Optimization of ultrasmall superparamagnetic iron oxide (P904)-enhanced magnetic resonance imaging of lymph nodes: initial experience in a mouse model

BACKGROUND

P904 is a novel ultra-small superparamagnetic iron oxide (USPIO) contrast agent. This study was conducted to investigate the optimal dose of P904 for magnetic resonance imaging (MRI) of lymph nodes.

MATERIALS AND METHODS

T2*-weighted 3T MRI was performed in 14 normal mice before and 24 h after P904 injection at varying doses. Normalized signal intensity (nSI), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and contrast ratio (CR) were calculated to determine the optimal dose. MRI of the metastatic lymph node models (n=5) was acquired using the optimal dose and correlated with pathological results to calculate sensitivity and specificity. The mean SI ratio between pre- and postcontrast MRI was also calculated for each lymph node.

RESULTS

The mean nSI and SNR values on postcontrast images were significantly lower at 300 μmol Fe/kg than at 75 μmol Fe/kg (p<0.001). The mean CNR and CR values were significantly higher at 300 μmol Fe/kg than at the other two doses (p<0.05). At the optimal dose of 300 μmol Fe/kg, the mean SI ratio of benign lymph nodes was significantly lower than that of metastatic lymph nodes (p<0.001). The Az (areas under the receiver operating characteristic curves) value for diagnosing lymph node metastasis at the optimal dose was 0.97.

CONCLUSION

The optimal dose for P904-enhanced MRI of the lymph nodes was 300 μmol Fe/kg, which could be used for the diagnosis of lymph node metastasis.

An NMR metabolomics approach for the diagnosis of leptomeningeal carcinomatosis in lung adenocarcinoma cancer patients

Leptomeningeal carcinomatosis (LC) is a metastatic cancer invading the central nervous system (CNS). We previously reported a metabolomic diagnostic approach as tested on an animal model and compared with current modalities. Here, we provide a proof of concept by applying it to human LC originating from lung cancer, the most common cause of CNS metastasis. Cerebrospinal fluid from LC (n = 26) and normal groups (n = 41) were obtained, and the diagnosis was established with clinical signs, cytology, MRI and biochemical tests. The cytology on the CSF, the current gold standard, exhibited 69% sensitivity (~100% specificity) from the first round of CSF tapping. In comparison, the nuclear magnetic resonance spectra on the CSF showed a clear difference in the metabolic profile between the LC and normal groups. Multivariate analysis and cross-validation yielded the diagnostic sensitivity of 92%, the specificity of 96% and the area under the curve (AUC) of 0.991. Further spectral and statistical analysis identified myo-inositol (p < 5 × 10(-14)), creatine (p < 7 × 10(-8)), lactate (p < 9 × 10(-4)), alanine (p < 7.9 × 10(-3)) and citrate (p < 3 × 10(-4)) as the most contributory metabolites, whose combination exhibited an receiver-operating characteristic diagnostic AUC of 0.996. In addition, the metabolic profile could be correlated with the grading of radiological leptomeningeal enhancement (R(2) = 0.3881 and p = 6.66 × 10(-4)), suggesting its potential utility in grading LC. Overall, we propose that the metabolomic approach might augment current diagnostic modalities for LC, the accurate diagnosis of which remains a challenge.

Reproducibility of histogram and texture parameters derived from intravoxel incoherent motion diffusion-weighted MRI of FN13762 rat breast Carcinomas

AIM

To determine the reproducibility of histogram and texture parameters derived from intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) of FN13762 rat breast carcinomas.

MATERIALS AND METHODS

IVIM diffusion-weighted MRI was performed twice, nine days after tumor implantation in 11 rats. At each session, histogram and texture parameters of entire tumors were extracted from apparent diffusion coefficient (ADC), true-diffusion coefficient (Dt), pseudo-diffusion coefficient (Dp), and perfusion fraction (Pf) maps. Intraobserver and interscan measurement reproducibilities were evaluated using intraclass correlation coefficients (ICC).

RESULTS

Mean, entropy, 5th, 10th, 25th percentiles from ADC and Dt maps revealed good intra-observer and interscan agreements [lower limits of 95% confidence interval (CI) for ICC≥0.75]. However, all parameters from Dp and Pf maps gave relatively poor intra-observer and interscan agreements (lower limits of 95% CI for ICC<0.75).

