Kota Arima

miR-9-3p plays a tumour-suppressor role by targeting TAZ (WWTR1) in hepatocellular carcinoma cells.

Background:The inactivation of the Hippo pathway lead to TAZ (PDZ-binding motif)/YAP (yes-associated protein) overexpression, and is associated with worse prognostic outcomes in various cancers including hepatocellular carcinoma (HCC). Although there are several reports of microRNA (miR) targeting for YAP, miR targeting for TAZ remains unclear. The aim of this study is to identify the miR targeting TAZ expression in HCC.Methods:MicroRNA expression was analysed using the Human miFinder 384HC miScript miR PCR array, and was compared between low and high TAZ expression cell lines. Then, we extracted miR-9-3p as a tumour-suppressor miR targeting TAZ. We examined the functional role of miR-9-3p using miR-9-3p mimic and inhibitor in HCC cell lines).Results:In HCC cell lines and HCC clinical samples, there was the inverse correlation between miR-9-3p and TAZ expressions. TAZ expression was induced by treatment of miR-9-3p inhibitor and was downregulated by treatment of miR-9-3p mimic. Treatment of miR-9-3p mimic inhibited cell proliferative ability with downregulated phosphorylations of Erk1/2, AKT, and β-catenin in HLF. Inversely, treatment of miR-9-3p inhibitor accelerated cell growth compared with control in HuH1.Conclusions:MicroRNA-9-3p was identified as the tumour-suppressor miR targetting TAZ expression in HCC cells.

C5a receptor (CD88) promotes motility and invasiveness of gastric cancer by activating RhoA

Purpose Anaphylatoxin C5a is a strong chemoattractant of the complement system that binds the C5a receptor (C5aR). The expression of C5aR is associated with poor prognosis in several cancers. However, the role of C5aR in gastric cancer (GC) is unknown. The aim of this study was to examine the role of C5aR on GC cell motility and invasion. Experimental Design The mechanism of invasion via C5aR was assessed by analyzing cytoskeletal rearrangement and RhoA activity after C5a treatment. Moreover, we investigated the relationship between C5aR expression and the prognosis of GC patients. Results Two human GC cell lines (MKN1 and MKN7) had high C5aR expression. An invasion assay revealed that C5a stimulation promoted the invasive ability of MKN1 and MKN7 cells and that this was suppressed by knockdown of C5aR using siRNA or a C5aR-antagonist. Moreover, overexpression of C5aR in GC cells enhanced the conversion of RhoA-guanosine diphosphate (RhoA-GDP) to RhoA-guanosine triphosphate (RhoA-GTP) after C5a stimulation and caused morphological changes, including increased expression of stress fibers and filopodia. Examination of tumor specimens from 100 patients with GC revealed that high C5aR expression (35 of 100 samples, 35.0%) was associated with increased invasion depth, vascular invasion and advanced stage. The 5-year overall survival of patients with high or low C5aR expression was 58.2% and 88.5%, respectively (p=0.008). Conclusions This study is the first to demonstrate that C5aR promotes GC cell invasion by activating RhoA and is associated with a poor prognosis in GC patients. Therefore, this study provides a biomarker for GC patients who require an advanced therapeutic strategy.

Intraoperative blood loss is not a predictor of prognosis for pancreatic cancer

PurposeThe relationship between intraoperative blood loss (IBL) and prognosis has been reported for some types of cancer, but not for pancreatic cancer, which has one of the highest mortality rates of any cancer. We conducted this study to analyze the relationship between IBL and clinical outcome for patients undergoing radical surgery for pancreatic cancer.MethodsThe subjects of this study were 144 patients who underwent curative pancreatectomy for invasive pancreatic cancer between 2002 and 2014. Clinicopathological characteristics were recorded and prognostic factors were identified by univariate and multivariate analyses.ResultsLarge IBL was significantly associated with advanced tumor stage, a long operation time, a large tumor, portal vein resection, and blood transfusion. According to univariate analysis, IBL was also significantly associated with overall survival (OS) and relapse-free survival (RFS); however, it was not an independent prognostic factor for OS and RFS in multivariate analysis. According to multivariate analysis, lymph node metastasis and R-status were independent prognostic factors for OS and RFS. A subgroup analysis of patients who received no blood transfusion showed similar results.ConclusionMinimizing IBL is very important; however, the present study found that positive lymph node metastasis and R-status were stronger independent prognostic factors for pancreatic cancer.

