SOCS3 inhibiting migration of A549 cells correlates with PYK2 signaling in vitro

Integrin αVβ1-activated PYK2 promotes the progression of non-small-cell lung cancer via the STAT3-VGF axis

BACKGROUND

Non-small-cell lung cancer (NSCLC) accounts for 80-85% of all lung cancer and is the leading cause of cancer-related deaths globally. Although various treatment strategies have been introduced, the 5-year survival rate of patients with NSCLC is only 20-30%. Thus, it remains necessary to study the pathogenesis of NSCLC and develop new therapeutic drugs. Notably, PYK2 has been implicated in the progression of many tumors, including NSCLC, but its detailed mechanism remains unclear. In this study, we aimed to elucidate the mechanisms through which PYK2 promotes NSCLC progression.

METHODS

The mRNA and protein levels of various molecules were measured using qRT-PCR, western blot (WB), and immunohistochemistry (IHC), respectively. We established stable PYK2 knockdown and overexpression cell lines, and CCK-8, EdU, and clonogenic assays; wound healing, transwell migration, and Matrigel invasion assays; and flow cytometry were employed to assess the phenotypes of tumor cells. Protein interactions were evaluated with co-immunoprecipitation (co-IP), immunofluorescence (IF)-based colocalization, and nucleocytoplasmic separation assays. RNA sequencing was performed to explore the transcriptional regulation mediated by PYK2. Secreted VGF levels were examined using ELISA. Dual-luciferase reporter system was used to detect transcriptional regulation site. PF4618433 (PYK2 inhibitor) and Stattic (STAT3 inhibitor) were used for rescue experiments. A public database was mined to analyze the effect of these molecules on NSCLC prognosis. To investigate the role of PYK2 in vivo, mouse xenograft models of lung carcinoma were established and examined.

RESULTS

The protein level of PYK2 was higher in human NSCLC tumors than in the adjacent normal tissue, and higher PYK2 expression was associated with poorer prognosis. PYK2 knockdown inhibited the proliferation and motility of tumor cells and caused G1-S arrest and cyclinD1 downregulation in A549 and H460 cells. Meanwhile, PYK2 overexpression had the opposite effect in H1299 cells. The siRNA-induced inhibition of integrins alpha V and beta 1 led to the downregulation of p-PYK2(Tyr402). Activated PYK2 could bind to STAT3 and enhance its phosphorylation at Tyr705, regulating the nuclear accumulation of p-STAT3(Tyr705). This further promoted the expression of VGF, as confirmed by RNA sequencing in a PYK2-overexpressing H1299 cell line and validated by rescue experiments. Two sites in promoter region of VGF gene were confirmed as binding sites of STAT3 by Dual-luciferase assay. Data from the TGCA database showed that VGF was related to the poor prognosis of NSCLC. IHC revealed higher p-PYK2(Tyr402) and VGF expression in lung tumors than in adjacent normal tissues. Moreover, both proteins showed higher levels in advanced TNM stages than earlier ones. A positive linear correlation existed between the IHC score of p-PYK2(Tyr402) and VGF. Knockdown of VGF inhibited tumor progression and reversed the tumor promoting effect of PYK2 overexpression in NSCLC cells. Finally, the mouse model exhibited enhanced tumor growth when PYK2 was overexpressed, while the inhibitors PF4618433 and Stattic could attenuate this effect.

CONCLUSIONS

The Integrin αVβ1-PYK2-STAT3-VGF axis promotes NSCLC development, and the PYK2 inhibitor PF4618433 and STAT3 inhibitor Stattic can reverse the pro-tumorigenic effect of high PYK2 expression in mouse models. Our findings provide insights into NSCLC progression and could guide potential therapeutic strategies against NSCLC with high PYK2 expression levels.

