Expression of macrophage migration inhibitory factor is associated with enhanced angiogenesis and advanced stage in gastric carcinomas

Macrophage Migration Inhibitory Factor (MIF) and D-Dopachrome Tautomerase (DDT): Pathways to Tumorigenesis and Therapeutic Opportunities

Discovered as inflammatory cytokines, MIF and DDT exhibit widespread expression and have emerged as critical mediators in the response to infection, inflammation, and more recently, in cancer. In this comprehensive review, we provide details on their structures, binding partners, regulatory mechanisms, and roles in cancer. We also elaborate on their significant impact in driving tumorigenesis across various cancer types, supported by extensive in vitro, in vivo, bioinformatic, and clinical studies. To date, only a limited number of clinical trials have explored MIF as a therapeutic target in cancer patients, and DDT has not been evaluated. The ongoing pursuit of optimal strategies for targeting MIF and DDT highlights their potential as promising antitumor candidates. Dual inhibition of MIF and DDT may allow for the most effective suppression of canonical and non-canonical signaling pathways, warranting further investigations and clinical exploration.

Macrophage migration inhibitory factor (MIF) promotes intervertebral disc degeneration through the NF-κB pathway, and the MIF inhibitor CPSI-1306 alleviates intervertebral disc degeneration in a mouse model

Lumbar intervertebral disc degeneration(IDD) is a prevalent inflammatory disease caused by many proinflammatory factors, such as TNF and IL-1β. Migration inhibitory factor (MIF) is an upstream inflammatory factor widely expressed in vivo that is associated with a variety of inflammatory diseases or malignant tumors and has potential therapeutic value in many diseases. We explored the role of MIF in intervertebral disc degeneration by regulating the content of exogenous MIF or the expression of MIF in cells. Upon inducing degeneration of nucleus pulposus (NP) cells with IL-1β, we found that the increase in intracellular and exogenous MIF promoted the catabolism induced by proinflammatory factors in NP cells, while silencing of the MIF gene alleviated the degeneration to some extent. In a mouse model, the intervertebral disc degeneration of MIF-KO mice was significantly less than that of wild-type mice. To explore the treatment of intervertebral disc degeneration, we selected the small-molecular MIF inhibitor CPSI-1306. CPSI-1306 had a therapeutic effect on intervertebral disc degeneration in the mouse model. In summary, we believe that MIF plays an important role in intervertebral disc degeneration and is a potential therapeutic target for the treatment of intervertebral disc degeneration.

Soluble factors in malignant ascites promote the metastatic adhesion of gastric adenocarcinoma cells

BACKGROUND

Adenocarcinoma of the proximal stomach is the fastest rising malignancy in North America. It is commonly associated with peritoneal accumulation of malignant ascites (MA), a fluid containing cancer and inflammatory cells and soluble proteins. Peritoneal metastasis (PM) is the most common site of gastric cancer (GC) progression after curative-intent surgery and is the leading cause of death among GC patients.

METHODS/RESULTS

Using a panel of gastric adenocarcinoma cell lines (human: MKN 45, SNU-5; murine: NCC-S1M), we demonstrate that prior incubation of GC cells with MA results in a significant (> 1.7-fold) increase in the number of cells capable of adhering to human peritoneal mesothelial cells (HPMC) (p < 0.05). We then corroborate these findings using an ex vivo PM model and show that MA also significantly enhances the ability of GC cells to adhere to strips of human peritoneum (p < 0.05). Using a multiplex ELISA, we identify MIF and VEGF as consistently elevated across MA samples from GC patients (p < 0.05). We demonstrate that agents that block the effects of MIF or VEGF abrogate the ability of MA to stimulate the adhesion of GC cells to adhere to human peritoneum and promote both ex vivo and in vivo metastases.

CONCLUSION

Agents targeting MIF or VEGF may be relevant to the treatment or prevention of PM in GC patients.

The Proinflammatory and Proangiogenic Macrophage Migration Inhibitory Factor Is a Potential Regulator in Proliferative Diabetic Retinopathy

The macrophage migration inhibitory factor (MIF)/CD74 signaling pathway is strongly implicated in inflammation and angiogenesis. We investigated the expression of MIF and its receptor CD74 in proliferative diabetic retinopathy (PDR) to reveal a possible role of this pathway in the pathogenesis of PDR. Levels of MIF, soluble (s)CD74, soluble intercellular adhesion molecule-1 (sICAM-1) and vascular endothelial growth factor (VEGF) were significantly increased in the vitreous from patients with PDR compared to nondiabetic control samples. We detected significant positive correlations between the levels of MIF and the levels of sICAM-1 (r = 0.43; p = 0.001) and VEGF (r = 0.7; p < 0.001). Through immunohistochemical analysis of PDR epiretinal membranes, significant positive correlations were also found between microvessel density (CD31 expression) and the numbers of blood vessels expressing MIF (r = 0.56; p = 0.045) and stromal cells expressing MIF (r = 0.79; p = 0.001) and CD74 (r = 0.59; p = 0.045). Similar to VEGF, MIF was induced in Müller cells cultured under hypoxic conditions and MIF induced phosphorylation of ERK1/2 and VEGF production in Müller cells. Intravitreal administration of MIF in normal rats induced increased retinal vascular permeability and significant upregulation of phospho-ERK1/2, NF-κB, ICAM-1 and vascular cell adhesion molecule-1 expression in the retina. MIF induced migration and proliferation of human retinal microvascular endothelial cells. These results suggest that MIF/CD74 signaling is involved in PDR angiogenesis.

