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Notch signaling regulates cell-fate decisions during development and postnatal life. Little is known, however, about the role of Delta-like-4 (Dll4)-Notch signaling between cancer cells, or how this signaling affects cancer metastasis. We, therefore, assessed the role of Dll4-Notch signaling in cancer metastasis. We generated a soluble Dll4 fused to the IgG1 constant region (Dll4-Fc) that acts as a blocker of Dll4-Notch signaling and introduced it into human small cell lung cancer (SCLC) cell lines expressing either high levels (SBC-3 and H1048) or low levels (SBC-5) of Dll4. The effects of Dll4-Fc on metastasis of SCLC were evaluated using a mouse model. Although Dll4-Fc had no effect on the liver metastasis of SBC-5, the number of liver metastasis inoculated with SBC-3 and H1048 cells expressing Dll4-Fc was significantly lower than that injected with control cells. To study the molecular mechanisms of the effects of Dll4-Fc on liver metastasis, a PCR array analysis was conducted. Because the expression of NF-κB target genes was affected by Dll4-Fc, we conducted an electrophoretic mobility shift assay and observed that NF-κB activities, both with and without stimulation by TNF-α, were downregulated in Dll4-Fc–overexpressing SBC-3 and H1048 cells compared with control cells. Moreover, Dll4-Fc attenuates, at least in part, the classical and alternative NF-κB activation pathway by reducing Notch1 signaling. These results suggest that Dll4-Notch signaling in cancer cells plays a critical role in liver metastasis of SCLC by regulating NF-κB signaling. Mol Cancer Ther; 11(12); 2578–87. ©2012 AACR.

PDF file - 330K, Dll4-Fc reduced NF-κB/DNA binding in SBC-3 and H1048 cells

PDF file - 245K, Dll4-Fc promoted excessive angiogenesis of liver metastasis without affecting VEGFA expression and HUVECs proliferation

PDF file - 50K, The effect of recombinant Dll4-Fc on the NF-κB activity of SBC-3-vector cells

PDF file - 116K, Extracellular domain of murine Dll4-fused to Fc (Dll4-Fc) expressed in H1048 and SBC-5 cells

PDF file - 83K

PDF file - 174K, Dll4-Fc suppressed TNF-α induced NF-κB activity without attenuation of the cytoplasmic sequestration of NF-κB subunit

PDF file - 69K, Dll4-Fc suppresses genes-associated with metastasis in SCLC cells

PDF file - 47K, Taqman gene expression assays

Aims In addition to potentially progressing to either cirrhosis or hepatocellular carcinoma, non-alcoholic steatohepatitis (NASH) is currently the leading indication for liver transplantation. Nintedanib has been clinically used to treat idiopathic pulmonary fibrosis for many years, but its effects in an animal model of NASH have not been tested. The purpose of this study was to evaluate the effects of nintendanib on NASH in choline-deficient, l -amino acid-defined, high-fat diet (CDAHFD)-fed mice. Main methods Male C57BL/6 mice were fed a CDAHFD for 6 weeks to induce NASH with liver fibrosis, and they were administered nintedanib (60 mg/kg/day) or distilled water orally in the last 2 weeks of the feeding period. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglyceride, and non-esterified fatty acids concentrations were measured. Serum cytokeratin 18 fragment (CK18) was detected using ELISA. Liver tissue sections from mice were stained with hematoxylin-eosin and Masson's trichrome to assess the level of steatohepatitis and fibrosis. Key findings CDAHFD-fed mice exhibited higher serum ALT, AST, and ALP levels compared with Control mice. A significant increase in the serum CK18 level was observed in the NASH group compared with the Control group. CDAHFD feeding also enhanced steatohepatitis and hepatic fibrosis pathological features, which were reduced after nintedanib treatment. Significance Nintedanib exerted anti-inflammatory and anti-fibrotic effects in CDAHFD-induced NASH mice.