CONCLUSION

Histogram and texture parameters derived from ADC and Dt maps were more reproducible than those from Dp and Pf maps.

Rat model of hindlimb ischemia induced via embolization with polyvinyl alcohol and N-butyl cyanoacrylate

Objective

To investigate the feasibility of a rat model on hindlimb ischemia induced by embolization from the administration of polyvinyl alcohol (PVA) particles or N-butyl cyanoacrylate (NBCA).

Materials and Methods

Unilateral hindlimb ischemia was induced by embolization with NBCA (n = 4), PVA (n = 4) or surgical excision (n = 4) in a total of 12 Sprague-Dawley rats. On days 0, 7 and 14, the time-of-flight magnetic resonance angiography (TOF-MRA) and enhanced MRI were obtained as scheduled by using a 3T-MR scanner. The clinical ischemic index, volume change and degree of muscle necrosis observed on the enhanced MRI in the ischemic hindlimb were being compared among three groups using the analysis of variance. Vascular patency on TOF-MRA was evaluated and correlated with angiographic findings when using an inter-rater agreement test.

Results

There was a technical success rate of 100% for both the embolization and surgery groups. The clinical ischemic index did not significantly differ. On day 7, the ratios of the muscular infarctions were 0.436, 0.173 and 0 at thigh levels and 0.503, 0.337 and 0 at calf levels for the NBCA, PVA and surgery groups, respectively. In addition, the embolization group presented increased volume and then decreased volume on days 7 and 14, respectively. The surgery group presented a gradual volume decrease. Good correlation was shown between the TOF-MRA and angiographic findings (kappa value of 0.795).

Conclusion

The examined hindlimb ischemia model using embolization with NBCA and PVA particles in rats is a feasible model for further research, and muscle necrosis was evident as compared with the surgical model.

Blood oxygen level-dependent MRI for evaluation of early response of liver tumors to chemoembolization: an animal study

AIM

To evaluate the feasibility of carbogen-challenge blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) for assessing the early response of liver tumors to chemoembolization in a rat hepatoma model.

MATERIALS AND METHODS

In a 9.4-Tesla scanner, a multiple gradient-recalled echo sequence was utilized for R2* measurement at 11 and 13 days after tumor implantation, first during room air breathing and then with carbogen gas (95% O2/5% CO2) breathing, to calculate the percentage changes of R2* values [ΔR2*(%)]. Transarterial chemoembolization was conducted 12 days after tumor implantation.

RESULTS

The ΔR2* value of the tumors was 10.61 ± 8.94% on pre-chemoembolization images and -0.16 ± 1.85% on post-chemoembolization images. There was a significant difference in the ΔR2* value of the tumors between pre-chemoembolization and post-chemoembolization BOLD MRI (p=0.013).

CONCLUSION

Carbogen-challenge BOLD MRI can be a non-invasive and useful method for the evaluation of early response of liver tumors to chemoembolization.

Sprague-Dawley rats bearing McA-RH7777 cells for study of hepatoma and transarterial chemoembolization

AIM

To evaluate the feasibility of the McA-RH7777 tumor model in Sprague-Dawley (SD) rats, for study of hepatoma and transarterial chemoembolization.

MATERIALS AND METHODS

McA-RH7777 rat hepatoma cells (1×10(7)) were inoculated into the left hepatic lobe of SD rats (n=38). Chemoembolization with left common carotid artery access was performed using an emulsion of iodized oil and doxorubicin, and polyvinyl alcohol particles. Tumor induction rate and response to chemoembolization were assessed by magnetic resonance imaging and histology.

RESULTS

Tumor induction rate of McA-RH7777 in SD rat livers was 73.3% (11/15). Hematoxylin-and-eosin staining revealed hypercellular tumor with a trabecular pattern that mimics human hepatocellular carcinoma. Chemoembolization was successfully conducted in all rats. There was a significant difference in tumor growth rates between the chemoembolization-treated and control groups (p<0.0001).

CONCLUSION

A rat tumor model of McA-RH7777 cells in SD rats is feasible and has the potential to be a good model for hepatoma and chemoembolization studies.