Carcinogenic Helicobacter pylori Strains Selectively Dysregulate the In Vivo Gastric Proteome, Which May Be Associated with Stomach Cancer Progression

Helicobacter pylori is the strongest risk factor for gastric cancer. Initial interactions between H. pylori and its host originate at the microbial-gastric epithelial cell interface, and contact between H. pylori and gastric epithelium activates signaling pathways that drive oncogenesis. One microbial constituent that increases gastric cancer risk is the cag pathogenicity island, which encodes a type IV secretion system that translocates the effector protein, CagA, into host cells. We previously demonstrated that infection of Mongolian gerbils with a carcinogenic cag+H. pylori strain, 7.13, recapitulates many features of H. pylori-induced gastric cancer in humans. Therefore, we sought to define gastric proteomic changes induced by H. pylori that are critical for initiation of the gastric carcinogenic cascade. Gastric cell scrapings were harvested from H. pylori-infected and uninfected gerbils for quantitative proteomic analyses using isobaric tags for relative and absolute quantitation (iTRAQ). Quantitative proteomic analysis of samples from two biological replicate experiments quantified a total of 2764 proteins, 166 of which were significantly altered in abundance by H. pylori infection. Pathway mapping identified significantly altered inflammatory and cancer-signaling pathways that included Rab/Ras signaling proteins. Consistent with the iTRAQ results, RABEP2 and G3BP2 were significantly up-regulated in vitro, ex vivo in primary human gastric monolayers, and in vivo in gerbil gastric epithelium following infection with H. pylori strain 7.13 in a cag-dependent manner. Within human stomachs, RABEP2 and G3BP2 expression in gastric epithelium increased in parallel with the severity of premalignant and malignant lesions and was significantly elevated in intestinal metaplasia and dysplasia, as well as gastric adenocarcinoma, compared with gastritis alone. These results indicate that carcinogenic strains of H. pylori induce dramatic and specific changes within the gastric proteome in vivo and that a subset of altered proteins within pathways with oncogenic potential may facilitate the progression of gastric carcinogenesis in humans.

The diagnostic value of macrophage migration inhibitory factor, carcinoembryonic antigen, and carbohydrate antigen 19-9 in gastric cancer

Introduction: Gastric cancer is a rather common malignancy worldwide and a major healthcare system issue. Lately, the importance of biomarkers such as macrophage migration inhibitory factor (MIF) has been demonstrated in the diagnosis of various gastrointestinal (GI) malignancies. The present study aimed to evaluate the diagnostic value of MIF, carcinoembryonic antigen (CEA), and carbohydrate antigen 19-9 (CA 19-9) in gastric cancer. Methods: In this descriptive-analytical study, 84 patients with gastric cancer referred to the gastroenterology clinic of Tabriz University of Medical Sciences, Tabriz, Iran, for diagnostic and therapeutic procedures, and 80 healthy individuals were enrolled. Serum levels of MIF, CEA, and CA 19-9 were measured in both groups. Further, the grade and stage of the cancer were determined in in the patient group. Results: Serum levels of all three MIF, CEA, and CA 19-9 biomarkers in patients with gastric cancer were significantly higher than those of the control group (P = 0.001). However, no statistically significant correlations were found between the studied biomarkers with the tumor grade and stage. The MIF cut-off point for the diagnosis of gastric cancer was found to be 7.05 pg/ml and its sensitivity and specificity were 85.7% and 73.8%, respectively. Conclusion: MIF biomarker may involve in the pathogenesis and development of gastric cancer and it is a potential diagnostic and therapeutic marker in this malignancy.

Regulation of tumor angiogenesis by microRNAs: State of the art

MicroRNAs (miRNAs, miRs) are small (21-25 nucleotides) endogenous and noncoding RNAs involved in many cellular processes such as apoptosis, development, proliferation, and differentiation via binding to the 3'-untranslated region of the target mRNA and inhibiting its translation. Angiogenesis is a hallmark of cancer, which provides oxygen and nutrition for tumor growth while removing deposits and wastes from the tumor microenvironment. There are many angiogenesis stimulators, among which vascular endothelial growth factor (VEGF) is the most well known. VEGF has three tyrosine kinase receptors, which, following VEGF binding, initiate proliferation, invasion, migration, and angiogenesis of endothelial cells in the tumor environment. One of the tumor microenvironment conditions that induce angiogenesis through increasing VEGF and its receptors expression is hypoxia. Several miRNAs have been identified that affect different targets in the tumor angiogenesis pathway. Most of these miRNAs affect VEGF and its tyrosine kinase receptors expression downstream of the hypoxia-inducible Factor 1 (HIF-1). This review focuses on tumor angiogenesis regulation by miRNAs and the mechanism underlying this regulation.

ZFPM2-AS1, a novel lncRNA, attenuates the p53 pathway and promotes gastric carcinogenesis by stabilizing MIF

Long non-coding RNAs (lncRNAs) are implicated to be involved in the pathogenesis of many cancers. Herein we report on our discovery of a novel lncRNA, ZFPM2 antisense RNA 1 (ZFPM2-AS1), and its critical role in gastric carcinogenesis. ZFPM2-AS1 expression in gastric cancer specimens was analyzed using Gene Expression Omnibus data set and validated in 73 paired gastric tumor and normal adjacent gastric tissue specimens using qRT-PCR. The effect of ZFPM2-AS1 expression on proliferation and apoptosis in gastric cancer cells was assessed by altering its expression in vitro and in vivo. Mechanistic investigation was carried out using cell and molecular biological approaches. ZFPM2-AS1 expression was higher in gastric tumors than in normal gastric tissue. Also, increased ZFPM2-AS1 expression in gastric cancer specimens was associated with tumor size, depth of tumor invasion, differentiation grade, and TNM stage. High ZFPM2-AS1 expression predicted markedly reduced overall and disease-free survival in gastric cancer patients. Functional experiments demonstrated that ZFPM2-AS1 expression promoted proliferation and suppressed apoptosis of gastric cancer cells in vitro and promoted tumor growth in vivo. This effect is associated with attenuated nuclear translocation of p53. Mechanistic experiments demonstrated that tumor-activated ZFPM2-AS1 could bind to and protect the degradation of macrophage migration inhibitory factor (MIF), a potent destabilizer of p53. Knockdown of MIF expression diminished ZFPM2-AS1's impact on p53 expression in gastric cancer cells. Our findings demonstrated that ZFPM2-AS1 regulates gastric cancer progression and revealed a novel ZFPM2-AS1/MIF/p53 signaling axis, shedding light on the molecular mechanisms underlying the tumorigenicity of certain malignant gastric cells.

