Yu-ichiro Koma

SgIGSF is a novel biliary-epithelial cell adhesion molecule mediating duct/ductule development

Spermatogenic immunoglobulin superfamily (SgIGSF) is an intercellular adhesion molecule of the nectin‐like family. While screening its tissue distribution, we found that it was expressed in fetal liver but not adult liver. In the present study, we examined which cells in developing and regenerating liver express SgIGSF via immunohistochemistry and Western blot analysis. In developing mouse liver, SgIGSF expression was transiently upregulated at perinatal ages and was restricted to the lateral membrane of biliary epithelial cells (BECs). In regenerating rat livers from the 2‐acetylaminofluorene/partial hepatectomy model, SgIGSF was detected exclusively in oval cells that aligned in ductal and trabecular patterns by the second week posthepatectomy. In human livers, fetal and newborn bile ducts and cirrhotic bile ductules were clearly positive for SgIGSF, whereas disease‐free adult bile ducts were negative. To investigate the role of SgIGSF in bile duct/ductule formation, we used an in vitro model in which rat hepatocyte aggregates embedded in collagen gels containing insulin and epidermal growth factor extend epithelial sheets and processes in the first week and form ductules within a month. The process and ductular cells were continuously positive for SgIGSF and cytokeratin 19, a BEC marker. When the aggregate culture was started in the presence of a function‐blocking anti‐SgIGSF antibody, the number of epithelial processes per aggregate was reduced by 80%. Conclusion: We propose that SgIGSF is a novel and functional BEC adhesion molecule that is expressed for a limited time during active bile duct/ductule formation. (HEPATOLOGY 2007;45:684–694.)

Cell Adhesion Molecule 1 Is a Novel Pancreatic–Islet Cell Adhesion Molecule That Mediates Nerve–Islet Cell Interactions

BACKGROUND & AIMS Cell adhesion molecule 1 (CADM1), mediates nerve-mast cell attachment and communication through homophilic binding. An immunohistochemical screen showed that CADM1 is expressed in pancreatic islets. Here, we determined the cell types expressing CADM1 and examined its role in nerve-islet cell interactions. METHODS Immunohistochemistry and double-staining immunofluorescence were performed on murine and human pancreases and on islet cell tumors (ICTs). alphaTC6 cells, a murine alpha cell line, were cultured on neurite networks of superior cervical ganglia. Neurite-alphaTC6 cell attachment and communication were examined after nerves were activated specifically by scorpion venom. RESULTS CADM1 was expressed on the plasma membrane in all 4 major types of islet cells, alpha, beta, D, and pancreatic polypeptide in human beings, but primarily in alpha cells in mice. In cocultures, alphaTC6 cell to neurite attachment was inhibited dose-dependently by an anti-CADM1 function-blocking antibody. In response to scorpion venom-evoked nerve activation, 36% of the alphaTC6 cells mobilized Ca(2+), and introduction of a CADM1-targeting small interfering RNA reduced the fraction of responding cells to 7%. In 21 human ICTs, CADM1 was present in the plasma membrane of 7, and the others were negative for CADM1. Six of the CADM1-expressing tumors were functional hormonally, whereas all but 2 of the CADM1-negative tumors were nonfunctional (P = .0032). CONCLUSIONS CADM1 is a novel islet cell adhesion molecule mediating nerve-islet cell interactions. The strong correlation between CADM1 expression and hormonally functional phenotypes suggests that CADM1 is involved in hormone secretion from ICTs.

Collaboration of cancer-associated fibroblasts and tumour-associated macrophages for neuroblastoma development.