Human cytomegalovirus pUL97 upregulates SOCS3 expression via transcription factor RFX7 in neural progenitor cells

Congenital human cytomegalovirus (HCMV) infection causes severe damage to the fetal brain, and the underlying mechanisms remain elusive. Cytokine signaling is delicately controlled in the fetal central nervous system to ensure proper development. Here we show that suppressor of cytokine signaling 3 (SOCS3), a negative feedback regulator of the IL-6 cytokine family signaling, was upregulated during HCMV infection in primary neural progenitor cells (NPCs) with a biphasic expression pattern. From viral protein screening, pUL97 emerged as the viral factor responsible for prolonged SOCS3 upregulation. Further, by proteomic analysis of the pUL97-interacting host proteins, regulatory factor X 7 (RFX7) was identified as the transcription factor responsible for the regulation. Depletion of either pUL97 or RFX7 prevented the HCMV-induced SOCS3 upregulation in NPCs. With a promoter-luciferase activity assay, we demonstrated that the pUL97 kinase activity and RFX7 were required for SOCS3 upregulation. Moreover, the RFX7 phosphorylation level was increased by either UL97-expressing or HCMV-infection in NPCs, suggesting that pUL97 induces RFX7 phosphorylation to drive SOCS3 transcription. We further revealed that elevated SOCS3 expression impaired NPC proliferation and migration in vitro and caused NPCs migration defects in vivo. Taken together, these findings uncover a novel regulatory mechanism of sustained SOCS3 expression in HCMV-infected NPCs, which perturbs IL-6 cytokine family signaling, leads to NPCs proliferation and migration defects, and consequently affects fetal brain development.

The Non-receptor Tyrosine Kinase Pyk2 in Brain Function and Neurological and Psychiatric Diseases

Pyk2 is a non-receptor tyrosine kinase highly enriched in forebrain neurons. Pyk2 is closely related to focal adhesion kinase (FAK), which plays an important role in sensing cell contacts with extracellular matrix and other extracellular signals controlling adhesion and survival. Pyk2 shares some of FAK’s characteristics including recruitment of Src-family kinases after autophosphorylation, scaffolding by interacting with multiple partners, and activation of downstream signaling pathways. Pyk2, however, has the unique property to respond to increases in intracellular free Ca²⁺, which triggers its autophosphorylation following stimulation of various receptors including glutamate NMDA receptors. Pyk2 is dephosphorylated by the striatal-enriched phosphatase (STEP) that is highly expressed in the same neuronal populations. Pyk2 localization in neurons is dynamic, and altered following stimulation, with post-synaptic and nuclear enrichment. As a signaling protein Pyk2 is involved in multiple pathways resulting in sometimes opposing functions depending on experimental models. Thus Pyk2 has a dual role on neurites and dendritic spines. With Src family kinases Pyk2 participates in postsynaptic regulations including of NMDA receptors and is necessary for specific types of synaptic plasticity and spatial memory tasks. The diverse functions of Pyk2 are also illustrated by its role in pathology. Pyk2 is activated following epileptic seizures or ischemia-reperfusion and may contribute to the consequences of these insults whereas Pyk2 deficit may contribute to the hippocampal phenotype of Huntington’s disease. Pyk2 gene, PTK2B, is associated with the risk for late-onset Alzheimer’s disease. Studies of underlying mechanisms indicate a complex contribution with involvement in amyloid toxicity and tauopathy, combined with possible functional deficits in neurons and contribution in microglia. A role of Pyk2 has also been proposed in stress-induced depression and cocaine addiction. Pyk2 is also important for the mobility of astrocytes and glioblastoma cells. The implication of Pyk2 in various pathological conditions supports its potential interest for therapeutic interventions. This is possible through molecules inhibiting its activity or increasing it through inhibition of STEP or other means, depending on a precise evaluation of the balance between positive and negative consequences of Pyk2 actions.

Alveolar macrophage secretion of vesicular SOCS3 represents a platform for lung cancer therapeutics

Lung cancer remains the leading cause of cancer-related death in the United States. Although the alveolar macrophage (AM) comprises the major resident immune cell in the lung, few studies have investigated its role in lung cancer development. We recently discovered a potentially novel mechanism wherein AMs regulate STAT-induced inflammatory responses in neighboring epithelial cells (ECs) via secretion and delivery of suppressors of cytokine signaling 3 (SOCS3) within extracellular vesicles (EVs). Here, we explored the impact of SOCS3 transfer on EC tumorigenesis and the integrity of AM SOCS3 secretion during development of lung cancer. AM-derived EVs containing SOCS3 inhibited STAT3 activation as well as proliferation and survival of lung adenocarcinoma cells. Levels of secreted SOCS3 were diminished in lungs of patients with non-small cell lung cancer and in a mouse model of lung cancer, and the impaired ability of murine AMs to secrete SOCS3 within EVs preceded the development of lung tumors. Loss of this homeostatic brake on tumorigenesis prompted our effort to "rescue" it. Provision of recombinant SOCS3 loaded within synthetic liposomes inhibited proliferation and survival of lung adenocarcinoma cells in vitro as well as malignant transformation of normal ECs. Intratumoral injection of SOCS3 liposomes attenuated tumor growth in a lung cancer xenograft model. This work identifies AM-derived vesicular SOCS3 as an endogenous antitumor mechanism that is disrupted within the tumor microenvironment and whose rescue by synthetic liposomes can be leveraged as a potential therapeutic strategy for lung cancer.

