IFI16 Induced by Direct Interaction between Esophageal Squamous Cell Carcinomas and Macrophages Promotes Tumor Progression via Secretion of IL-1α.

Tumor-associated macrophages (TAMs), one of the major components of the tumor microenvironment, contribute to the progression of esophageal squamous cell carcinoma (ESCC). We previously established a direct co-culture system of human ESCC cells and macrophages and reported the promotion of malignant phenotypes, such as survival, growth, and migration, in ESCC cells. These findings suggested that direct interactions between cancer cells and macrophages contribute to the malignancy of ESCC, but its underlying mechanisms remain unclear. In this study, we compared the expression levels of the interferon-induced genes between mono- and co-cultured ESCC cells using a cDNA microarray and found that interferon-inducible protein 16 (IFI16) was most significantly upregulated in co-cultured ESCC cells. IFI16 knockdown suppressed malignant phenotypes and also decreased the secretion of interleukin-1α (IL-1α) from ESCC cells. Additionally, recombinant IL-1α enhanced malignant phenotypes of ESCC cells through the Erk and NF-κB signaling. Immunohistochemistry revealed that high IFI16 expression in human ESCC tissues tended to be associated with disease-free survival and was significantly associated with tumor depth, lymph node metastasis, and macrophage infiltration. The results of this study reveal that IFI16 is involved in ESCC progression via IL-1α and imply the potential of IFI16 as a novel prognostic factor for ESCC.

Matrix Metalloproteinase 9 Induced in Esophageal Squamous Cell Carcinoma Cells via Close Contact with Tumor-Associated Macrophages Contributes to Cancer Progression and Poor Prognosis.

Tumor-associated macrophages (TAMs) contribute to disease progression in various cancers, including esophageal squamous cell carcinoma (ESCC). We have previously used an indirect co-culture system between ESCC cell lines and macrophages to analyze their interactions. Recently, we established a direct co-culture system to closely simulate actual ESCC cell-TAM contact. We found that matrix metalloproteinase 9 (MMP9) was induced in ESCC cells by direct co-culture with TAMs, not by indirect co-culture. MMP9 was associated with ESCC cell migration and invasion, and its expression was controlled by the Stat3 signaling pathway in vitro. Immunohistochemical analyses revealed that MMP9 expression in cancer cells at the invasive front ("cancer cell MMP9") was related to high infiltration of CD204 positive M2-like TAMs (p < 0.001) and was associated with worse overall and disease-free survival of patients (p = 0.036 and p = 0.038, respectively). Furthermore, cancer cell MMP9 was an independent prognostic factor for disease-free survival. Notably, MMP9 expression in cancer stroma was not associated with any clinicopathological factors or patient prognoses. Our results suggest that close interaction with TAMs infiltrating in cancer stroma or cancer nests induces MMP9 expression in ESCC cells, equipping them with more malignant features.

Roles of IL-7R Induced by Interactions between Cancer Cells and Macrophages in the Progression of Esophageal Squamous Cell Carcinoma.

High infiltration of tumor-associated macrophages (TAMs), which contribute to the progression of several cancer types, is correlated with poor prognosis of esophageal squamous cell carcinoma (ESCC). In addition to the previously reported increase in migration and invasion, ESCC cells co-cultured directly with macrophages exhibited enhanced survival and growth. Furthermore, interleukin-related molecules are associated with ESCC; however, the precise mechanism underlying this association is unclear. Therefore, we explored the role of interleukin-related molecules in ESCC progression. A cDNA microarray analysis of monocultured and co-cultured ESCC cells revealed that the interleukin 7 receptor (IL-7R) was upregulated in ESCC cells co-cultured with macrophages. Overexpression of IL-7R promoted the survival and growth of ESCC cells by activating the Akt and Erk1/2 signaling pathways. The IL-7/IL-7R axis also contributed to the promotion of ESCC cell migration via the Akt and Erk1/2 signaling pathways. Furthermore, immunohistochemistry showed that ESCC patients with high IL-7R expression in cancer nests exhibited a trend toward poor prognosis in terms of disease-free survival, and showed significant correlation with increased numbers of infiltrating macrophages and cancer-associated fibroblasts. Therefore, IL-7R, which is upregulated when directly co-cultured with macrophages, may contribute to ESCC progression by promoting the development of various malignant phenotypes in cancer cells.

