Anti-cancer effects of celecoxib on nasopharyngeal carcinoma HNE-1 cells expressing COX-2 oncoprotein

Targeting fatty acid synthase sensitizes human nasopharyngeal carcinoma cells to radiation via downregulating frizzled class receptor 10

Objective: Our aim was to test the hypothesis that fatty acid synthase (FASN) expression contributes to radioresistance of nasopharyngeal carcinoma (NPC) cells and that inhibiting FASN enhances radiosensitivity. Methods: Targeting FASN using epigallocatechin gallate (EGCG) or RNA interference in NPC cell lines that overexpress endogenous FASN was performed to determine their effects on cellular response to radiation in vitro using MTT and colony formation assays, and in vivo using xenograft animal models. Western blot, immunohistochemistry, real-time PCR arrays, and real-time RT-PCR were used to determine the relationship between FASN and frizzled class receptor 10 (FZD10) expression. FZD10 knockdown and overexpression were used to determine its role in mediating FASN function in cellular response to radiation. Immunohistochemical staining was used to determine FASN and FZD10 expressions in human NPC tissues, followed by analysis of their association with the overall survival of patients. Results: FASN knockdown or inhibition significantly enhanced radiosensitivity of NPC cells, both in vitro and in vivo. There was a positive association between FASN and FZD10 expression in NPC cell lines grown as monolayers or xenografts, as well as human tissues. FASN knockdown reduced FZD10 expression, and rescue of FZD10 expression abolished FASN knockdown-induced enhancement of radiosensitivity. FASN and FZD10 were both negatively associated with overall survival of NPC patients. Conclusions: FASN contributes to radioresistance, possibly via FZD10 in NPC cells. Both FZD10 and FASN expressions were associated with poor outcomes of NPC patients. EGCG may sensitize radioresistance by inhibiting FASN and may possibly be developed as a radiosensitizer for better treatment of NPCs.

Over-expression of cyclo-oxygenase-2 predicts poor survival of patients with nasopharyngeal carcinoma: a meta-analysis

OBJECTIVES

The conclusive prognostic significance of cyclo-oxygenase-2 has been determined in various cancers but not in nasopharyngeal carcinoma. Therefore, this study aimed to evaluate the relationship of cyclo-oxygenase-2 expression with the survival outcome and treatment response of nasopharyngeal carcinoma patients via a systematic meta-analysis approach.

METHODS

A meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses ('PRISMA') checklist. The primary clinical characteristics of patients, and hazard ratios with 95 per cent confidence intervals of overall survival data, were tabulated from eligible studies. The relationship of cyclo-oxygenase-2 expression with survival outcome (expressed as hazard ratio) and treatment response (expressed as odds ratio) in nasopharyngeal carcinoma patients was analysed, and explained with the aid of forest plot charts.

RESULTS AND CONCLUSION

The pooled hazard ratio for overall survival was 2.02 (95 per cent confidence interval = 1.65-2.47). This indicates that the over-expression of cyclo-oxygenase-2 is significantly associated with the poor survival of nasopharyngeal carcinoma patients. The pooled odds ratio of 0.98 (95 per cent confidence interval = 0.27-3.49) reveals that over-expression of cyclo-oxygenase-2 was not significantly related to the treatment outcome.

Cutaneous Application of Celecoxib for Inflammatory and Cancer Diseases

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and particularly selective cyclooxygenase-2 (COX-2) inhibitors such as celecoxib (Cxb) are considered promising cancer chemopreventive for colon, breast, prostate, lung, and skin cancers. However, the clinical application to the prevention is limited by concerns about safety, potential to serious toxicity (mainly for healthy individuals), efficacy and optimal treatment regimen. Cxb exhibits advantages as potent antiinflammatory and gastrointestinal tolerance compared with conventional NSAID's. Recent researches suggest that dermatological formulations of Cxb are more suitable than oral administration in the treatment of cutaneous disease, including skin cancer. To date, optimism has been growing regarding the exploration of the topical application of Cxb (in the prevention of skin cancers and treatment of cutaneous inflammation) or transdermal route reducing risks of systemic side effects.

OBJECTIVE

This paper briefly summarizes our current knowledge of the development of the cutaneous formulations or delivery systems for Cxb as anti-inflammatory drug (for topical or transdermal application) as well its chemopreventive properties focused on skin cancer.

