Kenichiro Araki

E/N-cadherin switch mediates cancer progression via TGF- β -induced epithelial-to-mesenchymal transition in extrahepatic cholangiocarcinoma

Background:Epithelial-to-mesenchymal transition (EMT) is a fundamental process governing not only morphogenesis in multicellular organisms, but also cancer progression. During EMT, epithelial cadherin (E-cadherin) is downregulated while neural cadherin (N-cadherin) is upregulated, referred to as ‘cadherin switch’. This study aimed to investigate whether cadherin switch promotes cancer progression in cholangiocarcinoma (CC).Methods:CC cell lines were examined for migration, invasion, and morphological changes with typical EMT-induced model using recombinant TGF-β1. The changes in E-cadherin and N-cadherin expression were investigated during EMT. We also examined E-cadherin and N-cadherin expression in resected specimens from extrahepatic CC patients (n=38), and the associations with clinicopathological factors and survival rates.Results:TGF-β1 treatment activated cell migration, invasion, and fibroblastic morphological changes, especially in extrahepatic CC HuCCT-1 cells. These changes occurred with E-cadherin downregulation and N-cadherin upregulation, that is, cadherin switch. Patients with low E-cadherin expression had a significantly lower survival rate than patients with high E-cadherin expression (P=0.0059). Patients with decreasing E-cadherin and increasing N-cadherin expression had a significantly lower survival rate than patients with increasing E-cadherin and decreasing N-cadherin expression (P=0.017).Conclusion:Cadherin switch promotes cancer progression via TGF-β-induced EMT in extrahepatic CC, suggesting a target for elucidating the mechanisms of invasion and metastasis in extrahepatic CC.

Transient gene silencing of galectin-3 suppresses pancreatic cancer cell migration and invasion through degradation of β-catenin

Pancreatic cancer is a leading cause of cancer‐related mortality and often has a poor prognosis because of its late diagnosis, aggressive local invasion, early metastasis and poor response to chemotherapy. The chemotherapeutic agent gemcitabine is effective for treating advanced pancreatic cancer, but its efficacy remains less than satisfactory. It is expected that further investigation of pancreatic cancer cell invasion and development of strategies to block this process should improve the disease prognosis. In this study, we tested our hypothesis that galectin‐3 (gal‐3), a multifunctional member of the β‐galactoside‐binding protein family, may regulate pancreatic cancer cell motility and silencing of it inhibit cell motility. Previous studies demonstrated that this protein is associated with tumor cell adhesion, proliferation, differentiation, angiogenesis, apoptosis and metastasis. Here, we used gal‐3 small interfering RNA (siRNA) to silence its expression in various pancreatic cancer cell lines to determine whether gal‐3 regulates cell proliferation, migration and invasion in vitro. We found that silencing gal‐3 reduced cellular migration and invasion, but failed to affect proliferation. In gal‐3 siRNA‐transfected cells, we detected a decrease in β‐catenin expression, an important signal for cancer cell invasion, which was caused by downregulation of phosphorylated Akt and GSK‐3β. We also found that matrix metalloproteinase (MMP)‐2 expression was reduced by gal‐3 silencing. These results indicate that gal‐3‐mediated invasion via MMP‐2 regulated by β‐catenin degradation is initiated by Akt phosphorylation in pancreatic cancer cells. Our results suggest that gal‐3 can be a novel therapeutic target in pancreatic cancer.

Intraoperative Ultrasonography of Laparoscopic Hepatectomy: Key Technique for Safe Liver Transection

@However, significant bleeding is more difficultto control during laparoscopic hepatectomy than duringan open approach, so prevention of vascular injury iscrucial. This should be achieved not only through anexcellent preoperative understanding of the vascular anat-omy derived from preoperative imaging, but also throughreal-time image guidance during surgery. Some proce-dures, such as posterosuperior segmentectomy (Sg7 orSg8) and limited resection for deeply located liver tumors,require expert laparoscopic hepatectomy techniques. Forthese procedures, accurate real-time imaging of liver anat-omy and a thought-out operative resection plan are neces-sary, and today this is accomplished with the use ofintraoperative ultrasound image.Intraoperative ultrasonography (IOUS) has beenreported as a useful tool for open liver surgery.