The feasibility and required sensitivity of circulating free DNA (cfDNA)-based detection methods in second-line epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment are not well elucidated. We examined T790M and other activating mutations of EGFR by cfDNA to assess the clinical usability. In 45 non-small cell lung cancer (NSCLC) patients harboring activating EGFR mutations, cfDNAs were prepared from the plasma samples. EGFR mutations in cfDNA were detected using highly sensitive methods and originally developed assays and these results were compared to tissue-based definitive diagnoses. The specificity of each cfDNA-based method ranged 96–100% whereas the sensitivity ranged 56–67%, indicating its low pseudo-positive rate. In EGFR-TKI failure cohort, 41–46% samples were positive for T790M by each cfDNA-based method, which was comparable to re-biopsy tissue-based T790M positive rates in literature. The concordance of the results for each EGFR mutation ranged from 83–95%. In eight patients, the results of the cfDNA-based assays and re-biopsy-derived tissue-based test were compared. The observed overall agreement ranged in 50–63% in T790M, and in 63–100% in activating EGFR mutations. In this study, we have newly developed three types of assay which have enough sensitivity to detect cfDNA. We also detected T790M in 44% of patients who failed prior EGFR-TKI treatment, indicating that cfDNA-based assay has clinical relevance for detecting acquired mutations of EGFR.

Background: TAS-117 is a potent oral allosteric non-ATP inhibitor selective for AKT. A phase 1 study with TAS-117 is ongoing in patients with endometrial cancer and ovarian clear cell carcinoma. Futibatinib (TAS-120) is a selective, irreversible small-molecule fibroblast growth factor receptor (FGFR) 1-4 inhibitor, with potent antiproliferative activity in preclinical models with FGFR aberrations. Phase 2 studies are ongoing in patients with various FGFR-deregulated cancers. We evaluated the antitumor activity of futibatinib plus TAS-117 in FGFR-aberrant cancer models. Methods: Effects of futibatinib plus TAS-117 were investigated in human endometrial FGFR2-N549K-mutated AN3CA cancer cells and small-cell lung cancer FGFR1-amplified DMS114 cells. Activation of RAS and PI3K pathways was assessed by detecting phosphorylation of ERK1/2, AKT, and S6. Antitumor combination indices (CI) for cell viability over time were determined with the Chou-Talalay median-effect method and CalcuSyn software; a CI Results: Futibatinib and TAS-117 synergistically increased cell death and decreased cell growth in AN3CA (CI Conclusions: Our findings suggest that futibatinib plus TAS-117 has synergistic antitumor effects in FGFR-aberrant tumors. A phase 1/2 study of this combination in advanced solid tumors (JapicCTI-194864) is ongoing. Citation Format: Junya Iwasaki, Takuya Kuramoto, Toshiharu Komori, Hitoshi Saito, Hiroshi Hirai. Synergistic antitumor activity of futibatinib, an FGFR1-4 inhibitor, and TAS-117, a selective AKT inhibitor, in FGFR-deregulated cancer models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 661.

Thymidine phosphorylase (TP) is a rate-limiting enzyme in the thymidine catabolic pathway. TP is identical to platelet-derived endothelial cell growth factor and contributes to tumour angiogenesis. TP induces the generation of reactive oxygen species (ROS) and enhances the expression of oxidative stress-responsive genes, such as interleukin (IL)-8. However, the mechanism underlying ROS induction by TP remains unclear. In the present study, we demonstrated that TP promotes NADPH oxidase-derived ROS signalling in cancer cells. NADPH oxidase inhibition using apocynin or small interfering RNAs (siRNAs) abrogated the induction of IL-8 and ROS in TP-expressing cancer cells. Meanwhile, thymidine catabolism induced by TP increased the levels of NADPH and intermediates of the pentose phosphate pathway (PPP). Both siRNA knockdown of glucose 6-phosphate dehydrogenase (G6PD), a rate-limiting enzyme in PPP, and a G6PD inhibitor, dihydroepiandrosterone, reduced TP-induced ROS production. siRNA downregulation of 2-deoxy-D-ribose 5-phosphate (DR5P) aldolase, which is needed for DR5P to enter glycolysis, also suppressed the induction of NADPH and IL-8 in TP-expressing cells. These results suggested that TP-mediated thymidine catabolism increases the intracellular NADPH level via the PPP, which enhances the production of ROS by NADPH oxidase and activates its downstream signalling.

