ICAM-1 (intercellular adhesion molecule-1) gene transfection inhibits lymph node metastasis by human gastric cancer cells

A Functional Analysis on the Interspecies Interaction between Mouse LFA-1 and Human Intercellular Adhesion Molecule-1 at the Cell Level

The interaction between intercellular adhesion molecules (ICAM) and the integrin leukocyte function-associated antigen-1 (LFA-1) is crucial for the regulation of several physiological and pathophysiological processes like cell-mediated elimination of tumor or virus infected cells, cancer metastasis, or inflammatory and autoimmune processes. Using purified proteins it was reported a species restriction for the interaction of ICAM-1 and LFA-1, being mouse ICAM-1 able to interact with human LFA-1 but not human ICAM-1 with mouse LFA-1. However, in vivo results employing tumor cells transfected with human ICAM-1 suggest that functionally mouse LFA-1 can recognize human ICAM-1. In order to clarify the interspecies cross-reactivity of the ICAM-1/LFA-1 interaction, we have performed functional studies analyzing the ability of human soluble ICAM-1 and human/mouse LFA-1 derived peptides to inhibit cell aggregation and adhesion as well as cell-mediated cytotoxicity in both mouse and human systems. In parallel, the affinity of the interaction between mouse LFA-1-derived peptides and human ICAM-1 was determined by calorimetry assays. According to the results obtained, it seems that human ICAM-1 is able to interact with mouse LFA-1 on intact cells, which should be taking into account when using humanized mice and xenograft models for the study of immune-related processes.

Celecoxib increases lung cancer cell lysis by lymphokine-activated killer cells via upregulation of ICAM-1

The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Using lung cancer cell lines (A549, H460) and metastatic cells derived from a lung cancer patient, the present study investigates the impact of celecoxib on the expression of intercellular adhesion molecule 1 (ICAM-1) and cancer cell lysis by lymphokine-activated killer (LAK) cells. Celecoxib, but not other structurally related selective COX-2 inhibitors (i.e., etoricoxib, rofecoxib, valdecoxib), was found to cause a substantial upregulation of ICAM-1 protein levels. Likewise, ICAM-1 mRNA expression was increased by celecoxib. Celecoxib enhanced the susceptibility of cancer cells to be lysed by LAK cells with the respective effect being reversed by a neutralizing ICAM-1 antibody. In addition, enhanced killing of celecoxib-treated cancer cells was reversed by preincubation of LAK cells with an antibody to lymphocyte function associated antigen 1 (LFA-1), suggesting intercellular ICAM-1/LFA-1 crosslink as crucial event within this process. Finally, celecoxib elicited no significant increase of LAK cell-mediated lysis of non-tumor bronchial epithelial cells, BEAS-2B, associated with a far less ICAM-1 induction as compared to cancer cells. Altogether, our data demonstrate celecoxib-induced upregulation of ICAM-1 on lung cancer cells to be responsible for intercellular ICAM-1/LFA-1 crosslink that confers increased cancer cell lysis by LAK cells. These findings provide proof for a novel antitumorigenic mechanism of celecoxib.

IFNγ-Dependent Interactions between ICAM-1 and LFA-1 Counteract Prostaglandin E2-Mediated Inhibition of Antitumor CTL Responses

Tumor-expressed ICAM-1 interaction with LFA-1 on naïve tumor-specific CD8(+) T cells not only stabilizes adhesion, but, in the absence of classical B7-mediated costimulation, is also able to provide potent alternative costimulatory signaling resulting in the production of antitumor cytotoxic T lymphocyte (CTL) responses. This study shows that overproduction of prostaglandin (PG) E2 by metastatic murine renal carcinoma (Renca) cells inhibited direct priming of tumor-specific CTL responses in vivo by preventing the IFNγ-dependent upregulation of ICAM-1 that is vital during the initial priming of naïve CD8(+) T cells. The addition of exogenous IFNγ during naïve CD8(+) T-cell priming abrogated PGE2-mediated suppression, and overexpression of ICAM-1 by tumor cells restored IFNγ production and proliferation among PGE2-treated tumor-specific CD8(+) T cells; preventing tumor growth in vivo These findings suggest that novel anticancer immunotherapies, which increase expression of ICAM-1 on tumor cells, could help alleviate PGE2-mediated immunosuppression of antitumor CTL responses. Cancer Immunol Res; 4(5); 400-11. ©2016 AACR.