Upregulation of Complement Factor H by SOCS-1/3⁻STAT4 in Lung Cancer

Complement factor H (CFH) is a fluid phase regulator of complement proteins and functions to prevent complement attack and immune surveillance. CFH is known to inactivate therapeutic antibody-dependent complement-mediated cellular cytotoxicity. We found that CFH was highly expressed in human lung cancer cells and tissues. To investigate mechanisms of CFH upregulation, we searched for a CFH transcription factor and its regulatory factors. First, signal transducer and activator of transcription 4 (STAT4) expression patterns coincided with CFH expression patterns in lung cancer tissues. Knockdown of STAT4 led to decreased CFH secretion from lung cancer cells. STAT4 bound directly to the CFH promoter, as demonstrated by luciferase reporter assay, electrophoretic mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) assay, suggesting that STAT4 is a transcription factor for CFH. In addition, a low level of suppressors of cytokine signaling (SOCS)-1/3, a Janus kinase (JAK) inhibitor, was observed in lung cancer cells and its transfection decreased CFH protein levels and promoter activity. Unexpectedly, the low level of SOCS-1/3 was not due to epigenetic silencing. Instead, differential methylation was found on the regulatory region of STAT4 between normal and lung cancer cells. In conclusion, our results demonstrated that CFH is upregulated by constitutive activation of STAT4, which is accounted for by SOCS silencing in lung cancer cells.

Role of Pyk2 in Human Cancers

Proline-rich tyrosine kinase 2 (Pyk2) plays essential roles in tumorigenesis and tumor progression. Pyk2 serves as a non-receptor tyrosine kinase regulating tumor cell survival, proliferation, migration, invasion, metastasis, and chemo-resistance, and is associated with poor prognosis and shortened survival in various cancer types. Thus, Pyk2 has been traditionally regarded as an oncogene and potential therapeutic target for cancers. However, a few studies have also demonstrated that Pyk2 exerts tumor-suppressive effects in some cancers, and anti-cancer treatment of Pyk2 inhibitors may only achieve marginal benefits in these cancers. Therefore, more detailed knowledge of the contradictory functions of Pyk2 is needed. In this review, we summarized the tissue distribution, expression, interactive molecules of Pyk2 in the signaling pathway, and roles of Pyk2 in cancers, and focused on regulation of the interconnectivity between Pyk2 and its downstream targets. The potential use of inhibitors of Pyk2 and its related pathways in cancer therapy is also discussed.

CD30 Is Highly Expressed in Chronic Obstructive Pulmonary Disease and Induces the Pulmonary Vascular Remodeling

Chronic obstructive pulmonary disease (COPD) is one of the common and underdiagnosed diseases with the highest morbidity and mortality in the world. The development of COPD can lead to pulmonary vascular remodeling and pulmonary hypertension, further causing the occurrence of pulmonary heart disease. Therefore, attenuation of pulmonary vascular remodeling and pulmonary hypertension caused by COPD can significantly delay cardiovascular complications. In the study, we firstly found that the expression of CD30 and CD30L was increased in COPD. Importantly, the serum CD30L levels were significantly higher in patients with stable COPD relative to those with acute exacerbation of COPD (AECOPD). This suggested that CD30 might be related to the development of COPD. In addition, we found that the expression of CD30 in the COPD rat model was significantly increased compared with control group. And treatment with the anti-CD30 antibody reduced the serum concentration and tissue expression of CD30 in rat. Importantly, anti-CD30 antibody alleviated pulmonary vascular remodeling in COPD model rats. This suggested that CD30 played an important role in the course of COPD. Finally, we found that, in the HPASMC and HPAEC cell lines, CD30 can affect the cell viability and cell migration and inhibited hypoxia-induced cell apoptosis in a concentration-dependent manner. We also found CD30 induced extracellular matrix formation through decreasing the expression of MMP-2, thus promoting the pulmonary vascular remodeling. The study indicated that CD30 and CD30L were involved in pulmonary vascular remodeling and inflammatory response in COPD. Altogether, CD30 might be a marker for the early diagnosis and progression of COPD.

