The expression of chemokine genes correlates with nuclear factor-kappaB activation in human pancreatic cancer cell lines

The Role of Salivary Vascular Endothelial Growth Factor A, Cytokines, and Amino Acids in Immunomodulation and Angiogenesis in Breast Cancer

In this work, we focused on the analysis of VEGF content in saliva and its relationship with pro-inflammatory cytokines and amino acids involved in immunomodulation and angiogenesis in breast cancer. The study included 230 breast cancer patients, 92 patients with benign breast disease, and 59 healthy controls. Before treatment, saliva samples were obtained from all participants, and the content of VEGF and cytokines in saliva was determined by an enzyme-linked immunosorbent assay, as well as the content of amino acids by high-performance liquid chromatography. It was found that VEGF was positively correlated with the level of pro-inflammatory cytokines IL-1β (r = 0.6367), IL-6 (r = 0.3813), IL-8 (r = 0.4370), and IL-18 (r = 0.4184). Weak correlations were shown for MCP-1 (r = 0.2663) and TNF-α (r = 0.2817). For the first time, we demonstrated changes in the concentration of VEGF and related cytokines in saliva in different molecular biological subtypes of breast cancer depending on the stage of the disease, differentiation, proliferation, and metastasis to the lymph nodes. A correlation was established between the expression of VEGF and the content of aspartic acid (r = -0.3050), citrulline (r = -0.2914), and tryptophan (r = 0.3382) in saliva. It has been suggested that aspartic acid and citrulline influence the expression of VEGF via the synthesis of the signaling molecule NO, and then tryptophan ensures tolerance of the immune system to tumor cells.

Innate and adaptive immune-directed tumour microenvironment in pancreatic ductal adenocarcinoma

One of the most deadly and aggressive cancers in the world, pancreatic ductal adenocarcinoma (PDAC), typically manifests at an advanced stage. PDAC is becoming more common, and by the year 2030, it is expected to overtake lung cancer as the second greatest cause of cancer-related death. The poor prognosis can be attributed to a number of factors, including difficulties in early identification, a poor probability of curative radical resection, limited response to chemotherapy and radiotherapy, and its immunotherapy resistance. Furthermore, an extensive desmoplastic stroma that surrounds PDAC forms a mechanical barrier that prevents vascularization and promotes poor immune cell penetration. Phenotypic heterogeneity, drug resistance, and immunosuppressive tumor microenvironment are the main causes of PDAC aggressiveness. There is a complex and dynamic interaction between tumor cells in PDAC with stromal cells within the tumour immune microenvironment. The immune suppressive microenvironment that promotes PDAC aggressiveness is contributed by a range of cellular and humoral factors, which itself are modulated by the cancer. In this review, we describe the role of innate and adaptive immune cells, complex tumor microenvironment in PDAC, humoral factors, innate immune-mediated therapeutic advances, and recent clinical trials in PDAC.

NF-κB Dependent Chemokine Signaling in Pancreatic Cancer

Pancreatic cancer is one of the carcinomas with the worst prognoses, as shown by its five-year survival rate of 9%. Although there have been new therapeutic innovations, the effectiveness of these therapies is still limited, resulting in pancreatic ductal adenocarcinoma (PDAC) becoming the second leading cause of cancer-related death in 2020 in the US. In addition to tumor cell intrinsic resistance mechanisms, this disease exhibits a complex stroma consisting of fibroblasts, immune cells, neuronal and vascular cells, along with extracellular matrix, all conferring therapeutic resistance by several mechanisms. The NF-κB pathway is involved in both the tumor cell-intrinsic and microenvironment-mediated therapeutic resistance by regulating the transcription of a plethora of target genes. These genes are involved in nearly all scenarios described as the hallmarks of cancer. In addition to classical regulators of apoptosis, NF-κB regulates the expression of chemokines and their receptors, both in the tumor cells and in cells of the microenvironment. These chemokines mediate autocrine and paracrine loops among tumor cells but also cross-signaling between tumor cells and the stroma. In this review, we will focus on NF-κB-mediated chemokine signaling, with an emphasis on therapy resistance in pancreatic cancer.