Intrinsic effects of gold nanoparticles on proliferation and invasion activity in SGC-7901 cells

Although biomedical applications of functionalized nanoparticles have taken significant strides, biological characterization of unmodified nanoparticles remains unclear. In the present study, we investigated the cell viability and invasion activity of gastric cancer cells after treatment with gold nanoparticles. The growth of SGC-7901 cells was inhibited significantly after treatment with 5-nm gold nanoparticles, and the cell invasion decreased markedly. These effects were not seen by different size gold nanoparticles (10, 20 and 40 nm). The attenuated invasion activity may be associated with the decreased expression of matrix metalloproteinase 9 and intercellular adhesion molecule-1. These data indicated that the response of SGC-7901 cells to gold nanoparticles was strongly associated with their unique size-dependent physiochemical properties. Therefore, we provided new evidence for the effect of gold nanoparticles on gastric cancer cell proliferation and invasion in vitro, making a contribution to the application of gold nanoparticles to novel therapies in gastric cancer.

A functional variant at miR-132-3p, miR-212-3p, and miR-361-5p binding site in CD80 gene alters susceptibility to gastric cancer in a Chinese Han population

A number of single-nucleotide polymorphisms within the 3'-UTR of genes have been shown to relate to the occurrence of cancers. In this study, by using polymerase chain reaction-restriction fragment length analysis method, we determined an SNP rs1599795 in the 3'-UTR of CD80 gene in 183 gastric cancer patients and 348 healthy controls. Statistical analysis results showed that SNP rs1599795 genotypes were significantly correlated with the risk of gastric cancer. Compared with the AA homozygotes, the TA heterozygotes were significantly more prevalent in the patients (OR 1.44, 95 % CI 0.98-2.11) with a larger tumor size (P = 0.001), deeper infiltration (P = 1.5 × 10(-5)), higher possibility of lymph node metastasis (P = 0.003), and more in the late stage (TNM stage III and IV; P = 0.003); the TT homozygotes had larger tumor size (P = 0.001) and lower degree of differentiation (P = 2.2 × 10(-4)). Dual-luciferase reporter assays showed that miR-132-3p, miR-212-3p, and miR-361-5p inhibited the expression of CD80 through binding with the CD80 3'-UTR, and this inhibitory role of miR-132-3p, miR-212-3p, and miR-361-5p was impacted by rs1599795. Our findings have shown that the SNP rs1599795 in CD80 3'-UTR, through disrupting the regulatory role of miR-132-3p, miR-212-3p, and miR-361-5p in CD80 expression, contributed to the occurrence of gastric cancer.

Leptin-mediated regulation of ICAM-1 is Rho/ROCK dependent and enhances gastric cancer cell migration

Background:

Our previous study indicates that leptin enhances gastric cancer (GC) invasion. However, the exact effect of leptin on GC metastasis and its underlying mechanism remain unclear. Intercellular adhesion molecule-1 (ICAM-1), a major molecule in stabilising cell–cell and cell–extracellular matrix interactions, is overexpressed and has crucial roles in tumour metastasis.

Methods:

Here, we investigated leptin and ICAM-1 expression in GC tissues. Furthermore, we characterised the influence of leptin on ICAM-1 expression in GC cells and elucidated the underlying mechanism.

Results:

Leptin and ICAM-1 were overexpressed in GC tissues, and a strong positive correlation was observed. They were also related with clinical stage or lymph node metastasis. Furthermore, leptin induced GC cell (AGS and MKN-45) migration by upregulating ICAM-1, and knockdown of ICAM-1 by small interference RNA (siRNA) blocked this process. Cell surface ICAM-1, as well as soluble ICAM-1 (sICAM-1), was also enhanced by leptin. Moreover, leptin increased ICAM-1 expression through Rho/ROCK pathway, which was attenuated by pharmacological inhibition of Rho (C3 transferase) or its downstream effector kinase Rho-associated protein kinase (ROCK) (Y-27632).

