Intrahepatic cholangiocarcinoma (iCCA) is a heterogeneous bile duct cancer with a poor prognosis. Integrin αvβ6 (β6) has been shown to be upregulated in iCCA and is associated with its ...subclassification and clinicopathological features. In the present study, two ITGB6-knockout HuCCT1 CCA cell lines (ITGB6-ko cells) were established using the clustered regulatory interspaced short palindromic repeats (CRISPR), an associated nuclease 9 (Cas9) system, and single-cell cloning. RNA sequencing analysis, real-time polymerase chain reaction (PCR), and immunofluorescent methods were applied to explore possible downstream factors. ITGB6-ko cells showed significantly decreased expression of integrin β6 on flow cytometric analysis. Both cell lines exhibited significant inhibition of cell migration and invasion, decreased wound-healing capability, decreased colony formation ability, and cell cycle dysregulation. RNA sequencing and real-time PCR analysis revealed a remarkable decrease in podocalyxin-like protein 2 (PODXL2) expression in ITGB6-ko cells. Colocalization of PODXL2 and integrin β6 was also observed. S100 calcium-binding protein P and mucin 1, which are associated with CCA subclassification, were downregulated in ITGB6-ko cells. These results describe the successful generation of ITGB6-ko CCA cell clones with decreased migration and invasion and downregulation of PODXL2, suggesting the utility of integrin β6 as a possible therapeutic target or diagnostic marker candidate.
Dilated cardiomyopathy (DCM) is a fatal heart disease characterized by left ventricular dilatation and cardiac dysfunction. Recent genetic studies on DCM have identified causative mutations in over ...60 genes, including RBM20, which encodes a regulator of heart-specific splicing. DCM patients with RBM20 mutations have been reported to present with more severe cardiac phenotypes, including impaired cardiac function, atrial fibrillation (AF), and ventricular arrhythmias leading to sudden cardiac death, compared to those with mutations in the other genes. An RSRSP stretch of RBM20, a hotspot of missense mutations found in patients with idiopathic DCM, functions as a crucial part of its nuclear localization signals. However, the relationship between mutations in the RSRSP stretch and cardiac phenotypes has never been assessed in an animal model. Here, we show that Rbm20 mutant mice harboring a missense mutation S637A in the RSRSP stretch, mimicking that in a DCM patient, demonstrated severe cardiac dysfunction and spontaneous AF and ventricular arrhythmias mimicking the clinical state in patients. In contrast, Rbm20 mutant mice with frame-shifting deletion demonstrated less severe phenotypes, although loss of RBM20-dependent alternative splicing was indistinguishable. RBM20
protein cannot be localized to the nuclear speckles, but accumulated in cytoplasmic, perinuclear granule-like structures in cardiomyocytes, which might contribute to the more severe cardiac phenotypes.
Histological identification of the human sinoatrial node (SAN) remains a challenge. Conventional identification methods, such as Lev’s method, have certain limitations. The aim of our study was to ...develop a new histological identification method that could properly identify the sinoatrial node, applicable to the immunohistochemical study of intra-nodal structures. Thirty-nine human autopsied hearts were included in this study. The cases included 23 men and 16 women ranging in age from 20 to 99 years. The sinoatrial area from eight control samples was cut in the vertical section using the conventional Lev’s method. In our new method, called the “En face one-block method,” the sinoatrial node was cut in “En face” at the junction of the right border of the right appendage and superior vena cava, placed in one long cassette, and serially cut using a microtome. Immunostaining was performed using primary antibodies against CD31, podoplanin (D2-40), S-100, and other proteins. The average area of the SAN on the slide glass in our new method was 32.2 mm
2
,
which was significantly larger than that (3.59 mm
2
) of the control samples by Lev’s method. The SAN area was positively correlated with age (
r
= 0.357;
p
= 0.026), especially in women (
r
= 0.626;
p
= 0.0095). The SAN group had significantly lower percentage of CD31-positive blood capillaries, higher percentage of podoplanin-positive lymphatic channels, and S-100-positive peripheral nerves. We successfully developed a novel cutting method applicable to immunohistochemical studies, with which we could provide a bird’s-eye view of the sinoatrial nodes.