NF-κB signaling and crosstalk during carcinogenesis

Transcription factors (TFs) are proteins that control the transcription of genetic information from DNA to mRNA by binding to specific DNA sequences either on their own or with other proteins as a complex. TFs thus support or suppress the recruitment of the corresponding RNA polymerase. In general, TFs are classified by structure or function. The TF, Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), is expressed in all cell types and tissues. NF-κB signaling and crosstalk are involved in several steps of carcinogenesis including in sequences involving pathogenic stimulus, chronic inflammation, fibrosis, establishment of its remodeling to the precancerous niche (PCN) and transition of a normal cell to a cancer cell. Triggered by various inflammatory cytokines, NF-κB is activated along with other TFs with subsequent stimulation of cell proliferation and inhibition of apoptosis. The involvement of NF-κB in carcinogenesis provides an opportunity to develop anti-NF-κB therapies. The complexity of these interactions requires that we elucidate those aspects of NF-κB interactions that play a role in carcinogenesis, the sequence of events leading to cancer.

Perioperative cytokine levels portend early death after pancreatectomy for ductal adenocarcinoma

BACKGROUND

Soluble signaling molecules may play an important role in malignant pathogenesis. We hypothesize that perioperative cytokine levels are associated with outcomes in patients with pancreatic adenocarcinoma (PDAC) undergoing surgical resection.

METHODS

One hundered and eighteen patients with benign or malignant pancreatic disease were enrolled in a prospective study through a protocol for banking biologic samples. Peripheral blood was drawn at time of operation, and a multiplex cytokine assay was performed. Statistical analysis was via χ2 and Kaplan Meier methods.

RESULTS

Of 118 patients enrolled, 85 (72%) had a diagnosis of PDAC, and 60 (70%) ultimately underwent partial pancreatectomy. Cytokine levels were not associated with postoperative complications in this initial cohort. A plasma level of monocyte chemoattractant protein-1 (MCP-1) pg/mL ≤118 was associated with better overall survival (OS) (median survival 21 months vs 12.8 months, P = 0.023), as was non-detectable interleukin-8 (IL-8) (19 months) versus detectable IL-8 (12.8 months, P = 0.05). Patients with both MCP-1 >118 pg/mL and detectable IL-8 had a median survival of 10.6 months (P = 0.028).

CONCLUSIONS

MCP-1 and IL-8 cytokine levels are associated with decreased survival following pancreatectomy for PDAC, and may be useful biomarkers. Measurement of these cytokine levels at different time points in future investigations will be important to validate these findings.

Biology of pancreatic stellate cells-more than just pancreatic cancer

Pancreatic stellate cells, normally quiescent, are capable of remarkable transition into their activated myofibroblast-like phenotype. It is now commonly accepted that these cells play a pivotal role in the desmoplastic reaction present in severe pancreatic disorders. In recent years, enormous scientific effort has been devoted to understanding their roles in pancreatic cancer, which continues to remain one of the most deadly diseases. Therefore, it is not surprising that considerably less attention has been given to studying physiological functions of pancreatic stellate cells. Here, we review recent advances not only in the field of pancreatic stellate cell pathophysiology but also emphasise their roles in physiological processes.

