Yuichiro Kubo

Tumor-associated macrophage promotes tumor progression via STAT3 signaling in hepatocellular carcinoma.

Objective: Signal transducer and activator of transcription 3 (STAT3) is activated in hepatocellular carcinoma (HCC), and tumor-associated macrophage plays an important role in tumor progression. Therefore, we examined STAT3 activation, cytokine expression and infiltration of tumor-associated macrophages in resected HCCs as well as the alteration of cell growth and migration by cytokine stimulation in HCC cell lines. Methods: Immunohistochemical staining of phosphorylated STAT3 (pSTAT3), CD163, interleukin (IL)-6, Ki-67 and Bcl-XL was performed for 101 cases of resected HCC, and correlations between pSTAT3 staining and clinicopathological findings were analyzed. In HCC cell lines (PLC/PRF/5 and Huh7), cell proliferation and migration by IL-6 stimulation and S3I-201 (STAT3 inhibitor) treatment were analyzed. Results: In HCC specimens, the pSTAT3-positive group showed high levels of α-fetoprotein (p = 0.0276), large tumor size (p = 0.0092), frequent intrahepatic metastasis (p = 0.0214), high Ki-67 (p = 0.0002) and Bcl-XL (p = 0.0001), poor prognosis (p = 0.0234), and high recurrence rate (p = 0.0003). CD163-positive cells were frequently observed in the pSTAT3-positive group (p = 0.0013). In two HCC cell lines, IL-6 stimulation promoted cell proliferation and migration via the STAT3 phosphorylation, and S3I-201 inhibited this activation. Conclusions: STAT3 activation was correlated with aggressive behavior of HCC and may be mediated via tumor-associated macrophage. We expect that STAT3 signaling and tumor-associated macrophages can be attractive therapeutic targets in HCC patients.

Different roles of s100p overexpression in intrahepatic cholangiocarcinoma : Carcinogenesis of perihilar type and aggressive behavior of peripheral type

S100P is expressed in several kinds of malignant tumors. Intracellular S100P interacts with ezrin, and extracellular S100P activates the receptor for advanced glycation endproducts. However, little is known about the biological significance of S100P and related proteins in cholangiocarcinoma. Biliary intraepithelial neoplasia (BilIN) is a precursor lesion of hilar or perihilar cholangiocarcinoma. We examined S100P, ezrin, and the receptor for advanced glycation end product expression in 39 BilIN and 110 intrahepatic cholangiocarcinoma (ICC) cases, and analyzed its relationship with clinicopathologic factors and outcomes. S100P expression increased from reactive epithelium to low-grade BilIN to high-grade BilIN. S100P and ezrin expression rates in perihilar-type ICC were higher than those in peripheral-type ICC (P<0.0001, P=0.0008, respectively). S100P nuclear expression in peripheral-type ICC significantly correlated with vascular invasion (P=0.0209), lymphatic invasion (P=0.0003), and lymph node metastasis (P=0.003). S100P and ezrin expression was significantly correlated. S100P-positive and ezrin-positive cases indicate shorter survival in survival analysis of the peripheral type (P=0.001, P=0.0728, respectively). Our results suggest that S100P-ezrin signaling has different roles of carcinogenesis of perihilar ICC and an aggressive course of peripheral ICC.

T1ρ Relaxation of the liver: A potential biomarker of liver function

To investigate the diagnostic potential of T1ρ relaxation for assessing liver function, liver fibrosis, or liver necroinflammation in patients with chronic liver disease (CLD).