Expression pattern of miR-451 and its target MIF (macrophage migration inhibitory factor) in colorectal cancer

AIMS

To investigate the expression pattern of microRNA-451 (miR-451) in patients with colorectal carcinoma and correlate with the expression of its target gene MIF (macrophage migration inhibitory factor).

METHODS

Matched cancer and non-cancer fresh frozen tissues were prospectively collected from 70 patients (35 men and 35 women) who underwent resection of colorectal adenocarcinoma. These tissues collected were extracted for miR and complementary DNA conversion. Then, miR-451 expressions in these tissues were measured by quantitative real-time PCR. The expression was correlated with clinical and pathological parameters of these patients. In addition, paraffin blocks of 10 colorectal carcinomas with lowest expression of miR-451 were used for the study of MIF protein expression by immunohistochemistry.

RESULTS

miR-451 was downregulated in majority of the colorectal cancer tissues when compared with their matched normal tissues (84.3%, n=59/70). Downregulation of miR-451 correlates significantly with presence of coexisting adenoma (91.4%, p=0.025). In addition, persistence of cancer or cancer recurrence after surgery showed significant correlation with downregulation of miR-451 (80% vs 0%; p=0.028). There is no significant correlation between miR-451 expression and age, gender of the patients as well as size, grades, pathological stages, presence of lymphovascular permeation, perineural invasion and microsatellite instability status of the colorectal carcinoma (p>0.05). Majority of the cases (80%) with low expression of miR-451 showed high levels of MIF protein expression confirming the inverse relationship between miR-451 and MIF expressions.

CONCLUSIONS

The results showed that miR-451 could play a role in development and progression of colorectal cancer and likely by targeting MIF.

25 Years On: A Retrospective on Migration Inhibitory Factor in Tumor Angiogenesis

Twenty-five years ago marked the publication of the first report describing a functional contribution by the cytokine, macrophage migration inhibitory factor (MIF), to tumor-associated angiogenesis and growth. Since first appearing, this report has been cited 304 times (as of this writing), underscoring not only the importance of this landmark study but also the importance of MIF in tumor neovascularization. Perhaps more importantly, this first link between MIF and stromal cell-dependent tumor angiogenesis presaged the subsequent identification of MIF in mediating protumorigenic contributions to several solid tumor stromal cell types, including monocytes, macrophages, T lymphocytes, NK cells, fibroblasts, endothelial progenitors and mesenchymal stem cells. This retrospective review will broadly evaluate both past and present literature stemming from this initial publication, with an emphasis on cellular sources, cellular effectors, signal transduction mechanisms and the clinical importance of MIF-dependent tumor vascularization.

Migration inhibitory factor enhances inflammation via CD74 in cartilage end plates with Modic type 1 changes on MRI

BACKGROUND

Type 1 Modic changes are characterized by edema, vascularization, and inflammation, which lead to intervertebral disc degeneration. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine closely related to the inflammatory cytokines detected in degenerative intervertebral disc tissues. However, the existence and role of MIF and its receptor CD74 in intervertebral disc degeneration have not been elucidated.

QUESTIONS/PURPOSES

We asked whether (1) MIF and its receptor CD74 are expressed in cartilage end plates with Type 1 Modic changes, (2) MIF is associated with cartilage end plate degeneration, (3) the MIF antagonist (S, R)-3(4-hydroxyphenyl)-4, 5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) suppresses MIF-induced inflammatory cytokine release, and (4) inflammatory cytokines are released by cartilage end plate chondrocytes via CD74 by activating the CD74 antibody (CD74Ab).

METHODS

We examined MIF and CD74 expression by human cartilage end plate chondrocytes and tissues with Type 1 Modic changes from eight patients using immunocytofluorescence and immunohistochemistry. MIF production by the chondrocytes was assessed by ELISA and PCR. We compared cytokine release by chondrocytes treated with MIF in the presence or absence of exogenous ISO-1 by ELISA. Cytokine release by chondrocytes after treatment with CD74Ab was determined by ELISA.

RESULTS

MIF was expressed in degenerated human cartilage end plate tissues and chondrocytes. Lipopolysaccharide and tumor necrosis factor α (TNF-α) upregulated MIF expression and increased MIF secretion in chondrocytes in a dose-dependent manner. MIF increased the secretion of IL-6, IL-8, and prostaglandin E2 (PGE2) in a dose-dependent manner. ISO-1 reduced the secretion of IL-6, IL-8, and PGE2. CD74Ab activated CD74 and induced release of inflammatory cytokines.

CONCLUSIONS

Chondrocytes in cartilage end plate with Type 1 Modic changes express MIF and its receptor CD74. MIF might promote the inflammatory response through CD74. MIF-induced cytokine release appears to be suppressed by ISO-1, and CD74Ab could induce cytokine release.

CLINICAL RELEVANCE

The MIF/CD74 pathway may represent a crucial target for treating disc degeneration since inhibiting the function of MIF with its antagonist ISO-1 can reduce MIF-induced inflammation and exert potent therapeutic effects.