Proline-Rich Protein Tyrosine Kinase 2 in Inflammation and Cancer

Focal adhesion kinase (FAK) and its homologous FAK-related proline-rich tyrosine kinase 2 (Pyk2) contain the same domain, exhibit high sequence homology and are defined as a distinct family of non-receptor tyrosine kinases. This group of kinases plays critical roles in cytoskeletal dynamics and cell adhesion by regulating survival and growth signaling. This review summarizes the physiological and pathological functions of Pyk2 in inflammation and cancers. In particular, overexpression of Pyk2 in cancerous tissues is correlated with poor outcomes. Pyk2 stimulates multiple oncogenic signaling pathways, such as Wnt/β-catenin, PI3K/Akt, MAPK/ERK, and TGF-β/EGFR/VEGF, and facilitates carcinogenesis, migration, invasion, epithelial⁻mesenchymal transition and metastasis. Therefore, Pyk2 is a high-value therapeutic target and has clinical significance.

SOCS3 revisited: a broad regulator of disease, now ready for therapeutic use?

Since their discovery, SOCS have been characterised as regulatory cornerstones of intracellular signalling. While classically controlling the JAK/STAT pathway, their inhibitory effects are documented across several cascades, underpinning their essential role in homeostatic maintenance and disease. After 20 years of extensive research, SOCS3 has emerged as arguably the most important family member, through its regulation of both cytokine- and pathogen-induced cascades. In fact, low expression of SOCS3 is associated with autoimmunity and oncogenesis, while high expression is linked to diabetes and pathogenic immune evasion. The induction of SOCS3 by both viruses and bacteria and its impact upon inflammatory disorders, underscores this protein's increasing clinical potential. Therefore, with the aim of highlighting SOCS3 as a therapeutic target for future development, this review revisits its multi-faceted immune regulatory functions and summarises its role in a broad ranges of diseases.

SOCS3 blocks HIF-1α expression to inhibit proliferation and angiogenesis of human small cell lung cancer by downregulating activation of Akt, but not STAT3

Suppressor of cytokine signaling 3 (SOCS3) is a major negative regulator of signal transducer and activator of transcription 3 (STAT3) during tumorigenesis. Previous studies have indicated that SOCS3 also regulates other signaling pathways, such as PI3K/Akt. However, little is known about the specific molecular mechanisms by which SOCS3 regulates the proliferation and angiogenesis of small cell lung cancer (SCLC) cells. The present study investigated the effect of SOCS3 upregulation on the expression of hypoxia-inducible factor-1α (HIF-1α) and how this affects the proliferation and angiogenesis of SCLC cells. It was investigated whether this interaction is associated with STAT3 or the Akt signaling pathway. The results of the present study revealed that SOCS3 negatively regulates proliferation and angiogenesis of NCI-H446 cells and that HIF-1α is required in this process. The results also suggested a suppressive role of SOCS3 in Akt signaling, but not STAT3 signaling to block HIF-1α expression and a previously unidentified regulatory mechanism for Akt function. In conclusion, the present study suggested that SOCS3 targets the Akt signaling pathway to inhibit HIF-1α expression and affect the growth and angio-genesis of SCLC cells, and may therefore be considered as a potential novel therapeutic for the treatment of SCLC.

SOCS3 expression is inversely correlated with Pyk2 in non-small cell lung cancer and exogenous SOCS3 inhibits proliferation and invasion of A549 cells

AIMS

We have confirmed that suppressor of cytokine signalling 3 (SOCS3) is silenced and proline-rich tyrosine kinase 2 (Pyk2) is over-expressed in non-small cell lung cancer (NSCLC). The aim of this study was to investigate the correlation of SOCS3 and Pyk2 expression in NSCLC, and the effects of SOCS3 up-regulation on A549 cells.

