The inhibitory effect of disease-modifying anti-rheumatic drugs and steroids on gliostatin/platelet-derived endothelial cell growth factor production in human fibroblast-like synoviocytes

Drug repositioning in non-small cell lung cancer (NSCLC) using gene co-expression and drug–gene interaction networks analysis

Lung cancer is the most common cancer in men and women. This cancer is divided into two main types, namely non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Around 85 to 90 percent of lung cancers are NSCLC. Repositioning potent candidate drugs in NSCLC treatment is one of the important topics in cancer studies. Drug repositioning (DR) or drug repurposing is a method for identifying new therapeutic uses of existing drugs. The current study applies a computational drug repositioning method to identify candidate drugs to treat NSCLC patients. To this end, at first, the transcriptomics profile of NSCLC and healthy (control) samples was obtained from the GEO database with the accession number GSE21933. Then, the gene co-expression network was reconstructed for NSCLC samples using the WGCNA, and two significant purple and magenta gene modules were extracted. Next, a list of transcription factor genes that regulate purple and magenta modules' genes was extracted from the TRRUST V2.0 online database, and the TF–TG (transcription factors–target genes) network was drawn. Afterward, a list of drugs targeting TF–TG genes was obtained from the DGIdb V4.0 database, and two drug–gene interaction networks, including drug-TG and drug-TF, were drawn. After analyzing gene co-expression TF–TG, and drug–gene interaction networks, 16 drugs were selected as potent candidates for NSCLC treatment. Out of 16 selected drugs, nine drugs, namely Methotrexate, Olanzapine, Haloperidol, Fluorouracil, Nifedipine, Paclitaxel, Verapamil, Dexamethasone, and Docetaxel, were chosen from the drug-TG sub-network. In addition, nine drugs, including Cisplatin, Daunorubicin, Dexamethasone, Methotrexate, Hydrocortisone, Doxorubicin, Azacitidine, Vorinostat, and Doxorubicin Hydrochloride, were selected from the drug-TF sub-network. Methotrexate and Dexamethasone are common in drug-TG and drug-TF sub-networks. In conclusion, this study proposed 16 drugs as potent candidates for NSCLC treatment through analyzing gene co-expression, TF–TG, and drug–gene interaction networks.

Mithramycin has inhibitory effects on gliostatin and matrix metalloproteinase expression induced by gliostatin in rheumatoid fibroblast-like synoviocytes

OBJECTIVES

Gliostatin (GLS) has angiogenic and arthritogenic activities and enzymatic activity as thymidine phosphorylase. Aberrant GLS production has been observed in the synovial membranes of patients with rheumatoid arthritis (RA). Matrix metalloproteinases (MMPs) are involved in joint destruction. Promoters of GLS and some MMP genes contain Sp1 binding sites. We examined the inhibitory effect of the Sp1 inhibitor mithramycin on GLS-induced GLS and MMP expression in cultured fibroblast-like synoviocytes (FLSs).

METHODS

Synovial tissue samples were obtained from patients with RA. FLSs pretreated with mithramycin were cultured with GLS. The mRNA expression levels of GLS and MMP-1, MMP-2, MMP-3, MMP-9, and MMP-13 were determined using reverse transcription polymerase chain reactions. Protein levels were measured using enzyme immunoassay and gelatin zymography.

RESULTS

GLS upregulated the expression of GLS itself and of MMP-1, MMP-3, MMP-9, and MMP-13, an effect significantly reduced by treatment with mithramycin. GLS and mithramycin had no effect on MMP-2 expression.

CONCLUSIONS

Mithramycin downregulated the increased expression of GLS and MMP-1, MMP-3, MMP-9, and MMP-13 in FLSs treated with GLS. Because GLS plays a pathological role in RA, blocking GLS stimulation using an agent such as mithramycin may be a novel approach to antirheumatic therapy.

Regulation and novel action of thymidine phosphorylase in non-small cell lung cancer: crosstalk with Nrf2 and HO-1

