Inflammatory bowel diseases, like ulcerative colitis and Crohn's disease are frequently accompanied by colorectal cancers. However, the mechanisms underlying colitis-associated cancers are not fully ...understood. Src Kinase Associated Phosphoprotein 2 (SKAP2), a substrate of Src family kinases, is highly expressed in macrophages. Here, we examined the effects of SKAP2 on inflammatory responses in a mouse model of tumorigenesis with colitis induced by azoxymethane/dextran sulfate sodium. SKAP2 knockout increased the severity of colitis and tumorigenesis, as well as lipopolysaccharide (LPS) induced acute inflammation. SKAP2 attenuated inflammatory signaling in macrophages induced by uptake of cancer cell-derived exosomes. SKAP2
mice were characterized by the activation of NF-κB signaling and the upregulation and release of cytokines including TNFα, IL-1β, IL-6, CXCL-9/-10/-13, and sICAM1; SKAP2 overexpression attenuated NF-κB activation. Mechanistically, SKAP2 formed a complex with the SHP-1 tyrosine phosphatase via association with the Sirpα transmembrane receptor. SKAP2 also physically associated with the TIR domain of MyD88, TIRAP, and TRAM, adaptors of toll-like receptor 4 (TLR4). SKAP2-mediated recruitment of the Sirpα/SHP-1 complex to TLR4 attenuated inflammatory responses, whereas direct interaction of SKAP2 with SHP-2 decreased SHP-2 activation. SHP-2 is required for efficient NF-κB activation and suppresses the TRAM/TRIF-INFβ pathway; therefore, SKAP2-mediated SHP-2 inhibition affected two signaling axes from TLR4. The present findings indicate that SKAP2 prevents excess inflammation by inhibiting the TLR4-NF-κB pathway, and it activates the TLR4-IFNβ pathway through SHP-1 and SHP-2, thereby suppressing inflammation-mediated tumorigenesis.
Epstein-Barr virus-positive gastric cancer EBV (+) GC is a distinct GC subtype with unique genetic and epigenetic aberrations. Here, we examined resected GC samples and publicly available microarray ...data and The Cancer Genome Atlas (TCGA) database to identify the mechanism underlying overexpression of PD-L1 in EBV (+) GC. We found that high levels of PD-L1 overexpression in EBV (+) GC were caused by focal amplification of CD274. By contrast, relatively high expression of PD-L1 in tumor tissue and infiltrating immune cells correlated with CD8 lymphocyte infiltration and IFN-γ expression via IRF3 activation. Since we reported previously that PD-L1 expression is associated both with the presence of CD8 T cells in the tumor microenvironment and with IFN-γ expression in GC, we examined a database to see whether IFN-γ-associated overexpression of PD-L1 plays a significant role in EBV (+) GC. Immunohistochemical staining showed that expression of the IRF3 signature in clinical GC samples was higher in EBV (+) than in EBV (-) cases. The data presented herein reveal a unique dual mechanism underlying PD-L1 overexpression in EBV (+) GC: high focal amplification of CD274 or IFN-γ-mediated signaling via activation of IRF3.
Tumor-derived extracellular vesicles (TEVs) secreted into the blood create a pre-metastatic niche in distant organs; however, it is unclear how TEVs are delivered and how they affect stromal cells in ...the tumor microenvironment. Tumor-associated macrophages (TAMs) have pivotal roles in cancer progression by interacting with cancer cells and other stromal cells. Here, we report a novel function of TAMs: delivery and transmission of TEV contents. TEV-incorporating macrophages (TEV-MΦs) showed increased invasiveness and were disseminated widely. Upon contact with host stromal cells (peritoneal mesothelial cells (PMCs), fibroblasts, and endothelial cells), TEV-MΦs released membrane blebs containing TEVs, a process dependent upon localized activation of caspase-3 in MΦs. Scattered blebs were incorporated into stromal cells, leading to transfer of cancer-derived RNA and proteins such as TGF-β, activated Src, Wnt3, and HIF1α. TEV-MΦ-secreted blebs containing cancer-derived components contributed to myofibroblastic changes in recipient stromal cells. TEVs delivered by MΦs penetrated deep into the parenchyma of the stomach in TEV-injected mice, and transmitted TEVs to PMCs lining the stomach surface; this process induced PMCs to undergo mesothelial-mesenchymal transition. PMCs infiltrated the gastric wall and created a niche, thereby promoting tumor invasion. Depletion of MΦs prevented these events. Moreover, TEV-MΦs created a pro-metastatic niche. Taken together, these results suggest a novel function for TAMs: transfer of cancer-derived components to surrounding stromal cells and induction of a pro-tumor microenvironment via an increase in the number of CAF-like cells.
