Identification of CXCL5/ENA-78 as a factor involved in the interaction between cholangiocarcinoma cells and cancer-associated fibroblasts

Knowledge of tumor-stromal interactions is essential for understanding tumor development. We focused on the interaction between cholangiocarcinoma and cancer-associated fibroblasts (CAFs) in intrahepatic cholangiocarcinoma and reported their positive interaction in vitro and in vivo. The aim of this study is to identify the key protein involved in the interaction between cholangiocarcinoma cells and CAFs and its role on cholangiocarcinoma progression. Using the conditioning medium from cholangiocarcinoma cells, hepatic stellate cells and coculture of them, Protein-Chip analysis with SELDI-TOF-MS showed that the peak of an 8,360-Da protein remarkably increased in the coculture medium. This protein was identified as CXCL5/ENA78, epithelial cell-derived neutrophil-activating peptide-78, by q-TOF/MS/MS analysis. Two cholangiocarcinoma cell lines, HuCCT1 and RBE, produced CXCL5 that promoted their invasion and migration in an autocrine fashion. These effects of CXCL5 significantly decreased by inhibition of CXC-receptor 2, which is the receptor for CXCL5. In addition, IL-1β produced by hepatic stellate cells induced the expression of CXCL5 in cholangiocarcinoma cells. In human tissue samples, a significant correlation was observed between CAFs and CXCL5 produced by cholangiocarcinoma cells in intrahepatic cholangiocarcinoma (p = 0.0044). Furthermore, the high-CXCL5-expression group exhibited poor overall survival after curative hepatic resection (p = 0.027). The presence of tumor-infiltrating neutrophils expressing CD66b was associated with CXCL5 expression in tumor cells (p < 0.0001). These data suggest that CXCL5 is important for the interaction between cholangiocarcinoma and CAFs, and inhibition of tumor-stromal interactions may be a useful therapeutic approach for cholangiocarcinoma.     

Efficacy and safety of endoscopic dilation of esophageal strictures in epidermolysis bullosa

BACKGROUND: Epidermolysis bullosa is a rare genetically determined disorder of the stratified squamous epithelium. Patients with the most severe forms develop scarring of the esophagus after ingestion of food. This results in dysphagia, which severely compromises the ability to eat. Maintenance of adequate nutritional intake is a central aim, but the most appropriate method is unknown. METHODS: The results of endoscopic through-the-scope balloon dilation under propofol anesthesia in 53 patients with epidermolysis bullosa and esophageal strictures are reported. RESULTS: Seventy-five percent of patients had a single stricture (range 1 to 6 strictures), most often in the proximal esophagus (median 20 cm from incisors). A total of 182 dilations were performed (median two per patient) over a median follow-up period of 3.5 years. For all but 3 patients, there was an improvement in the dysphagia score. There was a mean increase in weight after the procedure of 2.9 kg: 95% CI[2.0, 3.8]; p<0.001, over a median 29 days. There was no significant post-procedure morbidity. CONCLUSIONS: Endoscopic balloon dilation is a safe and effective treatment for the esophageal strictures of epidermolysis bullosa. In the majority of patients, dilation relieves dysphagia and improves nutritional status.     

Hepatic Stellate Cells Accelerate the Malignant Behavior of Cholangiocarcinoma Cells

Background

Although tumor–stromal interaction has been discussed, the role of hepatic stellate (HS) cells against cancer, especially cholangiocarcinoma (CC), has not been clarified. The aim of this study is to investigate the effect of HS cells on CC cell progression in vitro and in vivo.

Methods

The effects of CC conditioned medium (CC-CM) on activation and proliferation of HS cells (LI90 and LX-2), the influences of HS cell CM (HS-CM) on proliferation and invasion of CC cells (HuCCT-1 and RBE), and the effects of their interaction on HUVEC tube formation were assessed using each CM. The effect of HS cells on tumor growth was examined in vivo by subcutaneous co-injection. Cytokine array was performed to assess the secreted proteins induced by their coculture.

Results

CC-CM activated HS cells and increased their proliferation. HS-CM dose-dependently increased CC cell proliferation and invasion. Chemotherapy of CC cells was less effective when treated with HS-CM. HS-CM activated the mitogen-activated protein kinase and Akt pathways in tumor cells. The indirect interaction of CC and HS cells promotes tube formation of human umbilical venous endothelial cells. Subcutaneous co-injection of tumor cells with HS cells in nude mouse resulted in increased tumor size. Several proteins were found in the culture medium induced by their coculture, thought to be key proteins which regulated tumor–stromal interaction.

Conclusions

This study indicates that HS cells play an important role in accelerating cholangiocarcinoma progression and may be a therapeutic target in cholangiocarcinoma.     

