which were both associated with high LOXL2 expression. These three factors were independent poor prognostic factors. In addition, in the LOXL2-high group, prognosis significantly deteriorated with the presence of a global decrease in H3K4me3/H3K27me3. CONCLUSION: The higher proportion of NNMT-positive cancer stromal cells in gastric cancer serves as an indicator for identifying unfavorable prognostic CAFs that show a global decrease in H3K4me3/H3K27me3. This facilitates research on the nature of these cells and their characteristics.

Cytopathology of Chondromyxoid Fibroma: Report of 2 Cases with Immunocytochemical Expression of GRM1.

INTRODUCTION: Chondromyxoid fibroma (CMF) is a rare, benign bone tumor that occurs predominantly in the second and third decades of life, more frequently in males. Overexpression of GRM1 as a consequence of tumor-specific gene rearrangement of GRM1 has recently been reported as a useful immunohistochemical marker for histopathological diagnosis of CMF. However, the usefulness of GRM1 staining of cytology specimens has not yet been evaluated. In this report, the cytological findings and GRM1 immunocytochemistry of two cases of CMF are described. CASE PRESENTATIONS: Case 1 was a 15-year-old girl with a rib tumor. Imaging findings suggested a benign neurogenic tumor such as schwannoma. The tumor had increased in size over a 2-year period and was resected. Case 2 was a 14-year-old boy with a metatarsal tumor involving his left first toe. Imaging findings were suspicious of a benign neoplastic lesion. Biopsy findings suggested a benign tumor, and the patient underwent tumor resection. Cytologically, in both cases the tumor cells were predominantly spindle-shaped or stellate, with a myxoid to chondromyxoid background matrix and multinucleated giant cells, and these matrices were metachromatic with Giemsa staining. Cellular atypia was more accentuated in case 2 than in case 1. Immunocytochemical staining for GRM1 was positive in both cases. CONCLUSION: Due to the overlap in cytological findings, it is often difficult to differentiate CMF from chondroblastoma and chondrosarcoma grade 2. Immunocytochemical staining for GRM1 may support the diagnosis of CMF, and the reuse of Papanicolaou-stained specimens is applicable. The present cases further demonstrated the difficulty of differentiating CMF from other mimicking tumors such as chondroblastoma and chondrosarcoma grade 2. In such instances, immunocytochemistry for GRM1 is applicable to the diagnostic process, the value of which is strengthened by reusing Papanicolaou-stained specimens.

A Case of Fungal Maxillary Sinusitis Extending to the Contralateral Side Through the Nasal Septum.

Fungal rhinosinusitis (FRS) presents as various phenotypes ranging from asymptomatic colonization to life-threatening infections. Here, we report an atypical case of FRS of the left maxillary sinus that extended to the contralateral maxillary sinus through the nasal septum. An 80-year-old woman with a history of osteoporosis was referred to our hospital for further management of headaches and chronic rhinosinusitis. Computed tomography (CT) of the sinus revealed a mass lesion with calcification in the left maxillary sinus, extending to the contralateral maxillary sinus through the nasal septum. T1-weighted and T2-weighted magnetic resonance imaging revealed a mass lesion with low-intensity signals. Endoscopic sinus surgery was performed for the diagnosis and treatment. Histopathological examination revealed fungal elements in the caseous material of the left maxillary sinus. However, no tissue-invasive fungal forms were found. Additionally, eosinophilic mucin was not observed. Based on these findings, the patient was diagnosed with fungus ball (FB). To the best of our knowledge, there are no reports of a FB extending contralaterally through the nasal septum. This report serves as a reminder that FB can extend into contralateral paranasal sinuses through the nasal septum and the possibility that osteoporosis is a cause of extensive bone destruction.

The critical role of neutral cholesterol ester hydrolase 1 in cholesterol removal from human macrophages.