Role of Peroxisome Proliferator-Activated Receptor β/δ and B-Cell Lymphoma-6 in Regulation of Genes Involved in Metastasis and Migration in Pancreatic Cancer Cells

PPARβ/δ is a ligand-activated transcription factor that regulates various cellular functions via induction of target genes directly or in concert with its associated transcriptional repressor, BCL-6. Matrix remodeling proteinases are frequently over-expressed in pancreatic cancer and are involved with metastasis. The present study tested the hypothesis that PPARβ/δ is expressed in human pancreatic cancer cells and that its activation could regulate MMP-9, decreasing cancer cells ability to transverse the basement membrane. In human pancreatic cancer tissue there was significantly higher expression of MMP-9 and PPARβ/δ, and lower levels of BCL-6 mRNA. PPARβ/δ activation reduced the TNF α -induced expression of various genes implicated in metastasis and reduced the invasion through a basement membrane in cell culture models. Through the use of short hairpin RNA inhibitors of PPARβ/δ, BCL-6, and MMP-9, it was evident that PPARβ/δ was responsible for the ligand-dependent effects whereas BCL-6 dissociation upon GW501516 treatment was ultimately responsible for decreasing MMP-9 expression and hence invasion activity. These results suggest that PPARβ/δ plays a role in regulating pancreatic cancer cell invasion through regulation of genes via ligand-dependent release of BCL-6 and that activation of the receptor may provide an alternative therapeutic method for controlling migration and metastasis.

Iodide transporter NIS regulates cancer cell motility and invasiveness by interacting with the Rho guanine nucleotide exchange factor LARG

A number of solute carrier (SLC) proteins are subject to changes in expression and activity during carcinogenesis. Whether these changes play a role in carcinogenesis is unclear, except for some nutrients and ion carriers whose deregulation ensures the necessary reprogramming of energy metabolism in cancer cells. In this study, we investigated the functional role in tumor progression of the sodium/iodide symporter (NIS; aka SLC5A5), which is upregulated and mislocalized in many human carcinomas. Notably, we found that NIS enhanced cell migration and invasion without ion transport being involved. These functions were mediated by NIS binding to leukemia-associated RhoA guanine exchange factor, a Rho guanine exchange factor that activates the small GTPase RhoA. Sequestering NIS in intracellular organelles or impairing its targeting to the cell surface (as observed in many cancers) led to a further increase in cell motility and invasiveness. In sum, our results established NIS as a carrier protein that interacts with a major cell signaling hub to facilitate tumor cell locomotion and invasion.

Mast cell-derived TNF-α and histamine modify IL-6 and IL-8 expression and release from cutaneous tumor cells

The coincidence of skin tumors and elevated mast cell (MC) numbers has been known for many years. However, it has remained controversial whether, in this context, MCs promote or inhibit tumor growth. Addressing this problem, different melanoma and squamous cell carcinoma cell lines were co-cultivated with primary, dermal MC for 24 h and gene or protein expression of cytokines tumor necrosis factor (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) estimated. Co-culture with MCs led to an increase in IL-8 gene expression and IL-8 protein release from melanoma cells and IL-6 and IL-8 gene expression and protein release from squamous cell carcinoma cells, respectively. Moreover induction of IL-6 and IL-8 was primarily regulated by MC-derived TNF-α. Our data suggest an interplay between MCs and tumor cells, which results in altered cytokine release and may, thus, have an impact on tumor growth, invasion and neovascularisation.

Akt in the pathogenesis of COPD

In this review we consider the therapeutic potential of targeting Akt for the treatment of COPD. Akt is a serine/threonine protein kinase that functions as a signaling intermediate linked to multiple signaling programs involved in survival, inflammation, and growth. Akt is closely associated with key membrane-bound receptors and represents a convergent integration point for multiple stimuli implicated in COPD pathogenesis. Persistent activation of Akt secondary to somatic mutations in regulatory oncogenes, such as PTEN, may explain why inflammation in COPD does not resolve when smoking is ceased. Akt is also implicated in the systemic manifestations of COPD such as skeletal muscle wasting and metabolic disturbances. Furthermore, targeting Akt may provide a useful means of limiting the severity and duration of disease exacerbations in COPD. As such, Akt represents a particularly attractive therapeutic target for the treatment of COPD. Interestingly, current knowledge suggests that both inhibitors and activators of Akt may be useful for treating different clinical subpopulations of COPD patients.