Objective Thymidine phosphorylase (TP) in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) is induced by tumor necrosis factor α (TNFα) and other cytokines that have been reported to be major inflammation mediators in RA. We previously demonstrated that TP plays an important role in angiogenesis and tumor growth, invasion, and metastasis. The aim of this study was to investigate whether the role of TP in the pathogenesis of RA is similar to its role in tumors. Methods In FLS obtained from 2 patients with RA, the expression of TP, interferon-γ (IFNγ)–inducible protein 10 (CXCL10), and other cytokines was measured by quantitative real-time polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assays. Microarray analysis was performed using FLS transfected with TYMP complementary DNA and treated with a TP inhibitor. Results The expression of TP in FLS was up-regulated by TNFα, interleukin-1β (IL-1β), IL-17, IFNγ, and lipopolysaccharide. Microarray analysis of FLS overexpressing TP identified CXCL10 as a thymidine phosphorylase–related gene. The expression of CXCL10 was induced by TNFα, and this induction was suppressed by TYMP small interfering RNA and TP inhibitor. Furthermore, the combination of TNFα and IFNγ synergistically augmented the expression of TP and CXCL10. TP-induced CXCL10 expression was suppressed by the antioxidant EUK-8. In the synovial tissue of patients with RA, TP levels were significantly correlated with CXCL10 expression. Conclusion The combination of TNFα and IFNγ strongly induced the expression of thymidine phosphorylase in RA FLS. The induction of thymidine phosphorylase enhanced the expression of CXCL10, which may contribute to the Th1 phenotype and bone destruction observed in RA.

Surfactant protein A (SP-A) is a large multimeric protein found in the lungs. In addition to its immunoregulatory function in infectious respiratory diseases, SP-A is also used as a marker of lung adenocarcinoma. Despite the finding that SP-A expression levels in cancer cells has a relationship with patient prognosis, the function of SP-A in lung cancer progression is unknown. We investigated the role of SP-A in lung cancer progression by introducing the SP-A gene into human lung adenocarcinoma cell lines. SP-A gene transduction suppressed the progression of tumor in subcutaneous xenograft or lung metastasis mouse models. Immunohistochemical analysis showed that the number of M1 antitumor tumor-associated macrophages (TAMs) was increased and the number of M2 tumor-promoting TAMs was not changed in the tumor tissue produced by SP-A-expressing cells. In addition, natural killer (NK) cells were also increased and activated in the SP-A-expressing tumor. Moreover, SP-A did not inhibit tumor progression in mice depleted of NK cells. Taking into account that SP-A did not directly activate NK cells, these results suggest that SP-A inhibited lung cancer progression by recruiting and activating NK cells via controlling the polarization of TAMs.

Notch signaling regulates cell-fate decisions during development and postnatal life. Little is known, however, about the role of Delta-like-4 (Dll4)-Notch signaling between cancer cells, or how this signaling affects cancer metastasis. We, therefore, assessed the role of Dll4-Notch signaling in cancer metastasis. We generated a soluble Dll4 fused to the IgG1 constant region (Dll4-Fc) that acts as a blocker of Dll4-Notch signaling and introduced it into human small cell lung cancer (SCLC) cell lines expressing either high levels (SBC-3 and H1048) or low levels (SBC-5) of Dll4. The effects of Dll4-Fc on metastasis of SCLC were evaluated using a mouse model. Although Dll4-Fc had no effect on the liver metastasis of SBC-5, the number of liver metastasis inoculated with SBC-3 and H1048 cells expressing Dll4-Fc was significantly lower than that injected with control cells. To study the molecular mechanisms of the effects of Dll4-Fc on liver metastasis, a PCR array analysis was conducted. Because the expression of NF-κB target genes was affected by Dll4-Fc, we conducted an electrophoretic mobility shift assay and observed that NF-κB activities, both with and without stimulation by TNF-α, were downregulated in Dll4-Fc–overexpressing SBC-3 and H1048 cells compared with control cells. Moreover, Dll4-Fc attenuates, at least in part, the classical and alternative NF-κB activation pathway by reducing Notch1 signaling. These results suggest that Dll4-Notch signaling in cancer cells plays a critical role in liver metastasis of SCLC by regulating NF-κB signaling. Mol Cancer Ther; 11(12); 2578–87. ©2012 AACR.