Abstract Background Lifestyle-related diseases, such as obesity and dyslipidemia are important risk factors for atrial fibrillation (AF). However, the underlying mechanism linking these diseases and ...AF has not been fully investigated. Methods Adult male mice were fed a high-fat diet (HFD) or vehicle (NC) for 2 months. Electrocardiography and in vivo electrophysiological study were performed. Mice were then sacrificed for quantification of mRNA, microRNA, and protein in atria, in addition to histological analysis. Conduction velocity (CV) in right atrium was measured by optical mapping in Langendorff perfused hearts. Cultured atrial cardiomyocytes were treated with palmitate with or without a specific microRNA inhibitor. Twelve hours after stimulation, cells were lysed, and subjected to analysis with qPCR and Western blotting. Results HFD mice showed prolonged P wave duration, increased inducibility of sustained atrial tachycardia, and reduced atrial CV than NC mice. HFD mice also showed increased expression in inflammatory cytokines, whereas fibrotic area and signals relating fibrosis were not changed. HFD mice demonstrated reduced expression of Cx40 in mRNA and protein levels, and its lateralized expression in atria. MicroRNA array analysis revealed that miR-27b expression was up-regulated in HFD mice, and luciferase assay confirmed the direct interaction between miR-27b and Cx40 3′UTR. In palmitate-stimulated atrial cardiomyocytes, miR-27b up-regulation and Cx40 down-regulation were observed, while expression of inflammatory cytokines was not altered. Inhibition of miR-27b with antisense oligonucleotides reversed the alteration caused by palmitate stimulation. Conclusion HFD may increase the vulnerability to atrial arrhythmia by down-regulation of Cx40 via miR-27b, rather than fibrosis, which is independent of inflammation.
We have previously reported that promoter polymorphism of myocardin-related transcription factor A (MRTF-A) is associated with coronary atherosclerosis. However, the contribution of MRTF-A to the ...development of atherosclerosis remains unknown. Macrophages are known to be important mediators of atherosclerosis. It has been demonstrated that local proliferation and survival of macrophages are atherogenic. In this study, we found that MRTF-A was highly expressed in lesional macrophages in human carotid atherosclerotic plaque. We then investigated the role of macrophagic MRTF-A in the pathogenesis of atherosclerosis. ApoE null MRTF-A transgenic mice (ApoE−/−/MRTF-Atg/+), in which human MRTF-A was specifically overexpressed in monocytes/macrophages, were established and fed with normal diet to examine the progression of atherosclerosis. We found that ApoE−/−/MRTF-Atg/+ aggravated atherosclerosis and lesional macrophages were more prominently accumulated in the aortic sinus of ApoE−/−/MRTF-Atg/+ than in that of ApoE−/− littermates. We also found that MRTF-A promoted proliferation and mitigated apoptosis of macrophages both in vitro and in vivo, and down regulated the expression of cyclin-dependent kinase inhibitors. From these findings, we conclude that MRTF-A modulates functional properties of pro-atherogenic macrophages. Our study may play a valuable role in understanding the pathological role of macrophagic MRTF-A in the progression of atherosclerosis.
•Overexpression of MRTF-A in macrophages exacerbates atherosclerosis in ApoE knockout mice without altering plasma profile.•Overexpression of MRTF-A in macrophages facilitates local accumulation of lesional macrophages in atherosclerotic plaques.•MRTF-A mitigates apoptosis and promotes proliferation of macrophages.•MRTF-A regulates the expression level of cyclin-dependent kinase inhibitors.
Abstract Objective: To analyze the mismatched cases between liquid-based cytology (LBC) and cell block in effusion cytology and to confirm the utility of cell block. Methods: One hundred eighty-two ...samples of effusions were examined. Cell blocks were prepared from residual samples after LBC preparation, and the details about the diagnostic concordance and difference in cytological characteristics were investigated. Cell block immunostaining was performed to predict the histological type and the primary site of the carcinoma in 32 cases. ALK rearrangement and EGFR mutation were also analyzed using the cell block. Results: The diagnostic concordance rate between LBC and cell block was 97.3%. Diagnoses using LBC and cell block were mismatched in five cases. By immunostaining, the histological type was determined in 91.0% of carcinomas, and primary sites were identified in 76.5% of adenocarcinomas. ALK rearrangement was examined in two cases of lung carcinoma and EGFR mutation was examined in four cases of lung carcinoma. Conclusion: A high concordance rate between LBC and cell block in effusion cytology was found. The main cause of the mismatched diagnosis was the small amount of atypical cells in LBC or cell block. We also showed the utility of cell block in immunostaining and DNA analysis.