Functional disruption of macrophage migration inhibitory factor (MIF) suppresses proliferation of human H460 lung cancer cells by caspase-dependent apoptosis

Background

Macrophage migration inhibitory factor (MIF) is important in regulating cell proliferation and apoptosis in both normal and cancerous cells, and may be important in cancer progression and metastasis. In human non-small cell lung cancer (NSCLC), the underlying mechanisms responsible for MIF-dependent regulation of cellular proliferation, and cell death remain poorly appreciated.

Methods

The human H460 lung cancer cell-line was treated with an optimally determined dose of 50 pmol/ml MIF siRNA, following which cell proliferation, cell cycle and apoptosis were analyzed. Additionally, known pathways of apoptosis including expression of Annexin-V, enhanced production of caspases-3 and −4 and expression of the Akt signaling protein were assessed in an attempt to provide insights into the signaling pathways involved in apoptosis following disruption of MIF expression.

Results

Specific siRNA sequences markedly decreased MIF expression in H460 cells by 2 to 5-fold as compared with the negative control. Moreover, MIF miRNA dampened not only cellular proliferation, but increased the frequency of apoptotic cells as assessed by cell-surface Annexin-V expression. Entry of cells into apoptosis was partly dependent on enhanced production of caspases −3 and −4 while not affecting the expression of either caspase-8 or the Akt signaling pathway.

Conclusions

In a model of NSCLC, knockdown of MIF mRNA expression dampened H460 proliferation by mechanisms partly dependent on entry of cells into apoptosis and enhanced production of caspase-3 and −4. MIF expression may thus be important in NSCLC progression. Targeting MIF may have clinical utility in the management of human lung cancer.

Inhibitory effects of eupatilin on tumor invasion of human gastric cancer MKN-1 cells

Extracts of the whole herb of Artemisia asiatica Nakai (Asteraceae) are used in traditional oriental medicine to treat inflammation. Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is one of the pharmacologically active components found in A. asiatica, and has been shown to possess anti-tumoral effects in some malignancies, including gastric cancer. However, its anti-metastatic effect in gastric cancer is hardly known. In this study, anti-metastatic effect of eupatilin was investigated in the human gastric cancer cell line, MKN-1. Eupatilin inhibited MKN-1 growth in a dose- and a time-dependent manner, and induced apoptosis with a concomitant increase of caspase-3 activity. ELISA demonstrated that release of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-8) was significantly reduced by eupatilin. And p-AKT and p-ERK (p44/42) was reduced. Expression level of β-catenin and integrin was reduced and p-GSKβ was increased. In transcription reporter system, the activity of the transcriptional factor, NF-κB, was reduced by eupatilin and the expression of p65 was down-regulated when MKN-1 cells were treated with eupatilin. Moreover, a zymography study revealed that this reduction in invasive potential resulted from a reduction in type IV collagenolytic (gelatinolytic) activity. The expressions of metalloproteinases (MMP-2 and MMP-9) were also reduced in MKN-1 cells treated with eupatilin. In vitro invasion assay, eupatilin inhibited MKN-1 penetrating reconstituted basement membrane barriers. These results suggest that eupatilin inhibits the MKN-1 gastric cancer cell proliferation via activation of caspase-3 and the metastatic potential of gastric cancer cells via down-regulation of NF-κB activity followed by reduction of pro-inflammatory cytokine-mediated MMPs expressions.

Macrophage migration inhibitory factor and DJ-1 in gastric cancer: differences between high-incidence and low-incidence areas

BACKGROUND

There is a need for sensitive and specific blood-borne markers for the detection of gastric cancer. Raised serum macrophage inhibitory factor (MIF) levels have been proposed as a marker for gastric cancer diagnosis but, to date, studies have only encompassed patients from high-incidence areas.

METHODS

We have compared the serum concentration of MIF in a large cohort of UK and Japanese gastric cancer patients, together with appropriate control subjects (age and gender matched). Carcinoembryonic antigen and H. pylori IgG were also measured, as was DJ-1, a novel candidate protein biomarker identified by analysis of gastric cancer cell line secretomes.

RESULTS

Marked elevations of the serum concentration of MIF and DJ-1 were seen in Japanese patients with gastric cancer compared with Japanese controls, a trend not seen in the UK cohort. These results could not be accounted for by differences in age, disease stage or H. pylori status.

CONCLUSION

In regions of high, but not low incidence of gastric cancer, both MIF and DJ-1 have elevated serum concentrations in gastric cancer patients, compared with controls. This suggests that differing mechanisms of disease pathogenesis may be at play in high- and low-incidence regions.

Clinicopathological significance of macrophage migration inhibitory factor and its relation with p53 in gastric cancer

AIM

Based on previous investigations, the progress of gastritis may lead to gastric carcinomas. In some epithelial tumors, macrophage migration inhibitory factor (MIF), which is an inflammatory cytokine may inactivate p53 and play a role in tumorigenesis process. We decided to evaluate clinicopathological significance of MIF expression and the relation between p53 and MIF expressions in gastric adenocarcinomas.

METHODS

Seventy-three consecutive cases of gastric adenocarcinomas, the tissue samples of which were available, were included in this study. Tissue sections were stained for MIF and p53 expression by immunohistochemistry and the expression was defined as positive (for more than 10%) and negative (for less than 10%) groups. Location of the tumor, histological subtypes, and grade of the tumor were determined by using routine H&E staining. Distant metastasis, lymph node involvement, and consequently the stage of tumor were specified. The patients' age and gender were obtained from their medical records. The relationship between expression of MIF and these variables was determined.