Background and objective: Malignant pleural mesothelioma (MPM) is an aggressive neoplasm of the mesothelium with high chemotherapeutic resistance. In this study, the preclinical therapeutic activity of the multiple tyrosine kinase inhibitor, SU6668, against MPM was examined. Methods: Two human MPM cell lines with different pro-angiogenic cytokine expression, Y-MESO-14 cells that express high levels of vascular endothelial growth factor (VEGF) and MSTO-211H cells that express high levels of basic fibroblast growth factor (bFGF), were orthotopically inoculated into the thoracic cavities of mice with severe combined immunodeficiency. The mice with MPM were treated or not treated with SU6668 (200 mg/kg/day). Results: SU6668 abrogated the proliferation of endothelial cells stimulated by VEGF or bFGF, but did not directly affect the growth of human MPM cells in vitro. In this orthotopic implantation model, treatment with SU6668 effectively reduced tumour weight and pleural effusion volumes, in association with inhibition of the growth of tumour vasculature. More importantly, treatment with SU6668 significantly prolonged survival time in mice with MPM. Conclusions: These findings suggest that SU6668 has a promising therapeutic effect on the progression of MPM in vivo through its anti-angiogenic effects.

Alien Callosciurus squirrels cause severe damage to trees in forests, gardens, and commercial plantations (Jouanin 1986; Setoguchi 1990; Torii 1993; Aprile and Chicco 1999; Gurnell and Wauters 1999). Pallas’s squirrel (Callosciurus erythraeus) originally occurs in eastern India, Bhutan, southeast China, Taiwan, Indochina, and Malaya (Corbet and Hill 1992; Wilson and Reeder 2005). This squirrel was introduced into other countries as an exotic pet. At present, C. erythraeus populations are found in Argentina (e.g., Aprile and Chicco 1999), France (Jouanin 1986; Gurnell and Wauters 1999), and Japan (Ishii 2005; Tamura 2002, 2009; Ikeda et al. 2011). Under law number 78 of the Invasive Alien Species Act (Ministry of the Environment, Government of Japan, 2004: http://www.env.go.jp/nature/intro/index. html), import of C. erythraeus to Japan is strictly prohibited. This species is treated as ‘invasive alien species’ in Japan. Finlayson’s squirrel (C. finlaysonii), which originally occurs in the Indochina Peninsula (Corbet and Hill 1992; Wilson and Reeder 2005), was also introduced to Italy (Bertolino et al. 1999; Currado et al. 1999). Similar to C. erythraeus, C. finlaysonii is thought to cause damage to environments (Bertolino et al. 2004). It is difficult to distinguish this species from C. erythraeus based on external characteristics such as pelage patterns (e.g., Lekagul and McNeely 1988). Based on mitochondrial (mt) DNA control region sequences, Oshida et al. (2007) reported that C. finlaysonii was probably introduced to Hamamatsu, Shizuoka Prefecture, Japan (Fig. 1). They captured eight Callosciurus individuals in Hamamatsu. Of them, seven individuals had haplotypes closely related to that of C. finlaysonii from Laos (two C. finlaysonii haplotypes were detected), and one individual had a C. erythraeus haplotype. Therefore, we expect these two Callosciurus species exist sympatrically in Hamamatsu. Callosciurus finlaysonii, however, is not treated as an invasive alien species in Japan (law number 78 of the Invasive Alien Species Act, Ministry of the Environment, Government of Japan, 2004). Currently this species is treated as unidentified alien species. If the population of C. finlaysonii increases, this species should be added to the list of invasive alien species. To estimate whether C. finlaysonii is increasing, we investigated ratios of C. finlaysonii haplotype and C. erythraeus haplotype in the Hamamatsu population by using mtDNA control region sequences. We discuss the present situation of introduced C. finlaysonii in Hamamatsu. In addition, we compare control region sequences of specimens from Hamamatsu, Laos and Thailand, to identify the origin of introduced C. finlaysonii. The exact origin would be difficult to determine because we do not have sequence data from all C. finlaysonii populations occurring in the Indochina Peninsula. We, however, obtained successfully C. finlaysonii sequences from Thailand and Laos. Identifying whether the Hamamatsu population is more closely related to specimens from Thailand or Laos may help to prevent subsequent introductions of this squirrel into Japan with international legal and political action.