Neuroblastoma is the most common extracranial solid tumour in children and is histologically classified by its Schwannian stromal cells. Although having fewer Schwannian stromal cells is generally associated with more aggressive phenotypes, the exact roles of other stromal cells (mainly macrophages and fibroblasts) are unclear. Here, we examined 41 cases of neuroblastoma using immunohistochemistry for the tumour‐associated macrophage (TAM) markers CD68, CD163, and CD204, and a cancer‐associated fibroblast (CAF) marker, alpha smooth muscle actin (αSMA). Each case was assigned to low/high groups on the basis of the number of TAMs or three groups on the basis of the αSMA‐staining area for CAFs. Both the number of TAMs and the area of CAFs were significantly correlated with clinical stage, MYCN amplification, bone marrow metastasis, histological classification, histological type, and risk classification. Furthermore, TAM settled in the vicinity of the CAF area, suggesting their close interaction within the tumour microenvironment. We next determined the effects of conditioned medium of a neuroblastoma cell line (NBCM) on bone marrow‐derived mesenchymal stem cells (BM‐MSCs) and peripheral blood mononuclear cell (PBMC)‐derived macrophages in vitro. The TAM markers CD163 and CD204 were significantly up‐regulated in PBMC‐derived macrophages treated with NBCM. The expression of αSMA by BM‐MSCs was increased in NBCM‐treated cells. Co‐culturing with CAF‐like BM‐MSCs did not enhance the invasive ability but supported the proliferation of tumour cells, whereas tumour cells co‐cultured with TAM‐like macrophages had the opposite effect. Intriguingly, TAM‐like macrophages enhanced not only the invasive abilities of tumour cells and BM‐MSCs but also the proliferation of BM‐MSCs. CXCL2 secreted from TAM‐like macrophages plays an important role in tumour invasiveness. Taken together, these results indicate that PBMC‐derived macrophages and BM‐MSCs are recruited to a tumour site and activated into TAMs and CAFs, respectively, followed by the formation of favourable environments for neuroblastoma progression.

NCAM- and FGF-2-mediated FGFR1 signaling in the tumor microenvironment of esophageal cancer regulates the survival and migration of tumor-associated macrophages and cancer cells

Tumor-associated macrophages (TAMs) have important roles in the angiogenesis and tumor immunosuppression of various cancers, including esophageal squamous cell carcinomas (ESCCs). To elucidate the roles of TAMs in ESCCs, we compared the gene expression profiles between human peripheral blood monocyte-derived macrophage-like cells (Macrophage_Ls) and Macrophage_Ls stimulated with conditioned medium of the TE series human ESCC cell line (TECM) (TAM_Ls) using cDNA microarray analysis. Among the highly expressed genes in TAM_Ls, we focused on neural cell adhesion molecule (NCAM). NCAM knockdown in TAM_Ls revealed a significant decrease of migration and survival via a suppression of PI3K-Akt and fibroblast growth factor receptor 1 (FGFR1) signaling. Stimulation by TECM up-regulated the level of FGFR1 in Macrophage_Ls. Recombinant human fibroblast growth factor-2 (rhFGF-2) promoted the migration and survival of TAM_Ls and TE-cells through FGFR1 signaling. Our immunohistochemical analysis of 70 surgically resected ESCC samples revealed that the up-regulated FGF-2 in stromal cells, including macrophages, was associated with more aggressive phenotypes and a high number of infiltrating M2 macrophages. These findings may indicate a novel role of NCAM- and FGF-2-mediated FGFR1 signaling in the tumor microenvironment of ESCCs.

Constitutive suppression of PRL-3 inhibits invasion and proliferation of gastric cancer cell in vitro and in vivo

Objective: Overexpression of phosphatase of regenerating liver-3 (PRL-3) has been implicated in tumor progression and metastasis of gastric carcinoma. Here we examined what alterations occur in the phenotype of gastric cancer cells in vitro and in vivo when PRL-3 expression is knocked down. Methods: We constructed a small interfering RNA (siRNA)-expressing vector which stably interfered with PRL-3 expression and was transfected into SH101-P4 cells, which express the highest PRL-3 mRNA levels among 13 gastric cancer cell lines. The new SH101-P4 subclones, in which PRL-3 was stably reduced, were established and their in vitro growth, motility and abilities of liver metastasis from the injected spleen were analyzed in vivo. Results: PRL-3 knockdown effectively suppressed invasion and growth of SH101-P4 cells in vitro. Liver metastasis in vivo was significantly decreased when PRL-3 expression was suppressed. The primary tumor size in the injected spleen tended to be smaller in PRL-3 knockdown clones than in the controls. These findings suggest that PRL-3 expression may contribute not only to the establishment of metastasis but also to the growth of primary foci of human gastric cancer. Therefore, PRL-3 may be one of the target molecules in gastric cancer therapy.