Heterogeneity of KRAS Mutations in Pancreatic Ductal Adenocarcinoma

Objectives Activating Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are the most common and frequent changes observed in pancreatic cancer. This study aimed to determine the frequency and extent of intratumoral and metastatic lymph node KRAS mutation heterogeneity of resected pancreatic ductal adenocarcinoma. Methods Tumor tissues macrodissected from tumor centers, invasion fronts (n = 97), and lymph nodes (n = 11) were subjected to DNA extraction and mutation analysis of KRAS codons 12 and 13 by pyrosequencing. Results Activating mutations in codon 12 of KRAS were detected in 90 (92.8%) tumor centers. No mutations were detected in KRAS codon 13 in any patient. After a comparison of tumor centers and invasion fronts, intratumoral heterogeneity of KRAS was observed only in 4 (4.1%) cases. Additional invasion front tumor analysis revealed the same mutation status consistent with each tumor center. No heterogeneity was observed between primary tumors and metastatic lymph nodes. Conclusions Intratumoral heterogeneity of the KRAS mutational status is rare in pancreatic ductal adenocarcinoma. In addition, no KRAS heterogeneity between primary tumors and metastatic lymph nodes was detected in this study. This finding is consistent with the hypothesis that oncogenic activation of KRAS is the first driver mutation in pancreatic cancer.

Tumour-infiltrating inflammatory and immune cells in patients with extrahepatic cholangiocarcinoma

Background:Inflammation and immune characteristics of the tumour microenvironment have therapeutic significance. The aim of this study was to investigate the clinical impact on disease progression in human extrahepatic cholangiocarcinoma (ECC).Methods:A total of 114 consecutive ECC patients with curative resection between 2000 and 2014 were enrolled. Tumour infiltrating CD66b+ neutrophils (TANs; tumour associated neutrophils), CD163+ M2 macrophages (TAMs; tumour associated macrophages), CD8+ T cells, and FOXP3+ regulatory T cells (Tregs) were assayed by immunohistochemistry, and their relationships with patient clinicopathological characteristics and prognosis were evaluated.Results:Tumour associated neutrophils were inversely correlated with CD8+ T cells (P=0.0001) and positively correlated with Tregs (P=0.001). High TANs (P=0.01), low CD8+ T cells (P=0.02), and high Tregs (P=0.04) were significantly associated with poor overall survival (OS). A high-risk signature, derived from integration of intratumoural inflammatory and immune cells, was significantly associated with poor recurrence-free survival (P=0.01) and OS (P=0.0008). A high-risk signature was correlated with postoperative distant metastases. Furthermore, a high-risk signature was related to the resistance to gemcitabine-based chemotherapy used after recurrence.Conclusions:Our data showed that tumour infiltrating inflammatory and immune cells may play a pivotal role in ECC progression and a high-risk signature predicted poor prognosis in ECC patients.

Preoperative platelet-to-lymphocyte ratio can predict recurrence beyond the Milan criteria after hepatectomy for patients with hepatocellular carcinoma.

Postoperative recurrence beyond the Milan criteria is a poor prognostic factor for patients with hepatocellular carcinoma (HCC) treated with various therapies. We investigated the most useful inflammation‐based prognostic score for predicting recurrence beyond the Milan criteria after initial liver resection.

Inducible factors for cancer-associated fibroblasts in liver cancer versus myofibroblasts in inflammatory liver disease.

The importance of cancer-associated fibroblasts (CAFs) in liver cancer, cholangiocarcinoma (CC) and hepatocellular carcinoma (HCC), has been appreciated in the past 5 years. We focused on how they get activated in the tumor microenvironment in this review. Not only hepatic stellate cells (HSCs) but also portal fibroblasts (PFs) have been appreciated to be key players in liver fibrogenesis, and their different roles have just started to be recognized. Since the role of cholangiocyte in biliary fibrogenic disease might have some similarities to that of CC, we focused on the role of cholangiocytes activating stromal fibroblasts, which would presumably be helpful for better understanding the mechanism of tumor-CAFs interaction. In addition, the activation of CAFs should be different from that of CAFs in HCC, which we consider to be potentially similar to MFs in hepatocyte injury-dependent liver fibrogesis. Herein, we describe the activation of CAFs in CC in comparison to MFs seen in other liver diseases such as 1) MFs in liver fibrosis caused by hepatocyte injury such as alcoholic hepatitis, viral hepatitis, and nonalcoholic steatosis, 2) MFs in liver fibrosis caused by cholestatic disease, and 3) CAFs in hepatocellular carcinoma (HCC). This review on the activation of fibroblasts either in liver cancer or in chronic liver disease would contribute to CAF-targeted therapy in liver cancer.