Interstitial cystitis (IC) is a chronic bladder disease with urinary frequency, bladder discomfort or bladder pain of unknown etiology. Based on cystoscopic findings, patients with IC are classified ...as either Hunner-type/classic IC (HIC), presenting with a specific Hunner lesion, or non-Hunner-type IC (NHIC), presenting with no Hunner lesion, but post-hydrodistension mucosal bleeding. Inflammatory cell infiltration, composed predominantly of lymphocytes, plasma cells and epithelial denudation, has in the past been documented as a major pathological IC finding. However, the significance of the pathological evaluation of IC, especially with regard to the difference between HIC and NHIC, has been downplayed in recent years. In this study, we performed immunohistochemical quantification of infiltrating T-lymphocytes, B-lymphocytes and plasma cells, and measured the amount of residual epithelium in urinary bladder biopsy specimens taken from patients with HIC and NHIC, and those with no IC, using image analysis software. In addition, in situ hybridization of the light chains was performed to examine clonal B-cell expansion. Lymphoplasmacytic infiltration was significantly more severe in HIC specimens than in NHIC specimens (P <0.0001). Substantial lymphoplasmacytic inflammation (≥200 cells/mm2) was observed in 93% of HIC specimens, whereas only 8% of NHIC specimens were inflamed. Plasmacytic infiltration was more prominent in HIC specimens compared with NHIC and non-IC cystitis specimens (P <0.005). Furthermore, expansion of light-chain-restricted B-cells was observed in 31% of cases of HIC. The amount of residual epithelium was decreased in HIC specimens compared with NHIC specimens and non-IC cystitis specimens (P <0.0001). These results suggest that NHIC and HIC are distinct pathological entities, with the latter characterized by pancystitis, frequent clonal B-cell expansion and epithelial denudation. An abnormality in the B-cell population may be involved in the pathogenesis of HIC.
Cancer-associated fibroblasts (CAFs) interact closely with cancer cells, supporting their growth and invasion. To investigate the role of microRNA-21 (miR-21) in lung adenocarcinoma, and especially ...in its CAF component, in situ hybridisation was applied to samples from 89 invasive lung adenocarcinoma cases. MiR-21 expression was observed in both cancer cells and CAFs. When the patients were stratified by expression, miR-21 levels in CAFs (n = 9), but not in cancer cells (n = 21), were inversely correlated with patient survival; patients with miR-21
CAFs exhibited lower survival than those with miR-21
CAFs. The underlying mechanism was investigated in vitro. Conditioned medium (CM) from A549 lung cancer cells increased miR-21 expression in MRC-5 and IMR-90 lung fibroblasts through the transforming growth factor-β pathway, and induced CAF-like morphology and migratory capacity. MiR-21 up-regulation in lung fibroblasts induced a novel CAF-secreted protein, calumenin, as well as known CAF markers (periostin, α-smooth muscle actin, and podoplanin). Moreover, CM from the lung fibroblasts increased A549 cell proliferation in a calumenin-dependent manner. Thus, miR-21 expression in lung fibroblasts may trigger fibroblast trans-differentiation into CAFs, supporting cancer progression. Therefore, CAF miR-21 represents a pivotal prognostic marker for this scar-forming cancer of the lungs.
Abstract
Dilated cardiomyopathy (DCM) is a primary myocardial disease, the pathology of which is left ventricular or biventricular dilation and impaired myocardial contractility. The clinical and ...pathological diagnosis of DCM is difficult, and other cardiac diseases must be ruled out. Several studies have reported pathological findings that are characteristic of DCM, including cardiomyocyte atrophy, nuclear pleomorphism, and interstitial fibrosis, but none of these findings are DCM-specific. In this study, we examined the morphological differences in the intercalated discs (ICDs) between three groups of patients, a DCM group, a chronic heart failure group, and a control group. A total of 22 autopsy cases, including five DCM cases, nine CHF cases and eight control cases, were retrieved from the archives of the Department of Pathology at Akita University, Japan. The morphological differences were examined using multiple methods: macroscopic examination, light microscopy, immunohistochemistry, electron microscopy, and gene expression analyses. We observed disorganized ICDs, clearly illustrated by N-cadherin immunostaining in the DCM group. “Reduction of N-cadherin immunostaining intensity” and “ICD scattering” was DCM-specific. The results suggest that disorganized ICDs contribute to the development of DCM, and that N-cadherin immunostaining is useful for determining the presence of disorganized ICDs and for the pathological diagnosis of DCM.
AT-rich interactive domain 1A (ARID1A) functions as a tumor suppressor and several therapeutic targets in ARID1A-mutated cancers are under development. Here, we investigated the prognostic value of ...ARID1A for gastric cancer and its association with expression of PD-L1 and p53. ARID1A expression was examined by immunohistochemistry and negative expression of ARID1A was detected in 39 (19.5%) of 200 cases in a test cohort and in 40 (18.2%) of 220 cases in a validation cohort. Negative expression of ARID1A was associated with worse overall survival in undifferentiated cases, particularly early-stage cases. Negative expression of ARID1A was detected in 11 (50%) of 22 PD-L1-positive cases and in 68 (17.1%) of 398 PD-L1-negative cases in a combined cohort. Negative expression of ARID1A was detected in 45 (22%) of 205 p53-positive cases and in 34 (15.8%) of 215 p53-negative cases in a combined cohort. In addition, expression of EZH2, a potential synthetic lethal target in ARID1A-mutated tumors, was detected in 79 ARID1A-negative cases. An ARID1A-knockdown gastric cancer cell line was subjected to microarray analysis, but no actionable targets or pathways were identified. The present results indicate that ARID1A may serve as an early-stage prognostic biomarker for undifferentiated gastric cancer.