Simple and reliable transhiatal reconstruction after laparoscopic proximal gastrectomy with lower esophagectomy for Siewert type II tumors: y-shaped overlap esophagogastric tube reconstruction.

PURPOSE: Despite the increasing incidence of adenocarcinoma of the esophagogastric junction, laparoscopic proximal gastrectomy with lower esophagectomy (PGLE) is not widely accepted owing to the lack of standardized reconstruction techniques. In this study, we developed a new reconstruction method named y-shaped overlap esophagogastric tube reconstruction, which reproduces an angle of His and a pseudo-fornix, to be used in laparoscopic transhiatal PGLE. This study aimed to determine the feasibility of this novel reconstruction method. METHODS: This retrospective study included the analysis of short- and mid-term surgical outcomes of 30 consecutive patients with Siewert type II esophagogastric junction adenocarcinoma who underwent laparoscopic PGLE with y-shaped overlap esophagogastric tube reconstruction from April 2015 to August 2020. A novel method was used to form a 6-cm pseudo-fornix and an angle of His using the distal esophagus and a long gastric tube. RESULTS: The median operation time was 369 min, and the median blood loss was 28 mL. The median follow-up period after surgery was 37 months. Although two patients experienced postoperative anastomotic leakage, none of the patients developed stenosis. One patient experienced moderate reflux symptoms, whereas four patients developed moderate reflux esophagitis based on the 1-year follow-up endoscopic examination; the condition of all patients could be efficiently controlled with medication. CONCLUSION: The short- and mid-term surgical outcomes of y-shaped overlap esophagogastric tube reconstruction reflected the feasibility of this simple technique and suggested its potential utility as a reconstruction alternative for Siewert type II tumors.

S100A8/A9 Induced by Interaction with Macrophages in Esophageal Squamous Cell Carcinoma Promotes the Migration and Invasion of Cancer Cells via Akt and p38 MAPK Pathways.

Tumor-associated macrophages are associated with more malignant phenotypes of esophageal squamous cell carcinoma (ESCC) cells. Previously, an indirect co-culture assay of ESCC cells and macrophages was used to identify several factors associated with ESCC progression. Herein, a direct co-culture assay of ESCC cells and macrophages was established, which more closely simulated the actual cancer microenvironment. Direct co-cultured ESCC cells had significantly increased migration and invasion abilities, and phosphorylation levels of Akt and p38 mitogen-activated protein kinase (MAPK) compared with monocultured ESCC cells. According to a cDNA microarray analysis between monocultured and co-cultured ESCC cells, both the expression and release of S100 calcium binding protein A8 and A9 (S100A8 and S100A9), which commonly exist and function as a heterodimer (herein, S100A8/A9), were significantly enhanced in co-cultured ESCC cells. The addition of recombinant human S100A8/A9 protein induced migration and invasion of ESCC cells via Akt and p38 MAPK signaling. Both S100A8 and S100A9 silencing suppressed migration, invasion, and phosphorylation of Akt and p38 MAPK in co-cultured ESCC cells. Moreover, ESCC patients with high S100A8/A9 expression exhibited significantly shorter disease-free survival (P = 0.005) and cause-specific survival (P = 0.038). These results suggest that S100A8/A9 expression and release in ESCC cells are enhanced by direct co-culture with macrophages and that S100A8/A9 promotes ESCC progression via Akt and p38 MAPK signaling pathways.

Safety of laparoscopic local resection for gastrointestinal stromal tumors near the esophagogastric junction.