CONCLUSION

New perspectives emerge from the growing knowledge, bringing innovative techniques combining the action of Cxb with other substances or agents which act in a different way, but complementary, increasing the efficacy and minimizing toxicity.

Combining antiangiogenic therapy and radiation in nasopharyngeal carcinoma

Radiation therapy is the primary treatment in nasopharyngeal carcinoma (NPC), and the effect of radiation therapy is strongly related to the oxygen content of cancer cells. That means, it is imperative to balance the interactions between radiotherapy and anti-angiogenesis therapy when giving combination therapy to improve clinical outcomes. The complicated mechanisms between antiangiogenic agents and radiation involve many interactions between the cancer cells, vasculature, and cancer stroma. The proliferation and metastasis of cancer depends on angiogenesis, while rapid growth of cancers will cause hypoxia, which contributes to radioresistance. Antiangiogenic agents can modulate the cancer blood flow and oxygenation through target cancer vasculature, leading to increased radiosensitivity. This study discusses the mechanisms of the synergistic effect of the antiangiogenic therapy with radiation therapy in metastatic NPC, and reviews the data supporting this strategy as a promising treatment for metastatic NPC.

Celecoxib and fish oil: a combination strategy for decreased inflammatory mediators in early stages of experimental mammary cancer

Chronic inflammation has been directly linked to cancer progression. Therefore, current study was designed to understand the mechanism of action of chemo-preventive effect of celecoxib and fish oil on inflammatory mediators in experimental mammary carcinoma. Female Wistar rats were distributed into control and DMBA treated groups and further subdivided based on pretreatment with celecoxib and/or fish oil. Inflammation was measured by assessing expression of NF-κB, COX-2 and cytokines. The results indicated an elevation in expression of NF-κB, COX-2 and cytokines' levels (IFN-γ, IL-4 and IL-10) in DMBA group as compared to controls. On pretreatment with celecoxib and/or fish oil in DMBA treated animals, a significant reduction in expression of NF-κB, COX-2 and cytokines' levels was observed. The decrease was more pronounced with combinatorial regimen than either celecoxib or fish oil alone. To conclude, a combinatorial strategy of celecoxib and fish oil may generate an immune response against the tumor cell by altering cytokine repertoire and decrease the tendency of tumor cells to escape immune surveillance.

An in vitro model for spontaneous angiogenesis using rat mesenteric endothelial cells: possible therapeutic perspective for obesity and related disorders

CONTEXT

Abnormal obesity and the related diseases, such as diabetes and cardiovascular disease, are the main causes of mortality, around the world. A key feature of the adipogenesis and obesity is angiogenesis-dependent tissue growth accompanied with extracellular remodeling. In this way, suppression of angiogenesis may be a key point for preventing the adipogenesis.

OBJECTIVE

In the present study, to provide a deeper insight to understand obesity and screening for more effective therapeutics, we have developed a three-dimensional in vitro model of microvessel formation under collagen matrix culture using endothelial cells, extracted from a suitable tissue.

MATERIALS AND METHODS

In a successful approach for developing an angiogenesis model, the rat mesenteric microvascular endothelial cells (RMMECs) were isolated, coated on dextran beads and then suspended in collagen gel. Additionally, the proliferation as well as migration of endothelial cells were analyzed and compared with human umbilical vein endothelial cells (HUVECs).

RESULTS

RMMECs showed remarkable migration ability and had higher growth during the logarithmic growth phase, when compared with HUVECs. Also, no significance differences in morphogenesis were observed between HUVECs and RMMECs.

DISCUSSION AND CONCLUSION

The model may be useful in providing insights to develop potential intervention strategies in vivo against obesity-related disorders. Targeting endothelial cells is an interesting and exciting possibility that may be raised in further investigations.

The enhancement of radiosensitivity in human esophageal squamous cell carcinoma cells by zoledronic acid and its potential mechanism

Esophageal squamous cell carcinoma (ESCC) has a low 5-year patient survival rate. Radiotherapy, as a preoperative or postoperative treatment of surgery, has a crucial role in improving local control and survival of ESCC. Various chemotherapeutic and biologic agents have been used as radio-sensitizers in combination with radiotherapy. Here, we demonstrate that zoledronic acid (ZOL) has a radio-sensitizing effect on ESCC cells. Exposure of ESCC cancer cells to ZOL plus radiation resulted in increased cell death through arresting the cell cycle between S and G2/M phases. ZOL appeared to inhibit proliferation, tube formation and invasion of endothelial cells. These anti-angiogenetic effects were more marked concurrently with irradiation. In addition, synergistic suppressive effects on VEGF expression were observed after combined treatment. Our data suggest that the combination of ZOL and radiation is a promising therapeutic strategy to enhance radiation therapy for ESCC patients.

