Recently, the possibility of PD1 pathway-targeted therapy has been extensively studied in various human malignant tumors. However, no previous study has investigated their potential application for soft-tissue sarcomas (STS). In this study, we evaluated the clinical impact of intra-tumoral infiltration of PD1-positive lymphocytes and PD-L1 expression in tumor cells in 105 cases of STS. Intra-tumoral infiltration of PD1-positive lymphocytes and PD-L1 expression were seen in 65% and 58% of STS, respectively. Both PD1-positivity and PD-L1 expression were significantly associated with advanced clinicopathological parameters such as higher clinical stage, presence of distant metastasis, higher histological grade, poor differentiation of tumor, and tumor necrosis. Moreover, both PD1-positivity and PD-L1 positivity were independent prognostic indicators of overall survival (OS) and event-free survival (EFS) of STS by multivariate analysis. In addition, the combined pattern of PD1- and PD-L1-positivity was also an independent prognostic indicator for OS and EFS by multivariate analysis. The patents with a PD1+/PD-L1+ pattern had the shortest survival time. In conclusion, this study is the first to demonstrate that the infiltration of PD1 positive lymphocytes and PD-L1 expression in STS cells could be used as novel prognostic indicators for STS. Moreover, the evaluation of PD1- and PD-L1-positivity in STS is also available as possible criteria for selection of patients suitable for PD1-based immunotherapy.

Purpose: SIRT1 (silent mating-type information regulation 2 homologue 1) expression has been reported to predict poor survival in some cancers.We therefore investigated the expression levels of SIRT1 and its negative regulator, DBC1 (deleted in breast cancer 1), in gastric cancer patients. Experimental Design: We evaluated immunohistochemical expression of DBC1, SIRT1, and p53 using 3-mm tumor cores from 177 gastric cancer patients for tissue microarray. Results: Positive expressions of DBC1 and SIRT1 were seen in 62% (109 of 177) and in 73% (130 of 177) of patients, respectively. Expression of DBC1was significantly correlated with tumor stage (P = 0.007), lymph node metastasis (P < 0.001), tumor invasion (P = 0.001), venous invasion (P = 0.001), histologic types (P < 0.001), p53 expression (P < 0.001), and SIRT1 expression (P < 0.001). SIRT1 expression was also significantly correlated with tumor stage (P < 0.001), lymph node metastasis (P < 0.001), tumor invasion (P < 0.001), histologic types (P < 0.001), and p53 expression (P = 0.001). In addition, expression of DBC1 was significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P < 0.001 and P < 0.001, respectively). SIRT1 expression was also significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P = 0.001 and P = 0.001, respectively). Multivariate analysis showed that tumor stage and expression of DBC1 were independent prognostic factors significantly associated with overall survival and relapse-free survival. Conclusion: This study shows that expression of DBC1 and SIRT1 is a significant prognostic indicator for gastric carcinoma patients.

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Recently, the roles of sirtuins (SIRTs) in tumorigenesis have been of interest to oncologists, and protein kinase CK2 α1 (CSNK2A1) has been shown to be involved in tumorigenesis by phosphorylating various proteins, including SIRT1. Therefore, we evaluated the roles of CSNK2A1, SIRT6, and phosphorylated SIRT6 and their relationships in breast carcinoma. Nuclear expression of CSNK2A1 and SIRT6 predicted shorter overall survival and relapse-free survival by multivariate analysis. Inhibition of CSNK2A1 decreased the proliferative and invasive activity of cancer cells. In addition, CSNK2A1 was bound to SIRT6 and phosphorylated SIRT6; evidence for this is provided from immunofluorescence staining, co-immunoprecipitation of CSNK2A1 and SIRT6, a glutathione S-transferase pull-down assay, an in vitro kinase assay, and transfection of mutant CSNK2A1. Knockdown of SIRT6 decreased the proliferation and invasiveness of cancer cells. Overexpression of SIRT6 increased proliferation, but mutation at the Ser338 phosphorylation site of SIRT6 inhibited the proliferation of MCF7 cells. Moreover, both knockdown of SIRT6 and a mutation at the phosphorylation site of SIRT6 decreased expression of matrix metallopeptidase 9, β-catenin, cyclin D1, and NF-κB. Especially, SIRT6 expression was associated with the nuclear localization of β-catenin. This study demonstrates that CSNK2A1 and SIRT6 are indicators of poor prognosis for breast carcinomas and that CSNK2A1-mediated phosphorylation of SIRT6 might be involved in the progression of breast carcinoma.

