• BMB Reports
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• v.52 no.1
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• pp.42-46
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• 2019

Cellular senescence, a process of cell proliferation arrest in response to various stressors, has been considered to be important factor in age-related disease. Identification of senescent cells in tissues is limited and the role of senescent cells is poorly understood. Recently however, several studies showed the characterization of senescent cells in various pathologic conditions and the role of senescent cells in disease progression is becoming important. Senescent cells are growth-arrested cells, however, the senescence associated secretory phenotype (SASP) of senescent cells could modify the tissues' microenvironment. Here, we discuss the progress and understanding of the role of senescent cells in tissues of pathologic conditions and discuss the development of new therapeutic paradigms, such as senescent cells-targeted therapy.

• IMMUNE NETWORK
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• v.16 no.2
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• pp.134-139
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• 2016

Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN-γ secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3917-3922
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• 2015

Curcumin, a lipid-soluble compound extracted from the plant Curcuma Longa, has been found to exert immunomodulatory effects via macrophages. However, most studies focus on the low bioavailability issue of curcumin by nano and microparticles, and thus the role of macrophages in the anticancer mechanism of curcumin has received little attention so far. We have previously shown the potential biocompatibility, biodegradability and anti-cancer effects of dendrosomal curcumin (DNC). In this study, twenty-seven BALB/c mice were equally divided into control as well as 40 and 80 mg/kg groups of DNC to investigate the involvement of macrophages in the antitumor effects of curcumin in a typical animal model of metastatic breast cancer. At the end of intervention, the tumor volume and weight were significantly reduced in DNC groups compared to control (P<0.05). Histopathological data showed the presence of macrophages in tumor and spleen tissues. Real-time PCR results showed that DNC increased the expression of STAT4 and IL-12 genes in tumor and spleen tissues in comparison with control (P<0.05), referring to the high levels of M1 macrophages. Furthermore treatment with DNC decreased STAT3, IL-10 and arginase I gene expression (P<0.05), indicating low levels of M2 macrophage. The results confirm the role of macrophages in the protective effects of dendrosomal curcumin against metastatic breast cancer in mice.

• Journal of Digestive Cancer Research
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• v.2 no.1
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• pp.1-4
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• 2014

Palliative care for cancer aims to relieve the discomfort and pain from the cancer itself and associated conditions. Gastrointestinal cancers originate from the tube like structure of gastrointestinal tract and cause complications such as obstruction, bleeding, adhesion, invasion, and perforation to adjacent organ. Recent advances in interventional endoscopy enables endoscopy physicians to do safe and effective care for gastrointestinal cancer patients. Endoscopic palliation includes stent, hemostasis, nutritional support and targeted drug delivery. Self expandable metallic stent is one of the most important modalities in gastrointestinal palliation. Through the endoscopy or over the wire pre-placed by endoscopy, stents restore the gastrointestinal luminal patency and relieve the obstructive condition. Endoscopic hemostasis is another important palliation in gastrointestinal cancer patients. Epinephrine injection, argon plasma coagulation and thermal cauterization are usual modalities for hemostasis. Histoacryl glue and fibrin glue are also available. Hemostatic nanopowder spray is newly reported effective in benign disease and is supposed to be effective also in cancer bleeding. Enteral feeding tubes including gastro- or jejunostomy and nosoduodenal tubes are placed by using endoscopic guidance. Enteral feeding tubes role as the route of easily absorbable or semi-digested nutrients and effectively maintain both patients calorie requirements and gut microenvironment. Photodynamic therapy is the one of the outstanding medical employments of photo-physics. Especially for superficial cancers in esophagus, photodynamic therapy is very useful in cancer removal and maintaining organ structure. In biliary neoplasm, photodynamic therapy is well known to be effective in cancer ablation and biliary ductal patency restoration. Targeted drug delivery is the lastest issue in palliative endoscopy. Debates and questions are still on the table. In this article, the role of endoscopic interventions in palliative care for the gastrointestinal tumors will be thoroughly reviewed.

• Oncology Letters
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• v.41 no.1
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• pp.465-474
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• 2019

The tumor microenvironment plays an important role in cancer growth, invasion and metastasis. The stroma surrounding a tumor is known to contain a variety of factors that can increase angiogenesis, cancer growth and tumor progression. The aim of the present study was to determine the role of fascin in cancer growth and invasion and identify stromal factors involved in cancer progression. A fascin-depleted cell line (fascindep) was used to observe the role of fascin in cancer invasion. Compared with wild-type Mock cells, cancer cell invasion in Matrigel-coated Transwell and three-dimensional (3D) culture system were reduced by fascin depletion. Tumor cell growth in vivo was also significantly reduced in mice injected with fascindep cells. Notably, fascin expression was increased during Transwell invasion with Matrigel compared to Transwell invasion without Matrigel. TGF-β1, EGF and IL-1β significantly stimulated fascin expression. Such increased expression of fascin was also observed in cultured cells using conditioned media (CM) from cancer-associated fibroblasts (CAFs). However, no significant change in fascin expression was observed using CM from normal fibroblasts (NFs). Stimulated expression of fascin by Matrigel and CAFs was reduced by biological specific inhibitor of TGF-β1, EGF and IL-1β. Compared with wild-type Mock cells, the fascindep cell line showed low RhoA and NF-κB activity, suggesting that RhoA and NF-κB signals are involved in fascin expression. In conclusion, stromal factors are involved in cancer invasion and progression by activating intracellular signaling of cancer cells to increase fascin expression.