Thymosin Beta 4 is overexpressed in human pancreatic cancer cells and stimulates proinflammatory cytokine secretion and JNK activation

BACKGROUND

Thymosin beta 4 (T beta 4) has been shown to be associated with tumor metastasis and angiogenesis; however, its role in pancreatic cancer has not been understood. In the current study, we examined the expression of T beta 4 in pancreatic cancer cells, and determined the effect of exogenous T beta 4 on cytokine secretion, and signal transduction in human pancreatic cancer cells.

RESULTS

Pancreatic cancer cell lines expressed higher amount of T beta 4 mRNA than normal human pancreatic ductal epithelium (HPDE) cells. Exogenous T beta 4 increased the secretion of proinflammatory cytokines IL-6, IL-8 and MCP-1 in Panc-1 cells. In addition, T beta 4 activated Jun N-terminal Kinase (JNK) signaling pathways in pancreatic cancer cells.

METHODS

The mRNA levels of T beta 4 were determined by real-time RT PCR. Phosphorylation of JNK in pancreatic cancer cells was determined using Bio-Plex phosphoprotein assay. The expression of cytokines in human pancreatic cancer cell lines was determined with Bio-Plex cytokine assay.

CONCLUSIONS

T beta 4 might be involved in stimulating human pancreatic cancer progression by promoting proinflammatory cytokine environment and activating JNK signaling pathway. Targeting T beta 4 and related molecules may be a novel therapeutic strategy for pancreatic cancer.

Current update of cytokines in pancreatic cancer: pathogenic mechanisms, clinical indication, and therapeutic values

Pancreatic cancer is the fourth leading cause of cancer death with a 5-year survival less than 5 percent despite rigorous interventions. This largely is due to its late presentation, aggressive metastasis, and a lack of effective adjuvant therapies. Cytokines have been studied in many tumor types, where they have been shown to be an important influence in cancer cell behavior and to have potential as tumor markers, therapeutic targets, or as treatments themselves. Recently, the roles cytokines play in pancreatic cancer have become the subject of intense investigation. However, the story is complicated, largely because of the pleiotropic and overlapping nature of cytokine functions. This article attempts to provide a focused review of recent discoveries in this area by organizing the material along the pathophysiologic tasks a cancer cell must accomplish to achieve malignancy. We examined how cytokines act to create a microenvironment conducive to tumor cell survival and growth, discussed how cytokines affect proliferation, invasion, metastasis, and apoptosis in pancreatic cancer cells, and we summarized how this knowledge has been applied either to target cytokines or use them therapeutically.

The absence of CCL2 expression in cervical carcinoma is associated with increased survival and loss of heterozygosity at 17q11.2

To determine whether CCL2 mRNA expression is beneficial or detrimental for cervical cancer patients, the association between the expression of this molecule by cervical tumour cells, the number of tumour-associated macrophages, and clinicopathological parameters such as recurrence, relapse-free survival, and overall patient survival was investigated. In cervical cancer samples from 93 untreated cervical cancer patients, the CCL2 mRNA expression level was quantified using RNA in situ hybridization and verified using real-time quantitative RT-PCR. The number of tumour-associated macrophages was determined using immunohistochemistry. Furthermore, the study investigated whether lack of CCL2 expression was due to genetic alterations near the 17q11.2 (CCL2 genomic) region. CCL2 mRNA expression by cervical tumour cells was associated with the number of tumour-associated macrophages (p < 0.001). Lack of CCL2 mRNA expression (15 samples; 16%) was associated with increased cumulative relapse-free survival (log rank test, p = 0.030), increased cumulative overall survival (log rank test, p = 0.024), less post-operative surgery, reduced local and distant recurrence, reduced vascular invasion, and smaller tumour size (<40 mm). The absence of CCL2 mRNA expression corresponded with loss of heterozygosity (LOH) at 17q11.2 in five of six samples. The increased cumulative relapse-free survival and cumulative overall survival of cervical cancer patients lacking tumour cell-associated CCL2 mRNA suggest that the tumour-associated macrophages support tumour progression, presumably by promoting angiogenesis and production of growth factors.