An NMR metabolomics approach for the diagnosis of leptomeningeal carcinomatosis

Leptomeningeal carcinomatosis (LC) is the third most common metastatic complication of the central nervous system. However, the current modalities to reliably diagnose this condition are not satisfactory. Here, we report a preclinical proof of concept for a metabolomics-based diagnostic strategy using a rat LC model incorporating glioma cells that stably express green fluorescent protein. Cytologic diagnoses gave 66.7% sensitivity for the 7-day LC group and 0% for the 3-day LC group. MR imaging could not diagnose LC at these stages. In contrast, nuclear magnetic resonance-based metabolomics on cerebrospinal fluid detected marked differences between the normal and LC groups. Predictions based on the multivariate model provided sensitivity, specificity, and overall accuracy of 88% to 89% in both groups for LC diagnosis. Further statistical analyses identified lactate, acetate, and creatine as specific for the 7-day LC group, with glucose a specific marker of the normal group. Overall, we showed that the metabolomics approach provided both earlier and more accurate diagnostic results than cytology and MR imaging in current use.

Effects of Polycan, a β-glucan, on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats

BACKGROUND AND OBJECTIVE

Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of β-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats.

MATERIAL AND METHODS

 Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect.

RESULTS

Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1β, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement.

CONCLUSION

Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.

Imaging and quantification of metastatic melanoma cells in lymph nodes with a ferritin MR reporter in living mice

Cellular MRI with a reporter gene offers the opportunity to track small numbers of tumor cells and to study metastatic processes in their earliest developmental stages in the target organs of interest. This study demonstrates the feasibility of using the MR reporter ferritin for the noninvasive imaging and quantification of metastatic melanoma cells in the lymph nodes (LNs) of living mice. A B16F10 murine melanoma cell line expressing human ferritin heavy chain (hFTH) and green fluorescent protein (GFP) was constructed to allow the detection of cells by MRI and fluorescence imaging. Stable overexpression of hFTH and GFP in B16F10 murine melanoma cells was feasible and showed no cellular toxicity. In addition, hFTH cells were detectable by 9.4-T MRI in  vitro and in  vivo, yielding significant changes in T(2)* relative to control cells. In BALB/c nude mice, the presence of hFTH- and GFP-expressing metastatic melanoma cells in deep-seated axillary LNs was demonstrated as areas of low T(2)* on MRI, but the same LNs were not visible by fluorescence imaging because the light was unable to penetrate the tissue. Furthermore, the metastatic volume of each LN, which was assessed by cumulative histogram analysis of the T(2)* MRI data, correlated well with tumor burden, which was determined by histology (r = -0.8773, p = 0.0001). This study is the first to use MRI and an MR reporter gene for both the visualization and quantification of metastatic cancer cells in LNs.

Macrophages homing to metastatic lymph nodes can be monitored with ultrasensitive ferromagnetic iron-oxide nanocubes and a 1.5T clinical MR scanner

Background

Due to the ability of macrophages to specifically home to tumors, their potential use as a delivery vehicle for cancer therapeutics has been suggested. Tracking the delivery and engraftment of macrophages into human tumors with a 1.5T clinical MR scanner requires the development of sensitive contrast agents for cell labeling. Therefore, this study aimed to determine whether intravenously injected macrophages could target a primary tumor as well as metastatic LNs, and whether these cells could be detected in vivo by MRI.

Methodology

Peritoneal macrophages were obtained from BALB/c nude mice. The viability, phagocytotic capacity and migratory activity of the macrophages were assessed. MR imaging was performed using a clinical 1.5 T MR scanner and we estimated the T2* of the labeled macrophages. Metastatic lymph nodes were produced in BALB/c nude mice. We administrated 2×10⁶ macrophages labeled with 50 µg Fe/mL FIONs intravenously into the mice. In the 3D T2* GRE MR images obtained one day after the injection of the labeled macrophages or FION solution, the percentages of pixels in the tumors or LNs below the minimum normalized SI (signal intensity) threshold were summated and reported as the black pixel count (%) for the FION hypointensity. Tumors in the main tumor model as well as the brachial, axillary and inguinal lymph nodes in the metastatic LN models were removed and stained. For all statistical analyses, single-group data were assessed using t test or the Mann-Whitney test. Repeated measurements analysis of variance (ANOVA) with Tukey–Kramer post hoc comparisons were performed for multiple comparisons.

