Effects of cyclooxygenase-2 inhibition on serum and tumor gastrins and expression of apoptosis-related proteins in colorectal cancer

Combination of thalidomide and Clostridium butyricum relieves chemotherapy-induced nausea and vomiting via gut microbiota and vagus nerve activity modulation

Nausea and vomiting (CINV) are distressful and widespread side effects of chemotherapy, and additional efficient regimens to alleviate CINV are urgently needed. In the present study, colorectal cancer (CRC) mice model induced by Azoxymethane (AOM)/Dextran Sodium Sulfate (DSS) was employed to evaluate the cancer suppression and CINV amelioration effect of the combination of thalidomide (THD) and Clostridium butyricum. Our results suggested that the combination of THD and C. butyricum abundantly enhanced the anticancer effect of cisplatin via activating the caspase-3 apoptosis pathway, and also ameliorated CINV via inhibiting the neurotransmitter (e.g., 5-HT and tachykinin 1) and its receptor (e.g., 5-HT₃R and NK-1R) in brain and colon. Additionally, the combination of THD and C. butyricum reversed the gut dysbacteriosis in CRC mice by increasing the abundance of Clostridium, Lactobacillus, Bifidobacterium, and Ruminococcus at the genus level, and also led to increased expression of occludin and Trek1 in the colon, while decreased expression of TLR4, MyD88, NF-κB, and HDAC1, as well as the mRNA level of IL-6, IL-1β, and TNF-α. In all, these results suggest that the combination of THD and C. butyricum had good efficacy in enhancing cancer treatments and ameliorating CINV, which thus provides a more effective strategy for the treatment of CRC.

NF-κB in Gastric Cancer Development and Therapy

Gastric cancer is considered one of the most common causes of cancer-related death worldwide and, thus, a major health problem. A variety of environmental factors including physical and chemical noxae, as well as pathogen infections could contribute to the development of gastric cancer. The transcription factor nuclear factor kappa B (NF-κB) and its dysregulation has a major impact on gastric carcinogenesis due to the regulation of cytokines/chemokines, growth factors, anti-apoptotic factors, cell cycle regulators, and metalloproteinases. Changes in NF-κB signaling are directed by genetic alterations in the transcription factors themselves, but also in NF-κB signaling molecules. NF-κB actively participates in the crosstalk of the cells in the tumor micromilieu with divergent effects on the heterogeneous tumor cell and immune cell populations. Thus, the benefits/consequences of therapeutic targeting of NF-κB have to be carefully evaluated. In this review, we address recent knowledge about the mechanisms and consequences of NF-κB dysregulation in gastric cancer development and therapy.

Relationship between Barrett's esophagus and colonic diseases: a role for colonoscopy in Barrett's surveillance

BACKGROUND

Given that risk factors for Barrett's carcinogenesis are predictive, appropriate management and surveillance of Barrett's esophagus (BE) may be provided. The presence of colorectal neoplasms (CRNs) is a possible predictor of the development of BE and the progression to esophageal adenocarcinoma (EAC). We evaluated the relationship between BE or EAC and colonic diseases, including neoplasms and diverticulosis.

METHODS

Patients (N = 5606) who underwent both colonoscopy and esophagogastroduodenoscopy between January 2016 and December 2017 at three institutions were enrolled. The relationships between the presence of colonic diseases and BE or EAC and other clinical or endoscopic predictors of the presence of BE were investigated retrospectively.

RESULTS

The prevalence of BE ≥ 1 cm and ≥ 3 cm in length was 13.0% and 0.52%, respectively. BE was closely related with the presence of colorectal adenoma (48.4% vs. 37.2% in non-BE; P < 0.001), adenocarcinoma (16.6% vs. 8.4%, P < 0.001) and colonic diverticulosis (CD) (34.1% vs. 29.3%, P < 0.001). In patients with long-segment BE, CRNs (79.3%, P < 0.001) and CD (48.2%, P = 0.038) were more common. EAC patients also had a statistically significantly higher incidence of CRNs than non-BE patients (87.5% vs. 45.6%, P = 0.027). Diverticulosis at the distal colon correlated significantly with EAC and BE (50.0%, P = 0.010 and 15.4%, P = 0.024, vs. 12.0% in non-BE). Multivariate analysis showed that CRNs (t = 8.55, P < 0.001), reflux esophagitis (t = 5.26, P < 0.001) and hiatal hernia (t = 11.68, P < 0.001) were predictors of BE.