Conclusions:

Our findings indicate that leptin enhances GC cell migration by increasing ICAM-1 through Rho/ROCK pathway, which might provide new insight into the significance of leptin in GC.

Tumor interstitial fluid and gastric cancer metastasis: an experimental study to verify the hypothesis of "tumor-phlegm microenvironment"

OBJECTIVE

To extract tumor interstitial fluid (TIF) from MKN-45 gastric cancer which is similar to "muddy phlegm" in Chinese medicine and observe influences of MKN-45 tumor interstitial fluid (MKN-45 TIF) intervention on metastasis of gastric cancer and on the expressions of vascular endothelial growth factor (VEGF), kinase insert domain containing receptor (KDR), epithelial-cadherin (E-cad), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-1 (ICAM-1) and telomerase genes and proteins in primary tumor tissue.

METHODS

An MKN-45 tumor-bearing model was established in 50 nude mice. The modeled animals were equally randomized to 5 groups: the simple tumor-bearing group (model group), the normal saline (NS) via tail vein injection (i.v.) group (NS i.v. group), MKN-45 TIF i.v. group (TIF i.v. group), NS intraperitoneal injection (i.p.) group (NS i.p. group), and MKN-45 TIF i.p. group (TIF i.p. group). The TIF and NS intervention groups received injection (i.p. or i.v.) of MKN-45 TIF or NS twice a week, 0.2 mL at a time. After 8 weeks, the primary tumors were removed, weighed and HE stained to observe tumor metastasis. The primary tumor tissues were analyzed by immunohistochemistry and real-time quantitative PCR to detect expressions of VEGF, KDR, E-cad, COX-2, ICAM-1, and telomerase genes and proteins in different groups.

RESULTS

There were significant differences in tumor weight between TIF intervention groups and the model and NS intervention groups. Tumor metastasis was observed in all 5 groups, but the tumor metastasis rate in TIF intervention groups was significantly higher than those in the model and NS intervention groups. The gene and protein expressions of gastric cancer-related factors VEGF, KDR, COX-2, ICAM-1 and telomerase were unregulated while the gene and protein expressions of E-cad were downregulated in TIF intervention groups.

CONCLUSIONS

TIF promotes tumor growth, invasion and metastasis of gastric cancer. These findings provide preliminary experimental clues for verifying the hypothesis of "tumor-phlegm microenvironment".

Paeoniflorin suppresses the expression of intercellular adhesion molecule-1 (ICAM-1) in endotoxin-treated human monocytic cells

BACKGROUND AND PURPOSE

Paeoniflorin (PF) has ameliorative effects on learning and memory impairment and cerebral ischaemia in rats and has protective effects against the degeneration of dopaminergic neurons in substantia nigra. The neuroprotective effects of PF are most probably derived from its anti-inflammatory property. Abnormally high levels of intercellular adhesion molecule-1 (ICAM-1) have been found to be associated with a wide range of inflammatory and immune responses. Here we studied whether PF regulates the levels of ICAM-1 elevated in LPS-activated differentiated human monocytic U937 cells and TNF-α-stimulated human umbilical vein endothelial cells (HUVECs).

EXPERIMENTAL APPROACH

mRNA levels were evaluated by RT-PCR. Protein levels were evaluated by Western blot analysis. An immunofluorescence technique was used to estimate NF-κB translocation, and NF-κB binding to nuclear DNA was determined by EMSA.

KEY RESULTS

PF inhibited ICAM-1 expression elevated in LPS-induced U937 cells and TNF-α-stimulated HUVECs. Although previous reports showed that PF's action is mediated by activating adenosine A₁ receptors, application of a selective adenosine A₁ receptor antagonist did not change the inhibitory effect of PF in our experiments. To elucidate the underlying mechanisms of the effect of PF, we studied its effect on signalling pathways upstream of ICAM-1 expression. PF suppressed the activation of the NF-κB pathway, which regulates the expression of ICAM-1. The TLR4 and MAPK pathways were shown not to be involved in the effects of PF in these cells.

CONCLUSIONS AND IMPLICATIONS

PF inhibits ICAM-1 expression in LPS-treated U937 cells and TNF-α-stimulated HUVECs by suppressing the activation of the NF-κB pathway.

