Keiichiro Nojiri

The expression and function of Toll-like receptors 3 and 9 in human colon carcinoma

Toll-like receptors (TLRs) are pattern-recognition receptors that are important in immune signaling. TLR recognition of various viral components including double-stranded RNA (TLR3) and unmethylated CpG-DNA (TLR9) plays a crucial role in cell survival. However, TLR expression and function in colon carcinoma cells are not well clarified. We investigated the expression of TLR3 and TLR9 in colon carcinoma cells using immunohistochemical methods. The function of TLR3 and TLR9 signaling in carcinoma cell lines was studied by direct cell stimulation with, or by cell transfection of, polyinosinic-polycytidylic acid (Poly I:C), a synthetic form of dsRNA, and by cell stimulation with CpG-oligodeoxynucleotides (ODNs), respectively. Positive TLR3 and TLR9 immunohistochemical staining was observed in 91 and 86% of human hepatocellular carcinoma (HCC) tissues, respectively. Cell surface stimulation of TLR3 with Poly I:C did not affect cell viability but it did activate NF-κB activity. By contrast, stimulation of intracellular TLRs with transfected Poly I:C significantly induced apoptosis. Cell surface stimulation of TLR9 with CpG-ODNs promoted cell proliferation, and, furthermore, these CpG-ODN TLR9 agonists reduced the cytotoxicity of the anticancer drug adriamycin. Cell surface expression of TLR3 and TLR9 in colon carcinoma cells plays an important role in cell survival. In addition, the proapoptotic activity of intracellularly expressed TLR3 may provide the possibility of using TLR3 agonists as novel clinical cytotoxic agents against colon carcinoma cells.

Human β-defensin-3 inhibits migration of colon cancer cells via downregulation of metastasis-associated 1 family, member 2 expression. Corrigendum in /ijo/46/4/1858

The innate immune system plays an important role as the first line of defense against many types of microbes. Accumulating reports suggest that human β-defensins (hBDs) are expressed by and have certain roles in some cancer cells. In this study, we investigated the roles of hBD-3 in colon cancer cells. The expression of hBD-3 was examined by reverse transcriptase-polymerase chain reaction analysis of colon cancer cell lines and immunohistochemical staining of colon cancer tissues. The effect of hBD-3 on proliferation of colon cancer was assessed using the MTT assay and a real-time cell analyzer, and the effect of hBD-3 on the migration of colon cancer cells was also examined. The results showed that hBD-3 is not expressed in colon cancer cells but is produced by tumor-infiltrating monocytes. Migration of colon cancer cells was significantly inhibited by hBD-3 in a dose-dependent manner, although proliferation of colon cancer cells was not affected by administration of hBD-3. Moreover, reduced expression of metastasis-associated 1 family, member 2 (MTA2) mRNA in colon cancer cells was associated with exposure to hBD-3. In conclusion, progression of colon cancer was inhibited by hBD-3 in a paracrine fashion. Therefore, hBD-3 may be a potent new agent for treating colon cancer.

Second and Third-look Endoscopy for the Prevention of Post-ESD Bleeding

AbstractThe efficacy of 2nd-look esophagogastroduodenoscopy (EGD) with endoscopic hemostatic therapy (EHT) for the prevention of postendoscopic submucosal dissection (ESD) clinical bleeding remains controversial. The aim of this study was to estimate post-ESD bleeding rate using 2nd and 3rd-look strategy, and to determine risk factors for clinical bleeding, and for EHT at 2nd and 3rd-look EGDs.Three hundred forty-four consecutive patients with early gastric cancer or adenoma underwent ESD from January 2006 through March 2012. Second and 3rd-look EGDs were performed on day 1 (D1) and day 7 (D7), respectively, with EHT as needed.Post-ESD clinical bleeding rate was 2.6% (95% confidence interval [CI] 1.2%–4.9%). For clinical bleeding, adjusted odds ratios (ORs) for age <65 years and antithrombotic drug uses were 4.40 (95% CI 1.07–19.93) and 7.34 (95% CI 1.80–32.48), respectively. For D1 EHT, adjusted ORs of tumor location in the lower part of the stomach and maximum tumor diameter ≥60 mm were 2.16 (95% CI 1.35–3.51) and 2.20 (95% CI 1.05–4.98), respectively. For D7 EHT, adjusted OR of D1 EHT was 4.65 (95% CI 1.56–20.0).Post-ESD clinical bleeding rate was relatively low using 2nd and 3rd-look strategy. Age <65 years and antithrombotic drug use are significant risk factors for clinical bleeding. Regarding EHT, tumor location in the lower part of the stomach and maximum diameter of resected specimen ≥60 mm are significant predictors for D1 EHT. D1 EHT in turn is a significant risk factor for D7 EHT. The efficacy of sequential strategy for preventing post-ESD bleeding is promising.