METHODS

One hundred cases of NSCLC were detected for the expression of SOCS3 and Pyk2 by immunohistochemistry. The expression of SOCS3 and Pyk2 were also examined in human bronchial epithelial cells (HBE) and six lung cancer cell lines using Western blot and immunofluorescence staining. Then plasmid containing full-length SOCS3 was transfected into A549 cells to further investigate the effects of SOCS3 over-expression on proliferation, apoptosis and invasion of transfected cells, which were examined using MTT, flow cytometry and Transwell assays.

RESULTS

Our results showed a significant negative correlation between SOCS3 and Pyk2 in both NSCLC tissues and cell lines. Up-regulation of SOCS3 increased the apoptotic rates of transfected cells, while the numbers of proliferative and invasive cells were decreased.

CONCLUSIONS

Our data indicate that SOCS3 definitely plays roles in regulating Pyk2 expression, and up-regulation of SOCS3 could be an effective way to prevent the progression of NSCLC.

Molecular mechanism underlying the antiproliferative effect of suppressor of cytokine signaling-1 in non-small-cell lung cancer cells

Lung cancer (LC) is the major cause of death by cancer and the number of LC patients is increasing worldwide. This study investigated the therapeutic potential of gene delivery using suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of intracellular signaling pathways, for the treatment of LC. To examine the antitumor effect of SOCS-1 overexpression on non-small-cell lung cancer (NSCLC) cells, NSCLC cells (A549, LU65, and PC9) were infected with adenovirus-expressing SOCS-1 vector. The cell proliferation assay showed that A549 and LU65, but not PC9, were sensitive to SOCS-1 gene-mediated suppression of cell growth. Although JAK inhibitor I could also inhibit proliferation of A549 and LU65 cells, SOCS-1 gene delivery appeared to be more potent as SOCS-1 could suppress focal adhesion kinase and epidermal growth factor receptor, as well as the JAK/STAT3 signaling pathway. Enhanced phosphorylation of the p53 protein was detected by means of phospho-kinase array in SOCS-1 overexpressed A549 cells compared with control cells, whereas no phosphorylation of p53 was observed when JAK inhibitor I was used. Furthermore, treatment with adenoviral vector AdSOCS-1 in vivo significantly suppressed NSCLC proliferation in a xenograft model. These results suggest that the overexpression of SOCS-1 gene is effective for antitumor therapy by suppressing the JAK/STAT, focal adhesion kinase, and epidermal growth factor receptor signaling pathways and enhancing p53-mediated antitumor activity in NSCLC.

Construction of shRNA expression plasmids targeting the Pyk2 gene and their expression in Lovo cells

AIM: To construct the recombinant small hairpin RNA (shRNA) plasmids targeting the proline-rich tyrosine kinase 2 (Pyk2) gene (pGCsi-Pyk2 shRNA) and detect their expression in Lovo cells.

METHODS: Three pairs of Pyk2 shRNA sequences were designed and ligated to the pGCsi vector that contains U6 promoter and hygromycin B to obtain shRNA expression plasmids targeting the Pyk2. The recombinant pGCsi-Pyk2 shRNA plasmids were introduced into Lovo cells by liposome-mediated transfection and selected with hygromycin B. The expression of Pyk2 mRNA and protein was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively.

RESULTS: Restriction enzyme digestion and sequence analysis showed that recombinant pGCsi-Pyk2 shRNA plasmids were successfully constructed. The expression levels of Pyk2 mRNA and protein in Lovo cells transfected with pGCsi-Pyk2 shRNA plasmids were significantly lower than those in Lovo cells transfected with empty or negative plamsids.

CONCLUSION: Recombinant pGCsi-Pyk2 shRNA plasmids are successfully constructed. Their transfection can silence the expression of Pyk2 gene in Lovo cells. The pGCsi-Pyk2 shRNA plasmids obtained lay a foundation for further study of the role of the Pyk2 gene in the pathogenesis of colorectal cancer.

Cell aggregation induces phosphorylation of PECAM-1 and Pyk2 and promotes tumor cell anchorage-independent growth

BACKGROUND

Apoptosis caused by inadequate or inappropriate cell-matrix interactions is defined as anoikis. Although transformed cells are known to be anoikis-resistant, the underlying mechanisms have not been well understood. We investigated the mechanisms of anoikis resistance of tumor cells.