Cannabidiol inhibits lung cancer cell invasion and metastasis via intercellular adhesion molecule-1

Cannabinoids inhibit cancer cell invasion via increasing tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). This study investigates the role of intercellular adhesion molecule-1 (ICAM-1) within this action. In the lung cancer cell lines A549, H358, and H460, cannabidiol (CBD; 0.001-3 μM) elicited concentration-dependent ICAM-1 up-regulation compared to vehicle via cannabinoid receptors, transient receptor potential vanilloid 1, and p42/44 mitogen-activated protein kinase. Up-regulation of ICAM-1 mRNA by CBD in A549 was 4-fold at 3 μM, with significant effects already evident at 0.01 μM. ICAM-1 induction became significant after 2 h, whereas significant TIMP-1 mRNA increases were observed only after 48 h. Inhibition of ICAM-1 by antibody or siRNA approaches reversed the anti-invasive and TIMP-1-upregulating action of CBD and the likewise ICAM-1-inducing cannabinoids Δ(9)-tetrahydrocannabinol and R(+)-methanandamide when compared to isotype or nonsilencing siRNA controls. ICAM-1-dependent anti-invasive cannabinoid effects were confirmed in primary tumor cells from a lung cancer patient. In athymic nude mice, CBD elicited a 2.6- and 3.0-fold increase of ICAM-1 and TIMP-1 protein in A549 xenografts, as compared to vehicle-treated animals, and an antimetastatic effect that was fully reversed by a neutralizing antibody against ICAM-1 [% metastatic lung nodules vs. isotype control (100%): 47.7% for CBD + isotype antibody and 106.6% for CBD + ICAM-1 antibody]. Overall, our data indicate that cannabinoids induce ICAM-1, thereby conferring TIMP-1 induction and subsequent decreased cancer cell invasiveness.

Expression of intercellular adhesion molecule (ICAM)-1 or ICAM-2 is critical in determining sensitivity of pancreatic cancer cells to cytolysis by human gammadelta-T cells: implications in the design of gammadelta-T-cell-based immunotherapies for pancreatic cancer

BACKGROUND AND AIMS

gammadelta-T cells can recognize and kill malignant cells, particularly those of epithelial origin, through mechanisms which do not require the recognition of tumor-specific antigens (innate immune response). This natural ability of gammadelta-T cells to kill tumor cells in a tumor antigen-independent manner provides a strong rationale for developing clinical trials designed to exploit the innate antitumor properties of gammadelta-T cells.

METHODS

In vitro studies were carried out to asses the sensitivity of pancreatic cancer cells (MIA PaCa2, BxPC-3, PANC-1) to killing by ex vivo expanded human gammadelta-T cells.

RESULTS

The capacity of gammadelta-T cells to bind to as well as to kill pancreatic cancer cells correlated with the degree of surface expression of key intercellular adhesion molecules (ICAM) present on pancreatic cancer cells. Moreover, pancreatic cancer cells expressing neither ICAM-1 nor ICAM-2 were bound poorly by gammadelta-T cells and were found to be resistant to gammadelta-T-cell killing. However, upon transfection of resistant cells with ICAM-1 or ICAM-2, gammadelta-T cells were then able to bind to and subsequently kill these cells.

CONCLUSION

In vitro, the expression of ICAM-1 or ICAM-2 on human pancreatic cancer cells is critically important in determining the extent to which these cells are sensitive to killing by human gammadelta-T cells. Accordingly, in ongoing and future clinical studies using gammadelta-T cells for the treatment of a variety of epithelial-derived solid tumors-including pancreatic cancer-interventions intended to modulate ICAM expression on tumor cells may become important adjuncts to gammadelta-T-cell-based immunotherapies.