Histological features of precancerous and early cancerous lesions of biliary tract carcinoma

Biliary tract carcinoma develops within the intrahepatic or extrahepatic biliary tree and gallbladder. Primary sclerosing cholangitis, hepatolithiasis, congenital choledochal cyst, liver fluke infection, pancreatobiliary maljunction, toxic exposures and hepatitis virus infection are risk factors for the development of human biliary carcinoma. The precise molecular abnormalities of biliary carcinogenesis are still unknown, but chronic inflammatory conditions induce the production of reactive oxygen or nitrogen species leading to DNA damage. Recent studies indicate that cholangiocarcinoma of the large bile duct may arise in premalignant lesions such as biliary intraepithelial neoplasm (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB). BilIN and IPNB are generally confined to the large and septal‐sized bile duct. BilINs are occasionally observed in non‐biliary liver cirrhosis as well as chronic biliary disease. In contrast, the precursor lesion of intrahepatic cholangiocarcinoma of the small bile duct type remains unclear. We herein demonstrated the histological characteristics of different tumor development pathways from premalignant lesion to carcinoma in different sites of the biliary tree.

A male case of primary retroperitoneal mucinous cystadenoma: a diagnostic dilemma

We report a male case of primary retroperitoneal mucinous cystadenoma (PRMC) that was at initially misdiagnosed as a complicated renal cyst. On ultrasonography, a71-year-old man was found to have an abdominal mass suspicious for right renal cyst. The initial computed tomography scan showed an unenhanced, low-density mass that deformed the edge of the right kidney into a beak shape. Four years later, the mass had increased in size. Magnetic resonance imaging revealed a cystic lesion. Its intracystic content showed relatively high intensity on a T1-weighted image, and the coronal gadolinium-enhanced T1-weighted image with fat suppression clearly showed a multilocular cystic mass without enhancing mural nodules. The final diagnosis of PRMC was obtained pathologically after surgery. Because PRMC has malignant potential, this rare entity should be considered when a retroperitoneal cystic tumor is evaluated, even in a male patient.

Distinguishing intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma using precontrast and gadoxetic acid-enhanced MRI

PURPOSE We aimed to gain further insight in magnetic resonance imaging characteristics of mass-forming intrahepatic cholangiocarcinoma (mICC), its enhancement pattern with gadoxetic acid contrast agent, and distinction from poorly differentiated hepatocellular carcinoma (pHCC). METHODS Fourteen mICC and 22 pHCC nodules were included in this study. Two observers recorded the tumor shape, intratumoral hemorrhage, fat on chemical shift imaging, signal intensity at the center of the tumor on T2-weighted image, fibrous capsule, enhancement pattern on arterial phase of dynamic study, late enhancement three minutes after contrast injection (dynamic late phase), contrast uptake on hepatobiliary phase, apparent diffusion coefficient, vascular invasion, and intrahepatic metastasis. RESULTS Late enhancement was more common in mICC (n=10, 71%) than in pHCC (n=3, 14%) (P < 0.001). A fat component was observed in 11 pHCC cases (50%) versus none of mICC cases (P = 0.002). Fibrous capsule was observed in 13 pHCC cases (59%) versus none of mICC cases (P < 0.001). On T2-weighted images a hypointense area was seen at the center of the tumor in 43% of mICC (6/14) and 9% of pHCC (2/22) cases (P = 0.018). Other parameters were not significantly different between the two types of nodules. CONCLUSION The absence of fat and fibrous capsule, and presence of enhancement at three minutes appear to be most characteristic for mICC and may help its differentiation from pHCC.

Clinicopathological significance of the peritumoral decreased uptake area of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid in hepatocellular carcinoma

A faint hypointensity in the noncancerous tissue around hepatocellular carcinoma (HCC) in the hepatobiliary phase of Gd‐EOB‐DTPA‐enhanced magnetic resonance imaging (MRI) is encountered. The goal is to elucidate the significance of this type of pseudolesion designated as the peritumoral decreased uptake area of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd‐EOB‐DTPA) (PDUAE).

Decreased roundabout 1 expression promotes development of intrahepatic cholangiocarcinoma.