Bevacizumab exerts anti-angiogenic effects in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the development of resistance to the treatment. Such resistance can be regulated by various factors, although the underlying mechanisms remain incompletely understood. Here we show that bone marrow-derived fibrocyte-like cells, defined as alpha-1 type I collagen-positive and CXCR4-positive cells, contribute to the acquired resistance to bevacizumab. In mouse models of malignant pleural mesothelioma and lung cancer, fibrocyte-like cells mediate the resistance to bevacizumab as the main producer of fibroblast growth factor 2. In clinical specimens of lung cancer, the number of fibrocyte-like cells is significantly increased in bevacizumab-treated tumours, and correlates with the number of treatment cycles, as well as CD31-positive vessels. Our results identify fibrocyte-like cells as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy., Acquired resistance to anti-angiogenic drugs, including bevacizumab, may occur in cancer patients. In this study the authors identify in the tumour microenvironment, fibrocyte-like cells derived from the bone marrow that mediate the resistance to bevacizumab through the production of FGF2.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) show dramatic antitumor activity in a subset of patients with non-small cell lung cancer who have an active mutation in the epidermal growth factor receptor (EGFR) gene. On the other hand, some lung cancer patients with wild type EGFR also respond to EGFR-TKIs, suggesting that EGFR-TKIs have an effect on host cells as well as tumor cells. However, the effect of EGFR-TKIs on host microenvironments is largely unknown. A multiple organ metastasis model was previously established in natural killer cell-depleted severe combined immunodeficient mice using human lung cancer cells. This model was used to investigate the therapeutic efficacy of erlotinib, an EGFR-TKI, on multiple organ metastases induced by human small cell lung cancer cells (SBC-5 cells) that did not express EGFR. Although erlotinib did not have any effect on the proliferation of SBC-5 cells in vitro, it significantly suppressed bone and lung metastases in vivo, but not liver metastases. An immunohistochemical analysis revealed that, erlotinib significantly suppressed the number of osteoclasts in bone metastases, whereas no difference was seen in microvessel density. Moreover, erlotinib inhibited EGF-induced receptor activator of nuclear factor kappa-B expression in an osteoblastic cell line (MC3T3-E1 cells). These results strongly suggested that erlotinib prevented bone metastases by affecting host microenvironments irrespective of its direct effect on tumor cells.

The spark plasma sintering of tungsten wires to tungsten plates was investigated to assess the effect of the current. Neck growth between wires and plates was about 1.5 larger in the presence of current than when the current was absent. The neck growth was controlled by an evaporation–condensation mechanism. The mechanism, however, does not relate to the sintering of tungsten, but to the control of a surface oxide reduction, in agreement with previous investigations.

Purpose Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm. S-1 has been developed as a novel oral antineoplastic agent based on the modulation of 5-fluorouracil (5-FU) bioactivity. This study was conducted to investigate the preclinical therapeutic effect of S-1 on MPM. Methods We used three human MPM cell lines, Y-MESO-14, NCI-H290 and MSTO-211H. In vitro proliferation of human MPM cells was determined by MTT assay. Human MPM cells were orthotopically implanted into thoracic cavity of SCID mice. Tumor-bearing mice were treated with S-1 or vehicle. Results The combination of 5-FU and 5-chloro-2,4-dihydroxypyridine (CDHP) was more effective than 5-FU alone in inhibiting MPM cell proliferation in vitro. This combination was most effective in Y-MESO-14 cells, which co-expressed high protein level of dihydropyrimidine dehydrogenase (DPD) and thymidine phosphorylase (TP). In vivo data showed that treatment with S-1 significantly reduced thoracic tumors and pleural effusion produced by Y-MESO-14 cells. Moreover, treatment with S-1 prolonged the survival of Y-MESO-14 cell-bearing SCID mice. Conclusions We demonstrated that S-1 was effective for inhibiting the proliferation of MPM cells, particularly with both DPD and TP expressions, suggesting that S-1 might be therapeutically effective for control of MPM.