• BMB Reports
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• v.42 no.6
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• pp.344-349
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• 2009

Angiogenesis is crucial for solid tumor growth. By secreting angiogenic factors, tumor cells induce angiogenesis. However, targeting these angiogenic factors for cancer therapy is not always successful, suggesting that other factors may be involved in tumor angiogenesis. This work shows that 25 protein spots were differentially expressed by two-dimensional gel electrophoretic analysis when HepG2 cells induced endothelial cell differentiation to tube in vitro, and most of them were upregulated. Twenty-one proteins were identified with MALDITOF-MS, and the other four were identified by LTQ-MS/MS. Keratins were identified as one class of these upregulated proteins. Further study indicated that the expression of keratin 17 in cultured endothelial cells is likely microenvironment regulated, because its expression can be induced by HepG2 cells and bFGF as well as serum in culture media. Increased expression of keratins in endothelial cells, such as keratin 17, may contribute to the angiogenesis induced by HepG2 cells.

• Biomolecules & Therapeutics
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• v.26 no.1
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• pp.10-18
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• 2018

Tumors are dynamic metabolic systems which highly augmented metabolic fluxes and nutrient needs to support cellular proliferation and physiological function. For many years, a central hallmark of tumor metabolism has emphasized a uniformly elevated aerobic glycolysis as a critical feature of tumorigenecity. This led to extensive efforts of targeting glycolysis in human cancers. However, clinical attempts to target glycolysis and glucose metabolism have proven to be challenging. Recent advancements revealing a high degree of metabolic heterogeneity and plasticity embedded among various human cancers may paint a new picture of metabolic targeting for cancer therapies with a renewed interest in glucose metabolism. In this review, we will discuss diverse oncogenic and molecular alterations that drive distinct and heterogeneous glucose metabolism in cancers. We will also discuss a new perspective on how aberrantly altered glycolysis in response to oncogenic signaling is further influenced and remodeled by dynamic metabolic interaction with surrounding tumor-associated stromal cells.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.281-290
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• 2024

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis owing to its desmoplastic stroma. Therefore, therapeutic strategies targeting this tumor stroma should be developed. In this study, we describe the heterogeneity of cancer-associated fibroblasts (CAFs) and their diverse roles in the progression, immune evasion, and resistance to treatment of PDAC. We subclassified the spatial distribution and functional activity of CAFs to highlight their effects on prognosis and drug delivery. Extracellular matrix components such as collagen and hyaluronan are described for their roles in tumor behavior and treatment outcomes, implying their potential as therapeutic targets. We also discussed the roles of extracellular matrix (ECM) including matrix metalloproteinases and tissue inhibitors in PDAC progression. Finally, we explored the role of the adaptive and innate immune systems in shaping the PDAC microenvironment and potential therapeutic strategies, with a focus on immune cell subsets, cytokines, and immunosuppressive mechanisms. These insights provide a comprehensive understanding of PDAC and pave the way for the development of prognostic markers and therapeutic interventions.

• Oncology Letters
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• v.18 no.1
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• pp.283-290
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• 2019

Wnt3a is a glycosylated ligand that activates the β-catenin-dependent signaling pathway. Wnt signaling is also important in the prostate tumor microenvironment, and Wnt proteins secreted by the tumor stroma promote resistance to therapy. Bioactive Wnt3a production requires a number of dedicated factors in the secretory cell, but their coordinated functions are not fully understood. We previously reported transmembrane protein 64 (Tmem64) as a novel regulator of the Wnt/β-catenin signaling pathway, which is correlated with β-catenin regulation. In the present study, the role of Tmem64 in prostate cancer cells was investigated by modulating Wnt3a secretion. Overexpression of Tmem64 inhibited Wnt3a secretion and Lef/Tcf-sensitive transcription. By contrast, a Tmem64 mutation deleting the protein's transmembrane region restored Wnt3a secretion. Notably, Tmem64 protein and mRNA in PC3 cells were significantly overexpressed compared with that observed in LNCaP and DU145 cells. In a mouse metastasis model intracardially injected with PC3 cells, Tmem64 expression was downregulated in the metastatic spine and mandible lesions compared with in the primary injection regions. However, Wnt3a was strongly expressed in the metastatic spine and mandible lesions. Collectively, these findings suggest that Tmem64 is involved in the metastatic progression of prostate cancer cells by regulating Wnt3a secretion.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2569-2574
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• 2015

Necroptosis, also known as "programmed necrosis", has emerged as a critical factor in a variety of pathological and physiological processes and is considered a cell type-specific tightly regulated process with mechanisms that may vary rather greatly due to the change of cell line. Here we used HT-29, a human colon cancer cell line, to establish a necroptosis model and elucidate associated mechanisms. We discovered that cobalt chloride, a reagent that could induce hypoxia-inducible $factor-1{\alpha}(HIF1{\alpha})$ expression and therefore mimic the hypoxic microenvironment of tumor tissue in some aspects induces necroptosis in HT-29 cells when caspase activity is compromised. On the other hand, apoptosis appears to be the predominant death form when caspases are functioning normally. HT-29 cells demonstrated significantly increased RIPK1, RIPK3 and MLKL expression in response to cobalt chloride plus z-VAD treatment, which was accompanied by drastically increased $IL1{\alpha}$ and IL6 expression, substantiating the notion that necrosis can induce profound immune reactions. The RIPK1 kinase inhibitor necrostatin-1 and the ROS scavenger NAC each could prevent necrosis in HT-29 cells and the efficiency was enhanced by combined treatment. Thus by building up a necroptosis model in human colon cancer cells, we uncovered that mechanically RIP kinases collaborate with ROS during necrosis promoted by cobalt chloride plus z-VAD, which leads to inflammation. Necroptosis may present a new target for therapeutic intervention in cancer cells that are resistant to apoptotic cell death.