Roundabout 1 (Robo1) is a transmembrane receptor of the immunoglobulin family. Slit2 is one of its ligands. The function of Slit2/Robo1 signaling in the development of intrahepatic cholangiocarcinoma (ICC) remains to be elucidated. We examined the immunohistochemical expression of Robo1 and Slit2 and their clinicopathologic implications in 132 cases of ICC. Also, small interfering RNA of Robo1 was transfected into a high-expression ICC cell line, and a Robo1 vector was transfected into a low-Robo1 expression ICC cell line. The effect of Robo1 suppression and overexpression in cell proliferation and migration of cultured ICC cells with Slit2 stimulation was investigated. Immunohistochemical study of ICC in the low-Robo1 expression group showed larger tumors (P = .015), a higher Ki-67 labeling index (P = .021), and low expression of Slit2 (P = .0005). The low-Slit2 expression group frequently showed perineural invasion (P = .036) and lymph node metastases (P = .013). Low Robo1 expression was associated with a poor prognosis (P = .0207). Robo1 suppression in Huh28 cells tended to promote cell proliferation and migration, whereas Robo1 overexpression in RBE cells significantly suppressed cell proliferation and migration. Low Robo1 expression was associated with cell proliferation and migration in ICC and was one of the adverse prognostic factors in patients with these tumors.

Different roles of inducible nitric oxide synthase and cyclooxygenase-2 in carcinogenesis and metastasis of intrahepatic cholangiocarcinoma

Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) have been implicated in chronic inflammatory conditions and carcinogenesis. However, little is known about the biological significance of iNOS and COX-2 in cholangiocarcinoma or its precursors or metastatic lesions. We examined iNOS and COX-2 immunohisotochemical expression in 40 biliary intraepithelial neoplasias, 134 primary intrahepatic cholangiocarcinoma cases, and 27 metastatic lymph nodes and analyzed the correlations with grade of atypia of biliary intraepithelial neoplasia, clinicopathological factors and outcomes of intrahepatic cholangiocarcinoma. iNOS and COX-2 expression was highly expressed in reactive epithelium and biliary intraepithelial neoplasia. In intrahepatic cholangiocarcinoma, lymphatic invasion and lymph node metastasis were significantly correlated with negative iNOS expression (P = .0002, P = .0324, respectively) and positive COX-2 expression (P = .0012, P = .0063, respectively). Vascular endothelial growth factor-C expression was associated with COX-2 expression (P = .0053), but not with iNOS expression. COX-2 expression in primary intrahepatic cholangiocarcinoma was higher than that in metastatic lymph nodes (P < .0001). COX-2-positive expression indicated a poor intrahepatic cholangiocarcinoma outcome (P = .0273). This study indicates that iNOS and COX-2 may play roles in carcinogenesis via biliary intraepithelial neoplasia, but play different roles in metastasis of intrahepatic cholangiocarcinoma. COX-2 may participate in a higher lymphatic invasion and metastasis via the vascular endothelial growth factor-C pathway.

Bile duct adenoma and von Meyenburg complex-like duct arising in hepatitis and cirrhosis: pathogenesis and histological characteristics.

Morphologic features and neoplastic potentials of bile duct adenoma (BDA) and von Meyenburg complex (VMC)‐like duct arising in chronic liver disease were unknown. Thirty‐five BDAs and 12 VMC‐like duct lesions were observed in 39 cases with chronic liver disease. BDAs were divided into the EMA‐cytoplasmic type (n = 14) and EMA‐luminal type (n = 21). EMA‐cytoplasmic BDA composed of a proliferation of cuboidal to low‐columnar cells forming an open lumen with NCAM(+)/MUC6(‐), resembling an interlobular bile duct. EMA‐luminal BDA showed uniform cuboidal cells with narrow lumen, and NCAM(++)/MUC6(++), resembling a ductular reaction. VMC‐like duct showed positive MUC1 expression and negative MUC6. The expression of S100P, glucose transporter‐1 (GLUT‐1) and insulin‐like growth factor II mRNA‐binding protein 3 (IMP‐3) were not detected in three lesions. p16 expression was higher than those of the ductular reaction, and the Ki67 and p53 indexes were very low (<1.0%). Large‐sized EMA‐luminal BDA shows sclerotic stroma. We classified small nodular lesions of ductal or ductular cells in chronic hepatitis and cirrhosis into the following groups: BDA, interlobular bile duct type; BDA, ductular/peribiliary gland type; and VMC‐like duct. They may be reactive proliferation rather than neoplastic lesions.