RESULTS

Overexpression of MIF was observed in the cytoplasm of cancer cells in 46.6% (34/73) of cases and nuclear immunostaining of p53 was observed in 37% (27/73) of cases. Expression of MIF was significantly correlated with the location of tumor, but this expression has no statistically significant correlation with variables including: age, gender histological subtypes, distant metastasis, and lymph node involvement, stage and grade of the tumor, and p53 tumor suppressor gene expression.

CONCLUSIONS

Our study suggests that MIF in gastric adenocarcinomas versus many other epithelial tumors cannot have a prominent role in tumor progress and inactivation of p53 tumor suppressor gene.

Macrophage migration inhibitory factor (MIF): a promising biomarker

Macrophage migration inhibitory factor (MIF) is an immunoregulatory cytokine, the effect of which on arresting random immune cell movement was recognized several decades ago. Despite its historic name, MIF also has a direct chemokine-like function and promotes cell recruitment. Multiple clinical studies have indicated the utility of MIF as a biomarker for different diseases that have an inflammatory component; these include systemic infections and sepsis, autoimmune diseases, cancer, and metabolic disorders such as type 2 diabetes and obesity. The identification of functional promoter polymorphisms in the MIF gene (MIF) and their association with the susceptibility or severity of different diseases has not only served to validate MIF's role in disease development but also opened the possibility of using MIF genotype information to better predict risk and outcome. In this article, we review the clinical data of MIF and discuss its potential as a biomarker for different disease applications.

Macrophage migration inhibitory factor regulates proliferation of gastric cancer cells via the PI3K/Akt pathway

AIM

To investigate the effects of macrophage migration inhibitory factor (MIF) on proliferation of human gastric cancer MGC-803 cells and expression of cyclin D1 and p27(Kip1) in them, and further determine whether the effects are related to the PI3K/Akt signal transduction pathway.

METHODS

Gastric cancer MGC-803 cells were cultured and then treated with 50 microg/L recombinant human MIF (rhMIF) with and without a PI3K inhibitor, LY294002 (25 micromol/L). MTT assay was used to detect the proliferation of MGC-803 cells. Cell cycle was detected by flow cytometry. Expression of cyclin D1 and p27(Kip1) mRNA was by reverse transcription-polymerase chain reaction. Protein expression of phosphorylated Akt (p-Akt), Akt, cyclin D1 and p27(Kip1) was examined by immunocytochemistry and Western blotting.

RESULTS

rhMIF significantly stimulated the proliferation of MGC-803 cells and cell cycle progression from G1 phase to S phase in a concentration- and time-dependent manner. After the MGC-803 cells were treated with rhMIF for 24 h, the expression of cyclin D1 was significantly up-regulated compared with the cells not treated with rhMIF at both mRNA and protein levels (0.97 +/- 0.02 vs 0.74 +/- 0.01, P = 0.002; 0.98 +/- 0.05 vs 0.69 +/- 0.04, P = 0.003). The p27(Kip1) was down-regulated but only statistically significant at the protein level. rhMIF significantly increased the expression of p-Akt, which reached the peak at 30 min, but did not affect the expression of Akt. However, LY294002 inhibited all the effects of rhMIF.

CONCLUSION

Macrophage MIF increases the proliferation of gastric cancer cells, induces the expression of cyclin D1 at the transcriptional level and inhibits the expression of p27(Kip1) at the post-transcriptional level via the PI3K/Akt pathway.

Serum macrophage migration-inhibitory factor as a diagnostic and prognostic biomarker for gastric cancer

BACKGROUND

This study aimed to determine the potential diagnostic value of migration-inhibitory factor (MIF) for gastric cancer in patients presenting with dyspepsia and its prognostic value for gastric cancer.

METHODS

A cohort of 97 patients with histologically confirmed gastric adenocarcinoma and 222 patients with dyspepsia were recruited. Enzyme-linked immunosorbent assay was used to measure serum MIF and carcinoembryonic antigen (CEA).

RESULTS

The serum MIF concentrations were 6554.0 +/- 204.1 pg/mL and 1453.7 +/- 79.9 pg/mL, respectively, in gastric cancer patients and dyspeptic patients (P < .001). Serum MIF levels increased with the advancing gastric pathologies (P < .001). With the cutoff value of 3230 pg/mL, serum MIF had sensitivity, specificity, and accuracy of 83.5%, 92.3%, and 89.7%, respectively, in diagnosing gastric cancer, whereas the rates were 60.8%, 83.3%, and 76.5%, respectively, for serum CEA. Gastric cancer patients with serum MIF levels above 6600 pg/mL had a lower 5-year survival rate than those with serum MIF level below that level (P = .012). Higher serum CEA levels were also associated with poor survival. The prediction for 5-year survival was even better (P = .0001), using a combination of serum MIF and CEA.

CONCLUSIONS

Serum MIF level, which correlates with gastric MIF expression, is a better molecular marker than CEA in diagnosing gastric cancer in patients presenting with dyspepsia. A combination of serum MIF and CEA predicts 5-year survival better than the individual test.

Macrophage migration inhibitory factor regulates proliferation of gastric cancer cells via the PI3K/Akt pathway

AIM: To investigate the effects of macrophage migration inhibitory factor (MIF) on proliferation of human gastric cancer MGC-803 cells and expression of cyclin D1 and p27^Kip1 in them, and further determine whether the effects are related to the PI3K/Akt signal transduction pathway.

METHODS: Gastric cancer MGC-803 cells were cultured and then treated with 50 μg/L recombinant human MIF (rhMIF) with and without a PI3K inhibitor, LY294002 (25 μmol/L). MTT assay was used to detect the proliferation of MGC-803 cells. Cell cycle was detected by flow cytometry. Expression of cyclin D1 and p27^Kip1 mRNA was by reverse transcription-polymerase chain reaction. Protein expression of phosphorylated Akt (p-Akt), Akt, cyclin D1 and p27^Kip1 was examined by immunocytochemistry and Western blotting.