Microtubules (MTs) play crucial roles in a variety of cell functions, such as mitosis, vesicle transport and cell motility. MTs also compose specialized structures, such as centrosomes, spindles and cilia. However, molecular mechanisms of these MT-based functions and structures are not fully understood. Here, we analyzed MT co-sedimented proteins from rat brain by tandem mass spectrometry (MS) upon ion exchange column chromatography. We identified a total of 391 proteins. These proteins were grouped into 12 categories: 57 MT cytoskeletal proteins, including MT-associated proteins (MAPs) and motor proteins; 66 other cytoskeletal proteins; 4 centrosomal proteins; 10 chaperons; 5 Golgi proteins; 7 mitochondrial proteins; 62 nucleic acid-binding proteins; 14 nuclear proteins; 13 ribosomal proteins; 28 vesicle transport proteins; 83 proteins with diverse function and/or localization; and 42 uncharacterized proteins. Of these uncharacterized proteins, six proteins were expressed in cultured cells, resulting in the identification of three novel components of centrosomes and cilia. Our present method is not specific for MAPs, but is useful for identifying low abundant novel MAPs and components of MT-based structures. Our analysis provides an extensive list of potential candidates for future study of the molecular mechanisms of MT-based functions and structures.

We found that CEL-I was a potent cytotoxic lectin. MDCK, HeLa, and XC cells were highly sensitive to CEL-I cytotoxicity and killed in a dose-dependent manner, whereas CHO, L929, and RAW264.7 cells were relatively resistant to CEL-I, and no significant toxicity was observed up to 10 microg/ml. Among these cell lines, MDCK cells showed the highest susceptibility to CEL-I cytotoxicity. A binding study using FITC-labeled CEL-I (F-CEL-I) revealed that the amounts of bound F-CEL-I on the sensitive cell lines were evidently greater than those on the resistant cell lines, suggesting that the different susceptibility of the cell lines to CEL-I cytotoxicity is partly explained by different efficiencies of binding of CEL-I to these cell lines. Interestingly, the cytotoxicity of CEL-I toward MDCK cells was more potent than those of other lectins such as WGA, PHA-L, and Con A, even though these lectins were capable of binding to MDCK cells at comparable levels to CEL-I. Since the cytotoxicity of CEL-I was strongly inhibited by GalNAc, the binding to cell surface specific carbohydrates is essential for the CEL-I cytotoxicity. The trypan blue dye exclusion test indicated that CEL-I caused a disorder of plasma membrane integrity as a relatively early event. CEL-I failed to induce the release of carboxyfluorescein (CF) from CF-loaded MDCK cells as seen for pore-forming hemolytic isolectin CEL-III, suggesting that the primary cellular target of CEL-I may be the plasma membrane, but its action mechanism differs from that of CEL-III. Although CEL-I induced dramatic cellular morphological changes in MDCK cells, neither typical apoptotic nuclear morphological changes nor DNA fragmentation was observed in CEL-I-treated MDCK cells even after such cellular changes. Our results demonstrated that CEL-I showed a potent cytotoxic effect, especially on MDCK cells, by causing plasma membrane disorder without induction of apoptosis.

Thymidine phosphorylase (TP) in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) is induced by tumor necrosis factor α (TNFα) and other cytokines that have been reported to be major inflammation mediators in RA. We previously demonstrated that TP plays an important role in angiogenesis and tumor growth, invasion, and metastasis. The aim of this study was to investigate whether the role of TP in the pathogenesis of RA is similar to its role in tumors.In FLS obtained from 2 patients with RA, the expression of TP, interferon-γ (IFNγ)-inducible protein 10 (CXCL10), and other cytokines was measured by quantitative real-time polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assays. Microarray analysis was performed using FLS transfected with TYMP complementary DNA and treated with a TP inhibitor.The expression of TP in FLS was up-regulated by TNFα, interleukin-1β (IL-1β), IL-17, IFNγ, and lipopolysaccharide. Microarray analysis of FLS overexpressing TP identified CXCL10 as a thymidine phosphorylase-related gene. The expression of CXCL10 was induced by TNFα, and this induction was suppressed by TYMP small interfering RNA and TP inhibitor. Furthermore, the combination of TNFα and IFNγ synergistically augmented the expression of TP and CXCL10. TP-induced CXCL10 expression was suppressed by the antioxidant EUK-8. In the synovial tissue of patients with RA, TP levels were significantly correlated with CXCL10 expression.The combination of TNFα and IFNγ strongly induced the expression of thymidine phosphorylase in RA FLS. The induction of thymidine phosphorylase enhanced the expression of CXCL10, which may contribute to the Th1 phenotype and bone destruction observed in RA.