In some tumors, a small number of cancer cells are scattered in a large fibrotic stroma. Here, we demonstrate a novel mechanism for expansion of pro‐tumor fibroblasts via cancer‐associated fibroblast ...(CAF)‐mediated education of normal fibroblasts (NFs). When NFs were incubated with conditioned medium from CAFs, the resulting CAF‐educated fibroblasts (CEFs) generated reactive oxygen species, which induced NF‐κB‐mediated expression of inflammatory cytokines and the extracellular matrix protein asporin (ASPN), while expression of a common CAF marker gene, α‐SMA, was not increased. ASPN further increased CEF expression of downstream molecules, including indoleamine 2,3‐dioxygenase 1 (IDO‐1), kynureninase (KYNU), and pregnancy‐associated plasma protein‐A (PAPP‐A). These CEFs induce cytocidal effects against CD8+ T cells and IGF‐I activation in cancer cells. CEFs were generated without cancer cells by the direct mixture of NFs and CAFs in mouse xenografts, and once CEFs were generated, they sequentially educated NFs, leading to continuous generation of CEFs. In diffuse‐type gastric cancers, ASPNhigh/IDO‐1high/KYNUhigh/α‐SMA− CEFs were located at the distal invading front. These CEFs expanded in the fibrotic stroma and caused dissemination of cancer cells. ASPN may therefore be a key molecule in facilitating tumor spreading and T‐cell suppression.
Cancer‐associated fibroblast (CAF)‐educated fibroblasts (CEFs), a newly identified source of pro‐tumor fibroblasts, were generated from normal fibroblast (NFs) by CAF‐mediated education. CAFs activated reactive oxygen species production in NFs, reprogramming them to secrete inflammatory cytokines and ASPN. ASPN further induced expression of IDO‐1, KYNU, and PAPP‐A in CEFs, leading to cancer cell dissemination, CD8+ T‐cell cytotoxicity, and activation of IGF‐I signaling in cancer cells.
Fifteen percent of lung cancer cases occur in never-smokers and show characteristics that are molecularly and clinically distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene ...mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 cases of never-smoker lung cancer identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., up-regulated miR-21) and unidentified (e.g., down-regulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs, including miR-21, were more remarkable in cases with EGFR mutations than in those without these mutations. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggest that the EGFR signaling is a pathway positively regulating miR-21 expression. In the never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is enhanced further by the activated EGFR signaling pathway, plays a significant role in lung carcinogenesis in never-smokers, as well as in smokers, and is a potential therapeutic target in both EGFR-mutant and wild-type cases.
•Tumor stroma is the most suitable area to evaluate TAMs for the prognostification of NSCLC cases.•High TAMs infiltration of tumor stroma predicts worse survival rate of NSCLC cases.•In lung ...adenocarcinoma, CD204 is the preferable macrophage marker for prognostification.
Tumor-associated macrophages (TAMs) are believed to influence tumor progression and the prognosis of patients. The purpose of this study was to clarify the correlation between the TAM density or location and the clinicopathological features of non-small-cell lung cancer (NSCLC) as well as to explore the prognostic impact of TAMs in NSCLC.
CD68- and CD204-positive macrophages were detected in tumor islets, tumor stroma and alveolar space in 297 patients with NSCLC using immunochemistry. The clinicopathological and genetic factors surveyed were the disease-free survival, age, gender, smoking status, histological type, disease stage, histological grade, pleural invasion, lymph node metastasis, EGFR gene mutations and ALK rearrangements.
There were significantly more CD68-positive macrophages than CD204-positive macrophages in each location of the tumor islets, tumor stroma and alveolar spaces, and they were strongly correlated (P < 0.0001 each). Factors such as male gender, being a smoker, an advanced disease stage and histological grade, positive pleural invasion and node status and wild-type EGFR gene status were significantly correlated with a higher density of CD68- and CD204-positive TAMs in tumor stroma (P < 0.05 each). In contrast, the age of patients was not correlated with CD68- and CD204-positive TAMs (P > 0.05 each). Furthermore, survival analysis revealed that a high number of CD68- and CD204-positive TAMs in tumor stroma, but not in tumor islets or alveolar space, was a significant prognostic factor for the disease-free survival time of NSCLC (P < 0.05, respectively). Moreover, both univariate and multivariate analyses confirmed that higher numbers of CD204-positive TAMs in tumor stroma were an independent worse prognostic predictor for adenocarcinoma.
The tumor stroma is the most suitable intratumoral area for the evaluation of TAMs in the setting of the prognostic prediction of NSCLC patients. CD204-positive TAMs are the preferable marker for prognostic prediction in NSCLC, especially in lung adenocarcinoma.
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