CONCLUSIONS

The presence of CRNs was strongly associated with BE and EAC. Therefore, colonoscopy may be useful for establishing a strategy for the surveillance of BE.

Mitotic and apoptotic activity in colorectal neoplasia

Background

Colorectal cancer (CRC) is third most commonly diagnosed cancer worldwide. The aim of the prospective study was to evaluate mitosis and apoptosis of epithelial cells at each stage of colorectal neoplasia.

Methods

A total of 61 persons were enrolled into the study: 18 patients with non-advanced colorectal adenoma (non-a-A), 13 patients with advanced colorectal adenoma (a-A), 13 patients with CRC and 17 controls: individuals with normal findings on colonoscopy. Biopsy samples were taken from pathology (patients) and healthy mucosa (patients and healthy controls). Samples were formalin-fixed paraffin-embedded and stained with haematoxylin-eosin. Mitotic and apoptotic activity were evaluated in lower and upper part of the crypts and in the superficial compartment. Apoptotic activity was also assessed using detection of activated caspase-3.

Results

In controls, mitotic activity was present in lower part of crypts, accompanied with low apoptotic activity. Mitotic and apoptotic activity decreased (to almost zero) in upper part of crypts. In superficial compartment, increase in apoptotic activity was observed. Transformation of healthy mucosa into non-a-A was associated with significant increase of mitotic activity in lower and upper part of the crypts and with significant increase of apoptotic activity in all three compartments; p < 0.05. Transformation of non-a-A into a-A did not lead to any further significant increase in apoptotic activity, but was related to significant increase in mitotic activity in upper part of crypts and superficial compartment. A significant decrease in apoptotic activity was detected in all three comparments of CRC samples compared to a-A; p < 0.05. No differences in mitotic and apoptotic activity between biopsies in healthy controls and biopsy samples from healthy mucosa in patients with colorectal neoplasia were observed. Detection of activated caspase-3 confirmed the above findings in apoptotic activity.

Conclusions

Significant dysregulation of mitosis and apoptosis during the progression of colorectal neoplasia, corresponding with histology, was confirmed. In patients with sporadic colorectal neoplasia, healthy mucosa does not display different mitotic and apoptotic activity compared to mucosa in healthy controls and therefore adequate endoscopic/surgical removal of colorectal neoplasia is sufficient.

Role of gastrin-peptides in Barrett's and colorectal carcinogenesis

Gastrin is the main hormone responsible for the stimulation of gastric acid secretion; in addition, gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types. Gastrin synthesis and secretion are increased in certain situations, for example, when proton pump inhibitors are used. The impact of sustained hypergastrinemia is currently being investigated. In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates; although, this relationship is less clear in human beings. Higher gastrin levels have been shown to cause hyperplasia of several cell types; yet, the risk for developing cancer seems to be the same in normo- and hypergastrinemic patients. Some tumors also produce their own gastrin, which can act in an autocrine manner promoting tumor growth. Certain cancers are extremely dependent on gastrin to proliferate. Initial research focused only on the effects of amidated gastrins, but there has been an interest in intermediates of gastrin in the last few decades. These intermediates aren’t biologically inactive; in fact, they may exert greater effects on proliferation and apoptosis than the completely processed forms. In certain gastrin overproduction states, they are the most abundant gastrin peptides secreted. The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production, levels, and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett’s and colorectal carcinogenesis.

Comparison of Preincisional and Postincisional Parecoxib Administration on Postoperative Pain Control and Cytokine Response After Total Hip Replacement

Objective:

To investigate whether preincisional parecoxib administration can reduce postoperative pain and modulate the inflammatory cytokine response to a greater extent than preincisional parecoxib administration in total hip replacement patients.

Methods:

Patients were randomized to receive 40 mg parecoxib intravenously either before or after skin incision (preincisional and postincisional groups, respectively). Morphine was administered for postoperative analgesia. Visual analogue pain scale (VAS) scores and morphine consumption were recorded at 1, 6, 18 and 24 h postoperation. Plasma levels of interleukin (IL)-6, IL-8 and tumour necrosis factor-a were measured 30 min before skin incision and 6 h postoperation.