RESULTS

We observed that cell aggregation in suspension promoted cell survival and proliferation. We demonstrated a correlation between tumor cell aggregation in suspension and cell growth in soft agar. Analysis of tyrosine kinase-mediated cell survival and growth signaling pathways revealed increased levels of tyrosine-phosphorylation of PECAM-1 and Pyk2 in cell aggregates. We also showed that PECAM-1 and Pyk2 physically interact with each other, and that PECAM-1 carrying a deletion of exons 11-16 could no longer bind to Pyk2. Furthermore, RNA interference-mediated reduction of Pyk2 and PECAM-1 protein levels reduced cell aggregation and inhibited the growth of tumor cells in soft agar.

CONCLUSIONS

The data demonstrated that Pyk2 and PECAM-1 were critical mediators of both anchorage-independent growth and anoikis resistance in tumor cells.

Cytoplasmic Kaiso is associated with poor prognosis in non-small cell lung cancer

Background

Kaiso has been identified as a new member of the POZ-zinc finger family of transcription factors that are implicated in development and cancer. Although controversy still exists, Kaiso is supposed to be involved in human cancer. However, there is limited information regarding the clinical significance of cytoplasmic/nuclear Kaiso in human lung cancer.

Methods

In this study, immunohistochemical studies were performed on 20 cases of normal lung tissues and 294 cases of non-small cell lung cancer (NSCLC), including 50 cases of paired lymph node metastases and 88 cases with complete follow-up records. Three lung cancer cell lines showing primarily nuclear localization of Kaiso were selected to examine whether roles of Kaiso in cytoplasm and in nucleus are identical. Nuclear Kaiso was down-regulated by shRNA technology or addition a specific Kaiso antibody in these cell lines. The proliferative and invasive abilities were evaluated by MTT and Matrigel invasive assay, transcription of Kaiso's target gene matrilysin was detected by RT-PCR.

Results

Kaiso was primarily expressed in the cytoplasm of lung cancer tissues. Overall positive cytoplasmic expression rate was 63.61% (187/294). The positive cytoplasmic expression of Kaiso was higher in advanced TNM stages (III+IV) of NSCLC, compared to lower stages (I+II) (p = 0.019). A correlation between cytoplasmic Kaiso expression and lymph node metastasis was found (p = 0.003). In 50 paired cases, cytoplasmic expression of Kaiso was 78.0% (41/50) in primary sites and 90.0% (45/50) in lymph node metastases (p = 0.001). The lung cancer-related 5-year survival rate was significantly lower in patients who were cytoplasmic Kaiso-positive (22.22%), compared to those with cytoplasmic Kaiso-negative tumors (64.00%) (p = 0.005). Nuclear Kaiso staining was seen in occasional cases with only a 5.10% (15/294) positive rate and was not associated with any clinicopathological features of NSCLC. Furthermore, after the down-regulation of the nuclear expresses Kaiso in vitro, both proliferative and invasive abilities of three cancer cell lines were significantly enhanced, along with the up-regulation of Kaiso target gene, matrilysin.

Conclusion

Our data suggest cytoplasmic Kaiso expression is associated with poor prognosis of NSCLC and various subcellular localizations of Kaiso may play differential biological roles in NSCLC.

Impact of anti-inflammatory agents on the gene expression profile of stimulated human neutrophils: unraveling endogenous resolution pathways

Adenosine, prostaglandin E(2), or increased intracellular cyclic AMP concentration each elicit potent anti-inflammatory events in human neutrophils by inhibiting functions such as phagocytosis, superoxide production, adhesion and cytokine release. However, the endogenous molecular pathways mediating these actions are poorly understood. In the present study, we examined their impact on the gene expression profile of stimulated neutrophils. Purified blood neutrophils from healthy donors were stimulated with a cocktail of inflammatory agonists in the presence of at least one of the following anti-inflammatory agents: adenosine A(2A) receptor agonist CGS 21680, prostaglandin E(2), cyclic-AMP-elevating compounds forskolin and RO 20-1724. Total RNA was analyzed using gene chips and real-time PCR. Genes encoding transcription factors, enzymes and regulatory proteins, as well as secreted cytokines/chemokines showed differential expression. We identified 15 genes for which the anti-inflammatory agents altered mRNA levels. The agents affected the expression profile in remarkably similar fashion, suggesting a central mechanism limiting cell activation. We have identified a set of genes that may be part of important resolution pathways that interfere with cell activation. Identification of these pathways will improve understanding of the capacity of tissues to terminate inflammatory responses and contribute to the development of therapeutic strategies based on endogenous resolution.