RATIONALE: Hydrolysis of intracellular cholesterol ester (CE) is the key step in the reverse cholesterol transport in macrophage foam cells. We have recently shown that neutral cholesterol ester hydrolase (Nceh)1 and hormone-sensitive lipase (Lipe) are key regulators of this process in mouse macrophages. However, it remains unknown which enzyme is critical in human macrophages and atherosclerosis. OBJECTIVE: We aimed to identify the enzyme responsible for the CE hydrolysis in human macrophages and to determine its expression in human atherosclerosis. METHODS AND RESULTS: We compared the expression of NCEH1, LIPE, and cholesterol ester hydrolase (CES1) in human monocyte-derived macrophages (HMMs) and examined the effects of inhibition or overexpression of each enzyme in the cholesterol trafficking. The pattern of expression of NCEH1 was similar to that of neutral CE hydrolase activity during the differentiation of HMMs. Overexpression of human NCEH1 increased the hydrolysis of CE, thereby stimulating cholesterol mobilization from THP-1 macrophages. Knockdown of NCEH1 specifically reduced the neutral CE hydrolase activity. Pharmacological inhibition of NCEH1 also increased the cellular CE in HMMs. In contrast, LIPE was barely detectable in HMMs, and its inhibition did not decrease neutral CE hydrolase activity. Neither overexpression nor knockdown of CES1 affected the neutral CE hydrolase activity. NCEH1 was expressed in CD68-positive macrophage foam cells of human atherosclerotic lesions. CONCLUSIONS: NCEH1 is expressed in human atheromatous lesions, where it plays a critical role in the hydrolysis of CE in human macrophage foam cells, thereby contributing to the initial part of reverse cholesterol transport in human atherosclerosis.

A case of de novo focal segmental glomerulosclerosis occurred one and half years after kidney transplantation supposed to be caused by calcineurin inhibitor.

A 64-yr-old man with end-stage kidney disease caused by hypertensive nephrosclerosis underwent living-unrelated ABO-identical kidney transplantation (KTx) at the age of 60 yr from his 60-yr-old wife. Maintenance trough concentration of cyclosporine A (CsA) was 100 ± 30 ng/mL. Five months after KTx, proteinuria gradually increased to around 1 g/d. TRBx at eight months after KTx revealed the new-onset alteration of mild arteriolosclerosis with intimal hyalinosis, which might reflect calcineurin inhibitor (CNI)-associated arteriopathy (CAA). Nearly one and half years after KTx, urinary protein excretion became nearly 2 g/d. TRBx revealed the advanced CAA and findings of focal segmental glomerulosclerosis (FSGS). Then, CNI was switched from CsA to tacrolimus (TAC). TRBx at two and half years after KTx revealed progressed arteriolar transmural thickening and striped fibrosis, which were supposed to be induced by an increase in serum TAC concentration because of acute enterocolitis. Then, TAC dose was reduced to serum trough concentration 5-8 ng/mL, but urinary protein excretion was increased up to 10 g/d. Reduction of TAC to trough concentration 2.0 ± 0.5 ng/mL reduced urinary protein excretion. Attempts to elevate TAC trough concentration within normal range (4-8 ng/mL) reproducibly induced the recurrence of an increase in sCr or urinary protein excretion. All these findings supported the etiology of graft dysfunction, and proteinuria of this case was FSGS.

Analysis for the combination expression of CK20, FABP1 and MUC2 is sensitive for the prediction of peritoneal recurrence in gastric cancer.

Prediction of peritoneal recurrence in gastric cancer patients is important for application of adjuvant chemotherapy. After surgery, occasional patients have peritoneal recurrence despite negative cytology of the peritoneal washings. Thus, molecular detection of a subliminal number of cancer cells in peritoneal washings may overcome the sensitivity limitation of conventional cytology. In this study, expressions of five specific marker genes, namely, TFF1, TFF2, CK20, FABP1 and MUC2, were evaluated for their usefulness as markers of micro-dissemination. It was found that reverse transcriptase-polymerase chain reaction for these five genes yielded results highly specific for the depth of invasion and disease stage. Furthermore, the expression of CK20, FABP1 and MUC2 was a reliable prognostic indicator of peritoneal metastasis. Our results suggest that evaluation of the expression of CK20, FABP1 and MUC2 in peritoneal washings is a useful tool for identifying patients at high risk of peritoneal recurrence who may need adjuvant chemotherapy.