Conclusions

The FION-labeled macrophages, which could be non-invasively monitored using a 1.5 T clinical MR scanner, targeted both the main tumors and LN metastases. Overall, the results of this study suggest that the use of macrophages may have many future applications in the clinic for vectorizing therapeutic agents toward main tumors as well as LN metastases.

In vivo imaging of tumor transduced with bimodal lentiviral vector encoding human ferritin and green fluorescent protein on a 1.5T clinical magnetic resonance scanner

A combination of reporter genes for magnetic resonance imaging (MRI) and optical imaging can provide an additional level of noninvasive and quantitative information about biological processes occurring in deep tissues. We developed a bimodal lentiviral vector to monitor deep tissue events using MRI to detect myc-tagged human ferritin heavy chain (myc-hFTH) expression and fluorescence imaging to detect green fluorescent protein (GFP) expression. The transgene construct was stably transfected into MCF-7 and F-98 cells. After transplantation of the cells expressing myc-hFTH and GFP into mice or rats, serial MRI and fluorescence imaging were performed with a human wrist coil on a 1.5T MR scanner and optical imaging analyzer for 4 weeks. No cellular toxicity due to overexpression of myc-hFTH and GFP was observed in MTT and trypan blue exclusion assays. Iron accumulation was observed in myc-hFTH cells and tumors by Prussian blue staining and iron binding assays. The myc-hFTH cells and tumors had significantly lower signal intensities in T(2)-weighted MRI than mock-transfected controls (P ≤ 0.05). This is direct evidence that myc-hFTH expression can be visualized noninvasively with a 1.5T clinical MR scanner. This study shows that MRI and fluorescence imaging of transplanted cells at molecular and cellular levels can be performed simultaneously using our bimodal lentiviral vector system. Our techniques can be used to monitor tumor growth, metastasis, and regression during cell and gene-based therapy in deep tissues.

Isolated acute cellular rejection of the liver after simultaneous liver and kidney transplantation: a case report

Simultaneous liver and kidney transplantation (SLKT) is now considered the treatment of choice for patients with concurrent end-stage liver and kidney diseases. Even though the early postoperative mortality rate following SLKT is reported to be high compared to that of liver transplantation alone, the liver graft from the same donor has been argued to induce better kidney graft acceptance as evidenced by a low rate of acute renal rejection episodes. There have been many reports of a low incidence of acute renal rejection following SLKT; however, only a few cases were proven by simultaneous biopsies. The authors experienced a case of biopsy-proven isolated acute cellular rejection of the liver graft following SLKT.

Induction of MMP-13 expression by soluble human glucocorticoid-induced tumor necrosis factor receptor in fibroblast-like synovial cells

OBJECTIVE

We tested the hypothesis that human glucocorticoid-induced tumor necrosis factor receptor (hGITR/TR11) expressed on the surface of activated CD4(+) T cells is responsible for up-regulating the production of matrix metalloproteinase (MMP)-13 by fibroblast-like synoviocytes (FLSs).

METHODS

The level of MMP-13 was measured by Western blot and reverse transcriptase polymerase chain reaction (RT-PCR). Expressions of hGITR ligand (hGITRL) on the surface of FLSs and hGITR on the surface of human CD4(+) T cells were analyzed by flow cytometry and RT-PCR. Neutralizing antibodies (Abs) were used to block hGITRL and hGITR on the surface of FLSs and human CD4(+) T cells, respectively. Human CD4(+) T cells were cocultured with FLSs to facilitate interaction between hGITR on CD4(+) T cells and hGITRL on FLSs.

RESULTS

Soluble hGITR (shGITR) stimulated FLSs to produce MMP-13, and blockade of hGITRL reduced this effect. Direct contact between activated CD4(+) T and FLSs also induced the production of MMP-13, and neutralization of hGITR on activated CD4(+) T cells during coculture decreased the amount of MMP-13 produced by FLSs.