A synergistic antitumor effect of interleukin-2 addition with CD80 immunogene therapy for peritoneal metastasis of gastric carcinoma

The co-stimulatory molecule CD80 is a ligand of CD28, which plays a key role in the induction of cell-mediated immune responses. Many tumors, including gastric cancer, decrease the expression of CD80, which results in the failure of immune recognition. We evaluated the effect of interleukin-2 addition combined with CD80 infection on the peritoneal metastasis in gastric cancer. CD80 infection combined with interleukin-2 addition significantly increased the activated cytotoxicity of mononuclear cells compared to CD80 gene infection and compared to the lacZ control group. In vivo, the survival of animals with intraperitoneal tumor was longest in those given CD80 infection with interleukin-2 addition (median survival, 46 days), followed by those given interleukin-2 (39 days), those given CD80 infection (37 days), and those given lacZ (29 days). These results suggest that interleukin-2 addition might contribute to improving the observed outcome of CD80 immunogene therapy in peritoneal metastasis of gastric carcinoma.

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CD54 expression is predictive for lymphatic spread in human gastric carcinoma

Even among gastric carcinoma cases with a similar extent of lymphatic invasion, the number of diseased lymph nodes may vary. Other factors might also contribute to the process of lymphangitic metastasis. Primary gastric tumors with the same extent of pathologic lymphatic invasion were studied in 78 patients. We investigated the correlation between CD54 expression on cancer cells and clinicopathologic features. Decreased CD54 expression on cancer cells was significantly correlated with the number of involved lymph nodes and the extent of lymph node spread. The number of diseased lymph nodes was associated with the prognosis of patients with gastric carcinoma. The CD54-negative group had a significantly worse prognosis than the CD54-positive group. These findings suggested that CD54 expression is predictive for lymphatic spread and prognosis in human gastric carcinoma.

Up regulation of ICAM-1 gene expression inhibits tumour growth and liver metastasis in colorectal carcinoma

We have previously reported that decreased intercellular adhesion molecule-1 (ICAM-1) expression in cancer cells is associated with liver metastasis of colorectal cancer. In this study, we have investigated the effect of ICAM-1 gene transfection into the human colorectal cancer cell line LM-H3 on cell adhesiveness and cytotoxicity of peripheral blood mononuclear cells (PBMC) to cancer cells. Furthermore, we have investigated the effects of this gene transfer on subcutaneous tumour and liver metastases of LM-H3 in nude mice. More PBMC adhered to ICAM-1 transfected LM-H3 cells, LM-H3/ICAM-1, than to non-transfected LM-H3 cells and control LM-H3/Vector. Lysis of LM-H3/ICAM-1 cells by PBMC was significantly increased compared with LM-H3/Vector. Liver metastases with LM-H3/ICAM-1 cells were fewer in number and smaller than metastases with LM-H3/Vector. Intra-tumoural injection of ICAM-1 adenoviral vector significantly inhibited the growth of subcutaneous LM-H3 tumour. In conclusion ICAM-1 gene transfection using adenovirus vector might be an effective therapy for liver metastasis of colorectal carcinoma.

ICAM-2 gene therapy for peritoneal dissemination of scirrhous gastric carcinoma

PURPOSE

Human scirrhous gastric carcinoma develops peritoneal dissemination with high frequency, and the prognosis of patients with peritoneal metastasis is poor. There have been few reports of an immunogene therapy for peritoneal dissemination. Intercellular adhesion molecule (ICAM)-2 is a second ligand of leukocyte function-associated antigen-1, which functions as a costimulatory molecule for effector cells. In the present study, we examined whether ICAM-2 transfection using adenovirus vector is effective gene therapy for peritoneal metastasis of gastric cancer.

EXPERIMENTAL DESIGN

We constructed an adenovirus vector, AdICAM-2, that encodes the full-length human ICAM-2 gene under control of the cytomegalovirus promoter. This vector expresses high levels of ICAM-2 on the human gastric cancer cell line OCUM-2MD3, which has high peritoneal metastatic ability in nude mice. We investigated the antitumor effects of gene transfer of ICAM-2 using the adenovirus vector AdICAM-2 in vitro and in vivo.

RESULTS

ICAM-2 expressed on OCUM-2MD3 cells by AdICAM-2 demonstrated significantly high adhesiveness to and cytotoxicity against peripheral blood mononuclear cells in vitro compared with the control adenovirus vector AdlacZ. Intratumoral injection of AdICAM-2 significantly inhibited the growth of s.c. tumor. Mice with peritoneal metastasis survived for a significantly longer time after AdICAM-2 injection, compared with injection of AdlacZ. Histopathological findings revealed that many natural killer cells infiltrated the peritoneal metastatic lesions after AdICAM-2 injection.