Biomarker discovery from pancreatic cancer secretome using a differential proteomic approach

Quantitative proteomics can be used as a screening tool for identification of differentially expressed proteins as potential biomarkers for cancers. Candidate biomarkers from such studies can subsequently be tested using other techniques for use in early detection of cancers. Here we demonstrate the use of stable isotope labeling with amino acids in cell culture (SILAC) method to compare the secreted proteins (secretome) from pancreatic cancer-derived cells with that from non-neoplastic pancreatic ductal cells. We identified 145 differentially secreted proteins (>1.5-fold change), several of which were previously reported as either up-regulated (e.g. cathepsin D, macrophage colony stimulation factor, and fibronectin receptor) or down-regulated (e.g. profilin 1 and IGFBP-7) proteins in pancreatic cancer, confirming the validity of our approach. In addition, we identified several proteins that have not been correlated previously with pancreatic cancer including perlecan (HSPG2), CD9 antigen, fibronectin receptor (integrin beta1), and a novel cytokine designated as predicted osteoblast protein (FAM3C). The differential expression of a subset of these novel proteins was validated by Western blot analysis. In addition, overexpression of several proteins not described previously to be elevated in human pancreatic cancer (CD9, perlecan, SDF4, apoE, and fibronectin receptor) was confirmed by immunohistochemical labeling using pancreatic cancer tissue microarrays suggesting that these could be further pursued as potential biomarkers. Lastly the protein expression data from SILAC were compared with mRNA expression data obtained using gene expression microarrays for the two cell lines (Panc1 and human pancreatic duct epithelial), and a correlation coefficient (r) of 0.28 was obtained, confirming previously reported poor associations between RNA and protein expression studies.

Pancreatic cancer epidemiology

Carcinoma of the exocrine pancreas remains a challenging disease mainly due to advanced stage diagnosis, the early systemic dissemination, aggressive local tumor progression, and subsequent short patient survival. Thus, assessment of incidence markers instead of prevalence indicators is recommended because the time between diagnosis and death is usually very short. Investigations to date have led to the discovery of many rare genes and environmental factors that contribute to pancreatic cancer. However, common genes involved in genetic polymorphisms, and specific risk factors have not been identified. Furthermore, the role of gene-environment interactions on the tumorogenesis and progression of pancreatic cancer need to be further investigated. Given current therapeutic modalities, only early detection of cancer of the pancreas, followed by surgical resection, offers the possibility of lengthening survival time.

Expression of angiogenic factors vascular endothelial growth factor and interleukin-8/CXCL8 is highly responsive to ambient glutamine availability: role of nuclear factor-kappaB and activating protein-1

Vascular endothelial growth factor (VEGF) and interleukin-8/CXCL8 (IL-8) are prominent pro-angiogenic and pro-metastatic proteins that represent negative prognostic factors in many types of cancer. Hypoxia is thought to be the primary environmental cause of VEGF and IL-8 expression in solid tumors. We hypothesized that a lack of nutrients other than oxygen could stimulate the expression of these factors and previously demonstrated that expression of VEGF and IL-8 is responsive to amino acid deprivation. In the present study, we examined the effect of glutamine availability on the expression of these factors as well as the role of transcription factors NFkappaB and activating protein-1 (AP-1) in the response of TSE human breast carcinoma cells to glutamine deprivation. VEGF and IL-8 secretion and mRNA levels were dramatically induced by glutamine deprivation. mRNA stabilization contributed to this response. Glutamine deprivation increased NFkappaB (p65/p50) and AP-1 (Fra-1/c-Jun+JunD) DNA-binding activities. Blocking NFkappaB and AP-1 activation with curcumin as well as expression of dominant inhibitors, inhibitor of nuclear factor-kappaB (IkappaB) super repressor (IkappaBM), and a mutant form of c-Fos (A-Fos) demonstrated that the activation of NFkappaB and AP-1 transcription factors was necessary for the induction of IL-8 expression but dispensable for the induction of VEGF expression. A macro-array containing 111 NFkappaB target genes identified a total of 17 that were up-regulated 2-fold or more in response to glutamine deprivation. These included growth regulated oncogene alpha (GROalpha/GRO1/CXCL1), another neutrophil chemoattractant implicated in tumor angiogenesis and metastasis.