CONCLUSION

shGITR stimulated FLSs to produce MMP-13 via a signal through hGITRL. Direct contact between activated CD4(+) T cells and FLSs facilitated hGITR-hGITRL interaction, and resulted in inducing MMP-13. This effect may increase tissue destruction in chronic inflammation such as rheumatoid arthritis (RA).

Blockade of 4-1BB (CD137)/4-1BB ligand interactions increases allograft survival

We investigated the role of 4-1BB, a T cell co-stimulatory molecule, in alloimmune responses. In vivo mixed lymphocyte reactions showed that 4-1BB was preferentially expressed on actively dividing CD4(+) and CD8(+) T cells. Furthermore, following alloantigen challenge, the draining lymph nodes contained subpopulations of 4-1BB-expressing CD4(+) and CD8(+) T cells. 4-1BB-deficient C57BL/6 mice showed a delayed rejection of cardiac transplants mismatched for the major histocompatibility complex. Longer transplant survival was induced by blockade of 4-1BB/4-1BB ligand (4-1BBL) interactions using an anti-4-1BBL monoclonal antibody. Histological analysis showed that prolonged transplant survival in the 4-1BB-deficient and anti-4-1BBL-treated mice correlated with reduced lymphocytic infiltration and vasculitis in the donor heart tissue. Taken together, our data suggest that blockade of 4-1BB/4-1BBL interactions inhibited the expansion of alloreactive T cells and reduced CTL activity against host alloantigen, which in turn resulted in the prolongation of allograft survival. Blockade of the 4-1BB co-stimulatory pathway may be useful for preventing allograft rejection.

Analysis of expression and function of the costimulatory molecule 4-1BB in alloimmune responses

BACKGROUND

4-1BB (CD137) is a T cell costimulatory molecule that promotes T cell activation. In this study, we investigated the role of 4-1BB costimulation in allogeneic T cell responses.

METHODS

Vascularized heart transplantation, allogeneic mixed leukocyte reaction (MLR), and graft versus host disease models were used to examine 4-1BB and 4-1BBL expression. In addition, agonistic anti-4-1BB antibodies were used in MLR to functionally analyze T cell responses.

RESULTS

Using a heart transplant model, we found that 4-1BB and 4-1BBL transcripts were both expressed in rejecting cardiac grafts. In the allogeneic MLR, 4-1BB was expressed on both activated CD4 and CD8 T cells and 4-1BB was expressed on T cells after multiple cell divisions in vivo. Functionally, 4-1BB was a potent stimulator of proliferation, cytokine secretion, and CD25 expression by CD8 T cells, but 4-1BB signals had a weak effect on the proliferation of CD4 T cells. Because 4-1BB promoted the secretion of IL-2 and the expression of CD25 on CD8 T cells, we investigated whether IL-2 was the only factor whereby 4-1BB signals induced CD8 T cell proliferation. Although IL-2 was required for optimal CD8 T cell proliferation, 4-1BB also costimulated CD8 T cell proliferation independently of IL-2.

CONCLUSIONS

This study demonstrates that 4-1BB is expressed on activated, maximally divided T cells and shows that 4-1BB promotes CD8 T cell proliferation by enhancing signals through the IL-2 receptor and by other mechanisms independent of the IL-2 pathway.

Transplantation of the bone marrow microenvironment leads to hematopoietic chimerism without cytoreductive conditioning

BACKGROUND

It has been hypothesized that regimens to induce transplantation tolerance and long-term hematopoietic chimerism require recipient conditioning with whole body irradiation or a cytoablative regimen to create space within the marrow microenvironment to permit pluripotent stem cell engraftment. The purpose of this study was to determine if transplantation of an intact bone marrow microenvironment in the form of a bone graft would permit stable hematopoietic stem cell engraftment, shape the repertoire of developing T cells, and induce donor-specific unresponsiveness in the absence of a conditioning regimen.

METHODS

Fragments of femur were transplanted under the kidney capsule of recipient mice. At defined time points after bone graft transplantation recipients were assayed for chimerism, bone graft viability, and responses to donor and third party alloantigens in vitro and in vivo.