RESULTS: rhMIF significantly stimulated the proliferation of MGC-803 cells and cell cycle progression from G1 phase to S phase in a concentration- and time-dependent manner. After the MGC-803 cells were treated with rhMIF for 24 h, the expression of cyclin D1 was significantly up-regulated compared with the cells not treated with rhMIF at both mRNA and protein levels (0.97 ± 0.02 vs 0.74 ± 0.01, P = 0.002; 0.98 ± 0.05 vs 0.69 ± 0.04, P = 0.003). The p27^Kip1 was down-regulated but only statistically significant at the protein level. rhMIF significantly increased the expression of p-Akt, which reached the peak at 30 min, but did not affect the expression of Akt. However, LY294002 inhibited all the effects of rhMIF.

CONCLUSION: Macrophage MIF increases the proliferation of gastric cancer cells, induces the expression of cyclin D1 at the transcriptional level and inhibits the expression of p27^Kip1 at the post-transcriptional level via the PI3K/Akt pathway.

Histone deacetylase inhibitors repress macrophage migration inhibitory factor (MIF) expression by targeting MIF gene transcription through a local chromatin deacetylation

The cytokine macrophage migration inhibitory factor plays a central role in inflammation, cell proliferation and tumorigenesis. Moreover, macrophage migration inhibitory factor levels correlate with tumor aggressiveness and metastatic potential. Histone deacetylase inhibitors are potent antitumor agents recently introduced in the clinic. Therefore, we hypothesized that macrophage migration inhibitory factor would represent a target of histone deacetylase inhibitors. Confirming our hypothesis, we report that histone deacetylase inhibitors of various chemical classes strongly inhibited macrophage migration inhibitory factor expression in a broad range of cell lines, in primary cells and in vivo. Nuclear run on, transient transfection with macrophage migration inhibitory factor promoter reporter constructs and transduction with macrophage migration inhibitory factor expressing adenovirus demonstrated that trichostatin A (a prototypical histone deacetylase inhibitor) inhibited endogenous, but not episomal, MIF gene transcription. Interestingly, trichostatin A induced a local and specific deacetylation of macrophage migration inhibitory factor promoter-associated H3 and H4 histones which did not affect chromatin accessibility but was associated with an impaired recruitment of RNA polymerase II and Sp1 and CREB transcription factors required for basal MIF gene transcription. Altogether, this study describes a new molecular mechanism by which histone deacetylase inhibitors inhibit MIF gene expression, and suggests that macrophage migration inhibitory factor inhibition by histone deacetylase inhibitors may contribute to the antitumorigenic effects of histone deacetylase inhibitors.

Expression of CD74, the receptor for macrophage migration inhibitory factor, in non-small cell lung cancer

Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that is overexpressed in lung cancer. The MIF receptor was recently discovered and found to be the invariant chain of the HLA class II molecule, CD74. We hypothesized that the expression of this receptor-ligand pair in lung cancer is associated with the angiogenic activity and level of CXC chemokine expression in human specimens of non-small cell lung cancer. We, therefore, performed immunolocalization of CD74 and compared it with the localization of MIF in non-small cell lung cancer to determine their respective locations, as well as the relationship between the co-expression of MIF-CD74 and angiogenic CXC chemokines with tumor angiogenesis. We found intense CD74 expression by immunohistochemistry in 57 of 70 tumors with minimal to no staining in the remaining 13 tumors. Comparing the localization of CD74 with its putative ligand, MIF, we found that CD74 and MIF were co-expressed in tumors in close proximity, and that co-expression of the MIF-CD74 pair was associated with both higher levels of tumor-associated angiogenic CXC chemokines (ie, the ELR score) and greater vascularity compared with tumors in which MIF-CD74 co-expression was not present. We also found that MIF induced angiogenic CXC chemokine expression in an autocrine manner in vitro, a function that was specifically inhibited by antibodies to CD74.

Mechanisms of macrophage migration inhibitory factor (MIF)-dependent tumor microenvironmental adaptation

Since its activity was first reported in the mid-1960s, macrophage migration inhibitory factor (MIF) has gone from a cytokine activity modulating monocyte motility to a pleiotropic regulator of a vast array of cellular and biological processes. Studies in recent years suggest that MIF contributes to malignant disease progression on several different levels. Both circulating and intracellular MIF protein levels are elevated in cancer patients and MIF expression reportedly correlates with stage, metastatic spread and disease-free survival. Additionally, MIF expression positively correlates with angiogenic growth factor expression, microvessel density and tumor-associated neovascularization. Not coincidentally, MIF has recently been shown to contribute to tumoral hypoxic adaptation by promoting hypoxia-induced HIF-1alpha stabilization. Intriguingly, hypoxia is a strong regulator of MIF expression and secretion, suggesting that hypoxia-induced MIF acts as an amplifying factor for both hypoxia and normoxia-associated angiogenic growth factor expression in human malignancies. Combined, these findings suggest that MIF overexpression contributes to tumoral hypoxic adaptation and, by extension, therapeutic responsiveness and disease prognosis. This review summarizes recent literature on the contributions of MIF to tumor-associated angiogenic growth factor expression, neovascularization and hypoxic adaptation. We also will review recent efforts aimed at identifying and employing small-molecule antagonists of MIF as a novel approach to cancer therapeutics.