The organ microenvironment significantly affects the processes of cancer metastasis. Elucidating the molecular mechanisms of interaction between tumor cells and the organ microenvironment is crucial for the development of effective therapeutic strategies to eradicate cancer metastases. Macrophage stimulating protein (MSP), an activator of macrophages, regulates a pleiotropic array of effects, including proliferation, cellular motility, invasiveness, angiogenesis, and resistance to anoikis. However, the role of MSP in cancer metastasis is still largely unknown. In this study, the action of MSP on the production of metastases was determined in a multiple-organ metastasis model. The murine MSP gene was transfected into two human SCLC cell lines, SBC-5 and H1048, to establish transfectants secreting biologically active MSP. MSP gene transduction did not affect cell proliferation and motility in vitro. Intravenously inoculated MSP transfectants produced significantly larger numbers of liver metastases than parental cells or vector control clones, while there were no significant differences in bone or lung metastases among them. Immunohistochemical analyses of liver metastases revealed that tumor-associated microvessel density and tumor-infiltrating macrophages were significantly increased in lesions produced by MSP transfectants. MSP could stimulate the migration of murine macrophages and endothelial cells in vitro. Consequently, MSP may be one of the major determinants that affects the properties of tumor stroma and that produces a permissive microenvironment to promote cancer metastasis.

Lung cancer is commonly associated with multi-organ metastasis, and the bone is a frequent metastatic site for lung cancer. However, the molecular mechanism of organ-specific metastasis remains poorly understood. To elucidate this issue, we analyzed in this study genome-wide gene expression profiles of 15 metastatic lesions from three organs (bone, lung and liver) in a mouse model with multi-organ metastasis properties of human non-small cell lung cancer cells (ACC-LC319/bone2), using a combination of laser-microbeam microdissection and DNA microarrays. We identified 299 genes that could potentially be involved in the organ-selective nature of lung cancer metastasis. Among them, 77 were bone-specifically expressed elements, including genes involved in cell adhesion, cytoskeleton/cell motility, extracellular matrix remodeling and cell-cell signaling as well as genes already known to be involved in the bone metastasis of breast cancers. Quantitative RT-PCR confirmed the specific upregulation of eight genes in bone metastasis tumors, suggesting that these genes may be involved in bone metastasis. Our findings should be helpful for a better understanding of the molecular aspects of the metastatic process in different organs, and could lead to molecular target-based anticancer drugs and prevention of metastasis, especially bone metastasis.

Thymidine phosphorylase (TP) is an angiogenic factor that plays a pivotal role in tumor angiogenesis. Various kinds of solid tumors express TP and high TP activity is correlated with microvessel density. We have previously reported that TP enhances interleukin-8 (IL-8) expression in KB human epidermoid carcinoma cells. In this study, TP was shown to be involved in enhanced expression of IL-8 in EJ human bladder cancer cells and Yumoto human cervical cancer cells as well as KB human epidermoid carcinoma cells. The enzymatic activity of TP was required for the enhanced expression of IL-8. A degradation product of thymidine was implicated in the enhanced expression of IL-8. TP augmented reactive oxygen species (ROS) generation in KB and Yumoto cells, and the enzymatic activity of TP was again required for the generation of ROS. An antioxidant, N-acetylcysteine (NAC), attenuated the generation of ROS and IL-8 mRNA expression in KB and Yumoto cells, and H2O2 increased IL-8 mRNA expression in Yumoto cells, suggesting that ROS generated by TP caused the increased expression of IL-8 mRNA. Since TP also reduced cellular glutathione levels and transcription of γ-GCS in KB cells, the TP-induced augmentation of ROS may be partially attributed to the decreased glutathione. Our findings suggest that thymidine-derived sugars enhanced ROS generation and consequently increased IL-8 expression.

92 Background: Treatment of patients with lung cancer brain metastases remains a major challenge because of the limited availability of standard therapy. Thus, the development of successful treatment options for these patients is mandatory. Recently, the endothelin axis was reported to be involved in cancer progression through its pleiotropic biological effects on cell survival, proliferation, invasion, and metastasis. Methods: In this study, we evaluated both the in vitro and in vivoeffects of macitentan, an orally bioavailable, dual endothelin A receptor and endothelin B receptor antagonist, as monotherapy, and in combination with paclitaxel. Results: In human non-small cell lung cancer PC-14 cells, macitentan treatment inhibited cell proliferation, corresponding with inhibition of Akt and p42/44 mitogen-activated protein kinase phosphorylation, and increased apoptosis. The combination of macitentan and paclitaxel resulted in the potentiation of all of these effects, suggesting that macitentan could enhance sensitivity to paclitaxel. Moreover, macitentan completely abrogated astrocyte-mediated protection of tumor cells against paclitaxel. In an experimental brain metastasis model of human lung cancer, the combination of macitentan and paclitaxel significantly inhibited the growth of brain metastasis and produced a striking survival prolongation of tumor-bearing mice. Conclusions: The endothelin A and B receptor blockade by macitentan could be a promising therapeutic strategy for brain metastases of non-small cell lung cancer.