Results:

Compared with the post - incisional group, VAS pain scores at 1 and 6 h postoperation were significantly lower in the preincisional group. Morphine consumption was significantly lower in the preincisional group at 6, 18 and 24 h postoperation. In both groups, IL-6 and IL- 8 levels increased significantly at 6 h postoperation compared with pre - operation, and the preincisional group had significantly lower levels of IL-6 and IL-8 at 6 h postoperation compared with the postincisional group.

Conclusions:

Preincisional parecoxib administration reduced postoperative pain and morphine consumption compared with post - incisional administration, and attenuated IL-6 and IL-8 production 24 h after hip replacement surgery.

Progastrin Peptides Increase the Risk of Developing Colonic Tumors: Impact on Colonic Stem Cells

Pre-neoplastic lesions (ACF, aberrant-crypt-foci; Hp, hyperplastic/dysplastic polyps) are believed to be precursors of sporadic colorectal-tumors (Ad, adenomas; AdCA, adenocarcinomas). ACF/Hp likely originate due to abnormal growth of colonic-crypts in response to aberrant queues in the microenvironment of colonic-crypts. Thus identifying factors which regulate homeostatic vs aberrant proliferation/apoptosis of colonocytes, especially stem/progenitor cells, may lead to effective preventative/treatment strategies. Based on this philosophy, role of growth-factors/peptide-hormones, potentially available in the circulation/microenvironment of colonic-crypts is being examined extensively. Since the time gastrins were discovered as trophic (growth) factors for gastrointestinal-cells, the effect of gastrins on the growth of normal/cancer cells has been investigated, leading to many discoveries. Seminal discoveries made in the area of gastrins and colon-cancer, as it relates to molecular pathways associated with formation of colonic tumors will be reviewed, and possible impact on diagnostic/preventative/treatment strategies will be discussed.

Expression of the antiapoptotic protein survivin in colon cancer

BACKGROUND

The antiapoptotic protein survivin has been demonstrated to play an important role in colorectal carcinogenesis. However it is unclear whether the upregulation of survivin is maintained through progressive stages of disease, or if other apoptosis-related genes are coexpressed and/or repressed. We sought to evaluate survivin expression in colonic neoplasia and identify relationships with additional regulators of apoptosis.

PATIENTS AND METHODS

Tissue samples from 168 patients with primary colorectal cancer were profiled using the GeneChip Human Genome U133 Plus 2.0 Array (Affymetrix, Santa Clara, CA) and evaluated for survivin expression. Immunohistochemical staining for survivin and a panel of apoptosis-associated proteins were used in 86 patients with tissue microarray (TMA) blocks; scoring was by stain intensity and percentage of positive cells (range, 0-9).

RESULTS

Survivin mRNA was upregulated (1.8-fold increase) in primary colon cancers- irrespective of American Joint Committee on Cancer (AJCC) stage- and metastases compared with normal colonic tissue (P < .0001). Survivin staining was positive in 93% of adenocarcinomas (median immunohistochemistry [IHC] score: 2 [range, 1-6]), 100% of adenomas (1 [range,1-2]), and 43% of normal colonic mucosa (1, [range 1-2]) (P = .006). Survivin expression increased with worsening tumor grade (P < .05). In colon cancers, survivin expression positively correlated with the coexpression of PUMA (P < .001), TACE (P = .003), and MCL1 (P = .01), and trended toward an inverse correlation with BAX (P = .058).

CONCLUSIONS

Survivin expression increases during the normal mucosa-adenoma-carcinoma sequence and is maintained throughout progression of disease, which strengthens its appeal as a therapeutic target. Furthermore, we have demonstrated co-overexpression of several other apoptosis-related genes, which may in turn serve as additional and potentially synergistic therapeutic targets.

Pharmacological modulation by celecoxib of cachexia associated with experimental arthritis and atherosclerosis in rabbits

BACKGROUND AND PURPOSE

Non-steroidal anti-inflammatory drugs improve inflammatory cachexia in several conditions. Thus, we have explored inhibition of cyclooxygenase-2 (COX-2) in an experimental model of rheumatoid cachexia in rabbits.

EXPERIMENTAL APPROACH

Chronic arthritis was induced in immunized rabbits by repeated intra-articular injections of ovalbumin. To increase the degree of systemic inflammation and also to induce atherosclerotic lesions, the animals were fed a hyperlipidaemic diet (2% cholesterol and 6% peanut oil) and were given an endothelial injury of the femoral artery. Rabbits were randomized to receive the COX-2 inhibitor celecoxib (10 mg·kg⁻¹ ·day⁻¹) or no treatment. After 4 weeks, sera, peripheral mononuclear cells and vessel specimens were collected.