Clinical significance of CD163+ tumor‐associated macrophages in patients with adult T‐cell leukemia/lymphoma

In several malignant tumors including lymphoma, macrophages that infiltrate tumor tissues are called tumor‐associated macrophages (TAMs). We discovered that TAMs, especially the CD163⁺ alternatively activated phenotype (M2), were closely involved with progression of adult T‐cell leukemia/lymphoma (ATLL). We used CD68 (a pan‐macrophage marker) and CD163 (an M2 marker) to immunostain 58 ATLL samples. Statistical analyses showed that a high number of CD68⁺ TAMs and an increased percentage of CD163⁺ cells among the TAMs were associated with a worse clinical prognosis; multivariate analysis indicated that the percentage of CD163⁺ cells was an independent prognostic factor. We also carried out in vitro coculture experiments with ATLL cell lines (ATN‐1 and TL‐Mor) and monocyte‐derived macrophages and found that direct coculture with M2 macrophages significantly increased BrdU incorporation into ATLL cell lines. A cytokine array analysis showed that macrophage‐derived soluble factors including C5a, tumor necrosis factor‐α, growth‐related oncogene‐α, CCL1/I‐309, and interleukin‐6 stimulated ATLL cell lines. CD163 expression in macrophages was strongly induced by direct contact with ATN‐1 cells, and downregulation of CD163 in macrophages significantly suppressed growth of cocultured ATN‐1 cells. These results suggest that interaction between M2 macrophages and lymphoma cells may be an appropriate target in treatment of patients with ATLL.     

Intrahepatic dissemination of hepatocellular carcinoma after local ablation therapy

Background/Purpose  We aimed to clarify the histological features of and risk factors for intrahepatic dissemination after local ablation therapy (LAT) for hepatocellular carcinoma (HCC). Methods  Between April 1992 and December 2005, 192 HCC patients underwent hepatic resection at our department, among whom were 17 patients who had local recurrences after LAT. Eight of these 17 patients had intrahepatic dissemination. The clinical and histological characteristics of these 8 surgically treated patients with intrahepatic dissemination were investigated. Results  Histologically, numerous intrahepatic metastases were observed, mainly in the same section as the treated tumor, together with main or sectional portal vein tumor thrombi. Before the ablation therapy, the average tumor diameter was 2.1 cm, and 62.5% of the tumors were adjacent to the main or sectional portal vein. In terms of therapeutic factors, 25% of the patients had a prior needle biopsy and 62.5% had insufficient safety margins. Conclusions  LAT for HCCs (even those less than 3 cm in diameter) adjacent less than 5 mm to the main or sectional portal vein possibly promotes intrahepatic dissemination.     

Blocking cholesterol efflux mechanism is a potential target for antilymphoma therapy

Cholesterol is an essential plasma membrane lipid for the maintenance of cellular homeostasis and cancer cell proliferation. Free cholesterol is harmful to cells; therefore, excessive free cholesterol must be quickly esterified by acetyl‐coenzyme A:cholesterol acetyltransferase (ACAT) and exported by scavenger receptor class B member I (SR‐BI) or ATP‐binding cassette protein A1 from specific cells such as macrophage foam cells, which contain cholesteryl ester‐derived vacuoles. Many vacuoles are present in the cytoplasm of Burkitt lymphoma cells. In this study, we observed that these vacuoles are often seen in high‐grade lymphomas. Cell culture study using lymphoma cell lines found that esterified cholesterol is the main component of these vacuoles and the expression of cholesterol metabolism‐related molecules was significantly upregulated in lymphoma cell lines, with SR‐BI and ACAT inhibitors (BLT‐1 and CI‐976, respectively) impeding lymphoma cell proliferation. Cytoplasmic free cholesterol was increased by ACAT and SR‐BI inhibitors, and the accumulation of free cholesterol induced lymphoma cell apoptosis by inducing endoplasmic reticulum stress. Furthermore, synergistic effects of SR‐BI and ACAT inhibitors were observed in a preclinical study. Treatment with SR‐BI inhibitor suppressed lymphoma progression in a tumor‐bearing mouse model, whereas ACAT inhibitor did not. Therefore, SR‐BI inhibitors are potential new antilymphoma therapeutics that target cholesterol metabolism.     

Occurrence of hepatocellular carcinoma after hepatoblastoma resection in an adult with hepatitis C virus

Hepatoblastoma is a rare malignancy in adults. It is often diagnosed after the appearance of symptoms, therefore, the tumor size tends to be larger. In patients with no indication for a hepatic resection, the prognosis of adult hepatoblastoma is quite poor. A 54-year-old man with hepatitis C virus-associated liver cirrhosis was initially treated with a hepatic resection for a hepatic tumor, 3 cm in diameter. The tumor consisted of osteoid-like and cartilaginous foci, myxomatous stroma, and poorly differentiated hepatocellular carcinomatous cells and was diagnosed as a mixed epithelial and mesenchymal hepatoblastoma. Two years after the first operation, multicentric hepatocellular carcinomas developed in the remnant liver and were successfully treated with a secondary hepatic resection combined with radio-frequency ablation. The patient is now alive with no recurrence at 5 years after the initial hepatectomy. To the best of our knowledge, the primary hepatoblastoma was the smallest such tumor reported and this is the first report of a metachronous hepatoblastoma and hepatocellular carcinoma in an adult hepatitis patient.