Macrophage migration inhibitory factor promotes colorectal cancer

A growing body of evidence implicates macrophage migration inhibitory factor (MIF) in tumorigenesis and metastasis. In this study, we investigated whether MIF expression was associated with clinicopathologic features of colorectal carcinoma (CRC), especially in tumors with hepatic metastasis, and whether neutralization of endogenous MIF using anti-MIF therapeutics would inhibit tumor growth and/or decrease the frequency of colorectal hepatic metastases in a mouse colon carcinoma model. The concentration of serum MIF was positively correlated with an increased risk of hepatic metastasis in human patients with CRC (R = 1.25, 95% confidence internal = 1.02-1.52, P = 0.03). MIF was also dramatically upregulated in human colorectal tissue, with 20-40 times as many MIF-positive cells found in the mucosa of patients with CRC than in normal tissue (P < 0.001 ANOVA). Moreover, in those patients with metastatic colorectal cancer in the liver, MIF-positive cells were similarly increased in the diseased hepatic tissue. This increased MIF expression was restricted to diseased tissue and not found in areas of the liver with normal morphology. In subsequent in vitro experiments, we found that addition of recombinant MIF to colonic cell lines significantly increased their invasive properties and the expression of several genes (for example, matrix metalloproteinase 9 and vascular endothelial growth factor) known to be upregulated in cancerous tissue. Finally, we treated mice that had been given CT26 colon carcinoma cell transplants with anti-MIF therapeutics--either the MIF-specific inhibitor ISO-1 or neutralizing anti-MIF antibodies--and observed a significant reduction in tumor burden relative to vehicle-treated animals. Taken together, these data demonstrate that MIF expression was not only correlated with the presence of colorectal cancer but also may play a direct role in cancer development.

Identification of breast cancer peptide epitopes presented by HLA-A*0201

Cellular immune mechanisms detect and destroy cancerous and infected cells via the human leukocyte antigen (HLA) class I molecules that present peptides of intracellular origin on the surface of all nucleated cells. The identification of novel, tumor-specific epitopes is a critical step in the development of immunotherapeutics for breast cancer. To directly identify peptide epitopes unique to cancerous cells, secreted human class I HLA molecules (sHLA) were constructed by deletion of the transmembrane and cytoplasmic domain of HLA A*0201. The resulting sHLA-A*0201 was transferred and expressed in breast cancer cell lines MCF-7, MDA-MB-231, and BT-20 as well as in the immortal, nontumorigenic cell line MCF10A. Stable transfectants were seeded into bioreactors for production of > 25 mg of sHLA-A*0201. Peptides eluted from affinity purified sHLA were analyzed by mass spectroscopy. Comparative analysis of HLA-A*0201 peptides revealed 5 previously uncharacterized epitopes uniquely presented on breast cancer cells. These peptides were derived from intracellular proteins with either well-defined or putative roles in breast cancer development and progression: Cyclin Dependent Kinase 2 (Cdk2), Ornithine Decarboxylase (ODC1), Kinetochore Associated 2 (KNTC2 or HEC1), Macrophage Migration Inhibitory Factor (MIF), and Exosome Component 6 (EXOSC6). Cellular recognition of the MIF, KNTC2, EXOSC6, and Cdk2 peptides by circulating CD8+ cells was demonstrated by tetramer staining and IFN-gamma ELISPOT. The identification and characterization of peptides unique to the class I of breast cancer cells provide putative targets for the development of immune diagnostic tools and therapeutics.

Proteomic analysis of microvesicles derived from human colorectal cancer cells

Microvesicles (MV) are membrane vesicles secreted from the plasma and endosomal membrane compartment by various cell types such as hematopoietic, epithelial, and tumor cells. Actively growing tumor cells shed MV, and the rate of shedding increases in malignant tumors. Although recent progress in this area has revealed that tumor-derived MV play multiple roles in tumor growth and metastasis via immune escape, tumor invasion, and angiogenesis, the mechanism of vesicle formation and the biological roles of tumor-derived MV are not understood. Here, we report the first global proteomic analysis of highly purified MV from human colorectal cancer cells. Using 1D SDS gel electrophoresis and nano-LC-MS/MS analyses, we identified a total of 547 microvesicular proteins from three independent experiments with high confidence; 416 proteins were identified at least in two trials, including 181 as yet unreported proteins. We identified 49 proteins involved in the biogenesis of MV, including annexins, ADP-ribosylation factors, and Rab proteins. We also identified 28 proteins that may function in tumorigenesis via promotion of migration, invasion, and growth of tumor cells, immune modulation, metastasis, and angiogenesis. Taken together with previously reported results, our observations suggest that tumor-derived MV may act as communicasomes, that is, extracellular organelles that play diverse roles in intercellular communication. This information will help elucidate the biogenesis and functions of tumor-derived MV, and aid in the development of effective vaccines for various cancers, including colorectal cancer.

The role of macrophage migration inhibitory factor in maintaining the immune privilege at the fetal–maternal interface

Macrophage migration inhibitory factor (MIF) is a pivotal regulator of the innate and adaptive immunity affecting the response and behavior of macrophages and lymphocytes. MIF is also implicated in other fundamental cellular processes including angiogenesis and cell proliferation. Several studies examined the expression of MIF in reproductive organs and tissues and its involvement in different aspects of human and animal reproduction. The goal of this review was to summarize these findings and discuss, in particular, the role of MIF in the maintenance of the immune privilege at the human fetal-maternal interface.