PURPOSE: Laparoscopic local resection for gastrointestinal stromal tumors (GISTs) near the esophagogastric junction (EGJ) increases the risk of injuring the EGJ. We investigated the safety of laparoscopic local resection for GISTs near the EGJ according to the distance from the EGJ to the tumor edge. METHODS: We retrospectively evaluated 40 patients who had undergone laparoscopic local resection for GISTs near the EGJ between January 2009 and December 2019. After excluding 1 patient who had undergone right colectomy at the same time, 39 patients were classified according to distance of the GIST from the EGJ in the Near group (0-2.0 cm; n = 16) and the Far group (2.1-5.0 cm; n = 23). RESULTS: We found no marked differences in the operation time, blood loss, length of postoperative hospital stay, or postoperative complication rate in the two groups. Anastomotic leakage occurred with a tumor located on the EGJ. Three tumors recurred in the Near group, and all of them were located on the EGJ. CONCLUSION: Except for GISTs located on the EGJ, laparoscopic local resection for GISTs near the EGJ can be performed safely with few postoperative complications and a low risk of recurrence.

Metallothionein 2A Expression in Cancer-Associated Fibroblasts and Cancer Cells Promotes Esophageal Squamous Cell Carcinoma Progression.

Esophageal cancer has the sixth highest mortality rate worldwide. Cancer-associated fibroblasts (CAFs) are involved in the progression of various cancers. Previously, we demonstrated an association between high expression of the CAF marker, fibroblast activation protein, and poor prognosis of esophageal squamous cell carcinoma (ESCC). We also established CAF-like cells by indirect co-culture of bone marrow-derived mesenchymal stem cells with ESCC cell lines and found metallothionein 2A (MT2A) to be highly expressed in them. Here, to explore the function of MT2A in CAFs, we silenced MT2A in the CAF-like cells and ESCC cell lines using small interfering RNA. MT2A knockdown in the CAF-like cells suppressed expression and secretion of insulin-like growth factor binding protein 2 (IGFBP2); recombinant IGFBP2 promoted migration and invasiveness of ESCC cells via NFκB, Akt, and Erk signaling pathways. Furthermore, MT2A knockdown in the ESCC cell lines inhibited their growth, migration, and invasiveness. Immunohistochemistry demonstrated that high MT2A expression in the cancer stroma and cancer nest of ESCC tissues correlated with poor prognosis of ESCC patients. Hence, we report that MT2A in CAFs and cancer cells contributes to ESCC progression. MT2A and IGFBP2 are potential novel therapeutic targets in ESCC.

Chemokine (C-C Motif) Ligand 1 Derived from Tumor-Associated Macrophages Contributes to Esophageal Squamous Cell Carcinoma Progression via CCR8-Mediated Akt/Proline-Rich Akt Substrate of 40 kDa/Mammalian Target of Rapamycin Pathway.

Tumor-associated macrophages (TAMs) promote tumor progression. The number of infiltrating TAMs is associated with poor prognosis in esophageal squamous cell carcinoma (ESCC) patients; however, the mechanism underlying this phenomenon is unclear. cDNA microarray analysis indicates that the expression of chemokine (C-C motif) ligand 1 (CCL1) is up-regulated in peripheral blood monocyte-derived macrophages stimulated using conditioned media from ESCC cells (TAM-like macrophages). Here, we evaluated the role of CCL1 in ESCC progression. CCL1 was overexpressed in TAM-like macrophages, and CCR8, a CCL1 receptor, was expressed on ESCC cell surface. TAM-like macrophages significantly enhanced the motility of ESCC cells, and neutralizing antibodies against CCL1 or CCR8 suppressed this increased motility. Recombinant human CCL1 promoted ESCC cell motility via the Akt/proline-rich Akt substrate of 40 kDa/mammalian target of rapamycin pathway. Phosphatidylinositol 3-kinase or Akt inhibitors, CCR8 silencing, and neutralizing antibody against CCR8 could significantly suppress these effects. The overexpression of CCL1 in stromal cells or CCR8 in ESCC cells was significantly associated with poor overall survival (P = 0.002 or P = 0.009, respectively) and disease-free survival (P = 0.009 or P = 0.047, respectively) in patients with ESCC. These results indicate that the interaction between stromal CCL1 and CCR8 on cancer cells promotes ESCC progression via the Akt/proline-rich Akt substrate of 40 kDa/mammalian target of rapamycin pathway, thereby providing novel therapeutic targets.