CONCLUSIONS

These findings suggest that transduction of ICAM-2 into cancer cells enhances the adhesion and activation of natural killer cells, resulting in a reduction of peritoneal metastasis. ICAM-2 transfection using adenovirus vector might be an effective form of gene therapy for peritoneal metastasis of gastric cancer.

Usefulness of inhibiting the lymph node metastasis in human gastric carcinoma by B7-1 gene transfection

INTRODUCTION

Lymph node metastasis is one of the crucial prognostic factors in gastric cancer. We have reported that ICAM-1 gene transfection was effective against lymph node metastases of gastric cancer. B7-1, one of the co-stimulatory factors, was reported to induce cytotoxic T lymphocytes when using melanoma and bladder cancer cell lines, as well as ICAM-1. In this study, we investigated the inhibitory effect of B7-1 on lymph node metastasis by B7-1 gene transfection into gastric cancer cells.

MATERIALS AND METHODS

We transfected B7-1 genes into a gastric cancer cell line (OCUM-2MLN) and analyzed the effect of B7-1 transduction on lymph node metastasis, the in vitro adhesiveness and cytotoxicity assay of mononuclear lymphocytes to cancer cells and lymph node metastatic ability after orthotopic implantation of gastric cancer cells in vivo.

RESULTS

We revealed that mononuclear lymphocytes showed significantly stronger adherence and cytotoxicity to B7-1 transfected cells (2MLN/B7) than its parent OCUM-2MLN cells. The tumor growth rate of 2MLN/B7 xenograft was significantly slower than OCUM-2MLN xenograft in nude mice. In orthotopic implantation experiments for nude mice, 2MLN/B7 cells in stomach developed significantly less lymph node metastasis than OCUM-2MLN cells. Histologic findings showed that leukocytes were intensively infiltrated in both the 2MLN/B7 tumors and its metastatic lesions, however, were scarcely observed in the lesions associated with 2MLN cells.

CONCLUSION

B7-1 may play an important role in inhibiting lymph node metastasis by the mechanism of enhanced immunogenicity, and that B7-1 gene transduction might be effective against lymph node metastases of gastric cancer.

Recent advances in molecular diagnosis and therapy of gastric cancer

Gastric cancer is the fourth most common malignancy and the second most frequent cause of cancer-related death in the world. It is often diagnosed in advanced stages when treatment options are limited, leading to a poor prognosis. During the past 15 years, much has been learnt about the molecular mechanisms of gastric carcinogenesis and the development of metastases. This coincided with the development of new techniques for functional genomics, including both transcriptomics and proteomics, which significantly improve the ability to explore new molecular alterations involved in carcinogenesis and tumor progression. An improved understanding of the molecular pathology and pathogenesis of gastric cancer may lead to a more rapid development of molecular diagnostic and patient tailored therapeutic targets.

Requirements for ICAM-1 immunogene therapy of lymphoma

Intercellular cell adhesion molecule-1 (ICAM-1) is a cell-surface glycoprotein capable of eliciting bidirectional signals that activate signalling pathways in leukocytes, endothelial, and smooth muscle cells. Gene transfer of xenogeneic ICAM-1 into EL-4 lymphomas causes complete tumor rejection; however, it is unknown whether the mechanism responsible involves the "foreignness" of the ICAM-1 transgene, bidirectional signalling events, ICAM-1-receptor interaction, or a combination of the latter. To begin to address this question, we constructed four different therapeutic expression vectors encoding full-length ICAM-1, and forms in which the N-terminal ligand-binding domains and cytoplasmic tail had been deleted. Mouse EL-4 tumors (0.5 cm in diameter), which actively suppress the immune response, were significantly inhibited in their growth following injection of expression plasmids encoding either full-length xenogenic (human) ICAM-1, or a functional cytoplasmic domain-deficient form that retains ligand-binding activity. Efficacy of ICAM-1-mediated antitumor immunity was significantly augmented by administration of the antivascular drug 5,6-dimethylxanthenone-4-acetic acid (DMXAA), which suppressed blood supply to the tumor, leading to enhanced leukocyte infiltration, and complete tumor eradication in a gene dosage and CD8(+) T cell and NK cell-dependent fashion. Generation of potent cytotoxic T cell (CTL)-mediated antitumor immunity was reflected by ICAM-1-facilitated apoptosis of tumor cells in situ. In contrast, nonfunctional ICAM-1 lacking the N-terminal ligand-binding Ig domain failed to generate antitumor immunity, even in the presence of DMXAA. These studies demonstrate that ICAM-1-stimulated antitumor immunity can overcome tumor-mediated immunosuppression, particularly when employed in combination with an attack on the tumor vasculature. The ligand-binding domain of ICAM-1 is essential for generating antitumor immunity, whereas the cytoplasmic domain and bidirectional activation of tumor signalling pathways are not essential.