Intrahepatic cholangiocarcinoma (ICC) is a heterogeneous group of cancers of the intrahepatic biliary tract. However, few studies have evaluated integrin expression according to an ICC subgroup. We ...immunohistochemically investigated α6β4 (β4) and αvβ6 (β6) integrin expressions in 48 ICCs, and evaluated their relationship with clinical and pathological parameters and ligand expression, as well as transforming growth factor (TGF)-β1. β4 and β6 expressions were detected in 46 (96%) and 35 (73%) ICC cases, respectively. We classified ICC into negative, low (β4, 29 cases; β6, 36 cases), or high (β4, 19 cases; β6, 12 cases) integrin expression groups. β4 and β6 integrin levels were higher in the non-peripheral central localization type ICC than in the peripheral localization type; they were also higher in the periductal-infiltrating or intraductal-growth types than in the mass-forming type ICC; lastly, they were higher in the well-differentiated type than in the poorly-differentiated type ICC. High expression was related to bile duct invasion. In addition, β4 and β6 expressions were associated with mucin production and the expression of cytoplasmic epithelial membrane antigen, laminin-5, and tenascin-C. TGF-β1 was correlated with β6 expression and poor overall survival. These results suggest that integrin expression is associated with subclassification and clinicopathological features of ICC through the coincident expression of their ligands and TGF-β1.
Anaplastic lymphoma kinase‐rearranged (ALK+) lung cancers show characteristic histological features, such as solid signet ring cell patterns and mucinous cribriform patterns; however, these features ...are not always observed in ALK+ lung cancers. We noticed that club cell (Clara cell)‐like cells (CLCs) were frequently present in the papillary portion of ALK+ lung adenocarcinomas. In this study, we investigated the importance of CLCs in papillary patterns of ALK+ lung cancers. We compared the histological features of 18 ALK+ cases with 62 control cases (22 epidermal growth factor receptor‐positive (EGFR+) and 40 ALK‐ and EGFR‐negative (ALK−/EGFR−) cases). The present study analyzed presence of papillary pattern, proportion of papillary pattern area, presence of micropapillary pattern, frequency of CLCs and lengths of snout. The frequency of CLCs in ALK+ cases was significantly higher than that in EGFR+ cases and ALK−/EGFR− cases. Micropapillary pattern was more frequently observed in ALK+ cases than that in ALK−/EGFR− cases (P < 0.001). The present study indicated that the high frequency of CLCs in papillary patterns was significantly associated with ALK+ cases. When solid signet ring cell patterns and mucinous cribriform patterns are absent, the high frequency of CLCs in papillary adenocarcinoma could be a useful histological marker for ALK+ lung cancers.
Chromogenic in situ hybridization (CISH) is a molecular technique used to visualize specific genes. Both heat treatment and protease treatment play important roles for the success of CISH on ...formalin‐fixed paraffin‐embedded (FFPE) tissue sections. In contrast to heat treatment, the optimal condition of protease treatment may vary depending on each sample. Because trypsin has a substrate specificity to cleave lysine and arginine, we hypothesized that trypsin could effectively degrade histones rich in lysine and arginine and that the removal of histones from DNA following heat treatment could improve CISH results. We selected 21 patients with lung adenocarcinoma previously known to be positive or negative for anaplastic lymphoma kinase (ALK) gene rearrangement and used FFPE tissue sections collected from these patients. Then, we assessed histone degradation among the following protease treatments; trypsin, pepsin, and proteinase K, and compared the ALK CISH results with results obtained using commercially available kits and these protease treatments. The results showed that trypsin effectively degraded histones. Additionally, compared with the other treatments, ALK CISH with trypsin treatment showed the most evaluable cells and the smallest standard deviation. Our study suggests that the degradation of histones by trypsin subsequent to heat treatment might improve CISH results.
Abstract Clinicopathological parameters derived from initial transurethral resection of bladder tumor (TUR-Bt) have limitations in predicting tumor progression in bladder cancer. Reduced folate ...carrier 1 (RFC1) and equilibrative nucleoside transporter 1 (ENT1) are solute carrier (SLC) transporters supporting cellular uptake of endogenous bioactive substances and anti-cancer drugs. The aim of this study was to elucidate the role of SLC transporters in bladder cancer and investigate the potential of RFC1 and ENT1 expression as immunohistochemical markers for high-grade malignancy. We compared T-stage with the immunohistochemical expression of RFC1 and ENT1 and other clinicopathological parameters; moreover, we also used multiple logistic regression model to assess relative contributions for T-stage in bladder cancer (n = 130). Concurrently, 57 TUR-Bt-derived imprint cytological samples were stained to evaluate the implication of cytological analysis. Elevated expression levels of RFC1 and ENT1 were significantly correlated with higher T-stage (p < .0001) and efficiently predicted tumor progression, compared with other clinicopathological parameters (RFC1, p = .0325; ENT1, p = .0171). Independent variables of optimal model for predicting T-stage were gender, age, histological grade, expression levels of RFC1 and ENT1. Cytological analysis was consistent with immunostained-tissue data. We reveal RFC1 and ENT1 as potential immunohistocytochemical markers for high-grade malignancy in bladder cancer.
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