KEY RESULTS

Inhibition of COX-2 by celecoxib modulated the systemic inflammatory response and increased total cholesterol and triglyceride levels. Celecoxib also minimized weight loss and prevented serum albumin fall. At a vascular level, celecoxib reduced COX-2 protein in the femoral arterial wall, but did not modify size or the macrophage infiltration of femoral lesions nor the percentage of rabbits with spontaneous aortic plaques.

CONCLUSIONS AND IMPLICATIONS

Our animal model induced a severe inflammatory cachexia, comparable to that of persistently active rheumatoid arthritis. The inhibition of COX-2 by celecoxib improves this state, suggesting that COX products play an important role in its development, without affecting the development or the progression of vascular lesions. Overall, these results suggest that celecoxib might be considered as a new therapeutic tool for the treatment of rheumatoid cachexia.

Preincisional versus postincisional administration of parecoxib in colorectal surgery: effect on postoperative pain control and cytokine response. A randomized clinical trial

BACKGROUND

Preincisional pain management aims at reducing pain and inflammatory response. We investigated whether preincisional parecoxib administration reduces pain, opioid requirements, and cytokine production after surgery for colonic cancer.

METHODS

Forty one patients whose American Society of Anesthesiologists (ASA) status was I-II and who were scheduled for colorectal cancer surgery were randomly divided in two groups according to the timing of parecoxib administration: Group PRE (preincisional) received parecoxib 40 mg intravenously 30 min before skin incision and group POST (postincisional) received the same dose 30 min after skin incision. Postoperative analgesia involved the administration of patient-controlled analgesia (PCA) morphine to all patients. We recorded verbal rating scale (VRS) scores and morphine consumption at 1, 6, 18, and 24 h after surgery and blood levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha) 30 min before skin incision, at peritoneal closure, and 24 h postoperatively.

RESULTS

The VRS scores were similar between groups. Although morphine consumption was significantly lower in group PRE at 6, 18 and 24 h postoperatively (p = 0.044, p = 0.02, p < 0.001, respectively) morphine-related adverse effects did not differ between the two groups. The serum IL-6 was significantly (p = 0.042) elevated from the baseline value 24 h postoperatively in group POST.

CONCLUSIONS

Preincisional parecoxib administration compared to postincisional administration reduced postoperative morphine consumption, but without affecting morphine-related adverse effects and attenuated IL-6 production 24 h after surgery for colorectal cancer.

Non-Steroidal Anti-Inflammatory Drugs in the Carcinogenesis of the Gastrointestinal Tract

It is estimated that underlying infections and inflammatory responses are linked to 15–20% of all deaths from cancer worldwide. Inflammation is a physiologic process in response to tissue damage resulting from microbial pathogen infection, chemical irritation, and/or wounding. Tissues injured throughout the recruitment of inflammatory cells such as macrophages and neutrophils, generate a great amount of growth factors, cytokines, and reactive oxygen and nitrogen species that may cause DNA damage that in turn predisposes to the transformation from chronic inflammation to neoplasia. Cyclooxygenase (COX), playing a key role in cell homeostasis, angiogenesis and tumourigenesis, may represent the link between inflammation and cancer. Currently COX is becoming a pharmacological target for cancer prevention and treatment.

Nimesulide, a selective cyclooxygenase-2 inhibitor, inhibits the growth of esophageal carcinoma in vivo by modulating PPARγ signal transduction pathway

AIM: To detect the expression of cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptor γ (PPARγ) in human esophageal carcinoma, to investigate the inhibitory effects of nimesulide on tumor growth in esophageal carcinoma xenografts in nude mice, and to explore potential mechanisms involved.

METHODS: The expression of PPARγ and COX-2 in 18 normal esophageal epithelial specimens and 59 esophageal squamous cell carcinoma (ESCC) specimens were examined by immunohistochemistry. A nude mouse model bearing Eca-109 cell xenografts was established. The mice were divided randomly into control group and nimesulide group [treated with nimesulide at a dose of 20 mg/(kg•d) for 4 wk]. The tumor volume and reduced rate of tumor growth were calculated according to the length and width of xenograft tumors. Cell apoptosis was detected by flow cytometry. The expression of COX-2 and PPARγ mRNAs and proteins was detected by RT-PCR and immunohistochemistry, respectively.