Proangiogenic enzyme thymidine phosphorylase (TP) is a promising target for anticancer therapy, yet its action in non-small cell lung carcinoma (NSCLC) is not fully understood. To elucidate its role in NSCLC tumor growth, NCI-H292 lung mucoepidermoid carcinoma cells and endothelial cells were engineered to overexpress TP by viral vector transduction. NSCLC cells with altered expression of transcription factor Nrf2 or its target gene heme oxygenase-1 (HO-1) were used to study the regulation of TP and the findings from pre-clinical models were related to gene expression data from clinical NSCLC specimens. Overexpression of Nrf2 or HO-1 resulted in upregulation of TP in NCI-H292 cells, an effect mimicked by treatment with an antioxidant N-acetylcysteine and partially reversed by HO-1 knockdown. Overexpression of TP attenuated cell proliferation and migration in vitro, but simultaneously enhanced angiogenic potential of cancer cells supplemented with thymidine. The latter was also observed for SK-MES-1 squamous cell carcinoma and NCI-H460 large cell carcinoma cells. TP-overexpressing NCI-H292 tumors in vivo exhibited better oxygenation and higher expression of IL-8, IL-1β and IL-6. TP overexpression in endothelial cells augmented their angiogenic properties which was associated with enhanced generation of HO-1 and VEGF. Correlation of TP with the expression of HO-1 and inflammatory cytokines was confirmed in clinical samples of NSCLC. Altogether, the increased expression of IL-1β and IL-6 together with proangiogenic effects of TP-expressing NSCLC on endothelium can contribute to tumor growth, implying TP as a target for antiangiogenesis in NSCLC.

Thymidine phosphorylase regulates the expression of CXCL10 in rheumatoid arthritis fibroblast-like synoviocytes

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.

The Sp1 transcription factor is essential for the expression of gliostatin/thymidine phosphorylase in rheumatoid fibroblast-like synoviocytes

INTRODUCTION

Gliostatin/thymidine phosphorylase (GLS/TP) has angiogenic and arthritogenic activities, and aberrant GLS production has been observed in the active synovial membranes of rheumatoid arthritis (RA) patients. The human GLS gene promoter contains at least seven consensus binding sites for the DNA binding protein Sp1. Here we examined whether Sp1 is necessary for GLS production in RA. We also studied the effects of the Sp1 inhibitor mithramycin on GLS production in RA fibroblast-like synoviocytes (FLSs).

METHODS

FLSs from RA patients were treated with specific inhibitors. The gene and protein expression of GLS were studied using the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and an enzyme immunoassay. Intracellular signalling pathway activation was determined by western blotting analysis, a luciferase assay, a chromatin immunoprecipitation (ChIP) assay and a small interfering RNA (siRNA) transfection.

RESULTS

The luciferase and ChIP assays showed that Sp1 binding sites in the GLS promoter were essential for GLS messenger RNA (mRNA) expression. GLS production was suppressed in FLSs by siRNA against Sp1 transfection. Mithramycin decreased GLS promoter activity, mRNA and protein expression in FLSs. Tumour necrosis factor-α (TNF-α) significantly increased GLS expression in RA FLSs; this effect was reduced by pre-treatment with cycloheximide and mithramycin.

CONCLUSIONS

Pretreatment of mithramycin and Sp1 silencing resulted in a significant suppression of GLS production in TNF-α-stimulated FLSs compared to controls. GLS gene expression enhanced by TNF-α was partly mediated through Sp1. As physiological concentrations of mithramycin can regulate GLS production in RA, mithramycin is a promising candidate for anti-rheumatic therapy.

Pilot study of safety and effect of combined intravitreal bevacizumab and methotrexate for neovascular age-related macular degeneration

PURPOSE

To evaluate the safety and effect of combined intravitreal methotrexate and bevacizumab on choroidal neovascularization in age-related macular degeneration (AMD).

METHODS

Seven eyes of 7 patients (4 female; mean age 65.43±5.96 years) with choroidal neovascularization secondary to AMD were studied. Patients received intravitreal injection of methotrexate and bevacizumab and were examined every 1.5 months. Reinjections were performed with bevacizumab only.

RESULTS

Three patients had 3 months, 3 had 4.5 months, and 1 had 8 months of follow-up. Mean number of reinjections was 2.0. In all patients, best-corrected visual acuity (BCVA) improved compared to baseline. Central macular thickness (CMT) decreased in all but one patient who had no reduced visual acuity. Mean BCVA (logMAR) was 1.27±0.43 D at baseline, 1.1±0.38 D at week 6, and 0.93±0.31 D at month 3. Mean BCVA in 3 patients at 4.5 months was 1.1±0.15 D. There were statistically significant differences between BCVA before injection and at week 6 (p=0.017), 3 months (p=0.005), and 4.5 months (p=0.04). Mean baseline CMT was 389±177 µm, 371±154 µm at 6 weeks, and 317±108 µm at 3 months. Mean CMT in 3 patients at 4.5 months was 266±66 µm. There were no statistically significant differences between baseline CMT and after treatment. No scar formation, increase of scar, or adverse reaction to methotrexate injection were seen.

CONCLUSIONS

Addition of intravitreal methotrexate to bevacizumab was safe in 7 eyes of 7 patients. It may enhance the therapeutic effect in regression of neovascularization in AMD and may reduce development of a fibrous component and disciform scar formation.