The long-term effects of splenectomy and subsequent interferon therapy in patients with HCV-related liver cirrhosis

Partial splenic embolization (PSE) or splenectomy is widely performed to increase platelet counts for interferon (IFN) therapy. The aim of the present study was to evaluate the long-term effects of splenectomy and subsequent IFN therapy in patients with hepatitis C virus (HCV)-related liver cirrhosis (LC). The present study included 19 patients with HCV-related LC who underwent splenectomy for thrombo-cytopenia caused by hypersplenism. IFN therapy was performed in all 19 patients. The effects of splenectomy and subsequent IFN therapy on peripheral blood counts, liver function, carcinogenesis and survival rates were evaluated. Splenectomy was safely performed in all patients without major complications with the exception of portal thrombosis, which, however, it did not affect liver function when treated appropriately. Thrombocytopenia improved and IFN therapy could be performed in all the patients. A sustained virological response (SVR) was not observed in patients with genotype 1 although it was observed in 75% of patients with genotype 2. Due to severe side effects, five patients did not undergo scheduled IFN therapy. Over 5 years, the mean platelet number increased from 5.2 x 10(4) to 16.8 x 10(4)/mm3 (P<0.01) and liver function improved following splenectomy (albumin, Alb: 3.5‑3.8 g/dl; total bilirubin, T-Bil: 1.0‑0.7 mg/dl; prothrombin time, PT: 74.1‑97.7%; total cholesterol; T-cho: 140‑168 mg/dl; P<0.05). Hepatocellular carcinoma (HCC) occurred in only one patient during long‑term observation and follow‑up of the patients not presenting with HCC at entry. The results of the present study demonstrate that splenectomy followed by interferon therapy could be beneficial in patients with HCV-related LC.

Su2049 Radiofrequency Ablation Therapy for the Treatment of Metastatic Lung Tumor From Primary Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. The prevalence of HCC varies widely in different regions of the world. The impact of specific causes of chronic liver disease to HCC prevalence is well-established. In contrast, the contribution of the underlying genetic architecture to the risk of HCC remains undefined. Genome wide association studies have identified genetic polymorphisms associated with increased susceptibility to HCC. Our aim was to characterize evolutionary trends in the genetic profile of HCC. We hypothesized that negative selection would reduce susceptibility to genetic polymorphisms that increase risk of HCC. Methods: SNPs identified from genome wide association studies with an increased risk of HCC associated with HBV (rs17401966) or HCV (rs9275572, rs2596542) were analyzed. Genetic risk was determined from the risk odds ratio and the frequency of the risk alleles across 53 indigenous human populations across all continents using the Human Genome Diversity Project and ALFRED databases. The fixation index (Fst ) was used to describe the degree of population differentiation (low 1.5) as a measure of gene flow and similarity across subpopulations. A genetic risk score for HCC was determined based on the combined risk of five SNPs associated with increased risk of HCC [rs1800562, rs2596542, rs2267716, rs9275572 and rs17401966]. The frequency of each risk allele and the genetic risk score were correlated with geographic location and with temporal and spatial patterns of human migration. Results: A moderate increase in differentiation was noted for rs2596542 (Fst = 0.106) and rs17401966 (Fst =0.116). Both of these SNPs show an increase in allelic frequency with the most recent human migrations from East Asia, to Oceania and the Americas. In contrast, rs9275572 lacked differentiation (Fst=0.09) with stable allelic expression across populations. The percentile genetic risk score for HCC was greatest in populations from Africa (e.g. Mbuti pygymies 100, San 97), and decreased with subsequent migration into Europe and Asia through to East Asia (e.g. Lahu 1, Yi 1.5). However, a major increase was noted with most recent migrations into Oceania and the Americas (e.g. Karitiana 93.9). Conclusions: Population based studies of genomic variations provide insight into the role of migration on genetic risk for hepatocarcinogenesis. There are differences in directional differentiation of HCC risk alleles across human populations, indicating that susceptibility to HCC can be modified by factors other than genetic drift. Variations in allelic frequency of HCC associated SNPs can contribute to population-based differences in HCC prevalence, and need to be considered for developing regional strategies for screening and surveillance for HCC.