RESULTS: The immunohistochemical score of PPARγ was significantly lower in ESCC than in normal esophageal epithelium (2.88 ± 2.23 vs 6.29 ± 2.17, P < 0.05), while that of COX-2 was significantly higher in ESCC than in normal esophageal epithelium (2.12 ± 1.77 vs 0.82 ± 0.46, P < 0.05). The immunohistochemical score of PPARγ decreased as tumor pathological grade increased. The immunohistochemical score of PPARγ was closely related to tumor differentiation degree (P < 0.05). The expression level of COX-2 was significantly higher in well and moderately differentiated ESCC than in poorly differentiated ESCC (P < 0.05). Nimesulide significantly inhibited tumor growth in esophageal carcinoma xenografts when compared with the control group (tumor volume: 807.68 mm3 ± 217.76 mm3 vs 2116.77 mm3 ± 362.47 mm3; tumor weight: 0.81 g ± 0.21 g vs 1.45 g ± 0.39 g; both P < 0.05), and the reduced rate of tumor growth was 44.14% ± 6.3%. Nimesulide treatment increased the apoptosis rate from 15.86% ± 2.57% to 32.21% ± 5.98%. COX-2 expression was down-regulated, and PPARγ expression up-regulated in the nimesulide group when compared with the control group. A negative correlation was noted between the expression of COX-2 and PPARγ.

CONCLUSION: Down-regulation of PPARγ expression and up-regulation of COX-2 expression are related to the carcinogenesis of ESCC. Nimesulide inhibits tumor growth and induces apoptosis in esophageal carcinoma xenografts possibly by down-regulating COX-2 expression and up-regulating PPARγ expression.

Gastrin, inflammation, and carcinogenesis

PURPOSE OF REVIEW

Chronic infection of the gastric mucosa with Helicobacter pylori has long been recognized as a significant risk factor for gastric cancer, and indeed, this model represents the prototypical inflammation-associated cancer. In this review, we present the latest clinical and experimental evidence showing that gastrin peptides and their receptors [the cholecystokinin (CCK2) receptors] potentiate the progression of gastric cancer and other gastrointestinal malignancies in the presence of inflammation.

RECENT FINDINGS

We highlight the feed-forward mechanisms by which gastrin and CCK2 receptor expression are upregulated during inflammation and in gastrointestinal cancers, summarize gastrin's proinflammatory role by inducing the production of cyclooxgenase-2 (COX-2) and interleukin-8 (IL-8), and relate evidence suggesting that gastrin and their receptors modulate the function of immune cells and fibroblasts following cellular stress, injury, repair, as well as during cancer progression.

SUMMARY

We discuss trends for future studies directed toward the elucidation of gastrin peptides' role in regulating intercellular molecular signaling mechanisms between local and circulating immune cells, fibroblasts, epithelial cells, and other cell types in the microenvironments of inflammation-related cancers. Elucidation of the molecular and cellular pathways that relate inflammation with cancer may provide additional opportunities to develop complementary therapies that target the inflammatory microenvironment of the cancer.

Prostaglandin E2 upregulates survivin expression via the EP1 receptor in hepatocellular carcinoma cells

AIMS

Cyclooxygenase-2 (COX-2)-controlled production of prostaglandin E(2) (PGE(2)) has been implicated in cell growth and metastasis in many cancers. Recent studies have found that COX-2 is co-expressed with survivin in many cancers. Survivin is a member of the inhibitor-of-apoptosis protein family. Some COX-2 inhibitors (e.g., celecoxib) can reduce the expression of survivin. However, little is known about the mechanism of PGE(2)-mediated expression of survivin. This study was designed to uncover the effect of PGE(2) on survivin expression in hepatocellular carcinoma cells.

MAIN METHODS

The effects of PGE(2) and EP1 agonist on survivin expression were examined in HUH-7 and HepG2 cells. Plasmid transfection and EP1 siRNA were used to regulate the expression of COX-2 and the EP1 receptor protein.