Hepatocellular carcinoma producing a granulocyte colony‐stimulating factor: report of a resected case with a literature review

A complete resection of a hepatocellular carcinoma (HCC) producing the granulocyte colony‐stimulating factor (G‐CSF) was performed and is reported here. The patient had a few general symptoms and complications, such as the paraneoplastic syndrome. He had marked granulocytosis, and his serum levels of G‐CSF and interleukin‐6 were elevated. The pathological findings of the resected specimen revealed poorly differentiated HCC with sarcomatous change and showed, immunohistochemically, staining of G‐CSF. Only a few cases of G‐CSF‐producing HCC have been reported, and they resulted in rapid tumour growth and poor prognosis. The case presented here may be the first complete resection ever performed, but the patients prognosis was similar to that observed in typical cases.

Laparoscopic transabdominal with transdiaphragmatic access improves resection of difficult posterosuperior liver lesions

OBJECTIVE We describe the technical details and evaluate the safety, feasibility, and usefulness of a combined lateral and abdominal (CLA) approach for laparoscopic resection of liver segments 7 and 8. BACKGROUND Laparoscopic resection of lesions in the posterosuperior area of segments 7 and 8 is technically challenging, and currently there is no standardized laparoscopic approach. METHODS Through review of a prospectively maintained database, we identified 44 patients who underwent laparoscopic resection of lesions in segment 7 or 8. Twenty-five patients required the CLA approach because their lesions were more posterosuperior and intraparenchymal; 19 patients underwent resection with a regular abdominal-only approach of more accessible anteroinferior lesions. We reviewed operative details and video footage of these operations and compared the outcomes of the 2 groups. RESULTS In the group treated with the CLA approach, deep location was more frequent (88% vs 42%; P = 0.035), median tumor diameter was larger (24.5 mm vs 15 mm; P = 0.114), and the median weight of the excised parenchyma was greater (56.5 g vs 23 g; P = 0.093). Median operative time was longer in the CLA approach group (217.5 minutes vs 165 minutes; P = 0.046), but blood loss, rate of conversion to open surgery, surgical margin status, morbidity, and mortality were similar between the 2 groups. CONCLUSIONS The CLA approach permits safe laparoscopic resection of lesions in the posterosuperior area of segments 7 and 8, allowing surgeons to overcome the difficulties of limited visualization and access to the target lesions.

Transient silencing of galectin-3 expression promotes both in vitro and in vivo drug-induced apoptosis of human pancreatic carcinoma cells

Pancreatic cancer demonstrates a strong resistance to anticancer drugs, presumably due to its resistance to drug induced apoptosis. Although gemcitabine (GEM) might be partially effective for treating advanced pancreatic cancer, its efficacy is still less than satisfactory. Galectin-3 (gal-3), a member of the β-galactoside-binding protein family, is a multifunctional protein with roles in tumor cell adhesion, proliferation, differentiation, angiogenesis, metastasis, and apoptosis. We have utilized gal-3 small interfering RNA (siRNA) to probe whether gal-3 regulates anticancer drug-induced apoptosis in pancreatic cancer cells. We found that Gal-3 siRNA augmented GEM- and cisplatin-induced apoptosis in pancreatic cancer cell lines in vitro. Mitochondrial depolarization induction was increased in gal-3-silenced cells after GEM treatment, resulting in activation of caspase-9, but not caspase-8. Akt phosphorylation was significantly downregulated in gal-3- silenced cells in association with apoptosis. Moreover, intratumoral administration of gal-3 siRNA increased the GEM sensitivity of tumor xenografts produced by subcutaneous inoculation of pancreatic cancer cells into nude mice. These results suggest that gal-3 might provide a novel therapeutic target in pancreatic cancer.

Stathmin1 regulates p27 expression, proliferation and drug resistance, resulting in poor clinical prognosis in cholangiocarcinoma

Patients with extrahepatic cholangiocarcinoma (EHCC) have a poor prognosis; postoperative survival depends on cancer progression and therapeutic resistance. The mechanism of EHCC progression needs to be clarified to identify ways to improve disease prognosis. Stathmin1 (STMN1) is a major cytosolic phosphoprotein that regulates microtubule dynamics and is associated with malignant phenotypes and chemoresistance in various cancers. Recently, STMN1 was reported to interact with p27, an inhibitor of cyclin‐dependent kinase complexes. Eighty EHCC cases were studied using immunohistochemistry and clinical pathology to determine the correlation between STMN1 and p27 expression; RNA interference to analyze the function of STMN1 in an EHCC cell line was also used. Cytoplasmic STMN1 expression correlated with venous invasion (P = 0.0021) and nuclear p27 underexpression (P = 0.0011). Patients in the high‐STMN1‐expression group were associated with shorter recurrence‐free survival and overall survival than those in the low‐expression group. An in vitro protein‐binding assay revealed that cytoplasmic STMN1 bound to p27 in the cytoplasm, but not in the nucleus of EHCC cells. Moreover, p27 accumulated in EHCC cells after STMN1 suppression. STMN1 knockdown inhibited proliferation and increased the sensitivity of EHCC cells to paclitaxel. STMN1 contributes to a poor prognosis and cancer progression in EHCC patients. Understanding the regulation of p27 by STMN1 could provide new insights for overcoming therapeutic resistance in EHCC.