A comprehensive in vitro characterization of pancreatic ductal carcinoma cell line biological behavior and its correlation with the structural and genetic profile

There are a large number of stable pancreatic ductal carcinoma cell lines (PDCL) that are used by researchers worldwide. Detailed data about their differentiation status and genetic alterations are present in the literature, but a systematic correlation with cell biological behavior is often lacking. PDCL ( n=12) were clustered by source of tumor cell (ascites, primary tumor, metastasis), and the data of functional cell biology were correlated with the reported structural and genetic profiles. Major histocompatibility complex expression, chemosensitivity and aneuploidia appeared to be related to the source of PDCL, and proliferative capacity appeared to be related to the grade of differentiation. No correlation between genetic/structural features of PDCL and biological behavior was found. All the cell lines appeared generally insensitive to in vitro treatment with 5-fluorouracil and showed variable degrees of susceptibility to gemcitabine, raltitrexed and oxaliplatin. All the PDCL showed resistance to Fas-mediated apoptosis but were significantly sensitive to the pro-apoptotic effect of inflammatory cytokines [interleukin (IL)-1beta, tumor necrosis factor (TNF)alpha and interferon gamma]. PDCL were characterized for the secretion of several factors relevant to the tumor-immune cross talk. Vascular endothelial growth factor, CCL2, CCL5 and transforming growth factor beta were the factors most frequently released; less frequent was the secretion of CXCL8, CCL22, IL-6 and sporadically CXCL12, IL-10 and hepatocyte growth factor. The cytokines IL-1beta and TNFalpha were always undetectable. In conclusion, a clear correlation between structural/genetic features and function could not be detected, suggesting the weakness of a "morphological" classification for the in vitro studies of pancreatic cancer.

Glial cell line-derived neurotrophic factor enhances nuclear factor-kappaB activity and invasive potential in human pancreatic cancer cells

OBJECTIVES

The invasive potential is increased by glial cell line-derived neurotrophic factor (GDNF) in human pancreatic cancer cell lines. We researched whether the signaling pathway activated by GDNF correlates with the nuclear factor-kappaB (NF-kappaB) in human pancreatic cancer cell lines and whether the inhibition of NF-kappaB activity is associated with suppression of invasive potential.

METHODS

Proliferation of human pancreatic cancer cell lines (BxPC-3 and MIA PaCa-2) was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays (MTT assay). NF-kappaB activity was examined by dual luciferase assay and electrophoretic mobility shift assay. In addition, to investigate the invasive potential, an in vitro invasion assay was performed.

RESULTS

Proliferation of both cell lines was decreased by a proteasome inhibitor, MG132, in a dose-dependent manner, but proliferation of control and IkappaBalphaM vector-transfected BxPC-3 cells was similar. The invasion cell number and the NF-kappaB activity were increased by GDNF stimulation. However, in the presence of MG132 or IkappaBalphaM, which blocks the nuclear localization of NF-kappaB, both were significantly suppressed. Furthermore, reduced activity of both remained unchanged by GDNF stimulation.

CONCLUSION

These results indicate that GDNF promotes NF-kappaB activation and that the latter is involved in the invasive potential of human pancreatic cancer cells.