Amplification of tumor hypoxic responses by macrophage migration inhibitory factor-dependent hypoxia-inducible factor stabilization

Low oxygen tension-mediated transcription by hypoxia-inducible factors (HIF) has been reported to facilitate tumor progression, therapeutic resistance, and metastatic adaptation. One previously described target of hypoxia-mediated transcription is the cytokine/growth factor macrophage migration inhibitory factor (MIF). In studies designed to better understand hypoxia-stimulated MIF function, we have discovered that not only is MIF induced by hypoxia in pancreatic adenocarcinoma but MIF is also necessary for maximal hypoxia-induced HIF-1alpha expression. Cells lacking MIF are defective in hypoxia- and prolyl hydroxylase inhibitor-induced HIF-1alpha stabilization and subsequent transcription of glycolytic and angiogenic gene products. Moreover, COP9 signalosome subunit 5 (CSN5), a component of the COP9 signalosome previously reported to functionally interact with MIF, has recently been shown to interact with and stabilize HIF-1alpha. Our results indicate that MIF interacts with CSN5 in pancreatic cancer cells and that MIF-depleted cells display marked defects in hypoxia-induced CSN5/HIF-1alpha interactions. This functional interdependence between HIF-1alpha and MIF may represent an important and previously unrecognized pro-tumorigenic axis.

Expression of macrophage migration inhibitory factor and its effect on cell proliferation and angiogenesis in human liver cancer

AIM: To determine the expression of macro-phage migration inhibitory factor (MIF) in hepatocellular carcinoma (HCC) and its effect on cell proliferation and angiogenesis.

METHODS: The protein expression of MIF, interleukin-8 (IL-8), and vascular endothelial factor (VEGF) as well as microvessel density (MVD) were examined by immunochemistry in HCC tissues (n = 40), cancer-adjacent liver tissues (n = 40) and normal liver tissues (n = 10). At the same time, real time quantitative polymerase chain reaction (RQ-PCR) was used to detect the mRNA levels of MIF, VEGF and IL-8. After human hepatocarcinama cell line Bel-7402 was treated with recombinant MIF (rMIF), cell proliferation was detected by MTT assay and the secretion levels and mRNA expression of VEGF and IL-8 were examined by enzyme linked immunosorbent assay (ELISA) and RQ-PCR, respectively.

RESULTS: The positive rates of MIF, IL-8 and VEGF in HCC tissues were significantly higher than those in normal liver tissues (72.5% vs 30.0%, 67.5% vs 20.0%, 62.5% vs 30.0%, all P < 0.01). The expression of MIF and IL-8 were markedly correlated with VEGF expression (r = 0.271, P < 0.05) and MVD (r = 0.284, P < 0.05). VEGF concentration in the supernatant of Bel-7402 cells was higher (900.00 ± 264.58 ng/L) than that in the controls (180 ± 50 ng/L) at the 24^th hour after rMIF treatment (P < 0.01). However, there was no significant variation in IL-8 concentration (P > 0.05). The post-treatment level of VEGF mRNA was 6.86 times as high as that without treatment (P < 0.05), and there was no significant change in IL-8 mRNA expression (P > 0.05).

CONCLUSION: The over-expression of MIF plays a crucial role in the angiogenesis of liver cancer and the roles of MIF and IL-8 may be realized via VEGF.

Macrophage migration inhibitory factor manipulation and evaluation in tumoral hypoxic adaptation

Increasingly clear is an important regulatory role for hypoxia-inducible factor 1alpha (HIF-1alpha) in the expression of the cytokine/growth factor macrophage migration inhibitory factor (MIF). The functional significance of hypoxia-induced MIF expression is revealed by findings demonstrating that HIF-1alpha-dependent MIF expression is necessary for hypoxia-induced evasion from cell senescence and that MIF is necessary for HIF-1alpha stabilization induced by hypoxia and prolyl hydroxylase (PHD) inhibitors. Both of these activities attributed to MIF likely involve the modulation of protein degratory pathways mediated by cullin-dependent E3 ubiquitin ligase complexes and their regulation by the COP9 signalosome (CSN). As the importance of MIF in hypoxic adaptation of human tumors is now becoming fully realized, we review protocols designed to evaluate MIF expression, activity, and functional consequences in hypoxic environments.

Increased epithelial and serum expression of macrophage migration inhibitory factor (MIF) in gastric cancer: potential role of MIF in gastric carcinogenesis

AIMS

Macrophage migration inhibitory factor (MIF) is implicated in tumorigenesis. This study was conducted to determine whether MIF expression is associated with gastric pathology and whether MIF expression is increased in malignant gastric cells in vitro.

MATERIALS AND METHODS

Patients with a normal gastric mucosa, Helicobacter pylori infected gastritis, intestinal metaplasia, and gastric adenocarcinoma were included. Immunohistochemistry and enzyme linked immunosorbent assay (ELISA) were used to determine MIF expression in gastric epithelial cells and MIF levels in serum, respectively. Five gastric cancer cell lines (AGS, MKN-45, MKN-28, MGC-803, and SGC-7901) and one non-malignant gastric cell line (GES-1) were cultured for 24 hours. MIF protein in the supernatant and MIF mRNA in cultured cells were measured by ELISA and reverse transcription-polymerase chain reaction, respectively.

RESULTS

The percentage of MIF expressing epithelial cells was low in normal mucosa (12%) but substantially higher in gastritis (52%), intestinal metaplasia (66%), and gastric cancer (96%) (p<0.001, ANOVA). Serum MIF levels were low in patients with a normal mucosa (576 (82) pg/ml) but higher in patients with gastritis (2100 (349) pg/ml), intestinal metaplasia (4498 (253) pg/ml), and gastric cancer (9737 (1249) pg/ml) (p<0.001, ANOVA). There was a correlation between epithelial MIF expression and serum MIF levels (r = 0.776, p<0.001). In vitro, expression of MIF protein and mRNA was increased in malignant cells compared with non-malignant cells.

CONCLUSIONS

Epithelial and serum MIF expression was progressively increased in H pylori induced gastritis, intestinal metaplasia, and gastric cancer, suggesting that MIF is involved in gastric carcinogenesis and may be a valuable biomarker for the early detection of gastric cancer.