Cancer-associated fibroblasts in hepatocellular carcinoma

The hepatic stellate cells in the liver are stimulated sustainably by chronic injury of the hepatocytes, activating myofibroblasts, which produce abundant collagen. Myofibroblasts are the major source of extracellular proteins during fibrogenesis, and may directly, or secreted products, contribute to carcinogenesis and tumor progression. Cancer-associated fibroblasts (CAFs) are one of the components of the tumor microenvironment that promote the proliferation and invasion of cancer cells by secreting various growth factors and cytokines. CAFs crosstalk with cancer cells stimulates tumor progression by creating a favorable microenvironment for progression, invasion, and metastasis through the epithelial-mesenchymal transition. Basic studies on CAFs have advanced, and the role of CAFs in tumors has been elucidated. In particular, for hepatocellular carcinoma, carcinogenesis from cirrhosis is a known fact, and participation of CAFs in carcinogenesis is supported. In this review, we discuss the current literature on the role of CAFs and CAF-related signaling in carcinogenesis, crosstalk with cancer cells, immunosuppressive effects, angiogenesis, therapeutic targets, and resistance to chemotherapy. The role of CAFs is important in cancer initiation and progression. CAFtargeted therapy may be effective for suppression not only of fibrosis but also cancer progression.

Forkhead box protein C2 contributes to invasion and metastasis of extrahepatic cholangiocarcinoma, resulting in a poor prognosis

Extrahepatic cholangiocarcinoma (EHCC) is a cancer with a poor prognosis, and the postoperative survival of patients depends on the existence of invasion and metastasis. The epithelial‐to‐mesenchymal transition (EMT) is an important step in EHCC invasion and metastasis. Forkhead box protein C2 (FOXC2) is a transcription factor that has been reported to induce the EMT. Therefore we examined the correlation between FOXC2 expression and clinical pathological factors, and analysed the function of FOXC2. The expression of FOXC2 in 77 EHCC cases was investigated by immunohistochemical staining, and the relationship between FOXC2 expression and clinicopathological factor was assessed. Knockdown by small interfering RNA (siRNA) was performed to determine the roles of FOXC2 in EHCC cell line. FOXC2 expression correlated with lymph node metastasis (P = 0.0205). Patients in the high FOXC2 expression group had a poorer prognosis than the patients in the low FOXC2 expression group. Moreover, FOXC2 knockdown inhibited cell motility and invasion, and decreased the expression of EMT markers (N‐cadherin, and matrix metalloproteinase (MMP) ‐2) and Angiopietin‐2 (Ang‐2). The EMT inducer FOXC2 contributes to a poor prognosis and cancer progression. FOXC2 may be a promising molecular target for regulating EHCC metastasis.

Phosphoglucose isomerase/autocrine motility factor promotes melanoma cell migration through ERK activation dependent on autocrine production of interleukin-8

It is well known that phosphoglucose isomerase/autocrine motility factor (AMF) promotes cell migration in an autocrine manner in various tumor cells. However, it remains unclear whether certain cytokines modulate the effects of AMF on tumor cell migration. Because interleukin (IL)-8, a proinflammatory cytokine, is produced by melanoma cells and has been correlated with melanoma migration, the migratory ability of melanoma cells induced by AMF may also involve induction of IL-8 expression. In the present study, we assessed whether AMF promotes melanoma cell migration through autocrine production of IL-8. We found that AMF stimulation increased IL-8 production through up-regulation of IL-8 mRNA transcription, especially in biologically early stage melanoma cells. AMF-induced migration of these cells was inhibited by a specific neutralizing antibody against IL-8. The IL-8 production induced by AMF was mediated by the ERK1/2 pathways. These findings suggest that melanoma migration induced by AMF is mediated by autocrine production of IL-8 as a novel downstream modulator of the AMF signaling pathway.