PAI-1 derived from cancer-associated fibroblasts in esophageal squamous cell carcinoma promotes the invasion of cancer cells and the migration of macrophages.

Cancer-associated fibroblasts (CAFs) contribute to the progression of various cancers. Previously, we reported the significance of CAFs in esophageal squamous cell carcinoma (ESCC); however, the functions of CAFs in the ESCC microenvironment remain unknown. To investigate CAFs' function, we established an indirect coculture assay between human bone marrow-derived mesenchymal stem cells (MSCs) and ESCC cells. Cocultured MSCs expressed more fibroblast activation protein, one of the markers of CAFs, compared with monocultured MSCs. Therefore, we defined cocultured MSCs as CAF-like cells. To identify molecules associated with the ESCC progression in CAFs, we conducted a cDNA microarray analysis on monocultured MSCs and CAF-like cells to compare their gene expression profiles. We found that SERPINE1, which encodes plasminogen activator inhibitor-1 (PAI-1), was more abundant in CAF-like cells than in monocultured MSCs, and the PAI-1 derived from CAF-like cells induced the abilities of migration and invasion in both ESCC cells and macrophages by the Akt and Erk1/2 signaling pathways via the low-density lipoprotein receptor-related protein 1 (LRP1), which is a PAI-1 receptor. Based on immunohistochemistry assays of ESCC tissues, higher expression levels of PAI-1 and LRP1 were correlated with poor prognosis in ESCC patients. These results suggest that the PAI-1/LRP1 axis contributes to the progression of ESCC, making it a potential target for ESCC therapy.

Band Alignment of the CdS/Cu2Zn(Sn1- xGe x)Se4 Heterointerface and Electronic Properties at the Cu2Zn(Sn1- xGe x)Se4 Surface: x = 0, 0.2, and 0.4.

The surface electronic properties of the light absorber and band alignment at the p/n heterointerface are key issues for high-performance heterojunction solar cells. We investigated the band alignment of the heterointerface between cadmium sulfide (CdS) and Ge-incorporated Cu2ZnSnSe4 (CZTGSe), with Ge/(Ge + Sn) ratios ( x) between 0 and 0.4, by X-ray photoelectron, ultraviolet, and inversed photoemission spectroscopies (XPS, UPS, and IPES, respectively). In particular, we used interface-induced band bending in order to determine the conduction band offset (CBO) and valence-band offset (VBO), which were calculated from the core-level shifts of each element in both the CdS overlayer and the CZTGSe bottom layer. Moreover, the surface electronic properties of CZTGSe were also investigated by laser-irradiated XPS. The CBO at the CdS/CZTGSe heterointerface decreased linearly, from +0.36 to +0.20 eV, as x was increased from 0 to 0.4; in contrast, the VBO at the CdS/CZTGSe heterointerface was independent of Ge content. Both UPS and IPES revealed that the Fermi level at the CZTGSe surface is located near the center of the band gap. The hole concentration at the CZTGSe surface was on the order of 1011 cm-3, which is much smaller than that of the bulk (∼1016 cm-3). We discuss the differences in hole deficiencies near the surface and in the bulk on the basis of laser-irradiated XPS and conclude that hole deficiencies are due to defects distributed near the surface with densities that are lower than in the bulk, and the Fermi level is not pinned at the CZTGSe surface.