Colorectal Cancer Stem Cells Acquire Chemoresistance Through the Upregulation of F‐Box/WD Repeat‐Containing Protein 7 and the Consequent Degradation of c‐Myc

The cancer stem cell (CSC) paradigm suggests that tumors are organized hierarchically. Chugai previously established an LGR5+ human colorectal cancer (CRC) stem‐cell‐enriched cell line (colorectal CSCs) that expresses well‐accepted colorectal CSC markers and that can dynamically switch between proliferative and drug‐resistant noncycling states. We performed this study to elucidate the molecular mechanisms responsible for evading cell death in colorectal CSCs mediated by anticancer agents. During the cell cycle arrest caused by anticancer agents, we found that c‐Myc expression was substantially decreased in colorectal CSCs. The c‐Myc expression alterations were mediated by upregulation of F‐box/WD repeat‐containing protein 7 (FBXW7), as evidenced through FBXW7‐small interfering RNA knockdown experiments that resulted in enhanced cell sensitivity to anticancer agents. Upregulation of FBXW7 following drug treatment was not evident in commercially available cancer cell lines. Colorectal CSCs were induced to differentiation by Matrigel and fetal bovine serum. Differentiated CSCs treated with anticancer agents did not show upregulation of FBXW7 and were more sensitive to irinotecan (CPT‐11), highlighting the potential CSC‐specific nature of our data. The FBXW7 over‐expression was further validated in resected liver metastatic sites in CRC patients after chemotherapy. In conclusion, our study revealed that a CSC‐specific FBXW7‐regulatory mechanism is strongly associated with resistance to chemotherapeutic agents. Inhibition of FBXW7‐upregulation in CSCs following chemotherapy may enhance the response to anticancer agents and represents an attractive strategy for the elimination of colorectal CSCs. Stem Cells 2017;35:2027–2036

Diverse Basis of β-Catenin Activation in Human Hepatocellular Carcinoma: Implications in Biology and Prognosis

Aim β-catenin signaling is a major oncogenic pathway in hepatocellular carcinoma (HCC). Since β-catenin phosphorylation by glycogen synthase kinase 3β (GSK3β) and casein kinase 1ε (CK1ε) results in its degradation, mutations affecting these phosphorylation sites cause β-catenin stabilization. However, the relevance of missense mutations in non-phosphorylation sites in exon 3 remains unclear. The current study explores significance of such mutations in addition to addressing the clinical and biological implications of β-catenin activation in human HCC. Methods Gene alteration in exon3 of CTNNB1, gene expression of β-catenin targets such as glutamate synthetase (GS), axin2, lect2 and regucalcin (RGN), and protein expression of β-catenin were examined in 125 human HCC tissues. Results Sixteen patients (12.8%) showed conventional missense mutations affecting codons 33, 37, 41, and 45. Fifteen additional patients (12.0%) had other missense mutations in codon 32, 34, and 35. Induction of exon3 mutation caused described β-catenin target gene upregulation in HCC cell line. Interestingly, conventional and non-phosphorylation site mutations were equally associated with upregulation of β-catenin target genes. Nuclear localization of β-catenin was associated with poor overall survival (p = 0.0461). Of these patients with nuclear β-catenin localization, loss of described β-catenin target gene upregulation showed significant poorer overall survival than others (p = 0.0001). Conclusion This study suggests that both conventional and other missense mutations in exon 3 of CTNNB1 lead to β-catenin activation in human HCC. Additionally, the mechanism of nuclear β-catenin localization without upregulation of described β-catenin target genes might be of clinical importance depending on distinct mechanism.

Downregulation of 15-hydroxyprostaglandin dehydrogenase by interleukin-1β from activated macrophages leads to poor prognosis in pancreatic cancer

Chronic inflammation has a crucial role in cancer development and the progression of various tumors, including pancreatic ductal adenocarcinoma (PDAC). The arachidonate cascade is a major inflammatory pathway that produces several metabolites, such as prostaglandin E2. The enzyme 15‐hydroxyprostaglandin dehydrogenase (15‐PGDH) degrades prostaglandin and is frequently decreased in several types of cancer; however, the molecular mechanisms of 15‐PGDH suppression are unclear. The current study was carried out to elucidate the molecular mechanisms and clinical significance of 15‐PGDH suppression in PDAC. Here, we showed that interleukin‐1β (IL‐1β), a pro‐inflammatory cytokine, downregulates 15‐PGDH expression in PDAC cells, and that IL‐1β expression was inversely correlated with 15‐PGDH levels in frozen PDAC tissues. We also found that activated macrophages produced IL‐1β and reduced 15‐PGDH expression in PDAC cells. Furthermore, the number of CD163‐positive tumor‐associated macrophages was shown to be inversely correlated with 15‐PGDH levels in PDAC cells by immunohistochemical staining of 107 PDAC samples. Finally, we found that low 15‐PGDH expression was significantly associated with advanced tumors, presence of lymph node metastasis and nerve invasion, and poor prognosis in PDAC patients. Our results indicate that IL‐1β derived from TAMs suppresses 15‐PGDH expression in PDAC cells, resulting in poor prognosis of PDAC patients.