Cyr61 promotes CD204 expression and the migration of macrophages via MEK/ERK pathway in esophageal squamous cell carcinoma

Tumor‐associated macrophages (TAMs) are known to be involved in the progression of various human malignancies. We previously demonstrated that CD204 was a useful marker for TAMs contributing to the angiogenesis, progression, and prognosis of human esophageal squamous cell carcinoma (ESCC). We also showed that conditioned media of ESCC cell lines induced CD204 expression in THP‐1 human monocytic leukemia cells. Here, we performed a cDNA microarray analysis between THP‐1 cells stimulated with TPA (macrophage [MΦ]‐like THP‐1 cells) treated with and without conditioned medium of ESCC cell line to clarify the molecular characteristics of TAMs in ESCC. From the microarray data, we discovered that Cyr61 was induced in CD204‐positive‐differentiated THP‐1 cells (TAM‐like THP‐1 cells). In the ESCC microenvironment, not only cancer cells but also TAMs expressed Cyr61. Interestingly, the expression levels of Cyr61 showed a significant positive correlation with the number of CD204‐positive macrophages in ESCCs by immunohistochemistry. Recombinant human Cyr61 (rhCyr61) promoted cell migration and induced the expression of CD204 along with the activation of the MEK/ERK pathway in MΦ‐like THP‐1 cells. Pretreatment with a MEK1/2 inhibitor significantly inhibited not only the Cyr61‐mediated migration but also the CD204 expression in the MΦ‐like THP‐1 cells. These results suggest that Cyr61 may contribute to the expression of CD204 and the promotion of cell migration via the MEK/ERK pathway in TAMs in the ESCC microenvironment.

Software-assisted morphometric and phenotype analyses of human peripheral blood monocyte-derived macrophages induced by a microenvironment model of human esophageal squamous cell carcinoma.

Human macrophages play important roles in tumor promotion and are called tumor‐associated macrophages (TAMs). We previously demonstrated that human esophageal squamous cell carcinomas (ESCCs) contain TAMs and that these TAMs tend to have tumor‐supporting features. Here we exposed human macrophages to conditioned media of TE‐series human ESCC cell lines (TECMs) to generate an ESCC extracellular stimuli‐influenced TAM model. CD14+ peripheral blood monocytes (PBMos) from healthy donors were treated with M‐CSF and with additional IL‐4 or TECM exposure. Morphological changes of the cells and the induction of CD163/CD204 proteins were detected in the TECM‐exposed model TAMs by immunofluorescence. A software‐assisted immunofluorescent cell image analysis showed increased CD163/CD204 positivity in the model TAMs and a weak to moderate positive correlation between the cytoplasmic area and the sum fluorescent intensity of CD204. Morphological changes of the cells were significantly reflected by several cytomorphometric parameters. PBMos were elongated with M‐CSF treatment, then enlarged with TECM exposure. The cytoplasmic aspect ratio was decreased by M‐CSF treatment and slightly increased by TECM exposure. The nuclear‐cytoplasmic ratio decreased during the whole process of cell differentiation. This system is useful for quantitative assessments of TAM‐like morphological changes of macrophages and the induction of CD163/CD204 in a model ESCC microenvironment.

Polypoid leiomyosarcoma of the esophagus treated by endoscopic submucosal dissection.

We report a rare case of polypoid leiomyosarcoma of the esophagus that was treated by endoscopic submucosal dissection (ESD). A 63‐year‐old man with complaints of progressive dysphagia was referred to Hyogo Cancer Center for treatment of esophageal tumor. Esophagoscopy revealed a polypoid tumor 25 mm in diameter on the left side of the upper esophagus. Despite several biopsy specimens, the diagnosis could not be confirmed. Computed tomography showed a protruded, homogeneously enhancing mass in the upper esophagus, but no lymph node enlargement or metastasis. After 1.5 months, the esophagogram showed a filling defect 47 mm in diameter in the upper esophagus. Given this rapid tumor growth, en bloc resection was done by ESD for therapeutic diagnosis. After this treatment, the tumor seemed to grow larger, showing a short stalk and occupying the esophageal lumen. Histopathologically, the tumor comprised pleomorphic spindle cells with mitosis. Tumor invasion involved the lumina propria mucosae and contact with the muscularis mucosae, but not involving the submucosa. Immunohistochemical examination showed positive staining for smooth muscle actin and HHF35, but negative for desmin, caldesmon, CD34, c‐kit, DOG1, ALK, S‐100 protein and cytokeratin. These histopathological findings were compatible with a diagnosis of esophageal leiomyosarcoma derived from the muscularis mucosae.