RESULTS

In the absence of an immunological barrier, bone graft transplantation resulted in long-term multi-lineage hematopoietic chimerism in the peripheral blood. Nude bone graft transplantation into SCID recipients resulted in development of donor- derived T cells that underwent negative selection on bone graft derived I-E+ cells within the thymus. Across a fully allogeneic barrier in immunocompetent recipients treated with combined blockade of the CD40 and CD28 pathways bone graft transplantation resulted in long-term donor-specific hyporesponsiveness in vitro and acceptance of donor specific skin grafts.

CONCLUSIONS

Transplantation of bone marrow in the form of a bone graft may facilitate the production of hematopoietic chimerism and lead to long-term donor-specific hyporesponsiveness in the absence of a cytoreductive conditioning regimen.

Vigorous allograft rejection in the absence of danger

Tolerance to self is a necessary attribute of the immune system. It is thought that most autoreactive T cells are deleted in the thymus during the process of negative selection. However, peripheral tolerance mechanisms also exist to prevent development of autoimmune diseases against peripheral self-Ags. It has been proposed that T cells develop tolerance to peripheral self-Ags encountered in the absence of inflammation or "danger" signals. We have used immunodeficient Rag 1-/- mice to study the response of T cells to neo-self peripheral Ags in the form of well-healed skin and vascularized cardiac allografts. In this paper we report that skin and cardiac allografts without evidence of inflammation are vigorously rejected by transferred T cells or when recipients are reconstituted with T cells at a physiologic rate by nude bone graft transplantation. These results provide new insights into the role of inflammation or "danger" in the initiation of T cell-dependent immune responses. These findings also have profound implications in organ transplantation and suggest that in the absence of central deletional tolerance, peripheral tolerance mechanisms are not sufficient to inhibit alloimmune responses even in the absence of inflammation or danger.

Prolonged acceptance of concordant and discordant xenografts with combined CD40 and CD28 pathway blockade

BACKGROUND

The prompt and vigorous immune response to xenogenic tissue remains a significant barrier to clinical xenotransplantation. Simultaneous blockade of the CD28 and CD40 costimulatory pathways has been shown to dramatically inhibit the immune response to alloantigen.

METHODS

. In this study, we investigated the ability of simultaneous blockade of the CD28 and CD40 pathways to inhibit the immune response to xenoantigen in the rat-to-mouse and pig-to-mouse models.

RESULTS

Simultaneous blockade of the CD28 and CD40 pathways produced marked inhibition of the cellular response to xenoantigen in vivo and produced long-term acceptance of xenogeneic cardiac and skin grafts (rat-to-mouse), and markedly suppressed an evoked antibody response to xenoantigen. In addition, this strategy significantly prolonged the survival of pig skin on recipient mice.

CONCLUSIONS

Long-term hyporesponsiveness to xenoantigen across both a concordant and discordant species barrier, measured by the stringent criterion of skin grafting, can be achieved using a noncytoablative treatment regimen.

Reduced expression of tissue inhibitor of metalloproteinase in nodal metastasis of stomach cancer

The matrix metalloproteinases (MMPs) have been associated with tumor cell invasion and metastasis of human cancers by mediating the degradation of extracellular matrix components. Therefore, these enzymes and their inhibitor (TIMP-2) constitute promising targets in the development of anticancer therapies. In order to investigate the correlation between expressions of TIMP-2, MMPs and clinical outcome, immunohistochemical staining of MMP-2, MMP-9, and TIMP-2 were performed on paraffin-embedded tissue sections of 15 early gastric cancers (EGC) and 15 advanced gastric carcinomas (AGC) without nodal metastasis and 15 AGC with nodal metastasis (AGCn+). MMP-2 and MMP-9 were expressed in neoplastic cell plasma membrane in 83.3% and 88% of cases of AGC, respectively with inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining were not correlated with presence of nodal metastasis or degree of invasion depth at the time of diagnosis (p>0.05). The immunoreactivity of TIMP-2 was detected in the peri-tumoral stroma. Residual benign stomach tissue showed no or weak immunoreactivity for TIMP-2 staining. Among AGC, neoplasms with diffuse and strong TIMP-2 staining have less frequent metastasis (28.6%) than cases with focal and weak (68.8%) (p<0.05). Early gastric cancer revealed diffuse and strong TIMP-2 expressions. We conclude that clinical outcome such as depth of invasion or metastasis is more closely related to the expression of TIMP-2 than the corresponding MMPs.