Expression of the pro-angiogenic factors vascular endothelial growth factor and interleukin-8/CXCL8 by human breast carcinomas is responsive to nutrient deprivation and endoplasmic reticulum stress

Background

The expression of pro-angiogenic cytokines, such as vascular endothelial growth factor (VEGF) and interleukin-8/CXCL8 (IL-8), plays an important role in tumor growth and metastasis. Low oxygen tension within poorly-vascularized tumors is thought to be the prime stimulus causing the secretion of VEGF. The expression of IL-8 by solid tumors is thought to be primarily due to intrinsic influences, such as constitutive activation of nuclear factor kappa B (NF-κB). However, VEGF expression is responsive to glucose deprivation, suggesting that low concentrations of nutrients other than oxygen may play a role in triggering the pro-angiogenic phenotype. Glucose deprivation causes endoplasmic reticulum (ER) stress and alters gene expression through the unfolded protein response (UPR) signaling pathway. A branch of the UPR, known as the ER overload response (EOR), can cause NF-κB activation. Thus, we hypothesized that treatments that cause ER stress and deprivation of other nutrients, such as amino acids, would trigger the expression of angiogenic cytokines by breast cancer cell lines.

Results

We found that glutamine deprivation and treatment with a chemical inducer of ER stress (tunicamycin) caused a marked induction of the secretion of both VEGF and IL-8 protein by a human breast adenocarcinoma cell line (TSE cells). Glutamine deprivation, glucose deprivation and several chemical inducers of ER stress increased VEGF and IL-8 mRNA expression in TSE and other breast cancer cell lines cultured under both normoxic and hypoxic conditions, though hypoxia generally diminished the effects of glucose deprivation. Of all amino acids tested, ambient glutamine availability had the largest effect on VEGF and IL-8 mRNA expression. The induction of VEGF mRNA expression, but not IL-8, was sustained and closely corresponded with the upregulated expression of the ER stress-responsive genes glucose-regulated protein 78 (GRP78) and growth arrest and DNA damage inducible gene 153 (GADD153).

Conclusion

These results suggest that nutrient deprivation within the solid tumor microenvironment might contribute to the activation of a pro-angiogenic phenotype. The angiogenic switch may act to increase blood supply in response to nutrient deprivation as well as hypoxia.

Inhibition of TNF-alpha-induced RANTES expression in human hepatocyte-derived cells by fibrates, the hypolipidemic drugs

Increased concentrations and activity of plasma cytokines produced by monocytes, macrophages, and hepatocytes in patients with alcoholic liver diseases, correlate with the clinical course of liver diseases and are of prognostic value. Especially, high levels of circulating tumor necrosis factor (TNF)-alpha have been found to correlate with increased mortality in alcoholic hepatitis. Moreover, hepatic RANTES was increased in patients with alcoholic hepatitis. Thus, TNF-alpha-induced RANTES expression may have a critical role in cell-mediated liver injury associated with alcoholic hepatitis. Fibrates are widely used in the treatment of hyperlipidemia and lower triglyceride levels in patients with hyperlipidemia. Recently, several groups reported that bezafibrate, one of fibrates, is effective in primary biliary cirrhosis treatment. Additionally, it is reported that bezafibrate is effective in the treatment not only of primary biliary cirrhosis but also of chronic hepatitis C and tamoxifen-induced non-alcoholic steatohepatitis. We, here, presented that bezafibrate and fenofibrate repressed TNF-alpha-induced protein production and mRNA expression of RANTES in human hepatocyte-derived cells. Luciferase assay showed that bezafibrate and fenofibrate inhibited RANTES gene expression in response to TNF-alpha. Moreover, bezafibrate repressed TNF-alpha-induced DNA-binding activity of NF-kappaB. Thus, fibrates reduced TNF-alpha-induced NF-kappaB activation and RANTES expression, possibly suggesting that fibrates might be inhibitory agents of migration of inflammatory cells by RANTES to the liver in patients with alcoholic liver diseases. In line of these results, it might be possible that fibrates are therapeutic agents in alcoholic liver diseases.