Background: Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR)-activating mutations (EGFRmu) responds favorably to the EGFR tyrosine kinase inhibitors (EGFR-TKIs), gefitinib or erlotinib. However, 25–30% of patients with EGFRmu show intrinsic resistance, and the responders invariably acquire resistance to EGFR-TKIs. Here, we examined the role of hepatocyte growth factor (HGF), a specific ligand of MET, in gefitinib resistance of NSCLC with EGFRmu. Methods: NSCLC cells, PC-9 and HCC827, with EGFRmu, but not T790M second mutation in EGFR or MET amplification, were used in this study. Sensitivity to gefitinib was determined by MTT assay. Phosphorylation of MET, EGFR, ERBB3, and the PI3K/Akt pathway were examined by Western blotting. HGF expression in 20 tumors from 16 NSCLC patients with EGFRmu who were treated with gefitinib was determined by immunohistochemistry. Results: HGF induced resistance to gefitinib by restoring Akt phosphorylation independently of ErbB3. Specific down-regulation of MET, but not ErbB3, reversed gefitinib resistance and Akt phosphorylation induced by HGF. High levels of immunoreactivity for HGF were detected in cancer cells of 3 of 3 intrinsic resistant tumors and in one of 2 tumors with acquired resistance without T790M second mutation or MET amplification, suggesting HGF-induced resistance by autocrine mechanism. The lung cancer cells also became resistant to EGFR-TKIs when co-cultured in vitro with HGF-producing fibroblasts and co-injected into SCID mice. Importantly, combined use of gefitinib plus anti-HGF antibody or the HGF antagonist, NK4 successfully overcame the fibroblast-induced EGFR-TKI resistance both in vitro and in vivo. Co-localization of fibroblasts and HGF was detected in both xenograft tumors in mouse model and lung cancer patient specimens, suggesting HGF-induced resistance by paracrine mechanism. Conclusions: The findings indicate that HGF-mediated MET activation is a novel mechanism of intrinsic and acquired gefitinib-resistance in NSCLC with EGFRmu by both autocrine and paracrine mechanisms. Therefore, inhibition of HGF-MET signaling may be considerable strategy for more successful treatment with EGFR-TKIs. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A178.

Background: Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm, for which the therapeutic options are limited. Pemetrexed combined with cisplatin, which has been approved, still has poor overall outcome. Molecular targeted therapies represent a promising strategy for overcoming limitation in therapy of malignant neoplasm including MPM. TSU-68 (SU6668), a tyrosine kinase inhibitor targeting VEGFR2, PDGFRβ and FGFR1 can inhibit the growth of various tumors. However, the efficacy of TSU-68 on MPM has not been investigated. Purpose: Investigate the therapeutic efficacy of TSU-68 on the progression of human MPM cells in an orthotopical implantation model. Method: Y-MESO-14 cells (expressing high level of VEGF and low level of bFGF) and MSTO-211H cells (expressing low level of VEGF and high level of bFGF) were orthotopically inoculated into thoracic cavities of SCID mice. From day 7 after inoculation, mice were treated with either TSU-68 (200mg/kg/day) or vehicle for two weeks. At the end of treatment, mice were sacrificed for analyzing the characteristics of thoracic tumors and pleural effusion. Result: In both cells, TSU-68 inhibited the tumor size, pleural effusion volume and vessel density in the tumor compared to control group. Furthermore, TSU-68 inhibited the proliferation of endothelial cells stimulated by VEGF, bFGF, or supernatant of MPM cell culture media in vitro. Conclusion: TSU-68 has anti-tumor activity for MPM progression. via inhibiting angiogenesis These findings suggest that TSU-68 may be clinically useful to improve the treatment outcome of MPM. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B7.