Prognostic significance of expression of cyclooxygenase-2, vascular endothelial growth factor, and epidermal growth factor receptor in nasopharyngeal carcinoma

BACKGROUND

The association between expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), and the long-term outcomes in treated nasopharyngeal carcinoma (NPC) was studied.

METHODS

Expression of COX-2, VEGF, and EGFR by immunohistochemical (IHC) staining was assessed in 128 patients with NPC. Overall survival (OS), disease-free survival (DFS), locoregional control, and distant metastasis-free survival rates were compared for different expression levels of each marker. Multivariate analysis was by the Cox regression model.

RESULTS

Median follow-up after radiation therapy ± chemotherapy was 116 months. Univariate and multivariate analyses demonstrated that COX-2, VEGF, EGFR, and clinical stage were all independent predictors for OS, DFS, locoregional control, and distant metastasis-free survival rates.

CONCLUSIONS

High expression of COX-2, VEGF, and EGFR were independent adverse prognostic factors for long-term outcomes in nonmetastatic NPC independent of clinical stage.

Celecoxib induces apoptosis and cell-cycle arrest in nasopharyngeal carcinoma cell lines via inhibition of STAT3 phosphorylation

AIM

To investigate the mechanisms underlying the anticancer effect of celecoxib on nasopharyngeal carcinoma (NPC).

METHODS

NPC cell lines, HNE1 and CNE1-LMP1, were treated with various concentrations of celecoxib for 48 h. The antiproliferative effect of celecoxib was assessed using MTT assay. Both cell cycle profiles and apoptosis were analyzed using flow cytometry. Western blot was used to measure the levels of signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3(Y705) (pSTAT3(Y705)), COX-2, Survivin, Mcl-1, Bcl-2 and Cyclin D1.

RESULTS

Celecoxib (10-75 μmol/L) inhibited the proliferation of the NPC cell lines in a dose-dependent manner. Celecoxib (25 and 50 μmol/L) induced apoptosis and cell-cycle arrest at the G(0)/G(1) checkpoint in the NPC cell lines, which was associated with significantly reduced STAT3 phosphorylation. The genes downstream of STAT3 (ie, Survivin, Mcl-1, Bcl-2 and Cyclin D1) were significantly down-regulated after exposure to celecoxib (25 and 50 μmol/L).

CONCLUSION

The anticancer effects of celecoxib on NPC cell lines results from inducing apoptosis and cell cycle arrest, which may be partly mediated through the STAT3 pathway.

Phase I clinical trial of nasopharyngeal radiotherapy and concurrent celecoxib for patients with locoregionally advanced nasopharyngeal carcinoma

We evaluated the incidence of acute toxicity of concurrent cyclooxygenase-2 inhibitor (celecoxib) plus radiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). Thirty-four patients received an accumulated radiation dose of 72-76Gy in 36-38 fractions to the primary lesion and 60Gy in 30 fractions to cervical lymph-node lesions. Palpable residual nodes were boosted to 70Gy at the 90% isodose level with an electron field. Celecoxib was administered at escalating doses of 400, 600, and 800mg/day, starting 3days before the first fraction of radiotherapy and continuing throughout the course of radiotherapy. The majority of toxicities were grade 1, with mucositis and weight loss most frequently observed (28 of 34, 82.4%), followed by dermatitis (27 of 34, 79.4%) and otitis (14 of 34, 41.2%). The toxicities were not related to celecoxib dose (all P>0.05). Stomach pain was considered related to celecoxib, which developed in 2 patients at doses of 400mg and 800mg/day. No grade-3 or -4 toxicities or episodes of toxic death occurred. The tumors in 31 patients (31/34, 91.2%) showed a complete response, and 3 patients (3/34, 8.8%) had partial responses. The actuarial local progression-free survival was 96.6% at 1year, and the 2year overall survival rate was 84.6%. Celecoxib can be safely administered concurrently with nasopharyngeal radiotherapy at doses up to 800mg/day. The tumors responded well to treatment warranting further assessment in a phase II trial.