Fine tuning the transcriptional regulation of the CXCL1 chemokine

Constitutive activation of the transcription factor nuclear factor-κB (NF-κB) plays a major role in inflammatory diseases as well as cancer by inducing the endogenous expression of many proinflammatory proteins such as chemokines, and facilitating escape from apoptosis. The constitutive expression of chemokines such as CXCL1 has been correlated with growth, angiogenesis, and metastasis of cancers such as melanoma. The transcription of CXCL1 is regulated through interactions of NF-κB with other transcriptional regulatory molecules such as poly(ADP-ribose) polymerase-1 (PARP-1) and cAMP response element binding protein (CREB)-binding protein (CBP). It has been proposed that these two proteins interact with NF-κB and other enhancers to form an enhanceosome at the promoter region of CXCL1 and modulate CXCL1 transcription. In addition to these positive cofactors, a negative regulator, CAAT displacement protein (CDP), may also be involved in the transcriptional regulation of CXCL1. It has been postulated that the elevated expression of CXCL1 in melanomas is due to altered interaction between these molecules. CDP interaction with the promoter down-regulates transcription, whereas PARP and/or CBP interactions enhance transcription. Thus, elucidation of the interplay between components of the enhanceosome of this gene is important in finding more efficient and new therapies for conditions such as cancer as well as acute and chronic inflammatory diseases.

Mast cells may not play a crucial role in the pathogenesis of experimental closed duodenal loop-induced pancreatitis in rats

INTRODUCTION

Ws/Ws rats have a small deletion of the c-kit gene and are deficient in both mucosal-type mast cells and connective tissue-type mast cells.

AIM

To investigate the role of pancreatic mast cells in the development of experimental closed duodenal loop (CDL)-induced pancreatitis using Ws/Ws rats.

METHODOLOGY

Pancreatitis was induced by the CDL technique for 5 and 12 hours, and the subsequent ascites volume, wet pancreatic weight, pancreatic myeloperoxidase activities, and serum amylase levels were evaluated. The pancreatic tissue damage was also evaluated histologically.

RESULTS

The CDL technique induced equally severe ascites, pancreatic edema and hyperemia, and hyperamylasemia in the Ws/Ws versus the control (+/+) rats. The microscopic mucosal damage score was also equivalent in the Ws/Ws and control (+/+) rats, and there were no significant differences in mucosal myeloperoxidase activity between the Ws/Ws and control (+/+) rats.

CONCLUSION

These results indicate that mast cells may not be crucial for the development of CDL-induced pancreatitis.

Ligation of the Fas antigen stimulates chemokine secretion in pancreatic cancer cell line PANC-1

BACKGROUND AND AIM

The role of chemokines in the process of immune cell infiltration into pancreatic cancer tissue has been reported. In this study, we investigated the induction of chemokines (interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1) by Fas antigen (Ag)-stimulation in a human pancreatic cancer cell line, PANC-1.

METHODS

The chemokine secretion was evaluated by using an ELISA and a northern blot, and the activation of nuclear factor-kappa B (NF-kappa B) was assessed by using an electrophoretic gel mobility shift assay (EMSA).

RESULTS

The Fas antigen (Ag) stimulation clearly induced an increase in IL-8 and MCP-1 secretion in PANC-1 cells. This effect was also observed at the mRNA level. The induction of chemokine secretion by Fas Ag stimulation required de novo gene expression and protein synthesis. The pretreatment with interferon (IFN)-gamma markedly enhanced the effects of Fas Ag stimulation; IFN-gamma pretreatment and Fas Ag stimulation synergistically induced not only apoptosis but also IL-8 and MCP-1 secretion. Flow cytometric analysis demonstrated that IFN-gamma significantly enhanced Fas Ag expression. In addition, Fas Ag stimulation actually evoked NF-kappa B activation in this cell line.

CONCLUSION

Our results indicate that Fas Ag stimulation can induce chemokine secretion in PANC-1 cells, suggesting the contribution of Fas stimulation to the accumulation of immune cells in pancreatic cancer tissue.