Light stimulates IFNgamma-mediated intercellular adhesion molecule-1 upregulation of cancer cells

Intercellular adhesion molecule-1 (ICAM-1) works as one of the ligands for activating the killing activity of natural killer (NK) cells and cancer specific cytotoxic T lymphocytes (CTL). Expression of ICAM-1 enhances lymphocyte adhesion to the cancer cells in vivo. Cancer cell lines express significantly lower level of ICAM-1 than that of normal epithelium or benign cells. Overexpression of LIGHT (LIGHT: homologous to lymphotoxins, indicating inducible expression, and competes with herpes simplex virus glycoprotein D for herpes virus entry mediator [HVEM/TR2]) in MDA-MB-231 human breast cancer cells was observed to suppress tumor growth in vivo. In order to elucidate the mechanisms how LIGHT overexpression could trigger tumor suppression, the expression level of a panel of cell surface makers CD54, CD56, CD95, and CD119 was investigated in a group of cancer cells. Flow cytometry analysis results demonstrate that LIGHT gene expression in cancer cells can greatly increase ICAM-1 expression level, IFNgamma alone can stimulate cancer cells to express ICAM-1, which can be highly augmented by LIGHT in a dose-dependent manner. This upregulation of ICAM-1 expression is not only at ICAM-1 protein trafficking level on cell surface as demonstrated by flow cytometry analysis, but also at ICAM-1 total protein level as confirmed by Western blot. There is no difference of expression level among these cancer cell lines for the other three cell surface markers: CD56, CD95 (Fas), and CD119. It was confirmed that LIGHT enhancement upregulation of ICAM-1 expression is at least STAT1 and JAK1 dependent by using STAT1-deficient U3A and JAK1-deficient E2A4 cells. These findings suggest that LIGHT-induced inhibition of tumor growth is highly correlated with its upregulation of ICAM-1 expression.

ICAM-1 expression and the soluble ICAM-1 level for evaluating the metastatic potential of gastric cancer

ICAM-1 plays an important role in cell-cell and cell-extracellular matrix interactions, especially tumor invasion and cytotoxicity of lymphocytes. In the present study, the relationship between metastasis of gastric cancer and ICAM-1 expression by cancer cells or the serum level of s-ICAM-1 was (s-ICAM-1) was examined. ICAM-1 was detected by immunohistochemic staining in 49.0% of 108 patients with gastric cancer. The ICAM-1 expression rate was higher at a more advanced stage, based on lymph node metastasis, being 46.9% in node-negative and 56.1% in node-positive cases. In patients with liver metastasis, the rate was 90.9%, while it was 43.3% in patients without liver metastasis (p < 0.05). The serum s-ICAM-1 level was 262.1 ng/ml (median 205.5, range 176.0-271.0) in healthy subjects and 391.5 ng/ml (median 317.5, range 148.7-1,768.0) in gastric cancer patients (p < 0.001). The serum s-ICAM-1 level was significantly higher in patients with liver metastasis than in patients without liver metastasis (p < 0.0001). In addition, positive ICAM-1 expression cases had significantly higher s-ICAM-1 levels than negative ones, 408.9 +/- 188.4 and 308.1 +/- 88.1 ng/ml, respectively. These results suggested that ICAM-1 was overexpressed in cancer cells and released as s-ICAM-1, which would promote hematogenous metastasis by suppressing local anticancer immunity.