Stress that impairs endoplasmic reticulum (ER) function leads to an accumulation of unfolded or misfolded proteins in the ER (ER stress) and triggers the unfolded protein response (UPR). Recent studies suggest that ER stress is involved in idiopathic pulmonary fibrosis (IPF). The present study was undertaken to determine the role of ER stress on myofibroblastic differentiation of fibroblasts. Fibroblasts in fibroblastic foci of IPF showed immunoreactivity for GRP78. To determine the role of ER stress on α-smooth muscle actin (α-SMA) and collagen type I expression in fibroblasts, mouse and human lung fibroblasts were treated with TGF-β1, and expression of ER stress-related proteins, α-SMA, and collagen type I was analyzed by Western blotting. TGF-β1 significantly increased expression of GRP78, XBP-1, and ATF6α, which was accompanied by increases in α-SMA and collagen type I expression in mouse and human fibroblasts. A chemical chaperone, 4-PBA, suppressed TGF-β1-induced UPR and α-SMA and collagen type I induction. We also showed that TGF-β1-induced UPR was mediated through the reactive oxygen species generation. Our study provides the first evidence implicating the UPR in myofibroblastic differentiation during fibrosis. These findings of the role of ER stress and chemical chaperones in pulmonary fibrosis may improve our understanding of the pathogenesis of IPF.

Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent deacetylase. Recently, it is suggested that SIRT1 may be involved in the development of malignant tumors including mouse lymphoma. Therefore, we investigated the prevalence and the prognostic impact of SIRT1 expression in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical expression of SIRT1, p53, bcl2, CD10, bcl6, and multiple myeloma-1 (MUM1) were evaluated by using a 2 mm core from 104 DLBCL patients for tissue microarray. Positive expression of SIRT1 was seen in 74% (77/104) of patients. In total DLBCL patients, SIRT1 and p53 expression were significantly associated with shorter overall survival (OS) by univariate analysis (P=0.001 and P=0.011, respectively). SIRT1 was also an independent prognostic factor by multivariate analysis (P=0.01). According to the expression patterns of CD10, bcl6, and MUM1, germinal center B cell (GCB) types were represented in 38 cases (37%) and non-GCB types were represented in 66 cases (63%). In the GCB type, only p53 expression was associated with a significantly shorter OS (P=0.032). In the non-GCB type, expression of SIRT1 correlated with shorter OS by univariate analyses (P=0.005) and multivariate analyses (P=0.049). In conclusion, we showed that SIRT1 expression is a clinically significant prognostic indicator for DLBCL patients.

Background & Aims Ischemia and reperfusion injury are common causes of oxidative tissue damage associated with many liver diseases and hepatic surgery. The Wnt–β-catenin signaling pathway is an important regulator of hepatic development, regeneration, and carcinogenesis. However, the role of Wnt signaling in the hepatocellular response to ischemia–reperfusion (I/R) injury has not been determined. Methods Hepatic injury following ischemia or I/R was investigated in hepatocyte-specific, β-catenin–deficient mice, as well as Wnt1 overexpressing and wild-type (control) mice. Results Wnt–β-catenin signaling was affected by the cellular redox balance in hepatocytes. Following ischemia or I/R, mice with β-catenin–deficient hepatocytes were significantly more susceptible to liver injury. Conversely, mice that overexpressed Wnt1 in hepatocytes were resistant to hepatic I/R injury. Hypoxia inducible factor (HIF)-1α signaling was reduced in β-catenin–deficient liver but increased in hepatocytes that overexpressed Wnt1 under hypoxia and following I/R, indicating an interaction between β-catenin and HIF-1α signaling in the liver. The mechanism by which Wnt signaling protects against liver injury involves β-catenin’s role as a transcriptional co-activator of HIF-1α signaling, which promotes hepatocyte survival under hypoxic conditions. Conclusion Cellular redox balance affects Wnt–β-catenin signaling, which protects against hypoxia and I/R injury. These findings might be used to develop strategies for protection of hepatocytes, regeneration of liver, and inhibition of carcinogenesis.

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