FK506 inhibition of gliostatin/thymidine phosphorylase production induced by tumor necrosis factor-α in rheumatoid fibroblast-like synoviocytes

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities. The purpose of this study was to determine the inhibitory effects of FK506 (tacrolimus) on GLS production in rheumatoid arthritis (RA). We investigated the modulation of serum GLS by FK506 therapy and the effect of FK506 on the production of GLS in fibroblast-like synoviocytes (FLSs). Serum samples were collected from 11 RA patients with active disease at baseline and after 12 weeks of FK506 treatment. Serum concentrations of GLS and matrix metalloproteinase (MMP)-3 were measured by ELISA and found to be down-regulated in responders evaluated with a disease activity score. Patient FLSs were cultured and stimulated by tumor necrosis factor (TNF)-α with or without FK506. The expression levels of GLS were determined using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme immunoassay and shown to be significantly increased. GLS levels in TNF-α-stimulated FLSs were reduced by FK506 treatment. Our data show a novel mechanism for the action of physiological concentrations of FK506 in RA that regulates the production of GLS in FLSs.

TNF-alpha-induced aquaporin 9 in synoviocytes from patients with OA and RA

OBJECTIVES

To determine whether aquaporins (AQPs) are expressed in the synovial tissues of patients with OA and RA, and to examine the patterns of expression in patients with and without hydrarthrosis.

METHODS

AQPs were detected in synovial tissue samples from patients with OA and RA using RT-PCR and immunohistochemistry. Fibroblast-like synoviocytes (FLSs) from patients with OA and RA were cultured and stimulated with TNF-alpha. The expression of AQPs in FLSs was examined using RT-PCR and western blot analyses and the function of aquaglyceroporins was examined by a glycerol uptake assay.

RESULTS

AQP1, -3 and -9 mRNAs were expressed in synovial tissues from patients with OA and RA. AQP1, -3 and -9 proteins were also detected by immunohistochemistry. AQP9 mRNA was expressed more strongly in the synovial tissues of OA patients with hydrarthrosis than those without. AQP9 mRNA and protein expression were strongly induced with TNF-alpha treatment in FLSs, whereas the expression of AQP1 and -3 mRNAs was not induced with TNF-alpha treatment. AQP9 as an aquaglyceroporin was induced by TNF-alpha.

CONCLUSIONS

AQP9 mRNA was detected in synovial tissues from OA and RA patients with hydrarthrosis. AQP9 expression was strongly induced in FLSs with TNF-alpha. Although the functions of AQP1, -3 and -9 in synovial tissues remain to be elucidated, it suggested that AQP9 might be related to the pathogenesis of hydrarthrosis and inflammatory synovitis.

The dual role of thymidine phosphorylase in cancer development and chemotherapy

Thymidine phosphorylase (TP), also known as "platelet-derived endothelial cell growth factor" (PD-ECGF), is an enzyme, which is upregulated in a wide variety of solid tumors including breast and colorectal cancers. TP promotes tumor growth and metastasis by preventing apoptosis and inducing angiogenesis. Elevated levels of TP are associated with tumor aggressiveness and poor prognosis. Therefore, TP inhibitors are synthesized in an attempt to prevent tumor angiogenesis and metastasis. TP is also indispensable for the activation of the extensively used 5-fluorouracil prodrug capecitabine, which is clinically used for the treatment of colon and breast cancer. Clinical trials that combine capecitabine with TP-inducing therapies (such as taxanes or radiotherapy) suggest that increasing TP expression is an adequate strategy to enhance the antitumoral efficacy of capecitabine. Thus, TP plays a dual role in cancer development and therapy: on the one hand, TP inhibitors can abrogate the tumorigenic and metastatic properties of TP; on the other, TP activity is necessary for the activation of several chemotherapeutic drugs. This duality illustrates the complexity of the role of TP in tumor progression and in the clinical response to fluoropyrimidine-based chemotherapy.

Targeting platelet-derived endothelial cell growth factor/thymidine phosphorylase for cancer therapy

Thymidine phosphorylase (TP) is a key enzyme in the pyrimidine nucleoside salvage pathway, but it also recognizes and inactivates various anti-cancer chemotherapeutic agents. Moreover, TP is identical to platelet-derived endothelial cell growth factor (PD-ECGF), an angiogenic factor with anti-apoptotic properties. Increased expression of PD-ECGF/TP is found in many tumor and stromal cells, and elevated TP levels are associated with aggressive disease and/or poor prognosis. Thus, progression and metastasis of TP-expressing tumors might be abrogated by TP inhibitors that are used as single agents or in combination with (TP-sensitive) nucleoside analogues. On the other hand, increased TP activity in tumors may be exploited for the tumor-specific activation of fluoropyrimidine prodrugs, such as capecitabine. This review will focus on the different biological activities of PD-ECGF/TP and their implications for cancer progression and treatment.