KEY FINDINGS

PGE(2) treatment increased survivin expression 2.3-fold. COX-2 overexpression resulted in a similar level of survivin upregulation. However, this effect was suppressed by treatment with celecoxib. EP1 receptor transfection or treatment with a selective EP1 agonist mimicked the effect of PGE(2) treatment. Conversely, the PGE(2)-induced upregulation of survivin was blocked by treatment with a selective EP1 antagonist or siRNA against the EP1 receptor. The phosphorylation of EGFR and Akt were elevated in EP1 agonist-treated cells, and both EGFR and PI3K inhibitors suppressed the upregulation of survivin induced by PGE(2) or EP1 agonist.

SIGNIFICANCE

PGE(2) regulates survivin expression in hepatocellular carcinoma cells through the EP1 receptor by activating the EGFR/PI3K pathway. Targeting the PGE(2)/EP1/survivin signaling pathway may aid the development of new therapeutic strategies for both the prevention and treatment of this cancer.

Expression of Survivin, COX-2 and VEGF in colorectal cancer and its correlation with tumor angiogenesis

AIM: To simultaneously detect the expression of Survivin, cyclooxygenasa-2 (COX-2), vascular endothelial growth factor (VEGF) and CD34 in colorectal cancer and explore its correlation with tumor angiogenesis.

METHODS: All specimens (including 26 colorectal cancer specimens, 10 colorectal polyp specimens and 7 chronic colitis specimens) were collected from September 2007 to May 2008 at the Second Affiliated Hospital of Harbin Medical University. All specimens were pathologically reevaluated to confirm the initial diagnosis. The expression of Survivin, COX-2, VEGF and CD34 in these specimens was detected by immunohistochemistry.

RESULTS: The positive rates of Survivin, COX-2 and VEGF proteins in colorectal cancer tissue were 76.9%, 80.8% and 69.28% respectively, significantly higher than those in colorectal polyp and chronic colitis tissues (P < 0.01 or 0.05). The microvascular density (MVD) revealed by CD-34 immunostaining in colorectal cancer tissue was significantly higher than that in colorectal polyp and chronic colitis tissues (23.69 ± 9.96 vs 13.10 ± 7.05 and 10.43 ± 4.24, both P < 0.01). Furthermore, the expression of Survivin, COX-2 and VEGF proteins in colorectal cancer tissue is positively correlated with tumor microvessel count (all P < 0.05). In colorectal cancer tissue, the expression of Survivin was closely correlated with that of COX-2 and VEGF (χ² = 11.18, 4.72, P < 0.05).

CONCLUSION: Survivin is probably able to promote tumor angiogenesis through regulating the expression of COX-2 and VEGF in colorectal cancer.

Experimental arthritis inhibits the insulin-like growth factor-I axis and induces muscle wasting through cyclooxygenase-2 activation

Chronic arthritis induces cachexia associated with an inhibition of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) system and an activation of the E3 ubiquitin-ligating enzymes muscle atrophy F-box (MAFbx) and muscle Ring finger 1 (MuRF1) in the skeletal muscle. The aim of this work was to study the role of cyclooxygenase (COX)-2 in chronic arthritis-induced cachexia. Arthritis was induced in rats by Freund's adjuvant injection, and the effects of two COX inhibitors (indomethacin, a nonspecific inhibitor, and meloxicam, a selective COX-2 inhibitor on pituitary GH and on liver and serum IGF-I levels) were tested. Arthritis decreased body weight gain and GH and liver IGF-I gene expression. In the arthritic rats, both inhibitors, indomethacin and meloxicam, prevented the inhibitory effect of arthritis on body weight gain. Indomethacin and meloxicam administration to arthritic rats increased pituitary GH and liver IGF-I mRNA as well as serum levels of IGF-I. These data suggest that induction of COX-2 during chronic inflammation is involved in the inhibition of the GH-IGF-I axis and in the body weight loss. In the gastrocnemius muscle, arthritis increased the gene expression of tumor necrosis factor (TNF)-alpha, the E3 ubiquitin-ligating enzymes MAFbx and MuRF1, as well as of IGF-I and IGF-binding protein-5 (IGFBP-5). Inhibition of COX-2 by meloxicam administration increased gastrocnemius weight and decreased MAFbx, MuRF1, TNF-alpha, and IGFBP-5 gene expression. In summary, our data indicate that chronic arthritis-induced cachexia and muscle wasting are mediated by the COX-2 pathway resulting in a decreased GH-IGF-I secretion and increased expression of MAFbx and MuRF1 mRNA.