Advanced Verrucous Squamous Cell Carcinoma of the Esophagus: Case Report and Literature Review

Abstract Verrucous squamous cell carcinoma (VSCC) is a rare esophageal tumor histologically defined as a well-differentiated subtype. We present a rare case that was diagnosed as esophageal VSCC preoperatively. A 62-year-old Japanese male was referred to our hospital for further evaluation, presenting with anorexia and postcibal vomiting. An esophagogastroduodenoscopy (EGD) examination showed esophageal stricture with white-colored papillary nodules in the lower esophagus. We performed repeated superficial endoscopic biopsies of the lesion, but the histological findings showed nonspecific changes. With an endoscopic boring biopsy, the lesion showed an endophytic growth pattern, well-differentiated SCC with minimal cellular atypia and rare mitosis, and mature squamous epithelium with extensive keratinization. We preoperatively diagnosed the lesion as esophageal VSCC, and we performed a video-assisted thoracoscopic subtotal esophagectomy and cardiectomy with the patient in the prone position. Histological f...

Abstract 730: The roles of FGF-2-NCAM/FGFR1 interplay in esophageal squamous cell carcinomas and its microenvironment including tumor-associated macrophages

Tumor-associated macrophages (TAMs) have important roles in the angiogenesis, tumor immunosuppression and tumor infiltration of various cancers. Previously, we reported that a large number of infiltrated tumor promoting CD204+ TAMs within esophageal squamous cell carcinomas (ESCCs) contributed to the significant association of clinicopathological malignancy and poor disease free survival. However, the relevant malignant progression mechanisms have not been studied explicitly yet. To elucidate roles of TAMs in ESCCs, we established an in vitro macrophage model using human peripheral blood acquired by healthy volunteer donors. Peripheral blood monocytes were treated with 25 ng/mL recombinant human M-CSF for 6 days to induce macrophage-like differentiation (macrophage-like cells), then exposed to the conditioned media of TE series ESCC cell lines (TECM) for 2 days to induce TAM-like cells. From the cDNA microarray data between macrophages-like cells treated with and without TECM, we interested in upregulated genes. Among highly expressed genes in TAM-like cells, we focused on neural cell adhesion molecule (NCAM) which was a possibility to act on the regulation between tumor and its surrounding stroma. Gene knockdown of NCAM by siRNA in TAM-like cells revealed significant suppression of cell survival and migration via decrease of PI3K/Akt signaling and downregulation of fibroblast growth factor receptor 1 (FGFR1) expression. Interestingly, fibroblast growth factor-2 (FGF-2) derived from ESCCs promotes FGF2/FGFR1 autocrine loop, and activates FGFR1 signaling in TAM-like cells. Furthermore, we analyzed 70 ESCC tissue samples by immunohistochemistry whether the expression levels of FGF-2 were associated with clinicopathological background factors of ESCC patients. Relationships of the expression levels of FGF-2 in human ESCC stromal cells including macrophages had a correlation with the depth of invasion, blood vessel invasion, TNM classification UICC cancer staging and high number of infiltrating CD163 positive and CD204 positive macrophages as a marker for the M2 macrophage phenotype. These findings may indicate novel roles of FGF-2-NCAM/FGFR1 interplay in ESCCs and its microenvironment including TAMs. Citation Format: NOBUHISA TAKASE, Yuichiro Koma, Noriaki Arai, Himiko Kodaira, Masayoshi Hosono, Yumi Ichihara, Mari Nishio, Manabu Shigeoka, Hiroshi Yokozaki. The roles of FGF-2-NCAM/FGFR1 interplay in esophageal squamous cell carcinomas and its microenvironment including tumor-associated macrophages. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 730.