Abrogation of neutral cholesterol ester hydrolytic activity causes adrenal enlargement.

We have previously demonstrated that neutral cholesterol ester hydrolase 1 (Nceh1) regulates foam cell formation and atherogenesis through the catalytic activity of cholesterol ester hydrolysis, and that Nceh1 and hormone-sensitive lipase (Lipe) are responsible for the majority of neutral cholesterol ester hydrolase activity in macrophages. There are several cholesterol ester-metabolizing tissues and cells other than macrophages, among which adrenocortical cells are also known to utilize the intracellular cholesterol for steroidogenesis. It has been believed that the mobilization of intracellular cholesterol ester in adrenal glands was facilitated solely by Lipe. We herein demonstrate that Nceh1 is also involved in cholesterol ester hydrolysis in adrenal glands. While Lipe deficiency remarkably reduced the neutral cholesterol ester hydrolase activity in adrenal glands as previously reported, additional inactivation of Nceh1 gene completely abrogated the activity. Adrenal glands were enlarged in proportion to the degree of reduced neutral cholesterol ester hydrolase activity, and the enlargement of adrenal glands and the accumulation of cholesterol esters were most pronounced in the Nceh1/Lipe double-deficient mice. Thus Nceh1 is involved in the adrenal cholesterol metabolism, and the cholesterol ester hydrolytic activity in adrenal glands is associated with the organ enlargement.

Protective role of the leukotriene B4 receptor BLT2 in murine inflammatory colitis.

BLT2 is a low-affinity leukotriene B(4) (LTB(4)) receptor that is activated by 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT) and LTB(4). Despite the well-defined proinflammatory roles of BLT1, the in vivo functions of BLT2 remain elusive. To clarify the role of BLT receptors in intestinal inflammation, we assessed susceptibility to dextran sodium sulfate (DSS)-induced colitis in mice lacking either BLT1 or BLT2. BLT2(-/-) mice exhibited increased sensitivity to DSS as compared to wild-type and BLT1(-/-) mice, with more severe body weight loss and inflammation. Expression of inflammatory cytokines such as interferon (IFN)-γ, interleukin (IL)-1ß, and IL-6, chemokines such as CXC chemokine ligand 9 (CXCL9) and C-C motif chemokine 19 (CCL19), and metalloproteinases was highly up-regulated in the colons of DSS-treated BLT2(-/-) mice, and there was an enhanced accumulation of activated macrophages. Phosphorylation of the signal transducer and activator of transcription 3 (STAT3) was also markedly accelerated in the crypts of DSS-treated BLT2(-/-) mice. Madin-Darby canine kidney II (MDCKII) cells transfected with BLT2 exhibited enhanced barrier function as measured by transepithelial electrical resistance (TER) and FITC-dextran leakage through MDCK monolayers. Thus, BLT2 is expressed in colon cryptic cells and appears to protect against DSS-induced colitis, possibly by enhancing barrier function in epithelial cells of the colon. These novel results suggest a direct anti-inflammatory role of BLT2 that is distinct from the proinflammatory roles of BLT1.

Low MLL2 Protein Expression Is Associated With Fibrosis in Early Stage Gastric Cancer.

BACKGROUND/AIM: Myeloid/lymphoid or mixed lineage leukemia 2 (MLL2) gene is mutated in gastric cancer, with most resulting in inactivated proteins. In this study, we examined the expression of MLL2 protein in gastric cancers. PATIENTS AND METHODS: The expression of MLL2 protein in cancer cell nuclei was studied by immunohistochemistry in tissue microarrays of 529 human gastric cancers. MLL2 expression was classified into low and high expression from the point of zygosity, and its relationships with mismatch repair protein expression and clinicopathological features were examined. RESULTS: Low expression of MLL2 was associated with younger age, MSH6, and early cancers. MLL2-low pT1a cancers were associated with fibrosis, especially ulcer scars, and in 62.5% of them there was no direct contact between carcinoma and fibrosis. CONCLUSION: There is potentially an association between low expression of MLL2 protein and gastric malignancy from chronic fibrosis.